Compact high-temperature cell for Brillouin scattering measurements

A compact ceramic high-temperature cell for Brillouin spectroscopy was designed and tested. The cell can be mounted onto a three- or four-circle goniometer and allows collection of the full set of elastic constants of minerals to temperatures in excess of 1500 K from samples with dimensions of 100×100×20 µm or smaller. As a test of the instrument the single-crystal elastic constants of MgO were measured to 1510(10) K, and are found to be in excellent agreement with earlier independent results. The high-temperature cell should be useful for other types of spectroscopic measurements, and is especially useful in situations where spectral properties vary with the scattering geometry

Single-Crystal Elastic Constants of Yttria (Y2O3) Measured to High Temperatures

Yttria, or yttrium sesquioxide (Y2O3), has been considered for use in nuclear applications and has gained interest relatively recently for use in infrared optics. Single crystals of yttria have been grown successfully at the NASA Glenn Research Center using a laser-heated float zone technique in a fiber and rod. Such samples allow measurement of the single-crystal elastic properties, and these measurements provide useful property data for the design of components using single crystals. They also yield information as to what degree the elastic properties of yttria ceramics are a result of the intrinsic properties of the yttria crystal in comparison to characteristics that may depend on processing, such as microstructure and intergranular phases, which are common in sintered yttria. The single-crystal elastic moduli are valuable for designing such optical components. In particular, the temperature derivatives of elastic moduli allow the dimensional changes due to heating under physical constraints, as well as acoustic excitation, to be determined. The single-crystal elastic moduli of yttria were measured by Brillouin spectroscopy up to 1200 C. The room-temperature values obtained were C(sub 11) = 223.6 + 0.6 GPa, C(sub 44) = 74.6 + 0.5 GPa, and C(sub 12) = 112.4 + 1.0 GPa. The resulting bulk and (Voigt-Reuss-Hill) shear moduli were K = 149.5 + 1.0 GPa and G(sub VRH) = 66.3 + 0.8 GPa, respectively. Linear least-squares regressions to the variation of bulk and shear moduli with temperature resulted in derivatives of dK/dT = -17 + 2 MPa/C and dG(sub VRH)/dT = -8 + 2 MPa/ C. Elastic anisotropy was found to remain essentially constant over the temperature range studied

Features of heart remodeling in patients with chronic obstructive pulmonary disease in combination with chronic heart failure

Goal. Clinical, structural and functional features of right and left heart remodeling in patients with chronic obstructive pulmonary disease (COPD) were studied. Materials and methods. We examined 32 patients with COPD without exacerbation. Patients were divided into 2 groups: 1 - patients with COPD in combination with chronic heart failure (CHF); 2 - patients with COPD without CHF. 19 patients showed signs of CHF. Echocardiography (EchoCG) with additional parameters, spirometry, radiography, pulse oximetry was performed. The study also assessed level of highly sensitive C-reactive protein, acid-base blood composition, brain natriuretic peptide (NTproBNP). Results. In patients with combined pathology, there was a decrease in exercise tolerance, a greater body mass index and intensity of dyspnea. The left ventricular ejection fraction over 50% observed in the majority of patients (30) in both groups, therefore the signs of heart failure are explained precisely by diastolic dysfunction of the right and left ventricles. The conclusion. The use of tissue Doppler studies allows more accurate determination of the diastolic function of the right and left ventricles. Remodeling of the right and left ventricles are interdependent processes. The study of NTproBNP and additional EchoCG parameters - allow to reveal diastolic dysfunction of both ventricles of the heart at early stages.Цель. Исследовать клинические, структурно-функциональные особенности ремоделирования правых и левых отделов сердца у больных хронической обструктивной болезнью легких (ХОБЛ) в сочетании с хронической сердечной недостаточностью (ХСН). Материалы и методы. Обследовано 32 больных ХОБЛ вне обострения. Пациенты были распределены на 2 группы: 1 - пациенты с ХОБЛ в сочетании с ХСН (19); 2 - пациенты с ХОБЛ без ХСН (13). Проводили эхокардиографию, спирометрию, рентгенографию, пульсоксиметрию. Оценивали уровень высокочувствительного С-реактивного белка, кислотно-щелочного состава крови, мозгового натрийуретического пептида (NTproBNP). Результаты. У больных с сочетанной патологией отмечались снижение толерантности к физической нагрузке, больший индекс массы тела и интенсивность одышки. Сохраненная фракция выброса левого желудочка более 50% была отмечена у большинства больных (30) в обеих группах, поэтому признаки сердечной недостаточности объясняется именно диастолической дисфункцией правого и левого желудочков. Заключение. Использование тканевого допплеровского исследования позволяет более точно определить диастолическую функцию правого и левого желудочков. Ремоделирование правого и левого желудочков являются взаимозависимыми процессами. Исследование NTproBNP и дополнительных ЭхоКГ-параметров позволяют выявить диастолическую дисфункцию правого и левого желудочков сердца на ранних стадиях

The Transcription Factor YY1 Is a Substrate for Polo-Like Kinase 1 at the G2/M Transition of the Cell Cycle

Yin-Yang 1 (YY1) is an essential multifunctional zinc-finger protein. It has been shown over the past two decades to be a critical regulator of a vast array of biological processes, including development, cell proliferation and differentiation, DNA repair, and apoptosis. YY1 exerts its functions primarily as a transcription factor that can activate or repress gene expression, dependent on its spatial and temporal context. YY1 regulates a large number of genes involved in cell cycle transitions, many of which are oncogenes and tumor-suppressor genes. YY1 itself has been classified as an oncogene and was found to be upregulated in many cancer types. Unfortunately, our knowledge of what regulates YY1 is very minimal. Although YY1 has been shown to be a phosphoprotein, no kinase has ever been identified for the phosphorylation of YY1. Polo-like kinase 1 (Plk1) has emerged in the past few years as a major cell cycle regulator, particularly for cell division. Plk1 has been shown to play important roles in the G/M transition into mitosis and for the proper execution of cytokinesis, processes that YY1 has been shown to regulate also. Here, we present evidence that Plk1 directly phosphorylates YY1 in vitro and in vivo at threonine 39 in the activation domain. We show that this phosphorylation is cell cycle regulated and peaks at G2/M. This is the first report identifying a kinase for which YY1 is a substrate

A Note On Topological D-Posets Of Fuzzy Sets

. Kopka and Chovanec in [KCH] defined the difference poset (D-poset) as a partially ordered set with a partial difference operation. We show in this paper that every difference operation on a dense subset of h0; 1i is continuous with respect to the usual topology of the real line. We prove also some consequences for the continuity of the difference operation on D-posets of fuzzy sets. Difference posets were defined by Kopka and Chovanec in [KCH] and they are investigated in many recent papers (see for example [DR], [NP], [P] and [RB]). Definition 1. Difference poset (briefly D-poset) is a couple (D; \Psi), where D is a partially ordered set with the largest element 1 and the difference \Psi is the partial operation, which defines for every a; b 2 D, a b, an element b \Psi a in such a way that the following conditions are satisfied: i) b \Psi a b ii) b \Psi (b \Psi a) = a iii) if a b c, then c \Psi b c \Psi a and (c \Psi a) \Psi (c \Psi b) = b \Psi a. Special cases of D-posets..

Unusual Synthesis of Triosmium Carbene Clusters by Tandem Activation of Chlorohydrocarbons and Heterocyclic Amines

Reactions of the [Os3H2(CO)(10)] cluster complex (1) with six-membered heterocyclic amines (morpholine, thiomorpholine, piperidine) and halohydrocarbons (CH2Cl2, ClHC=CHCl, CH2=CCl2) at similar to 25 degrees C have been studied. Two main types of products are formed in all studied reactions. One product is carbene cluster [Os-3(mu-H)(mu-Cl){eta(1)-C(CH3)N(CH2CH2)(2)X}(CO)(9)] (X=O, S, CH2) (3, 3 a and 3 b). Second product is cluster containing enamine ligand [Os-3(mu-H){mu-CH=CHN(C2CH2)(2)X)}(2)(CO)(10)] (X=O, S, CH2) (2, 2 a and 2 b). The carbene ligand is assembled on a cluster, from three organic molecules, thus representing the first example of carbene ligands formed in this way. Clusters with carbene ligand exist as two stable isomers (rotamers hindered towards the Os-C bond), as confirmed by NMR studies and conformational analysis. We have found that in reactions of cluster 1 with acyclic amines containing an oxygen atom in gamma-position (likely morpholine in CH2Cl2), only complexes with bridging enamine ligands are formed. Compounds 2 a, 2 b, 3 and 3 b are characterized by single-crystal X-ray diffraction