Homoleptic Poly(nitrato) Complexes of Group 14 Stable at Ambient Conditions

Using a novel approach in homoleptic nitrate chemistry, Sn(NO3)62− (3c) as well as the previously unknown hexanitrato complexes Si(NO3)62− (1c), Ge(NO3)62− (2c) were synthesized from the element tetranitrates as salt-like compounds which were isolated and characterized using 1H, 14N, and 29Si NMR and IR spectroscopies, elemental and thermal analyses, and single-crystal XRD. All hexanitrates are moderately air-sensitive at 298 K and possess greater thermal stability toward NO2 elimination than their charge-neutral tetranitrato congeners as solids and in solution. The complexes possess distorted octahedral coordination skeletons and adopt geometries that are highly symmetric (3c) or deformed (1c, 2c) depending on the degree of steric congestion of the ligand sphere. As opposed to the κ2O,O′ coordination mode reported for Sn(NO3)4 previously,1 all nitrato ligands of 3c coordinate in κ1O mode. Six geometric isomers of E(NO3)62− were identified as minima on the PES using DFT calculations at the B3LYP/6-311+G(d,p) level of which two were observed experimentally

System for wireless power transfer

Поступила: 15.02.2021. Принята в печать: 10.03.2021.Received: 15.02.2021. Accepted: 10.03.2021.Рассмотрены вопросы беспроводной передачи энергии на малые расстояния. Подход может быть применим для беспроводной зарядки батарей беспилотных транспортных средств. Предлагается для передачи энергии использовать технику микрополосковых структур. При приближении микрополосковых структур друг к другу с лицевой части они образуют направленный ответвитель на симметричных полосковых линиях. Длина линий взаимодействия выбирается в несколько раз большей, чем четверть длины волны. Балластные сопротивления из схемы исключаются. Такой подход приводит к малым потерям передачи энергии при изменении расстояния между микрополосковыми структурами в широких пределах. Осуществлено моделирование работы системы передачи энергии, изготовлен экспериментальный образец и проведены экспериментальные исследования. Моделирование и эксперимент хорошо согласуются друг с другом.The issues of wireless power transfer over short distances are considered. The approach may be used for wireless charging of batteries in unmanned vehicles. It is proposed to use the technique of microstrip structures for power transfer. The microstrip structures form a directional coupler on symmetrical strip lines when approaching by front parts. The length of the interaction lines is chosen several times longer than a quarter of the wavelength. Ballast resistors are excluded from the circuit. This approach leads to small losses of power transfer when the distance between microstrip structures changes over a wide range. Modeling of the operation of the power transfer system has been carried out, an experimental sample has been made and experimental studies have been carried out. The simulation and experiment are well accorded.Работа выполнена при поддержке РФФИ и Севастопольского региона, проект № 20-48-920001.The research is carried out with the financial support of the RFBR and the Sevastopol region, project № 20-48-920001

Permafrost coverage, watershed area and season control of dissolved carbon and major elements in western Siberian rivers

Analysis of organic and inorganic carbon (DOC and DIC, respectively), pH, Na, K, Ca, Mg, Cl, SO₄ and Si in ~ 100 large and small rivers (< 10 to &le; 150 000 km²) of western Siberia sampled in winter, spring, and summer over a more than 1500 km latitudinal gradient allowed establishing main environmental factors controlling the transport of river dissolved components in this environmentally important region, comprising continuous, discontinuous, sporadic and permafrost-free zones. There was a significant latitudinal trend consisting in a general decrease in DOC, DIC, SO₄, and major cation (Ca, Mg, Na, K) concentration northward, reflecting the interplay between groundwater feeding (detectable mostly in the permafrost-free zone, south of 60° N) and surface flux (in the permafrost-bearing zone). The northward decrease in concentration of inorganic components was strongly pronounced both in winter and spring, whereas for DOC, the trend of concentration decrease with latitude was absent in winter, and less pronounced in spring flood than in summer baseflow. The most significant decrease in K concentration from the southern (< 59° N) to the northern (61–67° N) watersheds occurs in spring, during intense plant litter leaching. The latitudinal trends persisted for all river watershed size, from < 100 to > 10 000 km². Environmental factors are ranked by their increasing effect on DOC, DIC, δ¹³C_DIC, and major elements in western Siberian rivers as follows: watershed area < season < latitude. Because the degree of the groundwater feeding is different between large and small rivers, we hypothesize that, in addition to groundwater feeding of the river, there was a significant role of surface and shallow subsurface flow linked to plant litter degradation and peat leaching. We suggest that plant-litter- and topsoil-derived DOC adsorbs on clay mineral horizons in the southern, permafrost-free and discontinuous/sporadic permafrost zone but lacks the interaction with minerals in the continuous permafrost zone. It can be anticipated that, under climate warming in western Siberia, the maximal change will occur in small (< 1000 km² watershed) rivers DOC, DIC and ionic composition and this change will be mostly pronounced in summer

Structure and function analyses of the purified GPCR human vomeronasal type 1 receptor 1

The vomeronasal system is one of several fine-tuned scent-detecting signaling systems in mammals. However, despite significant efforts, how these receptors detect scent remains an enigma. One reason is the lack of sufficient purified receptors to perform detailed biochemical, biophysical and structural analyses. Here we report the ability to express and purify milligrams of purified, functional human vomeronasal receptor hVN1R1. Circular dichroism showed that purified hVN1R1 had an alpha-helical structure, similar to that of other GPCRs. Microscale thermophoresis showed that hVN1R1 bound its known ligand myrtenal with an EC50 ∼1 µM. This expression system can enable structural and functional analyses towards understanding how mammalian scent detection works

Резолюция Совета экспертов «Итоги многоцентрового рандомизированного двойного слепого плацебо-контролируемого исследования Артнео у пациентов с первичным остеоартритом коленного сустава II–III стадии

On August 31,2023 in V.A. Nasonova Research Institute of Rheumatology a meeting of the Expert Council was held at which the principal investigators and co-investigators of the ARTNEO-2021 protocol "Multicenter randomized double-blind, placebo-controlled study of ARTNEO in patients with stage II-III primary knee osteoarthritis" was held. A consensus position was developed on the possibility and feasibility of using a combination of undenatured (native) type II collagen, methylsulfonylmethane, boswellic acids, vitamins C and D (ARTNEO complex) in clinical practice. Based on the results of the study, the use of the ARTNEO complex can be recommended as part of a complex therapy for patients with osteoarthritis as a course treatment with total duration up to 6 months. The results of the study can only be interpreted in relation to ARTNEO and cannot be transferred to preparations with a different composition.31 августа 2023 г. в ФГБНУ «Научно-исследовательский институт ревматологии им. В.А. Насоновой» состоялось заседание Совета экспертов с участием главных исследователей и соисследователей по протоколу Artneo-2021 «Многоцентровое рандомизированное двойное слепое плацебо-контролируемое исследование Артнео у пациентов с первичным остеоартритом коленного сустава II–III стадии». Разработана согласованная позиция в отношении возможности и целесообразности использования комбинации неденатурированного (нативного) коллагена II типа, метилсульфонилметана, босвеллиевых кислот, витаминов С и D (комплекс Артнео) в клинической практике. Основываясь на результатах исследования, в составе комплексной терапии пациентов с остеоартритом может быть рекомендовано применение комплекса Артнео общим курсом до 6 мес. Результаты исследования могут быть интерпретированы только по отношению к Артнео и не могут распространяться на композиции с иным составом

Entrepreneurial-intention constraint model: A comparative analysis among post-graduate management students in India, Singapore and Malaysia

YesAlthough literature on entrepreneurship has increasingly focused on intention-based models, not much emphasis has been laid on understanding the combined effect of contextual and situational factors along with support of university environment on the formation of entrepreneurial intention among students. In an effort to make up for this shortfall, by taking Theory of Planned Behavior as basic framework, the present study seeks to understand the influence of three of the most important factors, viz. (a) endogenous barriers, (b) exogenous environment, and (c) university environment and support on the entrepreneurial intention among management students. The study sample consisted of 1,097 students, wherein 526 students were from India, 252 from Singapore, and 319 were from Malaysia. The results indicates that along with positive attitude and perceived behavioral control that directly influences entrepreneurial intention, university environment and support and exogenous environment also have an indirect but significant impact on shaping of entrepreneurial intention among students. With this, it was found that exogenous environment was found to have a negative relationship with both attitude towards behavior and perceived behavioral control for all three countries.The full-text of this article will be released for public view at the end of the publisher embargo on 2 Jun 2018

To the question of improving the outcomes of surgical treatment of genital prolapse in postmenopausal women

Currently, the frequency of genital prolapse in the structure of common gynecological diseases has no tendency to decrease and may take up to 15% of large gynecological operations. With the aim of improving outcomes of surgical treatment of this category of patients, at the stage of preoperative preparation and the postoperative period used vaginal capsules containing Lactobacillus + progesterone 2 mg + estriol 0.2 mg (Triozhinal). The study included 239 patients in postmenopausal women with genital prolapse and phenomena cystourethroscopy and vaginal atrophy. Of these, the main group consisted of 122 women who underwent the proposed scheme of preoperative preparation and postoperative period. Group comparisons were presented 117 patients admitted to the gynecological Department for surgical treatment of prolapse with traditional preoperative and postoperative management. The results of the study showed that in the group of patients receiving local therapy estriola in combination with progesterone and lactobacilli, was observed a significant improvement of the clinical picture of urinary disorders, quality of life, symptoms of urogenital atrophy during surgical correction of urinary incontinence or genital prolapse, and this tactic can be recommended as in the pre-and postoperative periods.В настоящее время частота пролапса гениталий в структуре гинекологических заболеваний не имеет тенденции к снижению и занимает до 15% гинекологических операций. С целью улучшения исходов хирургического лечения данной категории пациенток, на этапе предоперационной подготовки и в период послеоперационной реабилитации использованы вагинальные капсулы, содержащие лактобактерии + прогестерон 2мг + эстриол 0,2 мг (триожиналь). Под наблюдением находились 239 пациенток в постменопаузе с пролапсом гениталий и явлениями вагинальной и цистоуретральной атрофии. Из них основную группу составили 122 женщины, которым проводилась предложенная нами схема ведения предоперационной подготовки и послеоперационного периода. Группа сравнения была представлена 117 пациентками, поступившим в гинекологическое отделение с традиционной предоперационной подготовкой и послеоперационным ведением. Результаты исследования показали, что в группе пациенток, получающей локальную терапию эстриолом в сочетании с прогестероном и лактобактериями, наблюдалось значимое улучшение клинической картины расстройств мочеиспускания, показателей качества жизни, симптомов урогенитальной атрофии при хирургической коррекции недержания мочи или пролапса гениталий, и такая тактика может быть рекомендована как в пред-, так и в послеоперационном периодах

Rate-dependent Ca2+ signalling underlying the force-frequency response in rat ventricular myocytes: A coupled electromechanical modeling study

Rate-dependent effects on the Ca2+ sub-system in a rat ventricular myocyte are investigated. Here, we employ a deterministic mathematical model describing various Ca2+ signalling pathways under voltage clamp (VC) conditions, to better understand the important role of calmodulin (CaM) in modulating the key control variables Ca2+/calmodulin-dependent protein kinase-II (CaMKII), calcineurin (CaN), and cyclic adenosine monophosphate (cAMP) as they affect various intracellular targets. In particular, we study the frequency dependence of the peak force generated by the myofilaments, the force-frequency response (FFR). Our cell model incorporates frequency-dependent CaM-mediated spatially heterogenous interaction of CaMKII and CaN with their principal targets (dihydropyridine (DHPR) and ryanodine (RyR) receptors and the SERCA pump). It also accounts for the rate-dependent effects of phospholamban (PLB) on the SERCA pump; the rate-dependent role of cAMP in up-regulation of the L-type Ca2+ channel (ICa;L); and the enhancement in SERCA pump activity via phosphorylation of PLB.Our model reproduces positive peak FFR observed in rat ventricular myocytes during voltage-clamp studies both in the presence/absence of cAMP mediated -adrenergic stimulation. This study provides quantitative insight into the rate-dependence of Ca2+-induced Ca2+-release (CICR) by investigating the frequency-dependence of the trigger current (ICa;L) and RyR-release. It also highlights the relative role of the sodium-calcium exchanger (NCX) and the SERCA pump at higher frequencies, as well as the rate-dependence of sarcoplasmic reticulum (SR) Ca2+ content. A rigorous Ca2+ balance imposed on our investigation of these Ca2+ signalling pathways clarifies their individual roles. Here, we present a coupled electromechanical study emphasizing the rate-dependence of isometric force developed and also investigate the temperature-dependence of FFR. Our model provides mechanistic biophysically based explanations for the rate-dependence of CICR, generating useful and testable hypotheses. Although rat ventricular myocytes exhibit a positive peak FFR in the presence/absence of beta-adrenergic stimulation, they show a characteristic increase in the positive slope in FFR due to the presence of Norepinephrine or Isoproterenol. Our study identifies cAMP-mediated stimulation, and rate-dependent CaMKII-mediated up-regulation of ICa;L as the key mechanisms underlying the aforementioned positive FFR

Varfarin in the complex treatment of antiphospholipid syndrome: preliminary results

Objective. To assess efficacy and tolerance of varfarin in prophylaxis and therapy of thrombotic complications in patients with antiphospholipid syndrome (APS). Methods. 20 pts with APS (5 male and 15 female) received varfarin during a year. 8 of them had primary APS (PAPS) and 12 -systemic lupus erythematosus with APS (SLE+APS). 2 other pts (I with SLE+APS and I with PAPS) received varfarin during the last 4 years. Nobody from 9 pts with PAPS received corticosteroids (CS). In SLE+APS pts CS dose varied from 4 to 20 mg/day and was not increased during follow up. During the study prothrombine time (PT) was examined with thromboplastin ( manufactured by Renam) having international sensitivity index 1,2 and international normalization relation (INR). Depending on treatment scheme APS pts were divided into 3 groups. Group 1 included 8 pts with INR&lt;2,0, Group 2-7 with INR &gt;3,0, group 3 - 7 pts with INR&lt;2,0 receiving as additional treatment thrombo ASS 100 mg/day and vasonit from 600 to 1200 mg/day. Results. Two pts with INR = 1,8 had thrombosis recurrence (due to leg thrombophlebitis). There were no recurrences in other groups. 2 from 22 pts had "large" bleedings. "Small" bleedings episodes were noted in 7 from 22 pts. Largely that were subcutaneous bleedings (in 4 pts) no more than 5 cm of size. Two pts receiving varfarin with INR 1,8 and 2,4 had renal colic. Conclusion. Our preliminary results prove the necessity of inclusion of varfarin in the treatment of pts with APS and thrombosis but intensive anticoagulant effect is not always desired