|
Xylomannan
Xylomannan is an antifreeze molecule, found in the freeze-tolerant Alaskan beetle ''Upis ceramboides''. Unlike antifreeze proteins, xylomannan is not a protein. Instead, it is a combination of a sugar (saccharide) and a fatty acid that is found in cell membranes. As such is expected to work in a different manner than AFPs. It is believed to work by incorporating itself directly into the cell membrane and preventing the freezing of water molecules within the cell. Xylomannan is also found in the red seaweed '' Nothogenia fastigiata'' ( Scinaiaceae family). Fraction F6 of a sulphated xylomannan from ''Nothogenia fastigiata'' was found to inhibit replication of a variety of viruses, including Herpes simplex virus types 1 and 2 (HSV-1, HSV-2), Human cytomegalovirus (HCMV, HHV-5), Respiratory syncytial virus (RSV), Influenzavirus A, Influenzavirus B, Junin and Tacaribe virus, Simian immunodeficiency virus, and (weakly) Human immunodeficiency virus The human immunodeficiency ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upis Ceramboides
''Upis ceramboides'' is a species of beetle, one of many wood-living insects that benefit from forest fires. It often occurs in quantities below the bark on the fire-damaged birches, but can sometimes be seen on other deciduous trees such as willow and aspen. The larvae thrive in the inner bark which is rich in mycelia, and in the sapwood. They develop into pupae during the summer months under the bark, and they develop over two or three years. The following spring they reproduce themselves. It has over the years have disappeared from southern Sweden and is now only locally in the Norrland coast (Västerbotten and Norrbotten) as well as Canada and Alaska. The reason for the species' decline is probably the lack of fire-damaged forests and birch, and the modern forestry practices. ''Upis ceramboides'' is considered "vulnerable" in terms of species survival. In Vindeln municipality it is called ', because it occurs indoors when burning firewood in winter. The species' survival at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antifreeze Protein
Antifreeze proteins (AFPs) or ice structuring proteins refer to a class of polypeptides produced by certain animals, plants, fungi and bacteria that permit their survival in temperatures below the freezing point of water. AFPs bind to small ice crystals to inhibit the growth and recrystallization of ice that would otherwise be fatal. There is also increasing evidence that AFPs interact with mammalian cell membranes to protect them from cold damage. This work suggests the involvement of AFPs in cold acclimatization. Non-colligative properties Unlike the widely used automotive antifreeze, ethylene glycol, AFPs do not lower freezing point in proportion to concentration. Rather, they work in a non colligative manner. This phenomenon allows them to act as an antifreeze at concentrations 1/300th to 1/500th of those of other dissolved solutes. Their low concentration minimizes their effect on osmotic pressure. The unusual properties of AFPs are attributed to their selective a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scinaiaceae
Scinaiaceae is a family of red algae ( Rhodophyta) in the order Nemaliales. Huisman had placed former members of Galaxauraceae family, that were lacking lime into his new family of Scinaiaceae. Distribution The family has cosmopolitan distribution. Including being found in India, Arabian Sea, Brazil, North America (including Alaska, British Columbia, Washington, and Oregon) Chile, New Zealand (Tasmania and Campbell Island) and the Falkland Islands. Notes Molecular analyses of DNA on species of ''Nothogenia'' has been carried out to determine species relationships. Most Scinaiaceae species produce mucilage (thick, gluey substance) mainly in the cortical layer. Several species in the Scinaiaceae family (including '' Nothogenia fastigiata'' and '' Scinaia hatei'') have been screened for anti-viral activity (against herpes, Respiratory syncytial virus (RSV), Influenzavirus A, Influenzavirus B and simian immunodeficiency viruses). Sulfated polysaccharides (xylomannans) from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The National Academy Of Sciences
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disaccharide
A disaccharide (also called a double sugar or ''biose'') is the sugar formed when two monosaccharides are joined by glycosidic linkage. Like monosaccharides, disaccharides are simple sugars soluble in water. Three common examples are sucrose, lactose, and maltose. Disaccharides are one of the four chemical groupings of carbohydrates (monosaccharides, disaccharides, oligosaccharides, and polysaccharides). The most common types of disaccharides—sucrose, lactose, and maltose—have 12 carbon atoms, with the general formula C12H22O11. The differences in these disaccharides are due to atomic arrangements within the molecule. The joining of monosaccharides into a double sugar happens by a condensation reaction, which involves the elimination of a water molecule from the functional groups only. Breaking apart a double sugar into its two monosaccharides is accomplished by hydrolysis with the help of a type of enzyme called a disaccharidase. As building the larger sugar ejects a wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fatty Acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, from 4 to 28. Fatty acids are a major component of the lipids (up to 70% by weight) in some species such as microalgae but in some other organisms are not found in their standalone form, but instead exist as three main classes of esters: triglycerides, phospholipids, and cholesteryl esters. In any of these forms, fatty acids are both important dietary sources of fuel for animals and important structural components for cells. History The concept of fatty acid (''acide gras'') was introduced in 1813 by Michel Eugène Chevreul, though he initially used some variant terms: ''graisse acide'' and ''acide huileux'' ("acid fat" and "oily acid"). Types of fatty acids Fatty acids are classified in many ways: by length, by saturation vs unsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to io ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Alga
Red algae, or Rhodophyta (, ; ), are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae, containing over 7,000 currently recognized species with taxonomic revisions ongoing. The majority of species (6,793) are found in the Florideophyceae (class), and mostly consist of multicellular, marine algae, including many notable seaweeds. Red algae are abundant in marine habitats but relatively rare in freshwaters. Approximately 5% of red algae species occur in freshwater environments, with greater concentrations found in warmer areas. Except for two coastal cave dwelling species in the asexual class Cyanidiophyceae, there are no terrestrial species, which may be due to an evolutionary bottleneck in which the last common ancestor lost about 25% of its core genes and much of its evolutionary plasticity. The red algae form a distinct group characterized by having eukaryotic cells without flagella and centrioles, chloroplasts that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpes Simplex Virus
Herpes simplex virus 1 and 2 (HSV-1 and HSV-2), also known by their taxonomical names '' Human alphaherpesvirus 1'' and ''Human alphaherpesvirus 2'', are two members of the human ''Herpesviridae'' family, a set of viruses that produce viral infections in the majority of humans. Both HSV-1 and HSV-2 are very common and contagious. They can be spread when an infected person begins shedding the virus. As of 2016, about 67% of the world population under the age of 50 had HSV-1. In the United States, about 47.8% and 11.9% are estimated to have HSV-1 and HSV-2, respectively, though actual prevalence may be much higher. Because it can be transmitted through any intimate contact, it is one of the most common sexually transmitted infections. Symptoms Many of those who are infected ''never'' develop symptoms. Symptoms, when they occur, may include watery blisters in the skin or mucous membranes of the mouth, lips, nose, genitals, or eyes ( herpes simplex keratitis). Lesions heal w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Cytomegalovirus
''Human betaherpesvirus 5'', also called human cytomegalovirus (HCMV), is species of virus in the genus '' Cytomegalovirus'', which in turn is a member of the viral family known as ''Herpesviridae'' or herpesviruses. It is also commonly called CMV. Within ''Herpesviridae'', HCMV belongs to the ''Betaherpesvirinae'' subfamily, which also includes cytomegaloviruses from other mammals. CMV is a double-stranded DNA virus. Although they may be found throughout the body, HCMV infections are frequently associated with the salivary glands. HCMV infection is typically unnoticed in healthy people, but can be life-threatening for the immunocompromised, such as HIV-infected persons, organ transplant recipients, or newborn infants. Congenital cytomegalovirus infection can lead to significant morbidity and even death. After infection, HCMV remains latent within the body throughout life and can be reactivated at any time. Eventually, it may cause mucoepidermoid carcinoma and possibly oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory Syncytial Virus
Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a common, contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. Its name is derived from the large cells known as '' syncytia'' that form when infected cells fuse. RSV is the single most common cause of respiratory hospitalization in infants, and reinfection remains common in later life: it is a notable pathogen in all age groups. Infection rates are typically higher during the cold winter months, causing bronchiolitis in infants, common colds in adults, and more serious respiratory illnesses such as pneumonia in the elderly and immunocompromised. RSV can cause outbreaks both in the community and in hospital settings. Following initial infection via the eyes or nose, the virus infects the epithelial cells of the upper and lower airway, causing inflammation, cell damage, and airway obstruction. A var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
