A possible mechanism for cold denaturation of proteins at high pressure

We study cold denaturation of proteins at high pressures. Using multicanonical Monte Carlo simulations of a model protein in a water bath, we investigate the effect of water density fluctuations on protein stability. We find that above the pressure where water freezes to the dense ice phase ($\approx2$ kbar), the mechanism for cold denaturation with decreasing temperature is the loss of local low-density water structure. We find our results in agreement with data of bovine pancreatic ribonuclease A.Comment: 4 pages for double column and single space. 3 figures Added references Changed conten

RARE CASE OF ENDOGENOUS FAMILY HYPERCORTICISM (CLINICAL CASE)

We described a case of an endogenous hypercorticism in 18-years old patient with Itsenko - Cushing syndrome which was caused by a hormonally active adrenal tumor of the left adrenal gland. In a clinical picture of a disease the following symptoms dominated: arterial hypertension, increase in body weight, adiposity of the trunk, hands, neck, face, strips of extensions of skin on femurs. We found multiple nevus pigmentosus of black, yellowy-brown color from 1.5 to 10 mm on lips and mucous of a mouth, skin of a face and a trunk. The hormonal research established violations of a circadian rhythm of a hydrocortisone, increase in the free hydrocortisone of blood to 749.0 nmol/24 h (reference range 123.0-626.0), urine to 1314.0 nmol/24 h (reference range 60.0-413.0). The ACTH level decreased to 1.7 pg/ml (reference range 7.0-66.0). The negative result of the night overwhelming test with Dexamethazonum is received. Muitislice CT of adrenal glands revealed signs of a nodular hyperplasia of the left-hand adrenal gland. The laparoscopic adrenalectomy is made at the left. Pathoanathomical conclusion: a nodular pigmental hyperplasia of a glomerular and fascicular zone of bark of an adrenal gland with inclusion of a miyelolipomatoz. In the nodular corticocytes inclusions of lipofuscin granules were found. In the postoperative period symptoms of a hypercorticoidism regressed, throughout two years of observation there is no recurrence. Monitoring of hormones of blood in six months: hydrocortisone 359.5 nmol/l, ACTH 7.02 pg/ml. Retrospectively, the patient displays an infrequent heritable disease - Carney complex. The patient's mother at the age of 32 years underwent left-side adrenalectomy concerning Itsenko - Cushing disease with morphological confirmation of a nodular pigmental hyperplasia in adrenal gland. In both cases clinical convalescence occurred. Interest of the presented observation consists in its exclusive rarity. The unilateral adrenalectomy was efficient, but the probability of a recurrence of a hypercorticoidism and other manifestations of Carney complex remains

Solvent-induced micelle formation in a hydrophobic interaction model

We investigate the aggregation of amphiphilic molecules by adapting the two-state Muller-Lee-Graziano model for water, in which a solvent-induced hydrophobic interaction is included implicitly. We study the formation of various types of micelle as a function of the distribution of hydrophobic regions at the molecular surface. Successive substitution of non-polar surfaces by polar ones demonstrates the influence of hydrophobicity on the upper and lower critical solution temperatures. Aggregates of lipid molecules, described by a refinement of the model in which a hydrophobic tail of variable length interacts with different numbers of water molecules, are stabilized as the length of the tail increases. We demonstrate that the essential features of micelle formation are primarily solvent-induced, and are explained within a model which focuses only on the alteration of water structure in the vicinity of the hydrophobic surface regions of amphiphiles in solution.Comment: 11 pages, 10 figures; some rearrangement of introduction and discussion sections, streamlining of formalism and general compression; to appear in Phys. Rev.

ASVAL - A NEW METHOD OF TREATMENT OF VARICOSE VEINS OF THE LEGS

Chronic venous disease of lower extremities is a common vascular problem in the developed countries. The aim of our study was to explore a potency of ambulatory selective varicose vein ablation under local anesthesia (ASVAL) without vein stripping. ASVAL method was carried out in 12 patients. All patients had reflux of great saphenous vein verified by duplex ultrasound before surgical treatment. Exclusion criteria were reflux of small saphenous vein, reflux of perforator veins and clinical class 4-6 by classification CEAP. Design of the study was series cases. Follow-up time lasted one year. The surgery was performed by tumescent anesthesia of 0.01% Lidocain. All patients were given Diclofenac 100 mg for one postoperative day. In all patients we observed decrease of size or disappearance of great saphenous vein reflux verified by duplex ultrasound. No recurrence of varicose veins for one year was detected

Thermodynamics of Heat Shock Response

Production of heat shock proteins are induced when a living cell is exposed to a rise in temperature. The heat shock response of protein DnaK synthesis in E.coli for temperature shifts from temperature T to T plus 7 degrees, respectively to T minus 7 degrees is measured as function of the initial temperature T. We observe a reversed heat shock at low T. The magnitude of the shock increases when one increase the distance to the temperature $T_0 \approx 23^o$, thereby mimicking the non monotous stability of proteins at low temperature. Further we found that the variation of the heat shock with T quantitatively follows the thermodynamic stability of proteins with temperature. This suggest that stability related to hot as well as cold unfolding of proteins is directly implemented in the biological control of protein folding. We demonstrate that such an implementation is possible in a minimalistic chemical network.Comment: To be published in Physical Review Letter

A new estimation of the recent tropospheric molecular hydrogen budget using atmospheric observations and variational inversion

This paper presents an analysis of the recent tropospheric molecular hydrogen (H2) budget with a particular focus on soil uptake and European surface emissions. A variational inversion scheme is combined with observations from the RAMCES and EUROHYDROS atmospheric networks, which include continuous measurements performed between mid-2006 and mid-2009. Net H2 surface flux, then deposition velocity and surface emissions and finally, deposition velocity, biomass burning, anthropogenic and N2 fixation-related emissions were simultaneously inverted in several scenarios. These scenarios have focused on the sensibility of the soil uptake value to different spatio-temporal distributions. The range of variations of these diverse inversion sets generate an estimate of the uncertainty for each term of the H2 budget. The net H2 flux per region (High Northern Hemisphere, Tropics and High Southern Hemisphere) varies between −8 and +8 Tg yr−1. The best inversion in terms of fit to the observations combines updated prior surface emissions and a soil deposition velocity map that is based on bottom-up and top-down estimations. Our estimate of global H2 soil uptake is −59±9 Tg yr−1. Forty per cent of this uptake is located in the High Northern Hemisphere and 55% is located in the Tropics. In terms of surface emissions, seasonality is mainly driven by biomass burning emissions. The inferred European anthropogenic emissions are consistent with independent H2 emissions estimated using a H2/CO mass ratio of 0.034 and CO emissions within the range of their respective uncertainties. Additional constraints, such as isotopic measurements would be needed to infer a more robust partition of H2 sources and sinks

All Polymer Diffusion Regimes Covered by Combining Field-Cycling and Field-Gradient ¹H NMR

© 2015 American Chemical Society. Field-cycling and field-gradient 1H NMR experiments were combined to reveal the segmental mean-square displacement as a function of time for polydimethylsiloxane (PDMS) and polybutadiene (PB). Together, more than 10 decades in time are covered, and all four power-law regimes of the tube-reptation (TR) model are identified with exponents rather close to the predicted ones. Characteristic polymer properties like the tube diameter a0, the Kuhn length b, the mean-square end-to-end distance 02>, the segmental correlation time τs(T), the entanglement time τe(T), and the disengagement time τd(T) are estimated from the measurements and compared to results from literature. Concerning τd(T), fair agreement is found. In the case of τe, agreement with rheological data is achieved when the time constant is extracted from the minimum in the shear modulus G″(ω). Concerning the TR predictions the molar mass (M) dependence of τd is essentially reproduced. Yet, calculating τe from τd for PDMS yields agreement with experimental data while for PB it gets by 2 orders of magnitude too short. In no case τe is correctly reproduced from τs(T). Segmental and shortest Rouse times appear to coincide for PB, while in the case of PDMS the latter turns out to be longer by 1 decade

ЭФФЕКТИВНОСТЬ ПРИМЕНЕНИЯ БИОЛОГИЧЕСКИХ ПРЕПАРАТОВ В АГРОЦЕНОЗЕ КОРМОВЫХ БОБОВ В БЕЛАРУСИ

Production of domestic high protein fodder is a key problem for the livestock sector in the Republic of Belarus. It is possible to solve it due to extension of arable lands for legume crops, particularly for faba beans. The research on evaluating the efficiency of biological preparations applied to crops against diseases is highly prioritized. This allows obtaining organic products with a minimum impact on the environment. Presowing treatment of seeds with preparation Fungilex, L (Trichoderma sp. D-11) – (8.0–10.0 l/t) as well as with chemical protectant Scarlet, ME (imazalil, 100 g/l + tebuconazole, 40 g/l) – (0.4 l/t) allows reducing Alternaria blight by 73.8–78.8 % and Fusarium blight by 53.3–56.7 %, which ensures saving of 2.8–3.0 dt/ha of grains compared to the control. Soil application with microbiological inoculant Resoiler, L (Trichoderma sp. L-3 and Trichoderma sp. L-6) – (6.0 and 8.0 l/ha) before filed beans sowing contributes to growing vegetative mass by 3.2–3.5 %, decreasing Fusarium blight development by 69.1–70.6 % and increasing seed productivity by 3.1–3.6 dt/ha compared to the control. Combined use of biopreparations Fungilex, L (8.0 and 10.0 l/t) and Resoiler, L (6.0 and 8.0 l/ha) promotes the growth of aerial parts of the plant by 3.5–3.8 % and reduction of Alternaria blight development by 88.7–90.1 % and Fusarium blight development by 76.5–79.4 %. This ensures statistically significant saving of 5.1–5.6 dt/ha of grain in relation to the control and obtaining the maximum net profit of 231.5–249.5 rubles/ha, which is 32.6–50.6 rubles/ha higher in comparison with Scarlet, ME (0.4 l/t). It’s important to underline that a protective effect of the biological preparations as well as the chemical protectant was observed before the booting stage of the crop (BBCH 35). The application of biological preparations allows reducing pesticide load on the crop, protecting plants from diseases and obtaining organic products. The research findings can be widely applied in agriculture.Производство отечественного высокобелкового корма является ключевой проблемой в животноводческой отрасли Республики Беларусь, решить которую можно путем расширения посевных площадей под зернобобовые культуры, в частности кормовые бобы. Особую актуальность приобретают исследования по оценке эффективности биологических препаратов в посевах культуры против болезней как возможность получения экологически чистой продукции с минимальным негативным воздействием на окружающую среду. Предпосевная обработка семян биологическим препаратом Фунгилекс, Ж (Trichoderma sp. D-11) – (8,0–10,0 л/т) позволяет, наравне с химическим протравителем Скарлет, МЭ (имазалил, 100 г/л + тебуконазол, 40 г/л) – (0,4 л/т), снизить поражение посевов культуры альтернариозом на 73,8–78,8 %, фузариозом – на 53,3–56,7 %, что обеспечивает сохранение 2,8–3,0 ц/га зерна культуры относительно контроля. Внесение в почву перед посевом кормовых бобов инокулянта микробиологического Ресойлер, Ж (Trichoderma sp. L-3 и Trichoderma sp. L-6) – (6,0–8,0 л/га) способствует нарастанию вегетативной массы на 3,2–3,5 %, снижению развития фузариоза на 69,1–70,6 % и повышению семенной продуктивности на 3,1–3,6 ц/га относительно контроля. Комплексное применение биопрепаратов Фунгилекс, Ж (8,0 и 10,0 л/т) и Ресойлер, Ж (6,0 и 8,0 л/га) способствует нарастанию надземной части растений на 3,5–3,8 %, снижению развития альтернариоза на 88,7–90,1 %, фузариоза – на 76,5–79,4 %. Это обеспечивает статистически достоверное сохранение 5,1–5,6 ц/га зерна культуры относительно контроля и получение максимального чистого дохода 231,5–249,5 руб/га, что на 32,6–50,6 руб/га выше по сравнению с протравителем Скарлет, МЭ (0,4 л/т). Важно отметить, что защитное действие как биологических препаратов, так и химического протравителя отмечалось до фазы полного стеблевания культуры (ВВСН 35). Использование биологических препаратов позволяет снизить пестицидную нагрузку на культуру, защитить растения от болезней и обеспечить получение экологически чистой продукции. Результаты исследований могут широко применяться в сельском хозяйстве.

СТАЦИОНАРНОМУ ОПЫТУ ПО СЕВООБОРОТАМ 40 ЛЕТ: ОСНОВОПОЛАГАЮЩИЕ РАЗРАБОТКИ ДЛЯ ЗЕМЛЕДЕЛЬЧЕСКОЙ НАУКИ И ПРАКТИКИ БЕЛАРУСИ

Long-term stationary experiments are the necessary information base for the conducting of science oriented arable farming. The research results obtained in such experiments are of great importance not only for solving current issues in agricultural practice, but also for developing strategic global directions for improving agricultural systems and agricultural production in whole. In stationary experiments, it is possible to trace the dynamics of land capacity, soil fertility recovery, including changes of agrochemical, physical and biological properties, the phytosanitary state of crops and soil at different levels of intensification and technology used. This makes it possible to give justified recommendations for farming in enterprises with different levels of production at different stages and in different years with different weather conditions. In the meantime, the information obtained in such experiments can serve as a basis for forecasting and modeling of the most effective technologies and systems of arable farming in future. This can not be fully achieved and achieved with high significance in short-term experiments. The article presents the results of 40-year stationary experiment on the study of different types and kinds of crop rotations for agricultural enterprises of different specializations using different fertilizing systems and levels. Over 20 schemes of field and fodder crop rotations, permanent crops of cereals, legumes and fodder crops have been studied. As a result of long-term field experiments, the possibility of adjusting crop rotations under conditions of farming intensification has been substantiated, intensive crop rotations have been developed for farms specializing in production of milk, beef and pork. The evaluation of crops as predecessors in crop rotations with substantiation for cereals, legumes, perennial grasses and tilled crops in various types of crop rotations is given. The effect of different types and kinds of crop rotations on soil fertility was studied. Application of intermediate crops has been scientifically substantiated and schemes of crop rotations with intermediate crops have been developed.Длительные стационарные опыты являются необходимой информационной базой для ведения земледелия на научной основе. Результаты исследований, полученные в таких опытах, имеют важное значение не только для решения текущих вопросов в земледельческой практике, но и для разработки стратегических глобальных направлений совершенствования систем земледелия и в целом аграрного производства. В стационарных опытах представляется возможным проследить за динамикой производительной способности земли, воспроизводства плодородия почвы, включающего изменения агрохимических, физических и биологических свойств, фитосанитарного состояния посевов и почвы при различных уровнях применяемых средств интенсификации и технологий. Это позволяет на разных этапах давать обоснованные рекомендации для ведения земледелия в хозяйствах с разным уровнем производства, причём в разные по погодным условиям годы. Одновременно полученная информация в таких опытах может служить основанием для прогнозирования и моделирования наиболее эффективных технологий и систем земледелия в перспективе. Этого нельзя в полной мере и при высокой достоверности достигнуть в краткосрочных опытах. В статье изложены результаты 40-летнего стационарного опыта на дерново-подзолистой легкосуглинистой почве по изучению различных типов и видов севооборотов для хозяйств разной специализации при различных системах и уровнях удобрений. Изучено более 20 схем полевых и кормовых севооборотов, бессменных посевов зерновых, зернобобовых и кормовых культур. В результате длительных полевых опытов обоснована возможность специализации севооборотов в условиях интенсификации земледелия, разработаны интенсивные севообороты для хозяйств, специализирующихся на производстве молока, говядины и свинины. Дана оценка культур как предшественников в севооборотах с обоснованием размещения зерновых, зернобобовых, многолетних трав и пропашных культур в различных видах севооборотов. Изучено влияние разных типов и видов севооборотов на почвенное плодородие. Научно обосновано применение промежуточных культур и разработаны схемы севооборотов с промежуточными культурами.