Spectroscopic investigation of the spatiotemporal dynamics of an electric field in plasma of a beam-type high-voltage discharge in helium

In the present work, a method of determining the spatiotemporal characteristics of the electric field strength in an accelerating gap and a plasma flare of a beam-type high-voltage pulsed discharge in He at moderate pressure is presented. The method is based on spectroscopic data on the Stark splitting of π-components of He 2P–4Q transitions; Q = D(4921.93 Å), F(4920.35 Å) in the near-cathode region of the discharge and on the spatiotemporal characteristics of intensities of He(2s1S–3p1P0) spectral lines with λ = 5015 Å and He+(3d–4f) spectral lines with λ = 4685 Å measured experimentally and calculated from the data of statistical simulation of the electron kinetics by the Monte Carlo method. The shape and strength of the electric field of the space charge in the interelectrode gap and the drift region of the discharge are estimated. It is demonstrated that the electric field created by the current pulse of uncompensated space charge in the near-anode region changes the discharge regime and causes degradation of the electron beam in the plasma flare. It is established that the flux of secondary electrons from the drift region to the anode has significant effect on the radiation intensity distribution in this region of the discharge

Generating low-temperature glow discharge plasma in the atmospheric pressure helium after spark breakdown: Modelling plasma with the prescribed properties for biomedical applications

This paper concerns computational modelling of the low-temperature glow discharge plasma in the atmospheric pressure helium after spark breakdown and research on the dependence of a spatial distribution of plasma on the initial conditions of discharge and parameters of the external electric circuit. This study analysed the influence of the initial distribution of a space charge on the generation of the glow discharge plasma after the spark breakdown between flat electrodes by means of a 2D-axial symmetric model of the atmospheric pressure helium plasma in the drift-diffusion approximation. With the discharge current of 1–12 mA, the solution for a quasi-steady state of plasma is obtained. The dependence of a type of this discharge mode on the parameters of the external electric circuit and coefficient of the secondary cathode emission is studied

Supersymmetry of Tensionless Rotating Strings in AdS_5 x S^5, and Nearly-BPS Operators

It is shown that a class of rotating strings in AdS_5 x S^5 with SO(6) angular momenta (J,J',J') preserve 1/8-supersymmetry for large J,J', in which limit they are effectively tensionless; when J=0, supersymmetry is enhanced to 1/4. These results imply that recent checks of the AdS/CFT correspondence actually test a nearly-BPS sector.Comment: 12 pages, no figures; v2: new section on CFT operators and new references added, discussion section and acknowledgements modified, abstract rephrashe

IMPLEMENTATION OF A HIGH-EFFICIENT ELEMENTARY HEATER IN THE CIRCUIT OF AN EXISTING EVAPORATOR WITH THE PURPOSE OF SAVING HEATING STEAM

he paper gives a brief description of the method for producing alumina (Al2O3) by the Bayer method.This work was supported by the Russian Foundation for Basic Research (grant # 19-53-55002)

Lead content and isotopic composition in submound and recent soils of the Volga upland

Literature data on the historical reconstructions of the atmospheric lead deposition in Europe and the isotopic composition of the ores that are potential sources of the anthropogenic lead in the atmospheric deposition in the lower Volga steppes during different time periods have been compiled. The effect of the increasing anthropogenic lead deposition recorded since the Bronze Age on the level of soil contamination has been investigated. For the first time paleosol buried under a burial mound of the Bronze Age has been used as a reference point to assess of the current contamination level. The contents and isotopic compositions of the mobile and total lead have been determined in submound paleosols of different ages and their recent remote and roadside analogues. An increase in the content and fraction of the mobile lead and a shift of its isotopic composition toward less radiogenic values (typical for lead from the recent anthropogenic sources) has been revealed when going from a Bronze-Age paleosol to a recent soil. In the Bronze-Age soil, the isotopic composition of the mobile lead is inherited from the parent rock to a greater extent than in the modern soils, where the lead is enriched with the less radiogenic component. The effect of the anthropogenic component is traced in the analysis of the mobile lead, but it is barely visible for the total lead. An exception is provided by the recent roadside soils characterized by increased contents and the significantly less radiogenic isotopic composition of the mobile and total lead

DEVELOPMENT OF A HEAT EXCHANGER CONSTRUCTION FOR HEATING ALUMINUM SOLUTION WITH A BATTERY ASSEMBLY

The paper outlines the main reasons for the inlay of heat exchange equipment during heating of the aluminate solution. Considered methods of reducing scale formation on heat transfer surfaces. The design of the newly developed heat exchanger is described.В работе изложены основные причины забивки теплообменного оборудования при подогреве алюминатного раствора. Рассмотрены меры для снижения накипевыделения на теплообменных поверхностях. Описано конструктивное исполнение вновь разработанного теплообменника

ИНФИЦИРОВАННОСТЬ ДОНОРСКОГО МАТЕРИАЛА ВИРУСАМИ ГРУППЫ ГЕРПЕСА КАК ВОЗМОЖНАЯ ПРИЧИНА РАЗВИТИЯ БОЛЕЗНИ ТРАНСПЛАНТАТА ПРИ СКВОЗНОЙ КЕРАТОПЛАСТИКЕ

We present the study of outcomes of PCR-diagnostics directed on detection of DNA of herpes-family viruses in donor’s corneal tissues taken during penetrating keratoplasty (PK). In total, there were 46 patients, who under- went PKs. They were followed up from 14 days till 12 months. PCR-research of fragments of a donor cornea re- vealed existence of DNA in 21.7%. The retrospective analysis showed that in the presence of herpes-virus DNA in donor’s cornea is the risk factor of postoperative complications development and increases the rejection rate 2–3 times, reaching 100% – 70%. Thus the high risk of graft failures remains associated not only with the system immunosupressive therapy which is usually considered as the precondition of activization of chronic infections, but also in the absence of that. It gives the ground to conclude that preoperative preparation of a donor material, especially «fresh» corneas, should include expanded PCR-diagnostics on herpes-viruses and its obligatory dis- carding in cases of positive tests. В работе представлены результаты ПЦР-диагностики, направленной на обнаружение ДНК вирусов груп- пы герпеса (ВГЧ 1,2, ВЭБ, ВГЧ 6,7) ткани донорской роговицы, взятой во время операции сквозной кера- топластики (СКП). Под наблюдением находились 46 больных (глаз), перенесшие операцию сквозной ке- ратопластики (СКП). Сроки наблюдения больных после СКП – от 14 дней до 12 месяцев. ПЦР-исследование фрагментов донорской роговицы выявило наличие ДНК вирусов группы герпеса в 21,7%. Ретроспективный анализ показал, что при наличии ДНК вирусов группы герпеса в роговице до- нора риск развития послеоперационных осложнений и помутнения кератотрансплантата повышается в 2–3 раза, достигая 100 и 70% соответственно. При этом высокий риск неблагоприятных исходов сохра- няется не только на фоне системной иммуносупрессивной терапии, которая обычно учитывается как предпосылка активизации хронических инфекций, но и при отсутствии таковой. Это дает основание за- ключить, что предоперационная подготовка донорского материала, особенно «свежих» роговиц, должна включать расширенную ПЦР-диагностику на вирусы группы герпеса и обязательную его выбраковку в случаях положительных тестов.

Artificial intelligence for diagnosis and Gleason grading of prostate cancer: the PANDA challenge

Through a community-driven competition, the PANDA challenge provides a curated diverse dataset and a catalog of models for prostate cancer pathology, and represents a blueprint for evaluating AI algorithms in digital pathology.Artificial intelligence (AI) has shown promise for diagnosing prostate cancer in biopsies. However, results have been limited to individual studies, lacking validation in multinational settings. Competitions have been shown to be accelerators for medical imaging innovations, but their impact is hindered by lack of reproducibility and independent validation. With this in mind, we organized the PANDA challenge-the largest histopathology competition to date, joined by 1,290 developers-to catalyze development of reproducible AI algorithms for Gleason grading using 10,616 digitized prostate biopsies. We validated that a diverse set of submitted algorithms reached pathologist-level performance on independent cross-continental cohorts, fully blinded to the algorithm developers. On United States and European external validation sets, the algorithms achieved agreements of 0.862 (quadratically weighted kappa, 95% confidence interval (CI), 0.840-0.884) and 0.868 (95% CI, 0.835-0.900) with expert uropathologists. Successful generalization across different patient populations, laboratories and reference standards, achieved by a variety of algorithmic approaches, warrants evaluating AI-based Gleason grading in prospective clinical trials