978 resultados para sampling techniques
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The aim of this study was to review our experience in percutaneous endoscopic gastrostomy (PEG) performed in patients with cancer of the upper aerodigestive tract. Descriptive retrospective study of 142 patients (115 males, 27 females), mean age 62.4 years (25-84 years), with head and neck or esophageal cancer, who underwent PEG tube insertion between January 2006 and December 2008. The studied parameters were indications, success rate, rate and type of complications, and their management. Percutaneous endoscopic gastrostomy was inserted before chemoradiation therapy in 80% and during or after cancer treatment in 20% of the patients. PEG placement was possible in 137 patients (96%). Major complications were observed in 9 (7%) and minor complications in 22 (17%) of the 137 patients. Seven of the 9 patients with a major complication needed revision surgery. The mortality directly related to the procedure was 0.7%. Percutaneous endoscopic gastrostomy tube insertion has a high success rate. In patients with upper aerodigestive tract cancer, PEG should be the first choice for enteral nutrition when sufficient oral intake is not possible. Although apparently easy, the procedure may occasionally lead to severe complications. Therefore, a strict technique and knowledge of clinical signs of possible complications are mandatory.
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If single case experimental designs are to be used to establish guidelines for evidence-based interventions in clinical and educational settings, numerical values that reflect treatment effect sizes are required. The present study compares four recently developed procedures for quantifying the magnitude of intervention effect using data with known characteristics. Monte Carlo methods were used to generate AB designs data with potential confounding variables (serial dependence, linear and curvilinear trend, and heteroscedasticity between phases) and two types of treatment effect (level and slope change). The results suggest that data features are important for choosing the appropriate procedure and, thus, inspecting the graphed data visually is a necessary initial stage. In the presence of serial dependence or a change in data variability, the Nonoverlap of All Pairs (NAP) and the Slope and Level Change (SLC) were the only techniques of the four examined that performed adequately. Introducing a data correction step in NAP renders it unaffected by linear trend, as is also the case for the Percentage of Nonoverlapping Corrected Data and SLC. The performance of these techniques indicates that professionals" judgments concerning treatment effectiveness can be readily complemented by both visual and statistical analyses. A flowchart to guide selection of techniques according to the data characteristics identified by visual inspection is provided.
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The nose is the anatomical site usually recommended for methicillin-resistant Staphylococcus aureus (MRSA) screening. Other sites are also recommended, but are more controversial. We showed that the sensitivities of MRSA detection from nasal swabs alone were 48% and 62% by culture or by rapid PCR test, respectively. These percentages increased to 79% and 92% with the addition of groin swabs, and to 96% and 99% with the addition of groin and throat swabs. In conclusion, neither by culture nor by rapid PCR test is nose sampling alone sufficient for MRSA detection. Additional anatomical sites should include at least the groin and throat.
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This project was initiated in 1988 to study the effectiveness of four different construction techniques for establishing a stable base on a granular surfaced roadway. After base stabilization, the roadway was then seal coated, eliminating dust problems associated with granular surfaced roads. When monies become available, the roadway can be surfaced with a more permanent structure. A 2.8 mi (4.5 km) section of the Horseshoe Road in Dubuque County was divided into four divisions for this study. This report discusses the procedures used during construction of these different divisions. Problems and possible solutions have been analyzed to better understand the capabilities of the materials and construction techniques used on the project. The project had the following results: High structural ratings and soil K factors for the BIO CAT and Consolid bases did not translate to good roadway performance; the macadam base had the best overall performance; the tensar fabric had no noticeable effect on the macadam base; and the HFE-300 performed acceptably.
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OBJECTIVE To assess the specific risks of injury to neural and vascular structures inherent in two approaches to transobturator surgery for inserting a suburethral sling, i.e. the outside-in (standard technique) and inside-out approaches. MATERIALS AND METHODS The study comprised seven cadavers, providing 14 obturator regions. Five specimens had a tape inserted outside-in on one side, and inside-out on the other; of the remaining two cadavers, one had an inside-out tape and one an outside-in tape, bilaterally. After tape insertion, the cadavers were dissected. Particular attention was paid to the distances between the tape and the deep external pudendal vessels, and between the tape and the posterior branch of the obturator nerve. RESULTS With the inside-out technique, the safety margins were reduced, and the external pudendal vessels and the posterior branch of the obturator nerve were at greater risk of injury. CONCLUSION The two techniques are not equivalent, with a lower risk of injury to vascular and nerve structures with the outside-in technique.
MRI of coronary vessel walls using radial k-space sampling and steady-state free precession imaging.
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OBJECTIVE: The objective of our study was to investigate the impact of radial k-space sampling and steady-state free precession (SSFP) imaging on image quality in MRI of coronary vessel walls. SUBJECTS AND METHODS: Eleven subjects were examined on a 1.5-T MR system using three high-resolution navigator-gated and cardiac-triggered 3D black blood sequences (cartesian gradient-echo [GRE], radial GRE, and radial SSFP) with identical spatial resolution (0.9 x 0.9 x 2.4 mm3). The signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), vessel wall sharpness, and motion artifacts were analyzed. RESULTS: The mean SNR and CNR of the coronary vessel wall were improved using radial imaging and were best using radial k-space sampling combined with SSFP imaging. Vessel border definition was similar for all three sequences. Radial k-space sampling was found to be less sensitive to motion. Consistently good image quality was seen with the radial GRE sequence. CONCLUSION: Radial k-space sampling in MRI of coronary vessel walls resulted in fewer motion artifacts and improved SNR and CNR. The use of SSFP imaging, however, did not result in improved coronary vessel wall visualization.
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In recent years the Iowa Department of Transportation has shifted emphasis from the construction of new roads to the maintenance and preservation of existing highways. A need has developed for evaluating pavements structurally to select the correct rehabilitation strategy and to properly design a pavement overlay if necessary. Road Rater non-destructive testing has fulfilled this need and has been used successfully to evaluate pavement and subgrade conditions and to design asphaltic concrete overlays and portland cement concrete overlays. The Iowa Road Rater Design Method has been simplified so that it may be easily understood and used by various individuals who are involved in pavement restoration and management. Road Rater evaluation techniques have worked well to date and have been verified by pavement coring, soils sampling and testing. Void detection testing has also been performed, and results indicate that the Road Rater can be used to locate pavement voids and that Road Rater evaluation techniques are reasonably accurate. The success of Road Rater research and development has made dynamic deflection test data an important pavement management input.
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In recent years the Iowa DOT has shifted emphasis from the construction of new roads to the maintenance and preservation of existing highways. A need has developed for analyzing pavements structurally to select the correct rehabilitation strategy and to properly design a pavement overlay if necessary. This need has been fulfilled by Road Rater testing which has been used successfully on all types of pavements to evaluate pavement and subgrade conditions and to design asphaltic concrete overlays. The Iowa Road Rater Design Method has been simplified so that it may be easily understood and used by the widely diverse groups of individuals which may be involved in pavement restoration and management. Road Rater analysis techniques have worked well to date and have been verified by pavement coring, soils sampling and testing, and pavement removal by block sampling. Void detection testing has also been performed experimentally in Iowa, and results indicate that the Road Rater can be used to locate pavement voids and that Road Rater analysis techniques are reasonably accurate. The success of Road Rater research and development has made deflection test data one of the most important pavement management inputs.
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Transmission electron microscopy is a proven technique in the field of cell biology and a very useful tool in biomedical research. Innovation and improvements in equipment together with the introduction of new technology have allowed us to improve our knowledge of biological tissues, to visualizestructures better and both to identify and to locate molecules. Of all the types ofmicroscopy exploited to date, electron microscopy is the one with the mostadvantageous resolution limit and therefore it is a very efficient technique fordeciphering the cell architecture and relating it to function. This chapter aims toprovide an overview of the most important techniques that we can apply to abiological sample, tissue or cells, to observe it with an electron microscope, fromthe most conventional to the latest generation. Processes and concepts aredefined, and the advantages and disadvantages of each technique are assessedalong with the image and information that we can obtain by using each one ofthem.
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This Handbook contains a collection of articles describing instrumental techniques used for Materials, Chemical and Biosciences research that are available at the Scientific and Technological Centers of theUniversity of Barcelona (CCiTUB). The CCiTUB are a group of facilities of the UB that provide both the research community and industry with ready access to a wide range of major instrumentation.Together with the latest equipment and technology, the CCiTUB provide expertise in addressing the methodological research needs of the user community and they also collaborate in R+D+i Projectswith industry. CCiTUB specialists include technical and Ph.D.-level professional staff members who are actively engaged in methodological research. Detailed information on the centers’ resources andactivities can be found at the CCiTUB website www.ccit.ub.edu ...
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This article summarizes the basic principles of light microscopy, with examples of applications in biomedicine that illustrate the capabilities of thetechnique.
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Ce travail de recherche a été réalisé dans le laboratoire de pharmacologie clinique, au Centre Hospitalier Universitaire Sainte-Justine, à Montréal. C'est une étude rétrospective basée sur le suivi thérapeutique du Tacrolimus prescrit chez les enfants après transplantation hépatique. Ce suivi est nécessaire car le Tacrolimus possède une importante variabilité pharmacocinétique inter et intra-individuelle ainsi qu'un index thérapeutique très étroit. Actuellement, l'individualisation des doses prescrites est basée sur la mesure de la concentration de base - du médicament dans le sang (C0), mais des études récentes montrent que cette mesure ne reflète pas précisément l'exposition du Tacrolimus dans l'organisme chez les enfants. Le meilleur reflet de cette exposition est la mesure de l'aire sous la courbe (AUC). Cependant, cette dernière implique la mesure de multiples concentrations tout au long de l'intervalle entre 2 doses de médicament (Tacrolimus: 12 heures) ce qui est long, cher et impraticable en ambulatoire. De nouvelles méthodes utilisant un nombre limité de prélèvements ont donc été développées pour prédire au mieux cette AUC. Ce sont les "Limited sampling strategies" ou LSS. La plupart de ces LSS pour le Tacrolimus ont été développées et validées chez des patients transplantés adultes et leur application directe chez les transplantés pédiatriques n'est pas possible en raison de différences importantes au niveau des paramètres pharmacocinétiques du médicament entre ces deux populations. Aussi, le but de ce travail était de développer et valider, pour la première fois, des LSS chez les enfants transplantés hépatiques. Pour cela, une analyse de 36 profils pharmacocinétiques de 28 patients transplantés hépatiques âgés de 0.4- 18.5 ans a été effectuée. Tous les profils ont été réalisés au Centre Hospitalier Universitaire Sainte-Justine entre janvier 2007 et janvier 2009. Les LSS comportant au maximum 4 mesures de concentration ont été développées en utilisant une analyse de régression multiple. Parmi tous les modèles obtenus, cinq ont été sélectionnés sur la base de critères précis puis validés selon la méthode décrite par Sheiner et Beal.¦Les résultats montrent que ces cinq modèles peuvent prédire l'AUC du Tacrolimus avec une précision cliniquement acceptable de ± 15% alors que la C0 présente la plus faible corrélation avec l'AUC.¦En conclusion, cette étude confirme que la C0 ne permet pas de prédire de manière efficace l'exposition du Tacrolimus dans l'organisme dans notre population de patients pédiatriques contrairement aux LSS analysées qui offrent une méthode pratique et fiable. Par ailleurs, en permettant d'obtenir une estimation précise et simplifiée de l'AUC complète du Tacrolimus chez les patients, ces LSS ouvrent la porte à de futures études prospectives visant à mieux définir l'AUC cible du médicament et à déterminer si le suivi basé sur la mesure de l'AUC est plus efficace et plus sûr que celui basé sur la mesure de la C0.
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The 2009 International Society of Urological Pathology Consensus Conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the infiltration of tumor into the seminal vesicles and regional lymph nodes were coordinated by working group 4. There was a consensus that complete blocking of the seminal vesicles was not necessary, although sampling of the junction of the seminal vesicles and prostate was mandatory. There was consensus that sampling of the vas deferens margins was not obligatory. There was also consensus that muscular wall invasion of the extraprostatic seminal vesicle only should be regarded as seminal vesicle invasion. Categorization into types of seminal vesicle spread was agreed by consensus to be not necessary. For examination of lymph nodes, there was consensus that special techniques such as frozen sectioning were of use only in high-risk cases. There was no consensus on the optimal sampling method for pelvic lymph node dissection specimens, although there was consensus that all lymph nodes should be completely blocked as a minimum. There was also a consensus that a count of the number of lymph nodes harvested should be attempted. In view of recent evidence, there was consensus that the diameter of the largest lymph node metastasis should be measured. These consensus decisions will hopefully clarify the difficult areas of pathological assessment in radical prostatectomy evaluation and improve the concordance of research series to allow more accurate assessment of patient prognosis.