Properties of neutron doped multicrystalline silicon for solar cells

The technology of neutron transmutation doping of silicon wafers in MARIA nuclear research reactor is described. The studies of the radiation defects performed with positron annihilation confirmed that divacancies dominate in the irradiated material. Thermal treatment of irradiated silicon at 700-1000°C produces void - phosphorus complexes and void aggregates. The resistivity of the samples produced by neutron transmutation doping was found to be uniform within 2.5% limits. The severe reduction of the minority carrier lifetime in irradiated samples was confirmed

Influence of Heat Treatment on Defect Structures in Single-Crystalline Blade Roots Studied by X-ray Topography and Positron Annihilation Lifetime Spectroscopy

Single-crystalline superalloy CMSX-4 is studied in the as-cast state and after heat treatment, with material being taken from turbine blade castings. The effect of the heat treatment on the defect structure of the root area near the selector/root connection is emphasized. Multiscale analysis is performed to correlate results obtained by X-ray topography and positron annihilation lifetime spectroscopy (PALS). Electron microscopy observations were also carried out to characterize the inhomogeneity in dendritic structure. The X-ray topography was used to compare defects of the misorientation nature, occurring in as-cast and treated states. The type and concentration of defects before and after heat treatment in different root areas were determined using the PALS method, which enables voids, mono-vacancies, and dislocations to be taken into account. In this way, differences in the concentration of defects caused by heat treatment are rationalized

The Brustkrebs-Studien.de website for breast cancer patients: User acceptance of a German internet portal offering information on the disease and treatment options, and a clinical trials matching service

<p>Abstract</p> <p>Background</p> <p>The internet portal <url>http://www.brustkrebs-studien.de</url> (BKS) was launched in 2000 by the German Society of Senology (DGS) and the Baden-Württemberg Institute for Women's Health (IFG) to provide expert-written information on breast cancer online and to encourage and facilitate the participation of breast cancer patients in clinical trials. We describe the development of BKS and its applications, and report on website statistics and user acceptance.</p> <p>Methods</p> <p>Existing registries, including ClinicalTrials.gov, were analysed before we designed BKS, which combines a trial registry, a knowledge portal, and an online second opinion service. An advisory board guided the process. Log files and patient enquiries for trial participation and second opinions were analysed. A two-week user satisfaction survey was conducted online.</p> <p>Results</p> <p>During 10/2005-06/2010, the portal attracted 702,655 visitors, generating 15,507,454 page views. By 06/2010, the website's active scientific community consisted of 189 investigators and physicians, and the registry covered 163 clinical trial protocols. In 2009, 143 patients requested trial enrolment and 119 sought second opinions or individual treatment advice from the expert panel. During the two-week survey in 2008, 5,702 BKS visitors submitted 507 evaluable questionnaires. Portal acceptance was high. Respondents trusted information correctness (80%), welcomed self-matching to clinical trials (79%) and planned to use the portal in the future (76%) and recommend it to others (81%).</p> <p>Conclusions</p> <p>BKS is an established and trusted breast cancer information platform offering up-to-date resources and protocols to the growing physician and patient community to encourage participation in clinical trials. Further studies are needed to assess potential increases in trial enrolment by eligibility matching services.</p

Computational approaches for modeling human intestinal absorption and permeability

Human intestinal absorption (HIA) is an important roadblock in the formulation of new drug substances. Computational models are needed for the rapid estimation of this property. The measurements are determined via in vivo experiments or in vitro permeability studies. We present several computational models that are able to predict the absorption of drugs by the human intestine and the permeability through human Caco-2 cells. The training and prediction sets were derived from literature sources and carefully examined to eliminate compounds that are actively transported. We compare our results to models derived by other methods and find that the statistical quality is similar. We believe that models derived from both sources of experimental data would provide greater consistency in predictions. The performance of several QSPR models that we investigated to predict outside the training set for either experimental property clearly indicates that caution should be exercised while applying any of the models for quantitative predictions. However, we are able to show that the qualitative predictions can be obtained with close to a 70% success rate