EPR analysis of the local structure of Ni<Superscript>3+</Superscript> ions in Ni-based electrode materials obtained under high-pressure

X-band and high-frequency EPR spectroscopy was applied to monitor the short-range cation ordering in Ga, Al and Li substituted LiNiO₂ with a layered crystal structure. The mixed oxides were obtained by a high-pressure synthesis in an oxygen rich atmosphere. Analysis of the EPR line-width from the X-band experiments together with the values of the g-tensor from the high-frequency EPR experiments permits assesing the local structure of the mixed metal layers. The results obtained show that LiGa _y Ni_1−y O₂, LiAl _y Ni_1−y O₂ and Li_{1 + x} Ni_1−x O₂ are homogeneous solid solutions, whereas the Li_{1 + x} Ni_1−x−y Al _y O₂ compositions have rather a complex domain structure of the type (1−a)LiAl _y Ni_1−y O₂.aLi[Li_1/3Ni_2/3]O₂.     

Optimal visual perception and detection of oral cavity neoplasia

The most common way to detect disease is by visual inspection of the suspect tissue. However, the human eye is not optimized for this task because the perceived spectrum of light is divided into three channels, all of which have overlapping spectral sensitivity curves. Here, we present new methods to optimize visually perceived contrast based on spectral differences between normal and abnormal tissue. We apply these methods to the perception of fluorescence emission from the oral cavity. Abnormalities in the oral cavity are optimally perceived when the excitation is between nm. To optimally visualize fluorescence at 340-nm excitation, the emission should be observed through a blue bandpass filter transmitting light at 430 nm.     

Trypsin Induced Degradation of Amyloid Fibrils

Proteolytic enzymes are known to be involved in the formation and degradation of various monomeric proteins, but the effect of proteases on the ordered protein aggregates, amyloid fibrils, which are considered to be extremely stable, remains poorly understood. In this work we study resistance to proteolytic degradation of lysozyme amyloid fibrils with two different types of morphology and beta-2-microglobulun amyloids. We showed that the proteolytic enzyme of the pancreas, trypsin, induced degradation of amyloid fibrils, and the mechanism of this process was qualitatively the same for all investigated amyloids. At the same time, we found a dependence of efficiency and rate of fibril degradation on the structure of the amyloid-forming protein as well as on the morphology and clustering of amyloid fibrils. It was assumed that the discovered relationship between fibrils structure and the efficiency of their degradation by trypsin can become the basis of a new express method for the analysis of amyloids polymorphism. Unexpectedly lower resistance of both types of lysozyme amyloids to trypsin exposure compared to the native monomeric protein (which is not susceptible to hydrolysis) was attributed to the higher availability of cleavage sites in studied fibrils. Another intriguing result of the work is that the cytotoxicity of amyloids treated with trypsin was not only failing to decline, but even increasing in the case of beta-2-microglobulin fibrils.     

An algorithm for constructing Darboux transformations of type I for third-order hyperbolic operators of two variables

Darboux transformations of type I are invertible Darboux transformations with explicit short formulas for inverse transformations. These transformations are invariant with respect to gauge transformations, and, for gauge transformations acting on third-order hyperbolic operators of two variables, a general-form system of generating differential invariants is known. In the paper, first-order Darboux transformations of type I for this class of operators are considered. The corresponding operator orbits are directed graphs with at most three edges originating from each vertex. In the paper, an algorithm for constructing such orbits is suggested. We have derived criteria for existence of first-order Darboux transformations of type I in terms of the generating invariants, formulas for transforming invariants, and the so-called “triangle rule” property of orbits. The corresponding implementation in the LPDO package is described. The orbits are constructed in two different forms, one of which outputs the graph in the format of the well-known built-in Maple package Graph Theory.     

A verified realization of a Dempster–Shafer based fault tree analysis

Fault tree analysis is a method to determine the likelihood of a system attaining an undesirable state based on the information about its lower level parts. However, conventional approaches cannot process imprecise or incomplete data. There are a number of ways to solve this problem. In this paper, we will consider the one that is based on the Dempster–Shafer theory. The major advantage of the techniques proposed here is the use of verified methods (in particular, interval analysis) to handle Dempster–Shafer structures in an efficient and consistent way. First, we concentrate on DSI (Dempster–Shafer with intervals), a recently developed tool. It is written in MATLAB and serves as a basis for a new add-on for Dempster–Shafer based fault tree analysis. This new add-on will be described in detail in the second part of our paper. Here, we propagate experts’ statements with uncertainties through fault trees, using mixing based on arithmetic averaging. Furthermore, we introduce an implementation of the interval scale based algorithm for estimating system reliability, extended by new input distributions.     

High-sensitivity Q-band electron spin resonance imaging system with submicron resolution

A pulsed electron spin resonance (ESR) microimaging system operating at the Q-band frequency range is presented. The system includes a pulsed ESR spectrometer, gradient drivers, and a unique high-sensitivity imaging probe. The pulsed gradient drivers are capable of producing peak currents ranging from ～9 A for short 150 ns pulses up to more than 94 A for long 1400 ns gradient pulses. Under optimal conditions, the imaging probe provides spin sensitivity of ～1.6 × 10(8) spins∕√Hz or ～2.7 × 10(6) spins for 1 h of acquisition. This combination of high gradients and high spin sensitivity enables the acquisition of ESR images with a resolution down to ～440 nm for a high spin concentration solid sample (～10(8) spins∕μm(3)) and ～6.7 μm for a low spin concentration liquid sample (～6 × 10(5) spins/μm(3)). Potential applications of this system range from the imaging of point defects in crystals and semiconductors to measurements of oxygen concentration in biological samples.     

Note: High sensitivity pulsed electron spin resonance spectroscopy with induction detection

Commercial electron spin resonance spectroscopy and imaging systems make use of the so-called "induction" or "Faraday" detection, which is based on a radio frequency coil or a microwave resonator. The sensitivity of induction detection does not exceed ~3 × 10(8) spins/√Hz. Here we show that through the use of a new type of surface loop-gap microresonators (inner size of 20 μm), operating at cryogenic temperatures at a field of 0.5 T, one can improve upon this sensitivity barrier by more than 2 orders of magnitude and reach spin sensitivities of ~1.5 × 10(6) spins/√Hz or ~2.5 × 10(4) spins for 1 h.     

Influence of Tetraalkylammonium Compounds on Photocatalytic and Physical Properties of TiO<Subscript>2</Subscript>

A wide range of experimental data are reported for the first time on the TiO₂ prepared by hydrolysis of highly concentrated Ti(OⁱPr)₄ in water solutions of quaternary ammonium compounds (QACs). These TiO₂ materials have been shown to be photocatalytically active under visible light irradiation (LED, 450 nm) using acetone as a model substrate oxidized in the gas phase. Five-fold increase in activity in comparison with the commercial photocatalyst KRONOClean 7000 is achieved. Colloidal solutions of hydrolyzed Ti(OⁱPr)₄ have been studied by SAXS method suggesting the way in which QACs solutions may influence the final composition of TiO₂. Phase composition, morphology, texture and surface properties of the modified TiO₂ have been studied using XRD, BET, SEM and low-temperature FTIR with CO probe. The surface elemental composition has been investigated by XPS method. Additional low-energy levels and high concentration of acid surface sites originated from N/C-doping, are likely to be the main reasons for exceptional photocatalytic performance of these samples.

Graphical Abstract

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The Presence Of Strange Males’ Odor Induces Behavioral Responses And Elevated Levels Of Low Molecular Weight Proteins Excreted In The Urine Of Mature Water Vole Males (<Emphasis Type="Italic">Arvicola amphibius</Emphasis> L)

We hypothesized that low molecular weight urinary proteins play a role in male-male chemical communication in the water vole, Arvicola ampibius L. We studied the effect of placing soiled litter from strange males into the cage of another sexually mature male on the intensity of its digging and scattering, urination on the litter, and alteration in the levels of low molecular weight proteins (15–25 kDa) excreted in the urine before and after 4 days of exposure as determined by chip electrophoresis. The intensity of digging and scattering was positively correlated with levels of testosterone in serum of males exposed to strange male odors (r = 0.56; P < 0.01), as well as with the concentration of low molecular weight proteins in the donor’s urine (r = 0.52, P < 0.05). At the end of the experiment, the level of low molecular weight protein in excreted urine was elevated in the males exposed to the strange male’s litter. These results highlight the importance of quantitative inter-individual variation of low molecular weight urinary proteins in the modulation of the physiology and behavior of conspecifics.     

Intronic Polymorphisms in the CDKN2B-AS1 Gene Are Strongly Associated with the Risk of Myocardial Infarction and Coronary Artery Disease in the Saudi Population

Recent genome-wide association studies identified single nucleotide polymorphisms (SNPs) on the chromosome 9p21.3 conferring the risk for CAD (coronary artery disease) in individuals of Caucasian ancestry. We performed a genetic association study to investigate the effect of 12 candidate SNPs within 9p21.3 locus on the risk of CAD in the Saudi population of the Eastern Province of Saudi Arabia. A total of 250 Saudi CAD patients who had experienced an myocardial infarction (MI) and 252 Saudi age-matched healthy controls were genotyped using TaqMan assay. Controls with evidenced lack of CAD provided 90% of statistical power at the type I error rate of 0.05. Five percent of the results were rechecked for quality control using Sanger sequencing, the results of which concurred with the TaqMan genotyping results. Association analysis of 12 SNPs indicated a significant difference in the genotype distribution for four SNPs between cases and controls (rs564398 p = 0.0315, χ² = 4.6, odds ratio (OD) = 1.5; rs4977574 p = 0.0336, χ² = 4.5, OD = 1.4; rs2891168 p = 1.85 × 10 − 10, χ² = 40.6, OD = 2.1 and rs1333042 p = 5.14 × 10 − 9, χ² = 34.1, OD = 2.2). The study identified three protective haplotypes (TAAG p = 1.00 × 10 − 4; AGTA p = 0.022 and GGGCC p = 0.0175) and a risk haplotype (TGGA p = 2.86 × 10 − 10) for the development of CAD. This study is in line with others that indicated that the SNPs located in the intronic region of the CDKN2B-AS1 gene are associated with CAD.