947 research outputs found
Evaluation of a Liquid Amine System for Spacecraft Carbon Dioxide Control
The analytical and experimental studies are described which were directed toward the acquisition of basic information on utilizing a liquid amine sorbent for in use in a CO2 removal system for manned spacecraft. Liquid amine systems are successfully used on submarines for control of CO2 generated by the crew, but liquid amines were not previously considered for spacecraft applications due to lack of development of satisfactory rotary phase separators. Developments in this area now make consideration of liquid amines practical for spacecraft system CO2 removal. The following major tasks were performed to evaluate liquid amine systems for spacecraft: (1) characterization, through testing, of the basic physical and thermodynamic properties of the amine solution; (2) determination of the dynamic characteristics of a cocurrent flow absorber; and (3) evaluation, synthesis, and selection of a liquid amine system concept oriented toward low power requirements. A low weight, low power system concept was developed. Numerical and graphical data are accompanied by pertinent observations
FK506 and Cyclosporin A Enhance IL-6 Production in Monocytes: A single-Cell Assay
The effect of FK506 and cyclosporin A (CsA) on the production of
interleukin 6 (IL-6) in adherent monocytes was studied at a
single-cell level by the avidinbiotin- peroxidase complex methods.
The percentage of IL-6-producing monocytes increased when stimulated
with lipopolysaccharide (LPS) at concentrations between 10 ng/ml and
10 μg/ml, in a dose dependent manner. Both FK506 and CsA
enhanced the percentage of IL-6- producing monocytes stimulated with
100 pg/ml-1 μg/ml of LPS up to values near those
obtained with 10 μg/ml of LPS. The enhancement by FK506 and
CsA was not seen when monocytes were stimulated with a high
concentration of LPS (10 μg/ml). When monocytes were
stimulated with a low concentration of LPS (10 ng/ml), FK506 and
CsA enhanced IL-6 production in a dose dependent manner, at a drug
concentration of 0.12 nM–1.2 μM (0.1–1 000 ng/ml)
for FK506 and 0.83 nM–8.3 μM (1–10 000 ng/ml) for
CsA. The optimal effect of FK506 was achieved at a concentration
7-fold lower than that of CsA. In contrast, production of turnout
necrosis factor-α (TNFα and interleukin 1β
(IL-1β) was slightly suppressed by FK506 and CsA at the
concentrations tested. Moreover, pretreatment of monocytes with
FK506 and CsA had a significant enhancing effect on LPS-induced IL-6
production, while treatment with FK506 or CsA after LPS stimulation
had no effects on IL-6 production, suggesting that the enhancing
effect of each drug is exerted before LPS stimulation or at an early
stage of the post-receptor pathway after LPS stimulation. These
experiments demonstrate that FK506 and CsA can selectively enhance
IL-6 production in monocytes under certain conditions in
vitro and, possibly, also in vivo
A comparison study of regional atmospheric simulations with an elastic backscattering Lidar and sunphotometry in an urban area
We describe a comparison study of Aerosol Optical Thickness (AOT) from numerical simulations using a regional atmospheric model with an elastic backscattering lidar operating at 532 nm and a sunphotometer belonging to the AERONET network at São Paulo (23° S 46° W) city, Brazil, a very populated urban area. The atmospheric model includes an aerosol emission, transport and deposition module coupled to a radiative transfer parameterization, which takes the interaction between aerosol particles and short and long wave radiation into account. A period of one week was taken as case study during the dry season (late August) when intense biomass burning activities occur at remote areas in South America, and meteorological conditions disfavor the pollution dispersion in the city of São Paulo. The situation presented here showed how smoke from biomass burning in remote areas is transported to the south-east part of Brazil and affects the optical atmospheric conditions in São Paulo. The numerical simulations are corroborated by in situ measurements of AOT obtained by lidar and sun photometry
Restoration of endogenous wild-type p53 activity in a glioblastoma cell line with intrinsic temperature-sensitive p53 induces growth arrest but not apoptosis.
p53 protein is a transcription factor involved in multiple tumor-suppressor activities including cell cycle control and apoptosis. TP53 gene is frequently mutated in glioblastoma, suggesting the importance of inactivation of this gene product in gliomagenesis. Restoration of p53 function in glioblastoma cell lines deficient for p53 has shown that p53 induces growth arrest or apoptosis depending on the cell line and vector used to transduce wild-type TP53 alleles. Considering that astrocytes grow and express p53, it is not clear whether these results reflect physiologic responses or the result of p53 overexpression in combination with cellular responses to viral vector infection. Here, we reassessed this issue using a glioblastoma cell line (LN382) that expresses an endogenous temperature-sensitive mutant p53. This cell line expresses TP53 alleles (100% as determined by a p53 transcriptional assay in yeast) mutated at codon 197 GTG (Val) > CTG (Leu). We found that the p53 protein in these cells acted as an inactive mutant at 37 degrees C and as a functional wild-type p53 below 34 degrees C as demonstrated by several lines of evidence, including (i) restoration of transactivating ability in yeast, (ii) induction of p53-modulated genes such as CDKN1(p21) and transforming growth factor-alpha, (iii) disappearance of accumulated p53 protein in the nucleus and (iv) decrease in steady state p53 protein levels. This temperature switch allowed p53 levels, which were close to physiological levels to dramatically reduce LN382 cell proliferation by inducing a G(1)/S cell cycle block, but not to induce apoptosis. The lack of apoptosis was considered to be a result of the low level p53 expression, because increasing wild-type p53 levels by adenoviral-mediated gene transfer caused apoptosis in these cells. The LN382 cell line will be extremely useful for investigations into the roles of p53 in cellular responses to a variety of stimuli or damages
Bosonic t-J Model in a stacked triangular lattice and its phase diagram
In this paper, we study phase diagram of a system of two-component hard-core
bosons with nearest-neighbor (NN) pseudo-spin antiferromagnetic (AF)
interactions in a stacked triangular lattice. Hamiltonian of the system
contains three parameters one of which is the hopping amplitude between NN
sites, and the other two are the NN pseudo-spin exchange interaction and
the one that measures anisotropy of pseudo-spin interactions. We investigate
the system by means of the Monte-Carlo simulations and clarify the
low-temperature phase diagram. In particular, we are interested in how the
competing orders, i.e., AF order and superfluidity, are realized, and also
whether supersolid forms as a result of hole doping into the state of the
pseudo-spin pattern with the structure.Comment: 18 pages, 17 figures, Version to appear in J.Phys.Soc.Jp
Aplicativo Multiplataforma para Monitoramento de Diabetes Mellitus
O Brasil é o quinto no número de pessoas com mais de 65 anos com diabetes, 12,5 milhões de pessoas diagnosticadas com diabetes, o que coloca o Brasil na quarta posição entre os 10 países com o maior número de indivíduos com diabetes [IDF, 2017]. Considerando a necessidade dos diabéticos que necessitam de monitoramento constante e regular da glicose [Dovc et al., 2018], este artigo apresenta o desenvolvimento de uma aplicação multi-plataforma. integrado a um site consulto
Beam-Breakup Instability Theory for Energy Recovery Linacs
Here we will derive the general theory of the beam-breakup instability in
recirculating linear accelerators, in which the bunches do not have to be at
the same RF phase during each recirculation turn. This is important for the
description of energy recovery linacs (ERLs) where bunches are recirculated at
a decelerating phase of the RF wave and for other recirculator arrangements
where different RF phases are of an advantage. Furthermore it can be used for
the analysis of phase errors of recirculated bunches. It is shown how the
threshold current for a given linac can be computed and a remarkable agreement
with tracking data is demonstrated. The general formulas are then analyzed for
several analytically solvable cases, which show: (a) Why different higher order
modes (HOM) in one cavity do not couple so that the most dangerous modes can be
considered individually. (b) How different HOM frequencies have to be in order
to consider them separately. (c) That no optics can cause the HOMs of two
cavities to cancel. (d) How an optics can avoid the addition of the
instabilities of two cavities. (e) How a HOM in a multiple-turn recirculator
interferes with itself. Furthermore, a simple method to compute the orbit
deviations produced by cavity misalignments has also been introduced. It is
shown that the BBU instability always occurs before the orbit excursion becomes
very large.Comment: 12 pages, 6 figure
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