Science, 20 DEC 2024, Volume 386, Issue 6728
《科学》2024年12月20日，第386卷，6728期
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物理学Physics
Bright, circularly polarized black-body radiation from twisted nanocarbon filaments
扭曲纳米碳丝发出的明亮圆偏振黑体辐射
▲ 作者：JUN LU, HONG JU JUNG, JI-YOUNG KIM, AND NICHOLAS A. KOTOV
▲链接：
https://www.science.org/doi/10.1126/science.adq4068
▲摘要：
普朗克定律忽略但不禁止黑体辐射圆极化。由纳米碳或金属扭曲几何的纳米结构长丝制成的BBR在500至3000纳米范围内具有很强的椭圆性。这些细丝的亚微米级手性满足涨落耗散定理对维数的要求，并根据基尔霍夫定律要求吸收率和发射率的对称破缺。所得黑体辐射的发射各向异性和亮度比传统的手性光子发射器高出10到100倍。
这些细丝的螺旋结构使手性发射的精确光谱调谐成为可能，这可以使用电磁原理和手性度量来建模。将纳米碳丝封装在折射陶瓷中可以产生高效、可调和耐用的手性发射器，能够在以前认为无法实现的极端温度下工作。
▲ Abstract：
Planck’s law ignores but does not prohibit black-body radiation (BBR) from being circularly polarized. BBR from nanostructured filaments with twisted geometry from nanocarbon or metal has strong ellipticity from 500 to 3000 nanometers. The submicrometer-scale chirality of these filaments satisfies the dimensionality requirements imposed by fluctuation-dissipation theorem and requires symmetry breaking in absorptivity and emissivity according to Kirchhoff’s law. The resulting BBR shows emission anisotropy and brightness exceeding those of conventional chiral photon emitters by factors of 10 to 100. The helical structure of these filaments enables precise spectral tuning of the chiral emission, which can be modeled using electromagnetic principles and chirality metrics. Encapsulating nanocarbon filaments in refractive ceramics produces highly efficient, adjustable, and durable chiral emitters capable of functioning at extreme temperatures previously considered unattainable.
Hydrodynamic moiré superlattice
流体动力莫尔维尔超晶格
▲ 作者：GUOQIANG XU, XUE ZHOU, WEIJIN CHEN, GUANGWEI HU, ZHIYUAN YAN, ZHIPENG LI, SHUIHUA YANG, AND CHENG-WEI QIU
▲链接：
https://www.science.org/doi/10.1126/science.adq2329
▲摘要：
光子晶体的结构周期性保证了晶体的有效能带结构，是拓扑物理和莫尔物理的基础。然而，大多数流体的剪切模量接近于零，这使得流体很难保持类似于光子晶体的空间周期性。
我们在流体动力超材料中实现了周期性涡旋，并通过将两种涡旋流体叠加和扭转，形成了一个双层涡流超晶格。我们观察到，当扭转角分别导致流态摩尔超晶格中的毕达哥拉斯三元组和非毕达哥拉斯三元组时，能量离域和局域化。即使在具有满足毕达哥拉斯三元组的大晶格常数的相应的流体中，也发现了异常局域化。
我们的工作报告了流体中的莫尔现象，并通过流体莫尔超晶格中涡的复杂动力学，为控制能量传递，质量传递和粒子导航打开了一扇意想不到的大门。
▲ Abstract：
The structural periodicity in photonic crystals guarantees the crystal’s effective energy band structure, which is the fundamental cornerstone of topological and moiré physics. However, the shear modulus in most fluids is close to zero, which makes it challenging for fluids to maintain spatial periodicity akin to photonic crystals. We realized periodic vortices in hydrodynamic metamaterials and created a bilayer moiré superlattice by stacking and twisting two such vortex fluids. We observed energy delocalization and localization when the twist angles, respectively, result in the Pythagorean and non-Pythagorean triples in the fluidic moiré superlattice. Anomalous localization was found even in commensurate moiré fluids with large lattice constants that satisfy Pythagorean triples. Our work reports the moiré phenomena in fluids and opens an unexpected door to controlling the energy transfer, mass transport, and particle navigation through the elaborate dynamics of vortices in fluidic moiré superlattices.
月球地质学和地质微生物学Lunar Geology & Geomicrobiology
A sample of the Moon’s far side retrieved by Chang’e-6 contains 2.83-billion-year-old basalt
嫦娥六号从月球背面采集的样本含有28.3亿年前的玄武岩
▲ 作者：ZEXIAN CUI, QING YANG, YAN-QIANG ZHANG, CHENGYUAN WANG, HAIYANG XIAN, ZHIMING CHEN, ZHIYONG XIAO, YUQI QIAN, JAMES W. HEAD III, AND YI-GANG XU
▲链接：
https://www.science.org/doi/10.1126/science.adt1093
▲摘要：
中国科学院院士、中国科学院广州地球化学研究所研究员徐义刚和高级工程师张乐领衔的团队对玄武岩屑中微小含锆矿物（<5微米）以及斜长石和晚期填隙物开展了同位素分析，标定嫦娥六号低钛玄武岩形成于距今28.3亿年前的火山喷发，并指示其具有一个十分亏损不相容元素的月幔源区。这样的月幔源区难以发生显著规模的熔融及相应的玄武岩火山活动，并最终导致了南极—艾特肯盆地内缺乏大规模的月海玄武岩。
传统观点认为，月球背面的月壳较厚，抑制了月海玄武岩喷发，导致月球正面和背面的月海分布不对称。但这不能解释为什么月壳很薄的南极—艾特肯盆地也匮乏大规模的月海玄武岩。此次研究表明，月海玄武岩的分布除受月壳厚度影响外，月幔源区的物质组成也是重要的控制因素。
▲ Abstract：
Remote sensing observations have shown that the far side of the Moon (lunar farside) has different geology and rock composition to those of the nearside, including the abundances of potassium, rare earth elements, and phosphorus (collectively known as KREEP). The Chang’e-6 (CE-6) spacecraft collected samples from the South Pole–Aitken (SPA) basin on the farside and brought them to Earth. We used lead-lead and rubidium-strontium isotope systems to date low-titanium basalt in a CE-6 sample, finding a consistent age of 2830 (±5) million years. We interpret this as the date of volcanism in SPA and incorporate it into lunar crater chronology. Strontium, neodymium, and lead isotopes indicate that the volcanic magma was from a lunar mantle source depleted in incompatible elements and containing almost no KREEP component.
Hydrogenotrophic methanogens overwrite isotope signals of subsurface methane
氢营养型产甲烷菌覆盖了地下甲烷的同位素信号
▲ 作者：DAISUKE MAYUMI, HIDEYUKI, SOUICHIRO KATO, KENSUKE IGARASHI, ELLEN LALK, YASUNORI NISHIKAWA, HIDEKI MINAGAWA, TOMOYUKI SATO, SHUHEI ONO, AND SUSUMU SAKATA
▲链接：
https://www.science.org/doi/10.1126/science.ado0126
▲摘要：
甲烷是一种温室气体和能源，通常使用稳定同位素信号作为其形成过程的代用物进行研究。在地下环境中，甲烷经常表现出平衡同位素信号，但平衡过程从未在实验室中得到证实。研究者在模拟含甲烷地下环境的条件下（55°C，10兆帕斯卡），将一种氢营养型甲烷菌与一种产氢细菌共培养。
这导致甲烷生成几乎完全可逆，导致氢和碳同位素平衡。产甲烷菌不仅平衡了初始产甲烷的动力学同位素信号，而且修饰了修正后的热成因甲烷的同位素信号。这些发现表明，氢营养甲烷生成可以覆盖地下甲烷的同位素信号，扭曲其来源和地层温度的代用指标，而这些指标对天然气勘探至关重要。
▲ Abstract：
Methane, a greenhouse gas and energy source, is commonly studied using stable isotope signals as proxies for its formation processes. In subsurface environments, methane often exhibits equilibrium isotopic signals, but the equilibration process has never been demonstrated in the laboratory. We cocultured a hydrogenotrophic methanogen with an H2-producing bacterium under conditions (55°C, 10 megapascals) simulating a methane-bearing subsurface. This resulted in near-complete reversibility of methanogenesis, leading to equilibria for both hydrogen and carbon isotopes. The methanogen not only equilibrated kinetic isotope signals of initially produced methane but also modified the isotope signals of amended thermogenic methane. These findings suggest that hydrogenotrophic methanogenesis can overwrite the isotope signals of subsurface methane, distorting proxies for its origin and formation temperature—insights crucial for natural gas exploration.
化学和免疫学Chemistry & Immunology
Biocatalytic C–H oxidation meets radical cross-coupling: Simplifying complex piperidine synthesis
生物催化C-H氧化满足自由基交叉偶联：简化复杂的哌啶合成
▲ 作者：JIAYAN HE, KENTA YOKOI, BREANNA WIXTED, BENXIANG ZHANG , YU KAWAMATA , HANS RENATA , AND PHIL S. BARAN
▲链接：
https://www.science.org/doi/10.1126/science.adr9368
▲摘要：
现代药物化学家正在瞄准更复杂的分子来解决具有挑战性的生物学靶标，这带来合成具有更高sp3特征（Fsp3）的结构，以增强特异性和物理化学性质。虽然传统的扁平、高分数sp2分子，如吡啶，可以通过亲电芳香取代和钯（Pd）基交叉偶联来修饰，但衍生三维饱和分子的一般策略还远远不够发达。
研究者在此提出了一种快速、模块化、对映特异性和非对映选择性的哌啶（吡啶的饱和类似物）功能化方法，将强大的生物催化碳氢氧化与自由基交叉偶联相结合。这种组合直接类似于亲电芳香取代，然后是平面分子的Pd偶联，简化了三维分子的合成。这项研究有助为访问复杂的结构提供一种通用的策略，对药物和过程化学家具有吸引力。
▲ Abstract：
Modern medicinal chemists are targeting more complex molecules to address challenging biological targets, which leads to synthesizing structures with higher sp3 character (Fsp3) to enhance specificity as well as physiochemical properties. Although traditional flat, high-fraction sp2 molecules, such as pyridine, can be decorated through electrophilic aromatic substitution and palladium (Pd)–based cross-couplings, general strategies to derivatize three-dimensional (3D) saturated molecules are far less developed. In this work, we present an approach for the rapid, modular, enantiospecific, and diastereoselective functionalization of piperidine (saturated analog of pyridine), combining robust biocatalytic carbon-hydrogen oxidation with radical cross-coupling. This combination is directly analogous to electrophilic aromatic substitution followed by Pd-couplings for flat molecules, streamlining synthesis of 3D molecules. This study offers a generalizable strategy for accessing complex architectures, appealing to both medicinal and process chemists.
Coupling antigens from multiple subtypes of influenza can broaden antibody and T cell responses
来自多种流感亚型的偶联抗原可扩大抗体和T细胞反应
▲ 作者：VAMSEE MALLAJOSYULA, SABORNI CHAKRABORTY, ELSA SOLA, RYAN FURUICHI FONG, VISHNU, FEI GAO, ALLISON R. BURRELL , NEHA GUPTA , LISA E. WAGAR, AND MARK M. DAVIS
▲链接：
https://www.science.org/doi/10.1126/science.adi2396
▲摘要：
季节性流感疫苗含有来自不同亚型的病毒株，这些病毒株是独立生长的，然后结合在一起。然而，大多数个体对其中一种菌株表现出更强的反应，因此容易受到其他菌株的感染。通过对同卵双胞胎队列的研究，研究者发现尽管先前暴露是一个因素，但宿主遗传是流感病毒株亚型偏好的更强驱动因素。
研究发现，来自不同病毒株的异源血凝素（HA）的共价偶联可以在动物模型和人类扁桃体类器官系统中很大程度上消除亚型偏倚。作者提出异种抗原的偶联通过扩大T细胞帮助来改善流感毒株的抗体反应，使用这种方法大大提高了对禽流感HA的抗体反应。
▲ Abstract：
The seasonal influenza vaccine contains strains of viruses from distinct subtypes that are grown independently and then combined. However, most individuals exhibit a more robust response to one of these strains and thus are vulnerable to infection by others. By studying a monozygotic twin cohort, we found that although prior exposure is a factor, host genetics are a stronger driver of subtype bias to influenza viral strains. We found that covalent coupling of heterologous hemagglutinin (HA) from different viral strains could largely eliminate subtype bias in an animal model and in a human tonsil organoid system. We proposed that coupling of heterologous antigens improves antibody responses across influenza strains by broadening T cell help, and we found that using this approach substantially improved the antibody response to avian influenza HA.
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