《科學》（20240503出版）一周論文導讀

編譯 | 李言

Science, 3 MAY 2024, Volume 384 Issue 6695

《科學》2024年5月3日，第384卷，6695期

化學Chemistry

An active, stable cubic molybdenum carbide catalyst for the high-temperature reverse water-gas shift reaction

一種用于高溫逆向水瓦斯變換反應的活性、穩定的立方碳化钼催化劑

▲ 作者：MILAD AHMADI KHOSHOOEI, XIJUN WANG et al.

▲ 連結：

https://www.science.org/doi/10.1126/science.adl1260

▲ 摘要：

我們的研究展示了，通過簡單和可擴充的途徑制備的納米晶立方碳化钼（α-Mo2C），具有100%的CO2還原為CO的選擇性，同時在600度的惡劣反應條件下暴露超過500小時後，還能保持初始平衡轉化。

催化劑的現場原位和事後表征結合表明，其高活性、選擇性和穩定性分别歸因于晶體相純度、CO-Mo2C弱互相作用和間隙氧原子。機理研究和密度泛函理論（DFT）計算證明了反應是通過H2輔助氧化還原機制進行的。

▲ Abstract：

We show that nanocrystalline cubic molybdenum carbide (α-Mo2C), prepared through a facile and scalable route, offers 100% selectivity for CO2 reduction to CO while maintaining its initial equilibrium conversion at high space velocity after more than 500 hours of exposure to harsh reaction conditions at 600°C. The combination of operando and postreaction characterization of the catalyst revealed that its high activity, selectivity, and stability are attributable to crystallographic phase purity, weak CO-Mo2C interactions, and interstitial oxygen atoms, respectively. Mechanistic studies and density functional theory (DFT) calculations provided evidence that the reaction proceeds through an H2-aided redox mechanism.

實體學Physics

Atomic physics on a 50-nm scale: Realization of a bilayer system of dipolar atoms

50納米尺度上的原子實體學：實作偶極原子雙層系統

▲ 作者：LI DU, PIERRE BARRAL et al.

▲ 連結：

https://www.science.org/doi/10.1126/science.adh3023

▲ 摘要：

在這項研究中，我們實作了一種超分辨率技術，可以在小于50納米的尺度上定位和排列原子，而沒有任何基本的分辨率限制。

通過建立雙層镝原子，并經過層間交感冷卻和耦合集體激發觀察兩個實體分離層之間的偶極互相作用，我們得以驗證這項技術。

在50納米尺度上，偶極互相作用的強度是500納米的1000倍。對于光鑷中的兩個原子，這應該能實作具有千赫茲速度的純磁偶極門。

▲ Abstract：

In this work, we implemented a super-resolution technique that localizes and arranges atoms on a sub–50-nm scale, without any fundamental limit in resolution. We demonstrate this technique by creating a bilayer of dysprosium atoms and observing dipolar interactions between two physically separated layers through interlayer sympathetic cooling and coupled collective excitations. At 50-nm distance, dipolar interactions are 1000 times stronger than at 500 nm. For two atoms in optical tweezers, this should enable purely magnetic dipolar gates with kilohertz speed.

N-type semiconducting hydrogel

N型半導體水凝膠

▲ 作者：PEIYUN LI, WENXI SUN et al.

▲ 連結：

https://www.science.org/doi/10.1126/science.adj4397

▲ 摘要：

我們開發了基于水溶性N型半導體聚合物的單網絡和多網絡水凝膠，賦予傳統水凝膠以半導體性能。這些水凝膠具有良好的電子遷移率和高開/關比，能夠制造具有低功耗和高增益的互補邏輯電路和信号放大器。

我們證明了具有良好生物粘合劑和相容性界面的水凝膠電子元件可以感覺和放大電生理信号，并提高信噪比。

▲ Abstract：

We developed single- and multiple-network hydrogels based on a water-soluble n-type semiconducting polymer, endowing conventional hydrogels with semiconducting capabilities. These hydrogels show good electron mobilities and high on/off ratios, enabling the fabrication of complementary logic circuits and signal amplifiers with low power consumption and high gains. We demonstrate that hydrogel electronics with good bioadhesive and biocompatible interface can sense and amplify electrophysiological signals with enhanced signal-to-noise ratios.

醫學Medicine

Risk of meningomyelocele mediated by the common 22q11.2 deletion

常見的22q11.2缺失導緻腦膜脊膜膨出風險

▲ 作者：KENG IOI VONG, SANGMOON LEE et al.

▲ 連結：

https://www.science.org/doi/10.1126/science.adl1624

▲ 摘要：

腦脊膜脊髓膨出是神經管缺陷（NTDs）最嚴重的形式之一，也是中樞神經系統最常見的結構性先天缺陷。我們聯合了脊柱裂測序聯盟來确定原因。

通過對715對父母—後代三胞胎的外顯子組和基因組測序，我們發現了6例染色體22q11.2缺失的患者，這表明與一般人群相比，其風險增加了23倍。此外，對另一個22q11.2缺失序列的分析表明，腦膜脊膜膨出的NTD風險增加了12至15倍。

Crkl的缺失足以在小鼠中複制NTDs，其中外顯率和表達率都因母體葉酸缺乏而加劇。是以，常見的22q11.2缺失會增加腦膜脊膜膨出的風險，補充葉酸可以部分減輕這種風險。

▲ Abstract：

Meningomyelocele is one of the most severe forms of neural tube defects (NTDs) and the most frequent structural birth defect of the central nervous system. We assembled the Spina Bifida Sequencing Consortium to identify causes. Exome and genome sequencing of 715 parent-offspring trios identified six patients with chromosomal 22q11.2 deletions, suggesting a 23-fold increased risk compared with the general population. Furthermore, analysis of a separate 22q11.2 deletion cohort suggested a 12- to 15-fold increased NTD risk of meningomyelocele. The loss of Crkl, one of several neural tube–expressed genes within the minimal deletion interval, was sufficient to replicate NTDs in mice, where both penetrance and expressivity were exacerbated by maternal folate deficiency. Thus, the common 22q11.2 deletion confers substantial meningomyelocele risk, which is partially alleviated by folate supplementation.

網絡科學Network Science

Induction of social contagion for diverse outcomes in structured experiments in isolated villages

孤立村莊結構實驗中不同結果的社會傳染誘導

▲ 作者：EDOARDO M. AIROLDI AND NICHOLAS A. CHRISTAKIS

▲ 連結：

https://www.science.org/doi/10.1126/science.adi5147

▲ 摘要：

一些人在社會網絡中占據拓撲位置，這增強了他們誘導溢出效應的有效性。我們在洪都拉斯176個孤立村莊中24702人中建構了面對面網絡，并根據不同方法随機配置設定村莊，改變了接受22個月健康教育方法的家庭比例和選擇家庭的方法（随機配置設定法及“熟人推薦”法）。

我們評估了117個不同的知識、态度和實踐結果。“熟人推薦”法減少了達到全村特定水準所需的家庭數量。知識比行為更容易傳播，溢出效應擴充到不同程度。更易被采用的結果也表現出了更大的溢出效應。根據“熟人推薦”建立的社交網絡通過社會傳染有效促進了全民福利的改善。

▲ Abstract：

Certain people occupy topological positions within social networks that enhance their effectiveness at inducing spillovers. We mapped face-to-face networks among 24,702 people in 176 isolated villages in Honduras and randomly assigned villages to targeting methods, varying the fraction of households receiving a 22-month health education package and the method by which households were chosen (randomly versus using the friendship-nomination algorithm). We assessed 117 diverse knowledge, attitude, and practice outcomes. Friendship-nomination targeting reduced the number of households needed to attain specified levels of village-wide uptake. Knowledge spread more readily than behavior, and spillovers extended to two degrees of separation. Outcomes that were intrinsically easier to adopt also manifested greater spillovers. Network targeting using friendship nomination effectively promotes population-wide improvements in welfare through social contagion.

大氣科學Atmospheric Sciences

Locally narrow droplet size distributions are ubiquitous in stratocumulus clouds

部分狹窄的液滴尺寸分布在層積雲中普遍存在

▲ 作者：NITHIN ALLWAYIN, MICHAEL L. LARSEN et al.

▲ 連結：

https://www.science.org/doi/10.1126/science.adi5550

▲ 摘要：

目前，全球氣候模式（GCMs）将雲中的液滴尺寸分布參數化為廣泛的雲平均伽馬。通過使用離散層積雲體積的數字全息測量，我們發現雲中液滴尺寸分布在厘米尺度上更窄，與雲朵的平均值完全不同。

這些局部分布傾向于形成更相似的雲區域的“口袋”，每個區域的特征是尺寸分布形狀被稀釋到不同程度。這些觀察結果為微實體過程的建立模表征開辟了道路。

▲ Abstract：

Current global climate models (GCMs) parameterize cloud droplet size distributions as broad, cloud-averaged gammas. Using digital holographic measurements of discrete stratocumulus cloud volumes, we found cloud droplet size distributions to be narrower at the centimeter scale, never resembling the cloud average. These local distributions tended to form pockets of similar-looking cloud regions, each characterized by a size distribution shape that is diluted to varying degrees. These observations open the way for new modeling representations of microphysical processes.