621 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
Oral iron exacerbates colitis and influences the intestinal microbiome
Inflammatory bowel disease (IBD) is associated with anaemia and oral iron replacement to correct this can be problematic, intensifying inflammation and tissue damage. The intestinal microbiota also plays a key role in the pathogenesis of IBD, and iron supplementation likely influences gut bacterial diversity in patients with IBD. Here, we assessed the impact of dietary iron, using chow diets containing either 100, 200 or 400 ppm, fed ad libitum to adult female C57BL/6 mice in the presence or absence of colitis induced using dextran sulfate sodium (DSS), on (i) clinical and histological severity of acute DSS-induced colitis, and (ii) faecal microbial diversity, as assessed by sequencing the V4 region of 16S rRNA. Increasing or decreasing dietary iron concentration from the standard 200 ppm exacerbated both clinical and histological severity of DSS-induced colitis. DSS-treated mice provided only half the standard levels of iron ad libitum (i.e. chow containing 100 ppm iron) lost more body weight than those receiving double the amount of standard iron (i.e. 400 ppm); p<0.01. Faecal calprotectin levels were significantly increased in the presence of colitis in those consuming 100 ppm iron at day 8 (5.94-fold) versus day-10 group (4.14-fold) (p<0.05), and for the 400 ppm day-8 group (8.17-fold) versus day-10 group (4.44-fold) (p<0.001). In the presence of colitis, dietary iron at 400 ppm resulted in a significant reduction in faecal abundance of Firmicutes and Bacteroidetes, and increase of Proteobacteria, changes which were not observed with lower dietary intake of iron at 100 ppm. Overall, altering dietary iron intake exacerbated DSS-induced colitis; increasing the iron content of the diet also led to changes in intestinal bacteria diversity and composition after colitis was induced with DSS
Hepatic effects of tartrazine (E 102) after systemic exposure are independent of oestrogen receptor interactions in the mouse
Tartrazine is a food colour that activates the transcriptional function of the human oestrogen receptor alpha in an in vitro cell model. Since oestrogens are cholestatic, we hypothesised tartrazine will cause periportal injury to the liver in vivo. To test this hypothesis, tartrazine was initially administered systemically to mice resulting in a periportal recruitment of inflammatory cells, increased serum alkaline phosphatase activity and mild periportal fibrosis. To determine whether an oestrogenic effect may be a key event in this response, tartrazine, sulphonated metabolites and a food additive contaminant were screened for their ability to interact with murine oestrogen receptors. In all cases, there were no interactions as agonists or antagonists and further, no oestrogenicity was observed with tartrazine in an in vivo uterine growth assay. To examine the relevance of the hepatic effects of tartrazine to its use as a food additive, tartrazine was orally administered to transgenic NF-κB-Luc mice. Pre- and concurrent oral treatment with alcohol was incorporated given its potential to promote gut permeability and hepatic inflammation. Tartrazine alone induced NF- κB activities in the colon and liver but there was no periportal recruitment of inflammatory cells or fibrosis. Tartrazine, its sulphonated metabolites and the contaminant inhibited sulphotransferase activities in murine hepatic S9 extracts. Given the role of sulfotransferases in bile acid excretion, the initiating event giving rise to periportal inflammation and subsequent hepatic pathology through systemic tartrazine exposure is therefore potentially associated an inhibition of bile acid sulphation and excretion and not on oestrogen receptor-mediated transcriptional function. However, these effects were restricted to systemic exposures to tartrazine and did not occur to any significant effect after oral exposure
Effect of disorder on the vortex-lattice melting transition
We use a three dimensional stacked triangular network of Josephson junctions
as a model for the study of vortex structure in the mixed state of high Tc
superconductors. We show that the addition of disorder destroys the first order
melting transition occurring for clean samples. The melting transition splits
in two different (continuous) transitions, ocurring at temperatures Ti and Tp
(>Ti). At Ti the perpendicular-to-field superconductivity is lost, and at Tp
the parallel-to-field superconductivity is lost. These results agree well with
recent experiments in YBaCuO.Comment: 4 pages + 2 figure
1-(1-Carboxymethyl-1,4-anhydro-2,3-O-isopropylidene-α-d-erythrofuranosyl)thymine
X-Ray crystallography unequivocally determined the stereochemistry of the thymine base in the title compound, C14H18N2O7. The absolute stereochemistry was determined from the use of d-ribose as the starting material. There are two independent molecules in the asymmetric unit (Z′ = 2) which exist as N—H⋯O hydrogen-bonded pairs in the crystal structure
The role of the psychologist in the inpatient pain service: development and initial outcomes
© The British Pain Society 2020. Aim: This article describes the development and initial evaluation of introducing a psychologist role within an adult inpatient pain service (IPS) in a large North West of England National Health Service (NHS) trust. Background: The role of a psychologist in the management of outpatient chronic pain has been well documented, but their role within the IPS is less well described and rarely evaluated. We describe the development of a psychologist role within the team and initial service evaluation outcomes. Methods: Following an initial needs assessment, a band 8c psychologist joined the IPS one day per week offering brief one-to-one psychological interventions to people struggling with acute or chronic pain in hospital referred by inpatient pain team. The psychologist had an indirect role offering training, supervision and support to members of the inpatient pain team. Regarding direct patient work, following psychometric screening for pain-related disability and distress, a cognitive behavioural therapy (CBT) approach was applied including identifying unhelpful beliefs about pain, psychoeducation about acute and persistent pain, developing and sharing formulations, skills training including breathing and relaxation exercises and where appropriate, signposting onto an outpatient chronic pain services for further pain self-management advice (e.g. pain management programme. To explore the impact of this direct intervention, a prospective service evaluation with a controlled before and after design was conducted. This compared (a) number of admissions and (b) length-of-stay outcomes in the 12 months following psychometric screening for patients who received psychological input (n = 34, the treatment group) and a sample who did not receive input because of discharge before intervention or non-availability of the psychologist, for example, annual leave (n = 30, control group). Demographic information and summaries of psychometric questionnaires were also analysed. Results: Of the sample of 64 patients, 50 were women, ages ranged from 18–80 years, 72% reported being currently unemployed or off sick from work and on screening and 39% and 48% met criteria for severe depression and pain-related anxiety, respectively. Hospital admissions in the intervention group reduced significantly (by 60%) in the 12 months following screening but increased (by 7%) for the control group (F(1,62) = 7.21, p =.009). Days of stay in hospital reduced significantly more (by 84%) in the intervention group than in the control group (by 41%) (F(1,62) = 8.90, p =.004). Illustrated case studies of brief psychological intervention with three people struggling with pain-related distress are presented. Conclusions: The psychologist became a valuable member of the multi-disciplinary IPS team, offering brief direct and indirect psychological interventions. While a relatively small sample, our prospective service evaluation data suggest brief psychological intervention may contribute to reduced length of stay and hospital admissions for people experiencing pain-related distress in hospital
Vortex structure and resistive transitions in high-Tc superconductors
The nature of the resistive transition for a current applied parallel to the
magnetic field in high-Tc materials is investigated by numerical simulation on
the three dimensional Josephson junction array model. It is shown by using
finite size scaling that for samples with disorder the critical temperature Tp
for the c axis resistivity corresponds to a percolation phase transition of
vortex lines perpendicularly to the applied field. The value of Tp is higher
than the critical temperature for j perpendicular to H, but decreases with the
thickness of the sample and with anisotropy. We predict that critical behavior
around Tp should reflect in experimentally accessible quantities, as the I-V
curves.Comment: 8 pages + 6 figure
The phase diagram of high-Tc's: Influence of anisotropy and disorder
We propose a phase diagram for the vortex structure of high temperature
superconductors which incorporates the effects of anisotropy and disorder. It
is based on numerical simulations using the three-dimensional Josephson
junction array model. We support the results with an estimation of the internal
energy and configurational entropy of the system. Our results give a unified
picture of the behavior of the vortex lattice, covering from the very
anysotropic BiSrCaCuO to the less anisotropic YBaCuO, and from the first order
melting ocurring in clean samples to the continuous transitions observed in
samples with defects.Comment: 8 pages with 7 figure
Pseudo-cryptic speciation in coccolithophores
Coccolithophores are a group of calcifying unicellular algae that constitute a major fraction of oceanic primary productivity, play an important role in the global carbon cycle, and are key biostratigraphic marker fossils. Their taxonomy is primarily based on the morphology of the minute calcite plates, or coccoliths, covering the cell. These are diverse and include widespread fine scale variation, of which the biological/taxonomic significance is unknown. Do they represent phenotypic plasticity, genetic polymorphisms, or species-specific characters? Our research on five commonly occurring coccolithophores supports the hypothesis that such variation represents pseudocryptic speciation events, occurring between 0.3 and 12.9 million years ago from a molecular clock estimation. This finding suggests strong stabilizing selection acting on coccolithophorid phenotypes. Our results also provide strong support for the use of fine scale morphological characters of coccoliths in the fossil record to improve biostratigraphic resolution and paleoceanographic data retrieval
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