Persius/hicric huggingface dataset:
Parahexyl
Parahexyl (Synhexyl, n-hexyl-3THC) is a synthetic analogue of THC, which was invented in 1949 during attempts to elucidate the structure of 9-THC, the active component of cannabis.
Parahexyl is similar in both structure and activity to THC, differing only in the position of one double bond, and the lengthening of the 3-pentyl chain by one CH2 group to n-hexyl.  Parahexyl produces classic cannabis agonist effects in animals. It has a somewhat higher oral bioavailability than THC itself but is otherwise very similar.  Presumably it acts as a CB1 agonist in the same way as THC but as there has been no research published using Parahexyl since the discovery of the CB1 receptor this has not been definitively confirmed.
Parahexyl was made illegal under UN convention in 1982 on the basis of its structural similarity and similar effects profile to THC, despite never having had any recorded instances of abuse by humans or illicit sale. Parahexyl was placed into the most restrictive Schedule 1 as a compound with no medical use, even though it has never been properly researched to see whether it might have medical use or not.
Parecoxib

# Overview
Parecoxib is a water soluble and injectable prodrug of valdecoxib. It is marketed as Dynastat in the European Union.  Parecoxib is a COX2 selective inhibitor in the same category as celecoxib (Celebrex) and rofecoxib (Vioxx).  As it is injectable, it can be used perioperatively when patients are unable to take oral medications.  It is approved through much of Europe for short term perioperative pain control much in the same way ketorolac (Toradol) is used in the United States.  However, unlike ketorolac, parecoxib has no effect on platelet function and therefore does not promote bleeding during or after surgery.  In addition, ketorolac has a much higher gastrointestinal toxicity profile compared to most other nonsteroidal antiinflammatory drugs (NSAIDs) including ibuprofen and naprosyn.  However, in the United States ketorolac is the only injectable NSAID, although it is banned in many European countries due to concerns about surgical bleeding and stomach ulcers after surgery.
In 2005, the U.S. Food and Drug Administration (FDA) issued a letter of non-approval for parecoxib in the United States.  No reasons were ever documented publicly for the non-approval, although one study noted increased occurrences of heart attacks following cardiac bypass surgery compared to placebo when high doses of parecoxib were used to control pain after surgery.  It is also important to remember that rare but severe allergic reactions (Stevens-Johnson Syndrome, Lyell Syndrome) have been described with valdecoxib, the molecule to which parecoxib is converted.  The drug is not approved for use after cardiac surgery in Europe. Ketorolac, still banned in much of Europe, and IV Ibuprofen are therefore the only options for IV NSAIDs in the United States, and it is not clear whether parecoxib will be resubmitted to the FDA in the future.
All anti-inflammatory medications in the U.S. carry the same warning regarding skin reactions, and none are approved for use during CABG surgery, so the reason for the FDA denying the approval of parecoxib remains unknown, but was likely related to political pressure from the US Congress to not approve another COX-2 selective inhibitor in the wake of the Vioxx affair.  No COX-2 selective inhibitor has been approved in the US since that time, regardless of the safety profile of parecoxib in Europe.  Efforts to find out the scientific rationale, or more likely the lack thereof, that the FDA used to justify the non-approval of parecoxib in the USA have proven futile due to secrecy issues.
Paul Berg
Paul Berg (born June 30, 1926 in Brooklyn, New York, U.S.) is an American biochemist and professor emeritus at Stanford University. He graduated from Abraham Lincoln High School in 1943, received his B.S. in biochemistry from Penn State University in 1948 and Ph.D. in biochemistry from Case Western Reserve University in 1952. In 1980 he shared half of the Nobel Prize for Chemistry with the team of Walter Gilbert and Frederick Sanger.  All three were recognized for their important contributions to basic research in nucleic acids. His studies as a postgraduate involved the use of radioisotope tracers in intermediary metabolism. This resulted in the understanding of how foodstuffs are converted to cellular materials, through the use of isotopic carbons or heavy nitrogen atoms. Paul Berg's doctorate paper is now known as the conversion of formic acid, formaldehyde and methanol to fully reduced states of methyl groups in methionine. He was also one of the first to demonstrate that folic Acid and B12 cofactors had roles in the processes mentioned.
Paul's new research has ventured from metabolic biochemistry, and as a professor in Stanford University he now researches Molecular Biology and Recombinant DNA. His main goal now, is to target exogenous genes to specific loci in the genome at high frequencies. Other studies, involving the HIV-1 virus, are being conducted by his research team. The HIV-1 virus induces an immunodeficiency disease that infects T-helper cells.
Prof. Berg is a member of the Board of Sponsors of The Bulletin of the Atomic Scientists . He was also an organizer of the Asilomar conference on recombinant DNA in 1975.  The previous year, Berg and other scientists had called for a voluntary moratorium on certain recombinant DNA research until they could evaluate the risks.  That influential conference did evaluate the potential hazards and set guidelines for biotechnology research.  It can be seen as an early application of the precautionary principle.
Berg was also awarded the National Medal of Science in 1983, by Ronald Reagan.
Pax genes
Paired box (Pax) genes are a family of tissue specific transcription factors containing a PAIRED domain and usually a partial or complete homeodomain. An octapeptide may also be present. Pax proteins are important in early animal development for the specification of specific tissues, as well as during epimorphic limb regeneration in animals capable of such.

# Groups
Within the mammalian family, there are four well defined groups of Pax genes.
- Pax group 1 (Pax 1 and 9),
- Pax group 2 (Pax 2, 5 and 8),
- Pax group 3 (Pax 3 and 7) and
- Pax group 4 (Pax 4 and 6).
Orthologous genes exist throughout the Metazoa, including extensive study of the ectopic expression in Drosophila using murine Pax6.

# Members
- PAX1 has been identified in mice with the development of vertebrate and embryo segmentation, and some evidence this is also true in humans. It transcribes a 440 amino acid protein from 4 exons and 1,323bps in humans.
- PAX2 has been identified with kidney and optic nerve development. It transcribes a 417 amino acid protein from 11 exons and 4,261 bps in humans. Mutation of PAX2 in humans has been associated with renal-coloboma syndrome as well as oligomeganephronia.
- PAX3 has been identified with ear, eye and facial development. It transcribes a 479 amino acid protein in humans. Mutations in it can cause Waardenburg syndrome.
- PAX4 has been identified with pancreatic islet beta cells. It transcribes a 350 amino acid protein from 9 exons and 2,010 bps in humans.
- PAX5 has been identified with neural and spermatogenesis development and b-cell differentiation. It transcribes a 391 amino acid protein from 10 exons and 3,644bps in humans.
- PAX6 is the most researched and appears throughout the literature as a "master control" gene for the development of eyes and sensory organs, certain neural and epidermal tissues as well as other homologous structures, usually derived from ectodermal tissues.
- PAX7 has been possibly associated with myogenesis. It transcribes a protein of 520 amino acids from 8 exons and 2,260bps in humans.  PAX7 is required for the developmental specification of satellite cells in skeletal muscle.
- PAX8 has been associated with thyroid specific expression. It transcribes a protein of 451 amino acids from 11 exons and 2,526bps in humans.
- PAX9 has found to be associated with a number of organ and other skeletal developments, particularly teeth. It transcribes a protein of 341 amino acids from 4 exons and 1,644bps in humans.
Paxilline
Paxilline is a potassium channel blocker. Paxilline is a toxic, tremorgenic indole alkaloid produced by Penicillium paxilli.
Disambiguation:
Paxilline, a mycotoxin of penicillium origin, should not be confused with 
Paxillin, a signal transducing adaptor protein involved in cell migration (MESH, NCBI).

# Sources and references
-  Paxilline product page from Fermentek
Perfusion
In physiology, perfusion is the process of nutritive delivery of arterial blood to a capillary bed in the biological tissue.  The word is derived from the French verb "perfuse" meaning to "pour over or through."
Tests of adequate perfusion are a part of patient triage performed by medical or emergency personnel in a mass casualty incident.

# Calculation
Perfusion ("F") can be measured with the following formula, where Pa is mean arterial pressure, Pv is mean venous pressure, and R is vascular resistance: 
F =  \frac{ P_A - P_V }{ R} 
The term "Pa - Pv" is sometimes presented as "P", for the change in pressure.
The terms "perfusion" and "perfusion pressure" are sometimes used interchangeably, but the equation should make clear that resistance can have an effect on the perfusion, but not on the perfusion pressure.

# Overperfusion and underperfusion
The terms "overperfusion" and "underperfusion" are measured relative to the average level of perfusion across all tissues in an individual body, and the terms should not be confused with hypoperfusion and "hyperperfusion", which measure the perfusion level to the tissue's current need.
Tissues like the skin are considered overperfused and receive more blood than would be expected to meet the metabolic needs of the tissue. In the case of the skin, extra blood flow is used for thermoregulation.  In addition to delivering oxygen, the blood helps dissipate heat by redirecting warm blood close to the surface where it can cool the body through the sweating and thermal radiation.

# Measurement using fMRI
Two main categories of functional magnetic resonance imaging (fMRI) techniques can be used to measure tissue perfusion in vivo.
- The first is based on the use of injected contrast agent that changes the magnetic susceptibility of blood and thereby the MR signal which is repeatedly measured during bolus passage.
- The other category is based on Arterial spin labeling (ASL), where arterial blood is magnetically tagged before it enters into the tissue of interest and the amount of labeling is measured and compared to a control recording obtained without spin labeling.
Periodate
The periodate ion is IO4 or IO65.  It comes from periodic acid.
A periodate is a compound that contains this group.  Note that the pronunciation is per-iodate, not period-ate.

# Examples
- sodium periodate, NaIO4
- potassium periodate, KIO4
See category for a bigger list.

# Discussion
Periodates include two forms.  The metaperiodate ion is IO4; the orthoperiodate ion is IO65.
Periodate compounds include metaperiodates and orthoperiodates.  Usually both are called periodates.
In neutral or weak acid conditions, IO4 is most common, in equilibrium with a smaller amount of H4IO6.  In basic conditions, H3IO62 is formed, plus some other ions.
Like its neighbor, tellurium, and unlike lighter halogens, iodine tends to be hexacoordinate, and the units HnIO6(5n)- are quite common; but in the case of iodine, tetracoordinate units, such as IO4, are also quite common.

# Uses
Periodates can cleave carbon-carbon bonds when both carbon atoms bear an oxygen atom, either in the form of a hydroxyl or a carbonyl group. This property is often utilized in molecular biochemistry for the purposes of modifying saccharide rings, as many five- and six-membered sugars often have vicinal diols.
Periphery
Generally, a periphery is a boundary or outer part of any space or body.  It is derived from the Greek word , meaning a circumference or outer surface.
- In biology, the periphery of the body is the part that is away from the central or core regions.
For example, the peripheral nervous system is distinct from the central nervous system.
See also peripheral membrane protein.
- For example, the peripheral nervous system is distinct from the central nervous system.
- See also peripheral membrane protein.
- Peripheral vision is that part of visual perception that occurs in the periphery, i.e., near the edges, of the field of view.
- A computer peripheral is added to a host computer in order to expand its abilities.
- For peripheral submanifolds in mathematics, see boundary parallel.
- Periphery countries includes nations that are not core countries -  capitalist or industrialized nations. See Immanuel Wallerstein, Third World.
- The 13 peripheries of Greece are subnational subdivisions of that country, equivalent to regions.
- In the fictional universe of BattleTech, the Periphery is the region of interstellar space.
- In Issac Asimov's Foundation Series, the Periphery is that part of the Empire that lies on the very edge of the Milky Way Galaxy.  The Foundation, located on the planet Terminus lies in the Periphery, in the ancient imperial provence of Anacreon.
- Periphery also refers to the boundary of a town or city, also known as outskirts or suburbs ; it also refers to what is not mainstream or central.
de:Peripherie
simple:Peripheral (disambiguation)
Phagocyte
A phagocyte is a cell that ingests and destroys foreign matter such as microorganisms or debris by a process known as phagocytosis.

# Types of Phagocytes
There are two main categories of phagocytes: 
- macrophages (and monocytes)
- microphages, such as polymorphonuclear leukocytes (primarily neutrophils)

# Functions of Phagocytes
Phagocytes are extremely useful as an initial immune system response to infection. If the skin is broken, neutrophils are the first type of phagocyte to migrate to sites of injury and fight bacteria by releasing cytotoxic granules and by phagocytosis. Phagocytosis is an active process in wound healing.
Phagocytes contain many lysosomes that enable them to digest foreign material. Phagocytes engulf pathogens, debris, dead or dying cells and extracellular matrix. After engulfment into a phagosome, a lysosome which is filled with digestive enzymes (proteases and oxygen radicals) will fuse with it to form the phagolysosome. The two compartments become one phagolysosome, in which the phagocytosed material is digested.
In the case of pathogen phagocytosis, professional antigen-presenting cells (i.e.: dendritic cells and macrophages) will present on their surfaces small peptides that resulted from the digestion, bound to MHC class II molecules. Helper T cells (CD4+) later recognize these antigens presented through MHC class II complemented with a second signal and they will further supplement the cell mediated immune response.
In addition to engulfing and digesting foreign particles, phagocytes can induce apoptosis of normal and tumor cells, produce cationic proteins, complement components and clotting factors, arachidonic acid metabolites, prostaglandins, leukotrienes, thromboxanes, cytokines, proteases and hydrolases, reactive oxygen and nitrogen intermediates.

# Pathogen Resistance to phagocytes
Many pathogens can delay or prevent the creation of the phagolysosome such as Mycobacterium tuberculosis, Salmonella typhi and Legionella.  Others, such as the parasites of the genus Leishmania, are capable of resisting or circumventing being digested in the phagolysosome.
One function of T-helper cells is to activate phagocytes to digest intracellular pathogens.

# Etymology
The word phagocyte etymologically means "cell that eats", originating from the Greek words phagein, meaning 'eat', and kytos, meaning 'hollow'.
Phosducin
Phosducin, also known as PDC, is a human protein and gene. It belongs to the phosducin family of proteins.
This gene encodes a phosphoprotein, which is located in the outer and inner segments of the rod cells in the retina. This protein may participate in the regulation of visual phototransduction or in the integration of photoreceptor metabolism. It modulates the phototransduction cascade by interacting with the beta and gamma subunits of the retinal G-protein transducin. By associating with these subunits only, the Transducin alpha subunit will remain active for longer. This will increase the amount of time of visual excitation.
This gene is a potential candidate gene for retinitis pigmentosa and Usher syndrome type II. Alternatively spliced transcript variants encoding different isoforms have been identified.
Photopsia

# Overview
Photopsia is the presence of perceived flashes of light. It is most commonly associated with posterior vitreous detachment, migraine with aura, migraine aura without headache, retinal break or detachment, occipital lobe infarction, and sensory deprivation (ophthalmopathic hallucinations). Vitreous shrinkage or liquefaction, which are the most common causes of photopsia, cause a pull in vitreoretinal attachments, irritating the retina and causing it to discharge electrical impulses. These impulses are interpreted by the brain as 'flashes'.
This condition has also been identified as a common initial symptom of Punctate inner choroiditis (PIC), a rare retinal autoimmune disease believed to be caused by the immune system mistakenly attacking and destroying the retina.  During pregnancy, new-onset photopsia is concerning for severe preeclampsia.

# Differential diagnosis of causes of photopsia
It is most commonly associated with posterior vitreous detachment, migraine with aura, migraine aura without headache and retinal break or retinal detachment.

## Drug Side Effect
- Crizotinib
- Verteporfin
Picenadol
Picenadol (LY-150720) is a 4-phenylpiperidine derivative that is an opioid analgesic drug.
Picenadol is an effective analgesic with similar efficacy to pethidine (meperidine). It has been investigated for some applications such as obstetrics and dentistry, but never commercialised.
It is unusual in that one enantiomer is a pure -opioid agonist, while the other is an antagonist. The (3R,4R) isomer is the agonist, while (3S,4S) is antagonist. This means that the racemic mix of the two enantiomers is a mixed agonist-antagonist, with relatively low abuse potential, and little of the -opioid activity that tends to cause problems with other opioid mixed agonist-antagonists such as pentazocine.
Pinazepam

# Overview
Pinazepam (marketed under the brand name Domar and Duna) is a drug that is a benzodiazepine. It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties.
Pinazepam and its metabolite N-desmethyldiazepam (nordiazepam, nordazepam) are transferred to the developing fetus in utero, but the plasma drug level in the mother is usually significantly higher than in the fetus.
Pinazepam differs from other benzodiazepines in that it has a propargyl group at the N-1 position of the benzodiazepine structure. It is less toxic than diazepam and in animal studies it appears to produce anxiolytic and anti-agitation properties with limited hypnotic and motor coordination impairing properties. Pinazepam is rapidly absorbed after oral administration. The main active metabolites of pinazepam are depropargylpinazepam (N-desmethyldiazepam, nordazepam) and oxazepam. In humans pinazepam acts as a pure anxiolytic agent in that it does not possess to any significant degree the other pharmacological characteristics of benzodiazepines. Its lack of intellectual, motor and hypnotic impairing effects makes it more appropriate than other benzodiazepines for day time use. The elimination half-life is longer in the elderly.
Pipe tool
A pipe tool is any of a variety of small gadgets designed to aid in packing, smoking, and emptying tobacco pipes.
A typical pipe tool consists of a reamer, a tamper, and a scraper:
- The reamer is a narrow rod or pin that can be used to loosen tobacco or empty a pipe.
- The scraper is a flat instrument shaped like a dull pen-knife blade or a flattened spoon, used to scrape ash and unburned tobacco off the sides of a pipe, and to reduce the cake of ash on the inside of the bowl.
- The tamper is a blunt instrument, either a simple dowel or shaped like the top of a nail, with a flat end for tamping down the tobacco when the bowl is being packed, and for crushing the ash together to aid relighting.
mk:
Pipradrol

# Overview
Pipradrol (Meretran) is a mild central nervous system stimulant that is no longer widely used in most countries due to concerns about its abuse potential, although this is less of a problem than with other stimulants that still are in current use such as methylphenidate. Pipradrol is still used in some European countries, and even rarely in the USA.
Pipradrol was developed in the 1950s and found use initially for treating obesity. It was subsequently used for the treatment of a variety of other conditions such as narcolepsy, ADHD, and most particularly for counteracting the symptoms of senile dementia, this being the only application for which it is still used medically. Pipradrol proved useful for these applications as its relatively mild stimulant effects gave it a good safety profile compared to stronger stimulants. It was also trialled as an adjutant treatment for depression and schizophrenia although it was never widely used for these purposes.
Pipradrol was made illegal in many countries in the late 1970s, at the same time as many other drugs which had a history of abuse. The relatively mild stimulant effects of pipradrol meant that it was scheduled under the less restrictive classes in most countries (i.e. Class C in United Kingdom and New Zealand) but was still considered of sufficient abuse potential to be made an illegal drug. It is now an obscure compound that is virtually unknown as an illicit drug of abuse, but is still used for some scientific research, often as a comparison drug for testing other stimulants against.
Dosage is between 0.5 and 4 milligrams per day, typically taken as a single dose in the morning as the long duration of effects of pipradrol (up to 12 hours) means insomnia can be a problem especially if it is used at higher doses or taken too late in the day.
Common side effects include insomnia, anorexia, tachycardia, anxiety. Rarer side effects include dry mouth, tremor, hypertension, euphoria, depression, and very rarely psychosis or convulsions.