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Polybrominated Biphenyl
Polybrominated biphenyls (PBBs), also called brominated biphenyls or polybromobiphenyls, are a group of manufactured chemicals that consist of polyhalogenated derivatives of a biphenyl core. Their chlorine analogs are the PCBs. While once widely used commercially, PBBs are now controlled substances under the Restriction of Hazardous Substances Directive, which limits their use in electrical and electronic products sold in the EU. Characteristics PBBs usually exist as colorless to off-white solids. PBBs soften at 72 degrees Celsius and decompose above 300 degrees Celsius. They have low vapor pressure, are very soluble in benzene and toluene, and insoluble in water. They are degraded by UV light. Application PBBs are used as flame retardants of the brominated flame retardant group. They are added to plastics used in products such as home electrical appliances, textiles, plastic foams, laptop cabinets, etc. to make them difficult to burn. A number of substituted PBBs found appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polybrominated Biphenyls
Polybrominated biphenyls (PBBs), also called brominated biphenyls or polybromobiphenyls, are a group of manufactured chemicals that consist of polyhalogenated derivatives of a biphenyl core. Their chlorine analogs are the PCBs. While once widely used commercially, PBBs are now controlled substances under the Restriction of Hazardous Substances Directive, which limits their use in electrical and electronic products sold in the EU. Characteristics PBBs usually exist as colorless to off-white solids. PBBs soften at 72 degrees Celsius and decompose above 300 degrees Celsius. They have low vapor pressure, are very soluble in benzene and toluene, and insoluble in water. They are degraded by UV light. Application PBBs are used as flame retardants of the brominated flame retardant group. They are added to plastics used in products such as home electrical appliances, textiles, plastic foams, laptop cabinets, etc. to make them difficult to burn. A number of substituted PBBs found appli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bromophene
MC21-A (bromophene) is an bactericidal antibiotic isolated from the O-BC30 strain of a new marine bacterium Marine prokaryotes are marine bacteria and marine archaea. They are defined by their habitat as prokaryotes that live in marine environments, that is, in the saltwater of seas or oceans or the brackish water of coastal estuaries. All cellular ..., '' Pseudoalteromonas phenolica''. References Antibiotics Bromoarenes Phenols Biphenyls Halogen-containing natural products {{organohalide-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abdominal Pain
Abdominal pain, also known as a stomach ache, is a symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ... associated with both non-serious and serious medical issues. Common causes of pain in the abdomen include gastroenteritis and irritable bowel syndrome. About 15% of people have a more serious underlying condition such as appendicitis, leaking or ruptured abdominal aortic aneurysm, diverticulitis, or ectopic pregnancy. In a third of cases the exact cause is unclear. Given that a variety of diseases can cause some form of abdominal pain, a systematic approach to the examination of a person and the formulation of a differential diagnosis remains important. Differential diagnosis The most frequent reasons for abdominal pain are gastroenteritis (13%), irritable bowel syndr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 definitions of nausea were proposed in a 2011 book on the topic. Nausea is a non-specific symptom, which means that it has many possible causes. Some common causes of nausea are gastroenteritis and other gastrointestinal disorders, food poisoning, motion sickness, dizziness, migraine, fainting, low blood sugar, anxiety, and lack of sleep. Nausea is a side effect of many medications including chemotherapy, or morning sickness in early pregnancy. Nausea may also be caused by disgust and depression. Medications taken to prevent and treat nausea and vomiting are called antiemetics. The most commonly prescribed antiemetics in the US are promethazine, metoclopramide, and the newer ondansetron. The word nausea is from Lat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parts Per Billion
In science and engineering, the parts-per notation is a set of pseudo-units to describe small values of miscellaneous dimensionless quantities, e.g. mole fraction or mass fraction. Since these fractions are quantity-per-quantity measures, they are pure numbers with no associated units of measurement. Commonly used are parts-per-million (ppm, ), parts-per-billion (ppb, ), parts-per-trillion (ppt, ) and parts-per-quadrillion (ppq, ). This notation is not part of the International System of Units (SI) system and its meaning is ambiguous. Overview Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water. The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it is common to assume that the density of water is 1.00 g/mL. Therefore, it is common to equate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History
History (derived ) is the systematic study and the documentation of the human activity. The time period of event before the History of writing#Inventions of writing, invention of writing systems is considered prehistory. "History" is an umbrella term comprising past events as well as the memory, discovery, collection, organization, presentation, and interpretation of these events. Historians seek knowledge of the past using historical sources such as written documents, oral accounts, art and material artifacts, and ecological markers. History is not complete and still has debatable mysteries. History is also an Discipline (academia), academic discipline which uses narrative to describe, examine, question, and analyze past events, and investigate their patterns of cause and effect. Historians often debate which narrative best explains an event, as well as the significance of different causes and effects. Historians also debate the historiography, nature of history as an end in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michigan
Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the largest by area east of the Mississippi River.''i.e.'', including water that is part of state territory. Georgia is the largest state by land area alone east of the Mississippi and Michigan the second-largest. Its capital is Lansing, and its largest city is Detroit. Metro Detroit is among the nation's most populous and largest metropolitan economies. Its name derives from a gallicized variant of the original Ojibwe word (), meaning "large water" or "large lake". Michigan consists of two peninsulas. The Lower Peninsula resembles the shape of a mitten, and comprises a majority of the state's land area. The Upper Peninsula (often called "the U.P.") is separated from the Lower Peninsula by the Straits of Mackinac, a channel that joins Lak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Being
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedality, bipedalism and exceptional cognitive skills due to a large and complex Human brain, brain. This has enabled the development of advanced tools, culture, and language. Humans are highly social and tend to live in complex social structures composed of many cooperating and competing groups, from family, families and kinship networks to political state (polity), states. Social interactions between humans have established a wide variety of values, norm (sociology), social norms, and rituals, which bolster human society. Its intelligence and its desire to understand and influence the environment and to explain and manipulate Phenomenon, phenomena have motivated humanity's development of science, philosophy, mythology, religion, and other fields of study. Although some scientists equate the term ''humans'' with all members of the genus ''Homo'', in common usage, it generall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menarche
Menarche ( ; ) is the first menstrual cycle, or first menstrual bleeding, in female humans. From both social and medical perspectives, it is often considered the central event of female puberty, as it signals the possibility of fertility. Girls experience menarche at different ages. Having menarche occur between the ages of 9–16 in the west is considered normal.US National Health Statistics Report September 2020 Canadian psychological researcher Niva Piran claims that menarche or the perceived average age of puberty is used in many cultures to separate girls from activity with boys, and to begin confinement as a woman and future wife. The timing of menarche is influenced by female , as we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryl Hydrocarbon Receptor
The aryl hydrocarbon receptor (also known as AhR, AHR, ahr, ahR, or dioxin receptor) is a protein that in humans is encoded by the AHR gene. The aryl hydrocarbon receptor is a transcription factor that regulates gene expression. It was originally thought to function primarily as a sensor of xenobiotic chemicals and also as the regulator of enzymes such as cytochrome P450s that metabolize these chemicals. The most notable of these xenobiotic chemicals are aromatic (aryl) hydrocarbons from which the receptor derives its name. More recently, it has been discovered that AhR is activated (or deactivated) by a number of endogenous indole derivatives such as kynurenine. In addition to regulating metabolism enzymes, the AhR has roles in regulating immunity, stem cell maintenance, and cellular differentiation. The aryl hydrocarbon receptor is a member of the family of basic helix-loop-helix transcription factors. AHR binds several exogenous ligands such as natural plant flavonoids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toxicological Sciences
''Toxicological Sciences'' is a monthly peer-reviewed scientific journal which covers all aspects of research on toxicology. It is published by Oxford University Press on behalf of the Society of Toxicology. It was established in 1981 as ''Fundamental and Applied Toxicology'' and obtained its current name in 1998. The current editor-in-chief is Jeffrey M. Peters, a professor of molecular toxicology and carcinogenesis at The Pennsylvania State University, and the Managing Editor is Virginia F. Hawkins. The editorial staff also includes Associate Editors in subject areas and an editorial board of topic experts. While its ISO 4 abbreviation is ''Toxicol. Sci.'' it is commonly referred to as ''ToxSci''. Abstracting and indexing The journal is abstracted and indexed in Biological Abstracts, BIOSIS, CAB International, Chemical Abstracts Service, Current Contents, EMBASE, Health & Safety Science Abstracts, Science Citation Index, and Toxicology Abstracts. According to the ''Journal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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