Origin of the ungrouped achondrite NWA 4518: mineralogy and geochemistry of FeNi-metal

Ungrouped achondrite NWA 4518 is an ultramafic breccia with abundant siderophile rich IIA-like metal. Its silicate chemistry is similar to that of WINs, HEDs, and silicate inclusions of IIE irons. Oxygen isotopic composition is nearby IAB-IIICD-WIN

Dislocation structure and deformation hardening alloy fcc single crystals at the mesolevel

The article presents the evaluation results of impacts of various strengthening mechanisms to flow stress. Such evaluations were made on the basis of the measured parameters of the dislocation substructure formed in monocrystals of [001]-Ni3Fe alloy deformed by compression within the stage II. It was found that the main impact to deformation resistance in the alloys with net substructure is made by the mechanism of dislocation impediment, which is caused by contact interaction between moving dislocations and forest dislocations

Dislocation structure and deformation hardening alloy fcc single crystals at the mesolevel

The article presents the evaluation results of impacts of various strengthening mechanisms to flow stress. Such evaluations were made on the basis of the measured parameters of the dislocation substructure formed in monocrystals of [001]-Ni3Fe alloy deformed by compression within the stage II. It was found that the main impact to deformation resistance in the alloys with net substructure is made by the mechanism of dislocation impediment, which is caused by contact interaction between moving dislocations and forest dislocations

Photoelectric Fields and Band Gap in Doped Lithium Niobate Crystals

Photorefractive effect was researched and band gap was determined in nominally pure congruent and stoichiometric lithium niobate crystals, and in a series of congruent LiNbO3 crystals doped by Mg, Zn, B, Gd, Y, Er cations, and LiNbO3 single crystals with double doping Mg:Gd, Mg:Fe, Mg:Y, Mg:Ta by photoinduced light scattering and optical spectroscopy methods. Keywords: lithium niobate single crystal, doping, photorefractive effect, photoinduced light scattering, optical spectroscopy, band ga

Gallstone ileus in a middle-aged male with an atypical history: a case report

Currently, gallstone ileus is an unusual complication of cholelithiasis (0.3–3.0 %) and a rare cause of mechanical bowel obstruction (0.1–4.0 %). The rarity of the condition makes it impossible to plan the large prospective randomized clinical trials, so the analysis of case reports is significant for decision making in the management of gallstone ileus. We report a case of gallstone ileus in a middle-aged male who had a history of surgery for duodenal ulcer perforation in past. A combination of peptic ulcer disease and cholelithiasis is based on a reduced gastrointestinal hormones secretion. Clinical specialists need to consider information about the greater frequency and asymptomatic clinical course of gallstone disease against a background of duodenal ulcer. Duodenal ulcer scar and bulbar deformity may promote to the cholecystoduodenal fistula formation. In the presence of an acute bowel obstruction symptoms and the absence of gallbladder instrumental examination results, it is possible to recommend the prior gastroduodenoscopy for the pre-operative pneumobilia detection. The optimal surgical approaches for acute gallstone ileus are still controversial

SEQUENTIAL EXTRACTION OF SUBSTANCES WITH KNOWN Au SPECIATION – AN EXPERIMENTAL DATA

A study has been conducted on the features of distriburion of Au among the fractions of a 7-step sequential extraction procedure using model substances that are similar in composition to natural organic matter from the dispersion train of sulfide tailings. Use has been made of model substances with known Au speciations: bulk native gold, nanoscale native gold, Au-containing pyrite, humic acids, and Fe(III) oxides/hydroxides, which served as the basis for preparing mixtures with low-Au filler substances (quartz, limestone, humic acids, Fe(III) oxides/hydroxides).It has been stated that several Au species are leached in one fraction during sequential extraction. Nanoscale Au0 and gold bound to the organic matter are leached together in easily oxidizable (organic) fraction; gold bound to Fe(III) compounds and Au complexes chemisorbed on the surface of other minerals (sulfides, aluminosilicates) are leached in reducible (hydroxides) fraction; "invisible" gold in sulfides, nanoscale Au0 and, partially, >1 μm-seized bulk Au0 are leached in hardly oxidizable (sulfidic) fraction. Bulk native gold is leached predominantly in residual fraction. Mobile species are Au bound to water-soluble organic compounds and complexes of ionic Au desorbed from the surface of minerals

Checkpoint inhibitors in non-small cell lung carcinoma therapy for progression to the brain (clinical observation)

The development of a new area of antitumor drug therapy, immunotherapy using immune checkpoint inhibitors targeting PD-1/PD-L1, has significantly changed approaches to the treatment of advanced non-small cell lung cancer (NSCLC). Many clinical trials have demonstrated the clinical benefit as well as the long-term effect of these drugs. Currently, the problem of treatment of patients after disease progression against the background of the use of checkpoint inhibitors is relevant. Equally relevant is the issue of choosing the correct and most effective treatment tactics for NSCLC patients with oligoprogression, as well as with abscopal effect. This paper describes a clinical case of a patient with lung adenocarcinoma without driver mutations with PD-L1-positive status, who was treated with nivolumab after second-line chemotherapy for disease progression, and after oligoprogression of the disease into the brain was given stereotactic radiotherapy of metastatic lesion and continued therapy with nivolumab. Partial regression of metastases was achieved with a prolonged effect on the background of continued treatment with nivolumab for 24 months. Tolerability of therapy was satisfactory: no adverse events were observed. The patient retained the result for 1.5 years

Antiviral Activity of Extracts from Basidiomycetes for Orthopoxviruses

Carried out was evaluation of the effect of water extracts from basidiomycetes in Vero cell culture on variola virus, and vaccinia virus. Antiviral effect demonstrated Inonotus obliquus (Chaga), befungin and melanin from chaga, Ganoderma applanatum (Artist’s Bracket) , Fomitopsis officinalis (Larch Fungus)

Comparative Analysis of the Pathogen Structure in Patients with Community-Acquired and Nosocomial Pneumonia in Medical Organizations of the Rostov, Tyumen Regions and Khabarovsk Territory at the Current Stage of a New Coronavirus Infection Pandemic

The aim of the study was to conduct a comparative analysis of the spectrum and antibiotic resistance of secondary pneumonia pathogens isolated in the territories of the Rostov, Tyumen Regions and Khabarovsk Territory against the background of a new coronavirus infection pandemic.Materials and methods. We investigated sputum samples from coronavirus-positive and coronavirus-negative patients with community-acquired pneumonia from medical organizations using bacteriological method, PCR mass spectrometry.Results and discussion. The study of the etiological structure of secondary pneumonia agents isolated from patients in medical organizations of the Southern, Ural and Far Eastern Federal Districts has revealed that the dominant cultures in SARS‑CoV‑2 “+” and SARS‑CoV‑2 “–” patients were yeast and yeast-like fungi. It has been found that under diversity of isolated fungi, Candida albicans species prevailed. The bacterial microflora is represented by a variety of gram-positive and gram-negative bacteria, of which Staphylococcus aureus and Klebsiella pneumoniaе were most often present in sputum. It has also been established that even before hospitalization of patients, community-acquired pneumonia could be caused by microorganisms of the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniaе, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.), which are usually considered as polyantibiotic-resistant pathogens of nosocomial infections. Moreover, in coronavirus-positive patients with secondary community-acquired pneumonia, those pathogens were isolated 2–3 times more frequently than in coronavirus-negative ones. Assessment of sensitivity/resistance of isolated strains to antibacterial drugs has revealed a general trend: the majority of the strains, regardless of the type, were characterized by a narrow spectrum of sensitivity, having 3 or more markers of antibiotic resistance. This confirms the necessity and expediency of microbiological support of the patient during the entire infectious process. The most adequate drugs of choice, providing activity against 60–70 % of strains of the Enterobacteriaceae family, are amikacin and cefoperazone/sulbactam

ЭКСПЕРИМЕНТАЛЬНЫЕ ДАННЫЕ ПО СТУПЕНЧАТОМУ ВЫЩЕЛАЧИВАНИЮ ВЕЩЕСТВ С ИЗВЕСТНЫМИ ФОРМАМИ НАХОЖДЕНИЯ Au

A study has been conducted on the features of distriburion of Au among the fractions of a 7-step sequential extraction procedure using model substances that are similar in composition to natural organic matter from the dispersion train of sulfide tailings. Use has been made of model substances with known Au speciations: bulk native gold, nanoscale native gold, Au-containing pyrite, humic acids, and Fe(III) oxides/hydroxides, which served as the basis for preparing mixtures with low-Au filler substances (quartz, limestone, humic acids, Fe(III) oxides/hydroxides).It has been stated that several Au species are leached in one fraction during sequential extraction. Nanoscale Au0 and gold bound to the organic matter are leached together in easily oxidizable (organic) fraction; gold bound to Fe(III) compounds and Au complexes chemisorbed on the surface of other minerals (sulfides, aluminosilicates) are leached in reducible (hydroxides) fraction; "invisible" gold in sulfides, nanoscale Au0 and, partially, >1 μm-seized bulk Au0 are leached in hardly oxidizable (sulfidic) fraction. Bulk native gold is leached predominantly in residual fraction. Mobile species are Au bound to water-soluble organic compounds and complexes of ionic Au desorbed from the surface of minerals.Изучены особенности распределения Au по фракциям 7-ступенчатой методики выщелачивания с применением модельных веществ, приближенных по составу к природным образцам из ореола рассеяния сульфидных хвостохранилищ. Применялись модельные вещества с известными формами нахождения Au: крупное самородное золото, наноразмерное самородное золото, Au-содержащие пирит, гуминовые кислоты и оксиды/гидроксиды Fe(III). На их основе были приготовлены смеси с веществами-наполнителями с низкими содержаниями Au (кварц, известняк, гуминовые кислоты, оксиды/гидроксиды Fe(III)).Установлено, что при ступенчатом выщелачивании наблюдается совместное извлечение нескольких форм золота в одной фракции. Наноразмерное Au0 и золото, связанное с органическим веществом, совместно извлекаются в легкоокисляемой (органической) фракции; золото, связанное с соединениями Fe(III), и комплексы Au, хемосорбированные на поверхности других минералов (сульфиды, алюмосиликаты), – в восстанавливаемой (гидроксидной) фракции; «невидимое» золото в сульфидах, наноразмерное и, частично, крупное (с размером частиц >1 мкм) Au0 – в трудноокисляемой (сульфидной) фракции. Крупное Au0 извлекается преимущественно в остаточной фракции. Мобильные формы элемента представляют собой Au, связанное с легкорастворимыми органическими соединениями, и комплексы ионного Au, десорбированные с поверхности минералов