Sensor Development for Single-Photon Thermoelectric Detectors

As we reported earlier [1], thermoelectric detectors can be competitive as nondispersive energy resolving focal-plane instruments in X-ray/UV spectrum. The first generations of prototype devices demonstrated the viability of detector design and provided good agreement between theoretical expectations and experimental data. These devices exploited sensors made of gold with a small fraction of iron impurity. To get the projected high resolution one needs another type of material, namely, lanthanum-cerium hexaborides. We report on the first experimental tests of the feasibility of lanthanum-cerium films as sensor materials. Progress with thin films of these materials argues for the success of these thermoelectric detectors

Sub-Doppler spectroscopy of Rb atoms in a sub-micron vapor cell in the presence of a magnetic field

We report the first use of an extremely thin vapor cell (thickness ~ 400 nm) to study the magnetic-field dependence of laser-induced-fluorescence excitation spectra of alkali atoms. This thin cell allows for sub-Doppler resolution without the complexity of atomic beam or laser cooling techniques. This technique is used to study the laser-induced-fluorescence excitation spectra of Rb in a 50 G magnetic field. At this field strength the electronic angular momentum J and nuclear angular momentum I are only partially decoupled. As a result of the mixing of wavefunctions of different hyperfine states, we observe a nonlinear Zeeman effect for each sublevel, a substantial modification of the transition probabilities between different magnetic sublevels, and the appearance of transitions that are strictly forbidden in the absence of the magnetic field. For the case of right- and left- handed circularly polarized laser excitation, the fluorescence spectra differs qualitatively. Well pronounced magnetic field induced circular dichroism is observed. These observations are explained with a standard approach that describes the partial decoupling of I and J states

Optimization of nanoantenna-enhanced terahertz emission from photoconductive antennas

We present the results of hybrid photoconductive antenna THz emission enhanced by silver nanoantenna arrays. By varying the size of nanoantennas and the distance between them, we obtain the greatest value of optical-to-THz conversion efficiency reached so far. The results of experimental investigations are in a good agreement with numerical simulations. The conversion efficiency reveals over 5-fold improvement at certain frequencies, if compared with similar photoconductive antenna without silver nanoparticles, while previous results for this type of antenna barely exceeded 2-fold conversion efficiency gain

Voltage Responses to Optical Pulses of Unbiased Normal and Superconducting Samples

The direct transformation of the energy of an incident high-energy photon into a measurable potential difference within an absorbing metal is investigated. Experimental evidence is presented that the effect arises from the inherent energy dependence of the electronic density of states, rather than from a simple temperature excursion. The similarities between the results on Al and YBa2Cu3O7 samples indicate that the effect is universal in nature. We assert it may be used as the basis of a fast, energy resolving, individual photon detector for the ultraviolet radiation and x-rays

Клинические особенности течения риновирусной инфекции у детей

Acute respiratory viral infections remain the most common diseases in the world, accounting for about 90% of all infectious diseases. The possibilities of etiological decoding of ARVI using modern examination methods made it possible to establish an increase in the proportion of rhinovirus infection in the structure of ARVI.The aim of the study in this regard was to study the features of the clinical course of rhinovirus infection in children of different ages in modern conditions. The study included 50 patients with rhinovirus infection of children, among whom 1 2 children (24%) were under 1 year old; 34 children (68%) — 1—3 years old, 4 children (8%) — 3—7 years old. To confirm rhinovirus infection, a study of mucus from the nasopharynx by PCR was carried out.A thorough analysis of the symptom complex of the infection showed that in 1 3 (26%) patients the infectious process was limited to lesions of the upper respiratory tract, in 14 (28%) there were symptoms of acute stenosinglaryngotracheitis, in 1 1 (22%) children developed pneumonia, in 1 2 (24%) — bronchitis, with obstructive syndrome in 1 0 (83.3%) patients in this group.Острые респираторные вирусные инфекции остаются наиболее распространенными заболеваниями в мире, составляя около 90% всей инфекционной патологии. Возможности этиологической расшифровки ОРВИ с применением современных методов обследования позволили установить увеличение доли риновирусной инфекции в структуре ОРВИ.Целью исследования явилось изучение особенностей клинического течения риновирусной инфекции у детей различного возраста в современных условиях.Под наблюдением находилось 50 детей с риновирусной инфекцией: 12 детей (24%) были в возрасте до 1 года; 34 ребенка (68%) — 1 —3 лет, 4 ребенка (8%) — 3—7 лет. Для подтверждения риновирусной инфекции проводилось исследование слизи из носоглотки методом ПЦР.Тщательный анализ симптомокомплекса инфекции показал, что только у 13 (26%) больных инфекционный процесс ограничивался поражениями верхних дыхательных путей, у 14 (28%) отмечались явления острого стенозирующего ларинготрахеита, у 1 1 (22%) детей развивались пневмонии, у 12 (24%) — бронхиты, причём с обструктивным синдромом у 1 0 (83,3%) пациентов в этой группе

МЕТАПНЕВМОВИРУСНАЯ И БОКАВИРУСНАЯ РЕСПИРАТОРНЫЕ ИНФЕКЦИИ В СТРУКТУРЕ ОРВИ У ДЕТЕЙ

The article provides an overview of the literature data about new pneumotropic viruses - metapneumovirus and bokavirus: taxonomy, structural features, pathogenesis, laboratory diagnosis, clinical symptoms of the diseases they cause and complications. The high incidence and bokavirus metapnevmovirus structure of SARS infections in preschool children, the authors have shown the example carried out at the Department of Infectious Diseases in Children Medical University (now RNIMU named after N.I. Pirogov) and on the basis of clinical Institute of Virology, multicenter, randomized, blind, placebo-controlled study on the therapeutic efficacy and safety of interferon inducer Kagocel in 120 children aged 2 to 6 years. The findings to point out on significant reduction in the rate of relief of basic clinical manifestations of SARS, regardless of etiology, in children taking Kagocel in compare with a group of children who took a placebo.Представлены данные о новых пневмотропных вирусах — метапневмовирусы и бокавирусы: таксономия, особенности строения, патогенез, лабораторная диагностика, клинические симптомы вызываемыми ими заболеваний, осложнения. Высокую частоту встречаемости бокавирусной и метапневмовирусной инфекций в структуре ОРВИ у детей дошкольного возраста авторы показывают на примере проведенного на кафедре инфекционных болезней у детей РНИМУ им. Н. И. Пирогова и на клинической базе НИИ вирусологии многоцентрового рандомизированного, слепого плацебо-контролируемого исследования по изучению терапевтической эффективности и безопасности индуктора интерферона Кагоцел® у 120 детей в возрасте от 2 до 6 лет. Результаты исследования указывают на достоверное сокращение сроков купирования основных клинических проявлений ОРВИ, независимо от этиологии, у детей, получавших Кагоцел® по сравнению с группой детей, получавших плацебо

Physics of Neutron Star Crusts

The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.Comment: 182 pages, published version available at <http://www.livingreviews.org/lrr-2008-10

Функциональные изменения микроциркуляции у шахтеров в зависимости от стажа подземных работ

Objective: to study microcirculation in miners in relation to the length of their underground work. Subjects and methods. Microcirculation was studied in 328 miners who were divided into three groups according to the length of their underground work. It was examined in the skin of the outer lower third of the shoulder, by applying skin laser Doppler flowme-try by means of a ЛАКК-01 laser capillary blood flow analyzer (Lazma RPA, Russian Federation). Results. The performed studies determined a relationship between microcirculatory changes and the length of underground work. Group 1 (length, 1—9 years) showed a decrease in the major indicator of microcirculation through various mechanisms aimed at reducing peripheral resistance. As the length of underground work was more, there was an increase in total peripheral resistance and blood flow bypass. Conclusion. Microcirculatory deterioration occurs in miners who have worked underground longer. The found changes are comparable with the stages of total adjustment syndrome. The stress stage developing in miners with an underground work length of 1 to 9 years is characterized by decreased peripheral resistance. The resistance stage of adjustment syndrome occurs when different compensatory mechanisms are activated in miners who have been working under harmful conditions for 10 to 19 years. Dysadjustment signs characterized by increases in peripheral resistance and blood flow bypass occur with exhaustion of compensatory systems in miners who have been working underground for 20 years or more. Key words: microcirculation, miners, length of underground work.Цель исследования — изучить состояние микроциркуляции шахтеров в зависимости от стажа подземных работ. Материал и методы. Было проведено исследование микроциркуляции у 328-и шахтеров. Все шахтеры были разделены на три группы в зависимости от стажа подземных работ. Исследование микроциркуляции проводили на коже наружной нижней трети плеча с использованием накожной лазерной допплеровской флоуметрии с помощью лазерного анализатора капиллярного кровотока (ЛАКК-01) отечественного производства (НПО «Лазма», РФ). Результаты. В проведенных исследованиях была определена взаимосвязь изменений микроциркуляции со стажем подземных работ. В первой группе (стаж 1—9 лет) наблюдалось снижение основного показателя микроциркуляции за счет различных механизмов, направленных на уменьшение периферического сопротивления. С увеличением стажа подземных работ происходило увеличение общего периферического сопротивления и увеличение шунтирования кровотока. Заключение. У шахтеров с увеличением стажа подземных работ происходит ухудшение микроциркуляции. Выявленные изменения сопоставимы со стадиями общего адаптационного синдрома. Стадия напряжения, развивающаяся у шахтеров со стажем работы от одного года до 9-и лет, характеризуется снижением периферического сопротивления. При активизации различных компенсаторных механизмов у шахтеров, работающих во вредных условиях от 10-и до 19-и лет, наступает резистивная стадия адаптационного синдрома. При стаже работы 20 и более лет, с истощением компенсаторных систем, появляются признаки дезадаптации, характеризующиеся увеличением периферического сопротивления и нарастанием шунтирования кровотока. Ключевые слова: микроциркуляция, шахтеры, подземный стаж работы