891 research outputs found
Routine data linkage to identify and monitor diabetes in clozapine-treated patients with schizophrenia
No abstract available
Photonic Crystal Cavities and Waveguides
Recently, it has also become possible to microfabricate high reflectivity mirrors by creating two- and three-dimensional periodic structures. These periodic "photonic crystals" can be designed to open up frequency bands within which the propagation of electromagnetic waves is forbidden irrespective of the propagation direction in space and define photonic bandgaps. When combined with high index contrast slabs in which light can be efficiently guided, microfabricated two-dimensional photonic bandgap mirrors provide us with the geometries needed to confine and concentrate light into extremely small volumes and to obtain very high field intensities. Here we show the use of these "artificially" microfabricated crystals in functional nonlinear optical devices, such as lasers, modulators, and waveguides
Cladding strategies for building-integrated photovoltaics
Photovoltaic cladding on the surfaces of commercial buildings has the potential for considerable reductions in carbon emissions due to embedded renewable power generation displacing conventional power utilization. In this paper, a model is described for the optimization of photovoltaic cladding densities on commercial building surfaces. The model uses a modified form of the ‘fill factor’ method for photovoltaic power supply coupled to new regression-based procedures for power demand estimation. An optimization is included based on a defined ‘mean index of satisfaction’ for matched power supply and demand (i.e., zero power exportation to the grid). The mean index of satisfaction directly translates to the reduction in carbon emission that might be expected over conventional power use. On clear days throughout the year, reductions of conventional power use of at least 60% can be achieved with an optimum cladding pattern targeted to lighting and small power load demands
PLANTAR FORCE MEASURES DURING FORWARD SKATING IN ICE HOCKEY
The purpose of this project was to measure plantar pressure patterns during forward skating with ice hockey skates. Six elite ice hockey inter-university players volunteered to participate in the study. There was no significant change in push off force with velocity, but there was a decrease in contact time with increasing velocity. Given the decreased impulse with increasing speed, the increase in propulsion was the result of increasing stride rate. Comparison between anterior and posterior plantar regions as well as the medial and lateral regions revealed proportional loading changes with different speeds
Charge and spin distributions in GaMnAs/GaAs Ferromagnetic Multilayers
A self-consistent electronic structure calculation based on the
Luttinger-Kohn model is performed on GaMnAs/GaAs multilayers. The Diluted
Magnetic Semiconductor layers are assumed to be metallic and ferromagnetic. The
high Mn concentration (considered as 5% in our calculation) makes it possible
to assume the density of magnetic moments as a continuous distribution, when
treating the magnetic interaction between holes and the localized moment on the
Mn(++) sites. Our calculation shows the distribution of heavy holes and light
holes in the structure. A strong spin-polarization is observed, and the charge
is concentrated mostly on the GaMnAs layers, due to heavy and light holes with
their total angular momentum aligned anti-parallel to the average
magnetization. The charge and spin distributions are analyzed in terms of their
dependence on the number of multilayers, the widths of the GaMnAs and GaAs
layers, and the width of lateral GaAs layers at the borders of the structure.Comment: 12 pages,7 figure
Antimicrobial Susceptibility Trends Observed in Urinary Pathogens Obtained From New York State
International guidelines recommend using local susceptibility data to direct empiric therapy for acute uncomplicated cystitis. We evaluated outpatient urinary isolate susceptibility trends in New York State. Nitrofurantoin had the lowest resistance prevalence whereas trimethoprim-sulfamethoxazole and fluoroquinolones had higher prevalences. This study highlights the need for local outpatient antimicrobial stewardship programs
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Mental health in UK Biobank - development, implementation and results from an online questionnaire completed by 157 366 participants: a reanalysis
Background
UK Biobank is a well-characterised cohort of over 500 000 participants including genetics, environmental data and imaging. An online mental health questionnaire was designed for UK Biobank participants to expand its potential.
Aims
Describe the development, implementation and results of this questionnaire.
Method
An expert working group designed the questionnaire, using established measures where possible, and consulting a patient group. Operational criteria were agreed for defining likely disorder and risk states, including lifetime depression, mania/hypomania, generalised anxiety disorder, unusual experiences and self-harm, and current post-traumatic stress and hazardous/harmful alcohol use.
Results
A total of 157 366 completed online questionnaires were available by August 2017. Participants were aged 45–82 (53% were ≥65 years) and 57% women. Comparison of self-reported diagnosed mental disorder with a contemporary study shows a similar prevalence, despite respondents being of higher average socioeconomic status. Lifetime depression was a common finding, with 24% (37 434) of participants meeting criteria and current hazardous/harmful alcohol use criteria were met by 21% (32 602), whereas other criteria were met by less than 8% of the participants. There was extensive comorbidity among the syndromes. Mental disorders were associated with a high neuroticism score, adverse life events and long-term illness; addiction and bipolar affective disorder in particular were associated with measures of deprivation.
Conclusions
The UK Biobank questionnaire represents a very large mental health survey in itself, and the results presented here show high face validity, although caution is needed because of selection bias. Built into UK Biobank, these data intersect with other health data to offer unparalleled potential for crosscutting biomedical research involving mental health
Redox Reactions of the Pyranopterin System of the Molybdenum Cofactor
This work provides the first extensive study of the redox reactivity of the pyranopterin system that is a component of the catalytic site of all molybdenum and tungsten enzymes possessing molybdopterin. The pyranopterin system possesses certain characteristics typical of tetrahydropterins, such as a reduced pyrazine ring; however, it behaves as a dihydropterin in redox reactions with oxidants. Titrations using ferricyanide and dichloroindophenol (DCIP) prove a 2e(-)/2H(+) stoichiometry for pyranopterin oxidations. Oxidations of pyranopterin by Fe(CN)(6)(3-) or DCIP are slower than tetrahydropterin oxidation under a variety of conditions, but are considerably faster than observed for oxidations of dihydropterin. The rate of pyranopterin oxidation by DCIP was studied in a variety of media. In aqueous buffered solution the pyranopterin oxidation rate has minimal pH dependence, whereas the rate of tetrahydropterin oxidation decreases 100-fold over the pH range 7.4-8.5. Although pyranopterin reacts as a dihydropterin with oxidants, it resists further reduction to a tetrahydropterin. No reduction was achieved by catalytic hydrogenation, even after several days. The reducing ability of the commonly used biological reductants dithionite and methyl viologen radical cation was investigated, but experiments showed no evidence of pyranopterin reduction by any of these reducing agents. This study illustrates the dual personalities of pyranopterin and underscores the unique place that the pyranopterin system holds in the spectrum of pterin redox reactions. The work presented here has important implications for understanding the biosynthesis and reaction chemistry of the pyranopterin cofactor in molybdenum and tungsten enzymes
Transmission of pillar-based photonic crystal waveguides in InP technology
Waveguides based on line defects in pillar photonic crystals have been fabricated in InP/InGaAsP/InP technology. Transmission measurements of different line defects are reported. The results can be explained by comparison with two-dimensional band diagram simulations. The losses increase substantially at mode crossings and in the slow light regime. The agreement with the band diagrams implies a good control on the dimensions of the fabricated features, which is an important step in the actual application of these devices in photonic integrated circuit
Shape Transition in the Epitaxial Growth of Gold Silicide in Au Thin Films on Si(111)
Growth of epitaxial gold silicide islands on bromine-passivated Si(111)
substrates has been studied by optical and electron microscopy, electron probe
micro analysis and helium ion backscattering. The islands grow in the shape of
equilateral triangles up to a critical size beyond which the symmetry of the
structure is broken, resulting in a shape transition from triangle to
trapezoid. The island edges are aligned along directions. We have
observed elongated islands with aspect ratios as large as 8:1. These islands,
instead of growing along three equivalent [110] directions on the Si(111)
substrate, grow only along one preferential direction. This has been attributed
to the vicinality of the substrate surface.Comment: revtex version 3.0, 11 pages 4 figures available on request from
[email protected] - IP/BBSR/93-6
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