Belka is a modular microcar. Production and use in biology lessons of a dynamic model of the protein synthesis process Do-it-yourself protein structure model

05.11.2019

Engine

And theoretical chemistry and is used in biotechnology (when creating new ones) and in medicine (in pharmaceuticals). The effectiveness of the development of prediction methods is evaluated in the framework of a worldwide experiment, the intermediate results of which are summed up every two years, starting in 1994.

In the 1960s, the American biochemist Christian Anfinsen proposed a thermodynamic hypothesis, according to which the atoms of protein molecules, under natural conditions, are thermodynamically stable, which corresponds to the minimum free energy of the system. In other words, the protein takes on a certain spatial shape as a result of the constraints dictated by the composition and physicochemical properties that form it.

In turn, protein molecules with a similar spatial structure usually play a similar biological role in cellular level processes. Thus, the structure of a protein can be considered as an intermediate link between the chemical composition (primary structure) and the function of the protein.

Most protein amino acid sequences today are obtained by gene translation from nucleotide sequences, which are determined by large-scale research projects, such as the Human Genome Project.

At the same time, the methods for experimental determination of the protein structure are technologically complex, expensive, and significantly (by more than two orders of magnitude) lag behind the methods for determining the chemical composition in productivity. As of March 2010, almost 10,000,000 protein sequences have been deposited in public databases, and this number continues to increase at a rapid pace, despite the fact that, through the efforts of the world's major centers of structural genetics, only 60,000 structures have been filled in the centralized database of protein structures. It is assumed that the gap between the number of sequences and structures of proteins can be filled only by the method theoretical protein structure predictions.

Solving this problem means opening wide opportunities for introducing and improving various biotechnologies (today, computer prediction of protein structure is used in biology and medicine, in particular, in the development of drugs).

Knowledge of the protein structure can suggest potential partners for protein interaction and, thus, encourage researchers to develop or improve new ones, explain mutations, and indirectly, help in determining the place for mutations to change certain phenotypes.

Protein Structure Prediction Methods

Protein structure prediction is challenging for many reasons:

First, the number of possible spatial configurations of proteins is quite large,
Secondly, the physical foundations of protein structure formation and their stability are not yet fully understood.

To be successful in building a model for protein structure prediction, a strategy must initially be developed to effectively rebuild the space of possible structures and select the most likely candidates for the native structure.

Today, there are two main, conceptually different methods for narrowing the search space for structural conformations of proteins:

The first type of prediction methods use the assumption that the desired protein structure may be similar to one or more known protein structures, or at least be composed of the elementary building blocks of such proteins.

Second Type Prediction Methods do not use information about known structures, based mainly on simplified energy potentials, using approximate strategies for searching for a minimum of the energy landscape for modeling.

Protein Structure Predictions from a Sample (Template)

If among the known protein structures it is possible to find those for which it can be assumed that they can be, to a certain extent, similar to the object of modeling (prediction), then they can be used as a template (sample) for building a model. This method of homology modeling is called "prediction of protein structure from a sample (from a template") (Template-based modeling).

Prediction templates can be found using direct comparison of amino acid sequences (Comparative modeling methods), or more complex methods for recognizing structurally similar proteins with little or almost undetectable sequence similarity (fold recognition / threading methods).

The last group of methods is based on the principle that structure is evolutionarily conserved, as opposed to sequence, and it is sometimes possible to find related proteins with dissimilar sequences and then try to "trace" the sequence of the target protein through the template structure. Theoretically, such proteins can be identified by constructing and comparing sequence profiles of the desired protein and known structures.

Predicting the structure of a protein from a sample (template) has a huge practical potential, since if the structure is known at least one family protein, so you can try to build models for almost every protein in this family. As the structure database fills up, this modeling becomes possible for more and more proteins.

Template-free methods for protein structure prediction

If one of the above methods fails to find a template for protein structure prediction, template-free / de novo methods are used in this situation. Template-free prediction methods include fragment methods and purely physical methods.

Template-free prediction of the structure of proteins by molecular dynamics with an energy function (in particular, molecular dynamics and the Monte Carlo method, using the advantages of distributed and parallel computing), which takes into account the details of interaction at the atomic level, is practically unrealizable today due to high requirements for computing resources. It is for this reason that most ab initio methods use the simplified atomic structure of proteins.

The folding of small alpha-helical protein domains, e.g. protein, has been successfully predicted in silico. Through the use of hybrid prediction methods that combine standard molecular dynamics with quantum mechanics, the electronic states of the visual pigment rhodopsin have been investigated.

Template-free protein structure prediction methods are less reliable than template ones, but they allow one to construct models that have general form (English - Fold), close to the native structure of the desired protein.

Notes

Notes and explanations to the article "Protein Structure Prediction (Modeling)".

Protein, protein, protein - a high-molecular organic substance consisting of alpha-amino acids united by peptide bonds (formed when the amino group of one amino acid and the carboxyl group of another amino acid react with the release of a water molecule). There are two classes of proteins: a simple protein, which decomposes exclusively into amino acids during hydrolysis, and a complex protein (holoprotein, proteid) containing a prosthetic group (a subclass of cofactors), during the hydrolysis of a complex protein, in addition to amino acids, the non-protein part or its decay products are released. Enzyme proteins accelerate (catalyze) the course of biochemical reactions, having a significant impact on metabolic processes. Individual proteins perform mechanical or structural functions, forming a cytoskeleton that retains the shape of cells. Among other things, proteins play a key role in cell signaling systems, in the immune response, and in the cell cycle. Proteins are the basis for building muscle tissue, cells, tissues and organs in humans.
Molecular modeling, MM, Molecular modeling is a collective name for methods for studying the properties and structure of molecules using computer technology and subsequent visualization of the results, which, as a result, provides their three-dimensional representation under the conditions specified in the calculation.
in silico - a term denoting a computer simulation (modeling) of an experiment, usually a biological one. The roots of the term in silico lead to terms in vitro(in vitro) and in vivo(in a living organism). in silicio literally means "in silicon", thus symbolizing silicon as a semiconductor material that plays an important role in the creation of silicon microcircuits used in the manufacture of computer equipment.
Squirrel design, protein design is the rational construction of new protein molecules folded in the target structure of the protein in order to design its new functions and / or behavior. Thanks to the design, proteins can be developed both anew (new protein) and by changing existing ones, based on the known structure of the protein and its sequence (reconstruction).
Tertiary structure, three-dimensional structure - the spatial structure (including the conformation) of the entire protein molecule, another macromolecule consisting of a single chain.
bioinformatics- a set of approaches and methods used, in particular, in biophysics, biochemistry, ecology, including mathematical methods of computer analysis in comparative genomics, development of programs and algorithms for predicting the spatial structure of biopolymers, research strategies, appropriate computational methodologies, as well as general management information complexity of biological systems. Bioinformatics uses the methods of applied mathematics, informatics and statistics.
Enzymes, enzymes, enzymes - as a rule, protein molecules or ribozymes (RNA molecules) or their complexes that catalyze (accelerate) chemical reactions in living systems. Enzymes, like all proteins, are synthesized as a linear chain of amino acids that fold in a certain way. Each sequence of amino acids folds in a special way, resulting in the resulting protein globule (molecule) has unique properties. Enzymes are present in all living cells and contribute to the transformation of some substances into others. Enzymatic activity can be regulated by inhibitors and activators (inhibitors decrease, activators increase). According to the type of catalyzed reactions, enzymes are divided into six classes: oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. For the implementation of catalysis, individual enzymes require components of a non-protein nature - cofactors. Cofactors can be both inorganic (iron-sulfur clusters, metal ions, including) and organic (heme, flavin, including) molecules. Organic cofactors that are strongly associated with the enzyme are called prosthetic groups. Organic cofactors that can be separated from the enzyme are called coenzymes.
Critical assessment of the prediction of protein structures, Critical Assessment of protein Structure Prediction, CASP is a large-scale experiment on the prediction of protein structures, which is considered a worldwide competition in the science of structural modeling. The main goal of CASP is to coordinate efforts to improve methods for determining the three-dimensional structure of proteins from their amino acid sequences. As part of CASP, there is an objective testing of methods for predicting protein structures, followed by an independent assessment of structural modeling. More than 100 research groups participate in the experiment on an ongoing basis.
Christian Boehmer Anfinsen, Christian Boehmer Anfinsen (1916 - 1995) - American biochemist, Nobel Prize in Chemistry 1972 (together with Stanford Moore and William Stein), "for his work in establishing the relationship between the amino acid sequence of ribonuclease A and its biologically active conformation".
Conformation- the spatial arrangement of atoms in a molecule of a certain configuration, due to rotation around one or more single sigma bonds.
Amino acid is an organic compound that is a building material for protein structures, muscle fibers. The body uses amino acids for its own growth, strengthening and repair, for the production of various hormones, enzymes and antibodies.
Deoxyribonucleic acid, DNA, deoxyribonucleic acid, DNA is one of the three main macromolecules (two other RNAs and proteins), which provides storage, transmission from generation to generation and implementation of the genetic program for the development and functioning of living organisms. DNA stores information about the structure of various types of RNA and proteins. From a chemical point of view, DNA is a long polymeric molecule consisting of repeating blocks - nucleotides. Each nucleotide is made up of a nitrogenous base (cytosine, thymine, guanine, and adenine), a sugar (deoxyribose), and a phosphate group. The bonds between nucleotides in a chain are formed by deoxyribose and a phosphate group. In the vast majority of cases (with the exception of individual viruses containing single-stranded DNA), the DNA macromolecule consists of two chains oriented by nitrogenous bases to each other. The chains are intertwined with each other in the form of a spiral, hence the name of the structure of the DNA molecule - “double helix”.
, The Human Genome Project, The Human Genome Project, HGP is an international research project whose main goal was to determine the sequence of nucleotides that make up DNA and identify 20-25 thousand genes in the human genome. The project began in 1990 under the auspices of the US National Institutes of Health, in 2000 a working draft of the genome structure was released, the complete genome in 2003. Most of the sequencing was performed at universities and research centers in the US, UK and Canada.
Protein Data Bank, PDB is a database of 3-D structures of proteins and nucleic acids obtained by X-ray crystallography or NMR spectroscopy. The PDB is one of the most important resources for scientists working in the field of structural biology.
Antibodies, immunoglobulins, IG, antibody, Ab, immunoglobulins, Ig, is a class of complex glycoprotein proteins present as soluble molecules in tissue fluid and blood serum, in the form of membrane-bound receptors on the surface of B-lymphocytes. Antibodies are highly selective in binding to specific types of molecules (which are therefore called antigens). In humans, there are five classes of antibodies (immunoglobulins) that differ in the structure and amino acid composition of heavy chains and in the effector functions performed - IgG, IgA, IgM, IgD and IgE. Antibodies are the most important factor in specific immunity; they are used by the immune system to identify and neutralize foreign objects, including viruses and bacteria.
Phenotype(from the Greek `6, ^ 5, ^ 3, _7, ` 9, - “I discover, manifest” and ` 4, a3, ` 0, _9, ` 2, - "example, sample, pattern") - a set of characteristics, inherent in an individual at a certain stage of development (as a result of ontogenesis). The phenotype is formed on the basis of the genotype mediated by a number of environmental factors.
Villin is a tissue-specific protein of 92.5 kDa that binds actin filaments of brush borders. Villin contains repetitive gelsolin-like domains surmounted by a small (8.5 kDa) "head" at the C-terminus, consisting of rapidly and independently forming three-stranded sequences stabilized by hydrophobic interactions. The functions of villin are not fully understood, but it is assumed that he takes part in the nucleation, formation, joining into bundles and cutting of actin filaments.

When writing an article about the structure of a protein, as well as methods for predicting (simulating) the structure of a protein, materials from information and reference Internet portals, news sites NCBI.NLM.NIH.gov, ProteinStructures.com, Stanford.edu, ScienceDaily were used as sources. com, Genome.gov, FASTA.Bioch.Virginia.edu, FEN.NSU.ru, SGU.ru, VIGG.ru, Wikipedia, as well as the following publications:

Ginter E. K. “Medical genetics. Educational literature for students of medical universities. Publishing house "Medicine", 2003, Moscow,
Skalny A. V., Rudakov I. A. "Bioelements in medicine" Publishing house "Onyx", 2004, Moscow,
Mulberg A. A. "Squirrel folding" Publishing house "Publishing house of St. Petersburg State University", 2004, St. Petersburg,
Stefanov V. E., Mavropulo-Stolyarenko G. R. "Protein structure analysis by bioinformatics methods". Publishing house "Golden Section", 2007, St. Petersburg,
Konichev A. S., Sevastyanova G. A. “Molecular biology. Higher professional education”. Publishing house "Academy", 2008, Moscow,
Novoseletsky V. (editor) “Structure and function of proteins. Application of bioinformatics methods. Led by Daniel John Rigden. Publishing house "URSS", 2014, Moscow. (1 votes, average: 5,00 out of 5)

How to be a car design circle? What cars should be built in it? How to organize classes? These and many other questions were raised in recent publications by M. L. Larkin and I. F. Ryshkov “Project - model - car” and “Auto-designer for a car designer!” ("M-K" No. 1, 1979). Most of all, our readers were interested in the technical side of the matter - the device of a modular microcar. Today we offer the latest development of the auto-design laboratory of KYUT of the Siberian Branch of the USSR Academy of Sciences - the Belka microcar.

This small, elegant walking and sports "jeep" can radically change the whole look in just half an hour. It is worth rearranging two or three structural elements - and you have a buggy in front of you. And if there is a desire to stop the "Squirrel" in a tourist car, then it is enough to install a removable awning-fairing on it. Without much difficulty, it turns into a light truck. If necessary, the car can be easily disassembled and folded into its own cargo body, like in a box.

Despite the relatively small size ("Squirrel" is freely placed even on the desk!), This is not a toy, but a real car. Its speed is about 40 km / h, and the fuel in the gas tank is enough for 100 km.

How did the idea of a modular car come about? First of all, we were not satisfied with the timing of the design and construction of "traditional" cars - our boys had time to grow up, finish school and leave the club without ever sitting behind the wheel.

The schemes using a frame and non-technological profiled panels under the conditions of a circle were not suitable for us either. Such designs, in addition to the fact that their implementation requires too much time and effort, are also absolutely unchanged - it is very difficult to make another machine based on the old one. Building a new car without using elements of the old one is expensive.

1 - transverse spring, 2 - transverse link, 3 - front suspension pendulum, 4 - front suspension mounting eye, 5 - spinal frame, 6 - engine start lever, 7 - frame cross beam, 8 - rear suspension pendulum mounting eyes, 9 - rear suspension pendulum, 10 - rear wheel, 11 - longitudinal spring, 12 - VP-150 engine.

And the last thing that prompted to take up the development of a transformable microcar was the problem of storage. The number of our developments has slowly but steadily increased; we kept a few cars in the laboratory, the rest in the garage. Interest in them disappeared, because the guys wanted to try their hand at building their own car, and gradually the work of several generations of circle members turned into scrap metal.

All this made us turn to a fundamentally new idea - to design a multi-purpose block (modular) car.

There were, however, objections: some thought that the design of such a machine would put the young designer in a rigid framework that hindered the flight of creative imagination. But most of the guys were inclined to think that this would not happen. On the contrary, design limitations will allow the young car builder to show maximum ingenuity when working out his own version based on a standard set of elements.

Now let's mentally open the box-body and consider what makes up the basis of the autoconstructor.

The body of the Belka truck is a box assembled from six-millimeter plywood and edged with a duralumin corner. Above are the details of the driver's seat - the back and seat. They are simple - the base (plywood 6 mm thick) with foam glued on it is covered with red artificial leather. Overall dimensions of the seat 570X300 mm.

Under the details of the seat lies a steel sheet 720X510 mm 2 mm thick, glued on one side with corrugated rubber - this is the bottom of the car. Twelve holes Ø 4 mm along the edge of the sheet are designed for attaching the floor to the body.

After removing the bottom, you will find six side panels under it, which are the basis of the car body, since almost all other elements of the body are attached to them.

In the center of the box, between the side panels, there is space for four wheels 3.50-5 model V-25 A. They contain eight rims and two hubs with bearings and axles complete with pivot pins and longitudinal rods.

Even lower are two rocking chairs of the front axle, welded from gas pipes with an external Ø 20 mm. There is also a sub-frame, which simultaneously serves as the base of the rear axle and its suspension. It is welded from gas pipes Ø 30 mm.

In the same box-body, the spinal frame of a 40X40 mm square-section car with lugs welded to it for attaching the rocking chairs of the front and rear axles is also laid. Under the frame are two springs (front - transverse and rear - longitudinal) and four ladders with overlays for attaching the suspension to the frame. Strips of springs can be picked up from a Moskvich car of any brand.

The designer kit also includes a steering wheel, a steering column with brackets and leashes, and transverse rods with hinges. In a separate package - carburetor throttle, clutch and brake pedals. At the very bottom of the body, a hood panel, a windshield, a rear seat back support (it is also a gas tank hood), front and rear fenders, an instrument panel and two steel corner profiles 20X20 mm 720 mm long are laid. A special compartment contains headlights and sidelights, position lights, cables, speedometer, toggle switches, a set of electrical wiring elements and a package of fasteners - bolts, screws, washers and nuts. Socket wrenches and screwdrivers are not forgotten either.

The VP-150 engine is packed together with a gas tank, a fuel line hose and a kickstarter in a separate box.

A set of car parts is available. Now let's try to put together one of the variants of the autoconstructor, in particular, the Belka microcar - "jeep".

It is best to start assembling with the chassis. To do this, lay the spinal frame on the mounting platform and pivotally connect the sub-frame and front axle rockers to it with two M10 bolts. We insert the ends of the front transverse spring into the support brackets of the front axle rocking chairs, and fix its center with two stepladders on the frame.

The motor shaft is inserted into the left bushing of the sub-frame, and it is docked to the frame with two stop bolts. The axis of a free-rolling wheel with bearings and a cage is inserted into the right bushing of the sub-frame. After that, it is possible to mount the rear longitudinal spring, one of the ends of which should be in the support bracket of the under-engine swing frame, and the other is fixed with two ladders on the spinal frame.

Now let's start mounting the rear wheels. The first step is to assemble the tire with the camera and both disks with the help of three bolts and nuts and pump up the wheel. The wheels are mounted on the studs of the rear axle hubs equipped with brake pads and discs. The rear axle is thus completely assembled.

1 - emblem, 2 - instrument panel, 3 - hood, 4 - back support, 5, 17 - rear fender sidewalls, 6, 18 - body base, 7, 13 - side panels, 8, 14 - front fender sidewalls, 9, 15, 16 - front and rear wings (dimensions in brackets - for the rear wings), 10 - front panel, 11 - trim, 12 - bottom, 19 - rear panel.

The next step is to assemble the front axle. First, two swivel pins with axle shafts of the front wheels are installed on the fists of the rocking chairs, fixed with pivots and cotter pins. Hubs with bearings pressed into them are put on the axle shafts. The assembly of the front wheels is no different from the corresponding operations with the rear ones.

It remains to put the steering column and lateral rods in place, and work on the chassis can be considered complete.

Now it's the body's turn. To begin with, take a couple of body base panels and fasten them with four-millimeter bolts. Next, we mount the side panels, wings with the obligatory insertion of noise-absorbing elements. In the front and rear parts of the body, in the openings formed during assembly, we install two spacer corners and fix them with four bolts. We screw the bottom to the flanging of the wings.

Next, the hood is sequentially fixed (do not forget about the gaskets!), The windshield, the instrument panel (attached with self-tapping screws), headlights and rear position lights. And in conclusion, a gas tank is installed in the finished case, and a speedometer, toggle switches and an ignition switch are installed on the dashboard. The body is almost assembled, it remains to put the pedals and control levers in place and mount the electrical wiring.

Now the body can be docked with the chassis, install control cables and a gas line. The car "Squirrel" - "jeep" is assembled. You can hit the road.

M. LARKIN, head of the experimental laboratory

modeling and design of KYuT SB AS USSR

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Ground-based radars allow you to control the path in the direction. When flying from a radar, the control and correction of the path is carried out in the following order: 1. Request the position of the aircraft from the controller. 2. Convert the obtained azimuth to the MPS, compare it with the ZMPU and determine the lateral deviation of the MPS = A - (± Δm); BU = MPS - ZMPU. In cases where the angle of convergence between the meridian...

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The average torque of the rotor is:

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The shortest path approach provides for the approach to the given points of a rectangular route. A rectangular route is taken as the basis for constructing such an approach. However, it is not performed completely, but from the traverse of the LMP or from one of the turns. The descent from the route and the approach are performed under the same conditions and with the same restrictions as the direct approach.

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To prevent cases of getting into areas with dangerous meteorological phenomena for flights, it is necessary: 1) before the flight, carefully study the meteorological situation along the route and adjacent areas; 2) outline the procedure for avoiding dangerous weather conditions; 3) observe in flight weather changes, especially the development of phenomena dangerous for flights; 4) periodically receive by radio information about the state ...

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The formulas of the Glauert-Locke theory are derived for a rotor having any number of blades. Each blade is attached to the hub by a horizontal hinge, allowing it to swing in a plane passing through the longitudinal axis of the blade and the axis of the rotor. The vertical hinge of the blade, which allows it to oscillate in the plane of rotation, is not taken into account when considering the movement of the blade. Chord...

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The Penny helicopter model (Fig. 54) was developed by the American aircraft modeler D. Burkham. This miniature rubber-powered helicopter is equipped with a tail rotor and automatic stabilization. The basis of the model is a power rail made of pine 114 mm long and 5x5 mm in section. A foam plate 5 mm thick is glued on the side and rounded in side view; it turns out a kind of model body. Above...

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If the axis of the rotor and c. since the gyroplane lies in the plane of symmetry of the gyroplane (Fig. 92), then in a steady straight flight, the following fastening moments will act on the gyroplane: 1) the moment on the rotor head according to equation (78); 2) the moment from the transverse force, equal to: 3) during a motor flight, the reactive moment of the propeller, equal to:

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An aerodynamic calculation of a gyroplane is done to determine its flight characteristics, such as: 1) horizontal speeds - maximum and minimum, without reduction; 2) ceiling; 3) rate of climb; 4) speed along the trajectory during steep planning.

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Flying kites is an interesting sport for schoolchildren and adults. At present, in some countries, holidays and festivals of kites are held. In the USA, in Boston, they organize a competition for the best kite. In Japan, a national kite festival is held annually, where kites 20–25 m long are launched. Since 1963, it has been held throughout Poland ...

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Cylindrical projections are obtained by projecting the surface of the globe onto the side surface of a tangent or secant cylinder. Depending on the position of the axis of the cylinder relative to the axis of rotation of the Earth, cylindrical projections can be: 1) normal - the axis of the cylinder coincides with the axis of rotation of the Earth; 2) transverse - the axis of the cylinder is perpendicular to the axis of rotation of the Earth; 3) braid...

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The azimuth and range to the aircraft are determined by the controller on the indicator screen, on which the aircraft is depicted as a brightly lit mark. The azimuth is measured relative to the north direction of the true meridian on the indicator scale, which is digitized from 0 to 360°. The slant range to the aircraft is determined on the indicator by scale rings (Fig. 16.1). Range Accuracy...

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In order to ensure the regularity of flights, the ship's commander has the right to make a decision to take off if, due to meteorological conditions, he is not completely sure that it is possible to land at the destination aerodrome. Such a decision can be taken only with a full guarantee that, due to weather conditions, the landing of the aircraft is possible at one of the alternate aerodromes, including the aerodrome of departure. When making a decision to take off, it can be...

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In the practice of aircraft modeling, single-rotor helicopters are most widely used. The simplest model of helicopters only by the principle of flight resembles a prototype, it would be more accurate to call it a “flying propeller”. And among aircraft modellers, the name “fly” has become stronger behind such a propeller. The simplest helicopter - "fly" (Fig. 51) consists of two parts - a propeller and a rod.

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Aircraft navigation conditions over unorientated terrain. An area with a uniform background is called unorientated. These are taiga, steppe, desert, tundra, large forests, as well as poorly explored areas for which there are no accurate maps. Aircraft navigation over unorientated terrain is characterized by the following conditions:

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Radio deviation work is carried out by the navigator in order to determine, compensate for radio deviation and draw up a schedule of residual radio deviation in the following cases: 1) when installing a new radio compass or its individual blocks on an aircraft; 2) after performing routine maintenance, during which individual blocks of the radio compass were replaced; 3) if errors are detected in flight in the readings of the heading indicator ...

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Flight altitude H is the vertical distance from the aircraft to the level taken as the reference point. Height is measured in meters. Knowledge of the flight altitude is necessary for the crew to maintain a given flight profile and prevent the aircraft from colliding with the ground and artificial obstacles, as well as to solve some navigational problems. In piloting, depending on the level...

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To check the NI-50BM before the flight it is necessary: 1. Turn on the AC and DC power supply of the device. 2. Turn on and prepare for the work of the GEC. The indications of the GIC after coordination and the readings of the automatic course of the navigation indicator should not differ by more than ± 2 °. 3. Set MUK=MK of the aircraft on the heading machine and wind control. 4. Enter the direction in the wind generator...

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So history decreed that the aircraft on which the first human flight was carried out was a thermal balloon. It has long been noticed that both smoke and heated air rise up. The first attempts to build and fly on a thermal balloon date back to the middle of the 18th century. But the reliability of these facts has not yet been documented. One of the first who wanted to use those...

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To make a DOSAAF airframe model (Fig. 18), in addition to paper, scissors, a ruler and a pencil, you will also need glue. It is best to use PVA glue, and paper from sketchbooks. The shape of the fuselage is transferred from the drawing by cells to a paper blank folded in half and cut out. Then the wing, cargo, spar and keel are cut out in the same way. On the part templates, the arrow indicates...

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When the flight started during the day and ends at night or vice versa, it is necessary to know at what time the aircraft will meet with darkness or dawn and what is the duration of the night flight. The time and place of the meeting of the aircraft with darkness or dawn can be calculated using the NL-10M or according to the schedule. Consider the procedure for such a calculation using NL-10M.

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If, when designing a gyroplane, its main characteristic qualities are taken into account, such as: a steep landing angle and a low minimum speed of horizontal flight without a decrease, then the choice of the rotor diameter must be made by setting such a load w per unit surface of the swept rotor disk, at which the vertical speed is steep landing would be safe. Load values on swept by a rotor...

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The navigation indicator can be used in flight by the following methods: 1. Distance control method. 2. By the method of controlling the remaining distance (by the method of the arrival of the arrows to zero). 3. Method of conditional coordinates.

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To calculate the time and place of meeting of aircraft flying on a collision course, it is necessary to know the distance between the aircraft S ", the ground speeds of the aircraft W1 and W2 and the time of flight by the aircraft of reference points.

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Multiplication and division of numbers on the NL-10M is performed on scales of 1 and 2 or 14 and 15. When using these scales, the values of the numbers printed on them can be increased or decreased any number of times, a multiple of ten. To multiply numbers on scales 1 and 2, you need a rectangular index with a number. 10 or 100 of scale 2 is set to the multiplicand, and after breaking through the multiplier, count the desired product on scale 1.

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It was said above that the main rotor rotates freely during the movement of the gyroplane - it autorotates. The state of stable autorotation of the main rotor is an absolutely necessary condition for all possible flight modes of the autogyro, because the necessary lifting force develops only on the autorotating propeller. In addition, the rotor blades, in the presence of a hinged attachment to the hub, could, in the absence of...

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Apparently, it makes no sense to talk about equipping the circle of the pioneer camp with machine tools. This is only possible for large camps and requires special facilities. As practice shows, the "Skillful Hands" machine is quite accessible to any circle and has ample opportunities in work. For the normal operation of the air mug, a tool for general and individual use is needed. Basic tool...

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A flight from a ground-based direction finder can be carried out when it is located at the original route point (IPM), the route turning point (WFP) or at any other point on the LZP. When using VHF direction finders to control the path in the direction, the bearing is requested in telephone mode from the radio direction finder to the aircraft (direct bearing - PP) with the words "Give a direct bearing." Etc...

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The goal of this game is to achieve the greatest flight range. Before starting, it is necessary to specify how many times each participant will launch his model, in other words, how many test flights will be (usually three). And before them it is necessary to give the opportunity to make one or two training (sighting) launches. The starting order is usually determined by a draw.

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The control over the readiness of the crew for flight after its pre-flight navigational training is carried out by navigators (air squadrons, air squadrons, airport navigators on duty), and in their absence, by air traffic controllers of departure airports. In flight schools, the readiness of the crew for flight is controlled by the navigators of the air squadrons (air squadrons) and the flight director. Flag-navigator of the flight school...

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For those who do not have the opportunity to build a model from foam, we offer to make an electric aircraft of a typesetting structure (Fig. 46). The main material for the wing is bamboo. Edges, ribs and ends are made from it: for edges - with a section of 2x1.5 mm, for other parts - 1x1 mm. The spar is pulled out of a pine lath with a section of 1.5X1.5 mm. All connections are made with...

The size of molecules, as a rule, is incommensurably smaller than the limit that can be seen by the eye, even using the best optical microscope - after all, the wavelength of visible light significantly exceeds the characteristic dimensions of most molecules. Therefore, to study the fundamental foundations of life, one has to resort to simplifications - molecular models, - so that biological molecules from the area accessible exclusively to the intellect are transferred to the area of something visible (on a display or a piece of paper) or even tangible. However, molecules turned out to be not only a desirable object for study: their very essence became an object of inspiration for many scientists and artists - and a molecular sculpture.

Amazing aspiration of the human mind
building models and improving them,
until they get closer and closer to reality...
Ludwig Boltzmann
Truly incredible how little mutual penetration
science of the 20th century and art of the same century.
Charles Snow. Two cultures

Historical reference

The concept of the atomic structure of matter goes back to antiquity - they are attributed to the philosopher Democritus, who talked about the organization of everything that exists. However, attention scientific The world focused on the problem of the structure of matter already in the Middle Ages, when Johannes Kepler thought about the problems of symmetry of snowflakes and the symmetrical packing of spherical objects (a problem also known as Hilbert's 18th problem, which was solved only recently). At the beginning of the 19th century, John Dalton already spoke of atoms as real particles of different masses and sizes, and closer to the middle of the century, the Austrian scientist Josef Loschmidt depicted various molecules as a set of contiguous circles. Creation of the first spatial model of the molecule (it was methane) is attributed to August Wilhelm Hofmann, but the most important concept of chemical science is stereochemistry- was founded by Jacob Hendrik van't Hoff, who drew attention to the tetrahedral structure of the electron shell of the carbon atom in methane. The development of chemistry and X-ray crystallography led to the most important discoveries in the biology of the 20th century - the establishment of the spatial structure of DNA and protein molecules - and the problem of adequate representation of the structure of biological molecules, especially complex ones, became very acute. "Builders" were developed for assembling molecular models (some of them are still the industry standard), and the simultaneous development of computing technology and computer displays led to the emergence of programs aimed at visualizing and studying biomolecules.

Despite the unprecedented progress in the field of molecular graphics over the past 10-20 years, the "physical" models of molecules have not lost their significance. Edgar Meyer, one of the "characters" of this story, well noticed some inferiority of computer graphics: " My first encounter with biomolecules taught me reverence for Nature at the molecular level. Computer graphics, although attractive with their color dynamism, are unable to fully convey all the three-dimensional charms of molecules.».

Table 1. Chronology of the development of molecular models.

Authors)	Year	Technology	Description
Kepler	~1600	Packing spheres, symmetry of snowflakes
Loschmidt	1861	"Flat" drawings	Image of atoms and chemical bonds using touching spheres
Van't Hoff	1874	Paper	Tetrahedral models of atoms that led to the development of stereochemistry
Corey, Pauling, Koltun (CPK models)	1951	Spherical model of atoms (proportional to atomic radii)	The theory of chemical resonance developed by Pauling and the structure of the protein α-helix discovered by him largely determined the ideas about the structure of biomacromolecules.
Crick and Watson	1953	"Skeleton" model: small atoms connected by wire segments	The double-stranded structure of DNA was deciphered largely due to the presence of a high-quality "constructor"
Perutz, Kendrew	1958	Model of the electron density of a protein molecule glued together from several layers of material	The first obtained structures of protein molecules - myoglobin and hemoglobin - were not yet so accurate as to determine the exact position of individual atoms.
Molecular Graphics	1964	computer display	Molecular graphics, although it has largely replaced the "physical" models of molecules, is a successful addition to them.

3D Prototyping

The first models of the structure of proteins were constructed from a large number of balls, wires, bushings, screws and other parts. They were very bulky, fragile and required a lot of time and diligence to manufacture, even with the use of special "constructors" - sets of standard parts for assembly. At present, computers have almost completely replaced such construction kits, but to be able to look at a model of a molecule not only on a computer screen, but also “in real life” means to better understand its function and appreciate its beauty!

One of the modern methods for the production of "solid" models of molecules (we will not talk about "constructors" in detail here, because enough has already been said about them earlier) is 3D prototyping- a method of manufacturing three-dimensional layouts of any objects, used, in particular, in industrial design. Models are made on automated installations (including those controlled via the Internet), the input data for which is a CAD file or a file with the coordinates of protein atoms in the generally accepted pdb format. 3D Molecular Designs, one of the companies offering to make a "hard" model of a protein, has a whole arsenal of prototyping technologies: stereolithography, selective laser sintering, lamination production, sequential deposition modeling, and 3D printing. The latter technology is similar to conventional inkjet printing with the only fundamental difference that instead of ink, such a printer uses special polymerizing composites like gypsum or resin, and the object is printed layer by layer until the model is ready. 3D printing leads other prototyping technologies in terms of speed (although it loses a little in quality) and, in addition, it is the only one that allows you to print colored objects (due to the use of multi-colored "inks"). Models obtained using other technologies must be additionally painted after manufacturing, because the specific coloring of atoms is very important for the “models” of molecules.

Scientists note that such models are extremely useful in learning, because if a student can hold a molecule of chemotrypsin, hemoglobin or a ribosome in his own hands, he will immediately, on an intuitive level, feel how the structure of a protein is related to its function - and this is one of the most important aspects of molecular biology!

Russians go to 3D

One should not think that the issues of visual representation of molecules and science-intensive material in general occupy the minds of exclusively foreign scientists. The Moscow company Visual science offers its services in creating scientific illustrations, 3D models of biological objects, multimedia presentations and plastic models of biomolecules and other biomedical objects (produced using 3D printing technology). Among its goals, the company lists:

competent and visual presentation of scientific information using modern technologies;
creation of professional illustrations and diagrams for educational materials and textbooks;
illustrating popular science publications without the factual errors that modern publications abound.

protein crystals

Usually under protein crystals imply specially prepared protein samples, due to their highly ordered structure, capable of giving a clear diffraction pattern under X-ray irradiation (this effect is used for experimental study of the structure of proteins (see, for example,)). However, there are other crystals - a kind of miniature works of art on the theme of protein structure, made right in the thickness of the glass block.

Monument to the antibiotic

In front of the main entrance to the Institute of Bioorganic Chemistry of the Russian Academy of Sciences named after academicians M. M. Shemyakin and Yu. A. Ovchinnikov (where I work - A. Ch.) stands a kind of statue. " The sculpture depicts a complex of the antibiotic valinomycin with a potassium ion. The general principle of binding metal ions and their transfer through membranes using ionophores was discovered at the institute in 1963", reads the inscription on the pedestal.

Unusual models of molecules must be constructed from unusual materials. However, some molecular sculpting enthusiasts apparently don't have the funds for unusual building blocks - they use... regular balloons! (These are long inflatable tubes, twisting which clowns on stage create animal figurines.) On a special site dedicated to creating models of molecules from such balls, there are detailed instructions on the knots that you need to master to build, for example, an “inflatable” DNA molecule, and photographs of a large number of models are given. The creators of the site - three candidates of science (Ph.D.) from Germany - assure that their technology is indispensable in the educational process - at lectures and seminars.

DIY molecule

The inspiration evoked by biological molecules in scientists led them to dare to do more than create absolutely accurate "physical" models - even despite their bewitching appearance, meticulously copied from structural files, models remain just models. The romantic soul of the researchers demanded more, and some of them began to create works of art "based on" the structure of proteins.

Figure 8. "Polypeptide Waltz" by Mara Hazeltine. The sculpture is located at the Cold Spring Harbor Institute, USA. The BLyS protein (B-lymphocyte-stimulating protein responsible for the production of antibodies in the body) was discovered with the participation of Mara's father and, apparently, therefore became the central element of the composition.

Mara's father, William Hazeltine, is a renowned scientist and businessman who founded seven biotech companies, including Human Genome Sciences, engaged in genomic research aimed at combating incurable diseases such as many forms of cancer or AIDS. " [In this sculptural composition, BLyS] grows from a microscopic embryo into a full-sized molecule, - he comments on the creation of his daughter. - In science, form determines function. Knowing the structure is extremely important to understand how something works. This form is shown in Mara's works. She is beautiful in her dynamic variability". Mara herself admits that her father and other scientists have always been an inexhaustible source of inspiration for her. " This sculpture is dedicated to my dad and the great work he did", says the sculptor.

In 2006, the bronze sculpture “Inhibited SARS” was opened in Singapore, made by Mara Hazeltine at the special invitation of the leadership of the biotech consortium Biopolis, on whose territory the sculpture is located. During the 2003 Severe Acute Respiratory Syndrome (SARS) epidemic, Singaporean scientists from this consortium conducted a thorough genomic study of the disease-causing TOPC coronavirus and determined the spatial structure of the protease responsible for the entry of the virus into the cell. This sculpture (Fig. 9) became a monument to the work of scientists, thanks to which many human lives were saved.

Figure 9. A huge bronze sculpture located on the Biopolis campus (Singapore) reveals the mechanism of the SARS virus protease inhibitor discovered in this research center

« We are incredibly lucky to be endowed with a consciousness that allows us to enjoy the beauty of our planet and, thanks to modern technology, look simultaneously into the microscopic world that is in every cell of our existence, and into the vast depths of space. It is this phenomenon that I try to reveal in my work.”, - Hazeltine explains his creative role.

The article "The Statue of the Invisible" was originally published in Computerra.

Literature

Chugunov A.O. (2007). Statue of the invisible. "Computerra". 712 , 24–26.