Sökresultat

Filtyp

Din sökning på "*" gav 536668 sökträffar

Electronic structure of free-standing InP and InAs nanowires

An eight-band k.p theory that does not suffer from the spurious solution problem is demonstrated. It is applied to studying the electronic properties of InP and InAs free-standing nanowires. Band gaps and effective masses are reported as a function of size, shape, and orientation of the nanowires. We compare our results with experimental work and with other calculations.

Autofluorescence of various rodent tissues and human skin tumour samples

Fluorescence spectra from different organs in rats and mice have been recorded to explore the potential of non-intrusive tissue diagnostics. The fluorescence was induced by a nitrogen laser that emitted at a wavelength of 337 nm. Optical multichannel techniques were used for the detection. Spectra are given from 19 different sites in Wistar/Furth rats, including an inoculated malignant tumour. The

Aspects of photoinduction of carotenogenesis in the fungus Verticillium-Agricinum

An action spectrum for light induced carotenogenesis in V. agaricinum (Link) Corda (ATCC 24668) was obtained by exposing mycelial pads to monochromatic radiation. Action maxima occurred at 290 (main peak) and 390 nm and there was a minor peak at 483 nm. An interaction between the blue and UV light occurred. Blue light partly reversed the UV light induction of carotenogenesis when given after, but

Treatment-resistant detrusor overactivity - underlying pharmacology and potential mechanisms.

Bladder function during filling and micturition is regulated by peripheral and central nervous and hormonal control systems. Micturition occurs in response to afferent signals from the lower urinary tract, and distention of the bladder wall is the primary stimulus. In the animal and human bladder, efferent adrenergic, cholinergic and nonadrenergic, noncholinergic (NANC) neurotransmission has been

Self-regulated learning through writing on computers: Consequences for reading comprehension.

The overall aim for the present study was to analyze the consequences for reading ability among the children of a computer supported self-regulated learning environment in grade two. By means of a quasi-experimental design in a natural setting, an experimental group (n=39) was compared to a control group from a national sample (n=3409) on reading comprehension. The statistical analyses showed that

Global sequence and dispersion of ventricular repolarization: In vivo validation of non-invasive parameters using monophasic action potential mapping technique

The purposes are to validate the noninvasive parameters, QT interval, QT dispersion, Tpeak-Tend interval, and the activation recovery time (ART) for estimation of global dispersion of ventricular repolarization (DVR), and to investigate the changes of repolarization sequence and DVR by altered ventricular pacing sites. The material consisted of 12 patients (Study I) and two series healthy pigs wi

Hydrogen Addition For Improved Lean Burn Capability of Slow and Fast Burning Natural Gas Combustion Chambers

One way to extend the lean-burn limit of a natural gas engine is by addition of hydrogen to the primary fuel. This paper presents measurements made on a one-cylinder, 1.6- liter natural gas engine. Two combustion chambers, one slow and one fast burning, were tested with various amounts of hydrogen (0, 5, 10 and 15%-vol) added to natural gas. Three operating points were investigated for each combus

Production of phi mesons at midrapidity in root S-NN=200 GeVAu+Au collisions at relativistic energies

We present the results of phi meson production in the K+K- decay channel from Au+Au collisions at root s(NN) =200 GeV as measured at midrapidity by the PHENIX detector at Brookhaven National Laboratory's Relativistic Heavy Ion Collider. Precision resonance centroid and width values are extracted as a function of collision centrality. No significant variation from the Particle Data Group accepted v

Metastable VO2 complexes in silicon: experimental and theoretical modeling studies

We report on a combined experimental and theoretical study of the metastable form of the vacancy-dioxygen defect in Si labeled VO2*. Important new experimental observations are the 2 detection of mixed local vibrational modes of VO*(2) in O-16, O-18 co-doped samples, the determination of the position of LVM bands for the negatively charged defect, and an assignment of an acceptor level at about E-

Många vägar leder till artros. Kunskapen om riskfaktorer och sjukdomsmekanismer ökar snabbt

Osteoarthritis does not deserve the term "degenerative joint disease", the course of the disease is characterized by dynamic changes in both synthesis and degradation of cartilage and other joint tissues. At the end stage all tissues of the joint are involved, not only the cartilage. In the early phases of the disease, changes in cartilage metabolism can be detected through assay of biomarkers in

Differentiated Knowledge Bases and Varieties of Regional Innovation Systems

This article introduces a theoretical and analytical framework for discussing regional development and regional advantage with reference to a regional innovation system strategy. It uses the differentiated knowledge base approach to transcend the traditional codified-tacit dichotomy of knowledge, and for providing a trans-sectoral understanding of economic activities. Different regional innovation

Nocturnal colour vision in geckos

Nocturnal animals are said to sacrifice colour vision in favour of increased absolute sensitivity. This is true for most vertebrates that possess a dual retina with a single type of rod for colour-blind night vision and multiple types of cone for diurnal colour vision. However, among the nocturnal vertebrates, geckos are unusual because they have no rods but three cone types. Here, we show that ge

Optical properties of a silver-related defect in silicon

Doping crystalline silicon with silver results in a photoluminescence center with multiplet zero-phonon structure near 778.9 meV. We show that the published assignments of the vibronic sidebands are wrong, with severe implications for the relative transition probabilities of the luminescence transitions from the excited states. At low temperature, most of the luminescence intensity derives from th