Search results

Filter

Filetype

Your search for "*" yielded 534232 hits

A potential GSSP for the base of the uppermost Cambrian stage, coinciding with the first appearance of Lotagnostus americanus at Wa'ergang, Hunan, China

The first appearance datum (FAD) of the cosmopolitan agnostoid trilobite Lotagnostus americanus is a widely used marker for defining the base of the uppermost stage of the Cambrian System. Detailed field study on the L. americanus-bearing interval of the Wa'ergang section, Hunan, China, reveals the FAD of L. americanus to be 29.65m above the base of the Shengjiawan Formation. This horizon is close

Regioselectivity in C-H activation: reagent control in cyclometallation of 2-(1-naphthyl)-pyridine.

2-(1-Naphthyl)-pyridine () possesses sp(2) C-H bonds in both the γ- and δ-positions and is therefore a suitable substrate for studying the cyclometallation selectivity with different reagents and conditions. Such selectivity studies are reported. Based on deuterium-exchange experiments it is concluded that cycloruthenation with RuCl2(p-cymene) dimer is reversible with kinetic and thermodynamic pre

Superswollen Microemulsions Stabilized by Shear and Trapped by a Temperature Quench

We studied the solubilization of oil in the C16E8/hexadecane/H2O system. Close to the phase inversion temperature (PIT), the system, at equilibrium, can form either homogeneous states (i.e., microemulsions) at high surfactant concentrations or three-phase states at lower concentrations. We show that, under gentle shear, at a line we named the clearing boundary (CB), located a few degrees below the

An Adaptive Penalty Multi-Pitch Estimator with Self-Regularization

This work treats multi-pitch estimation, and in particular the common misclassification issue wherein the pitch at half the true fundamental frequency, the sub-octave, is chosen instead of the true pitch. Extending on current group LASSO-based methods for pitch estimation, this work introduces an adaptive total variation penalty, which enforces both group- and block sparsity, as well as deals with

Reconstruction of brain circuitry by neural transplants generated from pluripotent stem cells.

Pluripotent stem cells (embryonic stem cells, ESCs, and induced pluripotent stem cells, iPSCs) have the capacity to generate neural progenitors that are intrinsically patterned to undergo differentiation into specific neuronal subtypes and express in vivo properties that match the ones formed during normal embryonic development. Remarkable progress has been made in this field during recent years t

Effects of AZD0837, a Novel Direct Thrombin Inhibitor, on the Electrophysiological Properties of the Human Heart A Randomized, Double-Blind, Parallel-Group, Placebo-Controlled Study

Background: AZD0837 is an investigational oral anticoagulant that is bio-converted to its active form, AR-H067637, a selective direct thrombin inhibitor. Objectives: The objectives of the present study were to investigate if there are any clinically relevant adverse effects of intravenous AZD0837 on cardiac conduction, refractoriness and repolarization, and to study its safety and tolerability. Me

Interobserver variability in the evaluation of mismatch repair protein immunostaining

Immunohistochemical staining for mismatch repair proteins has during recent years been established as a routine analysis in many pathology laboratories with the aim to identify tumors linked to the hereditary nonpolyposis colorectal cancer syndrome. Despite widespread application, data on reliability are lacking. We therefore evaluated interobserver variability among 6 pathologists, 3 experienced

Hieracium sect. Oreadea (Asteraceae) in Sweden - from a complete mess to a preliminary taxonomic classification

Among Swedish Hieracium sect. Oreadea (Fr.) Arv.-Touv., more than 100 taxa have been recognized by various experts but, except for a regional monograph from 1894 there are no thorough published revisions of the group and many of the names have never been validly published. At the same time, some of the oldest names have been variously applied to morphologically clearly different species. In the pr

beta(2)-Glycoprotein I can exist in 2 conformations: implications for our understanding of the antiphospholipid syndrome

The antiphospholipid syndrome is defined by the presence of antiphospholipid antibodies in blood of patients with thrombosis or fetal loss. There is ample evidence that beta(2)-glycoprotein I (beta(2)GPI) is the major antigen for antiphospholipid antibodies. The autoantibodies recognize beta(2)GPI when bound to anionic surfaces and not in solution. We showed that beta(2)GPI can exist in at least 2

Sol-Gel-Derived Materials for Production of Pin-Printed Reporter Gene Living-Cell Microarrays

We report the fabrication of three-dimensional living-cell microarrays via pin-printing of soft sol-gel-derived silica materials containing bacterial cells. Bacterial cells entrapped in the silica-glycerol microarray spots can express reporter genes and produce strong fluorescence signals. The signals responded to the presence and concentration of inducers or repressors as expected, indicating tha

Cortisol, sleep, and recovery: some gender differences but no straight associations

Abstract in UndeterminedBACKGROUND: Work related fatigue has been suggested as a link in the assumed sequence of events between repeated adverse work demands and the development of work related stress, which may be associated with changes in concentrations of cortisol, psychological overload and, in the long run, health problems. Insufficient sleep is a contributing factor to lack of recovery, but

Coalescence of Repelling Colloidal Droplets: A Route to Monodisperse Populations

Populations of droplets or particles dispersed in a liquid may evolve through Brownian collisions, aggregation, and coalescence. We have found a Set of conditions under which these populations evolve spontaneously toward a narrow, size distribution. The experimental system of poly(methyl methacrylate) (PMMA) nanodroplets dispersed in a solvent (acetone) + nonsolvent (water) mixture. These droplets

Thrombus Aspiration during ST-Segment Elevation Myocardial Infarction.

Background The clinical effect of routine intracoronary thrombus aspiration before primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI) is uncertain. We aimed to evaluate whether thrombus aspiration reduces mortality. Methods We conducted a multicenter, prospective, randomized, controlled, open-label clinical trial, with enrollment of

Game theory sheds new light on ecological responses to current climate change when phenology is historically mismatched.

Phenological changes are well documented biological effects of current climate change but their adaptive value and demographic consequences are poorly known. Game theoretical models have shown that deviating from the fitness-maximising phenology can be evolutionary stable under frequency-dependent selection. We study eco-evolutionary responses to climate change when the historical phenology is mis

Modelling pesticide transport in a shallow groundwater catchment using tritium and helium-3 data

Using tritium and helium-3 data for calibration, a 2-D transport model was set up to explain the occurrence of bentazone, dichlorprop, glyphosate, isoproturon, MCPA and metamitron in a small groundwater catchment in southern Sweden. The model was parameterised with site-specific degradation and sorption data to enable transport simulations. Local climatological data and a 21-year record of agricul

Chronic exposure to cadmium and arsenic strongly influences concentrations of 8-oxo-7,8-dihydro-2'-deoxyguanosine in urine.

Exposure to arsenic (As), cadmium (Cd) and lead (Pb) may generate oxidative stress, which can be assessed by 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in urine, a sensitive marker of oxidatively damaged DNA. We have evaluated oxidative stress induced by mixed chronic exposure to As, Cd, Pb, as well as the influence of As metabolism and nutritional status, i.e. ferritin (Ft), selenium (Se), zin