Persius/hicric huggingface dataset:
Emtricitabine description

# Description
EMTRIVA is the brand name of emtricitabine, a synthetic nucleoside analog with activity against human immunodeficiency virus type 1 (HIV-1) reverse transcriptase.
The chemical name of emtricitabine is 5-fluoro-1-(2R,5S)-cytosine. Emtricitabine is the enantiomer of a thio analog of cytidine, which differs from other cytidine analogs in that it has a fluorine in the 5-position.
It has a molecular formula of C8H10FN3O3S and a molecular weight of 247.24. It has the following structural formula:
Emtricitabine is a white to off-white powder with a solubility of approximately 112 mg/mL in water at 25 C. The log P for emtricitabine is -0.43 and the pKa is 2.65.
EMTRIVA is available as capsules or as an oral solution.
EMTRIVA capsules are for oral administration. Each capsule contains 200 mg of emtricitabine and the inactive ingredients crospovidone, magnesium stearate, microcrystalline cellulose, povidone, titanium dioxide, gelatin, and FD&C blue No. 2.
EMTRIVA oral solution is for oral administration. One milliliter (1 mL) of EMTRIVA oral solution contains 10 mg of emtricitabine in an aqueous solution with the following inactive ingredients: cotton candy flavor, FD&C yellow No. 6, edetate disodium, methylparaben and propylparaben (added as preservatives), sodium phosphate (monobasic), propylene glycol, water, and xylitol (added as a sweetener). Sodium hydroxide and hydrochloric acid may be used to adjust pH.
Enterohepatic circulation

# Overview
Enterohepatic circulation refers to the circulation of bile from the liver, where it is produced, to the small intestine, where it aids in digestion of fats and other substances, back to the liver.
Liver hepatocytes metabolize cholesterol to cholic acid and chenodeoxycholic acid. These lipid soluble bile acids are conjugated mainly to glycine or taurine molecules to form water soluble primary conjugated bile acids.  These bile acids travel to the gall bladder during the interdigestive phase for storage and to the second part of the duodenum via the common bile duct during digestion.  95% of the bile acids which are delivered to the duodenum will be recycled by the enterohepatic circulation.
At the pH of the small intestine, most of the bile acids are ionized and mostly occur as their sodium salts which are then called primary conjugated bile salts.  In the lower small intestine and colon, bacteria dehydroxylate some of the primary bile salts to form secondary conjugated bile salts (which are still water soluble). Along the proximal and distal ileum, these conjugated primary bile salts are reabsorbed actively into hepatic portal circulation. Bacteria deconjugate some of the primary and secondary conjugated bile salts back to lipid soluble bile acids, which are passively absorbed into hepatic portal circulation. Finally, the conjugated bile acids which remained un-ionized conjugated bile acids are passively absorbed.
Venous blood from the ileum goes straight into the portal vein and then into the liver sinusoids.  There, hepatocytes extract bile acids very efficiently, and little escapes the healthy liver into systemic circulation.  If bile does escape, jaundice may be observed.
The net effect of enterohepatic recirculation is that each bile salt molecule is reused about 20 times, often multiple times during a single digestive phase.
Enterohepatic circulation also means that some molecules which would not otherwise be very toxic can become extremely hepatotoxic as they reach unexpectedly high hepatic concentrations. Drugs may remain in the enterohepatic circulation for a prolonged period of time as a result of this recycling process.
Environment (biophysical)
The environment, in the biophysical context, is the physical and biological factors along with their chemical interactions that affect an organism. In other contexts environment may also be used to refer to the immediate surroundings, to a milieu or to the environs within a system or topic, for instance computer science.
The scope of the biophysical environment is all that contained in the biosphere, which is that part of the Earth in which all life occurs. Ecosystems, of which there are numerous types and are a defined part of the biosphere, collectively make up the whole of the biosphere. Within an ecosystem there are habitats in which an organism (including humans) exists. The environment can be divided into two categories - the natural environment and the built environment, with some overlap between the two. At its most natural, an environment would lack any effects of human activity, although the scale of this activity is such that all areas of the Earth have had at least some influence by humans. At the other end of the scale is the built environment and in some cases it has the biotic component that is virtually absent.
The biophysical environment can vary in scale from microscopic to global in extent. They can also be subdivided according to their attributes. Some examples may be the marine environment, the atmospheric environment and the terrestrial environment.
Environmental science is the study of the interactions within the biophysical environment. Part of this scientific discipline is the investigation of the effect of human activity on the environment. Ecology, a sub-discipline of biology and a part of environmental sciences, is often mistaken as a study of human induced effects on the environment. Environmental studies is a broader academic discipline that is the systematic study of interaction of humans with their environment. It is a broad field of study that includes the natural environment, built environments and social environments.
Environmentalism is a broad social and philosophical movement that, in a large part, seeks to minimise or eliminate the effect of human activity on the biophysical environment. The issues of concern for environmentalists usually relate to the natural environment with the more important ones being old growth forest loss, pollution, climate change and species extinction.
Environmental degradation
Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems and the extinction of wildlife.
Environmental degradation is one of the ten threats officially cautioned by the High Level Threat Panel of the United Nations. WRI (the World Resources Institute), UNEP (the United Nations Environment Programme), UNDP (the United Nations Development Programme) and the World Bank have made public an important report on health and the environment worldwide on May 1, 1998.
Environmental Change and Human Health, a special section of World Resources 1998-99 in this report describes how preventable illnesses and premature deaths are still occurring in very large numbers. If vast improvements are made in human health, millions of people will be living longer, healthier lives than ever before. In these poorest regions of the world an estimated one in five children will not live to see their fifth birthday, primarily because of environment-related diseases. Eleven million children die worldwide annually, equal to the combined populations of Norway and Switzerland, and mostly due to malaria, acute respiratory infections or diarrhoea  illnesses that are largely preventable.
Epileptic (graphic novel)
Epileptic is the English title of L'ascension du haut mal (meaning The Rise of the High Evil), an autobiographical graphic novel by David B., originally published in French by L'Association in six volumes from 1996 to 2003. The first half of the series was published in English by Fantagraphics in one volume in 2002 (ISBN 2-84414-085-8); a complete edition was released by Pantheon in 2005.
The book tells the story of the artist's early childhood and adolescence, focusing on his relationship with his brother and sister. His brother develops severe and intractable epilepsy, causing the family to seek a variety of solutions from alternative medicine, most dramatically by moving to a commune based on macrobiotic principles. As the epileptic brother loses control of his own life, the artist develops solitary obsessions with cartoons, mythology and war. The book's graphic style becomes increasingly elaborate as the children's fantasy life takes over, with their dreams and fears (including epilepsy itself) appearing as living creatures. In brief interludes, the children appear as adults when the artist begins the process of writing the story.
The French title proved difficult to translate, as it contains several meanings: haut mal is an archaic term for epilepsy meaning literally "high evil" or "great sickness" (formerly used as a medical term in English, now replaced by grand mal), and ascension can mean either rise or climbing, as seen in a recurring image of the family climbing a steep slope into unknown terrain.
The English translation of the book received very good reviews from critics. The review aggregator Metacritic reported the book had an average score of 92 out of 100, based on 15 reviews. Publishers Weekly has called it "one of the greatest graphic novels ever published."
Eschenmoser fragmentation
The Eschenmoser fragmentation (also called the Eschenmoser-Tanabe fragmentation) is the chemical reaction of ,-epoxyketones (1) with aryl sulfonylhydrazines (2) to give alkynes (3) and carbonyl compounds (4). This reaction is named after Albert Eschenmoser, a Swiss chemist.
Several examples exist in the literature.

# Reaction mechanism
The mechanism of the Eschenmoser fragmentation begins with reaction of the ,-epoxyketone (1) with aryl sulfonylhydrazine (2) to give the intermediate hydrazone (3).  Proton transfer leads to intermediate 4, which undergoes the key fragmentation to the alkyne (6) and the carbonyl compound (7).
The proton transfers from hydrazone (3) to intermediate (4) can be catalyzed by pyridine, sodium bicarbonate, sodium carbonate, or silica gel.
Escherichia coli O104:H21
This page is about microbiologic aspects of the organism.  For clinical aspects of the disease, see Escherichia coli enteritis.
To view information about other strains of Escherichia coli, see Escherichia coli.
==Overview
Escherichia coli O104:H21 is a rare serotype of Escherichia coli, a species of bacteria that lives in the lower intestines of mammals. The presence of many serotypes of E. coli in animals is beneficial or does not cause disease. However, E. coli O121 has been recognized as a pathogenic serotype of bacteria.

# History
E. coli O104:H21 was discovered in 1982, when it caused an outbreak of severe bloody diarrhea. It had infected hamburgers, and those effected had eaten these hamburgers not fully-cooked.

# Effects
E. coli O104:H21 can cause outbreak of infection similar to that caused by E. coli O157:H7, the most common shiga-like toxin-producing E. coli (SLTEC). SLTECs are the most well-known causes of gastrointestinal illness and diarrhea.

# Treatment
The body usually rids itsself of harmful E. coli O104:H21 on its own within 5 to 10 days. Antibiotics should not be used, and neither should antidiarrheal agents such as loperamide.
Esophageal motility study

# Overview
An esophageal motility study (EMS) or esophageal manometry is a study performed to evaluate the pressure of the esophagus in various stages along its length.

# Indications
An EMS is typically done to evaluate suspected disorders of motility or peristalsis of the esophagus.  These include achalasia, diffuse esophageal spasm, nutcracker esophagus and hypertensive lower esophageal sphincter.  These disorders typically present with dysphagia, or difficulty swallowing, usually to both solids and liquids even initially.  Other patients with spasm disorders may have the test done to diagnose chest pain thought not to be of cardiac cause.  The test is not useful for anatomical disorders of the esophagus (that is, disorders that distort the anatomy of the esophagus), such as peptic strictures and esophageal cancer.

# Procedure
A technician places a catheter into the nose and guides it into the stomach. Once placed, the catheter is slowly withdrawn, allowing it to detect pressure changes and to record information for later review. The patient will be asked at various times to take a deep breath or to take some swallows of water. The degree of discomfort varies among patients. Patients are not sedated because sedatives would alter the functioning of the esophageal muscles. Overall the procedure takes about 45 minutes. After the procedure is complete, patients can usually resume their normal daily activities.
Tracheoesophageal fistula

# Overview
A tracheoesophageal fistula (TEF) is an abnormal connection (fistula) between the esophagus and the trachea.  TEF is a common congenital abnormality, but when occurring late in life is usually the sequela of surgical procedures such as a laryngectomy.

# Causes
Congenital TEF can arise due to failed fusion of the tracheoesophageal ridges during the third week of embryological development.  

# Associations
It is often found in association with coloboma of the iris, various heart abnormalities, choanal atresia, retardation, genital defects, and ear abnormalities-- an association known as the CHARGE syndrome.
TEF is also part of the VACTERL association.

# Classification
Fistula between the trachea and esophagus in the newborn can be of diverse morphology and anatomical location, however, various pediatric surgical publications have attempted a classification system comprised of the below specified types.
The letter codes are usually associated with the system used by Gross, while number codes are usually associated with Vogt.
(For the purposes of this discussion, proximal esophagus indicates normal esophageal tissue arising normally from the pharynx, and distal esophagus indicates normal esophageal tissue emptying into the proximal stomach.)

# Clinical presentation
Tracheoesophageal fistula is suggested in a newborn by copious salivation associated with choking, coughing, and cyanosis coincident with the onset of feeding.

# Treatment
It is surgically corrected, with resection of any fistula and anastomosis of any discontinuous segments.  Surgical repair is associated with complications, including
- Stricture, due to gastric acid erosion of the shortened esophagus.
- Leak of contents at the point of anastomosis.
- Recurrence of fistula.
Ethylene glycol dinitrate
Ethylene glycol dinitrate (EGDN), also known as nitroglycol, is a chemical compound a yellowish, oily explosive liquid obtained by nitrating ethylene glycol. Its formula is Template:Oxygen2Template:Nitrogen-O-Template:CarbonTemplate:Hydrogen2-CH2-O-NO2. It is similar to nitroglycerin in both manufacture and properties, though it is more volatile and less viscous.
EGDN was used in manufacturing explosives to lower the freezing point of nitroglycerin, in order to produce dynamite for use in colder weather. Due to its volatility it did serve as a detection taggant in some plastic explosives, eg. Semtex, to allow more reliable explosive detection, until 1995 when it was replaced by Dimethyldinitrobutane .
Like other organic nitrates, ethylene glycol dinitrate is a vasodilator.
The CH2 groups along the chain is known as a methylene group.
Examples of Markov chains
This page contains examples of Markov chains in action.

# Board games played with dice
A game of Monopoly, snakes and ladders or any other game whose moves are determined entirely by dice is a Markov chain.  This is in contrast to card games such as poker or blackjack, where the cards represent a 'memory' of the past moves.  To see the difference, consider the probability for a certain event in the game.  In the above mentioned dice games, the only thing that matters is the current state of the board.  The next state of the board depends on the current state, and the next roll of the dice.  It doesn't depend on how things got to their current state.  In a game such as poker or blackjack, a player can gain an advantage by remembering which cards have already been shown (and hence which cards are no longer in the deck), so the next state (or hand) of the game is not independent of the past states.

# A very simple weather model
The probabilities of weather conditions, given the weather on the preceding day,
can be represented by a transition matrix:
The matrix P represents the weather model in which a sunny day is 90%
likely to be followed by another sunny day, and a rainy day is 50% likely to
be followed by another rainy day.  The columns can be labelled "sunny" and
"rainy" respectively, and the rows can be labelled in the same order.
(P)i j is the probability that, if a given day is of type i, it will be
followed by a day of type j.
Notice that the rows of P sum to 1: this is because P is a stochastic matrix.

## Predicting the weather
The weather on day 0 is known to be sunny.  This is represented by a vector in which the "sunny" entry is 100%, and the "rainy" entry is 0%:
The weather on day 1 can be predicted by:
Thus, there is an 90% chance that day 1 will also be sunny.
The weather on day 2 can be predicted in the same way:
-r
General rules for day n are:

## Steady state of the weather
In this example, predictions for the weather on more distant days are increasingly
inaccurate and tend towards a steady state vector.  This vector represents
the probabilities of sunny and rainy weather on all days, and is independent
-f the initial weather.
The steady state vector is defined as:
but only converges to a strictly positive vector if P is a regular transition matrix (that is, there
is at least one Pn with all non-zero entries).
Since the q is independent from initial conditions, it must be unchanged when transformed by P.  This makes it an eigenvector (with eigenvalue 1), and means it can be derived from P.  For the weather example:
So 
and since they are a probability vector we know that 
q_1 + q_2 = 1.
Solving this pair of simultaneous equations gives the steady state distribution:
In conclusion, in the long term, 83% of days are sunny.

# Citation ranking
Google's page rank algorithm is essentially a Markov chain over the graph of
the Internet.  More information can be found in "The PageRank Citation Ranking: Bringing Order to the Web"
by Larry Page, Sergey Brin, R. Motwani, and T. Winograd.
Extensor digitorum muscle
The Extensor digitorum (Extensor digitorum communis) arises from the lateral epicondyle of the humerus, by the common tendon; from the intermuscular septa between it and the adjacent muscles, and from the antebrachial fascia.

# Origin, insertion, and relations
It divides below into four tendons, which pass, together with that of the Extensor indicis proprius, through a separate compartment of the dorsal carpal ligament, within a mucous sheath.
The tendons then diverge on the back of the hand, and are inserted into the second and third phalanges of the fingers in the following manner.
Opposite the metacarpophalangeal articulation each tendon is bound by fasciculi to the collateral ligaments and serves as the dorsal ligament of this joint; after having crossed the joint, it spreads out into a broad aponeurosis, which covers the dorsal surface of the first phalanx and is reinforced, in this situation, by the tendons of the Interossei and Lumbricalis.
Opposite the first interphalangeal joint this aponeurosis divides into three slips; an intermediate and two collateral: the former is inserted into the base of the second phalanx; and the two collateral, which are continued onward along the sides of the second phalanx, unite by their contiguous margins, and are inserted into the dorsal surface of the last phalanx. As the tendons cross the interphalangeal joints, they furnish them with dorsal ligaments.
The tendon to the index finger is accompanied by the Extensor indicis proprius, which lies on its ulnar side.
On the back of the hand, the tendons to the middle, ring, and little fingers are connected by two obliquely placed bands, one from the third tendon passing downward and lateralward to the second tendon, and the other passing from the same tendon downward and medialward to the fourth.
Occasionally the first tendon is connected to the second by a thin transverse band.

# Action
The Extensor digitorum communis extends the phalanges, then the wrist, and finally the elbow.
It acts principally on the proximal phalanges, the middle and terminal phalanges being extended mainly by the Interossei and Lumbricales.
It tends to separate the fingers as it extends them.
Extensor digitorum reflex
The Extensor digitorum reflex is tested as part of the neurological examination to asses the sensory and motor pathways within the C6 and C7 spinal nerves. It is also know as Braunecker-Effenberg reflex, BER.

# Testing
The test is performed by tapping the Extensor digitorum muscle while the the fingers are light or half flexed. A sudden contraction of the Musculus extensor digitorum and an extension of the fingers indicates a normal reflex.

# Absence of reflex
An absence of reflex can be an indicator for neuropathy within the C6 and C7 or the Deep branch of the radial nerve.
Superficial inguinal ring
In the aponeurosis of the external oblique, immediately above the crest of the pubis, is a triangular opening, the subcutaneous inguinal ring (superficial inguinal ring, external inguinal ring), formed by a separation of the fibers of the aponeurosis in this situation.
The subcutaneous inguinal ring is situated 1 centimeter above and lateral to the pubic tubercle. It has medial and lateral crura.
It is at the layer of the aponeurosis of the Obliquus externus abdominis.

# Clinical significance
The superficial ring is dilated in a condition called athletic pubalgia.
External cephalic version

# Overview
External cephalic version is a process by which a breech baby can sometimes be turned from buttocks or foot first to head first.  It should only be attempted from 34 weeks on and often is reserved for later due to the fact that breech presentation greatly decreases with every week.
In this procedure hands are placed on the mother's abdomen around the baby.  The baby is moved up and away from the pelvis and gently turned in several steps from breech, to a sideways position, and finally to a head first presentation.  In any attempt to move the baby should be encouraged to keep its knees pulled in so as not to further complicate things.
As with any procedure there can be complications most of which can be greatly decreased by having an experienced professional on the birth team.  An ultrasound to estimate a sufficient amount of amniotic fluid and monitoring of the fetus immediately after the procedure can also help minimize risks.
There are a few cases in which there can be a greater risk, these include pre-eclampsia, uterine scarring, and multiple pregnancies or fetal abnormality.