Sökresultat

Filtyp

Din sökning på "*" gav 534789 sökträffar

Whole-heart four-dimensional flow can be acquired with preserved quality without respiratory gating, facilitating clinical use : A head-to-head comparison

Background: Respiratory gating is often used in 4D-flow acquisition to reduce motion artifacts. However, gating increases scan time. The aim of this study was to investigate if respiratory gating can be excluded from 4D flow acquisitions without affecting quantitative intracardiac parameters. Methods: Eight volunteers underwent CMR at 1.5 T with a 5-channel coil (5ch). Imaging included 2D flow mea

Second-generation colon capsule endoscopy compared with colonoscopy

Background: Colon capsule endoscopy (CCE) represents a noninvasive technology that allows visualization of the colon without requiring sedation and air insufflation. A second-generation colon capsule endoscopy system (PillCam Colon 2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. Objective: To assess the feasibility, accurac

Palladium versus Platinum: The Metal in the Catalytic Center of a Molecular Photocatalyst Determines the Mechanism of the Hydrogen Production with Visible Light

To develop highly efficient molecular photocatalysts for visible light-driven hydrogen production, a thorough understanding of the photophysical and chemical processes in the photocatalyst is of vital importance. In this context, in situ X-ray absorption spectroscopic (XAS) investigations show that the nature of the catalytically active metal center in a (N boolean AND N)MCl2 (M=Pd or Pt) coordina

A strong quantitative trait locus for wing length on chromosome 2 in a wild population of great reed warblers.

Wing length is a key character for essential behaviours related to bird flight such as migration and foraging. In the present study, we initiate the search for the genes underlying wing length in birds by studying a long-distance migrant, the great reed warbler (Acrocephalus arundinaceus). In this species wing length is an evolutionary interesting trait with pronounced latitudinal gradient and sex

Scholarly communication in transition. Computer scientists' information behaviour over twenty years.

Introduction. The information behaviour of a group of Swedish computer scientists has been studied over a period of twenty years (1987-2006). Method. Five computer scientists have been interviewed and answered individual questionnaires. Together with four colleagues they were also the subjects of a qualitative study twenty years ago. Analysis. Data from interviews in 1987-88 and 2006, questionnair

Chemistry of Supported Palladium Nanoparticles during Methane Oxidation

Time-resolved in situ, energy-dispersive X-ray absorption spectroscopy and mass spectrometry are used to correlate changes in the chemical state of alumina- and ceria-supported palladium nanoparticles with changes in activity and selectivity for methane oxidation. Specifically, modulation excitation spectroscopy experiments are carried out by periodically cycling between net-reducing and net-oxidi

Modern accident investigation - Four major challenges

Nowadays, 'investigation' is a very commonly advocated approach and consequently is becoming an umbrella concept. 'Investigation' includes many types of approaches on different system levels. Originating from transport accidents and crime scenes, 'investigation' ranges from genocide, natural disasters, via discrimination, health care to crime fighting, economic fraud and ethical questions in engin

Growth of ectomycorrhizal fungal mycelium along a Norway spruce forest nitrogen deposition gradient and its effect on nitrogen leakage

Almost all boreal and temperate forest tree species live in symbiosis with ectomycorrhizal fungi (EMF); the trees transfer carbon (C) to the fungi in exchange for nutrients and water. Several studies have shown that experimental application of inorganic nitrogen (N) represses production of EMF extramatrical mycelia (EMM), but studies along N deposition gradients are underrepresented. Other environ

Historical trust levels predict current welfare state size

Despite the fact that large welfare states are vulnerable to free-riding, the idea that universal welfare states lead to higher trust levels in the population has received some attention and support among political scientists recently. This paper argues that the opposite direction of causality is more plausible, i.e. that populations with higher trust levels are more prone to creating and successf

Modeling electroporation of the non-treated and vacuum impregnated heterogeneous tissue of spinach leaves

Uniform electroporation of the heterogeneous structure of spinach leaf cross section is a technological challenge that is addressed in this investigation. Three dimensional models were created with cells arranged in specific tissue types, considering a leaf with its air fraction and a leaf where the air fraction was replaced by a solution of known properties using vacuum impregnation. The models w

Improved breakdown voltages for type I InP/InGaAs DHBTs

We have investigated the base-collector breakdown voltage of type I InGaAs/InP DHBTs, which is shown to be dominated by band-to-band tunneling in the base-collector grade. By optimizing the grade we obtain a 20% increase in the breakdown voltage compared with traditional grades.

Imaging a one-electron InAs quantum dot in an InAs/InP nanowire

Nanowire heterostructures define high-quality few-electron quantum dots for nanoelectronics, spintronics, and quantum information processing. We use a cooled scanning probe microscope (SPM) to image and control an InAs quantum dot in an InAs/InP nanowire using the tip as a movable gate. Images of dot conductance vs tip position at T=4.2 K show concentric rings as electrons are added, starting with

Is population structure in the European white stork determined by flyway permeability rather than translocation history?

European white stork are long considered to diverge to eastern and western migration pools as a result of independent overwintering flyways. In relatively recent times, the western and northern distribution has been subject to dramatic population declines and country-specific extirpations. A number of independent reintroduction programs were started in the mid 1950s to bring storks back to histori

Does the Neighborhood Area of Residence Influence Non-Attendance in an Urban Mammography Screening Program? A Multilevel Study in a Swedish City.

The public health impact of population-based mammography screening programs depends on high participation rates. Thus, monitoring participation rates, as well as understanding and considering the factors influencing attendance, is important. With the goal to acquire information on the appropriate level of intervention for increasing screening participation our study aimed to (1) examine whether, o

External and internal factors influencing self-directed online learning of physiotherapy undergraduate students in Sweden: a qualitative study.

Online courses have become common in health sciences education. This learning environment can be designed using different approaches to support student learning. To further develop online environment, it is important to understand how students perceive working and learning online. The aim of this study is to identify aspects influencing students' learning processes and their adaptation to self-dir