Persius/hicric huggingface dataset:
Headache overview

# Overview
A headache is a condition of pain in the head; sometimes neck or upper back pain may also be interpreted as a headache. It ranks amongst the most common local pain complaints.

# Historical Perspective
The first recorded classification system that resembles the modern ones was published by Thomas Willis, in De Cephalalgia in 1672. In 1787 Christian Baur generally divided headaches into idiopathic (primary headaches) and symptomatic (secondary ones), and defined 84 categories.

# Pathophysiology
The brain in itself is not sensitive to pain, because it lacks pain-sensitive nerve fibers. Several areas of the head can hurt, including a network of nerves which extend over the scalp and certain nerves in the face, mouth, and throat. The meninges and the blood vessels do have pain perception. Headaches often result from traction to or irritation of the meninges and blood vessels. The muscles of the head may similarly be sensitive to pain.

# Causes
The vast majority of headaches are benign and self-limiting. Common causes are tension, Neck pain, migraine, eye strain, dehydration, low blood sugar, and sinusitis. The vast majority of chronic headaches are multifactoral in nature. Much rarer are headaches due to life-threatening conditions such asmeningitis, encephalitis, cerebral aneurysms, extremely high blood pressure, and brain tumors. When the headache occurs in conjunction with a head injury the cause is usually quite evident. A large percentage of headaches among females are caused by ever-fluctuating estrogen during menstrual years. This can occur prior to, during or even midcycle menstruation.

# Natural History, Complications and Prognosis
The prognosis of headache depends on the underlying cause.

# Diagnosis

## Laboratory Findings
Blood tests may help narrow down the differential diagnosis, but are rarely confirmatory of specific headache forms.

## CT
Computed tomography (CT/CAT) scans of the brain or sinuses are commonly performed.

## MRI
Magnetic resonance imaging (MRI) of the brain and sinuses are done in specific settings.

# Treatment

## Medical Therapy
Headaches may be successfully treated through medical therapies such as analgesisa and, in some cases, a tandem approach with implanted electrodes.

## Primary Prevention
Some forms of headache, such as migraine, may be amenable to preventative treatment.
Sphincter of Oddi

# Overview
The Sphincter of Oddi, also called the hepatopancreatic sphincter or Glisson's sphincter, controls secretions from the liver, pancreas, and gallbladder into the duodenum of the small intestine.
It is a sphincter muscle located at the surface of the duodenum. It appears slightly distal to the joining of the common bile duct and pancreatic duct as they enter the descending duodenum and forms from the ampulla of Vater. Bile and pancreatic secretions enter the digestive system through this point. The opening on the inside of the descending duodenum after the sphincter of Oddi is called the major duodenal papilla.

# Clinical significance
Endoscopic retrograde cholangiopancreatograms (ERCPs), which are radiographic examinations of the biliary system, often involve assessment of the bile ducts with a esophagogastroduodenoscopy via the sphincter of Oddi before the injection of iodinated contrast medium.
Hirschberg's test
In the fields of ophthalmology and optometry, the Hirschberg test, also Hirschberg corneal reflex test, is a screening test that can be used to assess whether a person has strabismus (ocular misalignment).
A photographic version of the Hirschberg is used to quantify strabismus. 

# Technique
It is performed by shining a light in the persons eyes and observing where the light reflects off of the corneas.  In a person with normal ocular alignment the light lands on the centre of both corneas.  For an abnormal result, based on where the light lands on the cornea, the examiner can detect if there is an exotropia (abnormal eye is turned out), esotropia (abnormal eye is turned in), hypertropia (abnormal eye higher than the normal one) or hypotropia (abnormal eye is lower than the normal one).

## Interpretation
In exotropia the light lands on the medial aspect of the cornea.  In esotropia the light lands on the lateral aspect of the cornea.  In hypertropia the light lands on the inferior aspect of the cornea.  In hypotropia the light lands on the superior aspect of the cornea. A cover test can tell you the extent of the eso/exotropia.
Individuals can suffer from several tropias at once.  In Graves ophthalmopathy, it is not uncommon to see an esotropia (due to pathology of the medial rectus muscle) co-morbid with a hypotropia (due to pathology of the inferior rectus muscle).

# History
The technique was developed by German ophthalmologist Julius Hirschberg who in 1886 used a candle to observe the light reflex in an eye with strabismus.
Hofmeister series
The hofmeister series is a classification of ions in order of their ability to change water structure. The effects of these changes were first worked out by Franz Hofmeister, who studied the effects of cations and anions on the solubility of proteins.
Hofmeister discovered a series of salts that have consistent effects on the solubility of proteins and (it was discovered later) on the stability of their secondary and tertiary structure.  Anions appear to have a larger effect than cations, and are usually ordered
\mathrm{F^{-} \approx SO_{4}^{2-} > HPO_{4}^{2-} > acetate > Cl^{-} > NO_{3}^{-} > Br^{-} > ClO_{3}^{-} > I^{-} > ClO_{4}^{-} > SCN^{-}}
(This is a partial listing; many more salts have been studied.)
The order of cations is usually given as
\mathrm{NH_{4}^{+} > K^{+} > Na^{+} > Li^{+} > Mg^{2+} > Ca^{2+} > guanidinium}
The mechanism of the Hofmeister series is not entirely clear, but does not seem to result from changes in general water structure, instead more specific interactions between ions and proteins and ions and the water molecules directly contacting the proteins may be more important.
Early members of the series increase solvent surface tension and decrease the solubility of nonpolar molecules ("salting out"); in effect, they strengthen the hydrophobic interaction.  By contrast, later salts in the series increase the solubility of nonpolar molecules ("salting in") and increase the order in water; in effect, they weaken the hydrophobic effect. The salting out effect is commonly exploited in protein purification through the use of ammonium sulfate precipitation.
However, these salts also interact directly with proteins (which are charged and have strong dipole moments) and may even bind specifically (e.g., phosphate and sulfate binding to ribonuclease A). Ions that have a strong 'salting in' effect such as I- and SCN- are strong denaturants, because they salt in the peptide group, and thus interact much more strongly with the unfolded form of a protein than with its native form.  Consequently, they shift the chemical equilibrium of the unfolding reaction towards unfolded protein.
Hollywood (slang)
A Hollywood is a drug slang term referring to an unusually large and often dangerous single dosage, or line, of cocaine.
Depending on a user's experience with and tolerance of the drug, a typical line measures between 50-75mg of cocaine. However, a Hollywood line can exceed 200mg of cocaine in a single dosage. The term is derived from the very public, excessive, and often overindulgent use of cocaine by celebrities and other affluent residents in Hollywood.
A Hollywood line is a high-risk method of using cocaine and is much more dangerous than taking the same dosage in smaller increments over a period of hours. A cocaine overdose is typically caused by acute overuse of the drug rather than sustained use which can result in cardiac arrhythmias, hyperthermia, and other complications relating to increased heart rate, blood pressure, and increased adrenaline production. Large single doses of cocaine taken intranasally (snorted) are much more irritating to the mucous membranes of the nasal passages and can hasten the development of nasal ulcers and perforations of the septum.
Houston Food Bank
The Houston Food Bank is the fifth largest food bank in the United States and a member of America's Second Harvest. Founded in 1982, The Houston Food Bank is a private non-profit organization dedicated to combating hunger and food insecurity. The Houston Food Bank provides food to over 400 non-profit, hunger-relief agencies in southeast Texas. Within the 18-county service area, the Houston Food Bank serves a variety of programs including: food pantries, shelters for the homeless, safe havens for battered women, and nutrition centers for children and the elderly. In addition to providing nutritious food for approximately 80,000 individuals each week, the Houston Food Bank also provides nutrition education programs to the local community. These programs -- Backpack Buddy, Community Kitchen, Kids Cafe, and Operation Frontline empower participants with the knowledge and skills to make healthy food choices. For every dollar donated to the Houston Food Bank, $8.00 of wholesome nutritious food is distributed to individuals and families in need.
In 2005, the Houston Food Bank distributed over 38 million pounds of food  approximately 63,000 meals per day. As a primary food resource for many partner agencies and their clients, the Houston Food Bank acts as a safety net against hunger and food insecurity for the Houston metro community.
In the six months following Hurricane Katrina, the Houston Food Bank more than doubled its standard distribution rate of food and personal hygiene productsdistributing 7,800,000 pounds of disaster relief items to local agencies serving hurricane survivors. 
The Houston Food Bank has been noted for its low overheard  2.7% of operation costs.
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Human development
Human development may refer to:
- Human development (biology)
- "Human development (psychology)" or developmental psychology
- Human development can refer to anthropological, sociological, and psychological approaches to examining human development in context
- Human development (international or economic)
- Occasionally, it may refer to more than one of the above meanings.  Because each of these is an immense field of study, few if any contemporary academic discussions attempt to tackle both in a comprehensive way.  More typically, psychologists will take account of biological factors in their psychological analysis, and vice versa for biologists.
- Occasionally, it may refer to more than one of the above meanings.  Because each of these is an immense field of study, few if any contemporary academic discussions attempt to tackle both in a comprehensive way.  More typically, psychologists will take account of biological factors in their psychological analysis, and vice versa for biologists.
- Development as in international development or sustainable development
The Human Development Index is a comparative measure of the well-being of people in various world nations.
- The Human Development Index is a comparative measure of the well-being of people in various world nations.
Hydrogen fluoride
Hydrogen fluoride is a chemical compound with the formula HF. Together with hydrofluoric acid, it is the principal industrial source of fluorine and hence the precursor to many important compounds including pharmaceuticals and polymers (e.g. Teflon).  HF is widely used in the petrochemical industry and a component of many superacids. HF boils just below room temperature whereas the other hydrogen halides condense at much lower temperatures.  Aqueous solutions of HF, called hydrofluoric acid, are strongly corrosive.

# Structure of HF
HF forms orthorhombic crystals, consisting of zig-zag chains of HF molecules.  The HF molecules, with a short H-F bond of 0.95 A, are linked to neighboring molecules by intermolecular H--F distances of 1.55 A.
Liquid HF also consists of chains of HF molecules, but the chains are shorter, consisting on average of only five or six molecules. The higher boiling point of HF relative to analogous species, such as HCl, is attributed to hydrogen bonding between HF molecules, as indicated by the existence of chains even in the liquid state.

# Acidity
Dilute hydrogen fluoride solution is a weak acid due to the extensive intermolecular H-bonds present. The molecules tend to remain in chains rather than ionize to form H+ and F ions.
But in a more concentrated hydrogen fluoride solution, F ions forms a soluble (aq) complex with HF molecules. HF molecules remaining ionize to compensate the loss of F ions. More H+ ions are thus formed, making concentrated HF an effectively strong acid.
Anhydrous hydrogen fluoride is an extremely strong acid (H0 ~ -11), comparable in strength to anhydrous sulfuric acid (H0 ~ -12).

# Uses
HF is used for fluorinating polymers giving fluorocarbons, petroleum refining, glassmaking, aluminium manufacturing, titanium pickling, quartz purification, and metal finishing. It is also used to synthesize UF6, which is key to separating uranium isotopes.
Hydrogen fluoride can be found in consumer products for removing rust, cleaning brass, and glass etching, although use in consumer products is discouraged due to HF's corrosiveness and toxicity. Hydrogen fluoride is typically marketed in three common forms: anhydrous HF, aqueous 70% HF, aqueous 49% HF. HF is manufactured by the reaction of calcium fluoride (fluorspar) and sulfuric acid:
The vapors from this reaction are a mixture of hydrogen fluoride, sulfuric acid, and a few minor byproducts.

# Health effects
Upon contact with moisture, including tissue, hydrogen fluoride immediately converts to hydrofluoric acid, which is highly corrosive and toxic.
Hydrogen selenide
Hydrogen selenide is H2Se, the simplest hydride of selenium.  H2Se is a colorless, flammable gas under standard conditions.  It is the most toxic selenium compound with an exposure limit: 0.3 ppm over an 8 hour period.  This compound has a very irritating smell of decayed horseradish.

# Structure
H2Se adopts a "bent" structure with a H-Se-H bond angle of 91.  Consistent with this structure,  three IR-active vibrational bands are observed: 2358, 2345, and 1034 cm1.

# Properties
The properties of H2S and H2Se are similar,  although the selenide is more acidic with pKa = 3.89, and the second pKa = 11.0 at 25C.  Reflecting its acidity, H2Se is soluble in water.

# Preparation
H2Se can be purchased in cylinders.  A number of routes to H2Se have been reported, which are suitable for both large and small scale preparations.
- H2Se is usually prepared by the action of water on Al2Se3, concomitant with formation of hydrated alumina.  A related reaction involves the acid hydrolysis of FeSe.
- According to the Sonoda method, H2Se is generated from the reaction of H2O and CO on Se in the presence of Et3N.
- H2Se can by synthesized by the direct reaction of H2 with elemental selenium at >350C.
Selenium metal can be recovered from H2Se through a reaction with aqueous sulfur dioxide (SO2).

# Applications
- H2Se is commonly used in the synthesis of Se-containing compounds; it adds across alkenes.  Illustrative is the synthesis of selenoureas from nitriles.
- H2Se gas is used to dope semiconductors with selenium.
Hydropneumothorax
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# Overview
Hydropneumothorax implies presence of both air and fluid in the pleural space ( i.e. between two layers of pleura).

# Causes
- Iatrogenic: Introduction of air during pleural fluid aspiration in effusion.
- Presence of gas forming organism.
- Trauma

# Diagnosis

## Chest X Ray
An erect chest xray will show air fluid level.The horizontal fluid level is usually well defined and extends across the whole length of hemithorax.
Hyperbolic growth
When a quantity grows towards a singularity under a finite variation it is said to undergo hyperbolic growth. This growth is created by non-linear positive feedback mechanisms. Hyperbolic growth is highly nonlinear and it is a stronger form of growth than exponential growth.
Certain mathematical models suggest that the world population undergoes hyperbolic growth. However, since the world population cannot truly become infinite within some finite amount of time such models should only be seen as approximations that may be valid for certain time periods. Of course, the same is true for the exponential growth models that also may be valid for certain time periods only.
Another example of hyperbolic growth can be found in queuing theory: the average waiting time of randomly arriving customers grows hyperbolically as a function of the average load ratio of the server. The singularity in this case is when the average amount of work arriving to the server equals the server's processing capacity. If the processing needs exceed the server's capacity, then there is no well-defined average waiting time, as the queue can grow without bound. (A practical implication of this particular example is that for highly loaded queuing systems the average waiting time can be extremely sensitive to the processing capacity.)
Hypereosinophilia
Hypereosinophilia is a disease characterised by a marked increase in the eosinophil count in the bloodstream.
The eosinophil count in human blood is normally 0.4 x 109/L (0.1 - 0.6) and results from a balance between production of eosinophils and emigration through post-capillary venules (Yamaguchi et al 1991). Eosinophils are only a small minority of peripheral blood leucocytes and in normal subjects, most are found in the tissues of the lung and gastro-intestinal tract (Beeken et al 1987). Blood eosinophil counts are arbitrarily classified as mild - between 0.6 to 1.5 x 109/L; moderate between 1.5 to 5 x 109/L and severe when greater than 5 x 109/L.
An elevated blood eosinophil count may be associated with a number of reactive conditions and with clonal disorders of the bone marrow. However, when the blood eosinophil count is persistently greater than 1.5 x 109 /L, for a period of more than six months, damage to end organs such as the heart, lungs, skin, joints and nervous system can be demonstrated, and in the absence of any clonal or reactive cause, the term idiopathic hypereosinophilic syndrome (HES) is used.  The three defining criteria of HES are therefore:
1. Eosinophil count persistently greater than 1.5 x 109/L
2. Damage to end-organs
3. No ascertainable cause for the eosinophilia and no evidence of clonality.

# There are three categories of blood eosinophilia:
Reactive (non-clonal) eosinophilia: infections, parasitic infestations, asthma and allergies, respiratory diseases, cytokine infusions, vasculitides, non-haematological malignant diseases, drug reactions and connective tissue diseases, Hodgkin's and non-Hodgkin's lymphomas are included here as the eosinophils have not been shown to be clonal.
Clonal Disorders of the Bone Marrow associated with eosinophilia: Acute and chronic eosinophilic leukaemia, chronic myeloid leukaemia, polycythaemia rubra vera, essential thrombocythaemia, acute myeloid leukaemia. Chromosome 16 variants, the 8p11 myeloproliferative syndrome (EMS) and T lymphoblastic lymphoma with eosinophilia, acute lymphoblastic leukaemia, myelodysplastic disorders (MDS) with eosinophilia, systemic mastocytosis and acute lymphoblastic leukaemia (Bain 1996).
HES: After exclusion of the above two categories, cases of persistent, unexplained eosinophilia fall into the category of HES.
Hyperglycerolemia

# Overview
Hyperglycerolemia is a condition characterized by high levels of glycerides, including monoglycerides, diglycerides and triglycerides, in the blood stream. It is an X-linked genetic disorder caused by a mutation or deletion of Xp21.2, the glycerol kinase gene.
It is often accompanied with adrenal hypoplasia, whose locus is near that of hyperglycerolemia.
Hyperglycerolemia is also referred to as "glycerol kinase deficiency", "gk deficiency", "gkd", and "gk1 deficiency".