2,522 research outputs found

    Plexus anesthesia versus general anesthesia in patients for carotid endarterectomy with patch angioplasty:Protocol for a systematic review with meta-analyses and Trial Sequential Analysis of randomized clinical trials

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    Introduction: Traditional carotid endarterectomy is considered to be the standard technique for prevention of a new stroke in patients with a symptomatic carotid stenosis. Use of plexus anesthesia or general anesthesia in traditional carotid endarterectomy is, to date, not unequivocally proven to be superior to one other. A systematic review is needed for evaluation of benefits and harms to determine which technique, plexus anesthesia or general anesthesia is more effective for traditional carotid endarterectomy in patients with symptomatic carotid stenosis. Methods and outcomes: The review will be conducted according to this protocol following the recommendations of the ‘Cochrane Handbook for Systematic Reviews’ and reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Randomized Clinical Trials comparing plexus anesthesia versus general anesthesia in traditional carotid endarterectomy will be included. Primary outcomes will be postoperative death and/ or stroke (<30 days) and serious adverse events. Secondary outcomes will be non-serious adverse events. We will primarily base our conclusions on meta-analyses of trials with overall low risk of bias. We will use Trial Sequential Analysis to assist the evaluation of imprecision in Grading of Recommendations Assessment, Development and Evaluation. However, if pooled point-estimates of all trials are similar to pooled point-estimates of trials with overall low risk of bias and there is lack of a statistical significant interaction between estimates from trials with overall high risk of bias and trials with overall low risk of bias we will consider the Trial Sequential Analysis adjusted confidence interval precision of the estimate achieved in all trials as the result of our meta-analyses. Ethics and dissemination: The proposed systematic review will collect and analyze secondary data from already performed studies therefore ethical approval is not required. The results of the systematic review will be disseminated by publication in a peer-review journal and submitted for presentation at relevant conferences

    Plasma activation of N-2, CH4 and CO2: an assessment of the vibrational non-equilibrium time window

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    Vibrational excitation potentially enhances the energy efficiency of plasma dissociation of stable molecules and may open new routes for energy storage and process electrification. Electron, vibrational and rotational temperatures were measured by in situ Thomson and Raman scattering in order to assess the opportunities and limitations of the essential vibration-translation non-equilibria in N-2, CO2 and CH4 plasma. Electron temperatures of 1.1-2.8 eV were measured in N-2 and CH4. These are used to confirm predominant energy transfer to vibrations after an initial phase of significant electronic excitation and ionization. The vibrational temperatures initially exceed rotational temperatures by almost 8000 K in N-2, by 900 K in CO2, and by 300 K in CH4. Equilibration is observed at the 0.1 ms timescale. Based on the vibrational temperatures, the vibrational loss rates for different channels are estimated. In N-2, vibrational quenching via N atoms is identified as the dominant equilibration mechanism. Atomic nitrogen population reaches a mole fraction of more than 1%, as inferred from the afterglow emission decay, and explains a gas heating rate of 25 K mu s(-1). CH4 equilibration at 1200 K is predominantly caused by vibrational-translational relaxation in CH4-CH4 collisions. As for CO2, vibrational-translational relaxation via parent molecules is responsible for a large fraction of the observed heating, whereas product-mediated VT relaxation is not significantly contributing. It is suggested that electronic excitation, followed by dissociation or quenching contributes to the remaining heat generation. In conclusion, the time window to profit from vibrational excitation under the present conditions is limiting practical application.</p

    The (co-)occurrence of problematic video gaming, substance use, and psychosocial problems in adolescents

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    Aims. The current study explored the nature of problematic (addictive) video gaming and the association with game type, psychosocial health, and substance use. Methods. Data were collected using a paper and pencil survey in the classroom setting. Three samples were aggregated to achieve a total sample of 8478 unique adolescents. Scales included measures of game use, game type, the Video game Addiction Test (VAT), depressive mood, negative self-esteem, loneliness, social anxiety, education performance, and use of cannabis, alcohol and nicotine (smoking). Results. Findings confirmed problematic gaming is most common amongst adolescent gamers who play multiplayer online games. Boys (60%) were more likely to play online games than girls (14%) and problematic gamers were more likely to be boys (5%) than girls (1%). High problematic gamers showed higher scores on depressive mood, loneliness, social anxiety, negative self-esteem, and self-reported lower school performance. Nicotine, alcohol, and cannabis using boys were almost twice more likely to report high PVG than non-users. Conclusions. It appears that online gaming in general is not necessarily associated with problems. However, problematic gamers do seem to play online games more often, and a small subgroup of gamers – specifically boys – showed lower psychosocial functioning and lower grades. Moreover, associations with alcohol, nicotine, and cannabis use are found. It would appear that problematic gaming is an undesirable problem for a small subgroup of gamers. The findings encourage further exploration of the role of psychoactive substance use in problematic gaming

    Rainbow domination and related problems on some classes of perfect graphs

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    Let k∈Nk \in \mathbb{N} and let GG be a graph. A function f:V(G)→2[k]f: V(G) \rightarrow 2^{[k]} is a rainbow function if, for every vertex xx with f(x)=∅f(x)=\emptyset, f(N(x))=[k]f(N(x)) =[k]. The rainbow domination number γkr(G)\gamma_{kr}(G) is the minimum of ∑x∈V(G)∣f(x)∣\sum_{x \in V(G)} |f(x)| over all rainbow functions. We investigate the rainbow domination problem for some classes of perfect graphs

    Energiezuinige Teeltplanning voor Potplanten : een rekenplatform voor energie-efficiënte scenario's in de Poinsettiateelt

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    In het kader van het project Energiezuinige Teeltplanning voor Potplanten is gewerkt aan een adviessysteem dat potplantentelers in staat stelt om zelfstandig de energie-efficiĂ«ntie van teeltscenario’s te evalueren op basis van actuele, bedrijfsspecifieke gegevens. Daarnaast maakt het systeem het mogelijk om via internet teeltscenario’s te delen met teeltadviseurs en binnen bedrijfsvergelijkingsgroepen. Het systeem is gebaseerd op dynamische gewasmodellen voor Hortensia, Poinsettia en Ficus, en maakt voor het berekenen van kasklimaat en energiestromen gebruik van het rekenmodel KASPRO. Dit rapport beschrijft de werking van het systeem, de resultaten op 4 bedrijven per gewas, de reacties van de betrokken telers, en een evaluatie van het project. De belangrijkste mogelijkheden om de energie-efficiĂ«ntie van een teelt te verbeteren werden gevonden in verbeterde wijderzetschema’s en in het toepassen van de principes van ‘Het Nieuwe Telen’, door met name de temperatuur meer te laten variĂ«ren met het licht en het ontwikkelingsstadium van het gewas

    Defining type 2 diabetes polygenic risk scores through colocalization and network-based clustering of metabolic trait genetic associations

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    Background: Type 2 diabetes (T2D) is a heterogeneous and polygenic disease. Previous studies have leveraged the highly polygenic and pleiotropic nature of T2D variants to partition the heterogeneity of T2D, in order to stratify patient risk and gain mechanistic insight. We expanded on these approaches by performing colocalization across GWAS traits while assessing the causality and directionality of genetic associations. Methods: We applied colocalization between T2D and 20 related metabolic traits, across 243 loci, to obtain inferences of shared casual variants. Network-based unsupervised hierarchical clustering was performed on variant-trait associations. Partitioned polygenic risk scores (PRSs) were generated for each cluster using T2D summary statistics and validated in 21,742 individuals with T2D from 3 cohorts. Inferences of directionality and causality were obtained by applying Mendelian randomization Steiger’s Z-test and further validated in a pediatric cohort without diabetes (aged 9–12 years old, n = 3866). Results: We identified 146 T2D loci that colocalized with at least one metabolic trait locus. T2D variants within these loci were grouped into 5 clusters. The clusters corresponded to the following pathways: obesity, lipodystrophic insulin resistance, liver and lipid metabolism, hepatic glucose metabolism, and beta-cell dysfunction. We observed heterogeneity in associations between PRSs and metabolic measures across clusters. For instance, the lipodystrophic insulin resistance (Beta − 0.08 SD, 95% CI [− 0.10–0.07], p = 6.50 × 10−32) and beta-cell dysfunction (Beta − 0.10 SD, 95% CI [− 0.12, − 0.08], p = 1.46 × 10−47) PRSs were associated to lower BMI. Mendelian randomization Steiger analysis indicated that increased T2D risk in these pathways was causally associated to lower BMI. However, the obesity PRS was conversely associated with increased BMI (Beta 0.08 SD, 95% CI 0.06–0.10, p = 8.0 × 10−33). Analyses within a pediatric cohort supported this finding. Additionally, the lipodystrophic insulin resistance PRS was associated with a higher odds of chronic kidney disease (OR 1.29, 95% CI 1.02–1.62, p = 0.03). Conclusions: We successfully partitioned T2D genetic variants into phenotypic pathways using a colocalization first approach. Partitioned PRSs were associated to unique metabolic and clinical outcomes indicating successful partitioning of disease heterogeneity. Our work expands on previous approaches by providing stronger inferences of shared causal variants, causality, and directionality of GWAS variant-trait associations.</p

    Airway responsiveness after a single dose of salmeterol and during four months of treatment in children with asthma

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    Background: Inhalation of a single dose of the long-acting ÎČ2- adrenoceptor agonist salmeterol protects against methacholine-induced airway obstruction and other bronchoconstricting stimuli for at least 12 hours. Hypothetically, twice daily dosing of salmeterol may result in continuous protection. Objective: this study was designed to investigate the protective effect of a single dose of salmeterol and of continuous twice daily treatment on airway responsiveness to methacholine. Methods: In a double-blind, parallel study, salmeterol 50 ÎŒg twice daily was compared with salbutamol 200 ÎŒg twice daily. Thirty children with mild asthma, who had little or no bronchial obstruction and were hyperresponsive to methacholine (PD20 ≀ 150 ÎŒg) were allocated to receive either salmeterol or salbutamol. Airway responsiveness was measured before study entry, 12 hours after a single dose of drug was given, and monthly during 4 months of daily treatment. Measurements were always performed at the same time of the day, 12 hours after the last dose of medication was administered. Results: No significant differences in FEV1 were found between treatments at any time point. PD20 significantly increased after the first dose of salmeterol was given (geometric mean, 100 ÎŒg). Geometric mean PD20 values were significantly better during salmeterol treatment than during salbutamol treatment, 52 and 25 ÎŒg, respectively (p = 0.005). Conclusion: The protection provided by salmeterol during maintenance treatment was less than that provided after the first dose (p < 0.001). However, protection did not diminish during the 4- month treatment period and remained significant compared with baseline (p = 0.003)
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