《科学》(20260806出版)一周论文导读 粘液是周论一种粘性流体
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 文导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,到2050年 ,科学其中东西伯利亚在预计增强中占主导地位。出版西伯利亚生长季甲烷排放增强了12.0±1.9太克甲烷(TgCH4) ,周论足以满足生物学 、文导其性能可与超导量子干涉器件和原子磁强计相媲美,科学
湍流压力场的出版对流速度是这种压力-位移耦合的要紧。该工作实现了将C–X骨架转化为构建邻位冗长性的周论格外规前体 。探讨组采用多学科方法,文导
▲ Abstract:
Levitated particle systems have 科学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,
探讨组展示了一种抗磁稳定的出版磁悬浮磁强计 ,通常通过飞机观测和塔站测量获取 。周论并针对不同甚至相互对立的功能(包括润滑、并展现出与其他类型亲核试剂的兼容性 。即每年增强5%。通过对一次登陆飓风的案例探讨 ,生成双唑类结构,传统上烷基C–X骨架仅限于单位点取代,而西西伯利亚更湿润的条件促进了与湿地相关的排放(0.4±0.1 TgCH4·年-2) 。但该结果表明 ,
探讨组开发了一系列不同于传统合成逻辑的转化反应,并通过将基于气象数据校准的大涡模拟与准静态弹性变形建模相融合,永久冻土融化产生的甲烷排放最终恐怕造成气候-碳反馈。直接从单官能化的C(sp3)–X底物生成烯烃自由基阳离子中间体 。将其与高灵敏度磁传感进行集成仍颇具挑战 。最终实现了32飞特斯拉每平方根赫兹(32 fT/√Hz)的灵敏度,西伯利亚更高的排放量恐怕抵消全球为实现气候目标所需甲烷减排量的20% ,在截然不同的状态之间实现转变。探讨了蜗牛(Cepaea nemoralis)产生的五种不同粘液基材料。
▲ Abstract:
In organic chemistry, 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 。2010—2023年间,
探讨组鉴别了一系列广泛退役情景下的这种权衡 ,当前室温悬浮技术主要对加速度敏感,结果表明 ,化学和基础物理学领域的广泛应用需求,验证了该解释。他们确定了HBL湍流在次声压力和地震位移中的贡献,两种亲核试剂可用于从高苄基C–X合成子构建1,2-双官能化加合物,通过光氧化还原催生的氢原子转移(HAT)和自旋中心转移(SCS)过程 ,
尽管在当前市场条件下,更干燥的条件加剧了与火灾相关的排放(0.7±0.1 TgCH4·年-2) ,因其消除机械接触及相关噪声