Persius/hicric huggingface dataset:
Calvaria (skull)
The calvaria (or calva, or skullcap) is the roof of the skull. It is formed by the following bones:
- frontal bone
- parietal bones (two)
- temporal bones (two)
- occipital bone
In a fetus, the formation of the Calvaria involves a process known as intramembranous ossification, although the base of the skull (underlying the brain) develops through endochondral ossification.

# Inner surface of the skull-cap
The inner surface of the skull-cap is concave and presents depressions for the convolutions of the cerebrum, together with numerous furrows for the lodgment of branches of the meningeal vessels.
Along the middle line is a longitudinal groove, narrow in front, where it commences at the frontal crest, but broader behind; it lodges the superior sagittal sinus, and its margins afford attachment to the falx cerebri.
On either side of it are several depressions for the arachnoid granulations, and at its back part, the openings of the parietal foramina when these are present.
It is crossed, in front, by the coronal suture, and behind by the lambdoidal, while the sagittal lies in the medial plane between the parietal bones.
(Images courtesy of Melih Aktan M.D. Istanbul Medical Faculty, Turkey)
- Calvarium in multiple myeloma
- Calvarium in Thalassemia
Capillary refill

# Overview
Capillary refill is the rate at which blood refills empty capillaries. Capillary refill time (CRT) is defined as the time taken for colour to return to an external capillary bed after pressure is applied to cause blanching.  It can be measured by holding a hand higher than heart-level, pressing the soft pad of a finger until it turns white, and taking note of the time needed for the color to return once pressure is released. Normal capillary refill time is usually less than 2 seconds.
In newborn infants, capillary refill time can be measured by pressing on the sternum for five seconds with a finger or thumb, and noting the time needed for the colour to return once the pressure is released. The upper normal limit for capillary refill in newborns is 2 seconds. Capillary refill time can also be assessed in animals by pressing on their gums as opposed to the sternum which is generally covered with fur or inaccessible.

# Clinical Significance
A prolonged capillary refill time may be a sign of shock and can also indicate dehydration and decreased peripheral perfusion. It is generally accepted that the test is affected by many different external factors and therefore should not be relied upon as a universal diagnostic measure.
Captain Cutaneum
Captain Cutaneum is a character-superhero that was created by Phoenix-area dermatopathologist Ruskin R Lines, III, M.D. in 2006. The purpose behind the character is to spread awareness among children of skin health and especially the dangers of excessive sun exposure. Dr. Lines's campaign has been written about by many major newspapers and in the dermatology journal Skin and Allergy News.
The Captain Cutaneum campaign is directed mainly towards children in the fifth grade who are at risk for excessive sun exposure and who, according to Dr. Lines, "aren't blinded by the beauty of the tan." Wearing a costume that completely covers his skin (and which includes a large, wide blue hat), Captain Cutaneum attempts to teach children about sun safety and the types of cancers caused by sun exposure. During his visits, Lines teaches students what to look for, and shows them images of skin cancers. Lines's intention is not to shock but to teach children the signs of skin cancer and to make them realize that excessive sun exposure is dangerous. He told a reporter for the East Valley Tribune, "A person dies from melanoma every hour in the U.S. As a dermatologist I get to save a lot of lives because people come to see me."
Lines goes around to elementary schools teaching to teach children about sun protection while they are young, instead of telling them about it while removing their skin cancers. "Ive been saying there needs to be something, some program that we can teach these kids before theyve already figured out how much they like being tan," he says. 
Lines has also created a series of comic books that he does annually. Using colorful pictures and accurate writing, he hopes to educate as well as entertain people of all ages. In the comic, Captain Cutaneum fights the dread enemies Lentigo, Squamous, and (in the future) Melanoma. He also has a website that includes a number of songs about skin health intended to teach children about the importance of remaining safe in the Sun.

# Notes
-  KHOI article on Captain Cutaneum. Retrieved April 16, 2007.
-  "Superhero derm stresses sun safety", Skin and Allergy News, Vol. 37 No. 6 (June 1, 2006), pp. 1, 28. Retrieved April 16, 2007.
-  East Valley Tribune story on Captain Cutaneum. Retrieved April 16, 2007.
-  ABC 49 News Article on Captain Cutanuem. Retrieved April 18, 2007.
Carbon disulfide
Carbon disulfide is a colorless, volatile liquid with the formula CS2. The compound is used frequently as a building block in organic chemistry as well as an industrial and chemical non-polar solvent.  It has an "ether-like" odor, but commercial samples are typically contaminated with foul-smelling impurities.

# Occurrence and manufacture
Small amounts of carbon disulfide are released by volcanic eruptions and marshes.  CS2 once was manufactured by combining carbon (or coke) and sulfur at high temperatures.  A lower temperature reaction, requiring only 600 C utilizes natural gas as the carbon source in the presence of silica gel or alumina catalysts:
The reaction is analogous to the combustion of methane.  Although it is isoelectronic to carbon dioxide, CS2 is highly flammable:

# Reactions
Compared to CO2, CS2 is more reactive toward nucleophiles and more easily reduced. These differences in reactivity can be attributed to the weaker  donor-ability of the sulfido centers, which renders the carbon more electrophilic.  It is widely used in the synthesis of organosulfur compounds such as Metham sodium, a soil fumigant.

## Addition of nucleophiles
Nucleophiles such as amines afford dithiocarbamates:
Xanthates form similarly from alkoxides:
This reaction is the basis of the manufacture of regenerated cellulose, the main ingredient of viscose, rayon and cellophane.  Both xanthates and the related thioxanthates (derived from treatment of CS2 with sodium thiolates) are used as flotation agents in mineral processing.
Sodium sulfide affords trithiocarbonate:

## Reduction
Sodium reduces CS2 to give the heterocycle "dmit2-":
Direct electrochemical reduction affords the tetrathiooxalate anion:

## Chlorination
Chlorination of CS2 is the principal route to carbon tetrachloride:
This conversion proceeds via the intermediacy of thiophosgene, CSCl2.

## Coordination chemistry
CS2 is a ligand for many metal complexes, forming pi complexes.  One example is CpCo(2-CS2)(PMe3).

# Commercial Availability
CS2, being highly flammable and having one of the lowest autoignition temperatures, cannot be transported easily using commercial means. Worldwide exports of this chemical are negligible.

## Pressurized Liquid Nitrogen Based Sample
Johnson Matthey's sister company Alfa Aesar was the first company to introduce carbon disulfide in the form of pressurized bottle containing a solution of pressurized nitrogen, coupling agent, stablizer, and carbon disulfide, with an active carbon disulfide content of 85%. Dilution with nitrogen rendered contents nonflammable.  In 2007 Alfa Aesar stopped selling carbon disulfide samples.

# Health effects
At very high levels, carbon disulfide may be life-threatening because it affects the nervous system.  Significant safety data come from the viscose rayon Industry, where both carbon disulfide as well as small amounts of H2S may be present.
Cardiotocography

# Overview
In medicine (obstetrics) cardiotocography (CTG) is a technical means of recording (-graphy) the fetal heartbeat (cardio-) and the uterine contractions (-toco-) during childbirth. CTG can be used to identify signs of fetal distress.

# Method
Recordings are done by two separate transducers, one for the measurement of the fetal pulse and a second one for the contractions.
External measurement means taping or strapping the electrodes to the abdominal wall, with the heart electrode overlying the fetal heart and the contraction electrode measuring the tension of the abdominal wall, an indirect measure of the intrauterine pressure.
Internal measurement requires a certain degree of cervical dilatation, as it involves inserting a pressure catheter into the uterine cavity, as well as attaching a scalp electrode to the child's head to adequately measure the pulse. Internal measurement is more precise, and might be preferable when a complicated childbirth is expected.
A typical CTG reading is printed on paper or stored on a computer terminal for later reference.

# Interpretation
CTG times the contractions and the variability in the fetal heart rate. Baseline abnormalities in the heart rate (brady- or tachycardia) may be interpreted in the context of the presentation, as may absence of variability in the FHR.
Decelerations (slowing of the fetal heart rate) during a uterine contraction is normal (type 1 deceleration, or type I dips), but further slowing after resolution of the contraction (type II dips) is generally regarded as pathological and may be taken as a sign of fetal distress.
it:Cardiotocografia
Carlos J. Finlay

# Overview
Carlos Juan Finlay (born Carlos Juan Finlay y Barres on December 3 1833, Puerto Principe, Cuba   August 20 1915, Havana, Cuba), was a Cuban physician and scientist.
Finlay was born Juan Carlos Finlay in Puerto Principe, Cuba of French and Scottish descent. He changed his name to Carlos Juan Finlay later in his life. In 1853 he attended Jefferson Medical College in Philadelphia, Pennsylvania. He graduated in 1855, and completed his studies in Havana, and in Paris. Afterwards he settled in Havana and opened a medical practice.
Carlos Finlay became famous for his work in identifying the mosquito as a carrier of the organism causing yellow fever, now known as a disease vector. His theory was followed by the recommendation to control the mosquito population as a way to control the spread of yellow fever. His work, carried out during the 1870s finally came to prominence in 1900. He was the first to theorize in 1881 that a mosquito was the way by which yellow fever was transmitted; a mosquito that bites a victim of the disease could bite a healthy person and spread the disease. A year later he identified the organism transmitting yellow fever to be in the genus Aedes. His hypothesis and exhaustive proofs was confirmed nearly twenty years later by the Walter Reed Commission of 1900. Finlay went on to become the chief health officer of Cuba from 1902 to 1909.
In the words of General Leonard Wood, a physician and U.S. military governor of Cuba in 1900: "The confirmation of Dr. Finlay's doctrine is the greatest step forward made in medical science since Jenner's discovery of the vaccination."
This discovery helped William C. Gorgas of Alabama reduce the incidence and prevalence of mosquito-borne diseases in Panama during the American campaign from 1903 onwards to construct the Panama Canal. Prior to this about 10% of the workforce died each year from malaria and yellow fever.
In the city of Marianao in Havana, Cuba, there is a monument honoring Dr. Finlay. This monument has the shape of a syringe and it is usually referred to as "El Obelisco" ("The Obelisk"). Finlay was also commemorated on a 1981 Cuban stamp.   A statue commemorating Dr. Finlay is located on the bayfront in Panama City, near the canal he helped make possible. The United Nations {UNESCO) prize for Microbiology is named in his honor.
Carpal coalition
- Congenital coalition of carpal bones is a common anomaly that is usually discovered on imaging obtained for unrelated reasons.
- The lunate and triquetrum are most likely to show such coalition.  
- It is reported twice as frequently in women.
- It may occur as an isolated entity or as part of a syndrome and may show a familial pattern.
- It is caused by a failure of separation or segmentation of the carpal bones.

# Diagnostic Findings
- Carpal bone fusion

## MRI demonstrates lunatriquetral coalition
Cascade reaction

# Overview
A cascade reaction or tandem reaction or domino reaction is a consecutive series of intramolecular organic reactions which often proceed via highly reactive intermediates. It allows the organic synthesis of complex multinuclear molecules from a single acyclic precursor. The substrate contains many functional groups that take part in chemical transformations one at the time. Often a functional group is generated in situ from the previous chemical transformation. The definition includes the prerequisite intramolecular in order to distinguish this reaction type from a multi-component reaction. In this sense it differs from the definition of a biochemical cascade. The main advantages of a cascade reaction in organic synthesis are that the reaction is often fast due to its intramolecular nature, the reaction is also clean, displays high atom economy and does not involve workup and isolation of many intermediates.
A cascade reaction is sometimes called a living reaction because it shares some characteristics with a living polymerization. In cascade reactions one can identify an initiation site, a relay moiety and a termination moiety.  Examples of cascade reactions are numerous (e.g. the Aldol-Tishchenko reaction) and especially so in alkyne chemistry (the Banert cascade to name just one) or polyolefin polycycloisomerizations. Other alkyne coupling reactions are classified based on common features such as type of compound synthesised, for instance the spiro mode cascade :
-r the linear-fused mode cascade  ,through application of the intramolecular Heck reaction:
-r the zipper mode cascade .
Other cascade reactions are included in Diels-Alder reactions, oxirane ring-opening reactions   , and PausonKhand reactions .
An example of an oxirane cascade reaction is given by the synthesis of certain polyether ladder polymers :
This type of ladder compounds are found in marine lifeforms such as red tide.  The tri-epoxide is prepared from a triene through asymmetric Shi epoxidation and oxone as primary oxidizing agent. The hydroxyl group in the tri-epoxide is activated as a nucleophile by the presence of the base caesium carbonate The bulky trimethylsilyl groups make such that the polyether is formed with the correct stereochemistry and they are removed in situ by caesium fluoride.
Cat eye syndrome

# Overview
Cat Eye Syndrome is a very rare malformation involving Chromosome 22. The short arm (p) and a small section of the long arm (q) are present three (trisomic) or four times (tetrasomic) instead of the usual two times. The additional chromosome 22 usually arises spontaneously (de novo), though it has been reported to have been passed down in families, and some reports show the parents as mosaic for the marker chromosome but who show no phenotypic (outer) symptoms of the syndrome.
The chromosomal area included in the Cat Eye Syndrome "critical region" is 22pter-->q11.

# History
The first association of the common abnormalities common to CES was established over 100 years ago (1898) by Haab, and first described in association with a small marker chromosome in 1965 by Schachenmann.
A first report of a familial trisomy 22 pter-->q11happened in 1972 by Buhler et al. Early reports of Cat Eye Syndrome discuss the possibility of chromosome 13 involvement. Now, CES is considered to be present with the chromosome 22 trisomy findings.

# Genetics
22q11.2 is a very unstable region of chromosome 22, which is involved in other syndromes, such as 22q11 deletion (a microdeletion of that area of the chromosome) and supernumerary der(22) syndrome, also known as trisomy 22 or partial trisomy 11/22.

# Presentation
The most common association of symptoms include coloboma of the iris, renal abnormalities, and imperforate anus. Life expectancy is not significantly reduced in those patients who do not present with life threatening abnormalities.
The term "Cat Eye" syndrome was coined due to the particular appearance of the vertical colobomas in the eyes of some patients. However, over 1/2 of the CES patients in the literature do not display this trait.

# Characteristics
- Anal atresia (abnormal obstruction of the anus)
- Unilateral or bilateral iris coloboma (absence of tissue from the colored part of the eyes)
- Palpebral fissures (downward slanting openings between the upper and lower eyelids)
- Preauricular pits/tags (small depressions/growths of skin on the outer ears)
- Cardiac defects
- Kidney problems (missing, extra, or underdeveloped kidneys)
- Short stature
- Scoliosis/Skeletal problems
- Mental retardation -- although most are borderline normal to mildly retarded, and a few even have normal intelligence, CES patients occasionally exhibit moderate to severe retardation.
- Micrognathia (smaller jaw)
- Hernias
- Cleft palate
- Rarer malformations can affect almost any organ
Cavernous plexus
The cavernous plexus is situated below and medial to that part of the internal carotid artery which is placed by the side of the sella turcica in the cavernous sinus, and is formed chiefly by the medial division of the internal carotid nerve.
It communicates with the oculomotor, the trochlear, the ophthalmic and the abducent nerves, and with the ciliary ganglion, and distributes filaments to the wall of the internal carotid artery.
The branch of communication with the oculomotor nerve joins that nerve at its point of division; the branch to the trochlear nerve joins it as it lies on the lateral wall of the cavernous sinus; other filaments are connected with the under surface of the ophthalmic nerve; and a second filament joins the abducent nerve.

# Additional images
- Plan of oculomotor nerve.
Refsum's disease
Refsum's disease (Refsum-Thiebaut disease, Refsum-Thiebaut-Klenk-Kahlke disease), named after Norwegian neurologist Sigvald Bernhard Refsum (1907-1991), is neurological disease that results in the malformation of myelin sheaths around nerve cells. It is a peroxisomal disorder.

# Causes
Refsum's disease is caused by faulty enzymes during the alpha-oxidation of phytanic acid resulting in buildup of phytanic acid and its unsaturated fatty acid derivatives in the plasma and tissues.
This in turn can be due to deficiencies of phytanoyl-CoA hydroxylase (chromosome 10) or peroxin-7 (chromosome 6).

# Presentation
Patients with Refsum's Disease present with neurologic damage, cerebellar degeneration, and peripheral neuropathy. Onset is most commonly in childhood/adolescence with a progressive course, although periods of stagnation/remission occur.

# Differential diagnosis
Refsum's disease must be differentiated from other diseases that cause neurological manifestations in infants.

# Treatment
The most effective therapy in the classic Refsum disease is dietary treatment with a phytanic acid-restricted diet, such as exclusively avoiding consumption of beef, lamb, fatty fish such as tuna, cod, and haddock .  Recent research has shown that CYP4 isoform enzymes could eliminate the phytanic acid storage in vivo  and patients could try alternative natural remedies with either eatable marine invertebrates or with clofibrate supplement of which the component is usually rich in the excretion of high plant , , .  Currently, there is no clinical data to approve using this xenonbiotic drug for the treatment, perhaps due to its serious adverse effect and the major medical treatment of the disease only relies on the plasmapheresis.

# Reaction
Phytol (from chlorophyll in plant foods) ---> phytanic acid -x-> pristanic acid ---> propionyl CoA
Cerebral T waves
Synonyms and keywords: widely splayed T waves; cerebral Ts; cerebral T wave

# Overview
Cerebrovascular accidents can cause deep widely splayed T waves referred to as cerebral T waves.

# Electrocardiographic Findings
Shown above is an EKG showing T wave inversions and widely splayed T waves (cerebral T waves) in a patient with a subarrachnoid hemorrhage.
Circle of Willis

# Overview
The circle of Willis (also called the cerebral arterial circle or arterial circle of Willis) is a circle of arteries that supply blood to the brain. It is named after Thomas Willis (1621-1673), an English physician.

# Components
- Anterior cerebral artery (left and right)
- Anterior communicating artery
- Internal carotid artery (left and right)
- Posterior cerebral artery (left and right)
- Posterior communicating artery (left and right)
The basilar artery and middle cerebral arteries, though they supply the brain, are not considered part of the circle.

# Physiologic significance
The arrangement of the brain's arteries into the Circle of Willis creates redundancies in the cerebral circulation. If one part of the circle becomes blocked or narrowed (stenosed) or one of the arteries supplying the circle is blocked or narrowed, blood flow from the other blood vessels can often preserve the cerebral perfusion well enough to avoid the symptoms of ischemia.

# Anatomic variation
Considerable anatomic variation exists in the circle of Willis.  The "textbook version" of the circle, based on a series of 1413 brains, is only seen in 34.5% of cases.
In one common variation the proximal part of the posterior cerebral artery is narrow and its ipsilateral posterior communicating artery is large, so the internal carotid artery supplies the posterior cerebrum. In another variation the anterior communicating artery is a large vessel, such that a single internal carotid supplies both anterior cerebral arteries.

# Subclavian steal and the circle of Willis
The redundancies that the circle of Willis introduce can also lead to reduced cerebral perfusion.  In subclavian steal syndrome, which results from a proximal stenosis (narrowing) of the subclavian artery (a vessel that is supplied by the same vessel (the Aorta) that eventually feeds the circle of Willis via the Common carotid artery), blood is "stolen" from the circle of Willis to preserve blood flow to the upper limb.

# Origin of arteries
The left and right internal carotid arteries arise from the right and left common carotid arteries.
The Posterior Communicating Artery is given off as a branch of the Internal Carotid Artery just before it divides into its terminal branches - the Anterior and Middle Cerebral Arteries. The Anterior Cerebral Artery forms the anterolateral portion of the Circle of Willis, while the Middle Cerebral Artery does not contribute to the Circle.
The right and left posterior cerebral arteries arise from the basilar artery, which is formed by the left and right vertebral arteries.  The vertebral arteries arise from the subclavian arteries.
The anterior communicating artery connects the two anterior cerebral arteries and could be said to arise from either the left or right side.
All arteries involved give off cortical and central branches. The central branches supply the interior of the Circle of Willis, more specifically, the Interpeduncular fossa. The cortical branches are named for the area they supply. Since they do not directly affect the Circle of Willis, they are not dealt with here.