Search results

Filter

Filetype

Your search for "*" yielded 541482 hits

Comparison of the European and Nordic protocols on dosimetry in mammography involving a standard phantom

The purpose of this work was to implement the European Protocol on Dosimetry in Mammography in Sweden. The standard average glandular dose, AGD, was measured on 32 mammography units in southern Sweden, according to the European protocol as well as to the Nordic protocol. The most important difference is that the European protocol evaluates the half value layer, HVL, of the X ray beam with the comp

Kinetics and mechanisms in the ammoxidation of toluene over a V2O5 catalyst. Part 2: Non-selective reactions

In the ammoxidation of toluene over a V2O5 catalyst, the variation of initial rates with partial pressures of oxygen, toluene and ammonia was determined for formation of carbon oxides. Dependencies obtained were analyzed and expressed in terms of rate equations. It was found that CO and CO2 are initial products formed at different sites, none of which are involved in selective reactions. The mecha

Start of egg-laying in relation to latitude and elevation among Swedish Starlings Sturnus vulgaris in 1988-2003

The Starlings Sturnus vulgaris breeding in sixteen nest-box groups, three in northern and thirteen in southern Sweden, were monitored in 1988-2003. Date of the first egg was found to correlate with both latitude and elevation when all sites were included (13 degrees of latitude; 5-430 m elevation). Restricting the analysis to only the south Swedish sites (4 degrees of latitude; 5-230 m elevation),

On the geometry of harmonic morphisms

Let π:M→B be a horizontally conformal submersion. We give necessary curvature conditions on the manifolds M and B, which lead to non-existence results for certain horizontally conformal maps, and harmonic morphisms. We then classify all such maps between open subsets of Euclidean spaces, which additionally have totally geodesic fibres and are horizontally homothetic. They are orthogonal projection

Proton (1H) MR spectroscopy for routine diagnostic evaluation of brain lesions

PURPOSE: To describe the introduction and performance of proton MR spectroscopy (1H-MRS) in the daily routine of a modern standard MR unit. MATERIAL AND METHODS: Over an 8-month period, 52 patients with brain lesions were studied with 1H-MRS, using SE and STEAM sequences for chemical-shift imaging and single-volume spectroscopy. The quality of the spectra was graded from 1 (best) to 3, and the mai

Measuring nonaqueous phase liquid saturation in soil using time domain reflectometry

[1] Transport of nonaqueous phase liquids (NAPLs) in soils is becoming an increasingly serious threat to the environment. Detection and observation of these substances are thus an increasingly important issue. During recent years, studies have used the apparent dielectric constant (K-a) measured by time domain reflectometry (TDR) for determining the saturation of NAPLs (theta(NAPL)) in soils (m(3)

Au-free epitaxial growth of InAs nanowires

III-V nanowires have been fabricated by metal-organic vapor-phase epitaxy without using Au or other metal particles as a catalyst. Instead, prior to growth, a thin SiOx layer is deposited on the substrates. Wires form on various III-V substrates as well as on Si. They are nontapered in thickness and exhibit a hexagonal cross-section. From high-resolution X-ray diffraction, the epitaxial relation b

Are occupational, hobby, or lifestyle exposures associated with Philadelphia chromosome positive chronic myeloid leukaemia?

OBJECTIVES: To investigate a broad range of occupational, hobby, and lifestyle exposures, suggested as risk factors for Philadelphia chromosome positive (Ph+) chronic myeloid leukaemia (CML). METHODS: A case-control study, comprising 255 Ph+CML patients from southern Sweden and matched controls, was conducted. Individual data on work tasks, hobbies, and lifestyle exposures were obtained by telepho

Sensitivity, specificity, and stability of CSF-tau in AD in a community-based patient sample

OBJECTIVE: To evaluate the sensitivity and specificity of CSF-tau in clinical practice as a diagnostic marker for AD compared with normal aging and depression, to study the stability of CSF-tau in longitudinal samples, and to determine whether CSF-tau levels are influenced by different covariates such as gender, age, duration or severity of disease, or possession of the APOE-epsilon4 allele. METHO

Polarization patterns of thick clouds: overcast skies have distribution of the angle of polarization similar to that of clear skies

The distribution of polarization in the overcast sky has been practically unknown. Earlier the polarization of light from heavily overcast skies (when the Sun's disc was invisible) has been measured only sporadically in some celestial points by point-source polarimetry. What kind of patterns of the degree p and angle a of linear polarization of light could develop after transmission through a thic

XPS study of living tree

X-ray photoelectron spectroscopy (XPS) was used to study the distribution of elements and main wood components (cellulose and lignin) within the wood and at the bark/wood interface of a living hybrid aspen stem. The hybrid aspen was grown upright in a greenhouse and then tilted at similar to45degrees to induce tension wood formation and upright bending of the stem. The wood between the pith and th

Fate of N-15 labelled nitrate and ammonium in a fertilized forest soil

The possibility that long-term atmospheric nitrogen pollution and fertilization of forest soil may serve as a basis for adaptation for enhanced transformation rates of NO3- and NH4+ in soil. bacteria was elucidated in a laboratory bioassay. Bacteria extracted from soils that had been fertilized at various rates for the last 30 yr were characterised with respect to their capability to reduce or oxi

Synergism between vascular endothelial growth factor and placental growth factor contributes to angiogenesis and plasma extravasation in pathological conditions

Vascular endothelial growth factor (VEGF) stimulates angiogenesis by activating VEGF receptor-2 (VEGFR-2). The role of its homolog, placental growth factor (PlGF), remains unknown. Both VEGF and PlGF bind to VEGF receptor-1 (VEGFR-1), but it is unknown whether VEGFR-1, which exists as a soluble or a membrane-bound type, is an inert decoy or a signaling receptor for PlGF during angiogenesis. Here,

PGC-1alpha-responsive genes involved in oxidative phosphorylation are coordinately downregulated in human diabetes.

DNA microarrays can be used to identify gene expression changes characteristic of human disease. This is challenging, however, when relevant differences are subtle at the level of individual genes. We introduce an analytical strategy, Gene Set Enrichment Analysis, designed to detect modest but coordinate changes in the expression of groups of functionally related genes. Using this approach, we ide

Supramolecular Structures of Poly(γ-benzyl-L-glutamate) Self-Assembled on Mica Surface

This article reports the results of structural studies of poly (-benzyl-L-glutamate) (PBLG) layers self-assembled from dilute solutions in organic solvents on mica surface. Polarized dynamic light scattering and atomic force microscopy were used to study polymer properties in solutions and on the surface. The hierarchy of self-assembly from PBLG solutions in different solvents was investigated as

A systematic overview of radiation therapy effects in uterine cancer (corpus uteri)

A systematic review of radiation therapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for evaluation of the scientific literature are described separately (Acta Oncol 2003; 42: 357-365). This synthesis of the literature on radiation therapy for uterine cancer is based on data from one randomized study Moreover, da