996 resultados para CONTINUOUS-CULTURE


Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper presents the results of the static and dynamic testing of a three-span continuous I-beam highway bridge. Live load stress frequency curves for selected points are shown, and the static and dynamic load distribution to the longitudinal composite beam members are given. The bridge has four traffic lanes with a roadway width of 48 ft. Six longitudinal continuous WF beams act compositely with the reinforced concrete slab to carry the live load. The beams have partial length cover plates at the piers. Previous research has indicated that beams with partial length cover plates have a very low fatigue strength. It was found in this research that the magnitude of the stresses due to actual highway loads were very much smaller than those computed from specification loading. Also, the larger stresses which were measured occurred a relatively small number of times. These data indicate that some requirements for reduced allowable stresses at the ends of cover plates are too conservative. The load distribution to the longitudinal beams was determined for static and moving loads and includes the effect of impact on the distribution. The effective composite section was found at various locations to evaluate the load distribution data. The composite action was in negative as well as positive moment regions. The load distribution data indicate that the lateral distribution of live load is consistent with the specifications, but that there is longitudinal distribution, and therefore the specifications are too conservative.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this paper is to analyse how learning assessment, particularly the Continuous Assessment system, has been defined in the Public Administration and Management Diploma Course of the University of Barcelona (Spain). This course was a pioneering experiment at this university in implementing the guidelines of the European Higher Education Area (EHEA), and thus represents a good case study for verifying whether one of the cornerstones of the EHEA has been accomplished with success. Using data obtained from the Teaching Plans elaborated by the lecturers of each subject, we are able to establish that the CA system has been progressively accepted to such an extent that it is now the assessment formula used by practically all of the lecturers, conforming in this way to the protocols laid down by the Faculty of Law in which this diploma course is taught. Nevertheless, we find that high dispersion exists in how Continuous Assessment is actually defined. Indeed, it seems that there is no unified view of how Continuous Assessment should be performed. This dispersion, however, seems to diminish over time and raises some questions about the advisability of agreement on criteria, considering the potential which CA has as a pedagogical tool. Moreover, we find that the Unique Assessment system, which students may also apply for, is an option chosen only by a minority, with lecturers usually defining it as merely a theoretical and/or practical test, of little innovation in relation to traditional tests.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The risk of catheter-related infection or bacteremia, with initial and extended use of femoral versus nonfemoral sites for double-lumen vascular catheters (DLVCs) during continuous renal replacement therapy (CRRT), is unclear. STUDY DESIGN: Retrospective observational cohort study. SETTING & PARTICIPANTS: Critically ill patients on CRRT in a combined intensive care unit of a tertiary institution. FACTOR: Femoral versus nonfemoral venous DLVC placement. OUTCOMES: Catheter-related colonization (CRCOL) and bloodstream infection (CRBSI). MEASUREMENTS: CRCOL/CRBSI rates expressed per 1,000 catheter-days. RESULTS: We studied 458 patients (median age, 65 years; 60% males) and 647 DLVCs. Of 405 single-site only DLVC users, 82% versus 18% received exclusively 419 femoral versus 82 jugular or subclavian DLVCs, respectively. The corresponding DLVC indwelling duration was 6±4 versus 7±5 days (P=0.03). Corresponding CRCOL and CRBSI rates (per 1,000 catheter-days) were 9.7 versus 8.8 events (P=0.8) and 1.2 versus 3.5 events (P=0.3), respectively. Overall, 96 patients with extended CRRT received femoral-site insertion first with subsequent site change, including 53 femoral guidewire exchanges, 53 new femoral venipunctures, and 47 new jugular/subclavian sites. CRCOL and CRBSI rates were similar for all such approaches (P=0.7 and P=0.9, respectively). On multivariate analysis, CRCOL risk was higher in patients older than 65 years and weighing >90kg (ORs of 2.1 and 2.2, respectively; P<0.05). This association between higher weight and greater CRCOL risk was significant for femoral DLVCs, but not for nonfemoral sites. Other covariates, including initial or specific DLVC site, guidewire exchange versus new venipuncture, and primary versus secondary DLVC placement, did not significantly affect CRCOL rates. LIMITATIONS: Nonrandomized retrospective design and single-center evaluation. CONCLUSIONS: CRCOL and CRBSI rates in patients on CRRT are low and not influenced significantly by initial or serial femoral catheterizations with guidewire exchange or new venipuncture. CRCOL risk is higher in older and heavier patients, the latter especially so with femoral sites.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVES: We have sought to develop an automated methodology for the continuous updating of optimal cerebral perfusion pressure (CPPopt) for patients after severe traumatic head injury, using continuous monitoring of cerebrovascular pressure reactivity. We then validated the CPPopt algorithm by determining the association between outcome and the deviation of actual CPP from CPPopt. DESIGN: Retrospective analysis of prospectively collected data. SETTING: Neurosciences critical care unit of a university hospital. PATIENTS: A total of 327 traumatic head-injury patients admitted between 2003 and 2009 with continuous monitoring of arterial blood pressure and intracranial pressure. MEASUREMENTS AND MAIN RESULTS: Arterial blood pressure, intracranial pressure, and CPP were continuously recorded, and pressure reactivity index was calculated online. Outcome was assessed at 6 months. An automated curve fitting method was applied to determine CPP at the minimum value for pressure reactivity index (CPPopt). A time trend of CPPopt was created using a moving 4-hr window, updated every minute. Identification of CPPopt was, on average, feasible during 55% of the whole recording period. Patient outcome correlated with the continuously updated difference between median CPP and CPPopt (chi-square=45, p<.001; outcome dichotomized into fatal and nonfatal). Mortality was associated with relative "hypoperfusion" (CPP<CPPopt), severe disability with "hyperperfusion" (CPP>CPPopt), and favorable outcome was associated with smaller deviations of CPP from the individualized CPPopt. While deviations from global target CPP values of 60 mm Hg and 70 mm Hg were also related to outcome, these relationships were less robust. CONCLUSIONS: Real-time CPPopt could be identified during the recording time of majority of the patients. Patients with a median CPP close to CPPopt were more likely to have a favorable outcome than those in whom median CPP was widely different from CPPopt. Deviations from individualized CPPopt were more predictive of outcome than deviations from a common target CPP. CPP management to optimize cerebrovascular pressure reactivity should be the subject of future clinical trial in severe traumatic head-injury patients.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In IVF around 70% of embryos fail to implant. Often more than one embryo is transferred in order to enhance the chances of pregnancy, but this is at the price of an increased multiple pregnancy risk. In the aim to increase the success rate with a single embryo, research projects on prognostic factors of embryo viability have been initiated, but no marker has found a routine clinical application to date. Effects of soluble human leukocyte antigen-G (sHLA-G) on both NK cell activity and on Th1/Th2 cytokine balance suggest a role in the embryo implantation process, but the relevance of sHLA-G measurements in embryo culture medium and in follicular fluid (FF) are inconsistent to date. In this study, we have investigated the potential of sHLA-G in predicting the achievement of a pregnancy after IVF-ICSI in a large number of patients (n = 221). sHLA-G was determined in media and in FF by ELISA. In both FF and embryo medium, no significant differences in sHLA-G concentrations were observed between the groups "pregnancy" and "implantation failure", or between the groups "ongoing" versus "miscarried pregnancies". Our results do not favour routine sHLA-G determinations in the FF nor in embryo conditioned media, with the current assay technology available.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The kinetics and microstructure of solid-phase crystallization under continuous heating conditions and random distribution of nuclei are analyzed. An Arrhenius temperature dependence is assumed for both nucleation and growth rates. Under these circumstances, the system has a scaling law such that the behavior of the scaled system is independent of the heating rate. Hence, the kinetics and microstructure obtained at different heating rates differ only in time and length scaling factors. Concerning the kinetics, it is shown that the extended volume evolves with time according to αex = [exp(κCt′)]m+1, where t′ is the dimensionless time. This scaled solution not only represents a significant simplification of the system description, it also provides new tools for its analysis. For instance, it has been possible to find an analytical dependence of the final average grain size on kinetic parameters. Concerning the microstructure, the existence of a length scaling factor has allowed the grain-size distribution to be numerically calculated as a function of the kinetic parameters

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Does culture shape the demand for social insurance against risks to health and work? We study this issue across language groups in Switzerland where a language border sharply separates social groups at identical actual levels of publicly provided social insurance. We find substantially stronger support for expansions of social insurance among residents of French, Italian or Romansh-speaking language border municipalities compared with their German-speaking neighbours in adjacent municipalities. Informal insurance does not vary enough to explain stark differences in social insurance but differences in ideology and segmented media markets potentially contribute to the discrepancy in demand for social insurance.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Collection : Bibliothèque sociologique internationale ; 50

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVES: To determine the prevalence, predictors, and clinical significance of electrographic seizures (ESz) and other continuous electroencephalographic monitoring findings in critically ill patients with central nervous system infections. DESIGN: Retrospective cohort study. SETTING: Eighteen-bed neurocritical care unit. PATIENTS: We identified 42 consecutive patients with primary central nervous system infection (viral, 27 patients [64%]; bacterial, 8 patients [18%]; and fungal or parasitic, 7 patients [17%]) who underwent continuous electroencephalographic monitoring between January 1, 1996, and February 28, 2007. MAIN OUTCOME MEASURES: Presence of ESz or periodic epileptiform discharges (PEDs). RESULTS: Electrographic seizures were recorded in 14 patients (33%), and PEDs were recorded in 17 patients (40%). Twenty patients (48%) had either PEDs or ESz. Of the 14 patients with ESz, only 5 (36%) had a clinical correlate. Periodic epileptiform discharges (odds ratio=13.4; P=.001) and viral cause (odds ratio=13.0; P=.02) were independently associated with ESz. Both ESz (odds ratio=5.9; P=.02) and PEDs (odds ratio=6.1; P=.01) were independently associated with poor outcome at discharge (severe disability, vegetative state, or death). CONCLUSIONS: In patients with central nervous system infections undergoing continuous electroencephalographic monitoring, ESz and/or PEDs were frequent, occurring in 48% of our cohort. More than half of the ESz had no clinical correlate. Both ESz and PEDs were independently associated with poor outcome. Additional studies are needed to determine whether prevention or treatment of these electrographic findings improves outcome.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Résumé de l'étude La surveillance de la prescription des antibiotiques en milieu hospitalier est une des mesures recommandées pour prévenir l'émergence de bactéries résistantes. La consommation d'antibiotiques est généralement exprimée en termes de DDD (defined daily dose) rapporté au taux d'occupation (jours patients). Cette mesure ne tient cependant pas compte de la variation de la casuistique d'un service au cours du temps. La consommation d'antibiotiques est influencée par l'incidence des infections, qui peut être saisonnière ou varier selon les circonstances épidémiologiques, ainsi que par les habitudes des médecins en termes de prescription. Une échelle de mesure adaptée à ces paramètres est donc capitale pour rendre compte de la consommation d'antibiotiques au sein d'un service et identifier de possibles dérivations dans les habitudes de prescriptions. Nous avons émis l'hypothèse que le nombre de demandes d'hémocultures pouvait servir d'indicateur de la charge infectieuse d'un service. Une analyse préliminaire a permis d'établir une bonne relation entre ce paramètre et l'incidence d'événements infectieux en comparaison à d'autres paramètres testés (nombre de prélèvements microbiologiques provenant de sites stériles ou nombre total de prélèvements microbiologiques). Sur la base de cette hypothèse, nous avons analysé la consommation d'antibiotiques d'une unité de médecine générale (Service de Médecine Interne du CHUV) sur seize trimestres consécutifs en comparant deux échelles de mesures : la méthode standard en DDD par jours patients et une échelle ajustée à la charge infectieuse (DDD par nombre de demandes d'hémocultures). L'échelle ajustée aux hémocultures a permis d'identifier trois trimestres avec une consommation anormalement élevée qui n'avaient pas été classés comme tels par l'échelle standard (consommation dans les normes en DDD par jours patients). Une analyse détaillée d'un de ces trimestres a confirmé une incidence d'infections moins élevée en comparaison à un trimestre de référence (proche de la norme selon les deux échelles), alors que la corrélation entre infections et demandes d'hémocultures était similaire pour les deux périodes. De même, l'échelle ajustée ä la charge infectieuse a démontré une consommation dans la norme pour un trimestre avec une consommation en apparence trop élevée selon l'échelle standard en raison d'une incidence d'infections plus élevée pour cette période. Cette étude a donc permis une identification plus performante et plus précise de périodes avec des dérivations dans la pratique de la prescription des antibiotiques en utilisant une échelle de mesure ajustée à la charge infectieuse d'un service au cours du temps. Nous avons démontré que le nombre d'hémocultures prélevées était un indicateur stable de la charge infectieuse dans un service de médecine générale. Ceci ne permet cependant pas de généraliser l'usage de cet indicateur pour tous les types de service. La pratique des hémocultures peut, en effet, varier d'une unité à l'autre, ou entres différentes institutions. ll convient donc de tester la validité de ce paramètre dans un service avant de l'appliquer.

Relevância:

20.00% 20.00%

Publicador: