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Mimicking electron transfer reactions in photosystem II: Synthesis and photochemical characterization of a ruthenium(II) tris(bipyridyl) complex with a covalently linked tyrosine

In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor P-680, which subsequently retrieves electrons from a tyrosyl residue, functioning as an interface to the oxygen-evolving manganese complex. In a first step toward mimicking these reactions, we have made a Ru(II)-polypyridine complex with an attached tyrosyl moi

Improved subthreshold slope in an InAs nanowire heterostructure field-effect transistor

An n-type InAs/InAsP heterostructure nanowire field-effect transistor has been fabricated and compared with a homogeneous InAs field-effect transistor. For the same device geometry, by introduction of the heterostructure, the threshold voltage is shifted 4 V, the maximum current on-off ratio is enhanced by a factor of 10 000, and the subthreshold swing is lowered by a factor 4 compared to the homo

The FERRUM Project: Experimental transition probabilities of [Fe II] and astrophysical applications

We report on experimental transition probabilities for thirteenforbidden [Fe II] lines originating from three different metastable FeIi levels. Radiative lifetimes have been measured of two metastablestates by applying a laser probing technique on a stored ion beam.Branching ratios for the radiative decay channels, i.e. M1 and E2transitions, are derived from observed intensity ratios of forbiddenl

Clinical studies of calcium metabolism in essential hypertension

Many factors can ultimately lead to an increased blood pressure and it is a generally accepted view that an increase in the active tension of arterioles reflects an increase of the free calcium concentration in the cytosol of the vascular smooth muscle cells. Only recently, however, has the possibility been considered that blood pressure regulation could be influenced by calcium homeostasis. A bac

Strength at the extracellular matrix-muscle interface

Mechanical force is generated within skeletal muscle cells by contraction of specialized myofibrillar proteins. This paper explores how the contractile force generated at the sarcomeres within an individual muscle fiber is transferred through the connective tissue to move the bones. The initial key point for transfer of the contractile force is the muscle cell membrane (sarcolemma) where force is

Morphometric and psychometric comparisons between non-substance-abusing patients with posttraumatic stress disorder and normal controls

BACKGROUND: Hippocampal decrease in size in response to posttraumatic stress disorder (PTSD) is still a subject of controversy. The aims of this study were to: (1) confirm previous hippocampus findings in PTSD patients compared to controls, using ethnically similar study groups where alcohol and drug abuse were non-existent; (2) test influence of disease duration as well as depression scores on po

Globalization and risky human-capital investment

Globalization is supposed to increase the mobility of highly skilled labor and to reduce governments' scope for redistribution. We show that this increases the private incentives for education and may decrease, but may also increase, the government's incentives to provide education subsidies in a framework in which education investment is risky. Globalization shifts the cost of these subsidies to

Effects of pH management during selective antegrade cerebral perfusion on cerebral microcirculation and metabolism: alpha-stat versus pH-stat

BACKGROUND: Selective cerebral perfusion (SCP) is used for extending the period during which surgical procedures can be safely performed. We sought to determine the direct effects of pH management on cerebral microcirculation and metabolism during SCP. METHODS: An experimental SCP porcine model was created by selectively allowing cold perfusate only into the bicarotid brachiocephalic trunk during

Cerebrospinal Fluid Total Tau Is Associated with Shorter Survival in Dementia with Lewy Bodies.

A pathology typical of dementia with Lewy bodies (DLB) has been demonstrated to increase mortality to a greater extent than the pathology of Alzheimer's disease (AD). However, mortality in DLB has also been shown to increase with concomitant AD pathology. Furthermore, in a recent publication, we showed that there is a robust and specific increase in CSF calcium and magnesium in DLB patients compar

Can intergranular force transmission be identified in sand?

This work tackles the challenge of assessment of force distributions in granular media. Spatially resolved neutron and x-ray diffraction are used to measure internal strains of sand grains under load. These approaches are sensitive to the crystallographic strains of the sand grains (quartz crystals) such that each grain acts as a local 3D strain gauge and so, for elastic deformations, a force gaug

Do Genetic Factors Modify the Relationship Between Obesity and Hypertriglyceridemia? : Findings From the GLACIER and the MDC Studies

BACKGROUND: Obesity is a major risk factor for dyslipidemia, but this relationship is highly variable. Recently published data from 2 Danish cohorts suggest that genetic factors may underlie some of this variability.METHODS AND RESULTS: We tested whether established triglyceride-associated loci modify the relationship of body mass index (BMI) and triglyceride concentrations in 2 Swedish cohorts (t