Persius/hicric huggingface dataset:
Diarylethene
In chemistry, diarylethene is the general name of a class of compounds that have aromatic groups bonded to each end of a carbon-carbon double bond.
Under the influence of light, these compounds can generally perform two kinds of reversible isomerizations:
- E to Z isomerizations, most common for stilbenes (and azobenzenes).
- 6 electrocyclizations of the Z form, leading to an additional bond between the two aryl functionalities and a disruption of the aromatic character of these groups.
Both processes are often applied in molecular switches.
After the 6 electrocyclization of the Z form, most unsubstituted diarylethenes are prone to oxidation, leading to a re-aromatization of the -system. The most common example is E-stilbene, which upon irradiation undergoes an E to Z isomerization, which can be followed by a 6 electrocyclization. Reaction of the product of this reaction with molecular oxygen affords phenanthrene. Although both the E-Z isomerization and the 6 electrocyclization are reversible processes, this oxidation renders the entire sequence irreversible.

# Dithienylethenes
One solution to the problem of oxidation is to replace the hydrogens ortho to the carbon-carbon double bond by groups that can not be removed during the oxidation. The most common example are the dithienylethenes, i.e. alkenes with a thiophene ring on either side. The 2-position of the thiophenes is commonly substituted with a methyl group, preventing oxidation of the ring closed form.
Following the Woodward-Hoffmann rules, the photochemical 6 cyclization takes place in a conrotatory fashion, leading to products with an anti configuration of the methyl substitutents. Because the thermal ring-opening reaction is symmetry forbidden, this type of diarylethenes is exceptionally thermally stable. As both methyl groups are attached to a stereogenic center, two enantiomers (R,R and S,S) are formed, normally as a racemic mixture.

# Applications
Typically, the open-ring isomers are colorless compounds, whereas the closed-ring isomers have colors dependent on their chemical structure, due to the extended conjugation along the molecular backbone. Therefore many diarylethenes have photochromic behavior both in solution and in solid state. Moreover, these two isomers differ from one another not only in their absorption spectra but also in various physical and chemical properties, such as their refractive indices, dielectric constants, and oxidation-reduction potentials. These properties can be readily controlled by reversible isomerization between the open- and closed-ring states using photoirradiation. The closed form has a conjugated path from one end of the molecule to the other, whereas the open form has not. This allows for the electronic communication between functional groups attached to the far ends of the diarylethene to be switched on and off using UV and visible light.
Dicoronylene
Dicoronylene is the trivial name for a very large polycyclic aromatic hydrocarbon. Its formal name is benzophenanthrochrysenocoronene (IUPAC name) or benzodicoronene (name sometimes used in Chemical Abstracts). It has 15 rings and is a brick-red solid. Its formula is (C48H20). Dicoronylene sublimes under high vacuum, 0.001 torr, abetween 250 C and 300 C.
Due to its large size and limited availability, the organic chemistry of dicoronylene is little known. Dicoronylene does undergo Diels-Alder reaction with maleic anhydride on one or both of the central bay regions on either side of the bridging ring. The double-bond part of maleic anhydroide forms two carbon-carbon bonds on the ends of the bay region, making a new six-member ring. Heating removes the anhydride as carbon dioxide gas and gives the corresponding 16-ring and 17-ring PAHs.
Dicoronylene was first observed in the solid residue produced in coal gasification. This residue contained large amounts of coronene and ovalene. After these were extracted and identified, a reddish residue remained, which was sparingly soluble in organic solvents. Elemental analysis indicated that it was most likely the condensed dimer of coronene.
Dicoronylene was later discovered to occur as a by-product of the catalytic hydrocracking used in petroleum processing. It is formed when two coronene molecules fuse. It is estimated that catalytical hydrocracking produces several hundred metric tons of dicoronylene worldwide per year, making it the most prevalent large PAH. In this process the analogous 18-ring PAH formed from coronene and ovalene (C56H22) is also formed in 1% to 20% proportions. It is purple in color.
The formation of dicoronylene in hydrocracking reactors is a serious problem because its low solubility make it precipitate in any cooler part of the reactor flow path. This causes plugging of flow lines that require periodic shutdown and removal of the reddish deposits. Dicoronylene is also a constituent of coke formed on hydrocracking catalysts, which reduces their activity.
Thermal pyrolysis of coronene shows masses of dicoronylene and the condensed trimer, tetramer, and pentamer in the mass spectrum of the black product. These larger coronene condensates are black in color.
Dicoronylene is moderately soluble in 1,2,4-trichlorobenzene and these solutions have a greenish yellow fluorescence. Unlike coronene, dicoronylene has symmetrical fluorescence excitation and emission spectra. It is virtually insoluble in most solvents.
Dicoronylene has been studied as a model for interstellar PAHs. Its large size and planarity have also shown promise as a chromatographic separation material.
Diethylamine
Diethylamine is a secondary amine with the molecular structure CH3CH2NHCH2CH3.  It is a flammable, strongly alkaline liquid.    It is miscible with water and ethanol.
Diethylamine is manufactured from ethanol and ammonia and is obtained together with ethylamine and triethylamine.  It is used as a corrosion inhibitor and in the production of rubber, resins, dyes and pharmaceuticals.
Diethylamine is a corrosive chemical and contact with skin may cause irritation or burns.
Dilaceration

# Overview
Dilaceration is a developmental disturbance in shape of teeth. It refers to an angulation, or a sharp bend or curve, in the root or crown of a formed tooth.

# Description
The condition is thought to be due to trauma during the period in which tooth is forming. The result is that the position of the calcified portion of the tooth is changed and the remainder of the tooth is formed at an angle.
The curve or bend may occur anywhere along the length of the tooth, sometimes at the cervical portion, at other times midway along the root or even just at the apex of the root, depending upon the amount of root formed when the injury occurred.
Such an injury to a permanent tooth, resulting in dilaceration, often follows traumatic injury to the deciduous predecessor in which that tooth is driven apically into the jaw.
Disaccharide
A disaccharide is a sugar (a carbohydrate) composed of two monosaccharides.
'Disaccharide' is one of the four chemical groupings of carbohydrates  (monosaccharide, disaccharide, oligosaccharide, and polysaccharide).

# Formation
It is formed when two sugars are joined together and a molecule of water is removed. For example; milk sugar (lactose) is made from glucose and galactose whereas cane sugar (sucrose) is made from glucose and fructose.
The two monosaccharides are bonded via a dehydration reaction (also called a condensation reaction or dehydration synthesis) that leads to the loss of a molecule of water and formation of a glycosidic bond.

# Properties
The glycosidic bond can be formed between any hydroxyl group on the component monosaccharide.  So, even if both component sugars are the same (e.g., glucose), different bond combinations (regiochemistry) and stereochemistry (alpha- or beta-) result in disaccharides  that are diastereoisomers with different chemical and physical properties.
Depending on the monosaccharide constituents, disaccharides are sometimes crystalline, sometimes water-soluble, and sometimes sweet-tasting and sticky-feeling.

# Common disaccharides
Maltose and cellobiose are hydrolysis products of the polysaccharides, starch and cellulose, respectively.
Less common disaccharides include: Gentiobiose, that consists of two glucose monomers with an (16) linkage; Isomaltose, that consists of two glucose monomers with an (16) linkage; Kojibiose, that consists of two glucose monomers with an (12) linkage ; Laminaribiose, that consists of two glucose monomers with a (13) linkage; Mannobiose, that consists of two mannose monomers with either an (12), (13), (14), or an (16) linkage; Melibiose, that consists of a glucose monomer and a galactose monomer with an (16) linkage; Nigerose, that consists of two glucose monomers with an (13) linkage; Rutinose, that consists of a rhamnose monomer and a glucose monomer with an (16) linkage; and Xylobiose, that consists of two xylopyranose monomers with a (14) linkage.
Dog spinning
Dog spinning (Template:Lang-bg, trichane na kuche(ta)) is a ritual formerly practiced in a village in southeastern Bulgaria.
In dog spinning, a dog is suspended above water on a rope. This rope is then 'wound' by being twisted repeatedly in a given direction (clockwise or anticlockwise), before being released so that the suspended dog rotates rapidly around in the opposite direction (respectively, anticlockwise or clockwise). The ancient ritual of pagan origin was done in order to prevent rabies.
The first known reference to this practice in English is in a press release issued by the UK Green Party, issued on July 29 2005.
It includes a statement from Green Party MEP Dr Caroline Lucas, vice-president of the RSPCA and the European Parliament's cross-party Animal Welfare Intergroup. Dr Lucas criticised it as being cruel to dogs, saying "Dog-spinning is a barbaric practice and must not be allowed to continue into the 21st century."
Swedish newspaper Aftonbladet reported the practice in March 2005.  
It used to place in March every year, only in the village of Brodilovo.  The practice of the ritual was banned by the mayor of Tsarevo in 2006 after complaints by Bulgarian animal welfare organizations.
Dorsal aorta
Each primitive aorta receives anteriorly a veinthe vitelline veinfrom the yolk-sac, and is prolonged backward on the lateral aspect of the notochord under the name of the dorsal aorta.
The dorsal aort give branches to the yolk-sac, and are continued backward through the body-stalk as the umbilical arteries to the villi of the chorion.
The two dorsal aortae combine to become the descending aorta in later development.
Dose Profile

# Overview
In External Beam Radiotherapy, transverse and longitudinal dose measurements are taken by a radiation detector in order to characterise the radiation beams from medical linear accelerators. Typically, an ionisation chamber and water phantom are used to create these radiation dose profiles. Water is used due to its tissue equivalence.
Central Axis Dose profile for 15MV photon beam incident on water phantom. Here the linear accelerator collimation projects a 1x1 cm2 field at isocentre i.e. 100 cm SSD
Tranverse dose measurements are performed in the x (crossplane) or y (inplane) directions perpendicular to the radiation beam, and at a given depth (z) in the phantom. These are known dose profiles.
Dose measurements taken along the z direction create radiation dose distribution known as a depth-dose curve.
Dose dumping
Dose dumping is a phenomenon of drug metabolism in which environmental factors can cause the premature and exaggerated release of a drug. This can greatly increase the concentration of a drug in the body and thereby produce adverse effects or even drug-induced toxicity.
Dose dumping is most commonly seen in drugs taken by mouth and digested in the gastrointestinal tract. Around the same time patients take their medication, they can also ingest other substances like fatty meals or alcohol that increase drug delivery. The substances may act on the drug's capsule to speed up drug release, or they may stimulate the body's absorptive surfaces to increase the rate of drug uptake.
In general, drug companies try to avoid drugs with significant dose dumping effects. Such drugs are prone to problems and are often pulled from the market. Such was the case with the pain medication Palladone due to its dose-dumping effects when taken with alcohol.
Doublecortin
Neuronal migration protein doublecortin, also known as doublin or lissencephalin-X is a protein that in humans is encoded by the DCX gene.

# Function
Doublecortin (DCX) is a microtubule-associated protein expressed by neuronal precursor cells and immature neurons in embryonic and adult cortical structures. Neuronal precursor cells begin to express DCX while actively dividing, and their neuronal daughter cells continue to express DCX for 23 weeks as the cells mature into neurons. Downregulation of DCX begins after 2 weeks, and occurs at the same time that these cells begin to express NeuN, a marker for mature neurons.
Due to the nearly exclusive expression of DCX in developing neurons, this protein has been used increasingly as a marker for neurogenesis. Indeed, levels of DCX expression increase in response to exercise, and that increase occurs in parallel with increased BrdU labelling (which is currently a "gold standard" in measuring neurogenesis).
Doublecortin was found to bind to the microtubule cytoskeleton. In vivo and in vitro assays show that Doublecortin stabilises microtubules and causes bundling. Doublecortin is a basic protein with an iso-electric point of 10, typical of microtubule-binding proteins.

# Knock out mouse
In mice where the Doublecortin gene has been knocked out, cortical layers are still correctly formed. However, the hippocampi of these mice show disorganisation in the CA3 region. The normally single layer of pyramidal cells in mutants is seen as a double layer. These mice also have different behavior than their wild type littermates and are epileptic.

# Structure
The detailed sequence analysis of Doublecortin and Doublecortin-like proteins allowed the identification of a tandem repeat of evolutionarily conserved Doublecortin (DC) domains. These domains are found in the N terminus of proteins and consists of tandemly repeated copies of an around 80 amino acids region. It has been suggested that the first DC domain of Doublecortin binds tubulin and enhances microtubule polymerisation.
Doublecortin has been shown to influence the structure of microtubules. Microtubule nucleated in vitro in the presence of Doublecortin have almost exclusively 13 protofilaments, whereas microtubule nucleated without Doublecortin are present in a range of different sizes.

# Interactions
Doublecortin has been shown to interact with PAFAH1B1.

# Clinical significance
Doublecortin is mutated in X-linked lissencephaly and the double cortex syndrome, and the clinical manifestations are sex-linked. In males, X-linked lissencephaly produces a smooth brain due to lack of migration of immature neurons, which normally promote folding of the brain surface.  Double cortex syndrome is characterized by abnormal migration of neural tissue during development which results in two bands of misplaced neurons within the subcortical white, generating two cortices, giving the name to the syndrome; this finding generally occurs in females. The mutation was discovered by Joseph Gleeson and Christopher A. Walsh in Boston.
Dowell Myers
Dowell Myers is a professor of urban planning and demography in the School of Policy, Planning, and Development, at the University of Southern California (USC). He directs the schools Population Dynamics Research Group, whose recent projects have been funded by the National Institute of Health, the Haynes Foundation, Fannie Mae Foundation, and the Ford Foundation.
He leads the ongoing California Demographic Futures research project at USC. Recent applications have focused on the upward mobility of immigrants to the US and Southern California, trajectories into homeownership in the United States, changing transportation behavior, education and labor force trends, and projections for the future of the California population.
He is a well-known specialist in demographic trends and their relation to all areas of policy and planning.  In 2000 he was a member of the Census Advisory Committee of Professional Associations (Population Association of America) for the United States Census Bureau and is the author of the most widely referenced text on census analysis, Analysis with Local Census Data: Portraits of Change (Academic Press, 1992).
In March 2007, the Russell Sage Foundation published his newest book, Immigrants and Boomers: Forging a New Social Contract for the Future of America. In fall 2006, Dowell Myers was recipient of the Haynes Award for Research Impact that was issued on the occasion of the Haynes Foundations 80th anniversary.
His undergraduate degree in anthropology from Columbia University was followed by a Master of Planning degree from the University of California, Berkeley. His Ph.D. is in urban planning from MIT and he also studied demography and sociology at Harvard University.
Dowell Myers has recently testified before the House Committee on the Judiciary about the reform of U.S. immigration policy. 

# Published works

## Books
- The Future of America. New York: Russell Sage Foundation.  February 2007.
- Analysis with Local Census Data: Portraits of Change, New York: Academic Press, 1992; 15 chapters and 3 appendices.

# Notes
-  California Demographic Futures research project
-  Staff (2002) "Homeownership rates get boost from minorities, baby boomers" Multi-Housing News 37(3): p.8
-   Appendix D, Minutes of the Census Advistory Committee, p. 59
-   Myers's bio
-  Written testimony of Dowell Myers to the House Committee on the Judiciary
Drospirenone
Drospirenone is a synthetic progestin that is an  analog to spironolactone. Its molecular weight is  366.5 and its molecular formula is C24H30O3.

# Properties and uses
The compound is part of certain birth control formulations. Drospirenone differs from other synthetic progestins in that its pharmacological profile in preclinical studies shows it to be closer to the natural progesterone. As such it has anti-mineralocorticoid properties, counteracts the estrogen-stimulated activity of the renin-angiotensin-aldosterone system, and is not androgenic. With its activities similar to spironolactone it may lead to less water retention and breast tenderness and improved skin appearance (less acne).
Drospirenone is taken orally with about 76% bioavailability. It is not bound by sex hormone binding globulin or corticosteroid binding globulin, but by other serum proteins. Metabolites have not been shown to be biologically active, show up in urine and feces, and are essentially completely excreted within 10 days.
The compound is part of certain newer oral contraceptive formulations:
- Yasmin contains 3 mg drospirenone and 30 mcg ethinylestradiol per tablet. It is indicated for the prevention of pregnancy in women who elect an oral contraceptive.
- Yaz contains 3 mg drospirenone and 20 mcg ethinylestradiol per tablet and is given for 24/4 days with the same indications.
It has also been formulated in medication to manage menopausal symptoms using 0.5 mg drsp and 1 mg estradiol per day by oral application. This medication was introduced in the USA in 2007 as Angeliq.
Drospirenone, which can potentially cause hyperkalemia in high-risk patients, is comparable to a 25mg dose of spironolactone.
The medication is contraindicated in patients with hepatic dysfunction, renal insufficiency, adrenal insufficiency, or in whom the use of oral contraceptives is contraindicated, such as smokers and patients with a history of DVT, stroke, or other blood clots. Because of the anti-mineralocorticoid effects care needs to be exercised when other drugs that may increase potassium levels are taken. Such medications include ACE inhibitors, angiotensin-II receptor agonists, potassium-sparing diuretics, potassium supplementation, heparin, aldosterone antagonists, and NSAIDs.
Drug project

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Drug holiday
A drug holiday (sometimes also called a drug vacation, medication vacation or structured treatment interruption) is when a medicated patient stops taking a drug for a period of time, from a few days to several months.
Planned drug holidays are used in several fields of medicine. They are perhaps best known in HIV therapy, after a study showed that stopping medication may stimulate the immune system to attack the virus. 

# As a treatment for HIV
HIV selectively targets activated helper T-cells. Thus, over time, this means that HIV will tend to selectively destroy those helper T-cells most capable of fighting the HIV infection off, effectively desensitizing the immune system to the infection. The purpose of a structured treatment interruption in to create a short interval in which the virus becomes common enough to stimulate reproduction of T-cells capable of fighting the virus.
A 2006 HIV literature review noted that "two studies suggested that so-called drug holidays were of no benefit and might actually harm patients, while a third study suggested that the idea might still have value and should be revisited."

# Other uses
Another reason for drug holidays is to permit a drug to regain effectiveness after a period of continuous use, and to reduce the tolerance effect that may require increased dosages.
In addition to drug holidays that are intended for therapeutic effect, they are sometimes used to reduce drug side effects so that patients may enjoy a more normal life for a period of time such as a weekend or holiday, or engage in a particular activity. For example, it is common for patients using SSRI anti-depressant therapies to take a drug holiday to reduce or avoid side effects associated with sexual dysfunction.
Dry needling
Dry needling is a term for acupuncture when the acupuncture is performed by practitioners and therapists who have limited or little formal training in acupuncture. The term "dry needling" is purported to describe the technique of using acupuncture needles on trigger points to release tight muscles. This is part of traditional acupuncture therapy, and always has been.
Practitioners and therapists who attempt to draw a distinction between acupuncture and "dry needling" are demonstrating their lack of knowledge of the full range of acupuncture techniques, which has always included the use of "ashi points", or trigger points in the release of tight or knotted muscles.
The confusion perhaps arises when the distinction is made between "injection therapy", where substances are injected into acupuncture points, and "dry needling". Dry needling means using acupuncture needles and not a syringe. So, the distinction is between "injection therapy", which is not strictly speaking "acupuncture", and acupuncture.