348 research outputs found
Plasma probe characteristics in low density hydrogen pulsed plasmas
Probe theories are only applicable in the regime where the probe's
perturbation of the plasma can be neglected. However, it is not always possible
to know, a priori, that a particular probe theory can be successfully applied,
especially in low density plasmas. This is especially difficult in the case of
transient, low density plasmas. Here, we applied probe diagnostics in
combination with a 2D particle-in-cell model, to an experiment with a pulsed
low density hydrogen plasma. The calculations took into account the full
chamber geometry, including the plasma probe as an electrode in the chamber. It
was found that the simulations reproduce the time evolution of the probe IV
characteristics with good accuracy. The disagreement between the simulated and
probe measured plasma density is attributed to the limited applicability of
probe theory to measurements of low density pulsed plasmas. Indeed, in the case
studied here, probe measurements would lead to a large overestimate of the
plasma density. In contrast, the simulations of the plasma evolution and the
probe characteristics do not suffer from such strict applicability limits.
These studies show that probe theory cannot be justified through probe
measurements
Budget impact of eribulin in metastatic breast cancer in Russian Federation
Breast cancer is one of the most wide spread oncological disease and metastatic breast cancer is very severe, because of its high resistance. One of the recent drugs aimed for this group of patients is еribulin, which is microtubules dynamics inhibitor, leading to non-functional tubuline complex formation. Statistically relevant and clinically signifi cant еribulin action according to total survival was approved among HER2-negative and triple negative breast cancer. Eribulin is the only cytostatic approved as a monotherapy that leads to relevant and significant life prolongation among metastatic breast cancer patients, who had several regimens of therapy before.Aim. To determine budget impact and life years saved aft er adding Halaven® (еribulin) to the offi cial lists for metastatic breast cancer treatment.Methodology. Th is PHe was conducted according to standart implemented in the RF. All the breast cancer patients according to the state statics were included. The modelling horizon was 5 years. Drugs comparison are docetaxel, paclitaxel, kapezitabine, gemzitabine, vinorelbine, eribulin. Randomized controlled clinical trials investigating safety and effi cacy of these drugs, as well as performing head-to-head comparisons of some of them, were used as data source on safety and efficacy. A «decision tree» model was then constructed in order to estimate healthcare costs and patients outcomes. Two parameters were chosen as criteria for eff ectiveness assessment — overall survival and survival without progression. The results were used to perform Budget Impact Analysis (BIA) and evaluation of phramacoeconomic expediency and health impact.Results. Eribulin instead of standart therapy prolongs the patients’ life for 76 days. Budget impact analysis was performed to the terms of the treatment and adverse events correction. The profit of the eribulin treatment for every patient was 462858 rubles for 5 years or 5.59% of the budget impact. Sensitivity analysis confirms result stability, however, when price increase reaches 25%, the profit is 321356 rubles or 3.85% of the budget impact.Conclusion. It has been determined that eribulin is the most clinically and economically effective drug for metastatic breast cancer after 2nd line chemotherapy with the lowest budgetary burden
Dynamics of H atoms surface recombination in low-temperature plasma
The dynamics of H atom recombination on materials of interest for a EUV
lithographer was studied under a longterm low-pressure H2 plasma exposure. The
similarity of the experimental plasma with the typical EUV-induced plasma over
the multi-layer mirrors (MLMs) surface of the EUV lithographic machine is
demonstrated by means of 2D PIC MC simulation. The measurement of the temporal
dynamics of the H atom surface loss probability is chosen for testing the
surface modification during the treatment. Time-resolved actinometry of H atoms
with Kr as the actinometer gas was used to detect the dynamics of the H-atom
loss probability on the surface of Al, Ru, RVS and SiO2. It is demonstrated
that significant changes of the materials surface occur only at the very
beginning of the treatment and ist due to the surface heating and cleaning
effects. After that no changes of the H recombination rate are found,
indicating that the surface stays absolutely stable. A special test of the
sensitivity of the used method to the state of surface was carried out.
Dynamics of the H recombination rate changes with the small O2 addition clearly
demonstrated modification of the Al surface due to oxidation with the next
removal of the oxygen by the H2 plasma treatment. The rate of oxide removal is
shown to be determined by plasma parameters such as the ion energy and flux to
the surface
Phytochemistry and pharmacological activities of the genus Rhynchosia: a comprehensive review
Main conclusion: The genus Rhynchosia is a rich source of natural compounds especially flavonoids and prenylated isoflavonoids. Further experimental studies on Rhynchosia members may be result new and novel secondary metabolites with potent biological activities. Abstract: Traditionally, medicinal plants have played a significant role on human life since ancient days. At present, natural compounds are the major source for the modern drug discovery owing to their therapeutic selectivity, minutest of side effects, inexpensive source and serve as lead molecules for the discovery of new drugs. Rhynchosia species (Fabaceae) are extensively circulated throughout the tropical and subtropical areas around the world. A few plants of this genus were used in traditional medicine for the treatment of various ailments such as antibacterial, antidiabetic, abortifacients, healing of wounds, hepatoprotective, remedial of boils, rheumatic pains and skin infections. The present review compiles traditional uses, isolated chemical compounds and pharmacological activities of Rhynchosia species. So far, in total, seventy-seven compounds were isolated from the genus Rhynchosia, including flavonoids, isoflavonoids, flavan-3-ols, xanthones, biphenyls, simple polyphenols and sterols. It is interesting to note that the genus Rhynchosia is a rich source of C-glycosylflavonoids and prenylated isoflavonoids. Further, phytochemical and pharmacological studies on this genus are required since only few species have been investigated so far. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature
Effect of Fermi-liquid interactions on the low-temperature de Haas - van Alphen oscillations in quasi-two-dimensional conductors
In this work we present the results of theoretical analysis of the de
Haas-van Alphen oscillations in quasi-two-dimensional conductors. We have been
studying the effect of the Fermi-liquid correlations of charge carriers on the
above oscillations. It was shown that at reasonably low temperatures and weak
electron scattering the Fermi-liquid interactions may cause noticeable changes
in both amplitude and shape of the oscillations even at realistically small
values of the Fermi-liquid parameters. Also, we show that the Fermi-liquid
interactions in the system of the charge carriers may cause magnetic
instability of a quasi-two-dimensional conductor near the peaks of quantum
oscillations in the electron density of states at the Fermi surface, indicating
the possibility for the diamagnetic phase transition within the relevant ranges
of the applied magnetic fields.Comment: 10 pages, 4 figure
Experimental observation of spontaneous spin polarization of electrons in hybridized states of transition element impurities in semiconductors
Experimental evidence of the possible existence of spontaneous spin polarization of the electron system in hybridized states formed by transition element impurity atoms in the conduction band of semiconducting crystals is examined. The details of a quantitative interpretation of experiments on the temperature dependence of the specific heat and elastic moduli of mercury selenide crystals with iron impurities confirm the feasibility of establishing the presence of electron spin polarization in this type of experiment, as well as the possible existence of polarization in the crystals studied here. Theoretical arguments support the observation of a thermodynamic anomalous Hall effect owing to spontaneously polarized donor electrons from low-concentration impurities. © 2013 AIP Publishing LLC
Synthesis of Pah-Containing Copolymers on the Basis of Acrylic Acid
This work was funded by Russian Science Foundation (Ref no. 18-73-00301)
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