100 research outputs found
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Study of surface changes on industrial glasses with AFM, FE-SEM, EDX, SNMS and LM : Part 2. Surface changes by water drop etching, annealing at atmosphere and flame treatment
One of the possible defects in sputter coating layers are cone shaped rods which originate from the float glass surface on the
atmosphere side. The glass surface had been etched by wax-like corrosion droplets and holes were formed into the glass skin after
washing. This results in inhomogeneity on the surface, which induces an inhomogenous deposition pattern of the material on the
surface during the process of sputtering. In contrast, the tin bath side is shown to be an ideal coating surface without any inhomogen eity. In some eases however, it could not be bent above the glass transition temperature (Tg) in air due to formation of bloom patterns, which make the glass milky. Our studies revealed that phase separation is the ultimate cause of the observed bloom formation. In addition, sulphur flakes and needle-like nanocrystallites were detected on the tin bath side as well as hexagonal nanocrystallites on the atmosphere side of the annealed float glass.
It was also found that flame treatment of borosilieate and lead crystal glasses induced two changes on the glass surfaces. These are precipitation of evaporation products and phase separation beneath the glass skin. The samples were studied by a combination of field emission scanning electron microscopy (FE-SEM) with different accelerating voltages and atomic force microscopy (AFM)
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Study of surface changes on industrial glasses with AFM, FE-SEM, EDX, SNMS and LM : Part 1. Glass skin and corrosion
By combining different analytieal techniques, including modern high resolution imaging tools such as field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM), new phenomena in the surface, near surface and bulk structure of various industrial glasses (without any cleaning process) have been diseovered. Investigations of soda-lime-silica container glass and lead silicate glass tubings exposed to atmospheric and to dried air are presented. The results of the first part of this paper can be explained with an SiO2 rich skin on the glass, which can protect the glass against the attack of external media. If the skin was mechanically injured, inhomogeneous corrosion products on pm scale grew around the injured site after exposure to humid air for times between days up to one year. Microchannels were formed through the injured site due to restricted ion exchange, followed by a local increase of the pH value and consequently the dissolution of the glass network. Finally some stress in the glass, yielded during manufacture, can be partially released and the cutting behaviour is improved. Faster cooling results in a thinner skin and the ions in the glass are able to migrate to the surface more easily when surrounded by some reactive media. Slower cooling results in thicker skin and wax-like droplets instead of erystallites are formed on the surface at a later stage in humid air. The wax-like droplets can etch the glass skin locally, followed by the growth of inhomogeneous corrosion products similar to the injury induced corrosion. If the fresh glass surface was hot-end treated, the quality of the adjacent coating layer depended strongly on the thickness of the skin
Susceptibility to collagen-induced arthritis is modulated by TGFβ responsiveness of T cells
The objective of our study was to determine the regulatory effects that endogenous transforming growth factor β (TGFβ) exerts on T cells in the pathogenesis of collagen-induced arthritis (CIA). CIA was induced in transgenic mice expressing a dominant negative TGFβ type II receptor in T cells under the control of the human CD2 promoter. Clinical and histological arthritis scores were determined and experiments on disease induction and the healing phase of disease were performed. The proliferation and cytokine production of draining lymph node cells in vitro were analyzed. Transgenic mice were more susceptible to induction of CIA. The overall incidence was higher in transgenic mice than in wild-type mice (57% vs 35%, P < 0.05). Affected transgenic animals displayed a significantly higher clinical (4.5 ± 0.6 vs 1.67 ± 0.19, P = 0.001) and histological arthritis score (8.01 ± 0.9 vs 4.06 ± 1.1, P < 0.05). Draining lymph node cells of transgenic mice secreted more tumor necrosis factor α and IFNγ and proliferated more vigorously in response to collagen type II and upon CD3/CD28 costimulation in vitro. Therefore, the regulation of T cells by endogenous TGFβ is important for the maintenance of joint integrity after arthritis induction. Defects in TGFβ-signalling as a susceptibility factor for rheumatoid arthritis may warrant further investigation
Impaired cerebrovascular autoregulation in patients with severe sepsis and sepsis-associated delirium
Spectral and spatial shaping of laser-driven proton beams using a pulsed high-field magnet beamline
Intense laser-driven proton pulses, inherently broadband and highly
divergent, pose a challenge to established beamline concepts on the path to
application-adapted irradiation field formation, particularly for 3D. Here we
experimentally show the successful implementation of a highly efficient (50%
transmission) and tuneable dual pulsed solenoid setup to generate a homogeneous
(8.5% uniformity laterally and in depth) volumetric dose distribution
(cylindrical volume of 5 mm diameter and depth) at a single pulse dose of 0.7
Gy via multi-energy slice selection from the broad input spectrum. The
experiments have been conducted at the Petawatt beam of the Dresden Laser
Acceleration Source Draco and were aided by a predictive simulation model
verified by proton transport studies. With the characterised beamline we
investigated manipulation and matching of lateral and depth dose profiles to
various desired applications and targets. Using a specifically adapted dose
profile, we successfully performed first proof-of-concept laser-driven proton
irradiation studies of volumetric in-vivo normal tissue (zebrafish embryos) and
in-vitro tumour tissue (SAS spheroids) samples.Comment: Submitted to Scientific Report
Health financing reform in Kenya- assessing the social health insurance proposal
Kenya has had a history of health financing policy changes since its  independence in 1963. Recently, significant preparatory work was done on a new Social Health Insurance Law that, if accepted, would lead to universal health coverage in Kenya after a tr&nsition period. Questions of economic feasibility and political acceptability continue to be discussed, with  stakeholders voicing concerns on design features of the new proposal  submitted to the Kenyan parliament in 2004. For economic, social, political and organisational reasons a transition period will be necessary, which is likely to last more than a decade. However, important objectives such as access to health care and avoiding impoverishment due to direct health care payments should be recognised from the start so that steady progress towards effective universal coverage can be planned and achieved
A proposal for early dosing regimens in heart transplant patients receiving thymoglobulin and calcineurin inhibition
There is currently no consensus regarding the dose or duration of rabbit antithymocyte globulin (rATG) induction in different types of heart transplant patients, or the timing and intensity of initial calcineurin inhibitor (CNI) therapy in rATG-treated individuals. Based on limited data and personal experience, the authors propose an approach to rATG dosing and initial CNI administration. Usually rATG is initiated immediately after exclusion of primary graft failure, although intraoperative initiation may be appropriate in specific cases. A total rATG dose of 4.5 to 7.5 mg/kg is advisable, tailored within that range according to immunologic risk and adjusted according to immune monitoring. Lower doses (eg, 3.0 mg/kg) of rATG can be used in patients at low immunological risk, or 1.5 to 2.5 mg/kg for patients with infection on mechanical circulatory support. The timing of CNI introduction is dictated by renal recovery, varying between day 3 and day 0 after heart transplantation, and the initial target exposure is influenced by immunological risk and presence of infection. Rabbit antithymocyte globulin and CNI dosing should not overlap except in high-risk cases. There is a clear need for more studies to define the optimal dosing regimens for rATG and early CNI exposure according to risk profile in heart transplantation
Ancestral Informative Marker Selection and Population Structure Visualization Using Sparse Laplacian Eigenfunctions
Identification of a small panel of population structure informative markers can reduce genotyping cost and is useful in various applications, such as ancestry inference in association mapping, forensics and evolutionary theory in population genetics. Traditional methods to ascertain ancestral informative markers usually require the prior knowledge of individual ancestry and have difficulty for admixed populations. Recently Principal Components Analysis (PCA) has been employed with success to select SNPs which are highly correlated with top significant principal components (PCs) without use of individual ancestral information. The approach is also applicable to admixed populations. Here we propose a novel approach based on our recent result on summarizing population structure by graph Laplacian eigenfunctions, which differs from PCA in that it is geometric and robust to outliers. Our approach also takes advantage of the priori sparseness of informative markers in the genome. Through simulation of a ring population and the real global population sample HGDP of 650K SNPs genotyped in 940 unrelated individuals, we validate the proposed algorithm at selecting most informative markers, a small fraction of which can recover the similar underlying population structure efficiently. Employing a standard Support Vector Machine (SVM) to predict individuals' continental memberships on HGDP dataset of seven continents, we demonstrate that the selected SNPs by our method are more informative but less redundant than those selected by PCA. Our algorithm is a promising tool in genome-wide association studies and population genetics, facilitating the selection of structure informative markers, efficient detection of population substructure and ancestral inference
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