213 research outputs found
Physical properties of SrSn4 single crystals
We present detailed thermodynamic and transport measurements on single
crystals of the recently discovered binary intermetallic superconductor, SrSn4.
We find this material to be a slightly anisotropic three-dimensional,
strongly-coupled, possibly multi-band, superconductor. Hydrostatic pressure
causes a decrease in the superconducting transition temperature at the rate of
-0.068 K/kbar. Band structure calculations are consistent with experimental
data on Sommerfeld coefficient and upper superconducting critical field
anisotropy and suggest complex, multi-sheet Fermi surface formed by four bands.Comment: Figure 11 correcte
Influence of thermal history on the structure and properties of silicate glasses
We studied a set of float glass samples prepared with different fictive
temperature by previous annealing around the glass transition temperature. We
compared the results to previous measurements on a series of amorphous silica
samples, also prepared with different fictive temperature. We showed that the
modifications on the structure at a local scale are very small, the changes of
physical properties are moderate but the changes on density fluctuations at a
nanometer scale are rather large: 12 and 20% in float glass and silica, for
relative changes of fictive temperature equal to 13 and 25% respectively. Local
order and mechanical properties of silica vary in the opposite way compared to
float glass (anomalous behavior) but the density fluctuations in both glasses
increase with temperature and fictive temperature
Empirical Investigation on Agile Methods Usage: Issues Identified from Early Adopters in Malaysia
Agile Methods are a set of software practices that can help to produce products faster and at the same time deliver what customers want. Despite the benefits that Agile methods can deliver, however, we found few studies from the Southeast Asia region, particularly Malaysia. As a result, less empirical evidence can be obtained in the country making its implementation harder. To use a new method, experience from other practitioners is critical, which describes what is important, what is possible and what is not possible concerning Agile. We conducted a qualitative study to understand the issues faced by early adopters in Malaysia where Agile methods are still relatively new. The initial study involves 13 participants including project managers, CEOs, founders and software developers from seven organisations. Our study has shown that social and human aspects are important when using Agile methods. While technical aspects have always been considered to exist in software development, we found these factors to be less important when using Agile methods. The results obtained can serve as guidelines to practitioners in the country and the neighbouring regions
Survey of intestinal parasites among primary school children inhabitants of different rural communities in Rio Grande do Sul State
Um trabalho de extensão comunitária foi realizado em três assentamentos de colonos sem terra, Fazenda de São Pedro, Charqueadas e Capela de Santana, nas proximidades de Porto Alegre, RS. O objetivo desta pesquisa foi determinar o índice de infecção de parasitas intestinais nas crianças residentes nessas comunidades rurais. Este estudo, executado em 140 crianças, de zero a 14 anos revelou que 45% (63) estavam infectadas por uma ou mais espécies de enteroparasitas. O maior percentual obtido para protozoários foi de 15,7% (22) para Giardia lamblia e entre os helmintos, ancilostomídeos com 15,7% (22) e Strongyloides stercoralis e Hymenolepis nana com 7,9% (11) respectivamente.An integrated programma and a survey of intestinal parasites were carried out in three rural communities inhabitants of Fazenda de São Pedro, Charqueadas and Capela de Santana near Porto Alegre, RS. In order to determine the infection rate of intestinal parasites in primary school children from these communities a total of 140 stools specimens were collected and screened for the presence of intestinal protozoa and helminths. One or more parasites were demonstrated in 45% (63) of the students population. The most common intestinal parasites in this study were Giardia lamblia and hookworms, 15.7% (22). Other intestinal helminths found less frequently were Strongyloides stercoralis and Hymenolepis nana both with 7.85% (11)
The earliest thymic T cell progenitors sustain B cell and myeloid lineage potential
The stepwise commitment from hematopoietic stem cells in the bone marrow to T lymphocyte-restricted progenitors in the thymus represents a paradigm for understanding the requirement for distinct extrinsic cues during different stages of lineage restriction from multipotent to lineage-restricted progenitors. However, the commitment stage at which progenitors migrate from the bone marrow to the thymus remains unclear. Here we provide functional and molecular evidence at the single-cell level that the earliest progenitors in the neonatal thymus had combined granulocyte-monocyte, T lymphocyte and B lymphocyte lineage potential but not megakaryocyte-erythroid lineage potential. These potentials were identical to those of candidate thymus-seeding progenitors in the bone marrow, which were closely related at the molecular level. Our findings establish the distinct lineage-restriction stage at which the T cell lineage-commitment process transits from the bone marrow to the remote thymus. © 2012 Nature America, Inc. All rights reserved
Detailed stratified GWAS analysis for severe COVID-19 in four European populations
Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended genome-wide association meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ∼0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.publishedVersio
Angewandte Chemie
Extended Abstract Electrospinning has been recognized as an effective and inexpensive technique for fabrication of long fibers from various materials including polymers, composites and biomacromolecules with diameters ranging from a few nanometers to few micrometers Polymer-based drug delivery systems are used to improve the therapeutic properties of drugs in a safer, effective and reliable manner Gelatin is a natural biopolymer derived from animal collagen, having a long history of safe use in pharmaceuticals, cosmetics as well as food products In the current work electrospun fibers were developed as a new system for the delivery and release of an anticancer agent doxorubicin via electrospinning technique. The morphology of the fibers was analyzed by scanning electron microscopy(SEM), fourier transform infrared spectroscopy (FTIR). The fibers were made from gelatin as a biodegradable polymer and the release of doxorubicin was followed by UV-vis spectroscopy in phosphate buffer of pH 7.4 at 25 °C and 37 °C. The release profiles from gelatin electrospun fiber mats were compared with casting films with the same composition
- …