6631期

最新文章

• Asymmetric counteranion-directed photoredox catalysis AI翻译
  作者：Das, Sayantani; Zhu, Chendan; Demirbas, Derya; Bill, Eckhard; De, Chandra Kanta; List, Benjamin
  作者单位：Max Planck Society; Max Planck Society
  摘要：Photoredox catalysis enables distinctive and broadly applicable chemical reactions, but controlling their selectivity has proven to be difficult. The pursuit of enantioselectivity is a particularly daunting challenge, arguably because of the high energy of the activated radical (ion) intermediates, and previous approaches have invariably required pairing of the photoredox catalytic cycle with an additional activation mode for asymmetric induction. A potential solution for photoredox reactions ...
• As some postdocs' pay rises, funding fears grow Salary mandates in California and Washington leave many lab heads scrambling AI翻译
  作者：Langin, Katie
• Reports of Long Covid wane AI翻译
  作者：[Anonymous]
• NIH oversight of EcoHealth grant rapped AI翻译
  作者：Brainard, Jeffrey
  摘要：A federal watchdog has found the U.S. National Institutes of Health (NIH) did not properly oversee a grant to the EcoHealth Alliance, a New York City-based nonprofit that funded work at the Wuhan Institute of Virology (WIV) in China. In 2020, then-President Donald Trump claimed SARS-CoV-2 could have come from the WIV lab, an idea that many scientists continue to say lacks evidence. Soon after, NIH terminated the EcoHealth grant, which had provided $600,000 to WIV. The 18-month-long audit by th...
• Suppressing feedback signals to visual cortex abolishes attentional modulation AI翻译
  作者：Debes, Samantha R.; Dragoi, Valentin
  作者单位：University of Texas System; University of Texas Health Science Center Houston; Rice University
  摘要：Attention improves perception by enhancing the neural encoding of sensory information. A long-standing hypothesis is that cortical feedback projections carry top-down signals to influence sensory coding. However, this hypothesis has never been tested to establish causal links. We used viral tools to label feedback connections from cortical area V4 targeting early visual cortex (area V1). While monkeys performed a visual-spatial attention task, inactivating feedback axonal terminals in V1 witho...
• Neanderthals lived in groups big enough to eat giant elephants Meat from the butchered beasts would have fed hundreds AI翻译
  作者：Curry, Andrew
• Arid lands, imperial ambitions Desert knowledge exchange cloaked imperial goals, argues a political geographer AI翻译
  作者：Karimi, Pamela
• Revolt against educational rankings AI翻译
  作者：Thorp, H. Holden
  作者单位：Washington University (WUSTL); Washington University (WUSTL)
• The mechanics of plant morphogenesis AI翻译
  作者：Coen, Enrico; Cosgrove, Daniel J.
  作者单位：UK Research & Innovation (UKRI); Biotechnology and Biological Sciences Research Council (BBSRC); John Innes Center; Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park
• Single-carbon atom transfer to a,b-unsaturated amides from N-heterocyclic carbenes AI翻译
  作者：Kamitani, Miharu; Nakayasu, Bunta; Fujimoto, Hayato; Yasui, Kosuke; Kodama, Takuya; Tobisu, Mamoru
  作者单位：University of Osaka; University of Osaka
  摘要：Single-carbon atom transfer reactions are lacking in organic synthesis, partly because of the absence of atomic carbon sources under standard solution-phase conditions. We report here that N-heterocyclic carbenes can serve as atomic carbon donors through the loss of a 1,2-diimine moiety. This strategy is applicable to single-carbon atom transfer to a,b-unsaturated amides, which can be converted into homologated g-lactams through the formation of four single bonds to one carbon center in one op...