It is proposed that light-blue pigment be synthesized by co-precipitation of nickel and aluminum from nitrate solutions by the anionite AB-17-8 in OH form followed by calcination of a precursor at ...temperature 750°C. The product obtained is investigated by means of thermographic and x-ray diffraction analyses as well as spectrophotometry (IR and diffuse reflection). Electron microscopy shows the pigment particles to be 0.3 μm in size.
The molecular structure of 4-methylpiridine-N-oxide, 4-MePyO, has been studied by gas-phase electron diffraction monitored by mass spectrometry (GED/MS) and quantum chemical (DFT) calculations. Both, ...quantum chemistry and GED analyses resulted in CS molecular symmetry with the planar pyridine ring. Obtained molecular parameters confirm the hyperconjugation in the pyridine ring and the sp2 hybridization concept of the nitrogen and carbon atoms in the ring. The experimental geometric parameters are in a good agreement with the parameters for non-substituted N-oxide and reproduced very closely by DFT calculations. The presence of the electron-donating CH3 substituent in 4-MePyO leads to a decrease of the ipso-angle and to an increase of r(N→O) in comparison with the non-substituted PyO. Electron density distribution analysis has been performed in terms of natural bond orbitals (NBO) scheme. The nature of the semipolar N→O bond is discussed.
Display omitted
•The molecular structure of 4-methylpiridine-N-oxide has been studied by GED and quantum chemical calculations.•Electron density distribution analysis has been performed in terms of natural bond orbitals (NBO) scheme.•The molecule possesses CS symmetry with the planar pyridine ring.•Obtained molecular parameters confirm the hyperconjugation in the pyridine ring.•The presence of the electron-donating CH3 substituent in 4-MePyO results in an increase of r(N→O).
Objective To investigate the association of polymorphisms in the folate-metabolizing genes with idiopathic male infertility in a Russian population and to perform a meta-analysis. Design A ...case-control study. Setting Research laboratory. Patient(s) 275 men with idiopathic male infertility and a population sample of 349 men. Intervention(s) Determining the genotypes of polymorphisms MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G, SHMT1 C1420T, MTHFD1 G1958A, and CBS 844ins68. Main Outcome Measure(s) Semen analyses performed according to the World Health Organization guidelines (WHO, 1999) and Kruger strict morphology test. Result(s) None of the polymorphisms were significantly associated with idiopathic male infertility after the implementation of Bonferroni correction for multiple testing, although the MTHFD1 G1958A and MTR A2756G polymorphisms showed an association before the Bonferroni correction. Meta-analysis revealed an association by use of fixed-effects model of MTHFR C677T with the risk of azoospermia. Conclusion(s) These findings suggest that polymorphisms in folate-metabolizing genes could be involved in the etiology of male infertility. Additional studies performed on larger groups are necessary to investigate the possible associations.
Currently, the routine assessment of rheumatoid arthritis (RA) disease activity includes the determination of joint syndrome indicators, such as tender and swollen joint counts, as well as a number ...of laboratory indicators. The most interesting are the latter, which include rheumatoid factor, cyclic citrullinated peptide antibodies, and some acute-phase indicators. However, these tests have low sensitivity and specificity, especially at early stages of the disease, when it is still possible to bring the indicators to their age-specific normal values and to achieve a stable disease remission. In addition, some of these medical tests are quite expensive and not covered by compulsory health insurance. Most importantly, there are still no reliable tools to assess the development of RA-associated inflammatory processes in joints depending on the degree of RA severity and the treatment strategy being applied. Here, we analyze the possibility of using the 14-3-3η protein as a promising biomarker for assessing RA immunoinflammatory process activity in joints. We demonstrate a higher informative value of this marker in terms of its accuracy, sensitivity and specificity as compared to conventional acute-phase indicators, such as the erythrocyte sedimentation rate and C-reactive protein level.
Venom of the yellow sac spider Cheiracanthium punctorium (Miturgidae) was found unique in terms of molecular composition. Its principal toxic component CpTx 1 (15.1 kDa) was purified, and its full ...amino acid sequence (134 residues) was established by protein chemistry and mass spectrometry techniques. CpTx 1 represents a novel class of spider toxin with modular architecture. It consists of two different yet homologous domains (modules) each containing a putative inhibitor cystine knot motif, characteristic of the widespread single domain spider neurotoxins. Venom gland cDNA sequencing provided precursor protein (prepropeptide) structures of three CpTx 1 isoforms (a-c) that differ by single residue substitutions. The toxin possesses potent insecticidal (paralytic and lethal), cytotoxic, and membrane-damaging activities. In both fly and frog neuromuscular preparations, it causes stable and irreversible depolarization of muscle fibers leading to contracture. This effect appears to be receptor-independent and is inhibited by high concentrations of divalent cations. CpTx 1 lyses cell membranes, as visualized by confocal microscopy, and destabilizes artificial membranes in a manner reminiscent of other membrane-active peptides by causing numerous defects of variable conductance and leading to bilayer rupture. The newly discovered class of modular polypeptides enhances our knowledge of the toxin universe.
The aim of the work is to create a landscape-typological map of the territory to study the territorial differentiation of recreational activities. The variety of landscapes of the Baikal region is ...determined by a large number of landscape-forming factors, as well as the heterogeneity of the conditions in which geocomplexes are formed. A landscape-typological map of the territory was created on a scale of 1: 500 000. As an input data for creating the map, electronic topographic maps of the territory, space images of Landsat 5, 7, 8 for different seasons and years (including mosaic of MrSID for 2000 and Hansen mosaic for 2016), digital elevation models, landscape, geological, soil and geobotanical maps of different scale were used. A total of 56 landscape units were identified: 13 highland (goltzy, sub-mountain, reduced development mountain-taiga), 6 medium-mountain (limited development taiga), 14 lowland (optimal development mountain-taiga, steppe), 13 foothill (limited development taiga, optimal development taiga, subtaiga, steppe), 10 - intermontane depressions and valleys (limited development taiga, optimal development taiga, steppe). The conclusions drawn about the landscape structure and recreational properties of the territory are generalized. More detailed landscape research is needed, including comprehensive field work to clarify the landscape map and assess the recreational significance of landscapes.
We present the results from combining machine learning with the profile likelihood fit procedure, using data from the Large Underground Xenon (LUX) dark matter experiment. This approach demonstrates ...reduction in computation time by a factor of 30 when compared with the previous approach, without loss of performance on real data. We establish its flexibility to capture non-linear correlations between variables (such as smearing in light and charge signals due to position variation) by achieving equal performance using pulse areas with and without position-corrections applied. Its efficiency and scalability furthermore enables searching for dark matter using additional variables without significant computational burden. We demonstrate this by including a light signal pulse shape variable alongside more traditional inputs such as light and charge signal strengths. This technique can be exploited by future dark matter experiments to make use of additional information, reduce computational resources needed for signal searches and simulations, and make inclusion of physical nuisance parameters in fits tractable.
Dual-phase xenon time projection chamber (TPC) detectors have demonstrated superior search sensitivities to dark matter over a wide range of particle masses. To extend their sensitivity to include ...low-mass dark matter interactions, it is critical to characterize both the light and charge responses of liquid xenon to sub-keV nuclear recoils. In this work, we report a new nuclear recoil calibration in the LUX detector \(\textit{in situ}\) using neutron events from a pulsed Adelphi Deuterium-Deuterium neutron generator. We demonstrate direct measurements of light and charge yields down to 0.45 keV (1.4 scintillation photons) and 0.27 keV (1.3 ionization electrons), respectively, approaching the physical limit of liquid xenon detectors. We discuss the implication of these new measurements on the physics reach of dual-phase xenon TPCs for nuclear-recoil-based low-mass dark matter detection.
An increase in the concentration of protons in the synaptic cleft during neurotransmitters release is considered as one of the possible ways for postsynaptic membrane sensitization. The main sensors ...of acidification are acid-sensing ion channels (ASICs). The ASIC3 localized on the membrane of a sensing neuron contributes greatly to the perception of pain and is considered as one of the promising targets for the development of novel therapeutic agents. Despite a high degree of homology between mammalian ASIC3 channels, there is a number of differences among their orthologs. The major difference between human and rat ASIC3 is that, at physiological pH 7.4, the human ASIC3 responds to a fast acidic stimulus with practically a solitary sustained transmembrane current, while its rat ortholog generates a transient current with far higher amplitude, which precedes the sustained current. In this study, we demonstrate that the C-terminal intracellular domain (CTD) has a regulatory function, and its modification significantly affects transient current generation in human and rat ASIC3. A shortening of the CTD by 20 amino acid residues leads to a dramatic increase in the transient current and attenuation of the sustained current, while CTD modification in hASIC3 leads to the generation of a well-defined transient current like rASIC3, as demonstrated in whole-cell experiments on heterologically expressed channels. Furthermore, the deletion of 20 amino acid residues in the CTD increases the current amplitude by an order of magnitude both in rASIC3 and hASIC3. The obtained results demonstrate a prominent role of CTD in the intracellular regulation of ASIC3 channels.
PDF
