18 resultados para cut-to-length operations

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


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Tajikistan is judged to be highly vulnerable to risk, including food insecurity risks and climate change risks. By some vulnerability measures it is the most vulnerable among all 28 countries in the World Bank’s Europe and Central Asia Region – ECA (World Bank 2009). The rural population, with its relatively high incidence of poverty, is particularly vulnerable. The Pilot Program for Climate Resilience (PPCR) in Tajikistan (2011) provided an opportunity to conduct a farm-level survey with the objective of assessing various dimensions of rural population’s vulnerability to risk and their perception of constraints to farming operations and livelihoods. The survey should be accordingly referred to as the 2011 PPCR survey. The rural population in Tajikistan is highly agrarian, with about 50% of family income deriving from agriculture (see Figure 4.1; also LSMS 2007 – own calculations). Tajikistan’s agriculture basically consists of two groups of producers: small household plots – the successors of Soviet “private agriculture” – and dehkan (or “peasant”) farms – new family farming structures that began to be created under relevant legislation passed after 1992 (Lerman and Sedik, 2008). The household plots manage 20% of arable land and produce 65% of gross agricultural output (GAO). Dehkan farms manage 65% of arable land and produce close to 30% of GAO. The remaining 15% of arable land is held in agricultural enterprises – the rapidly shrinking sector of corporate farms that succeeded the Soviet kolkhozes and sovkhozes and today produces less than 10% of GAO (TajStat 2011) The survey conducted in May 2011 focused on dehkan farms, as budgetary constraints precluded the inclusion of household plots. A total of 142 dehkan farms were surveyed in face-to-face interviews. They were sampled from 17 districts across all four regions – Sughd, Khatlon, RRP, and GBAO. The districts were selected so as to represent different agro-climatic zones, different vulnerability zones (based on the World Bank (2011) vulnerability assessment), and different food-insecurity zones (based on WFP/IPC assessments). Within each district, 3-4 jamoats were chosen at random and 2-3 farms were selected in each jamoat from lists provided by jamoat administration so as to maximize the variability by farm characteristics. The sample design by region/district is presented in Table A, which also shows the agro-climatic zone and the food security phase for each district. The sample districts are superimposed on a map of food security phases based on IPC April 2011.

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L-type calcium channels are composed of a pore, alpha1c (Ca(V)1.2), and accessory beta- and alpha2delta-subunits. The beta-subunit core structure was recently resolved at high resolution, providing important information on many functional aspects of channel modulation. In this study we reveal differential novel effects of five beta2-subunits isoforms expressed in human heart (beta(2a-e)) on the single L-type calcium channel current. These splice variants differ only by amino-terminal length and amino acid composition. Single-channel modulation by beta2-subunit isoforms was investigated in HEK293 cells expressing the recombinant L-type ion conducting pore. All beta2-subunits increased open probability, availability, and peak current with a highly consistent rank order (beta2a approximately = beta2b > beta2e approximately = beta2c > beta2d). We show graded modulation of some transition rates within and between deep-closed and inactivated states. The extent of modulation correlates strongly with the length of amino-terminal domains. Two mutant beta2-subunits that imitate the natural span related to length confirm this conclusion. The data show that the length of amino termini is a relevant physiological mechanism for channel closure and inactivation, and that natural alternative splicing exploits this principle for modulation of the gating properties of calcium channels.

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OBJECTIVES: Endovascular repair of the descending thoracic aorta is a very promising technique in elective and, particularly, emergency situations. This study assessed the impact of urgency of the procedure on outcome and mid-term quality of life in surviving patients. METHODS: Post hoc analysis of prospectively collected data of 58 consecutive patients (January 2001-December 2005) with surgical pathologies of the descending thoracic aorta treated by endovascular means. Six patients were excluded due to recent operations on the ascending aorta before thoracic endovascular repair. The remaining patients (n=52) were 69+/-10 years old, and 43 were men (83%). Twenty-seven had been treated electively, and 25 for emergency indications. Reasons for emergency were acute type B aortic dissections with or without malperfusion syndrome in 14, and aortic ruptures in 11 cases. Follow-up was 29+/-16 months. Endpoints were perioperative and late morbidity and mortality rates and long-term quality of life as assessed by the short form health survey (SF-36) and Hospital Anxiety and Depression Scale questionnaires. RESULTS: Cohorts were comparable regarding age, sex, cardiovascular risk factors, and comorbidities. Perioperative mortality was somewhat higher in emergency cases (12% vs 4%, p=0.34). Paraplegia occurred in one patient in each cohort (4%). Overall quality of life after two and a half years was similar in both treatment cohorts: 72 (58-124) after emergency, and 85 (61-105) after elective endovascular aortic repair (p=0.98). Normal scores range from 85 to 115. Anxiety and depression scores were in the normal range and comparable. CONCLUSIONS: Thoracic endovascular aortic repair is an excellent and safe treatment option for the diseased descending aorta, particularly in emergency situations. Early morbidity and mortality rates can be kept very low. Mid-term quality of life was not affected by the urgency of the procedure. Similarly, mid-term anxiety and depression scores were not increased after emergency situations.

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BACKGROUND To date, the use of proton pump inhibitors (PPIs) has been associated with a low risk of hypomagnesaemia and associated adverse outcomes. We hypothesised that a better risk estimate could be derived from a large cohort of outpatients admitted to a tertiary emergency department (ED). METHODS A cross-sectional study was performed in 5118 patients who had measurements of serum magnesium taken on admission to a large tertiary care ED between January 2009 and December 2010. Hypomagnesaemia was defined as a serum magnesium concentration < 0.75 mmol/l. Demographical data, serum electrolyte values, data on medication, comorbidities and outcome with regard to length of hospital stay and mortality were analysed. RESULTS Serum magnesium was normally distributed where upon 1246 patients (24%) were hypomagnesaemic. These patients had a higher prevalence of out-of-hospital PPI use and diuretic use when compared with patients with magnesium levels > 0.75 mmol/l (both p < 0.0001). In multivariable regression analyses adjusted for PPIs, diuretics, renal function and the Charlson comorbidity index score, the association between use of PPIs and risk for hypomagnesaemia remained significant (OR = 2.1; 95% CI: 1.54-2.85). While mortality was not directly related to low magnesium levels (p = 0.67), the length of hospitalisation was prolonged in these patients even after adjustment for underlying comorbid conditions (p < 0.0001). CONCLUSION Use of PPIs predisposes patients to hypomagnesaemia and such to prolonged hospitalisation irrespective of the underlying morbidity, posing a critical concern.

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BACKGROUND Knee osteoarthritis is a leading cause of chronic pain, disability, and decreased quality of life. Despite the long-standing use of intra-articular corticosteroids, there is an ongoing debate about their benefits and safety. This is an update of a Cochrane review first published in 2005. OBJECTIVES To determine the benefits and harms of intra-articular corticosteroids compared with sham or no intervention in people with knee osteoarthritis in terms of pain, physical function, quality of life, and safety. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE (from inception to 3 February 2015), checked trial registers, conference proceedings, reference lists, and contacted authors. SELECTION CRITERIA We included randomised or quasi-randomised controlled trials that compared intra-articular corticosteroids with sham injection or no treatment in people with knee osteoarthritis. We applied no language restrictions. DATA COLLECTION AND ANALYSIS We calculated standardised mean differences (SMDs) and 95% confidence intervals (CI) for pain, function, quality of life, joint space narrowing, and risk ratios (RRs) for safety outcomes. We combined trials using an inverse-variance random-effects meta-analysis. MAIN RESULTS We identified 27 trials (13 new studies) with 1767 participants in this update. We graded the quality of the evidence as 'low' for all outcomes because treatment effect estimates were inconsistent with great variation across trials, pooled estimates were imprecise and did not rule out relevant or irrelevant clinical effects, and because most trials had a high or unclear risk of bias. Intra-articular corticosteroids appeared to be more beneficial in pain reduction than control interventions (SMD -0.40, 95% CI -0.58 to -0.22), which corresponds to a difference in pain scores of 1.0 cm on a 10-cm visual analogue scale between corticosteroids and sham injection and translates into a number needed to treat for an additional beneficial outcome (NNTB) of 8 (95% CI 6 to 13). An I(2) statistic of 68% indicated considerable between-trial heterogeneity. A visual inspection of the funnel plot suggested some asymmetry (asymmetry coefficient -1.21, 95%CI -3.58 to 1.17). When stratifying results according to length of follow-up, benefits were moderate at 1 to 2 weeks after end of treatment (SMD -0.48, 95% CI -0.70 to -0.27), small to moderate at 4 to 6 weeks (SMD -0.41, 95% CI -0.61 to -0.21), small at 13 weeks (SMD -0.22, 95% CI -0.44 to 0.00), and no evidence of an effect at 26 weeks (SMD -0.07, 95% CI -0.25 to 0.11). An I(2) statistic of ≥ 63% indicated a moderate to large degree of between-trial heterogeneity up to 13 weeks after end of treatment (P for heterogeneity≤0.001), and an I(2) of 0% indicated low heterogeneity at 26 weeks (P=0.43). There was evidence of lower treatment effects in trials that randomised on average at least 50 participants per group (P=0.05) or at least 100 participants per group (P=0.013), in trials that used concomittant viscosupplementation (P=0.08), and in trials that used concomitant joint lavage (P≤0.001).Corticosteroids appeared to be more effective in function improvement than control interventions (SMD -0.33, 95% CI -0.56 to -0.09), which corresponds to a difference in functions scores of -0.7 units on standardised Western Ontario and McMaster Universities Arthritis Index (WOMAC) disability scale ranging from 0 to 10 and translates into a NNTB of 10 (95% CI 7 to 33). An I(2) statistic of 69% indicated a moderate to large degree of between-trial heterogeneity. A visual inspection of the funnel plot suggested asymmetry (asymmetry coefficient -4.07, 95% CI -8.08 to -0.05). When stratifying results according to length of follow-up, benefits were small to moderate at 1 to 2 weeks after end of treatment (SMD -0.43, 95% CI -0.72 to -0.14), small to moderate at 4 to 6 weeks (SMD -0.36, 95% CI -0.63 to -0.09), and no evidence of an effect at 13 weeks (SMD -0.13, 95% CI -0.37 to 0.10) or at 26 weeks (SMD 0.06, 95% CI -0.16 to 0.28). An I(2) statistic of ≥ 62% indicated a moderate to large degree of between-trial heterogeneity up to 13 weeks after end of treatment (P for heterogeneity≤0.004), and an I(2) of 0% indicated low heterogeneity at 26 weeks (P=0.52). We found evidence of lower treatment effects in trials that randomised on average at least 50 participants per group (P=0.023), in unpublished trials (P=0.023), in trials that used non-intervention controls (P=0.031), and in trials that used concomitant viscosupplementation (P=0.06).Participants on corticosteroids were 11% less likely to experience adverse events, but confidence intervals included the null effect (RR 0.89, 95% CI 0.64 to 1.23, I(2)=0%). Participants on corticosteroids were 67% less likely to withdraw because of adverse events, but confidence intervals were wide and included the null effect (RR 0.33, 95% CI 0.05 to 2.07, I(2)=0%). Participants on corticosteroids were 27% less likely to experience any serious adverse event, but confidence intervals were wide and included the null effect (RR 0.63, 95% CI 0.15 to 2.67, I(2)=0%).We found no evidence of an effect of corticosteroids on quality of life compared to control (SMD -0.01, 95% CI -0.30 to 0.28, I(2)=0%). There was also no evidence of an effect of corticosteroids on joint space narrowing compared to control interventions (SMD -0.02, 95% CI -0.49 to 0.46). AUTHORS' CONCLUSIONS Whether there are clinically important benefits of intra-articular corticosteroids after one to six weeks remains unclear in view of the overall quality of the evidence, considerable heterogeneity between trials, and evidence of small-study effects. A single trial included in this review described adequate measures to minimise biases and did not find any benefit of intra-articular corticosteroids.In this update of the systematic review and meta-analysis, we found most of the identified trials that compared intra-articular corticosteroids with sham or non-intervention control small and hampered by low methodological quality. An analysis of multiple time points suggested that effects decrease over time, and our analysis provided no evidence that an effect remains six months after a corticosteroid injection.

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By measuring the total crack lengths (TCL) along a gunshot wound channel simulated in ordnance gelatine, one can calculate the energy transferred by a projectile to the surrounding tissue along its course. Visual quantitative TCL analysis of cut slices in ordnance gelatine blocks is unreliable due to the poor visibility of cracks and the likely introduction of secondary cracks resulting from slicing. Furthermore, gelatine TCL patterns are difficult to preserve because of the deterioration of the internal structures of gelatine with age and the tendency of gelatine to decompose. By contrast, using computed tomography (CT) software for TCL analysis in gelatine, cracks on 1-cm thick slices can be easily detected, measured and preserved. In this, experiment CT TCL analyses were applied to gunshots fired into gelatine blocks by three different ammunition types (9-mm Luger full metal jacket, .44 Remington Magnum semi-jacketed hollow point and 7.62 × 51 RWS Cone-Point). The resulting TCL curves reflected the three projectiles' capacity to transfer energy to the surrounding tissue very accurately and showed clearly the typical energy transfer differences. We believe that CT is a useful tool in evaluating gunshot wound profiles using the TCL method and is indeed superior to conventional methods applying physical slicing of the gelatine.

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Telomeres have emerged as crucial cellular elements in aging and various diseases including cancer. To measure the average length of telomere repeats in cells, we describe our protocols that use fluorescent in situ hybridization (FISH) with labeled peptide nucleic acid (PNA) probes specific for telomere repeats in combination with fluorescence measurements by flow cytometry (flow FISH). Flow FISH analysis can be performed using commercially available flow cytometers, and has the unique advantage over other methods for measuring telomere length of providing multi-parameter information on the length of telomere repeats in thousands of individual cells. The accuracy and reproducibility of the measurements is augmented by the automation of most pipetting (aspiration and dispensing) steps, and by including an internal standard (control cells) with a known telomere length in every tube. The basic protocol for the analysis of nucleated blood cells from 22 different individuals takes about 12 h spread over 2-3 days.

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The study is based on experimental work conducted in alpine snow. We made microwave radiometric and near-infrared reflectance measurements of snow slabs under different experimental conditions. We used an empirical relation to link near-infrared reflectance of snow to the specific surface area (SSA), and converted the SSA into the correlation length. From the measurements of snow radiances at 21 and 35 GHz , we derived the microwave scattering coefficient by inverting two coupled radiative transfer models (the sandwich and six-flux model). The correlation lengths found are in the same range as those determined in the literature using cold laboratory work. The technique shows great potential in the determination of the snow correlation length under field conditions.

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The synthesis is reported of a new series of oligo(aryleneethynylene) (OAE) derivatives of up to ca. 6 nm in molecular length (OAE9) using iterative Pd-mediated Sonogashira cross-coupling methodology. The oligo-p-phenyleneethynylene cores of the molecular wires are functionalized at both termini with pyridyl units for attachment to gold leads. The molecular structures determined by single-crystal X-ray analysis are reported for OAE4, OAE5, OAE7, and OAE8a. The charge transport characteristics of derivatives OAE3–OAE9 in single-molecular junctions have been studied using the mechanically controlled break junction technique. The data demonstrate that the junction conductance decreases with increasing molecular length. A transition from coherent transport via tunneling to a hopping mechanism is found for OAE wires longer than ca. 3 nm.

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The ActiGraph accelerometer is commonly used to measure physical activity in children. Count cut-off points are needed when using accelerometer data to determine the time a person spent in moderate or vigorous physical activity. For the GT3X accelerometer no cut-off points for young children have been published yet. The aim of the current study was thus to develop and validate count cut-off points for young children. Thirty-two children aged 5 to 9 years performed four locomotor and four play activities. Activity classification into the light-, moderate- or vigorous-intensity category was based on energy expenditure measurements with indirect calorimetry. Vertical axis as well as vector magnitude cut-off points were determined through receiver operating characteristic curve analyses with the data of two thirds of the study group and validated with the data of the remaining third. The vertical axis cut-off points were 133 counts per 5 sec for moderate to vigorous physical activity (MVPA), 193 counts for vigorous activity (VPA) corresponding to a metabolic threshold of 5 MET and 233 for VPA corresponding to 6 MET. The vector magnitude cut-off points were 246 counts per 5 sec for MVPA, 316 counts for VPA - 5 MET and 381 counts for VPA - 6 MET. When validated, the current cut-off points generally showed high recognition rates for each category, high sensitivity and specificity values and moderate agreement in terms of the Kappa statistic. These results were similar for vertical axis and vector magnitude cut-off points. The current cut-off points adequately reflect MVPA and VPA in young children. Cut-off points based on vector magnitude counts did not appear to reflect the intensity categories better than cut-off points based on vertical axis counts alone.

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Nonlinear computational analysis of materials showing elasto-plasticity or damage relies on knowledge of their yield behavior and strengths under complex stress states. In this work, a generalized anisotropic quadric yield criterion is proposed that is homogeneous of degree one and takes a convex quadric shape with a smooth transition from ellipsoidal to cylindrical or conical surfaces. If in the case of material identification, the shape of the yield function is not known a priori, a minimization using the quadric criterion will result in the optimal shape among the convex quadrics. The convexity limits of the criterion and the transition points between the different shapes are identified. Several special cases of the criterion for distinct material symmetries such as isotropy, cubic symmetry, fabric-based orthotropy and general orthotropy are presented and discussed. The generality of the formulation is demonstrated by showing its degeneration to several classical yield surfaces like the von Mises, Drucker–Prager, Tsai–Wu, Liu, generalized Hill and classical Hill criteria under appropriate conditions. Applicability of the formulation for micromechanical analyses was shown by transformation of a criterion for porous cohesive-frictional materials by Maghous et al. In order to demonstrate the advantages of the generalized formulation, bone is chosen as an example material, since it features yield envelopes with different shapes depending on the considered length scale. A fabric- and density-based quadric criterion for the description of homogenized material behavior of trabecular bone is identified from uniaxial, multiaxial and torsional experimental data. Also, a fabric- and density-based Tsai–Wu yield criterion for homogenized trabecular bone from in silico data is converted to an equivalent quadric criterion by introduction of a transformation of the interaction parameters. Finally, a quadric yield criterion for lamellar bone at the microscale is identified from a nanoindentation study reported in the literature, thus demonstrating the applicability of the generalized formulation to the description of the yield envelope of bone at multiple length scales.

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BACKGROUND Rapid pulmonary vein (PV) activity has been shown to maintain paroxysmal atrial fibrillation (AF). We evaluated in persistent AF the cycle length (CL) gradient between PVs and the left atrium (LA) in an attempt to identify the subset of patients where PVs play an important role. METHODS AND RESULTS Ninety-seven consecutive patients undergoing first ablation for persistent AF were studied. For each PV, the CL of the fastest activation was assessed over 1 minute (PVfast) using Lasso recordings. The PV to LA CL gradient was quantified by the ratio of PVfast to LA appendage (LAA) AF CL. Stepwise ablation terminated AF in 73 patients (75%). In the AF termination group, the PVfast CL was much shorter than the LAA CL resulting in lower PVfast/LAA ratios compared with the nontermination group (71±10% versus 92±7%; P<0.001). Within the termination group, PVfast/LAA ratios were notably lower if AF terminated after PV isolation or limited adjunctive substrate ablation compared with patients who required moderate or extensive ablation (63±6% versus 75±8%; P<0.001). PVfast/LAA ratio <69% predicted AF termination after PV isolation or limited substrate ablation with 74% positive predictive value and 95% negative predictive value. After a mean follow-up of 29±17 months, freedom from arrhythmia recurrence off-antiarrhythmic drugs was achieved in most patients with PVfast/LAA ratios <69% as opposed to the remaining population (80% versus 43%; P<0.001). CONCLUSIONS The PV to LA CL gradient may identify the subset of patients in whom persistent AF is likely to terminate after PV isolation or limited substrate ablation and better long-term outcomes are achieved.

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INTRODUCTION Spinal disc herniation, lumbar spinal stenosis and spondylolisthesis are known to be leading causes of lumbar back pain. The cost of low back pain management and related operations are continuously increasing in the healthcare sector. There are many studies regarding complications after spine surgery but little is known about the factors predicting the length of stay in hospital. The purpose of this study was to identify these factors in lumbar spine surgery in order to adapt the postoperative treatment. MATERIAL AND METHODS The current study was carried out as a post hoc analysis on the basis of the German spine registry. Patients who underwent lumbar spine surgery by posterior surgical access and with posterior fusion and/or rigid stabilization, whereby procedures with dynamic stabilization were excluded. Patient characteristics were tested for association with length of stay (LOS) using bivariate and multivariate analyses. RESULTS A total of 356 patients met the inclusion criteria. The average age of all patients was 64.6 years and the mean LOS was 11.9 ± 6.0 days with a range of 2-44 days. Independent factors that were influencing LOS were increased age at the time of surgery, higher body mass index, male gender, blood transfusion of 1-2 erythrocyte concentrates and the presence of surgical complications. CONCLUSION Identification of predictive factors for prolonged LOS may allow for estimation of patient hospitalization time and for optimization of postoperative care. In individual cases this may result of a reduction in the LOS.