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Betacoronaviruses
''Betacoronavirus'' (β-CoVs or Beta-CoVs) is one of four genera (''Alpha''-, ''Beta-'', '' Gamma-'', and '' Delta-'') of coronaviruses. Member viruses are enveloped, positive-strand RNA viruses that infect mammals (of which humans are part). The natural reservoir for betacoronaviruses are bats and rodents. Rodents are the reservoir for the subgenus ''Embecovirus'', while bats are the reservoir for the other subgenera. The coronavirus genera are each composed of varying viral lineages with the betacoronavirus genus containing four such lineages: A, B, C, D. In older literature, this genus is also known as "group 2 coronaviruses". The genus is in the subfamily ''Orthocoronavirinae'' in the family ''Coronaviridae'', of the order ''Nidovirales''. The betacoronaviruses of the greatest clinical importance concerning humans are OC43 and HKU1 (which can cause the common cold) of lineage A, SARS-CoV and SARS-CoV-2 (which has caused the disease COVID-19) of lineage B, and MERS-CoV o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Embecovirus
''Embecovirus'' is a subgenus of coronaviruses in the genus ''Betacoronavirus''. The viruses in this subgenus, unlike other coronaviruses, have a hemagglutinin esterase (HE) gene. The viruses in the subgenus were previously known as group 2a coronaviruses. Structure The viruses of this subgenus, like other coronaviruses, have a lipid bilayer envelope in which the membrane (M), envelope (E) and spike (S) structural proteins are anchored. Unlike other coronaviruses, viruses in this subgenus also have an additional shorter spike-like structural protein called hemagglutinin esterase (HE). Recombination Genetic recombination can occur when two or more viral genomes are present in the same host cell. The dromedary camel beta-coronavirus (Beta-CoV HKU23) exhibits genetic diversity in the African camel population.Diversity of Dromedary Camel Coronavirus HKU23 in African Camels Revealed Multiple Recombination Events among Closely Related Betacoronaviruses of the Subgenus Embecoviru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murine Coronavirus
Murine coronavirus (M-CoV) is a virus in the genus ''Betacoronavirus'' that infects mice. Belonging to the subgenus ''Embecovirus'', murine coronavirus strains are enterotropic or polytropic. Enterotropic strains include mouse hepatitis virus (MHV) strains D, Y, RI, and DVIM, whereas polytropic strains, such as JHM and A59, primarily cause hepatitis, enteritis, and encephalitis. Murine coronavirus is an important pathogen in the laboratory mouse and the laboratory rat. It is the most studied coronavirus in animals other than humans, and has been used as an animal disease model for many virological and clinical studies. Types Murine hepatitis virus Murine coronavirus was first discovered in 1949. The researchers isolated the virus from the brain, spinal cord, liver, lung, spleen, and kidney of a rat with symptoms of encephalitis and severe myelin injury, and gave it the strain name mouse hepatitis virus (MHV)-JHM. MHV is now the most studied coronavirus in animals other than huma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Coronavirus HKU1
''Human coronavirus HKU1'' (''HCoV-HKU1'') is a species of coronavirus in humans and animals. It causes an upper respiratory disease with symptoms of the common cold, but can advance to pneumonia and bronchiolitis. It was first discovered in January 2004 from one man in Hong Kong. Subsequent research revealed it has global distribution and earlier genesis. The virus is an enveloped, positive-sense, single-stranded RNA virus which enters its host cell by binding to the N-acetyl-9-O-acetylneuraminic acid receptor. It has the Hemagglutinin esterase (HE) gene, which distinguishes it as a member of the genus ''Betacoronavirus'' and subgenus ''Embecovirus''. History HCoV-HKU1 was first detected in January 2004, in a 71-year-old man who was hospitalized due to acute respiratory distress syndrome and radiographically confirmed bilateral pneumonia. The man had recently returned to Hong Kong from Shenzhen, China. Virology Woo and coworkers were unsuccessful in their attempts to gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Coronavirus OC43
Human coronavirus OC43 (HCoV-OC43) is a member of the species ''Betacoronavirus 1'', which infects humans and cattle. The infecting coronavirus is an enveloped, positive-sense, single-stranded RNA virus that enters its host cell by binding to the N-acetyl-9-O-acetylneuraminic acid receptor. OC43 is one of seven coronaviruses known to infect humans. It is one of the viruses responsible for the common cold and may have been responsible for the 1889–1890 pandemic. It has, like other coronaviruses from genus ''Betacoronavirus,'' subgenus ''Embecovirus'', an additional shorter spike protein called hemagglutinin-esterase (HE). Virology Four HCoV-OC43 genotypes (A to D) have been identified, with genotype D most likely arising from genetic recombination. The complete genome sequencing of genotypes C and D and bootscan analysis shows recombination events between genotypes B and C in the generation of genotype D. Of 29 viral variants identified, none belong to the more ancien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SARS-CoV-2 Beta Variant
The Beta variant, (B.1.351), was a variant of SARS-CoV-2, the virus that causes COVID-19. One of several SARS-CoV-2 variants initially believed to be of particular importance, it was first detected in the Nelson Mandela Bay metropolitan area of the Eastern Cape province of South Africa in October 2020, which was reported by the country's health department on 18 December 2020. Phylogeographic analysis suggests this variant emerged in the Nelson Mandela Bay area in July or August 2020. The World Health Organization labelled the variant as Beta variant, not to replace the scientific name but as a name for the public to commonly refer to. The WHO considers it to be a variant of concern no longer in circulation. Names The variant is also known as the ''South African variant''. Mutations File:SARS-CoV-2 Beta variant.svg, Amino acid mutations of SARS-CoV-2 Beta variant plotted on a genome map of SARS-CoV-2 with a focus on Spike. There are three mutations of particular interes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Corona
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma. The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar eclipse, but it is also observable with a coronagraph. Spectroscopic measurements indicate strong ionization in the corona and a plasma temperature in excess of , much hotter than the surface of the Sun, known as the photosphere. The word ''corona'' is , in turn derived . History In 1724, French-Italian astronomer Giacomo F. Maraldi recognized that the aura visible during a solar eclipse belongs to the Sun, not to the Moon. In 1809, Spanish astronomer José Joaquín de Ferrer coined the term 'corona'. Based in his own observations of the 1806 solar eclipse at Kinderhook (New York), de Ferrer also proposed that the corona was part of the Sun and not of the Moon. English astronomer Norman Lockyer identified the first element unknown on E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Alphabet
The Greek alphabet has been used to write the Greek language since the late 9th or early 8th century BCE. It is derived from the earlier Phoenician alphabet, and was the earliest known alphabetic script to have distinct letters for vowels as well as consonants. In Archaic Greece, Archaic and early Classical Greece, Classical times, the Greek alphabet existed in Archaic Greek alphabets, many local variants, but, by the end of the 4th century BCE, the Euclidean alphabet, with 24 letters, ordered from alpha to omega, had become standard and it is this version that is still used for Greek writing today. The letter case, uppercase and lowercase forms of the 24 letters are: : , , , , , , , , , , , , , , , , , /ς, , , , , , . The Greek alphabet is the ancestor of the Latin script, Latin and Cyrillic scripts. Like Latin and Cyrillic, Greek originally had only a single form of each letter; it developed the letter case distinction between uppercase and lowercase in parallel with Latin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Letter (alphabet)
A letter is a segmental symbol of a phonemic writing system. The inventory of all letters forms an alphabet. Letters broadly correspond to phonemes in the spoken form of the language, although there is rarely a consistent and exact correspondence between letters and phonemes. The word ''letter'', borrowed from Old French ''letre'', entered Middle English around 1200 AD, eventually displacing the Old English term ( bookstaff). ''Letter'' is descended from the Latin '' littera'', which may have descended from the Greek "διφθέρα" (, writing tablet), via Etruscan. Definition and usage A letter is a type of grapheme, which is a functional unit in a writing system: a letter (or group of letters) represents visually a phoneme (a unit of sound that can distinguish one word from another in a particular language). Letters are combined to form written words, just as phonemes are combined to form spoken words. A sequence of graphemes representing a phoneme is called a multigrap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta
Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiodental fricative while in borrowed words is instead commonly transcribed as μπ. Letters that arose from beta include the Roman letter and the Cyrillic letters and . Name Like the names of most other Greek letters, the name of beta was adopted from the acrophonic name of the corresponding letter in Phoenician, which was the common Semitic word ''*bait'' ('house'). In Greek, the name was ''bêta'', pronounced in Ancient Greek. It is spelled βήτα in modern monotonic orthography and pronounced . History The letter beta was derived from the Phoenician letter beth . Uses Algebraic numerals In the system of Greek numerals, beta has a value of 2. Such use is denoted by a number mark: Β′. Computing Finance Beta is used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic period (), and the Classical period (). Ancient Greek was the language of Homer and of fifth-century Athenian historians, playwrights, and philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Epic and Classical periods of the language. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regarded as a separate historical stage, although its earliest form closely resembles Attic Greek and its latest form approaches Medieval Greek. There were several regional dialects of Ancient Greek, of which Attic Greek developed into Koine. Dia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MERS-CoV
''Middle East respiratory syndrome–related coronavirus'' (''MERS-CoV''), or EMC/2012 ( HCoV-EMC/2012), is the virus that causes Middle East respiratory syndrome (MERS). It is a species of coronavirus which infects humans, bats, and camels. The infecting virus is an enveloped, positive-sense, single-stranded RNA virus which enters its host cell by binding to the DPP4 receptor. The species is a member of the genus ''Betacoronavirus'' and subgenus ''Merbecovirus''. Initially called simply novel coronavirus or nCoV, it was first reported in June 2012 after genome sequencing of a virus isolated from sputum samples from a person who fell ill in a 2012 outbreak of a new flu-like respiratory illness. By July 2015, MERS-CoV cases had been reported in over 21 countries, in Europe, North America and Asia as well as the Middle East. MERS-CoV is one of several viruses identified by the World Health Organization (WHO) as a likely cause of a future epidemic. They list it for urgent research ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December 2019. The disease quickly spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 are variable but often include fever, cough, headache, fatigue, breathing difficulties, Anosmia, loss of smell, and Ageusia, loss of taste. Symptoms may begin one to fourteen days incubation period, after exposure to the virus. At least a third of people who are infected Asymptomatic, do not develop noticeable symptoms. Of those who develop symptoms noticeable enough to be classified as patients, most (81%) develop mild to moderate symptoms (up to mild pneumonia), while 14% develop severe symptoms (dyspnea, Hypoxia (medical), hypoxia, or more than 50% lung involvement on imaging), and 5% develop critical symptoms (respiratory failure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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