Effect of natural surface-active substances on the rheological properties of emulsions

The effect of natural surface-active substances on the formation of emulsions in oils with different content of resin-asphaltene components (RAC) and paraffin hydrocarbons (PHC) (RAC/PHC from 0.7 to 95) is studied. The influence of oil composition and content of aqueous phase on microstructure, rheological properties, and activation energy of viscous flow of water-oil emulsions is shown. For oils with the ratio RAC/PHC < 1, the increase in water cut results in an increase in viscosity, activation energy of viscous flow, and pour point

The integrated effect on properties and composition of high-paraffin oil sludge

The study is devoted to the integrated effect of acoustic treatment and addition of an inhibitor on viscosity-temperature properties and n-alkane composition in high-paraffin oil sludge. Ultrasonic treatment for 1 minute and addition of the inhibitor at the concentration of 0.05% wt. decrease viscosity by 10 times and pour point by 8°С

Thyroid-stimulating hormone, leptin and insulin resistance in patients with obesity after bariatric surgery

BACKGROUND: The function of the thyroid gland effects on obesity and comorbidities. It has been proven for bariatric surgery to be the most effective in obesity treatment. AIM: to evaluate the dynamics of body weight, thyroid status, leptin and insulin resistance in obese patients after bariatric surgery. MATERIALS AND METHODS: 74 obese patients were observed after bariatric surgery (sleeve gastrectomy &ndash; 42, gastric bypass - 32); initial body mass index (BMI), thyroid stimulating hormone, free T4, fasting plasma leptin, insulin and glucose were estimated; the insulin resistance index HOMA-IR was calculated. The dynamics of body weight was estimated by BMI and the excess BMI loss (% EBMIL). After 3 years of follow-up, 48 patients were examined. RESULTS: Subclinical hypothyroidism (SH) was detected in 36.5% of patients with high degrees of obesity. A correlation was found between BMI and TSH level (R=0.5; p=0.01). HOMA-IR was increased in most patients with obesity of the II and III degree (4.8&plusmn;1.9 ng / ml). In the SH group, the leptin level was significantly higher than in the group with a normal TSH level of 43.0&plusmn;7.3 ng / ml and 33.2&plusmn;4.6 ng / ml (p=0.004). Among patients with initial SH, spontaneous reduction of TSH levels occurred in 45% patients 3 years after surgery. CONCLUSIONS: Postoperatively, the BMI decrease was associated with the decrease of TSH, leptin and HOMA-IR. The data obtained may reflect the effect of adipose tissue on the functional state of the thyroid gland in patients with high degrees of obesity after bariatric surgery. This seems to be extremely important for maintaining body weight

Five-year trends in epidemiology and prevention of mother-to-child HIV transmission, St. Petersburg, Russia: results from perinatal HIV surveillance

<p>Abstract</p> <p>Background</p> <p>The HIV epidemic in Russia has increasingly involved reproductive-aged women, which may increase perinatal HIV transmission.</p> <p>Methods</p> <p>Standard HIV case-reporting and enhanced perinatal HIV surveillance systems were used for prospective assessment of HIV-infected women giving birth in St. Petersburg, Russia, during 2004-2008. Trends in social, perinatal, and clinical factors influencing mother-to-child HIV transmission stratified by history of injection drug use, and rates of perinatal HIV transmission were assessed using two-sided χ²or Cochran-Armitage tests.</p> <p>Results</p> <p>Among HIV-infected women who gave birth, the proportion of women who self-reported ever using injection drugs (IDUs) decreased from 62% in 2004 to 41% in 2008 (<it>P </it>< 0.0001). Programmatic improvements led to increased uptake of the following clinical services from 2004 to 2008 (all <it>P </it>< 0.01): initiation of antiretroviral prophylaxis at ≤28 weeks gestation (IDUs 44%-54%, non-IDUs 45%-72%), monitoring of immunologic (IDUs 48%-64%, non-IDUs 58%-80%) and virologic status (IDUs 8%-58%, non-IDUs 10%-75%), dual/triple antiretroviral prophylaxis (IDUs 9%-44%, non-IDUs 14%-59%). After initial increase from 5.3% (95% confidence interval [CI] 3.5%-7.8%) in 2004 to 8.5% (CI 6.1%-11.7%) in 2005 (<it>P </it>< 0.05), perinatal HIV transmission decreased to 5.3% (CI 3.4%-8.3%) in 2006, and 3.2% (CI 1.7%-5.8%) in 2007 (<it>P </it>for trend <0.05). However, the proportion of women without prenatal care and without HIV testing before labor and delivery remained unchanged.</p> <p>Conclusions</p> <p>Reduced proportion of IDUs and improved clinical services among HIV-infected women giving birth were accompanied by decreased perinatal HIV transmission, which can be further reduced by increasing outreach and HIV testing of women before and during pregnancy.</p

Crystal structure and spin-trimer magnetism of Rb-2.3(H2O)(0.8)Mn-3[B4P6O24(O,OH)(2)]

The title borophosphate is characterized by a rare combination of the magnetic high-spin Mn2+ ions in both octahedral and tetrahedral coordinations. The crystal structure and magnetic properties are presented.</p

Structural and mechanical properties of highly paraffinic crude oil processed in high-frequency acoustic field

Methods of chromatography-mass spectrometry, IR spectroscopy, viscometry were used to study structural and mechanical properties of highly paraffinic crude oil processed in high-frequency acoustic field. It was shown that ultrasonic treatment leads to an increase in viscosity, yield stress, viscous flow activation energy and internal fracture energy of dispersion system with an increase in processing time. Proportion of n-alkanes С15Н32–С16Н34 and concentration of aromatic hydrocarbons increase in the composition of dispersed phase of processed crude oil according to chromatography-mass spectrometry

Structural and mechanical properties of highly paraffinic crude oil processed in high-frequency acoustic field

Methods of chromatography-mass spectrometry, IR spectroscopy, viscometry were used to study structural and mechanical properties of highly paraffinic crude oil processed in high-frequency acoustic field. It was shown that ultrasonic treatment leads to an increase in viscosity, yield stress, viscous flow activation energy and internal fracture energy of dispersion system with an increase in processing time. Proportion of n-alkanes С15Н32–С16Н34 and concentration of aromatic hydrocarbons increase in the composition of dispersed phase of processed crude oil according to chromatography-mass spectrometry

Short communication: Virulence of Puccinia triticina in the North Caucasus region of Russia

Aim of study: To analyze the structure of P. triticina populations by a virulence survey in the North Caucasus region of Russia from 2011 to 2015.Area of study: The North Caucasus region is a leading grain production region in Russia where wheat leaf rust causes losses in yield.Material and methods: Uredinial samples of leaf rust were collected in all agro-climatic zones of the North Caucasus on the production sites of winter wheat and on the plots of official state trials. Single uredinial isolates (a total of 564) were tested for virulence with 41 ˈThatcherˈ near isogenic lines with Lr resistance genes.Main results: Clones virulent to Lr9, Lr42, Lr47 and Lr50 were not found. Isolates virulent to the Lr19, Lr24, Lr29, Lr41, Lr43 + 24, Lr45, Lr52 genes were characterized by low frequencies. The 564 fungal isolates studied were represented by 564 virulence phenotypes, the majority of them with a virulence complexity from 9 to 19. A high level of intrapopulation fungus diversity in virulence was noticed during the whole period of research (Shannon diversity index from 2.994 to 3.314). The differences in the frequencies of virulences in the years of research were small (Rogers distance from 0.001 to 0.160).Research highlights: Due to the fact that the North Caucasus region is a zone of epiphytotic danger and high variability of the P. triticina population, the analysis of the genetics of the fungus population is important for the strategy of varietal distribution in the region and development of rust-resistant varieties

Effect of natural surface-active substances on the rheological properties of emulsions

The effect of natural surface-active substances on the formation of emulsions in oils with different content of resin-asphaltene components (RAC) and paraffin hydrocarbons (PHC) (RAC/PHC from 0.7 to 95) is studied. The influence of oil composition and content of aqueous phase on microstructure, rheological properties, and activation energy of viscous flow of water-oil emulsions is shown. For oils with the ratio RAC/PHC < 1, the increase in water cut results in an increase in viscosity, activation energy of viscous flow, and pour point