15 research outputs found
Efficient and Practical Transfer Hydrogenation of Ketones Catalyzed by a Simple Bidentate MnâNHC Complex
Catalytic reductions of carbonylâcontaining compounds are highly important for the safe, sustainable, and economical production of alcohols. Herein, we report on the efficient transfer hydrogenation of ketones catalyzed by a highly potent Mn(I)âNHC complex. MnâNHC 1 is practical at metal concentrations as low as 75â
ppm, thus approaching loadings more conventionally reserved for noble metal based systems. With these low Mn concentrations, catalyst deactivation is found to be highly temperature dependent and becomes especially prominent at increased reaction temperature. Ultimately, understanding of deactivation pathways could help close the activity/stabilityâgap with Ru and Ir catalysts towards the practical implementation of sustainable earthâabundant Mnâcomplexes
Donepezil Impairs Memory in Healthy Older Subjects: Behavioural, EEG and Simultaneous EEG/fMRI Biomarkers
Rising life expectancies coupled with an increasing awareness of age-related cognitive decline have led to the unwarranted use of psychopharmaceuticals, including acetylcholinesterase inhibitors (AChEIs), by significant numbers of healthy older individuals. This trend has developed despite very limited data regarding the effectiveness of such drugs on non-clinical groups and recent work indicates that AChEIs can have negative cognitive effects in healthy populations. For the first time, we use a combination of EEG and simultaneous EEG/fMRI to examine the effects of a commonly prescribed AChEI (donepezil) on cognition in healthy older participants. The short- and long-term impact of donepezil was assessed using two double-blind, placebo-controlled trials. In both cases, we utilised cognitive (paired associates learning (CPAL)) and electrophysiological measures (resting EEG power) that have demonstrated high-sensitivity to age-related cognitive decline. Experiment 1 tested the effects of 5 mg/per day dosage on cognitive and EEG markers at 6-hour, 2-week and 4-week follow-ups. In experiment 2, the same markers were further scrutinised using simultaneous EEG/fMRI after a single 5 mg dose. Experiment 1 found significant negative effects of donepezil on CPAL and resting Alpha and Beta band power. Experiment 2 replicated these results and found additional drug-related increases in the Delta band. EEG/fMRI analyses revealed that these oscillatory differences were associated with activity differences in the left hippocampus (Delta), right frontal-parietal network (Alpha), and default-mode network (Beta). We demonstrate the utility of simple cognitive and EEG measures in evaluating drug responses after acute and chronic donepezil administration. The presentation of previously established markers of age-related cognitive decline indicates that AChEIs can impair cognitive function in healthy older individuals. To our knowledge this is the first study to identify the precise neuroanatomical origins of EEG drug markers using simultaneous EEG/fMRI. The results of this study may be useful for evaluating novel drugs for cognitive enhancement
QUAREP-LiMi:A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy
Adapting cities to climate Change : a systemic modelling approach
International audienceTo answer the climate change challenge, all states have to reduce their greenhouse gas emissions, but also to adopt adaptation measures to limit the negative impacts of global warming on the population, the economy and the environment. The question arises especially for cities.Because of complex interactions between climate change, the evolution of cities and its inhabitants, studying adaptation strategies for cities requires a strong interdisciplinary approach: urban planners, architects, meteorologists, building engineers, economists, social sciences.Our four-step methodology consists firstly of defining interdisciplinary scenarios at several scales influencing the city evolution; secondly of simulating long term city evolution based on socio-economic and land-use models; thirdly of calculating impacts with physical models, and finally of calculating the indicators quantifying the adaptation strategies.Interdisciplinary systemic modelling performs well to evaluate several adaptation strategies for a very broad range of topics. Some of the results obtained for the agglomeration of Paris through our interdisciplinary research projects VURCA and MUSCADE will be discussed:A finding is that Urban planning strategies may have unexpected influence on city expansion when considered on the very long term of the climate change. Another is that the combine effect of global warming and UHI can lead in the future to larger energy consumption in summer than in winter.Indeed, air-conditioning will probably be necessary in 2100, because of expected stronger, and longer, heat waves. Limiting the UHI intensity allows for energy savings, and hence contributes to climate change mitigation. Adaptation strategies exist to limit air-conditioning use, both in time and intensity.Analysis of several vegetation strategies, at several spatial and planning scales (from agricultural practices in the city surroundings to urban trees and green-roofs) have been performed and evaluated. Architectural choices also allow to reduce the UHI. Finally, inhabitants' use and practices seem to be an efficient lever to reduce energy consumption in buildings and its impact on the urban climate
Sufi, Reformist and National Models of Identity: The History of a Muslim Village Festival in Sri Lanka
Beyond school: transnational differentiation and the shifting form of education in world society
Effect of evolocumab or ezetimibe added to moderate- or high-intensity statin therapy on LDL-C lowering in patients with hypercholesterolemia: the LAPLACE-2 randomized clinical trial.
Importance In phase 2 studies, evolocumab, a fully human monoclonal antibody to PCSK9, reduced LDL-C levels in patients receiving statin therapy.
Objective To evaluate the efficacy and tolerability of evolocumab when used in combination with a moderate- vs high-intensity statin.
Design, Setting, and Patients Phase 3, 12-week, randomized, double-blind, placebo- and ezetimibe-controlled study conducted between January and December of 2013 in patients with primary hypercholesterolemia and mixed dyslipidemia at 198 sites in 17 countries.
Interventions Patients (nâ=â2067) were randomized to 1 of 24 treatment groups in 2 steps. Patients were initially randomized to a daily, moderate-intensity (atorvastatin [10 mg], simvastatin [40 mg], or rosuvastatin [5 mg]) or high-intensity (atorvastatin [80 mg], rosuvastatin [40 mg]) statin. After a 4-week lipid-stabilization period, patients (nâ=â1899) were randomized to compare evolocumab (140 mg every 2 weeks or 420 mg monthly) with placebo (every 2 weeks or monthly) or ezetimibe (10 mg or placebo daily; atorvastatin patients only) when added to statin therapies.
Main Outcomes and Measures Percent change from baseline in low-density lipoprotein cholesterol (LDL-C) level at the mean of weeks 10 and 12 and at week 12.
Results Evolocumab reduced LDL-C levels by 66% (95% CI, 58% to 73%) to 75% (95% CI, 65% to 84%) (every 2 weeks) and by 63% (95% CI, 54% to 71%) to 75% (95% CI, 67% to 83%) (monthly) vs placebo at the mean of weeks 10 and 12 in the moderate- and high-intensity statin-treated groups; the LDL-C reductions at week 12 were comparable. For moderate-intensity statin groups, evolocumab every 2 weeks reduced LDL-C from a baseline mean of 115 to 124 mg/dL to an on-treatment mean of 39 to 49 mg/dL; monthly evolocumab reduced LDL-C from a baseline mean of 123 to 126 mg/dL to an on-treatment mean of 43 to 48 mg/dL. For high-intensity statin groups, evolocumab every 2 weeks reduced LDL-C from a baseline mean of 89 to 94 mg/dL to an on-treatment mean of 35 to 38 mg/dL; monthly evolocumab reduced LDL-C from a baseline mean of 89 to 94 mg/dL to an on-treatment mean of 33 to 35 mg/dL. Adverse events were reported in 36%, 40%, and 39% of evolocumab-, ezetimibe-, and placebo-treated patients, respectively. The most common adverse events in evolocumab-treated patients were back pain, arthralgia, headache, muscle spasms, and pain in extremity (all <2%).
Conclusions and Relevance In this 12-week trial conducted among patients with primary hypercholesterolemia and mixed dyslipidemia, evolocumab added to moderate- or high-intensity statin therapy resulted in additional LDL-C lowering. Further studies are needed to evaluate the longer-term clinical outcomes and safety of this approach for LDL-C lowering.
Trial Registration clinicaltrials.gov Identifier: NCT0176386
QUAREP-LiMi: A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy
A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated , quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist's experiments, while more than half have even failed to reproduce their own experiments. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g. DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common standards and guidelines for quality assessment and reproducibility. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models and tools, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper (1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; (2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of stakeholders including, researchers, imaging scientists, bioimage analysts, bioimage informatics developers, corporate partners, funding agencies, standards organizations, scientific publishers and observers of such; (3) outlines the current actions of the QUAREP-LiMi initiative and (4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics