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Drahoslav Lím
Drahoslav Lím (born September 30, 1925 in Czechoslovakia; died August 22, 2003 in San Diego, California) was a Czech chemist. He invented polyhydroxyethylmethacrylate, the synthetic material used for soft contact lenses (hydrogel). Lím worked as a member of the team of Otto Wichterle (the inventor of soft contact lenses) and in 1955, he came up with poly(hydroethyl-acrylate), the material later used for the lenses. This work was later published in Nature and was the subject of US patents.Otto Wichterle and Drahoslav Lim, "Cross-linked hydrophilic polymers and articles made therefrom", US Patent 3,220,960, November 30, 1965 During 1970 to 1974 he worked in Palo Alto, California, improving contact lenses materials and technology. When he returned to Czechoslovakia he was persecuted for political reasons and was not allowed to work in his specialisation. In 1979, he was allowed to emigrate to the United States. There Lím worked on materials for artificial kidneys and continued wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jimlín
Jimlín is a municipality and village in Louny District in the Ústí nad Labem Region of the Czech Republic. It has about 900 inhabitants. Jimlín lies approximately south-west of Louny, south-west of Ústí nad Labem, and north-west of Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate .... Administrative parts The village of Zěmechy is an administrative part of Jimlín. It is urbanistically fused with Jimlín. References Villages in Louny District {{ÚstínadLabem-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contact Lenses
Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes. Contact lenses are ocular prosthetic devices used by over 150 million people worldwide, and they can be worn to correct vision or for cosmetic or therapeutic reasons. In 2010, the worldwide market for contact lenses was estimated at $6.1 billion, while the US soft lens market was estimated at $2.1 billion.Nichols, Jason J., et a"ANNUAL REPORT: Contact Lenses 2010" January 2011. Multiple analysts estimated that the global market for contact lenses would reach $11.7 billion by 2015. , the average age of contact lens wearers globally was 31 years old, and two-thirds of wearers were female.Morgan, Philip B., et al"International Contact Lens Prescribing in 2010" ''Contact Lens Spectrum''. October 2011. People choose to wear contact lenses for many reasons. Aesthetics and cosmetics are main motivating factors for people who want to avoid wearing glasses or to change the appearance or c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Czech Inventors
Czech may refer to: * Anything from or related to the Czech Republic, a country in Europe ** Czech language ** Czechs, the people of the area ** Czech culture ** Czech cuisine * One of three mythical brothers, Lech, Czech, and Rus' Places *Czech, Łódź Voivodeship, Poland *Czechville, Wisconsin, unincorporated community, United States People * Bronisław Czech (1908–1944), Polish sportsman and artist * Danuta Czech (1922–2004), Polish Holocaust historian * Hermann Czech (born 1936), Austrian architect * Mirosław Czech (born 1968), Polish politician and journalist of Ukrainian origin * Zbigniew Czech (born 1970), Polish diplomat See also * Čech, a surname * Czech lands * Czechoslovakia * List of Czechs * * * Czechoslovak (other) * Czech Republic (other) * Czechia (other) {{disambiguation Language and nationality disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymer
A polymer (; Greek ''poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals. The term "polymer" derives from the Greek word πολύς (''polus'', meaning "many, much") and μέρος (''meros'', mean ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Kidney
Artificial kidney is often a synonym for hemodialysis, but may also refer to the other renal replacement therapies (with exclusion of kidney transplantation) that are in use and/or in development. This article deals mainly with bioengineered kidneys/bioartificial kidneys that are grown from renal cell lines/renal tissue. The first successful artificial kidney was developed by Willem Kolff in the Netherlands during the early 1940s: Kolff was the first to construct a working dialyzer in 1943. Medical uses Kidney failure Kidneys are paired vital organs located behind the abdominal cavity at the bottom of the ribcage corresponding to the levels T12-L3 of the spine vertebrae. They perform about a dozen physiologic functions and are fairly easily damaged. Some of these functions include filtration and excretion of metabolic waste products, regulation of necessary electrolytes and fluids and stimulation of red blood cell-production. These organs routinely filter about 100 to 140 lite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palo Alto, California
Palo Alto (; Spanish for "tall stick") is a charter city in the northwestern corner of Santa Clara County, California, United States, in the San Francisco Bay Area, named after a coastal redwood tree known as El Palo Alto. The city was established in 1894 by the American industrialist Leland Stanford when he founded Stanford University in memory of his son, Leland Stanford Jr. Palo Alto includes portions of Stanford University and borders East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. At the 2020 census, the population was 68,572. Palo Alto is one of the most expensive cities in the United States in which to live, and its residents are among the most educated in the country. However, it also has a youth suicide rate four times higher than the national average, often attributed to academic pressure. As one of the principal cities of Silicon Valley, Palo Alto is headquarters to a number of high-tech companies, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otto Wichterle
Otto Wichterle (; 27 October 1913 – 18 August 1998) was a Czech chemist, best known for his invention of modern soft contact lenses. Wichterle is the author or co-author of approximately 180 patents and over 200 publications. The studies and independent books covered various aspects of organic, inorganic and macromolecular chemistry, polymer science and biomedical materials. He had an even higher number of patents out for organic synthesis, polymerization, fibres, the synthesis and shaping of biomedical materials, production methods and measuring devices related to biomedical products. This was typical of his attitude to scientific research which, he considered, ought to serve society and its requirements by any means possible, without distinction as to "pure" and "applied" science. Schooling and chemistry background Wichterle's father Karel was co-owner of a successful farm-machine factory and small car plant but Otto chose science for his career. After finishing high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogel
A hydrogel is a crosslinked hydrophilic polymer that does not dissolve in water. They are highly absorbent yet maintain well defined structures. These properties underpin several applications, especially in the biomedical area. Many hydrogels are synthetic, but some are derived from nature. The term 'hydrogel' was coined in 1894. Chemistry Classification The crosslinks which bond the polymers of a hydrogel fall under two general categories: physical and chemical. Chemical hydrogels have covalent cross-linking bonds, whereas physical hydrogels have non-covalent bonds. Chemical hydrogels result in strong irreversible gels due to the covalent bonding, and they may also possess harmful properties which makes them unfavourable for medical applications. Physical hydrogels on the other hand have high biocompatibility, aren’t toxic, and are also easily reversible, by simply changing an external stimulus such as pH or temperature; thus they are favourable for use in medical applicat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon- hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Livin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Czechoslovakia
, rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 = , s1 = Czech Republic , flag_s1 = Flag of the Czech Republic.svg , s2 = Slovakia , flag_s2 = Flag of Slovakia.svg , image_flag = Flag of Czechoslovakia.svg , flag = Flag of Czechoslovakia , flag_type = Flag(1920–1992) , flag_border = Flag of Czechoslovakia , image_coat = Middle coat of arms of Czechoslovakia.svg , symbol_type = Middle coat of arms(1918–1938 and 1945–1961) , image_map = Czechoslovakia location map.svg , image_map_caption = Czechoslovakia during the interwar period and the Cold War , national_motto = , anthems = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyhydroxyethylmethacrylate
Poly(2-hydroxyethyl methacrylate) (pHEMA) is a polymer that forms a hydrogel in water. Poly (hydroxyethyl methacrylate) (PHEMA) hydrogel for intraocular lens (IOL) materials was synthesized by solution polymerization using 2- hydroxyethyl methacrylate (HEMA) as raw material, ammonium persulfate and sodium pyrosulfite (APS/SMBS) as catalyst, and triethyleneglycol dimethacrylate (TEGDMA) as cross-linking additive. It was invented by Drahoslav Lim and Otto Wichterle for biological use. Together they succeeded in preparing a cross-linking gel which absorbed up to 40% of water, exhibited suitable mechanical properties and was transparent. They patented this material in 1953. Applications Contact lenses In 1954, this material was first used as an optical implant. Wichterle thought pHEMA might be a suitable material for a contact lens and gained his first patent for soft contact lenses. By late 1961, he succeeded in producing the first four pHEMA hydrogel contact lenses on a home-ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
