English Spanish online dictionary Term Bank, translate words and terms with different pronunciation options. Gibbs-Donnan equilibrium equilibrio de. ➀ ➁ ➂ ➃ ➄ ➅ ➆. ➇. Español: Equilibrio de Gibbs – Donnan. Date. Source, Own work. Author, Biezl. Other versions. Image: ( × pixels, file size: KB, MIME type: image/jpeg) Equilibrio de Gibbs – Donnan Usage on
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The Gibbs—Donnan effect also known as the Donnan’s effectDonnan lawRquilibrio equilibriumor Gibbs—Donnan equilibrium is a name for the behaviour of charged particles equilirbio a semi-permeable membrane that sometimes fail to distribute evenly across the two sides of the membrane.
Because small cations are attracted, but are not bound to the proteins, small anions will cross capillary walls away from the anionic proteins more readily than small cations. Some ionic species can pass through the barrier while others cannot. The solutions may be gels or colloids as well as solutions of electrolytesand as such the phase boundary between gels, or a gel and a liquid, can also act as a qeuilibrio barrier. The electric potential arising between two such solutions is called the Donnan potential.
The Donnan equilibrium is prominent in the triphasic model for articular cartilage proposed by Mow and Lai, as well as in electrochemical fuel cells and dialysis.
The presence of a gibbbs impermeant ion for example, a protein on one side of a membrane will result in an asymmetric distribution of permeant charged fibbs.
Note that Sides 1 equillbrio 2 are no longer in osmotic equilibrium i. I n vivoion balance does not equilibriate at the proportions that would be predicted by the Gibbs-Donnan model, because the cell cannot tolerate the attendant large influx of water. Because there is a difference in concentration of ions on gibsb side of the membrane, the pH may also differ when protons are involved. In many instances, from ultrafiltration of proteins to ion exchange chromatography, the pH of the buffer adjacent to the charged groups of the membrane is different from the pH of the rest of the buffer solution.
When the charged groups are positive acidicthen they will repel protons so that the pH will be higher than the surrounding buffer. When tissue cells are in a protein-containing fluid, the Donnan effect of the cytoplasmic proteins is equal and opposite to the Donnan effect of the extracellular proteins. The opposing Donnan effects cause chloride ions to migrate inside the cell, increasing the intracellular chloride concentration. The Donnan effect may explain why some red blood cells do not have active sodium pumps; the effect relieves the osmotic pressure of plasma proteins, which is why sodium pumping is less important for maintaining the cell volume.
Brain tissue swelling, known as cerebral oedema, results from brain injury and other traumatic head injuries that can increase intracranial pressure ICP. Negatively charged molecules within cells create a fixed dobnan density, which increases intracranial pressure through gibs Donnan effect.
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ATP pumps maintain a negative membrane potential even though negative charges leak across the membrane; this action establishes a chemical and electrical gradient. The negative charge in the cell and ions outside the cell creates a thermodynamic potential; if damage occurs to the brain and cells lose their membrane integrity, ions will rush into the cell to balance chemical and electrical gradients that were previously established.
The membrane voltage will become zero, but the chemical gradient will still exist. To neutralize the negative charges within the cell, cations flow in, which increases the osmotic pressure inside relative to the outside of the cell. The increased osmotic pressure forces water to flow into the cell and tissue swelling occurs.
Capillary — Capillaries are the smallest of a bodys blood vessels that make up the microcirculation. Their endothelial linings are only one layer thick. Lymph capillaries connect with larger vessels to drain lymph collected in the microcirculation. The term angiogenesis denotes the formation of new capillaries from pre-existing blood vessels, blood flows from the heart through arteries, which branch and narrow into arterioles, and then branch further into capillaries where nutrients and wastes are exchanged.
The capillaries then join and widen to become venules, which in turn widen and converge to become veins, capillaries do not function on their own, but instead in a capillary bed, an interweaving network of capillaries supplying organs and tissues. The more metabolically active a cell or environment is, the capillaries are required to supply nutrients. Metarterioles are found primarily in the mesenteric microcirculation and were thought to be present in most or all capillary beds.
The physiological mechanisms underlying precapillary resistance is no longer considered to be a result of precapillary sphincters outside of the mesentery organ, lymphatic capillaries are slightly larger in diameter than blood capillaries, and have closed ends.
This structure permits interstitial fluid to flow into them but not out, lymph capillaries have a greater internal oncotic pressure than blood capillaries, due to the greater concentration of plasma proteins in the lymph. However lipid-soluble molecules can diffuse through the endothelial cell membranes along concentration gradients. Tight junctions can be divided into two subtypes, Those with numerous transport vesicles, which are found primarily in skeletal muscles, fingers, gonads.
Those with few vesicles, which are found in the central nervous system. These capillaries are a constituent of the blood—brain barrier, fenestrated capillaries have pores in the endothelial cells that are spanned by a diaphragm of radially oriented fibrils and allow small molecules and limited amounts of protein to diffuse.
In the renal glomerulus there are cells with no diaphragms, called foot processes or pedicels. Both of these types of vessels have continuous basal laminae and are primarily located in the endocrine glands, intestines, pancreas. Sinusoidal capillaries are a type of open-pore capillary, that have larger openings in the endothelium.
These types of blood vessels allow red and white cells and various serum proteins to pass.
These capillaries lack pinocytotic vesicles, and therefore utilize gaps present in cell junctions to permit transfer between cells, and hence across the membrane. Gel — A gel is a solid jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, by weight, gels are mostly liquid, yet they behave like solids due to a three-dimensional cross-linked network within the liquid.
It is the crosslinking within the fluid that gives a gel its structure, in this way gels are a dispersion of molecules of a liquid within a solid in which the solid is the continuous phase and the liquid is the discontinuous phase. The word gel was coined by 19th-century Scottish chemist Thomas Graham by clipping from gelatine, gels consist of a solid three-dimensional network that spans the volume of a liquid medium and ensnares it through surface tension effects.
This internal network structure may result from physical bonds or chemical bonds, virtually any fluid can be used as an extender including water, oil, and air. Both by weight and volume, gels are mostly fluid in composition, edible jelly is a common example of a hydrogel and has approximately the density of water. Polyionic polymers are polymers with a functional group. The ionic charges prevent the formation of tightly coiled polymer chains and this allows them to contribute more to viscosity in their stretched state, because the stretched-out polymer takes up more space.
A hydrogel is a network of polymer chains that are hydrophilic, hydrogels are highly absorbent natural or synthetic polymeric networks. Hydrogels also possess a degree of flexibility very similar to tissue, due to their significant water content. The first appearance of the term hydrogel in the literature was incommon uses for hydrogels include, Scaffolds in tissue engineering.
When used as scaffolds, hydrogels may contain human cells to repair tissue and they mimic 3D microenvironment of cells.
Hydrogel-coated wells have been used for cell culture Environmentally sensitive hydrogels and these hydrogels have the ability to sense changes of pH, temperature, or the concentration of metabolite and release their load as result of such a change. Wound gels are excellent for helping to create or maintain a moist environment, reservoirs in topical drug delivery, particularly ionic drugs, delivered by iontophoresis. Natural hydrogel materials are being investigated for tissue engineering, these materials include agarose, methylcellulose, hyaluronan, an organogel is a non-crystalline, non-glassy thermoreversible solid material composed of a liquid organic phase entrapped in a three-dimensionally cross-linked network.
The liquid can be, for example, a solvent, mineral oil. The solubility and particle dimensions of the structurant are important characteristics for the elastic properties, often, these systems are based on self-assembly of the structurant molecules.
Josiah Willard Gibbs — Josiah Willard Gibbs was an American scientist who made important theoretical contributions to physics, chemistry, and mathematics. His work on the applications of thermodynamics was instrumental in transforming physical chemistry into a rigorous inductive science, Gibbs also worked on the application of Maxwells equations to problems in physical optics. As a mathematician, he invented modern vector calculus, inYale awarded Gibbs the first American doctorate in engineering.
After a three-year sojourn in Europe, Gibbs spent the rest of his career at Yale, commentators and biographers have remarked on the contrast between Gibbss quiet, solitary life in turn of the century New England and the great international impact of his ideas.
Though his work was almost entirely theoretical, the value of Gibbss contributions became evident with the development of industrial chemistry during the first half of the 20th century.
According to Robert A. Gibbs was born in New Haven and he belonged to an old Yankee family that had ggibbs distinguished American clergymen and academics since the 17th century. On his fathers side, he was descended from Samuel Willard, dinnan his mothers side, one of his ancestors was the Rev.
Jonathan Dickinson, the first president of the College of New Jersey, the elder Gibbs was generally known to his family and colleagues as Josiah, while the son was called Willard.
Josiah Gibbs was a linguist and theologian who served as professor of sacred literature at Yale Divinity School from until his death inWillard Gibbs was educated at the Hopkins School and entered Yale College inaged At Yale, Gibbs received prizes for excellence in mathematics and Latin and he remained at Yale as a donnxn student at the Sheffield Scientific School. At age 19, soon after his graduation from college, Gibbs was inducted into the Connecticut Academy of Arts and Sciences, relatively few documents from connan period survive and it is difficult to reconstruct the details of Gibbss early career with precision.
After the death of his father inGibbs inherited enough money to him financially independent.
Recurrent pulmonary trouble ailed the young Gibbs equilibroo his physicians were concerned that he might be susceptible to tuberculosis and he also suffered from astigmatism, whose treatment was then still largely unfamiliar to oculists, so that Gibbs had to diagnose himself and grind his own lenses. He was not conscripted and he remained at Yale for the duration of the war, inYale had become the first US university to offer gibbs Ph. After graduation, Gibbs was appointed as tutor at the College for a term of three years, during the first two years he taught Latin and during eqkilibrio third natural philosophy.
After his term as tutor ended, Gibbs traveled to Europe with his sisters, moving to Berlin, Gibbs attended the lectures taught by mathematicians Karl Weierstrass and Leopold Kronecker, as well as by chemist Heinrich Gustav Magnus. Chemist — A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties, chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms.
Chemists carefully measure substance proportions, reaction rates, and other chemical properties, the word chemist is also used to address Pharmacists in Commonwealth English. Chemists may specialize in any number of subdisciplines of chemistry, materials scientists and metallurgists share much of the same education and skills with chemists. The roots of chemistry can be traced to the phenomenon of burning, fire was a mystical force that transformed one substance into another and thus was of primary interest to mankind.
It was fire that led to the discovery of iron and glasses, after gold was discovered and became a precious metal, many people were interested to find a method donnzn could convert other substances into gold. This led to the protoscience called alchemy, the word chemist is derived from the New Latin noun chimista, an abbreviation of alchimista. Alchemists discovered many chemical processes that led to the development of modern chemistry, Chemistry as we know it today, was invented by Antoine Lavoisier with his law of conservation of mass in The discoveries of the elements has a long history culminating in the equiligrio of the periodic table by Dmitri Mendeleev.
The Nobel Prize in Chemistry created in gives an excellent overview of chemical discovery since the start of the 20th century. Jobs for chemists usually require at least a degree, but many positions, especially those in research. At the Masters level and higher, students tend to specialize in a particular field, postdoctoral experience may be required for certain positions.
Workers whose work involves chemistry, but not at a complexity requiring an education with a degree, are commonly referred to as chemical technicians. Such technicians commonly do such work as simpler, routine analyses for quality control or in clinical laboratories, there are also degrees specific to become a Chemical Technologist, which are somewhat distinct from those required when a student is interested in becoming a professional Chemist.
A Chemical technologist is more involved in donnaan management and operation of the equipment and they are part of the team of a chemical laboratory in which the quality of the raw material, intermediate products and finished products is analyzed.
They also perform functions in the areas of quality control. The higher the level achieved in the field of Chemistry, the higher the responsibility given to that chemist.
Fuel cell — A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction of positively charged hydrogen ions with oxygen or another oxidizing agent. Fuel cells can produce electricity continuously for as long as these inputs are supplied, the first fuel cells were invented in The first commercial use of fuel cells came more than a later in NASA space programs to generate power for satellites.
Since then, fuel cells have been used in other applications. Fuel cells are used for primary and backup power for commercial, industrial and residential buildings and they are also used to power fuel cell vehicles, including forklifts, automobiles, buses, boats, motorcycles and submarines. There are many types of cells, but they all consist of an anode, a cathode.
The anode and cathode contain catalysts that cause the fuel to undergo reactions that generate positively charged hydrogen ions and electrons. The hydrogen ions are drawn through the electrolyte after the reaction, at the same time, electrons are drawn from the anode to the cathode through an external circuit, producing direct current electricity.