245 research outputs found

    Recent Developments in Copper-Based Catalysts for Enhanced Electrochemical CO<sub>2</sub> Reduction

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    The drastic climate change imposing adverse environmental effects receives serious research attention for finding a suitable solution. The replacement of conventional fossil energy sources with renewable and sustainable energy sources is the potential route; and thus, manifests as a viable solution. Accordingly, the electrocatalytic carbon dioxide (CO2) reduction process coupled with the renewable energy source is an emerging strategy for adopting a sustainable approach. However, the existing challenges in designing suitable catalyst, support material, electrolyte, inadequate selectivity, and intermediate reactions of CO2 reduction demand substantial research advancement. Numerous studies reported for the CO2 reduction process highlight the importance of catalyst design and product selectivity. Importantly, the copper-based catalysts, capable in the output of multi-carbon products, are reported as a “star” material. This review; therefore, focuses on catalyst design strategies, unique structural/morphological features, and product selectivity of diverse copper-based catalysts. The outstanding findings of copper-based catalysts and the corresponding products are critically discussed with adequate figures of merits. The impact of structural/morphological features on product selectivity is discussed in detail. The future scope and author perspectives on copper-based catalysts for the feasible electrocatalytic CO2 reduction application are summarized.</p

    Feasibility of Using Ultra-High Field (7 T) MRI for Clinical Surgical Targeting

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    The advantages of ultra-high magnetic field (7 Tesla) MRI for basic science research and neuroscience applications have proven invaluable. Structural and functional MR images of the human brain acquired at 7 T exhibit rich information content with potential utility for clinical applications. However, (1) substantial increases in susceptibility artifacts, and (2) geometrical distortions at 7 T would be detrimental for stereotactic surgeries such as deep brain stimulation (DBS), which typically use 1.5 T images for surgical planning. Here, we explore whether these issues can be addressed, making feasible the use of 7 T MRI to guide surgical planning. Twelve patients with Parkinson's disease, candidates for DBS, were scanned on a standard clinical 1.5 T MRI and a 7 T MRI scanner. Qualitative and quantitative assessments of global and regional distortion were evaluated based on anatomical landmarks and transformation matrix values. Our analyses show that distances between identical landmarks on 1.5 T vs. 7 T, in the mid-brain region, were less than one voxel, indicating a successful co-registration between the 1.5 T and 7 T images under these specific imaging parameter sets. On regional analysis, the central part of the brain showed minimal distortion, while inferior and frontal areas exhibited larger distortion due to proximity to air-filled cavities. We conclude that 7 T MR images of the central brain regions have comparable distortions to that observed on a 1.5 T MRI, and that clinical applications targeting structures such as the STN, are feasible with information-rich 7 T imaging

    Mutation of the Zebrafish Nucleoporin elys Sensitizes Tissue Progenitors to Replication Stress

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    The recessive lethal mutation flotte lotte (flo) disrupts development of the zebrafish digestive system and other tissues. We show that flo encodes the ortholog of Mel-28/Elys, a highly conserved gene that has been shown to be required for nuclear integrity in worms and nuclear pore complex (NPC) assembly in amphibian and mammalian cells. Maternal elys expression sustains zebrafish flo mutants to larval stages when cells in proliferative tissues that lack nuclear pores undergo cell cycle arrest and apoptosis. p53 mutation rescues apoptosis in the flo retina and optic tectum, but not in the intestine, where the checkpoint kinase Chk2 is activated. Chk2 inhibition and replication stress induced by DNA synthesis inhibitors were lethal to flo larvae. By contrast, flo mutants were not sensitized to agents that cause DNA double strand breaks, thus showing that loss of Elys disrupts responses to selected replication inhibitors. Elys binds Mcm2-7 complexes derived from Xenopus egg extracts. Mutation of elys reduced chromatin binding of Mcm2, but not binding of Mcm3 or Mcm4 in the flo intestine. These in vivo data indicate a role for Elys in Mcm2-chromatin interactions. Furthermore, they support a recently proposed model in which replication origins licensed by excess Mcm2-7 are required for the survival of human cells exposed to replication stress
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