Science最新文献

英文中文

Palladium-catalyzed cross-coupling of alcohols with olefins by positional tuning of a counteranion 通过反阴离子的位置调节，钯催化醇与烯烃的交叉偶联。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.ado8027

Sven H. M. Kaster, Lei Zhu, William L. Lyon, Rulin Ma, Stephen E. Ammann, M. Christina White

Transition metal–catalyzed cross-couplings have great potential to furnish complex ethers; however, challenges in the C(sp³)–O functionalization step have precluded general methods. Here, we describe computationally guided transition metal–ligand design that positions a hydrogen-bond acceptor anion at the reactive site to promote functionalization. A general cross-coupling of primary, secondary, and tertiary aliphatic alcohols with terminal olefins to furnish >130 ethers is achieved. The mild conditions tolerate functionality that is prone to substitution, elimination, and epimerization and achieve site selectivity in polyol settings. Mechanistic studies support the hypothesis that the ligand’s geometry and electronics direct positioning of the phosphate anion at the π-allyl-palladium terminus, facilitating the phosphate’s hydrogen-bond acceptor role toward the alcohol. Ligand-directed counteranion positioning in cationic transition metal catalysis has the potential to be a general strategy for promoting challenging bimolecular reactivity.

过渡金属催化的交叉偶联反应在生成复杂的醚类化合物方面具有巨大潜力；然而，C(sp3)-O 功能化步骤所面临的挑战排除了通用方法。在这里，我们介绍了计算指导下的过渡金属配体设计，该设计将氢键受体阴离子置于反应位点以促进官能化。我们实现了伯、仲、叔脂肪醇与末端烯烃的一般交叉偶联，生成大于 130 个醚。温和的条件可以容忍容易发生取代、消除和表聚合反应的官能度，并在多元醇中实现位点选择性。机理研究支持这样的假设，即配体的几何形状和电子元件将磷酸阴离子直接定位在π-烯丙基钯末端，从而促进了磷酸对醇的氢键接受作用。在阳离子过渡金属催化中，配体引导的反阴离子定位有可能成为促进具有挑战性的双分子反应的通用策略。

{"title":"Palladium-catalyzed cross-coupling of alcohols with olefins by positional tuning of a counteranion","authors":"Sven H. M. Kaster, Lei Zhu, William L. Lyon, Rulin Ma, Stephen E. Ammann, M. Christina White","doi":"10.1126/science.ado8027","DOIUrl":"10.1126/science.ado8027","url":null,"abstract":"<div >Transition metal–catalyzed cross-couplings have great potential to furnish complex ethers; however, challenges in the C(sp<sup>3</sup>)–O functionalization step have precluded general methods. Here, we describe computationally guided transition metal–ligand design that positions a hydrogen-bond acceptor anion at the reactive site to promote functionalization. A general cross-coupling of primary, secondary, and tertiary aliphatic alcohols with terminal olefins to furnish >130 ethers is achieved. The mild conditions tolerate functionality that is prone to substitution, elimination, and epimerization and achieve site selectivity in polyol settings. Mechanistic studies support the hypothesis that the ligand’s geometry and electronics direct positioning of the phosphate anion at the π-allyl-palladium terminus, facilitating the phosphate’s hydrogen-bond acceptor role toward the alcohol. Ligand-directed counteranion positioning in cationic transition metal catalysis has the potential to be a general strategy for promoting challenging bimolecular reactivity.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":null,"pages":null},"PeriodicalIF":44.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Sweden is shooting brown bears in the dark 瑞典在黑暗中射击棕熊。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adq7487

Cyril Milleret, Pierre Dupont, Guillaume Chapron, Jon E. Swenson, Richard Bischof

引用次数: 0

The long shadow of biodiversity loss 生物多样性丧失的长长阴影。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adq2373

Ashley E. Larsen, Dennis Engist, Frederik Noack

引用次数: 0

Einstein’s Oxford years 爱因斯坦的牛津岁月

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adq4247

Andrew Robinson

引用次数: 0

Turning tissues temporarily transparent 使组织暂时透明。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adr7935

Christopher J. Rowlands, Jon Gorecki

It is often said that life imitates art, but rarely does it do so with such a pronounced combination of precision and delay. In H. G. Wells’s 1897 novel The Invisible Man, the protagonist invents a serum that renders the cells in his body transparent by precisely controlling their refractive index to match that of the surrounding medium, air. Because light scattering only occurs at the boundary of two media with dissimilar refractive indices, the cells would no longer scatter light, thus rendering them invisible. One hundred twenty-seven years later, Ou et al. (1) report, on page 1061 of this issue, that biocompatible dyes make living tissues transparent by tuning the refractive index of the surrounding medium to match that of the cells. This approach offers a new means of visualizing the structure and activity of deep tissues and organs in vivo in a safe, temporary, and noninvasive manner.

一种食品染料可抑制生物组织中的光散射，从而实现深度活体成像。

引用次数: 0

Ecological restoration for China’s mines 中国矿山的生态恢复。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adr1001

Hong Yang, Xiang Gao, Jianhua Wu, Julian R. Thompson, Roger J. Flower

引用次数: 0

Oxygen- and proton-transporting open framework ionomer for medium-temperature fuel cells 用于中温燃料电池的氧和质子传输开放式框架离子聚合物。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adq2259

Jianwei Yang, Hengyu Xu, Jie Li, Ke Gong, Feiyu Yue, Xianghao Han, Ke Wu, Pengpeng Shao, Qingling Fu, Yuhao Zhu, Wenli Xu, Xin Huang, Jing Xie, Fengchao Wang, Wenxiu Yang, Teng Zhang, Zengshi Xu, Xiao Feng, Bo Wang

Medium-temperature proton exchange membrane fuel cells (MT PEMFCs) operating at 100° to 120°C have improved kinetics, simplified thermal and water management, and broadened fuel tolerance compared with low-temperature PEMFCs. However, high temperatures lead to Nafion ionomer dehydration and exacerbate gas transportation limitations. Inspired by osmolytes found in hyperthermophiles, we developed α-aminoketone–linked covalent organic framework (COF) ionomers, interwoven with Nafion, to act as “breathable” proton conductors. This approach leverages synergistic hydrogen bonding to retain water, enhancing hydration and proton transport while reducing oxygen transport resistance. For commercial Pt/C, the MT PEMFCs achieved peak and rated power densities of 18.1 and 9.5 Watts per milligram of Pt at the cathode at 105°C fueled with H₂ and air, marking increases of 101 and 187%, respectively, compared with cells lacking the COF.

与低温质子交换膜燃料电池相比，工作温度在 100° 至 120°C 的中温质子交换膜燃料电池（MT PEMFC）改善了动力学性能，简化了热管理和水管理，并扩大了燃料耐受性。然而，高温会导致 Nafion 离子膜脱水，并加剧气体输送的限制。受嗜热生物中渗透溶解物的启发，我们开发了与α-氨基酮连接的共价有机框架（COF）离聚物，与 Nafion 相互交织，作为 "可呼吸 "的质子导体。这种方法利用氢键的协同作用保留水分，增强了水合作用和质子传输，同时降低了氧气传输阻力。对于商用 Pt/C，MT PEMFC 在 105°C 温度下以 H2 和空气为燃料，阴极每毫克 Pt 的峰值功率密度和额定功率密度分别达到 18.1 瓦特和 9.5 瓦特，与缺乏 COF 的电池相比，分别提高了 101% 和 187%。

{"title":"Oxygen- and proton-transporting open framework ionomer for medium-temperature fuel cells","authors":"Jianwei Yang, Hengyu Xu, Jie Li, Ke Gong, Feiyu Yue, Xianghao Han, Ke Wu, Pengpeng Shao, Qingling Fu, Yuhao Zhu, Wenli Xu, Xin Huang, Jing Xie, Fengchao Wang, Wenxiu Yang, Teng Zhang, Zengshi Xu, Xiao Feng, Bo Wang","doi":"10.1126/science.adq2259","DOIUrl":"10.1126/science.adq2259","url":null,"abstract":"<div >Medium-temperature proton exchange membrane fuel cells (MT PEMFCs) operating at 100° to 120°C have improved kinetics, simplified thermal and water management, and broadened fuel tolerance compared with low-temperature PEMFCs. However, high temperatures lead to Nafion ionomer dehydration and exacerbate gas transportation limitations. Inspired by osmolytes found in hyperthermophiles, we developed α-aminoketone–linked covalent organic framework (COF) ionomers, interwoven with Nafion, to act as “breathable” proton conductors. This approach leverages synergistic hydrogen bonding to retain water, enhancing hydration and proton transport while reducing oxygen transport resistance. For commercial Pt/C, the MT PEMFCs achieved peak and rated power densities of 18.1 and 9.5 Watts per milligram of Pt at the cathode at 105°C fueled with H<sub>2</sub> and air, marking increases of 101 and 187%, respectively, compared with cells lacking the COF.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":null,"pages":null},"PeriodicalIF":44.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

PLK1-mediated phosphorylation cascade activates Mis18 complex to ensure centromere inheritance PLK1 介导的磷酸化级联激活 Mis18 复合物，确保中心粒遗传。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.ado8270

Pragya Parashara, Bethan Medina-Pritchard, Maria Alba Abad, Paula Sotelo-Parrilla, Reshma Thamkachy, David Grundei, Juan Zou, Christos Spanos, Chandni Natalia Kumar, Claire Basquin, Vimal Das, Zhaoyue Yan, Asma Abdullah Al-Murtadha, David A. Kelly, Toni McHugh, Axel Imhof, Juri Rappsilber, A. Arockia Jeyaprakash

Accurate chromosome segregation requires the attachment of microtubules to centromeres, epigenetically defined by the enrichment of CENP-A nucleosomes. During DNA replication, CENP-A nucleosomes undergo dilution. To preserve centromere identity, correct amounts of CENP-A must be restored in a cell cycle–controlled manner orchestrated by the Mis18 complex (Mis18α-Mis18β-Mis18BP1). We demonstrate here that PLK1 interacts with the Mis18 complex by recognizing self-primed phosphorylations of Mis18α (Ser⁵⁴) and Mis18BP1 (Thr⁷⁸ and Ser⁹³) through its Polo-box domain. Disrupting these phosphorylations perturbed both centromere recruitment of the CENP-A chaperone HJURP and new CENP-A loading. Biochemical and functional analyses showed that phosphorylation of Mis18α and PLK1 binding were required to activate Mis18α-Mis18β and promote Mis18 complex-HJURP interaction. Thus, our study reveals key molecular events underpinning the licensing role of PLK1 in ensuring accurate centromere inheritance.

染色体的准确分离需要微管附着在中心粒上，而中心粒是由 CENP-A 核小体的富集所决定的。在DNA复制过程中，CENP-A核小体会发生稀释。为了保持中心粒的特性，必须在 Mis18 复合物（Mis18α-Mis18β-Mis18BP1）的协调下以细胞周期控制的方式恢复 CENP-A 的正确数量。我们在此证明，PLK1通过其Polo-box结构域识别Mis18α（Ser54）和Mis18BP1（Thr78和Ser93）的自发磷酸化，从而与Mis18复合体相互作用。破坏这些磷酸化会扰乱 CENP-A 合子 HJURP 的中心粒招募和新的 CENP-A 负载。生化和功能分析显示，Mis18α的磷酸化和PLK1的结合是激活Mis18α-Mis18β和促进Mis18复合物-HJURP相互作用的必要条件。因此，我们的研究揭示了 PLK1 在确保准确的中心粒遗传中发挥许可作用的关键分子事件。

{"title":"PLK1-mediated phosphorylation cascade activates Mis18 complex to ensure centromere inheritance","authors":"Pragya Parashara, Bethan Medina-Pritchard, Maria Alba Abad, Paula Sotelo-Parrilla, Reshma Thamkachy, David Grundei, Juan Zou, Christos Spanos, Chandni Natalia Kumar, Claire Basquin, Vimal Das, Zhaoyue Yan, Asma Abdullah Al-Murtadha, David A. Kelly, Toni McHugh, Axel Imhof, Juri Rappsilber, A. Arockia Jeyaprakash","doi":"10.1126/science.ado8270","DOIUrl":"10.1126/science.ado8270","url":null,"abstract":"<div >Accurate chromosome segregation requires the attachment of microtubules to centromeres, epigenetically defined by the enrichment of CENP-A nucleosomes. During DNA replication, CENP-A nucleosomes undergo dilution. To preserve centromere identity, correct amounts of CENP-A must be restored in a cell cycle–controlled manner orchestrated by the Mis18 complex (Mis18α-Mis18β-Mis18BP1). We demonstrate here that PLK1 interacts with the Mis18 complex by recognizing self-primed phosphorylations of Mis18α (Ser<sup>54</sup>) and Mis18BP1 (Thr<sup>78</sup> and Ser<sup>93</sup>) through its Polo-box domain. Disrupting these phosphorylations perturbed both centromere recruitment of the CENP-A chaperone HJURP and new CENP-A loading. Biochemical and functional analyses showed that phosphorylation of Mis18α and PLK1 binding were required to activate Mis18α-Mis18β and promote Mis18 complex-HJURP interaction. Thus, our study reveals key molecular events underpinning the licensing role of PLK1 in ensuring accurate centromere inheritance.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":null,"pages":null},"PeriodicalIF":44.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Emotional contagion builds resilience 情绪感染能增强复原力。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adr9296

Martin Metzger, Jose Donato Jr.

In a world with multiple ongoing conflicts, an increasing number of people witness others in distress, either in person or online. Some develop anxiety disorders or even major depressive disease, whereas others become resilient to such distress, maintaining psychological wellbeing in the face of adversity. However, how resilience is established remains unclear. On page 1081 of this issue, Mondoloni et al. (1) report a brain circuit that promotes resilience in mice witnessing the suffering of cage mates—a phenomenon known as negative emotional contagion (NEC). This involves the release of serotonin (5-HT) from neurons originating in the raphe nuclei, a region in the brain stem, into a structure in the epithalamus called the habenula, where 5-HT dampens burst firing, a distinct firing pattern of habenular neurons. The findings elucidate the mechanisms involved in resilience and have potential implications for the treatment of anxiety and depression (see the figure).

目睹笼中同伴受难的小鼠对未来负面情绪的承受能力更强。

引用次数: 0

Organizing the coactivity structure of the hippocampus from robust to flexible memory 从稳健记忆到灵活记忆，组织海马的协同活动结构。

IF 44.7 1区综合性期刊 Q1 MULTIDISCIPLINARY SCIENCES

Science

Pub Date : 2024-09-05 DOI: 10.1126/science.adk9611

Giuseppe P. Gava, Laura Lefèvre, Tabitha Broadbelt, Stephen B. McHugh, Vítor Lopes-dos-Santos, Demi Brizee, Katja Hartwich, Hanna Sjoberg, Pavel V. Perestenko, Robert Toth, Andrew Sharott, David Dupret

New memories are integrated into prior knowledge of the world. But what if consecutive memories exert opposing demands on the host brain network? We report that acquiring a robust (food-context) memory constrains the mouse hippocampus within a population activity space of highly correlated spike trains that prevents subsequent computation of a flexible (object-location) memory. This densely correlated firing structure developed over repeated mnemonic experience, gradually coupling neurons in the superficial sublayer of the CA1 stratum pyramidale to whole-population activity. Applying hippocampal theta-driven closed-loop optogenetic suppression to mitigate this neuronal recruitment during (food-context) memory formation relaxed the topological constraint on hippocampal coactivity and restored subsequent flexible (object-location) memory. These findings uncover an organizational principle for the peer-to-peer coactivity structure of the hippocampal cell population to meet memory demands.

新的记忆会与先前对世界的了解融为一体。但是，如果连续的记忆对宿主大脑网络提出了相反的要求呢？我们报告说，获得稳健的（食物-语境）记忆会将小鼠海马限制在高度相关的尖峰列车的群体活动空间内，从而阻止后续灵活的（物体-位置）记忆的计算。这种密集相关的发射结构是在反复记忆的过程中形成的，逐渐将CA1锥体层表层亚层的神经元与整个群体的活动联系起来。在（食物-情境）记忆形成过程中，应用海马θ驱动的闭环光遗传抑制来减轻这种神经元招募，从而放松了对海马协同作用的拓扑限制，并恢复了随后的灵活（物体-位置）记忆。这些发现揭示了海马细胞群点对点协同作用结构的组织原则，以满足记忆需求。

{"title":"Organizing the coactivity structure of the hippocampus from robust to flexible memory","authors":"Giuseppe P. Gava, Laura Lefèvre, Tabitha Broadbelt, Stephen B. McHugh, Vítor Lopes-dos-Santos, Demi Brizee, Katja Hartwich, Hanna Sjoberg, Pavel V. Perestenko, Robert Toth, Andrew Sharott, David Dupret","doi":"10.1126/science.adk9611","DOIUrl":"10.1126/science.adk9611","url":null,"abstract":"<div >New memories are integrated into prior knowledge of the world. But what if consecutive memories exert opposing demands on the host brain network? We report that acquiring a robust (food-context) memory constrains the mouse hippocampus within a population activity space of highly correlated spike trains that prevents subsequent computation of a flexible (object-location) memory. This densely correlated firing structure developed over repeated mnemonic experience, gradually coupling neurons in the superficial sublayer of the CA1 stratum pyramidale to whole-population activity. Applying hippocampal theta-driven closed-loop optogenetic suppression to mitigate this neuronal recruitment during (food-context) memory formation relaxed the topological constraint on hippocampal coactivity and restored subsequent flexible (object-location) memory. These findings uncover an organizational principle for the peer-to-peer coactivity structure of the hippocampal cell population to meet memory demands.</div>","PeriodicalId":21678,"journal":{"name":"Science","volume":null,"pages":null},"PeriodicalIF":44.7,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142140989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"综合性期刊","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

首页上一页

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Science

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀