Persius/hicric huggingface dataset:
Hematoma
Synonyms and keywords: Haematoma

# Overview
A hematoma, or haematoma, is a collection of blood, generally the result of hemorrhage, or, more specifically, internal bleeding. Hematomas exist as bruises (ecchymoses), but can also develop in organs. Hematomas can also be under the nails, causing a brown-black discoloration. Some hematomas form into a welt- like formation that is hard to the touch, which is a sac of blood that the body creates to keep internal bleeding to a minimum. In most cases the sac of blood eventually dissolves, however in some cases they may continue to grow or show no change. If the sac of blood does not disappear it may need to be surgically removed.
It is not to be confused with hemangioma which is an abnormal build up of blood vessels in the skin or internal organs.
Hematomas can gradually migrate, as the effused cells and pigment move in the connective tissue. For example, a patient who injures the base of his thumb might cause a hematoma which will slowly move all through the finger within a week. Gravity is the main determinant of this process.
Hematomas on articulations can reduce mobility of a member and present roughly the same symptoms as a  fracture.

# Classification
- Head/brain:
Subgaleal hematoma  between the galea aponeurosis and periosteum
Cephalhematoma  between the periosteum and skull
Epidural hematoma  between the skull and dura mater
Subdural hematoma  between the dura mater and arachnoid mater
Subarachnoid hematoma  between the arachnoid mater and pia mater (the subarachnoid space)
- Subgaleal hematoma  between the galea aponeurosis and periosteum
- Cephalhematoma  between the periosteum and skull
- Epidural hematoma  between the skull and dura mater
- Subdural hematoma  between the dura mater and arachnoid mater
- Subarachnoid hematoma  between the arachnoid mater and pia mater (the subarachnoid space)
- Perichondral hematoma (ear)

# Degrees of Hematoma
- Hematoma - bruise
- Petechiae - hematoma less than 12 mm in diameter
- Purpura - hematoma of 13 mm to 25 mm in diameter
- Ecchymoses or eccymosis - hematoma of greater than 25 mm in diameter
Hairball

# Overview
A hairball is a small collection of hair or fur formed in the stomach of animals that is occasionally vomited up when it becomes too big. Hairballs are primarily a tight elongated cylinder of packed fur, but may include bits of other elements such as swallowed food. Hairballs are sometimes mistaken for other conditions of the stomach such as lymphosarcoma, tuberculosis, and tumour of the spleen.  Cats are especially prone to hairball formation since they groom themselves by licking their fur, and thereby ingest it. Rabbits are also prone to hairballs because they groom themselves in the same fashion as cats, but hairballs are especially dangerous for rabbits because they cannot regurgitate them. Because the digestive system of a rabbit is very fragile, rabbit hairballs must be treated immediately or they may cause the animal to stop feeding and ultimately die due to dehydration. Cattle are also known to accumulate hairballs, but as they do not vomit, these are found usually after death and can be quite large.

# Clinical significance
A trichobezoar is a bezoar (a mass found trapped in the gastrointestinal system) formed from the ingestion of hair.  Trichobezoars are often associated with trichotillomania (compulsive hair pulling), are rare, and can be fatal if undetected.  Surgical intervention is often required.

# Diagnosis

## Physical Examination

### Hair
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.
- Trichotillomania-trichobezoars. Adapted from Dermatology Atlas.

# Society and culture
Although uncommon in humans, some hairballs have been reported. These hairballs occur when hair strands collect in the stomach and are unable to be ejected as a result of the friction on the surface of the gastric mucosa. Hairballs are often seen in young girls as a result of trichophagia, trichotillomania and pica. In 2003, a 3-year old girl in Red Deer, Alberta, Canada had a grapefruit-sized hairball surgically removed from her stomach; in 2004, an 18-year old woman from McAdam, New Brunswick, Canada, had a 2.3 kg hairball surgically removed from her lower intestine; and in 2014, a 9 pound hairball was removed from the stomach of an 18-year old in Kyrgyzstan. Hairballs can be quite hazardous in humans, since hair cannot be digested or passed by the human gastrointestinal system, and (assuming it is identified) even vomiting may be ineffective at removing the hair mass. This can result in the general impairment of the digestive system.
Halfsies
Halfsies were a breakfast cereal manufactured by Quaker Oats from 1983 through 1984.  They were the result of the so-called "sugar backlash" in which the amount of sugar in children's breakfast cereals became an issue.  The premise was they contained half the sugar of regular breakfast cereals.  The cereal nuggets were shaped as half a normal cereal ring, like the letter C.
They were corn based and, essentially, were Cap'n Crunch (another Quaker Oats product) with half the sugar and a slightly different texture.
The marketing campaign was headed by the King of The Land of Half who presided over The Land of Half.  The box featured Half Land where houses, cars, food, etc. was all cut in half (i.e. only half of a house would be present with the walls open on one half and you could see into the house, etc.)
Halfsies were discontinued due to poor sales.
Hangnail
A hangnail or agnail is a small, loose strip of torn skin near a fingernail or toenail. Hangnails are usually caused by dry skin or (in the case of fingernails) nail biting, and may be prevented with proper moisturization of the skin.
When attempting to remove a hangnail, additional skin may be painfully ripped off if its attachment is not broken properly. This may lead to a painful infection called paronychia.  Therefore, hangnails should usually be cut using nail scissors or a nail clipper; biting them frequently makes it worse. People with a hangnail should be careful to cut it all off and rub hand lotion into the cuticles two to three times a day. 
The term "hangnail" is misleading, as a hangnail is not an actual part of the nail. It's dead, dried skin, not nail, the latter being made up of mostly calcium and a fibrous protein, known as keratin.

# Etymology
Agnail is the Middle English term meaning "corn on the foot." It comes from the Old English term angngl (from ang- tight/painful + ngl- nail). Agnail was adapted to hangnail by a process of folk etymology.
Heat map
A heat map is a graphical representation of data where the values taken by a variable in a two-dimensional map are represented as colours. A very similar presentation form is a Tree map.
Heat maps are typically used in Molecular Biology to represent the level of expression of many genes across a number of comparable samples (e.g. cells in different states, samples from different patients) as they are obtained from DNA microarrays.
Heat maps are also used in places where the data is volatile and representation of this data as a heat map improves usablity. For example, NASDAQ uses heat maps to show the NASDAQ 100 index volatility. There are also heat maps for showing the housing price in various regions.
Hemozoin
Hemozoin is a disposal product formed from the digestion of blood by some blood-feeding parasites. Haematophagous organisms such as Malaria parasites (Plasmodium spp.), Rhodnius and Schistosoma digest hemoglobin  and release high quantities of free heme, which is the non-protein component of hemoglobin. A heme or haem is a prosthetic group that consists of an iron atom contained in the center of a large heterocyclic organic ring called a porphyrin. This process is much-studied in Plasmodium since it is an attractive target for developing drugs to treat malaria.

# Formation
The monomeric and potentially toxic -hematin (ferriprotoporphyrin IX) is detoxified by biocrystallization into insoluble, chemically inert  -hematin crystals (hemozoin).  Several mechanisms have been proposed for this reaction and the area is controversial, with membrane lipids, histidine-rich proteins, or even a combination of the two, being proposed to catalyse the formation of hemozoin.

# Structure
In -hematin a unique iron oxygen coordinate bond links the central iron of one heme to the oxygen of the carboxylate side chain of the adjacent heme. -hematin can either be a cyclic dimer or a linear polymer , a polymeric form has never been found in hemozoin. Hemozoin crystals have a distinct triclinic structure and are weakly magnetic. They also exhibit optical dichroism, which means that they absorb light more strongly along their length than across their width, and this allows the automated detection of malaria. Hemozoin  is produced in a form that under the action of an applied magnetic field gives rise to an induced optical dichroism characteristic of the hemozoin concentration and  precise measurement of this induced dichroism may be used to determine the level of malarial infection.
Hemp oil
Hemp oil can be extracted from the seed of the hemp plant, which contains between 30-35% oil by weight, which is high in essential fatty acids. The plant can also be pressed for oil. Cold-pressed, unrefined hemp oil is light green, with a nutty, grassy flavour.
Refined hemp oil is clear with little flavour. It is widely used in body care products, lubricants, paints and industrial uses. 
Antimicrobial properties make it a useful ingredient for soaps, shampoos and detergents. The oil is of high nutritional value because its 3:1 ratio of omega-6 to omega-3 essential fatty acids matches the balance required by the human body. It has also received attention in recent years as a possible source of biodiesel. There are a number of organisations that promote the production and use of hemp oil.
Hemp oil is deliberately manufactured to contain no significant amounts of THC and is not considered as a psychoactive drug.

# Nutrition
3035% of the weight of hempseed is oil containing 80% essential fatty acids (EFAs), linoleic acid (LA, 50-70%), alpha-linolenic acid (ALA, 1525%) and Gamma-Linolenic acid (GLA, 16%).  The proportions of linoleic acid and alpha-linolenic acid in hempseed oil meet human requirements for EFAs. Unfortunately the unsaturated fat makes the oil rancid quickly, unless it is stored in dark coloured bottles or mixed with chemical preservatives. This makes hemp oil difficult to transport or store.  The high unsaturated fat content also makes the oil unsuitable for frying. This severely limits hemp oil's potential on the food market, although some marketing potential exists as a nutritional supplement.  Cooking of any oil reduces its nutritional value, and may convert beneficial fatty acids to less benign substances.
Hepatica
Hepatica is a genus of herbaceous perennial plants belonging to the buttercup family, Ranunculaceae. A native of central and northern Europe, Asia and northeastern North America, Hepatica is sometimes called liverleaf or "liverwort". It should not be confused with liverworts, which may also be called "Hepaticae". A few botanists include Hepatica within a wider interpretation of Anemone, as Anemone hepatica.
Between two and ten species of Hepatica are recognised, with some of the taxa more often treated as varieties:
- Hepatica nobilis - Common Hepatica
H. nobilis var. pyrenaica (H. pyrenaica) - Pyrenees
H. nobilis var. japonica (H. japonica) - Japan
H. nobilis var. nobilis - European Hepatica - Alps north to Scandinavia
H. nobilis var. pubescens (H. pubescens) - Japan
H. nobilis var. acuta (H. acutiloba) - Sharp-lobed Hepatica - North America
H. nobilis var. obtusa (H. americana) - Round-lobed Hepatica - North America
- H. nobilis var. pyrenaica (H. pyrenaica) - Pyrenees
- H. nobilis var. japonica (H. japonica) - Japan
- H. nobilis var. nobilis - European Hepatica - Alps north to Scandinavia
- H. nobilis var. pubescens (H. pubescens) - Japan
- H. nobilis var. acuta (H. acutiloba) - Sharp-lobed Hepatica - North America
- H. nobilis var. obtusa (H. americana) - Round-lobed Hepatica - North America
- Hepatica transsilvanica - Carpathian Mountains and Transylvania
Hepatica cultivation has been popular in Japan since the 18th Century (mid-Edo period),  where flowers with doubled petals and a range of colour patterns have been developed .
Noted for their tolerance of alkaline limestone-derived soils, Hepatica may grow in a wide range of conditions; it can be found either in deeply shaded deciduous (especially beech) woodland and scrub or grassland in full sun. Hepatica will also grow in both sandy and clay-rich substrates, being associated with limestone. Moist soil and winter snowfall is a requirement; Hepatica is tolerant of winter snow cover, but less so of dry frost.
Hepatica reaches a height of 10 cm and produces hermaphroditic flowers from February to May. The leaves are basal and dark leathery green, each with three lobes. The flowers may be white, bluish purple or pink; they are supported singly on hairy, largely leafless stems. Butterflies, moths, bees, flies and beetles are known to act as pollinators for Hepatica.
Hepatica is named from its leaves, which, like the human liver (Greek hepar), have three lobes. It was once used as a medicinal herb. Owing to the doctrine of signatures, the plant was thought an effective treatment for liver disorders. Although poisonous in large doses, the leaves and flowers may be used as an astringent, demulcent for slow-healing injuries and as a diuretic .

# Gallery
- Hepatica nobilis
Hepatica nobilis
- Hepatica nobilis
Hepatica nobilis
- Hepatica nobilis
Hepatica nobilis
Lymphoma

# Overview
Lymphoma is  a type of cancer that originates in lymphocytes (a type of white blood cell in the vertebrate immune system). There are many types of lymphoma. Lymphomas are part of the broad group of diseases called hematological neoplasms. It was discovered by Thomas Hodgkin in 1832 and was called Hodgkin's Disease throughout the 19th and 20th centuries. Colloquially, lymphoma is broadly categorized as Hodgkin's lymphoma or non-Hodgkin lymphoma (all other types of lymphoma). Scientific classification of the types of lymphoma is more detailed. Although older classifications referred to histiocytic lymphomas, these are recognized in newer classifications as of B, T or NK cell lineage. Histiocytic malignancies are rare and are classified as sarcomas.

# Classification

# Differentiating Lymphoma From Other Diseases
CNS lymphoma must be differentiated from other causes of seizures, headache, and fever in immunocompromised patients such as disseminated tuberculosis and disseminated aspergillosis.

# Epidemiology and Demographics
- According to the U.S. National Institutes of Health, lymphomas account for about five percent of all cases of cancer in the United States.
- Hodgkin's lymphoma in particular accounts for less than one percent of all cases of cancer in the United States
Oligomer

# Overview
In chemistry, an oligomer consists of a finite number of monomer units (, or oligos, is Greek for "a few"), in contrast to a polymer which, at least in principle, consists of an unbounded number of monomers.
In biochemistry, the term oligomer is used for short, single stranded DNA fragments, generally used in hybridization experiments (bound to glass slides or nylon membranes). It can also refer to a protein complex made of two or more subunits. In this case, a complex made of several different protein subunits is called a hetero-oligomer. When only one type of protein subunit is used in the complex, it is called homo-oligomer.
In oligomerization a chemical process only converts monomers to a finite degree of polymerization. The actual figure is a matter of debate, often a value between 10 and 100.
Hexacene
Hexacene is an aromatic molecule consisting of six linearly-fused benzene rings. Hexacene and its derivatives are investigated for potential applications as organic semiconductor.
Hexacene is one of a series of linear acenes, the previous one being pentacene (five fused benzene rings)  and the next one being heptacene (seven fused benzene rings) .
Hexacene is very unstable, being highly reactive in the 6, 15 positions due to pi electron localization. Its spectra must be collected on freshly purified samples handled in an inert atmosphere such as nitrogen or argon. Only with very large substituents it is possible to isolate an hexacene for instance the compound 6,15-bis(tri-t-butylsilylethynyl)hexacene which melts with decomposition at 96C. 
The first reported synthesis of hexacene itself dates back to 1942  In 1955 the compound is synthesized by dehydrogenation of hexacosadehydrohexacene by palladium on carbon . In 1982 hexacene is reported as a bluish green compound with decomposition at 380 degrees . In 2007, a research group claimed the first reproducible unsubstituted hexacene synthesis (invalidating the previous claims) based on photochemical decarbonylation of a dione precursor :
The compound cannot be isolated: it dimerizes even at concentration as low as 10-4 M and reacts in solution with oxygen to the organic peroxide. In a PMMA polymer matrix on the other hand these side-reactions are limited and the compound can survive up to 12 hours. The next homologue heptacene also studied by this group, is even more unstable (decomposes within 4 hours).
Hfr cell
An hfr cell (also called hfr strain) is a bacterium with a conjugative plasmid (often F) integrated into its genomic DNA. Hfr is the abbreviation for high frequency recombination, which was first characterized by Luca Cavalli-Sforza. Unlike a normal F+ cell, hfr strains will, upon conjugation with a F cell, attempt to transfer their entire DNA through the mating bridges (called pili) to the F cell.  This occurs because the F factor has integrated itself via an insertion point in the bacterial chromosome. Due to the F factor's inherent nature to transfer itself over the pilus during bacteria conjugation, the rest of the bacterial genome is dragged along with it, thus making such cells very useful and interesting in terms of studying gene linkage and recombination. Because the genome's rate of transfer through the pilus is constant, molecular biologists and geneticists can use Hfr strain of bacteria (often E. coli) to study genetic linkage and map the chromosome. The procedure commonly used for this is called interrupted mating.
A bacterium may undergo conjugation. During this process, genetic material is transferred to another bacterium through the sex pili. To form sex pili and donate DNA during conjugation, an F plasmid is required. The F plasmid consists of around 25 genes which are mostly required for the production of the sex pili. F+ denotes cells that contain the F plasmid, while F cells do not. The F plasmid is considered to be an episome which may become integrated into the main chromosome. When the F genes become integrated into the chromosome, the cell is said to be Hfr (high frequency of recombination). An Hfr cell may transfer F genes to an F cell. During this transfer of genetic material, the F episome may take chromosomal DNA with it. The donor cell does not lose any genetic material as anything transferred is also replicated concurrently. It is extremely rare that an Hfr cell's chromosome is transferred in its entirety. Homologous recombination occurs when the newly acquired DNA crosses over with the homologous region of its own chromosome.
A structure as fragile as a mating bridge will, however, likely break, and so the transfer is rarely complete.  Thus, the F cell uses only part of the genomic DNA of the Hfr cell for recombination. Though there is some debate on the issue, the pili themselves do not seem to be the structures through which the actual exchange of DNA takes place; rather, some proteins seem to open a channel between the bacteria.
de:Hfr-Stamm
Horchata
Horchata or orxata is the name for several kinds of vegetable beverages, made of ground almonds, rice, barley or tigernuts (chufas).

# Etymology
The name comes from Valencian orxata, probably from ordiata, made from  ordi (barley) (Latin *hordeata < hordeum). The French and English 'orgeat', the Italian 'orzata', and the Surinamese Dutch orgeade have the same origin, though the beverages themselves have diverged, and none of them is typically made from barley anymore. 
According to a folk etymology, James I of Aragon was offered a glass of the beverage by an Arab girl after his conquest of Valencia, and exclaimed, Aixo es or, xata! (This is gold, girl!).

# Spain
In Spain, it usually refers to orxata de xufes (horchata de chufas), made from tigernuts, water and sugar. Originally from Valencia, it is served ice cold as a refreshment. It has a regulating council to ensure the quality of the product and the villages where it can come from, with the Denomination of Origin. Classics get an A. The village of Alboraia is well known for the quality of their horchatas.  The idea of making horchata from tigernuts comes from the period of Muslim presence in Valencia (from the 8th to 13th century).

# Latin America
While in some countries the drink is usually tan and "milky", some recipes call for milk, and others do not. Other ingredients often include sugar, cinnamon, and vanilla. Though horchata was once typically homemade, it is now available in both ready-to-drink (shelf-stable or refrigerated) and powdered form in grocery stores.
In the US, rice-based or morro horchata is served in many Mexican restaurants, and the horchata de chufas is virtually unknown. Rice-based horchata is also sometimes available in US grocery and convenience stores, especially in Latino neighborhoods.
Horchata, together with tamarindo and jamaica, are the three typical drink flavors of Mexican aguas frescas.
The horchata found in El Salvador is often made of a mixture of herbs, not rice. In El Salvador, horchata is typically flavored with Morro (Calabash tree) seed, ground cocoa and cinnamon as well as sesame seeds, and in some cases is strained.
In Nicaragua and Honduras horchata refers to the drink known as semilla de jicaro, made from the Jicaro seeds ground up with rice and spices. The drink is made with cold milk and sugar and is very popular nationally. Recently Nicaragua has began exporting this product primarily to the United States.

# As an alcoholic mixer
Some Latin-American bars in Southern California use horchata as a mixer in a cocktail known as a Rice Rocket. The drink is made of 2 parts horchata, 1 part coconut-flavored rum and a dash of Goldschlager over ice.