|
Euparal
Euparal is a synthetic microscopy mountant originally formulated in 1904 by Professor G. Gilson, the professor of Zoology at Louvain University, Louvain, Belgium. It has been manufactured by several companies, but is now exclusively manufactured by ASCO Laboratories, Manchester, England. Euparal is used extensively in the mounting of entomological and histological specimens, and has gained much favour as a microscopy mountant due to its low refractive index of 1.483. Microscopic objects, such as cells, are stained with carmine or other stains and slides are passed through dehydration grades and finally mounted in a drop of Euparal. Euparal is a mixture of camsal (itself a mixture of camphor and salol), sandarac, eucalyptol, and paraldehyde Paraldehyde is the cyclic trimer of acetaldehyde molecules. Formally, it is a derivative of 1,3,5-trioxane, with a methyl group substituted for a hydrogen atom at each carbon. The corresponding tetramer is metaldehyde. A colourless liquid, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscopy
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy. Optical microscopy and electron microscopy involve the diffraction, reflection, or refraction of electromagnetic radiation/electron beams interacting with the specimen, and the collection of the scattered radiation or another signal in order to create an image. This process may be carried out by wide-field irradiation of the sample (for example standard light microscopy and transmission electron microscopy) or by scanning a fine beam over the sample (for example confocal laser scanning microscopy and scanning electron microscopy). Scanning probe microscopy involves the interaction of a scanning probe with the surface of the objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoology
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the Animal, animal kingdom, including the anatomy, structure, embryology, evolution, Biological classification, classification, Ethology, habits, and distribution of all animals, both living and extinction, extinct, and how they interact with their ecosystems. The term is derived from Ancient Greek , ('animal'), and , ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and made use of this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle. He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and the function of their parts. The Greek physician Galen studied human anatomy and was one of the greatest surgeons of the a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catholic University Of Leuven (1834–1968)
The Catholic University of Leuven or Louvain (french: Université catholique de Louvain, nl, Katholieke Hogeschool te Leuven, later ''Katholieke Universiteit te Leuven'') was founded in 1834 in Mechelen as the Catholic University of Belgium, and moved its seat to the town of Leuven in 1835, changing its name to Catholic University of Leuven.''Encyclopédie théologique'', tome 54, ''Dictionnaire de l'histoire universelle de l'Église'', Paris : éd. J.P. Migne, 1863, ''sub verbo'' ''Grégoire XVI'', col. 1131 : "Après sa séparation de la Hollande en 1830, la Belgique libérale a vu son Église jouir d'une véritable indépendance. Les évêques s'assemblent en conciles, communiquent avec le Saint-Siège en toute liberté. Sur l'article fondamental des études, ils ont fondé l'université catholique de Louvain, où les jeunes Belges vont en foule puiser aux sources les plus pures toutes les richesses de la science". And : Edward van Even, ''Louvain dans le passé et dans le prà ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leuven
Leuven (, ) or Louvain (, , ; german: link=no, Löwen ) is the capital and largest city of the province of Flemish Brabant in the Flemish Region of Belgium. It is located about east of Brussels. The municipality itself comprises the historic city and the former neighbouring municipalities of Heverlee, Kessel-Lo, a part of Korbeek-Lo, Wilsele and Wijgmaal. It is the eighth largest city in Belgium, with more than 100,244 inhabitants. KU Leuven, Belgium's largest university, has its flagship campus in Leuven, which has been a university city since 1425. This makes it the oldest university city in the Low Countries. The city is home of the headquarters of Anheuser-Busch InBev, the world's largest beer brewer and sixth-largest fast-moving consumer goods company. History Middle Ages The earliest mention of Leuven (''Loven'') dates from 891, when a Viking army was defeated by the Frankish king Arnulf of Carinthia (see: Battle of Leuven). According to a legend, the city's red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belgium
Belgium, ; french: Belgique ; german: Belgien officially the Kingdom of Belgium, is a country in Northwestern Europe. The country is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeast, France to the southwest, and the North Sea to the northwest. It covers an area of and has a population of more than 11.5 million, making it the 22nd most densely populated country in the world and the 6th most densely populated country in Europe, with a density of . Belgium is part of an area known as the Low Countries, historically a somewhat larger region than the Benelux group of states, as it also included parts of northern France. The capital and largest city is Brussels; other major cities are Antwerp, Ghent, Charleroi, Liège, Bruges, Namur, and Leuven. Belgium is a sovereign state and a federal constitutional monarchy with a parliamentary system. Its institutional organization is complex and is structured on both regional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Refractive Index
In optics, the refractive index (or refraction index) of an optical medium is a dimensionless number that gives the indication of the light bending ability of that medium. The refractive index determines how much the path of light is bent, or refracted, when entering a material. This is described by Snell's law of refraction, , where ''θ''1 and ''θ''2 are the angle of incidence and angle of refraction, respectively, of a ray crossing the interface between two media with refractive indices ''n''1 and ''n''2. The refractive indices also determine the amount of light that is reflected when reaching the interface, as well as the critical angle for total internal reflection, their intensity ( Fresnel's equations) and Brewster's angle. The refractive index can be seen as the factor by which the speed and the wavelength of the radiation are reduced with respect to their vacuum values: the speed of light in a medium is , and similarly the wavelength in that medium is , where ''Π... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camphor
Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel ('' Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the kapur tree ( ''Dryobalanops'' sp.), a tall timber tree from South East Asia. It also occurs in some other related trees in the laurel family, notably '' Ocotea usambarensis''. Rosemary leaves (''Rosmarinus officinalis'') contain 0.05 to 0.5% camphor, while camphorweed (''Heterotheca'') contains some 5%. A major source of camphor in Asia is camphor basil (the parent of African blue basil). Camphor can also be synthetically produced from oil of turpentine. The compound is chiral, existing in two possible enantiomers as shown in the structural diagrams. The structure on the left is the naturally occurring (+)-camphor ((1''R'',4''R'')-bornan-2-one), while its mirror image shown on the right is the (−)-camphor ((1''S'',4''S'')-bornan-2-one). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salol
Phenyl salicylate, or salol, is the organic compound with the formula C6H5O2C6H4OH. It is a white solid. It is occasionally used in sunscreens and as an antiseptic. Production and reactions The title compound was synthesized first in 1883 by the Polish chemist and doctor Marceli Nencki (who didn't publish his findings) and then independently in 1885 by the German chemist Richard Seifert ( de) (1861–1919) (who did publish his findings). It is synthesized by heating salicylic acid with phenol in the presence of phosphoryl chloride. It also arises from heating salicylic acid: :2HOC6H4CO2H → C6H5O2C6H4OH + CO2 + H2O The conversion entails dehydration and decarboxylation. Heating phenyl salicylate in turn gives xanthone. :2C6H5O2C6H4OH → 2C6H5OH + O 2CO + CO2 In this conversion, phenol is produced as well as carbon dioxide. Salol reaction In the salol reaction, phenyl salicylate reacts with ''o''-toluidine in 1,2,4-trichlorobenzene at elevated temperatures to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandarac
Sandarac (or sandarach) is a resin obtained from the small cypress-like tree ''Tetraclinis articulata''. The tree is native to the northwest of Africa with a notable presence in the Southern Morocco part of the Atlas mountains. The resin exudes naturally on the stems of the tree. It is also obtained by making cuts on the bark. It solidifies when exposed to the air. It comes to commerce in the form of small solid chips, translucent, and having a delicate yellow tinge. Morocco has been the main place of origin of sandarac. A similar resin is obtained in southern Australia from some species of the Australian cypress-like trees ''Callitris'', but the resin has not been systematically collected in Australia.''Analysis of Resins, Balsams and Gum-Resins'' by Karl Dieterich (1920), Chapter II, Section 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eucalyptol
Eucalyptol is a monoterpenoid. A colorless liquid, it is a bicyclic ether. Eucalyptol has a fresh mint-like smell and a spicy, cooling taste. It is insoluble in water, but miscible with organic solvents. Eucalyptol makes up ~70% - 90% of eucalyptus oil. Eucalyptol forms crystalline adducts with hydrohalic acids, ''o''-cresol, resorcinol, and phosphoric acid. Formation of these adducts is useful for purification. In 1870, F. S. Cloez identified and ascribed the name "eucalyptol" to the dominant portion of ''Eucalyptus globulus'' oil. Uses Because of its pleasant, spicy aroma and taste, eucalyptol is used in flavorings, fragrances, and cosmetics. Cineole-based eucalyptus oil is used as a flavouring at low levels (0.002%) in various products, including baked goods, confectionery, meat products, and beverages. In a 1994 report released by five top cigarette companies, eucalyptol was listed as one of the 599 additives to cigarettes. It is claimed to be added to improve the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraldehyde
Paraldehyde is the cyclic trimer of acetaldehyde molecules. Formally, it is a derivative of 1,3,5-trioxane, with a methyl group substituted for a hydrogen atom at each carbon. The corresponding tetramer is metaldehyde. A colourless liquid, it is sparingly soluble in water and highly soluble in ethanol. Paraldehyde slowly oxidizes in air, turning brown and producing an odour of acetic acid. It quickly reacts with most plastics and rubber. Paraldehyde was first observed in 1835 by the German chemist Justus Liebig; its empirical formula was determined in 1838 by Liebig's student Hermann Fehling. The German chemist Valentin Hermann Weidenbusch (1821–1893), another of Liebig's students, synthesized paraldehyde in 1848 by treating acetaldehyde with acid (either sulfuric or nitric acid) and cooling to 0°C. He found it quite remarkable that when paraldehyde was ''heated'' with a trace of the same acid, the reaction went the other way, recreating acetaldehyde. Paraldehyde has uses i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
