Stability of Triple Star Systems with Highly Inclined Orbits

It is well established that certain detached eclipsing binary stars exhibit apsidal motions whose value is in disagreement with with calculated deviations from Keplerian motion based on tidal effects and the general theory of relativity. Although many theoretical senarios have been demonstrated to bring calculations into line with observations, all have seemed unlikely for various reasons. In particular, it has been established that the hypothesis of a third star in an orbit almost perpendicular to the orbital plane of the close binary system can explain the anomalous motion in at least some cases. The stability of triple star systems with highly inclined orbits has been in doubt, however. We have found conditions which allow the long term stability of such systems so that the third body hypothesis now seems a likely resolution of the apsidal motion problem. We apply our stability criteria to the cases of AS Cam and DI Her and recommend observations at the new Keck interferometer which should be able to directly observe the third bodies in these systems.Comment: edited to match published versio

Тактика хирургического лечения пациентов с инфарктом мозжечка

The aim of the study is to specify tactics of surgical treatment of cerebellar infarction (CI).Material and methods. The results of treatment of 80 patients with CI were studied. According to the clinical course of stroke, the patients were divided into 2 groups. The group of malicious cerebellar infarction included 55 patients (69%) (Group I), the group cerebellar infarction with benign course included 25 patients (31%) (Group II). Patients of Group I were divided into subgroups, in one of them surgical treatment was performed (surgical subgroup), and in the another one, only conservative (conservative subgroup) treatment was performed. In the surgical subgroup, 16 patients underwent isolated ventriculostomy, 5 - posterior fossa decompression (PFD), 18 - combination of ventriculostomy and PFD. The criteria of efficacy of surgery were recovery of consciousness and/or IV ventricle and the quadrigeminal cistern configurations. Results of treatment were assessed according to the Glasgow Outcome Scale.Results. Malicious cerebellar infarctions occurred more frequently in patients with volume of ischemia exceeding 20 cm3 in the first day of the disease. The threshold value of mass effect, which may cause further a malocious cerebellar infarction, in the first day of the disease was score 3 according to the M. Jauss scale. In group of patients with malicious cerebellar infarction, surgical treatment reduced the mortality rate of occlusion and dislocation syndrome by 35.8%. The most effective type of intervention was a combination of decompressive trepanation of the posterior cranial fossa and external ventricular drainage. Combined ventriculostomy and PFD were 34 % more effective than just ventriculostomy, and 38 % more effective than just PFD.Conclusion. Patients with cerebellar infarction of more than 20 cm3 and signs of a mass effect in the posterior cranial fossa score 3 or higher according to M. Jauss scale, are prone to developing a malicious course of the disease. After the development of clinical manifestations of occlusive and dislocation syndrome, they need surgical treatment.In the surgical treatment of malignant cerebellar infarction, ventriculostomy with PFD are advisable, as each operation separately does not always provide a necessary effect in decompensation of dislocation syndrome.Цель исследования материал и методы. Исследованы результаты лечения 80 пациентов с ИМ. По характеру клинического течения ИМ пациенты были распределены на две группы. В группу злокачественного течения ИМ вошли 55 пациентов (69%) (группа I), в группу доброкачественного течения ИМ - 25 пациентов (31%) (группа II). Пациенты I группы были дополнительно разделены на подгруппы, в которых проводили хирургическое (хирургическая подгруппа) и только консервативное (консервативная подгруппа) лечение. В хирургической подгруппе 16 пациентов перенесли ликворошунтирующие операции (ЛО), 5 - декомпрессивную трепанацию задней черепной ямки (ДКТ ЗЧЯ), 18 - ЛО в сочетании с ДКТ ЗЧЯ. Критериями эффективности хирургического лечения считали восстановление сознания до ясного и/или восстановление конфигурации IV желудочка и четверохолмной цистерны. Результаты лечения оценивали по шкале исходов Глазго.Результаты. Злокачественное течение ИМ чаще возникало у пациентов с объемом ишемии, превышающим 20 см3 в 1-е сут заболевания. Пороговое значение масс-эффекта в первые сутки заболевания по шкале М. Jouss, которое может в последующем вызвать злокачественный ИМ, составило 3 балла. У больных со злокачественным ИМ хирургическое лечение позволило снизить летальность от окклюзионно-дислокационного синдрома (ОДС) на 35,8%. Эффективность хирургического лечения среди больных, которым выполнили ДКТ ЗЧЯ совместно с ЛО, была выше на 34% по сравнению с ЛО и на 38% по сравнению с результатами больных с изолированной ДКТ ЗЧЯ.Заключение. Пациенты с ИМ объемом более 20 см3, сопровождающимся масс-эффектом в ЗЧЯ 3 балла и более по шкале М. Jouss, склонны к развитию злокачественного течения заболевания. При развитии клинической картины ОДС им показано хирургическое лечение.При хирургическом лечении злокачественного ИМ целесообразно выполнять совместно с вентрикулостомией ДКТ ЗЧЯ, так как каждая операция по отдельности не исключает дальнейшего прогрессирования ОДС

ВОЗМОЖНОСТИ ХИРУРГИЧЕСКОЙ КОРРЕКЦИИ ТРОМБОЗА ВНУТРЕННЕЙ СОННОЙ АРТЕРИИ У ПАЦИЕНТОВ С ОСТРЫМ ИШЕМИЧЕСКИМ ИНСУЛЬТОМ

Objective. To estimate the efficacy of surgical treatment of internal carotid artery (ICA) thrombosis in patients suffered from acute ischemic stroke (AIS).Material and methods. Author operated 25 patients suffered from AIS and ICA thrombosis from 01 Feb, 2014 till 31 Aug, 2016 in Neurosurgical Department of N.V. Sklifosovsky Research Institute for Emergency Medicine. Among them, 15 patients had total thrombosis of ICA and were operated on, 10 patients had partial mural thrombosis or floating thrombus (6 patients were operated on). There were 7 thrombectomies with the removal of intima, 13 superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses, 1 ICA stent installation.Results. The excellent outcomes were seen in 7 (33.4%) patients, good outcomes — in 11 (52.3%) and satisfactory outcomes were observed in 3 (14.3%) patients. The improvement of functional deficit in the early post-operative period was 4.85 scores according to NIHSS, 1.2 scores according to Rankin scale and 2.3 scores according to Rivermead mobility index. The regress of neurological deficit was more significant among patients with severe focal disturbances; better outcomes were among patients operated on within first 3 days from an onset of the disease. There was no significant improvement among non-operated patients at the moment of discharge from hospital. Thrombectomy with the removal of intima performed in 2 (40%) patients with partial mural thrombosis was complicated by repeated thrombosis of ICA. The improvement of cerebral blood supply was verified in 16 (76.2%) operated patients according to the data of cerebral perfusion examination.Conclusions. The early surgical treatment is indicated for patients with acute total thrombosis of ICA. It is possible to perform STA-MCA bypass in case of inability to perform endovascular thrombextraction or open thrombectomy with the removal of intima. The conservative treatment is indicated for patients with partial mural thrombosis while urgent operation is necessary among patient with floating thrombus to decrease the risk of cerebral embolism. Цель. Оценить эффективность хирургического лечения тромбоза внутренней сонной артерии (ВСА) у пациентов с острым ишемическим инсультом (ОИИ).Материал и методы. В период с 1.02.2014 по 31.08.2016 гг. в нейрохирургическом отделении НИИ СП им. Н.В. Склифосовского пролечены 25 пациентов с ОИИ и тромбозом ВСА. У 15 больных выявлен полный тромбоз (все 15 оперированы), у 10 — неполный пристеночный или флотирующий тромб (6 оперированы). Выполнено 7 тромбинтимэктомий (ТИЭ), 13 экстра-интракраниальных микроанастомозов (ЭИКМА), одно стентирование ВСА. Результаты. Отличные исходы получены у 7 (33,4%), хорошие — у 11 (52,3%), удовлетворительные — у 3 (14,3%) больных. Снижение функционального дефицита в раннем послеоперационном периоде состави- ло 4,85 балла по шкале NIHSS, 1,2 балла по шкале Рэнкина и 2,3 балла по индексу мобильности Ривермид. Регресс неврологического дефицита был более выражен у пациентов со значительными очаговыми нарушениями; лучшие исходы имели пациенты, оперированные в первые 3 сут заболевания. У неоперированных пациентов достоверного улучшения к моменту выписки не было. ТИЭ по поводу пристеночных тромбозов в 2 наблюдениях (40%) сопровождалась ретромбозом ВСА. У 16 оперированных пациентов (76,2%) отмечено улучшение кровоснабжения головного мозга по данным исследований его перфузии.Заключение. Пациентам с острым полным тромбозом ВСА показано проведение раннего хирургического лечения. При невозможности проведения эндовазальной тромбэкстракции или открытой ТИЭ предлагается выполнить обходное шунтирование (ЭИКМА). Пациентам с неполным пристеночным тромбозом показано проведение консервативного лечения. Больным с неполным флотирующим тромбозом и высоким риском эмболии в головной мозг показано проведение экстренной операции.

The Tactics of Surgical Treatment in Patients with Cerebellar Infarction

The aim of the study is to specify tactics of surgical treatment of cerebellar infarction (CI).Material and methods. The results of treatment of 80 patients with CI were studied. According to the clinical course of stroke, the patients were divided into 2 groups. The group of malicious cerebellar infarction included 55 patients (69%) (Group I), the group cerebellar infarction with benign course included 25 patients (31%) (Group II). Patients of Group I were divided into subgroups, in one of them surgical treatment was performed (surgical subgroup), and in the another one, only conservative (conservative subgroup) treatment was performed. In the surgical subgroup, 16 patients underwent isolated ventriculostomy, 5 - posterior fossa decompression (PFD), 18 - combination of ventriculostomy and PFD. The criteria of efficacy of surgery were recovery of consciousness and/or IV ventricle and the quadrigeminal cistern configurations. Results of treatment were assessed according to the Glasgow Outcome Scale.Results. Malicious cerebellar infarctions occurred more frequently in patients with volume of ischemia exceeding 20 cm3 in the first day of the disease. The threshold value of mass effect, which may cause further a malocious cerebellar infarction, in the first day of the disease was score 3 according to the M. Jauss scale. In group of patients with malicious cerebellar infarction, surgical treatment reduced the mortality rate of occlusion and dislocation syndrome by 35.8%. The most effective type of intervention was a combination of decompressive trepanation of the posterior cranial fossa and external ventricular drainage. Combined ventriculostomy and PFD were 34 % more effective than just ventriculostomy, and 38 % more effective than just PFD.Conclusion. Patients with cerebellar infarction of more than 20 cm3 and signs of a mass effect in the posterior cranial fossa score 3 or higher according to M. Jauss scale, are prone to developing a malicious course of the disease. After the development of clinical manifestations of occlusive and dislocation syndrome, they need surgical treatment.In the surgical treatment of malignant cerebellar infarction, ventriculostomy with PFD are advisable, as each operation separately does not always provide a necessary effect in decompensation of dislocation syndrome

High-temperature LPP collector mirror

The EUV source output power and the collector optics lifetime have been identified as critical key issues for EUV lithography. In order to meet these requirements a heated collector concept was realized for the first time. An ellipsoidal collector Substrate with an outer diameter of 320 mm was coated with a laterally graded high-temperature multilayer. The interface-engineered Mo/Si multilayer coating was optimized in terms of high peak reflectivity at 13.5 nm and a working temperature of 400 °C. Barrier layers were introduced on both interfaces to block thermally induced interdiffusion processes of molybdenum and silicon to provide long-term optical stability of the multilayer at elevated temperatures. A normal-incidence reflectance of more than 40 % at 13.55 nm was measured after heating. After initial annealing at 400 °C for one hour, no degradation of the optical properties of these multilayer coatings occurred during both long-term heating tests for up to 100 hours and multiple annealing cycles. The successful realization of this high-temperature sub-aperture collector mirror represents a major step towards the implementation of the heated collector concept and illustrates the great potential of high-temperature EUV multilayer coatings

POSSIBILITIES OF SURGICAL CORRECTION OF INTERNAL CAROTID ARTERY THROMBOSIS IN PATIENTS WITH ACUTE ISCHEMIC STROKE

Objective. To estimate the efficacy of surgical treatment of internal carotid artery (ICA) thrombosis in patients suffered from acute ischemic stroke (AIS).Material and methods. Author operated 25 patients suffered from AIS and ICA thrombosis from 01 Feb, 2014 till 31 Aug, 2016 in Neurosurgical Department of N.V. Sklifosovsky Research Institute for Emergency Medicine. Among them, 15 patients had total thrombosis of ICA and were operated on, 10 patients had partial mural thrombosis or floating thrombus (6 patients were operated on). There were 7 thrombectomies with the removal of intima, 13 superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses, 1 ICA stent installation.Results. The excellent outcomes were seen in 7 (33.4%) patients, good outcomes — in 11 (52.3%) and satisfactory outcomes were observed in 3 (14.3%) patients. The improvement of functional deficit in the early post-operative period was 4.85 scores according to NIHSS, 1.2 scores according to Rankin scale and 2.3 scores according to Rivermead mobility index. The regress of neurological deficit was more significant among patients with severe focal disturbances; better outcomes were among patients operated on within first 3 days from an onset of the disease. There was no significant improvement among non-operated patients at the moment of discharge from hospital. Thrombectomy with the removal of intima performed in 2 (40%) patients with partial mural thrombosis was complicated by repeated thrombosis of ICA. The improvement of cerebral blood supply was verified in 16 (76.2%) operated patients according to the data of cerebral perfusion examination.Conclusions. The early surgical treatment is indicated for patients with acute total thrombosis of ICA. It is possible to perform STA-MCA bypass in case of inability to perform endovascular thrombextraction or open thrombectomy with the removal of intima. The conservative treatment is indicated for patients with partial mural thrombosis while urgent operation is necessary among patient with floating thrombus to decrease the risk of cerebral embolism