calcium期刊最新论文

编译 | 李言

Science , 12 NOV 2021, VOL 374, ISSUE 6569

《科学》 2021年11月12日，第374卷，6569期

地球科学 Geoscience

Discovery of davemaoite, CaSiO3-perovskite, as a mineral from the lower mantle

下地幔中发现CaSiO3-钙钛矿

作者：OLIVER TSCHAUNER, SHICHUN HUANG, SHUYING YANG, MUNIR HUMAYUN et al.

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摘要

下地幔中的硅酸盐钙钛矿CaSiO3具有重要的地球化学意义，因为它富集了上地幔中不相容的元素，包括产生热量的钍和铀，它们的半衰期比地球的地质 历史 还要长。

我们报告的CaSiO3-钙钛矿是一种已验证认可的矿物（IMA2020-012a），名称为毛钙硅石（davemaoite）。毛钙硅石天然标本证实了下地幔内部存在成分不均一性。

我们的观察表明，毛钙硅石在其结构中除了含有铀和钍外，还含有钾。因此，区域和全球毛钙硅石的丰度影响深部地幔的热收支，该矿物是热力学稳定的。

Abstract

Calcium silicate perovskite, CaSiO3, is arguably the most geochemically important phase in the lower mantle, because it concentrates elements that are incompatible in the upper mantle, including the heat-generating elements thorium and uranium, which have half-lives longer than the geologic history of Earth. We report CaSiO3-perovskite as an approved mineral (IMA2020-012a) with the name davemaoite. The natural specimen of davemaoite proves the existence of compositional heterogeneity within the lower mantle. Our observations indicate that davemaoite also hosts potassium in addition to uranium and thorium in its structure. Hence, the regional and global abundances of davemaoite influence the heat budget of the deep mantle, where the mineral is thermodynamically stable.

Age and composition of young basalts on the Moon, measured from samples returned by Chang’e-5

由嫦娥五号返回的样品测量月球上玄武岩的年龄和组成

作者：XIAOCHAO CHE, ALEXANDER NEMCHIN, DUNYI LIU, TAO LONGCHEN WANG et al.

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摘要

轨道数据显示，月球上最年轻的火山是位于大洋州普罗塞拉姆的玄武岩熔岩，该地区具有高水平的产热元素钾、钍和铀。嫦娥五号任务收集了这些月球玄武岩样本，并将它们带回地球进行实验室分析。

我们认为这些熔岩的年龄为1963 5700万年，并确定了它们的化学和矿物组成。这个时间范围限制了太阳系内部的月球撞击年代学和月球的热演化。没有证据表明，在月球的地幔深处有高浓度的产热元素产生了这些熔岩，因此，对于月球岩浆活动的持久，还需要其他的解释。

Abstract

Orbital data indicate that the youngest volcanic units on the Moon are basalt lavas in Oceanus Procellarum, a region with high levels of the heat-producing elements potassium, thorium, and uranium. The Chang’e-5 mission collected samples of these young lunar basalts and returned them to Earth for laboratory analysis. We measure an age of 1963 57 million years for these lavas and determine their chemical and mineralogical compositions. This age constrains the lunar impact chronology of the inner Solar System and the thermal evolution of the Moon. There is no evidence for high concentrations of heat-producing elements in the deep mantle of the Moon that generated these lavas, so alternate explanations are required for the longevity of lunar magmatism.

化学 Chemistry

Methoxyl stable isotopic constraints on the origins and limits of coal-bed methane

甲氧基稳定同位素对煤层气成因和限制的制约

作者：M. K. LLOYD, E. TREMBATH-REICHERT, K. S. DAWSON, S. J. FEAKINS et al.

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摘要

微生物煤层气是一种重要的经济资源，也是一种强效温室气体的来源，但人们对其形成的控制机制知之甚少。为了测试煤的微生物降解性是否限制微生物甲烷的生成，我们监测了从木材到烟煤成熟度范围内的全球样品组中的甲氧基去甲基反应——一种促进甲烷生成的反应。

残留甲氧基的碳同位素组成与热反应不一致。这表明，在地质时间尺度上，深层生物圈群落参与了植物到煤的转化，甲氧基丰度影响煤层气产量。微生物甲基化导致的碳同位素富集也解释了来自煤和常规烃矿床的微生物甲烷中碳-13含量的神秘抵消。

Abstract

Microbial coal-bed methane is an important economic resource and source of a potent greenhouse gas, but controls on its formation are poorly understood. To test whether the microbial degradability of coal limits microbial methane, we monitored methoxyl group demethylation—a reaction that feeds methanogenesis—in a global sample suite ranging in maturity from wood to bituminous coal. Carbon isotopic compositions of residual methoxyl groups were inconsistent with a thermal reaction, instead implying a substrate-limited biologic process. This suggests that deep biosphere communities participated in transforming plant matter to coal on geologic time scales and that methoxyl abundance influences coal-bed methane yield. Carbon isotopic enrichments resulting from microbial methylotrophy also explain an enigmatic offset in the carbon-13 content of microbial methane from coals and conventional hydrocarbon deposits.

Real-space imaging of anisotropic charge of σ-hole by means of Kelvin probe force microscopy

利用开尔文显微镜对σ-空穴各向异性电荷进行实空间成像

作者：B. MALLADA, A. GALLARDO, M. LAMANEC, B. DE LA TORRE, V. ŠPIRKO et al.

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摘要

各向异性电荷在单个原子上的分布，如σ-空穴，可能会强烈地影响系统的材料和结构特性。然而，原子上这种各向异性电荷分布的空间分辨率是一个长期存在的实验挑战。特别是卤素原子上σ-空穴的存在，只能通过含卤素有机分子的晶体结构测定或理论计算间接证明，因而需要直接的实验可视化。

我们证明了开尔文显微镜与适当的功能化探针可以成像的各向异性电荷的σ-空穴和一氧化碳分子的四极电荷。这为表征各向异性原子电荷起决定性作用的生物和化学系统提供了一种新的方法。

Abstract

An anisotropic charge distribution on inpidual atoms, such as σ-holes, may strongly affect the material and structural properties of systems. However, the spatial resolution of such anisotropic charge distributions on an atom represents a long-standing experimental challenge. In particular, the existence of the σ-hole on halogen atoms has been demonstrated only indirectly through the determination of the crystal structures of organic molecules containing halogens or with theoretical calculations, consequently calling for its direct experimental visualization. We show that Kelvin probe force microscopy with a properly functionalized probe can image the anisotropic charge of the σ-hole and the quadrupolar charge of a carbon monoxide molecule. This opens a new way to characterize biological and chemical systems in which anisotropic atomic charges play a decisive role.

动物学 Zoology

Origins and evolution of extreme life span in Pacific Ocean rockfishes

太平洋岩鱼长寿的起源和进化

作者：SREE ROHIT RAJ KOLORA, XGREGORY L. OWENS, JUAN MANUEL VAZQUEZ , ALEXANDER STUBBS et al.

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摘要

太平洋岩鱼（石鲈属）在寿命上表现出极大的差异，其中一些种类是现存最长寿的脊椎动物。我们重组了88种岩鱼的基因组，并从这些已确认的长寿类群DNA修复通路和137个长寿相关基因中收集了这些基因。

这些基因通过胰岛素信号直接影响寿命，并通过体型和环境适应产生多效效应。对结构变异的全基因组筛选揭示了长寿物种免疫调节butyrophilin基因家族的拷贝数明显增加。

不同岩鱼生活史的进化与遗传多样性耦合，并重塑突变谱，在长寿物种中分离CpG TpG变异。这些分析强调了生命 历史 特征适应的基础上的遗传创新，以及它们如何塑造基因组多样性。

Abstract

Pacific Ocean rockfishes (genus Sebastes ) exhibit extreme variation in life span, with some species being among the most long-lived extant vertebrates. We de novo assembled the genomes of 88 rockfish species and from these identified repeated signatures of positive selection in DNA repair pathways in long-lived taxa and 137 longevity-associated genes with direct effects on life span through insulin signaling and with pleiotropic effects through size and environmental adaptations. A genome-wide screen of structural variation reveals copy number expansions in the immune modulatory butyrophilin gene family in long-lived species. The evolution of different rockfish life histories is coupled to genetic persity and reshapes the mutational spectrum driving segregating CpG TpG variants in long-lived species. These analyses highlight the genetic innovations that underlie life history trait adaptations and, in turn, how they shape genomic persity.

公共卫生 Public Health

Monetary incentives increase COVID-19 vaccinations

货币激励增加了COVID-19疫苗接种率

作者：POL CAMPOS-MERCADE, ARMANDO N. MEIER, FLORIAN H. SCHNEIDER , STEPHAN MEIER et al.

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摘要

低COVID-19疫苗接种率正在威胁公共卫生。为了提高疫苗接种率，世界各国政府都在考虑使用货币激励政策。在此，我们证实有保障的奖金对COVID-19疫苗接种的影响。我们在瑞典进行了一项大规模的预先注册随机对照试验（有8286名参与者），并将数据与全人群的行政接种记录联系起来。

我们发现，只需支付24美元（200瑞典克朗），疫苗接种率就从的基线接种率提高了个百分点（P = ）。相比之下，行为推动增加了接种疫苗的意愿，但对接种率的影响很小，在统计学上不显著。研究结果突出表明，适度的货币激励有可能提高疫苗接种率。

Abstract

The stalling of COVID-19 vaccination rates threatens public health. To increase vaccination rates, governments across the world are considering the use of monetary incentives. Here we present evidence about the effect of guaranteed payments on COVID-19 vaccination uptake. We ran a large preregistered randomized controlled trial (with 8286 participants) in Sweden and linked the data to population-wide administrative vaccination records. We found that modest monetary payments of 24 US dollars (200 Swedish kronor) increased vaccination rates by percentage points (P = ), from a baseline rate of . By contrast, behavioral nudges increased stated intentions to become vaccinated but had only small and not statistically significant impacts on vaccination rates. The results highlight the potential of modest monetary incentives to raise vaccination rates.