53 research outputs found
ТЕХНОЛОГИИ ВТОРИЧНЫХ ТУГОПЛАВКИХ РЕДКИХ МЕТАЛЛОВ (Обзор)
A brief review of A.V. Yelutin’s and his coworkers’ works in the field of rare metals is given. Zirconium, hafnium, tungsten, tantalum and niobium extraction processes from various types of recycled materials: scrap metal, scrap refractory materials, waste and scrap of hard metal, dormant scrap of capacitors are considered. The opportunities of improving the purity of these metals by electrolytic refining and electron-beam melting are shown.Приведен краткий обзор работ А.В. Елютина с его сотрудниками в области редких металлов. Рассмотрены технологии извлечения циркония, гафния, вольфрама, тантала и ниобия из различных видов вторичного сырья: металлических отходов, лома огнеупоров, отходов и лома твердых сплавов, амортизационного лома конденсаторов. Показаны возможности повышения чистоты этих металлов методами электролитического рафинирования и электронно-лучевой плавки
HEMITSELLYULOZA AND THEIR NANOBIOCOMPOSITES - PERSPECTIVE NANOSTRUCTURED SINBIOTICS
Natural nanocomposites hemicellulose arabinogalactan and flavonoids isolated (from Siberian larch) and characterized. Additionally nitro- and sulfo-esters of arabinogalactan and its calcium salt are synthesized and. characterized. All of the derivatives of the beta-hemicellulose arabinogalactan. are water-soluble and are promising prebiotics on the example test-strain Bifidobacterium bifidum. (except for the nitrate esters of arabinogalactan)
Species substrate specificity of growth of lactobacilli isolated from vaginal biotope on culture medium with inclusions of different types of natural nanopolysaccharides
The article presents the research of substrate and prebiotic properties of natural nanopolysaccharides for several species of lactobacilli isolated from vaginal biotope of women, with assessment of their species combinations. Most of typeable lactobacilli species prefer to grow on media containing polysaccharides, mainly in nutrient broth supplemented with galactomannan and carageenan. Using galactomannan increases the frequency of detection, as compared with the isolation from the starting material, twice
Excess maternal salt intake produces sex-specific hypertension in offspring: putative roles for kidney and gastrointestinal sodium handling.
Hypertension is common and contributes, via cardiovascular disease, towards a large proportion of adult deaths in the Western World. High salt intake leads to high blood pressure, even when occurring prior to birth - a mechanism purported to reside in altered kidney development and later function. Using a combination of in vitro and in vivo approaches we tested whether increased maternal salt intake influences fetal kidney development to render the adult individual more susceptible to salt retention and hypertension. We found that salt-loaded pregnant rat dams were hypernatraemic at day 20 gestation (147±5 vs. 128±5 mmoles/L). Increased extracellular salt impeded murine kidney development in vitro, but had little effect in vivo. Kidneys of the adult offspring had few structural or functional abnormalities, but male and female offspring were hypernatraemic (166±4 vs. 149±2 mmoles/L), with a marked increase in plasma corticosterone (e.g. male offspring; 11.9 [9.3-14.8] vs. 2.8 [2.0-8.3] nmol/L median [IQR]). Furthermore, adult male, but not female, offspring had higher mean arterial blood pressure (effect size, +16 [9-21] mm Hg; mean [95% C.I.]. With no clear indication that the kidneys of salt-exposed offspring retained more sodium per se, we conducted a preliminary investigation of their gastrointestinal electrolyte handling and found increased expression of proximal colon solute carrier family 9 (sodium/hydrogen exchanger), member 3 (SLC9A3) together with altered faecal characteristics and electrolyte handling, relative to control offspring. On the basis of these data we suggest that excess salt exposure, via maternal diet, at a vulnerable period of brain and gut development in the rat neonate lays the foundation for sustained increases in blood pressure later in life. Hence, our evidence further supports the argument that excess dietary salt should be avoided per se, particularly in the range of foods consumed by physiologically immature young
Effect of nucleation centers on the formation of nanostructure during decomposition of metal-organic compounds
Normal-range urinary albumin excretion associates with blood pressure and renal electrolyte handling in pregnancy
BACKGROUND: Albuminuria in the pathological range is a significant predictor of preeclampsia. In healthy persons, high-normal urine albumin predicts later incidence of hypertension and is associated with salt-sensitivity of blood pressure. We hypothesized that in pregnancy urine albumin in the normal range associates with blood pressure through activation of distal sodium reabsorption and renal salt retention by plasma factors co-filtered with albumin. METHODS: We analyzed 24-hour urine collections and plasma samples from gestational week 29 of 560 pregnant women from the Odense Child Cohort, a Danish population-based cohort. Plasma and urine aldosterone were measured by ELISA. Plasma and urine sodium, potassium, chloride and creatinine were also determined. Predictive values of urine albumin were assessed by linear mixed, multiple and Cox regression analyses. Primary outcomes were blood pressure and renal electrolyte handling. RESULTS: 24h urinary albumin excretion at gestational week 29 associated with gestational blood pressure trajectory, adjusted β coefficients (95% CI) for each 10-fold increase in urine albumin: 5.71 (1.60 to 9.81) mmHg for systolic and 4.39 (1.41 to 7.38) mmHg for diastolic blood pressure. Urine albumin was inversely associated with fractional excretion rates of sodium, potassium and chloride, adjusted β coefficients (95% CI) for each 10-fold increase in urine albumin: -0.25 (-0.35 to -0.14), -5.06 (-6.81 to -3.30) and -0.28 (-0.41 to -0.15), respectively. CONCLUSIONS: At gestational week 29, urinary albumin excretion in the normal range associated with blood pressure and renal electrolyte handling independent of potential confounders
Effect of combination antihypertensive therapy, including renin-angiotensin-aldosterone system inhibitors, on oxidative stress and arterial remodeling in hypertensive patients with heart failure with preserved ejection fraction
Aim. To study the effect of triple combination therapy on oxidative stress and arterial remodeling in hypertensive patients with heart failure with preserved ejection fraction (HFpEF).Material and methods. The study involved 76 people with diagnosed HFpEF. After a comprehensive examination, patients were randomized into two equal groups: first group — patients who received perindopril 10 mg, indapamide 2,5mg and amlodipine 5 mg; second — patients who received losartan 100 mg, indapamide 2,5 mg, amlodipine 5 mg. Before and 16 weeks after the therapy initiation, cardiac ultrasound, assessment of endothelial function with estimating endothelium-dependent vasodilation, assessment of vascular stiffness by photoplethysmography and compression oscillometry were carried out. The plasma concentration of oxidative stress marker 8-isoprostane was studied.Results. During the follow-up period, a significant improvement in endothelial function was noted: in the first group — from 8,1% to 11,4% (p=0,001), in the second — from 5,8% to 8,3% (p=0,0007). In both groups, there was an improvement in microvessel elasticity: a significant decrease in specific peripheral vascular resistance, as well as a significant decrease in total peripheral resistance in the first group (p<0,002) and a tendency to decrease in the second one (p>0,05). There was a significant increase in the stiffness of the aorta and muscular arteries in both groupsю In the first group, a stiffness index decreased from 10,38 m/s to 8,33 m/s (p<0,0001), in the second — from 10,6 m/s to 9,3 m/s (p<0,01). In addition, resistance index in the first group decreased from 71,5% to 60% (p<0,0001), while in the second — from 68% to 60% (p=0,006). Also, both groups showed a significant decrease in the left atrial diastolic dimension and the left atrial volume index. A decrease in the 8-isoprostane plasma levels was noted, which indicates a decrease in oxidative stress.Conclusion. Oxidative stress, which develops due to chronic systemic inflammation, plays a key role in the pathogenesis of HFpEF. The results obtained show an improved endothelial function as a result of decrease in oxidative stress, which is accompanied by an improvement in vessel wall elasticity, thereby slowing down the heart failure progression
Normobaric hypoxic conditioning in men with metabolic syndrome
The evidence that physical exercise lowers metabolic and cardiovascular risk is undisputed. Normobaric hypoxia training has been introduced to facilitate the effects of exercise. We tested the hypothesis that hypoxia training augments exercise-related effects. We randomized 23 men with metabolic-syndrome to single-blinded exercise at normoxia (FiO2 21%) or hypoxia (FiO2 15%). Six weeks endurance training on a treadmill, 3 days per week, over 60 min at 60% VO2 max was required. The study included the following: (1) metabolic phenotyping by indirect calorimetry and adipose and muscle tissue microdialysis to gain insight into effects on resting, postprandial, and exercise metabolism, (2) cardiac imaging, and (3) biopsies. Primary endpoint was the change in cardiorespiratory fitness; secondary endpoints were as follows: changes in body weight, waist circumference, blood pressure, cardiac dimensions, and adipose and muscle tissue metabolism and gene expression. Our subjects reduced waist circumference and improved several cardiovascular risk markers including blood pressure. However, these effects were similar in both training groups. Cardiac dimensions were not influenced. We focused on glucose metabolism. After an oral glucose load, adipose tissue metabolism was significantly shifted to a more lipolytic state under hypoxia, whereas muscle metabolism was similar under both conditions. Postprandial energy expenditure was significantly increased under hypoxia, whereas activity energy expenditure was improved under normoxia. Gene expression was not consistently influenced by FiO2 . Adipose tissue triglyceride lipase, leptin, and hypoxia-inducible factor-alpha expression were increased by normoxia but not hypoxia
Insights into Particle-Bound Metal(loid)s in Winter Snow Cover: Geochemical Monitoring of the Korkinsky Coal Mine Area, South Ural Region, Russia
Snow plays an important role in air quality and winter geochemical monitoring in the South Ural region. This study deals with the air pollution monitoring of particle-bound metal(loid) concentrations using snow cover around the deepest coal mine in Eurasia, the Korkinsky coal mine. We studied the concentrations and ratios of suspended and dissolved forms of metal(loid)s (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Sr, and Zn) in snow samples. We examined 56 snow cover samples, collected at 12 sites located north, south, east and west of the Korkinsky coal mine. All snow samples were taken in January 2020. The spectral reflectance curves, cluster analysis, and spatial distribution maps were used to evaluate the potential sources of PM-bound metal(loid)s and the potential relationship among them. The highest concentrations (μg/L) were reported for Fe, Al, and Zn. In addition to the mine influence, burning coal for residential heating was identified as the major anthropogenic metal(loid) source. It was shown that elevated concentrations of some trace metals in snow samples were associated with southerly winds and the location of spoil heaps
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