Continuous wave near‐infrared atomic Xe laser excited by a radio frequency discharge in a slab geometry

Near‐infrared atomic Xe laser lines have been generated from an Ar:He:Xe laser gas mixture excited by a radio frequency (rf) discharge in a slab geometry. A maximum continuous wave (cw) output power of 1.5 W (270 W/l) was obtained at an rf frequency of 125 MHz from a gas mixture containing Ar:He:Xe (50:49:1) at a total gas pressure of 90 Torr

Non-reciprocal light scattering by lattice of magnetic vortices

We report on experimental study of optical properties of two-dimensional square lattice of triangle Co and CoFe nanoparticles with a vortex magnetization distribution. We demonstrate that intensity of light scattered in diffraction maxima depends on the vorticity of the particles magnetization and it can be manipulated by applying an external magnetic field. The experimental results can be understood in terms of phenomenological theory.Comment: 10 pages, 4 figure

Enhanced gain and output power of a sealed‐off rf‐excited CO2 waveguide laser with gold‐plated electrodes

The small‐signal gain and the laser output power have been measured in a cw sealed‐off rf‐excited CO2waveguide laser for two different electrodematerials, gold‐plated copper and aluminum, at several excitation frequencies, gas pressures and mixture compositions. In the case of the gold‐plated electrodes an enhancement of the gain up to a factor of 2 and the output power up to a factor of 1.4 with time at a frequency of 190 MHz and 60 Torr of 1:1:5+5% (CO2:N2:He+Xe) mixture is observed. This is believed to be the result of the goldcatalytic activities which are favored by increased electrode temperatures and helium rich gas compositions

New continuous wave infrared Ar‐Xe laser at intermediate gas pressures pumped by a transverse radio frequency discharge

An atomic Xe laser with a transverse rf excitation has been operated in a cw mode in the intermediate pressure regime. The laser output spectrum consisted of 5 Xe lines with wavelengths of 2.03, 2.63, 2.65, 3.37, and 3.51 μm. The unoptimized total output power of 330 mW was obtained for a gas mixture Ar:He:Xe=59:40:1 at a pressure of 85 Torr and a rf input power of 150 W and excitation frequency of 121 MHz

Modeling of genetic processes underlying the development of resistance to fipronil in the Colorado potato beetle (Leptinotarsa decemlineata Say)

The main method of pest control is by applying chemical insecticides. The efficacy of insecticides is reduced due to the development of resistance by pest populations. This is an especially important problem with the Colorado potato beetle. There are different strategies for the use of insecticides to slow the development of resistance. Based on long lasing research, we propose a hypothesis about delaying the development of resistance by applying insecticides at low doses. To test this hypothesis, we have built predictive discrete genetic models of resistance in Colorado potato beetle populations. The model based on the classical equations of population genetics has been supplemented by various factors. Calculations of the survival rates of Colorado potato beetle individuals were carried out taking into account the statistical regularities of the distribution of the toxic substance after treatment by insecticides. We have calculated the survival rates of different genotypes using a lognormal distribution after changing the insecticide dose two-fold or more. The factor of differentiated mortality during the winter was additionally introduced into the model. The use of phenetic markers of nonspecific resistance to environmental factors allowed us to compute the model with mediated intergenic interactions. Various hypotheses about strategies in overcoming resistance have been tested using this model. Calculations demonstrated that the use of insecticides at minimum effective doses (low dose) leads to a slower increase in the proportion of resistant individuals in populations of the Colorado potato beetle for two seasons. Resistance develops much more slowly following alternate treatment with insecticides from different chemical classes. The best strategy is through off-season treatment with insecticides of different chemical classes at lower doses

Anti-vortex state in cross-like nanomagnets

We report on results of computer micromodelling of anti-vortex states in asymmetrical cross-like ferromagnetic nanostructures and their practical realization. The arrays of cobalt crosses with 1 mkm branches, 100 nm widths of the branches and 40 nm thicknesses were fabricated using e-beam lithography and ion etching. Each branch of the cross was tapered at one end and bulbous at the other. The stable formation of anti-vortex magnetic states in these nanostructures during magnetization reversal was demonstrated experimentally using magnetic force microscopy.Comment: 19 pages, 9 figure

Определение валидности шкалы дыхательных нарушений у пациентов с острым поражением нервной системы

The aim of study: to investigate validity of respiratory insufficiency scale (RIS) in patients with acute lesions of nervous system.Material and methods. The prospective observational study included neurocritical care patients (n=179), admitted to the resuscitation and intensive care unit with independent breathing and RIS score 1 and higher. Patients were assessed according to RIS every 12 hours during the the period of RICU stay until the beginning of artificial lung ventilation or transfer to a specialized department. The RIS score did not influence the physician's decision upon intubation. The treatment was performed in accordance with national and international recommendations.Depending on the tracheal intubation and ALV, patients were divided into 3 groups. Group I (n=65): 0% tracheal intubation and ALV; Group II (n =54): 42,6% cases of intubation and ALV; Group III (n=60): 100% patients requiring intubation and ALV.The statistical analysis was performed using Shapiro—Wilk test, Mann-Whitney test, Kruskal—Wallis test, Chi-squared test. The ROC analysis was carried out to determine the sensitivity and specificity of the RIS scale.Results. Patients with RIS score 1 — 2 did not require intubation and ALV. Patients with RIS 5 or more required urgent intubation and ALV. In patients with RIS score 3—4 the need for intubation and ALV was unpredictable. If RIS score 4 was sustainig during several hours, or if increased from 3 to 4, a patient required intubation and initiation of ALV.Conclusion. RIS helps objectify indications for intubation and ALV in patients with acute neural lesions.Цель исследования. Исследовать валидность шкалы дыхательных нарушений (ШДН) у пациентов с острым повреждением нервной системы.Материал и методы. В проспективное обсервационное исследование включили нейрореанимационных пациентов (n=179), поступавших в отделение реанимации и интенсивной терапии (ОРИТ) c сохраненным самостоятельным дыханием с оценкой по ШДН, равной 1 и более балла. Пациентов оценивали по ШДН каждые 12 ч до момента интубации трахеи или до перевода из ОРИТ в профильное отделение. Оценка пациента по ШДН не влияла на принятие решения лечащим врачом об интубации трахеи. Ведение пациентов осуществляли в соответствии с национальными и международными рекомендациями. Пациентов разделили на 3 группы в зависимости от степени необходимости произвести интубацию трахеи и искусственную вентиляцию легких (ИВЛ). В группе I (n=65) — 0% интубации трахеи и ИВЛ; в группе II (n=54) — 42,6% интубации трахеи и ИВЛ; в группе III (n=60) — 100% интубации трахеи и ИВЛ. Статистический анализ проводили с применением методик Шапиро–Уилка, тестов Манна–Уитни, Крускала–Уоллиса, критерия согласия Пирсона Хи-квадрат (χ2). ROC-анализ был проведен для определения чувствительности и специфичности ШДН-шкалы.Результаты. При оценке по ШДН, равной 1–2 балла, пациенты не нуждаются в интубации трахеи и ИВЛ, при сумме 5 и более баллов необходима незамедлительная интубация трахеи и ИВЛ, при сумме 3– 4 балла необходимость в ИВЛ непредсказуема. При сохраняющейся в течение нескольких часов оценке по ШДН, равной 4 баллам, или при ее увеличении с 3 баллов до 4 необходимы интубация трахеи и начало ИВЛ.Заключение. У пациентов с острым поражением нервной системы применение оценки дыхательных нарушений по ШДН позволяет объективизировать показания для интубации трахеи и начала ИВЛ