117 research outputs found
Optical conductivity of Bismuth-based topological insulator
The optical conductivity and the spectral weight of four topological
insulators with increasing chemical compensation (Bi2Se3, Bi2-xCaxSe3,
Bi2Se2Te, Bi2Te2Se) have been measured from 5 to 300 K and from sub-THz to
visible frequencies. The effect of compensation is clearly observed in the
infrared spectra, through the suppression of an extrinsic Drude term and the
appearance of strong absorption peaks, that we assign to electronic transitions
among localized states. From the far-infrared spectral weight of the most
compensated sample (Bi2Te2Se) one can estimate a density of charge-carriers in
the order of 10^17/cm^3 in good agreement with transport data. Those results
demonstrate that the low-energy electrodynamics in single crystals of
topological insulators, even at the highest degree of compensation presently
achieved, is still affected by extrinsic charge excitations.Comment: 5 pages, 4 figure
A Survey of Volunteered Open Geo-Knowledge Bases in the Semantic Web
Over the past decade, rapid advances in web technologies, coupled with
innovative models of spatial data collection and consumption, have generated a
robust growth in geo-referenced information, resulting in spatial information
overload. Increasing 'geographic intelligence' in traditional text-based
information retrieval has become a prominent approach to respond to this issue
and to fulfill users' spatial information needs. Numerous efforts in the
Semantic Geospatial Web, Volunteered Geographic Information (VGI), and the
Linking Open Data initiative have converged in a constellation of open
knowledge bases, freely available online. In this article, we survey these open
knowledge bases, focusing on their geospatial dimension. Particular attention
is devoted to the crucial issue of the quality of geo-knowledge bases, as well
as of crowdsourced data. A new knowledge base, the OpenStreetMap Semantic
Network, is outlined as our contribution to this area. Research directions in
information integration and Geographic Information Retrieval (GIR) are then
reviewed, with a critical discussion of their current limitations and future
prospects
Leukaemia incidence among workers in the shoe and boot manufacturing industry: a case-control study
BACKGROUND: Previous reports have indicated an excess of leukaemia in Broome County, New York, particularly in the Town of Union. Surveillance of cancer incidence data indicates that a large proportion of these cases occurred among males ages 65 and older. Shoe and boot manufacturing has been the largest single industry in this area throughout much of the past century. Occupational studies from Europe suggest a link between leukaemia and employment in the shoe and boot manufacturing industry. However, researchers have not found a positive association between leukaemia and employment in the shoe industry among workers in the United States. METHODS: A matched case-control study was conducted to investigate the association between leukaemia incidence among males 65 and older and employment in the shoe and boot manufacturing industry. Thirty-six cases of leukaemia occurring between 1981ā1990; among males age 65 and older; residing in the town of Union met the study case criteria. Death certificates were obtained for each of the cases. These were matched to death certificates of 144 controls on date of death and date of birth +/- 1 year. Death certificates were then examined to determine the employer and occupation of each study subject. Conditional logistic regression was used to determine the risk of leukaemia among those working in the industry. RESULTS: The risk of both leukaemia (OR = 1.47; 95% CI 0.70, 3.09) and acute myeloid leukaemia (OR = 1.19; 95% CI 0.33, 4.28) were elevated among those employed in the shoe and boot manufacturing industry, however neither was statistically significant. CONCLUSION: The results, though suggestive of an association between leukaemia and employment in the shoe and boot manufacturing industry, were not statistically conclusive due mainly to limited study power. Several additional limitations may also have prevented the observance of more conclusive findings. Better exposure assessment, information on length of exposure and types of job held, control of confounding factors and information on chemicals used by this company would strengthen any future investigation
The Current State of Proteomics in GI Oncology
Proteomics refers to the study of the entire set of proteins in a given cell or tissue. With the extensive development of protein separation, mass spectrometry, and bioinformatics technologies, clinical proteomics has shown its potential as a powerful approach for biomarker discovery, particularly in the area of oncology. More than 130 exploratory studies have defined candidate markers in serum, gastrointestinal (GI) fluids, or cancer tissue. In this article, we introduce the commonly adopted proteomic technologies and describe results of a comprehensive review of studies that have applied these technologies to GI oncology, with a particular emphasis on developments in the last 3Ā years. We discuss reasons why the more than 130 studies to date have had little discernible clinical impact, and we outline steps that may allow proteomics to realize its promise for early detection of disease, monitoring of disease recurrence, and identification of targets for individualized therapy
Novel avian single-chain fragment variable (scFv) targets dietary gluten and related natural grain prolamins, toxic entities of celiac disease
Posttraumatische VerƤnderungen der NFkB-Konfiguration humaner Makrophagen des peripheren Blutes (PBMC)
Immundysfunktion von dendritischen Zellen wƤhrend der polymikrobiellen Sepsis - Keine Hilfe aus dem Knochenmark
Die Endotoxintoleranz reduziert das Kapillarleck aber erhƶht die LeukozytenadhƤsion am Mesenterium der Ratte nach erneuter LPS-Gabe
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