468 research outputs found
Temperature dependent photoluminescence of single CdS nanowires
Temperature dependent photoluminescence (PL) is used to study the electronic
properties of single CdS nanowires. At low temperatures, both near-band edge
(NBE) photoluminescence (PL) and spatially-localized defect-related PL are
observed in many nanowires. The intensity of the defect states is a sensitive
tool to judge the character and structural uniformity of nanowires. As the
temperature is raised, the defect states rapidly quench at varying rates
leaving the NBE PL which dominates up to room temperature. All PL lines from
nanowires follow closely the temperature-dependent band edge, similar to that
observed in bulk CdS.Comment: 11 pages, 4 figure
Low temperature photoluminescence imaging and time-resolved spectroscopy of single CdS nanowires
Time-resolved photoluminescence (PL) and micro-PL imaging were used to study
single CdS nanowires at 10 K. The low-temperature PL of all CdS nanowires
exhibit spectral features near energies associated with free and bound exciton
transitions, with the transition energies and emission intensities varying
along the length of the nanowire. In addition, several nanowires show spatially
localized PL at lower energies which are associated with morphological
irregularities in the nanowires. Time-resolved PL measurements indicate that
exciton recombination in all CdS nanowires is dominated by non-radiative
recombination at the surface of the nanowires.Comment: 9 pages, 3 figures, to be published in Applied Physics Letter
Pertussis immunity in pregnant women and factors associated with seronegative status
Despite high level of vaccination coverage, pertussis remains a serious problem of modern medicine. Pertussis cases are registered among infants, adolescents, and adults. Infants younger than three months of age have the highest rate of serious clinical pertussis course. Transplacental transfer of pertussis-specific antibodies induce protection against infection. The available data regarding anti-pertussis antibody level in pregnant women in Russia remain sparce. To evaluate the humoral immunity to Bordetella pertussis in pregnant women and factors associated with seronegative status, we performed a cross-sectional study with 388 participants. SeroPertussis IgG (Israel) ELISA kit was used to quantitate antibodies against pertussis toxin/hemagglutinin. Binary logistic regression analysis was performed to assess factors associated with seronegative status. The median age of the subjects was 30 years old, more than half of which (51.3%) provided no verified pertussis vaccination data so that their children will not receive transplacental anti-infectious immunity. Gestational age was significantly associated with seronegative status. Compared to women tested during the first trimester, participants in the third trimester of pregnancy were more likely to be seronegative against pertussis. The odds of being susceptible rose with increased gestational period (p < 0.01 for linear trend). Age, number of pregnancies and vaccination status revealed no impact on significant differences between seropositive and seronegative subjects. Pertussis booster vaccinations for preschool children, adolescents and healthcare workers dealing with pregnant women and neonates as well as cocoon vaccination strategy and vaccination during pregnancy were necessary to be implemented to protect infants against pertussis
Problems and prospects of human capital development in modern Russia
Purpose: In the context of dynamically changing modern labor market there is a need to develop a model of congruence and correlation of the process of building professional competencies provided by educational standards. Design/Methodology/Approach: The study was performed using monographic, abstract logical, sociological and statistical methods. However, this approach does not imply the formation of supra-professional competencies, which generally predetermine the success of professional tasks performed by a specialist. Findings: The article discusses the role of human capital as a fundamental factor affecting the increase in the competitiveness of production. Practical implications: The study focusses on the most demanded competencies for the development of digital society. The authors have grouped countries by level of human capital use. Originality/Value: At present, the appropriate parameters for measuring professional and general cultural competencies have been adopted as a system for assessing the quality of education in general and the quality of specialist training.peer-reviewe
Pathogenesis, diagnostics and treatment of diseases in the newborn
ДЕТСКИЕ БОЛЕЗНИДИАГНОСТИКА ЗАБОЛЕВАНИЙНОВОРОЖДЕННЫЙ, БОЛЕЗНИПЕДИАТРИЯВ пособии освещены вопросы патогенеза, диагностики и лечения болезней новорожденных
Трофічні зв’язки личинок Aedes vexans (Diptera: Culicidae) заплавних дібров р. Дніпро
Ae. vexans larvae are attributed to pseudobenthos. During feeding they are able both to filtrate and to scratch a periphyton from the substratum. As to larvae of Ae. vexans in flood oakwoods of the Dnipro River the detritus makes up two third, but algae – one third of the ration.Личинки Ae. vexans відносяться до планктобентосу. вони під час живлення можуть як безвибірково фільтрувати, так і зішкрібати перифітон із субстрату. Для личинок Ae. vexans заплавних дібров р. Дніпро, впродовж усього періоду їх розвитку, детрит складає дві третини, а водорості –близько третини раціону. Личинки Ae. vexans відносяться до планктобентосу. Вони під час живлення можуть як безвибірково фільтрувати, так і зішкрібати перифітон із субстрату. Для личинок Ae. vexans заплавних дібров р. Дніпро, впродовж усього періоду їх розвитку, детрит складає дві третини, а водорості – близько третини раціону
Structural and Functional Organization of the Vestibular Apparatus in Rats Subjected to Weightlessness for 19.5 Days Aboard the Kosmos-782 Satellite
The vestibular apparatus was investigated in rats subjected to weightlessness for 19.5 days. The vestibular apparatus was removed and its sections were fixed in a glutaraldehyde solution for investigation by light and electron microscopes. Structural and functional charges were noted in the otolith portions of the ear, with the otolith particles clinging to the utricular receptor surface and with the peripheral arrangement of the nucleolus in the nuclei of the receptor cells. It is possible that increased edema of the vestibular tissue resulted in the destruction of some receptor cells and in changes in the form and structure of the otolith. In the horizontal crista, the capula was separated
Imaging and optical properties of single core-shell GaAs-AlGaAs nanowires
We study the optical properties of a single core-shell GaAs-AlGaAs nanowire
(grown by VLS method) using the technique of micro-photoluminescence and
spatially-resolved photoluminescence imaging. We observe large linear
polarization anisotropy in emission and excitation of nanowires.Comment: IEEE Nano 2006 Proceeding
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