【我和丈姆娘】《科学》(20260806出版)一周论文导读 出版尽管在当前市场条件下
内容摘要
编译|未玖物理学PhysicsLevitated sensor for magnetometry in ambient environment磁悬浮传感器助力环境条件下的磁力测量▲ 作者:Wei Ji
▲ Abstract :

Mucus is 科学known as a viscous fluid; yet, snails manufacture various mucus-based materials with much higher cohesion and tailored to different and even antagonistic functions, including lubrication, adhesion, protection, and defense. To gain insight into this versatility, we use a multidisciplinary approach to investigate five different mucus-based materials produced by the snail Cepaea nemoralis. Our results demonstrate that snails use collagen VI as a main structural component and add amorphous calcium carbonate (ACC) during mucus secretion. ACC functions as an ion source in wet mucus types, most likely for cross-linking, or as a mineral precursor in dry mucus types. These findings shed light on the versatility of these viscoelastic materials, which are able to switch between very different properties on the basis of calcium and protein content.

化学Chemistry

Vicinal disubstitution of alkyl C–X synthons via alkene radical cation generation
烯烃自由基阳离子生成助力烷基C–X合成子邻位双取代
▲ 作者:Yufei Zhang, Tamal Das, Zi Xuan, Mrinmoy Das, Hammed O. Bisiriyu, Alon Nudler, Ben D. Parasch, et al.
▲链接:
https://www.science.org/doi/10.1126/science.aef0766
▲摘要:
在有机化学中,通过光氧化还原催生的出版氢原子转移(HAT)和自旋中心转移(SCS)过程,
▲ Abstract :
Levitated particle systems have 周论我和丈姆娘gained attention as a rapidly advancing platform for precision sensing, offering low-loss, highly isolated environments by eliminating mechanical contact and associated noise. Current room-temperature levitation techniques are primarily sensitive to acceleration, and it remains challenging to integrate them with high-sensitivity magnetic sensing. In this work, we demonstrate a diamagnetically stabilized magnetically levitated magnet magnetometer, where the motion of the magnet is detected optically. We achieved a sensitivity of 32 femtoteslas per square root of Hertz, which is adequate for a wide range of applications in biology, chemistry, and fundamental physics, matching the performance of superconducting quantum interference devices and atomic magnetometers, while offering the advantage of operating at room temperature and under Earth’s magnetic field.
材料科学Materials Science
Calcium tunes snail mucus–based materials to multiple functions
钙调控蜗牛粘液基材料的多功能性
▲ 作者:Mariella Gabler, Emeline Raguin, Ernesto Scoppola, Barbara Steigenberger, Assa Yeroslaviz, Peter Werner, et al.
▲链接:
https://www.science.org/doi/10.1126/science.adx7367
▲摘要:
众所周知 ,
▲ Abstract :
Internal combustion engine (ICE) vehicles represent the single largest source of carbon dioxide emissions for most US households. Although battery electric vehicles (BEVs) considerably reduce use-phase emissions,文导 the transition poses a fundamental life cycle optimization challenge: Is there a net climate benefit to retiring a functional ICE vehicle before its end of life? Retiring a functioning ICE vehicle incurs a fundamental trade-off between BEV manufacturing emissions and decreased vehicle operation emissions. In this study, we evaluated this trade-off across a comprehensive range of retirement scenarios and found that scrappage-and-replacement yields consistent emissions reductions across most contexts, including the retirement of new ICE vehicles. Although scrapping a functional asset remains economically prohibitive under current market conditions, these results demonstrate a major mitigation potential for policy interventions, such as enhanced scrappage subsidies, to address the emissions of an increasingly durable ICE fleet.
Decadal doubling of Siberian methane emissions due to warming-induced fires and methanogenesis
变暖催生的火灾与产甲烷作用造成西伯利亚甲烷排放十年翻倍
▲ 作者:Sihong Zhu, Yi Liu, Paul I. Palmer, Liang Feng, Dongxu Yang, Shangfeng Chen, et al.
▲链接:
https://www.science.org/doi/10.1126/science.aea5828
▲摘要:
北方永久冻土区储存的碳量约为大气中的两倍 ,电子离域和氢键溶剂分子网络共同促进了一种协同的科学“HAT+SCS”机制 。两个相邻碳原子的出版官能化通常以烯烃或已双取代的前体为起始原料。提供低损耗和高隔离环境而受到广泛关注 。周论尽管纯电动汽车(BEV)大幅缩减了使用阶段排放,文导而西西伯利亚更湿润的科学条件促进了与湿地相关的排放(0.4±0.1 TgCH4·年-2)。结果表明 ,出版我和丈姆娘
▲ Abstract:
In organic chemistry,周论 functionalization of two adjacent carbons often starts from alkenes or already disubstituted precursors. Here, we report an exergonic activation mode that directly generates alkene radical cation intermediates from monofunctional C(sp3)–X handles through a photoredox-triggered hydrogen-atom abstraction (HAT) and spin-center shift (SCS) process. Computations show that electron delocalization and a network of hydrogen-bonding solvent molecules facilitate a concerted [HAT+SCS] mechanism. The catalytic platform was used to design a transfer of electrophilic reactivity (C–X) from one carbon to another, which we refer to as electrophilic shuttling. Thus, two nucleophiles can be used in the construction of 1,2-difunctionalization adducts from homobenzylic C–X synthons, delivering bisazole architectures and demonstrating compatibility with other nucleophile classes. We developed a suite of transformations that departs from conventional synthetic logic, for which alkyl C–X scaffolds are confined to single-site substitutions, now transforming them into nonintuitive precursors for building vicinal complexity.
地球科学Earth Science
The climate benefits of retiring a fully operational internal combustion engine vehicle
放弃功能完好内燃机汽车的气候效益
▲ 作者 :J. Elliott Campbell and Roland Geye
▲链接 :
https://www.science.org/doi/10.1126/science.adv5441
▲摘要 :
内燃机(ICE)汽车是大多数美国家庭最大的二氧化碳排放源