Persius/hicric huggingface dataset:
Flammable liquid

# Overview
Generally, a flammable liquid means a liquid which may catch fire easily.
In the USA, there is a precise definition of flammable liquid as one with a flashpoint below 100 degrees Fahrenheit. Less-flammable liquids (with a flashpoint between 100 degrees and 200 degrees Fahrenheit) are defined as combustible liquid.  This definition is used by the National Fire Protection Association, The US Department of Transportation, the US Environmental Protection Agency, the US Occupational Safety and Health Administration and others.
These categories are further subdivided, depending on the liquid's flash point and boiling point.
- Class IA flammable liquids have a flash point below 73 F and a boiling point below 100 F
- Class IB flammable liquids have a flash point below 73 F and a boiling point greater than or equal to 100 F
- Class IC flammable liquids have a flash point greater than or equal to 73 F and below 100 F
- Class II combustible liquids have a flash point greater than or equal to 100 F and below 140 F
- Class IIIA combustible liquids have a flash point greater than or equal to 140 F and below 200 F
- Class IIIB combustible liquids have a flash point greater than or equal to 200 F
Flavored tobacco
Smoking flavored tobacco is becoming an increasing social activity in the United States. The flavored tobacco is usually smoked in a hookah or sometimes known as a shisha. It originated in India and has been a important part of the Middle Eastern culture for centuries.

# Components of a hookah
The hookah itself is structured with a glass jar base (usually to be filled with water), the body (a hollow tube), a bowl for the head (where the tobacco is placed), the bowl is then covered with aluminum foil so that heated coal can be placed on top of it, and lastly a hose with a mouth piece (from which smoke is inhaled)

# Tobacco flavors
Tobacco flavors usually consists of flower scents (rose), fruits (apple, strawberry, mango), and other flavors such as chocolate and vanilla.
T wave inversion
Synonyms and keywords: negative T wave; negative T waves; inverted Ts;flipped T waves; flipped T wave; flipped Ts

# Overview
T wave inversion is a non-specific electrocardiographic sign in which the T wave, an electrical signal that occurs when the heart is repolarizing or recharging itself, it is upside down instead of upright.

# Classification

## Primary T Wave Inversion
These changes in the T wave represent a primary abnormality in electrical repolarization (i.e. they are not due to or secondary to a change in conduction). Examples include the dig effect, myocardial ischemia or central nervous system events such as subarachnoid hemorrhage.

## Secondary T Wave Inversion
The T wave may be inverted as a result of changes in the sequence of ventricualr activation such as is seen with premature ventricular contractions (PVCs), left bundle branch block, right bundle branch block (RBBB) and pre excitation syndromes like WPW.

# Causes
- Arrhythmogenic RV dysplasia should be suspected in this cohort if the T wave inversion persists beyond lead V1 in a post pubertal male athlete
- Cerebrovascular accidents can cause deep widely splayed T waves referred to as cerebral T waves
- Digoxin effect or Dig effect
- Electrolyte disturbance
- Ischemic heart disease including non ST segment elevation MI or prior MI
- Left bundle branch block, it is normal for the T wave to be inverted if the QRS complex is upright
- Left ventricular hypertrophy with strain
- Myocarditis
- Persistent juvenile T-wave pattern
- Premature ventricular contraction
- Pulmonary embolism, particularly in the anterior precordium
- Restrictive cardiomyopathy
- Subarachnoid hemorrhage
- Unstable angina
- Wellens' syndrome
- Wolff-Parkinson-White syndrome (WPW)

## Causes by Organ System

## Causes in Alphabetical Order
Fourth ventricle

# Overview
The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. These cavities, known collectively as the ventricular system, consist of the left and right lateral ventricles, the third ventricle, and the fourth ventricle. The fourth ventricle extends from the cerebral aqueduct (aqueduct of Sylvius) to the obex, and is filled with cerebrospinal fluid (CSF).
The fourth ventricle has a characteristic diamond shape in cross-sections of the human brain. It is located within the pons or in the upper part of the medulla. CSF entering the fourth ventricle through the cerebral aqueduct can exit to the subarachnoid space of the spinal cord through two lateral foramina of Luschka (singular: foramen of Luschka) and a single, midline  foramen of Magendie (see List of human anatomical parts named after people).

# Roof and floor
The fourth ventricle has a "roof"  dorsally and a "floor" ventrally.   The roof of the fourth ventricle is formed by the cerebellum (superior and inferior medullary velums), the floor by the rhomboid fossa, and the side "walls" formed by the cerebellar peduncles. Among the prominent features of the floor of the fourth ventricle are the:
- facial colliculus: formed by the internal part of the facial nerve as it loops around the abducens nucleus in the lower pons;
- sulcus limitans: which represents the border between the alar plate and the basal plate of the developing neural tube;
- obex: represents the caudal tip of the fourth ventricle; the obex is also a marker for the level of the foramen magnum of the skull and therefore is a marker for the imaginary dividing line between the medulla and spinal cord.

# Additional images
- Transverse section of medulla oblongata below the middle of the olive.
- Diagram showing the course of the arcuate fibers.
- The formatio reticularis of the medulla oblongata, shown by a transverse section passing through the middle of the olive.
- Coronal section of the pons, at its upper part.
- Sagittal section of the cerebellum, near the junction of the vermis with the hemisphere.
- Rhomboid fossa.
- Mesal aspect of a brain sectioned in the median sagittal plane.
- Median sagittal section of brain.
- Drawing of a cast of the ventricular cavities, viewed from the side.
- Terminal nuclei of the vestibular nerve, with their upper connections.
- Diagram showing the positions of the three principal subarachnoid cistern.
Frasier syndrome

# Overview
Frasier syndrome is a urogenital anomaly associated with the WT1 (Wilms tumor 1 gene) gene.

# Historical Perspective
It was first characterized in 1964.

# Presentation
Frasier syndrome presents at birth with male pseudohermaphroditism (the external genitalia have a female appearance despite an XY genotype), streak gonads and progressive glomerulonephropathy (focal segmental glomerulosclerosis). Patients are also at increased risk of genito-urinary tumors (usually gonadoblastoma).
The glomerulonephropathy presents later than in Denys-Drash syndrome, and the tumour risk phenotype is different - whilst DDS is associated with Wilms' tumour, Frasier syndrome is associated with gonadoblastoma. Differentiating between the two syndromes can be challenging.

## Inheritance pattern
Frasier syndrome is inherited in an autosomal dominant fashion, indicating the need for only one mutated allele in a cell to lead to expression of the disease. Mutations predominantly occur de novo, allowing for expression in an individual that has no family history of it. The mutations occur during gamete formation or early in embryogenesis.

# WT1 gene and mutations
The WT1 gene exists on chromosome 11 (at 11p13), and codes for a four zinc finger transcription factor. Its role as a transcription factor is related to proper kidney and gonadal development. The link between kidney and gonadal development and WT1 was highlighted in past studies looking at the related Denys-Drash syndrome. Results of various investigations identified the loss of function of WT1 to be a prerequisite of Wilms' tumour development, and also a key trait of individuals with genital abnormalities.
Mutations responsible for Frasier syndrome predominantly occur in intron 9 of the WT1 gene, specifically nucleotide substitutions that influence an intron splice site. Mutations in this region proved for the absence of three amino acidsKTSbetween the third and fourth WT1 zinc fingers. Referring to the autosomal dominant expressive nature of this disease, it is only necessary for an individual to have one compliment of the mutated intronic sequence to appear affected. Differing from the similar Denys-Drash syndrome, where a mutated form of the WT1 protein exists, Frasier syndrome expression works solely on the existence of a changed ratio of KTS isoforms: normal WT1 proteins including the KTS site (+KTS), and mutated, shortened proteins lacking the KTS site (KTS). Through alternative splicing, a specific ratio of the two isoforms normally exists, though the mutation in the intron 9 splice site severely lowers levels of the +KTS isoform; this leads to Frasier syndrome.
Frederick Pei Li

# Overview
Frederick Pei Li (born 1940) is an American physician.
Frederick Pei Li was born in Canton, China (Guangzhou), and raised in New York City where his parents operated a Chinese restaurant. He received a B.A. in physics from New York University, an M.D. from the University of Rochester, and M.A. in demography from Georgetown University. In 1967 he joined the Epidemiology Branch of the National Cancer Institute (NCI). He served for 24 years, mostly at the NCI's field station at the Dana-Farber Cancer Institute in Boston. In 1991, he became head of Dana-Farber's Division of Cancer Epidemiology and Control.
Currently, Dr. Li is Professor of Clinical Cancer Epidemiology at the Harvard School of Public Health, Professor of Medicine at the Harvard Medical School, and the Harry and Elsa Jiler American Cancer Society Clinical Research Professor. In 1996, Dr. Li was appointed by President Bill Clinton to NCI's National Cancer Advisory Board.
This is Li's presentation of himself and his work:
Research Interests : Molecular Epidemiology of Hereditary Cancers
Recent data have established that the basic molecular defects in cancer are genetic changes that result in loss of normal cellular control mechanisms. Some of these mutations can be inherited through the germline. "I have been studying inherited susceptibility of cancer through affected families. The goal is to identify genes that are involved in cancer development".
"I was attracted to studies of cancer families because epidemiological studies show that virtually all cancers manifest a tendency to aggregate in families. Close relatives of a cancer patient are at increased risk of that neoplasm, and perhaps other forms of cancer. The excess site-specific cancer risk is exceptionally high for carriers of certain cancer genes, in whom the attack rate can approach 100 percent. In candidate cancer families, the possibility that clustering is on the basis of chance must be excluded through epidemiological studies that establish the presence of an excess cancer risk. Predisposed families are candidates for laboratory studies to identify the inherited susceptibility factors. These investigations have lead to the identification and isolation of human cancer genes, the tumor suppressor genes. These cancer genes are among more than 200 single-gene traits associated with the development of cancer. Approximately a dozen inherited susceptibility genes have been definitively identified, and many more are being sought. From studies of retinoblastoma and other rare cancers, important new information was generated about the fundamental biology of cancers that arise in many patients. Isolation of an inherited cancer susceptibility gene provides opportunities for presymptomatic testing of at-risk relatives. However, testing of healthy individuals also raise important issues regarding informed consent, confidentiality and potential for adverse psychological, social and economic effects."
"My colleagues and I are using families with inherited mutations in the p53 gene, which predisposes to breast cancer and diverse childhood cancers, as a model for developing a genetic testing program".
Free association
Free association (Psychodynamic theory) is a technique used in psychology, devised by Sigmund Freud
In free-association, patients are asked to continually relate anything which comes into their minds, regardless of how superficially unimportant or potentially embarrassing the memory threatens to be. This technique assumes that all memories are arranged in a single associative network, and that sooner or later the subject will stumble across the crucial memory.
Suggested influences on the technique include Husserl's version of epoche and the work of Sir Francis Galton. Freud developed the technique as an alternative to hypnosis, both because of its perceived fallibility and because he found that patients could recover and comprehend crucial memories while conscious. However, Freud found that despite a subject's effort to remember, a certain resistance kept him or her from the most painful and important memories. He eventually came to the view that certain items were completely repressed, and off-limits to the conscious realm of the mind.
Freud's eventual practice of psychoanalysis focused not so much on the recall of these memories as on the internal mental conflicts which kept them buried deep within the mind, though the technique of free association still plays a role today in the study of the mind.
Frequency domain
Frequency domain is a term used to describe the analysis of mathematical functions or signals with respect to frequency.
Speaking non-technically, a time-domain graph shows how a signal changes over time, whereas a frequency-domain graph shows how much of the signal lies within each given frequency band over a range of frequencies.  A frequency-domain representation can also include information on the phase shift that must be applied to each sinusoid in order to be able to recombine the frequency components to recover the original time signal.
The frequency domain relates to the Fourier transform or Fourier series by decomposing a function into an infinite or finite number of frequencies. This is based on the concept of Fourier series that any waveform can be expressed as a sum of sinusoids (sometimes infinitely many.)
A spectrum analyzer is the tool commonly used to visualize real-world signals in the frequency domain.

# Magnitude and phase
In using the Laplace, Z-, or Fourier transforms, the frequency spectrum is complex, describing the magnitude and phase of a signal, or of the response of a system, as a function of frequency.  In many applications, phase information is not important.  By discarding the phase information it is possible to simplify the information in a frequency domain representation to generate a frequency spectrum or spectral density.  A spectrum analyzer is a device that displays the spectrum.
The power spectral density is a frequency-domain description that can be applied to a large class of signals that are neither periodic nor square-integrable; to have a power spectral density a signal needs only to be the output of a wide-sense stationary random process.

# Partial frequency-domain example
Due to popular simplifications of the hearing process and titles such as Plomp's "The Ear as a Frequency Analyzer," the inner ear is often thought of as converting time-domain sound waveforms to frequency-domain spectra.  The frequency domain is not actually a very accurate or useful model for hearing, but a time/frequency space or time/place space can be a useful description.
Frey's procedure

# Overview
Frey's procedure is a surgical technique used in the treatment of chronic pancreatitis in which the diseased portions of the pancreas head are cored out. A lateral pancreaticojejunostomy (LRLPJ) is then performed in which a loop of the jejunum is then mobilized and attached over the exposed pancreatic duct to allow better drainage of the pancreas, including its head.

# Indication
Frey's operation is indicated on patients with chronic pancreatitis who have "head dominant" disease.

# Comparison to Puestow procedure
Compared with a Puestow procedure, a Frey's procedure allows for better drainage of the pancreatic head.

# Complications
Postoperative complications after LRLPJ are usually septic in nature and are likely to occur more often in patients in whom endoscopic pancreatic stenting has been performed before surgical intervention.
Functional group

# Overview
In organic chemistry, functional groups (or moieties) are specific groups of atoms within molecules, that  are responsible for the characteristic chemical reactions of those molecules.  The same functional group will undergo the same or similar chemical reaction(s) regardless of the size of the molecule it is a part of.
Combining the names of functional groups with the names of the parent alkanes generates a powerful systematic nomenclature for naming organic compounds.
The non-hydrogen atoms of functional groups are always associated with each other and with the rest of the molecule by covalent bonds. When the group of atoms is associated with the rest of the molecule primarily by ionic forces, the group is referred to more properly as a polyatomic ion or complex ion. And all of these are called radicals, by a meaning of the term radical that predates the free radical.
The first carbon atom after the carbon that attaches to the functional group is called the alpha carbon.
Functional groups are attached to the carbon backbone of organic molecules.  They determine the characteristics and chemical reactivity of molecules.  Functional groups are far less stable than the carbon backbone and are likely to participate in chemical reactions.

# Table of common functional groups
The following is a list of common functional groups. In the formulas, the symbols R and R' usually denote an attached hydrogen, or a hydrocarbon side chain of any length, but may sometimes refer to any group of atoms.

# Hydrocarbons
Functional groups which vary based upon the number and order of  bonds impart different chemistry.  Each listing below contains C-H bonds, but each one differs in type (and scope) of reactivity.

# Groups containing halogens
Haloalkanes are a class of molecule which is defined by a carbon-halogen bond.  This bond can be relatively weak (in the case of an iodoalkane) or quite stable (as in the case of a fluoroalkane).  In general, with the exception of fluorinated compounds, haloalkanes readily undergo nucleophilic substitution reactions or elimination reactions.  The substitution on the carbon, the acidity of an adjacent proton, the solvent conditions, etc. all can influence the outcome of the reactivity.

# Groups containing oxygen
Compounds which contain C-O bonds each possess differing reactivity based upon the location and hybridization of the C-O bond, owing to the electron-withdrawing effect of sp2 hybridized oxygen and the donating effects of sp3 hybridized oxygen.

# Groups containing nitrogen
Compounds which contain Nitrogen in this category may contain C-O bonds, such as in the case of amides.

# Groups containing phosphorus and sulfur
Compounds which contain sulfur and phosphorus exhibit unique chemistry due to their ability to form more bonds than nitrogen and oxygen, their lighter analogues on the periodic table.

# Other
- Methyl
- Methylene
- Ethyl
- Propyl
- Butyl
- Hydroxy
- Methoxy
- Hydroxymethyl
- Methylenedioxy
- Phenyl
- Acetyl
- Acetoxy
- Thioamide
- Thioester
- Thioketone
Fundamental unit
A set of fundamental units is a set of units for physical quantities from which every other unit can be generated.
In the language of measurement, quantities are quantifiable aspects of the world, such as time, distance, velocity, mass, momentum, energy, and weight, and units are used to describe their measure. Quantities are sometimes also referred to as dimensions (i.e. "The dimensions of the package to be mailed are 12" x 8" x 4".") although the term is normally meant to apply to the class of physical quantity (length, time, mass, momentum, energy, etc.) being measured (see dimensional analysis).
A system of fundamental quantities (or sometimes fundamental dimensions) is such that every other physical quantity (or dimension of physical quantity) can be generated from them. The traditional fundamental dimensions of physical quantity are mass, length, time, and temperature, but in principle, other fundamental quantities could be used. Some physicists have not recognized temperature as a fundamental dimension of physical quantity since it simply expresses the energy per particle per degree of freedom which can be expressed in terms of energy (or mass, length, and time). In addition, some physicists recognize electric charge as a separate fundamental dimension of physical quantity, even if it has been expressed in terms of mass, length, and time in unit systems such as the electrostatic cgs system. There are also physicists who have cast doubt on the very existence of incompatible fundamental quantities.
The fundamental units of the SI system are kilogram, second, ampere, kelvin, and mole. The metre and candela were formerly fundamental units but have been redefined in terms of the other units. They are still considered SI base units, however, mainly for historical reasons. Other units such as the newton, joule, and volt can be derived from the SI base units and are therefore termed SI derived units.
The dimension speed, for example, is length divided by time, so its unit m/s can be generated from the fundamental unit of seconds (the metre being also defined in terms of the second).
An important basic fact of dimensional analysis is that the fundamental units can be regarded as the basis of a special kind of vector space, the space of all units. This is a vector space over the field of rational numbers where the vector addition is given by the multiplication of units and the scalar multiplication is exponentiation of units.
Not all physically salient values have units: dimensionless numbers occur in many fields of science.  In fact, dimensionless quantities are fundamentally what we measure, even when we are measuring dimensionful quantities.   We always measure a physical quantity against a like dimensioned standard. When one measures a length with a ruler or tape-measure, that person is actually counting tick marks on the ruler (a standard used to measure length) and the net result is a dimensionless number.  But when that quantity is expressed as the dimensionless number attached to (multiplying) a dimensionful unit, it becomes, conceptually, a dimensionful quantity.
Fundus (stomach)

# Overview
The fundus of the stomach is the left portion of the stomach's body, and is marked off from the remainder of the body by a plane passing horizontally through the cardiac orifice.
As the rounded part of the upper stomach, it allows for an accumulation of gases produced by chemical digestion.
It will also store undigested food for up to 1 hour.
Fusion inhibitor
A fusion inhibitor is a class of antiretroviral drugs used to treat viral infections  such as HIV. It works by blocking the virus from fusing with a cell's membrane to enter and infect the cell.
For example, HIV binds to host cell receptor CD4 by the protein gp120.  Upon binding GP120 deforms allowing the viral protein gp41 to embed itself into the host cell's plasma membrane, entry inhibitors bind to GP41 preventing the creation of an entry pore for the capsid of the virus keeping it out of the cell. 
It has been found that a component in green tea, EGCG, competes for gp120, and Theaflavins found in black tea competes for gp41 with HIV.
Fusion mechanism
The fusion mechanism is the mechanism by which cell fusion takes place. Cell fusion is the formation of a hybrid cell from two different cells of different species.
The term cell fusion mechanism refers to the receptors required for cells to fuse, whereas the term cell fusion refers to the action of formation of the new cell.
One example of the cellular fusion mechanism is that of HIV infecting the body. HIV infects by fusing with the membranes of immune system cells. In order for HIV to fuse with a cell, it must be able to bind to the receptors CD4, CCR5, and CXCR4.