Persius/hicric huggingface dataset:
Gold standard (test)
In medicine, a gold standard test or criterion standard test is a diagnostic test or benchmark that is regarded as definitive. This can refer to diagnosing a disease process, or the criteria by which scientific evidence is evaluated. For example, in resuscitation research, the gold standard test of a medication or procedure is whether or not it leads to an increase in the number of neurologically intact survivors that walk out of the hospital. Other types of medical research might regard a significant decrease in 30 day mortality as the gold standard. The AMA Style Guide prefers the phrase Criterion Standard instead of Gold Standard, and many medical journals now mandate this usage in their instructions for contributors.  For instance, Archives of Physical Medicine and Rehabilitation specifies this usage.
A hypothetical ideal gold standard test has a sensitivity, or statistical power, of 100% (it identifies all individuals with a disease process; it does not have any false-negative results) and a  specificity of 100% (it does not falsely identify someone with a condition that does not have the condition; it does not have any false-positive results).  In practice, there are no ideal gold standard tests.
Because tests can be incorrect (either a false-negative or a false-positive result), results should be interpreted in the context of the history, physical findings, and other test results in the individual that is being tested.  It is within this context that the sensitivity and specificity of the gold standard test is determined.
Quite often the gold standard test is not the test performed in a particular individual.  In fact, many gold standard tests are not performed in the clinical practice of medicine at all.  This is because the gold standard test may be difficult to perform or may be impossible to perform on a living person (i.e. the test is performed as part of an autopsy), or may take too long for the results of the test to be available to be clinically useful.
As new diagnostic methods become available, the gold standard test may change over time.  For instance, for the diagnosis of aortic dissection, the gold standard test used to be the aortogram, which had a sensitivity as low as 83% and a specificity as low as 87%.  Since the advancements of magnetic resonance imaging, the magnetic resonance angiogram (MRA) has become the new gold standard test for aortic dissection, with a sensitivity of 95% and a specificity of 92%.  Before widespread acceptance of any new test, the former test retains its status as the gold standard.
Ullmann condensation
The Ullmann condensation or Ullmann ether synthesis is a variation of the Ullmann reaction, in which a phenol is coupled to an aryl halide to a diaryl ether in the presence of a copper compound. The corresponding aniline or aryl amide reaction is sometimes called  Goldberg reaction, named after Irma Goldberg.
An active copper powder that is required for this reaction can be prepared by the reduction of copper sulfate by zinc metal in hot water causing the precipitation of elementary copper.
Recently an Ullmann-type aromatic amination reaction between an aryl iodide and an aryl amine as coupling partners has been published. The catalyst used is formed from copper(I) iodide and phenanthroline.  As this reaction proceeds well with an electron-rich aryl iodide it is a valuable alternative to the Buchwald-Hartwig amination reaction, which gives best yields with electron-poor aryl halides.
Gradenigo's syndrome
Gradenigo's syndrome is a complication of otitis media and mastoiditis involving the apex of the petrous temporal bone.
Gradenigo's syndrome is sometimes called petrous apicitis.  It is a syndrome consisting of:
- Deep Seated Orbital (or) Retro-orbital pain in the area supplied by the ophthalmic branch of the trigeminal nerve (fifth cranial nerve),
- Diplopia - ipsilateral paralysis of the abducens nerve (sixth cranial nerve), and
- Persistent Ear Discharge - otitis media
Other symptoms can include photophobia, excessive lacrimation, fever, and reduced corneal sensitivity.
The syndrome is usually caused by the spread of an infection into the petrous apex of the temporal bone.
Diagnosis confirmed by X-Ray (Towne's View & Stenver's View) and by CT Scan of Temporal bone
Treatment - Cortical (or) Modified Radical (or) Radical Mastoidectomy.

# Etymology
The syndrome is named after Giuseppe Conte Gradenigo, an Italian Otolaryngologist.
de:Gradenigo-Syndrom
Graham-Steell murmur

# Overview
The Graham Steell murmur is a heart murmur typically associated with pulmonary regurgitation.  It is a high pitched early diastolic murmur heard best at the left sternal edge in the second intercostal space during  inspiration .

# Historical Perspective
It is named for Graham Steell.

# Pathophysiology
The murmur is heard due to a high velocity regurgitant flow across the pulmonary valve.

# Differential Diagnosis of Underlying Causes
The Graham Steel murmur is most often a consequence of pulmonary hypertension.  The Graham Steell murmur is often heard in patients with chronic cor pulmonale (pulmonary heart disease) as a result of chronic obstructive pulmonary disease.

# Diagnosis

## Physical Examination
The murmur is high-pitched and "blowing", and has a decrescendo configuration like that of aortic regurgitation. Differentiation is difficult by auscultation alone. The murmur may increase in intensity during inspiration and can be more localized. It is best heard over the left second and third intercostal space 
It begins with an accentuated P2 component of S2 and can be of variable duration. It may occupy all of diastole if there is a pandiastolic gradient between the pulmonary artery and the right ventricular diastolic pressure.
Guanylate cyclase 2C
Guanylate cyclase 2C, also known as guanylyl cyclase C (GC-C), intestinal guanylate cyclase, guanylate cyclase-C receptor, or the heat-stable enterotoxin receptor (hSTAR) is an enzyme that in humans is encoded by the GUCY2C gene.
Guanylyl cyclase is an enzyme found in the luminal aspect of intestinal epithelium and dopamine neurons in the brain.  The receptor has an extracellular ligand-binding domain, a single transmembrane region, a region with sequence similar to that of protein kinases, and a C-terminal guanylate cyclase domain.  Tyrosine kinase activity mediates the GC-C signaling pathway within the cell.

# Functions
GC-C is a key receptor for heat-stable enterotoxins that are responsible for acute secretory diarrhea.  Heat-stable enterotoxins are produced by pathogens such as Escherichia coli.  Knockout mice deficient in the GC-C gene do not show secretory diarrhea on infection with E. coli, though they do with cholera toxin.  This demonstrates the specificity of the GC-C receptor.

# Diagnostic application
Because GC-C is tissue-specific for intestinal epithelium, it can be used for detection of metastatic disease.
Guanylyl transferase
Guanylyl transferase enzymes transfer one molecule of guanosine triphosphate (GTP) to another molecule, releasing pyrophosphate. Many eukaryotic guanylyl transferases are capping enzymes that catalyze the formation of the 5' cap in the post-transcriptional modification of messenger RNA. Because the 5' end of the RNA molecule ends in a phosphate group, the bond formed between the RNA and the GTP molecule is an unusual 5'-5' triphosphate linkage, instead of the 3'-5' linkages between the other nucleotides that form an RNA strand. In capping enzymes, a highly conserved lysine residue serves as the catalytic residue that forms a covalent enzyme-GMP complex.
The transfer RNA (tRNA) for histidine is unique among eukaryotic tRNAs in requiring the addition of a guanine nucleotide before being aminoacylated by the histidine tRNA synthetase. The yeast guanylyl transferase specific to tRNAHis is unique in being the only known non-tRNA synthetase enzyme that specifically recognizes the tRNA anticodon.
Guanylyl transferases also exist for transferring guanosine nucleotides to sugar molecules, such as mannose and fucose.
HAZMAT Class 2 Gases

# Overview
The HAZMAT Class 2 in United States law includes all gases which are compressed and stored for transportation.  Class 2 has three divisions: Flammable (also called combustible), Non-Flammable/Non-Poisonous, and Poisonous.

# Divisions
Division 2.1: Flammable Gas
454 kg (1001 lb) of any material which is a gas at 20 C (68 F) or less and 101.3 kPa (14.7 psi) of pressure (a material which has a boiling point of 20 C (68 F) or less at 101.3 kPa (14.7 psi)) which-
- Is ignitable at 101.3 kPa (14.7 psi) when in a mixture of 13 percent or less by volume with air; or
- Has a flammable range at 101.3 kPa (14.7 psi) with air of at least 12 percent regardless of the lower limit.
Except for aerosols, the limits specified in paragraphs (a)(1) and (a)(2) of this section shall be determined at 101.3 kPa (14.7 psi) of pressure and a temperature of 20 C (68 F) in accordance with ASTM E681-85, Standard Test Method for Concentration Limits of Flammability of Chemicals or other equivalent method approved by the Associate Administrator for Hazardous Materials Safety. The flammability of aerosols is determined by the tests specified in 49CFR 173.306(i).
Division 2.2: Non-Flammable, Non-Poisonous Gas
This division includes compressed gas, liquefied gas, pressurized cryogenic gas, compressed gas in solution, asphyxiant gas and oxidizing gas. A non-flammable, nonpoisonous compressed gas (Division 2.2) means any material (or mixture) which:
- Exerts in the packaging an absolute pressure of 280 kPa (40.6 psia) or greater at 20 C (68 F), and
- Does not meet the definition of Division 2.1 or 2.3.
Division 2.2: Oxygen
This is an optional placard to the 2.2 Non-flammable Gas placard for compressed Oxygen in either the gas or liquid state. Oxygen is considered a non-flammable because it in and of itself does not burn. It is, however, required for combustion to take place. High concentrations of oxygen greatly increases the rate and intensity of combustion.
Division 2.3: Poison Gas
Gas poisonous by inhalation means a material which is a gas at 20 C or less and a pressure of 101.3 kPa (a material which has a boiling point of 20 C or less at 101.3kPa (14.7 psi)) and which:
- Is known to be so toxic to humans as to pose a hazard to health during transportation, or
- In the absence of adequate data on human toxicity, is presumed to be toxic to humans because when tested on laboratory animals it has an LC50 value of not more than 5000 ml/m3. See 49CFR 173.116(a) for assignment of Hazard Zones A, B, C or D. LC50 values for values for mixtures may be determined using the formula in 49 CFR 173.133(b)(1)(i)

# Placards

# Compatibility table
Habenular commissure

# Overview
The habenular commissure, is a brain commissure (a band of nerve fibers) situated in front of the pineal gland that connects the habenular nucleus on one side of the diencephalon with that on the other side.
The habernular commissure is part of the trigonum habenul (a small depressed triangular area situated in front of the superior colliculus and on the lateral aspect of the posterior part of the tnia thalami). The trigonum habenul also contains groups of nerve cells termed the ganglion habenul. Fibers enter the trigonum habenul from the stalk of the pineal gland, and the habenular commissure. Most of the trigonum habenul's fibers are, however, directed downward and form a bundle, the fasciculus retroflexus of Meynert, which passes medial to the red nucleus, and, after decussating with the corresponding fasciculus of the opposite side, ends in the interpeduncular ganglion.
Nerve cell fibers enter the trigonum habenul from the stalk of the pineal body, and the habernular commissure.
Hemodynamic response

# Overview
Haemodynamics is a medical term for the dynamic regulation of the blood flow in the brain. It is the principle on which functional magnetic resonance imaging is based.
Neurons, like all other cells, require energy to function.  This energy is supplied in the form of glucose and oxygen (the oxygen being carried in haemoglobin).  The blood supply of the brain is dynamically regulated to give active neural assemblies more energy whilst inactive assemblies receive less energy.

# The molecular biology of haemodynamic regulation
The precise mechanism behind neurovascular coupling is currently under active research and furious debate, but roughly the following model has gained consensus:
- Active excitatory neurons release the neurotransmitter glutamate
- Glutamate opens NMDA receptors on other neurons which allows calcium ions into the neuron
Calcium activates nitric oxide synthase which produces nitric oxide
Nitric oxide diffuses out and dilates smooth muscle surrounding local arterioles
This dilation allows more blood into the local capillaries
Hence more oxygen and glucose reaches the neurons 
- Calcium activates nitric oxide synthase which produces nitric oxide
- Nitric oxide diffuses out and dilates smooth muscle surrounding local arterioles
- This dilation allows more blood into the local capillaries
- Hence more oxygen and glucose reaches the neurons 
- Glutamate also binds to the metabotropic glutamate receptor on astrocytes
This allow calcium into the astrocyte
Which activates phospholipase A2 (PLA2)
Which produces arachidonic acid (AA)
Which is converted by cyclo-oxygenase
Into PGE2 and released through the astrocytic endfeet
Which dilates local smooth muscle and allows greater blood flow
- This allow calcium into the astrocyte
- Which activates phospholipase A2 (PLA2)
- Which produces arachidonic acid (AA)
- Which is converted by cyclo-oxygenase
- Into PGE2 and released through the astrocytic endfeet
- Which dilates local smooth muscle and allows greater blood flow
Hand transplantation

# Overview
Hand transplantation is a surgical procedure to transplant a hand from one human to another.
The operation is carried out in the following order: bone fixation, tendon repair, artery repair, nerve repair, then vein repair. The operation typically lasts 8 to 12 hours  by comparison a typical heart transplant operation lasts 6 to 8 hours.
The recipient of a hand transplant needs to take immunosuppressive drugs, as the body's natural immune system will try to reject the hand. These drugs cause the recipient to have a weaker immune system, and suffer severely even from minor illnesses.
A hand transplant was performed in Ecuador in 1964, but the patient suffered from transplant rejection after only 2 weeks.
The first short-term success in human hand transplantion occurred with New Zealander, Clint Hallam. The operation was performed on September 23, 1998 in Lyon, France. After the operation, Hallam wasn't comfortable with the idea of his transplanted hand, and failed to follow the post operation drug and physiotherapy programme, and his body started rejecting the hand.  The transplanted hand was removed at his request on February 2, 2001.
The Hallam case demonstrates the risk of performing these procedures in unsuitable patients. Hallam, a convicted con-man, had many red-flags which made him a poor candidate for undertaking the rigorous post-operative regimen required for success. The French surgical team and their process for patient selection were criticized by many peers for seeming to seek media publicity for being the first to perform the procedure instead of carefully selecting a better candidate.
The first hand transplant to achieve prolonged success was directed by University of Louisville surgeons Drs. Warren Breidenbach and Tsu-Min Tsai in cooperation with the Kleinert Hand Institute and Jewish Hospital in Louisville, Kentucky. The procedure was performed on New Jersey native Matthew Scott on January 24, 1999. Scott had lost his hand in a fireworks accident at age 24.
In contrast to the earlier attempts at hand transplantation, the Louisville group had performed much of the basic science research and feasibility studies on the proposed procedure. There also was considerable transparency and internal review board oversite involved in the screening and selection of prospective patients.
University of Louisville doctors also performed a successful hand transplant on Michigan native Jerry Fisher in February 2001.
On January 14, 2004, the team of Professor Jean-Michel Dubernard (Edouard-Herriot Hospital, France) declared a five-year old double hand transplant a success. The lessons learned in this case, and in the 26 other hand tranplants (6 double) which occurred between 2000 and 2005, might open the way for more common transplant operations of such organs as the face or larynx.
Haplogroup A (Y-DNA)
In human genetics, Haplogroup A (M91) is a Y-chromosome haplogroup.
Haplogroup A is localized to East Africa and Southern Africa and represents the oldest and most diverse of the human Y-chromosome haplogroups.  It is believed to be the haplogroup corresponding to Y-chromosomal Adam.
It is common among the Khoisan people, including the Bushmen, which - together with its high diversity - suggests that it was their original ancestral haplogroup. For example, Knight et al. (2003) reported 12-44% presence of haplogroup A in various Khoisan tribes. Surprisingly, it was not found in a sample of the Hadzabe  from Tanzania, who are traditionally considered as an ancient remnant of Khoisan people because of the presence of click consonants in their language. Yet it is present in high frequency in East Africa.
Semino et al. 2001 found haplogroup A in 10.3% of an Oromo sample and 14.6% of an Amhara sample from Ethiopia. Especially high frequency (41%) can be found in Ethiopian Jews (Cruciani et al. 2002) and important percentages are also shared by Bantus from Kenya (14%, Luis et al. 2004), a small sample of Iraqw from Tanzania (17%, Knight et al. 2003), and Fulbe from Cameroon (12%, Cruciani et al. 2002). However, the highest presence of haplogroup A in East Africa was discovered in a sample of the Sudanese population - 42.5% (Underhill et al. 2000).
It must be noted, however, that the subclade found in East Africa (A3b2) is different from those found in the Khoisan samples and only remotely related to them (it is actually only one of many subclades within haplogroup A). This finding suggests an ancient divergence of the East African group from the same ancestral population in the south.
In 2007, seven men from Yorkshire, England sharing a distinctive surname were identified as being from the A1 subgroup of haplogroup A.  It was discovered that these men had a common male-line ancestor from the 18th century, but no previous information about African ancestry was known.  The A1 subgroup is extremely rare.  In addition to the seven Yorkshire men, only 25 living carriers of the A1 subgroup are known, all of West African ancestry.
Haplogroup A (mtDNA)
In human genetics, Haplogroup A is a human mitochondrial DNA (mtDNA) haplogroup.
Haplogroup A is believed to have arisen in Asia some 60,000 years before present.  Its ancestral haplogroup was Haplogroup N.
Haplogroup A is found throughout modern Asia.  Its subgroup A1 is found in northern and central Asia, while its subgroup A2 is found in Siberia and is also one of five haplogroups found in the indigenous peoples of the Americas, the others being B, C, D, and X.
The mummy "Juanita" of Peru, also called the "Ice Maiden", has been shown to belong to mitochondrial haplogroup A.
In his popular book The Seven Daughters of Eve, Bryan Sykes named the originator of this mtDNA haplogroup Aiyana.
Haplogroup B (mtDNA)
In mitochondrial genetics, Haplogroup B is a human mitochondrial DNA (mtDNA) haplogroup.
Haplogroup B is believed to have arisen in Asia some 50,000 years before present.  Its ancestral haplogroup was Haplogroup R.
Haplogroup B is found throughout modern Asia.  Its subgroup B2 is one of five haplogroups found in the indigenous peoples of the Americas, the others being A, C, D, and X.
Since the migration to the Americas by the ancestors of Native Americans is generally believed to have been from Siberia, it is especially surprising that Haplogroup B is the only haplogroup found in Native Americans which is not found in modern North Siberian populations. However, Haplogroup B has been found among Southern Siberians, such as Tuvans, Altays, and Buryats. This haplogroup is also found in Mongolians, Tibetans, Koreans, Japanese, populations of Central China, Taiwan, Indonesia, Polynesia and Micronesia.
In his popular book The Seven Daughters of Eve, Bryan Sykes named the originator of this mtDNA haplogroup Ina.
Haplogroup C (mtDNA)
In human mitochondrial genetics, Haplogroup C is a human mitochondrial DNA (mtDNA) haplogroup.
Haplogroup C is believed to have arisen in Asia some 60,000 years before present.  It is a descendant of the haplogroup M.
Haplogroup C is found in Northeast Asia (including Siberia) and is also one of five haplogroups found in the indigenous peoples of the Americas, the others being A, B, D, and X.
In his popular book The Seven Daughters of Eve, Bryan Sykes named the originator of this mtDNA haplogroup Chochmingwu.
Haplogroup D (mtDNA)
In human genetics, Haplogroup D is a human mitochondrial DNA (mtDNA) haplogroup.
Haplogroup D is believed to have arisen in Asia some 60,000 years before present.  It is a descendant haplogroup of haplogroup M.
Haplogroup D is found in Northeast Asia (including Siberia) and is also one of five haplogroups found in the indigenous peoples of the Americas, the others being A, B, C, and X.
Haplogroup E (Y-DNA)
In human genetics, Haplogroup E (M96) is a human Y-chromosome DNA haplogroup.
This haplogroup is found in Africa, the Middle East, and Europe. Haplogroup E is found in Africa, Asia and Europe and it is divided into three clades: E1 and E2 are found exclusively in Africa, while E3 is observed in Africa, Europe and western Asia. E3 is further divided into E3a and E3b, but only E3b is observed in significant frequency in Europe and western Asia in addition to Africa. E3b is estimated to be 25 600 years old.   Most Sub-Saharan Africans belong to E(xE3b), while most non-Africans belong to the E3b clade of the E haplogroup.

# Subgroups
Subbranches include E1, E2, E3a (M2) and E3b (M35).

## E1
E1 (M33) headed for West Africa and today it is mainly present in the region of Mali.

## E2
E2 (M75) is present both in West and East Africa.

## E3
E3, by far the most frequent subbranch of E, diverged into two main subbranches E3a (M2) and E3b (M35) approximately 24-27 000 years ago (Cruciani et al. 2004). The bearers of E3a populated the coastal region of West Africa, where they largely mixed with indigenous Pygmy populations and gave birth to modern West Africans speaking languages of the Niger-Congo family. As a result of the historical migrations of the agricultural Bantu-speaking cultures that started ca. 3000 BC, E3a is the most frequent Y-haplogroup in Sub-Saharan Africa today. It is also the most common Y-haplogroup among African American men.
Within eastern Africa, the haplogroup appears to be restricted to Ethiopia but E-M34 chromosomes have been found in a large majority of the populations from the Near East. E-M34 chromosomes from Ethiopia show lower variances than those from the Near East and appear closely related in the E-M34 network. Thus, it is assumed that E-M34 chromosomes were introduced into Ethiopia from the Near East.
In populations of Europe, particularly among those that reside near the Mediterranean, Haplogroup E3b is believed to represent ancient genetic influence from Near East, mediated by West Asian populations entering Europe during the Neolithic revolution (the spread of agriculture from Asia Minor). The subbranch E3b1 is present at high frequencies among the Greeks, Albanians, and South Italians (up to 25%), but its percentage gradually falls below 10% in the Carpathian basin and Iberia, and is negligible in other parts of Europe. Some E3b is instead explained by more recent genetic influence from North Africa.