Persius/hicric huggingface dataset:
Actinic elastosis
Synonyms and keywords: Solar elastosis.

# Overview
Actinic, or solar, elastosis is an accumulation of abnormal elastin (elastic tissue) in the dermis of the skin, and in the conjunctiva of the eye, which occurs as a result of the cumulative effects of prolonged and excessive sun exposure, a process known as photoaging.

# Clinical features
Actinic elastosis usually appears as thickened, dry, wrinkled skin.  Several clinical variants have been recorded.  One of the most readily identifiable is the thickened, deeply fissured skin seen on the back of the chronically sun-exposed neck, known as cutis rhomboidalis nuchae. These features are a part of the constellation of changes that are seen in photoaged skin.

# Causes / Aetiology
The origin of the elastotic material in the dermis remains a subject of debate.  Theories on the formation of the elastotic material include actinic stimulation of fibroblasts, promoting synthesis of this material; or that the material is a degradation product of collagen, elastin or both.

# Histopathology
In the earlier stages of actinic elastosis, elastic fiber proliferation can be seen in the dermis. As the condition becomes more established, the collagen fibers of the papillary dermis and reticular dermis become increasingly replaced by thickened and curled fibers that form tangled masses and appear basophilic under routine haematoxylin and eosin staining.  These fibers stain black with the Verhoeff stain.

# Physical examination

## Gallery
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# Treatment
There are numerous treatment options for photoaged skin.  These include dermabrasion, topical application of retinoic acid, carbon dioxide laser resurfacing, hyaluronic acid injection into the dermis, imiquimod, tacrolimus ointment and topical oestrogen therapy.  These treatments have variable efficacy.
The most effective prevention strategy for photoaging remains minimization of sun-exposure through use of sunscreen and other sun exposure avoidance measures.
Activated alumina
Activated alumina is manufactured from aluminium hydroxide by dehydroxylating it in a way that produces a highly porous material; this material can have a surface area significantly over 200 square metres/g.  The compound is used as a desiccant (to keep things dry by absorbing water from the air) and as a filter of fluoride, arsenic and selenium in drinking water. It is made of aluminium oxide (alumina; Al2O3), the same chemical substance as sapphire and rubies (but without the impurities that give those gems their color). It has a very high surface-area-to-weight ratio. That means it has a lot of very small pores, almost like tunnels, that run throughout it.

# Catalyst applications
Activated alumina is used for a wide range of adsorbent and catalyst applications including the adsorption of catalysts in polyethylene production, in hydrogen peroxide production, as a selective adsorbent for many chemicals including arsenic, fluoride, in sulfur removal from gas streams (Claus Catalyst process).

# Desiccant
Use as a desiccant, it works by a process called adsorption. The water in the air actually sticks to the alumina itself in between the tiny passages, as the air passes through them. The water molecules become trapped so that the air is dried out as it passes through the filter. This process is reversible, and if the alumina desiccant is heated to about 200C it will release all of the water stored in it. This process is called regenerating the desiccant. Air always has some water in it; one way to measure the amount of water in the air is the air's dew point.

# Fluoride absorbent
Activated alumina is also widely used to remove fluoride from drinking water. In the US, there are widespread programs to fluoridate drinking water.  However, in certain regions, such as the Jaipur region of India, there is enough fluorine in the water to cause fluorosis. Activated alumina filters can easily reduce fluoride levels from .5 ppm to less than .1 ppm.  The amount of fluoride leached from the water being filtered depends on how long the water is actually touching the alumina filter media. Basically, the more alumina in the filter, the less fluoride will be in the final, filtered water. Lower temperature water, and lower pH water (acidic water) are filtered more effectively too.
Activated alumina, when used as a fluoride filter, can be regenerated by a solution of lye (sodium hydroxide; NaOH), sulfuric acid (H2SO4), or alum (KAl(SO4)2).
Active ingredient
An active ingredient, also active pharmaceutical ingredient (or API), is the substance in a drug that is pharmaceutically active.  Some medications may contain more than one active ingredient.  The traditional word for the API is pharmacon (from Greek: (), adapted from pharmacos) which originally denoted a magical substance or drug.
A dosage form of a drug is traditionally composed of two things: The API, which is the drug itself; and an excipient, which is the substance of the tablet, or the liquid the API is suspended in, or other material that is pharmaceutically inert.  Drugs are chosen primarily for their active ingredients.
In phytopharmaceutical or herbal medicine the active ingredient be a result of the interplay of a variety of constituents both acting on a pathogen and upon a variety of body systems involved in immunity.  The API may be either unknown or may require cofactors in order to achieve therapeutic goals.  One way manufacturers have attempted to indicate strength is to engage in standardization to a marker compound.  However standardization has not been standardized yet: different companies use different markers, or different levels of the same markers, or different methods of testing for marker compounds.   For instance St. Johnswort is often standardized to the hypericin which is now known not to be the "active ingredient" for antidepressant use.  Other companies standardize to hyperforin or both, although there may be some 24 known possible active constituents. Many herbalists believe that the active ingredient in a plant is the plant itself.
Herbalist and manufacturer David Winston points out that whenever different compounds are chosen as "active ingredients" for different herbs, there is a chance that suppliers will get a substandard batch (low on the chemical markers) and mix it with a batch higher in the desired marker to compensate for the difference.  This could result in a product that does not have the full spectrum of properties that would come from a properly selected and harvested herbal source.
Adderall overdose
Individual patient response to amphetamines varies widely. Toxic symptoms may occur idiosyncratically at low doses.

# Overdosage topics
Manifestations
Treatment

## Manifestations
Manifestations of acute overdosage with amphetamines include restlessness, tremor, hyperreflexia, rapid respiration, confusion, assaultiveness, hallucinations, panic states, hyperpyrexia and rhabdomyolysis. Fatigue and depression usually follow the central stimulation. Cardiovascular effects include arrhythmias, hypertension or hypotension and circulatory collapse. Gastrointestinal symptoms include nausea, vomiting, diarrhea, and abdominal cramps. Fatal poisoning is usually preceded by convulsions and coma. Return to top

## Treatment
Consult with a Certified Poison Control Center for up to date guidance and advice. Management of acute amphetamine intoxication is largely symptomatic and includes gastric lavage, administration of activated charcoal, administration of a cathartic and sedation. Experience with hemodialysis or peritoneal dialysis is inadequate to permit recommendation in this regard. Acidification of the urine increases amphetamine excretion, but is believed to increase risk of acute renal failure if myoglobinuria is present. If acute, severe hypertension complicates amphetamine overdosage, administration of intravenous phentolamine has been suggested. However, a gradual drop in blood pressure will usually result when sufficient sedation has been achieved. Chlorpromazine antagonizes the central stimulant effects of amphetamines and can be used to treat amphetamine intoxication. Return to top
Adapted from the FDA Package Insert.
Addition reaction
An addition reaction, in chemistry, is in its simplest terms an organic reaction where two or more molecules combine to form a larger one.
There are two main types of polar addition reactions:
- Electrophilic addition
- Nucleophilic addition
Other non-polar addition reactions exists as well:
- Free radical addition
Addition reactions are limited to chemical compounds that have multiply-bonded atoms:
- Molecules with carbon-carbon double bonds or triple bonds
- Molecules with carbon - hetero double bonds like C=O or C=N
An addition reaction is the opposite of an elimination reaction. For instance the hydration reaction of an alkene and the dehydration of an alcohol are addition-elimination pairs.

# Addition-elimination reaction
In the related Addition-elimination reaction an addition reaction is followed by an elimination reaction. In the majority of reactions it involves addition of nucleophiles to carbonyl compounds in what is called nucleophilic acyl substitution .
Other addition-elimination reactions are:
- reaction of an aliphatic amine to an imine and an aromatic amine to a Schiff base in alkylimino-de-oxo-bisubstitution
- Hydrolysis of nitriles to carboxylic acids
Adenylate cyclase

# Overview
Adenylate cyclase (EC 4.6.1.1, also known as adenylyl cyclase or AC) is a lyase enzyme.

# Types
There are ten known adenylate cyclases in mammals:
- ADCY1
- ADCY2
- ADCY3
- ADCY4
- ADCY5
- ADCY6
- ADCY7
- ADCY8
- ADCY9
- ADCY10

# Reaction
Adenylate cyclase catalyzes the conversion of ATP to 3',5'-cyclic AMP (cAMP) and pyrophosphate.
cAMP is an important molecule in eukaryotic signal transduction, a so-called second messenger. Adenylate cyclase can be activated or inhibited by G proteins, which are coupled to membrane receptors and thus can respond to hormonal or other stimuli. Following activation of adenylate cyclase, the resulting cAMP acts as a second messenger by interacting with and regulating other proteins such as protein kinase A and cyclic nucleotide-gated ion channels.
Photoactivatable adenylate cyclase (PAC) was discovered in E. gracilis and can be expressed in other organisms through genetic manipulation. Shining blue light on a cell containing PAC activates it and abruptly increases the rate of conversion of ATP to cAMP. This is a useful technique for researchers in neuroscience because it allows them to quickly increase the intracellular cAMP levels in particular neurons, and to study the effect of that increase in neural activity on the behavior of the organism. For example, PAC expression in certain neurons has been shown to alter the grooming behavior in fruit flies exposed to blue light . Researchers also use channelrhodopsin-2 in a similar fashion.

# Structure
Adenylyl cyclase is a transmembrane protein. It passes through the plasma membrane twelve times.
The important parts for its function are located in the cytoplasm and can be subdivided into the N-terminus, C1a, C1b, C2a and C2b.
The C1 region exists between transmembrane helices six and seven and the C2 region follows transmembrane helix 12.
The C1a and C2a domains form a catalytic dimer where ATP binds and is converted to cAMP.

# Regulation
Adenylate cyclase is stimulated by G proteins, and by forskolin, as well as other class-specific substrates:
- Isoforms I, III and VIII are also stimulated by Ca2+/calmodulin.
- Isoforms V and VI are inhibited by Ca2+ in a calmodulin-independent manner.
In neurons, adenylate cyclases are located next to calcium ion channels for faster reaction to Ca2+ influx; they are suspected of playing an important role in learning processes. This is supported by the fact that adenylate cyclases are coincidence detectors, meaning that they are only activated by several different signals occurring together.

# Additional images
- Beta adrenergic receptor kinase pathway
Adherens junction

# Overview
Adherens junctions (or zonula adherens) are protein complexes that occur at cell-cell junctions in epithelial tissues, usually more basal than tight junctions.
They can appear as bands encircling the cell (zonula adherens) or as spots of attachment to the extracellular matrix (adhesion plaques).

# Proteins
They are composed of three major proteins:
- cadherins. The cadherins are a family of transmembrane proteins that form homodimers in a calcium-dependent manner with other cadherin molecules on adjacent cells.
- -catenin and -catenin. The catenins both form a complex with the intracellular portion of the cadherin molecule.

# Models
Adherens junctions were, for many years, thought to share the characteristic of anchoring cells through their cytoplasmic actin filaments.
The accepted model has been that adherens junctions serve as a bridge connecting the actin cytoskeleton of neighboring cells through direct interaction.  However, scientists have not been able to isolate the quaternary complex of cadherin-catenin-catenin-actin in vitro.  Recent data (2005) from 2 labs at Stanford University published in the journal Cell demonstrates that membrane associated actin is several fold less stable compared to components of the adherens junctional complex.
Additionally, the authors found that monomeric -catenin preferentially binds to the cadherin junction complex through -catenin.  Dimeric -catenin preferentially binds to actin and suppresses Arp2/3 complex-mediated actin branching, thus acting as a molecular switch to regulate actin polymerization.
Adherens junctions may serve as a regulatory module to maintain the actin contractile ring with which it is associated in microscopic studies.
Ahmad ibn Farrokh
Ahmad ibn Farrukh, also written Ahmad-i Farrokh, was a 12th century Persian physician from Herat.
He was one of the teachers of Al-Jurjani.
He is author of a Persian medicine encyclopaedia titled Kifayah that is no longer extant though it had a high reputation among scholars long after al-Jurjani's day.
The National Library of Medicine has in its collection a formulary of compound remedies (Qarabadhin). 
This formulary in 11 short chapters (babs), and it appears to be the only preserved example of the writings of Ahmad ibn Farrukh.
Airway resistance

# Overview
Airway resistance is a concept used in respiratory physiology to describe mechanical factors which limit the access of inspired air to the pulmonary alveoli, and thus determine airflow. Resistance is greatest at the bronchi of intermediate size, in between the fourth and eighth bifurcation. Because airway resistance is dictated by the diameter of the airways and by the density of the inspired gas, the low density of heliox reduces airway resistance, and makes it easier to ventilage the lungs. Resistance can be calculated using Ohm's law or Poiseuille's law.

## Ohm's law
- R = resistance
- P = pressure
- V- = airflow (the asterisk should be read as a dot over the letter, which is used to denote rate in respiratory physiology.)

## Poiseuille's law
- R = resistance
- n = viscosity
- l = length
- r = radius
Because of the fourth power in the denominator, resistance increases rapidly as diameter decreases.

# Related Chapters
- Turbulent flow
- Laminar flow
- Reynolds number
- Upper Airway Resistance Syndrome (UARS)
Alchemical symbol
Alchemic symbols, originally devised as part of the protoscience of alchemy, were used to denote some elements and some compounds until the 18th century. Note that while notation like this was mostly standardized, style and symbol varied between alchemists, so this page lists the most common.

# Three Primes
According to Paracelsus, the Three Primes or Tria Prima are:
- Sulfur (omnipresent spirit of life)
- Mercury (fluid connection between the High and the Low)
- Salt (base matter)

# Four basic Elements
- Fire
- Water
- Earth
- Air

# Seven Planetary Metals
File:Astrological Glyphs.svg
Planetary metals were "dominated" or "ruled" by one of the seven planets known by the ancients. Although they occasionally have a symbol of their own (denoted by also:), they were usually symbolized by the planet's symbol.
- Gold dominated by Sol   ( File:Sun symbol.svg )
- Silver dominated by Luna  ( File:Crescent.svg )
- Copper dominated by Venus  (also: File:Copper symbol.svg )
- Iron dominated by Mars  ( File:Mars symbol.svg )
- Tin dominated by Jupiter  ( File:Jupiter symbol.svg )
- Mercury (Quicksilver) dominated by Mercury  (  )
- Lead dominated by Saturn  ( File:Saturn symbol.svg )
The planets Uranus, Neptune, and the Dwarf Planet Pluto were discovered after the time Alchemy had been largely replaced by Chemistry, and are not part of traditional Alchemical symbols. Some modern alchemists consider the symbols for these planets to represent the radioactive metals Uranium, Neptunium and Plutonium, respectively.

# Mundane Elements
- Antimony  File:Antimony-symbol.svg
- Arsenic Error creating thumbnail: File missing
- Bismuth File:Bismuth symbol.png
- Boron
- Magnesium 
- Phosphorus
- Platinum  
- Potassium
- Stone File:Stone symbol.svg
- Sulfur File:Sulfur symbol 1.svg File:Sulfur symbol 2.svg
- Zinc

# Alchemical Compounds
- Sal ammoniac *
- Aqua Fortis A.F.
- Aqua Regia A.R.
- Spirit of Wine S.V.
- Amalgama
- Cinnabar (Mercury sulfide) File:Cinnabar Symbol.svg
- Vitriol

# 12 Core Alchemical processes
The 12 Alchemical processes are considered to be the basis of modern Chemical processes. Each of these processes is "dominated" or "ruled" by one of the 12 Zodiac signs.
- Decomposition through Calcination (Aries File:Aries.svg)
- Decomposition through Digestion (Leo File:Leo.svg)
- Decomposition through Fermentation/Putrefaction (CapricornFile:Capricorn.svg)
- Modification through Congelation/Coagulation (Taurus File:Taurus.svg)
- Modification through Fixation (Gemini File:Gemini.svg)
- Modification through Ceration (Sagittarius File:Sagittarius.svg)
- Separation through Distillation (Virgo File:Virgo.svg)
- Separation through Sublimation (Libra File:Libra.svg)
- Separation through Filtration (Scorpio File:Scorpio.svg)
- Union through Solution (Cancer File:Cancer.svg)
- Union through Multiplication (Aquarius File:Aquarius.svg)
- Union through Projection (Pisces File:Pisces.svg)
Alexia (disorder)
Synonyms and Keywords: Word blindness; text blindness; visual aphasia.

# Overview
Alexia (from the Greek Template:Polytonic, privative, expressing negation, and Template:Polytonic = "word") is an acquired type of sensory aphasia where damage to the brain causes a patient to lose the ability to read.

# Differential Diagnosis of Causes of Alexia
Alexia typically occurs following damage to the left hemisphere of the brain or to the areas of the occipital and temporal lobes, which are responsible for processing auditory, phonological and visual aspects of language. The region at the junction of occipital and temporal lobes (sometimes called the occipito-temporal junction) coordinates information that is gathered from visual and auditory processing and assigns meaning to the stimulus.  Alexia can also occur following damage to the inferior frontal lobe, especially Broca's area. Damage to these different areas cortex result in somewhat different patterns of difficulty in affected individuals.

# Diagnosis

## Signs and Symptoms
Alexia may be accompanied by expressive and/or receptive aphasia (the inability to produce or comprehend spoken language). Alexia can also co-occur with agraphia, the specific loss of the ability to produce written language even when other manual motor abilities are intact. In other cases, damage is restricted to areas responsible for input processing. The result is known as alexia without agraphia. In this scenario, an individual's ability to produce written language is spared even though they are unable to understand written text.
Alexia without agraphia results from a left occipital splenium of the corpus callosum lesion.
Alkyne metathesis
Alkyne metathesis is an organic reaction involving the redistribution of alkyne chemical bonds. This reaction is closely related to olefin metathesis. Alkyne metathesis was first observed in 1974  by A. Mortreux as an alkyne scrambling phenomenon in which an asymmetric alkyne forms an equilibrium with its two symmetrical counterparts.

# Overview
The Mortreux system consists of the molybdenum catalyst molybdenum hexacarbonyl Mo(CO)6 and resorcinol cocatalyst. In 1975 T.J. Katz proposed a metal carbyne and a metallacyclobutadiene as an intermediate and in 1981 R.R. Schrock characterized several metallacyclobutadiene complexes that were capable of catalytic turnover.
The Schrock catalyst system Tris(t-butoxy)(2,2-dimethylpropylidyne)(VI)tungsten  is based on tungsten . This catalyst is not reactive towards alkenes in olefin metathesis. On the other hand Fischer carbenes have no value in alkyne metathesis.
The Schrock catalyst is commercially available and is prepared by amidation of tetrachloro tungsten with lithium dimethylamide to a di-tungsten complex followed by replacing the amide groups with tert-butoxy groups with tert-butanol.
This organometallic alkyne then undergoes a metathesis reaction with neoheptyne to the final product. In 2001 A. Furstner developed a new molybdenum catalyst replacing carbon monoxide with aniline ligands .

# Ring closing alkyne metathesis
Alkyne metathesis is extensively used in ring closing operations and RCAM stands for ring closing alkyne metathesis. The olfactory molecule civetone can be synthesised from a di-alkyne. After ring closure the new triple bond is stereoselectively reduced with hydrogen and the lindlar catalyst in order to obtain the Z-alkene (cyclic E-alkenes are available through the Birch reduction). An important driving force for this type of reaction is the expulsion of small gaseous molecules such as acetylene or 2-butyne.
The same two-step procedure was used in the synthesis of the naturally occurring cyclophane turriane.

# Nitrile-Alkyne Cross-Metathesis
By replacing a tungsten alkylidyne by a tungsten nitride and introducing a nitrile Nitrile-Alkyne Cross-Metathesis or NACM couples two nitrile groups together to a new alkyne. Nitrogen is collected by use of a sacrificial alkyne (elemental N2 is not formed)  :
Allen Brain Atlas

# Overview
The Allen Brain Atlas is a project within the Allen Institute for Brain Science which seeks to combine genomics with neuroanatomy by creating gene expression maps for the mouse brain. It was initiated in September 2003 with a $100 million donation from Paul G. Allen. 
The atlas went public in September 2006. Not all known genes have been mapped at this point but approximately 20,000 protein-coding mRNAs have been. Data were generated using automated high-throughput procedures for in situ hybridization and data acquisition, and are publicly accessible online. 
Work on the brain atlas was performed by the Allen Institute for Brain Science, which is located in Seattle, Washington, 551 N 34th Street, 98102 (the Fremont neighborhood).