原文地址：http://news.sciencenet.cn/htmlnews/2024/3/519657.shtm
編譯｜李言
Science, 22 MAR 2024, VOL 383, ISSUE 6689
《科學》2024年3月22日，第383卷，6689期
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物理學Physics
Stable quantum-correlated many-body states through engineered dissipation
工程耗散的穩定量子相關多體態
▲ 作者：X. MI, A. A. MICHAILIDIS et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adh9932
▲ 摘要：
利用多達49個超導量子比特，我們通過耦合耗散輔助量子比特制備了橫場伊辛模型的低能態。在一維上，我們觀察到遠程量子相關性和基態保真度為0.86，在臨界點處有18個量子位。在二維中，我們發現了超越相鄰區域的相互信息。
最后，通過將系統耦合到具有不同化學勢的輔助模擬儲層，我們探索了量子海森堡模型中的輸運情況。我們的研究結果建立了工程耗散作為一種可擴展的替代方案，用于在噪聲量子處理器上制備糾纏多體態。
▲ 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.
化學Chemistry
Alcohol-alcohol cross-coupling enabled by SH2 radical sorting
SH2自由基分選使交叉醇偶聯
▲ 作者：RUIZHE CHEN, NICHOLAS E. INTERMAGGIO et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adl5890
▲ 摘要：
在化學合成時代，優先考慮減少目標時間和最大化探索化學空間，并利用這些構建塊進行碳—碳鍵形成反應是有機化學的關鍵目標。尤其是利用單一激活模式，從兩個醇亞基形成新的C(sp3)–C(sp3)鍵，使其具有非凡的結構多樣性。在這項研究中，我們報告了鎳自由基分選介導的交叉醇偶聯，其中兩個醇片段被脫氧并在一個開放于空氣的反應容器中偶聯。
▲ 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
鐵電液晶的手性基態
▲ 作者：PRIYANKA KUMARI, BIJAYA BASNET et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adl0834
▲ 摘要：
我們證明不受外部施加取向方向約束的鐵電向列平板的基態是手性的，并且具有左旋和右旋極化。雖然螺旋變形和缺陷壁會使相反手性域分開，增加彈性，但扭曲降低了靜電，并且在材料中摻雜離子時會變得更弱。這項研究表明分子的極性取向順序可以在沒有化學誘導手性中心的軟物質中觸發手性。
▲ 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.
生物學Biology
Repeated co-option of HMG-box genes for sex determination in brown algae and animals
褐藻和動物中HMG-box基因性別決定的重復選擇
▲ 作者：RéMY LUTHRINGER, MORGANE RAPHALEN et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adk5466
▲ 摘要：
在許多真核生物中，基因性別決定不是由XX/XY或ZW/ZZ系統決定的，而是由U（雌性）或V（雄性）性染色體上的一個特殊區域決定的，但我們對此研究甚少。
在此，我們證明HMG-box基因在褐藻中作為雄性決定因子，反映了HMG-box基因在動物性別決定中的作用。在十億年的進化時間里，這些譜系都獨立地選擇了HMG-box基因來決定雄性，這代表了進化能力反復使用相同的基因“工具包”來完成類似任務的范例。
▲ 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
擬南芥ABCB19蛋白在油菜素內酯運輸中的結構和功能
▲ 作者：WEI YING, YAOWEI WANG et al.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adj4591
▲ 摘要：
在這里，我們展示了ATP結合盒式蛋白（ABC）轉運蛋白超家族的成員ABCB19，作為油菜素內酯運輸者。我們介紹了它在底物非結合狀態和油菜素內酯結合狀態下的結構。
生物活性油菜素內酯是ABCB19 ATP水解活性的有效激活劑，實驗表明ABCB19可以運輸油菜素內酯。在擬南芥中，ABCB19及其近親ABCB1正調控油菜素內酯反應。我們的研究結果揭示了與油菜素內酯信號密切協調的生物活性油菜素內酯的運輸機制。
▲ 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.
農學Agronomy
Spillover effects of organic agriculture on pesticide use on nearby fields
有機農業對周邊農田農藥使用的溢出效應
▲ 作者：ASHLEY E. LARSEN, FREDERIK NOACK, AND L. CLAIRE POWERS
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adf2572
▲ 摘要：
有機農業對環境的影響并不是非常明晰，而這些實踐是否會對附近農田的害蟲或害蟲防治活動產生溢出效應這一點仍不得而知。通過2013年到2019年在加州克恩縣的約14000次實地觀察，我們發現有機作物生產者受益于周圍有機農田減少的總體農藥使用，特別是針對害蟲的農藥使用。
相比之下，隨著周圍有機農田面積的增加，普通農田往往會增加農藥的使用。我們的模擬實驗表明，有機農田集群可以緩解導致農藥凈使用量增加的溢出效應。
▲ Abstract：