Persius/hicric huggingface dataset:
Scalene muscles
The scalene muscles are a group of three pairs of muscles in the lateral neck, namely the scalenus anterior, scalenus medius, and scalenus posterior.  They originate from the transverse processes from the cervical vertebrae of CII to CVII and insert onto the first and second ribs.  Thus they are called the lateral vertebral muscles. They are innervated by the spinal nerves C3-C7.  The action of the anterior and middle scalene muscles is to elevate the first rib and rotate the neck to the opposite side; the action of the posterior scalene is to elevate the second rib and tilt the neck to the same side.
The scalene muscles have an important relationship to other structures in the neck.  The brachial plexus and subclavian artery pass between the anterior and middle scalenes.  The subclavian vein and phrenic nerve pass anteriorly to the anterior scalene as it crosses over the first rib.
They also act as accessory muscles of inspiration, along with the sternocleidomastoids.
The passing of the brachial plexus and the subclavian artery through the space of the anterior and middle scalene muscles constitute the scalene hiatus. The region in which this lies is referred to as the scaleotracheal fossa. It is bound by the clavicle inferior anteriorly, the trachea medially, posteriorly by the trapezius, and anteriorly by the platysma muscle. If you look closely, you can also see the branches off that subclavian which will form the common carotid artery, which will further go up and split into the two branches, internal and external located at the junction of the carotid sinus.  With these you will also see the Vagus Nerve (Cranial nerve X)
Law of identity
In logic, the law of identity states that an object is the same as itself (A  A).  Any reflexive relation upholds the law of identity; when discussing equality, the fact that "A is A" is a tautology.
In philosophy, the law is often mistakenly attributed to Aristotle, who actually wrote:
Wilhelm Wundt credits Gottfried Leibniz with the symbolic formulation, "A is A."
In 2002 Jonathon Keats held a petition drive to pass, A=A  as statutory law in Berkeley, California. Specifically, the proposed law stated that, "every entity shall be identical to itself". Any entity caught being unidentical to itself was to be subject to a fine of up to one tenth of a cent. The law did not pass. However it did spark a copycat petition drive in Santa Cruz, California.
LeFort fracture

# Overview
LeFort fractures (also spelled as Le Fort fractures) are types of facial fractures that are classic in trauma.  Diagnosis is by physician and is usually done in an Emergency room.  The patient is taken for radiography of the head and neck then after obvious fracture signs the patient is taken to CT scan where sharper images are produced.  To qualify for LeFort Fractures the pterygoid plates must be involved.  Also, look for mobile palate in almost all cases.
There are 3 types of LeFort fractures:
- 1)  LeFort I includes the maxilla
- 2)  LeFort II includes the pyramidal fracture on the nasofrontal suture
- 3)  LeFort III includes total craniofacial malfunction
The Le Fort fracture was named after French surgeon Rene Le Fort (1869-1951).
CT images demonstrate of Lefort 1 fracture

# Related Chapters
- Oral and maxillofacial surgery
- Orthognathic surgery
Lead(II) iodide
Lead (II) iodide (PbI2) is a toxic, yellowish solid. In its crystalline form it is used as a detector material for high energy photons including x-rays and gamma rays.  It is also known as plumbous iodide. The CAS registry number is 10101-63-0. Molecular weight  461.05 g.mol-1.
Lead iodide is toxic due to its lead content.
In the nineteenth century it was used as an artists' pigment under the name Iodine Yellow, but it was too unstable to be useful.
Lead iodide is formed via precipitation by mixing lead(II) nitrate and potassium iodide:
Pb(NO3)2 (aq) + 2KI (aq)    PbI2 (s) + 2KNO3 (aq)
Testicular vein

# Overview
The testicular vein (or spermatic vein), the male gonadal vein, carries deoxygenated blood from its corresponding testis to the inferior vena cava or one of its tributaries.  It is the male equivalent of the ovarian vein, and is the venous counterpart of the testicular artery.
It a paired vein, with one supplying each testis
- The right testicular vein generally joins the inferior vena cava.
- The left testicular vein, unlike the right, often joins the left renal vein instead of the inferior vena cava.
The veins emerge from the back of the testis, and receive tributaries from the epididymis; they unite and form a convoluted plexus, called the pampiniform plexus, which constitutes the greater mass of the spermatic cord; the vessels composing this plexus are very numerous, and ascend along the cord, in front of the ductus deferens.
Below the subcutaneous inguinal ring they unite to form three or four veins, which pass along the inguinal canal, and, entering the abdomen through the abdominal inguinal ring, coalesce to form two veins, which ascend on the Psoas major, behind the peritoneum, lying one on either side of the internal spermatic artery.
These unite to form a single vein, which opens on the right side into the inferior vena cava, at an acute angle; on the left side into the left renal vein, at a right angle.
The spermatic veins are provided with valves.
The left spermatic vein passes behind the iliac colon, and is thus exposed to pressure from the contents of that part of the bowel.
Legius syndrome
Synonyms and keywords: Neurofibromatosis, type 1-like syndrome

# Overview
Legius syndrome (LS) is an autosomal dominant condition characterized by cafe au lait spots.

# Historical Perspective
- It was first described in 2007 and is often mistaken for Neurofibromatosis type I (NF-1).
- The syndrome is named after Eric Legius, Professor at the Katholieke Universiteit Leuven|Catholic University of Leuven.

# Pathophysiology

## Genetics
It is caused by mutations in the SPRED1 gene.

# Differentiating Legius syndrome from other Diseases
Neurofibromatosis type 1
- Features common in neurofibromatosis - lisch nodules, bone abnormalities, neurofibromas, optic nerve gliomas and malignant peripheral nerve sheath tumors - are absent in this condition.
- The similarity of symptoms stem from the fact that the different genes affected in the two syndromes code for proteins that carry out a similar task in the same reaction pathway.
- A genetic test is often the only way to make sure a person has Legius syndrome and not NF-1.
- Because of this difference, Legius syndrome is often seen as the less severe of the two syndromes.

# Diagnosis

## Symptoms
- Learning disabilities
- Developmental delay

## Physical Examination

### Skin
- Nearly all patients show multiple cafe au lait spots.
- Freckles in the armpits and/or groin
- Lipomas

### Head
- Macrocephaly

### Neurologic
- Developmental delay

### Other
- ADHD

## Other Diagnostic Studies
- Genetic testing is necessary to identify the syndrome.
- The test checks for loss of function mutations in the SPRED1 gene.
Levomepromazine

# Overview
Levomepromazine (INN, BAN, USAN), also known as methotrimeprazine (common use in America; sold as Nosinan, Nozinan, Levoprome) is an phenothiazine neuroleptic drug. It is a low-potency antipsychotic (approximately half as potent as chlorpromazine) with strong analgesic, hypnotic and antiemetic properties that is primarily used in palliative care.
Serious side effects include tardive dyskinesia, akathisia, abnormalities in the electrical cycle of the heart, low blood pressure and the potentially fatal neuroleptic malignant syndrome.
As is typical of phenothiazine antipsychotics, levomepromazine is a "dirty drug", that is, it exerts its effects by blocking a variety of receptors, including adrenergic receptors, dopamine receptors, histamine receptors, muscarinic acetylcholine receptors and serotonin receptors.

# Medical uses
Levomepromazine is used for the treatment of psychosis, particular those of schizophrenia, and manic phases of bipolar disorder. It should be used only with caution in the treatment of agitated depressions, as it can cause akathisia as a side effect, which could worsen the agitation.
Levomepromazine is also used at lower doses for the treatment of nausea and insomnia.
Levomepromazine is frequently prescribed and valued worldwide in palliative care medicine for its multimodal action, to treat intractable nausea or vomiting, and for severe delirium/ agitation in the last days of life. Palliative care physicians will commonly prescribe it orally or via subcutaneous syringe drivers in combination with more potent opiate analgesics such as Hydromorphone.

# Adverse effects
The most common side effect is akathisia. Levomepromazine has prominent sedative and anticholinergic/sympatholytic effects (dry mouth, hypotension, sinus tachycardia, night sweats) and may cause weight gain. These side effects normally preclude prescribing the drug in doses needed for full remission of schizophrenia, so it has to be combined with a more potent antipsychotic. In any case, blood pressure and EKG should be monitored regularly.
A rare but life-threatening side effect is neuroleptic malignant syndrome (NMS). The symptoms of NMS include muscle stiffness, convulsions and fever.
Lingual thyroid
Synonyms and keywords: LT

# Overview
Lingual Thyroid (LT) is a rare developmental thyroid anomaly in which the thyroid gland is located in the medial line at the base of the tongue.

# Demographics and Epidemiology

## Incidence
The incidence is 1 in 100,000.  This condition represents 90% of all cases of ectopic thyroid.

## Sex
Females are affected more frequently.

## Age
There is no age predisposition.

# Pathophysiology
Although the pathogenesis of lingual thyroid is not fully understood, it has been speculated to be due to failure of migration of thyroid tissue along the path from ventral floor of the pharynx to its normal location and sequestration within the tongue substance leads to the development of lingual thyroid. 

# Diagnosis

## Symptoms

### Infants and Children
The abnormality may be identified during routine screening.

### Adolescents
Adolescents may present with dysphagia or symptoms of oropharyngeal obstruction.  As a response to the increased metabolic demands for thyroid hormone during puberty, hypertrophy of the gland may be seen.

### Conditions of Metabolic Stress
A similar response is also encountered during other metabolic stress conditions like pregnancy, infections, trauma, menopause. 

## Physical Examination
LT usually presents itself as a midline, nodular mass at the base of the tongue. The surface of the lesion is usually smooth and vascularity can be seen.

## Imaging
A scintigraphic scan is the imaging modality of choice. It detects the ectopic thyroid tissue within the lingual thyroid, and also confirms the presence of a functioning thyroid gland, which is reported to be absent in 70% of LT cases.

## Laboratory Findings
Its reported that up to 70% of patients with lingual thyroid have hypothyroidsm and 10% suffer from cretinism.

# Treatment

## Indications for Treatment
Surgical treatment is indicated when there are symptoms such as dysphagia or dyspnea, and/or complications such as ulceration, bleeding or the presence of rapidly growing mass, suggesting malignant transformation.

## Iodine 131 Ablation
In patient with obstructive symptom, Iodine 131 ablation of the ectopic thyroid tissue has been proven successful and may be less invasive than syrgery.

## Surgical Approaches

### Transoral Approach
The transoral approach is the most frequent approach.

### Lateral Pharyngotomy
Lateral pharyngotomy is useful only in the treatment of lesions located in the posterior wall or lateral walls of hypopharynx. It provides a wide exposure compared to transoral approach.

### Transhyoid Approach
Another approach is transhyoid which is more advantageous than the other two approaches in that it provides wider and a direct exposition through the midline.

# Transplantation of Thyroid Tissue
In patient lacking thyroid tissue in the neck, the lingual thyroid can be excised and autotransplanted to the muscles of the neck.
Lingual tonsils

# Overview
The lingual tonsils are rounded masses of lymphatic tissue that cover the posterior region of the tongue.
They are on the dorsal surface at the base of the tongue.

# Additional images
- Lingual tonsils not labeled, but would be at very back of tongue.
- Lymphatics of the tongue.
Lipohemarthosis

# Overview
Lipohemarthrosis results from the extrusion of fat and blood from bone marrow into the joint space after an intraarticular fracture. Lipohemarthrosis is most common in knee fractures, especially tibial plateau fractures.

# Diagnosis
The imaging findings are
- Because fat floats on the associated blood, a fat-fluid level is present and may be shown on radiographs when the image is taken with a horizontal beam.
- Both CT and MRI can provide a more specific assessment than conventional radiography of the composition of joint effusions.
Patient #1: Lateral tibial plateau fracture
Patient #2: MRI image demonstrates an ankle lipohemarthrosis
Liquid paraffin

# Overview
Medicinal liquid paraffin, also known as paraffinum liquidum, is a very highly refined mineral oil used in cosmetics and for medical purposes.  This is a UK definition (British Pharmacopoeia) and the term may have different uses in other countries.  The cosmetic or medicinal liquid paraffin should not be confused with the paraffin (or kerosene) used as a fuel.
The term paraffinum perliquidum is sometimes used to denote light liquid paraffin. Conversely, the term paraffinum subliquidum is sometimes used to denote a thicker (more viscus/oily) mineral oil.

# Usage and Side effects
Liquid paraffin is considered to have a limited usefulness as an occasional laxative, but is unsuitable for regular use as it can seep from the anus and cause irritation; it can interfere with the absorption of fat-soluble vitamins; it can be absorbed into the intestinal wall and may cause foreign-body granulamatous reactions; and if it enters the lungs it can cause lipoid pneumonia.
Liquid paraffin is also used in combination with magnesium as an osmotic laxative, sold under the trade name Mil-Par (among others).
Lissajous curve
In mathematics, a Lissajous curve (Lissajous figure or Bowditch curve)  is the graph of the system of parametric equations
which describes complex harmonic motion. This family of curves was investigated by Nathaniel Bowditch  in 1815, and later in more detail by Jules Antoine Lissajous in 1857.
The appearance of the figure is highly sensitive to the ratio a/b. For a ratio of 1, the figure is an ellipse, with special cases including circles (A = B,  = /2 radians) and lines ( = 0). Another simple Lissajous figure is the parabola (a/b = 2,  = /2). Other ratios produce more complicated curves, which are closed only if a/b is rational. The visual form of these curves is often suggestive of a three-dimensional knot, and indeed many kinds of knots, including those known as Lissajous knots, project to the plane as Lissajous figures.
Lissajous figures where a=1, b=N (natural number) and \delta=\frac{N-1}{N}\frac{\pi}{2} are Chebyshev polynomials of the first kind of degree N.
Lissajous figures are sometimes used in graphic design as logos. Examples include the logos of the Australian Broadcasting Corporation (a = 1, b = 3,  = /2) and the Lincoln Laboratory at MIT (a = 4, b = 3,  = 0).
Prior to modern computer graphics, Lissajous curves were typically generated using an oscilloscope (as illustrated).  Two phase-shifted sinusoid inputs are applied to the oscilloscope in X-Y mode and the phase relationship between the signals is presented as a Lissajous figure.  Lissajous curves can also be traced mechanically by means of a harmonograph.
In oscilloscope we suppose x is CH1 and y is CH2, A is amplitude of CH1 and B is amplitude of CH2, a is frequency of CH1 and b is frequency of CH2, so a/b is a ratio of frequency of two channels, finally, \delta is the phase shift of CH1.
Below are some examples of Lissajous figures with  = /2, a odd, b even, |a  b| = 1.
- a = 1, b = 2 (1:2)
a = 1, b = 2 (1:2)
- a = 3, b = 2 (3:2)
a = 3, b = 2 (3:2)
- a = 3, b = 4 (3:4)
a = 3, b = 4 (3:4)
- a = 5, b = 4 (5:4)
a = 5, b = 4 (5:4)
- a = 5, b = 6 (5:6)
a = 5, b = 6 (5:6)
- a = 9, b = 8 (9:8)
a = 9, b = 8 (9:8)

# Spirograph
Even though they look similar, Spirographs are different as they are generally enclosed by a circular boundary where a Lissajous curve is bounded by a rectangle (A, B).
Lithium bromide

# Overview
Lithium bromide, or LiBr, is a chemical compound of lithium and bromine. Its extreme hygroscopic character makes LiBr useful as a desiccant in certain air conditioning systems.

# Production and properties
LiBr is prepared by treatment of lithium carbonate with hydrobromic acid. The salt forms several crystalline hydrates, unlike the other alkali metal bromides.  The anhydrous salt forms cubic crystals similar to salt

# Uses
Lithium bromide is used in air-conditioning systems as desiccant. Otherwise the salt is useful as a reagent in organic synthesis. For example it reversibly forms adducts with some pharmaceuticals.

## Medical applications
Lithium bromide was used as a sedative beginning in the early 1900s, but it fell into disfavor in the 1940s when some heart patients died after using it as a salt substitute.  Like lithium carbonate and lithium chloride it was used as treatment for Bipolar disorder.

# Hazards
Lithium salts are psychoactive and somewhat corrosive. Dosages for lithium carbonate are ca. 200 mg/day.
Lithium carbide
Lithium carbide, Li2C2, often known as dilithium acetylide, is a chemical compound of lithium and carbon. It is an intermediate compound produced during radiocarbon dating procedures. Li2C2 is one of an extensive range of lithium carbon compounds which include the lithium rich; Li4C, Li6C2, Li8C3, Li6C3, Li4C3, Li4C5, and the graphite intercalation compounds LiC6, LiC12, and LiC18. Li2C2 is the thermodynamically stable lithium rich compound and is the only one of them that can be obtained directly from the elements. It was first produced by Moissan, in 1896 who reacted coal with lithium carbonate. The other lithium rich compounds are produced by reacting lithium vapour with chlorinated hydrocarbons e.g. CCl4.
Lithium carbide is sometimes confused  with the drug lithium carbonate, Li2CO3, because of the similarity of its name.

## Preparation and chemistry
To prepare pure samples in the laboratory molten lithium + graphite are reacted at high temperature. Li2C2 can also be prepared by reacting CO2 with molten lithium. It is reactive and hydrolyses very readily to form acetylene gas , C2H2, and LiOH.

## Structure
Li2C2 is an ionic salt and is formulated 2Li+ C22. It has a similar structure to Rb2O2 and Cs2O2. At high temperatures Li2C2 transforms reversibly to a cubic anti-fluorite structure.

## Use in radiocarbon dating
There are a number of procedures employed, some that burn the sample producing CO2 prior that is then reacted  with lithium, and others where the carbon containing sample is reacted directly with lithium metal.. The outcome is the same, Li2C2 is produced. Note that lithium nitride may be formed and this produces ammonia when hydrolysed, which contaminates the acetylene gas.

# General references
- Structural Phase Transition in Li2C2  U. Ruschewitz R Pottgen Zeitschrift fur  anorganische und allgemeine Chemie Volume  625, Issue 10 , Pages 1599 - 1603

# Footnotes
-   H. Moissan Comptes Rendus hebd. Seances Acad. Sci. 122, 362 (1896)
-  The direct conversion of wood charcoal to lithium carbide in the production of acetylene for radiocarbon dating Swart E.R., Cellular and Molecular Life Sciences  Volume 20, Number 1 (1964), 47-48  DOI: 10.1007/BF02146038
Lithium nitride

# Overview
Lithium nitride is a compound of lithium and nitrogen with the formula Li3N. It is the only stable alkali metal nitride. The solid is a red or purple color, has a high melting point and is ionic. It has an unusual crystal structure which consists of two different types of layer, one sheet, composition Li2N, containing 6 coordinate lithium ions and the other consisting only of lithium ions. Solid lithium nitride is a  fast ion conductor and has the highest conductivity of any inorganic lithium salt. It has been studied extensively as a solid electrolyte and an anode material for use in batteries.. It can be formed by direct reaction of the elements, either by burning lithium metal in pure nitrogen gas or by reacting nitrogen gas with lithium dissolved in liquid sodium metal. The second method gives a purer product. Lithium nitride reacts violently with water to produce ammonia:
Li3N (s) + 3 H2O (l)  3 LiOH (aq) + NH3 (g)
All ionic nitrides display this pattern, due to the N3 ion being an extremely strong Bronsted base. It easily qualifies as a superbase. It is, in fact, a stronger base than the hydride ion, so deprotonates hydrogen itself:
Li3N (s) + 2 H2 (g)  LiNH2 (s) + 2 LiH (s).
Lithium nitride is being investigated as a potential storage medium for hydrogen gas, as the reaction is reversible at 270oC. Up to 11.5% by weight absorption of hydrogen has been achieved.
Lithium orotate
Lithium orotate, is a  lithium salt of pyrimidinecarboxylic acid and lithium. It is available as the monohydrate, LiC5H3N2O4H2O.
Lithium orotate has controversially been promoted as an alternative to lithium carbonate. In this compound, lithium is coupled with an orotate ion, rather than to a carbonate ion.  Lithium orotate is sold under a wide variety of brand names and is available at some drugstores and health food stores.

# Scientific studies
There is no evidence for the use of lithium orotate in clinical treatment in preference to lithium carbonate, and some suggest that it may be harmful. However, there is some evidence that lithium orotate may be useful in the treatment of addictions. Some patients prefer to use it in place of lithium carbonate, as they believe that it is more bioavailable and the side effects tend to be significantly reduced.
Lithium orotate is generally marketed as a dietary supplement used in small doses to treat conditions including stress, manic depression, alcoholism, ADHD and ADD, aggression, PTSD, Alzheimer's and to improve memory.
An animal study by Smith and Schou suggests that the kidneys clear lithium orotate significantly less effectively than lithium carbonate, and that this accounts for the higher serum levels of lithum when lithium orotate is taken compared to the equivalent amount of lithium carbonate. They conclude: "The higher lithium concentrations could be accounted for by the lower kidney function. It seems inadvisable to use lithium orotate for the treatment of patients."
Ironically, this study which concluded that lithium orotate was inadvisable for treatment of patients was done as a direct follow-up study to one performed by Kling, Manowitz and Pollack in 1978. Their study suggested that lithium orotate could be used in lower amounts than required of lithium carbonate to achieve therapeutic results. 
Although some psychiatrists prescribe lithium orotate to their patients, it is most often naturopaths and other health practictioners who recommend this mineral to their patients. There currently is a non-scientific study going on for current users of lithium orotate to make up for the gaps in our knowledge on the effects this mineral has in the body of humans. The last study presented was completed in 1979 and involved guinea pigs taking extremely high dosages of lithium orotate, which contradicted an earlier study.
It should be noted that self-treatment of a psychiatric disorder without medical monitoring is potentially dangerous.  The active principle in these salts is the lithium ion Li+, which interacts with the normal function of sodium ions to produce numerous changes in the neurotransmitter activity of the brain. Therapeutically useful amounts of lithium are only slightly lower than toxic amounts when lithium carbonate or lithium citrate are used, so the blood levels of lithium must be carefully monitored during treatment.  When lithium orotate is used, these near-toxic levels of lithium are not reached as only very small amounts of lithium are administered for treatment.