348 research outputs found
The study of the ferroelectric properties of lithium-titanium ferrite
Loop-shaped dependences of the electric polarization on the electric field strength (the dielectric hysteresis) are registered for the first time for polycrystalline Li-Ti ferrite. Temperature evolution of the hysteresis loop parameters is investigated for ferrite samples. A thermal Barkhausen effect is detected during heating and cooling of ferrite specimens prepolarized in an electric field. The results obtained can be interpreted from the viewpoint of the Maxwell-Wagner relaxation polarization or induced ferroelectric-like state in the electric ferrite subsystem
Detection of hydrolases of different subclasses in cell-free fractions of Vibrio cholerae O1 and O139 serogroups using radial enzymatic diffusion in agarose gel
Cholera remains an actual infection worldwide, which dictates the need for a comprehensive study of its pathogens and, in particular, their hydrolytic enzymes that interact with the cells of the macroorganism. We determined the presence of hydrolases from different subclasses in preparations of cell-free fractions obtained from 58 strains of Vibrio cholerae O1 and O139 serogroups of different epidemic significance and origins using radial enzyme diffusion in agarose gels with various substrates. The analysis revealed statistically significant differences in enzyme activity depending on the origin and epidemiological significance of the original strain. We found that preparations obtained from non-toxigenic strains had increased activity of proteases and chitinolytic enzymes, while those from toxigenic strains showed high activity of mucinases, lipolytic enzymes, and nucleases. These data can be applied in the microbiological diagnosis of cholera as an additional biochemical characterization of Vibrio cholerae strains, as well as contribute to the understanding of the role of enzymes in the pathogenesis and adaptation of cholera pathogens
Signatures of Molecular Unification and Progressive Oxidation Unfold in Dissolved Organic Matter of the Ob-Irtysh River System along Its Path to the Arctic Ocean
The Ob-Irtysh River system is the seventh-longest one in the world. Unlike the other Great Siberian rivers, it is only slightly impacted by the continuous permafrost in its low flow. Instead, it drains the Great Vasyugan mire, which is the world largest swamp, and receives huge load of the Irtysh waters which drain the populated lowlands of the East Siberian Plain. The central challenge of this paper is to understand the processes responsible for molecular transformations of natural organic matter (NOM) in the Ob-Irtysh river system along the South-North transect. For solving this task, the NOM was isolated from the water samples collected along the 3,000?km transect using solid-phase extraction. The NOM samples were further analyzed using high resolution mass spectrometry and optical spectroscopy. The obtained results have shown a distinct trend both in molecular composition and diversity of the NOM along the South-North transect: the largest diversity was observed in the Southern “swamp-wetland” stations. The samples were dominated with humic and lignin-like components, and enriched with aminosugars. After the Irtysh confluence, the molecular nature of NOM has changed drastically: it became much more oxidized and enriched with heterocyclic N-containing compounds. These molecular features are very different from the aliphatics-rich permafrost NOM. They witnesses much more conservative nature of the NOM discharged into the Arctic by the Ob-Irtysh river system. In general, drastic reduction in molecular diversity was observed in the northern stations located in the lower Ob flow
Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial
Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials.
Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure.
Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.
Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049
Mass Spectrometric detection of SARS-CoV-2 virus in scrapings of the epithelium of the nasopharynx of infected patients via Nucleocapsid N protein
Detection of viral RNA by PCR is currently the main diagnostic tool for COVID-19 [1]. The PCR-based test, however, shows limited sensitivity, especially at early and late stages of the disease development [2,3], and is relatively time consuming. Fast and reliable complementary methods for detecting the viral infection would be of help in the current pandemia conditions. Mass-spectrometry is one of such possibilities. We have developed a mass-spectrometry based method for the detection of the SARS CoV-2 virus in nasopharynx epithelial swabs, based on the detection of the viral nucleocapsid N protein. The N protein of the SARS-COV-2 virus, the most abundant protein in the virion, is the best candidate for mass-spectrometric detection of the infection, and MS-based detection of several peptides from the SARS-COoV-2 nucleoprotein has been reported earlier by the Sinz group [4]. Our approach shows confident identification of the N protein in patient samples even with the lowest viral loads and a much simpler preparation procedure. Our main protocol consists of virus inactivation by heating and adding of isopropanol, and tryptic digestion of the proteins sedimented from the swabs followed by MS analysis. A set of unique peptides, produced as a result of proteolysis of the nucleocapsid phosphoprotein of SARS-CoV-2, is detected. The obtained results can further be used to create fast parallel mass-spectrometric approaches for the detection of the virus in the nasopharyngeal mucosa, saliva, sputum and other physiological fluids
The Coup d’etat in Kiev in February 2014: International Law Context and Consequences
The article is devoted to the coup d’etat in Kiev in February 2014. The fact is totally ignored in relevant documents of the US President and in the EU documents. The consequences of the coup d’etat in Kiev was its recognition as legitimate by one part of the population in Kiev and in the western and central regions of the former Ukraine and non-recognition by another part of the population - in south-east regions, Donbas and Lugansk. The military attempts of Kiev to subdue Donbas and Lugansk population to new authorities of Kiev is qualified as illegal. Peaceful legal arrangements between new authorities of Kiev and Donetsk and Lugansk Peoples Republics are suggested
Analysis of <sup>16</sup>O/<sup>18</sup>O and H/D Exchange Reactions between Carbohydrates and Heavy Water Using High-Resolution Mass Spectrometry
Mono- and polysaccharides are an essential part of every biological system. Identifying underivatized carbohydrates using mass spectrometry is still a challenge because carbohydrates have a low capacity for ionization. Normally, the intensities of protonated carbohydrates are relatively low, and in order to increase the corresponding peak height, researchers add Na+, K+, or NH4+to the solution. However, the fragmentation spectra of the corresponding ions are very poor. Based on this, reliably identifying carbohydrates in complex natural and biological objects can benefit frommeasuring additional molecular descriptors, especially those directly connected to the molecular structure. Previously, we reported that the application of the isotope exchange approach (H/D and 16O/18O) to high-resolution mass spectrometry can increase the reliability of identifying drug-like compounds. Carbohydrates possess many –OH and –COOH groups, making it reasonable to expect that the isotope exchange approach would have considerable potential for detecting carbohydrates. Here, we used a collection of standard carbohydrates to investigate the isotope exchange reaction (H/D and 16O/18O) in carbohydrates and estimate its analytical applications
- …