Influence of parameter changes to stability behavior of rotors

The occurrence of unstable vibrations in rotating machinery requires corrective measures for improvement of the stability behavior. A simple approximate method is represented to find out the influence of parameter changes to the stability behavior. The method is based on an expansion of the eigenvalues in terms of system parameters. Influence coefficients show the effect of structural modifications. The method first of all was applied to simple nonconservative rotor models. It was approved for an unsymmetric rotor of a test rig

Diversification and hybridization in firm knowledge bases in nanotechnologies

The paper investigates the linkages between the characteristics of technologies and the structure of a firms' knowledge base. Nanotechnologies have been defined as converging technologies that operate at the nanoscale, and which require integration to fulfill their economic promises. Based on a worldwide database of nanofirms, the paper analyses the degree of convergence and the convergence mechanisms within firms. It argues that the degree of convergence in a firm's nano-knowledge base is relatively independent from the size of the firm's nano-knowledge base. However, while firms with small nano-knowledge bases tend to exploit convergence in each of their patents/publications, firms with large nano-knowledge bases tend to separate their nano-R&D activities in the different established fields and achieve diversity through the juxtaposition of the output of these independent activitie

A Systematic Review and Metaanalysis on the Effects of Garlic Preparations on Blood Pressure in Individuals With Hypertension

BACKGROUND Many patients prefer herbal medications to conventional drugs. Limited trial evidence suggests that garlic preparations reduce high blood pressure (BP). METHODS We searched electronic databases through March 2014 to identify all randomized controlled trials that compared a garlic preparation to placebo in hypertensive patients. Trials were required to report BP values at baseline and after a follow-up of at least 4 weeks. RESULTS Nine double-blind trials with 482 individuals fulfilled our inclusion criteria. Included trials were rather small, and the quality of the majority of included trials was moderate. Follow-up ranged from 8 to 26 weeks. All trials reported office BP measurements. Systolic BP and diastolic BP (SBP and DBP) were more effectively reduced in individuals treated with garlic preparations than in individuals treated with placebo. However, heterogeneity was high (weighted mean difference (WMD) for SBP was −9.1mm Hg; 95% confidence interval (CI), −12.7 to −5.4; P for heterogeneity = 0.0006; and I 2 = 71%; WMD for BP was −3.8mm Hg; 95% CI, −6.7 to −1.0; P for heterogeneity = 0.00001; I 2 = 80%). When analyses were restricted to higher-quality trials using intention-to-treat analysis or to trials with concealed treatment allocation and standardized and blinded BP measurement, effect sizes for SBP but not for DBP were lower and heterogeneity disappeared. CONCLUSIONS Although evidence from this review suggests that garlic preparations may lower BP in hypertensive individuals, the evidence is not strong. A well-conducted and powered trial of longer duration is needed to confirm these finding

Clinical outcomes of stents versus balloon angioplasty in non-acute coronary artery disease: A meta-analysis of randomized controlled trials

Aims To evaluate whether stents as compared to balloon angioplasty reduce mortality in patients with non-acute coronary artery disease. Methods and results We identified randomized controlled trials comparing stents to balloon angioplasty for the treatment of non-acute coronary artery disease by searching major medical databases from 1979 to March 2002. Two independent reviewers selected and extracted data from trials that had to report data on death and myocardial infarction. Nineteen trials, with a total of 8004 patients, fulfilled our inclusion criteria. For 1000 patients treated with stents rather than balloon angioplasty, 3 (95% CI 0-6), 5 (95% CI 0-9), and 6 (95% CI -1-12) additional lives were saved at 30 days, 6 and 12 months. At 12 months, for 1000 patients treated with stents rather than balloon angioplasty 46 (95% CI 25-66) additional target vessel revascularizations were avoided, but 25 (95% CI 15-34) additional bleeding complications with need for blood transfusion or surgical intervention occurred. In sensitivity analysis 11 (95% CI 2-20) and 2 (95% CI -4-7) deaths were avoided per 1000 patients treated with stents rather than PTCA in trials that routinely used compared to trials that did not use glycoprotein IIb/IIIa inhibitors. Conclusion In non-acute coronary disease stents may reduce overall mortality, but this benefit seems to be limited to stents used in conjunction with glycoprotein IIb/IIIa inhibitors. Stents compared to PTCA reduce target vessel revascularizations, but increase the risk of bleeding complication

Predominance of CTX-M–type extended-spectrum β-lactamase genes among enterobacterial isolates from outpatients in Brazil

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Ten simple rules for supporting a temporary online pivot in higher education

As continued COVID-19 disruption looks likely across the world, perhaps until 2021, contingency plans are evolving in case of further disruption in the 2020–2021 academic year. This includes delivering face-to-face programs fully online for at least part of the upcoming academic year for new and continuing cohorts. This temporary pivot will necessitate distance teaching and learning across almost every conceivable pedagogy, from fundamental degrees to professionally accredited ones. Each institution, program, and course will have its own myriad of individualized needs; however, there is a common question that unites us all: how do we provide teaching and assessment to students in a manner that is accessible, fair, equitable, and provides the best learning whilst acknowledging the temporary nature of the pivot? No “one size fits all” solution exists, and many of the choices that need to be made will be far from simple; however, this paper provides a starting point and basic principles to facilitate discussions taking place around the globe by balancing what we know from the pedagogy of online learning with the practicalities imposed by this crisis and any future crises

Direct detection of extended-spectrum-β-lactamase-producers in Enterobacterales from blood cultures: a comparative analysis.

Accurate detection of extended-spectrum-β-lactamase (ESBL)-producing Enterobacterales from bloodstream infection (BSI) is of paramount importance for both epidemiological and clinical purposes, especially for optimization of antibiotic stewardship interventions. Three phenotypic methods for the detection of ESBL phenotype in Klebsiella pneumoniae and Escherichia coli BSI were compared over a 4-month period (May-August 2021) in a main University Hospital from Northern Italy. The methods were the biochemical Rapid ESBL NP®, the immunological NG-Test CTX-M MULTI®, and the E-test technique based on ESBL E-test®. One hundred forty-two blood cultures (BCs) positive for K. pneumoniae or E. coli were included. ESBL and carbapenemase phenotype were detected in 26.1% (n = 37) and 16.9% (n = 24), respectively. The Rapid ESBL NP®, NG-Test CTX-M MULTI®, and direct ESBL E-test® positive and negative predictive values with 95% confidence intervals were 1 (0.87-1) and 0.97 (0.92-0.99), 1 (0.87-1) and 0.97 (0.92-0.99), and 1 (0.88-1) and 1 (0.96-1), respectively. The three phenotypic methods evaluated showed good performance in the detection of ESBL phenotype from K. pneumoniae- or E. coli-positive BCs. Rapid ESBL NP® and NG-test CTX-M® offer the important advantage of a turnaround time of 15 to 45 min, and the Rapid ESBL NP test in addition detects any type of ESBL producers

EVALUATION OF PREHOSPITAL BLOOD PRODUCTS TO ATTENUATE ACUTE COAGULOPATHY OF TRAUMA IN A MODEL OF SEVERE INJURY AND SHOCK IN ANESTHETIZED PIGS

This material is licensed under the terms of the Open Government Licence except where otherwise statedUK Ministry of Defence

How to detect carbapenemase producers? A literature review of phenotypic and molecular methods

© 2014 Elsevier B.V. This review describes the current state-of-art of carbapenemase detection methods. Identification of carbapenemases is first based on conventional phenotypic tests including antimicrobial susceptibility testing, modified-Hodge test and carbapenemase-inhibitor culture tests. Second, molecular characterization of carbapenemase genes by PCR sequencing is essential. Third, innovative biochemical and spectrometric detection may be applied

Uncertainty analysis of the use of a retailer fidelity card scheme in the assessment of food additive intake

International audienceThe feasibility of using a retailer fidelity card scheme to estimate food additive intake has been investigated in an earlier study. Fidelity card survey information was combined with information provided by the retailer on levels of the food colour Sunset Yellow (E110) in the foods to estimate a daily exposure to the additive in the Swiss population. As with any dietary exposure method the fidelity card scheme is subject to uncertainties and in this paper the impact of uncertainties associated with input variables including amounts of food purchased, levels of E110 in food, proportion of food purchased at retailer, rate of fidelity card usage, proportion of foods consumed outside of home and bodyweights and with systematic uncertainties has been assessed using a qualitative, deterministic and probabilistic approach. An analysis of the sensitivity of the results to each of the probabilistic inputs was also undertaken. The analysis was able to identify the key factors responsible for uncertainty within the model and demonstrate how the application of some simple probabilistic approaches can be used to quantitatively assess uncertainty