955 resultados para 5-37


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OBJECTIVE: The aim of this study was to assess the microcirculatory and metabolic consequences of reduced mesenteric blood flow. DESIGN: Prospective, controlled animal study. SETTING: The surgical research unit of a university hospital. SUBJECTS: A total of 13 anesthetized and mechanically ventilated pigs. INTERVENTIONS: Pigs were subjected to stepwise mesenteric blood flow reduction (15% in each step, n = 8) or served as controls (n = 5). Superior mesenteric arterial blood flow was measured with ultrasonic transit time flowmetry, and mucosal and muscularis microcirculatory perfusion in the small bowel were each measured with three laser Doppler flow probes. Small-bowel intramucosal Pco2 was measured by tonometry, and glucose, lactate (L), and pyruvate (P) were measured by microdialysis. MEASUREMENTS AND MAIN RESULTS: In control animals, superior mesenteric arterial blood flow, mucosal microcirculatory blood flow, intramucosal Pco2, and the lactate/pyruvate ratio remained unchanged. In both groups, mucosal blood flow was better preserved than muscularis blood flow. During stepwise mesenteric blood flow reduction, heterogeneous microcirculatory blood flow remained a prominent feature (coefficient of variation, approximately 45%). A 30% flow reduction from baseline was associated with a decrease in microdialysis glucose concentration from 2.37 (2.10-2.70) mmol/L to 0.57 (0.22-1.60) mmol/L (p < .05). After 75% flow reduction, the microdialysis lactate/pyruvate ratio increased from 8.6 (8.0-14.1) to 27.6 (15.5-37.4, p < .05), and arterial-intramucosal Pco2 gradients increased from 1.3 (0.4-3.5) kPa to 10.8 (8.0-16.0) kPa (p < .05). CONCLUSIONS: Blood flow redistribution and heterogeneous microcirculatory perfusion can explain apparently maintained regional oxidative metabolism during mesenteric hypoperfusion, despite local signs of anaerobic metabolism. Early decreasing glucose concentrations suggest that substrate supply may become crucial before oxygen consumption decreases.

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Objective: Identification of the ventrointermediate thalamic nucleus (Vim) in modern 3T high-field MRI for image-based targeting in deep brain stimulation (DBS) is still challenging. To evaluate the usefulness and reliability of analyzing the connectivity with the cerebellum using Q-ball-calculation we performed a retrospective analysis. Method: 5 patients who underwent bilateral implantation of electrodes in the Vim for treatment of Essential Tremor between 2011 and 2012 received additional preoperative Q-ball imaging. Targeting was performed according to atlas coordinates and standard MRI. Additionally we performed a retrospective identification of the Vim by analyzing the connectivity of the thalamus with the dentate nucleus. The exact position of the active stimulation contact in the postoperative CT was correlated with the Vim as it was identified by Q-ball calculation. Results: Localization of the Vim by analysis of the connectivity between thalamus and cerebellum was successful in all 5 patients on both sides. The average position of the active contacts was 14.6 mm (SD 1.24) lateral, 5.37 mm (SD 0.094 posterior and 2.21 mm (SD 0.69) cranial of MC. The cranial portion of the dentato-rubro-thalamic tract was localized an average of 3.38 mm (SD 1.57) lateral and 1.5 mm (SD 1.22) posterior of the active contact. Conclusions: Connectivity analysis by Q-ball calculation provided direct visualization of the Vim in all cases. Our preliminary results suggest, that the target determined by connectivity analysis is valid and could possibly be used in addition to or even instead of atlas based targeting. Larger prospective calculations are needed to determine the robustness of this method in providing refined information useful for neurosurgical treatment of tremor.

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Il contributo ripercorre la relazione uomo-castagno partendo dalle ultime glaciazioni per arrivare ai giorni nostri, con una crescente attenzione per le contrade insubriche, dove la castanicoltura raggiunse livelli straordinari di sviluppo. Dopo una sintesi critica sui primi indizi di coltivazione, si esamina la castanicoltura nel mondo greco e romano fino all’introduzione della coltivazione del castagno nell’area insubrica. Particolare attenzione è riservata al periodo aureo tardomedievale della castanicoltura nella Svizzera italiana, comprovato con dati linguistici, con l’analisi dei sistemi produttivi (composizione varietale, tecniche di essiccazione) e delle consuetudini locali. Si indagano in seguito le ragioni e le tappe storiche del declino della castanicoltura tradizionale. Si conclude discutendo la situazione attuale e le prospettive future dei castagneti a Sud delle Alpi, confrontati con alcuni problemi incalzanti come l’invecchiamento delle ceppaie nei cedui abbandonati e la comparsa di un insidioso parassita, il cinipide galligeno.

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Aims: We sought to analyse local distribution of aortic annulus and left ventricular outflow tract (LVOT) calcification in patients undergoing transcatheter aortic valve replacement (TAVR) and its impact on aortic regurgitation (AR) immediately after device placement. Methods and results: A group of 177 patients with severe aortic stenosis undergoing multislice computed tomography of the aortic root followed by TAVR were enrolled in this single-centre study. Annular and LVOT calcifications were assessed per cusp using a semi-quantitative grading system (0: none; 1 [mild]: small, non-protruding calcifications; 2 [moderate]: protruding [>1 mm] or extensive [>50% of cusp sector] calcifications; 3 [severe]: protruding and extensive calcifications). Any calcification of the annulus or LVOT was present in 107 (61%) and 63 (36%) patients, respectively. Prevalence of annulus/LVOT calcifications in the left coronary cusp was 42% and 25%, respectively, in the non-coronary cusp 28% and 13%, in the right coronary cusp 13% and 5%. AR grade 2 to 4 assessed by the method of Sellers immediately after TAVR device implantation was observed in 55 patients (31%). Multivariate regression analysis revealed that the overall annulus calcification (OR [95% CI] 1.48 [1.10-2.00]; p=0.0106), the overall LVOT calcification (1.93 [1.26-2.96]; p=0.0026), any moderate or severe LVOT calcification (5.37 [1.52-18.99]; p=0.0092), and asymmetric LVOT calcification were independent predictors of AR. Conclusions: Calcifications of the aortic annulus and LVOT are frequent in patients undergoing TAVR, and both the distribution and the severity of calcifications appear to be independent predictors of aortic regurgitation after device implantation. - See more at: http://www.pcronline.com/eurointervention/77th_issue/126/#sthash.Hzodgju5.dpuf

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BACKGROUND Data on the association between subclinical thyroid dysfunction and fractures conflict. PURPOSE To assess the risk for hip and nonspine fractures associated with subclinical thyroid dysfunction among prospective cohorts. DATA SOURCES Search of MEDLINE and EMBASE (1946 to 16 March 2014) and reference lists of retrieved articles without language restriction. STUDY SELECTION Two physicians screened and identified prospective cohorts that measured thyroid function and followed participants to assess fracture outcomes. DATA EXTRACTION One reviewer extracted data using a standardized protocol, and another verified data. Both reviewers independently assessed methodological quality of the studies. DATA SYNTHESIS The 7 population-based cohorts of heterogeneous quality included 50,245 participants with 1966 hip and 3281 nonspine fractures. In random-effects models that included the 5 higher-quality studies, the pooled adjusted hazard ratios (HRs) of participants with subclinical hyperthyroidism versus euthyrodism were 1.38 (95% CI, 0.92 to 2.07) for hip fractures and 1.20 (CI, 0.83 to 1.72) for nonspine fractures without statistical heterogeneity (P = 0.82 and 0.52, respectively; I2= 0%). Pooled estimates for the 7 cohorts were 1.26 (CI, 0.96 to 1.65) for hip fractures and 1.16 (CI, 0.95 to 1.42) for nonspine fractures. When thyroxine recipients were excluded, the HRs for participants with subclinical hyperthyroidism were 2.16 (CI, 0.87 to 5.37) for hip fractures and 1.43 (CI, 0.73 to 2.78) for nonspine fractures. For participants with subclinical hypothyroidism, HRs from higher-quality studies were 1.12 (CI, 0.83 to 1.51) for hip fractures and 1.04 (CI, 0.76 to 1.42) for nonspine fractures (P for heterogeneity = 0.69 and 0.88, respectively; I2 = 0%). LIMITATIONS Selective reporting cannot be excluded. Adjustment for potential common confounders varied and was not adequately done across all studies. CONCLUSION Subclinical hyperthyroidism might be associated with an increased risk for hip and nonspine fractures, but additional large, high-quality studies are needed. PRIMARY FUNDING SOURCE Swiss National Science Foundation.

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OBJECTIVE There is debate on how the methodological quality of clinical trials should be assessed. We compared trials of physical therapy (PT) judged to be of adequate quality based on summary scores from the Physiotherapy Evidence Database (PEDro) scale with trials judged to be of adequate quality by Cochrane Risk of Bias criteria. DESIGN Meta-epidemiological study within Cochrane Database of Systematic Reviews. METHODS Meta-analyses of PT trials were identified in the Cochrane Database of Systematic Reviews. For each trial PeDro and Cochrane assessments were extracted from the PeDro and Cochrane databases. Adequate quality was defined as adequate generation of random sequence, concealment of allocation, and blinding of outcome assessors (Cochrane criteria) or as trials with a PEDro summary score ≥5 or ≥6 points. We combined trials of adequate quality using random-effects meta-analysis. RESULTS Forty-one Cochrane reviews and 353 PT trials were included. All meta-analyses included trials with PEDro scores ≥5, 37 (90.2%) included trials with PEDro scores ≥6 and only 22 (53.7%) meta-analyses included trials of adequate quality according to the Cochrane criteria. Agreement between PeDro and Cochrane was poor for PeDro scores of ≥5 points (kappa = 0.12; 95% CI 0.07 to 0.16) and slight for ≥6 points (kappa 0.24; 95% CI 0.16-0.32). When combining effect sizes of trials deemed to be of adequate quality according to PEDro or Cochrane criteria, we found that a substantial difference in the combined effect size (≥0.15) was evident in 9 (22%) out of the 41 meta-analyses for PEDro cutoff ≥5 and 10 (24%) for cutoff ≥6. CONCLUSIONS The PeDro and Cochrane approaches lead to different sets of trials of adequate quality, and different combined treatment estimates from meta-analyses of these trials. A consistent approach to assessing RoB in trials of physical therapy should be adopted.

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di Georgio Philippo Telemann

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The uranium content of glass from chilled margins of oceanic tholeiitic basalt flows is generally <0.1 ppm, even for old samples with highly altered crystalline interiors. Such low values represent the original whole rock concentrations, although subsequent to eruption low-temperature weathering has added uranium, and other elements, to the crystalline portions of these basalts. Consideration of the K/U ratios of altered samples suggests that basalt weathering may provide the major oceanic sink for these two elements.

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To establish a natural background and its temporal and spatial variability for the area around Casey Station in the Windmill Islands, East Antarctica, the authors studied major and trace element concentrations and the distribution of organic matter in marine and lacustrine sediments. A wide range of natural variability in trace metal concentrations was identified between sites and within a time scale of 9 ka (e.g., Ni 5-37 mg/kg, Cu 20-190 mg/kg, Zn 50-300 mg/kg, Pb 4.5- 34 mg/kg). TOC concentrations are as high as 3 wt.% at the marine sites and 20 wt.% at the lacustrine sites, and indicate highly productive ecosystems. These data provide a background upon which the extent of human impact can be established, and existing data indicate negligible levels of disturbance. Geochemical and lithological data for a lacustrine sediment core from Beall Lake confirm earlier interpretation of recent climatic changes based on diatom distribution, and the onset of deglaciation in the northern part of the Windmill Islands between 8.6 and 8.0 ka BP. The results demonstrate that geochemical and lithological data can not only be used to define natural background values, but also to assess long-term climatic changes of a specific environment. Other sites, however, preserve a completely different sedimentary record. Therefore, inferred climatic record, and differences between sites, can be ascribed to differences in elevation, distance from the shore, water depth, and local catchment features. The extreme level of spatial variability seems to be a feature of Antarctic coastal areas, and demonstrates that results obtained from a specific site cannot be easily generalized to a larger area.

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Probable in-situ manganese deposits larger than 1 cm in diameter buried in ODP/DSDP cores were selected for study after examining previous descriptions of the manganese deposits in site reports and the ODP data base. Most of the selected samples from 11 cores occur at or just above sedimentary hiatuses or in slowly deposited sediments and are overlain by rapidly deposited sediments of biogenic, terrigenous or volcanogenic origin. The changes in sedimentation recorded in the lithostratigraphic sections around these deposits are closely related to changes in tectonic evolution, deep water circulation or biological productivity at the sites. The similarity in composition and structure of the buried deposits to those of the modern manganese nodules and crusts with no evidence of post-depositional change suggest that buried manganese deposits may be used as indicators of past sedimentary conditions during which they formed. Their major components are hydrogenetic and earlydiagenetic manganese minerals as well as detrital minerals. The characteristics of these manganese deposits suggests that similar processes of deposition have taken place since the Paleogene or older.

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A partir de los años cuarenta, se desarrolló en Argentina la Orientación Profesional, según las orientaciones que en aquellos momentos provenían de España, Francia, Bélgica y Suiza. El trabajo, analiza las primeras experiencias en orientación profesional, desarrolladas tanto en las grandes urbes industriales como Buenos Aires y Rosario, y en pequeños centros urbanos como Tucumán o San Luis. Asimismo, se analiza el contexto institucional y político de tales experiencias, y el decidido respaldo del Estado a las mismas.

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El artículo historiza el desarrollo del campo de las Ciencias de la Educación en la Universidad de la República de Uruguay en la segunda mitad del siglo XX y comienzos del siglo XXI. Para ello plantea algunos momentos destacados en dicho proceso. También presenta una caracterización inicial acerca de la actual constitución del campo profesional en el país. Concluye subrayando los elementos fundamentales de lo planteado y ofreciendo algunos interrogantes en relación a las posibilidades de consolidación de un campo de estudios sobre educación en la Universidad