997 resultados para Artefact studies


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BACKGROUND: Practicing physicians are faced with many medical decisions daily. These are mainly influenced by personal experience but should also consider patient preferences and the scientific evidence reflected by a constantly increasing number of medical publications and guidelines. With the objective of optimal medical treatment, the concept of evidence-based medicine is founded on these three aspects. It should be considered that there is a high risk of misinterpreting evidence, leading to medical errors and adverse effects without knowledge of the methodological background. OBJECTIVES: This article explains the concept of systematic error (bias) and its importance. Causes and effects as well as methods to minimize bias are discussed. This information should impart a deeper understanding, leading to a better assessment of studies and implementation of its recommendations in daily medical practice. CONCLUSION: Developed by the Cochrane Collaboration, the risk of bias (RoB) tool is an assessment instrument for the potential of bias in controlled trials. Good handling, short processing time, high transparency of judgements and a graphical presentation of findings that is easily comprehensible are among its strengths. Attached to this article the German translation of the RoB tool is published. This should facilitate the applicability for non-experts and moreover, support evidence-based medical decision-making.

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The results of several large multicenter CMR studies were reported in 2012, thus, constantly corroborating the evidence on CMR performance. In this review, we present results of the MR-IMPACT programme and the CE-MARC study, which demonstrated the superiority of perfusion-CMR over gated SPECT for the workup of suspected CAD, the currently available data from the European CMR registry, comprising almost 30,000 patients from 57 participating centers in 15 European countries, and finally, the results of the Advisa-MRI study, which documented the safety of a MRI-compatible pacemaker system. These large trials and others set the basis for the recommendations in the new European guidelines on heart failure to use CMR as a first line method if echocardiographic quality is inadequate or the etiology of heart failure is unclear.

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BACKGROUND: Many clinical studies are ultimately not fully published in peer-reviewed journals. Underreporting of clinical research is wasteful and can result in biased estimates of treatment effect or harm, leading to recommendations that are inappropriate or even dangerous. METHODS: We assembled a cohort of clinical studies approved 2000-2002 by the Research Ethics Committee of the University of Freiburg, Germany. Published full articles were searched in electronic databases and investigators contacted. Data on study characteristics were extracted from protocols and corresponding publications. We characterized the cohort, quantified its publication outcome and compared protocols and publications for selected aspects. RESULTS: Of 917 approved studies, 807 were started and 110 were not, either locally or as a whole. Of the started studies, 576 (71%) were completed according to protocol, 128 (16%) discontinued and 42 (5%) are still ongoing; for 61 (8%) there was no information about their course. We identified 782 full publications corresponding to 419 of the 807 initiated studies; the publication proportion was 52% (95% CI: 0.48-0.55). Study design was not significantly associated with subsequent publication. Multicentre status, international collaboration, large sample size and commercial or non-commercial funding were positively associated with subsequent publication. Commercial funding was mentioned in 203 (48%) protocols and in 205 (49%) of the publications. In most published studies (339; 81%) this information corresponded between protocol and publication. Most studies were published in English (367; 88%); some in German (25; 6%) or both languages (27; 6%). The local investigators were listed as (co-)authors in the publications corresponding to 259 (62%) studies. CONCLUSION: Half of the clinical research conducted at a large German university medical centre remains unpublished; future research is built on an incomplete database. Research resources are likely wasted as neither health care professionals nor patients nor policy makers can use the results when making decisions.

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Regulator of G-protein signalling (RGS) proteins negatively regulate heterotrimeric G-protein signalling through their conserved RGS domains. RGS domains act as GTPase-activating proteins, accelerating the GTP hydrolysis rate of the activated form of Gα-subunits. Although omnipresent in eukaryotes, RGS proteins have not been adequately analysed in non-mammalian organisms. The Drosophila melanogaster Gαo-subunit and the RGS domain of its interacting partner CG5036 have been overproduced and purified; the crystallization of the complex of the two proteins using PEG 4000 as a crystallizing agent and preliminary X-ray crystallographic analysis are reported. Diffraction data were collected to 2.0 Å resolution using a synchrotron-radiation source.

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The two goals of this project stated in the Proposal were: (1) study lime diffusion in clayey soils, and (2) find the role of MgO in soil-dolomitic lime stabilization. Because of the practice significance of these goals we temporarily overstaffed this project, giving somewhat a "crash" program. As a result, proposed work was finished up early (as were the funds), and more important, some of the findings were early enough and of sufficient merit to put into field trials in the Fall of 1964. The work now being completed and the funds all being expended, this Final Report is therefore submitted before the anticipated project termination date.

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Approximately 520 Wilson disease-causing mutations in the ATP7B gene have been described to date. In this study we report DNA and RNA analyses carried out for molecular characterization of a consensus sequence splicing mutation found in homozygosity in a Swiss Wilson disease patient. RNA analysis of 1946 +6 T→C in both the peripheral lymphoblasts and liver resulted in the production in the propositus of only an alternative transcript lacking exons 6, 7, and 8 resulting most likely in alterations of cell biochemistry and disease. The patient presents an early form of severe hepatic disease characterized by hepatosplenomegaly, reduced hepatic function, anemia and thrombocytopenia indicating that 1946 +6 T→C is a severe mutation. Since identical results were obtained from both peripheral lymphoblasts and liver they also suggest that RNA studies of illegitimate transcripts can be safely used for molecular characterization of ATP7B splicing mutations, thus improving genetic counseling and diagnosis of Wilson disease. Moreover these studies, contribute to reveal the exact molecular mechanisms producing Wilson disease.

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The BPR type Roughometer has been used by the Iowa State Highway Commission since 1955 for the evaluation of the relative roughness of the various Iowa road surfaces. Since the commencement of this program, standardized information about the roughness of the various Iowa roads with respect to their type, construction, location and usage has been obtained. The Roughometer has also served to improve the economics and quality of road construction by making the roughness results of various practices available to all who are interested. In 1965, the Portland Cement Association developed a device known as the PCA Road Meter for measuring road roughness. Mounted in a regular passenger car, the Road Meter is a simple electromechanical device of durable construction which can perform consistently with extremely low maintenance. In 1967, the Iowa State Highway Commission's Laboratory constructed a P.C.A. type Road Meter in order to provide an efficient and reliable method for measuring the Present Serviceability Index for the state's highways. Another possibility was that after considerable testing the Road Meter might eventually replace the Roughometer. Some advantages of the Road Meter over the Roughometer are: (1) Road Meter tests are made by the automobile driver and one assistant without the need of traffic protection. The Roughometer has a crew of four men; two operating the roughometer and two driving safety vehicles. (2) The Road Meter is able to do more miles of testing because of its faster testing speed and the fa.ct that it is the only vehicle involved in the testing. (3) Because of the faster testing speed, the Road Meter gives a better indication of how the road actually rides to the average highway traveler. (4) The cost of operating a Road Meter is less than that of a Roughometer because of the fewer number of vehicles and men needed in testing.

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This investigation was conducted to study the performance characteristics of low cost roadway surfaces of soil-aggregate-sodium chloride mixtures. Many roads have been successfully stabilized with sodium chloride. However, little information is available on either the properties of the road materials or the effects of sodium chloride on the materials. The performance of some of the sodium chloride stabilized roads in Franklin County, Iowa, and the performance of some near-by nonchemically treated roads has been studied. The study of sodium chloride stabilized roads was restricted to the roads in which the binder soil used in construction came from the same source. The effects of sodium chloride on some of the engineering properties of the soil and soil-aggregate mixtures used were studied in the laboratory.

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Whole-grain foods are touted for multiple health benefits, including enhancing insulin sensitivity and reducing type 2 diabetes risk. Recent genome-wide association studies (GWAS) have identified several single nucleotide polymorphisms (SNPs) associated with fasting glucose and insulin concentrations in individuals free of diabetes. We tested the hypothesis that whole-grain food intake and genetic variation interact to influence concentrations of fasting glucose and insulin. Via meta-analysis of data from 14 cohorts comprising ∼ 48,000 participants of European descent, we studied interactions of whole-grain intake with loci previously associated in GWAS with fasting glucose (16 loci) and/or insulin (2 loci) concentrations. For tests of interaction, we considered a P value <0.0028 (0.05 of 18 tests) as statistically significant. Greater whole-grain food intake was associated with lower fasting glucose and insulin concentrations independent of demographics, other dietary and lifestyle factors, and BMI (β [95% CI] per 1-serving-greater whole-grain intake: -0.009 mmol/l glucose [-0.013 to -0.005], P < 0.0001 and -0.011 pmol/l [ln] insulin [-0.015 to -0.007], P = 0.0003). No interactions met our multiple testing-adjusted statistical significance threshold. The strongest SNP interaction with whole-grain intake was rs780094 (GCKR) for fasting insulin (P = 0.006), where greater whole-grain intake was associated with a smaller reduction in fasting insulin concentrations in those with the insulin-raising allele. Our results support the favorable association of whole-grain intake with fasting glucose and insulin and suggest a potential interaction between variation in GCKR and whole-grain intake in influencing fasting insulin concentrations.

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The communication presents the results of an investigation of exploratory and comparative character which objective is to analyze the influence of the actual labour situation into the demand of official master studies in the field of education. The study has been developed in two countries with a very different labour situation: Brasil, country of economic expansion and Spain, in recession due to the actual economic crisis. In that sense, the study provides data for deep thinking about the influence of the constriction or expansion of employment on the behaviour and demand of the students who access master studies and on how the previous formative and labour trajectory affects their expectations, demands and future projects. The working methodology is qualitative and the strategy for data collection the “focus group”. As a first approach, two groups of discussion have been formed with master students. A first one with students from Universidad de Barcelona- España and another one with members of Universidade do Vale do Itajaí- Brasil. Then, we constituted a mixed group of discussion in order to analyze differences and similarities.

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The precise generic delimitation of Aliella andPhagnalon, and their closest relatives within the Gnaphalieae are discussed in this review. Among the main results obtained, wehave found that the genera Aliella and Phagnalon are nested withinthe “Relhania clade” and Anisothrix, Athrixia and Pentatrichia aretheir closest relatives. Macowania is also part of the “Relhaniaclade”, whereas the subtribal affinities of Philyrophyllum liewithin the “crown radiation clade”. The monophyly of Aliellaand Phagnalon is not supported statistically. In addition,Aliella appears to be paraphylethic in most of the analysesperformed. The resulting phylogeny suggests an African origin forthe ancestor of Aliella and Phagnalon and identifies three mainclades within Phagnalon that constitute the following naturalgroups on a geographic basis: (1) the Irano-Turanian clade; (2) the Mediterranean-Macaronesian clade; and (3) the Yemen-Ethiopian clade. Some endemics to Yemen and Ethiopia appeared merged in the Mediterranean-Macaronesian clade, providing new evidence of the phytogeographical links betweenMacaronesia, Eastern Africa and Southern Arabia. Incongruities between thechloroplast and nuclear molecular data and the lack of resolution in some clades mayindicate that hybridization could have played an important role in the evolution anddiversification of both Phagnalon and Aliella.

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Der Sammelband ,,Right-wing extremism" hat ein doppeltes Ziel. Zum einen soll er das Nationale Forschungsprogramm 40plus und seine Projekte präsentieren (die alle mit Beiträgen präsent sind), zum anderen sollen diese nationalen Beiträge in eine internationale Perspektive gestellt werden, sodass in der Übersicht und Umschau eine Verortung der schweizerischen Forschung (und damit auch des NFP40plus selbst) und ihrer Resultate möglich wird. Eingeladen wurden dazu führende europäische Forscher auf dem Gebiet des Rechtsextremismus.

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We review the key topics of one of the areas with the biggest impact of the last years in the chemical and pharmaceutical industry that is Crystal Engineering. The relevance of polymorphs and co-crystals from different points of view is been highlighted and broadly illustrated by means of several recent examples of studies carried out in this field. In addition, the most suitableinstrumental techniques and the intellectual property implications are reviewed.