Torus invariant divisors

Using the language of polyhedral divisors and divisorial fans we describe invariant divisors on normal varieties X which admit an effective codimension one torus action. In this picture X is given by a divisorial fan on a smooth projective curve Y. Cartier divisors on X can be described by piecewise affine functions h on the divisorial fan S whereas Weil divisors correspond to certain zero and one dimensional faces of it. Furthermore we provide descriptions of the divisor class group and the canonical divisor. Global sections of line bundles O(D_h) will be determined by a subset of a weight polytope associated to h, and global sections of specific line bundles on the underlying curve Y.Comment: 16 pages; 5 pictures; small changes in the layout, further typos remove

Affine T-varieties of complexity one and locally nilpotent derivations

Let X=spec A be a normal affine variety over an algebraically closed field k of characteristic 0 endowed with an effective action of a torus T of dimension n. Let also D be a homogeneous locally nilpotent derivation on the normal affine Z^n-graded domain A, so that D generates a k_+-action on X that is normalized by the T-action. We provide a complete classification of pairs (X,D) in two cases: for toric varieties (n=\dim X) and in the case where n=\dim X-1. This generalizes previously known results for surfaces due to Flenner and Zaidenberg. As an application we compute the homogeneous Makar-Limanov invariant of such varieties. In particular we exhibit a family of non-rational varieties with trivial Makar-Limanov invariant.Comment: 31 pages. Minor changes in the structure. Fixed some typo

Features of Polymeric Structures By Surface—Selective Laser Sintering of Polymer Particles Using Water as Sensitizer

The development of scaffolds with strictly specific properties is a key aspect of functional tissue regeneration, and it still remains one of the greatest challenges for tissue engineering. This study is aimed to determine the possibility of producing three-dimensional polylactide (PLA) scaffolds using the method of surface-selectiv  laser sintering (SSLS) for bone tissue regeneration. In this work, the authors also improved PLA scaffold adhesion properties, which are crucial for successful cellular growth and expansion. Thus, SSLS method proved to be effective in designing threedimensional porous scaffolds with differentiated mechanical properties. Keywords: regenerative medicine, scaffolds, polylactide, surface – selective laser . sintering, tissue engeneering

Classification of Reductive Monoid Spaces Over an Arbitrary Field

In this semi-expository paper we review the notion of a spherical space. In particular we present some recent results of Wedhorn on the classification of spherical spaces over arbitrary fields. As an application, we introduce and classify reductive monoid spaces over an arbitrary field.Comment: This is the final versio

Harmonic analysis on spherical homogeneous spaces with solvable stabilizer

For all spherical homogeneous spaces G/H, where G is a simply connected semisimple algebraic group and H a connected solvable subgroup of G, we compute the spectra of the representations of G on spaces of regular sections of homogeneous line bundles over G/H.Comment: v2: 14 pages, minor correction

Local delivery of pirfenidone by pla implants modifies foreign body reaction and prevents fibrosis

Peri-implant fibrosis (PIF) increases the postsurgical risks after implantation and limits the efficacy of the implantable drug delivery systems (IDDS). Pirfenidone (PF) is an oral anti-fibrotic drug with a short (1100 Μm in control groups) approaching the intact derma thickness value (302 ± 15 Μm). In PLA@PF group, the implant biodegradation developed faster, while arginase-1 expression was suppressed in comparison with other groups. This study proves the feasibility of the local control of fibrotic response on implants via modulation of foreign body reaction with slowly biodegradable PF-loaded IDDS

StopCOVID cohort : An observational study of 3,480 patients admitted to the Sechenov University hospital network in Moscow city for suspected COVID-19 infection

© 2020 Oxford University Press. This is a pre-copyedited, author-produced PDF of an article accepted for publication in Clinical Infectious Diseases following peer review. The version of record is available online at: https://doi.org/10.1093/cid/ciaa1535.BACKGROUND: The epidemiology, clinical course, and outcomes of COVID-19 patients in the Russian population are unknown. Information on the differences between laboratory-confirmed and clinically-diagnosed COVID-19 in real-life settings is lacking. METHODS: We extracted data from the medical records of adult patients who were consecutively admitted for suspected COVID-19 infection in Moscow, between April 8 and May 28, 2020. RESULTS: Of the 4261 patients hospitalised for suspected COVID-19, outcomes were available for 3480 patients (median age 56 years (interquartile range 45-66). The commonest comorbidities were hypertension, obesity, chronic cardiac disease and diabetes. Half of the patients (n=1728) had a positive RT-PCR while 1748 were negative on RT-PCR but had clinical symptoms and characteristic CT signs suggestive of COVID-19 infection.No significant differences in frequency of symptoms, laboratory test results and risk factors for in-hospital mortality were found between those exclusively clinically diagnosed or with positive SARS-CoV-2 RT-PCR.In a multivariable logistic regression model the following were associated with in-hospital mortality; older age (per 1 year increase) odds ratio [OR] 1.05 (95% confidence interval (CI) 1.03 - 1.06); male sex (OR 1.71, 1.24 - 2.37); chronic kidney disease (OR 2.99, 1.89 - 4.64); diabetes (OR 2.1, 1.46 - 2.99); chronic cardiac disease (OR 1.78, 1.24 - 2.57) and dementia (OR 2.73, 1.34 - 5.47). CONCLUSIONS: Age, male sex, and chronic comorbidities were risk factors for in-hospital mortality. The combination of clinical features were sufficient to diagnoseCOVID-19 infection indicating that laboratory testing is not critical in real-life clinical practice.Peer reviewe

Метод оценки надежности арктических тр убопроводов в пространстве нагрузок

Arctic pipelines (PL) are located north of the 60th parallel. The main factors that characterize features of such pipelines are the climatic conditions in their areas of installation. Arctic pipeline routes pass through tundra with dwarf vegetation, marshes, and large areas with permafrost lenses, in watery and swampy areas with unique geological and hydrological conditions. The absolute difference of temperatures ranges from –56 degrees Centigrade in winter to 34 Centigrade in summer; and strong winds with speed over 40 m/s. Under these conditions, reliability and safety assessment of pipelines is associated with many principal difficulties, one of which is the need to take into account the simultaneous action (a combination) of many natural and technological loads on the pipeline infrastructure, which are random by nature and can be adequately described only by stochastic processes. Currently, reliability assessment of such systems is not performed due to lack of valid calculation methods. In this paper a description is given of the first stage of assessing reliability of a pipeline subject to a combination of loads described as random Markov processes. This method, developed by S. A. Timashev in [1], a. k.a. assessment of reliability in the space of loads, assumes the ability of constructing admissible areas in this load space with respect to different limit states. The method is applied to a segment of an above ground arctic oil pipeline with surface corrosion type defects, subjected to a combination (simultaneous action) of four loads: 1) dead weight of the pipe with insulation and oil being pumped, 2) operating pressure, 3) wind load, and 4) exposure to a uniform wall thickness thinning. The pipeline is considered as a continuous multi-bay thin wall cylindrical beam. The pipeline design is performed according to the (conditional) limit state which is reached when the equivalent stresses in pipe wall reach the yield stress of pipe material. The main purpose of the presented work is reliability assessment of PL in the space of load (impacts). At this the dead load of the pipeline structure is considered to be deterministic. The influence of the wind load, uniform corrosion, and operating pressure (OP) are considered to be variables. For them the permissible region is constructed using the above limit state.Арктические трубопроводы находятся к северу от 60?й параллели. Основными факторами, характеризующими особенности таких трубопроводов, являются климатические условия в местах их прокладки. Арктические трассы трубопроводов проходят через тундру с карликовой растительностью, болота и большие территории с вечной мерзлотой, обводненную и заболоченную местность с уникальными геологическими и гидрологическими условиями. Разница температур составляет от –56 зимой до +34 °C в летний период; скорость ветра свыше 40 м/с. В таких условиях оценка надежности и безопасности трубопроводов связана с множеством проблем, одной из которых является необходимость учитывать одновременное воздействие на трубопроводы многих природных и технологических нагрузок, которые носят случайный характер и могут быть адекватно описаны только с помощью случайных процессов. В настоящее время оценка надежности таких систем не выполняется из-за отсутствия научно обоснованных методов расчета. В данной статье описывается первый этап оценки надежности трубопровода при условии описания сочетания нагрузок как случайного процесса Маркова. Этот метод, разработанный С. А. Тимашевым [1], называется методом оценки надежности в пространстве нагрузок и предполагает возможность построения допустимых областей в пространстве нагрузки с учетом различных предельных состояний. Метод применен к сегменту наземного арктического нефтепровода с коррозией поверхности, подверженному комбинации (одновременному действию) четырех нагрузок: 1) собственный вес трубы с изоляцией и перекачиваемой нефти, 2) рабочее давление, 3) ветровая нагрузка и 4) утоньшение стенки. Трубопровод рассматривается как непрерывная многосекционная тонкостенная цилиндрическая балка. Проектирование трубопровода осуществляется по предельному состоянию, которое достигается, когда эквивалентные напряжения в стенке трубы достигают предела текучести материала трубы. Основной целью данной работы является оценка надежности трубопровода в пространстве нагрузок (воздействий). Здесь постоянные нагрузки на трубопровод считаются неизменными. Влияние ветровой нагрузки, равномерной коррозии и рабочее давление считаются переменными. Для них построена допустимая область с учетом описанного выше предельного состояния

Influence of tetrafunctional polylactide morphology on regeneration of bone tissue defects

Определено влияние длины разветвленных цепей сшитых тетрафункциональных полилкатидов на микроморфологию поверхности. Оценены механические свойства структурированных скаффолдов в режиме PeakForce QNM (MultiMode 8, ruker, США). Подобран оптимальный по своим механическим и поверхностным характеристикам тип полилактидов для полной регенерации созданного костного дефекта ткани мышиThe influence of the length of branched chains of cross-linked tetrafunctional polyclatides on the surface micromorphology is determined. The mechanical properties of structured scaffolds are estimated in the PeakForce QNM mode (MultiMode 8, Bruker, USA). Optimal type of polylactide for its mechanical and surface characteristics was selected for complete regeneration of the created bone defect in mouse tissue