1,054 research outputs found
The course of experimental staphylococcus infection in albino mice during action of certain factors of space flight
A study was made of the effect of certain factors of space flight, acceleration and hypokinesia, on the course of experimental staphylococcus infection in mice. Combined action of hypokinesia and acceleration caused a marked depression of the phagocytic activity of leukocytes and formation of a considerable amount of alpha toxin
The role of alkane coordination in C–H bond cleavage at a Pt(II) center
The rates of CFormula H bond activation for various alkanes by [(N–N)Pt(Me)(TFEd3)]+ (N Formula N = ArFormula NFormula C(Me)Formula C(Me)Formula NFormula Ar; Ar = 3,5-di-tert-butylphenyl; TFE-d3 = CF3CD2OD) were studied. Both linear and cyclic alkanes give the corresponding alkene-hydride cation [(N–N)Pt(H)(alkene)]+ via (i) rate determining alkane coordination to form a CFormula H {sigma} complex, (ii) oxidative cleavage of the coordinated CFormula H bond to give a platinum(IV) alkyl-methyl-hydride intermediate, (iii) reductive coupling to generate a methane {sigma} complex, (iv) dissociation of methane, and (v) beta-H elimination to form the observed product. Second-order rate constants for cycloalkane activation (CnH2n), are proportional to the size of the ring (k ~ n). For cyclohexane, the deuterium kinetic isotope effect (kH/kD) of 1.28 (5) is consistent with the proposed rate determining alkane coordination to form a CFormula H {sigma} complex. Statistical scrambling of the five hydrogens of the Pt-methyl and the coordinated methylene unit, via rapid, reversible steps ii and iii, and interchange of geminal CFormula H bonds of the methane and cyclohexane CFormula H {sigma} adducts, is observed before loss of methane
VR Technologies in Vocational Education
Раскрыты основные понятия виртуальной реальности и ее системы. Дана характеристика трекинговых систем, основных технических средств (гарнитур). Показано влияние технологии виртуальной реальности в различных сферах деятельности. Обучение в VR является трендом в современном мире, что оказало влияние на создание программ с использованием иммерсивной технологии в обучении. Указаны проблемы и риски в использовании VR-технологий, а также ее преимущества в профессиональном образовании.The basic concepts of virtual reality and its systems are revealed. The characteristics of tracking systems, basic technical means (headsets) are given. The influence of virtual reality technology in various fields of activity is shown. VR learning is a trend in the modern world, which has influenced the creation of programs using immersive technology in learning. The problems and risks in using VR technology in the vocational education, as well as its advantages, are indicated
A Chebyshev minimax technique oriented to aerospace trajectory optimization problems.
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76822/1/AIAA-6604-910.pd
Pattern of Laboratory Parameters and Management of Secondary Hyperparathyroidism in Countries of Europe, Asia, the Middle East, and North America
Introduction
This analysis explored laboratory mineral and bone disorder parameters and management of secondary hyperparathyroidism in patients undergoing hemodialysis in Belgium, Canada, China, France, Germany, Italy, Japan, Russia, Saudi Arabia, Spain, Sweden, the UK, and the USA.
Methods
Analyses used demographic, medication, and laboratory data collected in the prospective Dialysis Outcomes and Practice Patterns Study (2012\u20132015). The analysis included 20,612 patients in 543 facilities. Descriptive data are presented as regional mean (standard deviation), median (interquartile range), or prevalence, weighted for facility sampling fraction. No testing of statistical hypotheses was conducted.
Results
The frequency of serum intact parathyroid hormone levels\u2009>\u2009600 pg/mL was lowest in Japan (1%) and highest in Russia (30%) and Saudi Arabia (27%). The frequency of serum phosphorus levels\u2009>\u20097.0 mg/dL was lowest in France (4%), the UK (6%), and Spain (6%), and highest in China (27%). The frequency of serum calcium levels\u2009>\u200910.0 mg/dL was highest in the UK (14%) and China (13%) versus 2% to 9% elsewhere. Dialysate calcium concentrations of 2.5 mEq/mL were common in the USA (78%) and Canada (71%); concentrations of 3.0\u20133.5 mEq/L were almost universal at facilities in Italy, France, and Saudi Arabia (each 65\u200999%).
Conclusions
Wide international variation in mineral and bone disorder laboratory parameters and management practices related to secondary hyperparathyroidism suggests opportunities for optimizing care
Constructions of regular algebras
Criterion of (Shilov) regularity for weighted algebras on a
locally compact abelian group is known by works of Beurling (1949) and
Domar (1956). In the present paper this criterion is extended to translation
invariant weighted algebras with . Regular algebras
are constructed on any sigma-compact abelian group . It was proved earlier
by the author that sigma-compactness is necessary (in the abelian case) for the
existence of weighted algebras with .Comment: Submitted to Mat. Sborni
High frequency magnetic oscillations of the organic metal -(ET)ZnBr(CHCl) in pulsed magnetic field of up to 81 T
De Haas-van Alphen oscillations of the organic metal
-(ET)ZnBr(CHCl) are studied in pulsed magnetic
fields up to 81 T. The long decay time of the pulse allows determining reliable
field-dependent amplitudes of Fourier components with frequencies up to several
kiloteslas. The Fourier spectrum is in agreement with the model of a linear
chain of coupled orbits. In this model, all the observed frequencies are linear
combinations of the frequency linked to the basic orbit and to the
magnetic-breakdown orbit .Comment: 6 pages, 4 figure
Therapeutic complement targeting in ANCA-associated vasculitides and thrombotic microangiopathy
Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) are a group of systemic autoimmune disorders characterized by necrotizing inflammation of medium-to-small vessels, a relative paucity of immune deposits, and an association with detectable circulating ANCAs. AAVs include granulomatosis with polyangiitis (renamed from Wegener's granulomatosis), microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome). Until recently, AAVs have not been viewed as complement-mediated disorders. However, recent findings predominantly from animal studies demonstrated a crucial role of the complement system in the pathogenesis of AAVs. Complement activation or defects in its regulation have been described in an increasing number of acquired or genetically driven forms of thrombotic microangiopathy. Coinciding with this expanding spectrum of complement-mediated diseases, the question arises as to which AAV patients might benefit from a complement-targeted therapy. Therapies directed against the complement system point to the necessity of a genetic workup of genes of complement components and regulators in patients with AAV. Genetic testing together with pluripotent stem cells and bioinformatics tools may broaden our approach to the treatment of patients with aggressive forms of AAV
Differential Form Valued Forms and Distributional Electromagnetic Sources
Properties of a fundamental double-form of bi-degree for are
reviewed in order to establish a distributional framework for analysing
equations of the form where
is the Hodge-de Rham operator on forms on .
Particular attention is devoted to singular distributional solutions that arise
when the source is a singular form distribution. A constructive
approach to Dirac distributions on (moving) submanifolds embedded in is developed in terms of (Leray) forms generated by the geometry of the
embedding. This framework offers a useful tool in electromagnetic modeling
where the possibly time dependent sources of certain physical attributes, such
as electric charge, electric current and polarization or magnetization, are
concentrated on localized regions in space.Comment: 40 page
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