1,317 research outputs found
Extravehicular activities limitations study. Volume 1: Physiological limitations to extravehicular activity in space
This report contains the results of a comprehensive literature search on physiological aspects of EVA. Specifically, the topics covered are: (1) Oxygen levels; (2) Optimum EVA work; (3) Food and Water; (4) Carbon dioxide levels; (5) Repetitive decompressions; (6) Thermal, and (7) Urine collection. The literature was assessed on each of these topics, followed by statements on conclusions and recommended future research needs
Clinical Use of Cinacalcet in MEN1 Hyperparathyroidism
Background. Management of multiple-endocrine neoplasia type 1- (MEN1-) associated hyperparathyroidism is associated with high recurrence rates and high surgical morbidity due to multiple neck explorations. Cinacalcet, a calcimimetic agent licensed for the treatment of secondary hyperparathyroidism and parathyroid carcinoma, may provide a medical alternative for the management of these complex patients. Methods. A prospective audit was performed of eight patients; three males and five females, aged 20â38 at diagnosis. Two patients commenced cinacalcet as primary treatment and six had previous surgery. Six patients had complications of hyperparathyroidism: renal calculi, renal dysfunction, and reduced bone mineral density. All were commenced on cinacalcet 30âmg bd for MEN1 associated hyperparathyroidism; doses were subsequently reduced to 30âmg od in four patients. Results. Significant reductions were observed in serum calcium and PTH measurements. Serum calcium reduced by a median of 0.35âmmol/L (P = .012 Wilcoxon Signed Rank). Serum PTH levels decreased by a median of 5.05âpmol/L (P = .012). There was no change in urine calcium.
Duration ranged from 10â35 months with maintenance of control. Cinacalcet was well tolerated by six patients; one experienced nausea and one experienced diarrhoea. Conclusion. Cinacalcet is an effective and well-tolerated medical treatment for the management of complex primary hyperparathyroidism
Reaction-diffusion dynamics: confrontation between theory and experiment in a microfluidic reactor
We confront, quantitatively, the theoretical description of the
reaction-diffusion of a second order reaction to experiment. The reaction at
work is \ca/CaGreen, and the reactor is a T-shaped microchannel, 10 m
deep, 200 m wide, and 2 cm long. The experimental measurements are
compared with the two-dimensional numerical simulation of the
reaction-diffusion equations. We find good agreement between theory and
experiment. From this study, one may propose a method of measurement of various
quantities, such as the kinetic rate of the reaction, in conditions yet
inaccessible to conventional methods
Regular Incidence Complexes, Polytopes, and C-Groups
Regular incidence complexes are combinatorial incidence structures
generalizing regular convex polytopes, regular complex polytopes, various types
of incidence geometries, and many other highly symmetric objects. The special
case of abstract regular polytopes has been well-studied. The paper describes
the combinatorial structure of a regular incidence complex in terms of a system
of distinguished generating subgroups of its automorphism group or a
flag-transitive subgroup. Then the groups admitting a flag-transitive action on
an incidence complex are characterized as generalized string C-groups. Further,
extensions of regular incidence complexes are studied, and certain incidence
complexes particularly close to abstract polytopes, called abstract polytope
complexes, are investigated.Comment: 24 pages; to appear in "Discrete Geometry and Symmetry", M. Conder,
A. Deza, and A. Ivic Weiss (eds), Springe
Empirical 2MASS-WFC3/IR filter transformations from synthetic photometry
Near-infrared bandpasses on spaceborne observatories diverge from their
ground-based counterparts as they are free of atmospheric telluric absorption.
Available transformations between respective filter systems in the literature
rely on theoretical stellar atmospheres, which are known to have difficulties
reproducing observed spectral energy distributions of cool giants. We present
new transformations between the 2MASS and HST WFC3/IR F110W, F125W, &
F160W photometric systems based on synthetic photometry of empirical stellar
spectra from four spectral libraries. This sample comprises over 1000
individual stars, which together span nearly the full HR diagram and sample
stellar populations from the solar neighborhood out to the Magellanic Clouds,
covering a broad range of ages, metallicities, and other relevant stellar
properties. In addition to global color-dependent transformations, we examine
band-to-band differences for cool, luminous giant stars in particular,
including multiple types of primary distance indicators.Comment: 24 pages, 15 figures, accepted to A
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