Satellite-based quantum terminals are a feasible way to extend the reach of quantum communication protocols such as quantum key distribution (QKD) to the global scale. To that end, prior demonstrations have shown QKD transmissions from airborne platforms to receivers on ground, but none have shown QKD transmissions from ground to a moving aircraft, the latter scenario having simplicity and flexibility advantages for a hypothetical satellite. Here we demonstrate QKD from a ground transmitter to a receiver prototype mounted on an airplane in flight. We have specifically designed our receiver prototype to consist of many components that are compatible with the environment and resource constraints of a satellite. Coupled with our relocatable ground station system, optical links with distances of 3-10 km were maintained and quantum signals transmitted while traversing angular rates similar to those observed of low-Earth-orbit satellites. For some passes of the aircraft over the ground station, links were established within 10 s of position data transmission, and with link times of a few minutes and received quantum bit error rates typically ≈3-5 %, we generated secure keys up to 868 kb in length. By successfully generating secure keys over several different pass configurations, we demonstrate the viability of technology that constitutes a quantum receiver satellite payload and provide a blueprint for future satellite missions to build upon.
The endoscopic transclival approach may be used to access midline tumors of the posterior cranial fossa. The approach is an alternative to transcranial approaches in surgical treatment of clival region lesions. This approach provides results comparable (and sometimes better) to those of the transcranial and transfacial approaches.
РезюмеЦель исследования. Сравнить реактивность сосудов головного мозга (РСГМ) у больных ревматоидным артритом (РА) в сочетании с эссенциальной артериальной гипертонией -АГ (1-я группа) и на фоне нормального артериального давления -АД (2-я группа). Материалы и методы. В рамках исследования у 37 больных 1-й и у 12 больных 2-й групп оценивали распространенность традиционных факторов риска развития сердечно-сосудистых заболеваний, выполняли суточное мониторирование АД, изучали РСГМ с помощью транскраниальной допплерографии (ТКД) средних мозговых артерий (СМА) с проведением гипероксической и гиперкапнической проб, зависимую от эндотелия (ЗЭВД) и независимую от эндотелия вазодилатацию (НЭВД) плечевой артерии. Группы сопоставимы по полу, возрасту, степени активности и стадии РА, объему противоревматической терапии. Результаты. По результатам ТКД СМА нарушение РСГМ регистрировали в гипероксической пробе у 34 (92%) больных 1-й группы и 10 (83%) больных 2-й группы; в гиперкапнической пробе -у 19 (51%) и 6 (50%) больных соответственно. Наиболее часто в гипероксической пробе наблюдали недостаточное снижение линейных скоростей кровотока (ЛСК) в СМА у 31 (84%) больных 1-й группы и 8 (66%) больных 2-й группы, в гиперкапнической пробе -чрезмерное увеличение ЛСК в СМА у 12 (32%) и 4 (33%) больных соответственно. Установлена высокая частота нарушения ЭЗВД у 32 (86%) больных 1-й группы и у 9 (75%) больных 2-й группы. Заключение. По результатам ТКД СМА у больных РА в сочетании с АГ и без нее выявлена высокая и сопоставимая частота нарушения РСГМ при проведении гипероксической и гиперкапнической проб.Ключевые слова: реактивность сосудов головного мозга, ревматоидный артрит, артериальная гипертония, дисфункция эндотелия. Aim.To compare cerebrovascular reactivity (CVR) in patients with rheumatoid arthritis (RA) concurrent with essential hypertension (Group 1) and in those with RA and normal blood pressure (BP) (Group 2). Subjects and methods. During the study of Groups 1 (n=37) and 2 (n=12), the investigators estimated the prevalence of traditional cardiovascular risk factors, performed 24-hour BP monitoring, investigated CVR by transcranial Doppler (TCD) of the middle cerebral arteries (MCA) by hyperoxic and hypercapnic tests, and endothelium-dependent vasodilation (EDV) and endotheliumindependent vasodilation of the brachial artery. The groups were matched for gender, age, RA activity and stage, and antirheumatic therapy volume. Results. According to the results of MCA TCD, the hyperoxic test recorded impaired CVR in 34 (92%) and 10 (83%) patients in Group 1 and 2, respectively; the hypercapnic test revealed this condition in 19 (51%) and 6 (50%) patients in these groups, respectively. The hyperoxic test most commonly showed an insufficient decrease in MCA linear blood flow velocities (LBFV) in 31 (84%) and 8 (66%) patients in Groups 1 and 2, respectively; the hypercapnic test did an excessive increase in MCA LBFV in 12 (32%) and 4 (33%) patients, respectively. There was a high rate of impaired EDV in 32 (86%) and 9 (75%) patients i...
morPHo-toPometriC VariaBilitY oF anatomiCal struCtures in tHoraCiC sPinea b s t r a C t -We studied the size-related features (body height, intervertebral discs, horizontal and vertical diameters of intervertebral foramina) on CT-grams of the thoracic spine in people whose age belongs to the first adulthood period (60 men aged 22-35 and 65 females aged 21-35) with no signs of the spine disease or any systemic and traumatic lesions. We have identified topographical variability, gender dimorphism as well as the interconnection of the parameters under study. K E y w o r d s -thoracic spine, vertebrae body, intervertebral discs, intervertebral foramen.
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