Sökresultat

Filtyp

Din sökning på "*" gav 533449 sökträffar

The nature of hypervelocity stars as inferred from their Galactic trajectories

We have computed the Galactic trajectories of 12 hypervelocity stars (HVSs) under the assumption that they originated in the Galactic Centre. We show that eight of these 12 stars are bound to the Galaxy. We consider the subsequent trajectories of the bound stars to compute their characteristic orbital period, which is 2 Gyr. All eight bound stars are moving away from the centre of the Galaxy, whic

Treatment with tumor necrosis factor blockers is associated with a lower incidence of first cardiovascular events in patients with rheumatoid arthritis

Objective. To investigate the risk of cardiovascular disease (CVD) in patients with rheumatoid arthritis (RA) treated with tumor necrosis factor (TNF) inhibitors, compared to a standard RA population. Methods. Patients were recruited from a regional register, which includes over 90% of patients with RA started on TNF blockers in 1999 or later, and a local community based cohort of RA patients, est

Ab Initio Density Fitting: Accuracy Assessment of Auxiliary Basis Sets from Cholesky Decompositions

The accuracy of auxiliary basis sets derived by Cholesky decompositions of the electron repulsion integrals is assessed in a series of benchmarks on total ground state energies and dipole moments of a large test set of molecules. The test set includes molecules composed of atoms from the first three rows of the periodic table as well as transition metals. The accuracy of the auxiliary basis sets a

How nitrogen and sulphur addition, and a single drought event affect root phosphatase activity in Phalaris arundinacea

Conservation and restoration of fens and fen meadows often aim to reduce soil nutrients, mainly nitrogen (N) andphosphorus (P). The biogeochemistry of P has received much attention as P-enrichment is expected to negatively impact on species diversity in wetlands. It is known that N, sulphur (S) and hydrological conditions affect the biogeochemistry of P, yet their interactive effects on P-dynamics

Preruptive effect of NaF tablets on caries in children from 12 to 17 years of age

The purpose of this study was to evaluate the preeruptive effect of NaF tablets on caries in proximal surfaces of permanent molars and premolars. The material consisted of 47 subjects who had consumed fluoride tablets for a minimum of 5 yr between 1/2 and 6 yr of age in accordance with recommendations from the National Swedish Board of Health and Welfare (F+-group) and 69 comparable children who h

Differences in prevalence and treatment of Pseudomonas aeruginosa in cystic fibrosis centres in Denmark, Norway and Sweden

Background: Chronic Pseudomonas aeruginosa (PA) infection causes increased morbidity and mortality in cystic fibrosis (CF). This study aimed to answer the following questions: Does the prevalence of chronic infection with PA differ between the CF centres in Scandinavia? Which differences exist concerning segregation and treatment of PA? Methods: 989 patients (86%) from all eight CF-centres in Scan

Schwertmannite precipitated from acid mine drainage: phase transformation, sulphate release and surface properties

Schwertmannite precipitated from acid mine drainage at the Kristineberg Zn-Cu mine in northern Sweden has been characterised regarding elemental composition, phase transformation as a function of pH and time. SO42- release and speciation of SO42- associated with the solid. The elemental analysis gave the composition FeSOS(OH)(5.02)(-SO4)(1.49) . 0.5H(2)O where approximately 1/3 of the SO42- is ads

Delay From First Medical Contact to Primary PCI and All-Cause Mortality: A Nationwide Study of Patients With ST-Elevation Myocardial Infarction.

Early reperfusion in the setting of an ST-elevation myocardial infarction (STEMI) is of utmost importance. However, the effects of early versus late reperfusion in this patient group undergoing primary percutaneous coronary intervention (PCI) have so far been inconsistent in previous studies. The purpose of this study was to evaluate in a nationwide cohort the effects of delay from first medical c

Postprandial apoE Isoform and Conformational Changes Associated with VLDL Lipolysis Products Modulate Monocyte Inflammation

Objective: Postprandial hyperlipemia, characterized by increased circulating very low-density lipoproteins (VLDL) and circulating lipopolysaccharide (LPS), has been proposed as a mechanism of vascular injury. Our goal was to examine the interactions between postprandial lipoproteins, LPS, and apoE3 and apoE4 on monocyte activation. Methods and Results: We showed that apoE3 complexed to phospholipi

The Dead Sea Future Elevation

In this paper water and salt mass balances for the Dead Sea were modeled. Precipitation, evaporation, river discharges, ground water flows, input/output from potash companies and salt production, and brine discharge were included in the models. The mixing time in the Dead Sea was modeled using a single-layer (well-mixed) a two-layer (stratified) system. Using the single-layer approach the water le

The development of public attitudes towards the Stockholm congestion trial

A full-scale congestion charging trial was carried out in Stockholm the first months of 2006. Almost half of respondents in a county-wide survey stated that they changed their attitudes towards congestion charges during the trial. Most of them became more positive. An analysis of media shows that the attitudinal change in media towards the trial coincides with the attitudinal change of the public.

STIM evaluation in GeoPIXE to complement the quantitative dynamic analysis

The GeoPIXE software for quantitative PIXE trace element imaging and analysis is a well established package for evaluation of characteristic X-ray data for both PIXE and SXRF. For the case of microbeam applications on semi-thick samples knowledge of the local areal density distribution is important for precise quantification. A technique is reported to achieve this using the measurement of beam pa

Terrestrial Gross Carbon Dioxide Uptake: Global Distribution and Covariation with Climate

Terrestrial gross primary production (GPP) is the largest global CO2 flux driving several ecosystem functions. We provide an observation-based estimate of this flux at 123 +/- 8 petagrams of carbon per year (Pg C year(-1)) using eddy covariance flux data and various diagnostic models. Tropical forests and savannahs account for 60%. GPP over 40% of the vegetated land is associated with precipitatio

Convergence of QM/MM free-energy perturbations based on molecular-mechanics or semiempirical simulations.

Lately, there has been great interest in performing free-energy perturbation (FEP) at the combined quantum mechanics and molecular mechanics (QM/MM) level, e.g. for enzyme reactions. Such calculations require extensive sampling of phase space, which typically is prohibitive with density-functional theory or ab initio methods. Therefore, such calculations have mostly been performed with semiempiric

LiZn4 - x (x = 0.825) as a (3 + 1)-dimensional modulated derivative of hexagonal close packing.

The (3+1)-dimensional modulated structure of the LiZn4 - x (x = 0.825) binary compound has been determined in the superspace. The compound crystallizes in the orthorhombic superspace group Cmcm(α00)0s0 with a = 2.7680 (6), b = 4.7942 (6), c = 4.3864 (9) Å, modulation wavevector: q ≃ 4/7a*. The structure is a derivative from the hexagonal close packing. The cubo-octahedron as a coordination polyhed

Effects of influenza A virus infection on migrating mallard ducks

The natural reservoir of influenza A virus is waterfowl, particularly dabbling ducks (genus Anas). Although it has long been assumed that waterfowl are asymptomatic carriers of the virus, a recent study found that low-pathogenic avian influenza (LPAI) infection in Bewick's swans (Cygnus columbianus bewickii) negatively affected stopover time, body mass and feeding behaviour. In the present study,

Early diphtheria-tetanus-pertussis vaccination associated with higher female mortality and no difference in male mortality in a cohort of low birthweight children: an observational study within a randomised trial

Background Studies from low-income countries have suggested that diphtheria-tetanus-pertussis (DTP) vaccine provided after Bacille Calmette-Guerin (BCG) vaccination may have a negative effect on female survival. The authors examined the effect of DTP in a cohort of low birthweight (LBW) infants. Methods 2320 LBW newborns were visited at 2, 6 and 12 months of age to assess nutritional and vaccinati

Unusual extraction and characterization of nanocrystalline cellulose from cellulose derivatives

Unlike many nanomaterials, nanocrystalline cellulose (CNC) is not synthesized from molecular or atomic components but rather extracted from naturally occurring cellulose. Undoubtedly, the exploitation of CNCs will become a bridge between nanoscience and natural resource products, which could play a major role in reviving the forest industry. In this work, CNC was successfully extracted from unusua