Sökresultat

Filtyp

Din sökning på "*" gav 531394 sökträffar

Structure and magnetism of MnAs nanocrystals embedded in GaAs as a function of post-growth annealing temperature

Self-organized Ga(Mn)As nanoclusters, embedded in GaAs, were formed during post-growth thermal annealing of Ga1-xMnxAs layers. Structural and magnetic properties of such composites were systematically studied as a function of the annealing temperature. Small (similar to 3 nm) Mn-rich zinc-blende Mn(Ga)As clusters, coherent with the GaAs matrix, were formed at the annealing temperature of 500 degre

Designing proteins to crystallize through beta-strand pairing

Inherent difficulties in growing protein crystals are major concerns within structural biology and particularly in structural proteomics. Here, we describe a novel approach of engineering target proteins by surface mutagenesis to increase the odds of crystallizing the molecules. To this end, we have exploited our recent triad-hypothesis using proteins with crystallographically defined beta-structu

Does the strength of an immune response reflect its energetic cost?

The energetic cost of immune responses has been proposed to be an important basis for trade-offs between life-history traits, such as between survival and reproduction. A critical assumption of this hypothesis is that the magnitude of the energetic cost increases with the strength of an immune response, so that energy can be saved by partly suppressing a response. Here, we test this assumption exp

Mortality in systemic lupus erythematosus

Objective. To examine mortality rates in the largest systemic lupus erythematosus (SLE) cohort ever assembled. Methods. Our sample was a multisite international SLE cohort (23 centers, 9,547 patients). Deaths were ascertained by vital statistics registry linkage. Standardized mortality ratio (SMR; ratio of deaths observed to deaths expected) estimates were calculated for-all deaths and by cause. T

Particle Size Distribution and Human Respiratory Deposition of Trace Metals in Indoor Work Environments

Respiratory response to inhalation of fine particles has been investigated for the aerosol generated by welding. Particles were sampled using a pair of 5-stage cascade impactors operating at 1 l./min flow rate. The subject exhaled into one impactor through an air ballast arrangement, and the other impactor simultaneously sampled the surrounding air. Particle size fractions were analyzed for princi

National security versus moral responsibility: An analysis of integration programs in Malmo, Sweden

This article proposes that people working with integration projects in Sweden are driven by a wish to help immigrants integrate into the host society. At the same time, however, the practices of multiculturalism tend to reproduce narratives that depict immigrants as threats to the host society and as inherently different from it. This tension can be analyzed through the intersections of a dilemma

Study of interhalogens/silver trifluoromethanesulfonate as promoter systems for high-yielding sialylations

We have studied interhalogen/silver trifluoromethanesulfonate (IX/AgOTf) promoted glycosylations and found differences in the sensitivity of the formed oxocarbenium ions (e.g. from compounds with or without participating groups) toward halide nucleophiles. These differences can be explained using the HSAB theory. By applying this theory on sialylations, we increased the yield for a model reaction

Smoking, information sources, and risk perceptions - New results on Swedish data

Using data on Swedish adolescents, this study examines (1) perceptions of the addictiveness and mortality risk of smoking, (2) the effects of these perceptions on smoking behaviour, and (3) the role of various smoking risk information sources. The average respondent believed that 46 out of 100 smokers would die from diseases caused by their smoking. As to addictiveness perceptions, the average res

Induced Growth and Maturation of the Gastrointestinal Tract After Phaseolus vulgaris Lectin Exposure in Suckling Rats

Objectives: In mammals, the postnatal development of the gastrointestinal tract is characterized by vast structural and functional changes. Using a suckling rat model, we investigated whether red kidney bean lectin, phytohemagglutinin (PHA), a potent gut mitogen in adult rats, can accelerate the growth and maturation of the gastrointestinal tract. Methods: At either 10 or 14 days of age, suckling

Characterization of micromachined ultrasonic transducers using light diffraction tomography

This paper demonstrates that light diffraction tomography can be used to measure the acoustic field of micromachined ultrasonic transducers (MUT) in cases in which standard methods like hydrophone and microphone measurements fail. Two types of MUTs have been characterized with the method, one air-coupled capacitive MUT (cMUT) and one waterloaded continuous wave (CW) miniature multilayer lead zirco

Variable Be-10 fluxes in lacustrine sediments from Tristan da Cunha, South Atlantic: a solar record?

A 650-yr-long sediment sequence from a crater lake on Tristan da Cunha, South Atlantic, was analysed for its Be-10 content. Based on C-14 dating, and sedimentary, geochemical, magnetic and palynological records, the period between 900 and 1450 AD appears to have been unusually stable in terms of sedimentation and vegetation and therefore this period was chosen for analysis of the Be-10 content. Du

2MOLCAS as a development platform for quantum chemistry software

This work presents the quantum chemistry package MOLCAS, with emphasis on its usefulness as a platform for developing new quantum chemical codes, and the reader is assumed to be familiar with such a process. The development of new codes for quantum chemistry is a time-consuming job that can be dramatically simplified by using libraries for standard problems (such as calculation of integrals), and

Tipping the balance of deterministic lateral displacement devices using dielectrophoresis.

We report the use of dielectrophoresis (DEP) to achieve tunability, improve dynamic range and open up for the separation of particles with regard to parameters other than hydrodynamic size in deterministic lateral displacement (DLD) devices. DLD devices have been shown capable of rapidly and continuously separating micrometer sized plastic spheres by size with a resolution of 20 nm in diameter and

Effects of wind and weather on red admiral, Vanessa atalanta, migration at a coastal site in southern Sweden

Each autumn, large numbers of red admirals migrate throughout northern Europe,flying south, to reach areas with conditions suitable for surviving the winter. We observed the visible butterfly migration at Falsterbo peninsula, the southwesternmost point in Sweden, where red admirals are seen most autumns. ying towards the Danish coast on their way to more southern parts of Europe. Weather parameter

Barriers and distances as determinants for the evolution of bird migration links: the arctic shorebird system

We analysed migratory connectivity between different winter quarters and breeding sectors in the circumpolar tundra region for arctic shorebirds, in relation to migratory distances and ecological barriers. Total distances and barriers were calculated and measured for all potential migratory orthodrome links between 10 selected winter regions and 12 breeding sectors. The migratory segment between t

Dynamic light scattering and fluorescence study of the interaction between double-stranded DNA and poly(amido amine) dendrimers

The interaction between a cationic poly(amido amine) (PAMAM) dendrimer of generation 4 and double-stranded salmon sperm DNA in 10 mM NaBr solution has been investigated using dynamic light scattering (DLS) and steady-state fluorescence spectroscopy. The structural parameters of the formed aggregates as well as the complex formation process were studied in dilute solutions. When DNA is mixed with P