《科学》(20241129出版)一周论文导读

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摘要:▲ 作者:MADELEINE S. JUNKINS, NI Y. FENG, DANA K. MERRIMAN, SVIATOSLAV N. BAGRIANTSEV, AND ELENA O. GRACHEVA

编译|冯维维

Science, 29 November 2024, Volume 386, Issue 6725

《科学》2024年11月29日,第386卷,6725期

生物学Biology

Suppression of neurons in circumventricular organs enables months-long survival without water in thirteen-lined ground squirrels

这样做可让十三纹地松鼠在缺水情况下存活数月

▲ 作者:MADELEINE S. JUNKINS, NI Y. FENG, DANA K. MERRIMAN, SVIATOSLAV N. BAGRIANTSEV, AND ELENA O. GRACHEVA

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▲摘要:

任何经常锻炼的人都知道口渴是什么感觉。这种对水的强烈需求在哺乳动物中很常见,并确保人们对水的生理需求得到满足。然而在冬眠的动物中,饮水和口渴会被抑制数月。

Junkins等人观察了十三纹地松鼠的这一现象,发现它们即使面对水分不足的生理指标,也能持续数月的抑制口渴。这种抑制是由脑室周围器官的神经元活性降低介导的,这些器官在冬季功能降低。

▲ Abstract:

Anyone who exercises regularly knows what it is like to feel intensely thirsty. This powerful drive for water is common within mammals and ensures that our physiological need for water is met. In animals that hibernate, however, drinking and thirst are suppressed for months. Junkins et al. looked at this phenomenon in the thirteen-lined ground squirrel, a well-studied hibernating rodent, and found that their months-long suppression of thirst comes even in the face of physiological indicators of fluid deficit. This suppression is mediated by reduced activity of neurons in the circumventricular organs, which experience reduced function in winter.

Exposure to sugar rationing in the first 1000 days of life protected against chronic disease

出生后头1000天接受糖配给,可预防慢性疾病

▲ 作者:TADEJA GRACNER, CLAIRE BOONE, AND PAUL J. GERTLER

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▲摘要:

作者利用1953年9月英国糖配给结束后的准实验变化,研究了怀孕后1000天内限制糖摄入对2型糖尿病和高血压的影响。配给制将糖的摄入量限制在当前膳食指南的范围内,配给制结束后,糖的摄入量几乎立即翻了一番。

他们使用英国生物银行数据进行事件研究设计,比较定量配给结束前后怀孕的成年人,发现早期定量配给使2型糖尿病和高血压的风险分别降低了35%和20%,并将疾病发病时间分别推迟了4年和2年。

在子宫内接触糖的保护作用很明显,产后限制糖的保护作用增强,尤其是在6个月后,可能开始吃固体食物。在子宫内,仅糖配给就占了风险降低的三分之一。

▲ Abstract:

We examined the impact of exposure to sugar restrictions within 1000 days after conception on type 2 diabetes and hypertension, leveraging quasi-experimental variation from the end of the United Kingdom’s sugar rationing in September 1953. Rationing restricted sugar intake to levels within current dietary guidelines, and consumption nearly doubled immediately after rationing ended. Using an event study design with UK Biobank data comparing adults conceived just before or after rationing ended, we found that early-life rationing reduced type 2 diabetes and hypertension risk by about 35 and 20% and delayed disease onset by 4 and 2 years, respectively. Protection was evident with in utero exposure and increased with postnatal sugar restriction, especially after 6 months, when eating of solid foods likely began. In utero sugar rationing alone accounted for about one-third of the risk reduction.

信息学和机器人Informatics & Robotics

Misinformation exploits outrage to spread online

虚假信息利用愤怒在网上传播

▲ 作者:KILLIAN L. MCLOUGHLIN, WILLIAM J. BRADY, ADEN GOOLSBEE, BEN KAISER, KATE KLONICK, AND M. J. CROCKETT

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▲摘要:

虚假信息仍然是对民主完整性、国家安全和公共卫生的重大威胁。然而,社交媒体平台难以遏制有害但吸引人的内容的传播。在不同平台上,作者研究了情绪,特别是道德义愤(厌恶和愤怒的混合)在错误信息传播中的作用。

与可靠的新闻来源相比,来自虚假信息来源的帖子引起的愤怒反应和愤怒多于快乐或悲伤的情绪。用户被激励去转发那些引起愤怒的内容,并且在没有先阅读内容以辨别其准确性的情况下进行分享。仅仅强调准确分享的干预措施可能无法遏制错误信息,因为用户可能会分享令人发指的、不准确的内容,以表明他们的道德立场或对政治团体的忠诚。

▲ Abstract:

Misinformation remains a major threat to US democratic integrity,national security, and public health. However, social media platforms struggle to curtail the spread of the harmful but engaging content. Across platforms, McLoughlin et al. examined the role of emotions, specifically moral outrage (a mixture of disgust and anger), in the diffusion of misinformation. Compared with trustworthy news sources, posts from misinformation sources evoked more angry reactions and outrage than happy or sad sentiments. Users were motivated to reshare content that evoked outrage and shared it without reading it first to discern accuracy. Interventions that solely emphasize sharing accurately may fail to curb misinformation because users may share outrageous, inaccurate content to signal their moral positions or loyalty to political groups.

Magnetically programmed diffractive robotics

磁编程衍射机器人

▲ 作者:CONRAD L. SMART, TANNER G. PEARSON, ZEXI LIANG, MELODY X. LIM, MOHAMED I. ABDELRAHMAN, FRANCESCO MONTICONE, ITAI COHEN, AND PAUL L. MCEUEN

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▲摘要:

具有与光的波长相当特征的微型机器人为探索微观世界和在微观尺度上控制光提供了新的途径。研究者介绍了一类在可见光衍射极限下工作的新型磁控微型机器人,并将其称之为衍射机器人。

他们将纳米厚的机械膜、可编程纳米磁体和衍射光学元件结合在一起,创造出了不受束缚的微型机器人,小到足以衍射可见光,又足够灵活,可以在毫拉级磁场中进行复杂的重新配置。研究者还展示了它们的应用,包括使用一种结构照明显微镜的变体进行亚衍射成像,用于光束转向和聚焦的可调谐衍射光学元件,以及具有皮牛顿灵敏度的力传感。

▲ Abstract:

Microscopic robots with features comparable with the wavelength of light offer new ways of probing the microscopic world and controlling light at the microscale. We introduce a new class of magnetically controlled microscopic robots (microbots) that operate at the visible-light diffraction limit, which we term diffractive robots. We combined nanometer-thick mechanical membranes, programmable nanomagnets, and diffractive optical elements to create untethered microbots small enough to diffract visible light and flexible enough to undergo complex reconfigurations in millitesla-scale magnetic fields. We demonstrated their applications, including subdiffractive imaging by using a variant of structured illumination microscopy, tunable diffractive optical elements for beam steering and focusing, and force sensing with piconewton sensitivity.

化学和物理学Chemistry & Physics

Aromatic-aliphatic hydrocarbon separation with oriented monolayer polyhedral membrane

定向单层多面体膜分离芳烃—脂肪族烃

▲ 作者:HAO SUN, NAIXIN WANG, YINGHUI XU, FENGKAI WANG, JUN LU, HUANTING WANG, AND QUAN-FU AN

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▲摘要:

芳烃—脂肪族烃分离是一项具有挑战性的重要工业工艺。渗透蒸发膜技术具有分离这些混合物的潜力。研究者开发了一种定向单层多面体(OMP)膜,它由一层有序的多面体粒子组成,并由超支化聚合物锚定。

它含有高密度的直的、选择性的纳米通道,使芳香分子优先运输。与传统的随机取向混合基质膜相比,OMP膜提高了芳烃—脂肪烃与C6和C7化合物混合物的渗透汽化分离指标,性能是现有膜的3 ~ 10倍。这种高性能证明了OMP膜在烃类分子分离及其在石脑油原料增值分离中的应用潜力。

▲ Abstract:

Aromatic-aliphatic hydrocarbon separation is a challenging but important industrial process. Pervaporation membrane technology has the potential for separating these mixtures. We developed an oriented monolayer polyhedral (OMP) membrane that consists of a monolayer of ordered polyhedral particles and is anchored by hyperbranched polymers. It contains a high density of straight, selective nanochannels, enabling the preferential transport of aromatic molecules. Compared with traditional mixed-matrix membranes with random orientations, the OMP membrane improves the pervaporation separation index for aromatic-aliphatic hydrocarbon mixtures with C6 and C7 compounds, surpassing the performance of existing membranes by 3 to 10 times. This high performance demonstrates the potential of OMP membranes for hydrocarbon molecular separation and their application in the value-added separation of naphtha feedstocks.

Realization of one-dimensional anyons with arbitrary statistical phase

具有任意统计相位的一维任意子的实现

▲ 作者:JOYCE KWAN, PERRIN SEGURA, YANFEI LI, SOOSHIN KIM, ALEXEY V. GORSHKOV, ANDRé ECKARDT, BRICE BAKKALI-HASSANI, AND MARKUS GREINER

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▲摘要:

低维量子系统可以容纳任何粒子,这些粒子的交换统计量既不是玻色子也不是费米子。然而,一维上的任意子的物理学在很大程度上仍未被探索。在这项工作中,研究者利用光学晶格中的超冷原子实现了具有任意交换统计量的一维阿贝尔任意子,其中我们通过密度依赖的佩尔相来设计统计相。

他们探索了两个任意子在量子行走中的动力学行为,并观察了任意子的Hanbury Brown-Twiss效应以及在没有现场相互作用的情况下束缚态的形成。一旦引入相互作用,他们观察到与玻色子和费米子的对称动力学相反的空间不对称输运。该工作为探索一维任意子的多体行为奠定了基础。

▲ Abstract:

Low-dimensional quantum systems can host anyons, particles with exchange statistics that are neither bosonic nor fermionic. However, the physics of anyons in one dimension remains largely unexplored. In this work, we realize Abelian anyons in one dimension with arbitrary exchange statistics using ultracold atoms in an optical lattice, where we engineer the statistical phase through a density-dependent Peierls phase. We explore the dynamical behavior of two anyons undergoing quantum walks and observe the anyonic Hanbury Brown–Twiss effect as well as the formation of bound states without on-site interactions. Once interactions are introduced, we observe spatially asymmetric transport in contrast to the symmetric dynamics of bosons and fermions. Our work forms the foundation for exploring the many-body behavior of one-dimensional anyons.

来源:新浪财经

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