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Background: The technological developments for nanocellulose production from cheaper plant materials compared to wood, in particular, agricultural waste is an urgent task of nanobiophysics. The discovery of possibility of expanding the functional characteristics of materials in compositions with modified cellulose particles essentially stimulated the interest of researchers in cellulose composites. Surface modification of cellulose particles by functional materials, such as dyes, metal oxides, silicon, allows applying composites with modified cellulose in various areas of modern industry. A significant improvement in the operational performances of functionalized cellulose particles can be achieved by using them as filler in polymers. Epoxy resin compositions with modified and unmodified cellulose particles, studied in present work, are an example of hybrid biosystem. The interfacial interaction of filler particles with the epoxy matrix, their concentration and dispersion can change the physical and chemical properties of the biopolymer and the functional parameters of biocomposites. Studying the influence of external fields on the physical and chemical properties of epoxy resin-based biosystems and their influence on operational parameters seems to be an urgent problem of advanced and sustained materials science. Objectives: The purpose of this work was to develop an effective nanocellulose synthesis from plant materials and surface functionalization of micro- and nanocellulose particles with clathrochelate iron (ΙΙ) dye as well obtaining biocompositions of epoxy resin with functionalized and non-functionalized micro- and nanocellulose, and to explore of the morphology, chemical resistance, mechanical and thermal properties of epoxy composites with cellulose micro and nanoparticles. Materials and methods: The studying objects were the composites of epoxy resin Eposir-7120 with a polyethylene polyamine “PEPA” hardener in a ratio of 6.2:1 and 10% cellulose micro and nanoparticles. The microcellulose obtained from wood has been a commercial product. Nanocellulose has been synthesized from organosolv cellulose obtained from Miscanthus x giganteus stalks. Surface modification of micro- and nanocellulose was performed using the clathrochelate iron (ΙΙ) dye. The specific surface area of cellulose particles was determined using low-temperature nitrogen adsorption-desorption according to the Brunauer-Emmett-Teller method. Mechanical parameters were determined using universal Shopper and UMM-10 machines. Thermal analysis was performed using Q1500 analyzer. Swelling was determined by the gravimetric method. Results: Elastic modulus E, compressive strength σ and thermogravimetric parameters were determined. It was shown that in composites with micro and nanocellulose the E rises in 7.0–12.2% while the σ increases in 9.1% for composites with cellulose micro particles. The loading resin with nanocellulose and modified cellulose microparticles no affects the σ value of composites. The thermal stability of epoxy polymer (310°C) reduces after loading with micro and nanocellulose to 290 and 300°C, respectively. Chemical resistance of composites with both celluloses to 20% nitric acid reduces. In neutral medium swelling characterizes by rapid sorption to saturation of 15–20% acetone in 36 hours. Conclusions: Thus, the synthesis method of nanocellulose from plant materials and functionalization of its surface with clathrochelate iron (ΙΙ) were developed. Light response of dye was detected in visible spectral range. Epoxy resin composites with 10% micro and nanocellulose were obtained. The filling effect with micro- and nanocellulose at elastic modulus, compressive strength, and thermal stability of epoxycomposites was studied. The swelling processes run similarly in composites with cellulose micro and nanoparticles.

Background Hot start can greatly improve specificity, sensitivity and yield of PCR. Non-specific amplification can occur in PCR when reaction mixture is prepared at room temperature, because Taq DNA polymerase is active and the primers can hybridize non-specifically. Hot start Taq DNA polymerases remain inactive at room temperature and are activated after heating at 95°C preventing non-specific amplification. Monoclonal antibodies against Taq DNA polymerase is the first line of reagents used for turn on regular Taq DNA polymerase into Hot start one. The goal of this research was to produce and evaluate Hot Start antibodies derived from chicken eggs. Results We performed affinity purification of yolk immunoglobulin (IgY) and obtained polyclonal Hot Start antibodies. The yield of specific antibodies was 0.36 mg per egg or 0.2% of total yolk antibodies. The protocol for real time measurement and Hot start IgY activity assessment was developed. We found that Hot start IgY can reversibly block Taq DNA polymerase activity at 50°C and have no negative impact neither on the Taq DNA polymerase activity after denaturation nor on the reverse transcriptase. We estimated that 1.0 μg of Hot start IgY effectively blocks 5 U activity of Taq DNA polymerase. Conclusions Egg derived Hot Start polyclonal antibodies are the cheapest source of Hot start antibodies, from one immune egg we can isolate 0.36 mg IgY, this quantity is enough for producing 1800 U activity of Hot start Taq DNA Polymerase. How to cite: Spyrydonov V, Pihida D, Sereda A, et al. Production and evaluation of egg derived hot start antibodies. Electron J Biotechnol 2020;44. https://doi.org/10.1016/j.ejbt.2020.01.005 .

Aim. To synthesize 1-phenyl-3-(4-alkoxyphenyl)pyrazole-4-carbaldehydes and determine the direction of their interaction in the three-component condensation with 3-methyl-5-aminopyrazole and 2,2-dimethyl-1,3-dioxane-4,6-dione. Results and discussion. A series of 1-phenyl-3-(4-alkoxyphenyl)pyrazole-4-carbaldehydes was synthesized from arylhydrazone by the Vilsmeier–Haak reaction. The domino-reactions of these aldehydes with 3-methyl-5-aminopyrazole and 2,2-dimethyl-1,3-dioxane-4,6-dione lead to pyrazolo[3,4-b]pyridone systems. Experimental part. The synthesis of 1-phenyl-3-(4-alkoxyphenyl)pyrazole-4-carbaldehyde was carried out by formylation of arylhydrazones under the conditions of the Vilsmeier–Haack reaction with the yield of 55 – 88 %. Refluxing in 2-propanol equimolar amounts of these aldehydes, 3-methyl-5-aminopyrazole and 2,2-dimethyl-1,3-dioxane-4,6-dione gave 3-methyl-4-(1',3'-diarylpyrazol-4'-yl)tetrahydropyrazolo[3,4-b]pyridin-6-ones with the yield of 48 – 75 %. The structure and composition of all substances synthesized were proven by 1 H NMR, IR-spectra and elemental analysis. Conclusions. It has been found that the reactions of 1,3-diaryl substituted pyrazole-4-carbaldehydes with 3-methyl-5-aminopyrazole and 2,2-dimethyl-1,3-dioxane-4,6-dione are regioselective and lead to the formation of pyrazolo[3,4-b]pyridone systems. This orientation of the process corresponds to the interaction of the β-carbon atom of the probable intermediate, which is formed at the first stage of the reaction from dioxandione and aldehyde, with the carbon nucleophilic center in the aminoazole molecule, and then the exocyclic amino group in the heterylamine attacks the C=O group in the dioxane-4,6-dione fragment.

This paper reports the results of studying epoxy compositions with gypsum taken in the form of dispersed powders in the original and water-hardened form. The exact pattern has been shown in the way the introduction of a gypsum additive in the amount of 50 % by weight affects the strength, chemical stability, and morphology of the composites.Under conventional heat treatment (60‒110 °C) of the hardened composites, the maximum stress at compression σm and the elasticity module at compression Ес, as well as wear resistance, decrease after the introduction of gypsums (of both types). At the same time, after a hard (destructive) heating at 250‒260 °C, the elasticity module Ес of the hardened composites increases. The maximum stress at compression σm is also increased. The same applies to the wear resistance, which grows especially noticeably after 250 °C.The micro-hardness after filling is prone to increase but the fragility of epoxy-gypsum composites does not make it possible to measure it when a punch (a steel hemisphere) penetrates it deeper than 20 µm. However, after the heat treatment at 250‒260 °C, the unfilled polymer, on the contrary, is embrittled while the filled ones are plasticized, thus showing a high micro-hardness at significant (30‒50 µm) immersion.The composites with gypsum, in contrast to the unfilled ones, do not disintegrate in acetone and retain integrity at any aging duration (up to 75 days and beyond). In this case, the original gypsum produces a composite with less swelling in acetone than the hardened gypsum. Based on the data from atomic-strength microscopy (ASM) microscopy, the morphologies of the non-filled composite, the composites with the hardened gypsum and original gypsum are different. The original gypsum forms a composite with a more pronounced (possibly crystalline) filler structure; the morphology for the hardened composite reflects the distribution of inert particles; for the unfilled composite (H-composite), only pores are visible against the background of a relatively smooth relief, Представлены результаты исследования эпоксидных композиций с гипсом, взятым в виде дисперсных порошков в исходном и водо-отверждённом виде. Показано, как именно введение 50 мас. % добавки гипса влияет на прочность, химстойкость и морфологию композитов.При обычной термообработке (60–110 °С) отверждённых композитов максимальное напряжение при сжатии σм и модуль упругости при сжатии Ес, а также стойкость к истиранию, снижаются после введения гипсов (обоих типов). В то же время после жёсткого (деструктирующего) прогрева 250–260 °С отверждённых композитов модуль упругости Ес повышается. Также повышается и максимальное напряжение при сжатии σм. То же – для стойкости к истиранию, которая после 250 °С растёт особенно заметно.Микротвёрдость после наполнения склонна к повышению, однако хрупкость эпокси-гипсовых композитов не позволяет измерить её при погружениях пуансона (стальная полусфера) свыше 20 мкм. Но после термообработки 250–260 °С наоборот – ненаполненный полимер охрупчивается, тогда как наполненные – пластифицируются, показывая высокую микротвёрдость при значительных (30–50 мкм) погружениях.Композиты с гипсом, в отличие от ненаполненного, в ацетоне не распадаются и сохраняют цельность при любом времени выдержки (до 75 суток и далее). При этом гипс исходный даёт композит с меньшим набуханием в ацетоне, чем гипс отверждённый. Согласно данным атомно–силовой (АСМ) микроскопии, морфология композитов ненаполненного, с отверждённым и исходным гипсом отличается. Исходный гипс формирует композит с более выраженной (возможно кристаллической) структурой наполнителя, морфология для отверждённого отражает распределение инертных частиц; для ненаполненного композита (Н-композита) – видны лишь поры на фоне сравнительно гладкого рельефа, Представлені результати дослідження епоксидних композицій з гіпсом, узятим у вигляді дисперсних порошків в початковому і водо-затверділому стані. Показано, як саме введення 50 мас. % добавки гіпсу впливає на міцність, хімстійкість і морфологію композитів.При звичайній термообробці (60–110 °С) композитів максимальна напруга при стискуванні σм і модуль пружності при стисканні Ес, а також стійкість до стирання знижуються після введення гіпсів (обох типів). У той же час після жорсткого прогріву 250–260 °С композитів модуль пружності Ес підвищується. Також підвищується і максимальна напруга при стискуванні σм. Те ж – для стійкості до стирання, яка після 250 °С зростає особливо помітно.Мікротвердість після наповнення схильна до підвищення, однак крихкість епокси-гіпсових композитів не дозволяє виміряти її при зануреннях пуансона (сталева півсфера) понад 20 мкм. Але після термообробки 250–260 °С навпаки – ненаповнений полімер стає крихким, тоді як наповнені – пластифікуються, показуючи високу мікротвердість при значних (30–50 мкм) зануреннях.Композити з гіпсом, на відміну від ненаповненого, в ацетоні не розпадаються і зберігають цілісність при будь-якому часі витримки (до 75 діб і далі). При цьому композит із гіпсом, як наповнювачем, має менше набухання в ацетоні, ніж гіпс. Згідно з даними атомно-силової (АСМ) мікроскопії, морфологія композитів ненаповненого та з гіпсом відрізняється. Гіпс формує композит з більш кристалічною структурою наповнювача. Морфологія відображає розподіл інертних частинок; для ненаповненого композиту (Н-композит), де видно лише пори на тлі порівняно гладкого рельєфу. Введення гіпсу в епоксидну смолу змінює консистенцію композиції і морфологію композитів, яка також залежить від типу гіпсу (вихідний напівводяний або затверділий двохводний

Composites based on epoxy oligomers filled by fibers and biomaterials, due to their high adhesion, heat resistance...

The aim of the research is to determine morphological changes in the area of implantation of the polypropylene mesh implant and to determine the effect on the integration of the prosthesis of locally introduced adipose tissue and platelet rich plasma. Materials and methods. The experiment was performed on 36 sexually mature males of the Wistar line rats. The experiment simulated, studied and quantified local morphological responses and changes in developing in biological tissues that are in contact with implanted highly porous lightweight (80 g/m2) mesh implant in isolation and also in conditions of local administration of fatty graft and platelet rich plasma. Results: Assuming introduction of adipose tissue and platelet rich plasma in the zone of integration of mesh alloprosthesis under the influence of introduced regenerative cytokines as well as stromal stem cells activated by them there is an earlier activation of regenerative processes, enhanced angiogenesis which determines the optimal nature of the integration of the prosthesis with the formation of thin collagen fibers in more early terms minimizing excess peri-prosthetic fibrosis. Isolated introduction into the implantation zone of fatty suspension determines similar changes that have a slightly less pronounced character. These changes are quantitatively studied and the results obtained are statistically significant. Conclusions: Applying a fatty graft together with platelet rich plasma in the area of implantation of the lung polypropylene prosthesis, there was an accelerated tissue reaction from the integration of the prosthesis. Mesenchymal stem cells of adipose tissue that is a target for plasma cytokines enriched with thrombocytes have a more pronounced effect in stimulating reparative processes provided that they are simultaneously administered with PRP compared with isolated administration without PRP. The use of platelet rich plasma and adipose tissue design has a significant positive effect on local angiogenesis. Under conditions of improved angiogenesis and other stimulating factors in the conditions of introduction of adipose tissue and PRP, the integration of the prosthesis occurs with significantly lower peri-prosthetic fibrosis.

6-Arylidene-2,3-dihydroimidazo[2,1-b][1,3]thiazol-5(6Н)-ones reacted with N-alkylazomethine ylides by [2+3] cycloaddition mechanism, resulting in the formation of diastereomeric spiro[imidazo[2,1-b][1,3]thiazole-6,3'-pyrrolidin]-5(6Н)-ones, which were separated by column chromatography.

We demonstrate a strongly thresholded response in cyclotrimethylene trinitramine (RDX) when it is cylindrically shocked using a novel waveguide geometry. Using ultrafast single-shot multi-frame imaging, we demonstrate that 100 ns after the shock first arrives in the crystal. We use in-situ imaging and time-resolved photoemission to demonstrate that short-lived chemistry occurs with complex deformation pathways. Using scanning electron microscopy and ultrasmall-angle X-ray scattering, we demonstrate that the shock-induced dynamics leave behind porous crystals, with pore shapes and sizes that change significantly with shock energy. A threshold pressure of ~ 12 GPa at the center of convergence separated the single-mode planar crystal deformations from the chemistry-coupled multi-plane dynamics at higher pressures. Our observations indicate preferential directions for deformation for our cylindrically shocked system, despite the applied stress along many different crystallographic planes.

We use a hybrid fluorescence spectroscopic toolkit to monitor T4 Lysozyme (T4L) in action by unraveling the kinetic and dynamic interplay of the conformational states. In particular, by combining single-molecule and ensemble multiparameter fluorescence detection, EPR spectroscopy, mutagenesis, and FRET-positioning and screening, and other biochemical and biophysical tools, we characterize three short-lived conformational states over the ns-ms timescale. The use of 33 FRET-derived distance sets, to screen available T4L structures, reveal that T4L in solution mainly adopts the known open and closed states in exchange at 4 µs. A newly found minor state, undisclosed by, at present, more than 500 crystal structures of T4L and sampled at 230 µs, may be actively involved in the product release step in catalysis. The presented fluorescence spectroscopic toolkit will likely accelerate the development of dynamic structural biology by identifying transient conformational states that are highly abundant in biology and critical in enzymatic reactions., T4 Lysozyme (T4L) is a model protein whose structure is extensively studied. Here the authors combine single-molecule and ensemble FRET measurements, FRET-positioning and screening and EPR spectroscopy to study the structural dynamics of T4L and describe its conformational landscape during the catalytic cycle by an extended Michaelis–Menten mechanism and identify an excited conformational state of the enzyme.

The aim of the research is to develop a technology for the preparation and drying of moulds and cores based on sand-plaster mixtures, which allows obtaining exact details of a complex form of required quality. The levels of the basic properties of sand-plaster moulds and cores – strength, durability, gas permeability, friability – making up the quality of a casting have been determined in the research paper. Mathematical patterns of the properties of the moulding mixture on the basis of plaster have been developed. The composition of the mixture satisfying the requirements of the quality of castings has been determined experimentally with the use of multifactorial optimization methods. The research studies of the process of plaster mould drying have been done, and the technological process of mould drying has been developed using a microwave machine. Manufactured cores and moulds have not only possessed high strength properties but also have allowed escaping from such defects as gas holes in die castings (castings). The proposed mode of drying can reduce the drying time by 40–50% and reduce costs by 30–70% depending on the size of the core.

The sands of various dispersion&origin can watch as basic filler for tonnage build & industrial compounds. The work is devoted to the urgent topic of obtaining cheapened epoxy materials with a high content of natural and building sand. In the case of composite optimization, it is possible to obtain valuable competitive multitonnage composites, moreover, while maintaining the original performance properties or even improving them. In our work, the sand from Ukrainian mines & rivers were used. It is tree types of sand: A) “Quarry” – from industrial carrier in nord of Ukraina; B) “Bottom” – from bottom of big river (Desna); C) “Fabric” – industrial sand TM Stark, Ukraina. A number of practically important properties of composite materials based on epoxy resin and sand of various types and dispersions (50 wt%) have been established. It is shown that 50 wt% of all used sands leads to essential increasing of AbrasiveResistance and SwellingResistance, and microhardness. At same time, 50%-filling decreases investigated strength parameters (to compression & to bending). Is important that sands let reach a high esthetic characteristics of composites: in this simple method can obtain wood-, stone-, honey-like composite materials for building, design & décor. The prospects for the implementation of these results are quite wide, since they cover both large-tonnage construction and repair, innovative industries, as well as small repair segments that are now developed (car service, museum restoration) and handmade. At the same time, this work only opens up these prospects and can become the basis for further scientific and practical research

The purpose of the article was to analyze the histological changes in the gastrocnemius muscle under conditions of experimental ischemia of different duration and simultaneously administration of C60 fullerenes as an antioxidant.The experiment was conducted on inbred Wistar line rats weighing 140-160 g. The animals were divided in groups: control; animals with ischemia (1, 2 and 3 hours); control, animals with ischemia (1, 2 and 3 h), animals with ischemia (1, 2 and 3 h) and C60 fullerenes administration. Unilateral vascular ischemia was induced by tourniquet ligating the main arteries. Histologic processing of the tissue was carried out according to standard histological methods, stained with Van Gison method. Morphometric indices (thickness of muscle fibers and the size of interfibrillary space) were measured using the VideoTest Morphology 5.0 program. The therapeutic effect of an aqueous colloidal solution of C60 fullerenes on the level of pathomorphological changes in the test muscle was also analyzed. The musculus gastrocnemius is resistant to light ischemic damages under condition of intraperitoneal administration of C60 fullerenes, which are potent antioxidants and are able to absorb free radicals effectively. However, studies have shown that with increasing the duration of ischemic damage, the protective effect of fullerenes decreases in proportion to the duration of ischemia. In particular, the initial tendency to the destruction of muscle fibers, the disturbance of the membrane integrity, the replacement of the muscle tissue by the connective tissue , the severance of sarcomeres, the loss of the transverse striated , the absence of nuclei, the hyperemia of the capillary duct are noted. Necrotic-destructive changes that occur due to the excess of no inactivated superoxide and hydroxide radicals also observed. Thus, the laboratory study can serve as a basis for the development of drugs for muscle pathologies, and will help to develop a comprehensive methodology for the treatment of early stages of ischemic damage to human skeletal muscle.

A range of 1,2,4-triazolylacetic acids and their derivatives with various substituents at the triazole ring position 3 have been synthesized. The properties of the obtained compounds were studied, showing that: 1) triazolylacetic esters are strong acylating agents; 2) all the obtained triazolylacetic acids underwent decarboxylation when heated to the melting point; 3) the CH2 group in the acetyl moiety can react as methylene component in condensation reactions.

The use of ferritic-martensitic steels, for example, Fe-Cr and Fe-Cr-Al alloys as structural material for fast neutron reactors has been advocated due to their relatively low rate of swelling at elevated temperatures. Because of the high Cr-content, the Fe-Cr alloys are not suitable for use at temperatures around 500°С due to the miscibility gap in the Fe-Cr system. Phase separation in such alloys can also be prevented by doping with elements that impede the segregation of chromium. In solid state physics for calculating phase separation in similar metal systems are used physicochemical and phase-field modeling. The aim of the work is the physicochemical modeling of diffusion phase transformation and determination of the long-term microstructural stability of the Fe-21.4 Cr-1.16 Mo. A conventional Fe-21.4 Cr alloy is used as a reference material. The article proposes an integral approach to modeling phase separation in chromium alloys, combining the determination of diffusion coefficients and fluxes of elements, taking into account their dependences on the concentration and an assessment of the mutual diffusion of elements, using the provisions of nonequilibrium thermodynamics. The calculated values of diffusion fluxes are used to calculate the current concentrations of carbon and chromium in the alloy and the size of chromium formations. They show that the thermal stability of the Fe - 21.4% Cr alloy with 1.16% Mo is much higher than without molybdenum. In alloy Fe – 21,4% Cr – 1,16% Mo at a temperature of 973°K, the chromium concentration during the same operation time decreases three times slower with the formation of inclusions of the σ-phase about 6 microns in size.

Background: Oxidative stress is the main cause of mortality in chemical burn-induced esophageal injury. Melanin, a natural antioxidant compound from yeast-like fungus Nadsoniella nigra strain X- 1, has been shown to decrease the content of lipid peroxidation products after burn. The aim of this study was to investigate the protective effect of melanin in the treatment of esophageal injury after a chemical burn. Methods: A alkali burn model was used to induce injury to the esophagus in immature rats. Changes in the levels of malondialdehyde, secondary products of lipid peroxidation (thiobarbituric acid reactive substances), superoxidase dismutase, and catalase in the blood, as well as changes in the esophagus tissue, were examined. Results: Melanin decreased the content of lipid peroxidation products following burn injury. Melanin increased the activity of superoxidase dismutase and reduced the activity of catalase, as well as reduced esophagus oxidative injury in our chemical burn model. Conclusion: Melanin treatment may protect against chemical burninduced esophageal injury, possibly by inhibiting burn-induced oxidative stress.

In the paper mechanisms of merocyanine–spiropyran transformation were investigated. It was shown that in dark conditions for such transformation it is necessary to overcome the potential barrier with height of ~0.6 eV. A barrierless transformation into the spiropyran molecule is possible due to the rotation of the phenyl moiety of the merocyanine molecule by 90∘ relative to the plane of the molecule. It was proved that a 90∘ orientation of moieties in the merocyanine molecule is achievable only in a photochemical way because in S1 state of the molecule energy of the potential surface is lowered by rotation the phenyl moiety relative to its plane.

The work presents the results of the study of the photoluminescence spectra of the (111) growth surface of an opal - Bi12SiO20 matrix nanocomposite filled with europium (III) acetate hydrate (C6H9EuO6 × H2O). An increase in the integral luminescence intensity of the matrix composite opal - Bi12SiO20: Eu3+ compared to composite opal: Eu3+ was found. The measured photoluminescence spectra of the Bi3+ ions in the opal pores indicate its participation in optical processes as a co-activator of luminescence. A change in the character of the splitting of the main luminescence bands of Eu3+ ions in the region of 575–635 nm and the integral luminescence intensity after dehydration of the crystalline hydrate in opal pores has been established.

Background: Rhodopsins are chromoproteins, which contain retinal, with various necessary functions for energy or photoreception of a cell. Many homologues of rhodopsins were found in the microorganisms of different taxa. Siberian permafrost is a unique biological community, unifying microorganisms adapted to long-term frosts, high osmolarity and lack of light. Exiguobacterium sibiricum is one of the microorganisms that can withstand a wide range of growth conditions. For a long time, the possible role of the found rhodopsin remained unclear in adaptation to extreme environmental conditions. Methods: In this work, we studied complexes of rhodopsin ESR (Exiguobacterium sibiricum rhodopsin - ESR) solubilized in amphipathic polymers (amphipols) A8-35 and PMAL-C12. ESR was expressed in E. coli, purified and inserted in amphipols by standard protocols. The complexes were characterized using the dynamic light scattering method and flash-photolysis, which was the author's designed device for measuring photocycles. Results: Diameters were 4.8 and 5.4 nanometers, all samples were monodisperse and stable for long period. This size indicates the monomericity of the protein. The photocycle of ESR in amphipols was about 150 milliseconds, which was 1.5 times longer than the photocycle of ESR in DDM micelles. This difference could be accounted for by decreasing the conformational mobility of rhodopsin solubilized with into amphipols, rather than detergent micelles. Conclusion: According to this study, the amphipols is a good membrane mimetic for ESR. The protein is stable and functionally active as a light-driven proton pump, which makes it a good candidate for an optogenetic tool. This method could be used for other retinal proteins and lead to the understanding of the physiological necessity of rhodopsin ESR expression by the microorganism E. sibiricum.

The chemical composition marble goby and sunflower meal is presented. The experimental results of enzymatic hydrolysis velocity in dependence of the protein concentration in substrate systems are set. Michaelis constants values for industrial proteolytic enzymes Corolase ® L10 and Corolase ® L7089 are calculated. The application experimental - theoretical kinetic analysis for protease / proteins congeniality determine in complex dispersion substrate systems expediency was confirmed. It is determined that microbial enzyme drag Corolase ® L7089 has a higher congeniality to proteins of all the tested substrates than plant enzyme drag Corolase ® L10

Thermally stable mesoporous nanocrystalline ТiО2 with a pure anatase structure was obtained by sol–gel synthesis (in combination with hydrothermal treatment) using titanium tetrabutoxide and dibenzo-18-crown-6 as a structure-directing agent in presence of surfactant and/or La3+ ions additives. Nanocrystalline TiO2 demonstrates various textures with a well-defined spherical morphology (micro- and nanospheres), a crystallite size of no greater than 10 nm (XRD), and a narrow pore size distribution. Spherical particles of micrometer scale in the presence of La3+ ions do not form. TiO2 calcined (at 500 °C) after hydrothermal treatment (at 175 °C) has a significantly more developed porous structure as compared with TiO2 which was not treated hydrothermally. For example, specific surface area amounts 137 m2 g−1 and 69 m2 g−1, pore volume 0.98 cm3 g−1 and 0.21 cm3 g−1, pore diameter 17.5 nm and 12.5 nm respectively for samples hydrothermally treated and not treated.

The composites of the epoxypolymer (EP) with the brick powder (BP) are new materials that combine high characteristics with the low price. Herein we d iscuss about the several such compositions and evaluate some physical characteristics for them. Presented data suggest that BP (at the concentration range from 5 to 50 wt%) increases strength characteristics of the epoxypoly mer's co mpression and abrasion, and reduce his shrinkiness. At the same t ime, the BP in 10 wt% concentration leads to the frustration and defectation in co mposite structure. Under the h igh concentrations of the BP (50 wt%) the plastic deformation disappears, the compression strength increases, contraction decreases, and the destruction of template goes through formation of Chernov-Luders Diagonal; but at the same time usage of high concentrations of the BP leads to increase of swelling of the polymer. The obtained results show that particles of brick powder ab le to significantly strengthen and structurize the EP-co mposite, at the same time make it more susceptible for liquid corrosion.

The swelling dynamic and epoxy resin structure changes of nanosilica (NS) with different specific surface in concentrated nitric acid were studied. It is established that with increasing of specific surface area of unmodified NS swelling degree decreases and stability of the composite in the acid goes up. Resistance of NS to the HNO3 can be achieved by choosing the optimal concentration and modifications of NS’s surface. According to electron microscopy and X-ray diffraction, the structure of composite can be changed due to appearance of ordered structural zones.

This work describes the electrical characteristics of thin film sandwich cells with vanadyl phthalocyanine complex as a photoactive material in air and in water vapors. The characteristics are altered by the incorporation of an ultrathin metallic layer in phthalocyanine, so that the cells with the aluminum layer in the presence of mixed water/ammonia vapors may generate a significant output power in dark. The effect is assigned to the contribution of mobile ions appeared owing to electrochemical reactions at the metallic interlayer.

The introduction of an ultrathin zinc oxide (ZnO) layer formed by the atomic layer deposition (ALD) technique was found to improve the operation parameters of nickel phthalocyanine (NiPc) based photovoltaic cells with a transparent bottom electrode, indium tin oxide (ITO). This improvement is attributed to several reasons, such as I) increase of photovoltaic yield in ITO/p-NiPc/n-ZnO/Al cells incorporating a hybrid heterojunction as compared to single-layer ITO/NiPc/Al cells, II) enhancement of the overall spectral response in the double-layer cells and III) extension of long-term operational stability.

Preliminary small-angle neutron scattering investigations on aqueous suspensions of several cobalt doped ferrites (CoxFe3-xO4, x=0; 0.5; 1) nanoparticles prepared by chemical co-precipitation method, are reported. The measurements were accomplished at the YuMO instrument in function at the IBR-2 reactor. Results of intermediary data treatment are presented and discussed.

Intense debate exists on the possibility that unfolded proteins show, to certain extent, residual secondary structure. Transient structure formation might facilitate folding (nucleation site) and/ or enhance binding to ligands. Some proteins such as those categorized as intrinsically disordered proteins take advantage of these features. Here, we used the model enzyme lysozyme from the phage T4 (T4L), a simple two subdomain protein, which already exists in an equilibrium of at least three conformations under native conditions. We created a set of 24 double mutants of the cysteine-free pseudo-wild type by inserting an unnatural amino acid and a cysteine mutation and site-specifically labeled them using orthogonal chemistry with a Forster resonance energy transfer (FRET) dye pair. Our set of variants allows us to build up a network of distances spanning the enzyme in order to monitor the ensemble of conformations. The behavior of the protein under highly denaturing conditions was observed by a combination of ensemble (ensemble time-resolved fluorescence lifetime and anisotropy) and single-molecule spectroscopic (multiparameter fluorescence detection, photon distribution analysis, (filtered) fluorescence correlation spectroscopy) methods. Our network covered all possible directions over the whole protein allowing us to map specifically the local motions (dye mobility) and global changes. We identified regions with residual structure which exist even under highly denaturing conditions. Additionally, the combination of ensemble and single-molecule methods allows us to resolve the full heterogeneity of the proteins’ denatured conformations.

The reaction of 4-chloro-3-nitrocoumarin with 1,3-bis(silyloxy)buta-1,3-dienes and subsequent reductive cyclization provides a convenient synthesis of a variety of chromeno[3,4-b]pyrrol-4(3H)-ones.

The formation of stable partially folded structures on the folding pathway of a protein plays an important role for its correct function. Intermediate states mediate protein (sub-) domain folds to reach the most stable native conformational state. Serious diseases can be triggered if proteins are incorrectly folded stabilizing misfolded conformational states. Currently, no single biophysical tool exist that could provide the overall map all conformational transitions during fondling or unfolding kinetics. Here, we used the model enzyme lysozyme from the phage T4 (T4L), a simple two-subdomain protein, from which is known from prior NMR and stopped-flow experiments that it unfolds via at least two intermediate states. To complete the kinetic gap, we created a library of double mutants of the cysteine-free pseudo-wild type by inserting an unnatural amino acid and a cysteine mutation. We proceeded to site-specifically labeled them using orthogonal chemistry with a Forster resonance energy transfer (FRET) dye pair to build up a network of distance restrains spanning the enzyme. The unfolding process was monitored using traditional ensemble methods like CD- spectroscopy and fluorescence spectroscopic methods (ensemble time correlated single photon counting, single molecule fluorescence spectroscopy, (filtered) fluorescence correlation spectroscopy). Single molecule high precision FRET, with its high temporal and spatial resolution, covering over seven orders of magnitude on time, enables us to determine equilibrium transition rates between conformational states in denatured conditions. By using a priori knowledge from earlier studies, we are able to assign the formerly unknown rates to the folding and unfolding intermediate formation steps. The previously reported millisecond process, belonging to the interconversion of both intermediates, can be observed in our single-molecule multiparameter fluorescence detection histograms.

In order to understand how enzymes work it is required to know about its conformational landscape, its enzymatic state or interaction with the substrate or product, and the exchange times between conformations and enzymatic states. Experimentally this is extremely challenging because it requires to sample over large time domains, as well as resolving low transiently populated states. Using a hybrid approach involving multiparameter fluorescence spectroscopy, multiscale computer simulations and mutagenesis we are able to map the conformational landscape involving three conformational states (C1, C2, and C3) that are sampled from ns to ms. Furthermore, we present a state matrix that links the enzyme state of the bacteriophage T4 (T4L) as it follows a Michaelis-Menten like formalism. In all we identify T4L as a three state system linking each of the fundamental steps in enzyme function: Substrate binding in C1, catalysis in C2, and product release in C3. We validate the conformational state C1 against the crystallographic structure with identification code in the protein data bank (PDBID) 172L with an accuracy of 1.8 A RMSD and 2σ precision of 0.6 A. The C2 agrees very well with the PDBID 148L with an accuracy of 2.1 A RMSD and 2σ precision of 0.9 A. The conformational state C3 has not been identified before and has a 2σ precision of 2.6 A. Our findings for T4L demonstrate that a fine-tuned shift of conformational equilibrium leads to motions of active cleaning where the energies of substrate binding and product formation drive the conformational equilibrium. The directionality of the overall process is manifested by the free reaction enthalpy of the glycosidic bond cleavage. In all, our work highlights the potential of our hybrid approach to observe thermally accessible, low-populated intermediates with high spatial and temporal resolution.

About 30 % of human proteins do not fold into a stable 3D arrangement of secondary structure elements, but stay predominantly unfolded -similar to proteins under highly denaturing conditions. These proteins are involved in many cell signaling processes. Their characterization poses a great challenge for current experimental methods as they consist of an ensemble of rapidly interconverting conformations. Intense debate exists on the possibility that they show, to certain extent, residual structure, which might facilitate folding or enhance ligand binding. To study the unfolded state conformational heterogeneity using Forster resonance energy transfer (FRET), we used the lysozyme from the phage T4 (T4L) in denaturing conditions as a model system. We built an elastic network model that spans T4L's topology in order to evaluate local and global conformational changes by combining ensemble (ensemble time-resolved fluorescence lifetime and anisotropy) and single-molecule spectroscopic (multiparameter fluorescence detection, photon distribution analysis, (filtered) fluorescence correlation spectroscopy) methods. Through extensive comparison of models, we identified regions with apparent residual structure under highly denaturing conditions, which might serve as folding nuclei; and additionally we showed that chemically denatured T4L is not a random coil as previously thought. By using obtained distance restraints we determined that denatured T4L shows a native-like mean structure, albeit larger in size compared to the native state. We demonstrate here the necessity of careful data interpretation, but also the potential of a multidimensional approach to characterize an ensemble of states, which can be applied generally to unstructured or denatured proteins.

It is established that the filling with graphenes increases (by 1.3-1.8 times) the strength at normal adhesion to steel. At same time, filling reduces the compressive strength and abrasion resistance and also resistance to aggressive liquids (conc. nitric acid, chloromethylene; mixture acetone-ethylacetate). The most probable reason for this may be the features of the graphene plate structure, prone to deactivation (self-rotation) of particles and therefore sensitive to the technology of hardening. Studies have shown the limited positive effects of graphene as a filler of epoxydes, although its introduction can significantly improve certain practical characteristics (adhesion, thermal and electrical conductivity).

In this paper results are presented on experimental studies of the temporal characteristics of spike extreme ultraviolet (EUV) radiation in the spectral range of 12.2 ÷ 15.8 nm from the anode region of high-current (I = 40 kA) pulsed discharges in tin vapor. It is observed that the intense multi-spike radiation in this range arises at an inductive stage of the discharge. It has been shown that the radiation spikes correlate with the sharp increase of active resistance and of pumped power, due to plasma heating by an electron beam, formed in the double layer of charged particles. It has been observed that for large number of spikes the conversion efficiency of pumped energy into radiationat double layer formation is essentially higher in comparison with collisional heating.

The report deals with damage kinetics, defect evolution and radiation response of binary and multicomponent solids irradiated with MeV electrons. Studies were made into such systems as metallic alloys, semiconductors, high‐Tc superconductors and bulk metallic glasses. The common features of the studies involve the efficient use of MeV dc electron beams as generators of point‐like defects in solids, precise low‐temperature (5–80 K) irradiation conditions, and, as a rule, in situ measurements of irradiated material parameters. To exemplify, successful investigations on the following topics are reported here: (1) Annealing of radiation defects in binary zirconium‐base alloys. (2) Impact of defect density on electronic properties of nanocrystalline hydrogenated silicon. (3) Pinning process in high‐Tc YBa2Cu3O7−x single crystals irradiated with MeV electrons. (4) Accumulation and recovery kinetics of radiation defects in bulk metallic glasses.

Studies were made into the influence of oversized rare-earth atoms on the processes of radiation defect accumulation and annealing in two-component zirconium alloys. Zr and Zr-X alloys (where X = Sc, Dy, Y, Gd and La) have been irradiated with 2 MeV electrons at 82 K. The radiation-induced resistivity has been measured in situ as a function of dose. As compared to unalloyed zirconium, the alloys have exhibited a decrease in the resistivity gain, this decrease being proportional to both the concentration and the size of dopant atoms. A possible explanation for the effect is offered. The difference between the recovery processes in zirconium and in its alloys has been studied. To this end, the irradiated specimens were subjected to isochronal annealing at temperatures between 82 and 350 K. It is shown that Dy, Y, Gd and La atoms trap interstitial atoms at stage I of the recovery. The dissociation of interstitial-impurity complexes takes place at stage II. In zirconium alloys with Dy, Y and Gd, splitting of recovery stage III into two substages has been revealed. The Zr-La alloy has not shown this splitting. Isothermal annealing data were used to determine the activation energies of recovery stages, and also to calculate the activation energy spectra for zirconium and its alloys. The oversized atoms of rare-earth metals are shown to interact effectively with both the interstitials and the vacancies in the zirconium matrix. This effect must be taken into account when developing new radiation-resistant Zr-base alloys or modifying the ones already existing.

The PtSi layer and PtSi/Al, PtSi/AlCuSi, PtSi / TiW / AlCuSi, Ti /Ni / Ag, Al / Ti / Ni / Ag stacks were tested as the anode contact of high-power P-i-N diode. The forward voltage drop (VF), differential resistance (Rdiff) and crossing point current (IXing) of diodes were evaluated from the forward I-V curves at different temperatures measured in four point arrangement. The lowest magnitude of contact resistivity and poor thermal stability were obtained for the case of diode with PtSi contact. The additional layers have improved the temperature stability of this contact. It has led to the increase of contact resistance, but the PtSi layer is still possible to use as a source of Pt for further local lifetime control operation.© (2005) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Understanding how a linear strand of amino acids folds into an active protein in the cell is still one of the challenges in biochemistry. Moreover, as quite a distinct amount of misfolded proteins are responsible for diseases, e. g. Alzheimer's. Thus, understanding the folding pathway, hence describing the energy landscape, of a protein is of critical importance. Here, we used the model enzyme lysozyme from the phage T4 (T4L), a simple two domain protein, which already exists in an equilibrium of at least three conformations in the folded state, a situation expected from most other proteins as well.Thus, we created a set of double mutants of the cysteine-free pseudo-wild type by inserting an unnatural amino acid and a cysteine mutation, which builds up a network of distances spanning the enzyme. Later, we site-specifically labeled them using orthogonal chemistry with a Forster resonance energy transfer (FRET) dye pair. The unfolding process was monitored on the one hand using traditional ensemble methods like CD- spectroscopy and on the other hand with our fluorescence spectroscopic methods (ensemble steady-state fluorescence, ensemble time correlated single photon counting, single molecule fluorescence spectroscopy, filtered fluorescence correlation spectroscopy). Single molecule high precision FRET, with its high temporal and spatial resolution covering seven time decades, enables us to determine transition rates between conformational states in equilibrium and in denatured conditions. The combination of our fluorescence spectroscopic tool provides enough information to describe the energy landscape of the unfolding process of T4L and its paths to the unfolded conformations.

A method of impurity laser gettering applicable to complex semiconductors of the CdTe type is suggested and investigated. The methods of photoluminescence and structural analysis revealed the efficiency of laser recrystallization of a semiconductor plate non-operating area which further serves as the getter zone. The mode of laser radiation from the self-absorption area, which leads to priority evaporation of a more volatile component in the complex semiconductor, forms a stable zone of mechanical stresses which in further heat treatment serves as an efficient run-off for undesired impurities and dot defects.