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Science,3 FEB 2023, VOLUME 379 ISSUE 6631

《自然科学》2023年2月3日，第379卷6631期

生物化学Chemistry

Computer-aided key step generation in alkaloid total synthesis

有效成分全制备中数字图像处理重要环节聚合

▲ 译者：YINGFU LIN, RUI ZHANG, DI WANG, AND TIM CERNAK

▲ 快照：

https://www.science.org/doi/10.1126/science.ade8459

▲ 全文：

高效率的生物化学制备对满足用户今后对抗生素、金属材料和化肥危险品的市场需求非常重要。数十年来，对适当繁杂大分子的反向制备预测已经同时实现了智能化。前段时间，潜在性女团方向的统计数据核爆对排序机应用软件和应用软件逐步形成了考验。

译者积极探索了一类排序思路，将数字图像处理制备总体规划与大分子图撰稿并重，以最大限度地增加制造有效成分所需的制备关键步骤。

▲ Abstract：

Efficient chemical synthesis is critical to satisfying future demands for medicines, materials, and agrochemicals. Retrosynthetic analysis of modestly complex molecules has been automated over the course of decades, but the combinatorial explosion of route possibilities has challenged computer hardware and software until only recently. Here, we explore a computational strategy that merges computer-aided synthesis planning with molecular graph editing to minimize the number of synthetic steps required to produce alkaloids.

Asymmetric counteranion-directed photoredox catalysis

不等距反阴离子或非效果显著还原成催化剂

▲ 译者：SAYANTANI DAS, CHENDAN ZHU, DERYA DEMIRBAS, ECKHARD BILL, CHANDRA KANTA DE, AND BENJAMIN

▲ 快照：

https://www.science.org/doi/10.1126/science.ade8190

▲ 全文：

效果显著还原成催化剂要借助光诱导的天然树脂和脯氨酸间的电子零件迁移来推动生物化学变化性。在脯氨酸与天然树脂不协同的情况下，掌控三维特异性可能将具备诱惑力。

译者报导了一类度三维优先选择的方式，将阴离子天然树脂与分子结构阴离子张佩佩。在天然树脂还原成后，阴离子与再生的脯氨酸张佩佩，在此种情况下，水解丙烯类似物可进行[2+2]环酮式，进而有助于三种潜在性快照乙醛中一类的逐步形成。

▲ Abstract：

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 proceeding via radical ions would be catalytic pairing with enantiopure counterions. However, although attempts toward this approach have been described, high selectivity has not yet been accomplished. Here we report a potentially general solution to radical cation–based asymmetric photoredox catalysis. We describe organic salts, featuring confined imidodiphosphorimidate counteranions that catalyze highly enantioselective [2+2]-cross cycloadditions of styrenes.

A room temperature rechargeable Li2O-based lithium-air battery enabled by a solid electrolyte

由固体电解质驱动的室温可充电锂空气电池

▲ 译者：ALIREZA KONDORI, MOHAMMADREZA ESMAEILIRAD, AND MOHAMMAD ASADI

▲ 快照：

https://www.science.org/doi/10.1126/science.abq1347

▲ 全文：

在能量密度方面，锂空气电池有能力与汽油电池竞争。然而，在大多数体系中，反应途径要么涉及一个或两个电子零件迁移，分别导致过水解锂（Li2O2）或超水解物锂（LiO2）。

译者研究了一类使用陶瓷-聚乙烯水解物基复合固体电解质的锂-空气电池，发现它可以通过锂水解物（Li2O）的逐步形成和分解进行四电子零件水解还原成反应。该复合电解质通过四电子零件迁移过程表现出较高的离子导电性和稳定性。

▲ Abstract：

Lithium-air batteries have scope to compete with gasoline in terms of energy density. However, in most systems, the reaction pathways either involve one- or two-electron transfer, leading to lithium peroxide (Li2O2) or lithium superoxide (LiO2), respectively. Kondori et al. investigated a lithium-air battery that uses a ceramic-polyethylene oxide–based composite solid electrolyte and found that it can undergo a four-electron redox reaction through lithium oxide (Li2O) formation and decomposition. The composite electrolyte embedded with Li10GeP2S12 nanoparticles shows high ionic conductivity and stability and high cycle stability through a four-electron transfer process.

地球物理学Geophysics

Smoke-weather interaction affects extreme wildfires in diverse coastal regions

烟-天气相互作用影响不同沿海地区的极端野火

▲ 译者：XIN HUANG, KE DING, JINGYI LIU, ZILIN WANG, RONG TANG, LIAN XUE, HAIKUN WANG, QIANG ZHANG, ZHE-MIN TAN, AND AIJUN DING

▲ 快照：

https://www.science.org/doi/10.1126/science.add9843

▲ 全文：

极端野火威胁着人类生命、空气质量和生态系统。译者展示了天气尺度反馈在地中海和美国西海岸和东南亚季风气候体系中对驱动极端火灾的首要作用。

他们发现，烟雾气溶胶的辐射效应可以改变近地表风、空气干燥和降雨，进而通过增强火焰排放以及削弱扩散加剧空气污染。野火、烟雾和天气间错综繁杂的相互作用逐步形成了一个正反馈循环，大大增加了空气污染的暴露。

▲ Abstract：

Extreme wildfires threaten human lives, air quality, and ecosystems. Here, we show the primacy of synoptic-scale feedback in driving extreme fires in Mediterranean and monsoon climate regimes in the West Coast of the United States and Southeastern Asia. We found that radiative effects of smoke aerosols can modify near-surface wind, air dryness, and rainfall and thus worsen air pollution by enhancing fire emissions and weakening dispersion. The intricate interactions among wildfires, smoke, and weather form a positive feedback loop that substantially increases air pollution exposure.

The magmatic web beneath Hawai‘i

夏威夷地表下的岩浆网

▲ 译者：JOHN D. WILDING, WEIQIANG ZHU, ZACHARY E. ROSS, AND JENNIFER M. JACKSON

▲ 快照：

https://www.science.org/doi/10.1126/science.ade5755

▲ 全文：

夏威夷岛是由著名的莫纳克亚火山、莫纳罗亚火山和基拉韦厄火山逐步形成的。目前最活跃的是基拉韦厄火山，但其他火山仍然可能将爆发。译者使用超过20万次地震事件，绘制出40公里深处流入这些火山的岩浆的几何形状。

岩浆逐步形成了连接基拉韦厄和莫纳罗亚火山的基岩综合体，并且有一些与莫纳克亚火山有关的证据。观测结果表明火山间有更大的地下联系，为岩浆运输提供了有趣的见解。

▲ Abstract：

The island of Hawai‘i is shaped by its well-known volcanoes, Mauna Kea, Mauna Loa, and Kīlauea. Although Kīlauea is currently by far the most active, the other volcanoes could still erupt as well. Wilding et al. used more than 200,000 seismic events to map out the geometry of the magma feeding into these volcanoes at a 40-kilometer depth (see the Perspective by Flinders). The magma forms a sill complex that connects Kīlauea and Mauna Loa, and there is some evidence of connection to Mauna Kea. The observations suggest far greater underground connections between the volcanoes and provide an interesting insight into magma transport.

物理学Physics

Medium-density amorphous ice

中密度非晶冰

▲ 译者：ALEXANDER ROSU-FINSEN, MICHAEL B. DAVIES, ALFRED AMON, HAN WU, ANDREA SELLA, ANGELOS MICHAELIDES, AND CHRISTOPH G. SALZMANN

▲ 快照：

https://www.science.org/doi/10.1126/science.abq2105

▲ 全文：

水冰有许多晶体相，还有一些无定形结构。繁杂的结构图对理解冰的重要性很重要。Rosu-Finsen等人发现了在低温下球磨六方冰逐步形成的中密度非晶冰。

其独特的密度和结构有助于将其确定为一类新形式的冰，进而提出了关于此种重要金属材料的稳定无定形结构的问题。

▲ Abstract：

Amorphous ices govern a range of cosmological processes and are potentially key materials for explaining the anomalies of liquid water. A substantial density gap between low-density and high-density amorphous ice with liquid water in the middle is a cornerstone of our current understanding of water. However, we show that ball milling “ordinary” ice Ih at low temperature gives a structurally distinct medium-density amorphous ice (MDA) within this density gap. These results raise the possibility that MDA is the true glassy state of liquid water or alternatively a heavily sheared crystalline state. Notably, the compression of MDA at low temperature leads to a sharp increase of its recrystallization enthalpy, highlighting that H2O can be a high-energy geophysical material.