378 research outputs found
Radiative Decay Width of Neutral non-Strange Baryons from PWA
An overview of the GW SAID and ITEP groups effort to analyze pion
photoproduction on the neutron-target will be given. The disentanglement the
isoscalar and isovector EM couplings of N* and Delta* resonances does require
compatible data on both proton and neutron targets. The final-state interaction
plays a critical role in the state-of-the-art analysis in extraction of the
gamma n --> pi N data from the deuteron target experiments. It is important
component of the current JLab, MAMI-C, SPring-8, ELSA, and ELPH programsComment: 7 pages, 7 figures, 1 table; Proceedings of International Conference
Dark Matter, Hadron Physics and Fusion Physics, Messina, Italy, Sept. 2014;
will be published in EPJ Web of Conference
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Radiofrequency Hyperthermia of Cancer Cells Enhanced by Silicic Acid Ions Released during the Biodegradation of Porous Silicon Nanowires
The radiofrequency (RF) mild hyperthermia effect sensitized by biodegradable nanoparticles is a promising approach for therapy and diagnostics of numerous human diseases including cancer. Herein, we report the significant enhancement of local destruction of cancer cells induced by RF hyperthermia in the presence of degraded low-toxic porous silicon (PSi) nanowires (NWs). Proper selection of RF irradiation time (10 min), intensity, concentration of PSi NWs, and incubation time (24 h) decreased cell viability to 10%, which can be potentially used for cancer treatment. The incubation for 24 h is critical for degradation of PSi NWs and the formation of silicic acid ions H+ and H3SiO4- in abundance. The ions drastically change the solution conductivity in the vicinity of PSi NWs, which enhances the absorption of RF radiation and increases the hyperthermia effect. The high biodegradability and efficient photoluminescence of PSi NWs were governed by their mesoporous structure. The average size of pores was 10 nm, and the sizes of silicon nanocrystals (quantum dots) were 3-5 nm. Degradation of PSi NWs was observed as a significant decrease of optical absorbance, photoluminescence, and Raman signals of PSi NW suspensions after 24 h of incubation. Localization of PSi NWs at cell membranes revealed by confocal microscopy suggested that thermal poration of membranes could cause cell death. Thus, efficient photoluminescence in combination with RF-induced cell membrane breakdown indicates promising opportunities for theranostic applications of PSi NWs. © 2019 American Chemical Society
Time trends in smoking in Russia in the light of recent tobacco control measures: synthesis of evidence from multiple sources
Background - The study aims at identifying long-term trends and patterns of current smoking by age, gender, and education in Russia, including the most recent period from 2008 during which tobacco control policies were implemented, and to estimate the impact on mortality of any reductions in prevalence. We present an in-depth analysis based on an unprecedentedly large array of survey data.
Methods - We examined pooled micro-data on smoking from 17 rounds of the Russian Longitudinal Monitoring Study of 1996–2016, 11 other surveys conducted in Russia in 1975–2017, and two comparator surveys from England and the USA. Standardization by age and education, regression and meta-analysis were used to estimate trends in the prevalence of current smoking by gender, age, and educational patterns.
Results - From the mid-1970s to the mid-2000s smoking prevalence among men was relatively stable at around 60%, after which time prevalence declined in every age and educational group. Among women, trends in smoking were more heterogeneous. Prevalence more than doubled above the age of 55 years from very low levels (
Conclusions - The implementation of an effective tobacco control strategy in Russia starting in 2008 coincided with a decline in smoking prevalence among men from what had been stable, high levels over many decades regardless of age and education. Among women, the declines have been more uneven, with young women showing recent downturns, while the smoking prevalence in middle age has increased, particularly among those with minimal education. Among men, these positive changes will have made a small contribution to the reduction in mortality seen in Russia since 2005
Effect of Temperature on Physical and Mechanical Properties of Monolithic Polycarbonate
The study of the physical and mechanical properties of polycarbonate under various temperature conditions, taking into account its widespread use as a base material of monolithic polycarbonate systems in various climatic regions, will ensure a high degree of reliability of structures during operation in a wide temperature range. The authors of the article conducted a series of tensile tests of monolithic polycarbonate in the temperature range from -60 to +80 °C. The influence of temperature on the following characteristics of monolithic polycarbonate was evaluated: elongation at break, tensile yield strength, tensile stress at break, strains at the end of the elastic stage of the material. As a result of the conducted experimental studies, the relationship between the strength properties of monolithic polycarbonate and the operating temperature was revealed. The values of elongation at break at temperatures exceeding 15 °C for various samples generally correspond to the values obtained during tests conducted under standard conditions
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Snake venom phospholipase A2s exhibit strong virucidal activity against SARS-CoV-2 and inhibit the viral spike glycoprotein interaction with ACE2.
The COVID-19 pandemic caused by SARS-CoV-2 requires new treatments both to alleviate the symptoms and to prevent the spread of this disease. Previous studies demonstrated good antiviral and virucidal activity of phospholipase A2s (PLA2s) from snake venoms against viruses from different families but there was no data for coronaviruses. Here we show that PLA2s from snake venoms protect Vero E6 cells against SARS-CoV-2 cytopathic effects. PLA2s showed low cytotoxicity to Vero E6 cells with some activity at micromolar concentrations, but strong antiviral activity at nanomolar concentrations. Dimeric PLA2 from the viper Vipera nikolskii and its subunits manifested especially potent virucidal effects, which were related to their phospholipolytic activity, and inhibited cell-cell fusion mediated by the SARS-CoV-2 spike glycoprotein. Moreover, PLA2s interfered with binding both of an antibody against ACE2 and of the receptor-binding domain of the glycoprotein S to 293T/ACE2 cells. This is the first demonstration of a detrimental effect of PLA2s on β-coronaviruses. Thus, snake PLA2s are promising for the development of antiviral drugs that target the viral envelope, and could also prove to be useful tools to study the interaction of viruses with host cells
Long-term trends in blood pressure and hypertension in Russia: an analysis of data from 14 health surveys conducted in 1975-2017
Background
Hypertension is recognized as an important contributor to high cardiovascular mortality in Russia. A comprehensive analysis of data from Russian studies that measured blood pressure in population-based samples has not been previously undertaken. This study aims to identify trends and patterns in mean blood pressure and the prevalence of hypertension in Russia over the most recent 40 years.
Methods
We obtained anonymized individual records of blood pressure measurements from 14 surveys conducted in Russia in 1975-2017 relating to a total of 137,687 individuals. For comparative purposes we obtained equivalent data from 4 surveys in the USA and England for 23,864 individuals. A meta-regression on aggregated data adjusted for education was undertaken to estimate time trends in mean systolic and diastolic blood pressure, the prevalence of elevated blood pressure (> 140/90 mmHg), and hypertension (defined as elevated blood pressure and/or the use of blood pressure-lowering) medication. A meta-analysis of pooled individual-level data was used to assess male-female differences in blood pressure and hypertension.
Results
During the period 1975-2017 mean blood pressure, the prevalence of elevated blood pressure and hypertension remained stable among Russian men. Among Russian women, mean systolic blood pressure decreased at an annual rate of 0.25 mmHg (p < 0.1) at age 35-54 years and by 0.8 mmHg (p < 0.01) at ages 55 and over. The prevalence of elevated blood pressure also decreased by 0.8% per year (p < 0.01), but the prevalence of hypertension remained stable. Mean blood pressure and prevalence of hypertension were higher in Russia compared to the USA and England at all ages and for both sexes.
Conclusions
In contrast to the generally observed downward trend in elevated blood pressure in many other countries, levels in Russia have changed little over the past 40 years, although there are some positive trends among women. Improved strategies to bring down the high levels of mean blood pressure and hypertension in Russia compared to countries such as England and the USA are important to further reduce the high burden of CVD in Russia
Seroprevalence of SARS-Cov-2 Antibodies in Adults, Arkhangelsk, Russia.
Population-based data on coronavirus disease in Russia and on the immunogenicity of the Sputnik V vaccine are sparse. In a survey of 1,080 residents of Arkhangelsk 40-75 years of age, 65% were seropositive for IgG. Fifteen percent of participants had been vaccinated; of those, 97% were seropositive
Effective Chiral Lagrangian from Dual Resonance Models
Parameters of the effective chiral lagrangian (EChL) of orders and
are extracted from low--energy behaviour of dual resonance models for
and scattering amplitudes. Dual resonance models are
considered to be good candidates for the resonance spectrum and for hadronic
scattering amplitudes in the large limit of QCD. We discuss dual
resonance models in the presence of spontaneous and explicit chiral symmetry
breaking. Obtained parameters of the EChL are used to estimate chiral
corrections up to the sixth order to various low--energy characteristics of
and scattering amplitudes.Comment: 32 pages, the references list is updated, comparison with chiral
quark model is done in more detail
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