44 research outputs found
A fiber injection unit for the Keck Planet Imager and Characterizer (KPIC)
Coupling a high-contrast imaging instrument to a high-resolution spectrograph has the potential to enable the most detailed characterization of exoplanet atmospheres, including spin measurements and Doppler mapping. The high-contrast imaging system serves as a spatial filter to separate the light from the star and the planet while the high-resolution spectrograph acts as a spectral filter, which differentiates between features in the stellar and planetary spectra. The Keck Planet Imager and Characterizer (KPIC) located downstream from the current W. M. Keck II adaptive optics (AO) system will contain a fiber injection unit (FIU) combining a high-contrast imaging system and a fiber feed to Keck’s high resolution infrared spectrograph NIRSPEC. Resolved thermal emission from known young giant exoplanets will be injected into a single-mode fiber linked to NIRSPEC, thereby allowing the spectral characterization of their atmospheres. Moreover, the resolution of NIRSPEC (R = 37,500) is high enough to enable spin measurements and Doppler imaging of atmospheric weather phenomenon. The module will be integrated and tested at Caltech before being transferred to Keck in 2018
Phenomenological description of the microwave surface impedance and complex conductivity of high- single crystals
Measurements of the microwave surface impedance and
of the complex conductivity of high-quality, high- single
crystals of YBCO, BSCCO, TBCCO, and TBCO are analyzed. Experimental data of
and are compared with calculations based on a modified
two-fluid model which includes temperature-dependent quasiparticle scattering
and a unique temperature variation of the density of superconducting carriers.
We elucidate agreement as well as disagreement of our analysis with the salient
features of the experimental data. Existing microscopic models are reviewed
which are based on unconventional symmetry types of the order parameter and on
novel mechanisms of quasiparticle relaxation.Comment: 15 pages, 17 figures, 1 tabl
Применение рекомбинантного активированного протеина С в терапии сепсиса у детей после кардиохирургических вмешательств
Sepsis is the principal cause of hospital death among children and ranks fourth among all causes of death in infants under 1 year of age and second in 1-to-14-year-old children. Objective: to assess whether activated protein C (APC) infusion may be incorporated into the complex intensive therapy for sepsis in babies of the first year of life. Subjects and methods. In January 2005 to April 2007, APC was used in the complex intensive therapy for sepsis in 36 infants of the first year of life. APC therapy was initiated in the first 24 hours after the occurrence of organ dysfunction in 29 (80%) patients and in the first 48 hours in others cases. Results. Status stabilization and multiple organ dysfunction (MOD) regression were noted in most patients during APC infusion. Ten (28%) patients died; mortality rates in the groups of patients with early and late infusion were 17 and 71%, respectively. The baseline APC level failed to affect 28-day survival. By the end of infusion, the mean level of protein C was much higher in the group of survivors than that in the deceased. Conclusion. APC as a part of the complex intensive therapy for sepsis should be given to infants of the first year of life who had multiple organ dysfunctions within the first 24 hours after the occurrence of organ dysfunction. Key words: pediatric sepsis, activated a-drotrecogin, multiple organ dysfunction.Сепсис является основной причиной госпитальной летальности среди детей и занимает четвертое место среди всех причин смерти детей до 1 года, второе — среди причин смерти детей от 1 года до 14 лет. Цель работы . Оценить возможность включения инфузии активированного протеина С (АПС) в комплексную интенсивную терапию сепсиса у детей первого года жизни после кардиохирургических вмешательств. Материал и методы. С января 2005 по апрель 2007 года АПС применен в комплексной интенсивной терапии сепсиса у 36 детей 1-го года жизни. Терапия АПС была начата в первые 24 часа после появления органной дисфункции у 29 (80%) пациентов; в остальных случаях в течение первых 48 часов. Результаты. У большинства пациентов на фоне инфузии АПС отмечена стабилизация состояния и регресс синдрома полиорганной недостаточности (СПОН). Умерли 10 (28%) больных, смертность в группе больных с ранним началом инфузии составила 17%, с поздним — 71%. Исходный уровень АПС не влиял на 28-дневную выживаемость. В группе выживших больных в среднем уровень протеина С к концу инфузии был значительно выше, чем у умерших. Заключение. АПС в комплексной интенсивной терапии сепсиса детей 1-го года жизни с полиорганной недостаточностью должен быть назначен в первые 24 часа после появления органной дисфункции. Ключевые слова: педиатрический сепсис, дротрекогин a-активированный, полиорганная недостаточность
A fiber injection unit for the Keck Planet Imager and Characterizer (KPIC)
Coupling a high-contrast imaging instrument to a high-resolution spectrograph has the potential to enable the most detailed characterization of exoplanet atmospheres, including spin measurements and Doppler mapping. The high-contrast imaging system serves as a spatial filter to separate the light from the star and the planet while the high-resolution spectrograph acts as a spectral filter, which differentiates between features in the stellar and planetary spectra. The Keck Planet Imager and Characterizer (KPIC) located downstream from the current W. M. Keck II adaptive optics (AO) system will contain a fiber injection unit (FIU) combining a high-contrast imaging system and a fiber feed to Keck’s high resolution infrared spectrograph NIRSPEC. Resolved thermal emission from known young giant exoplanets will be injected into a single-mode fiber linked to NIRSPEC, thereby allowing the spectral characterization of their atmospheres. Moreover, the resolution of NIRSPEC (R = 37,500) is high enough to enable spin measurements and Doppler imaging of atmospheric weather phenomenon. The module will be integrated and tested at Caltech before being transferred to Keck in 2018
ДИАГНОСТИКА НАРУШЕНИЙ В СИСТЕМЕ ГЕМОСТАЗА ПРИ ПРИМЕНЕНИИ ВАРФАРИНА У БОЛЬНЫХ КАРДИОХИРУРГИЧЕСКОГО ПРОФИЛЯ
Objective: to reveal early changes in the hemostatic system during warfarin therapy in cardiac surgical patients, by comprehensively evaluating their hemostatic status.Subjects and methods. Seventyfive patients receiving cardiac surgical treatment were examined. All the patients took warfarin for 5±1.5 days. Laboratory studies involving the determination of routine coagulogram readings and thrombodynamic indicators (lag time (Tlag) and rate (Vs) of clot growth, and concentrations of individual Factors II, VI, IX, and X) were used to evaluate the patients' hemostatic status.Results. 28% of the patients were found to have an international normalized ratio (INR) of above 3.0. There was a correlation of Tlag with INR (R2=0.66). Both indicators were comparatively highly correlated with Factor II and Factor X concentrations (R2=0.50 and 0.40 for Tlag; R2=0.53 and 0.48 for INR) and were uncorrelated with Factor IX levels (R2=0.20 for Tlag and 0.34 for INR). However, there was a difference in Factor VII concentrations: no correlation for Tlag (R2=0.20) whereas it for INR was rather high (R2=0.42). The index Vs was uncorrelated with INR (R2=0.24) and the concentration of blood coagulation factors (R2<0.1). There was a high correlation between Factor II and Factor X concentrations (R2=0.87); the correlation between the concentrations of all other pairs of coagulation factors was substantially lower (R20.45). The lack of correlation of a thrombodynamic indicator, such as clot growth rate, with the concentration of coagulation factors points to the fact that warfarin acts mainly on the phase of coagulation activation rather than that of clot propagation.Conclusion. The weak correlation between coagulation factors (except that of a pair of Factor II and Factor X) is indicative of the individual response of the patients to warfarin treatment and the need to monitor the hemostatic status by global hemostatic tests rather than by individual proteins. The thrombodynamic indicator Tlag reflects the effect of warfarin in proportion to INR. Warfarin virtually fails to affect the rate of clot growth so this indicator may be used to evaluate the patient's procoagulant status uncompensated for with warfarin intake. Цель работы. Выявление ранних изменений в системе гемостаза при терапии варфарином у кардиохирургических больных путем комплексной оценки гемостатического статуса пациентов.Материалы и методы. Исследовано 75 пациентов, проходивших кардиохирургическое лечение. Все пациенты получали варфарин (продолжительность лечения больных — 5±1,5 суток). Для оценки гемостатического статуса больных использовали лабораторные методы, включающие определение рутинных показателей коагулограммы, тромбодинамики (время задержки Tlag и скорости роста сгустка (Vs), исследования концентрации II, VII, IX, X факторов).Результаты. Установлено, что у 28%больных показатель МНО находился в области свыше 3.0. Установлена корреляция Tlag с MНО (R2=0,66). Оба показателя имеют сравнительно высокую корреляцию с концентрацией FII и FX (R2=0,50 и 0,40 для Tlag, R2=0,53 и 0,48 для МНО) и не коррелируют с концентрацией FIX (R2=0,20 для Tlag и 0,34 для МНО). Однако наблюдается расхождение в случае концентрации FVII: корреляция для Tlag отсутствует (R2=0,20), тогда как для МНО она достаточно высока (R2=0,42). Параметр Vs не коррелирует с МНО (R2=0,24) и концентрацией факторов свертывания (R2<0,1). Обнаружена высокая корреляция между концентрациями факторов FII и FX (R2=0,87), корреляция между концентрациями всех других пар факторов свертывания существенно ниже (R20,45). Отсутствие корреляции такого показателя тромбодинамики как скорость роста сгустка от концентрации факторов указывает на то, что варфарин действует преимущественно на фазу активации свертывания, но не на фазу распространения сгустка.Заключение. Слабая корреляция факторов свертывания между собой (за исключением пары фактор II — фактор X) указывает на индивидуальный ответ больных на лечение варфарином и необходимость мониторинга состояния гемостаза не по отдельным белкам, а глобальными тестами. Параметр Tlag в тромбодинамике отражает эффект варфарина пропорционально МНО. Варфарин практически не влияет на скорость роста сгустка Vs, поэтому данный параметр можно использовать для оценки прокоагулянтного состояния пациента, не компенсируемого приемом варфарина
ASSESSMENT OF EFFECT OF COAGULATION AND SEDIMENTATION OF DUST PARTICLES ON OPERATION STABILITY OF ALUMINIUM ELECTROLYZER BURNERS
ASSESSMENT OF EFFECT OF COAGULATION AND SEDIMENTATION OF DUST PARTICLES ON OPERATION STABILITY OF ALUMINIUM ELECTROLYZER BURNERS
Prototypical pacemaker neurons interact with the resident microbiota
Pacemaker neurons exert control over neuronal circuit function by their intrinsic ability to generate rhythmic bursts of action potential. Recent work has identified rhythmic gut contractions in human, mice, and hydra to be dependent on both neurons and the resident microbiota. However, little is known about the evolutionary origin of these neurons and their interaction with microbes. In this study, we identified and functionally characterized prototypical ANO/SCN/TRPMion channel-expressing pacemaker cells in the basal metazoan Hydra by using a combination of single-cell transcriptomics, immunochemistry, and functional experiments. Unexpectedly, these prototypical pacemaker neurons express a rich set of immune-related genes mediating their interaction with the microbial environment. Furthermore, functional experiments gave a strong support to a model of the evolutionary emergence of pacemaker cells as neurons using components of innate immunity to interact with the microbial environment and ion channels to generate rhythmic contractions