Persius/hicric huggingface dataset:
Choroid
The choroid, also known as the choroidea or choroid coat, is the vascular layer of the eye lying between the retina and the sclera, with a thickness about 0.5 mm. The choroid provides oxygen and nourishment to the outer layers of the retina .
Along with the ciliary body and iris, the choroid forms the uveal tract. In humans and other primates, darkly colored melanin pigment in the choroid helps limit reflections within the eye that would potentially result in the perception of confusing images. Poor vision frequently results from lack of this pigmentation in human albinos. By contrast, the choroid of many other animals contains reflective materials that help to collect light in dim situations; this is one type of tapetum lucidum.
The red eye effect on photos is caused by the reflection of light from choroid.  It appears red because of the choroid's blood vessels.

# Layers
The structure of the choroid is generally divided into four layers:
- Haller's layer - outermost layer of the choroid consisting of larger diameter blood vessels
- Sattler's layer - layer of medium diameter blood vessels
- Choriocapillaris - layer of capillaries
- Bruch's membrane - innermost layer of the choroid
Citrate
A citrate is an ionic form of citric acid, such as C3H5O(COO)33, that is, citric acid minus three hydrogen ions.

# Citrate family
Citrates are compounds containing this group, either ionic compounds, the salts, or analogous covalent compounds, esters. An example of a salt is sodium citrate and an ester is trimethyl citrate. See category for a bigger list.

# Other citric acid ions
Since citric acid is a multifunctional acid, intermediate ions exist, hydrogen citrate ion, HC6H5O72 and dihydrogen citrate ion, H2C6H5O7. These may form salts as well, called acid salts.

# pH
Salts of the hydrogen citrate ions are weakly acidic, while salts of the citrate ion itself (with an inert cation such as sodium ion) are weakly basic.

# Buffering
Citrate is a key component in the commonly used SSC 20X hybridization buffer. There exists authoritative literature (Maniatis) that incorrectly instructs the preparation of this buffer to include 3M NaCl and 0.3M Sodium Citrate, to be titrated up with NaOH to a pH of 7. When the two components are actually mixed together, the pH is slightly basic. Therefore, the pH of the solution should instead be titrated down to 7 with HCl.
Citric acid can act as a mild chelating agent.

# Metabolism

## TCA cycle
Citrate is an intermediate in the TCA (Krebs) Cycle. After the pyruvate dehydrogenase complex forms acetyl CoA, from pyruvate and five cofactors (Thiamine pyrophosphate, lipoamide, FAD, NAD+, and CoA), citrate synthase catalyzes the condensation of oxaloacetate with Acetyl CoA to form citrate. Citrate continues in the TCA cycle via aconitase with the eventual regeneration of oxaloacetate, which can combine with another molecule of acetyl CoA and continue cycling.
See also TCA cycle

## Role in Glycolysis
High concentration of citrate can inhibit phosphofructokinase, the pace-maker of glycolysis.
Tacrine

# Overview
Tacrine is a parasympathomimetic and a centrally acting cholinesterase inhibitor (anticholinesterase). It was the first centrally-acting cholinesterase inhibitor approved for the treatment of Alzheimer's disease, and was marketed under the trade name Cognex. Tacrine was first synthesised by Adrien Albert at the University of Sydney.

# Clinical use
Tacrine was the prototypical cholinesterase inhibitor for the treatment of Alzheimer's disease. Studies have found that it may have a small beneficial effect on cognition and other clinical measures, though adequate study data is limited and the clinical relevance of these findings is unclear.
The use of tacrine is limited by poor oral bioavailability, the necessity for four-times daily dosing, and considerable adverse drug reactions (including nausea, diarrhea, urinary incontinence and hepatotoxicity) such that few patients could tolerate therapeutic doses.
Other newer cholinesterase inhibitors, such as donepezil, are now preferred over tacrine.

# Overdosage/Toxicity
As stated above, overdosage of tacrine may giva rise to severe side effects such as nausea, vomiting, salivation, sweating, bradycardia, hypotension, collapse, and colvulsions. Tertiary anticholinergics, such as atropine, may be used as an antidote for overdose.
Major form of metabolism is in the liver via hydroxylation of benzylic carbon by CYP450.  This forms the major metabolite 1-hydroxy-tacrine (velnacrine) which is still active.
Colicin
A colicin is a type of bacteriocin.
Colicins are composed of three globular domains.  One domain regulates the target and binds to the receptor on the sensitive cell.  The second is involved with translocation, co-opting the machinery of the target cell.  The third is the 'killing' domain and may produce a pore in the target cell membrane, or act as a nuclease to chop up the DNA or RNA of the target cell.  Because they target specific receptors and use specific translocation machinery, cells can make themselves resistant to the colicin by repressing or deleting the genes for these proteins.  Such resistant cells may suffer the lack of a key nutrient (such as iron or vitamin B) but benefit by not being killed.  Colicins exhibit a '1-hit killing kinetic' which doesn't necessarily mean a single molecule is sufficient to kill, but certainly that it only takes a small number.  In his Nobel Laureate speech, Salvador E. Luria, 1969, speculated that colicins could only be this toxic by causing a domino effect that destabilized the cell membrane   He was not entirely correct, but pore-forming colicins do de-polarize the membrane and thus eliminate the energy source for the cell.  The colicins are highly effective toxins.
Virtually all colicins are carried on plasmids.  There are two general classes of colicinogenic plasmids, large, low-copy number plasmids, and small high copy number plasmids.  The larger plasmids carry other genes as well as the colicin operon.  The colicin operons are generally organized with several major genes.  These include an immunity gene, a colicin structural gene, and a BRP (bacteriocin release protein), or lysis, gene.  The immunity gene is often produced constitutively, while the BRP is generally produced only as a read-through of the stop codon on the colicin structural gene.  The colicin itself is repressed by the SOS response and may be regulated in other ways as well.
Research indicates that retaining the colicin plasmid is very important for cells that live with their relatives, because if a cell loses the immunity gene, it quickly becomes subject to destruction by circulating colicin.  At the same time, colicin is only released from a producing cell by the use of the lysis protein, which results in that cell's death.  This suicidal production mechanism would appear to be very costly, except for the fact that it is regulated by the SOS response, which responds to significant DNA damage.  In short, colicin production may only occur in terminally-ill cells.  Still these matters require further research.
Concave
The word concave means  curving in or hollowed inward. The term is most commonly used to refer to:
- Concave lens, a lens with inward-curving (concave) surfaces.
- Concave polygon, a polygon which is not convex.
- Concave function, a type of function which is related to convex functions.
- Concave mirror
In addition, the term concave upwards is used for convex functions, and concave downwards for concave functions.
Cowlick
A cowlick appears when the growth direction of the hair forms a spiral pattern. The hair in a cowlick either stands straight up or lies at an extreme angle and seems to be always at odds with the style in which the rest of the hair is worn. They can show up anywhere. The most common site is in the crown like the one belonging to Carl "Alfalfa" Switzer of the Our Gang comedy series of the 1930s and 1940s, or on Dennis the Menace.
The term cowlick dates from the late 16th century, when Richard Haydocke used it in his translation of Lomazzo: "The lockes or plaine feakes of haire called cow-lickes, are made turning upwards."  Also, the Latin word "calyx" is often pronounced this way and literally means a whorled look or appearance on something, and the "cowlick" always has a whorled appearance. 

# Management
Many people find Cowlicks to be extremely irritating, as they often conflict with the desired hairstyle. There are several methods of taming the unruly cowlick. For most people, a combination of the right hairstyle, length, product used, and styling technique can overcome the appearance. For people more serious about cowlick management, more drastic measures may be used. Electrology, waxing, and even cosmetic surgery can be used to more permanently correct the cowlick.
Cricoid
The cricoid cartilage, or simply cricoid (from the Greek krikoeides meaning "ring-shaped"), is the only complete ring of cartilage around the trachea.

# Location
It sits just inferior to the thyroid cartilage in the neck, and is joined to it medially by the median cricothyroid ligament and postero-laterally by the cricothyroid joints. Inferior to it are the rings of cartilage around the trachea (which are not continuous - rather they are C-shaped with a gap posteriorly). The cricoid is joined to the first tracheal ring by the cricotracheal ligament, and this can be felt as a more yielding area between the firm thyroid cartilage and firmer cricoid.
It is also anatomically related to the thyroid gland; although the thyroid isthmus is inferior to it, the two lobes of the thyroid extend superiorly on each side of the cricoid as far as the thyroid cartilage above it.
The posterior part of the cricoid is slightly broader than the anterior and lateral parts, and is called the lamina, while the anterior part is the band; this may be the reason for the common comparison made between the cricoid and a signet ring.

# Function
The function of the cricoid is to provide attachments for the various muscles, cartilages, and ligaments involved in opening and closing the airway and in speech production.

# Composition
It is made of hyaline cartilage, and so can become calcified or even ossified, particularly in old age.

# Clinical significance
When intubating a patient under general anesthesia prior to surgery, the anesthesiologist will press on the cricoid cartilage to compress the esophagus behind it so as to prevent gastric reflux from occurring.
Gastric reflux could cause aspiration if this is not done considering the general anesthesia can cause relaxation of the gastro-esophageal sphincter allowing stomach contents to ascend through the esophagus into the trachea.

# Additional images
- Larynx
- Tracheotomy neck profile
Tracheotomy neck profile
- Muscles of the pharynx and cheek.
- The cartilages of the larynx. Posterior view.
- Ligaments of the larynx. Posterior view.
- Sagittal section of the larynx and upper part of the trachea.
- Coronal section of larynx and upper part of trachea.
- The entrance to the larynx, viewed from behind.
- Muscles of larynx. Side view. Right lamina of thyroid cartilage removed.
- Muscles of the larynx, seen from above.
- Sagittal section of nose mouth, pharynx, and larynx.
- Front view of neck.
Cubilin
Cubilin is a protein that in humans is encoded by the CUBN gene.

# Function
Cubilin (CUBN) acts as a receptor for intrinsic factor-vitamin B12 complexes. The role of receptor is supported by the presence of 27 CUB domains. Cubilin shows a restricted mode of expression according to protein profiling and transcriptomics analyses, and is essentially only present in the kidneys and small intestine.  Mutations in CUBN may play a role in autosomal recessive megaloblastic anemia. A complex of amnionless and cubilin forms the cubam receptor.
It can be found in the proximal tubule forming part complexes with megalin; the function of these complexes is reabsorptive and can be inhibited by sodium maleate.

# Clinical significance
Cubilin is a potential diagnostic and prognostic cancer biomarker for kidney cancer. Based on patient survival data, high levels of cubilin in tumor cells is a favourable prognostic biomarker in renal cell carcinoma.
Cuticle

# Overview
In biology, the term cuticle or cuticula is given to a variety of tough but flexible, non-mineral outer coverings of an organism, or part of an organism, that provide protection. They are non-homologous, differing in their origin, structure and chemical composition.

# In human anatomy
In human anatomy, cuticle refers to the dead layers of epidermal cells or keratinocytes that produce the horn protein keratin, to the strip of dead skin cells at the base and sides of the fingernail, the eponychium and also to the superficial layer of overlapping cells covering the hair shaft (cuticula pili) that locks the hair into its follicle.

# In invertebrate zoology
In zoology, the invertebrate cuticle or cuticula is a multi-layered structure outside the epidermis of many invertebrates, notably roundworms and arthropods, in which it forms an exoskeleton.
The main structural components of the nematode cuticle are proteins, highly cross-linked collagens and specialised insoluble proteins known as "cuticlins", together with glycoproteins and lipids. .
The main structural component of arthropod cuticle is a polysaccharide, chitin, composed of N-acetylglucosamine units, together with proteins and lipids.

# In botany
In botany, plant cuticles are protective waxy coverings produced by the epidermal cells of leaves, young shoots and all other aerial plant organs.
The main structural components of plant cuticles are the unique polymers cutin and/or cutan, impregnated with wax.
The cuticles of plants function as permeability barriers for water and water-soluble materials. The cuticle both prevents plant surfaces from becoming wet and helps to prevent plants from drying out. Xerophytic plants such as Cactus have very thick cuticles to help them survive in their arid climates. Plants that live in range of sea's spray also tend to have thicker cuticles, to protect them from the toxic effects of salt.
Cyanate

# Overview
The cyanate ion is an anion consisting of one oxygen atom, one carbon atom, and one nitrogen atom, , in that order, and possesses 1 unit of negative charge, borne mainly by the nitrogen atom. In organic compounds the cyanate group is a functional group.
The structure of cyanate can be considered to resonate between two canonical forms:
The resonance hybrid resulting from these two contributory structures can be represented as
The cyanate ion is isoelectronic with carbon dioxide, and so shares its linear shape.
The cyanate ion is an ambident nucleophile in nucleophilic substitution because it can react to form an alkyl cyanate R-OCN (exception) or an alkyl isocyanate R-NCO (rule). Aryl cyanates (C6H5OCN) can be formed by a reaction of phenol with cyanogen chloride (ClCN) in the presence of a base.
Cyanates are salts or esters of cyanic acid, for example potassium cyanate (KOCN) or methyl cyanate.
The cyanate ion is relatively non-toxic in comparison with cyanides.  Use of this fact is made in cyanide decontamination processes where a permanganate oxidation converts toxic cyanide to safer cyanate.
The fulminate ion  has the same chemical formula but a different structure  it is a structural isomer of cyanate.
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de:Cyansaure#Cyanate
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sv:Cyanater
Cypress

# Overview
Cypress is the name applied to many plants in the cypress family Cupressaceae, which is a conifer of northern temperate regions. Most cypress species are trees, while a few are shrubs.  Most plants bearing the common name cypress are in the genera Cupressus and Chamaecyparis, but several other genera in the family also carry the name.
Cupressus sempervirens is famous for its longevity, and has been a popular garden plant for thousands of years.
The word "cypress" is derived from Old French "cipres", which was imported from Latin "cyparissus," the latinisation of the Greek  (kyparissos).
- African Cypress (Widdringtonia species)
- Bald, Pond, and Montezuma Cypresses (Taxodium species, native to North America)
- Chinese Swamp Cypress (Glyptostrobus pensilis)
- Cordilleran Cypress (Austrocedrus chilensis)
- Cypress (Callitropsis species)
- Cypress (Cupressus species)
- Cypress-pines (Actinostrobus species)
- Cypress-pines (Callitris species)
- "False" Cypress (Chamaecyparis species)
- Fujian Cypress (Fokienia hodginsii)
- Guaitecas Cypress (Pilgerodendron uviferum)
- Patagonian Cypress (Fitzroya cupressoides)
- Sargent Cypress (Cupressus sargentii)
- Siberian Cypress (Microbiota decussata)
The Cupressaceae family also contains 13-16 other genera (not listed above) that as of yet do not bear cypress in their common names.
The word cypress is also used as a descriptor for the angiosperm vine in the bindweed family Convolvulaceae, known as the Cypress vine  (Ipomoea quamoclit).
The plant called "summer cypress" is Bassia scoparia (Amaranthaceae).
Cystine
Cystine is the amino acid formed when of a pair of cysteine molecules are joined by a disulfide bond.  It is described by the formula (SCH2CH(NH2)CO2H)2. It is a colorless solid, and melts at 247-249 C.  It was discovered in 1810 by William Hyde Wollaston but was not recognized as a component of proteins until it was isolated from the horn of a cow in 1899. Through formation of disulfide bonds within and between protein molecules, cystine is a significant determinant of the tertiary structure of most proteins. Disulfide bonding, along with hydrogen bonding and hydrophobic interactions is partially responsible for the formation of the gluten matrix in bread. Human hair contains approximately 5% cystine by mass.

# Properties
The disulfide link is readily reduced to give the corresponding thiol, cysteine.  This reaction is typically effected with thiols such as mercaptoethanol or dithiothreitol.

# Nutritional sources
Supplemental N-acetyl cysteine is claimed to be a source of cystine, but the dose of this supplement is limited by side effects.  One of the richest nutritional sources of cystine in the diet is undenatured whey proteins from milk. The disulfide-bonded cystine is not digested or significantly hydrolized by the stomach, but is transported by the blood stream to the tissues of the body. Here, within the cells of the body, the weak disulfide bond is cleaved to give cysteine, from which glutathione can be synthesized.

### In animal feed
Disulfide bonds can be broken at temperatures above about 150 C, especially at low moisture levels (below about 20%).

# Side effects
Nutritional sources of cystine are virtually free of the toxic side effects associated with the single molecule of cysteine, N-acetyl cysteine.  The greatest dietary source of cystine is bio-active, unpasteurized or low-heat pasteurized undenatured whey proteins.
Cytosol
The cytosol (cf. cytoplasm, which also includes the organelles) is the internal fluid of the cell, and a portion of cell metabolism occurs here. Proteins within the cytosol play an important role in signal transduction pathways and glycolysis. They also act as intracellular receptors and form part of the ribosomes, enabling protein synthesis.
In prokaryotes, all chemical reactions take place in the cytosol. In eukaryotes, the cytosol surrounds the cell organelles; this is collectively called cytoplasm. In plants, the amount of cytosol can be reduced because of the large tonoplast (central vacuole) that takes up most of the cell interior volume. The portion of cytosol in the nucleus is called nucleohyaloplasm.
The cytosol also surrounds the cytoskeleton, which is made of fibrous proteins (e.g. microfilaments, microtubules, and intermediate filaments). In many organisms, the cytoskeleton maintains the shape of the cell, anchors organelles, and controls internal movement of structures (e.g. transport vesicles).
The cytosol is a "soup" with free-floating particles, but is highly organized on the molecular level. As the concentration of soluble molecules increases within the cytosol, an osmotic gradient builds up toward the outside of the cell. Water flows into the cell, making the cell bigger. To prevent the cell from bursting apart, molecular pumps in the plasma membrane, the cytoskeleton, the tonoplast or the cell wall (if present), are used to counteract the osmotic pressure.
Cytosol mostly consists of water, dissolved ions, small molecules, and large water-soluble molecules (such as protein). It contains about 20% to 30% protein.
Normal human cytosolic pH is (roughly) 7.0 (i.e. neutral), whereas the pH of the extracellular fluid is 7.4.
DCLRE1A
DNA cross-link repair 1A protein is a protein that in humans is encoded by the DCLRE1A gene.
DNA interstrand cross-links prevent strand separation, thereby physically blocking transcription, replication, and segregation of DNA. DCLRE1A is one of several evolutionarily conserved genes involved in repair of interstrand cross-links (Dronkert et al., 2000).

# Function
The protein DCLRE1A (DNA cross-link repair 1A) is also referred to as SNM1A (sensitive to nitrogen mustard 1A).  DCLRE1A is a 5 to 3 exonuclease that forms a complex with the Cockayne syndrome B (CSB) protein.  In this complex, CSB modulates the exonuclease activity of DCLRE1A and coordinates the efficient assembly of DCLRE1A to sites of DNA damage.  In human cells, this complex is recruited to DNA inter-strand cross-links, a form of DNA damage.  The complex then participates in the repair of the cross-linked DNA. DCLRE1A protein is thought to be recruited by CSB to facilitate cross-link unhooking following incision 5 to the cross-link by another complex, the ERCC1/XPF nuclease complex.  Failure of the DCLRE1A/CSB complex to carry out its repair function may contribute to the degenerative pathologies and premature aging features of Cockayne syndrome.
DCLRE1B
DNA cross-link repair 1B protein is a protein that in humans is encoded by the DCLRE1B gene.
DNA interstrand cross-links prevent strand separation, thereby physically blocking transcription, replication, and segregation of DNA. DCLRE1B is one of several evolutionarily conserved genes involved in repair of interstrand cross-links (Dronkert et al., 2000).

# Function
The DCLRE1B/SNM1B/Apollo protein is a repair exonuclease that digests double-stranded and single-stranded DNA with a 5 to 3 directionality.
Using an SNM1B/Apollo knockout mouse model, evidence was obtained that SNM1B/Apollo protein is required to protect telomeres against illegitimate non-homologous end joining that can result in genomic instabilityy and consequently in multi-organ developmental failure.
In a human patient with Hoyeraal-Hreidarsson syndrome, a dominant negative mutation in the SNM1B/Apollo gene was discovered.  This mutation hampered the proper replication of telomeres, leading to major telomeric dysfunction and cellular senescence.  SNM1B/Apollo protein appears to be a crucial factor in telomere maintenance, independent of its function in repairing DNA inter-strand crosslinks.
DEFB126
Beta-defensin 126 is a protein that in humans is encoded by the DEFB126 gene.

# Function
Defensins are cysteine-rich cationic polypeptides that are important in the immunologic response to invading microorganisms. The protein encoded by this gene is secreted and is a member of the beta defensin protein family. Beta defensin genes are found in several clusters throughout the genome, with this gene mapping to a cluster at 20p13. The encoded protein is highly similar to an epididymal-specific secretory protein (ESP13.2) from cynomolgus monkey.
It has been suggested that a common variation in the DEFB126 gene generates abnormal mRNA and can somewhat impair fertility.