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Science,  22 SEP 2023, VOLUME 381, ISSUE 6664

《明升体育app》2023年9月22日，第381卷，6664期

天体明升手机Astrochemistry

Endogenous CO2 ice mixture on the surface of Europa and no detection of plume activity

木卫二表面的内源性干冰混合物

▲ 作者：G. L. VILLANUEVA L. ROTH, K. P. HAND, L. PAGANINI, J. STANSBERRY , AND G. LIUZZI

▲ 链接：http://www.science.org/doi/full/10.1126/science.adg4270

▲ 摘要：

木卫二在冰冷的地壳下有一个地下海洋。其海洋内部情况尚不清楚，也不清楚它是否与海面相连。研究者用詹姆斯·韦布太空望远镜观察木卫二，通过探测其表面和大气来寻找活跃的物质释放。

对羽流的搜索没有检测到水、一氧化碳、甲醇、乙烷或甲烷荧光辐射，但检测了干冰的四种光谱特征；它们的光谱形状和在木卫二表面的分布表明，二氧化碳与其他化合物混合在一起，集中在塔拉地区。研究者认为观测结果表明碳来自木卫二内部。

▲ Abstract：

Jupiter’s moon Europa has a subsurface ocean beneath an icy crust. Conditions within the ocean are unknown, and it is unclear whether it is connected to the surface. We observed Europa with the James Webb Space Telescope (JWST) to search for active release of material by probing its surface and atmosphere. A search for plumes yielded no detection of water, carbon monoxide, methanol, ethane, or methane fluorescence emissions. Four spectral features of carbon dioxide (CO2) ice were detected; their spectral shapes and distribution across Europa’s surface indicate that the CO2 is mixed with other compounds and concentrated in Tara Regio. We interpret these observations as indicating that carbon is sourced from within Europa.The distribution of CO2 on Europa indicates an internal source of carbon

二氧化碳在木卫二上的分布表明了碳的内部来源

▲ 作者：SAMANTHA K. TRUMBO AND MICHAEL E. BROWN

▲ 链接：http://www.science.org/doi/full/10.1126/science.adg4155

▲ 摘要：

木卫二地下海洋明升手机成分在很大程度上是未知的。以前在木卫二表面检测到二氧化碳，但无法确定它是来自地下海洋明升手机，由撞击带来的，还是由撞击带来的物质的辐射处理在表面产生的。

研究者利用詹姆斯·韦布太空望远镜获得的观测数据绘制了木卫二上二氧化碳的分布图。他们在塔拉地区发现了高浓度的二氧化碳，这是最近重新地表的地形。这表明二氧化碳来源于内部碳源。

研究者认为二氧化碳是在海洋内部形成的，尽管不能排除二氧化碳是通过海洋有机物或碳酸盐的辐射分解转化在海洋表面形成的。

▲ Abstract：

Jupiter’s moon Europa has a subsurface ocean, the chemistry of which is largely unknown. Carbon dioxide (CO2) has previously been detected on the surface of Europa, but it was not possible to determine whether it originated from subsurface ocean chemistry, was delivered by impacts, or was produced on the surface by radiation processing of impact-delivered material. We mapped the distribution of CO2 on Europa using observations obtained with the James Webb Space Telescope (JWST). We found a concentration of CO2 within Tara Regio, a recently resurfaced terrain. This indicates that the CO2 is derived from an internal carbon source. We propose that the CO2 formed in the internal ocean, although we cannot rule out formation on the surface through radiolytic conversion of ocean-derived organics or carbonates.　

明升手机Chemistry

Solid-solvent processing of ultrathin, highly loaded mixed-matrix membrane for gas separation

固溶处理超薄、高负荷混合基质膜用于气体分离

▲ 作者：GUINING CHEN, CAILING CHEN, YANAN GUO, ZHENYU CHU, YANG PAN, GUOZHEN LIU, GONGPING LIU , YU HAN, WANQIN JIN, AND NANPING XU

▲ 链接：http://www.science.org/doi/full/10.1126/science.adi1545

▲ 摘要：

以沸石和金属有机骨架（MOF）为代表的纳米多孔晶体材料，自然包含连续的孔隙系统，可以使气体分离，但很难将它们加工成坚固的大薄片。

研究者开发了一种固体溶剂技术，用于制造薄的、高负载的、无缺陷的混合基质膜。前体金属盐溶解在聚合物中，然后转化为MOF材料。研究者证明了氢和二氧化碳的分离，具有高渗透和选择性。

▲ Abstract：

Nanoporous crystalline materials, represented by zeolites and metal-organic frameworks (MOFs), naturally contain continuous pore systems that can enable the separation of gases, but it is difficult to process them into robust, large sheets. Chen et al. developed a solid-solvent technique for making thin, highly loaded, and defect-free mixed matrix membranes. Precursor metal salts are dissolved into a polymer and then converted into a MOF material. The authors demonstrate the separation of hydrogen and carbon dioxide, with high permeance and selectivity.

Disequilibrating azobenzenes by visible-light sensitization under confinement

约束下可见光敏化偶氮苯的失平衡

▲ 作者：JULIUS GEMEN, JONATHAN R. CHURCH, TERO-PETRI RUOKO, NIKITA DURANDIN, MICHA? J. BIA?EK, MAREN WEISSENFEL, MORAN FELLER, MIRI KAZES, MAGDALENA ODAYBAT, AND RAFAL KLAJN

▲ 链接：http://www.science.org/doi/full/10.1126/science.adh9059

▲ 摘要：

明升手机家常常努力将反应推向更高的能量较低的产物。其中面临的挑战是如何防止这些产品再次下滑。研究者手机版了一种巧妙的策略，将偶氮苯扭曲成其能量更高的Z构象。

具体来说，他们将更稳定的E异构体与光敏剂一起吸引到超分子宿主中。当可见光注入能量来诱导扭曲时，Z异构体不再适合腔体，因此在更多的光将其扭转回来之前，它被推出腔体。

▲ Abstract：

Chemists often strive to push reactions metaphorically uphill toward less energetically favorable products. The challenge is to keep those products from rolling right back down. Gemen et al. report a clever tactic for twisting azobenzene into its higher-energy Z conformation. Specifically, they lured the more stable E isomer into a supramolecular host, along with a photosensitizer. When visible light injects energy to induce the twist, the Z isomer no longer fits in the cavity, so it gets pushed out before more light can twist it back.

生态学Ecology

Impacts of metal mining on river systems: a global assessment

金属采矿对河流系统的影响：一项全球评估

▲ 作者：M. G. MACKLIN, C. J. THOMAS, A. MUDBHATKAL, P. A. BREWER, K. A. HUDSON-EDWARDS, J. LEWIN, P. SCUSSOLINI, D. EILANDER, A. LECHNER , AND K. R. MANGALAA

▲ 链接：http://www.science.org/doi/full/10.1126/science.adg6704

▲ 摘要：

全球估计有2300万人生活在洪泛区，受到过去和现在金属采矿活动产生的有毒废物的潜在危险浓度的影响。

研究者分析了这一危害的全球范围，特别是铅、锌、铜和砷，他们使用了一个地理参考的全球数据库，详细列出了所有已知的金属采矿地点以及完整和失效的尾矿储存设施。然后，使用基于过程和经验检验的模型，对河流系统中的金属采矿污染以及暴露的人口和牲畜数量进行了全球评估。

在世界范围内，金属矿山影响着47.92万公里的河道和16.4万平方公里的洪泛平原。长期向河流排放采矿废物所造成污染的人数几乎是直接受尾矿坝溃坝影响人数的50倍。

▲ Abstract：

An estimated 23 million people live on floodplains affected by potentially dangerous concentrations of toxic waste derived from past and present metal mining activity. We analyzed the global dimensions of this hazard, particularly in regard to lead, zinc, copper, and arsenic, using a georeferenced global database detailing all known metal mining sites and intact and failed tailings storage facilities. We then used process-based and empirically tested modeling to produce a global assessment of metal mining contamination in river systems and the numbers of human populations and livestock exposed. Worldwide, metal mines affect 479,200 kilometers of river channels and 164,000 square kilometers of floodplains. The number of people exposed to contamination sourced from long-term discharge of mining waste into rivers is almost 50 times greater than the number directly affected by tailings dam failures.

生物学Biology

Accurate proteome-wide missense variant effect prediction with AlphaMissense

利用AlphaMissense预测蛋白质组错义变异效应

▲ 作者：JUN CHENG, GUIDO NOVATI, JOSHUA PAN, CLARE BYCROFT, AKVIL? ?EMGULYT?, TAYLOR APPLEBAUM, ALEXANDER PRITZEL, LAI HONG WONG, MICHAL ZIELINSKI, AND ?IGA AVSEC

▲ 链接：http://www.science.org/doi/full/10.1126/science.adh9059

▲ 摘要：

在人类基因组中观察到的绝大多数错义变异具有未知的临床意义。研究者开发了AlphaMissense，这是一种基于蛋白质结构预测工具AlphaFold2的深度学习模型。

通过AlphaMissense对人类和灵长类动物变异种群频率数据库进行微调，以预测错义变异的致病性。通过结合结构背景和进化守恒，该模型在广泛的遗传和实验基准中获得了最先进的结果，这些都没有在数据上进行明确的训练。

基因的平均致病性评分也可以预测它们的重要性，能够识别现有统计方法无法检测到的短必要基因。研究者提供了一个数据库，预测所有可能的人类单氨基酸替换，并将89%的错义变异分类为可能是良性的或可能是致病的。

▲ Abstract：

The vast majority of missense variants observed in the human genome are of unknown clinical significance. We present AlphaMissense, an adaptation of AlphaFold fine-tuned on human and primate variant population frequency databases to predict missense variant pathogenicity. By combining structural context and evolutionary conservation, our model achieves state-of-the-art results across a wide range of genetic and experimental benchmarks, all without explicitly training on such data. The average pathogenicity score of genes is also predictive for their cell essentiality, capable of identifying short essential genes that existing statistical approaches are underpowered to detect. As a resource to the community, we provide a database of predictions for all possible human single amino acid substitutions and classify 89% of missense variants as either likely benign or likely pathogenic.