10 research outputs found

    Solid-State Ion-Exchanged Cu/Mordenite Catalysts for the Direct Conversion of Methane to Methanol

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    The selective oxidation of methane to methanol is a highly challenging target, which is of considerable interest to gain value-added chemicals directly from fuel gas. Copper-containing zeolites, such as Cu/mordenite, have been currently reported to be the most efficient catalysts for this reaction. In this work, it is shown that solid-state ion-exchanged Cu/mordenites exhibit a significantly higher activity for the partial oxidation of methane to methanol than comparable reference catalysts, i.e., Cu/mordenites prepared by the conventional liquid-phase ion exchange procedure. The efficiency of these Cu/mordenites remained unchanged over several successive cycles. From temperature-programmed reduction (TPR) measurements, it can be concluded that the solid-state protocol accelerates Cu exchange at the small pores of mordenite: those are positions where the most active Cu species are presumably located. <i>In situ</i> ultraviolet–visible (UV-vis) spectroscopy furthermore indicates that different active clusters including dicopper- and tricopper-oxo complexes are formed in the catalyst upon oxygen treatment. Notably after activation of methane, different methoxy intermediates seem to be generated at the Cu sites from which one is preferably transformed to methanol by reaction with water. It is furthermore described that the applied reaction conditions have considerable influence on the finally observed methanol production from methane

    Design of the circulation improving resuscitation care (CIRC) trial: a new state of the art design for out-of-hospital cardiac arrest research

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    Purpose Mechanical chest compression devices, such as the AutoPulse®, have been developed to overcome problems associated with manual CPR (M-CPR). Animal and human studies have shown that AutoPulse CPR improves hemodynamic parameters over M-CPR. However, human studies conducted in the prehospital setting have conflicting results as to the AutoPulse's efficacy in improving survival. The Circulation Improving Resuscitation Care (CIRC) Trial is designed to evaluate the effectiveness of integrated AutoPulse-CPR (iA-CPR) (i.e., M-CPR followed by AutoPulse®-CPR) in a randomized controlled trial that addresses methodological issues that may have influenced the results of previous studies. Methods This paper describes the methodology of the CIRC trial. Results Unlike previous trials the CIRC trial studies iA-CPR where emphasis is placed on reducing “hands-off” time. The trial has six unique features: (1) training of all EMS providers in a standardized deployment strategy that reduces hands-off time and continuous monitoring for protocol compliance. (2) A pre-trial simulation study of provider compliance with the trial protocol. (3) Three distinct study phases (in-field training, run-in, and statistical inclusion) to minimize the Hawthorne effect and other biases. (4) Monitoring of the CPR process using either transthoracic impedance or accelerometer data. (5) Randomization at the subject level after the decision to resuscitate is made to reduce selection bias. (6) Use of the Group Sequential Double Triangular Test with sufficient power to determine superiority, inferiority, or equivalence. Conclusion This unique, large, multicenter study comparing the effectiveness of iA-CPR to M-CPR will contribute to the science of the treatment of out-of-hospital cardiac arrest as well as to the design of future trials

    Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest:the randomized CIRC trial

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    Objective: To compare integrated automated load distributing band CPR (iA-CPR) with high-quality manual CPR (M-CPR) to determine equivalence, superiority, or inferiority in survival to hospital discharge. Methods: Between March 5, 2009 and January 11, 2011 a randomized, unblinded, controlled group sequential trial of adult out-of-hospital cardiac arrests of presumed cardiac origin was conducted at three US and two European sites. After EMS providers initiated manual compressions patients were randomized to receive either iA-CPR or M-CPR. Patient follow-up was until all patients were discharged alive or died. The primary outcome, survival to hospital discharge, was analyzed adjusting for covariates, (age, witnessed arrest, initial cardiac rhythm, enrollment site) and interim analyses. CPR quality and protocol adherence were monitored (CPR fraction) electronically throughout the trial. Results: Of 4753 randomized patients, 522 (11.0%) met post enrollment exclusion criteria. Therefore, 2099 (49.6%) received iA-CPR and 2132 (50.4%) M-CPR. Sustained ROSC (emergency department admittance), 24 h survival and hospital discharge (unknown for 12 cases) for iA-CPR compared to M-CPR were 600 (28.6%) vs. 689 (32.3%), 456 (21.8%) vs. 532 (25.0%), 196 (9.4%) vs. 233 (11.0%) patients, respectively. The adjusted odds ratio of survival to hospital discharge for iA-CPR compared to M-CPR, was 1.06 (95% CI 0.83–1.37), meeting the criteria for equivalence. The 20 min CPR fraction was 80.4% for iA-CPR and 80.2% for M-CPR. Conclusion: Compared to high-quality M-CPR, iA-CPR resulted in statistically equivalent survival to hospital discharge

    Clinical Paper Manual vs. integrated automatic load-distributing band CPR with equal survival after out of hospital cardiac arrest. The randomized CIRC trial ଝ,ଝଝ

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    a b s t r a c t Objective: To compare integrated automated load distributing band CPR (iA-CPR) with high-quality manual CPR (M-CPR) to determine equivalence, superiority, or inferiority in survival to hospital discharge. Methods: Between March 5, 2009 and January 11, 2011 a randomized, unblinded, controlled group sequential trial of adult out-of-hospital cardiac arrests of presumed cardiac origin was conducted at three US and two European sites. After EMS providers initiated manual compressions patients were randomized to receive either iA-CPR or M-CPR. Patient follow-up was until all patients were discharged alive or died. The primary outcome, survival to hospital discharge, was analyzed adjusting for covariates, (age, witnessed arrest, initial cardiac rhythm, enrollment site) and interim analyses. CPR quality and protocol adherence were monitored (CPR fraction) electronically throughout the trial. Results: Of 4753 randomized patients, 522 (11.0%) met post enrollment exclusion criteria. Therefore, 2099 (49.6%) received iA-CPR and 2132 (50.4%) M-CPR. Sustained ROSC (emergency department admittance), 24 h survival and hospital discharge (unknown for 12 cases) for iA-CPR compared to M-CPR were 600 (28.6%) vs. 689 (32.3%), 456 (21.8%) vs. 532 (25.0%), 196 (9.4%) vs. 233 (11.0%) patients, respectively. The adjusted odds ratio of survival to hospital discharge for iA-CPR compared to M-CPR, was 1.06 (95% CI 0.83-1.37), meeting the criteria for equivalence. The 20 min CPR fraction was 80.4% for iA-CPR and 80.2% for M-CPR. Conclusion: Compared to high-quality M-CPR, iA-CPR resulted in statistically equivalent survival to hospital discharge

    Prevalence and correlates of gout in a large cohort of patients with chronic kidney disease: the German Chronic Kidney Disease (GCKD) study

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    Background: Reduced kidney function is a risk factor for hyperuricaemia and gout, but limited information on the burden of gout is available from studies of patients with chronic kidney disease (CKD). We therefore examined the prevalence and correlates of gout in the large prospective observational German Chronic Kidney Disease (GCKD) study. Methods: Data from 5085 CKD patients aged 18–74 years with an estimated glomerular filtration rate (eGFR) of 30–<60 mL/min/1.73 m2 or eGFR ≥60 and overt proteinuria at recruitment and non-missing values for self-reported gout, medications and urate measurements from a central laboratory were evaluated. Results: The overall prevalence of gout was 24.3%, and increased from 16.0% in those with eGFR ≥60 mL/min/1.73 m2 to 35.6% in those with eGFR <30. Of those with self-reported gout, 30.7% of individuals were not currently taking any gout medication and among gout patients on urate lowering therapy, 47.2% still showed hyperuricaemia. Factors associated with gout were serum urate, lower eGFR, advanced age, male sex, higher body mass index and waist-to-hip ratio, higher triglyceride and C-reactive protein (CRP) concentrations, alcohol intake and diuretics use. While lower eGFR categories showed significant associations with gout in multivariable-adjusted models (prevalence ratio 1.46 for eGFR <30 compared with eGFR ≥60, 95% confidence interval 1.21–1.77), associations between gout and higher urinary albumin-to-creatinine ratio in this CKD population were not significant. Conclusions: Self-reported gout is common among patients with CKD and lower GFR is strongly associated with gout. Pharmacological management of gout in patients with CKD is suboptimal. Prospective follow-up will show whether gout and hyperuricaemia increase the risk of CKD progression and cardiovascular events in the GCKD study

    Glycaemic control and antidiabetic therapy in patients with diabetes mellitus and chronic kidney disease - cross-sectional data from the German Chronic Kidney Disease (GCKD) cohort

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    Genetic risk variants for membranous nephropathy: extension of and association with other chronic kidney disease aetiologies

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