partially or fully ionized gas formed from neutral atoms (or molecules) and charged particles (ions and electrons). The most important feature of plasma is its quasi-neutrality, which means that the volume densities of positive and negative charged particles from which it is formed turn out to be almost the same. A gas passes into a plasma state if some of its constituent atoms (molecules) for some reason have lost one or more electrons, i.e. turned into positive ions. In some cases, negative ions can also appear in plasma as a result of the "sticking" of electrons to neutral atoms. If no neutral particles remain in the gas, the plasma is said to be fully ionized.

There is no sharp boundary between gas and plasma. Any substance that is initially in a solid state begins to melt as the temperature rises, and evaporates upon further heating, i.e. turns into gas. If it is a molecular gas (for example, hydrogen or nitrogen), then with a subsequent increase in temperature, the gas molecules disintegrate into individual atoms (dissociation). At an even higher temperature, the gas ionizes, positive ions and free electrons appear in it. Freely moving electrons and ions can carry electric current, so one of the definitions of a plasma is that a plasma is a conducting gas. Heating a substance is not the only way to obtain a plasma.

Plasma The fourth state of matter, it obeys the laws of gases and in many ways behaves like a gas. At the same time, the behavior of plasma in a number of cases, especially when exposed to electric and magnetic fields, turns out to be so unusual that it is often referred to as a new fourth state of matter. In 1879, the English physicist W. Crooks, who studied an electric discharge in tubes with rarefied air, wrote: "Phenomena in evacuated tubes open up a new world for physical science, in which matter can exist in the fourth state." Ancient philosophers believed that the basis of the universe is four elements: earth, water, air and fire. . In a certain sense, this corresponds to the currently accepted division into aggregate states of matter, and the fourth element, fire, obviously corresponds to plasma.

The term "plasma" itself, as applied to a quasi-neutral ionized gas, was introduced by the American physicists Langmuir Tonks in 1923 when describing phenomena in a gas discharge. Until that time, the word "plasma" was used only by physiologists and denoted a colorless liquid component of blood, milk or living tissues, but soon the concept of "plasma" was firmly established in the international physical dictionary, having received the widest distribution.

Frank-Kamenetsky D.A. Plasma the fourth state of matter. M., Atomizdat, 1963
Artsimovich L.A. Elementary Plasma Physics. M., Atomizdat, 1969
Smirnov B.M. Introduction to Plasma Physics. M., Science, 1975
Milantiev V.P., Temko S.V. Plasma physics. M., Enlightenment, 1983
Chen F. Introduction to Plasma Physics. M., Mir, 1987

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One and the same substance in nature has the ability to radically vary its properties depending on temperature and pressure. An excellent example of this is water, which exists as solid ice, liquid, and vapor. These are the three states of aggregation of this substance, which has the chemical formula H 2 O. Other substances in natural conditions are able to change their characteristics in a similar way. But in addition to those listed, in nature there is another state of aggregation - plasma. It is quite rare in earthly conditions, endowed with special qualities.

Molecular structure

What do the 4 states of matter in which matter resides depend on? From the interaction of the elements of the atom and the molecules themselves, endowed with the properties of mutual repulsion and attraction. These forces are self-compensated in the solid state, where the atoms are geometrically correct, forming a crystal lattice. At the same time, a material object is able to retain both of the above-mentioned qualitative characteristics: volume and shape.

But as soon as the kinetic energy of the molecules increases, moving chaotically, they destroy the established order, turning into liquids. They have fluidity and are characterized by the absence of geometric parameters. But at the same time, this substance retains its ability not to change the total volume. In the gaseous state, the mutual attraction between the molecules is completely absent, so the gas has no shape and has the possibility of unlimited expansion. But the concentration of the substance at the same time drops significantly. The molecules themselves do not change under normal conditions. This is the main feature of the first 3 of the 4 states of matter.

State transformation

The process of turning a solid into other forms can be carried out by gradually increasing the temperature and varying the pressure. In this case, the transitions will occur abruptly: the distance between molecules will noticeably increase, intermolecular bonds will be destroyed with a change in density, entropy, and the amount of free energy. It is also probable that a solid body will immediately transform into a gaseous form, bypassing intermediate stages. It is called sublimation. Such a process is quite possible under ordinary terrestrial conditions.

But when the temperature and pressure indicators reach a critical level, the internal energy of the substance is formed so much that the electrons, moving at a frantic speed, leave their intra-atomic orbits. In this case, positive and negative particles are formed, but their density in the resulting structure remains almost the same. Thus, plasma arises - an aggregate state of matter, which, in fact, is a gas, fully or partially ionized, the elements of which are endowed with the ability to interact with each other over long distances.

High-temperature plasma of space

Plasma, as a rule, is a neutral substance, although it consists of charged particles, because the positive and negative elements in it, being approximately equal in number, compensate each other. This state of aggregation under normal terrestrial conditions is less common than the others mentioned earlier. But despite this, most cosmic bodies consist of natural plasma.

An example of this is the Sun and other numerous stars of the Universe. There temperatures are fantastically high. Indeed, on the surface of the main luminary of our planetary system, they reach 5,500 ° C. This is more than fifty times higher than the parameters that are necessary for water to boil. In the center of the fire-breathing ball, the temperature is 15,000,000°C. It is not surprising that gases (mainly hydrogen) are ionized there, reaching the aggregate state of the plasma.

Low temperature plasma in nature

The interstellar medium that fills the galactic space also consists of plasma. But it differs from its high-temperature variety described earlier. Such a substance consists of ionized matter arising from the radiation emitted by stars. This is a low temperature plasma. In the same way, the sun's rays, reaching the limits of the Earth, create the ionosphere and the radiation belt above it, consisting of plasma. The differences are only in the composition of the substance. Although all the elements presented in the periodic table can be in a similar state.

Plasma in the laboratory and its application

According to the laws, it is easily obtained in the conditions familiar to us. When conducting laboratory experiments, a capacitor, a diode and a resistance connected in series are sufficient. A similar circuit is connected to a current source for a second. And if you touch the wires to a metal surface, then the particles of it itself, as well as the molecules of vapor and air located near it, are ionized and find themselves in the aggregate state of the plasma. Similar properties of matter are used to create xenon and neon screens and welding machines.

Plasma and natural phenomena

Under natural conditions, plasma can be observed in the light of the Northern Lights and during thunderstorms in the form of ball lightning. An explanation for some natural phenomena, which were previously attributed to mystical properties, has now been given by modern physics. Plasma, formed and glowing at the ends of tall and sharp objects (masts, towers, huge trees) in a special state of the atmosphere, centuries ago was taken by sailors as a messenger of good luck. That is why this phenomenon was called "Fires of St. Elmo."

Seeing a corona discharge in the form of luminous tassels or beams during a thunderstorm in a storm, travelers took this as a good omen, realizing that they had avoided danger. It is not surprising, because the objects rising above the water, suitable for the "signs of the saint", could talk about the approach of the ship to the shore or prophesy a meeting with other ships.

Non-equilibrium plasma

The above examples eloquently indicate that it is not necessary to heat the substance to fantastic temperatures in order to achieve the state of the plasma. For ionization, it is enough to use the strength of the electromagnetic field. At the same time, the heavy constituent elements of matter (ions) do not acquire significant energy, because the temperature during this process may well not exceed several tens of degrees Celsius. Under such conditions, light electrons, breaking away from the main atom, move much faster than more inert particles.

Such a cold plasma is called non-equilibrium. In addition to plasma TVs and neon lamps, it is also used in the purification of water and food, and is used for disinfection for medical purposes. In addition, cold plasma can help accelerate chemical reactions.

Principles of use

An excellent example of how artificially created plasma is used for the benefit of mankind is the manufacture of plasma monitors. The cells of such a screen are endowed with the ability to emit light. The panel is a kind of "sandwich" of glass sheets, close to each other. Between them are boxes with a mixture of inert gases. They can be neon, xenon, argon. And phosphors of blue, green, red color are applied to the inner surface of the cells.

Outside the cells, conductive electrodes are connected, between which a voltage is created. As a result, an electric field arises and, as a result, the gas molecules are ionized. The resulting plasma emits ultraviolet rays, which are absorbed by the phosphors. In view of this, the phenomenon of fluorescence occurs by means of the photons emitted in this case. Due to the complex connection of the rays in space, a bright image of a wide variety of shades arises.

Plasma Horrors

This form of matter assumes a deadly appearance during a nuclear explosion. Plasma in large volumes is formed during the course of this uncontrolled process with the release of a huge amount of various types of energy. resulting from the launch of the detonator, breaks out and heats the surrounding air to gigantic temperatures in the first seconds. At this point, a deadly fireball appears, growing at an impressive rate. The visible area of ​​the bright sphere is enlarged by ionized air. Clots, clubs and jets of explosion plasma form a shock wave.

At first, the luminous ball, advancing, instantly absorbs everything in its path. Not only human bones and tissues turn into dust, but also solid rocks, even the most durable artificial structures and objects are destroyed. Armored doors to safe shelters do not save, tanks and other military equipment are flattened.

Plasma in its properties resembles a gas in that it does not have certain shapes and volumes, as a result of which it is able to expand indefinitely. For this reason, many physicists are of the opinion that it should not be considered a separate state of aggregation. However, its significant differences from just hot gas are obvious. These include: the ability to conduct electric currents and exposure to magnetic fields, instability and the ability of composite particles to have different speeds and temperatures, while collectively interacting with each other.

Thousands of years of intensive development, the study of life and nature have led man to the knowledge of the four states of matter. Plasma turned out to be the most mysterious of them. From the moment when man first discovered its existence, the study of plasma and its practical application has gone by leaps and bounds. Such a promising science today as plasma chemistry arose and began to actively develop.

Even in the days of Ancient Greece, the scientist Aristotle knew that all bodies consist of four lower elements-elements: earth, water, air and fire. Today these concepts have changed their names, but not the meaning. Indeed, everyone knows that matter can be in four states: solid, liquid, gaseous and plasma.

The fourth state of matter was discovered by W. Crookes in 1879 and named "plasma" by I. Langmuir in 1928.

Plasma (from the Greek. Plasma - fashioned, decorated), partially or completely ionized gas, in which the density of positive and negative charges are almost the same.

Plasma is a gas composed of positively and negatively charged particles in such ratios that their total charge is zero. Freely moving charged particles can carry electric current, therefore, plasma is a gas with electrical conductivity. Compared to known conductors, in particular metals - electrolytes, plasma is thousands of times lighter.

There is no difference between gases and plasmas in some respects. Plasma obeys gas laws and in many ways behaves like a gas.

An important feature of a plasma is the chaotic motion of particles inherent in a gas, which can be ordered in a plasma. Under the influence of an external magnetic or electric field, it is possible to give direction to the movement of plasma particles. Therefore, plasma can be thought of as a fluid medium that has the property of conducting an electric current.

The concept of plasma, or the plasma state of matter, covers both hot and cold gases that have luminescence and electrical conductivity. There are two types of plasma: isometric, which occurs at a gas temperature high enough for strong thermal ionization, and gas-discharge, which is formed during electrical discharges in gases.

In an isometric plasma, the average kinetic energy of particles: electrons, ions, neutral and excited atoms and molecules is the same. In thermal equilibrium with the environment, such a plasma can exist indefinitely. A gas-discharge plasma is stable only in the presence of an electric field in the gas that accelerates electrons. The temperature of the gas-discharge plasma is higher than the temperature of the neutral gas. Thus, the plasma state is unstable, and when the electric field stops, the gas-discharge plasma disappears within a fraction of a second, namely 10-5 and 10-7 seconds, since deionization of gases occurs during this period. Therefore, plasma is, on the one hand, the state of a gas and, on the other hand, a mixture of several gases. It consists of normal molecules, free electrons, ions and photons. The set of particles of each kind forms its own gas, consisting of neutral molecules, electrons, ions and photons. All these gases, taken together, form what is called plasma.

Plasma arises as a result of ionization of molecules: when two particles of molecules with high energy collide, when molecules collide with electrons or ions, when photons act on molecules. All these processes are reversible, since recombination processes occur in the plasma - the restoration of the neutral state. In practice, plasma can be formed when a fire burns, when an electric current is passed through a gas, at elevated temperatures, etc.

According to today's ideas, the phase state of most of the matter (by mass approx. 99.9%) in the Universe is plasma. All stars are made of plasma, and even the space between them is filled with plasma, albeit very rarefied. For example, the planet Jupiter has concentrated in itself almost all the matter of the solar system, which is in a "non-plasma" state (liquid, solid and gaseous). At the same time, the mass of Jupiter is only about 0.1% of the mass of the solar system, and the volume is even less: only 10–15%. At the same time, the smallest dust particles that fill outer space and carry a certain electric charge can be considered in aggregate as a plasma consisting of superheavy charged ions.

Plasma has different properties. The main ones are:

• 1. Electrical conductivity is the main property of plasma. Another property is associated with electrical conductivity, namely, luminescence, as a result of the excitation of molecules. The internal energy of the plasma is 3 cal/deg * mol for a monatomic gas, and 12 cal/deg * mol for polyatomic molecules, such as benzene. For the plasma state, the heat capacity is 100-200 cal / deg - mol, i.e. 40-50 times greater than that of gases. The high heat capacity is explained by the fact that during the transition of a substance from the ordinary to the plasma state, part of the energy is spent on ionization. This energy, as we see, is quite large.
• 2. Plasma has a specific movement. It is caused by the presence of a large number of charges that determine the electrical conductivity of the plasma, which leads to a new motion of the plasma, which is not present in any of the other states of aggregation. As is known, in non-ionized systems it occurs under the action of gravity, inertia, elasticity, and here - under the influence of magnetic and electric forces. The random movement of electrons and ions leads to the fact that the density of equally charged particles in some areas becomes greater or less, as a result of which the charge intensity in some areas either increases or decreases, which causes the movement of positively charged particles towards more intense charges of negative particles. As a result of this movement, oscillations of the pendulum type arise, since the movement of a negatively charged field to a positive one, in turn, causes new sections with different charge densities of the same sign, i.e., waves of positive and negative electricity arise.
• 3. One of the most important properties of plasma is the possibility of the occurrence of electromagnetic oscillations in an extremely wide range under the influence of motion occurring in the plasma itself or under the influence of an electric current flowing in the plasma. In the presence of an external strong magnetic field, the plasma begins to move in the direction perpendicular to the current, which allows, acting by an electromagnetic field, to close the plasma motion in a circle.

This property of plasma is very important for obtaining high temperatures.

Nuclear synthesis

It is believed that the reserves of chemical fuel for mankind will be enough for several decades. The explored reserves of nuclear fuel are also limited. Controlled thermonuclear reactions in plasma can save humanity from energy starvation and become an almost inexhaustible source of energy.

1 liter of ordinary water contains 0.15 ml of heavy water (D2O). The fusion of deuterium nuclei from 0.15 ml of D2O releases as much energy as it is generated during the combustion of 300 liters of gasoline. Tritium practically does not exist in nature, but it can be obtained by bombarding the n isotope of lithium with neutrons.

The nucleus of a hydrogen atom is nothing but a proton p. The deuterium nucleus contains, in addition, one more neutron, and the tritium nucleus contains two neutrons. Deuterium and tritium can react with each other in ten different ways. But the probabilities of such reactions sometimes differ by hundreds of trillions of times, and the amount of energy released - by 10-15 times. Only three of them are of practical interest.

If all the nuclei in some volume simultaneously react, energy is released instantly. A thermonuclear explosion occurs. In the reactor, the synthesis reaction should proceed slowly.

So far, controlled thermonuclear fusion has not been achieved, and it promises considerable advantages. The energy that is released during thermonuclear reactions per unit mass of fuel is millions of times higher than the energy of chemical fuel and, therefore, hundreds of times cheaper. In thermonuclear energy, there is no release of combustion products into the atmosphere and radioactive waste. Finally, an explosion is ruled out at a thermonuclear power plant.

During fusion, the bulk of the energy (more than 75%) is released as the kinetic energy of neutrons or protons. If neutrons are slowed down in a suitable substance, it heats up; The resulting heat can easily be converted into electrical energy. The kinetic energy of charged particles - protons - is directly converted into electricity.

In a fusion reaction, the nuclei must combine, but they are positively charged and, therefore, according to Coulomb's law, they repel. To overcome the repulsive forces, even the nuclei of deuterium and tritium, which have the smallest charge (Z. = 1), need an energy of about 10 or 100 keV. It corresponds to a temperature of the order of 108-109 K. At such temperatures, any substance is in a state of high-temperature plasma.

From the standpoint of classical physics, the fusion reaction is impossible, but here a purely quantum tunneling effect comes to the rescue. It is calculated that the ignition temperature, starting from which the energy release exceeds its losses, for the deuterium-tritium (DT) reaction is approximately 4.5x107 K, and for the deuterium-deuterium (DD) reactions it is about 4x108 K. Naturally, the DT reaction is preferable. Plasma is heated by electric current, laser radiation, electromagnetic waves and other methods. But it's not just the heat that matters.

The higher the concentration, the more often the particles collide with each other, so it may seem that it is better to use high-density plasma to carry out thermonuclear reactions. However, if 1 cm 3 of plasma contained 1019 particles (the concentration of molecules in a gas under normal conditions), the pressure in it at temperatures of thermonuclear reactions would reach about 106 atm. No structure can withstand such pressure, and therefore the plasma must be rarefied (with a concentration of about 1015 particles per 1 cm 3). Collisions of particles in this case occur less frequently, and in order to maintain the reaction, it is necessary to increase their residence time in the reactor, or retention time. This means that for the implementation of a thermonuclear reaction, it is necessary to consider the product of the concentration of plasma particles and the time of their retention. For DD reactions, this product (the so-called Lawson criterion) is 1016 s/cm 3 , and for the DT reaction it is 1014 s/cm 3 .

Blood plasma: constituent elements (substances, proteins), functions in the body, use

Blood plasma is the first (liquid) component of the most valuable biological medium called blood. Blood plasma takes up to 60% of the total blood volume. The second part (40 - 45%) of the fluid circulating in the bloodstream is taken over by formed elements: erythrocytes, leukocytes, and platelets.

The composition of blood plasma is unique. What is not there? Various proteins, vitamins, hormones, enzymes - in general, everything that ensures the life of the human body every second.

Composition of blood plasma

A yellowish transparent liquid released during the formation of a convolution in a test tube - is it plasma? No - this blood serum, in which there is no coagulated protein (factor I), it went into a clot. However, if you take blood into a test tube with an anticoagulant, then it will not allow it (blood) to clot, and heavy shaped elements will sink to the bottom after a while, while on top there will also be a yellowish, but somewhat cloudy, unlike serum, liquid, here it is and eat blood plasma, the turbidity of which is given by the proteins contained in it, in particular, fibrinogen (FI).

The composition of blood plasma is striking in its diversity. In it, in addition to water, which is 90 - 93%, there are components of protein and non-protein nature (up to 10%):

plasma in the blood

• , which take on 7 - 8% of the total volume of the liquid part of the blood (1 liter of plasma contains from 65 to 85 grams of proteins, the norm of total protein in the blood in biochemical analysis: 65 - 85 g / l). The main plasma proteins are recognized (up to 50% of all proteins or 40 - 50 g / l), (≈ 2.7%) and fibrinogen;
• Other substances of protein nature (complement components, carbohydrate-protein complexes, etc.);
• Biologically active substances (enzymes, hematopoietic factors - hemocytokines, hormones, vitamins);
• Low molecular weight peptides are cytokines, which, in principle, are proteins, but with a low molecular weight, they are produced mainly by lymphocytes, although other blood cells are also involved in this. Despite their "small growth", cytokines are endowed with the most important functions, they carry out the interaction of the immune system with other systems when triggering the immune response;
• Carbohydrates that are involved in metabolic processes that constantly occur in a living organism;
• Products resulting from these metabolic processes, which will subsequently be removed by the kidneys (, etc.);
• In the blood plasma, the vast majority of the elements of the table of D. I. Mendeleev are collected. True, some representatives of inorganic nature (potassium, iodine, calcium, sulfur, etc.) in the form of circulating cations and anions are easy to count, others (vanadium, cobalt, germanium, titanium, arsenic, etc.) - due to the meager amount, calculated with difficulty. Meanwhile, the share of all chemical elements present in the plasma is from 0.85 to 0.9%.

Thus, plasma is a very complex colloidal system in which everything "floats" that is contained in the human and mammalian body and everything that is being prepared for removal from it.

Water is a source of H 2 O for all cells and tissues, being present in plasma in such significant quantities, it provides a normal level (BP), maintains a more or less constant volume of circulating blood (BCC).

Differing in amino acid residues, physicochemical properties and other characteristics, proteins form the basis of the body, providing it with life. By dividing plasma proteins into fractions, one can find out the content of individual proteins, in particular, albumins and globulins, in blood plasma. This is done for diagnostic purposes in laboratories, this is done on an industrial scale to obtain very valuable therapeutic drugs.

Among the mineral compounds, the largest share in the composition of blood plasma belongs to sodium and chlorine (Na and Cl). These two elements occupy ≈ 0.3% of the mineral composition of the plasma, that is, they are, as it were, the main ones, which is often used to replenish the volume of circulating blood (BCC) in case of blood loss. In such cases, an affordable and cheap drug is prepared and transfused - isotonic sodium chloride solution. At the same time, 0.9% NaCl solution is called physiological, which is not entirely true: the physiological solution should, in addition to sodium and chlorine, contain other macro- and microelements (correspond to the mineral composition of the plasma).

Video: what is blood plasma

The functions of blood plasma are provided by proteins

The functions of blood plasma are determined by its composition, mainly protein. This issue will be considered in more detail in the sections below, devoted to the main plasma proteins, however, it will not hurt to briefly note the most important tasks that this biological material solves. So, the main functions of blood plasma:

1. Transport (albumin, globulins);
2. Detoxification (albumin);
3. Protective (globulins - immunoglobulins);
4. Coagulation (fibrinogen, globulins: alpha-1-globulin - prothrombin);
5. Regulatory and coordination (albumin, globulins);

This is briefly about the functional purpose of the fluid, which, as part of the blood, constantly moves through the blood vessels, ensuring the normal functioning of the body. But still, some of its components should have been given more attention, for example, what did the reader learn about blood plasma proteins, having received so little information? But it is they who, in the main, solve the listed tasks (functions of blood plasma).

blood plasma proteins

Of course, to give the fullest amount of information, affecting all the features of the proteins present in plasma, in a small article devoted to the liquid part of the blood, is probably difficult to do. Meanwhile, it is quite possible to acquaint the reader with the characteristics of the main proteins (albumins, globulins, fibrinogen - they are considered the main plasma proteins) and mention the properties of some other substances of a protein nature. Especially since (as mentioned above) they ensure the high-quality performance of their functional duties with this valuable liquid.

The main plasma proteins will be discussed somewhat below, however, I would like to present the reader with a table that shows which proteins represent the main blood proteins, as well as their main purpose.

Table 1. Major plasma proteins

Major Plasma Proteins	Content in plasma (norm), g/l	The main representatives and their functional purpose
Albumins	35 - 55	"Building material", a catalyst for immunological reactions, functions: transport, neutralization, regulation, protection.
Alpha Globulin α-1	1,4 – 3,0	α1-antitrypsin, α-acid protein, prothrombin, cortisol-transporting transcortin, thyroxin-binding protein, α1-lipoprotein, transporting fats to organs.
Alpha Globulin α-2	5,6 – 9,1	α-2-macroglobulin (the main protein in the group) is a participant in the immune response, haptoglobin forms a complex with free hemoglobin, ceruloplasmin carries copper, apolipoprotein B transports low-density lipoproteins ("bad" cholesterol).
Beta Globulins: β1+β2	5,4 – 9,1	Hemopexin (binds hemoglobin heme, which prevents the removal of iron from the body), β-transferrin (transfers Fe), complement component (participates in immunological processes), β-lipoproteins - a “vehicle” for cholesterol and phospholipids.
Gamma globulin γ	8,1 – 17,0	Natural and acquired antibodies (immunoglobulins of 5 classes - IgG, IgA, IgM, IgE, IgD), which mainly carry out immune protection at the level of humoral immunity and create an allergostatus of the body.
fibrinogen	2,0 – 4,0	The first factor of the blood coagulation system is FI.

Albumins

Albumins are simple proteins that, compared to other proteins:

albumin structure

• They show the highest stability in solutions, but at the same time they dissolve well in water;
• They tolerate sub-zero temperatures well, not being particularly damaged when re-freezing;
• Do not collapse when dried;
• Staying for 10 hours at a temperature that is quite high for other proteins (60ᵒС), they do not lose their properties.

The ability of these important proteins is due to the presence in the albumin molecule of a very large number of polar decaying side chains, which determines the main functional responsibilities of proteins - participation in metabolism and the implementation of an antitoxic effect. The functions of albumin in blood plasma can be represented as follows:

1. Participation in water metabolism (due to albumins, the required volume of fluid is maintained, since they provide up to 80% of the total colloid osmotic blood pressure);
2. Participation in the transportation of various products, and especially those that are difficult to dissolve in water, for example, fats and bile pigment - bilirubin (bilirubin, having contacted albumin molecules, becomes harmless to the body and in this state is transferred to the liver);
3. Interaction with macro- and microelements entering the plasma (calcium, magnesium, zinc, etc.), as well as with many drugs;
4. Binding of toxic products in tissues where these proteins freely penetrate;
5. Carbohydrate transfer;
6. Binding and transfer of free fatty acids - fatty acids (up to 80%), sent to the liver and other organs from fat depots and, conversely, fatty acids do not show aggression against red blood cells (erythrocytes) and hemolysis does not occur;
7. Protection against fatty hepatosis of hepatic parenchyma cells and degeneration (fatty) of other parenchymal organs, and, in addition, an obstacle to the formation of atherosclerotic plaques;
8. Regulation of the "behavior" of certain substances in the human body (since the activity of enzymes, hormones, antibacterial drugs in a bound form falls, these proteins help direct their action in the right direction);
9. Ensuring the optimal level of cations and anions in plasma, protection from the negative effects of heavy metal salts that accidentally enter the body (they are complexed with them using thiol groups), neutralization of harmful substances;
10. Catalysis of immunological reactions (antigen→antibody);
11. Maintaining a constant blood pH (the fourth component of the buffer system is plasma proteins);
12. Assistance in the "construction" of tissue proteins (albumins, together with other proteins, constitute a reserve of "building materials" for such an important matter).

Albumin is synthesized in the liver. The average half-life of this protein is 2 - 2.5 weeks, although some "live" for a week, while others "work" up to 3 - 3.5 weeks. By fractionating proteins from the plasma of donors, a valuable therapeutic drug (5%, 10% and 20% solution) is obtained, which has a similar name. Albumin is the last fraction in the process, so its production requires considerable labor and material costs, hence the cost of the therapeutic agent.

Indications for the use of donor albumin are various (in most cases quite severe) conditions: a large life-threatening blood loss, a drop in albumin levels and a decrease in colloid osmotic pressure due to various diseases.

Globulins

These proteins take up a smaller proportion compared to albumin, but quite tangible among other proteins. Under laboratory conditions, globulins are divided into five fractions: α-1, α-2, β-1, β-2 and γ-globulins. Under production conditions, to obtain preparations from fraction II + III, gamma globulins are isolated, which will subsequently be used to treat various diseases accompanied by a violation in the immune system.

variety of forms of plasma protein species

Unlike albumins, water is not suitable for dissolving globulins, since they do not dissolve in it, but neutral salts and weak bases are quite suitable for preparing a solution of this protein.

Globulins are very important plasma proteins, in most cases they are acute phase proteins. Despite the fact that their content is within 3% of all plasma proteins, they solve the most important tasks for the human body:

• Alpha globulins are involved in all inflammatory reactions (an increase in the α-fraction is noted in the biochemical blood test);
• Alpha and beta globulins, being part of lipoproteins, carry out transport functions (fats in the free state in plasma appear very rarely, except after an unhealthy fatty meal, and under normal conditions, cholesterol and other lipids are associated with globulins and form a water-soluble form , which is easily transported from one organ to another);
• α- and β-globulins are involved in cholesterol metabolism (see above), which determines their role in the development of atherosclerosis, so it is not surprising that in pathologies that occur with lipid accumulation, the values ​​of the beta fraction change upwards;
• Globulins (alpha-1 fraction) carry vitamin B12 and certain hormones;
• Alpha-2-globulin is part of haptoglobin, which is very actively involved in redox processes - this acute phase protein binds free hemoglobin and thus prevents the removal of iron from the body;
• Part of the beta-globulins, together with gamma-globulins, solves the problems of the body's immune defense, that is, they are immunoglobulins;
• Representatives of alpha, beta-1 and beta-2 fractions tolerate steroid hormones, vitamin A (carotene), iron (transferrin), copper (ceruloplasmin).

Obviously, within their group, globulins differ somewhat from each other (primarily in their functional purpose).

It should be noted that with age or with certain diseases, the liver may begin to produce not quite normal alpha and beta globulins, while the altered spatial structure of the protein macromolecule will not have the best effect on the functional abilities of globulins.

Gamma globulins

Gamma globulins are blood plasma proteins with the lowest electrophoretic mobility; these proteins make up the bulk of natural and acquired (immune) antibodies (AT). Gamma globulins formed in the body after encountering a foreign antigen are called immunoglobulins (Ig). At present, with the advent of cytochemical methods in the laboratory service, it has become possible to study serum in order to determine immune proteins and their concentrations in it. Not all immunoglobulins, and there are 5 classes of them, have the same clinical significance, in addition, their plasma content depends on age and changes in different situations (inflammatory diseases, allergic reactions).

Table 2. Classes of immunoglobulins and their characteristics

Immunoglobulin (Ig) class	Plasma (serum) content, %	Main functional purpose
G	OK. 75	Antitoxins, antibodies directed against viruses and gram-positive microbes;
A	OK. 13	Anti-insular antibodies in diabetes mellitus, antibodies directed against capsular microorganisms;
M	OK. 12	Direction - viruses, gram-negative bacteria, Forsman and Wasserman antibodies.
E	0,0…	Reagins, specific antibodies against various (certain) allergens.
D	In the embryo, in children and adults, it is possible to detect traces	They are not taken into account because they have no clinical significance.

The concentration of immunoglobulins of different groups has noticeable fluctuations in children of younger and middle age categories (mainly due to class G immunoglobulins, where quite high rates are noted - up to 16 g / l). However, after about 10 years of age, when vaccinations are done and the main childhood infections are transferred, the content of Ig (including IgG) decreases and is set at the level of adults:

IgM - 0.55 - 3.5 g / l;

IgA - 0.7 - 3.15 g / l;

IgG - 0.7 - 3.5 g / l;

fibrinogen

The first coagulation factor (FI - fibrinogen), which, during the formation of a clot, passes into fibrin, which forms a convolution (the presence of fibrinogen in plasma distinguishes it from serum), in fact, refers to globulins.

Fibrinogen is readily precipitated with 5% ethanol, which is used in protein fractionation, as well as half-saturated sodium chloride solution, plasma treatment with ether, and refreezing. Fibrinogen is thermolabile and completely folds at a temperature of 56 degrees.

Without fibrinogen, fibrin is not formed, and bleeding does not stop without it. The transition of this protein and the formation of fibrin is carried out with the participation of thrombin (fibrinogen → intermediate product - fibrinogen B → platelet aggregation → fibrin). The initial stages of coagulation factor polymerization can be reversed, however, under the influence of a fibrin-stabilizing enzyme (fibrinase), stabilization occurs and the course of the reverse reaction is excluded.

Participation in the blood coagulation reaction is the main functional purpose of fibrinogen, but it also has other useful properties, for example, in the course of performing its duties, it strengthens the vascular wall, makes a small “repair”, sticking to the endothelium and thereby closing small defects, which then things arise in the course of a person's life.

Plasma proteins as laboratory parameters

In laboratory conditions, to determine the concentration of plasma proteins, you can work with plasma (blood is taken into a test tube with an anticoagulant) or conduct a study of serum taken into a dry dish. Serum proteins are no different from plasma proteins, with the exception of fibrinogen, which, as you know, is absent in the blood serum and which, without an anticoagulant, goes to form a clot. Basic proteins change their digital values ​​in the blood during various pathological processes.

An increase in the concentration of albumin in serum (plasma) is the rarest phenomenon that occurs with dehydration or with excessive intake (intravenous administration) of high concentrations of albumin. Decreased albumin levels may indicate depletion of liver function, kidney problems, or disorders in the gastrointestinal tract.

An increase or decrease in protein fractions is characteristic of a number of pathological processes, for example, acute-phase proteins alpha-1- and alpha-2-globulins, increasing their values, may indicate an acute inflammatory process localized in the respiratory organs (bronchi, lungs), affecting the excretory system (kidneys) or the heart muscle (myocardial infarction).

A special place in the diagnosis of various conditions is given to the fraction of gamma globulins (immunoglobulins). The determination of antibodies helps to recognize not only an infectious disease, but also to differentiate its stage. More detailed information about the change in the values ​​of various proteins (proteinogram), the reader can find in a separate one.

Deviations from the norm of fibrinogen manifest themselves as disturbances in the hemocoagulation system, therefore this protein is the most important laboratory indicator of blood coagulation abilities (coagulogram, hemostasiogram).

As for other proteins that are important for the human body, when examining serum, using certain techniques, you can find almost any that are of interest for diagnosing diseases. For example, by calculating the concentration (beta-globulin, acute phase protein) in the sample and considering it not only as a “vehicle” (although this is probably in the first place), the doctor will know the degree of protein binding of ferric iron released by red blood cells, because Fe 3+ , as you know, being present in the free state in the body, gives a pronounced toxic effect.

The study of serum in order to determine the content (acute phase protein, metal glycoprotein, copper carrier) helps to diagnose such a severe pathology as Konovalov-Wilson's disease (hepatocerebral degeneration).

Thus, by examining plasma (serum), it is possible to determine in it the content of both those proteins that are vital and those that appear in a blood test as an indicator of a pathological process (for example,).

Blood plasma is a remedy

The preparation of plasma as a therapeutic agent began in the 30s of the last century. Now native plasma, obtained by spontaneous sedimentation of formed elements within 2 days, has not been used for a long time. The obsolete ones were replaced by new methods of blood separation (centrifugation, plasmapheresis). Blood after preparation is subjected to centrifugation and divided into components (plasma + shaped elements). The liquid part of the blood obtained in this way is usually frozen (fresh frozen plasma) and, in order to avoid infection with hepatitis, in particular hepatitis C, which has a rather long incubation period, is sent for quarantine storage. Freezing this biological medium at ultra-low temperatures makes it possible to store it for a year or more, so that later it can be used for the preparation of preparations (cryoprecipitate, albumin, gamma globulin, fibrinogen, thrombin, etc.).

Currently, the liquid part of blood for transfusions is increasingly prepared by plasmapheresis, which is the safest for the health of donors. Formed elements after centrifugation are returned by intravenous injection, and proteins lost with plasma in the body of a person who has donated blood are quickly regenerated, come to a physiological norm, while not violating the functions of the body itself.

In addition to fresh frozen plasma transfused in many pathological conditions, immune plasma obtained after immunization of a donor with a specific vaccine, for example, staphylococcal toxoid, is used as a therapeutic agent. Such plasma, which has a high titer of anti-staphylococcal antibodies, is also used to prepare anti-staphylococcal gamma globulin (human anti-staphylococcal immunoglobulin) - the drug is quite expensive, since its production (protein fractionation) requires considerable labor and material costs. And the raw material for it is blood plasma immunized donors.

Anti-burn plasma is also a kind of immune environment. It has long been noted that the blood of people who have experienced such a horror initially carries toxic properties, but after a month, burn antitoxins (beta and gamma globulins) begin to be detected in it, which can help "friends in misfortune" in the acute period of burn disease.

Of course, obtaining such a therapeutic agent is accompanied by certain difficulties, despite the fact that during the recovery period the lost liquid part of the blood is replenished with donor plasma, since the body of burnt people experiences protein depletion. However donor must be an adult and otherwise healthy, and his plasma must have a certain antibody titer (at least 1:16). The immune activity of convalescent plasma persists for about two years, and one month after recovery, it can be taken from convalescent donors without compensation.

From the plasma of donor blood for people suffering from hemophilia or other clotting pathology, which is accompanied by a decrease in antihemophilic factor (FVIII), von Willebrand factor (VWF) and fibrinase (factor XIII, FXIII), a hemostatic agent called cryoprecipitate is prepared. Its active ingredient is clotting factor VIII.

Video: about the collection and use of blood plasma

Fractionation of plasma proteins on an industrial scale

Meanwhile, the use of whole plasma in modern conditions is by no means always justified. Moreover, both from a therapeutic and economic point of view. Each of the plasma proteins has its own unique physicochemical and biological properties. And thoughtlessly infusing such a valuable product to a person who needs a specific plasma protein, and not all plasma, makes no sense, besides, it is expensive in material terms. That is, the same dose of the liquid part of the blood, divided into components, can benefit several patients, and not one patient who needs a separate drug.

The industrial production of drugs was recognized in the world after the developments in this direction by scientists at Harvard University (1943). Plasma protein fractionation was based on the Kohn method, the essence of which is the precipitation of protein fractions by the gradual addition of ethyl alcohol (concentration at the first stage - 8%, at the final stage - 40%) at low temperatures (-3ºС - stage I, -5ºС - last) . Of course, the method has been modified several times, but now (in various modifications) it is used to obtain blood products throughout the planet. Here is his short outline:

• Protein is precipitated in the first step fibrinogen(precipitate I) - this product, after special processing, will go to the medical network under its own name or will be included in a set to stop bleeding, called "Fibrinostat");
• The second stage of the process is the supernatant II + III ( prothrombin, beta and gamma globulins) - this fraction will go to the production of a drug called normal human gamma globulin, or will be released as a remedy called antistaphylococcal gamma globulin. In any case, from the supernatant obtained in the second stage, it is possible to prepare a preparation containing a large amount of antimicrobial and antiviral antibodies;
• The third, fourth stages of the process are needed in order to get to the sediment V ( albumen+ admixture of globulins);
• 97 – 100% albumen it comes out only at the final stage, after which it will take a long time to work with albumin until it enters medical institutions (5, 10, 20% albumin).

But this is just a brief outline, such production actually takes a lot of time and requires the participation of numerous personnel of varying degrees of qualification. At all stages of the process, the future most valuable medicine is under the constant control of various laboratories (clinical, bacteriological, analytical), because all the parameters of the blood product at the outlet must strictly comply with all the characteristics of transfusion media.

Thus, plasma, in addition to the fact that it ensures the normal functioning of the body in the blood, can also be an important diagnostic criterion that shows the state of health, or it can save the lives of other people using its unique properties. And it's not all about blood plasma. We did not begin to give a complete description of all its proteins, macro- and microelements, to thoroughly describe its functions, because all the answers to the remaining questions can be found on the pages of VesselInfo.

Ministry of Education and Science of the Russian Federation

Federal Agency for Education

Pacific State Economic University

Department of Physics

Topic: Plasma - the fourth state of matter

Performed:

Aggregate state - a state of matter characterized by certain qualitative properties: the ability or inability to maintain volume and shape, the presence or absence of long-range and short-range order, and others. A change in the state of aggregation may be accompanied by a jump-like change in free energy, entropy, density, and other basic physical properties.

It is known that any substance can exist only in one of three states: solid, liquid or gaseous, a classic example of which is water, which can be in the form of ice, liquid and vapor. However, there are very few substances that exist in these considered indisputable and common states, if we take the entire Universe as a whole. They hardly exceed what in chemistry are considered negligible traces. All other matter of the Universe is in the so-called plasma state.

The word "plasma" (from the Greek "plasma" - "decorated") in the middle of XIX

in. began to call the colorless part of the blood (without red and white bodies) and

fluid that fills living cells. In 1929, the American physicists Irving Langmuir (1881-1957) and Levi Tonko (1897-1971) named the ionized gas in a gas discharge tube a plasma.

English physicist William Crookes (1832-1919), who studied electrical

discharge in tubes with rarefied air, wrote: “Phenomena in evacuated

tubes open up a new world for physical science in which matter can exist in a fourth state.”

Depending on the temperature, any substance changes its

condition. So, water at negative (Celsius) temperatures is in a solid state, in the range from 0 to 100 "C - in a liquid state, above 100 ° C - in a gaseous state. If the temperature continues to rise, atoms and molecules begin to lose their electrons - they are ionized and gas turns into plasma.At temperatures above 1000000 ° C, the plasma is absolutely ionized - it consists only of electrons and positive ions.Plasma is the most common state of matter in nature, it accounts for about 99% of the mass of the Universe.The sun, most stars, nebulae are fully ionized plasma The outer part of the earth's atmosphere (ionosphere) is also plasma.

Even higher are the radiation belts containing plasma.

Auroras, lightning, including balls, are all different types of plasma that can be observed in natural conditions on Earth. And only an insignificant part of the Universe is made up of matter in a solid state - planets, asteroids and dust nebulae.

Plasma in physics is understood as a gas consisting of electrically

charged and neutral particles, in which the total electric charge is zero, t. the condition of quasi-neutrality is satisfied (therefore, for example, a beam of electrons flying in a vacuum is not a plasma: it carries a negative charge).

1.1. The most typical forms of plasma

The most typical forms of plasma
Artificially created plasma Plasma panel (TV, monitor) Substance inside fluorescent (including compact) and neon lamps Plasma rocket engines Gas-discharge corona of an ozone generator Controlled thermonuclear fusion research Electric arc in an arc lamp and in arc welding Plasma lamp (see figure) Arc discharge from the Tesla transformer Impact on matter by laser radiation Glowing sphere of a nuclear explosion	Terrestrial natural plasma Lightning Fires of Saint Elmo Ionosphere Flames (low temperature plasma)	Space and astrophysical plasma Sun and other stars (those that exist due to thermonuclear reactions) Solar wind Outer space (the space between planets, stars and galaxies) Interstellar nebulae

Properties and parameters of plasma

Plasma has the following properties:

Sufficient density: Charged particles must be close enough to each other that each of them interacts with a whole system of closely spaced charged particles. The condition is considered satisfied if the number of charged particles in the sphere of influence (a sphere with Debye radius) is sufficient for the occurrence of collective effects (such manifestations are a typical property of plasma). Mathematically, this condition can be expressed as follows:

, where is the concentration of charged particles.

Priority of internal interactions: the Debye screening radius must be small compared to the characteristic size of the plasma. This criterion means that the interactions occurring inside the plasma are more significant than the effects on its surface, which can be neglected. If this condition is met, the plasma can be considered quasi-neutral. Mathematically, it looks like this:

Plasma frequency: The average time between particle collisions must be large compared to the period of plasma oscillations. These oscillations are caused by the action of an electric field on the charge, which arises due to the violation of the quasi-neutrality of the plasma. This field seeks to restore the disturbed balance. Returning to the equilibrium position, the charge passes this position by inertia, which again leads to the appearance of a strong returning field, typical mechanical vibrations occur. When this condition is met, the electrodynamic properties of the plasma prevail over the molecular kinetic ones. In the language of mathematics, this condition has the form:

2.1. Classification

Plasma is usually divided into ideal and non-ideal, low-temperature and high-temperature, equilibrium and non-equilibrium, while quite often cold plasma is non-equilibrium, and hot plasma is equilibrium.

2.2. Temperature

When reading popular scientific literature, the reader often sees plasma temperatures of the order of tens, hundreds of thousands, or even millions of °C or K. To describe plasma in physics, it is convenient to measure the temperature not in °C, but in units of the characteristic energy of particle motion, for example, in electron volts (eV). To convert the temperature to eV, you can use the following relationship: 1 eV = 11600 K (Kelvin). Thus, it becomes clear that a temperature of "tens of thousands of ° C" is quite easily achievable.

In a nonequilibrium plasma, the electron temperature substantially exceeds the temperature of the ions. This is due to the difference in the masses of the ion and electron, which hinders the process of energy exchange. This situation occurs in gas discharges, when ions have a temperature of about hundreds, and electrons about tens of thousands of K.

In an equilibrium plasma, both temperatures are equal. Since temperatures comparable to the ionization potential are required for the implementation of the ionization process, the equilibrium plasma is usually hot (with a temperature of more than several thousand K).

The concept of high-temperature plasma is usually used for fusion plasma, which requires temperatures of millions of K.

2.3. Degree of ionization

In order for the gas to pass into the plasma state, it must be ionized. The degree of ionization is proportional to the number of atoms that donated or absorbed electrons, and most of all depends on temperature. Even a weakly ionized gas, in which less than 1% of the particles are in an ionized state, can exhibit some typical plasma properties (interaction with an external electromagnetic field and high electrical conductivity). The degree of ionization α is defined as α = ni/(ni + na), where ni is the concentration of ions and na is the concentration of neutral atoms. The concentration of free electrons in an uncharged plasma ne is determined by the obvious relationship: ne= ni, where - the average value of the charge of plasma ions.

A low-temperature plasma is characterized by a low degree of ionization (up to 1%). Since such plasmas are quite often used in technological processes, they are sometimes called technological plasmas. Most often, they are created using electric fields that accelerate electrons, which in turn ionize atoms. Electric fields are introduced into the gas by inductive or capacitive coupling (see inductively coupled plasma). Typical applications of low temperature plasma include plasma surface modification (diamond films, metal nitriding, wettability modification), plasma etching of surfaces (semiconductor industry), gas and liquid cleaning (water ozonation and soot combustion in diesel engines).