51期

最新文章

• Two distinct populations of dark comets delineated by orbits and sizes AI翻译
  作者：Seligman, Darryl Z.; Farnocchia, Davide; Micheli, Marco; Hainaut, Olivier R.; Hsieh, Henry H.; Feinstein, Adina D.; Chesley, Steven R.; Taylor, Aster G.; Masiero, Joseph; Meech, Karen J.
  作者单位：Michigan State University; Cornell University; Cornell University; California Institute of Technology; National Aeronautics & Space Administration (NASA); NASA Jet Propulsion Laboratory (JPL); European Space Agency; European Southern Observatory; University of Colorado System; University of Colorado Boulder; University of Michigan System; University of Michigan; California Institute of Technology; University of Hawaii System
  摘要：Small bodies are capable of delivering essential prerequisites for the development of life, such as volatiles and organics, to the terrestrial planets. For example, empirical evidence suggests that water was delivered to the Earth by hydrated planetesimals from distant regions of the Solar System . Recently, several morphologically inactive near- Earth objects were reported to experience significant nongravitational accelerations inconsistent with radiation-based effects, and possibly explaine...
• A self- learning magnetic Hopfield neural network with intrinsic gradient descent adaption AI翻译
  作者：Niu, Chang; Zhang, Huanyu; Xu, Chuanlong; Hu, Wenjie; Wu, Yunzhuo; Wu, Yu; Wang, Yadi; Wu, Tong; Zhu, Yi; Zhu, Yinyan; Wang, Wenbin; Wu, Yizheng; Yin, Lifeng; Xiao, Jiang; Yu, Weichao; Guo, Hangwen; Shen, Jian
  作者单位：Fudan University; Fudan University; Fudan University; Hefei National Laboratory; Collaborative Innovation Center of Advanced Microstructures (CICAM)
  摘要：Physical neural networks (PNN) using physical materials and devices to mimic synapses and neurons offer an energy- efficient way to implement artificial neural networks. Yet, training PNN is difficult and heavily relies on external computing resources. An emerging concept to solve this issue is called physical self- learning that uses intrinsic physical parameters as trainable weights. Under external inputs (i.e., training data), training is achieved by the natural evolution of physical parame...
• The shard test and nanoporomechanics reverse classical paradigm of cement hydration being contractive AI翻译
  作者：Rosa, Raul E. Marrero; Bhibho, Tapiwanashe; Donmez, Ahmet A.; Cusatis, Gianluca; Bazant, Zdenek P.
  作者单位：Northwestern University
  摘要：Le Chatelier in 1887 and Powers in 1947 demonstrated that the volume of nanoscale C-S-H (calcium silicate hydrate) particles formed during hydration is smaller than the combined volume of the reactants-the anhydrous Portland cement and water. Hydration has thus been considered as contractive. An experiment shows that the opposite is true above the nanoscale. The porous skeleton of cement paste expands as the growing C-S-H particles push each other apart, similar to crystal growth pressure. Thi...
• Molecular basis of lipid and ligand regulation of prostaglandin receptor DP2 AI翻译
  作者：Xu, Jiuyin; Xu, Youwei; Hou, Li; He, Xinheng; Li, Yang; Zhao, Jing; Meng, Xue; Wang, James Jiqi; Wu, Yanli; Zhang, Heng; Li, Yunhai; Hu, Wen; Yuan, Qingning; Wu, Kai; Cheng, Xi; Jiang, Yi; Xia, Yu; Xu, H. Eric; Wu, Canrong
  作者单位：Chinese Academy of Sciences; Shanghai Institute of Materia Medica, CAS; ShanghaiTech University; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Nanjing University of Chinese Medicine; Tsinghua University; Huazhong University of Science & Technology; Xiamen University; Chinese Academy of Sciences; Shanghai Jiao Tong University; Lingang Laboratory
  摘要：Prostaglandin D2 receptor 2 (DP2) is an important anti- inflammatory and antiallergic drug target. While inactive DP2 structures are known, its activation mechanisms and biased signaling remain unclear. Here, we report cryo-EM structures of an apo DP2-Gi complex, a DP2-Gi complex bound to the endogenous ligand Prostaglandin D2 (PGD2), and a DP2-Gi complex bound to indomethacin, an arrestin- biased ligand, at resolutions of 2.5 & Aring;, 2.8 & Aring;, and 2.3 & Aring;, respectively. These struc...
• Structural stability and thermodynamics of artistic composition AI翻译
  作者：Chan, San To; Fried, Eliot
  作者单位：Okinawa Institute of Science & Technology Graduate University
  摘要：Inspired by the way that digital artists zoom out of the canvas to assess the visual impact of their works, we introduce a conceptually simple yet effective metric for quantifying the clarity of digital images. This metric contrasts original images with progressively melted counterparts, produced by randomly flipping adjacent pixel pairs. It measures the presence of stable structures, assigning the value zero to completely uniform or random images and finite values for those with discernible p...
• Large-scale CRISPR/Cas9 deletions within the WFDC gene cluster uncover gene functionality and critical roles in mammalian reproduction AI翻译
  作者：Kent, Katarzyna; Nozawa, Kaori; Parkes, Rachel; Dean, Laura; Daniel, Frey; Leng, Mei; Jain, Antrix; Malovannaya, Anna; Matzuk, Martin M.; Garcia, Thomas X.
  作者单位：Baylor College of Medicine; Baylor College of Medicine; Baylor College of Medicine; Baylor College of Medicine; Baylor College of Medicine; Baylor College of Medicine
  摘要：Despite 96 million years of evolution separating humans and rodents, 11 closely related the 13 reproductive tract- specific orthologous genes in mice, form highly conserved syntenic gene clusters indicative of conserved, combined critical functions. Further, despite significant progress toward a nonhormonal male contraceptive targeting the protein encoded by one of these genes, epididymal peptidase inhibitor (EPPIN), and associations found between mutations in EPPIN and an increased risk of ma...
• Modeling protein motions through reinforcement learning AI翻译
  作者：Ghafarollahi, Alireza; Buehler, Markus J.
  作者单位：Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT); Massachusetts Institute of Technology (MIT)
• Some coral reef communities may degrade and change but persist AI翻译
  作者：Knowlton, Nancy
  作者单位：Smithsonian Institution; Smithsonian National Museum of Natural History
• E93 controls adult differentiation by repressing broad in Drosophila AI翻译
  作者：Cruz, Josefa; Urena, Enric; Iniguez, Luis P.; Irimia, Manuel; Franch-Marro, Xavier; Martin, David
  作者单位：Pompeu Fabra University; Consejo Superior de Investigaciones Cientificas (CSIC); CSIC-UPF - Institut de Biologia Evolutiva (IBE); Barcelona Institute of Science & Technology; Pompeu Fabra University; Centre de Regulacio Genomica (CRG); Pompeu Fabra University; ICREA; University of London; University College London
  摘要：In Drosophila melanogaster, successful development relies on the precise coordination of both spatial and temporal regulatory axes. The temporal axis governs stage- specific identity and developmental transitions through a number of genes, collectively forming the Metamorphic Gene Network. Among these, Ecdysone inducible protein 93F (E93) serves as the critical determinant for adult specification, but its mechanism of action remains unclear. Here, we found that, rather than acting mainly as an...
• Informing public health protection under new patterns of wildfire smoke AI翻译
  作者：Sacks, Jason D.
  作者单位：United States Environmental Protection Agency