The English Language Essay Example for Free

The English Language EssayLanguage is a constant. It is a component that entrust be forever intertwined into the fabrication of our global society. This multi-sensory means of communication, consists of not only the verbal and writing, but also touch, smell, sound, body, and gestural elements. As human beings ar favorable animals, people have the instinct to communicate with others, to shargon our feelings and thoughts, and as a result, diction development in each individual becomes an instinct (Pinker, 1994). Since language is the creature used for communication, Wittgenstein says, The limits of my language argon the limits of my world. It is imp craftd that people speak just one language and thus live in only one world, and if you argon not capable of using the language, your world is narrowed. However, genius has an opposite opinion he devalues the importance of language and says, The words of a language as they are written and spoken do not seem to play any role in the mechanism of my thought.It is widely believed believe that language is the bridge connecting individuals and the right(prenominal) world thus, it is a crucial element of human life. Language can be inextricably tied to identity, and it can also be disentangled. In Einsteins quote, he says that the language of speech and writing doesnt influence his thought, because the mechanism of his thought is extraordinary. As a widely recognized great scientist, his billet might be that people should think something beyond what is already written, and also, the sum of human wisdom is not contained in any one language, and no private language is CAPABLE of expressing all forms and degrees of human comprehension. (Ezra Pound, The ABC of Reading). With language as your tool, you are capable of exploring other worlds. Wittgensteins statement failed to include the fact that at that place are worlds formed based on different languages. It is through such(prenominal) language that one is either i ncluded or excluded from mixer groups.Language pervades kind life. It is the principal vehicle for the transmission of heathen knowledge, and the primary means by which we gain access to the contents of others minds. Language is implicated in most of the phenomena that lie at the core of affable psychology attitude change, social perception, personal identity, social interaction, intergroup bias and stereotyping, attribution, and so on. Just as language use pervades social life, the elements of social life constitute an intrinsic part of the way language is used. Linguists regard language as an abstract structure that exists independently of specific instances of recitation (much as the calculus is a logico-mathematical structure that is independent of its application to concrete problems), but any communicative exchange is situated in a social context that constrains the linguistic forms participants use. How these participants define the social situation, their perceptions of what others know, think and believe, and the claims the make about their own and others identities go forth affect the form and content of their acts of utter.For present purposes, it may be more helpful to think about language as a set of complex, organized systems that operate in concert. A particular act of speaking can be examined with respect to any of these systems (G. Miller, 1975), and each level of analysis can have significance for social behaviour. For example, languages are made up of quartet systemsthe phonological, the morphological, the syntactic, and the semanticwhich, taken together, constitute its grammar. Australia is often described as one of the classical countries of immigration. The concept of being a nation of immigrants is at the marrow squash of Australian identity.Australia is a unique country, and it has a long history of population growth due to immigration. Australia is a young country and has not fully developed. It is unremarkably called The Lan d of Opportunity. Such grammar can be exclusive to specific culture along with social purposes. Melbourne, for example, has many sub-cultures that combine to create the overwhelmingly diverse and generalise culture that defines the city as a whole. We are constantly influence through the language that other cultures have introduced into our traditional linguistics. The English Language has changed and shifted drastically form the Anglo-Saxon version to our current speech. Over time, linguistics from cultures such as French, Latin and Greek have evaded our traditional tongue, creating a new cultural identity ever evolving and adapting to the modern world.In the modern world, human need to belong still influences language development and identity established through such language. People are proud of their accents, dialects, and languages. It is a mark of uniqueness and simultaneously a mark of belonging and excluding. People who live in different areas are proud to speak the way the y do, because they are different from the rest, but are still part of a group. Whereas, accents and dialects are marks of belonging, and something that most people are proud of, language development has been influenced by less idealistic reasons. We can see how important language is in both the purpose of communication and widening the world of an individual it is a way of knowing.If an individual is not capable of using a language, his world is limited yet it is reasonable to assume that the language used by most people is not always significant in mechanism of everybodys thoughts, because somebodys mind might employ differently. Throughout history, human needs have affected their behaviour, how they lived, and how their language develops. Food, water, and a place to belong were some of the major needs to begin with, but as time went by, they were joined by other needs. Economic, political and scholarly needs also influence language development. The influence of human development and need will continue to effect language expansion, and will continue to as long as the world lasts.

The Reasons We Drink Beer Essay Example for Free

The Reasons We Drink Beer EssayThere ar most likely hundreds of reasons, good and bad, why the great unwashed drink beer. Everyone who drinks beer has their own personal reasons. Beer is a worldwide commonly known and used beverage that has become a part of our society. Its been brewed and consumed for everyplace several thousand years. Why is this drink so popular? Today well explore a handful of reasons why people drink beer. Taste Beer is an acquired taste. I doubt there are many an(prenominal) people who admit that the very first beer they ever tried in life tasted very good. But those who kept trying beer grew accustomed to how it smelled, felt in the communicate and tingled the tongue. Once your taste buds lose their training wheels a whole vernal world of flavors are opened up to you. Buzz Lets impudence it, alcohol is a big reason why many people drink beer. It provides mind altering capabilities that offer some people enjoyment, others a distraction, and dummy u p for others nothing more than problems. Getting a beer buzz is an attraction for many as well as a regrettable side affect. Everyone has different limits, so get to know simply how much beer is enough to get your buzz on.Social Sharing a beer with friends or acquaintances is one way of sparking conversation and just being, well, sociable. It becomes a common bond between partakers. Not only does it loosen the tongue a bit, but also causes some to open up a bit. Identity Its funny how some people find a beer they like and stick to it. For some, it becomes part of their identity. Brand loyalty is hard to break for some. The beers you started imbibing when you were a young adult often become the beverage of choice later in life.Many beer drinkers will try other beers for a new experience and find a new brand to identify themselves with. The typesetters case of beer you drink may say something about you that you didnt realize. Variety Beer comes in over 100 different styles and i n thousands of different brands. No one beer brand is identical to the next. You could spend your entire life trying to sample all of the beers that are available in the world and still not be able to try them all. Very few beverages can claim this kind of variety. Health This could be an entire subject in of itself.There must be dozens of reasons why beer is sanguine for you. Taken in moderation, beer is good for your liver. It expands the blood vessels and helps speed up metabolism. can help lower your risk of heart attacks and stroke. prevents cholesterol from oxidizing. Some hop compounds prevent LDL from oxidizing and clogging arteries. boosts vitamin B5, B12, folate and other valuable mineral levels. Unfiltered beers have more of this benefit. may help in combating cancer. The compounds in some hops are showing promise for preventing certain types of cancer.(Bingham report 1998) helps ensure healthy bones. Bone improving nutrients are leached from the brewing process i n a form that is readily accessible to the body. helps you relax and sleep more easily. Two vitamins, hepatoflavin and nicotinic acid are present in many beers and helps to promote sleep. Beer is also a natural sedative. Contains antioxidants that can help slow the aging process. Contains fiber. A l of beer can have up to 60% of your daily recommended fiber. Helps fend off gallstones and kidney stones. Peer Pressure One of the sad reasons why many drink beer.The draw to conform and fit in with others is a constant issue. Many people, especially teens, drink beer just because their friends are doing it. For others, drinking beer is a right of passage in life. Heritage Breweries have been part of communities for generations and generations. Many communities in ancient and modern society rally around their local brewpubs and breweries throughout the world. Beer was one of the many bounties of a year long harvest. Locally made beers garner more loyalty. Colorado we live in one of states that produces the most amount of beer in the nation.With nearly 100 different breweries and brewpubs, the availability of hundreds of quality craft beers simply cant be ignored. Colorado is a travel destination for many of the worlds beer drinkers. Even one of the biggest beer festivals in the world, the Great American Beer Festival, is held here each year in October. Food Beer makes the perfect compliment for lashings of different kinds of food. Pairing food and beer is becoming quite popular, just as it has been for wine. There are beers that go well with just about every type of food, from meats, appetizers (cheeses, breads, snacks) and desserts.

Geography

GeographyGeographyLocationThe community lies in the Weschnitz valley in the Odenwaldsome 25km sum of Heidelbergand about 20km north eastmost of Mannheim. It is on Bundesstrae38, and the river Weschnitz flows through it. The land is hilly, green and dotted with horse farms and forests.Neighbouring communitiesBirkenau borders in the north on the community of Mrlenbach, in the east on the community ofAbtsteinach, in the south on the community ofGorxheimertaland in the west on the towns of Weinheimand Hemsbach(both in Rhein-Neckar-KreisinBaden-Wrttemberg).Constituent communitiesBirkenaus Ortsteileare Birkenau, Buchklingen, Hornbach, Kallstadt, Lhrbach, Nieder-Liebersbach, Reisen and Schnorrenbach.ClimateOwing to its attitude near the Bergstrae, a mild climate prevails in Birkenau, which can often be seen in what for Germany is a very early blossoming ofalmondtrees.History Schloss BirkenauBirkenau had its start-off documentary mention in 795 in the Lorsch Codexas a cell of the Lorsch A bbey. As one of the Abbeys holdings, it passed into the ownership of the Archbishopric of Mainz in 1232. The centres of Hornbach and Balzenbach, on the other hand, belonged to Electoral Palatinate, meaning that afterward the Reformation, they belonged to different denominations. In 1532 the town hall was built, and in 1771 the palace, Schloss Birkenau, of the Lords of Wambolt von Umstadt. By 1964, the population had grown to more than 5,000. In 1967 the community was recognized as a volunteer(a) resort (Erholungsort) and in 1979 as an open-air resort (Luftkurort). Owing to the only slight tourism, however, it has not reapplied for this designation. In 1995, Birkenau celebrated its 1,200-year jubilee.

A study of girish karnads yayati

A study of girish karnads yayatiAs a reader of Karnads plays, one has to pay attention to their initiations. Al more or less e in truth(prenominal) text has a source in that the plot is derived from somewhere. The common sources of his plays include invention, folk tale, Puranas, historical chronicles, epics etc. He seems to have providential from Shakespeare who follows the same tendency of adapting recognized plots. The juvenile dramatists tend to use original plots, or all well known historical or political event, or adapt a popular classical figment. There is nothing wrong with the apply of adapting any known or unknown text since it may provide you with the new insight into the source text. few critics even say that every literature is based on an otherwise literature as it carries the echoes of its procreator. For Peter Allen, literary texts are built from systems, codes, and traditions established by previous works of literature (2000 1). The exercise of finding how the original texts are adapt and the new meaning generated in the process is worth attempting it offers us with a new perspective on the subject, event, plot etc.The adaptation is normally a process of chuckting a source text into another genre, a kind of switch everywhere. Many fictions have been transformed into successful plays or films and vice versa Jhumph Lahiris Name pastime, for instance, is made into a film. In the West, it is a popular practice to aggrandize a prose narrative or fiction. Sometimes, the fitted text provides a kind of commentary on a source text (Sanders 18). It offers a new perspective, a viewpoint which is not realized or centraliseed in the source text. It tries to simplify a difficult or unintelligible text to the new readership. innovational Shakespeare is a very good example of much(prenominal) practice. It is a kind of reinterpretation of the canonical texts either by moulding them into a different genre or relocating their cultural context. B esides, the more the adaptation deviates from the source text, the more creative and original it becomes. The question of fidelity towards the source text is irrelevant as it undermines the creativity and innovativeness of the adapted text. The recent success of adaptations is a clear rejection of all those who term these acts as imitations, copying or plagiarism, or repetition. This is because they sustain or prolong our pleasure of the source text. As John Ellis puts it, Adaptation into another medium becomes a means of prolonging the pleasure of the original presentation, and repeating the production of a memory (1982 4-5). Adaptation is a never ending process as long as the source text sustains its relevance, a need to adapt it would be felt.Adaptation of a popular story is a profitable enterprise for many reasons. It has already attracted the attention of readers. It has toped a large section of people, and its properties- title, author, portions-may be a franchise in or of t hemselves already (wikipedia). All these reasons prompt writers to attempt adaptations regularly thereby to be assured of the success of their works. Though adaptation into a stage play is a common activity, it has its own limitations due to the spacio-temporal restrictions of the stage. A playwright has to work within these restrictions by adopting various techniques such as ellipsis, interpolation, narrative etc.Karnad engages him self in what Genette calls transgeneric practice i.e. adapting mythic narratives, folk narratives and historical chronicles into drama. He takes plots from these sources and delivers them in new dramatic forms. In that sense all his plays are transpositions in which the original narratives are adapted with the aesthetic conventions of an entirely different generic process (Sanders 20). Moulded into a new form these texts offer a new perspective of liveness which is relevant in the present context. Karnad derives plots from these sources because he feels that they are relevant and enable him to reflect on the contemporary social and political life in a more astute and systematic way. There are many taboos and forbidden things in the world which can not be discussed overtly. Otherwise you would invite the irk of society unnecessarily. Sources such as myth, folk or historical events/lives of historical figures offer him with a safety valve which enables the expression of the unacceptable or forbidden ideas in an acceptable manner. To put it simply, one can camouflage ones comment on the present social and political conditions with these adaptations. Take the example of Tughlaq which is considered to be a critique of Post-Nehru era in Indian politics. Tughlaq helps Karnad in expressing the disillusionment after the goal of Pandit Nehru effectively.The play that started Girish Karnads successful career as a playwright was Yayati. It was penned over a few weeks in 1960 when Karnad was planning to leave India for Oxford as a Rhodes Sch olar for three years against the wishes of his parents. Hence, the play had its relevance that older generation demand sacrifices on the dowry of jr. generation.Unlike his other play, it was Priya Adarkar who first translated the play. It served the purpose until Girish Karnad himself felt the need to translate it in 2008. Actually he was reluctant to touch the play, a work of his juvenilia ( write when he was only twenty two.) The present translation of the play by Karnad is, therefore, modified and enriched with the suggestions from Satyadev Dubey, Dr. Shreeram Lagoo, and C. R. Simha.On the suggestion of Kurtkoti, Karnad, in Yayati, tried to reinterpret the myth psychoanalytically like Eugene ONeill. Karnad was very much influenced by ONeills Mourning Becomes Electra and wanted to achieve the same kind of intensity. Karnad put up the myth of Yayati-Devayani-Sharmishtha rich in possibilities for the expression of psychological and physiological unavoidably of human beings and so cial obligations. It was moulded on John Anouilhs plays as he was influenced by Alkazi (who had tremendous influence of Anouilh). He experienced Anouilh through Alkazi and wrote his first play Yayati which was inspired from Anitigone.The myth of Yayati-Devayani-Sharmishtha has been continuously adapted in Indian literature. It has been turned into many plays and novels. There are films based on the myth. In Marathi literature, the two Jnanapith Awardees Khandekar and Shiravadkar (Kusumagraj) adapted the myth into a novel and a stage play respectively. Indian writers fascination with the myth of Yayati still exists and works based on the myth pour in every year. However, Karnads adaptation holds an important place in these outnumbering adaptations. He challenges the very authority of parents by inventing the character of Chitralekha who questions the moral authority of Yayati in taking over her husbands youth on the very first night of their marriage.According to Devdutta Pattaniak ( 2006 article Myth Theory), in Hindu mythology there is a famous Yayati Complex, that is, parents expecting sacrifices on the part of their children to fulfill their selfish motives. He termed it as reverse Oedipus Complex. In Greek mythology, there are numerous tales depicting a son responsible for the death of his father. For example, the famous tale of Oedipus Rex. However, in Hindu mythology we have the reverse situation i.e. a father destroys his son to fulfill his ambitions. Whether it is Bhisma, Rama or Pooru, they have to sacrifice for the sake of their fathers. The Yayati Complex indicates the moral obligations in Indian family which even Karnad had to abide by when he decided to go to Oxford as a Rhodes Scholar for three years. Hence, Karnad diligent the myth to show the intricacies of Indian family structure and challenge its moral authority which makes sons like Pooru to sacrifice their prime and precious things to keep it intact. He writes,While I was writing the play, I saw it only as an escape from my stressful situation. But looking back, I am amazed at how precisely the myth reflected my anxieties at that moment, my resentment with all those who seemed to demand that I sacrifice my future. By the time I had finished working on Yayati-during the three weeks it took the ship to reach England and in the lonely cloisters of the university the myth had enabled me to articulate to myself a set of values that I had been unable to arrive at rationally. Whether to bring round home finally seemed the most minor of issues the myth had nailed me to the past (2008 74).Karnad sticks to the original story as far as the past of the characters is concerned. The prenuptial conflicting relation of Devayani and Sharmishtha, Yayatis encounter with Devayani whom he found in a well after her quarrel with Sharmishtha, and his marriage with Devayani form the part of exposition which is spread through the play. In the play, Yayatis liaison with Sharmishtha and willin gness to marry her angers Devayani. She makes her father Shukracharya curse Yayati for his transgression to become decrepitude. In the original story, Devayani learns about the marriage between Sharmishtha and Yayati from their sons.Interpolation is a common feature in adaptations. Karnad too invents the character of Chitralekha as a wife of Pooru. Her function is to questions the moral authority of Yayati in taking her husbands youth for his sensuous pleasure. She suggests Yayati to take over the role of husband.Chitralekha I did not know Prince Pooru when I married him. I married him for his youth. For his potential to plant the seed of the Bharatas in my womb. He has lost that potency now. He doesnt possess any of the qualities for which I married him. But you do.Yayati (flabbergast) ChitralekhaChitralekha You have taken over your sons youth. It follows that you should accept everything that comes attached to it.Yayati Whore Are you inviting me to fornification? (200865-66)The su ggestion of Chitralekha makes Yayati realize his mistake and her suicide forces him to return Poorus youth. Swarnalatas character like that of Chitralekha is invented and runs parallel to the disenchantment experienced by the latter. She has also lost her husband and thinks that death brings peace, the deliverance from uncertainty (2008 60). However, she repents her proposition when she finds Chitralekha, taking prompt from her speech, commits suicide. Just as Swarnalatas husband deserted her when he learned about her relationship with her teacher, Devayani too deserts Yayati after he makes love to Sharmishtha. Swarnalatas married life is Karnads addition to the original tale.Tranpositional practices form the core of adaptation activity as genre-switch is mostly what is expected of it. Karnad takes the story from one genre i.e. mythic story as it appeared in Mahabharata and delivers it to new audiences by means of the aesthetic conventions of an entirely different generic process, a stage play. Yayatis story which happened over many years is shown to be happening in a very limited span of time in Karnads Yayati. He has to cut or shorten many action units to focus on the core part of the myth i.e. transplantation of age. Most of the events are merely narrated and conveyed or suggested by characters the past of Devayani and Sharmishtha, Shukracharya cursing Yayati, Poorus marriage and many other events.The identity of Poorus mother is not revealed until the trinity and fourth Act. In the first Act, there is an impression that Devayani is Poorus mother unlike in the original tale. However, it becomes clear from the third Act that it is Sharmishtha not Devayani who is the mother of Pooru. The revelation of Sharmishtha as Poorus mother makes us understand that Yayati has been in love with her for a long time keeping Devayani in ignorance. It is only in the second Act that she becomes witness to their transgression and decides to leave the palace. That means Sha rmishtha is not shown married to Yayati as in the original tale. And it is more than mere vengeance on the part of Sharmishtha in the play. She remains firm behind Yayati and tries to prevent him from exchanging his decrepitude with anyone including Pooru. She wants him to accept his fate and lead a life of an ascetic. general Karnad has been faithful to the source text of Yayati. However, he has made few changes to intensify the theme of social obligations and ripeness is all. As Karnad saysold age brings no knowledge, no self realization, only the senselessness of a punishment meted out for an act in which he (Pooru) had not even participated (2008 73).The play shows that mere old age (i.e.Yayati) should not be revered but the maturity of a youth (i.e. Pooru). The adaptation of the myth of Yayati by Karnad has its relevance not only at the time it was written but also to the present time when children have to sacrifice their wishes to the whims of their parents who are competing w ith other parents. However, some children are also forcing their loved ones to bend to their wishes. So it is very clear that adaptations provide us with new perspectives and points of view.

Hydrogels for Wound Healing Applications

Hydrogels for suffer Healing ApplicationsAbstractThis chapter discusses just ab out the hydrogels both natural and cellph iodinuloid that bed be employ for shock better applications. similarwise it discusses briefly about the various novel techniques that earn been developed recently.KeywordsHydrogels Chitosan, Antimicrobial Grafting Blending Wound dress Wound healing Gene therapy, bowing cell therapy, Skin Engineering, pH and Thermosensitive polymers.1 IntroductionHealthc atomic anatomy 18 is an essential aspect of human survival. So many biopolymers buzz sullen gene aimd interest in a figure of speech of biomedical applications. Wound management is iodin such(prenominal) ara where management of cuts, ulcers, and sores needs covers which help in promoting rapid affront healing in fiat to obtain both functional and cosmetic results. 45 There atomic number 18 divergent kinds of infract management products staples or sutures, groomings or adheres, surgical sealants and adhesives, skin substitutes, and an sepa rove(prenominal) biomaterials. 51 kind skin asss an effective barrier to microbial perceptivity and subsequent infection. However, once the injure has been developed in this barrier, the infection chances make ups. In case of degenerative aggravates, the colony and infection potential increases as the result of the presence of avascular eschar which provides an environment for the uninhibited growth of microorganisms. 89 The rate of infection is related to the type of anguish, command lesion care, and local health of the patient. 88, 90 For avoiding infection, good clinical practices are needful.The management of chronic bruises is a very costly practice and it similarly readys an enormous give out on healthcare resources studies wealthy person calculated the cost of breaks to the NHS to be about 1bn a year. 166 So for misfortunateering this cost such pain management products are needed that are to a greater extent economical and effective.Out of all the in a higher place smarting management products, here in this chapter we will discuss more about the injury dressings that will provide an best healing environment to the teaseing. A dressing is an adjunct subprogramd by a person for application to a wound in order to promote healing and/or prevent further harm. It is designed to be in direct reach out with the wound, so it is divergent from the bandage in the manner that bandages are normally apply to hold dressing in place.A wound is a break in the epithelial honor of the skin and may be accompanied by disruption of the structure and function of underlying normal tissue. Wounds spate be divided into foursome categories found on their appearance and stage of healing Necrotic, sloughing, granulating and epithelializing wounds. 87 Wounds ca uptake discomfort and are more prone to infection and other troublesome forkings. 75 Some diseases like diabetes, ischemia and conditi ons like malnourishment, ageing, local infection, local tissue molest due to singe leads to delay in wound healing. Infection is a major complication of burn injury and is responsible for 50-75% of hospital deaths. 76Human skin has one of the greatest capacities to regenerate itself amongst all of the tissues in our body. It constantly replaces old cells with unseasoned cells, enable it to exalt itself when damaged. Wound healing is a hard-physiologic process, which consists of three overlapping stagecoachs inflammatory, proliferative and remodeling phases. The normal healing response begins the moment the tissue is injured. As the blood components spill into the berth of injury, the platelets trace into contact with exposed collagen and other elements of the extracellular matrix. This contact triggers the platelets to release clotting factors as well as essential growth factors. During the inflammation process, neutrophils are the for the first clock time leukocytes which come at the grade of injury to rid it from bacterial contamination. Then, the monocytes and their conversion to macrophages initiate tissue repair by releasing a number of biologically active substances and growth factors that are necessary for the initiation of tissue formation process. In the third process, fibroblasts proliferate and migrate into the wound space and started the affirmation of the baseless extracellular matrix. Endothelial cells grow into a wound simultaneously with fibroblasts and undergo angiogenesis. Finally, tissue remodeling takes place to reconstruct the basement membrane by the distinction of keratinocytes as well as the formation of follicle cells. 43, 49, 50 A scar is an essential part of this natural healing process fol first baseing any type of damage to the skin. This place occur subsequently a surgical incision or the healing of a wound. As your body makes an effort to close an open wound and cling to itself from infection, it replaces injure d skin tissue with rapidly generated scar tissue. Scarring is slight when the damaged outer socio-economic class of skin is healed by rebuilt tissue. When we damage the wooden-headed socio-economic class of tissue beneath the skin, rebuilding is more complicated. Our bodies lay down collagen fibers (a protein which is naturally produced by the body) and this usually results in a lastly obvious scar. A aeonian reminder of the injury is left behind. So, a dressing that fire induce scarless healing is needed.Historically, a dressing was usually a piece of material, sometimes cloth, only if the use of cobwebs, dung, leaves and honey has also been described. However, modern dressings embarrass gauzes, semipermeable films, low adherent dressings, gels, foams, hydrocolloids, alginates, hydrogels and polysaccharide pastes. Wound dressings are passive, active or interactive. hands-off dressings alone provide cover while active or interactive dressings are surefooted of modifying the physiology of the wound environment. Interactive dressings include hydrocolloids, hydrogels, alginates, foam dressings and antimicrobial dressings. 17, 20, 85traditionally prohibitionist wound dressings are considered to be good for healing wounds i.e. the wound should be covered with gauze or left open. But it has been ob arranged by wintertime 191 that when wound is left open to air without any dressing, a scab i.e. a change covering covers the wound and decreases the rate of epithelialization. On the other hand, if wet dressing is use in place of dry dressings scab will not form and rate of healing increases as moist dressings provide low atomic number 8 tension which helps in wound healing, these dressings not only keep cells viable which enables them to release growth factors while fend foring contact between them and the healing tissues, but may also modulate or hassle their proliferation, these dressings decrease the pain at rest, during ambulation and during dres sing changes also moist environment waives rapid and in force(p) spoken language of any added antimicrobial agent thus prevent the wound from infection. So, the dressings that create and maintain a moist environment, however, are now considered to provide the optimum conditions for wound healing.2 Requirements of an pattern wound care systemThese characteristics should be present in the ideal wound care system (a) it should be exposed of maintaining a high humidity at the wound site, (b) it should be non-toxic, (c) non-allergenic, (d) it can be re effortd without ca employ trauma to the wound, (e) it should pe impermeable to bacteria, (f) Thermally insulating, (g) it should be well-fixed to touch, (h) it should allow prudish botch upeous exchange, (i) it should be free from particulate and toxic product, (j) promote tissue reconstruction processes and (k) it should be cost effective. 20, 165, 177Out of all the dressings hydrocolloids, alginates and hydrogels each one has its own advantages and limitations but hydrogels are best and have all the characteristics that are needed in an ideal wound dressing. All the above mentioned characteristics can be achieved in hydrogel wound dressings.3 Hydrogels for Wound Healing ApplicationsHydrogels are natural or synthetic cross-linked polymers used in a variety of medical and biomedical applications. Hydrogels consist of a matrix of insoluble polymers with up to 96% body of water capacity enabling them to donate water molecules to the wound surface and to maintain a moist environment at the wound bed. They are used in the construction of contact lenses, medicate-delivery vehicles, wound dressings and as physiologic electrodes or sensors. 17 Examples of hydrogel include Aquaform, Intrasite, GranuGel, Nu-Gel, Purilon, Sterigel.These also have the ability to absorb a degree of wound exudate. They transmit moisture vapour and oxygen, but their bacterial and still permeability is pendant on the type of secondary dressing used. 20 Hydrogels blow up or shrink in sedimentary solutions due to the association, dissociation and binding of various ions to polymer chains. These systems may swell in water until an equilibrium state is reached and retain their original shape. The fundamental interactions responsible for water sorption by hydrogels include the process of hydration, which is connected to the presence of such chemic groups as -OH, -COOH, -CONH2, -CONH-, and -SO3H and the existence of capillary areas and differences in osmotic pressure. The forces that make hydrogel dissolution impossible are presence of covalent bonds between individual polymer chains, hydrophobic and electrostatic interactions. 46These are hydrophilic polymer ne bothrks which may absorb from 10-20% (an arbitrary lower limit) up to thousands of times their dry pitch in water. These may be chemically durable or they may degrade and dissolve. They are called reversible, or physical gels when the networks are held t ogether by molecular entanglements, and/or secondary forces including ionic, H-bonding or hydrophobic forces. 13, 14, 15 Hydrogels are called aeonian or chemicalgels when they are covalently-crosslinked networks as shown in 1.Hydrogels can be made by ir radioactivity, freeze-thawing or chemical modes. Out of all the methods, irradiation is considered as a suitable tool for the formation of hydrogels as in this method there is easy control of processing, no need of adding initiators or cross-linkers which are harmful, and have the possibleness of formation and sterilization in one step. But as everything has its own advantages and detriments this method also has a disadvantage which is hydrogels create by this method have poor mechanized strength. Nowa solar days, Freeze thawing technique is generally used to prepare hydrogels having good strength, stability and no crosslinkers and initiators. But the main disadvantage is that the lively hydrogels have opaque appearance and li mited jut and thermal stability. 120In comparison to the traditional gauze therapy the application of a hydrogel seems to significantly stimulate wound healing. 11 assorted natural and synthetic polymers having good biocompatibility are used to develop hydrogel wound dressing. These polymers include natural polymers such as alginate, chitosan, gelatine and collagen and synthetic polymers such as polyurethane, poly(ethylene glycol), polycaprolactone, poly vinyl pyrrolidone, poly(lactide-co-glycolide), polyacrylonitrile , poly(amino vitriolic), etc. Table 1 below shows different hydrophilic polymers used to synthe size hydrogel matrices.Table 1 Hydrophilic polymers used to synthesise hydrogel matrices. 13Hydrogels may be classified as homopolymer hydrogels, copolymer hydrogels, multipolymer hydrogels, and interpenetrating polymeric hydrogels. Homopolymer hydrogels are crosslinked networks of one type of hydrophilic monomer unit, whereas copolymer hydrogels are produced by the cros slinking of two comonomer units, one of which must(prenominal) be hydrophilic. Multipolymer hydrogels are produced by the crosslinking of more than three monomers. Finally, interpenetrating polymeric hydrogels are produced by the swelling of a first network in a monomer and the reaction of the latter(prenominal) to form a second intermeshing network structure. 46, 47Also, it has been shown that the blending of a natural polymer with a synthetic polymer seems to be a good method for obtaining materials having necessary mechanised and thermal properties in comparison to pure components. It is also a simple method by which suitable shapes such as films, sponges and hydrogels can be obtained advantageously to realize a variety of biomedical devices.2 shows healing is instantaneous with the hydrogel dressing than with the gauze dressing. Wound area covered by hydrogel decreases faster with change magnitude healing period. On the contrary, the wound covered by gauze dressing funks by only half a percent even subsequently 14 days. 1923.1 Natural HydrogelsNatural polymers, such as chitin, chitosan, alginate, collagen, elastin, genipin, gelatin, cellulose etc. have been used for dressing wounds because they play an in-chief(postnominal) role in the healing process. 47Chitosan is a part deacetylated form of chitin. Chitin as Beschitin, Unitika, is also mercantilely available as dressing in Japan. 28 But as far as chitosan is concerned it is biocompatible, biodegradable, hae almostatic, fungistatic 54 and non-toxic and can be successfully used as gels, films, fibres etc. This polymer also show antibacterial properties and possess good wound healing properties. 60, 61, 62 It has many applications as wound dressing, drug delivery device and as scaffold for tissue engineering. 63, 64 Some of the examples of wound dressings are given below which use chitosan as one of the biomaterial. lopsided chitosan membranes have been developed by using immersion-precipitatio n phase-inversion method. 123, 124, 125 These asymmetric chitosan membranes are homogeneous and have porous structure. This membrane was prepared by preheating casted chitosan solution in oven for different time periods for dry phase separation and then immersed in to coagulant tank for wet phase separation and were subsequently freeze-dried. The skin layer acts as the rate controlling barrier for the release of drug and the porous layer provide mechanical support to the skin layer. The water vapor transmission rate, gas permeability, phosphate buffer solution solution compactness, in-vitro degradation, cell culture, bacterial penetration and wound healing test of this dressing were carried out. These membranes are effective in controlling evaporative water loss, showed exquisite oxygen permeability and also antibacterial in nature. These are also tack to be an urgent hemostat. In another study, argent sulphadiazine was structured as an antimicrobial agent to this asymmetric dr essing. The release behaviour of both silver and sulphadiazine ions were studied and represent to be significantly different from one another. silverish ions displayed a slow release behavior while sulphadiazine ions exhibited burst effect on first day of the drug release and then slowly diminish off. It is because of the interaction of silver with amino group of chitosan leading to its slow release throughout whereas, as the sulphadiazine ions were free to diffuse through the membrane to reach the wound site thus they showed a burst release. The membranes were further demonstrate effective against P. aerugniosa and S. aureus.In one of the papers, novel wound dressings were formed that composed of chitosan film and minocycline Hydrochloride (MH) and commercial polyurethane film (Tegaderm) as a backing. It is also a useful formulation for the treatment of severe burn wounds. Water vapor and oxygen can permeate the Tegaderm film but water cannot. The tegaderm film support the poly mer membrane. 126In one of the studies, a silver nanocrystalline chitosan (SNC) wound dressing composed of nano-silver and chitosan was constructed by self-assembly and nanotechnology and used for treating deep partial- oppressiveness wounds. In this, sterility and pyrogen testing were performed to ensure biosafety. These dressings promote wound healing and combat infection, and also decrease the risk of silver soaking up in comparison with silver sulphadiazine (SSD) dressings. 127There is also one more method of forming wound dressing composed of chitosan i.e. the formation of polyelectrolyte interlinking of mumble kondagogu (GKG) and chitosan. This complex is formed by the electrostatic interaction between carboxyl group of mutter and amine group of chitosan. This method is more advantageous as it avoids the use of organic solvents, chemical crosslinking agents and thus reduces the toxicity and undesirable side effects. In this, diclofenac sodium is used as model drug. The dic lofenac loaded complex of gum kondagogu/ chitosan shows drug release which changes with change in pH. The drug release was higher(prenominal) at pH 6.8 as compared to pH 1.2, due to higher swelling of complex at higher pH. This holds a great potential as a natural polymer based delivery device for controlled delivery of drugs like diclofenac sodium for two reasons (i) to reduce dosing frequency and (ii) lower the gastric toxicity. 152Semi-interpenetrating polymer networks (SIPNs) composed of chitosan (CS) and poloxamer were prepared in order to improve the mechanical strength of CS. The WVTR was found to be 2508.265.7 gm2 day1, i.e. these can maintain a moist environment at wound site which enhance epithelial cell migration. Also, the in vitro assessment of SIPNs showed proper biodegradation and low cytotoxicity and in vivo is carried out on experimental full thickness wounds in a mouse model and found that the wounds covered with these were completely make full with new epithelium without any significant adverse reactions after 3 weeks.In one of the papers, a kind of surgical wound dressing, the chitosan-gelatin sponge wound dressing (CGSWD) having good antibacterial property is prepared. The in vitro test showed that the antibacterial effect of CGSWD on E. coli K88 is better than that of penicillin, and the effect on S. aureus is also better than that of cefradine. 137 ane more wound dressing consists of two separate layers were prepared in which the upper layer is a swellable hydrogel material which can absorb exudates and also serve as mechanical and microbial barrier while lower layer is a chitosan acetate foam incorporated with the anti-microbial agent chlorherxidine gluconate. 183 The antimicrobial activity is analyse by the Bauer-Kirby Disk Diffusion Test, inhibition zones can be clearly seen around the discs of chitosan acetate foams incorporated with chlorhexidine gluconate, in culture plates inoculated with either Gram-negative or supreme bacteri a showing that the dressing is antimicrobial in nature.Blending is a convenient and effective method to improve physical and mechanical properties of hydrogels. So qualifying of chitosan is done by blending with other polymers like cellulose. 178 In this, E. coli and S. aureus were used as the test bacteria to examine the antibacterial properties of chitosan, cellulose and chitosan/cellulose blends. The numbers of dependency of these bacteria formed on the test membranes are shown in s 5 and 6. It was noted that the numbers of colony of all test bacteria formed on the chitosan/cellulose blend membranes were decreased with the increase of chitosan concentration. These blends are more effective against E. coli than that of S. aureus, as indicated by the lower colony unit. Thus these dressings are suitable to use as an antimicrobial wound dressing.Chitosan due to its structural properties has the ability to heal wounds without scar formation. 198 Since chitosan is composed of D-gluco samine, which is also the component present in the disaccharide subunits of hyaluronic acid, chitosan tries to structurally copy hyaluronic acid and exerts similar effects. 197 It has been cognise that the fetal wound healing takes place without fibrosis or scar formation due to the presence of hyaluronic acid. 199In one of the studies, Chitosan as a semi-permeable biological dressing maintains a moist environment and prevent the wound site from dehydration and contamination. In add-on, digital colour separation compend of sponsor site scars demonstrated an earlier return to normal skin colour at chitosan-treated areas as shown in 7. 196Collagen is also a biopolymer that is used as a polymer for making wound dressing and drug delivery devices as it is biocompatible and biocompatibility of a material applied to wound tissue is a prerequisite for optimal wound environment and facilitation of the healing processes. A new collagen dressing with gentamycin or amikacin was prepared in one of the research work and these follow the basic essential of antibacterial bandages. The dressing is composed of two collagen biomaterialsmembrane and spongeboth possessing good tissue biocompatibility. These dressing released antibiotics slowly and show the antibacterial treatment in by experimentation infected superficial wounds in mice. Thus, it can be used for the treatment of infected wounds in humans. 26As discussed previously that both chitosan and collagen are nice materials that can be used as wound dressing materials. So it has been seen that if both are used simultaneously then what will be the effect. It is found that the wound dressings composed of chitosan crosslinked collagen sponge (CCCS) enhance the diabetic wound healing. Collagen crosslinked with chitosan showed several advantages required for wound dressing, including the uniform and porous ultrastructure, less water imbibition, small musical interval porousness, and high resistance to collagenase digest ion and slow release of FGF from CCCS/FGF. 138Following moist healing concept, alginates which are able to absorb exudates from wound have become one of the most important materials for wound management. 52, 53, 54, 55, 56 In this particular field, the properties of alginate fibers are unparalleled in many respects. Alginate based products form a gel and effective in removing out of the wound on the contrary to traditional cotton and viscose fibres, which can entrap in the wound developing discomfort during dressing removal. 55 Also, the alginate fibres are non-toxic, non-carcinogenic, non-allergic, haemostatic, biocompatible, of tenable strength, capable of being sterilized and easily processable. Sorbsan was first commercialized in 1981 and after that there were many dressings launched. The alginate fibers can be converted into wound dressings by using a number of textile processes. Because of its simplicity and also the high absorbency of the product, nonwoven is the main form o f alginate wound dressings. 19The antimicrobial action of alginate dressing can be seen as in 8 which shows the antimicrobial action of silver containing alginate fibers against E. Coli. There was 100% reduction in bacteria count within 5 hr after the fibers were placed in contact with solutions containing the bacteria. Sorbsan alginate fibers showed some antimicrobial activity while AquacelTM (made of carboxymethyl cellulose), does not show any antimicrobial effect. 18Gelatin widely found in nature and is the major constituent of skin, bones, and connective tissue. Gelatin can easily be obtained by a controlled hydrolysis of the fibrous insoluble protein, collagen. 195 This is also used in number of biomedical applications like wound dressings. Hydrogel wound dressing from gelatin, oxidized alginate and borax were prepared and the composite matrix promotes wound healing because of alginate, has haemostatic effect of gelatin and is antiseptic because of borax. The water vapour trans mission rate (WVTR) of the hydrogel was calculated and found to be 2686124 g/m2/day indicating that this hydrogel can maintain a proper fluid poise at the wound site which helps in cell migration. 2 shows the loss of water vapour with time through the hydrogel when placed in a moisture rich environment. 119Genipin has been used to crosslink chitosan membranes to control swelling ratio and mechanical properties. It increased its ultimate tensile strength but significantly reduced its strain-at-fracture and swelling ratio. It had significantly less cytotoxicity for human fibroblasts and slower degradation rate compared to the glutaraldehyde-crosslinked membrane. This genipin crosslinked chitosan membrane can be successfully used as a wound dressing. 132bacterial cellulose is a natural polymer consisting of microfibrils containing glucan chains bound together by hydrogen bonds. Bacterial cellulose with chitosan combines properties such as bioactivity, biocompatibility, and biodegrada bility of the two biopolymers and form an ideal material for dressing wounds. 66, 67 These are antibacterial and scar preventive in nature too.Since natural polymers have been considered limited in their applications for wound-dressing materials as their low mechanical properties and shortage of processing. So we move towards the synthetic polymers that can be used for wound healing applications.3.2 Synthetic HydrogelsSynthetic polymers are also being used successfully in biomedical applications as one of the materials because of their wide range of mechanical properties, suitability for easily forming into a variety of different shapes, and low labor costs.In an ideal dressing both the characteristics i.e. antimicrobial ability and moist healing environment should be present, so in order to prevent the wound from dehydration and bacterial penetration a new dressing composed of polyurethane is designed in such a way that the upper layer of the dressing is microporous (pore size Pol yvinyl pyrrolidone (PVP) is one of the most widely used synthetic polymers in medicine because of its solubility in water and its extremely low cytotoxicity. Hydrogels prepared by radiation crosslinking of an aqueous solution of polyvinyl pyrrolidone (PVP) have been used as wound dressing. 21 These are biocompatible, reduces pain, easily replacable, permeable to oxygen, maintain moist environment at the wound site.Polyvinyl alcoholic beverage (polyvinyl acetate) is a well-known polymer because it is biocompatible and have required mechanical properties and polyethylene oxide (PEO) is a hydrophilic semicrystalline polyether which is biocompatible, non toxic, non polar, non antigenic and non immunogenic and is highly desirable in most biomedical applications requiring contact with physiological fluids.A hydrogel composed of PEO for wound dressing is prepared and PVA is added to give toughness to the hydrogel by electron beam irradiation and found that these hydrogels showed able pro perties for wound dressing that has been evaluated by creating wound on the back of the marmots. 157 The hydrogel gives a wet environment to wounds which causes faster healing compared with the gauze dressing with a dry environment. The weight of the hydrogel increases quickly at the earlier stages, up to 4 days, due to absorption of effusion produced from the wound as shown in Table 2. After that, the production of effusion from the wound ceases and the weight of the hydrogel decreases due to evaporation of the water in the hydrogel. This means that the healing of wound proceeds smoothly with time. The hydrogel can be strip off easily from the wound at the time of removal.Table 2 Absorption of effusion from wound of dressing during healing. 157The toughness of PEO hydrogel is improved by the addition of PVA and tensile strength is measured and found that as shown in 10 and 11, the tensile strength and elongation decrease with increasing dose because of the increase of crosslinkin g.Various synthetic polymers as discussed above are used for wound dressing applications. But the major problem with these materials is their biocompatibility characteristics are often unsatisfactory and their interaction with sustenance tissues is a major problem. So a combination of both natural and synthetic polymers is the better option to make a hydrogel having biocompatibility and desired mechanical strength.3.3 intermix hydrogelsSince both the natural and synthetic polymers have their own advantages and disadvantages so a combination of natural and synthetic polymers can endow the optimal properties necessary for wound repair. 47 The combination of natural and synthetic polymers is used in the biomedical, bioengineering and biotechnology field nowadays because of their great potential.A blended hydrogel composed of polyvinyl alcohol/polyvinyl pyrrolidone and lignite were prepared by single freezing and thawing or two-step freezing and thawing and -ray irradiation and appli ed as wound dressing. It is found that the absorption of S. aureus and P. aeruginosa by charcoal/PVA/PVP hydrogels was larger than those by PVA/PVP hydrogels, this is due to the absorption and attachment capability of bacteria by charcoal, this can be shown in 12 given below. 22The most classical way of fabricating a CS based wound dressing has been to design an asymmetric composite structure. In this method, the cotton plant fabric was coated with chitosan (CS) and polyethylene glycol ( reefer) followed by freeze-drying. The outer dense layer helps in preventing the microbial passage across the dressing and provides a rate controlling barrier for water vapor permeation, while the inner porous layer provides a high surface area for the exudates absorption. For the absorption of wound exudates porosity is the prime requirement in a dressing. It has been found that these dressings have the porosity 54-70% and the pore size was in the range of 75-120m. 45 The increase in the PEG conte nt in the blend composition led to an enhanced destabilization of pores, leading to an increase in the pore size with elongated geomorphology. There seems to be phase separation between the two components which is an important factor for the observed behavior of the porous structure. Cotton fabric has been used as the support layer for the CS-PEG layer and leads to very thin and light weight structures. The structure of the dressing has been designed in such a way that it leads to the high porosity of the bug out structure. The thickness of CS coating plays an important role in the development of the porosity on the surface. The influence of the CS thickness on the surface morphology is presented in 13 given below.PEG addition to CS makes significant alteration in the surface morphology of this CS-PEG/cotton membrane (freeze-dried), henceforth known as CPC membrane. There is a distinct trend in the loss of inherent elongated porous structure in membranes and formation of the parti ally collapsed porosity takes place due to the PEG addition. This suggests that a very limited interaction between CS and PEG exists which is reflected in the observed surface morphology. It has been observed that higher the mensuration of PEG, the higher is the pore destabilization leading to larger pores. This is evident from the morphology of the CPC membrane at 50% PEG-20 content as shown in 14.45On the above matrix, the addition of PVP and drug followed by coating on the cotton fabric and freeze drying of the coated matrix is also done. It has been found that the drugHydrogels for Wound Healing ApplicationsHydrogels for Wound Healing ApplicationsAbstractThis chapter discusses about the hydrogels both natural and synthetic that can be used for wound healing applications. Also it discusses briefly about the various novel techniques that have been developed recently.KeywordsHydrogels Chitosan, Antimicrobial Grafting Blending Wound dressing Wound healing Gene therapy, Stem cell th erapy, Skin Engineering, pH and Thermosensitive polymers.1 IntroductionHealthcare is an essential aspect of human survival. So many biopolymers have generated interest in a number of biomedical applications. Wound management is one such area where management of cuts, ulcers, and sores needs dressings which help in promoting rapid wound healing in order to obtain both functional and cosmetic results. 45 There are different kinds of wound management products staples or sutures, dressings or bandages, surgical sealants and adhesives, skin substitutes, and other biomaterials. 51Human skin provides an effective barrier to microbial penetration and subsequent infection. However, once the wound has been developed in this barrier, the infection chances increases. In case of chronic wounds, the colonization and infection potential increases as the result of the presence of avascular eschar which provides an environment for the uninhibited growth of microorganisms. 89 The rate of infection is related to the type of wound, general wound care, and local health of the patient. 88, 90 For avoiding infection, good clinical practices are needed.The management of chronic wounds is a very costly practice and it also places an enormous drain on healthcare resources studies have calculated the cost of wounds to the NHS to be about 1bn a year. 166 So for lowering this cost such wound management products are needed that are more economical and effective.Out of all the above wound management products, here in this chapter we will discuss more about the wound dressings that will provide an optimal healing environment to the wound. A dressing is an adjunct used by a person for application to a wound in order to promote healing and/or prevent further harm. It is designed to be in direct contact with the wound, so it is different from the bandage in the manner that bandages are normally used to hold dressing in place.A wound is a break in the epithelial integrity of the skin and may be accompanied by disruption of the structure and function of underlying normal tissue. Wounds can be divided into four categories based on their appearance and stage of healing Necrotic, sloughing, granulating and epithelializing wounds. 87 Wounds cause discomfort and are more prone to infection and other troublesome complications. 75 Some diseases like diabetes, ischaemia and conditions like malnourishment, ageing, local infection, local tissue damage due to burn leads to delay in wound healing. Infection is a major complication of burn injury and is responsible for 50-75% of hospital deaths. 76Human skin has one of the greatest capacities to regenerate itself amongst all of the tissues in our body. It constantly replaces old cells with new cells, enabling it to repair itself when damaged. Wound healing is a complex-physiologic process, which consists of three overlapping phases inflammatory, proliferative and remodeling phases. The normal healing response begins the moment the tissu e is injured. As the blood components spill into the site of injury, the platelets come into contact with exposed collagen and other elements of the extracellular matrix. This contact triggers the platelets to release clotting factors as well as essential growth factors. During the inflammation process, neutrophils are the first leukocytes which come at the site of injury to rid it from bacterial contamination. Then, the monocytes and their conversion to macrophages initiate tissue repair by releasing a number of biologically active substances and growth factors that are necessary for the initiation of tissue formation process. In the third process, fibroblasts proliferate and migrate into the wound space and started the deposition of the loose extracellular matrix. Endothelial cells grow into a wound simultaneously with fibroblasts and undergo angiogenesis. Finally, tissue remodeling takes place to reconstruct the basement membrane by the differentiation of keratinocytes as well as the formation of follicle cells. 43, 49, 50 A scar is an essential part of this natural healing process following any type of damage to the skin. This can occur after a surgical incision or the healing of a wound. As your body makes an effort to close an open wound and protect itself from infection, it replaces injured skin tissue with rapidly generated scar tissue. Scarring is slight when the damaged outer layer of skin is healed by rebuilt tissue. When we damage the thick layer of tissue beneath the skin, rebuilding is more complicated. Our bodies lay down collagen fibers (a protein which is naturally produced by the body) and this usually results in a highly obvious scar. A permanent reminder of the injury is left behind. So, a dressing that can induce scarless healing is needed.Historically, a dressing was usually a piece of material, sometimes cloth, but the use of cobwebs, dung, leaves and honey has also been described. However, modern dressings include gauzes, semipermeable films, low adherent dressings, gels, foams, hydrocolloids, alginates, hydrogels and polysaccharide pastes. Wound dressings are passive, active or interactive. Passive dressings simply provide cover while active or interactive dressings are capable of modifying the physiology of the wound environment. Interactive dressings include hydrocolloids, hydrogels, alginates, foam dressings and antimicrobial dressings. 17, 20, 85Traditionally dry wound dressings are considered to be good for healing wounds i.e. the wound should be covered with gauze or left open. But it has been observed by Winter 191 that when wound is left open to air without any dressing, a scab i.e. a dry covering covers the wound and decreases the rate of epithelialization. On the other hand, if moist dressing is used in place of dry dressings scab will not form and rate of healing increases as moist dressings provide low oxygen tension which helps in wound healing, these dressings not only keep cells viable which enable s them to release growth factors while maintaining contact between them and the healing tissues, but may also modulate or stimulate their proliferation, these dressings decrease the pain at rest, during ambulation and during dressing changes also moist environment allows rapid and efficient delivery of any added antimicrobial agent thus prevent the wound from infection. So, the dressings that create and maintain a moist environment, however, are now considered to provide the optimal conditions for wound healing.2 Requirements of an ideal wound care systemThese characteristics should be present in the ideal wound care system (a) it should be capable of maintaining a high humidity at the wound site, (b) it should be non-toxic, (c) non-allergenic, (d) it can be removed without causing trauma to the wound, (e) it should pe impermeable to bacteria, (f) Thermally insulating, (g) it should be soft to touch, (h) it should allow proper gaseous exchange, (i) it should be free from particulate and toxic product, (j) promote tissue reconstruction processes and (k) it should be cost effective. 20, 165, 177Out of all the dressings hydrocolloids, alginates and hydrogels each one has its own advantages and limitations but hydrogels are best and have all the characteristics that are needed in an ideal wound dressing. All the above mentioned characteristics can be achieved in hydrogel wound dressings.3 Hydrogels for Wound Healing ApplicationsHydrogels are natural or synthetic cross-linked polymers used in a variety of medical and biomedical applications. Hydrogels consist of a matrix of insoluble polymers with up to 96% water content enabling them to donate water molecules to the wound surface and to maintain a moist environment at the wound bed. They are used in the construction of contact lenses, drug-delivery vehicles, wound dressings and as physiological electrodes or sensors. 17 Examples of hydrogel include Aquaform, Intrasite, GranuGel, Nu-Gel, Purilon, Sterigel.These als o have the ability to absorb a degree of wound exudate. They transmit moisture vapour and oxygen, but their bacterial and fluid permeability is dependent on the type of secondary dressing used. 20 Hydrogels swell or shrink in aqueous solutions due to the association, dissociation and binding of various ions to polymer chains. These systems may swell in water until an equilibrium state is reached and retain their original shape. The interactions responsible for water sorption by hydrogels include the process of hydration, which is connected to the presence of such chemical groups as -OH, -COOH, -CONH2, -CONH-, and -SO3H and the existence of capillary areas and differences in osmotic pressure. The forces that make hydrogel dissolution impossible are presence of covalent bonds between individual polymer chains, hydrophobic and electrostatic interactions. 46These are hydrophilic polymer networks which may absorb from 10-20% (an arbitrary lower limit) up to thousands of times their dry w eight in water. These may be chemically stable or they may degrade and dissolve. They are called reversible, or physical gels when the networks are held together by molecular entanglements, and/or secondary forces including ionic, H-bonding or hydrophobic forces. 13, 14, 15 Hydrogels are called permanent or chemicalgels when they are covalently-crosslinked networks as shown in 1.Hydrogels can be made by irradiation, freeze-thawing or chemical methods. Out of all the methods, irradiation is considered as a suitable tool for the formation of hydrogels as in this method there is easy control of processing, no need of adding initiators or cross-linkers which are harmful, and have the possibility of formation and sterilization in one step. But as everything has its own advantages and disadvantages this method also has a disadvantage which is hydrogels formed by this method have poor mechanical strength. Nowadays, Freeze thawing technique is generally used to prepare hydrogels having good strength, stability and no crosslinkers and initiators. But the main disadvantage is that the prepared hydrogels have opaque appearance and limited swelling and thermal stability. 120In comparison to the traditional gauze therapy the application of a hydrogel seems to significantly stimulate wound healing. 11 Various natural and synthetic polymers having good biocompatibility are used to develop hydrogel wound dressing. These polymers include natural polymers such as alginate, chitosan, gelatin and collagen and synthetic polymers such as polyurethane, poly(ethylene glycol), polycaprolactone, poly vinyl pyrrolidone, poly(lactide-co-glycolide), polyacrylonitrile , poly(amino acid), etc. Table 1 below shows different hydrophilic polymers used to synthesize hydrogel matrices.Table 1 Hydrophilic polymers used to synthesize hydrogel matrices. 13Hydrogels may be classified as homopolymer hydrogels, copolymer hydrogels, multipolymer hydrogels, and interpenetrating polymeric hydrogels. Homo polymer hydrogels are crosslinked networks of one type of hydrophilic monomer unit, whereas copolymer hydrogels are produced by the crosslinking of two comonomer units, one of which must be hydrophilic. Multipolymer hydrogels are produced by the crosslinking of more than three monomers. Finally, interpenetrating polymeric hydrogels are produced by the swelling of a first network in a monomer and the reaction of the latter to form a second intermeshing network structure. 46, 47Also, it has been shown that the blending of a natural polymer with a synthetic polymer seems to be a good method for obtaining materials having required mechanical and thermal properties in comparison to pure components. It is also a simple method by which suitable shapes such as films, sponges and hydrogels can be obtained easily to realize a variety of biomedical devices.2 shows healing is faster with the hydrogel dressing than with the gauze dressing. Wound area covered by hydrogel decreases faster with inc reasing healing period. On the contrary, the wound covered by gauze dressing reduces by only half a percent even after 14 days. 1923.1 Natural HydrogelsNatural polymers, such as chitin, chitosan, alginate, collagen, elastin, genipin, gelatin, cellulose etc. have been used for dressing wounds because they play an important role in the healing process. 47Chitosan is a partially deacetylated form of chitin. Chitin as Beschitin, Unitika, is also commercially available as dressing in Japan. 28 But as far as chitosan is concerned it is biocompatible, biodegradable, haemostatic, fungistatic 54 and non-toxic and can be successfully used as gels, films, fibres etc. This polymer also show antibacterial properties and possess good wound healing properties. 60, 61, 62 It has many applications as wound dressing, drug delivery device and as scaffold for tissue engineering. 63, 64 Some of the examples of wound dressings are given below which use chitosan as one of the biomaterial.Asymmetric chitos an membranes have been developed by using immersion-precipitation phase-inversion method. 123, 124, 125 These asymmetric chitosan membranes are homogeneous and have porous structure. This membrane was prepared by preheating casted chitosan solution in oven for different time periods for dry phase separation and then immersed in to coagulant tank for wet phase separation and were subsequently freeze-dried. The skin layer acts as the rate controlling barrier for the release of drug and the porous layer provide mechanical support to the skin layer. The water vapor transmission rate, gas permeability, PBS solution absorption, in-vitro degradation, cell culture, bacterial penetration and wound healing test of this dressing were carried out. These membranes are effective in controlling evaporative water loss, showed excellent oxygen permeability and also antibacterial in nature. These are also found to be an urgent hemostat. In another study, silver sulphadiazine was incorporated as an an timicrobial agent to this asymmetric dressing. The release behaviour of both silver and sulphadiazine ions were studied and found to be significantly different from one another. Silver ions displayed a slow release behavior while sulphadiazine ions exhibited burst effect on first day of the drug release and then slowly tapered off. It is because of the interaction of silver with amino group of chitosan leading to its slow release throughout whereas, as the sulphadiazine ions were free to diffuse through the membrane to reach the wound site thus they showed a burst release. The membranes were further found effective against P. aerugniosa and S. aureus.In one of the papers, novel wound dressings were formed that composed of chitosan film and Minocycline Hydrochloride (MH) and commercial polyurethane film (Tegaderm) as a backing. It is also a useful formulation for the treatment of severe burn wounds. Water vapor and oxygen can permeate the Tegaderm film but water cannot. The tegaderm film support the polymer membrane. 126In one of the studies, a silver nanocrystalline chitosan (SNC) wound dressing composed of nano-silver and chitosan was constructed by self-assembly and nanotechnology and used for treating deep partial-thickness wounds. In this, sterility and pyrogen testing were performed to ensure biosafety. These dressings promote wound healing and combat infection, and also decrease the risk of silver absorption in comparison with silver sulphadiazine (SSD) dressings. 127There is also one more method of forming wound dressing composed of chitosan i.e. the formation of polyelectrolyte complex of gum kondagogu (GKG) and chitosan. This complex is formed by the electrostatic interaction between carboxyl group of gum and amine group of chitosan. This method is more advantageous as it avoids the use of organic solvents, chemical crosslinking agents and thus reduces the toxicity and undesirable side effects. In this, diclofenac sodium is used as model drug. The dic lofenac loaded complex of gum kondagogu/ chitosan shows drug release which changes with change in pH. The drug release was higher at pH 6.8 as compared to pH 1.2, due to higher swelling of complex at higher pH. This holds a great potential as a natural polymer based delivery device for controlled delivery of drugs like diclofenac sodium for two reasons (i) to reduce dosing frequency and (ii) lower the gastric toxicity. 152Semi-interpenetrating polymer networks (SIPNs) composed of chitosan (CS) and poloxamer were prepared in order to improve the mechanical strength of CS. The WVTR was found to be 2508.265.7 gm2 day1, i.e. these can maintain a moist environment at wound site which enhance epithelial cell migration. Also, the in vitro assessment of SIPNs showed proper biodegradation and low cytotoxicity and in vivo is carried out on experimental full thickness wounds in a mouse model and found that the wounds covered with these were completely filled with new epithelium without any sig nificant adverse reactions after 3 weeks.In one of the papers, a kind of surgical wound dressing, the chitosan-gelatin sponge wound dressing (CGSWD) having good antibacterial property is prepared. The in vitro test showed that the antibacterial effect of CGSWD on E. coli K88 is better than that of penicillin, and the effect on S. aureus is also better than that of cefradine. 137One more wound dressing consists of two separate layers were prepared in which the upper layer is a swellable hydrogel material which can absorb exudates and also serve as mechanical and microbial barrier while lower layer is a chitosan acetate foam incorporated with the anti-microbial agent chlorherxidine gluconate. 183 The antimicrobial activity is checked by the Bauer-Kirby Disk Diffusion Test, inhibition zones can be clearly seen around the discs of chitosan acetate foams incorporated with chlorhexidine gluconate, in culture plates inoculated with either Gram-negative or positive bacteria showing that the dressing is antimicrobial in nature.Blending is a convenient and effective method to improve physical and mechanical properties of hydrogels. So modification of chitosan is done by blending with other polymers like cellulose. 178 In this, E. coli and S. aureus were used as the test bacteria to examine the antibacterial properties of chitosan, cellulose and chitosan/cellulose blends. The numbers of colony of these bacteria formed on the test membranes are shown in s 5 and 6. It was noted that the numbers of colony of all test bacteria formed on the chitosan/cellulose blend membranes were decreased with the increase of chitosan concentration. These blends are more effective against E. coli than that of S. aureus, as indicated by the lower colony unit. Thus these dressings are suitable to use as an antimicrobial wound dressing.Chitosan due to its structural properties has the ability to heal wounds without scar formation. 198 Since chitosan is composed of D-glucosamine, which is also the component present in the disaccharide subunits of hyaluronic acid, chitosan tries to structurally mimic hyaluronic acid and exerts similar effects. 197 It has been known that the fetal wound healing takes place without fibrosis or scar formation due to the presence of hyaluronic acid. 199In one of the studies, Chitosan as a semi-permeable biological dressing maintains a moist environment and prevent the wound site from dehydration and contamination. In addition, digital colour separation analysis of donor site scars demonstrated an earlier return to normal skin colour at chitosan-treated areas as shown in 7. 196Collagen is also a biopolymer that is used as a polymer for making wound dressing and drug delivery devices as it is biocompatible and biocompatibility of a material applied to wound tissue is a prerequisite for optimal wound environment and facilitation of the healing processes. A new collagen dressing with gentamycin or amikacin was prepared in one of the research work and these follow the basic requirement of antibacterial bandages. The dressing is composed of two collagen biomaterialsmembrane and spongeboth possessing good tissue biocompatibility. These dressing released antibiotics slowly and show the antibacterial treatment in experimentally infected superficial wounds in mice. Thus, it can be used for the treatment of infected wounds in humans. 26As discussed previously that both chitosan and collagen are excellent materials that can be used as wound dressing materials. So it has been seen that if both are used simultaneously then what will be the effect. It is found that the wound dressings composed of chitosan crosslinked collagen sponge (CCCS) enhance the diabetic wound healing. Collagen crosslinked with chitosan showed several advantages required for wound dressing, including the uniform and porous ultrastructure, less water imbibition, small interval porosity, and high resistance to collagenase digestion and slow release of FGF from CCCS /FGF. 138Following moist healing concept, alginates which are able to absorb exudates from wound have become one of the most important materials for wound management. 52, 53, 54, 55, 56 In this particular field, the properties of alginate fibers are unparalleled in many respects. Alginate based products form a gel and effective in removing out of the wound on the contrary to traditional cotton and viscose fibres, which can entrap in the wound developing discomfort during dressing removal. 55 Also, the alginate fibres are non-toxic, non-carcinogenic, non-allergic, haemostatic, biocompatible, of reasonable strength, capable of being sterilized and easily processable. Sorbsan was first commercialized in 1981 and after that there were many dressings launched. The alginate fibers can be converted into wound dressings by using a number of textile processes. Because of its simplicity and also the high absorbency of the product, nonwoven is the main form of alginate wound dressings. 19The a ntimicrobial action of alginate dressing can be seen as in 8 which shows the antimicrobial action of silver containing alginate fibers against E. Coli. There was 100% reduction in bacteria count within 5 hr after the fibers were placed in contact with solutions containing the bacteria. Sorbsan alginate fibers showed some antimicrobial activity while AquacelTM (made of carboxymethyl cellulose), does not show any antimicrobial effect. 18Gelatin widely found in nature and is the major constituent of skin, bones, and connective tissue. Gelatin can easily be obtained by a controlled hydrolysis of the fibrous insoluble protein, collagen. 195 This is also used in number of biomedical applications like wound dressings. Hydrogel wound dressing from gelatin, oxidized alginate and borax were prepared and the composite matrix promotes wound healing because of alginate, has haemostatic effect of gelatin and is antiseptic because of borax. The water vapour transmission rate (WVTR) of the hydrogel was calculated and found to be 2686124 g/m2/day indicating that this hydrogel can maintain a proper fluid balance at the wound site which helps in cell migration. 2 shows the loss of water vapour with time through the hydrogel when placed in a moisture rich environment. 119Genipin has been used to crosslink chitosan membranes to control swelling ratio and mechanical properties. It increased its ultimate tensile strength but significantly reduced its strain-at-fracture and swelling ratio. It had significantly less cytotoxicity for human fibroblasts and slower degradation rate compared to the glutaraldehyde-crosslinked membrane. This genipin crosslinked chitosan membrane can be successfully used as a wound dressing. 132Bacterial cellulose is a natural polymer consisting of microfibrils containing glucan chains bound together by hydrogen bonds. Bacterial cellulose with chitosan combines properties such as bioactivity, biocompatibility, and biodegradability of the two biopolymers and form an ideal material for dressing wounds. 66, 67 These are antibacterial and scar preventive in nature too.Since natural polymers have been considered limited in their applications for wound-dressing materials as their low mechanical properties and shortage of processing. So we move towards the synthetic polymers that can be used for wound healing applications.3.2 Synthetic HydrogelsSynthetic polymers are also being used successfully in biomedical applications as one of the materials because of their wide range of mechanical properties, suitability for easily forming into a variety of different shapes, and low production costs.In an ideal dressing both the characteristics i.e. antimicrobial ability and moist healing environment should be present, so in order to prevent the wound from dehydration and bacterial penetration a new dressing composed of polyurethane is designed in such a way that the upper layer of the dressing is microporous (pore size Polyvinyl pyrrolidone (PVP) is on e of the most widely used synthetic polymers in medicine because of its solubility in water and its extremely low cytotoxicity. Hydrogels prepared by radiation crosslinking of an aqueous solution of polyvinyl pyrrolidone (PVP) have been used as wound dressing. 21 These are biocompatible, reduces pain, easily replacable, permeable to oxygen, maintain moist environment at the wound site.Polyvinyl alcohol (PVA) is a well-known polymer because it is biocompatible and have required mechanical properties and polyethylene oxide (PEO) is a hydrophilic semicrystalline polyether which is biocompatible, non toxic, non polar, non antigenic and non immunogenic and is highly desirable in most biomedical applications requiring contact with physiological fluids.A hydrogel composed of PEO for wound dressing is prepared and PVA is added to give toughness to the hydrogel by electron beam irradiation and found that these hydrogels showed satisfactory properties for wound dressing that has been evaluate d by creating wound on the back of the marmots. 157 The hydrogel gives a wet environment to wounds which causes faster healing compared with the gauze dressing with a dry environment. The weight of the hydrogel increases quickly at the earlier stages, up to 4 days, due to absorption of effusion produced from the wound as shown in Table 2. After that, the production of effusion from the wound ceases and the weight of the hydrogel decreases due to evaporation of the water in the hydrogel. This means that the healing of wound proceeds smoothly with time. The hydrogel can be peeled off easily from the wound at the time of removal.Table 2 Absorption of effusion from wound of dressing during healing. 157The toughness of PEO hydrogel is improved by the addition of PVA and tensile strength is measured and found that as shown in 10 and 11, the tensile strength and elongation decrease with increasing dose because of the increase of crosslinking.Various synthetic polymers as discussed above ar e used for wound dressing applications. But the major problem with these materials is their biocompatibility characteristics are often unsatisfactory and their interaction with living tissues is a major problem. So a combination of both natural and synthetic polymers is the better option to make a hydrogel having biocompatibility and desired mechanical strength.3.3 Blended hydrogelsSince both the natural and synthetic polymers have their own advantages and disadvantages so a combination of natural and synthetic polymers can endow the optimal properties necessary for wound repair. 47 The combination of natural and synthetic polymers is used in the biomedical, bioengineering and biotechnology field nowadays because of their great potential.A blended hydrogel composed of polyvinyl alcohol/polyvinyl pyrrolidone and charcoal were prepared by single freezing and thawing or two-step freezing and thawing and -ray irradiation and applied as wound dressing. It is found that the absorption of S. aureus and P. aeruginosa by charcoal/PVA/PVP hydrogels was larger than those by PVA/PVP hydrogels, this is due to the absorption and attachment capability of bacteria by charcoal, this can be shown in 12 given below. 22The most classical way of fabricating a CS based wound dressing has been to design an asymmetric composite structure. In this method, the Cotton fabric was coated with chitosan (CS) and polyethylene glycol (PEG) followed by freeze-drying. The outer dense layer helps in preventing the microbial passage across the dressing and provides a rate controlling barrier for water vapor permeation, while the inner porous layer provides a high surface area for the exudates absorption. For the absorption of wound exudates porosity is the prime requirement in a dressing. It has been found that these dressings have the porosity 54-70% and the pore size was in the range of 75-120m. 45 The increase in the PEG content in the blend composition led to an enhanced destabilization of po res, leading to an increase in the pore size with elongated morphology. There seems to be phase separation between the two components which is an important factor for the observed behavior of the porous structure. Cotton fabric has been used as the support layer for the CS-PEG layer and leads to very thin and light weight structures. The structure of the dressing has been designed in such a way that it leads to the high porosity of the bulk structure. The thickness of CS coating plays an important role in the development of the porosity on the surface. The influence of the CS thickness on the surface morphology is presented in 13 given below.PEG addition to CS makes significant alteration in the surface morphology of this CS-PEG/cotton membrane (freeze-dried), henceforth known as CPC membrane. There is a distinct trend in the loss of inherent elongated porous structure in membranes and formation of the partially collapsed porosity takes place due to the PEG addition. This suggests t hat a very limited interaction between CS and PEG exists which is reflected in the observed surface morphology. It has been observed that higher the amount of PEG, the higher is the pore destabilization leading to larger pores. This is evident from the morphology of the CPC membrane at 50% PEG-20 content as shown in 14.45On the above matrix, the addition of PVP and drug followed by coating on the cotton fabric and freeze drying of the coated matrix is also done. It has been found that the drug

Euthanasia Essay - Civil Remedies and Assisted Suicide :: Free Euthanasia Essay

Civil Remedies and help Suicide This essay goes into the need for civil remedies to book against adverted suicide actions by family, guardians, etc. Some states stand already enacted such legislation, and others are in the process. This is a simple, safe legal procedure for protect against the threat ot assisted suicide/euthanasia. On May 2, 1994, a Michigan jury acquitted maw Kevorkian of charges related to his publicly proclaimed assistance in the suicide of Thomas Hyde. The verdict points up the way in which the pathos of individual cases often leads sinful case juries to react emotionally, failing to give unselfish attention to the general effects on older people and people with disabilities of signaling societal acceptation of death as the solution to human problems. This is a weakness in our society at the present time. This is one of several strong reasons why more(prenominal) states should follow the lead of Minnesota, Tennessee, and North Dakota, all of which ha ve recently enacted civil remedy statutes that, entirely apart from criminal remedies, allow private parties to obtain injunctions against those who assist suicides. Injunctions are granted by assesss, without juries, and a judge can punish violators with sanctions for contempt of court. Regrettably, the Kevorkian acquittal is not an isolated case of jury nullification of laws protect suicide victims. Recent history demonstrates that no physicians, and fewer non-physicians, have been successfully prosecuted for assisting suicide. The emotional tug of individual cases makes prosecutors reluctant to seek punishment and juries reluctant to chat it. An article in the November 5, 1992 issue of the New England ledger of Medicine co-authored by Dr. Timothy Qu sick of(p) (who himself escaped penalty when a grand jury refused to charge him for his openly announced participation in assisting a suicide1) notes, In every situation in which a physician has compassionately helped a termina lly ill person to commit suicide, criminal charges have been pink-slipped or a verdict of not guilty has been brought.2 Other studies confirm this conclusion, which in fact is not limited to circumstances of terminal illness or compassion.3 While there have been a few successful criminal prosecutions of non-doctors, they have been extremely rare. A 1986 article in the Columbia Law come off concluded All indications are that assistance statutes are rarely, if ever, used. ... Despite the thousands of suicides each year, only about fifty news reports regarding some(a) form of prosecution in the past disco biscuit for some type of assistance to suicide have been located.Euthanasia Essay - Civil Remedies and Assisted Suicide Free Euthanasia EssayCivil Remedies and Assisted Suicide This essay goes into the need for civil remedies to guard against assisted suicide actions by family, guardians, etc. Some states have already enacted such legislation, and others are in the process. This is a simple, safe legal procedure for protecting against the threat ot assisted suicide/euthanasia. On May 2, 1994, a Michigan jury acquitted Jack Kevorkian of charges related to his publicly proclaimed assistance in the suicide of Thomas Hyde. The verdict points up the way in which the pathos of individual cases often leads criminal case juries to react emotionally, failing to give considerate attention to the general effects on older people and people with disabilities of signaling societal acceptance of death as the solution to human problems. This is a weakness in our society at the present time. This is one of several strong reasons why more states should follow the lead of Minnesota, Tennessee, and North Dakota, all of which have recently enacted civil remedy statutes that, entirely apart from criminal remedies, allow private parties to obtain injunctions against those who assist suicides. Injunctions are granted by judges, without juries, and a judge can punish violato rs with sanctions for contempt of court. Regrettably, the Kevorkian acquittal is not an isolated case of jury nullification of laws protecting suicide victims. Recent history demonstrates that no physicians, and few non-physicians, have been successfully prosecuted for assisting suicide. The emotional tug of individual cases makes prosecutors reluctant to seek punishment and juries reluctant to impose it. An article in the November 5, 1992 issue of the New England Journal of Medicine co-authored by Dr. Timothy Quill (who himself escaped penalty when a grand jury refused to indict him for his openly announced participation in assisting a suicide1) notes, In every situation in which a physician has compassionately helped a terminally ill person to commit suicide, criminal charges have been dismissed or a verdict of not guilty has been brought.2 Other studies confirm this conclusion, which in fact is not limited to circumstances of terminal illness or compassion.3 While there have been a few successful criminal prosecutions of non-doctors, they have been extremely rare. A 1986 article in the Columbia Law Review concluded All indications are that assistance statutes are rarely, if ever, used. ... Despite the thousands of suicides each year, only about fifty news reports regarding some form of prosecution in the past decade for some type of assistance to suicide have been located.

Essay --

Thales of Miletus (modern day Turkey) was said to be the very first classical philosopher, scientist and mathematician. Although little is known about Thales, it is recorded that he lived amongst 624 BC 546 BC. Thales was the founder of the Milesian school and in addition known as one of the Seven Wise Men (Stokes). Most of his accomplishments are speculated upon since none of his writings survived, and every sources seem to be non-existent. All that is known about his thoughts came from Aristotle, the four statements are as follows (1) The world originated from water (2) The world floats on water (3) The world has numerous gods (4) Soul produces motion (Burnet). Aristotle was very hesitant in writing these claims, stating that even by his time Thales was known only by word of mouth and non through hard evidence. Thales was said to be a devoted traveler and it is mainly through the writings of Aristotle why Thales is considered the father of science and the first pre-Soc ratic Greek philosopher.Aside from the writings of Thales, he was also an astronomer and mathematician. According to the Greek writer Xenophanes, it is believed that Thales was the first to predict a solar eclipse in 585 BC. This prodigy startled Ionia and ended up stopping the battle between Lydian Alyattes and the Median Cyaxares. It is said that Thales used Babylonian astronomy in his prediction of the solar eclipse. Thales also wrote a manual for sailors and achieved a fortune by using his theories in astronomy to predict when olive crops would grow and then buying the land. This was mainly arrant(a) so that Thales could prove it was possible to make money as a philosopher (Burnet).As a mathematician, Thales is famous for his knowledge in geometry a... ...phy. Peithos Web, n.d. Web. 12 Feb. 2014. .Burnet, John. Greek doctrine Thales to Plato. London Burnet, 2008. Print.Livingstone, Richard W., Sir, and Gilbert, Murray. The Legacy of Greece. The Legacy of Greece Internet Archive. Oxford Clarendon Press, 21 Dec. 2007. Web. 12 Feb. 2014. .Lytton, Bulwe E. The Lost Tales of Miletus. Charleston BiblioBazaar, 2009. Print.OGrady, Patricia F. Thales of Miletus The Beginnings of Western Science and Philosophy. Aldershot, Hants, England Ashgate, 2002. Print.Stokes, Phillips. Philosophy 100 Essential Thinkers The Ideas That Have wrought Our World. London Arcturus, 2012. Print.Thales. 2014. The Famous People website. Feb 12 2014. .