Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 120
Filtrar
1.
Vestn Otorinolaringol ; 87(4): 32-37, 2022.
Artigo em Russo | MEDLINE | ID: mdl-36107178

RESUMO

OBJECTIVE: To study reflexes coming from the chemoreceptors in the humoral-isolated vertebral artery zone on systemic arterial pressure, cerebral and intra-ear hemodynamics in separate stimulation with angioprotectors. RESULTS: A more pronounced reflex depression of the above-described effectors was caused by Nicergoline, it was less pronounced when using Vinpocetine and Pentoxifylline. Correlation analysis in doing so of the dynamics of arterio-venular coefficient of bulbar conjunctiva vessels and the membrane of the ears labyrinth round window revealed a direct relationship. CONCLUSION: These studies objectivize the therapy of ear labyrinth discirculation with angioprotectives.


Assuntos
Nicergolina , Pentoxifilina , Pressão Arterial , Orelha , Humanos , Pentoxifilina/farmacologia , Artéria Vertebral
2.
J Environ Radioact ; 214-215: 106152, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32063284

RESUMO

Luminescence dosimetry was performed using bricks from the former settlement of Metlino, Southern Urals, Russia, to investigate the feasibility of validating the Techa River Dosimetry System (TRDS) 2016 for the shore of the Metlinsky Pond, upper Techa River region. TRDS is a code for estimating external and internal doses for members of the Extended Techa River Cohort. Several brick samples were taken from the north-western wall of the granary, facing the Metlinsky Pond. Samples were measured at different heights and at different depths into the bricks. Dating of the granary was performed by analyzing well shielded bricks. Assessment of the gamma dose-rate at the sample positions was done by thermoluminescent dosimeters and the dose-rate in front of the granary mapped with a dose-rate meter. Anthropogenic doses in bricks vary from 0.8 to 1.7 Gy and show an increase with sampling height. A similar height profile is observed for the current gamma dose-rate, which is compatible with the results of the dose-rate mapping. Implications for validating the TRDS are discussed.


Assuntos
Lagoas , Monitoramento de Radiação , Estudos de Viabilidade , Luminescência , Federação Russa , Poluentes Radioativos da Água
3.
Radiat Environ Biophys ; 56(2): 139-159, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28374124

RESUMO

In the first years of its operation, the Mayak Production Association, a facility part of the Soviet nuclear weapons program in the Southern Urals, Russia, discharged large amounts of radioactively contaminated effluent into the nearby Techa River, thus exposing the people living at this river to external and internal radiations. The Techa River Cohort is a cohort intensely studied in epidemiology to investigate the correlation between low-dose radiation and health effects on humans. For the individuals in the cohort, the Techa River Dosimetry System describes the accumulated dose in human organs and tissues. In particular, organ doses from external exposure are derived from estimates of dose rate in air on the Techa River banks which were estimated from measurements and Monte Carlo modelling. Individual doses are calculated in accordance with historical records of individuals' residence histories, observational data of typical lifestyles for different age groups, and age-dependent conversion factors from air kerma to organ dose. The work here describes an experimentally independent assessment of the key input parameter of the dosimetry system, the integral air kerma, for the former village of Metlino, upper Techa River region. The aim of this work was thus to validate the Techa River Dosimetry System for the location of Metlino in an independent approach. Dose reconstruction based on dose measurements in bricks from a church tower and Monte Carlo calculations was used to model the historic air kerma accumulated in the time from 1949 to 1956 at the shoreline of the Techa River in Metlino. Main issues are caused by a change in the landscape after the evacuation of the village in 1956. Based on measurements and published information and data, two separate models for the historic pre-evacuation geometry and for the current geometry of Metlino were created. Using both models, a value for the air kerma was reconstructed, which agrees with that obtained in the Techa River Dosimetry System within a factor of two.


Assuntos
Meio Ambiente , Modelos Biológicos , Resíduos Radioativos/análise , Rios , Inquéritos e Questionários , Poluentes Radioativos da Água/análise , Humanos , Medições Luminescentes , Radiometria , Federação Russa , Poluentes Radioativos da Água/metabolismo
5.
Vopr Onkol ; 61(6): 949-55, 2015.
Artigo em Russo | MEDLINE | ID: mdl-26995985

RESUMO

According to results of the study, which included 52 patients with malignant pleural effusion of unknown etiology, it could be concluded that the method of choice in differential diagnosis of pleural effusion is the immunocytochemistry as the most informative method (efficacy 94,2%). Based on own experience of treatment of 137 patients with recurrent malignant pleural effusions, we can say that the first stage of treatment of pleural effusions is carrying out pleurodesis in outpatient conditions. The choice of pleurodesis method, first of all, depends on the aggressiveness of tumor pleurisy: in a case of daily exudation till 300 ml we choose talc pleurodesis, from 300 to 700--bleomycin pleurodesis, more than 700--combined (talc and bleomycin pleurodesis). The overall efficiency of produced pleurodesis is 64.5%.


Assuntos
Assistência Ambulatorial , Pacientes Ambulatoriais , Derrame Pleural Maligno/diagnóstico , Derrame Pleural Maligno/terapia , Pleurodese/métodos , Adulto , Idoso , Assistência Ambulatorial/métodos , Antibióticos Antineoplásicos/administração & dosagem , Bleomicina/administração & dosagem , Diagnóstico Diferencial , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Federação Russa , Talco/administração & dosagem , Resultado do Tratamento
7.
Phys Rev Lett ; 112(16): 162701, 2014 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-24815644

RESUMO

Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with 2.85 MeV/nucleon mercury beams from REX-ISOLDE. Magnitudes and relative signs of the reduced E2 matrix elements that couple the ground state and low-lying excited states in Hg182-188 were extracted. Information on the deformation of the ground and the first excited 0+ states was deduced using the quadrupole sum rules approach. Results show that the ground state is slightly deformed and of oblate nature, while a larger deformation for the excited 0+ state was noted in Hg182,184. The results are compared to beyond mean field and interacting-boson based models and interpreted within a two-state mixing model. Partial agreement with the model calculations was obtained. The presence of two different structures in the light even-mass mercury isotopes that coexist at low excitation energy is firmly established.

8.
Phys Rev Lett ; 110(11): 115002, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25166547

RESUMO

A high-power active microwave pulse compressor is described that operates by modulating the quality factor of an energy storage cavity by means of mode conversion controlled by a triggered electron-beam discharge across a switch cavity. This Letter describes the principle of operation, the design of the switch cavity, the configuration used for the tests, and the experimental results. The pulse compressor produced output pulses with 140-165 MW peak power, record peak power gains of 16∶1-20∶1, and FWHM pulse duration of 16-20 ns at a frequency of 11.43 GHz.

9.
Tsitologiia ; 54(11): 862-9, 2012.
Artigo em Russo | MEDLINE | ID: mdl-23402004

RESUMO

An algoriphm for plant parenchimal cell delineation is developed. It works with digital photos made by polarized light microscope and allows digitize many parameter of each cell thus providing a lot of data characterizing plant tissue. Examples are given for unisratose lamina of leaves of two closely related moss species. Plagiomnium elatum and P. medium. We demonstrate a comparison of dimensional patterns in leaves and ability of formalization of such a structural character as arrangement of cells in oblique rows.


Assuntos
Microscopia de Polarização , Células Vegetais/ultraestrutura , Folhas de Planta/ultraestrutura , Briófitas/ultraestrutura , Fotografação , Processamento de Sinais Assistido por Computador
10.
Phys Rev Lett ; 105(25): 252502, 2010 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-21231583

RESUMO

A very exotic process of ß-delayed fission of 180Tl is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment mass distribution of the post-ß-decay daughter nucleus 180Hg (N/Z=1.25) is asymmetric. This asymmetry is more surprising since a mass-symmetric split of this extremely neutron-deficient nucleus would lead to two 90Zr fragments, with magic N=50 and semimagic Z=40. This is a new type of asymmetric fission, not caused by large shell effects related to fragment magic proton and neutron numbers, as observed in the actinide region. The newly measured branching ratio for ß-delayed fission of 180Tl is 3.6(7) × 10(-3)%, approximately 2 orders of magnitude larger than in an earlier study.

11.
J Food Sci ; 74(7): R79-83, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19895493

RESUMO

The potential difference induced by the interaction of samples with electromagnetic radiation in the visible region is used for food characterization. In this article we show that the above effect can be applied for the understanding of specific reactions and processes taking place in milk such as change of the acidity and changes caused by an added reagent. We also propose a technique for instantaneous detection of inhibitors of starter bacteria in milk. We suggest possible methods for quality control of milk and other foods. Instantaneous results, practically no expenses for consumables, and possibilities for field measurements will be some of the advantages of this approach.


Assuntos
Técnicas Eletroquímicas/métodos , Leite/química , Animais , Antibacterianos/análise , Técnicas Eletroquímicas/instrumentação , Análise de Alimentos/métodos , Leite/normas , Controle de Qualidade
13.
J Eur Acad Dermatol Venereol ; 23(5): 499-504, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19192020

RESUMO

A review of the literature concerning psychogenic purpura is presented. The diagnosis is usually based on typical anamnestic data, clinical presentation (painful inflammatory skin lesions, which progressed to ecchymoses during the next 24 h) and positive diagnostic tests with intracutaneous injections of 80% solution of washed autologous erythrocytes. No pathological findings of blood coagulation parameters are usually detected. Histopathological evaluations of lesional biopsies revealed non-specific changes. Taking into account the high frequency of psychic disorders and stress dependence of skin symptoms, therapy with psychotropic drugs (according to indications) and psychotherapy are pathogenetically grounded methods of treatment in psychogenic purpura, and should be provided together with symptomatic therapy.


Assuntos
Doenças Autoimunes , Eritrócitos/imunologia , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/patologia , Doenças Autoimunes/psicologia , Doenças Autoimunes/terapia , Humanos
14.
Phys Rev Lett ; 101(1): 012502, 2008 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-18764107

RESUMO

The reduced transition probabilities, B(E2; 0(gs)+ -->2(1)+), have been measured in the radioactive isotopes (108,106)Sn using subbarrier Coulomb excitation at the REX-ISOLDE facility at CERN. Deexcitation gamma rays were detected by the highly segmented MINIBALL Ge-detector array. The results, B(E2;0(gs)+ -->2(1)+)=0.222(19)e2b2 for 108Sn and B(E2; 0(gs)+-->2(1)+)=0.195(39)e2b2 for 106Sn were determined relative to a stable 58Ni target. The resulting B(E2) values are approximately 30% larger than shell-model predictions and deviate from the generalized seniority model. This experimental result may point towards a weakening of the N=Z=50 shell closure.

15.
Phys Rev Lett ; 100(11): 112502, 2008 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-18517779

RESUMO

Collective properties of the low-lying levels in the odd-A 67-73Cu were investigated by Coulomb excitation with radioactive beams. The beams were produced at ISOLDE and postaccelerated by REX-ISOLDE up to 2.99 MeV/u. In 67,69Cu, low-lying 1/2(-), 5/2(-), and 7/2(-) states were populated. In 71,73Cu, besides the known transitions deexciting the single-particle-like 5/2(-) and core-coupled 7/2(-) levels, gamma rays of 454 and 135 keV, respectively, were observed for the first time. Based on a reanalysis of beta-decay work and comparison with the systematics, a spin 1/2(-) is suggested for these excited states. Three B(E2) values were determined in each of the four isotopes. The results indicate a significant change in the structure of the odd-A Cu isotopes beyond N=40 where single-particle-like and collective levels are suggested to coexist at very low excitation energies.

16.
Phys Rev Lett ; 99(14): 142501, 2007 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-17930664

RESUMO

Neutron-rich, radioactive Zn isotopes were investigated at the Radioactive Ion Beam facility REX-ISOLDE (CERN) using low-energy Coulomb excitation. The energy of the 2(1)+ state in 78Zn could be firmly established and for the first time the 2+ --> 0(1)+ transition in 80Zn was observed at 1492(1) keV. B(E2,2(1)+ --> 0(1)+) values were extracted for (74,76,78,80)Zn and compared to large scale shell model calculations. With only two protons outside the Z=28 proton core, 80Zn is the lightest N=50 isotone for which spectroscopic information has been obtained to date. Two sets of advanced shell model calculations reproduce the observed B(E2) systematics. The results for N=50 isotones indicate a good N=50 shell closure and a strong Z=28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus 78Ni.

17.
Phys Rev Lett ; 98(12): 122701, 2007 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-17501116

RESUMO

We report on the first low-energy Coulomb excitation measurements with radioactive Ipi=6- beams of odd-odd nuclei 68,70Cu. The beams were produced at ISOLDE, CERN and were post-accelerated by REX-ISOLDE to 2.83 MeV/nucleon. Gamma rays were detected with the MINIBALL spectrometer. The 6- beam was used to study the multiplet of states (3-, 4-, 5-, 6-) arising from the pi2p3/2 nu 1g9/2 configuration. The 4- state of the multiplet was populated via Coulomb excitation and the B(E2;6--->4-) value was determined in both nuclei. The results obtained illustrate the fragile stability of the Z=28 shell and N=40 subshell closures. A comparison with large-scale shell-model calculations using the 56Ni core shows the importance of the proton excitations across the Z=28 shell gap to the understanding of the nuclear structure in the neutron-rich nuclei with N approximately 40.

18.
Phys Rev Lett ; 98(7): 072501, 2007 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-17359019

RESUMO

Using a method whereby molecular and atomic ions are independently selected, an isobarically pure beam of 70Se ions was postaccelerated to an energy of 206 MeV using REX-ISOLDE. Coulomb-excitation yields for states in the beam and target nuclei were deduced by recording deexcitation gamma rays in the highly segmented MINIBALL gamma-ray spectrometer in coincidence with scattered particles in a silicon detector. At these energies, the Coulomb-excitation yield for the first 2+ state is expected to be strongly sensitive to the sign of the spectroscopic quadrupole moment through the nuclear reorientation effect. Experimental evidence is presented here for a prolate shape for the first 2+ state in 70Se, reopening the question over whether there are, as reported earlier, deformed oblate shapes near to the ground state in the light selenium isotopes.

20.
Opt Express ; 15(21): 13936-41, 2007 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-19550666

RESUMO

We study the origin of antisymmetric perturbation of the fiber in arc-induced long-period gratings that couple the core mode into the antisymmetric cladding modes. We demonstrate that this perturbation is caused by the temperature gradient in the fiber, which is induced, in turn, by the temperature gradient in the arc discharge. The reproducibility of the process of the grating inscription is higher when the fiber is placed in a region with larger temperature gradient.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA