2,483 research outputs found
Superfluidity versus localization in bulk 4He at zero temperature
We present a zero-temperature quantum Monte Carlo calculation of liquid
He immersed in an array of confining potentials. These external potentials
are centered in the lattice sites of a fcc solid geometry and, by modifying
their well depth and range, the system evolves from a liquid phase towards a
progressively localized system which mimics a solid phase. The superfluid
density decreases with increasing order, reaching a value when the Lindemann's ratio of the model equals the experimental
value for solid He.Comment: 5 pages,5 figure
Intentions to Prevent Weight Gain in Older and Younger Adults; The Importance of Perceived Health and Appearance Consequences
Objectives: This study investigates whether health and appearance consequences predict intentions to prevent weight gain and whether these relationships differ in younger versus older adults and in men versus women. Methods: UK adults aged 18-26 years (younger adults; n = 584) or > 45 years (older adults; n = 107) participated in an online survey. Logistic regression assessed associations between intentions to avoid gaining weight and age, gender as well as perceived negative consequences of weight gain for health and appearance. Co-variates were ethnicity, education, weight perception and perceived weight gain vulnerability. Interactions between age, gender and perceived health and appearance consequences of weight gain were also tested. Results: Perceived negative appearance consequences of weight gain predicted weight gain prevention intentions (OR = 9.3, p 0.01). Conclusion: Concerns about feeling unattractive predict intentions to prevent weight gain. However, health consequences of weight gain are only important motivators for older adults. Future research should identify ways to shift the focus of young people from appearance concerns towards the health benefits of maintaining a healthy weight
The effects of deoxycholate and sodium dodecyl sulphate on the serological reactivity of antigens isolated from six Bacteroides reference strains
Abstract
The detergents sodium dodecyl sulphate (SDS) and sodium deoxycholate (NaD) are frequently used as solvents for macromolecular polysaccharide complexes in immunochemical and serological techniques. The influence of the disaggregating surfactants on the serological reactivity of endotoxins isolated from six serotype specific reference strains of the Bacteroides fragilis group was investigated by comparing haemagglutinating and precipitating reactivities of antigen solutions in phosphate buffered saline (PBS), NaD and SDS. All antigens were phenol/water extracted endotoxins. Solutions of antigens isolated from serotypes A, B, C and D in PBS exhibited mainly serotype specificity and a few well known low-titer cross reactions; solutions in NaD showed additional cross reactivity, which was enhanced by solubilization of the antigens in SDS. In immunoelectrophoresis endotoxins isolated from serotypes A and C and dissolved in NaD or SDS showed additional precipitation lines compared to solutions of the same antigens in PBS.
These changes in the serological reactivity are of relevance for investigations where the serological specificty of antigens is in question
Size dependence of the photoinduced magnetism and long-range ordering in Prussian blue analog nanoparticles of rubidium cobalt hexacyanoferrate
Nanoparticles of rubidium cobalt hexacyanoferrate
(RbCo[Fe(CN)]HO) were synthesized using different
concentrations of the polyvinylpyrrolidone (PVP) to produce four different
batches of particles with characteristic diameters ranging from 3 to 13 nm.
Upon illumination with white light at 5 K, the magnetization of these particles
increases. The long-range ferrimagnetic ordering temperatures and the coercive
fields evolve with nanoparticle size. At 2 K, particles with diameters less
than approximately 10 nm provide a Curie-like magnetic signal.Comment: 10 pages, 6 figures in text, expanded text and dat
Detection of Bacteroides fragilis endotoxin in amniotic fluid by counterimmunoelectrophoresis
The ability of counter immunoelectrophoresis (CIE) to detectBacteroides fragilis endotoxin in amniotic fluid in small concentrations was evaluated. A method was developed which, in combination with ultrafiltration, permits detection ofB. fragilis endotoxin in amniotic fluid in a concentration of 40 ng/ml or more. The sensitivity threshold was reduced to 2 ng/ml by using a highly reactive IgG-fraction isolated from rabbit anti-B. fragilis IPL E 323 antiserum
Magnetic Neutron Scattering of Thermally Quenched K-Co-Fe Prussian Blue Analogue Photomagnet
Magnetic order in the thermally quenched photomagnetic Prussian blue analogue
coordination polymer K0.27Co[Fe(CN)6]0.73[D2O6]0.27 1.42D2O has been studied
down to 4 K with unpolarized and polarized neutron powder diffraction as a
function of applied magnetic field. Analysis of the data allows the onsite
coherent magnetization of the Co and Fe spins to be established. Specifically,
magnetic fields of 1 T and 4 T induce moments parallel to the applied field,
and the sample behaves as a ferromagnet with a wandering axis
Genetic testing and personalized ovarian cancer screening: a survey of public attitudes
Background
Advances in genetic technologies are expected to make population-wide genetic testing feasible. This could provide a basis for risk stratified cancer screening; but acceptability in the target populations has not been explored.
Methods
We assessed attitudes to risk-stratified ovarian cancer (OC) screening based on prior genetic risk assessment using a survey design. Home-based interviews were carried out by the UK Office of National Statistics in a population-based sample of 1095 women aged 18–74. Demographic and personal correlates of attitudes to risk-stratified OC screening based on prior genetic risk assessment were determined using univariate analyses and adjusted logistic regression models.
Results
Full data on the key analytic questions were available for 829 respondents (mean age 46 years; 27 % ‘university educated’; 93 % ‘White’). Relatively few respondents felt they were at ‘higher’ or ‘much higher’ risk of OC than other women of their age group (7.4 %, n = 61). Most women (85 %) said they would ‘probably’ or ‘definitely’ take up OC genetic testing; which increased to 88 % if the test also informed about breast cancer risk. Almost all women (92 %) thought they would ‘probably’ or ‘definitely’ participate in risk-stratified OC screening. In multivariate logistic regression models, university level education was associated with lower anticipated uptake of genetic testing (p = 0.009), but with more positive attitudes toward risk-stratified screening (p <0.001). Perceived risk was not significantly associated with any of the outcome variables.
Conclusions
These findings give confidence in taking forward research on integration of novel genomic technologies into mainstream healthcare
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