Science,22 May 2025,Volume 388, Issue 6749

《科学》2025年5月22日，第388卷，6749期

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物理学 Physics

A pulsar-helium star compact binary system formed by common envelope evolution

由共同包层演化形成的脉冲星-氦星致密双星系统

▲ 作者：Z. L. YANG, J. L. HAN, D. J. ZHOU, W. C. JING, W. C. CHEN, T. WANG, X. D. LI, S. WANG, B. WANG , AND C. F. ZHANG

▲链接：

https://www.science.org/doi/10.1126/science.ado0769

▲摘要：双星系统中的恒星可以相互作用，从而影响两个天体的演化。理论预测，一些双星系统经历了一个共同的包络阶段，其中一个天体在其伴星的外层内运行，但这还没有被直接观察到。研究者发现了一颗快速旋转的脉冲星，它与一颗伴星氦恒星在近轨道上运行。

与理论模型的比较表明，该系统最近经历了一个共同的包络阶段，脉冲星在主序伴星的包络内运行。伴星的外壳在一千年内被抛出，形成了氦星，一些质量被转移到脉冲星上，增加了它的自旋速率。

▲ Abstract：Stars in binary systems can interact, which affects the evolution of both objects. Theory predicts that some binary systems experience a common envelope phase in which one object orbits within the outer layers of its companion, but this has not been directly observed. Yang et al. identified a rapidly spinning pulsar on a close orbit with a companion helium star. Comparison with theoretical models showed that this system recently underwent a common envelope phase, with the pulsar orbiting inside the envelope of a main sequence companion. The companion’s envelope was ejected within a thousand years, producing the helium star, and some mass was transferred to the pulsar, increasing its spin rate. 

Erasure cooling, control, and hyperentanglement of motion in optical tweezers

光镊中原子运动态的量子操控与超纠缠冷却新机制

▲ 作者：ADAM L. SHAW, PASCAL SCHOLL, RAN FINKELSTEIN, RICHARD BING-SHIUN TSAI, JOONHEE CHOI, AND MANUEL ENDRES 

▲链接：

https://www.science.org/doi/10.1126/science.adn2618

▲摘要：被困在光镊中的原子是一个很有前途的量子信息处理平台。通常在这样的系统中，量子信息被编码在原子的电子或核状态中。然而，它们的运动状态对环境影响更强，也可以用于量子信息。

研究者用一组充满锶原子的光学镊子演示了这种方法。他们首先以高保真度将原子冷却到运动基态，然后继续在运动和电子自由度上创造贝尔状态，这被称为超纠缠。

▲ Abstract：Atoms trapped in optical tweezers are a promising platform for quantum information processing. Typically in such systems, quantum information is encoded in the atoms’ electronic or nuclear states. However, their motional states, which are more robust to environmental effects, could also be exploited for quantum information. Shaw et al. have demonstrated this approach using an array of optical tweezers filled with strontium atoms. The researchers first cooled the atoms to their motional ground state with high fidelity and then went on create a Bell state in both motional and electronic degrees of freedom, which is known as hyperentanglement. 

生物学 Biology

The emergence and demise of giant sloths

巨型树懒的出现和消亡

▲ 作者：ALBERTO BOSCAINI, DANIEL M. CASALI, NéSTOR TOLEDO, JUAN L. CANTALAPIEDRA, M. SUSANA BARGO, GERARDO DE IULIIS, TIMOTHY J. GAUDIN, MAX C. LANGER, RACHEL NARDUCCI, AND IGNACIO M. SOTO

▲链接：

https://www.science.org/doi/10.1126/science.adu0704

▲摘要：现今，有六种树懒，它们都有类似的生态环境，比如树栖和缓慢的新陈代谢。这些物种是一个曾经多样化的美洲分支的一小部分残余，这个分支主要由大型物种组成。作者研究了树懒的进化史，揭示了树懒的祖先群体是陆生的和大型的，较小的物种被衍生出来并聚集在一起。

在3000万年的时间里，树懒家族在美洲各地多样化，从一个像大象一样大的物种演化成一个完全水生的物种。不幸的是，像大多数其他大型更新世食草动物一样，这个进化支几乎被新到达的人类完全消灭了。

▲ Abstract：Today, there are six species of sloths, all of which have similar ecologies such as arboreality and a slow metabolism. These species are a tiny remnant of a once diverse American clade that was mostly made up of large-bodied species. Boscaini et al. looked across the evolutionary history of sloths and reveal that the ancestral groups were terrestrial and large, with smaller species being derived and convergent. For 30 million years, the sloth family diversified across the Americas, from a species as large as an elephant to one that was entirely aquatic. Unfortunately, like most other large Pleistocene herbivores, the clade was almost entirely eradicated by newly arriving humans. 

Deep learning–guided design of dynamic proteins

基于深度学习的动态蛋白质设计

▲ 作者：AMY B. GUO, DENIZ AKPINAROGLU, CHRISTINA A. STEPHENS, MICHAEL GRABE, COLIN A. SMITH, MARK J. S. KELLY, AND TANJA KORTEMME

▲链接：

https://www.science.org/doi/10.1126/science.adr7094

▲摘要：许多信号蛋白和酶会对小分子或离子的结合作出反应，通过改变动力学倾向于一种结构构象而不是另一种结构构象。这种行为是生物功能的关键。但在设计的蛋白质中设定出这些特性是非常具有挑战性的。研究者开发了一种算法来设计这种可以感知并响应钙离子结合的动态蛋白质。

从结合钙离子的静态蛋白质开始，研究者确定了潜在的替代构象，并使用AlphaFold2预测来识别与两种结构兼容的序列。分子动力学模拟和核磁共振实验验证了一种动态的多态设计，可以在离子结合时转变为单一构象。

▲ Abstract：Many signaling proteins and enzymes respond to binding of a small molecule or ion by shifting dynamics to favor one structural conformation over another. This behavior is key to biological function, but engineering these properties in designed proteins is very challenging. Guo et al. developed a computational approach to designing such dynamic proteins that can sense and respond to binding of a calcium ion. Starting with a static protein that binds a calcium ion, the authors identified potential alternate conformations and used AlphaFold2 predictions to identify sequences that were compatible with both structures. Validation with molecular dynamics simulations and nuclear magnetic resonance experiments confirmed a dynamic, multistate design that could be shifted into a single conformation upon ion binding. 

生态学 Ecology

Functional biogeography of marine microbial heterotrophs

海洋微生物异养生物的功能生物地理学

▲ 作者：EMILY J. ZAKEM, JESSE MCNICHOL, J. L. WEISSMAN, YUBIN RAUT, LIANG XU, ELISA R. HALEWOOD, CRAIG A. CARLSON, STEPHANIE DUTKIEWICZ, JED A. FUHRMAN, AND NAOMI M. LEVINE 

▲链接：

https://www.science.org/doi/10.1126/science.ado5323

▲摘要：在海洋中，碳循环主要由微生物光合作用和呼吸作用驱动。有几种方法将碳以不稳定和顽固性的溶解有机碳形式封存在深处。研究者认识到，目前微生物动力学在海洋碳储存中的作用的生物地球化学模型是不充分的。

为了改进模型，他们利用来自太平洋、大西洋和印度洋样带的可用数据集来调查海洋微生物群落的结构，然后研究这种结构与功能的关系。在低纬度地区，可以看出垂直梯度——在表层有寡养生物，而在中上层深处有越来越多的共养生物，它们避免被表层捕食，生长缓慢，是调节海洋中溶解碳储量的关键。

▲ Abstract：In the ocean, the carbon cycle is driven mainly by microbial photosynthesis and respiration. Several processes sequester carbon at depth in labile and recalcitrant forms of dissolved organic carbon. Zakem et al. recognized that current biogeochemical models for the roles of microbial dynamics in ocean carbon storage are inadequate. To improve models, the authors harnessed available datasets from Pacific, Atlantic, and Indian Ocean transects to investigate the structure of oceanic microbial communities and then studied how this structure relates to function. At low latitudes, a vertical gradient can be discerned, with oligotrophs on the surface and increasingly copiotrophic populations at mesopelagic depths that avoid surface predation, grow slowly, and are key to regulating the amount of dissolved carbon stored in the ocean. 

化学 Chemistry

Turf algae redefine the chemical landscape of temperate reefs, limiting kelp forest recoveryl

草皮藻类重新定义温带珊瑚礁的化学景观

▲ 作者：SHANE P. FARRELL, DANIEL PETRAS, PAOLO STINCONE, DARA S. YIU, JOHN A. BURNS, ABZER KELMINAL PAKKIR SHAH, AARON C. HARTMANN, DAMIAN C. BRADY, AND DOUGLAS B. RASHER 

▲链接：

https://www.science.org/doi/10.1126/science.adt6788

▲摘要：在经历海洋快速变暖的温带地区，海带森林正在被化学成分丰富的草皮藻类所取代。然而，这些草皮藻类在多大程度上改变了周围的化学环境或影响海带森林的反弹潜力仍然未知。

研究者使用水下视觉调查、综合化学分析和实验室实验来揭示草皮藻类向水中释放生物活性化合物，从根本上改变了珊瑚礁的“化学景观”，并直接抑制了海带的形成。

研究表明，化学生态学在塑造现代海带森林生态系统及其恢复能力方面至关重要。此外，该研究表明扭转气候驱动的国家转变不仅需要遏制全球碳排放，还需要实施有针对性的地方干预措施，打破有害的生态反馈循环，促进恢复。

▲ Abstract：In temperate regions experiencing rapid ocean warming, kelp forests are being replaced by chemically rich turf algae. However, the extent to which these turf algae alter the surrounding chemical environment or affect the rebound potential of kelp forests (through chemically mediated interactions) remains unknown. Here, we used underwater visual surveys, comprehensive chemical profiling, and laboratory experiments to reveal that turf algae release bioactive compounds into the water that fundamentally alter the reef “chemical landscape” and directly suppress kelp recruitment. Therefore, our study reveals that chemical ecology is critical in shaping modern kelp forest ecosystems and their resilience. Further, it demonstrates that reversing climate-driven state shifts will require not only curbing global carbon emissions but also implementing targeted local interventions that break harmful ecological feedback loops and foster recovery.