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Coronavirinae
Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the common cold (which is also caused by other viruses, predominantly rhinoviruses), while more lethal varieties can cause SARS, MERS and COVID-19, which is causing the ongoing pandemic. In cows and pigs they cause diarrhea, while in mice they cause hepatitis and encephalomyelitis. Coronaviruses constitute the subfamily ''Orthocoronavirinae'', in the family ''Coronaviridae'', order '' Nidovirales'' and realm '' Riboviria''. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. The genome size of coronaviruses ranges from approximately 26 to 32 kilobases, one of the largest among RNA viruses. They have characteristic club-shaped spikes that project from their surface, which in ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronaviridae
''Coronaviridae'' is a family of enveloped, positive-strand RNA viruses which infect amphibians, birds, and mammals. The group includes the subfamilies ''Letovirinae'' and ''Orthocoronavirinae;'' the members of the latter are known as coronaviruses. The viral genome is 26–32 kilobases in length. The particles are typically decorated with large (~20 nm), club- or petal-shaped surface projections (the "peplomers" or "spikes"), which in electron micrographs of spherical particles create an image reminiscent of the solar corona. Virology The 5' and 3' ends of the genome have a cap and poly(A) tract, respectively. The viral envelope, obtained by budding through membranes of the endoplasmic reticulum (ER) or Golgi apparatus, invariably contains two virus-specified glycoprotein species, known as the spike (S) and membrane (M) proteins. The spike protein makes up the large surface projections (sometimes known as peplomers), while the membrane protein is a triple-spanning t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COVID-19 Pandemic
The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identified in an outbreak in the Chinese city of Wuhan in December 2019. Attempts to contain it there failed, allowing the virus to spread to other areas of Asia and later worldwide. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern on 30 January 2020, and a pandemic on 11 March 2020. As of , the pandemic had caused more than cases and confirmed deaths, making it one of the deadliest in history. COVID-19 symptoms range from undetectable to deadly, but most commonly include fever, dry cough, and fatigue. Severe illness is more likely in elderly patients and those with certain underlying medical conditions. COVID-19 transmits when people breathe in air contaminated by droplets and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Cold
The common cold or the cold is a viral infectious disease of the upper respiratory tract that primarily affects the respiratory mucosa of the nose, throat, sinuses, and larynx. Signs and symptoms may appear fewer than two days after exposure to the virus. These may include coughing, sore throat, runny nose, sneezing, headache, and fever. People usually recover in seven to ten days, but some symptoms may last up to three weeks. Occasionally, those with other health problems may develop pneumonia. Well over 200 virus strains are implicated in causing the common cold, with rhinoviruses, coronaviruses, adenoviruses and enteroviruses being the most common. They spread through the air during close contact with infected people or indirectly through contact with objects in the environment, followed by transfer to the mouth or nose. Risk factors include going to child care facilities, not sleeping well, and psychological stress. The symptoms are mostly due to the body's immune ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genome
In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as regulatory sequences (see non-coding DNA), and often a substantial fraction of 'junk' DNA with no evident function. Almost all eukaryotes have mitochondria and a small mitochondrial genome. Algae and plants also contain chloroplasts with a chloroplast genome. The study of the genome is called genomics. The genomes of many organisms have been sequenced and various regions have been annotated. The International Human Genome Project reported the sequence of the genome for ''Homo sapiens'' in 200The Human Genome Project although the initial "finished" sequence was missing 8% of the genome consisting mostly of repetitive sequences. With advancements in technology that could handle sequenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive-strand RNA Virus
Positive-strand RNA viruses (+ssRNA viruses) are a group of related viruses that have positive-sense, single-stranded genomes made of ribonucleic acid. The positive-sense genome can act as messenger RNA (mRNA) and can be directly translated into viral proteins by the host cell's ribosomes. Positive-strand RNA viruses encode an RNA-dependent RNA polymerase (RdRp) which is used during replication of the genome to synthesize a negative-sense antigenome that is then used as a template to create a new positive-sense viral genome. Positive-strand RNA viruses are divided between the phyla ''Kitrinoviricota'', ''Lenarviricota'', and ''Pisuviricota'' (specifically classes ''Pisoniviricetes'' and '' Stelpavirictes'') all of which are in the kingdom '' Orthornavirae'' and realm '' Riboviria''. They are monophyletic and descended from a common RNA virus ancestor. In the Baltimore classification system, +ssRNA viruses belong to Group IV. Positive-sense RNA viruses include pathogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enveloped Virus
A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. Numerous human pathogenic viruses in circulation are encased in lipid bilayers, and they infect their target cells by causing the viral envelope and cell membrane to fuse. Although there are effective vaccines against some of these viruses, there is no preventative or curative medicine for the majority of them. In most cases, the known vaccines operate by inducing antibodies that prevent the pathogen from entering cells. This happens in the case of enveloped viruses when the antibodies bind to the viral envelope proteins. The membrane fusion event that triggers viral entrance is caused by the viral fusion protein. Many enveloped viruses only have one protein visible on the surface of the particle, which is required for both mediating adhesion to the cell surface and for the subsequent membrane fusi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riboviria
''Riboviria'' is a realm of viruses that includes all viruses that use a homologous RNA-dependent polymerase for replication. It includes RNA viruses that encode an RNA-dependent RNA polymerase, as well as reverse-transcribing viruses (with either RNA or DNA genomes) that encode an RNA-dependent DNA polymerase. RNA-dependent RNA polymerase (RdRp), also called RNA replicase, produces RNA (ribonucleic acid) from RNA. RNA-dependent DNA polymerase (RdDp), also called reverse transcriptase (RT), produces DNA ( deoxyribonucleic acid) from RNA. These enzymes are essential for replicating the viral genome and transcribing viral genes into messenger RNA (mRNA) for translation of viral proteins. ''Riboviria'' was established in 2018 to accommodate all RdRp-encoding RNA viruses and was expanded a year later to also include RdDp-encoding retroviruses. These two groups of viruses are assigned to two separate kingdoms: ''Orthornavirae'' for RdRp-encoding RNA viruses, and ''Pararnavirae'' for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nidovirales
''Nidovirales'' is an order of enveloped, positive-strand RNA viruses which infect vertebrates and invertebrates. Host organisms include mammals, birds, reptiles, amphibians, fish, arthropods, molluscs, and helminths. The order includes the families ''Coronaviridae'', ''Arteriviridae, Roniviridae,'' and ''Mesoniviridae''. Member viruses have a viral envelope and a positive-sense, single-stranded RNA genome which is capped and polyadenylated. Nidoviruses are named for the Latin ''nidus'', meaning nest, as all viruses in this order produce a 3' co-terminal nested set of subgenomic mRNAs during infection. Virology Structure Nidoviruses have a viral envelope and a positive-sense, single-stranded RNA genome which is capped and polyadenylated. The group expresses structural proteins separately from the nonstructural ones. The structural proteins are encoded at the 3’ region of the genome and are expressed from a set of subgenomic mRNAs. Member viruses encode one main protei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subfamily
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae". See also * International Code of Nomenclature for algae, fungi, and plants * International Code of Zoological Nomenclature * Rank (botany) * Rank (zoology) In biological classification, taxonomic rank is the relative level of a group of organisms (a taxon) in an ancestral or hereditary hierarchy. A common system consists of species, genus, family, order, class, phylum, kingdom, domain. While ... Sources {{biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encephalomyelitis
Encephalomyelitis is inflammation of the brain and spinal cord. Various types of encephalomyelitis include: * ''Acute disseminated encephalomyelitis'' or ''postinfectious encephalomyelitis'', a demyelinating disease of the brain and spinal cord, possibly triggered by viral infection. * ''Encephalomyelitis disseminata'', a synonym for multiple sclerosis. * ''AntiMOG associated encephalomyelitis'', one of the underlying conditions for the phenotype neuromyelitis optica and in general all the spectrum of MOG autoantibody-associated demyelinating diseases. * '' Eastern equine encephalitis'', ''Japanese encephalitis'', ''Venezuelan equine encephalitis'', and ''Western equine encephalitis'': a group of viral illnesses that can affect horses and humans; collectively termed ''Equine encephalitis''. * ''Experimental autoimmune encephalomyelitis'' (EAE), an animal model of brain inflammation. * Progressive encephalomyelitis with rigidity and myoclonus (PERM) – A kind of stiff person synd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hepatitis
Hepatitis is inflammation of the liver tissue. Some people or animals with hepatitis have no symptoms, whereas others develop yellow discoloration of the skin and whites of the eyes (jaundice), poor appetite, vomiting, tiredness, abdominal pain, and diarrhea. Hepatitis is ''acute'' if it resolves within six months, and '' chronic'' if it lasts longer than six months. Acute hepatitis can resolve on its own, progress to chronic hepatitis, or (rarely) result in acute liver failure. Chronic hepatitis may progress to scarring of the liver (cirrhosis), liver failure, and liver cancer. Hepatitis is most commonly caused by the virus ''hepatovirus A'', '' B'', '' C'', '' D'', and '' E''. Other viruses can also cause liver inflammation, including cytomegalovirus, Epstein–Barr virus, and yellow fever virus. Other common causes of hepatitis include heavy alcohol use, certain medications, toxins, other infections, autoimmune diseases, and non-alcoholic steatohepatitis (NASH). Hepa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diarrhea
Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin with loss of the normal stretchiness of the skin and irritable behaviour. This can progress to decreased urination, loss of skin color, a fast heart rate, and a decrease in responsiveness as it becomes more severe. Loose but non-watery stools in babies who are exclusively breastfed, however, are normal. The most common cause is an infection of the intestines due to either a virus, bacterium, or parasite—a condition also known as gastroenteritis. These infections are often acquired from food or water that has been contaminated by feces, or directly from another person who is infected. The three types of diarrhea are: short duration watery diarrhea, short duration bloody diarrhea, and persistent diarrhea (lasting more than two weeks, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
