Science, 10 July 2025, Volume 389, Issue 6756
《科學》2025年7月10日，第389卷，6756期
生態地理Ecological Geography
Single- and multithread rivers originate from (im)balance between lateral erosion and accretion
單線程與多線程河流的形成及侵蝕與沉積的平衡性
▲ 作者：AUSTIN J. CHADWICK, EVAN GREENBERG, AND VAMSI GANTI
▲鏈接：https://www.science.org/doi/10.1126/science.ads6567
▲摘要：河流為何將水流約束在單一通道或分流為多條交織路徑（即“河道分支”），這一直是河流科學領域懸而未決的基礎性問題。研究者通過粒子圖像測速技術，分析了全球84條河流36年來的衛星影像數據，繪制河道分支動態變化圖，揭示了河道形態的起源機制。
結果表明：單線程河道的形成源于側向侵蝕與沉積的平衡，這種平衡使河道在遷移過程中能維持穩定寬度；多線程河道則源于失衡狀態——單個河道分支的侵蝕速率超過沉積，導致河道不斷拓寬并發生分裂。
這種“河道寬度失衡”機制不僅為地球及其他行星上多線程河道的形成提供了理論解釋，在實際應用層面，還能幫助降低基于自然解決方案的河流修復工程成本。
▲ Abstract：Why river channels confine flow to a single pathway or divide flow into multiple interwoven pathways (threads) forms a long-standing fundamental question in river science, which to date remains poorly understood. In this study, we probed channel-pattern origins by mapping thread dynamics along 84 rivers from 36 years of global satellite imagery using particle image velocimetry. Results show that single-thread channels originate from a balance between lateral erosion and accretion, which enables a thread to migrate while maintaining equilibrium width. In contrast, multithread channels originate from imbalance—erosion outpaces accretion in individual threads, causing threads to repeatedly widen and split. Thread-width imbalance provides a mechanistic explanation for how multithread channels develop on Earth and other planets and, in application, can help lower the cost of nature-based river restoration projects.
Overturning circulation structures the microbial functional seascape of the South Pacific
翻轉環流構建南太平洋微生物功能景觀
▲ 作者：BETHANY C. KOLODY, ROHAN SACHDEVA, HONG ZHENG, ZOLTN FSSY, EUNICE TSANG, ROLF E. SONNERUP, SARAH G. PURKEY, ERIC E. ALLEN, JILLIAN F. BANFIELD, AND ANDREW E. ALLEN
▲鏈接：https://www.science.org/doi/10.1126/science.adv6903
▲摘要：全球海洋被大規模水體運動分割成不同區域，這些運動勾勒出的物理化學區域可能代表不同的生態系統。構建海洋功能生態系統圖譜將幫助人們理解生物化學循環和碳儲存的機制。
研究者在南太平洋觀測到“系統發育躍變層”——從表層低物種豐富度到混合層下方持續高豐富度的陡峭過渡。他們還識別出水團特異性的細菌群落聚類，將其劃分為6個空間組織分類群和10個獨特生物群落區。
▲ Abstract：The oceans of our planet are divided into regions by massive water movements that delineate physicochemical regimes that may represent ecosystems. A functional ecosystem atlas of the ocean will help us understand what happens to biochemical cycling and storage of carbon. For the South Pacific, Kolody et al. observed a “phylocline,” a steep transition from low local species richness at the surface to consistently high richness below the mixed layer. They also discerned water mass–specific clustering of bacterial communities into six spatially organized taxonomic cohorts and 10 distinct biomes.
化學Chemistry
Harnessing carbene polarity: Unified catalytic access to donor, neutral, and acceptor carbenes
利用卡賓極性：通過統一催化途徑獲得給體、中性和受體卡賓
▲ 作者：KHUE N. M. NGUYEN, XUELING MO, BETHANY M. DEMUYNCK, MOHAMED ELSAYED, JACOB J. A. GARWOOD, DUONG T. NGO, ILIAS KHAN RANA, AND DAVID A. NAGIB
▲鏈接：https://www.science.org/doi/10.1126/science.adw4177
▲摘要：卡賓是具有未成鍵電子對的二配位高活性碳中心，是眾多反應中的重要中間體。然而其前體化合物往往自身不穩定且具有危險性。
研究者報道了一種創新方法：在鐵催化劑和鋅還原劑作用下，可從相對穩定的二氯化物出發合成具有多種取代基的卡賓。由于采用通用合成路徑，研究者還能系統評估取代基的供電子或吸電子效應對卡賓反應活性的影響。
▲ Abstract：Carbenes are reactive, two-coordinate carbon centers with an unbonded electron pair. They are useful intermediates in numerous reactions, but their precursors are themselves often unstable and hazardous. Nguyen et al. now report a protocol to generate carbenes with a very wide variety of substituents from relatively stable dichloride compounds using an iron catalyst and a zinc reductant. Because of the common mode of access, the authors can also systematically classify the electron-donating or -withdrawing influence of the substituents on carbene reactivity.
Stable and uniform self-assembled organic diradical molecules for perovskite photovoltaics
穩定均一的自組裝有機雙自由基分子用于鈣鈦礦光伏器件
▲ 作者：WENPING WU, HAN GAO, LINGBO JIA, YUAN LI, DEZHONG ZHANG, HONGMEI ZHAN, JIANAN XU, BINHE LI, ZIRAN GENG , AND CHUANJIANG QIN
▲鏈接：https://www.science.org/doi/10.1126/science.adv4551
▲摘要：自組裝有機分子作為鈣鈦礦太陽能電池的關鍵材料，其性能提升對光伏技術發展至關重要。通過強給體—受體相互作用、共面共軛和空間位阻的協同設計，構建具有雙自由基特性的自組裝單分子層材料，可作為鈣鈦礦太陽能電池高效穩定的空穴傳輸層。
研究者采用掃描電化學顯微鏡—薄層循環伏安技術，系統評估了雙自由基分子薄膜在空穴傳輸性能、穩定性和均一性方面的提升。基于該材料的微型組件（10平方厘米）實現了23.6%的光電轉換效率，鈣鈦礦—硅疊層器件（1平方厘米）更獲得34.2%的認證效率，且在45℃下連續運行2000小時后仍保持>97%的初始效率。
▲ Abstract：The incorporation of strong donor-acceptor interactions, coplanar conjugation, and steric hindrance creates diradical self-assembled monolayer molecules that function as a robust and efficient hole transporter for perovskite solar cells. Wu et al. used scanning electrochemical cell microscopy–thin-layer cyclic voltammetry to determine the improvements in the hole transport properties, stability, and uniformity of diradical molecular films. Mini-modules incorporating these molecules reached a power conversion efficiency (PCE) of 23.6% for an area of 10 square centimeters, and silicon-perovskite tandem devices reached a certified PCE of 34.2% for a 1-square-centimeter cell.
神經元科學NEUROSCIENCE
Human neuron subtype programming via single-cell transcriptome-coupled patterning screens
人類神經元亞型編程
▲ 作者：HSIU-CHUAN LIN, JASPER JANSSENS, BENEDIKT EISINGER, PHILIPP HORNAUER, ANN-SOPHIE KROELL, MALGORZATA SANTEL, MARIA PASCUAL-GARCIA, RYOKO OKAMOTO, KYRIAKI KARAVA , AND BARBARA TREUTLEIN
▲鏈接：https://www.science.org/doi/10.1126/science.adn6121
▲摘要：人類誘導多能干細胞被用于生成誘導神經元，這一技術廣泛應用于從疾病建模到藥物篩選的各類神經科學研究中。然而，重現人類神經元的高度異質性仍面臨挑戰。
研究者對480種形態發生素組合進行了系統篩選，同時過表達兩種不同轉錄因子中的一種，以此生成誘導神經元庫，并通過單細胞 RNA 測序對其進行連續分析。
他們識別出多種神經元亞型，并將它們沿著神經管發育的前后軸和背腹軸進行了定位。研究結果為人類神經元的工程化構建提供了寶貴資源。
▲ Abstract：The use of human induced pluripotent stem cells to generate induced neurons is used in a broad range of neuroscience studies, from disease modeling to drug screening. However, replicating the large heterogeneity of human neurons is challenging. Lin et al. performed a systematic screening of 480 morphogen combinations coupled with overexpression of one of two different transcription factors to generate a library of induced neurons successively analyzed using single-cell RNA sequencing. The authors identified a broad range of neuronal subtypes and mapped them along the anterior-posterior and dorsal-ventral axes of neural tube development. The results provide a valuable resource for engineering human neurons.
Microglia replacement halts the progression of microgliopathy in mice and humans
小膠質細胞替換阻止細胞病變
▲ 作者：JINGYING WU, YAFEI WANG, XIAOYU LI, PEI OUYANG, YUANYUAN CAI, YANG HE, MENGYUAN ZHANG, XINGHUA LUAN, YUXIAO JIN , AND BO PENG
▲鏈接：https://www.science.org/doi/10.1126/science.adr1015
▲ 摘要：集落刺激因子1受體（CSF1R）基因突變會導致一種嚴重的神經系統疾病——成人型軸突球樣變性和色素膠質細胞性腦白質病（ALSP），目前尚無有效治療方法。在大腦中，CSF1R主要由小膠質細胞表達。
研究者通過構建ALSP小鼠模型，發現利用骨髓移植（BMT）將CSF1R缺陷的小膠質細胞替換為正常表達CSF1R的小膠質細胞，可顯著減輕腦病理損傷。具有重要臨床意義的是，骨髓移植成功阻斷了4例ALSP患者的疾病進展，表明這可能是治療CSF1R相關疾病的有效策略。
▲ Abstract：Mutations in the gene encoding colony stimulating factor 1 receptor (CSF1R) lead to a severe neurological disease called adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), for which there are no treatments. In the brain, CSFR1 is mainly expressed by microglia. Wu et al. developed and used mouse models of ALSP to show that replacing CSF1R-deficient microglia with CSF1R-normal microglia using bone marrow transplantation (BMT) strongly attenuated brain pathology. Of major clinical relevance, BMT halted disease progression in four individuals, suggesting that this might be an effective therapeutic strategy for treating CSF1R-associated disorders.
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