Search results

Filter

Filetype

Your search for "*" yielded 525377 hits

Reading mathematics representations: an eye-tracking study

We use eye tracking as a method to examine how different mathematical representations of the same mathematical object are attended to by students. The results of this study show that there is a meaningful difference in the eye movements between formulas and graphs. This difference can be understood in terms of the cultural and social shaping of human perception, as well as in terms of differences

Safety of etoricoxib, celecoxib and non-selective NSAIDs in Ankylosing spondylitis and other Spondyloarthritis patients: A Swedish national population based cohort study.

Objective: Safety data regarding the usage of etoricoxib and other nonsteroidal anti-inflammatory drugs (NSAIDs) in ankylosing spondylitis (AS) and other spondyloarthritis (SpA) patients are rather limited. To estimate and compare rates of gastrointestinal, renovascular, and cardiovascular adverse events in patients exposed to etoricoxib, celecoxib, non-selective NSAIDs (nsNSAIDs) or totally unexp

Preparation and characterization of uniform molecularly imprinted polymer beads for separation of triazine herbicides

Uniform molecularly imprinted polymer beads were synthesized by precipitation polymerization for separation of triazine herbicides. A series of imprinted polymers were prepared using ametryn as template and divinylbenzene as crosslinking monomer, in combination with three different functional monomers under different solvent conditions. Under optimized reaction conditions, we obtained uniform mole

The epidemiology of Lp-PLA(2): Distribution and correlation with cardiovascular risk factors in a population-based cohort.

Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an enzyme that is produced by inflammatory cells (macrophages, T-lymphocytes and mast cells) and hydrolyzes oxidized phospholipids in LDL. Several epidemiology studies indicate that Lp-PLA(2) appears to be an independent marker of cardiovascular risk. This study was conducted to define the distribution of Lp-PLA(2) in a large population-base

A model for peak and width of signaling windows: Ips duplicatus and Chilo partellus pheromone component proportions - Does response have a wider window than production?

Pheromone communication systems have a reliable signal with a restricted window of amounts and ratios released and perceived. We propose a model based on a Gaussian response profile that allows a quantification of the response peak (location of optimum) and a measure of the peak width (response window). Interpreting the Gaussian curve, fitted by nonlinear regression (NLR), as a standard normal dis

New mechanism for amino acid influx into human epidermal Langerhans cells: L-dopa/proton counter-transport system.

We have characterized a stereospecific transport mechanism for L-dopa into human epidermal Langerhans cells (LCs). It is different from any other amino acid transport system. It is highly concentrative, largely pH-independent, and independent of exogenous Na+, glucose and oxygen, and fuelled by a renewable intracellular energy source inhibited by iodoacetate but not by arsenate. We propose that th

Biological filtering of correlated environments: towards a generalised Moran theorem

Many species from diverse taxa are known to display synchronous fluctuations across vast geographical ranges. It is often thought that climate factors influencing the growth of conspecific populations are correlated over large distances and hence produce the synchronous population dynamics - an effect known as the Moran effect. However, for species embedded in a food web the Moran effect needs not

Hydrophobic Interaction Capillary Electrochromatography of Protein Mutants. Use of Lipid-Based Liquid Crystalline Nanoparticles as Pseudostationary Phase.

Nanoparticle-based hydrophobic interaction-capillary electrochromatography was utilized for separation of proteins with similar mass-to-charge ratio at neutral pH without organic modifier. Lipid-based liquid crystalline nanoparticles were prepared and used as pseudostationary phase, benefiting from their high biocompatibility, ease of preparation, and suspension stability at high concentrations. U

Gender differences and cognitive aspects on functional outcome after hip fracture-a 2 years' follow-up of 2,134 patients

Objective: we analysed outcome after hip fracture with respect to gender and cognitive function. Design: population-based, prospective cohort study. Setting: four university hospitals in Stockholm, Sweden. Subjects: a total of 2,134 consecutive patients admitted with hip fracture during 2003. Methods: gender differences in residence, walking ability and activity of daily living (ADL) were analysed

Exogenous leptin controls the development of the small intestine in neonatal piglets

Leptin, a hormone produced and secreted by adipose tissue, muscles and stomach, is involved in the regulation of adipose tissue mass, food intake and body weight in neonatal animals. It is also produced in the mammary glands and secreted into the colostrum and milk. Since leptin receptors are widely distributed in the small intestine mucosa, the aim of the present study was to investigate the effe

The reductive fragmentation of 7-hydroxy-9,10-dioxotaxoids.

The retro-aldol reductive fragmentation of different structural types of 7-hydroxy-9,10-dioxotaxoids was investigated, showing that the reaction is typical of taxanes and requires cerium(III) promotion with NaBH4 in protic medium and alkylboron (aluminium) hydrides in aprotic solvents. The resulting 7,8-seco-taxanes are key intermediates for the synthesis of a novel class of anticancer taxanes end

Influence of Maturity on Creep of High Performance Concrete.

This article outlines an experimental and numerical study of basic creep in High Performance Concrete. About 100 cylinders (studies of creep and shrinkage) and 400 cubes (for studies of hydration, internal relative humidity, and strength) were tested. The ambient climate was held constant at 20°C. One concrete was studied at other temperatures between -20°C and 60°C. Analyses were carried out of q

Identification of Genetic Regions of Importance for Reproductive Performance in Female Mice.

Both environmental and genetic factors can dramatically affect reproductive performance in mice. In this study we have focused on the identification of genetic regions, quantitative trait loci (QTL), which affect the breeding capacity of female mice. We have identified polymorphic microsatellite markers for the mouse strains used and performed a genomewide scan on 237 females from a gene-segregati

Reactivity of the unsaturated triosmium cluster Os-3(CO)(8)(mu(3)-eta(2)-Ph2PCH2P(Ph)C6H4)(mu-H) with benzothiophene: Activation of a P-C bond in diphosphine and a C-H bond in benzothiophene

Treatment of the electronically unsaturated cluster Os-3(CO)(8)(mu(3)-eta(2)-Ph2PCH2P(Ph)C6H4)(mu-H) (1) with benzothiophene in refluxing m-xylene afforded Os-3(CO)(7)(mu-PPh2)(mu-PMePh)(mu(3)-eta(2)-C6H4) (2), Os-3(CO)(7)(mu(3)-eta(2)-PPh(C6H4)CH2PPh)(mu(3)-eta(3)-SC8H5)(mu-H) (3), and Os-3(CO)(8)(mu-CO)(mu(3)-eta(2)-PPh(C6H4)CH2PPh) (4). Thermolysis of 1 in refluxing toluene for 35 h afforded on

CCK stimulates growth of both the pancreas and the liver

BACKGROUND: The pancreas is the main target of the trophic effect of cholecystokinin (CCK), with a transient increase in cell proliferation and persistent effect on DNA content and weight gain when given continuously. Whether CCK exerts similar effects on the liver and biliary tract is not known. Most studies on this subject have hitherto been done in the rat. The aim of the present experiments wa

Macronutrients in tree stems and foliage: a comparative study of six temperate forest species planted at the same sites

Common European tree species ( oak, ash, beech, birch, lime and spruce) planted in adjacent stands on six sites were compared in terms of macronutrient concentrations in foliar and stem wood ( including bark) biomass. The nutrient concentrations in both biomass compartments were much more dependent on species than on site although soil conditions differed between the sites. Differences between spe

Toll-like receptor 4 expression and cytokine responses in the human urinary tract mucosa.

Mucosal pathogens trigger a local innate host response by activating epithelial cells. Bacterial adherence and Toll-like receptor 4 (TLR4) signaling have been implicated as key events in this process. This study addressed the molecular basis of the epithelial response to gram-negative infection in the human urinary tract. Mucosal biopsies were obtained from kidneys, ureters, and bladders of patien

Grafting of Polyurethane Surfaces with Poly(Ethylene Glycol)

Films of a commercial poly (ether urethane), Pellethane 2363-80AE, were prepared through solvent casting from dimethyl formamide. The films were grafted with poly (ethylene glycol) (PEG) by a two-step procedure. In the first step, the film surfaces were treated with hexamethylene diisocyanate in toluene in the presence of triethylamine as a catalyst. In the second step, PEG 1500 was allowed to rea