《科学》（20250124出版）一周论文导读
发布时间: 2025-01-27 09:20:43
Science,24 JAN 2025, VOL 387, ISSUE 6732
《科学》2025年1月24日，第387卷，6732期
材料科学Materials Science
Ductilization of 2.6-GPa alloys via short-range ordered interfaces and supranano precipitates
短程有序界面和超纳析出相实现2.6GPa级合金的优异均匀延伸率
▲ 作者：YONG-QIANG, WEN-HAO CHA et al.
▲链接：
https://www.science.org/doi/10.1126/science.adr4917
▲摘要：
我们提出了一种针对晶粒内部和晶界区域的超纳米（<10纳米）和短程有序化设计。这种设计应用于基于钒、钴和镍的细晶合金，并添加了钨、铜、铝和硼。通过短程有序化在晶界附近的偏聚，显著实现了晶界相关的强化和塑化机制。
此外，尺寸较大的超纳米有序化对位错和层错具有更强的钉扎效应，这些位错和层错在塑性变形过程中在晶粒内部持续增殖和累积。这些机制促使合金在10%应变下断裂时，流变应力持续增加，达到2.6GPa的拉伸应力。
▲ Abstract：
We present a supranano (<10 nanometers) and short-range ordering design for grain interiors and grain boundary regions, respectively, in fine-grained alloys based on vanadium, cobalt, and nickel, with additions of tungsten, copper, aluminum, and boron. The pronounced grain boundary–related strengthening and ductilization mechanism is realized through segregation of the short-range ordering near the grain boundary. Furthermore, the supranano ordering with a larger size has an enhanced pinning effect for dislocations and stacking faults, multiplied and accumulated in grain interiors during plastic deformation. These mechanisms promote continuously increased flow stress until fracture of the alloy at 10% strain with 2.6-gigapascal tensile stress.
Photo-induced chirality in a nonchiral crystal
非手性晶体中的光诱导手性
▲ 作者：Z. ZENG, M. F?RST et al.
▲链接：
https://www.science.org/doi/10.1126/science.adr4713
▲摘要：
在此，我们展示了通过太赫兹脉冲辐照，可以在非手性的压电材料硼磷酸盐（BPO4）中诱导出任意手性的手性特征。两个正交的、简并的振动模式中任何一个的共振激发决定了诱导手性序参数的信号。
光诱导相的光学活性与典型手性物质α-石英的静态值相当。我们的研究结果为复杂材料中非平衡量子现象的调控提供了新的前景。
▲ Abstract：
Here, we show that chirality of either handedness can be induced in the nonchiral piezoelectric material boron phosphate (BPO4) by irradiation with terahertz ulses. Resonant excitation of either one of two orthogonal, degenerate vibrational modes determines the sign of the induced chiral order parameter. The optical activity of the photo-induced phases is comparable to the static value of prototypical chiral α-quartz. Our findings offer new prospects for the control of out-of-equilibrium quantum phenomena in complex materials.
生态学Ecology
Variable impacts of land-based climate mitigation on habitat area for vertebrate diversity
陆地气候变化减缓措施对脊椎动物多样性栖息地面积的多种影响
▲ 作者：JEFFREY R. SMITH, EVELYN M. BEAURY et al.
▲链接：
https://www.science.org/doi/10.1126/science.adm9485
▲摘要：
在此，我们对14234种脊椎动物的气候和栖息地需求进行了建模，并表明这些策略对物种栖息地面积的影响并非主要通过气候变化减缓实现，而是通过栖息地转换。
在不同地区，通过土地覆盖变化和气候变化减缓，重新造林能为物种提供更多的栖息地，而造林和生物能源作物种植所导致的栖息地丧失通常超过了气候变化减缓带来的好处。这项研究表明，如何以及在哪里部署基于土地的减缓策略，才不会无意中减少全球生物多样性的栖息地面积。
▲ Abstract：
Here, we modeled the climate and habitat requirements of 14,234 vertebrate species and show that the impact of these strategies on species’ habitat area tends not to arise through climate mitigation, but rather through habitat conversion. Across locations, reforestation tends to provide species more habitat through both land-cover change and climate mitigation, whereas habitat loss from afforestation and bioenergy cropping typically outweighs the climate mitigation benefits. This work shows how and where land-based mitigation strategies can be deployed without inadvertently reducing the area of habitat for global biodiversity.
Antarctic krill vertical migrations modulate seasonal carbon export
南极磷虾的垂直迁移行为调节季节性碳输出
▲ 作者：A. J. R. SMITH, S. WOTHERSPOON et al.
▲链接：
https://www.science.org/doi/10.1126/science.adq5564
▲摘要：
通过消耗表层浮游植物并在深海排泄，海洋生物的垂直迁移行为促进了碳的输出。然而，由于生物地球化学模型缺乏观测数据，导致对像南极磷虾（Euphausia superba）一样的迁移生物的碳循环过程的描述过于简化。利用在东南极地区一年的声学观测数据构建的数值模型，我们估算出南极磷虾粪便颗粒的总颗粒有机碳（POC）通量为每平方米每天9.68毫克碳。
最多有25%的磷虾迁移超过200米的深度，且这一过程具有强烈的季节性特征，将总磷虾POC通量中不到10%的部分（每平方米每天1.28毫克碳）输送到深海。准确的碳通量估算对于制定气候政策和减排策略至关重要，如果未能掌握到这种季节性特征，包含垂直迁移过程的模型可能会高估碳输出。
▲ Abstract：
Vertical migrations by marine organisms contribute to carbon export by consumption of surface phytoplankton followed by defecation in the deep ocean. However, biogeochemical models lack observational data, leading to oversimplified representation of carbon cycling by migrating organisms, such as Antarctic krill (Euphausia superba). Using a numerical model informed by 1 year of acoustic observations in the East Antarctic, we estimated the total particulate organic carbon (POC) flux from krill fecal pellets to be 9.68 milligrams of carbon per square meter per day (mg C m?2day?1). A maximum of 25% of krill migrated to depths >200 m with a strong seasonality component, transporting <10% of the total krill POC flux (1.28 mg Cm?2day?1) to the deep ocean. Accurate carbon flux estimates are essential to inform climate policy and mitigation strategies, and models that include vertical migration will overestimate carbon export if this seasonality is not captured.
生物学Biology
Identification of the subventricular tegmental nucleus as brainstem reward center
脑室下被盖核是脑干的奖赏中枢
▲ 作者：KRISZTIáN ZICHó, BOLDIZSáR ZSOLT BALOG et al.
▲链接：
https://www.science.org/doi/10.1126/science.adr2191
▲摘要：
我们认为脑室下被盖核（SVTg）是脑干的奖赏中枢。在小鼠身上，奖励及其预期能够激活SVTg，而SVTg的刺激会导致位置偏好、焦虑减少以及伏隔核多巴胺的释放。小鼠会自行刺激SVTg，而该区域也可以被新皮层直接激活，从而有效抑制与抑郁相关联的侧背侧丘脑。
这种机制或许也能解释为什么抑制SVTg会导致厌恶情绪的增加以及恐惧感的增强。这些发现的转化相关性得到了大鼠、猴和人类脑干研究的证据支持，从而确立了SVTg作为奖赏处理、情绪价值和动机的关键枢纽。
▲ Abstract：
We identified the subventricular tegmental nucleus (SVTg) as a brainstem reward center. In mice, reward and its prediction activate the SVTg, and SVTg stimulation leads to place preference, reduced anxiety, and accumbal dopamine release. Mice self-stimulate the SVTg, which can also be activated directly by the neocortex, resulting in effective inhibition of the lateral habenula, a region associated with depression. This mechanism may also explain why SVTg suppression induces aversion and increases fear. The translational relevance of these findings is supported by evidence in the rat, monkey, and human brainstem, establishing SVTg as a key hub for reward processing, emotional valence, and motivation.
A single gene orchestrates androgen variation underlying male mating morphs in ruffs
单个基因调控雄性鹬求偶形态的雄激素差异
▲ 作者：JASMINE L. LOVELAND, ALEX ZEMELLA et al.
▲链接：
https://www.science.org/doi/10.1126/science.adp5936
▲摘要：
我们发现在鹬鸟（ruff sandpipers）的三种雄性求偶形态之间，血液中雄激素的差异与17β-羟基类固醇脱氢酶2（HSD17B2）有关。该酶由决定这些形态的超基因中的一个基因编码。低睾酮雄性个体的血液中HSD17B2的表达水平高于高睾酮雄性个体，同时在与社会行为和睾酮生成相关的大脑区域中也是如此。
衍生的HSD17B2同工酶在高睾酮雄性中缺失，但在低睾酮雄性中会被优先表达。它们将睾酮转化为雄烯二酮的速度比同工酶更快。因此，单个基因在调控、序列和结构上的进化变化共同引入了生殖表型背后的内分泌差异。
▲ Abstract：
We show that differences in circulating androgens between the three male mating morphs in ruff sandpipers are linked to 17-beta hydroxysteroid dehydrogenase 2 (HSD17B2), encoded by a gene within the supergene that determines the morphs. Low-testosterone males had higher HSD17B2 expression in blood than high-testosterone males, as well as in brain areas related to social behaviors and testosterone production. Derived HSD17B2 isozymes, which are absent in high-testosterone males but preferentially expressed in low-testosterone males, converted testosterone to androstenedione faster than the ancestral isozyme. Thus, a combination of evolutionary changes in regulation, sequence, and structure of a single gene introduces endocrine variation underlying reproductive phenotypes.
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