|
Dimethylaminobenzaldehyde
''para''-Dimethylaminobenzaldehyde is an organic compound containing amine and aldehyde moieties which is used in Ehrlich's reagent and Kovac's reagent to test for indoles. The carbonyl group typically reacts with the electron rich 2-position of the indole but may also react at the C-3 or N-1 positions. It may also be used for determination of hydrazine. Ehrlich's reagent ''para''-Dimethylaminobenzaldehyde is the main ingredient in Ehrlich's reagent. It acts as a strong electrophile which reacts with the electron-rich α-carbon (2-position) of indole rings to form a blue-colored adduct. It can be used to detect the presence of indole alkaloids. Not all indole alkaloids give a colored adduct as result of steric hindrance which does not allow the reaction to proceed. Ehrlich's reagent is also used as a stain in thin layer chromatography and as a reagent to detect urobilinogen in fresh, cool urine. If a urine sample is left to oxidize in air to form urobilin the reagent will no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ehrlich's Reagent
Ehrlich's reagent or Ehrlich reagent is a reagent containing ''p''-dimethylaminobenzaldehyde (DMAB) and thus can act as an indicator to presumptively identify indoles and urobilinogen. Several Ehrlich tests use the reagent in a medical test; some are drug tests and others contribute to diagnosis of various diseases or adverse drug reactions. It is named after Nobel Prize winner Paul Ehrlich who used it to distinguish typhoid from simple diarrhoea. The Ehrlich reagent works by binding to the C2 position of two indole moieties to form a resonance stabilised carbenium ion compound. Medical testing Ehrlich reagent can be used to detect urobilinogen, which can indicate jaundice or other liver-related issues. A very common Ehrlich test is a simple spot test to identify possible psychoactive compounds such as tryptamines (e.g. DMT) and lysergamides (e.g. LSD). It gives a negative test-result for 25I-NBOMe and many other non-indole-related psychoactives. The reagent will also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urobilinogen
Urobilinogen is a yellow by-product of bilirubin reduction. It is formed in the intestines by the bacterial enzyme bilirubin reductase. About half of the urobilinogen formed is reabsorbed and taken up via the portal vein to the liver, enters circulation and is excreted by the kidney. Increased amounts of bilirubin are formed in hemolysis, which generates increased urobilinogen in the gut. In liver disease (such as hepatitis), the intrahepatic urobilinogen cycle is inhibited also increasing urobilinogen levels. Urobilinogen is converted to the yellow pigmented urobilin apparent in urine. The urobilinogen in the intestine is directly reduced to brownish colour stercobilin, which gives the feces their characteristic color. It can also be reduced to stercobilinogen, which can then be further oxidized to stercobilin. In biliary obstruction, below-normal amounts of conjugated bilirubin reach the intestine for conversion to urobilinogen. With limited urobilinogen available for reabsorpt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine
In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of electrons. Amines can also exist as hetero cyclic compounds. Aniline is the simplest aromatic amine, consisting of a benzene ring bonded to an amino group. Amines are classified into three types: primary (1°), secondary (2°), and tertiary (3°) amines. Primary amines (1°) contain one alkyl or aryl substituent and have the general formula RNH2. Secondary amines (2°) have two alkyl or aryl groups attached to the nitrogen atom, with the general formula R2NH. Tertiary amines (3°) contain three substituent groups bonded to the nitrogen atom, and are represented by the formula R3N. The functional group present in primary amines is called the amino group. Classification of amines Amines can be classified according to the nature and number o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectrophotometric
Spectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. Spectrophotometry uses photometers, known as spectrophotometers, that can measure the intensity of a light beam at different wavelengths. Although spectrophotometry is most commonly applied to ultraviolet, Visible spectrum, visible, and infrared radiation, modern spectrophotometers can interrogate wide swaths of the electromagnetic spectrum, including x-ray, ultraviolet, Visible spectrum, visible, infrared, or microwave wavelengths. Overview Spectrophotometry is a tool that hinges on the quantitative analysis of molecules depending on how much light is absorbed by colored compounds. Important features of spectrophotometers are spectral bandwidth (the range of colors it can transmit through the test sample), the percentage of sample transmission, the logarithmic range of sample absorptio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Citrate
Sodium citrate may refer to any of the sodium salts of citric acid (though most commonly the third): * Monosodium citrate * Disodium citrate * Trisodium citrate The three forms of salt are collectively known by the E number E331. Applications Food Sodium citrates are used as acidity regulators in food and drinks, and also as emulsifiers for oils. They enable cheeses to melt without becoming greasy and also reduce the acidity of food. They are generally considered safe and are designated GRAS by the FDA. Blood clotting inhibitor Sodium citrate is used to prevent donated blood from clotting in storage, and can also be used as an additive for apheresis to prevent clots forming in the tubes of the machine. By binding with calcium ions in the blood it prevents the process of coagulation. It is also used as an anticoagulant for laboratory testing, in that blood samples are collected into sodium citrate-containing tubes for tests such as the PT (INR), APTT, and fibrinogen levels ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NESFA
The New England Science Fiction Association, or NESFA, is a science fiction club centered in the New England area. It was founded in 1967, "by fans who wanted to ''do'' things in addition to socializing". NESFA is currently registered as a non-profit literary organization under IRS section 501(c)(3). The organization holds regular meetings (at their dedicated site, the NESFA Clubhouse) of and for members and other interested parties. A weekly meeting is held most Wednesday evenings, for socializing, projects, and miscellaneous business. Two weekend meetings are held every month: a Business Meeting (for administration), and the Other Meeting. The club also publishes a regular newsletter, ''Instant Message''. There are two book groups that meet on a monthly basis, as well as a monthly Game Day, and a monthly Game Night. In addition, there is a monthly Media day. This involves showings of two episodes of an anime series, two TV series episodes and a movie choice. All are science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filk
Filk music is a musical culture, genre, and community tied to science fiction, fantasy, and horror fandom and a type of fan labor. The genre has existed since the early 1950s and been played primarily since the mid-1970s. The genre has a niche but faithful popularity in the underground. Etymology and definitions The term "filk" (originally a typographical error) predates 1955. (See also below.) Interfilk, a charity registered in California to " romotecultural exchange through filk music", offered multiple sources of definitions, without summary, for filk music , but since relies almost entirely on an article by Jordin Kare titled "Filk Music", originally published by '' Sing Out!'' magazine, for their definition. Kare quotes Nick Smith of the Los Angeles Filkharmonics as stating:It is a mixture of song parodies and original music, humorous and serious, about subjects like science fiction, fantasy, computers, cats, politics, the space program, books, movies, TV shows, l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irish Language
Irish (Standard Irish: ), also known as Irish Gaelic or simply Gaelic ( ), is a Celtic language of the Indo-European language family. It is a member of the Goidelic languages of the Insular Celtic sub branch of the family and is indigenous language, indigenous to the island of Ireland. It was the majority of the population's first language until the 19th century, when English (language), English gradually became dominant, particularly in the last decades of the century, in what is sometimes characterised as a result of linguistic imperialism. Today, Irish is still commonly spoken as a first language in Ireland's Gaeltacht regions, in which 2% of Ireland's population lived in 2022. The total number of people (aged 3 and over) in Ireland who declared they could speak Irish in April 2022 was 1,873,997, representing 40% of respondents, but of these, 472,887 said they never spoke it and a further 551,993 said they only spoke it within the education system. Linguistic analyses o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Irish Washerwoman
"The Irish Washerwoman" is a traditional jig known to have been played throughout Britain and Ireland and in North America. Although usually considered an Irish tune, some scholars claim that it is English in origin, derived from the seventeenth-century tune " Dargason". According to the "tunearch" website, the earliest appearance is in Robert Petrie's "Collection of Strathspeys Reels and Country Dances" 1790. A different page on the same website mentions that a version by Niel Gow appeared in 1792 in "A Third Collection of Strathspey Reels". The second half of the tune is identical to "The Star at Liwis" printed about 1730 in "Caledonian Country Dances" by J Walsh. The earliest recording appears to be Patsy Touhey in 1907, available on "The Piping of Patsy Touhey". This later became available on the album "The Piping of Patsy Touhey" in 2005 on the Na Píobairí Uilleann label. A more famous recording is on the album "In Full Spate" by Paddy Glackin (1991). Scan Tester (1887-1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, projected to rise to 158 million at mid 2025, Java is the world's List of islands by population, most populous island, home to approximately 55.7% of the Demographics of Indonesia, Indonesian population (only approximately 44.3% of Indonesian population live outside Java). Indonesia's capital city, Jakarta, is on Java's northwestern coast. Many of the best known events in Indonesian history took place on Java. It was the centre of powerful Hindu-Buddhist empires, the Islamic sultanates, and the core of the colonial Dutch East Indies. Java was also the center of the History of Indonesia, Indonesian struggle for independence during the 1930s and 1940s. Java dominates Indonesia politically, economically and culturally. Four of Indonesia's eig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frankincense
Frankincense, also known as olibanum (), is an Aroma compound, aromatic resin used in incense and perfumes, obtained from trees of the genus ''Boswellia'' in the family (biology), family Burseraceae. The word is from Old French ('high-quality incense'). There are several species of ''Boswellia'' that produce true frankincense: ''Boswellia sacra'' (synonym (taxonomy), syn. ''B. bhaw-dajiana'', syn. ''B. carteri''), ''Boswellia frereana, B. frereana'', ''Boswellia serrata, B. serrata'' (''B. thurifera''), and ''Boswellia papyrifera, B. papyrifera''. Resin from each is available in various grades, which depends on the time of harvesting. The resin is hand-sorted for quality. Etymology The English word ''frankincense'' derives from the Old French expression , meaning 'true incense', maybe with the sense of 'high quality incense'. The adjective in Old French meant 'noble, true', in this case perhaps 'pure'; although ''franc'' is ultimately derived from the tribal name of the Franks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Etymology
Etymology ( ) is the study of the origin and evolution of words—including their constituent units of sound and meaning—across time. In the 21st century a subfield within linguistics, etymology has become a more rigorously scientific study. Most directly tied to historical linguistics, philology, and semiotics, it additionally draws upon comparative semantics, morphology, pragmatics, and phonetics in order to attempt a comprehensive and chronological catalogue of all meanings and changes that a word (and its related parts) carries throughout its history. The origin of any particular word is also known as its ''etymology''. For languages with a long written history, etymologists make use of texts, particularly texts about the language itself, to gather knowledge about how words were used during earlier periods, how they developed in meaning and form, or when and how they entered the language. Etymologists also apply the methods of comparative linguistics to reconstruct in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
