6 resultados para welding procedure test

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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BACKGROUND/AIMS Several countries are working to adapt clinical trial regulations to align the approval process to the level of risk for trial participants. The optimal framework to categorize clinical trials according to risk remains unclear, however. Switzerland is the first European country to adopt a risk-based categorization procedure in January 2014. We assessed how accurately and consistently clinical trials are categorized using two different approaches: an approach using criteria set forth in the new law (concept) or an intuitive approach (ad hoc). METHODS This was a randomized controlled trial with a method-comparison study nested in each arm. We used clinical trial protocols from eight Swiss ethics committees approved between 2010 and 2011. Protocols were randomly assigned to be categorized in one of three risk categories using the concept or the ad hoc approach. Each protocol was independently categorized by the trial's sponsor, a group of experts and the approving ethics committee. The primary outcome was the difference in categorization agreement between the expert group and sponsors across arms. Linear weighted kappa was used to quantify agreements, with the difference between kappas being the primary effect measure. RESULTS We included 142 of 231 protocols in the final analysis (concept = 78; ad hoc = 64). Raw agreement between the expert group and sponsors was 0.74 in the concept and 0.78 in the ad hoc arm. Chance-corrected agreement was higher in the ad hoc (kappa: 0.34 (95% confidence interval = 0.10-0.58)) than in the concept arm (0.27 (0.06-0.50)), but the difference was not significant (p = 0.67). LIMITATIONS The main limitation was the large number of protocols excluded from the analysis mostly because they did not fit with the clinical trial definition of the new law. CONCLUSION A structured risk categorization approach was not better than an ad hoc approach. Laws introducing risk-based approaches should provide guidelines, examples and templates to ensure correct application.

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Tick-borne encephalitis (TBE), a viral infection of the central nervous system, is endemic in many Eurasian countries. In Switzerland, TBE risk areas have been characterized by geographic mapping of clinical cases. Since mass vaccination should significantly decrease the number of TBE cases, alternative methods for exposure risk assessment are required. We established a new PCR-based test for the detection of TBE virus (TBEV) in ticks. The protocol involves an automated, high-throughput nucleic acid extraction method (QIAsymphony SP system) and a one-step duplex real-time reverse transcription-PCR (RT-PCR) assay for the detection of European subtype TBEV, including an internal process control. High usability, reproducibility, and equivalent performance for virus concentrations down to 5 x 10(3) viral genome equivalents/microl favor the automated protocol compared to the modified guanidinium thiocyanate-phenol-chloroform extraction procedure. The real-time RT-PCR allows fast, sensitive (limit of detection, 10 RNA copies/microl), and specific (no false-positive test results for other TBEV subtypes, other flaviviruses, or other tick-transmitted pathogens) detection of European subtype TBEV. The new detection method was applied in a national surveillance study, in which 62,343 Ixodes ricinus ticks were screened for the presence of TBE virus. A total of 38 foci of endemicity could be identified, with a mean virus prevalence of 0.46%. The foci do not fully agree with those defined by disease mapping. Therefore, the proposed molecular test procedure constitutes a prerequisite for an appropriate TBE surveillance. Our data are a unique complement of human TBE disease case mapping in Switzerland.

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BACKGROUND: The rigorous test to which homeopathy was subject in our recent double-blind clinical trail of homeopathic treatment of attention deficit hyperactivity disorder (ADHD) necessitated optimized treatment meeting the highest standards. METHODS: Optimization was performed in three steps: (1) In successfully treated children, prescriptions leading to an insufficient response were analysed by a general questionnaire to identify unreliable symptoms. (2) Polarity analysis, a further development of Bönninghausen's concept of contraindications, was introduced in response to the frequently one-sided symptoms. This enabled us to use few but specific symptoms to identify the medicine whose genius symptoms exhibit the closest match to the patient's characteristic symptoms. (3) We investigated the influence of the primary perception symptoms on the result of the repertorization. Perception symptoms are not normally recorded during a patient interview even though they are among the most reliable facts related by the patients. At the same time we were able to improve the continuity of improvement of ADHD symptoms using liquid Q-potencies. RESULTS: Introducing the questionnaire, polarity analysis, and including perception symptoms, lead to an improvement in the success rate of the first prescription from 21% to 54%, of the fifth prescription from 68% to 84%.

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The tumour suppressor p53 is commonly detected in tissues of companion animals by means of antibodies raised against the human protein. The following three-step procedure was devised to test the suitability of such antibodies for immunohistochemistry on canine tissues. (1) Western blot and immunohistochemical analyses on bacterially expressed recombinant canine protein to assess human-to-canine cross-reactivity. (2) Immunohistochemistry of cultured, UVB-irradiated canine keratinocytes to evaluate suitability for detection of endogenous p53. (3) Immunohistochemistry on tissue arrays to further substantiate suitability of the antibodies on a panel of normal and neoplastic human and canine tissues. Five of six antibodies cross-reacted with recombinant canine p53. Three of these (PAb122, PAb240, CM-1) also immunolabelled stabilized wild type p53 in cell cultures and elicited a consistent, characteristic labelling pattern in a subset of tumours. However, two alternative batches of polyclonal antibody CM-1 failed to detect p53 in cell cultures, while showing a characteristic labelling pattern of a completely different subset of tumours and unspecific labelling of normal tissues. The test system described is well suited to the selection of antibodies for immunohistochemical p53 detection. The results emphasize the need to include appropriate controls, especially for polyclonal antibodies.

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PURPOSE: Resonance frequency analysis (RFA) offers the opportunity to monitor the osseointegration of an implant in a simple, noninvasive way. A better comprehension of the relationship between RFA and parameters related to bone quality would therefore help clinicians improve diagnoses. In this study, a bone analog made from polyurethane foam was used to isolate the influences of bone density and cortical thickness in RFA. MATERIALS AND METHODS: Straumann standard implants were inserted in polyurethane foam blocks, and primary implant stability was measured with RFA. The blocks were composed of two superimposed layers with different densities. The top layer was dense to mimic cortical bone, whereas the bottom layer had a lower density to represent trabecular bone. Different densities for both layers and different thicknesses for the simulated cortical layer were tested, resulting in eight different block combinations. RFA was compared with two other mechanical evaluations of primary stability: removal torque and axial loading response. RESULTS: The primary stability measured with RFA did not correlate with the two other methods, but there was a significant correlation between removal torque and the axial loading response (P < .005). Statistical analysis revealed that each method was sensitive to different aspects of bone quality. RFA was the only method able to detect changes in both bone density and cortical thickness. However, changes in trabecular bone density were easier to distinguish with removal torque and axial loading than with RFA. CONCLUSIONS: This study shows that RFA, removal torque, and axial loading are sensitive to different aspects of the bone-implant interface. This explains the absence of correlation among the methods and proves that no standard procedure exists for the evaluation of primary stability.

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The Implicit Association Test (IAT) had already gained the status of a prominent assessment procedure before its psychometric properties and underlying task structure were understood. The present critique addresses five major problems that arise when the IAT is used for diagnostic inferences: (1) the asymmetry of causal and diagnostic inferences; (2) the viability of the underlying association model; (3) the lack of a testable model underlying IAT-based inferences; (4) the difficulties of interpreting difference scores; and (5) the susceptibility of the IAT to deliberate faking and strategic processing. Based on a theoretical reflection of these issues, and a comprehensive survey of published IAT studies, it is concluded that a number of uncontrolled factors can produce (or reduce) significant IAT scores independently of the personality attribute that is supposed to be captured by the IAT procedure.