編譯 | 馮維維
SCIENCE, January 2023, Volume 379 Issue 6628
《科學》2023年1月，第379卷，6628期
物理學Physics
Ductile 2-GPa steels with hierarchical substructure
具有分層子結構的2吉帕韌性鋼
▲ 作者：YUNJIE LI, GUO YUAN, LINLIN LI, JIAN KANG, FENGKAI YAN, PENGJU DU, DIERK RAABE, AND GUODONG WANGAuthors Info & Affiliations
▲ 鏈接：
https://www.science.org/doi/10.1126/science.add7857
▲ 摘要：
從交通運輸到輕量化設計再到安全的基礎設施，很多領域都需要機械強度和延展性的承重材料。但其中一大挑戰是在一種材料中統一這兩種功能。
作者研究表明，在均勻伸長率>20%的情況下，普通中錳鋼可以加工成抗拉強度>2.2吉帕。這需要多個橫向鍛造、深冷處理和回火步驟的結合。由層狀和雙重拓撲排列的馬氏體與精細分散的保留奧氏體組成的分層微結構，同時激活多種微觀機制來增強和延展性材料。
組織良好的馬氏體中的位錯滑移和漸進變形刺激相變協同作用產生了較高的延性。研究者表示，該納米結構設計策略可以生產出強度為2吉帕且具有延展性的鋼，具有大規模工業生產的潛力。
▲ Abstract：
Mechanically strong and ductile load–carrying materials are needed in all sectors, from transportation to lightweight design to safe infrastructure. Yet, a grand challenge is to unify both features in one material. We show that a plain medium-manganese steel can be processed to have a tensile strength >2.2 gigapascals at a uniform elongation >20%. This requires a combination of multiple transversal forging, cryogenic treatment, and tempering steps. A hierarchical microstructure that consists of laminated and twofold topologically aligned martensite with finely dispersed retained austenite simultaneously activates multiple micromechanisms to strengthen and ductilize the material. The dislocation slip in the well-organized martensite and the gradual deformation-stimulated phase transformation synergistically produce the high ductility. Our nanostructure design strategy produces 2 gigapascal–strength and yet ductile steels that have attractive composition and the potential to be produced at large industrial scales.
Unveiling facet-dependent degradation and facet engineering for stable perovskite solar cells
穩定鈣鈦礦太陽能電池的面依賴性降解和面工程
▲ 作者：CHUNQING MA, FELIX T. EICKEMEYER, SUN-HO LEE, DONG-HO KANG, SEOK JOON KWON, MICHAEL GR?TZEL , AND NAM-GYU PARK
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adf3349
▲ 摘要：
有大量研究和策略致力于提高鈣鈦礦薄膜的穩定性；然而，不同鈣鈦礦晶面在穩定性中的作用仍然未知。作者揭示了甲胺碘化鉛（FAPbI3）薄膜的面依賴性降解的潛在機制。研究明，（100）面基本上比（111）面更容易受到水分誘導的降解。
通過實驗和理論研究相結合，研究揭示了降解機理；隨著鉛-碘鍵長距離的延長，觀察到強烈的水黏附，這導致（100）面上的δ相變。通過工程設計，可以獲得更高的（111）面表面分數，（111）為主的晶體FAPbI3薄膜表現出優異的抗潮氣穩定性。該發現闡明了未知的面相關降解機制和動力學。
▲ Abstract：
A myriad of studies and strategies have already been devoted to improving the stability of perovskite films; however, the role of the different perovskite crystal facets in stability is still unknown. Here, we reveal the underlying mechanisms of facet-dependent degradation of formamidinium lead iodide (FAPbI3) films. We show that the (100) facet is substantially more vulnerable to moisture-induced degradation than the (111) facet. With combined experimental and theoretical studies, the degradation mechanisms are revealed; a strong water adhesion following an elongated lead-iodine (Pb-I) bond distance is observed, which leads to a δ-phase transition on the (100) facet. Through engineering, a higher surface fraction of the (111) facet can be achieved, and the (111)-dominated crystalline FAPbI3 films show exceptional stability against moisture. Our findings elucidate unknown facet-dependent degradation mechanisms and kinetics.
微生物學Microbiology
Dome1–JAK–STAT signaling between parasite and host integrates vector immunity and development
寄生蟲和宿主間信號傳遞整合媒介免疫和發育
▲ 作者：VIPIN S. RANA, CHRYSOULA KITSOU, SHRABONI DUTTA, MICHAEL H. RONZETTI, MIN ZHANG, QUENTIN BERNARD, ALEXIS A. SMITH, JULEN TOMáS-CORTáZAR, XIULI YANG, UTPAL PAL, etc.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.abl3837
▲ 摘要：
蜱起源于近2.25億年前的一種自由生活的食腐螨，已經進化成一種具有高度適應性的單系吸血體外寄生蟲。與大多數喜歡單一脊椎動物宿主的地理活動受限的蜱種不同，硬蜱可以寄生在許多脊椎動物體內，傳播不同的病原體。
硬蜱在其多年的生命周期中只經歷三次進食活動，攝取的血餐幾乎是它們體重的100倍。它們特有的生理適應可能是由其復雜的吸血和與共同進化的脊椎動物宿主的聯系所形成的。蜱蟲如何維持其復雜的胚胎后發育程序以及它們的媒介能力的分子基礎尚不清楚。
作者發現，蜱含有一種功能性的JAK-STAT信號級聯，可誘導強有力的抗菌反應，能夠限制蜱傳病原體的增殖。該途徑在許多節肢動物中被 UPD等細胞因子樣分子激活。但硬蜱基因組異常缺乏可識別的UPD直系同源物。
▲ Abstract：
Ticks have evolved into a monophyletic group of highly adapted blood-feeding ectoparasites that originated from a clade of free-living scavenger mites nearly 225 million years ago. Unlike most geographically confined tick species that prefer a single vertebrate host, Ixodes spp. can parasitize many vertebrates and transmit diverse pathogens. Ixodid ticks undergo only three feeding events during their multiyear lifespan, ingesting blood meals that are nearly 100 times their weight. Their characteristic physiological adaptations were likely shaped by their sophisticated hematophagy and associations with coevolving vertebrate hosts. The molecular basis of how ticks maintain their complex postembryonic developmental program as well as their vectorial competence remains unclear. Ticks contain a functional JAK–STAT signaling cascade that induces robust antibacterial responses capable of limiting the proliferation of tick-borne pathogens. The pathway is activated in many arthropods by cytokine-like molecules such as Unpaired (UPD). However, the Ixodes scapularis genome is unusually devoid of recognizable UPD orthologs.
ApoE isoform– and microbiota-dependent progression of neurodegeneration in a mouse model of tauopathy
Tau小鼠病理模型解析依賴ApoE亞型和微生物群的神經退行性疾病
▲ 作者：DONG-OH SEO, DAVID O’DONNELL, NIMANSHA JAIN, JASON D. ULRICH, JASMIN HERZ, YUHAO LI, MACKENZIE LEMIEUX, JIYE CHENG, HAO HU,, AND DAVID M. HOLTZMAN, etc.
▲ 鏈接：
https://www.science.org/doi/10.1126/science.add1236
▲ 摘要：
大腦中某些形式的Tau蛋白的積累與神經細胞的損失、炎癥以及阿爾茨海默病和其他幾種神經退行性疾病的認知能力下降有關。
載脂蛋白-E（APOE）是阿爾茨海默病最強的遺傳風險因素，調節腦炎癥和Tau介導的腦損傷；然而，腸道菌群也調節大腦炎癥。
在Tau介導的腦損傷小鼠模型中，研究者發現，腸道微生物群的操縱導致炎癥、Tau病理和腦損傷因性別和APOE依賴的方式大幅減少。
▲ Abstract：
The accumulation of certain forms of the tau protein in the brain is linked to loss of nerve cells, inflammation, and cognitive decline in Alzheimer’s disease and several other neurodegenerative diseases. Apolipoprotein-E (APOE), the strongest genetic risk factor for Alzheimer’s disease, regulates brain inflammation and tau-mediated brain damage; however, the gut microbiota also regulates brain inflammation. In a mouse model of tau-mediated brain injury, Seo et al. found that manipulation of the gut microbiota resulted in a strong reduction of inflammation, tau pathology, and brain damage in a sex- and APOE-dependent manner.
生物物理學Biophysics
Neuromorphic functions with a polyelectrolyte-confined fluidic memristor
聚電解質受限流體憶阻器的神經形態功能
▲ 作者：TIANYI XIONG, CHANGWEI LI, XIULAN HE, BOYANG XIE, JIANWEI ZONG, YANAN JIANG, WENJIE MA, FEI WU, JUNJIE FEI, AND LANQUN MAO
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adc9150
▲ 摘要：
利用人工流體系統再現基于離子通道的神經功能一直是神經形態計算和生物醫學應用的一個理想目標。在這項研究中，聚電解質-受限流體憶阻器（PFM）成功地實現了神經形態功能，其中受限的聚電解質-離子相互作用導致了滯后的離子傳輸，從而導致了離子記憶效應。
采用超低能耗的PFM模擬了各種不同的電脈沖模式。PFM的流體特性使模擬化學調節電脈沖成為可能。更重要的是，化學-電信號轉導是由單個PFM實現的。由于其結構與離子通道相似，PFM是通用的，易于與生物系統接口，為通過引入豐富的化學設計構建具有高級功能的神經形態設備鋪平了道路。
▲ Abstract
Reproducing ion channel–based neural functions with artificial fluidic systems has long been an aspirational goal for both neuromorphic computing and biomedical applications. In this study, neuromorphic functions were successfully accomplished with a polyelectrolyte-confined fluidic memristor (PFM), in which confined polyelectrolyte–ion interactions contributed to hysteretic ion transport, resulting in ion memory effects. Various electric pulse patterns were emulated by PFM with ultralow energy consumption. The fluidic property of PFM enabled the mimicking of chemical-regulated electric pulses. More importantly, chemical-electric signal transduction was implemented with a single PFM. With its structural similarity to ion channels, PFM is versatile and easily interfaces with biological systems, paving a way to building neuromorphic devices with advanced functions by introducing rich chemical designs.
Long-term memory and synapse-like dynamics in two-dimensional nanofluidic channels
二維納米流體通道中的長時記憶和突觸樣動力學
▲ 作者：P. ROBIN, T. EMMERICH, A. ISMAIL, A. NIGUèS, Y. YOU, G.-H. NAM, A. KEERTHI, A. SIRIA, A. K. GEIM, AND L. BOCQUET
▲ 鏈接：
https://www.science.org/doi/10.1126/science.adc9931
▲ 摘要：
通過納米級孔隙進行微調的離子傳輸是許多生物過程的關鍵，包括神經傳遞。最近的進展使水和離子的限制成為二維，揭示了在更大尺度上無法實現的傳輸特性，并引發了重現生物系統離子機械的希望。
作者通過實驗證明了記憶出現在水電解質運輸（亞）納米級通道。他們揭示了兩種類型的納米流體憶阻器，取決于通道材料和限制，記憶范圍從分鐘到小時。研究解釋了離子自組裝或表面吸附等界面過程如何出現大的時間尺度，能夠用納米流控系統實現Hebbian學習。該結果為水電解芯片的仿生計算奠定了基礎。
▲ Abstract：
Fine-tuned ion transport across nanoscale pores is key to many biological processes, including neurotransmission. Recent advances have enabled the confinement of water and ions to two dimensions, unveiling transport properties inaccessible at larger scales and triggering hopes of reproducing the ionic machinery of biological systems. Here we report experiments demonstrating the emergence of memory in the transport of aqueous electrolytes across (sub)nanoscale channels. We unveil two types of nanofluidic memristors depending on channel material and confinement, with memory ranging from minutes to hours. We explain how large time scales could emerge from interfacial processes such as ionic self-assembly or surface adsorption. Such behavior allowed us to implement Hebbian learning with nanofluidic systems. This result lays the foundation for biomimetic computations on aqueous electrolytic chips.
