46期

最新文章

• Aerodynamic efficiency explains flapping strategies used by birds AI翻译
  作者：Johansson, L. Christoffer
  作者单位：Lund University
  摘要：A faster cruising speed increases drag and thereby the thrust (T) needed to fly, while weight and lift (L) requirement remains constant. Birds can adjust their wingbeat in multiple ways to accommodate this change in aerodynamic force, but the relative costs of different strategies remain largely unknown. To evaluate the efficiency of several kinematic strategies, I used a robotic wing [E. Ajanic, A. Paolini, C. Coster, D. Floreano, C. Johansson, Adv. Intell. Syst. 5 , 2200148 (2023)] and quant...
• Iron- molybdenum cofactor synthesis by a thermophilic nitrogenase devoid of the scaffold NifEN AI翻译
  作者：Paya-Tormo, Lucia; Echavarri-Erasun, Carlos; Makarovsky-Saavedra, Natalia; Perez-Gonzalez, Ana; Yang, Zhi-Yong; Guo, Yisong; Seefeldt, Lance C.; Rubio, Luis M.
  作者单位：Universidad Politecnica de Madrid; Consejo Superior de Investigaciones Cientificas (CSIC); Instituto Nacional Investigacion Tecnologia Agraria Alimentaria (INIA); Universidad Politecnica de Madrid; Utah System of Higher Education; Utah State University; Carnegie Mellon University
  摘要：The maturation and installation of the active site metal cluster (FeMo-co, Fe7S9CMo-R-homocitrate) in Mo-dependent nitrogenase requires the protein product of the nifB gene for production of the FeS cluster precursor (NifB-co, [Fe8S9C]) and the action of the maturase complex composed of the protein products from the nifE and nifN genes. However, some putative diazotrophic bacteria, like Roseiflexus sp. RS-1, lack the nifEN genes, suggesting an alternative pathway for maturation of FeMo-co that...
• Christopher Columbus' flu was different to ours AI翻译
  作者：Uzoigwe, Chika Edward
• Spin-orbit enabled unconventional Stoner magnetism AI翻译
  作者：Yu, Yue; Shishidou, Tatsuya; Sumita, Shuntaro; Weinert, Michael; Agterberg, Daniel F.
  作者单位：University of Wisconsin System; University of Wisconsin Milwaukee; University of Tokyo; University of Tokyo; RIKEN
  摘要：The Stoner instability remains a cornerstone for understanding metallic ferromagnets. This instability captures the interplay of Coulomb repulsion, Pauli exclusion, and twofold fermionic spin degeneracy. In materials with spin-orbit coupling, this fermionic spin is generalized to a twofold degenerate pseudospin which is typically believed to have symmetry properties as spin. Here, we identify a distinct symmetry of this pseudospin that forbids it to couple to a Zeeman field. This spinless prop...
• Characterization of the enzyme for 5-hydroxymethyluridine production and its role in silencing transposable elements in dinoflagellates AI翻译
  作者：Li, Chongping; Li, Ying; Wang, Yuci; Meng, Xiangrui; Shi, Xiaoyan; Zhang, Yangyi; Liang, Nan; Huang, Hongda; Li, Yue; Zhou, Hui; Xu, Jiawei; Xu, Wenqi; Chen, Hao
  作者单位：Zhengzhou University; Henan Academy of Innovations in Medical Science; Southern University of Science & Technology; Southern University of Science & Technology; Fudan University
  摘要：Dinoflagellate chromosomes are extraordinary, as their organization is independent of architectural nucleosomes unlike typical eukaryotes and shows a cholesteric liquid crystal state. 5- hydroxymethyluridine (5hmU) is present at unusually high levels and its function remains an enigma in dinoflagellates chromosomal DNA for several decades. Here, we demonstrate that 5hmU contents vary among different dinoflagellates and are generated through thymidine hydroxylation. Importantly, we identified t...
• Genomic perspectives on foodborne illness AI翻译
  作者：Lipman, David J.; Cherry, Joshua L.; Strain, Errol; Agarwala, Richa; Musser, Steven M.
  作者单位：US Food & Drug Administration (FDA); National Institutes of Health (NIH) - USA; NIH National Library of Medicine (NLM); National Institutes of Health (NIH) - USA; NIH Fogarty International Center (FIC)
  摘要：Whole- genome sequencing of bacterial pathogens is used by public health agencies to link cases of food poisoning caused by the same source of contamination. The vast majority of these appear to be sporadic cases associated with small contamination episodes and do not trigger investigations. A contamination episode refers to one or more contamination events from a single source over a period of time. We examine clusters of sequenced clinical isolates of Salmonella, Escherichia coli, Campylobac...
• VEGF inhibition increases expression of HIF- regulated angiogenic genes by the RPE limiting the response of wet AMD eyes to aflibercept AI翻译
  作者：Sharma, Deepti; Lau, Evan; Qin, Yu; Jee, Kathleen; Rodrigues, Murilo; Guo, Chuanyu; Dinabandhu, Aumreetam; Mcintyre, Emma; Salman, Shaima; Hwang, Yousang; Moshiri, Ala; Semenza, Gregg L.; Montaner, Silvia; Sodhi, Akrit
  作者单位：Johns Hopkins University; Johns Hopkins Medicine; China Medical University; University System of Maryland; University of Maryland Baltimore; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; Johns Hopkins University; University of California System; University of California Davis
  摘要：Neovascular age- related macular degeneration (nvAMD) is the leading cause of severe vision loss in the elderly in the developed world. While the introduction of therapies targeting vascular endothelial growth factor (VEGF) has provided the first opportunity to significantly improve vision in patients with nvAMD, many patients respond inadequately to current anti-VEGF therapies. It was recently demonstrated that expression of a second angiogenic mediator, angiopoietin-like 4 (ANGPTL4), synergi...
• Profile of Catherine Drennan AI翻译
  作者：Viegas, Jennifer
• Analysis of the structure and interactions of the SARS-CoV-2 ORF7b accessory protein AI翻译
  作者：Ha Nguyen, Minh-; Palfy, Gyula; Fogeron, Marie-Laure; Pedrosa, Marti Ninot; Zehnder, Johannes; Rimal, Vaclav; Callon, Morgane; Lecoq, Lauriane; Barnes, Alexander; Meier, Beat H.; Bockmann, Anja
  作者单位：Universite Claude Bernard Lyon 1; Centre National de la Recherche Scientifique (CNRS)
  摘要：SARS-CoV-2 carries a sizeable number of proteins that are accessory to replication but may be essential for virus-host interactions and modulation of the host immune response. Here, we investigated the structure and interactions of the largely unknown ORF7b, a small membranous accessory membrane protein of SARS- CoV-2. We show that structural predictions indicate a transmembrane (TM) leucine zipper for ORF7b, and experimentally confirm the predominantly alpha- helical secondary structure withi...
• Opportunities for carbon sequestration from removing or intensifying pasture- based beef production AI翻译
  作者：Hayek, Matthew N.; Piipponen, Johannes; Kummu, Matti; Sahlin, Kajsa Resare; McClelland, Shelby C.; Carlson, Kimberly
  作者单位：New York University; Aalto University; Stockholm University; Cornell University
  摘要：Pastures, on which ruminant livestock graze, occupy one third of the earth's surface. Removing livestock from pastures can support climate change mitigation through carbon sequestration in regrowing vegetation and recovering soils, particularly in potentially forested areas. However, this would also decrease food and fiber production, generating a tradeoff with pasture productivity and the ruminant meat production pastures support. We evaluate the magnitude and distribution of this tradeoff gl...