编译|李言

Science, 22 NOV 2024, Volume 386 Issue 6724

《科学》2024年11月22日，第386卷，6724期

  ?

化学物理Chemical Physics

Ultrafast all-optical coherence of molecular electron spins in room-temperature water solution

室温水溶液中分子电子自旋的超快全光相干性

▲ 作者：ERICA SUTCLIFFE, NATHANAEL P. KAZMIERCZAK, AND RYAN G. HADT

▲ 链接：https://www.science.org/doi/10.1126/science.ads0512

▲摘要：

在这项研究中，我们利用泵浦—探测偏振光谱来初始化和跟踪分子中的电子自旋相干性。通过设计使自旋与光高效耦合，水溶性的六氯铱酸钾（IV）在室温和微摩尔浓度下，可以检测几皮秒的自由感应衰变信号。

我们发现，黏度对退相干寿命变化影响很大。该方法将实验时间分辨率提高了5个数量级，使得在传统技术只能显示25K以下相干性的系统中观察分子电子自旋相干性成为可能。

▲ Abstract：

In this study, we utilized pump-probe polarization spectroscopy to initialize and track electron spin coherence in a molecule. Designed to efficiently couple spins to light, aqueous potassium hexachloroiridate(IV) enabled detection of few-picosecond free-induction decay at room temperature and micromolar concentrations. Viscosity was found to strongly vary decoherence lifetimes. This approach has improved the experimental time resolution by up to five orders of magnitude, making it possible to observe molecular electron spin coherence in a system that only exhibits coherence below 25 kelvin with traditional techniques.

材料科学Material Sciences

Mechanically strong yet metabolizable supramolecular plastics by desalting upon phase separation

通过相分离脱盐，获得机械强度高但可代谢的超分子塑料

▲ 作者：YIREN CHEN, EIJI HIRANO, HAO WANG et al.

▲链接：

https://www.science.org/doi/10.1126/science.ado1782

▲摘要：

在海洋中可代谢的塑料对于可持续发展非常重要。在这项研究中，我们报告了前所未有的塑料的非共价合成，这种塑料机械强度高，但由于其与电解质的解离性质，在生物相关条件下可代谢。

盐桥接六偏磷酸钠与二或三位硫酸胍在水中形成交联的超分子网络，除非电解质重新补给，否则该连接是稳定的。这种不寻常的稳定性是由液—液相分离引起的，这种分离将盐桥接产生的硫酸钠排出到富水相中。

干燥剩余的冷凝液相产生可热重塑的玻璃塑料，如热塑性塑料，甚至在疏水性聚对二甲苯涂层的水介质中也可用。这种方法可以扩展到适用于三维打印的多糖基超分子塑料。

▲ Abstract：

Plastics that can metabolize in oceans are highly sought for a sustainable future. In this work, we report the noncovalent synthesis of unprecedented plastics that are mechanically strong yet metabolizable under biologically relevant conditions owing to their dissociative nature with electrolytes. Salt-bridging sodium hexametaphosphate with di- or tritopic guanidinium sulfate in water forms a cross-linked supramolecular network, which is stable unless electrolytes are resupplied. This unusual stability is caused by a liquid-liquid phase separation that expels sodium sulfate, generated upon salt bridging, into a water-rich phase. Drying the remaining condensed liquid phase yields glassy plastics that are thermally reshapable, such as thermoplastics, and usable even in aqueous media with hydrophobic parylene C coating. This approach can be extended to polysaccharide-based supramolecular plastics that are applicable for three-dimensional printing.

地球科学Earth Sciences

Ship collision risk threatens whales across the world’s oceans

船舶碰撞风险威胁全球海洋里的鲸鱼

▲ 作者：ANNA C. NISI, HEATHER WELCH et al.

▲链接：

https://www.science.org/doi/10.1126/science.adp1950

▲摘要：

在商业捕鲸几乎完全停止后，船舶碰撞已成为大型鲸鱼的主要威胁，但世界上大多数海洋区域都缺乏对碰撞风险的了解。我们建立了一个包含43.5万鲸鱼位置的数据集，以生成4个遍布全球的种群的分布模型。

然后，我们将17.6万艘船的超过350亿个位置结合起来，得出了全球捕鲸船碰撞风险的估计。92%的鲸鱼活动范围内都有航运活动，不到7%的风险热点包含减少碰撞的管理策略。只要将管理范围扩大到2.6%的海洋表面，就可以实现热点地区的全面覆盖。在航运业快速发展的背景下，这些结论可支持大型鲸鱼种群的持续恢复。

▲ Abstract：

After the near-complete cessation of commercial whaling, ship collisions have emerged as a primary threat to large whales, but knowledge of collision risk is lacking across most of the world’s oceans. We compiled a dataset of 435,000 whale locations to generate global distribution models for four globally ranging species. We then combined >35 billion positions from 176,000 ships to produce a global estimate of whale-ship collision risk. Shipping occurs across 92% of whale ranges, and <7% of risk hotspots contain management strategies to reduce collisions. Full coverage of hotspots could be achieved by expanding management over only 2.6% of the ocean’s surface. These inferences support the continued recovery of large whales against the backdrop of a rapidly growing shipping industry.

生物学Biology

Reconstruction of the human amylase locus reveals ancient duplications seeding modern-day variation

重建人类淀粉酶位点揭示了古代基因拷贝是现代变异的起源

▲ 作者：FEYZA YILMAZ, CHARIKLEIA KARAGEORGIOU et al.

▲链接：

https://www.science.org/doi/10.1126/science.adn0609

▲摘要：

我们在98名现代人中以核苷酸分辨率鉴定了30种结构上不同的单倍型，揭示了AMY1拷贝的编码序列在负选择下进化。对古人类和古人类基因组中这些单倍型的基因组分析表明，一种可以追溯到80万年前的常见三拷贝单倍型，通过反复出现的非等位基因同源重组，促使快速演化的重排。

此外，在过去的4000年里，AMY1拷贝数超过3个的单倍型在欧洲农民中出现的频率显著增加，这可能是对淀粉消化增加的适应性响应。

▲ Abstract：

We identified 30 structurally distinct haplotypes at nucleotide resolution among 98 present-day humans, revealing that the coding sequences of AMY1 copies are evolving under negative selection. Genomic analyses of these haplotypes in archaic hominins and ancient human genomes suggest that a common three-copy haplotype, dating as far back as 800,000 years ago, has seeded rapidly evolving rearrangements through recurrent nonallelic homologous recombination. Additionally, haplotypes with more than three AMY1 copies have significantly increased in frequency among European farmers over the past 4000 years, potentially as an adaptive response to increased starch digestion.

动物学Zoology

Direct hearing measurements in a baleen whale suggest ultrasonic sensitivity

须鲸的直接听力测量表明它对超声波很敏感

▲ 作者：DORIAN S. HOUSER, PETTER H. KVADSHEIM et al.

▲链接：

https://www.science.org/doi/10.1126/science.ado7580

▲摘要：

缺乏有关海洋动物听力的信息，阻碍了预测和减轻人为噪音对海洋动物的影响。我们制定了一个捕获和释放计划，在夏季迁徙期间暂时扣留青春期小须鲸进行听力测试。

2023年，两只小须鲸贡献了听觉脑干反应的测量结果和听力频率范围的数据。结果表明，小须鲸对高达45至90千赫兹的声音频率非常敏感。这些测试提供了可能影响小须鲸和其他相关须鲸物种的人为噪音类型的信息。

▲ Abstract：

Predicting and mitigating the impacts of anthropogenic ocean noise on marine animals is hindered by a lack of information on hearing in these species. We established a catch-and-release program to temporarily hold adolescent minke whales (Balaenoptera acutorostrata) for hearing tests during their summer migration. In 2023, two minke whales provided measures of the auditory brainstem response and data on the frequency range of their hearing. Results show that minke whales are sensitive to sound frequencies as high as 45 to 90 kilohertz. These tests provide information on the types of anthropogenic noise that could affect minke whales and potentially, other related baleen whale species.

Population connectivity shapes the distribution and complexity of chimpanzee cumulative culture

种群连通性决定了黑猩猩累积文化的分布和复杂性

▲ 作者：CASSANDRA GUNASEKARAM, FEDERICO BATTISTON et al.

▲链接：

https://www.science.org/doi/10.1126/science.adk3381

▲摘要：

在此，我们研究了黑猩猩累积文化的进化起源以及为什么它仍然处于初级阶段。为了追踪四个黑猩猩亚种之间的文化传播，我们基于最近迁移的遗传标记和共享的文化特征比较了种群网络。

我们表明，有限的群体连接水平有利于黑猩猩中积累文化的一些实例的出现。就像人类一样，文化的复杂化可能是逐步发生的，包括人群之间的传播、渐进式的变化和技术的重新利用。我们认为，在社会模式上的分歧导致了人属物种之间的流动性增加,导致了对文化交流和性别化的不可逆转的依赖。

▲ Abstract：

Here, we investigated the evolutionary origins of chimpanzee cumulative culture and why it remained incipient. To trace cultural transmission among the four chimpanzee subspecies, we compared population networks based on genetic markers of recent migration and shared cultural traits. We show that limited levels of group connectivity favored the emergence of a few instances of cumulative culture in chimpanzees. As in humans, cultural complexification likely happened in steps, with transmission between populations, incremental changes, and repurposing of technologies. We propose that divergence in social patterns led to increased mobility between groups in the genus Homo, resulting in irreversible dependence on cultural exchange and complexification.