《科学》(20210716出版)一周论文导读

编译 | 未玖 Science, 16 JULY 2021, VOL 373, ISSUE 6552 《科学》…

编译 | 未玖

Science, 16 JULY 2021, VOL 373, ISSUE 6552

《科学》2021年7月16日,第373卷,6552期

材料科学Materials Science

Autonomous self-repair in piezoelectric molecular crystals

压电分子晶体的自主型自修复

▲ 作者:Surojit Bhunia, Shubham Chandel, Sumanta Kumar Karan, Somnath Dey, Akash Tiwari, Susobhan Das, et al.

▲ 链接:

https://science.sciencemag.org/content/373/6552/321

▲ 摘要

活组织利用应力积累的电荷来愈合伤口。自修复合成材料通常很软且无定形,往往需要外部刺激、长时间的物理接触和较长的愈合时间。

研究组在压电双吡唑有机晶体中克服了这些限制,这种晶体在机械断裂后无需任何外部定向就可以重新组合,并在毫秒内以晶体学精度自动自愈。

开尔文探针力显微镜、双折射实验和原子分辨率结构研究表明,这些具有氢键和色散相互作用的非中心对称晶体在断裂面上产生了大量应力诱导的相反电荷,通过无扩散自愈的方式促进静电驱动的碎片精确重组。

▲ Abstract

Living tissue uses stress-accumulated electrical charge to close wounds. Self-repairing synthetic materials, which are typically soft and amorphous, usually require external stimuli, prolonged physical contact, and long healing times. We overcome many of these limitations in piezoelectric bipyrazole organic crystals, which recombine following mechanical fracture without any external direction, autonomously self-healing in milliseconds with crystallographic precision. Kelvin probe force microscopy, birefringence experiments, and atomic-resolution structural studies reveal that these noncentrosymmetric crystals, with a combination of hydrogen bonds and dispersive interactions, develop large stress-induced opposite electrical charges on fracture surfaces, prompting an electrostatically driven precise recombination of the pieces via diffusionless self-healing.

Wafer-scale heterostructured piezoelectric bio-organic thin films

晶圆级异质结压电生物有机薄膜

▲ 作者:Fan Yang, Jun Li, Yin Long, Ziyi Zhang, Linfeng Wang, Jiajie Sui, et al.

▲ 链接:

https://science.sciencemag.org/content/373/6552/337

▲ 摘要

压电生物材料天然适合于在生物系统中耦合机械能和电能,以实现体内实时传感、驱动和发电。然而,无法大规模合成和校准压电相位仍是实际应用的障碍。

研究组提出了一种基于γ-甘氨酸晶体的压电生物材料薄膜的晶圆级制备方法。该薄膜具有三明治结构,其中结晶甘氨酸层在两个聚乙烯醇(PVA)薄膜之间自组装并自动校准。

异质结甘氨酸-PVA薄膜的压电系数为5.3 pC/N或157.5×10−3 Vm/N,与纯甘氨酸晶体相比,其机械柔韧性提高了近一个数量级。甘氨酸-PVA薄膜具有天然相容性和在生理环境中可降解性,为瞬态植入式机电器件的开发提供了可能。

▲ Abstract

Piezoelectric biomaterials are intrinsically suitable for coupling mechanical and electrical energy in biological systems to achieve in vivo real-time sensing, actuation, and electricity generation. However, the inability to synthesize and align the piezoelectric phase at a large scale remains a roadblock toward practical applications. We present a wafer-scale approach to creating piezoelectric biomaterial thin films based on γ-glycine crystals. The thin film has a sandwich structure, where a crystalline glycine layer self-assembles and automatically aligns between two polyvinyl alcohol (PVA) thin films. The heterostructured glycine-PVA films exhibit piezoelectric coefficients of 5.3 picocoulombs per newton or 157.5 × 10−3 volt meters per newton and nearly an order of magnitude enhancement of the mechanical flexibility compared with pure glycine crystals. With its natural compatibility and degradability in physiological environments, glycine-PVA films may enable the development of transient implantable electromechanical devices.

Universal phase dynamics in VO2 switches revealed by ultrafast operando diffraction

超快操作衍射揭示VO2开关的普遍相动力学

▲ 作者:Aditya Sood, Xiaozhe Shen, Yin Shi, Suhas Kumar, Su Ji Park,Marc Zajac, et al.

▲ 链接:

https://science.sciencemag.org/content/373/6552/352

▲ 摘要

了解电驱动绝缘体-金属跃迁的路径和时间尺度对于揭示器件运行的基本限制至关重要。利用频闪电子衍射,研究组对二氧化钒(VO2)开关中的原子运动和电子输运进行了同步时间分辨测量。

他们发现了一个电触发、在微秒时间尺度上瞬时形成的同构状态,相场模拟表明,这种状态是由平衡相之间的局部异质和界面相互作用来稳定的。这种亚稳相类似于皮秒范围内光激发下形成的亚稳相,暗示了一种普遍的转化途径。

研究组的结果建立了一种电激发途径,可用于揭示相关材料中的非平衡和亚稳相,为纳米电子学的工程动力学行为开辟了道路。

▲ Abstract

Understanding the pathways and time scales underlying electrically driven insulator-metal transitions is crucial for uncovering the fundamental limits of device operation. Using stroboscopic electron diffraction, we perform synchronized time-resolved measurements of atomic motions and electronic transport in operating vanadium dioxide (VO2) switches. We discover an electrically triggered, isostructural state that forms transiently on microsecond time scales, which is shown by phase-field simulations to be stabilized by local heterogeneities and interfacial interactions between the equilibrium phases. This metastable phase is similar to that formed under photoexcitation within picoseconds, suggesting a universal transformation pathway. Our results establish electrical excitation as a route for uncovering nonequilibrium and metastable phases in correlated materials, opening avenues for engineering dynamical behavior in nanoelectronics.

Design and applications of surfaces that control the accretion of matter

控制物质积聚的表面的设计和应用

▲ 作者:Abhishek Dhyani, Jing Wang, Alex Kate Halvey, Brian Macdonald, Geeta Mehta, Anish Tuteja

▲ 链接:

https://science.sciencemag.org/content/373/6552/eaba5010

▲ 摘要

能控制液体、固体或蒸汽积聚的表面为许多植物、昆虫和动物提供了进化优势。受这些天然表面启发的合成表面可对各种商业应用产生重大影响。

工程液体和固体排斥表面通常被设计成可控制物质、相或污垢长度尺度的单一状态。然而,在不同实际应用中使用的表面需要有效控制多种相和不同污垢长度尺度的物质累积。

研究组分析了表面设计策略,旨在控制物质不同状态的积聚,特别是那些跨越多种长度尺度和不同污染物的积聚。同时还强调了一些重要应用,以及这些设计表面规模化和商业化的相关挑战。

▲ Abstract

Surfaces that provide control over liquid, solid, or vapor accretion provide an evolutionary advantage to numerous plants, insects, and animals. Synthetic surfaces inspired by these natural surfaces can have a substantial impact on diverse commercial applications. Engineered liquid and solid repellent surfaces are often designed to impart control over a single state of matter, phase, or fouling length scale. However, surfaces used in diverse real-world applications need to effectively control the accrual of matter across multiple phases and fouling length scales. We discuss the surface design strategies aimed at controlling the accretion of different states of matter, particularly those that work across multiple length scales and different foulants. We also highlight notable applications, as well as challenges associated with these designer surfaces’ scale-up and commercialization.

地球科学Earth Science

A massive rock and ice avalanche caused the 2021 disaster at Chamoli, Indian Himalaya

大规模岩石和冰川崩塌导致了2021年印度查莫里地区的大灾难

▲ 作者:D. H. Shugar, M. Jacquemart, D. Shean, S. Bhushan, K. Upadhyay, A. Sattar, et al.

▲ 链接:

https://science.sciencemag.org/content/373/6552/300

▲ 摘要

2021年2月7日,一场灾难性的特大洪水袭击了印度北阿坎德邦查莫里地区的伦蒂加德、里希甘加和杜利甘加山谷,造成大面积损毁,并严重破坏了两个水电站项目。超过200人死亡或失踪。

研究组对卫星图像、地震记录、数值模型结果和目击者视频的分析显示,约27×106立方米的岩石和冰川从伦蒂峰陡峭的北面坍塌。岩石和冰川的崩塌迅速转变为一个特大移动泥石流,裹挟直径超过20米的巨石,并将山谷壁冲刷到高于谷底220米的地方。

危险级联与下游基础设施的交叉导致了这场灾难,这突出了对喜马拉雅山以及其他偏远高山环境的充分监测和可持续发展的关键问题。

▲ Abstract

On 7 February 2021, a catastrophic mass flow descended the Ronti Gad, Rishiganga, and Dhauliganga valleys in Chamoli, Uttarakhand, India, causing widespread devastation and severely damaging two hydropower projects. More than 200 people were killed or are missing. Our analysis of satellite imagery, seismic records, numerical model results, and eyewitness videos reveals that ~27 × 106 cubic meters of rock and glacier ice collapsed from the steep north face of Ronti Peak. The rock and ice avalanche rapidly transformed into an extraordinarily large and mobile debris flow that transported boulders greater than 20 meters in diameter and scoured the valley walls up to 220 meters above the valley floor. The intersection of the hazard cascade with downvalley infrastructure resulted in a disaster, which highlights key questions about adequate monitoring and sustainable development in the Himalaya as well as other remote, high-mountain environments.

公共卫生Public Health

Senolytics reduce coronavirus-related mortality in old mice

抗衰老药降低老年小鼠冠状病毒相关死亡率

▲ 作者:Christina D. Camell, Matthew J. Yousefzadeh, Yi Zhu, Larissa G. P. Langhi Prata, Matthew A. Huggins, Mark Pierson, et al.

▲ 链接:

https://science.sciencemag.org/content/373/6552/eabe4832

▲ 摘要

COVID-19大流行揭示了老年人和慢性病患者在新冠病毒发病率和死亡率方面的明显脆弱性。细胞衰老导致炎症、多种慢性疾病和年龄相关性功能障碍,但对病毒感染应答的影响尚不清楚。

研究组证明衰老细胞(SnCs)对病原体相关分子模式(PAMPs,包括SARS-CoV-2刺突蛋白-1)产生高炎症反应,通过旁分泌机制增加病毒侵入蛋白的表达,并减少非SnCs中抗病毒基因的表达。

老年小鼠急性感染包括SARS-CoV-2相关小鼠β冠状病毒在内的病原体后,衰老和炎症加剧,死亡率接近100%。在病原体暴露前或暴露后使用抗衰老药物靶向SNC可显著降低死亡率、细胞衰老和炎症标志物,并增加抗病毒抗体。

因此,降低慢性病患者或老年人的SnC负担可有助于增强抵抗力,降低病毒感染(包括SARS-CoV-2)后的死亡率。

▲ Abstract

The COVID-19 pandemic has revealed the pronounced vulnerability of the elderly and chronically ill to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–induced morbidity and mortality. Cellular senescence contributes to inflammation, multiple chronic diseases, and age-related dysfunction, but effects on responses to viral infection are unclear. Here, we demonstrate that senescent cells (SnCs) become hyper-inflammatory in response to pathogen-associated molecular patterns (PAMPs), including SARS-CoV-2 spike protein-1, increasing expression of viral entry proteins and reducing antiviral gene expression in non-SnCs through a paracrine mechanism. Old mice acutely infected with pathogens that included a SARS-CoV-2–related mouse β-coronavirus experienced increased senescence and inflammation, with nearly 100% mortality. Targeting SnCs by using senolytic drugs before or after pathogen exposure significantly reduced mortality, cellular senescence, and inflammatory markers and increased antiviral antibodies. Thus, reducing the SnC burden in diseased or aged individuals should enhance resilience and reduce mortality after viral infection, including that of SARS-CoV-2.

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