Nanocrystalline Porous Hydrogen Storage Based on Vanadium and Titanium Nitrides

This review summarizes results of our study of the application of ion-beam assisted deposition (IBAD) technology for creation of nanoporous thin-film structures that can absorb more than 6 wt.% of hydrogen. Data of mathematical modeling are presented highlighting the structure formation and component creation of the films during their deposition at the time of simultaneous bombardment by mixed beam of nitrogen and helium ions with energy of 30 keV. Results of high-resolution transmission electron microscopy revealed that VNx films consist of 150–200 nm particles, boundaries of which contain nanopores of 10–15 nm diameters. Particles themselves consist of randomly oriented 10–20 nm nanograins. Grain boundaries also contain nanopores (3–8 nm). Examination of the absorption characteristics of VNx, TiNx, and (V,Ti)Nx films showed that the amount of absorbed hydrogen depends very little on the chemical composition of films, but it is determined by the structure pore. The amount of absorbed hydrogen at 0.3 MPa and 20°C is 6-7 wt.%, whereas the bulk of hydrogen is accumulated in the grain boundaries and pores. Films begin to release hydrogen even at 50°C, and it is desorbed completely at the temperature range of 50–250°C. It was found that the electrical resistance of films during the hydrogen desorption increases 104 times

Superhigh-frequency characteristics of optical modulators on the basis of InGaAlAs resonance-tunnel heterostructures

The impedance of InGaAlAs resonance-tunnel heterostructures used for modulation of optical radiation is experimentally studied in the frequency range from 45 to 18 MHz. The dependence of their equivalent circuit on the bias voltage is determined. The spectrum of the harmonics of the current in the resistive frequency multiplication in such structures is calculated. The results confirm that these structures are promising as applied to the frequency multiplication. The effect of frequency multiplication is demonstrated experimentally at low frequencies

Giant suppression of shot noise as signature of coherent transport in double barrier resonant diodes

Shot noise suppression in double barrier resonant tunnelling diodes with a Fano factor well below the value of 0.5 is theoretically predicted. This giant suppression is found to be a signature of the coherent transport regime and can occur near zero temperature as a consequence of the Pauli principle or above about 77 K as a consequence of long range Coulomb interaction. These predictions are validated by experimental data

Coherent approach to transport and noise in double-barrier resonant diodes

We implement a quantum approach which includes long range Coulomb interaction and investigate current voltage characteristics and shot noise in double-barrier resonant diodes. The theory applies to the region of low applied voltages up to the region of the current peak and considers the wide temperature range from zero to room temperature. The shape of the current voltage characteristic is well reproduced and we confirm that even in the presence of Coulomb interaction the shot noise can be suppressed with a Fano factor well below the value of 0.5. This feature can be an indication of coherent tunneling since the standard sequential tunneling predicts in general a Fano factor equal to or greater than the value 0.5. This giant suppression is a consequence of Pauli principle as well as long range Coulomb interaction. The theory generalizes previous findings and is compared with experiments

Giant suppression of shot noise in double barrier resonant diode: a signature of coherent transport

Shot noise suppression in double barrier resonant tunnelling diodes with a Fano factor well below the value of 0.5 is theoretically predicted. This giant suppression is found to be a signature of coherent transport regime and can occur at zero temperature as a consequence of the Pauli principle or at sufficiently high temperatures above 77 K as a consequence of a long-range Coulomb interaction. These predictions are in agreement with experimental data

Total linear polarization in the OH maser W75N: VLBA polarization structure

W75N is a star-forming region containing various ultracompact HII regions and OH, water, and methanol maser emission. Our VLBA map shows that the OH masers are located in a thin disk rotating around an O-star which is the exciting star of the ultracompact HII region VLA1. A separate set of maser spots is connected with the ultracompact HII region VLA2. The radial velocity of OH maser spots varies across the disk from 3.7 km/s to 10.9 km/s. The diameter of the disk is 4000 A.U. All maser spots are strongly polarized. This are the first OH masers showing nearly 100 per cent linear polarization in several spots. Two maser spots seem to be Zeeman pairs corresponding to a magnetic field of 5.2 mgauss and 7.7 mgauss, and in one case we tentatively found a Zeeman pair consisting of two linearly polarized components. The linearly polarized maser spots are shown to be sigma-components which is the case of the magnetic field being perpendicular to the line of sight. The direction of the magnetic field as determined from linearly polarized spots is perpendicular to the plane of the disk, although the galactic Faraday rotation may significantly affect this conclusion.Comment: 14 figures, 1 table, 27 pages. accepted for publication in ApJ, scheduled for v.564, N1, 200

Содержание альвеоломуцина в крови и клеточный состав бронхоальвеолярных смывов у электросварщиков

The article demonstrates results of study of alveolomucin 3EG5, oncomarkers CA-125 and CA-15.3 in the blood and cell compound of bronchoalveolar washes in 40 welders. Among fhem 18 patients were diagnosed pneumoconiosis, 6 patients suffered from chronic bronchitis, 2 patients had vibration disease and the others exposed to the welding aerosol have not got any occupational diseases. An increased level of alveolomucin was found in 23% of the patients with various diseases including those without pulmonary clinical signs. This fact evidences the hyperplasia of alveolocytes type 2 and moderate interstitial pulmonary fibrosis, sometimes of latent course, in workers exposed to the welding aerosol. The cell compound of the bronchoalveolar washes suspected neutrophil alveolitis in the welders.В статье приведены результаты исследования альвеоломуцина 3EG5, онкомаркеров СА-125 и СА-15.3 в крови, клеточном составе бронхоальвеолярных смывов у 40 электросварщиков, из них у 18 диагностирован пневмокониоз, у 6 — хронический обструктивный бронхит от воздействия сварочного аэрозоля, у 2 — вибрационная болезнь, у остальных, экспонированных к сварочному аэрозолю, профзаболеваний не выявлено. Повышенное содержание альвеоломуцина было выявлено у 23% больных с различными заболеваниями, в том числе без клинических проявлений легочной патологии. Эти данные свидетельствуют о том, что при воздействии сварочного аэрозоля у рабочих наблюдается гиперплазия альвеолоцитов 2-го типа и умеренно активный интерстициальный фиброз, в ряде случаев латентного течения. Цитологический состав бронхоальвеолярного смыва указывает на наличие у электросварщиков нейтрофильного альвеолита

Paragonimus westermani ichunensis и парагонимоз на юге Дальнего Востока России: вчера, сегодня и завтра

Paragonimosis is a severe parasitic disease, which causative agent (on the territory of Russia, trematode Paragonimus westermani ichunensis Chung, Hsu et Kao, 1978) circulates in the south of the Far East. Two forms of paragonimosis are known: pulmonary and muscular (larval) with clinical manifestations like diseases of a different etiology, mimicking the symptoms of malignant tumors, and in cases of late diagnosis and improper treatment, leading to death. Long-term studies of the ecology and biology of the parasite, as well as monitoring the incidence among residents of the southern Far East of Russia made it possible to analyze the situation with paragonimosis in the designated region. Based on the available data, until the mid-1990s, natural sites of disease were found almost everywhere in the river basins inhabited by mollusks of the genus Parajuga and crayfish of the genus Cambaroides as parasite intermediate hosts. During this period, according to official information, the population invasion rate reached 6%. Then, as a result of the mass extinction of freshwater crayfish, the population of P. westermani ichunensis was on the brink of survival, and from that moment on, the number of diagnosed cases of paragonimosis in the inhabitants of the region began to decline, down to zero in recent years. Currently, the population of crayfish Cambaroides is reviving and a case of P. westermani ichunensis infestation of a tiger cub has been recorded, which indicates the population restoration of the parasite itself. This indicates the functioning resumption of the Paragonimus sp. infection centers in the south of the Russian Far East. It is necessary to be prepared for the possibility of an exponential growth in the number of infected animals with such a developmentтof events. Due to the complexity of the disease diagnosing and the lack of certain knowledge about the parasite biology among the majority of medical workers, it is necessary to be ready to low detection rate among the region population.Парагонимоз – тяжелое паразитарное заболевание, возбудитель которого (на территории России трематода Paragonimus westermani ichunensis Chung, Hsu et Kao, 1978) циркулирует на юге Дальнего Востока. Известны две формы парагонимоза – легочная и мышечная (ларвальная) с клиническими проявлениями, сходными с заболеваниями иной этиологии, имитирующие симптомы злокачественных образований, и в случаях поздней диагностики и неправильного лечения, приводящие к летальному исходу. Многолетние исследования экологии и особенностей биологии паразита, а также мониторинг заболеваемости среди жителей юга Дальнего Востока России позволили провести анализ ситуации по парагонимозу в обозначенном регионе. Исходя из имеющихся данных, до середины 1990-х годов природные очаги заболевания находились практически повсеместно в бассейнах рек, населенных первыми – моллюсками рода Parajuga и вторыми – раками рода Cambaroides промежуточными хозяевами паразита. В этот период, по официальной информации, инвазированность населения достигала 6%. Затем, в результате массового вымирания пресноводных раков, популяция P. westermani ichunensis оказалась на грани выживания, и с этого момента число диагностированных случаев парагонимоза у жителей региона стало сокращаться, вплоть до нулевых показателей в последние годы. В настоящее время происходит возрождение популяции раков Cambaroides и был зарегистрирован случай инвазирования P. westermani ichunensis тигренка, что свидетельствует о восстановлении популяции самого паразита. Это указывает на возобновление функционирования очагов парагонимозной инвазии на юге Дальнего Востока России. При таком развитии событий необходимо быть готовыми к возможности экспоненциального роста числа зараженных и, в связи со сложностью диагностирования заболевания, и отсутствию у большинства медицинских работников определенных знаний о биологии паразита, к низкой его выявляемости среди населения региона

МЕТАСТАЗ РАКА ПОЧКИ В ЛЕВОЙ МОЛОЧНОЙ ЖЕЛЕЗЕ: ОПИСАНИЕ КЛИНИЧЕСКОГО НАБЛЮДЕНИЯ

The main method of treatment of local stages of clear cell renal cancer is surgical. The question of conducting adjuvant irradiation and chemotherapy after radical operations is open. Patients with solitary distant metastases and a favorable prognosis may become candidates for surgical treatment. Surgical removal of isolated solitary metastases allows to achieve 35–60  % of 5-year overall survival. The patient, observed in N.N.  Blokhin National Medical Research Center of Oncology with metastasis of renal cancer in the pancreas, and then in the breast is an extremely rare clinical case presented in this article.Основным методом лечения локальных стадий рака почки является хирургический. Вопрос о проведении адъювантного лечения после радикальных операций остается нерешенным. Пациенты с солитарными отдаленными метастазами могут стать кандидатами для хирургического лечения. Хирургическое удаление изолированных солитарных метастазов позволяет достигнуть 35–60  % 5-летней общей выживаемости. Больная, наблюдавшаяся в НМИЦ  онкологии им. Н.Н. Блохина с метастазом рака почки в поджелудочной железе, а затем в молочной железе и мягких тканях правого плеча, является крайне редким клиническим случаем, представленным в данной статье