Science,  10 July 2025, Volume 389, Issue 6756

《科学》2025年7月10日，第389卷，6756期

生态地理Ecological Geography

Single- and multithread rivers originate from (im)balance between lateral erosion and accretion

单线程与多线程河流的形成及侵蚀与沉积的平衡性

▲ 作者：AUSTIN J. CHADWICK, EVAN GREENBERG, AND VAMSI GANTI 

▲链接：https://www.science.org/doi/10.1126/science.ads6567

▲摘要：河流为何将水流约束在单一通道或分流为多条交织路径（即“河道分支”），这一直是河流科学领域悬而未决的基础性问题。研究者通过粒子图像测速技术，分析了全球84条河流36年来的卫星影像数据，绘制河道分支动态变化图，揭示了河道形态的起源机制。

结果表明：单线程河道的形成源于侧向侵蚀与沉积的平衡，这种平衡使河道在迁移过程中能维持稳定宽度；多线程河道则源于失衡状态——单个河道分支的侵蚀速率超过沉积，导致河道不断拓宽并发生分裂。

这种“河道宽度失衡”机制不仅为地球及其他行星上多线程河道的形成提供了理论解释，在实际应用层面，还能帮助降低基于自然解决方案的河流修复工程成本。

▲ 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

翻转环流构建南太平洋微生物功能景观

▲ 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 

▲链接：https://www.science.org/doi/10.1126/science.adv6903

▲摘要：全球海洋被大规模水体运动分割成不同区域，这些运动勾勒出的物理化学区域可能代表不同的生态系统。构建海洋功能生态系统图谱将帮助人们理解生物化学循环和碳储存的机制。

研究者在南太平洋观测到“系统发育跃变层”——从表层低物种丰富度到混合层下方持续高丰富度的陡峭过渡。他们还识别出水团特异性的细菌群落聚类，将其划分为6个空间组织分类群和10个独特生物群落区。

▲ 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.

化学Chemistry

Harnessing carbene polarity: Unified catalytic access to donor, neutral, and acceptor carbenes

利用卡宾极性：通过统一催化途径获得给体、中性和受体卡宾

▲ 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 

▲链接：https://www.science.org/doi/10.1126/science.adw4177

▲摘要：卡宾是具有未成键电子对的二配位高活性碳中心，是众多反应中的重要中间体。然而其前体化合物往往自身不稳定且具有危险性。

研究者报道了一种创新方法：在铁催化剂和锌还原剂作用下，可从相对稳定的二氯化物出发合成具有多种取代基的卡宾。由于采用通用合成路径，研究者还能系统评估取代基的供电子或吸电子效应对卡宾反应活性的影响。

▲ 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

稳定均一的自组装有机双自由基分子用于钙钛矿光伏器件

▲ 作者：WENPING WU, HAN GAO, LINGBO JIA, YUAN LI, DEZHONG ZHANG, HONGMEI ZHAN, JIANAN XU, BINHE LI, ZIRAN GENG , AND CHUANJIANG QIN

▲链接：https://www.science.org/doi/10.1126/science.adv4551

▲摘要：自组装有机分子作为钙钛矿太阳能电池的关键材料，其性能提升对光伏技术发展至关重要。通过强给体—受体相互作用、共面共轭和空间位阻的协同设计，构建具有双自由基特性的自组装单分子层材料，可作为钙钛矿太阳能电池高效稳定的空穴传输层。

研究者采用扫描电化学显微镜—薄层循环伏安技术，系统评估了双自由基分子薄膜在空穴传输性能、稳定性和均一性方面的提升。基于该材料的微型组件（10平方厘米）实现了23.6%的光电转换效率，钙钛矿—硅叠层器件（1平方厘米）更获得34.2%的认证效率，且在45℃下连续运行2000小时后仍保持>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.

神经元科学NEUROSCIENCE

Human neuron subtype programming via single-cell transcriptome-coupled patterning screens

人类神经元亚型编程

▲ 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 

▲链接：https://www.science.org/doi/10.1126/science.adn6121

▲摘要：人类诱导多能干细胞被用于生成诱导神经元，这一技术广泛应用于从疾病建模到药物筛选的各类神经科学研究中。然而，重现人类神经元的高度异质性仍面临挑战。

研究者对480种形态发生素组合进行了系统筛选，同时过表达两种不同转录因子中的一种，以此生成诱导神经元库，并通过单细胞 RNA 测序对其进行连续分析。

他们识别出多种神经元亚型，并将它们沿着神经管发育的前后轴和背腹轴进行了定位。研究结果为人类神经元的工程化构建提供了宝贵资源。

▲ 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

小胶质细胞替换阻止细胞病变

▲ 作者：JINGYING WU, YAFEI WANG, XIAOYU LI, PEI OUYANG, YUANYUAN CAI, YANG HE, MENGYUAN ZHANG, XINGHUA LUAN, YUXIAO JIN , AND BO PENG 

▲链接：https://www.science.org/doi/10.1126/science.adr1015

▲ 摘要：集落刺激因子1受体（CSF1R）基因突变会导致一种严重的神经系统疾病——成人型轴突球样变性和色素胶质细胞性脑白质病（ALSP），目前尚无有效治疗方法。在大脑中，CSF1R主要由小胶质细胞表达。

研究者通过构建ALSP小鼠模型，发现利用骨髓移植（BMT）将CSF1R缺陷的小胶质细胞替换为正常表达CSF1R的小胶质细胞，可显著减轻脑病理损伤。具有重要临床意义的是，骨髓移植成功阻断了4例ALSP患者的疾病进展，表明这可能是治疗CSF1R相关疾病的有效策略。

▲ 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.