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#1 Re: This is Cool » Miscellany » Today 00:25:37

885) Plasma

Plasma, also called blood plasma, the liquid portion of blood. Plasma serves as a transport medium for delivering nutrients to the cells of the various organs of the body and for transporting waste products derived from cellular metabolism to the kidneys, liver, and lungs for excretion. It is also a transport system for blood cells, and it plays a critical role in maintaining normal blood pressure. Plasma helps to distribute heat throughout the body and to maintain homeostasis, or biological stability, including acid-base balance in the blood and body.

Plasma is derived when all the blood cells—red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes)—are separated from whole blood. The remaining straw-coloured fluid is 90–92 percent water, but it contains critical solutes necessary for sustaining health and life. Important constituents include electrolytes such as sodium, potassium, chloride, bicarbonate, magnesium, and calcium. In addition, there are trace amounts of other substances, including amino acids, vitamins, organic acids, pigments, and enzymes. Hormones such as insulin, corticosteroids, and thyroxine are secreted into the blood by the endocrine system. Plasma concentrations of hormones must be carefully regulated for good health. Nitrogenous wastes (e.g., urea and creatinine) transported to the kidney for excretion increase markedly with renal failure.

Plasma contains 6–8 percent proteins. One critical group is the coagulation proteins and their inhibitors, synthesized primarily in the liver. When blood clotting is activated, fibrinogen circulating in the blood is converted to fibrin, which in turn helps to form a stable blood clot at the site of vascular disruption. Coagulation inhibitor proteins help to prevent abnormal coagulation (hypercoagulability) and to resolve clots after they are formed. When plasma is allowed to clot, fibrinogen converts to fibrin, trapping the cellular elements of blood. The resulting liquid, devoid of cells and fibrinogen, is called serum. Biochemical testing of plasma and serum is an important part of modern clinical diagnosis and treatment monitoring. High or low concentrations of glucose in the plasma or serum help to confirm serious disorders such as diabetes mellitus and hypoglycemia. Substances secreted into the plasma by cancers may indicate an occult malignancy; for instance, an increased concentration of prostate-specific antigen (PSA) in a middle-aged asymptomatic man may indicate undiagnosed prostate cancer.

Serum albumin, another protein synthesized by the liver, constitutes approximately 60 percent of all of the plasma proteins. It is very important in maintaining osmotic pressure in the blood vessels; it is also an important carrier protein for a number of substances, including hormones. Other proteins called alpha and beta globulins transport lipids such as cholesterol as well as steroid hormones, sugar, and iron.

The gamma globulins, or immunoglobulins, are an important class of proteins that are secreted by B lymphocytes of the immune system. They include most of the body’s supply of protective antibodies produced in response to specific viral or bacterial antigens. Cytokines are proteins synthesized by cells of various organs and by cells found in the immune system and bone marrow in order to maintain normal blood cell formation (hematopoiesis) and regulate inflammation. For example, one cytokine called erythropoietin, synthesized by specialized kidney cells, stimulates bone marrow blood progenitor cells to produce red blood cells. Other cytokines stimulate the production of white blood cells and platelets. Another protein system in the plasma, called complement, is important in mediating appropriate immune and inflammatory responses to a variety of infectious agents.

The electrolytes and acid-base system found in the plasma are finely regulated. For example, potassium is normally present in plasma in a concentration of only 4 milliequivalents per litre. A slight rise in plasma potassium (to 6–7 milliequivalents per litre) can result in death. Likewise, sodium, chloride, bicarbonate, calcium, and magnesium levels in the plasma must be precisely maintained within a narrow range. Smaller molecules such as sodium, potassium, glucose, and calcium are primarily responsible for the concentration of dissolved particles in the plasma. However, it is the concentration of much larger proteins (especially albumin) on either side of semipermeable membranes such as the endothelial cells lining the capillaries that creates crucial pressure gradients necessary to maintain the correct amount of water within the intravascular compartment and, therefore, to regulate the volume of circulating blood. So, for example, patients who have kidney dysfunction or low plasma protein concentrations (especially low albumin) may develop a migration of water from the vascular space into the tissue spaces, causing edema (swelling) and congestion in the extremities and vital organs, including the lungs.

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#2 Re: Ganesh's Puzzles » Doc, Doc! » Today 00:14:09

Hi,

#1581. What does the medical term 'Psychopharmacology' mean?

#3 Re: Ganesh's Puzzles » English language puzzles » Today 00:13:24

Hi,

#3805. What does the noun fare mean?

#3806. What does the noun farewell mean?

#4 Re: Ganesh's Puzzles » Oral puzzles » Today 00:12:58

Hi,

#4904. The sum of the squares of three consecutive odd natural numbers is 1595. What is the largest number?

#5 Re: Ganesh's Puzzles » Oral puzzles » Yesterday 13:57:14

Hi,

Well tried!

#4903. What is the product of two consecutive odd numbers, the difference of whose squares is 40?

#6 Re: Ganesh's Puzzles » 10 second questions » Yesterday 13:40:44

Hi,

Neat work!

#7885. If the simple interest for 6 years be equal to 30% of the principal, then it will be equal to the principal after how many years?

#7 Re: Exercises » Compute the solution: » Yesterday 13:35:22

Hi zainyusufazam and irspow,

Neat work!

852. Find the probability of all the Ss coming together in the word 'ASSISTANCE'.

#8 Re: This is Cool » Miscellany » Yesterday 00:45:47

884) Placenta

Placenta, in zoology, the vascular (supplied with blood vessels) organ in most mammals that unites the fetus to the uterus of the mother. It mediates the metabolic exchanges of the developing individual through an intimate association of embryonic tissues and of certain uterine tissues, serving the functions of nutrition, respiration, and excretion.

All of the fetal membranes function by adapting the developing fetus to the uterine environment. Lying in the chorionic cavity (a thin liquid-filled space) between two membranous envelopes (chorion and amnion) is a small balloon-like sac, yolk sac, or vitelline sac, attached by a delicate strand of tissue to the region where the umbilical cord (the structure connecting the fetus with the placenta) leaves the amnion. Two large arteries in the umbilical cord radiate from the attachment of the cord on the inner surface of the placenta and divide into small arteries that penetrate outward into the depths of the placenta through hundreds of branching and interlacing strands of tissue known as villi. The chorionic villi cause the mother’s blood vessels in their vicinity to rupture, and the villi become bathed directly in maternal blood. The constant circulation of fetal and maternal blood and the very thin tissue separation of fetal blood in the capillaries from maternal blood bathing the villi provide a mechanism for efficient interchange of blood constituents between the maternal and fetal bloodstreams without (normally) allowing any opportunity for the blood of one to pour across into the blood vessels of the other.

Nutrients, oxygen, and antibodies (proteins formed in response to a foreign substance, or antigen), as well as other materials in the mother’s blood, diffuse into the fetal blood in the capillaries of the villi, and nitrogenous wastes and carbon dioxide diffuse out of these capillaries into the maternal blood circulation. The purified and enriched blood in the capillaries of the villi is collected into fetal veins, which carry it back to the inner surface of the placenta and collect at the attachment of the cord to form the umbilical vein. This vein enters the cord alongside the two arteries and carries the blood back to the fetus, thus completing the circuit to and from the placenta.

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#9 Re: Dark Discussions at Cafe Infinity » crème de la crème » Yesterday 00:29:26

811) Arne Tiselius

Arne Wilhelm Kaurin Tiselius was born August 10, 1902, in Stockholm. After the early loss of his father, the family moved to Gothenburg where he went to school, and after graduation at the local “Realgymnasium” in 1921, he studied at the University of Uppsala, specializing in chemistry. He became research assistant in The Svedberg‘s laboratory in 1925 and obtained his doctor’s degree in 1930 on a thesis “The moving-boundary method of studying the electrophoresis of proteins” (published in Nova Acta Regiae Societatis Scientiarum Upsaliensis, Ser. IV, Vol. 7, No. 4) and was appointed Docent (Assistant Professor) in Chemistry from 1930 on. During the years 1931-1935 Tiselius published a number of papers on diffusion and adsorption phenomena in naturally occurring base-exchanging zeolites, and these studies were continued during a year’s visit to H.S. Taylor’s laboratory in Princeton with support of a Rockefeller Foundation Fellowship. Stimulated by many contacts with American biochemists and physical chemists during this visit, Tiselius on his return to Uppsala resumed his interest in proteins, and the application of physical methods to biochemical problems in general. This led among other things to a much improved method of electrophoretic analysis, published in the Transactions of the Faraday Society, 33 (1937) 524. This method as applied to the study of serum proteins and to a number of other biochemical problems kept Tiselius and an increasing number of collaborators occupied for the following years. In 1938 a special research professorship was established for Tiselius through a donation to the University of Uppsala by Major Herbert Jacobsson and his wife. Some space was put at the disposal of the new professor in the Institute of Physical Chemistry (Prof. The Svedberg). In 1946 biochemistry was established as an independent department and in 1950-1952 obtained a new building, the present Institute of Biochemistry.

Under the leadership of Tiselius this institute has contributed to the development and improvement of a number of useful methods in biochemistry, such as electrophoresis, chromatography, phase partition, gel filtration, etc. These methods and others have been applied to studies of large molecular weight substances, chiefly proteins and enzymes, but also polysaccharides (dextran) and nucleic acids. There has always been a close contact between the methodological work and the research into special problems where the methods find their application. Tiselius took an active part in the reorganization of scientific research in Sweden in the years following World War II. Thus he was Chairman of the Swedish Natural Science Research Council 1946-1950, and Chairman of the Research Committee of the Swedish Cancer Society 1951-1955. He was President of the International Union of Pure and Applied Chemistry 1951-1955, became Vice President of the Nobel Foundation in 1947 and President since 1960. He has also served as member of the Nobel Committee for Chemistry since 1946.

He was married (1930) with Ingrid Margareta (Greta) Dalén, daughter of city judge Per Dalén of Gothenburg. They have two children: Eva (b. 1932), married to Dr. Torgny Bohlin, Lund; and Per (b. 1934), physician at the Academic Hospital, Uppsala.

Arne Tiselius died on October 29, 1971.

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#10 Re: Ganesh's Puzzles » English language puzzles » Yesterday 00:02:14

Hi,

#3803. What does the adjective fantastic mean?

#3804. What does the noun farce mean?

#11 Re: Ganesh's Puzzles » General Quiz » Yesterday 00:01:23

Hi,

#7757. Name the term is astronomy : A measure of a star's absolute brightness. It is defined as the apparent magnitude the star would show if it were located at a distance of 10 parsecs, or 32.6 light-years.

#7758. Name the term in astronomy : A roughly circular mass of diffuse material in orbit around a central object, such as a star or black hole. The material is acquired from a source external to the central object, and friction causes it to spiral inward towards the object.

#12 Re: Ganesh's Puzzles » Oral puzzles » 2021-01-14 14:30:18

Hi,

Neat work!

#4902. Three-fifth of a number is 35 times more than its one-fourth. Find the number.

#13 Re: Ganesh's Puzzles » 10 second questions » 2021-01-14 14:19:03

Hi,

Neat work!

#7884. Alfred invested an amount for three years at a simple interest at 9% per annum. He got an amount of $19,050 at the end of three years. What principal amount did he invest?

#14 Re: Exercises » Compute the solution: » 2021-01-14 14:10:04

Hi,

851. A letter is selected at random from 'Malignant' and another is selected from 'Negligent'. Find the probability of having the same letters.

#15 Re: This is Cool » Miscellany » 2021-01-14 00:34:12

883) Iris

Iris, in anatomy, the pigmented muscular curtain near the front of the eye, between the cornea and the lens, that is perforated by an opening called the pupil. The iris is located in front of the lens and ciliary body and behind the cornea. It is bathed in front and behind by a fluid known as the aqueous humour. The iris consists of two sheets of smooth muscle with contrary actions: dilation (expansion) and contraction (constriction). These muscles control the size of the pupil and thus determine how much light reaches the sensory tissue of the retina. The sphincter muscle of the iris is a circular muscle that constricts the pupil in bright light, whereas the dilator muscle of the iris expands the opening when it contracts. The amount of pigment contained in the iris determines eye colour. When there is very little pigment, the eye appears blue. With increased pigment, the shade becomes deep brown to black. Inflammation of the iris is termed iritis or anterior uveitis, a condition that commonly has no determinable cause. As a result of inflammation, the iris sticks to the lens or the cornea, blocking the normal flow of fluid in the eye. Complications of iritis include secondary glaucoma and blindness; treatment usually involves topical steroid eyedrops.

The-human-eye-with-the-cornea-lens-optic-nerve-retina-and-fovea-all-indicated.png

#16 Re: Ganesh's Puzzles » Doc, Doc! » 2021-01-14 00:18:35

Hi,

#1580. What does the medical term 'Enophthalmos' mean?

#17 Re: Ganesh's Puzzles » Oral puzzles » 2021-01-14 00:03:32

Hi,

#4901. If a number is increased by 4 and divided by 8, the result is 6. What would be the reseult if 2 is added to the number and then it is didided by 23?

#18 Re: Exercises » Compute the solution: » 2021-01-14 00:02:14

Keep trying!

850. P and Q roll a pair of dice one after the other. If P throws 5 before Q throws 6, P wins but if Q throws 6 before P throws 5, Q wins. If P throws first, find their respective chances of winning.

#19 Re: Ganesh's Puzzles » 10 second questions » 2021-01-13 14:05:11

Hi,

Good work!

#7883. What interest will be had on $450 for 2 years if an interest of $0.40 is charged on $1 for 4 years?

#20 Re: Ganesh's Puzzles » English language puzzles » 2021-01-13 00:34:22

Hi,

#3801. What does the noun fang mean?

#3802. What does the noun fantasia mean?

#21 Re: Ganesh's Puzzles » General Quiz » 2021-01-13 00:03:56

Hi,

#7755. Name the term in geology : A body of saturated rock or sediment through which water can move readily.

#7756. Name the term in geology : A sedimentary clastic rock with sand grain size between 0.0625 mm (0.00246 in) and 2 mm (0.08 in) and contain less than 15% matrix.

#22 Re: Dark Discussions at Cafe Infinity » crème de la crème » 2021-01-13 00:03:27

810) Bernardo Houssay

Bernardo Alberto Houssay was born in Buenos Aires, Argentina, on April 10, 1887, one of the eight children of Dr. Albert and Clara (née Laffont) Houssay, who had come to Argentina from France. His father was a barrister. His early education was at a private school, the Colegio Británico. He then entered the School of Pharmacy of the University of Buenos Aires at the exceptionally early age of 14, graduating in 1904. He had already begun studying medicine and, in 1907, before completing his studies, he took up a post in the Department of Physiology. He began here his research on the hypophysis which resulted in his M.D.-thesis (1911), a thesis which earned him a University prize.

In 1910 he was appointed Professor of Physiology in the University’s School of Veterinary Medicine. During this time he had been doing hospital practice and, in 1913, became Chief Physician at the Alvear Hospital. In addition to this he was also in charge of the Laboratory of Experimental Physiology and Pathology in the National Department of Hygiene from 1915 to 1919. In 1919 he became Professor of Physiology in the Medical School at Buenos Aires University. He also organized the Institute of Physiology at the Medical School, making it a centre with an international reputation. He remained Professor and Director of the Institute until 1943. In this year the Government then in power deprived him of his post, as a result of his voicing his opinion that there should be effective democracy in the country. Although receiving many invitations from abroad, he continued his work in an institute which he organized with the support of funds contributed by the Sauberan Foundation and other bodies. This was the ‘Instituto de Biología y Medicina Experimenta’l, where he still remains as Director. In 1955 a new Government reinstated him in the University.

He has worked in almost every field of physiology, having a special interest in the endocrine glands. He has made a lifelong study of the hypophysis and his most important discovery concerns the role of the anterior lobe of the hypophysis in carbohydrate metabolism and the onset of diabetes. He has worked on many other topics in physiology and pharmacology, including the physiology of circulation and respiration, the processes of immunity, the nervous system, digestion, and snake and spider venoms.

Apart from his research, he has been active in promoting the advancement of university and medical education, and of scientific research, in Argentina.

Dr. Houssay is the author of over 500 papers and of several books. He has won many prizes ranging in time from that of the National Academy of Sciences, Buenos Aires, in 1923, to the Dale Medal of the Society of Endocrinology (London) in 1960.

He holds honorary degrees of twenty-five universities and is a member of the Argentine National Academy of Medicine, the Academy of Letters, the National Academy of Sciences of Buenos Aires, the Academy of Moral and Political Sciences of Buenos Aires, and of the Pontifical Academy of Sciences. He is honorary professor of 15 universities, foreign associate of 11 academies or learned societies, member (honorary or correspondent) of 38 Academies, 16 Societies of Biology, 11 of Endocrinology, 7 of Physiology and 5 of Cardiology. He has been decorated by the governments of several countries.

He married Dr. Maria Angelica Catan, a chemist, who died in 1962. They have three sons, Alberto, Hector, and Raul.

Bernardo Houssay died on September 21, 1971.

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#23 Re: This is Cool » Miscellany » 2021-01-13 00:02:54

882) Cornea

Cornea, dome-shaped transparent membrane about 12 mm (0.5 inch) in diameter that covers the front part of the eye. Except at its margins, the cornea contains no blood vessels, but it does contain many nerves and is very sensitive to pain or touch. It is nourished and provided with oxygen anteriorly by tears and is bathed posteriorly by aqueous humour. It protects the pupil, the iris, and the inside of the eye from penetration by foreign bodies and is the first and most powerful element in the eye’s focusing system. As light passes through the cornea, it is partially refracted before reaching the lens. The curvature of the cornea, which is spherical in infancy but changes with age, gives it its focusing power; when the curve becomes irregular, it causes a focusing defect called astigmatism, in which images appear elongated or distorted.

The cornea itself is composed of multiple layers, including a surface epithelium, a central, thicker stroma, and an inner endothelium. The epithelium (outer surface covering) of the cornea is an important barrier to infection. A corneal abrasion, or scratch, most often causes a sensation of something being on the eye and is accompanied by intense tearing, pain, and light sensitivity. Fortunately, the corneal epithelium is able to heal quickly in most situations.

The collagen fibres that make up the corneal stroma (middle layer) are arranged in a strictly regular, geometric fashion. This arrangement has been shown to be the essential factor resulting in the cornea’s transparency. When the cornea is damaged by infection or trauma, the collagen laid down in the repair processes is not regularly arranged, with the result that an opaque patch or scar may occur. If the clouded cornea is removed and replaced by a healthy one (i.e., by means of corneal transplant), usually taken from a deceased donor, normal vision can result.

The innermost layer of the cornea, the endothelium, plays a critical role in keeping the cornea from becoming swollen with excess fluid. As endothelial cells are lost, new cells are not produced; rather, existing cells expand to fill in the space left behind. Once loss of a critical number of endothelial cells has occurred, however, the cornea can swell, causing decreased vision and, in severe cases, surface changes and pain. Endothelial cell loss can be accelerated via mechanical trauma or abnormal age-related endothelial cell death (called Fuchs endothelial dystrophy). Treatment may ultimately require corneal transplant.

Tampa-Cornea.jpg

#24 Re: Ganesh's Puzzles » Oral puzzles » 2021-01-12 13:52:44

Hi,

Neat work!

#4900. The age of Patrick is four times the sum of the ages of his two grandsons. Five years hence, his age will be 40 years more than the sum of the ages of his grandsons. Find Patrick's present age.

#25 Re: Ganesh's Puzzles » 10 second questions » 2021-01-12 13:44:32

Hi,

Good work!

#7882. What would be the simple interest obtained on an amount of $6535 at the rate of 10% per annum after 6 years?

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