Persius/hicric huggingface dataset:
Systemic circulation

# Overview
Systemic circulation is the portion of the cardiovascular system which carries oxygenated blood away from the heart, to the body, and returns deoxygenated blood back to the heart. The term is contrasted with pulmonary circulation.

# Course
In the systematic circulation, arteries bring oxygenated blood to the tissues. As blood circulates through the body, oxygen diffuses from the blood into cells surrounding the capillaries, and carbon dioxide diffuses into the blood from the capillary cells. Veins bring deoxygenated blood back to the heart.

## Arteries
Oxygenated blood enters the systemic circulation when leaving the left ventricle, through the aortic semi-lunar valve. The first part of the systemic circulation is the artery aorta, a massive and thick-walled artery. The aorta arches and gives off major arteries to the upper body before piercing the diaphragm in order to supply the lower parts of the body with its various branches.

## Capillaries
Blood passes from arteries to capillaries, which are the thinnest and most numerous of the blood vessels. These capillaries help to join tissue with arterioles for transportation of nutrition to the cells, which absorb oxygen and nutrients in the blood. Peripheral tissues do not fully deoxygenate the blood, so venous blood does have oxygen, but in a lower concentration than in arterial blood. In addition, carbon dioxide and wastes are added.

## Venules
The deoxygenated blood is then collected by venules, from where it flows first into veins, and then into the inferior and superior venae cavae, which return it to the right heart, completing the systemic cycle. The blood is then re-oxygenated through the pulmonary circulation before returning again to the systemic circulation.

## Veins
The relatively de-oxygenated blood collects in the venous system which coalesces into two major veins: the superior vena cava (roughly speaking from areas above the heart) and the inferior vena cava (roughly speaking from areas below the heart). These two great vessels exit the systemic circulation by emptying into the right atrium of the heart. The coronary sinus empties the heart's veins themselves into the right atrium.

# Advantage
Because the systemic circulation is powered by the left ventricle (which is very muscular), one advantage of this form of circulation - as opposed to open circulation, or the gill system that fishes use to breathe - is that there is simultaneous high-pressure oxygenated blood delivered to all parts of the body.
Peterson olefination
The Peterson olefination (also called the Peterson reaction) is the chemical reaction of -silyl carbanions 1 with ketones (or aldehydes) to form a -hydroxysilane 2 which eliminates to form alkenes 3.
Several reviews have been published.

# Reaction mechanism
One attractive feature of the Peterson olefination is that it can be used to prepare either cis- or trans-alkenes from the same -hydroxysilane. Treatment of the -hydroxysilane with acid will yield one alkene, while treatment of the same -hydroxysilane with base will yield the alkene of opposite stereochemistry.

## Basic elimination
The action of base upon a -hydroxysilane 1 results in a concerted syn elimination of 2 or 3 to form the desired alkene. The penta-coordinate silicon intermediate 3 is postulated, but no proof exists to date.
Potassium alkoxides eliminate quickly, while sodium alkoxides generally require heating. Magnesium alkoxides only eliminate in extreme conditions. The order of reactivity of alkoxides, K > Na >> Mg, is consistent with higher electron density on oxygen, hence increasing the alkoxide nucleophilicity.

## Acidic elimination
The treatment of the -hydroxysilane 1 with acid results in protonation and an anti elimination to form the desired alkene.

## Alkyl substituents
When the -silyl carbanion contains only alkyl, hydrogen, or electron-donating substituents, the stereochemical outcome of the Peterson olefination can be controlled, because at low temperature the elimination is slow and the intermediate -hydroxysilane can be isolated.
Once isolated, the diastereomeric -hydroxysilanes are separated. One diastereomer is treated with acid, while the other is treated with base, thus converted the material to an alkene with the required stereochemistry.

## Electron-withdrawing substituents
When the -silyl carbanion contains electron-withdrawing substituents, the Peterson olefination directly forms the alkene. The intermediate -hydroxysilane cannot be isolated as it eliminates in-situ. The basic elimination pathway has been postulated in these cases.

# Variations
Acidic elimination conditions are sometimes not feasible as the acid also promotes double bond isomerization. Additionally, elimation using sodium or potassium hydride may not be feasible due to incompatible functional groups. Chan et al. have found that acylation of the intermediate silylcarbinol with either acetyl chloride or thionyl chloride gives a -silyl ester that will eliminate spontaneously at 25C giving the desired alkene. Corey and co-workers developed a method (sometimes dubbed the Corey-Peterson olefination) using a silylated imine to yield an ,-unsaturated aldehyde from a carbonyl compound in one step. 
For an example for its use in total synthesis see: Kuwajima Taxol total synthesis
Pharmaceutical codes
Pharmaceutical codes are used in medical classification to uniquely identify medication. Examples of coding systems include:
- Anatomical Therapeutic Chemical Classification System (AT, or ATC/DDD) -- administered by World Health Organization
- National Drug Codes (NDC) -- administered by Food and Drug Administration 
- SNOMED -- C axis
Phase Z of A-Z Trial

# Objective
To compare early initiation of an intensive statin regimen with delayed initiation of a less intensive regimen in patients with ACS.

# Methods
The Z phase of A-Z trial was a multicentered, randomized, double blinded trial which enrolled 4497 patients with acute coronary syndrome who had an initial total cholesterol level 250 mg/dL. All the patients were randomized to treatment with either 40 mg/d of simvastatin for 1 month followed by 80 mg/d thereafter or placebo for 4 months followed by 20 mg/d of simvastatin. All the patients were followed-up for 6 months to 24 months. Primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, readmission for ACS, and stroke.

# Results
- In the less intense treatment group, median LDL-C level achieved while taking placebo was 122 mg/dL at 1 month and was 77 mg/dL at 8 months while taking 20 mg/d of simvastatin. Corresponding values in the simvastatin only group were 68 mg/dL at 1 month while taking 40 mg/d of simvastatin and 63 mg/dL at 8 months while taking 80 mg/d of simvastatin.
- Primary endpoint was reached in 16.7% in the placebo plus simvastatin group compared with 14.4% in the simvastatin only group.
- Cardiovascular death occurred in 5.4% and 4.1% of the patients in the 2 groups but no differences were observed in other individual components of the primary end point.

# Conclusion
The pre-specified end point was not achieved by the trial. However the early initiation of an aggressive simvastatin regimen, in patients with ACS, resulted in a favorable trend toward reduction of major cardiovascular events.
Phosphorus triiodide
Phosphorus triiodide (PI3) is an unstable red solid which reacts violently with water.  It is a common misconception that PI3 is too unstable to be stored; it is, in fact, commercially available.  It is widely used in organic chemistry for converting alcohols to alkyl iodides.  It is also a powerful reducing agent.  Note that phosphorus also forms a lower iodide, P2I4, but the existence of PI5 is doubtful at room temperature.

# Physical properties
PI3 has essentially zero dipole moment in carbon disulfide solution, because the P-I bond has almost no dipole.  The P-I bond is also weak; PI3 is much less stable than PBr3 and PCl3, with a standard enthalpy of formation for PI3 of only -46 kJ/ mol (solid). The phosphorus atom has an NMR chemical shift of 178 ppm (downfield of H3PO4).

# Chemical properties
Phosphorus triiodide reacts vigorously with water, producing phosphorous acid (H3PO3) and hydroiodic acid (HI), along with smaller amounts of phosphine and P-P compounds.  Alcohols likewise form alkyl iodides, this providing the main use for PI3.
PI3 is also a powerful reducing agent and deoxygenating agent.  It reduces sulfoxides to thioethers, even at -78 C.  Meanwhile heating a 1-iodobutane solution of PI3 with red phosphorus causes reduction to P2I4.

# Preparation
The usual method or preparation is by the union of the elements, often by addition of iodine to a solution of white phosphorus in carbon disulfide:
Alternatively, PCl3 may be converted to PI3 by the action of hydrogen iodide or certain metal iodides.

# Uses
Phosphorus triiodide is commonly used in the laboratory for the conversion of primary or secondary alcohols to alkyl iodides.  Often the PI3 is made in situ by the reaction of red phosphorus with iodine in the presence of the alcohol.
The alcohol is frequently used as the solvent.  A primary alcohol such as 1-butanol gives a 1-iodobutane in 90% yield.
These alkyl iodides are useful compounds for nucleophilic substitution reactions, and for the preparation of Grignard reagents.
Photothermal Therapy

# Overview
Photothermal Therapy (PTT) is an extremely new therapeutic use of electromagnetic radiation (most often in the form of visible light) that is proposed to treat various medical conditions, including cancer. The basic model for its use is derived in part from Photodynamic Therapy, whereas a photosensitizer is excited with specific band light. This activation brings the sensitizer to an excited state where it then releases vibrational energy (heat). The heat is the actual method of therapy that interacts with whatever agent has been targeted (cancer cells, for example). The increase in temperature can cause numerous biological interactions that will be the result of the therapy (protein denaturization, cancer cell necrosis or apoptosis, etc).

## Photothermal Therapy vs Photodynamic Therapy
Being in close relation to Photodynamic Therapy, the two are often compared as potential methods to treat cancer, among other applications. Photothermal therapy is listed as being advantageous in that it does not require oxygen to interact with the target cells or tissues. Current studies also show that Photothermal therapy is able to use longer wavelegth light (which is less energetic and therefore less harmful to other cells and tissues). Challenges of Photothermal therapy mostly lay it its novelty, as it is much less studied, however some research has indicated problems with aggregation of the photosensitizers, local shock waves, hyperthermic effects, and otherwise little phototoxicity.
As this is a brand new field of therapy, many of the side effects and complications, as well as the potential applications of Photothermal Therapy, are unknown.
Phrenic Nerve Pacing
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# Overview
Phrenic Nerve Pacing (PNP) or diaphragm pacing, is the rhythmic application of electrical impulses to the diaphragm, resulting in respiration for patients who would otherwise be dependent on a mechanical ventilator.
This concept was originally referred to as electrophrenic respiration, although the Food and Drug Administration identifies the device as a diaphragmatic/phrenic nerve stimulator.  A phrenic nerve pacemaker is a Class III medical device which requires premarket approval.  It should not be confused with an experimental device currently under development (see diaphragmatic pacemaker) at Case Western Reserve University.

# Indications for Use
According to Medicare, phrenic nerve stimulators are indicated for selected patients with partial or complete respiratory insufficiency and can only be effective if the patient has an intact phrenic nerve and diaphragm. (Medicare National Coverage Determinations Manual, Chapter 1, Part 2, Section 160.19)  Common patient diagnoses for phrenic nerve pacing include patients with spinal cord injury, central sleep apnea (ie, Ondine's curse), and diaphragm paralysis.

# Surgery
The surgery is performed by placing an electrode around the phrenic nerve, either in the neck (ie, cervically), or in the chest (ie, thoracically).  This electrode is connected to a radiofrequency receiver which is implanted just under the skin.  An external transmitter sends radio signals to the device by an antenna which is worn over the receiver.
For the cervical surgical technique, the phrenic nerve is approached via a small (~5 cm) incision slightly above, and midline to, the clavic.  The phrenic nerve is then isolated under the scalenus anticus muscle.
For the thoracic surgical technique, a small (~5 cm) incisions over the 2nd or 3rd intercostal space.  The electrodes are placed around the phrenic nerves alongside the pericardium.  Use of a thorascope allows for this technique to be performed in a minimally-invasive manner.
Patients are usually hospitalized for 1-3 days post-operatively, although some implantations can be performed on an outpatient basis.

# Availability
There are currently two commercially distributed phrenic nerve stimulators made by Avery Biomedical Devices, Inc. (USA) and Atrotech OY (Finland).  The Avery device (Mark IV Breathing Pacemaker) is distributed worldwide.  The Atrotech device (Atrostim Jukka) is not available in the United States.
de:Elektrolunge
Pithecellobium dulce
Pithecellobium dulce (Manila tamarind, Monkeypod) is a native flowering plant from Mexico and was introduced and naturalised in the Caribbean, Florida, Guam and Southeast Asia. It is also considered as a weed in Hawaii. It is called (English) manila tamarind, (Hawaii) 'opiuma, and (Filipino) kamatsile, Jungle jalebi and Madras thorn.
The tree is about 5 to 8 meters high. Its trunk is spiny and its leaves are bipinnate. Each pinna has a single pair of ovate-oblong leaflets that are about 2 to 4 cm long. The flowers are greenish-white, fragrant, sessile and reach about 12 cm long though looks shorter due to coiling. The flowers produce a pod with an edible pulp. The seeds are black.
The seeds is propagated via birds that feeds on the sweet pod. The Manila tamarind is drought-resistant and can survive in dry land from sea level to 300m elevation. Because of these characteristics they are usually cultivated as street trees.

# Uses
In folk medicine, a decoction of its bark can cure frequent bowel movement. The leaves can be applied as plasters for pain and veneral sores. Decoctions of leaves are also used for indigestion and abortifacient.
Its fruit's pulp is sweet and can be eaten raw or prepared as beverage.
Its bark is also used due to its high tannin content and might be the reason behind its introduction to Guam from Mexico via the Philippines.
Polemonium caeruleum
Jacob's Ladder or Greek valerian (Polemonium caeruleum) is a hardy perennial flowering plant. The plant produces cup-shaped, lavender-coloured flowers. It is native to temperate regions of Europe.
The plant usually reaches a height from 45 to 60 centimeters (18 to 24 inches), but some occasionally will be taller than 90 centimeters (35 inches.) The spread of the plant is also 45 to 60 centimeters. It can grow in North American hardiness zone 2.

# Habitat
The plant is native to damp grasslands, woodlands, meadows and rocky areas in temperate areas of Europe.

# Cultivation
The plant normally prefers soil that is rich in moisture and lime and does not require as much sunlight as other plants. Depending on the conditions, it will need varying amounts of water in the summer. If it is hot summer, the plant may require extra water. If it is an average summer, it probably won't need extra water.
Cats are attracted to the scent of the plant, particularly younger plants. A person who is growing this plant in a container or home garden should protect the plants if they own a cat.

# Uses

## Medical Uses
The plant was first used as a medicinal herb in ancient Greece. The ancient Greeks used the root to treat dysentery, toothaches and animal bites. The plant was also found in a few European pharmacies during the nineteenth century and was used as an antisyphilitic agent and to treat rabies. Today, the plant is not usually used medically.

## Other Uses
The flower is used on the unofficial flag of Derbyshire.
Today, the plant is usually used in potpourris and is boiled in olive oil to make black dyes and hair dressing, but it has few other significant uses.
Polyposis registries

# Overview
Polyposis registries  exist for the purpose of understanding the genetic disease familial adenomatous polyposis.  The registries provide a service to doctors for identification, surveillance and management of families and individuals with high colorectal cancer risk from Familial Adenomatous Polyposis (FAP) and Hereditary Non-Polyposis Colorectal Cancer (HNPCC).   The Centers for Disease Control of the United States provides, royalty-free,  Registry Plus software for collecting and processing cancer registry data compliant with national standards established by health professionals and regulators to understand and address the burden of cancer more effectively.
Polyposis registries have been used in numerous academic studies to assess morbidity and mortality of colorectal cancer related to FAP, and use of registry data has resulted in improved treatment and reduced mortality from polyposis-related colorectal cancer.
The University of Texas M. D. Anderson Cancer Center maintains an international list of registries related to hereditary colon cancer.
Some of the registries include:

## North America
Steve Atanas Stavro Familial Gastrointestinal Cancer Registry (Mount Sinai Hospital, Toronto, Ontario, Canada)

## Europe
St. Mark's Hospital Polyposis Registry (St Mark's Hospital Foundation, St Mark's Hospital, Middlesex, United Kingdom)

## Asia
Singapore Polyposis Registry (Singapore General Hospital, Singapore)
Polyposis ventriculi
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# Pathological Findings
Image courtesy of Professor Peter Anderson DVM PhD and published with permission  PEIR, University of Alabama at Birmingham, Department of Pathology
- Stomach: Polyps: Gross, natural color, an excellent example of multiple gastric polyps
Polypropylene glycol
Polypropylene glycol or polypropylene oxide is the polymer of propylene glycol. Chemically it is a polyether. The term polypropylene glycol or PPG is reserved for low to medium range molar mass polymer when the nature of the end-group, which is usually a hydroxyl group, still matters. The term "oxide" is used for high molar mass polymer when end-groups no longer affect polymer properties. In 2003, 60% of the annual production of propylene oxide of 6.6106 tonnes was converted into the polymer.

# Polymerization
Polypropylene glycol is produced by anionic ring-opening polymerization of propylene oxide. The initiator is an alcohol and the catalyst a base, usually potassium hydroxide. When the initiator is ethylene glycol or water the polymer is linear. With a multifunctional initiator like glycerine, pentaerythritol or sorbitol the polymer branches out.
Conventional polymerization of propylene oxide results in an atactic polymer. The isotactic polymer can be produced from optically active propylene oxide, but at a high cost.  A salen cobalt catalyst has recently been reported to provide isotactic polymerization of the racemic propylene oxide 1.

# Properties
PPG has many properties in common with polyethylene glycol. The polymer is a liquid at room temperature. Solubility in water decreases rapidly with increasing molar mass. Secondary hydroxyl groups in PPG are less reactive than primary hydroxyl groups in polyethylene glycol.

# Uses
PPG is used in many formulations for polyurethanes. It is used as a rheology modifier.
Polypyrimidine tract
The polypyrimidine tract is a region of messenger RNA (mRNA) that promotes the assembly of the spliceosome, the protein complex specialized for carrying out RNA splicing during the process of post-transcriptional modification. The region is rich with pyrimidine nucleotides, especially uracil, and is usually 15-20 base pairs long, located about 5-40 base pairs before the 3' end of the intron to be spliced.
A number of protein factors bind to or associate with the polypyrimidine tract, including the spliceosome component U2AF and the polypyrimidine tract-binding protein (PTB), which plays a regulatory role in alternative splicing. PTB's primary function is in exon silencing, by which a particular exon region normally spliced into the mature mRNA is instead left out, resulting in the expression of an isoform of the protein for which the mRNA codes. Because PTB is ubiquitously expressed in many higher eukaryotes, it is thought to suppress the inclusion of "weak" exons with poorly defined splice sites.  However, PTB binding is not sufficient to suppress "robust" exons.
The suppression or selection of exons is critical to the proper expression of tissue-specific isoforms. For example, smooth muscle and skeletal muscle express alternate isoforms distinguished by mutually exclusive exon selection in alpha-tropomyosin.
Retromandibular vein
The retromandibular vein (temporomaxillary vein, posterior facial vein), formed by the union of the superficial temporal and  internal maxillary veins, descends in the substance of the parotid gland, superficial to the external carotid artery but beneath the facial nerve, between the ramus of the mandible and the Sternocleidomastoideus muscle.
It divides into two branches:
- an anterior, which passes forward and unites with the anterior facial vein to form the common facial vein.
- a posterior, which is joined by the posterior auricular vein and becomes the external jugular vein.