Persius/hicric huggingface dataset:
Stereocenter

# Overview
A stereocenter, or stereogenic centre, is any atom in a molecule bearing groups such that an interchanging of any two groups leads to a stereoisomer . In organic chemistry this usually refers to  a carbon, phosphorus or sulfur atom, though it is also possible for other atoms to be stereocenters in organic and inorganic chemistry.
A molecule can have multiple stereocenters, giving it many stereoisomers. In compounds whose stereoisomerism is due to tetrahedral stereogenic centers, the total number of hypothetically possible stereoisomers will not exceed 2n, where n is the number of tetrahedral stereocenters. Molecules with symmetry frequently have fewer than the maximum possible number of stereoisomers.
The term stereocenter was introduced in 1984 by Mislow and Siegel .
The broad term stereocenter is often confused with that of the narrower set of chirality center. It is important to remember that a compound like 2-butene has two stereocenters forming two possible stereoisomers (cis and trans 2-butene) (and not 4!) and is not considered a meso compound 

# Exceptions
Having two chiral centers may give a meso compound which is achiral. Certain configurations may not exist due to steric reasons. Cyclic compounds with chiral centers may not exhibit chirality due to the presence of a two-fold rotation axis. Planar chirality may also provide for chirality without having an actual chiral center present.

# Chiral carbon
A chiral carbon is a carbon atom which is asymmetric. Having a chiral carbon is usually a prerequisite for a molecule to have chirality, though the presence of a chiral carbon does not necessarily make a molecule chiral. A chiral carbon is often denoted by C*.
For the carbon to be chiral, it follows that:
- the carbon atom is sp3-hybridized
- there are four different groups attached to the carbon atom.
Almost any other configuration for the carbon would produce a center of symmetry. For example, an sp or sp2 hybridized molecule would be planar, with a mirror plane. Two identical groups would give a mirror plane bisecting the molecule.
The exceptions, probably due to the form of chirality exhibited (Axial chirality), are hardly ever mentioned in normal-level discussions on strereochemistry and form two groups:
- Allenes which are of the form RR'C=C=CRR'
- Spiranes which have asymmetric rings, which can be identical.

# Other chiral centers
Chirality is not limited to carbon atoms, though carbon atoms are often centers of chirality due to its ubiquity in organic chemistry.
Nitrogen and phosphorus atoms are also tetrahedral. Racemization by Walden inversion may be restricted (such as ammonium or phosphonium cations), or slow. This allows the presence of chirality.
Metal atoms with tetrahedral or octahedral geometries may also be chiral due to having different ligands. For the octahedral case, several chiralities are possible. Having three ligands of two types, the ligands may be lined up along the meridian, giving the mer-isomer, or forming a face  the fac isomer. Having three bidentate ligands of only one type gives a propeller-type structure, with two different enantiomers denoted  and .
Chloramine-T
N-chloro tosylamide sodium salt, sold as chloramine-T, is a N-chlorinated and N-deprotonated sulfonamide used as a biocide and a mild disinfectant. It is a white powder that gives unstable solutions with water.

# Chemistry
As a N-chloro compound, it contains active (electrophilic) chlorine and can be compared to the O-chlorinated sodium hypochlorite. Chloramine-T is nearly neutral (pH typically 8.5). In water, it breaks down to the disinfectant hypochlorite. It can be used as a source of electrophilic chlorine in organic synthesis.
The sulfur adjacent to the nitrogen can stabilize a nitrogen anion (R2N), so that the N-chloro sulfonyamide moiety can be deprotonated at nitrogen even with only sodium hydroxide.

# Use as a biocide
Chloramine-T is used for disinfection and as an algicide, bactericide, germicide, for parasite control, and for drinking water disinfection. The molecular structure of toluenesulfonylamide is similar to para-aminobenzoic acid, an intermediate in bacterial metabolism, which is disrupted by this sulfonamide (in the same way as by a sulfa drug). Therefore, chloramine-T is capable of inhibiting with bacterial growth with two mechanisms, with the phenylsulfonamide moiety and the electrophilic chlorine.
Chlormethine

# Overview
Chlormethine (INN, BAN), mechlorethamine (widely used in the US, not the USAN, however) also known as mustine and HN2 and in former USSR known as Embichin is a nitrogen mustard sold under the brand name Mustargen. It is the prototype of alkylating agents, a group of anticancer chemotherapeutic drugs. It works by binding to DNA, crosslinking two strands and preventing cell duplication. It binds to the N7 nitrogen on the DNA base guanine. As the chemical is a blister agent, its use is strongly restricted within the Chemical Weapons Convention where it is classified as a Schedule 1 substance.
Mechlorethamine belongs to the group of nitrogen mustard alkylating agents.

# Uses
It has been derivatized into the estrogen analogue estramustine, used to treat prostate cancer. It can also be used in chemical warfare where it has the code-name HN2. This chemical is a form of nitrogen mustard gas and a powerful vesicant. Historically, some uses of mechlorethamine have included lymphoid malignancies such as Hodgkins disease, lymphosarcoma, chronic myelocytic leukemia, polycythemia vera, and bronchogenic carcinoma  Mechlorethamine is often administered intravenously, but when compounded into a topical formulation it can also be used to treat skin diseases. There have been studies demonstrating that topical administration of mechlorethamine has efficacy in mycosis fungoides-type cutaneous T cell lymphoma 
Another important use of chlormethine is in the synthesis of meperidine (aka pethidine, demerol).

# Side effects
Mechlorethamine is a highly toxic medication, especially for women who are pregnant, breastfeeding, or of childbearing age.
The adverse effects of mechlorethamine depend on the formulation. Adverse effect include:
Hypersensitivity reactions, including anaphylaxis.... Nausea, vomiting and depression of formed elements in the circulating blood are dose-limiting side effects and usually occur with the use of full doses of MUSTARGEN. Jaundice, alopecia, vertigo, tinnitus and diminished hearing may occur infrequently. Rarely, hemolytic anemia associated with such diseases as the lymphomas and chronic lymphocytic leukemia may be precipitated by treatment with alkylating agents including MUSTARGEN. Also, various chromosomal abnormalities have been reported in association with nitrogen mustard therapy.

# History
Successful clinical use of chlormethine (mechlorethamine) resulted in development of the field of anticancer chemotherapy, led by Cornelius P. Rhoads at Memorial Sloan-Kettering.  The drug is a nitrogen-based analogue of mustard gas (which is sulfur-based) and was derived from chemical warfare research.  Secret clinical trials of the agent for Hodgkin's disease and several other lymphomas and leukemias in humans began in December 1942.  Because of wartime secrecy restrictions, it was not until 1946 that the results of these trials were published openly.
Chromophobia

# Overview
Chromophobia (also known as chromatophobia or chrematophobia) is a persistent, irrational fear of, or aversion to, colors and is usually a conditioned response. While actual clinical phobias to color are rare, colors can elicit hormonal responses and psychological reactions.
Chromophobia may also refer to an aversion of use of color in products or design. Within cellular biology, "Chromophobe cell|chromophobic" cells are a classification of cells that do not attract hematoxylin, and is related to chromatolysis.
Names exist that mean fear of specific colors such as erythrophobia for the fear of red and leukophobia for the fear of white. A fear of the color red may be associated with a fear of blood.
In his book Chromophobia  published in 2000, David Batchelor (artist and writer)|David Batchelor says that in Western culture, color has often been treated as corrupting, foreign or superficial. Michael  Taussig states that the cultural aversion to color can be traced back a thousand years, with Batchelor stating that it can be traced back to Aristotle's privileging of line over color.
In a study, hatchling Loggerhead sea turtles were found to have an aversion to lights in the yellow wave spectrum which is thought to be a characteristic that helps orient themselves toward the ocean. The Mediterranean sand smelt, Atherina hepsetus, has shown an aversion to red objects placed next to a tank while it will investigate objects of other colors. In other experiments, geese]] have been conditioned to have adverse reactions to foods of a particular color, although the reaction was not observed in reaction to colored water.
The title character in Alfred Hitchcock]]'s Marnie (film)|Marnie has an aversion to the color red caused by a trauma during her childhood which Hitchcock presents through expressionistic techniques, such as a Wash (visual arts)|wash of red coloring a close up of Marnie.
Chronophilia
Chronophilia refers to a group of patterns of sexual arousal associated with age discrepancy between the sexual partners. The term was coined by John Money, from the Greek roots chronos, "time" and philia, "love". The term has not been widely adopted by  sexologists, who instead use terms that that refer to the specific age range in question.

# Sexual Preferences Based on Age
- Pedophilia refers to a sexual preference for prepubescent children (by definition including nepiophilia). It differs from all these conditions in that it is a clinically-recognized disorder in the Diagnostic and Statistical Manual of Mental Disorders.
- Hebephilia refers to a sexual preference for pubescent children. The term was introduced by Glueck (1955).
- Ephebophilia refers to a sexual preference for individuals in mid- to late adolescence, usually 15-19 years old.
- Teleiophilia (from Greek teleios, "full grown") is a term coined by sexologist Ray Blanchard to refer to the sexual interest in adults. It is used by professional sexologists when comparing (for example) pedophiles with teleiophiles, and Diederik Janssen, MD uses the term "Peripubescent Teleiophilia" in reference to "crush" phenomenon.. For gender-specific attractions to people in this age range, see gynephilia and androphilia.
- Gerontophilia refers to the sexual preference for the elderly.
Chronotropic

# Overview
Chronotropic effects (from chrono-, meaning time) are those that change the heart rate.
Chronotropic drugs may change the heart rate by affecting the nerves controlling the heart, or by changing the rhythm produced by the sinoatrial node. Positive chronotropes increase heart rate; however, negative chronotropes decrease heart rate.
A dromotrope affects Atrioventricular node (AV node) conduction. A positive dromotrope increases AV nodal conduction, and a negative dromotrope decreases AV nodal conduction. A lusitrope is an agent that affects diastolic relaxation.
Many positive inotropes affect preload and afterload.

# Negative Chronotropes
Chronotropic variables in systolic myocardial performance can be split left and right. Left sided systolic chronotropy can be appreciated as Aortic Valve open to close time. Right sided variables are represented by Pulmonary valve open to close time. Inverted as diastolic chronotropy, the variables are aortic valve close to open and pulmonic close to open time. Pharmaceutical manipulation of chronotropic properties was perhaps first appreciated by the introduction of digitalis.
- Beta-blockers
- Acetylcholine
- Digoxin
- Diltiazem
- Verapamil
- Ivabradine
- Metoprolol

# Positive Chronotropes
- Atropine
- Quinidine
- Dopamine
- Dobutamine
- Epinephrine
- Isuprel
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Ciliary body
The ciliary body is the circumferential tissue inside the eye composed of the ciliary muscle and ciliary processes. It is part of the uveal tractthe layer of tissue which provides most of the nutrients in the eye.  There are three sets of ciliary muscles in the eye, the longitudinal, radial, and circular muscles.  They are near the front of the eye, above and below the lens.  They are attached to the lens by connective tissue called the zonule of Zinn, and are responsible for shaping the lens to focus light on the retina.
When the ciliary muscle relaxes, it flattens the lens, generally improving the focus for farther objects.  When it contracts, the lens becomes more convex, generally improving the focus for closer objects.

# Functions
The ciliary body has three functions: accommodation, aqueous humor production and the production and maintenance of the lens zonules.  One of the most essential roles of the ciliary body is the production of the aqueous humor, which is responsible for providing most of the nutrients for the lens and the cornea and involved in waste management of these areas.

# Clinical significance
It is the main target of drugs against glaucoma, as the ciliary body is responsible for aqueous humor production; lowering aqueous humor production will cause a subsequent drop in the intraocular pressure.
Cladosporium
Cladosporium is a genus of fungi including some of the most common indoor and outdoor molds. Species produce olive-green to brown or black colonies, and have dark-pigmented conidia that are formed in simple or branching chains.
The many species of Cladosporium are commonly found on living and dead plant material. Some species are plant pathogens, others parasitize other fungi. Cladosporium spores are wind-dispersed and they are often extremely abundant in outdoor air. Indoors Cladosporium species may grow on surfaces when moisture is present.
Cladosporium fulvum, cause of tomato leaf mould, has been an important genetic model, in that the genetics of host resistance are understood.

# Health Effects
Cladosporium species are rarely pathogenic to humans, but have been reported to cause infections of the skin and toenails, as well as sinusitis and pulmonary infections. If left untreated, these infections could turn into respiratory infections like pneumonia.
The airborne spores of Cladosporium species are significant allergens, and in large amounts they can severely affect asthmatics and people with respiratory diseases. Cladosporium species produce no major mycotoxins of concern, but do produce volatile organic compounds (VOCs) associated with odours.
Clark's rule
Clark's Rule is a medical term referring to a procedure used to calculate the amount of medicine to give to a child aged 2-17. The procedure is to take the child's weight in pounds, divide by 150 lb, and multiply the fractional result by the adult dose to find the equivalent child dosage.
For example: If an adult dose of medication calls for 30 mg and the child weighs 30 lb.  Divide the weight by 150 (30/150) to get 1/5.  Multiply 1/5 times 30 mg to get 6 mg.
Clark's Rule is not used clinically, but it is a popular dosage calculation formula for pediatric nursing instructors.
MHC class II
MHC Class II molecules are found only on a few specialized cell types, including macrophages, dendritic cells and B cells, all of which are professional antigen-presenting cells (APCs).
The peptides presented by class II molecules are derived from extracellular proteins (not cytosolic as in class I); hence, the MHC class II-dependent pathway of antigen presentation is called the endocytic or exogenous pathway.
Loading of class II molecules must still occur inside the cell; extracellular proteins are endocytosed, digested in lysosomes, and bound by the class II MHC molecule prior to the molecule's migration to the plasma membrane.

# Structure
Like MHC class I molecules, class II molecules are also heterodimers, but in this case consist of two homologous peptides, an  and  chain, both of which are encoded in the MHC.
Because the peptide-binding groove of MHC class II molecules is open at both ends while the corresponding groove on class I molecules is closed at each end, the peptides presented by MHC class II molecules are longer, generally between 15 and 24 amino acid residues long.

# Reaction to bacteria
Because class II MHC is loaded with extracellular proteins, it is mainly concerned with presentation of extracellular pathogens (for example, bacteria that might be infecting a wound or the blood).  Class II molecules interact exclusively with CD4+ ("helper") T cells (THs). The helper T cells then help to trigger an appropriate immune response which may include localized inflammation and swelling due to recruitment of phagocytes or may lead to a full-force antibody immune response due to activation of B cells.

# Synthesis
During synthesis, MHC class II is the result of dimerization of  and  chains, with the assistance of an invariant chain.

# Genes
Ectrodactyly
Ectrodactyly, commonly known as lobster claw syndrome , sometimes known as Karsch-Neugebauer syndrome, is a rare congenital deformity of the hand where the middle digit is missing, and the hand is cleft where the metacarpal of the finger should be. This split gives the hands the appearance of lobster claws.
Ectrodactyly may also be known as "lobster claw hand", "split hand deformity", "split hand/foot malformation (SHFM)", "cleft hand", "ectrodactilia of the hand" or "Karsch-Neugebauer syndrome", after J. Karsch and H. Neugebauer .

# Genetics
There are different forms of the disorder and each of them are connected with a different genetic mutation. Type I, the most frequent form has been found to be a mutation on chromosome 7 in a region that contains two homeobox genes, DLX5 and DLX6. Both are near SHFM1 ("split hand/foot malformation type 1").
Ectrodactyly is an inherited dysmelia, and often occurs in both the hands and the feet. Its inheritance pattern is autosomal dominant. It affects about 1 in 90,000 babies, with males and females equally likely to be affected.
Ectrodactylia may not be isolated and may exist in certain syndromes. EEC ie Ectrodactyly-ectodermal dysplasia-cleft syndrome happens due to a mutation in p63 a homologue of the famous p53.

# Treatment
It is treated surgically to improve function and appearance. Prosthetics may also be used, and genetic counselling given to parents with the condition.

# Famous people with ectrodactyly
- Vadoma
- Bree Walker - News anchor for 20 years KCBS news in Los Angeles; actress on HBO drama Carnivale. She also appears in the fourth season premiere of FX's Nip/Tuck playing a real estate agent counseling parents expecting a child with ectrodactyly.  Also appeared, along with her 2 children who also suffer from Ectrodactyly, on an episode of "My Unique Family" on The Learning Channel.
- Grady "Lobster Boy" Stiles
Co-amilozide
Co-amilozide (BAN) is a non-proprietary name used to denote a combination of amiloride and hydrochlorothiazide. Co-amilozide is used in the treatment of hypertension and congestive heart failure with the tendency of the thiazide to cause low potassium levels (hypokalaemia) offset by the potassium-sparing effects of amiloride.

# Formulation
Two strengths of co-amilozide is currently available in the UK:
- 2.5 mg amiloride and 25 mg hydrochlorothiazide, BAN of Co-amilozide 2.5/25 (brand name Moduretic 25)
- 5 mg amiloride and 50 mg hydrochlorothiazide, BAN of Co-amilozide 5/50 (brand name Moduretic)
Cocoa butter
Cocoa butter, also called theobroma oil, is the pale-yellow, pure edible vegetable fat of the cacao bean. It is the substance used to make solid chocolate bars. It is mixed with varying amounts of cocoa powder to produce solid pieces of chocolate. Cocoa butter is extracted from the cacao beans and can be used to make chocolate, cocoa powder, pharmaceuticals, ointments, and toiletries. Cocoa butter has a mild chocolate flavor and aroma.

# Creation
During processing of the cacao bean, cocoa solids and cocoa butter are separated out at an early stage. The two are recombined in the manufacture of regular (brown) chocolate bars. The confection known as white chocolate contains cocoa butter but not cocoa powder.

# Uses
Because of the melting temperature of cocoa butter, it is often used in pharmaceuticals as a base for suppositories. It is able to be stored at room temperature, but readily melts at body temperature, releasing the medication.
Cocoa butter is one of the most stable fats known, containing natural antioxidants that prevent rancidity and give it a storage life of two to five years, making it a good choice for non-food products. The smooth texture, sweet fragrance and emollient property of cocoa butter make it a popular ingredient in cosmetics and skin care products, such as soaps and lotions.

# Chemical properties
The most common form of Cocoa butter has a melting point of around 34 to 38 degres Celsius (93 to 100 degrees Fahrenheit), rendering chocolate a solid at room temperature that readily melts once inside the mouth.  Cocoa butter displays polymorphism, having , , ', and  crystals, with melting points of 17, 23, 26, and 3537 C respectively. The production of chocolate typically uses only the  crystal for its high melting point. A uniform crystal structure will result in smooth texture, sheen, and snap. Overheating cocoa butter converts the structure to a less stable form that melts below room temperature. Given time, it will naturally return to the most stable  crystal form.
Coffee enema

# Overview
Coffee enemas are the enema-related procedure of inserting coffee into the anus to cleanse the rectum and small intestines. This procedure, although well documented, is considered by most medical authorities to be unproven, rash and possibly dangerous. A Murphy drip is an example of an apparatus that may be used to administer this medical procedure.

# History
While the idea of anal cleansing dates back to the Egyptians, the notion of caffeine as an enema-related substance is relatively new. It was conceived as early as 1917, and was even in the Merck Manual until 1972.
In 1920, German scientists investigated caffeine's effect on the bile duct and small intestines. Dr. Max Gerson proposed coffee enemas had a positive effect of the gastro-intestinal tract; Gerson said that coffee enemas had positive effects on patients with tuberculosis, and later even cancer. He claimed that unlike saline enemas, the caffeine traveled through the smooth muscle of the small intestine, and into the liver. This, he said, cleared even more the gastro-intestinal tract and removed more toxins and bile than a normal enema. He told his patients often that the "coffee enemas are not given for the function of the intestines but for the stimulation of the liver."

## Claims of efficacy
Caffeine, theophylline and theobromine stimulate the relaxation of smooth muscles in the anus and small intestine, which cause dilatation of blood vessels and bile ducts. This, combined with the close proximity of the anal walls and veins which make the caffeine enter the blood more quickly and in greater quantity, arguably have a better cleaning effect than a regular saline enema.  Coffee can cause diarrhea which believers say aids in the detoxification process.

# Dangers
Coffee enemas are believed to have caused three deaths in the United States, described in the following references. Coffee enemas may cause electrolyte imbalances that, if severe enough, can cause death. Other adverse reactions that have been reported include enteric septicemia in a patient with widespread cancer, hepatic dysfunction and ascites, which the authors believed made this patient more likely to suffer from infections. If the coffee is inserted too quickly or too hot, it could cause internal burning or tearing. Because of the close proximity between veins and anal walls, caffeine finds itself in the veins in much greater quantities, and may lead to caffeine overdose, though since the coffee enema is expelled the likelihood of overdose may be less than when coffee is ingested and must remain in the body until metabolized. Excessive enemas may cause dehydration, and this is only amplified by the diuretic effect of caffeine in the coffee. Also, like all uses of coffee, it risks raising blood pressure, though not to a great extent in most individuals.