Optical absorption in boron clusters B6_{6} and B6+_{6}^{+} : A first principles configuration interaction approach

The linear optical absorption spectra in neutral boron cluster B$_{6}$ and cationic B$_{6}^{+}$ are calculated using a first principles correlated electron approach. The geometries of several low-lying isomers of these clusters were optimized at the coupled-cluster singles doubles (CCSD) level of theory. With these optimized ground-state geometries, excited states of different isomers were computed using the singles configuration-interaction (SCI) approach. The many body wavefunctions of various excited states have been analysed and the nature of optical excitation involved are found to be of collective, plasmonic type.Comment: 22 pages, 38 figures. An invited article submitted to European Physical Journal D. This work was presented in the International Symposium on Small Particles and Inorganic Clusters - XVI, held in Leuven, Belgiu

Violation of the Hormonal Spectrum in Polycystic Ovaries in Combination with Insulin Resistance. What is the Trigger: Insulin Resistance or Polycystic Ovary Disease?

متلازمة المبيض متعدد التكيسات هي السبب الرئيس للعقم لدى النساء. حيث يناقش البحث دور مقاومة الأنسولين في تطور تكيس المبايض. تم تحليل الطيف الهرموني للمرضى الذين يعانون من متلازمة تكيس المبايض و / أو مقاومة الأنسولين. اشتملت الدراسة على مرضى يعانون من متلازمة تكيس المبايض دون مقاومة الأنسولين (عددهم = 48) ومقاومة الأنسولين (عددهم = 39). كانت مجموعات المقارنة من المرضى الذين ليس لديهم تاريخ من متلازمة تكيس المبايض: مجموعة تحكم بدون مقاومة الأنسولين (عددهم = 46) ومجموعة من المرضى الذين يعانون من مقاومة الأنسولين (عددهم = 45). تم تحديد المعلمات التالية في المرضى: FSH ، LH ، TSH ، T3f ، T4f، PRL ، E2 ، 17-OHd ، Pr ، AMH ، مجموع الاختبار ، Testf ، DHEAS ، DHEAS ، SHBG ، ACTH ، الكورتيزول ، IRI ، IGF-1 ، C- الببتيد ، ومستوى الجلوكوز. تم حساب مؤشر HOMA-IR ونسبة LH / FSH واختبار إجمالي / SHBG. تم إجراء تحليل الارتباط أيضًا بين HOMA IR ومؤشرات المظهر الهرموني و IGF-1 و C-peptide. تم العثور على تغيرات أحادية الاتجاه في مستويات الهرمونات التالية في مقاومة الأنسولين و / أو متلازمة تكيس المبايض و / أو مقاومة الأنسولين بالنسبة لقيم التحكم: استراديول ، هرمون التستوستيرون الكلي ، الكورتيزول ، البرولاكتين ، AMG ، و SHBG. نتيجة لتحليل الارتباط ، تم إنشاء علاقات سلبية بين مؤشر HOMA .IR ومستويات E2 والكورتيزول و AMH في المرضى (باستثناء المجموعة الضابطة) تفترض الدراسة أن تكوين النمط الظاهري للمبيض المتعدد الكيسات مع مزيج من مقاومة الأنسولين يمكن أن يتشكل في المرضى الذين يعانون من مقاومة الأنسولين نتيجة لانخفاض مستوى الاستراديول ، SHBG وزيادة محتوى التستوستيرون الكلي و AMH.Polycystic ovary syndrome (PCOS) is the main cause of female infertility. The role of insulin resistance in the development of polycystic ovary is actively discussed here. The study included patients with PCOS without insulin resistance (n = 48) and with insulin resistance (n = 39). The comparison groups were patients with no history of PCOS: a control group without insulin resistance (n = 46) and a group of patients with insulin resistance (n = 45). The following parameters were determined in patients: FSH, LH, TSH, T3f, T4f, PRL, E2, 17-OHd, Pr, AMH, Test total, Testf, DHEAS, DHEASs, SHBG, ACTH, cortisol, IRI, IGF-1, C-peptide, and glucose level. The HOMA-IR index and the LH / FSH ratio and the total / SHBG test were calculated. Correlation analysis was also performed between HOMA IR and indicators of the hormonal profile, IGF-1, and C-peptide.Unidirectional changes in the levels of the following hormones were found in insulin resistance, PCOS and / or insulin resistance relative to control values: estradiol, total testosterone, cortisol, prolactin, AMG, and SHBG. As a result of the correlation analysis, negative relationships were established between the HOMA IR Index and the levels of E2, cortisol and AMH in patients (except for the control group).We assume that the formation of the phenotype of polycystic ovary with a combination of insulin resistance can be formed in patients with insulin resistance as a result of a decrease in the level of estradiol, SHBG and an increase in the content of total testosterone and AMH

Evidence that phosphorylation of the alpha-subunit of eIF2 does not essentially inhibit mRNA translation in wheat germ cell-free system.

A mechanism based on reversible phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2α) has been confirmed as an important regulatory pathway for inhibition of protein synthesis in mammalian and yeast cells, while plants constitute the significant exception. We studied the induction of TaeIF2α phosphorylation in germinated wheat (Triticum aestivum) embryos subjected to different adverse conditions. Data confirmed that formation of TaeIF2(αP) was not a general response, as no phosphorylation was observed under salt, oxidative or heat stress. Nevertheless, treatment by salicylic acid, UV-light, cold shock and histidinol did induce phosphorylation of TaeIF2α of wheat, as has been established previously for AteIF2α in Arabidopsis (Arabidopsis thaliana). Influence of TaeIF2α phosphorylation on translation of reporter mRNA with different 5′-untranslated regions (5′UTRs) was studied in wheat germ cell-free system (WG-CFS), in which TaeIF2α was first phosphorylated either by heterologous recombinant human protein kinase, HsPKR (activated by double-stranded (ds)RNA), or by endogenous protein kinase TaGCN2 (activated by histidinol). Pre-treatment of WG-CFS with HsPKR in the presence of dsRNA or with histidinol resulted in intense phosphorylation of TaeIF2α; however, the translation levels of all tested mRNAs decreased by only 10–15% and remained relatively high. In addition, factor OceIF2 from rabbit (Oryctolagus cuniculus) bound GDP much more strongly than the homologous factor TaeIF2 from wheat germ. Furthermore, factor OceIF2B was able to stimulate guanine nucleotides exchange (GDP→GTP) on OceIF2 but had no effect on the similar exchange on TaeIF2. These results suggest that the mechanism of stress response via eIF2α phosphorylation is not identical in all eukaryotes and further research is required to find and study in detail new plant-specific mechanisms that may inhibit overall protein synthesis in plants under stress

Aromaticity in a Surface Deposited Cluster: Pd4_4 on TiO2_2 (110)

We report the presence of \sigma-aromaticity in a surface deposited cluster, Pd$_4$ on TiO$_2$ (110). In the gas phase, Pd$_4$ adopts a tetrahedral structure. However, surface binding promotes a flat, \sigma-aromatic cluster. This is the first time aromaticity is found in surface deposited clusters. Systems of this type emerge as a promising class of catalyst, and so realization of aromaticity in them may help to rationalize their reactivity and catalytic properties, as a function of cluster size and composition.Comment: 4 pages, 3 figure

Kinetic-scale magnetic turbulence and finite Larmor radius effects at Mercury

We use a nonstationary generalization of the higher-order structure function technique to investigate statistical properties of the magnetic field fluctuations recorded by MESSENGER spacecraft during its first flyby (01/14/2008) through the near Mercury's space environment, with the emphasis on key boundary regions participating in the solar wind -- magnetosphere interaction. Our analysis shows, for the first time, that kinetic-scale fluctuations play a significant role in the Mercury's magnetosphere up to the largest resolvable time scale ~20 s imposed by the signal nonstationarity, suggesting that turbulence at this planet is largely controlled by finite Larmor radius effects. In particular, we report the presence of a highly turbulent and extended foreshock system filled with packets of ULF oscillations, broad-band intermittent fluctuations in the magnetosheath, ion-kinetic turbulence in the central plasma sheet of Mercury's magnetotail, and kinetic-scale fluctuations in the inner current sheet encountered at the outbound (dawn-side) magnetopause. Overall, our measurements indicate that the Hermean magnetosphere, as well as the surrounding region, are strongly affected by non-MHD effects introduced by finite sizes of cyclotron orbits of the constituting ion species. Physical mechanisms of these effects and their potentially critical impact on the structure and dynamics of Mercury's magnetic field remain to be understood.Comment: 46 pages, 5 figures, 2 table

Synthesis of 8-phenyl substituted 3-benzazecines with allene moiety, their thermal rearrangement and evaluation as acetylcholinesterase inhibitors

Various 4′-R-substituted phenyl azacyclic allenes were synthesized in good yields, and their thermal transformations were studied. For the first time, the obtained rearrangement products—new N-bridged cyclopenta[a]indenes, and the corresponding parent allenes were evaluated as potential inhibitors of acetyl- and butyrylcholinesterase. Among the tested compounds, the allene derivative 2g proved to competitively inhibit human AChE with inhibition constant value (Ki) in the low micromolar range. Graphic abstract: [Figure not available: see fulltext.

Качество статистической информации о причинах смерти в Российской Федерации

The authors of this article quality assessment of the information collected in the Russian Federation on population mortality in order to ensure reliability and international comparability of data of the important section of demographic statistics. The study was conducted within the framework of the tasks in reforming information support of the implementation of the Russian healthcare modernization program aimed, in particular, at changing the unfavorable trends in morbidity and mortality, which play a major role in the current demographic situation.Авторами статьи дана оценка качества собираемой в Российской Федерации информации о смертности населения с целью обеспечения достоверности и международной сопоставимости данных важного раздела демографической статистики. Исследование осуществлено в рамках задачи реформирования информационного обеспечения реализации российской Программы модернизации здравоохранения, направленной, в частности, и на изменение неблагоприятных тенденций в заболеваемости и смертности, которые играют большую роль в существующей демографической ситуации

Evolution of a Polydisperse Ensemble of Spherical Particles in a Metastable Medium with Allowance for Heat and Mass Exchange with the Environment

Motivated by a wide range of applications in various fields of physics and materials science, we consider a generalized approach to the evolution of a polydisperse ensemble of spherical particles in metastable media. An integrodifferential system of governing equations, consisting of a kinetic equation for the particle-size distribution function (Fokker–Planck type equation) and a balance equation for the temperature (concentration) of a metastable medium, is formulated. The kinetic equation takes into account fluctuations in the growth/reduction rates of individual particles, the velocity of particles in a spatial direction, the withdrawal of particles of a given size from the metastable medium, and their source/sink term. The heat (mass) balance equation takes into account the growth/reduction of particles in a metastable system as well as heat (mass) exchange with the environment. A generalized system of equations describes various physical and chemical processes of phase transformations, such as the growth and dissolution of crystals, the evaporation of droplets, the boiling of liquids and the combustion of a polydisperse fuel. The ways of analytical solution of the formulated integrodifferential system of equations based on the saddle-point technique and the separation of variables method are considered. The theory can be applied when describing the evolution of an ensemble of particles at the initial and intermediate stages of phase transformation when the distances between the particles are large enough, and interactions between them can be neglected. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Russian Foundation for Basic Research, РФФИ: 20-08-00199; Ministry of Education and Science of the Russian Federation, Minobrnauka: FEUZ-2020-0057Funding: This paper comprises two parts of research studies, including (i) the model generalization and discussion of governing equations, analytical solutions, analysis of the results obtained, and (ii) checking the mathematics, numerical calculations, visualization, and discussion of the functions obtained. Two parts of this review article were supported by two financial sources. The first part was supported by the Russian Foundation for Basic Research (grant no. 20-08-00199). At the same time, the authors are grateful to the Ministry of Science and Higher Education of the Russian Federation (grant no. FEUZ-2020-0057) for the support of the second part of the research studies