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Urushi
''Toxicodendron vernicifluum'' (formerly ''Rhus verniciflua''), also known by the common name Chinese lacquer tree, is an Asian tree species of genus ''Toxicodendron'' native to China and the Indian subcontinent, and cultivated in regions of China, Japan and Korea. Other common names include ''Japanese lacquer tree'', ''Japanese sumac'', and ''varnish tree''. The trees are cultivated and tapped for their toxic sap, which is used as a highly durable lacquer to make Chinese, Japanese, and Korean lacquerware. The trees grow up to 20 metres tall with large leaves, each containing from 7 to 19 leaflets (most often 11–13). The sap contains the allergenic compound urushiol, which gets its name from this species' Japanese name urushi (); "urushi" is also used in English as a collective term for all kinds of Asian lacquerware made from the sap of this and related Asian tree species, as opposed to European "lacquer" or Japanning made from other materials. Urushiol is also the oil foun ...
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Urushiol
Urushiol is an oily mixture of organic compounds with allergenic properties found in plants of the family Anacardiaceae, especially ''Toxicodendron'' ''spp.'' (e.g., poison oak, Chinese lacquer tree, poison ivy, poison sumac), ''Comocladia spp.'' (maidenplums), ''Metopium spp''. (poisonwood), and also in parts of the mango tree as well as the fruit of the cashew tree. In most individuals, urushiol causes an allergic skin rash on contact, known as urushiol-induced contact dermatitis. The name urushiol is derived from the Japanese word for the lacquer tree, . The oxidation and polymerization of urushiol in the tree's sap in the presence of moisture allows it to form a hard lacquer, which is used to produce traditional Chinese, Korean and Japanese lacquerware. History Although urushiol-containing lacquers and their skin-irritating properties were well known in East Asia for several millennia, its first recorded Western texts were in 1624 by John Smith and he initially likene ...
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Lacquer
Lacquer is a type of hard and usually shiny coating or finish applied to materials such as wood or metal. It is most often made from resin extracted from trees and waxes and has been in use since antiquity. Asian lacquerware, which may be called "true lacquer", are objects coated with the treated, dyed and dried sap of ''Toxicodendron vernicifluum'' or related trees, applied in several coats to a base that is usually wood. This dries to a very hard and smooth surface layer which is durable, waterproof, and attractive in feel and look. Asian lacquer is sometimes painted with pictures, inlaid with shell and other materials, or carved, as well as dusted with gold and given other further decorative treatments. In modern techniques, lacquer means a range of clear or pigmented coatings that dry by solvent evaporation to produce a hard, durable finish. The finish can be of any sheen level from ultra matte to high gloss, and it can be further polished as required. Lacquer finishes ...
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Lacquerware
Lacquerware are objects decoratively covered with lacquer. Lacquerware includes small or large containers, tableware, a variety of small objects carried by people, and larger objects such as furniture and even coffins painted with lacquer. Before lacquering, the surface is sometimes painted with pictures, inlaid with shell and other materials, or carved. The lacquer can be dusted with gold or silver and given further decorative treatments. East Asian countries have long traditions of lacquer work, going back several thousand years in the cases of China, Japan and Korea. The best known lacquer, an urushiol-based lacquer common in East Asia, is derived from the dried sap of ''Toxicodendron vernicifluum''. Other types of lacquers are processed from a variety of plants and insects. The traditions of lacquer work in Southeast Asia, South Asia and the Americas are also ancient and originated independently. True lacquer is not made outside Asia, but some imitations, such as Japanning ...
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Toxicodendron Vernicifluum 03
''Toxicodendron'' is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words τοξικός (''toxikos''), meaning "poison," and δένδρον (''dendron''), meaning "tree". The best known members of the genus in North America are poison ivy ''(T. radicans)'', practically ubiquitous throughout most of eastern North America, and western poison oak ('' T. diversilobum''), similarly ubiquitous throughout much of the western part of the continent. The genus is a member of the '' Rhus complex'', and has at various times been categorized as being either its own genus or a sub-genus of ''Rhus.'' There is evidence which points to keeping ''Toxicodendron'' as a separate monophyletic genus, but researchers have stated that ...
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Toxicodendron
''Toxicodendron'' is a genus of flowering plants in the sumac family, Anacardiaceae. It contains trees, shrubs and woody vines, including poison ivy, poison oak, and the lacquer tree. All members of the genus produce the skin-irritating oil urushiol, which can cause a severe allergic reaction. The generic name is derived from the Greek words τοξικός (''toxikos''), meaning "poison," and δένδρον (''dendron''), meaning "tree". The best known members of the genus in North America are poison ivy ''(T. radicans)'', practically ubiquitous throughout most of eastern North America, and western poison oak ('' T. diversilobum''), similarly ubiquitous throughout much of the western part of the continent. The genus is a member of the ''Rhus complex'', and has at various times been categorized as being either its own genus or a sub-genus of ''Rhus.'' There is evidence which points to keeping ''Toxicodendron'' as a separate monophyletic genus, but researchers have stated that t ...
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Japanning
Japanning is a type of finish that originated as a European imitation of East Asian lacquerwork. It was first used on furniture, but was later much used on small items in metal. The word originated in the 17th century. American work, with the exception of the carriage and early automobile industries, is more often called toleware. It is distinct from true East Asian lacquer, which is made by coating objects with a preparation based on the dried sap of the ''Toxicodendron vernicifluum'' tree, which was not available in Europe. Japanning is most often a heavy black "lacquer", almost like enamel paint. Black is common and japanning is often assumed to be synonymous with black japanning. The European technique uses varnishes that have a resin base, similar to shellac, applied in heat-dried layers which are then polished, to give a smooth glossy finish. It can also come in reds, greens and blues. Originating in India, China and Japan as a decorative coating for pottery, authent ...
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Chinese Traditional Medicine
Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of action. Medicine in traditional China encompassed a range of sometimes competing health and healing practices, folk beliefs, literati theory and Confucian philosophy, herbal remedies, food, diet, exercise, medical specializations, and schools of thought. In the early twentieth century, Chinese cultural and political modernizers worked to eliminate traditional practices as backward and unscientific. Traditional practitioners then selected elements of philosophy and practice and organized them into what they called "Chinese medicine" (''Zhongyi''). In the 1950s, the Chinese government sponsored the integration of Chinese and Western medicine, and in the Great Proletarian Cultural Revolution of the 1960s, promoted Chinese medicine as inexpensive a ...
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Resin
In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on naturally occurring resins. Plants secrete resins for their protective benefits in response to injury. The resin protects the plant from insects and pathogens. Resins confound a wide range of herbivores, insects, and pathogens, while the volatile phenolic compounds may attract benefactors such as parasitoids or predators of the herbivores that attack the plant. Composition Most plant resins are composed of terpenes. Specific components are alpha-pinene, beta-pinene, delta-3 carene, and sabinene, the monocyclic terpenes limonene and terpinolene, and smaller amounts of the tricyclic sesquiterpenes, longifolene, caryophyllene, and delta-cadinene. Some resins also contain a high proportion of resin acids. Rosins on the other hand are less ...
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Adhesive
Adhesive, also known as glue, cement, mucilage, or paste, is any non-metallic substance applied to one or both surfaces of two separate items that binds them together and resists their separation. The use of adhesives offers certain advantages over other binding techniques such as sewing, mechanical fastenings, or welding. These include the ability to bind different materials together, the more efficient distribution of stress across a joint, the cost-effectiveness of an easily mechanized process, and greater flexibility in design. Disadvantages of adhesive use include decreased stability at high temperatures, relative weakness in bonding large objects with a small bonding surface area, and greater difficulty in separating objects during testing. Adhesives are typically organized by the method of adhesion followed by ''reactive'' or ''non-reactive'', a term which refers to whether the adhesive chemically reacts in order to harden. Alternatively, they can be organized eithe ...
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Butein
Butein is a chalcone of the chalconoids. It can be found in ''Toxicodendron vernicifluum'' (or formerly ''Rhus verniciflua''), ''Dahlia'', '' Butea'' ('' Butea monosperma'') and ''Coreopsis'' It has antioxidative, aldose reductase and advanced glycation endproducts inhibitory effects. It is also a sirtuin-activating compound, a chemical compound having an effect on sirtuins, a group of enzymes that use NAD+ to remove acetyl groups from proteins. Buteins possess a high ability to inhibit aromatase process in the human body, for this reason, the use of these compounds in the treatment of breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ... on the estrogen ground has been explored. The first attempts of sport pro-hormone supplementation with the use of buteins took place i ...
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Jewelry
Jewellery ( UK) or jewelry (U.S.) consists of decorative items worn for personal adornment, such as brooches, rings, necklaces, earrings, pendants, bracelets, and cufflinks. Jewellery may be attached to the body or the clothes. From a western perspective, the term is restricted to durable ornaments, excluding flowers for example. For many centuries metal such as gold often combined with gemstones, has been the normal material for jewellery, but other materials such as glass, shells and other plant materials may be used. Jewellery is one of the oldest types of archaeological artefact – with 100,000-year-old beads made from ''Nassarius'' shells thought to be the oldest known jewellery.Study reveals 'oldest jewellery'
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Humid
Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depends on the temperature and pressure of the system of interest. The same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is the dew point. The amount of water vapor needed to achieve saturation increases as the temperature increases. As the temperature of a parcel of air decreases it will eventually reach the saturation point without adding or losing water mass. The amount of water vapor contained within a parcel of air can vary significantly. For example, a parcel of air near saturation may contain 28 g of water per cubic metre of air at , but only 8 g of water per cubic metre of air at . Three primary measurements of humidity are widely employed: absolute, relative, and specific. Abs ...
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