編譯 | 李言
Science, 16 Oct 2025, VOL 390, ISSUE 6770
《科學(xué)》2025年10月16日，第390卷，6770期
材料科學(xué)Material Sciences
Electrically controlled interlayer trion fluid in electron-hole bilayers
電子—空穴雙層結(jié)構(gòu)中的電控層間三子流體
▲ 作者：Ruishi Qi, Qize Li et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adn4584
▲摘要：在量子電子—空穴（e-h）流體中的排斥性與吸引性庫(kù)侖相互作用共同作用，可產(chǎn)生多粒子電荷復(fù)合體的相關(guān)相態(tài)，如激子、三子和雙激子。研究者報(bào)道了在范德瓦爾斯異質(zhì)結(jié)中實(shí)現(xiàn)電控層間三子流體的實(shí)驗(yàn)成果。在強(qiáng)耦合電子—空穴雙層結(jié)構(gòu)中，電子與空穴自發(fā)形成三粒子三子束縛態(tài)。層間三子可呈現(xiàn)1e-2h與2e-1h兩種構(gòu)型。
研究發(fā)現(xiàn)，1e-2h三子中的兩個(gè)空穴會(huì)形成自旋單重態(tài)，其自旋能隙約為1毫電子伏特。通過(guò)靜電柵壓調(diào)控，該平衡態(tài)可連續(xù)轉(zhuǎn)變?yōu)榧ぷ恿黧w、三子流體、激子—三子混合態(tài)或三子—電荷混合態(tài)。這項(xiàng)研究為了解可調(diào)諧玻色—費(fèi)米混合體的相關(guān)相態(tài)提供了新平臺(tái)。
▲ 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.
生物學(xué)Biology
“Kiss-shrink-run” unifies mechanisms for synaptic vesicle exocytosis and hyperfast recycling
“親完就跑” 統(tǒng)一了突觸小泡胞吐與超快速循環(huán)的機(jī)制
▲ 作者：Chang-Lu Tao, Chong-Li Tian et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.ads7954
▲ 摘要：突觸小泡（SV）胞吐作用是神經(jīng)元通信的基礎(chǔ)，但由于原位觀測(cè)快速動(dòng)態(tài)過(guò)程的技術(shù)限制，其納米尺度動(dòng)力學(xué)機(jī)制尚未明晰。研究者通過(guò)光遺傳學(xué)耦合的時(shí)間分辨冷凍電子斷層掃描技術(shù)，成功捕獲了大鼠海馬區(qū)突觸中小泡的胞吐過(guò)程。
在突觸激活后的4毫秒內(nèi)，突觸小泡會(huì)短暫“親吻”觸質(zhì)膜，形成一個(gè)約4納米寬的脂質(zhì)融合孔，其兩側(cè)可見疑似可溶性NSF附著蛋白受體；隨后小泡迅速“收縮”至原表面積的一半左右。至70毫秒時(shí)，多數(shù)收縮后的小泡通過(guò)“逃逸”途徑完成循環(huán)，其余小泡則與突觸前膜融合。100毫秒后，超快內(nèi)吞作用會(huì)回收擴(kuò)張的突觸前膜。
這些發(fā)現(xiàn)揭示了突觸小泡胞吐與超快速循環(huán)的“親完就跑”機(jī)制，調(diào)和了現(xiàn)有理論模型的矛盾，并闡明了突觸傳遞的高效性與保真度基礎(chǔ)。
▲ 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
昆蟲后腿上的防御性真菌共生現(xiàn)象
▲ 作者：Takanori Nishino, Minoru Moriyama et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adp6699
▲ 摘要：兜蝽科臭蟲（Dinidorid stinkbug）的雌性后腿上具有一個(gè)顯著的鼓膜器官。本研究表明，該器官并非用于感知聲音，而是特化為儲(chǔ)存微生物共生體。其表面并非膜質(zhì)結(jié)構(gòu)，而是由多孔角質(zhì)層構(gòu)成，每個(gè)孔洞均與腺體分泌細(xì)胞相連。
在繁殖期的雌性個(gè)體中，后腿器官表面覆蓋著從孔洞中生長(zhǎng)出的真菌菌絲。產(chǎn)卵時(shí)，雌性會(huì)將真菌從該器官轉(zhuǎn)移至卵粒表面，菌絲通過(guò)物理屏障作用保護(hù)蟲卵免受蜂類寄生。這些真菌主要由多種低致病性蟲草科物種組成，具有豐富的多樣性。
▲ 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.
動(dòng)物學(xué)Zoology
Head-direction cells as a neural compass in bats navigating outdoors on a remote oceanic island
頭部方向細(xì)胞在偏遠(yuǎn)海島上戶外導(dǎo)航的蝙蝠中起到神經(jīng)羅盤的作用
▲ 作者：Shaked Palgi, Saikat Ray et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adw6202
▲摘要：動(dòng)物和人類依賴導(dǎo)航能力得以生存。然而，大腦“導(dǎo)航回路”中的空間神經(jīng)元此前從未在真實(shí)環(huán)境條件下被研究過(guò)。研究者在野外對(duì)空間神經(jīng)元開展了電生理研究。他們記錄了在偏遠(yuǎn)海島上任意飛行的蝙蝠的海馬體中頭部方向細(xì)胞的活動(dòng)。
這些神經(jīng)元在島嶼全域范圍內(nèi)均能穩(wěn)定表征蝙蝠的朝向定位，且不受月球與銀河動(dòng)態(tài)變化的影響。從初次探索該島嶼開始，方向調(diào)諧特性經(jīng)過(guò)數(shù)個(gè)夜晚逐漸趨于穩(wěn)定。
這些結(jié)果表明，頭部方向細(xì)胞能夠作為經(jīng)過(guò)學(xué)習(xí)形成的可靠神經(jīng)羅盤，為真實(shí)環(huán)境中的導(dǎo)航服務(wù)——彰顯了將神經(jīng)科學(xué)研究推向野外環(huán)境的重要價(jià)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.
地球科學(xué)Earth Science
Global mean sea level over the past 4.5 million years
全球平均海平面在過(guò)去450萬(wàn)年間的變化
▲ 作者：Peter U. Clark, Jeremy D. Shakun et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.adv8389
▲ 摘要：晚新生代全球平均海平面（GMSL）的變化仍不確定。研究者利用對(duì)海水氧—18同位素變化的重建，重建了自450萬(wàn)年前以來(lái)的全球平均海平面情況。這一重建考慮了溫度驅(qū)動(dòng)的全球冰蓋氧—18同位素的變化。在450萬(wàn)年至300萬(wàn)年前期間，海平面高位期仍比現(xiàn)在高出最多20 米，而首次低于現(xiàn)在的海平面低位期表明北半球冰川作用始于400萬(wàn)年前。
全球冰川作用的加劇發(fā)生在300萬(wàn)年至250萬(wàn)年前，其頂峰時(shí)期的低海平面位與21000年前末次盛冰期的低海平面位相似，并在整個(gè)更新世的大部分時(shí)間里反復(fù)出現(xiàn)。我們將冰蓋變異性的中更新世轉(zhuǎn)型期歸因于約10萬(wàn)年周期的二氧化碳變率增加對(duì)4.1萬(wàn)年周期斜率強(qiáng)迫的調(diào)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
干旱強(qiáng)度與持續(xù)時(shí)間共同作用會(huì)放大初級(jí)生產(chǎn)力損失
▲ 作者：Timothy Ohlert, Melinda D. Smith et al.
▲鏈接：
https://www.science.org/doi/10.1126/science.ads8144
▲摘要：隨著干旱期延長(zhǎng)且加劇，其對(duì)陸地初級(jí)生產(chǎn)力的影響將逐步擴(kuò)大。然而，部分生態(tài)系統(tǒng)似乎能適應(yīng)多年干旱，在干旱持續(xù)期間生產(chǎn)力下降幅度保持穩(wěn)定或逐漸收窄。
研究者通過(guò)全球74處草原與灌叢地的觀測(cè)數(shù)據(jù)，量化了干旱持續(xù)時(shí)間與強(qiáng)度對(duì)地上生產(chǎn)力的復(fù)合影響。除極端干旱事件外，這些生態(tài)系統(tǒng)總體上表現(xiàn)出對(duì)多年干旱的適應(yīng)能力。當(dāng)遭遇連續(xù)四年的極端干旱時(shí)，生態(tài)系統(tǒng)生產(chǎn)力損失較首年增加約2.5倍。
這些結(jié)果表明：若干旱持續(xù)時(shí)間與強(qiáng)度持續(xù)增加，生態(tài)系統(tǒng)行為將發(fā)生根本性轉(zhuǎn)變——從長(zhǎng)期維持低水平功能狀態(tài)，轉(zhuǎn)向在極端干旱時(shí)出現(xiàn)持續(xù)且嚴(yán)重的生產(chǎn)力損失。
▲ 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.
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