48 research outputs found

    The superimposed photospheric and stellar wind variability of the O-type supergiant alpha Cam

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    (Abridged) We provide empirical constraints on the different physical components that can act to yield temporal variability in predominantly or partially wind-formed optical lines of luminous OB stars, and thus potentially affect the reliable determination of fundamental parameters, including mass-loss rates via clumped winds. Using time-series spectroscopy from epochs spread over \sim 4 years, a case study of the O9.5 supergiant α\alpha Cam is presented. We demonstrate that the He I 5876 (23^3P0^0--33^3D) line is an important diagnostic for photospheric and wind variability in this star. The optical line profiles of α\alpha Cam are affected by (i) deep-seated fluctuations close to, or at, the photosphere, (ii) atmospheric velocity gradients, and (iii) large-scale stellar wind structure. This study provides new empirical perspectives on accurate line-synthesis modelling of stellar wind signatures in massive luminous stars. Using a pure Halpha line-synthesis code we interpret maximum changes in the red-ward and peak emission of α\alpha Cam in terms of mass-loss rate differences in the range \sim 5.1 ×\times 106^{-6} to 6.5 ×\times 106^{-6} M_\odot yr1^{-1}. However, the models generally fail to reproduce the morphology of blueward (possibly absorptive) regions of the profiles.Comment: Accepted for pulication in A&A; 9 pages and 8 figure

    Large-scale wind structures in OB supergiants: a search for rotationally modulated H\alpha variability

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    We present the results of a long-term monitoring campaign of the H\alpha line in a sample of bright OB-supergiants (O7.5-B9) that aims at detecting rotationally modulated changes potentially related to the existence of large-scale wind structures. A total of 22 objects were monitor ed during 36 nights spread over 6 months in 2001-2002. Coordinated broad-band photometric observations were also obtained for some targets. Conspicuous evidence for variability in H\alpha is found for the stars displaying a feature contaminated by wind emission. Most changes take place on a daily time-scale, although hourly variations are also occasionally detected. Convincing evidence for a cyclical pattern of variability in H\alpha has been found in 2 stars: HD 14134 and HD 42087 (periodic signals are also detected in other stars, but independent confirmation is required). Rotational modulation is suggested from the similarity between the observed recurrence time-scales (in the range 13-25 days) and estimated periods of stellar rotation. We call attention to the atypical case of HD 14134 which exhibits a clear 12.8-d periodicity both in the photometric and in the spectroscopic data sets. This places this object among a handful of early-type stars where one may observe a clear link between extended wind structures and photospheric disturbances. Further modelling may test the hypothesis that azimuthally-extended wind streams are responsible for the patterns of spectral variability in our target stars.Comment: 18 pages, accepted for publication in MNRA

    ЭФФЕКТИВНОСТЬ ЗОЛЕДРОНОВОЙ КИСЛОТЫ В ПРОФИЛАКТИКЕ КОСТНЫХ МЕТАСТАЗОВ У ПАЦИЕНТОВ С МЕСТНО-РАСПРОСТРАНЕННЫМ РАКОМ ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ

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    The analysis of the performed study has established that zoledronic acid is an effective agent in multimodality therapy for locally advanced prostate cancer (PC) and allows long-term stabilization of bone tissue. In addition, there is evidence for the efficacy of zoledronic acid in preventing bone metastases (BM) and increasing the time to the first BM. The currently accumulated experience with zoledronic acid used in PC permits one to consider its use as standard concomitant therapy.На основании анализа проведенного исследования установлено, что золедроновая кислота является эффективным препаратом в комплексной терапии местно-распространенного рака предстательной железы (РПЖ) и позволяет стабилизировать в течение длительного времени состояние костной ткани. Кроме того, подтверждена эффективность золедроновой кислоты в профилактике костных метастазов (КМ), а также в увеличении времени до появления первого КМ. Накопленный к настоящему времени опыт использования золедроновой кислоты при РПЖ позволяет рассматривать ее назначение как стандартную сопроводительную терапию

    Determination of the neutron fluence, the beam characteristics and the backgrounds at the CERN-PS TOF facility

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    COMPLICATIONS OF TERMINAL COLOSTOMY IN PATIENTS WITH TUMOROUS LARGE INTESTINE ILEUS AND THEIR SURGICAL MANAGEMENT

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    The article analyzed the structure, incidence rate and results of surgical treatment of paracolostomal complications in 69 patients out of 134 (aged from 23 to 77 years old). The patients were divided into 2 groups according to the variant of terminal colostomy. The single-barrel colostomy was formed by classical (intraperitoneal) method using «proboscis» design in 58 patients (43,3%) of the first group. Various complications were developed in the area of colostomy in 42 (72,4%) patients. The single-barrel flat colostomy was applied at the skin level using the method modified by the authors in 76 (56,7%) patients of the second group. The authors designed the method of controlled intra- and postoperative decompression and lavage of the colon by a new model of aspiration-irrigation device in order to unload the colon through colostomy. There were noted complications in the area of colostomy in 27 (35,5%) cases. The developed rational method of terminal colostomy formation, upgrading the ways of intra- and postoperative decompression and lavage of the colon facilitated to decrease of the rate of postcolostomy complications more than two times (from 72,4 to 35,5%). The author’s method led to optimization of immediate and long-term results of surgical treatment

    POSTOPERATIVE INTRAABDOMINAL COMPLICATIONS IN COLON CANCER SURGERY COMPLICATED BY BOWEL OBSTRUCTION AND PERFORATION OF THE TUMOR

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    The article presents a retrospective analysis of the results of surgical treatment of postoperative intraabdominal complications in 42 patients with colon cancer complicated by bowel obstruction and perforation of the tumor. The pyoinflammatory processes such as peritonitis and abscesses of abdominal cavity took a leading place in the structure of postoperative complications according to the authors. Method of «closed» decompression and intraluminal irrigation of the large intestine without wide opening of organ lumen was developed and applied into practice as perioperative prophylaxis of pyoinflammatory processes. These measures allowed reducing the rate of postoperative intraabdominal complications from 19,2 to 7,7%
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