编译 | 李言

Science, 16 Oct 2025, VOL 390, ISSUE 6770

《科学》2025年10月16日，第390卷，6770期

材料科学Material Sciences

Electrically controlled interlayer trion fluid in electron-hole bilayers

电子—空穴双层结构中的电控层间三子流体

▲ 作者：Ruishi Qi, Qize Li et al.

▲链接：

https://www.science.org/doi/10.1126/science.adn4584

▲摘要：在量子电子—空穴（e-h）流体中的排斥性与吸引性库仑相互作用共同作用，可产生多粒子电荷复合体的相关相态，如激子、三子和双激子。研究者报道了在范德瓦尔斯异质结中实现电控层间三子流体的实验成果。在强耦合电子—空穴双层结构中，电子与空穴自发形成三粒子三子束缚态。层间三子可呈现1e-2h与2e-1h两种构型。

研究发现，1e-2h三子中的两个空穴会形成自旋单重态，其自旋能隙约为1毫电子伏特。通过静电栅压调控，该平衡态可连续转变为激子流体、三子流体、激子—三子混合态或三子—电荷混合态。这项研究为了解可调谐玻色—费米混合体的相关相态提供了新平台。

▲ Abstract：The combination of repulsive and attractive Coulomb interactions in a quantum electron-hole (e-h) fluid can produce correlated phases of multiparticle charge complexes, such as excitons, trions, and biexcitons. We report an experimental realization of an electrically controlled interlayer trion fluid in van der Waals heterostructures. In strongly coupled e-h bilayers, electrons and holes spontaneously form three-particle trion bound states. The interlayer trions can assume 1e-2h and 2e-1h configurations. We show that the two holes in 1e-2h trions form a spin-singlet with a spin gap of approximately one milli–electron volt. By electrostatic gating, the equilibrium state can be continuously tuned into an exciton fluid, a trion fluid, an exciton-trion mixture, or a trion-charge mixture. Our work demonstrates a platform to study correlated phases of tunable Bose-Fermi mixtures.

生物学Biology

“Kiss-shrink-run” unifies mechanisms for synaptic vesicle exocytosis and hyperfast recycling

“亲完就跑” 统一了突触小泡胞吐与超快速循环的机制

▲ 作者：Chang-Lu Tao, Chong-Li Tian et al.

▲链接：

https://www.science.org/doi/10.1126/science.ads7954

▲ 摘要：突触小泡（SV）胞吐作用是神经元通信的基础，但由于原位观测快速动态过程的技术限制，其纳米尺度动力学机制尚未明晰。研究者通过光遗传学耦合的时间分辨冷冻电子断层扫描技术，成功捕获了大鼠海马区突触中小泡的胞吐过程。

在突触激活后的4毫秒内，突触小泡会短暂“亲吻”触质膜，形成一个约4纳米宽的脂质融合孔，其两侧可见疑似可溶性NSF附着蛋白受体；随后小泡迅速“收缩”至原表面积的一半左右。至70毫秒时，多数收缩后的小泡通过“逃逸”途径完成循环，其余小泡则与突触前膜融合。100毫秒后，超快内吞作用会回收扩张的突触前膜。

这些发现揭示了突触小泡胞吐与超快速循环的“亲完就跑”机制，调和了现有理论模型的矛盾，并阐明了突触传递的高效性与保真度基础。

▲ Abstract：Synaptic vesicle (SV) exocytosis underpins neuronal communication, yet its nanoscale dynamics remain poorly understood owing to limitations in visualizing rapid events in situ. Here, we used optogenetics-coupled, time-resolved cryo–electron tomography to capture SV exocytosis in rat hippocampal synapses. Within 4 milliseconds of synaptic activation, SVs transiently “kiss” the plasma membrane, forming a ~4-nanometer lipidic fusion pore flanked by putative soluble NSF-attachment protein receptor (SNARE) complexes and then rapidly “shrink” to approximately half of their original surface area. By 70 milliseconds, most shrunken SVs recycle via a “run-away” pathway, whereas others collapse into the presynaptic membrane. Ultrafast endocytosis retrieves the expanded presynaptic membrane after 100 milliseconds. These findings reveal a “kiss-shrink-run” mechanism of SV exocytosis and hyperfast recycling, reconciling conflicting models and elucidating the efficiency and fidelity of synaptic transmission.

Defensive fungal symbiosis on insect hindlegs

昆虫后腿上的防御性真菌共生现象

▲ 作者：Takanori Nishino, Minoru Moriyama et al.

▲链接：

https://www.science.org/doi/10.1126/science.adp6699

▲ 摘要：兜蝽科臭虫（Dinidorid stinkbug）的雌性后腿上具有一个显著的鼓膜器官。本研究表明，该器官并非用于感知声音，而是特化为储存微生物共生体。其表面并非膜质结构，而是由多孔角质层构成，每个孔洞均与腺体分泌细胞相连。

在繁殖期的雌性个体中，后腿器官表面覆盖着从孔洞中生长出的真菌菌丝。产卵时，雌性会将真菌从该器官转移至卵粒表面，菌丝通过物理屏障作用保护虫卵免受蜂类寄生。这些真菌主要由多种低致病性虫草科物种组成，具有丰富的多样性。

▲ Abstract：Dinidorid stinkbugs were reported to possess a conspicuous tympanal organ on female hindlegs. In this study, we show that this organ is specialized to retain microbial symbionts rather than to perceive sound. The organ’s surface is not membranous but consists of porous cuticle in which each pore connects to glandular secretory cells. In reproductive females, the hindleg organ is covered with fungal hyphae that grow from the pores. Upon oviposition, the females transfer the fungi from the organ to the eggs, where the hyphae physically protect the eggs against wasp parasitism. The fungi comprise a diversity of mostly low-pathogenicity Cordycipitaceae.

动物学Zoology

Head-direction cells as a neural compass in bats navigating outdoors on a remote oceanic island

头部方向细胞在偏远海岛上户外导航的蝙蝠中起到神经罗盘的作用

▲ 作者：Shaked Palgi, Saikat Ray et al.

▲链接：

https://www.science.org/doi/10.1126/science.adw6202

▲摘要：动物和人类依赖导航能力得以生存。然而，大脑“导航回路”中的空间神经元此前从未在真实环境条件下被研究过。研究者在野外对空间神经元开展了电生理研究。他们记录了在偏远海岛上任意飞行的蝙蝠的海马体中头部方向细胞的活动。

这些神经元在岛屿全域范围内均能稳定表征蝙蝠的朝向定位，且不受月球与银河动态变化的影响。从初次探索该岛屿开始，方向调谐特性经过数个夜晚逐渐趋于稳定。

这些结果表明，头部方向细胞能够作为经过学习形成的可靠神经罗盘，为真实环境中的导航服务——彰显了将神经科学研究推向野外环境的重要价值。

▲ Abstract：Animals and humans rely on their navigation skills to survive. However, spatial neurons in the brain’s “navigation circuit” had not previously been studied under real-world conditions. We conducted an electrophysiological study of spatial neurons in the wild: We recorded head-direction cells from the presubiculum of bats flying unconstrained and navigating outdoors on a remote oceanic island. These neurons represented the bats’ orientation stably across the island’s entire geographical scale and irrespective of the dynamics of the Moon and the Milky Way. The directional tuning stabilized over several nights from the first exploration of the island. These results imply that head-direction cells can serve as a learned, reliable neural compass for real-world navigation—highlighting the power of taking neuroscience out into the wild.

地球科学Earth Science

Global mean sea level over the past 4.5 million years

全球平均海平面在过去450万年间的变化

▲ 作者：Peter U. Clark, Jeremy D. Shakun et al.

▲链接：

https://www.science.org/doi/10.1126/science.adv8389

▲ 摘要：晚新生代全球平均海平面（GMSL）的变化仍不确定。研究者利用对海水氧—18同位素变化的重建，重建了自450万年前以来的全球平均海平面情况。这一重建考虑了温度驱动的全球冰盖氧—18同位素的变化。在450万年至300万年前期间，海平面高位期仍比现在高出最多20 米，而首次低于现在的海平面低位期表明北半球冰川作用始于400万年前。

全球冰川作用的加剧发生在300万年至250万年前，其顶峰时期的低海平面位与21000年前末次盛冰期的低海平面位相似，并在整个更新世的大部分时间里反复出现。我们将冰盖变异性的中更新世转型期归因于约10万年周期的二氧化碳变率增加对4.1万年周期斜率强迫的调制作用。

▲ Abstract：Changes in global mean sea level (GMSL) during the late Cenozoic remain uncertain. We use a reconstruction of changes in δ18O of seawater to reconstruct GMSL since 4.5 million years ago (Ma) that accounts for temperature-driven changes in the δ18O of global ice sheets. Between 4.5 and 3 Ma, sea level highstands remained up to 20 m above present whereas the first lowstands below present suggest onset of Northern Hemisphere glaciation at 4 Ma. Intensification of global glaciation occurred from 3 Ma to 2.5 Ma, culminating in lowstands similar to the Last Glacial Maximum lowstand at 21,000 years ago and that reoccurred throughout much of the Pleistocene. We attribute the middle Pleistocene transition in ice sheet variability (1.2 Ma to 0.62 Ma) to modulation of 41-thousand-year (kyr) obliquity forcing by an increase in ~100-kyr CO₂ variability.

Drought intensity and duration interact to magnify losses in primary productivityt

干旱强度与持续时间共同作用会放大初级生产力损失

▲ 作者：Timothy Ohlert, Melinda D. Smith et al.

▲链接：

https://www.science.org/doi/10.1126/science.ads8144

▲摘要：随着干旱期延长且加剧，其对陆地初级生产力的影响将逐步扩大。然而，部分生态系统似乎能适应多年干旱，在干旱持续期间生产力下降幅度保持稳定或逐渐收窄。

研究者通过全球74处草原与灌丛地的观测数据，量化了干旱持续时间与强度对地上生产力的复合影响。除极端干旱事件外，这些生态系统总体上表现出对多年干旱的适应能力。当遭遇连续四年的极端干旱时，生态系统生产力损失较首年增加约2.5倍。

这些结果表明：若干旱持续时间与强度持续增加，生态系统行为将发生根本性转变——从长期维持低水平功能状态，转向在极端干旱时出现持续且严重的生产力损失。

▲ Abstract：As droughts become longer and more intense, impacts on terrestrial primary productivity are expected to increase progressively. Yet, some ecosystems appear to acclimate to multiyear drought, with constant or diminishing reductions in productivity as drought duration increases. We quantified the combined effects of drought duration and intensity on aboveground productivity in 74 grasslands and shrublands distributed globally. Ecosystem acclimation with multiyear drought was observed overall, except when droughts were extreme (i.e., ≤1-in-100-year likelihood of occurrence). Productivity losses after four consecutive years of extreme drought increased by ~2.5-fold compared with those of the first year. These results portend a foundational shift in ecosystem behavior if drought duration and intensity increase, from maintenance of reduced functioning over time to progressive and profound losses of productivity when droughts are extreme.