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Science, 22 MAR 2024, VOL 383, ISSUE 6689

《明升体育app》2024年3月22日，第383卷，6689期

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物理学Physics

Stable quantum-correlated many-body states through engineered dissipation

工程耗散的稳定量子相关多体态

▲ 作者：X. MI, A. A. MICHAILIDIS et al.

▲ 链接：

http://www.science.org/doi/10.1126/science.adh9932

▲ 摘要：

利用多达49个超导量子比特，我们通过耦合耗散辅助量子比特制备了横场伊辛模型的低能态。在一维上，我们观察到远程量子相关性和基态保真度为0.86，在临界点处有18个量子位。在二维中，我们发现了超越相邻区域的相互信息。

最后，通过将系统耦合到具有不同明升手机势的辅助模拟储层，我们探索了量子海森堡模型中的输运情况。我们的研究结果建立了工程耗散作为一种可扩展的替代方案，用于在噪声量子处理器上制备纠缠多体态。

▲ Abstract：

Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

明升手机Chemistry

Alcohol-alcohol cross-coupling enabled by SH2 radical sorting

SH2自由基分选使交叉醇偶联

▲ 作者：RUIZHE CHEN, NICHOLAS E. INTERMAGGIO et al.

▲ 链接：

http://www.science.org/doi/10.1126/science.adl5890

▲ 摘要：

在明升手机合成时代，优先考虑减少目标时间和最大化探索明升手机空间，并利用这些构建块进行碳—碳键形成反应是有机明升手机的关键目标。尤其是利用单一激活模式，从两个醇亚基形成新的C(sp3)–C(sp3)键，使其具有非凡的结构多样性。在这项研究中，我们手机版了镍自由基分选介导的交叉醇偶联，其中两个醇片段被脱氧并在一个开放于空气的反应容器中偶联。

▲ Abstract：

In an era of chemical synthesis that prioritizes reducing time to target and maximizing exploration of chemical space, harnessing these building blocks for carbon-carbon bond-forming reactions is a key goal in organic chemistry. In particular, leveraging a single activation mode to form a new C(sp3)–C(sp3) bond from two alcohol subunits would enable access to an extraordinary level of structural diversity. In this work, we report a nickel radical sorting–mediated cross-alcohol coupling wherein two alcohol fragments are deoxygenated and coupled in one reaction vessel, open to air.

Chiral ground states of ferroelectric liquid crystals

铁电液晶的手性基态

▲ 作者：PRIYANKA KUMARI, BIJAYA BASNET et al.

▲ 链接：

http://www.science.org/doi/10.1126/science.adl0834

▲ 摘要：

我们证明不受外部施加取向方向约束的铁电向列平板的基态是手性的，并且具有左旋和右旋极化。虽然螺旋变形和缺陷壁会使相反手性域分开，增加弹性，但扭曲降低了静电，并且在材料中掺杂离子时会变得更弱。这项研究表明分子的极性取向顺序可以在没有明升手机诱导手性中心的软物质中触发手性。

▲ Abstract：

We demonstrate that the ground state of a flat slab of a ferroelectric nematic unconstrained by externally imposed alignment directions is chiral, with left- and right-handed twists of polarization. Although the helicoidal deformations and defect walls that separate domains of opposite handedness increase the elastic energy, the twists reduce the electrostatic energy and become weaker when the material is doped with ions. This work shows that the polar orientational order of molecules could trigger chirality in soft matter with no chemically induced chiral centers.

生物学Biology

Repeated co-option of HMG-box genes for sex determination in brown algae and animals

褐藻和动物中HMG-box基因性别决定的重复选择

▲ 作者：RéMY LUTHRINGER, MORGANE RAPHALEN et al.

▲ 链接：

http://www.science.org/doi/10.1126/science.adk5466

▲ 摘要：

在许多真核生物中，基因性别决定不是由XX/XY或ZW/ZZ系统决定的，而是由U（雌性）或V（雄性）性染色体上的一个特殊区域决定的，但我们对此研究甚少。

在此，我们证明HMG-box基因在褐藻中作为雄性决定因子，反映了HMG-box基因在动物性别决定中的作用。在十亿年的进化时间里，这些谱系都独立地选择了HMG-box基因来决定雄性，这代表了进化能力反复使用相同的基因“工具包”来完成类似任务的范例。

▲ Abstract：

In many eukaryotes, genetic sex determination is not governed by XX/XY or ZW/ZZ systems but by a specialized region on the poorly studied U (female) or V (male) sex chromosomes. Here, we demonstrate that an HMG-box gene acts as the male-determining factor in brown algae, mirroring the role HMG-box genes play in sex determination in animals. Over a billion-year evolutionary timeline, these lineages have independently co-opted the HMG box for male determination, representing a paradigm for evolution’s ability to recurrently use the same genetic “toolkit” to accomplish similar tasks.

Structure and function of the Arabidopsis ABC transporter ABCB19 in brassinosteroid export

拟南芥ABCB19蛋白在油菜素内酯运输中的结构和功能

▲ 作者：WEI YING, YAOWEI WANG et al.

▲ 链接：

http://www.science.org/doi/10.1126/science.adj4591

▲ 摘要：

在这里，我们展示了ATP结合盒式蛋白（ABC）转运蛋白超家族的成员ABCB19，作为油菜素内酯运输者。我们介绍了它在底物非结合状态和油菜素内酯结合状态下的结构。

生物活性油菜素内酯是ABCB19 ATP水解活性的有效激活剂，实验表明ABCB19可以运输油菜素内酯。在拟南芥中，ABCB19及其近亲ABCB1正调控油菜素内酯反应。我们的研究结果揭示了与油菜素内酯信号密切协调的生物活性油菜素内酯的运输机制。

▲ Abstract：

Here, we show that a member of the ATP-binding cassette (ABC) transporter superfamily, ABCB19, functions as a brassinosteroid exporter. We present its structure in both the substrate-unbound and the brassinosteroid-bound states. Bioactive brassinosteroids are potent activators of ABCB19 ATP hydrolysis activity, and transport assays showed that ABCB19 transports brassinosteroids. In Arabidopsis thaliana, ABCB19 and its close homolog, ABCB1, positively regulate brassinosteroid responses. Our results uncover an elusive export mechanism for bioactive brassinosteroids that is tightly coordinated with brassinosteroid signaling.

农学Agronomy

Spillover effects of organic agriculture on pesticide use on nearby fields

有机农业对周边农田农药使用的溢出效应

▲ 作者：ASHLEY E. LARSEN, FREDERIK NOACK, AND L. CLAIRE POWERS

▲ 链接：

http://www.science.org/doi/10.1126/science.adf2572

▲ 摘要：

有机农业对环境的影响并不是非常明晰，而这些实践是否会对附近农田的害虫或害虫防治活动产生溢出效应这一点仍不得而知。通过2013年到2019年在加州克恩县的约14000次实地观察，我们发现有机作物生产者受益于周围有机农田减少的总体农药使用，特别是针对害虫的农药使用。

相比之下，随着周围有机农田面积的增加，普通农田往往会增加农药的使用。我们的模拟实验表明，有机农田集群可以缓解导致农药净使用量增加的溢出效应。

▲ Abstract：

The environmental impacts of organic agriculture are only partially understood and whether such practices have spillover effects on pests or pest control activity in nearby fields remains unknown. Using about 14,000 field observations per year from 2013 to 2019 in Kern County, California, we postulate that organic crop producers benefit from surrounding organic fields decreasing overall pesticide use and, specifically, pesticides targeting insect pests. Conventional fields, by contrast, tend to increase pesticide use as the area of surrounding organic production increases. Our simulation suggests that spatially clustering organic cropland can entirely mitigate spillover effects that lead to an increase in net pesticide use.