Proceedings of the National Academy of Sciences of the United States of America

最新文章

• Homologous mutations in human β, embryonic, and perinatal muscle myosins have divergent effects on molecular power generation AI翻译
  作者：Liu, Chao; Karabina, Anastasia; Meller, Artur; Bhattacharjee, Ayan; Agostino, Colby J.; Bowman, Greg R.; Ruppel, Kathleen M.; Spudich, James A.; Leinwand, Leslie A.
  作者单位：Stanford University; Stanford University; United States Department of Energy (DOE); Lawrence Livermore National Laboratory; University of Colorado System; University of Colorado Boulder; University of Colorado System; University of Colorado Boulder; Washington University (WUSTL); Washington University (WUSTL); University of Pennsylvania
  摘要：Mutations at a highly conserved homologous residue in three closely related muscle myosins cause three distinct diseases involving muscle defects: R671C in beta- cardiac myosin causes hypertrophic cardiomyopathy, R672C and R672H in embryonic skeletal myosin cause Freeman-Sheldon syndrome, and R674Q in perinatal skeletal myosin causes trismus- pseudocamptodactyly syndrome. It is not known whether their effects at the molecular level are similar to one another or correlate with disease phenotype...
• Polytypic species concept and subspecies in the genomic era AI翻译
  作者：Lukhtanov, Vladimir A.
  作者单位：Russian Academy of Sciences; Zoological Institute of the Russian Academy of Sciences
• Dark and Dronc activation in Drosophila melanogaster AI翻译
  作者：Tian, Lu; Li, Yini; Shi, Yigong
  作者单位：Tsinghua University; Westlake Laboratory; Westlake University; Westlake University; Westlake University
  摘要：The onset of apoptosis is characterized by a cascade of caspase activation, where initiator caspases are activated by a multimeric adaptor complex known as the apoptosome. In Drosophila melanogaster, the initiator caspase Dronc undergoes autocatalytic activation in the presence of the Dark apoptosome. Despite rigorous investigations, the activation mechanism for Dronc remains elusive. Here, we report the cryo- EM structures of an auto- inhibited Dark monomer and a single- layered, multimeric D...
• Centimeter- sized diamond composites with high electrical conductivity and hardness AI翻译
  作者：Yang, Xigui; Zang, Jinhao; Zhao, Xingju; Ren, Xiaoyan; Ma, Shuailing; Zhang, Zhuangfei; Zhang, Yuewen; Li, Xing; Cheng, Shaobo; Li, Shunfang; Liu, Bingbing; Shan, Chongxin
  作者单位：Zhengzhou University; Henan Academy of Sciences; Ningbo University; Jilin University
  摘要：Achieving high- performance materials with superior mechanical properties and electrical conductivity, especially in large - sized bulk forms, has always been the goal. However, it remains a grand challenge due to the inherent trade - off between these properties. Herein, by employing nanodiamonds as precursors, centimeter - sized diamond/graphene composites were synthesized under moderate pressure and temperature conditions (12 GPa and 1,300 to 1,500 degrees C celsius), and the composites con...
• Diverse cytomegalovirus US11 antagonism and MHC- A evasion strategies reveal a tit- for- tat coevolutionary arms race in hominids AI翻译
  作者：Zimmermann, Cosima; Watson, Gabrielle M.; Bauersfeld, Liane; Berry, Richard; Ciblis, Barbara; Lan, Huan; Gerke, Carolin; Oberhardt, Valerie; Fuchs, Jonas; Hofmann, Maike; Freund, Christian; Rossjohn, Jamie; Momburg, Frank; Hengel, Hartmut; Halenius, Anne
  作者单位：University of Freiburg; Monash University; Monash University; Free University of Berlin; University of Freiburg; University of Freiburg; Cardiff University; Helmholtz Association; German Cancer Research Center (DKFZ)
  摘要：Recurrent, ancient arms races between viruses and hosts have shaped both host immu-nological defense strategies as well as viral countermeasures. One such battle is waged by the glycoprotein US11 encoded by the persisting human cytomegalovirus. US11 mediates degradation of major histocompatibility class I (MHC- I) molecules to prevent CD8+ T- cell activation. Here, we studied the consequences of the arms race between US11 and primate MHC- A proteins, leading us to uncover a tit-for-tat coevolu...
• Measuring long-term exposure to wildfire PM2.5 in California: Time-varying inequities in environmental burden AI翻译
  作者：Casey, Joan A.; Kioumourtzoglou, Marianthi-Anna; Padula, Amy; Gonzalez, David J. X.; Elser, Holly; Aguilera, Rosana; Northrop, Alexander J.; Tartof, Sara Y.; Mayeda, Elizabeth Rose; Braun, Danielle; Dominici, Francesca; Eisen, Ellen A.; Morello-Frosch, Rachel; Benmarhnia, Tarik
  作者单位：Columbia University; University of Washington; University of Washington Seattle; University of California System; University of California San Francisco; University of California System; University of California Berkeley; University of California System; University of California Berkeley; University of Pennsylvania; University of California System; University of California San Diego; Scripps Institution of Oceanography; Columbia University; Kaiser Permanente; University of California System; University of California Los Angeles; Harvard University; Harvard T.H. Chan School of Public Health; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute
  摘要：Wildfires have become more frequent and intense due to climate change and outdoor wildfire fine particulate matter (PM2.5) concentrations differ from relatively smoothly varying total PM2.5. Thus, we introduced a conceptual model for computing long-term wildfire PM2.5 and assessed disproportionate exposures among marginalized communities. We used monitoring data and statistical techniques to characterize annual wildfire PM2.5 exposure based on intermittent and extreme daily wildfire PM2.5 conc...
• Adaptive nonequilibrium design of actin-based metamaterials: Fundamental and practical limits of control AI翻译
  作者：Chennakesavalu, Shriram; Manikandan, Sreekanth K.; Hu, Frank; Rotskoff, Grant M.
  作者单位：Stanford University; Stanford University
  摘要：The adaptive and surprising emergent properties of biological materials self -assembled in far -from -equilibrium environments serve as an inspiration for efforts to design nanomaterials. In particular, controlling the conditions of self -assembly can modulate material properties, but there is no systematic understanding of either how to parameterize external control or how controllable a given material can be. Here, we demonstrate that branched actin networks can be encoded with metamaterial ...
• Link prediction using low-dimensional node embeddings: The measurement problem AI翻译
  作者：Menand, Nicolas; Seshadhri, C.
  作者单位：University of Pennsylvania; University of California System; University of California Santa Cruz
  摘要：Graph representation learning is a fundamental technique for machine learning (ML) success in link prediction. On closer investigation, we observe that the performance is measured by the AUC (area under the curve), which suffers biases. Since the ground truth in link prediction is sparse, we design a vertex-centric measure of performance, called the VCMPR@k plots. Under this measure, we show that link predictors using graph representations show poor scores. Despite having extremely high AUC sc...
• Evolution and diversification of carboxylesterase- like [4+2] cyclases in aspidosperma and iboga alkaloid biosynthesis AI翻译
  作者：Demars, Matthew D.; O'Connor, Sarah E.
  作者单位：Max Planck Society
  摘要：Monoterpene indole alkaloids (MIAs) are a large and diverse class of plant natural products, and their biosynthetic construction has been a subject of intensive study for many years. The enzymatic basis for the production of aspidosperma and iboga alkaloids, which are produced exclusively by members of the Apocynaceae plant family, has recently been discovered. Three carboxylesterase (CXE)-like enzymes from Catharanthus roseus and Tabernanthe iboga catalyze regio- and enantiodivergent [4+2] cy...
• Quantum interference in superposed lattices AI翻译
  作者：Feng, Yejun; Wang, Yishu; Rosenbaum, T. F.; Littlewood, P. B.; Chen, Hua
  作者单位：Okinawa Institute of Science & Technology Graduate University; University of Tennessee System; University of Tennessee Knoxville; University of Tennessee System; University of Tennessee Knoxville; California Institute of Technology; University of Chicago; University of Chicago; University of St Andrews; Colorado State University System; Colorado State University Fort Collins
  摘要：Charge transport in solids at low temperature reveals a material's mesoscopic properties and structure. Under a magnetic field, Shubnikov-de Haas (SdH) oscillations inform complex quantum transport phenomena that are not limited by the ground state characteristics and have facilitated extensive explorations of quantum and topological interest in two- and three-dimensional materials. Here, in elemental metal Cr with two incommensurately superposed lattices of ions and a spin-density-wave ground...