Persius/hicric huggingface dataset:
McMurray test
The McMurray test, also known as the McMurray circumduction test is used to evaluate individuals for tears in the meniscus of the knee.  It is a rotation test for demonstrating torn cartilage of the knee.  A tear in the meniscus may cause a pedunculated tag of the meniscus which may become jammed between the joint surfaces.
To perform the test, the knee is held by one hand, which is placed along the joint line, and flexed to ninety degrees while the foot is held by the sole with the other hand.  The examiner then places one hand on the lateral side of the knee to stabilize the joint and provide a valgus stress. The other hand rotates the leg externally while extending the knee. If pain or a "click" is felt, this constitutes a "positive McMurray test" for a tear in the medial meniscus. Likewise the medial knee can be stablized and the leg internally rotated as the leg is extended. A tag, caused by a tear will cause a palpable or even audible click on extension of the knee.  A positive test indicates a tear of the lateral meniscus.
The other leg must also be checked for completeness because clicks can arise from normal tendon movement.
According to some sources, the sensitivity of the McMurray test for medial meniscus tears is 53% and the specificity is 59%.  In a recent study, clinical test results were compared with arthroscopic and/or arthrotomy findings as reference. The clinical test had a sensitivity of 58.5%, a specificity of 93.4%, and the predictive value of a positive result was 82.6%. The test therefore seems to be of limited value in current clinical practice.
The McMurray test is named after Thomas Porter McMurray, a British orthopedic surgeon from the late nineteenth and early twentieth century.
Mean lifetime

# Overview
Given an assembly of elements, the number of which decreases ultimately to zero, the lifetime (also called the mean lifetime) is a certain number that characterizes the rate of reduction ("decay") of the assembly.  Specifically, if the individual lifetime of an element of the assembly is the time elapsed between some reference time and the removal of that element from the assembly, the mean lifetime is the arithmetic mean of the individual lifetimes.
Typically, the notion of mean lifetime is used in connection with exponential decay.  The remainder of this article confines itself to this particular decay pattern.

# Mean lifetime in exponential decay
The mean lifetime  of elements in an exponentially decaying assembly is equal to the reciprocal of the decay constant (cf. exponential decay).  Thus, it is the time needed for the assembly to be reduced by a factor of e.  It is related to the half-life t_{1/2} by
Thus the mean lifetime is 44% longer than the half-life, e.g. Polonium-210 has a half-life of 138 days, and a mean lifetime of 200 days.

## Derivation
In exponential decay, the population is governed by the following formula:
where t is the time, N is the number of elements in the assembly at that time, N_0 is the population at the initial reference t=0, and \lambda is a parameter characteristic of the decay called the decay constant.  The mean lifetime \tau is the expected value of the amount of time before an unstable object undergoes a decay.  First, we let c be the normalizing factor to convert to a probability space.
We see that exponential decay is a scalar multiple of the exponential distribution, which has a well-known expected value.  We can compute it here using integration by parts.
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Temporal lobe

# Overview
The temporal lobes are part of the cerebrum. They lie at the sides of the brain, beneath the lateral or Sylvian fissure. Seen in profile, the human brain looks something like a boxing glove. The temporal lobes are where the thumbs would be.
The temporal lobe is involved in auditory processing and is home to the primary auditory cortex.  It is also heavily involved in semantics both in speech and vision.  The temporal lobe contains the hippocampus and is therefore involved in memory formation as well.

# Function
The superior temporal gyrus includes an area (within the Sylvian fissure) where auditory signals from the cochlea (relayed via several subcortical nuclei) first reach the cerebral cortex. This part of the cortex (primary auditory cortex) is involved in hearing. Adjacent areas in the superior, posterior and lateral parts of the temporal lobes are involved in high-level auditory processing. In humans this includes speech, for which the left temporal lobe in particular seems to be specialized. Wernicke's area, which spans the region between temporal and parietal lobes, plays a key role (in tandem with Broca's area, which is in the frontal lobe). The functions of the left temporal lobe are  not limited to low-level perception but extend to comprehension, naming, verbal memory and other language functions. Sound processing is controlled by the temporal lobes- in the Brocas area and Wernickes area.
The underside (ventral) part of the temporal cortices appear to be involved in high-level visual processing of complex stimuli such as faces (fusiform gyrus) and scenes (parahippocampal gyrus). Anterior parts of this ventral stream for visual processing are involved in object perception and recognition.
The medial temporal lobes (near the Sagittal plane that divides left and right cerebral hemispheres) are thought to be involved in episodic/declarative memory. Deep inside the medial temporal lobes, the hippocampi seem to be particularly important for memory function - particularly transference from short to long term memory and control of spatial memory and behavior.

# Additional images
- Lobes of the brain.
- Base of brain.
- Coronal section through anterior cornua of lateral ventricles.
- Drawing to illustrate the relations of the brain to the skull.
- The dorsal stream (green) and ventral stream (purple) in the temporal lobe are shown.
- Drawing showing the hippocampus in 3-Space.

# See Also
- Lobes of the brain
- Area TG of Bonin-1947
- Brain
- lobe (anatomy)
- Hippocampus
- Temporal lobe epilepsy
Medical model
Medical model is the term (cited by psychiatrist Ronald D. Laing in his The Politics of the Family and Other Essays) for the "set of procedures in which all doctors are trained." This set includes complaint, history, examination, ancillary tests if needed, diagnosis, treatment, and prognosis with and without treatment. Sociologist Erving Goffman, in his Asylums, favorably compared the medical model, which was a post-Industrial Revolution occurrence, with the conduct in the tinkering trades (watch, radio, TV repair).
The medical model also describes the approach to illness which is dominant in Western medicine. It aims to find medical treatments for diagnosed symptoms and syndromes and treats the human body as a very complex mechanism (hence, Goffman's tinkering trade analogy). Among critics of medical psychiatry, Laing observed that because the diagnosis of a mental illness was based on conduct or patient behavior and not on evident pathology, it (the "diagnosis") essentially contravened standard medical procedure and hence the medical model: examination and ancillary tests were conducted, if at all, only after the diagnosis was made.
At all events, whereas heart diseases, cancers, and broken bones were diagnosed by evident pathology discovered during examination and ancillary tests, a mental illness was diagnosed by patient's conduct (paranoid delusions, catatonia, hypermania, etc.), with only an implication of a genuine pathology not cited at the time of diagnosis.
The medical model drives research and theorizing about physical or psychological difficulties on a basis of causation and remediation.
It can be contrasted with the holistic model of the alternative health movement and the social model of the Disability rights movement, as well as to biopsychosocial and recovery model's of mental disorder.
Medullary ray

# Overview
The medullary ray is the middle part of the cortical lobule or renal lobule, consisting of a group of straight tubes to the collecting ducts.
Their name is potentially misleading -- the "medullary" refers to their destination, not their location. They are located only in the renal cortex, and not in the renal medulla.
Medullary rays can also refer to a characteristic found in woods. In this context the term refers to radial sheets or ribbons extending vertically through the tree across and perpendicular to the growth rings. Also called pith rays or wood rays, these formations of primarily parenchyma cells allow the radial transmission of sap. In quartersawn material, where the wood is cut in to boards with the growth rings roughly perpendicular to the face of the board, the medullary rays often produce beautiful figure such as silver grain, medullary spots, pith flecks, etc.
Memory B cell
Memory B cells are a B cell sub-type that are formed following primary infection.

# Primary response, paratopes, and epitopes
In wake of first (primary response) infection involving a particular antigen, the responding nave (ones which have never been exposed to the antigen) cells proliferate to produce a colony of cells, most of which differentiate into the plasma cells or the effector B cells (which produce the antibodies) and clear away with the resolution of infection, and the rest persist as the memory cells that can survive for years, or even a lifetime.
To understand the events taking place, it is important to appreciate that the antibody molecules present on a clone (a group of genetically identical cells) of B cells have a unique paratope (the sequence of amino acids that binds to the epitope on an antigen).
And, each time these cells are induced to proliferate due to an infection, the genetic region coding for the paratope undergoes spontaneous mutations with a frequency of about 1 in every 1600 cell-divisions (this is a very high frequency considering the frequency with which these cells divide; compare with frequency of mutations in other cells--1 in 106).

# Secondary response and memory
All these events occur in the highly "eventful" germinal centers of lymphoid follicles, within the lymph nodes.
Some of the resulting paratopes (and the cells elaborating them) have a better affinity for the antigen (actually, the epitope) and are more likely to proliferate than the others (not unlike Charles Darwin's concept of "natural selection").
Moreover, with each such exposure to the antigen the number of different clones responding to the same antigen increase (polyclonal response), and a greater number of memory cells persist. Thus, a stronger (basically, more number of antibody molecules) and more specific antibody-production are the hallmarks of secondary antibody response.
The facts that all the cells of a single clone elaborate one and only one paratope, and that the memory cells survive for long periods, are what impart a "memory" to the immune response.
This is the principle behind vaccination and administration of booster doses.
Memory T cell

# Overview
Memory T cells are a specific type of infection-fighting T cell (also known as a T lymphocyte) that can recognize foreign invaders such as bacteria or viruses, that were encountered during a prior infection or vaccination. At a second encounter with the invader, memory T cells can reproduce to mount a faster and stronger immune response than the first time the immune system responded to the invader. This behaviour is utilized in T lymphocyte proliferation assays, which can reveal exposure to specific antigens.

# Sub-populations
Within the human cytotoxic T cell population, three distinct sub-populations have now been described:
- central memory (TCM). The TCM cells are thought to represent memory stem cells. TCM display a capacity for self-renewal due to high levels of phosphorylation of an important transcription factor known as STAT5. 
- two highly related effector memory sub-types, which strongly express genes for molecules essential to the cytotoxic function of CD8 T cells:
effector memory (TEM)
effector memory RA (TEMRA)
- effector memory (TEM)
- effector memory RA (TEMRA)
Memory T cells can be recognized by the differential expression of certain molecules.
- Central memory TCM cells express L-selectin and the chemokine receptor CCR7, they secrete IL-2, but not IFN or IL-4.
- Effector memory TEM cells, however,  do not express L-selectin or CCR7 but produce effector cytokines like IFN and IL-4.
Antigen-specific memory T cells against viruses or other microbial molecules can be found in both TCM and TEM subsets. Although most information is currently based on observations in the Cytotoxic T cells (CD8-positive) subset, similar populations appear to exist for both the Helper T cells (CD4-positive) and the cytotoxic T cells.
Meniscal cyst
A meniscal cyst is a  well-defined cystic lesion located along the peripheral margin of the meniscus, a part of the knee, nearly always associated with horizontal meniscal tears.

# Etiology
Various etiologies have been proposed, including trauma, hemorrhage, chronic infection, and mucoid degeneration. The most widely accepted theory describes meniscal cysts resulting from extrusion of synovial fluid through a peripherally extended horizontal meniscal tear, accumulating outside the joint capsule. They arise more commonly from the medial joint margin, and occur most often in 20 to 40 year old males.

# Signs/Symptoms
Pain and swelling or focal mass at the level of the joint. The pain may be related to a meniscal tear or distension of the knee capsule or both. The mass varies in consistency from soft/fluctuant to hard. Size is variable, and meniscal cysts are known to change in size with knee flexion/extension.

# Radiologic Findings
Magnetic resonance imaging is the modality of choice for diagnosis of meniscal cysts. In their most subtle form, meniscal cysts present as focal areas of high signal intensity within a swollen meniscus. It is not uncommon for radiologists to miss this type of meniscal cyst because the signal intensity is not quite as great as fluid on T2 weighted sequences.2 When this fluid is extruded into the adjacent soft tissues, the swollen meniscus subsequently assumes a more normal shape, and the extruded fluid demonstrates a relatively higher T2 signal typical of parameniscal cysts.
Medial meniscus horizontal tear extending into a meniscal cyst.
Sagittal T2 images of a medial meniscus horizontal tear extending into a meniscal cyst.
Large medial meniscus cyst.

# Treatment
Treatment of meniscal cysts consists of a combination of cyst decompression (intraarticular decompression versus open cystectomy) and arthroscopic repair of any meniscal abnormalities. Success rates are significantly higher when both the cyst and meniscal tear are treated compared to treating only one disease process.
Mephentermine

# Overview
Mephentermine is a cardiac stimulant.  It was formerly used in Wyamine nasal decongestant inhalers and before that as a stimulant in psychiatry.
It has been used as a treatment for low blood pressure.
ATC Classification: 	C01CA11 - mephentermine ; Belongs to the class of adrenergic and dopaminergic cardiac stimulants excluding glycosides. Used in the treatment of heart failure.

# Mechanism of Action
Mephentermine appears to act by indirect stimulation of -adrenergic receptors causing the release of norepinephrine from its storage sites. It has a positive inotropic effect on the myocardium. AV conduction and refractory period of AV node is shortened with an increase in ventricular conduction velocity. It dilates arteries and arterioles in the skeletal muscle and mesenteric vascular beds, leading to an increase in venous return.
Onset: 5-15 minutes (IM), immediate (IV).
Duration: 4 hr (IM), 30 minutes (IV).

# Indication & Dosage
Maintenance of blood pressure in hypotensive states
Adult: 30-45 mg as a single dose, repeated as necessary or followed by IV infusion of 0.1% mephentermine in 5% dextrose, rate and duration of administration will depend on patient's response.
Hypotension secondary to spinal anaesthesia in obstetric patients
Adult: 15 mg as a single dose, repeat if needed.

# Caution

## Contraindications
Low blood pressure caused by phenothiazines. Hypertension. Pheochromocytoma.

## Special Precautions
Patient on MAOIs. 
For shock due to loss of blood or fluid, give fluid replacement therapy primarily, CVS disease, hypertension, hyperthyroidism, chronic illnesses, lactation, pregnancy.

## Adverse Drug Reactions
Drowsiness, incoherence, hallucinations, convulsions, fast heart rate. Fear, anxiety, restlessness, tremor, insomnia, confusion, irritability, and psychosis. Nausea, vomiting, reduced appetite, urinary retention, dyspnea, weakness.
Potentially Fatal: AV block, CNS stimulation. Cerebral hemorrhage and pulmonary edema, ventricular arrhythmias.

## Drug Interactions
Antagonizes effect of agents that lower blood pressure. Severe hypertension with MAOIs and possibly tricyclic antidepressants. Additive vasoconstricting effects with ergot alkaloids, oxytocin.
Potentially Fatal: Risk of abnormal heart rhythm in people undergoing anesthesia with cyclopropane and halothane.
Wolffian duct

# Overview
The Wolffian duct (also known as archinephric duct, Leydig's duct, mesonephric duct, or nephric duct) is a paired organ found in mammals including humans during embryogenesis.
It connects the primitive kidney Wolffian body (or mesonephros) to the cloaca and serves as the anlage for certain male reproductive organs.

# Development
In both the male and the female the Wolffian duct develops in to the trigone of urinary bladder, a part of the bladder wall. However, further development differentiates between the sexes in the development of the urinary and reproductive organs.

## Male development
In a male, it develops into a system of connected organs between the testis and the prostate, namely the rete testis, the efferent ducts, the epididymis, the vas deferens, the seminal vesicle, and the prostate.
For this it is critical that the ducts are exposed to testosterone during embryogenesis. Testosterone binds to and activates androgen receptor, affecting intracellular signals and modifying the expression of numerous genes.
In the mature male, the function of this system is to store and mature sperm, and provide accessory semen fluid.

## Female development
In the female, in the absence of testosterone support, the Wolffian ducts regresses,and inclusions may persist .
As a residual the epoophoron and Skene's glands may be present. Also, lateral to the wall of the vagina a Gartner's duct or cyst could develop as a remnant.

# History
It is named after Caspar Friedrich Wolff who described the mesonephros and its ducts in his dissertation in 1759. 

# Additional images
- Diagram of a transverse section, showing the mode of formation of the amnion in the chick.
- Reconstruction of a human embryo of 17 mm.
- Cloaca of human embryo from twenty-five to twenty-seven days old.
- Broad ligament of adult, showing epoophoron.
- Transverse section of human embryo eight and a half to nine weeks old.
- Tail end of human embryo twenty-five to twenty-nine days old.
- Tail end of human embryo thirty-two to thirty-three days old.
- Tail end of human embryo; from eight and a half to nine weeks old.
- Primitive kidney and bladder, from a reconstruction.
Metallic bond
The metallic bond accounts for many physical characteristics of metals, such as strength, malleability, ductility, conduction of heat and electricity, and lustre.
Metallic bonding is the electrostatic attraction between delocalized electrons, called conduction electrons, and the metallic ions within metals. Because it involves the sharing of free electrons among a lattice of positively-charged metal ions, metallic bonding may be compared to that within molten salts.
Metallic bonds are non-polar, because in alloys there is little difference among the electronegativities of the atoms participating in the bonding interaction (and in pure elemental metals, none at all), and the electrons involved in the interaction are delocalized throughout the crystalline structure of the metal.
Metal atoms contain few electrons in their valence shells relative to their periods or energy levels. Such electrons can stray easily from the atoms and become delocalized, forming a sea of electrons permeating a giant lattice of positive ions. The freedom of conduction electrons to migrate gives metal atoms, or layers of them, the capacity to slide past each other, giving rise to metals' typical characteristic phenomena of malleability and ductility.
The electrons and positive ions in metals have a strong attractive force between them. Much energy is required to overcome it. Therefore, metals often have high melting and boiling points. The principle is similar to that of ionic bonds.
Because metals' conduction electrons move independently in a sea of negative charge, metals exhibit electrical conductivity, allowing charge to pass quickly through them, manifested as current. A few non-metals conduct electricity, notably graphite (which, like metals, has free electrons) and molten and aqueous ionic compounds, which have free ions.
Heat conduction works on the same principle; free electrons can transfer energy at a faster rate than the fixed electrons of other substances, such as those which are covalently bonded.
Metal atoms have at least one valence electron which they do not share with neighboring atoms, nor do they lose electrons to form ions. Instead the outer energy levels of the metal atoms overlap. They are similar to covalent bonds.