bluuebunny/crossref_metadata_2025 huggingface dataset:
Fast Ionic Actuators with Silver–Silver Chloride Electrodes and a Mixed Ionic Liquid Electrolyte
Authors: Sideris Eva A. , de Lange Hendrik C. , Aabloo Alvo , Johanson Urmas , Tamm Tarmo , Must Indrek
Published: September 2023

Excellent conductivity makes silver (Ag) an attractive electrode and current collector material for a variety of devices, also promising faster soft actuators. However, high reactivity challenges the use of Ag in electrochemical systems, as dendritic growth can create undesired conduction pathways and short‐circuit the oppositely polarized electrodes. The challenge of rapid Ag electrochemical migration is addressed using a mixed mixed‐room temperature ionic liquid (RTIL) system (l‐ethyl‐3‐methylimidazolium bis‐(trifluoromethylsulfonyl)‐imide and trihexyl(tetradecyl)phosphonium chloride) that prevents short‐circuiting by engaging the produced Ag+ ions with Cl− anions. The stability of the system is demonstrated on an ionic actuator using Ag–silver chloride (AgCl) electrodes and a mixed‐RTIL electrolyte. The work demonstrates fast (in 5 s) transfer of a large (0.2 C cm−2) charge to high‐specific‐surface‐area carbon without observable dendritic growth in cycling and good electromechanical performance: 4° s−1 deflection rate at 0.8 V s−1 scan rate. Simple spray‐deposition of the Ag–AgCl electrodes promises scalable and cost‐effective fabrication. The combination of high stability and vast charge capacity encourages the engagement of Ag‐based electrodes for many electrochemical applications involving organic electrolytes also beyond robotics.
Microstructural Transformation and Enhanced Strength of Wire‐Feed Electron‐Beam Additive Manufactured Ti–6Al–4V Alloy Induced by High‐Pressure Torsion
Authors: Valiev Roman R. , Panin Alexey V. , Usmanov Emil I. , Savina Yana N. , Valiev Ruslan Z.
Published: September 2023

For the first time, the present study demonstrates the influence of high‐pressure torsion (HPT) on microstructural refinement and mechanical strength of Ti–6Al–4V titanium alloy produced by wire‐feed electron‐beam additive manufacturing. This technology has attracted an increasing interest presently from manufacturers of products with complex shapes and it allows for producing a titanium alloy with a unique microstructure that consists of martensitic α′ phase, separated by thin interlayers of residual β phase. Further processing of the alloy by HPT results in the formation of an ultrafine‐grained (UFG) structure with an average grain size of about 25 ± 10 nm, significantly increasing its microhardness up to 448 ± 5 HV. Microscopic studies reveal that the attained UFG structure consists predominantly of the grains of α and β phases in the ratio of 92.8% and 7.2%, respectively. This article also considers the nature of the high strength of Ti–6Al–4V subjected to HPT.
Analysis of Die Compaction of Chip Geometry through Porous Continuum Model‐Based Approach
Authors: Lee Jeong Ah , Kwon Jihye , Kwon Gihyeok , Hong Soon Jik , Kim Hyoung Seop
Published: September 2023

Metal swarf has the advantage of being eco‐friendly due to their ability to be recycled and reused, in addition to being lightweight, energy‐absorbing, and cost‐effective. For practical applications in various industrial fields, effective and accurate modeling for each case should be developed in consideration of its physical properties. This study investigates the mechanical behavior of aluminum chip compaction employing a new computational simulation approach based on a pressure‐dependent porous continuum model. Two material parameters of densification rate (n) and the ratio of shear modulus (m) are proposed and adjusted for different swarf. The numerical results show good agreement with the experimentally obtained axial stress—relative density relation of three various samples, demonstrating a close relationship between the parameters n and the chip geometry. This study can be applied for further investigation and analysis utilizing metal swarf of different geometries in various industrial applications.
Enhancement of Piezoelectric Response in Yttrium Aluminum Nitride (YxAl1‐xN) Thin Films
Authors: Pandit Shardul , Schneider Michael , Schwarz Sabine , Schmid Ulrich
Published: September 2023

Alloying rare earth elements into aluminum nitride (AlN) thin films to increase the piezoelectric response has gained a lot of attention in the past few years. Many rare earth elements are investigated in which scandium alloying resulted in the highest piezoelectric response for AlN. At the same time, researchers have also theoretically explored yttrium alloying as a feasible and economical alternative to scandium. Herein, for the first time, experimentally, the increase of the piezoelectric response of sputter‐deposited YxAl1–xN thin films as a function of increasing yttrium concentration as predicted by density functional theory calculations is demonstrated. Using differently manufactured targets, YxAl1–xN thin films with four different yttrium alloying concentrations (9, 12, 15, and 20 at%). are synthesized. Detailed thin‐film analysis is carried out and the highest value of d33 measured is 12 pC N−1 for Y0.2Al0.8N, which is a 250% increase compared to pure AlN. Even more, the Young's modulus decreases with increasing yttrium concentration in excellent agreement with theoretical predictions. Finally, Y0.15Al0.85N and Y0.2Al0.8N layers show high crystalline stability in pure oxygen environment up to 800 °C, demonstrating high oxidation resistance even under harsh environmental conditions.
Additive Manufacturing of High‐Temperature Preceramic‐Derived SiOC Hybrid Functional Ceramics
Authors: Li Zheng , Khuje Saurabh , Islam Abdullah , Ren Shenqiang
Published: September 2023

High‐temperature capable materials, metals, and ceramics are attracting significant interest for applications in extreme environmental conditions. Herein, a hybrid metal‐reinforced ceramic matrix material consisting of preceramic‐derived high‐temperature SiOC and copper nanoplates is reported, enabling the manufacturing of high‐temperature sensing electronics. The preceramic polymer precursors including polydimethylsiloxane and polydimethylsilane, together with copper nanoplates, are thermally converted into durable copper‐reinforced SiOC ceramics. The presence of copper in SiOC ceramics enhances its electrical conductivity, while SiOC suppresses oxygen uptake and acts as a shield for oxidation to achieve high‐temperature thermal resistance and negative temperature coefficient at high temperatures. A comprehensive electric and sensing performance, combined with cost‐effectiveness and scalability, can facilitate the utilization of hybrid Cu and SiOC composites in high‐temperature electronics.
Instrumented Dynamic Penetration of Sandwich Panels with Auxetic and Non‐Auxetic Core using Direct Impact Hopkinson Bar
Authors: Šleichrt Jan , Falta Jan , Neuhäuserová Michaela , Drechslerová Veronika , Koudelka Petr , Rada Václav , Fíla Tomáš , Jiroušek Ondřej
Published: September 2023

This article deals with the dynamic penetration of 3D‐printed panels with auxetic and conventional honeycomb unit cell‐based cores. The geometry of the unit cells and their periodic assembly in the resulting lattices are selected to ensure the same relative density and overall weight of the individual sample types. Such a similarity of both specimen types allows for the evaluation of differences between conventional and auxetic lattices in terms of penetration characteristics and deformation energy mitigation properties. Dynamic penetration of the samples is performed using a fully strain‐gauge instrumented open Hopkinson pressure bar at three impact velocities resulting in three loading scenarios. All the performed experiments are captured by two optical cameras for detailed observation and to track the impactor movement using digital image correlation. The force‐penetration depth relation is used to evaluate the elastic and postyield compression characteristics of the lattices together with their deformation energy mitigation capabilities. The results show that the main differences in the deformation response of the lattices consist of lower overall stiffness and effective yielding of the auxetic lattices at a higher penetration depth. Numerical simulation using an explicit solver is performed to analyze the deformation mechanism of the individual core types.
Effect of Al Content on Microstructure, Mechanical, and Corrosion Properties of (Fe33Cr36Ni15Co15Ti1)100−xAlx High‐Entropy Alloys
Authors: Zheng Qifeng , Lu Weiyan , Han Dong , Li Tianrun , Guo Hui , Qiu Keqiang , Yang Baijun , Wang Jianqiang
Published: September 2023

(Fe33Cr36Ni15Co15Ti1)100−xAlx (x = 0, 3, 5, 6, 7, 8) high‐entropy alloys (HEAs) are prepared by arc melting. The influence of Al element addition on the microstructure, mechanical properties, and anticorrosion in 3.5 wt% NaCl aqueous solution is systematically investigated. The microstructure analysis indicates that HEAs possess varying phases from face center cubic/face‐centered cubic (FCC) + sigma to FCC + body‐centered cubic (BCC) and then FCC + BCC +sigma, the last to BCC + sigma with the increase of Al content. The compressive results suggest that the Al addition exhibits a significant elevation in strength. Particularly, Al7 alloy shows a superior strength and plasticity, which presents a yield strength of 1315.3 MPa and a compressive strain over 50%. Order strengthening and coherent strengthening of nanosized phase are regarded as main strengthening effects. In addition, Al element is harmful for the corrosion resistance of (Fe33Cr36Ni15Co15Ti1)100−xAlx HEAs system, which is ascribed to the weakened passive film stability. It is also noted that pits tend to be initiated in relatively Cr‐depleted phases (FCC or B2 phase) due to the inhomogeneous elemental distribution‐induced galvanic corrosion. In spite of this, all HEAs exhibit superior corrosion resistance than that of 304SS.
H‐BN‐Encapsulated Uncooled Infrared Photodetectors Based on Tantalum Nickel Selenide
Authors: Zhang Shi , Han Li , Xiao Kening , Zhang Libo , Shi Chaofan , Xu Leijun , Deng Ke , Zou Yuanchen , Jiang Mengjie , Lv Xuyang , Zhu Yulin , Li Qing , Liu Changlong , Tang Weiwei , Li Guanhai , Ding Songyuan , Chen Xiaoshuang , Lu Wei
Published: September 2023

Uncooled broadband spectrum detection, spanning from visible to mid‐wave‐infrared regions, offers immense potential for applications in environmental monitoring, optical telecommunications, and radar systems. While leveraging proven technologies, conventional mid‐wave‐infrared photodetectors are encumbered by high dark currents and the necessity for cryogenic cooling. Correspondingly, innovative low‐dimensional materials like black phosphorus manifest weak photoresponse and instability. Here, tantalum nickel selenide (Ta2NiSe5) infrared photodetectors with an operational wavelength range from 520 nm to 4.6 µm, utilizing a hexagonal boron nitride (h‐BN) encapsulation technique are introduced. The h‐BN encapsulated metal‐Ta2NiSe5‐metal photodetector demonstrates a responsivity of 0.86 A W−1, a noise equivalent power of 1.8 × 10−11 W Hz−1/2, and a peak detectivity of 8.75 × 108 cm Hz1/2 W−1 at 4.6 µm under ambient conditions. Multifaceted mechanisms of photocurrent generation in the novel device prototype subject are scrutinized to varying wavelengths of radiation, by characterizing the temporal‐, bias‐, power‐, and temperature‐dependent photoresponse. Moreover, the photopolarization dependence is delved and concealed‐target imaging is demonstrated, which exhibits polarization angle sensitivity and high‐fidelity imaging across the visible, short‐wave, and mid‐wave‐infrared bands. The observations, which reveal versatile detection modalities, propose Ta2NiSe5 as a promising low‐dimensional material for advanced applications in nano‐optoelectronic device.
Ultra‐High‐Energy Density in Layered Sodium‐Ion Battery Cathodes through Balancing Lattice‐Oxygen Activity and Reversibility
Authors: Lu Hangyu , Chu Shiyong , Tian Jiaming , Wang Qi , Sheng Chuanchao , Cheng Chen , Liu Rixin , D'Angelo Anita M. , Pang Wei Kong , Zhang Liang , Zhou Haoshen , Guo Shaohua
Published: September 2023

Lattice‐oxygen redox in layered metal oxide cathodes offers a promising way to exploit high‐energy density sodium‐ion batteries. However, oxidation and reduction of lattice‐oxygen are always asymmetric, showing poor reversibility upon charging and discharging due to the activated oxygen loss and subsequent structural rearrangement. Here, a layered Na0.7[Li0.2Mn0.7Co0.1]O2 (NLMCO) is developed by balancing lattice‐oxygen activity and reversibility, which can deliver a record energy density of 729.7 Wh kg−1, further exceeding the state‐of‐the‐art Na0.75[Li0.25Mn0.75]O2 (NLMO, 638.4 Wh kg−1). In light of electron paramagnetic resonance spectroscopy, in situ differential electrochemical mass spectroscopy, and electrochemical testing results, the highly activated lattice‐oxygen is effectively stabilized in NLMCO without oxygen molecule release while obvious oxygen release is detected in the highly activated NLMO. Benefiting from the enhanced transition metal‐oxygen covalency and reduced band energy gap, the NLMCO electrode demonstrates simultaneously high lattice‐oxygen activity and reversibility, thus resulting in excellent rate and cycling performance, as well as ultra‐high energy density. The findings highlight the critical association of energy density and lattice‐oxygen redox reversibility, which will inspire more interest in anionic redox‐based high‐energy batteries.
Patterning of a High Surface Area Liquid Metal‐Carbon Composite Film Using Laser Processing
Authors: Frey Ethan J. , Im Sooik , Bachmann Adam L. , Genzer Jan , Dickey Michael D.
Published: September 2023

Liquid metal is a compelling material for making soft and stretchable devices due to its high electrical conductivity and extreme stretchability. One way to pattern liquid metal is to nebulize it into small droplets, spray it onto a surface as a film, and then use a laser to “sinter” it into circuit patterns. Here, it is shown that including poly(amic acid) in the spray‐deposited film has multiple benefits: it (1) allows the unsintered regions to be removed easily, (2) lowers the power required for sintering, (3) converts to carbon upon exposure to create a carbon‐metal composite, and (4) increases the surface area of the film by 2632% compared to bulk EGaIn. The conductive liquid metal‐carbon circuits can also be transferred to a soft substrate to produce stretchable conductors. The circuits slightly increase in conductivity up to ≈30% strain and then decrease such that by 100% strain, the resistance is only ≈1.02 times its initial resistance. Lastly, the film is highly reactive with water molecules in the air, increasing in resistance over time in humid conditions. The high reactivity and surface area of the film indicate potential applications in batteries, catalysts, and capacitors. Meanwhile, the facile patterning indicates potential applications in soft circuits.
Assembly of Multisurfaced Van der Waals Layered Compound GaSe via Thermal Oxidation
Authors: Zheng Sikang , Li Jingwei , Zhang Daliang , Zhou Zizhen , Liu Jie , Tao Yanyan , Fang Xuan , Yang Xiaolong , Han Guang , Lu Xu , Wang Guoyu , Zhang Bin , Wang Dengkui , Zhou Xiaoyuan
Published: September 2023

The investigation of the oxidation behavior of van der Waals chalcogenides holds significant importance in terms of preventing and controlling oxidation, utilizing surface oxidation structures to regulate properties, and advancing applications. Here, taking GaSe as a candidate, its thermal oxidation and surface structure evolution are intensively studied. Through systematic microscopic analyses, oxidized structures at multi‐scale (from atomic scale to millimeters) are resolved, and various assembly heterogeneous surfaces including Ga2Se3/Ga2O3 and Ga2O3 multilayers are uncovered at different oxidation temperatures. The temperature‐dependent oxidation behavior and surface structure evolution of the GaSe are revealed, and the oxidation mechanisms in the entire temperature range are also disclosed. Finally, the photoluminescence regulation of the GaSe is initially explored via thermal oxidation, demonstrating great potential for surface oxidation engineering. This study is not only of great importance for the deep understanding and utilization of GaSe oxidation, but also beneficial for materials/device design and development of relative systems.
Hydroxyapatite‐Coated Small Intestinal Submucosa Membranes Enhanced Periodontal Tissue Regeneration through Immunomodulation and Osteogenesis via BMP‐2/Smad Signaling Pathway
Authors: Cheng Guoping , Guo Shujuan , Li Maoxue , Xiao Shimeng , Jiang Bo , Ding Yi
Published: September 2023

Periodontitis, a chronic infection causing periodontal tissue loss, may be effectively addressed with in situ tissue engineering. Small intestinal submucosa (SIS) offers exceptional biocompatibility and biodegradability but lacks sufficient osteoconductive and osteoinductive properties. This study develops and characterizes SIS coated with hydroxyapatite (SIS‐HA) and gelatin methacrylate hydroxyapatite (SIS‐Gel‐HA) using biomineralization and chemical crosslinking. The impact on periodontal tissue regeneration is assessed by evaluating macrophage immune response and osteogenic differentiation potential of periodontal ligament stem cells (PDLSCs) in vitro and rat periodontal defects in vivo. The jejunum segment, with the highest collagen type I content, is optimal for SIS preparation. SIS retains collagen fiber structure and bioactive factors. Calcium content is 2.21% in SIS‐HA and 2.45% in SIS‐Gel‐HA, with no significant differences in hydrophilicity, physicochemical properties, protein composition, or biocompatibility among SIS, SIS‐HA, SIS‐Gel, and SIS‐Gel‐HA. SIS is found to upregulate M2 marker expression, both SIS‐HA and SIS‐Gel‐HA enhance the osteogenic differentiation of PDLSCs through the BMP‐2/Smad signaling pathway, and SIS‐HA demonstrates superior in vitro osteogenic activity. In vivo, SIS‐HA and SIS‐Gel‐HA yield denser, more mature bones with the highest BMP‐2 and Smad expression. SIS‐HA and SIS‐Gel‐HA demonstrate enhanced immunity–osteogenesis coupling, representing a promising periodontal tissue regeneration approach.
Hypoxic Microenvironment Reconstruction with Synergistic Biofunctional Ions Promotes Diabetic Wound Healing
Authors: Chen Xiaochen , Zhang Liyan , Chai Wenwen , Tian Pengfei , Kim Jua , Ding Jingxin , Zhang Hao , Liu Chunyu , Wang Deping , Cui Xu , Pan Haobo
Published: September 2023

Chronic hypoxia and ischemia make diabetic wounds non‐healing. Cellular functions of diabetic chronic wounds are inhibited under a pathological environment. Therefore, this work develops a composite hydrogel system to promote diabetic wound healing. The composite hydrogel system consists of ε‐poly‐lysine (EPL), calcium peroxide (CP), and borosilicate glass (BG). The hydrogel supplies continuous dissolved oxygen molecules to the wound that can penetrate the skin tissue to restore normal cellular function and promote vascular regeneration. Biofunctional ions released from BGs can recruit more macrophages through neovascularization and modulate macrophage phenotypic transformation. Combining oxygen‐mediated vascular regeneration and ion‐mediated inflammatory regulation significantly accelerated diabetic wound healing. These findings indicate that this composite hydrogel system holds promise as a novel tissue engineering material.
Polysulfides in Magnesium‐Sulfur Batteries
Authors: Luo Tongtong , Wang Yang , Elander Brooke , Goldstein Michael , Mu Yu , Wilkes James , Fahrenbruch Mikayla , Lee Justin , Li Tevin , Bao Junwei Lucas , Mohanty Udayan , Wang Dunwei
Published: September 2023

Mg‐S batteries hold great promise as a potential alternative to Li‐based technologies. Their further development hinges on solving a few key challenges, including the lower capacity and poorer cycling performance when compared to Li counterparts. At the heart of the issues is the lack of knowledge on polysulfide chemical behaviors in the Mg‐S battery environment. In this Review, a comprehensive overview of the current understanding of polysulfide behaviors in Mg‐S batteries is provided. First, a systematic summary of experimental and computational techniques for polysulfide characterization is provided. Next, conversion pathways for Mg polysulfide species within the battery environment are discussed, highlighting the important role of polysulfide solubility in determining reaction kinetics and overall battery performance. The focus then shifts to the negative effects of polysulfide shuttling on Mg‐S batteries. The authors outline various strategies for achieving an optimal balance between polysulfide solubility and shuttling, including the use of electrolyte additives, polysulfide‐trapping materials, and dual‐functional catalysts. Based on the current understanding, the directions for further advancing knowledge of Mg polysulfide chemistry are identified, emphasizing the integration of experiment with computation as a powerful approach to accelerate the development of Mg‐S battery technology.
Shape‐Configurable MXene‐Based Thermoacoustic Loudspeakers with Tunable Sound Directivity
Authors: Kim Jinyoung , Jung Geonyoung , Jung Seokhee , Bae Myung Hwan , Yeom Jeonghee , Park Jonghwa , Lee Youngoh , Kim Young‐Ryul , Kang Dong‐hee , Oh Joo Hwan , Park Seungyoung , An Ki‐Seok , Ko Hyunhyub
Published: September 2023

Film‐type shape‐configurable speakers with tunable sound directivity are in high demand for wearable electronics. Flexible, thin thermoacoustic (TA) loudspeakers—which are free from bulky vibrating diaphragms—show promise in this regard. However, configuring thin TA loudspeakers into arbitrary shapes is challenging because of their low sound pressure level (SPL) under mechanical deformations and low conformability to other surfaces. By carefully controlling the heat capacity per unit area and thermal effusivity of an MXene conductor and substrates, respectively, it fabricates an ultrathin MXene‐based TA loudspeaker exhibiting high SPL output (74.5 dB at 15 kHz) and stable sound performance for 14 days. Loudspeakers with the parylene substrate, whose thickness is less than the thermal penetration depth, generated bidirectional and deformation‐independent sound in bent, twisted, cylindrical, and stretched‐kirigami configurations. Furthermore, it constructs parabolic and spherical versions of ultrathin, large‐area (20 cm × 20 cm) MXene‐based TA loudspeakers, which display sound‐focusing and 3D omnidirectional‐sound‐generating attributes, respectively.
Technology and Integration Roadmap for Optoelectronic Memristor
Authors: Wang Jinyong , Ilyas Nasir , Ren Yujing , Ji Yun , Li Sifan , Li Changcun , Liu Fucai , Gu Deen , Ang Kah‐Wee
Published: September 2023

Optoelectronic memristors (OMs) have emerged as a promising optoelectronic Neuromorphic computing paradigm, opening up new opportunities for neurosynaptic devices and optoelectronic systems. These OMs possess a range of desirable features including minimal crosstalk, high bandwidth, low power consumption, zero latency, and the ability to replicate crucial neurological functions such as vision and optical memory. By incorporating large‐scale parallel synaptic structures, OMs are anticipated to greatly enhance high‐performance and low‐power in‐memory computing, effectively overcoming the limitations of the von Neumann bottleneck. However, progress in this field necessitates a comprehensive understanding of suitable structures and techniques for integrating low‐dimensional materials into optoelectronic integrated circuit platforms. This review aims to offer a comprehensive overview of the fundamental performance, mechanisms, design of structures, applications, and integration roadmap of optoelectronic synaptic memristors. By establishing connections between materials, multilayer optoelectronic memristor units, and monolithic optoelectronic integrated circuits, this review seeks to provide insights into emerging technologies and future prospects that are expected to drive innovation and widespread adoption in the near future.
All‐Screen‐Coatable Photo‐Thermoelectric Imagers for Physical and Thermal Durability Enhancement
Authors: Li Kou , Matsuzaki Yuto , Takahara Sota , Sakai Daiki , Aoshima Yuto , Takahashi Norika , Yamamoto Minami , Kawano Yukio
Published: September 2023

Carbon nanotube (CNT) film photo‐thermoelectric (PTE) imagers are suitable for non‐destructive inspection techniques owing to their functionalities. Simultaneously, their practical application remains a crucial bottleneck due to low yield handling in the device fabrication (e.g., disconnections between photo absorbent channels and readout electrodes). However, studies clarifying the above malfunction mechanism and associated dominant factors in device handling, such as specific fabrication or material selection steps, still need to be completed. To address this issue, this work introduces all‐screen‐coatable fabrication techniques for CNT film PTE imagers to enhance their physical and thermal durabilities. First, this work determined that the transfer of CNT films on supporting substrates dominantly governs the mechanical robustness of the channels and that thermal curing in the subsequent fabrication process is an essential factor in the yields of channel‐electrode connections. The proposed approach ensures a transfer‐free direct coating of the CNT film on diverse substrates and is sufficiently durable against thermal curing‐induced disconnections at the channel‐electrode interfaces. The screen‐coating technique is also available for whole device materials of solution‐processable CNT film PTE imagers, simplifying fabrication processes. All‐screen‐coatable CNT film PTE imagers synergize their inherent functional sensing and high‐yield operations toward versatile applications.
Feedback Optimization Strategy for Rotational Alignment Echo Spectroscopy
Authors: Bournazel Manon , Espaignol Antoine , Béjot Pierre , Hertz Edouard , Billard Franck , Faucher Olivier
Published: September 2023

The recent discovery of rotational echoes has contributed to extend the applications of field‐free molecular alignment to short time scales, namely to a temporal region preceding the first alignment revival of the molecule. Most echo measurements require adjusting the position of the echo over time, which in the case of molecular alignment echo unavoidably leads to a change in its amplitude, unless the intensity of the pulse sequence triggering the echo is properly modified. Herein, it is proposed to avoid this drawback by using an optical pulse shaper steered by a learning algorithm. It is demonstrated that a temporal shaping, whose characteristics are optimized to maintain a constant echo amplitude regardless of its creation time, can be generated by controlling the spectral phase and amplitude of the laser pulse which are then used in an open‐loop control system. As a proof of principle, the optimization strategy is applied to the observation of short‐term dissipative dynamics of laser‐aligned molecules exposed to collisions and to the measurement of associated decoherence and population decay time constants.
Au(I) and HOTf‐Catalyzed Cascade [5+1]‐Annulations between Allenylacetals and Diazo Esters To Form 1,3‐ and 2,3‐Disubstituted Naphthoates, Respectively
Authors: Bhausaheb Dawange Satish , Liu Rai‐Shung
Published: September 2023

Gold‐catalyzed [5+1]‐annulations between allenylacetals with diazo esters to form 1,3‐disubstituted naphthoate derivatives are described. Notably, this reaction chemoselectivity is switched to 2,3‐naphthoate products when using the HOTf catalyst. Mechanistic studies of these reactions support an acetal activation, in which oxoniums are formed initially, followed by attack of the allene, generating allyl cations to trap α‐diazo esters. In gold catalysis, such diazo addition intermediates undergo Roskamp rearrangement, whereas in HOTf catalysis the same intermediates undergo a Conia‐ene reaction instead.
Ring‐Opening‐Recombination Strategy Based on 2‐Methylbenzothiazole Salts: Syntheses of Thiazinopyrrole Fused‐Ring Derivatives
Authors: Xu Shengting , Zhu Zhongzhi , Yang Zhendong , Mai Zuyu , Chen Tianxiang , Ma Aijun , Chen Xiuwen
Published: September 2023

This study presents a method for the synthesis of thiazinopyrrole fused ring derivatives utilizing a ring‐opening recombination strategy with benzothiazole salts. Thiazolium salts, aldehydes, and amines undergo a cascade cyclization reaction in a one‐pot under the solvent conditions of ethanol.
Expanding Synthetic Applications of Δ1‐Piperidine‐2‐carboxylate/Δ1‐pyrroline‐2‐carboxylate Reductase from Pseudomonas syringae (DpkAPsyrin). Biocatalytic Asymmetric Synthesis of (S,E)‐2‐hydroxy‐4‐arylbut‐3‐enoic Acid Derivatives
Authors: Moreno Carlos J. , Gittings Samantha , Schollmeyer Dieter , Joglar Jesús , Bujons Jordi , Hernández Karel , Clapés Pere
Published: September 2023

Chiral 2‐hydroxy‐4‐arylbut‐3‐enoic acid derivatives are important precursors for the synthesis of angiotensin converting enzyme (ACE) inhibitors, such as enalapril, lisinopril, cilapril or benazepril. In this work, we take advantage of the unexplored promiscuous ketoreductase activity of Δ1‐piperidine‐2‐carboxylate/Δ1‐pyrroline‐2‐carboxylate reductase from Pseudomonas syringae pv. tomato DSM 50315 (DpkAPsyrin) for the synthesis of (S,E)‐2‐hydroxy‐4‐arylbut‐3‐enoic acids. The strategy was designed as an enzymatic cascade comprising an aldol condensation between pyruvate with aryl aldehydes, catalyzed by the trans‐o‐hydroxybenzylidene pyruvate hydratase‐aldolase from Pseudomonas putida (HBPAPputida), for the construction of carbon scaffold, and an ensuing asymmetric reduction of the carbonyl group catalyzed by DpkAPsyrin. The enzymatic cascade provided quantitative conversions, with global isolated yields between 57–85%. A total of nine structurally diverse (S,E)‐2‐hydroxy‐4‐arylbut‐3‐enoic acids were prepared in ee between 87–99%.
In Situ Cocktail Nanovaccine for Cancer Immunotherapy
Authors: Liu Mohan , Xie Daoyuan , Hu Die , Zhang Rui , Wang Yusi , Tang Lin , Zhou Bailing , Zhao Binyan , Yang Li
Published: September 2023

In situ vaccination is a desirable strategy for cancer immunotherapy due to its convenience and capacity to target tumor antigens. Here, an in situ nanovaccine based on a cationic peptide with cholesterol‐modified, DP7‐C, for cancer immunotherapy is rationally designed, and developed a cancer nanovaccine that is easy to preparate. The nanovaccine includes cocktail small interfering RNAs (siRNAs) and immunologic adjuvant CpG ODNs, has synergistic effect in the cancer treatment. This nanovaccine can induce tumor cell death, promote antigen presentation and relieve immune suppression in the tumor microenvironment (TME). Moreover, this nanovaccine is administered to CT26 (hot) and B16F10 (cold) tumor model mice, in which it targeted the primary tumors and induced systemic antitumor immunity to inhibit metastasis. It is validated that the nanovaccine can convert cold tumors into hot tumors. Furthermore, the nanovaccine increased the immune response to anti‐PD‐1 therapy by modulating the TME in both CT26‐ and B16F10‐tumor‐bearing mice. The siRNA cocktail/CpG ODN/self‐assembling peptide nanovaccine is a simple and universal tool that can effectively generate specific tumor cell antigens and can be combined with immuno‐oncology agents to enhance antitumor immune activity. The versatile methodology provides an alternative approach for developing cancer nanovaccines.
Fundamental Limitation in Electrochemical Methane Oxidation to Alcohol: A Review and Theoretical Perspective on Overcoming It
Authors: Kishore M.R. Ashwin , Lee Sungwoo , Yoo Jong Suk
Published: September 2023

The direct conversion of gaseous methane to energy‐dense liquid derivatives such as methanol and ethanol is of profound importance for the more efficient utilization of natural gas. However, the thermo‐catalytic partial oxidation of this simple alkane has been a significant challenge due to the high C−H bond energy. Exploiting electrocatalysis for methane activation via active oxygen species generated on the catalyst surface through electrochemical water oxidation is generally considered as economically viable and environmentally benign compared to energy‐intensive thermo‐catalysis. Despite recent progress in electrochemical methane oxidation to alcohol, the competing oxygen evolution reaction (OER) still impedes achieving high faradaic efficiency and product selectivity. In this review, an overview of current progress in electrochemical methane oxidation, focusing on mechanistic insights on methane activation, catalyst design principles based on descriptors, and the effect of reaction conditions on catalytic performance are provided. Mechanistic requirements for high methanol selectivity, and limitations of using water as the oxidant are discussed, and present the perspective on how to overcome these limitations by employing carbonate ions as the oxidant.
Recent Progress in Flexible and Wearable All Organic Photoplethysmography Sensors for SpO2Monitoring
Authors: Dcosta Jostin Vinroy , Ochoa Daniel , Sanaur Sébastien
Published: September 2023

Flexible and wearable biosensors are the next‐generation healthcare devices that can efficiently monitor human health conditions in day‐to‐day life. Moreover, the rapid growth and technological advancements in wearable optoelectronics have promoted the development of flexible organic photoplethysmography (PPG) biosensor systems that can be implanted directly onto the human body without any additional interface for efficient bio‐signal monitoring. As an example, the pulse oximeter utilizes PPG signals to monitor the oxygen saturation (SpO2) in the blood volume using two distinct wavelengths with organic light emitting diode (OLED) as light source and an organic photodiode (OPD) as light sensor. Utilizing the flexible and soft properties of organic semiconductors, pulse oximeter can be both flexible and conformal when fabricated on thin polymeric substrates. It can also provide highly efficient human‐machine interface systems that can allow for long‐time biological integration and flawless measurement of signal data. In this work, a clear and systematic overview of the latest progress and updates in flexible and wearable all‐organic pulse oximetry sensors for SpO2monitoring, including design and geometry, processing techniques and materials, encapsulation and various factors affecting the device performance, and limitations are provided. Finally, some of the research challenges and future opportunities in the field are mentioned.
Unlocking the Potential of CuAgZr Metallic Glasses: A Comprehensive Exploration with Combinatorial Synthesis, High‐Throughput Characterization, and Machine Learning
Authors: Wieczerzak Krzysztof , Groetsch Alexander , Pajor Krzysztof , Jain Manish , Müller Arnold M. , Vockenhuber Christof , Schwiedrzik Jakob , Sharma Amit , Klimashin Fedor F. , Michler Johann
Published: September 2023

In this work, the CuAgZr metallic glasses (MGs) are investigated, a promising material for biomedical applications due to their high strength, corrosion resistance, and antibacterial activity. Using an integrated approach of combinatorial synthesis, high‐throughput characterization, and machine learning (ML), the mechanical properties of CuAgZr MGs are efficiently explored. The investigation find that post‐deposition oxidation in inter‐columnar regions with looser packing causes high oxygen content in Cu‐rich regions, significantly affecting the alloys' mechanical behavior. The study also reveals that nanoscale structural features greatly impact plastic yielding and flow in the alloys. ML algorithms are tested, and the multi‐layer perceptron algorithm produced satisfactory predictions for the alloys' hardness of untested alloys, providing valuable clues for future research. The work demonstrates the potential of using combinatorial synthesis, high‐throughput characterization, and ML  techniques to facilitate the development of new MGs with improved strength and economic feasibility.
Metaverse Wearables for Immersive Digital Healthcare: A Review
Authors: Kim Kisoo , Yang Hyosill , Lee Jihun , Lee Won Gu
Published: September 2023

The recent exponential growth of metaverse technology has been instrumental in reshaping a myriad of sectors, not least digital healthcare. This comprehensive review critically examines the landscape and future applications of metaverse wearables toward immersive digital healthcare. The key technologies and advancements that have spearheaded the metamorphosis of metaverse wearables are categorized, encapsulating all‐encompassed extended reality, such as virtual reality, augmented reality, mixed reality, and other haptic feedback systems. Moreover, the fundamentals of their deployment in assistive healthcare (especially for rehabilitation), medical and nursing education, and remote patient management and treatment are investigated. The potential benefits of integrating metaverse wearables into healthcare paradigms are multifold, encompassing improved patient prognosis, enhanced accessibility to high‐quality care, and high standards of practitioner instruction. Nevertheless, these technologies are not without their inherent challenges and untapped opportunities, which span privacy protection, data safeguarding, and innovation in artificial intelligence. In summary, future research trajectories and potential advancements to circumvent these hurdles are also discussed, further augmenting the incorporation of metaverse wearables within healthcare infrastructures in the post‐pandemic era.
Machine Learning‐Enabled Tactile Sensor Design for Dynamic Touch Decoding
Authors: Lu Yuyao , Kong Depeng , Yang Geng , Wang Ruohan , Pang Gaoyang , Luo Huayu , Yang Huayong , Xu Kaichen
Published: September 2023

Skin‐like flexible sensors play vital roles in healthcare and human–machine interactions. However, general goals focus on pursuing intrinsic static and dynamic performance of skin‐like sensors themselves accompanied with diverse trial‐and‐error attempts. Such a forward strategy almost isolates the design of sensors from resulting applications. Here, a machine learning (ML)‐guided design of flexible tactile sensor system is reported, enabling a high classification accuracy (≈99.58%) of tactile perception in six dynamic touch modalities. Different from the intuition‐driven sensor design, such ML‐guided performance optimization is realized by introducing a support vector machine‐based ML algorithm along with specific statistical criteria for fabrication parameters selection to excavate features deeply concealed in raw sensing data. This inverse design merges the statistical learning criteria into the design phase of sensing hardware, bridging the gap between the device structures and algorithms. Using the optimized tactile sensor, the high‐quality recognizable signals in handwriting applications are obtained. Besides, with the additional data processing, a robot hand assembled with the sensor is able to complete real‐time touch‐decoding of an 11‐digit braille phone number with high accuracy.
Regulation of Ion Homeostasis for Enhanced Tumor Radio‐Immunotherapy
Authors: Qian Rui , Yi Xuan , Liu Teng , Chen Hua , Wang Yuhong , Hu Lin , Guo Lingchuan , Yang Kai , Deng Haijun
Published: September 2023

Intra/extracellular ion content affects the growth and metastasis of tumor cells, as well as the efficacy of various antitumor therapies. Herein, a carbonic anhydrase inhibitor (CAI) is loaded onto pH‐responsive calcium carbonate (CaCO3) nanoparticles and then modify theses nanoparticles with liposomes to obtain biocompatible CaCO3/CAI@Lipsome (CCL) for enhance tumor radio‐immunotherapy. CCL can specially decompose in tumor microenvironment, releasing calcium ion (Ca2+) and CAI, as well as increasing the pH value of extracellular fluid. CAI restrains the flow of hydrogen ion (H+) inside and outside the tumor cells, resulting in the reversal of tumor acidic microenvironment and the increase of intracellular H+, both of which can improve the sensitivity of tumor to radiotherapy. Afterward, the increased intracellular H+ together with radiotherapy‐causes reactive oxygen species promotes calcium influx, leading to cellular calcium overload. Moreover, the CCL‐tailored content of H+ and Ca2+ strengthens radiotherapy‐induced immunogenic cell death and dendritic cell maturation, amplifying systemic anti‐tumor adaptive immunity. Meanwhile, macrophages in the CCL‐treated tumors are polarized from pro‐tumor M2 to anti‐tumor M1 under X‐ray exposure, owing to the neutralization of tumor acidic microenvironment and enhances Ca2+ content. Therefore, multi‐directional regulation of the intra/extra tumor cell pH/calcium by simple nano‐preparation would provide a powerful way to improve the efficacy of radio‐immunotherapy.
Micellar Solubilization for High‐Energy‐Density Aqueous Organic Redox Flow Batteries
Authors: Kim Youngsu , Kwon Giyun , Park Sung‐O , Kim Heechan , Kim Jihyeon , Kim Kyoungoh , Yoo Jaekyun , Lee Donghwan , Kang Kisuk
Published: September 2023

High solubility of active materials is crucial for achieving a high‐energy‐density catholyte/anolyte in redox flow batteries. However, solubility largely depends on the compatibility with electrolyte, limiting the types of redox‐active materials that can be used in aqueous electrolytes. Herein, a universal strategy is introduced to attain a high solubility of active materials regardless of the compatibility with aqueous electrolytes while preserving their intrinsic redox activity via micellar solubilization. Leveraging the amphiphilic nature of surfactant molecules, insoluble redox‐active materials are encapsulated by surfactants to be dissolvable with significant solubility. As a demonstration, it is showed that an order‐of‐magnitude solubility enhancement can be achieved for (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) in aqueous catholyte (≈0.8 m). Consequently, the catholyte performance of TEMPO is fully harnessed, leading to an energy density enhancement of more than ten times compared to that in bare electrolyte. It is also observed that micellar solubilization unexpectedly improves the cycle stability, attributed to the mitigation of intermolecular side reactions and reduced crossover. Finally, the fundamental electrochemical reaction mechanism of micelle‐encapsulated TEMPO is discussed. This strategy offers a new insight regarding the solubility and stability of the catholyte/anolyte, and is expected to be applicable to other redox‐active molecules, opening up an unexplored micellar chemistry in redox flow batteries.
Ultra‐Stable Zinc Metal Anodes Enabled by Uniform Zn Deposition on A Preferential Crystal Plane
Authors: Zeng Wei , Wei Pingdong , Chen Juner , Wang Guangzhao , Yan Yu , Yu Huihuang , Yang Chunyang , Zhang Guanhua , Jiang Hanqing
Published: September 2023

The unsatisfactory electrochemical performance of Zn metal batteries (ZMBs) caused by uncontrollable Zn dendrite growth and detrimental parasitic reactions has significantly hindered their large‐scale applications. Herein, periodic hemispherical structures with a preferential exposure of Cu (100) crystal plane are designed and obtained using facile photolithography, which is followed by wet etching treatment. An exposed zincophilic Cu (100) crystal plane with low nucleation barriers acts as the preferred deposition site to induce homogeneous Zn deposition. Additionally, the periodic hemispherical structure with an enlarged surface area not only suppresses the Zn dendrite growth by reducing the local current density, but also synergistically buffers the volume expansion during the cycling process. As a result, the as‐prepared faceted Cu hemispherical electrodes achieve ultra‐stable Coulombic efficiency of over 99.9% for 1500 cycles at a current density of 5 mA cm−2. This work has significant potential for the rational design of dendrite‐free Zn anodes to boost their potential for practical applications.
Reevaluation of the degree day base 60°F concept in US cotton (Gossypium hirsutumL.) production
Authors: Raper Tyson B. , Ward Rebecca , Rushing Cheyenne , Brown Steve , Sandlin Tyler , Norton Randy , Hutmacher Bob , Snider John L. , Fromme Dan , Dodds Darrin , Jones Michael , Edmisten Keith , Collins Guy , Byrd Seth , Griffin James , Maeda Murilo , Frame Hunter , Pieralisi Brian , Meeks Calvin , Whitaker Jared , Nichols Robert L. , Morgan Gaylon
Published: September 2023

Cotton (Gossypium hirsutumL.) management decisions to abet early growth, fruit set, boll maturation, and harvest preparation are often facilitated by prediction of the date when critical developmental stages are reached. In the United States, growing degree days calculated with a base 60°F (DD60s) are commonly used to predict cotton development. Observations suggest development of modern cultivars differs from previously established guidelines. The objectives were to (1) reevaluate DD60s required for an early, mid‐maturing and late maturing cultivar to reach key growth stages across the US Cotton Belt; and (2) determine if predictions of growth stages are strengthened by optimizing base temperature or including an upper threshold by growth stage. During 2018 and 2019, 22 field trials were established in 10 states. Plant growth stages were monitored weekly and air temperature was computed from interpolated surface observations weighted by a physical, geographic model. Observed DD60s to reach growth stages varied slightly by cultivar and region (≤85 DD60s and ≤130 DD60s, respectively). Required DD60s to reach growth stages exceeded most published ranges. Optimization of base temperature and inclusion of an upper threshold by growth stage did not substantially decrease errors in predicting date of growth stage occurrence. The DD55 and DD55 with an upper threshold of 86°F calculations resulted in slightly lower errors in predicting date of growth stage occurrence than the DD60 calculation. Although guidelines should be updated, it is unlikely slight modification in base temperature or upper thresholds will drastically increase the predictive ability over the DD60 calculation.
Environmental clusters defining breeding zones for tropical irrigated rice in Brazil
Authors: Costa‐Neto Germano , Matta David Henriques da , Fernandes Igor Kuivjogi , Stone Luís Fernando , Heinemann Alexandre Bryan
Published: September 2023

Geographic and seasonal effects are important in driving selection decisions in rice breeding research. Adopting new strategies for characterizing environmental–phenotype associations is critical to understanding these effects, and the outcomes of their study could reflect the benefits of developing locally adapted cultivars. This study aimed to characterize Brazil's tropical irrigated rice (IR) environment, Latin America's largest rice production system. We integrated unsupervised (K‐means clustering) and supervised (decision tree classifier) algorithms to identify environmental clusters (EC) based on historical yield data. The data set included 31 locations and 471 genotypes from 1982 to 2017. We used environmental features (EF), such as weather and geography, as input variables for our analysis, assuming the model as EC ∼ f (EF). Results indicate that the tropical IR production region can be divided into four primary breeding zones, with temperature emerging as a significant factor in the study area. After employing a linear mixed model analysis, we observed that the current relationship between genetics (G), environmental variation (E), and their interaction (G×E) in Brazil's tropical IR has a 1:6:2 ratio. However, when introducing our data‐driven model based on EC, we reduced this ratio to 1:5:1. Therefore, the selection for local adaptability across a large region became more reliable. Our approach successfully identified EC in Brazil's tropical production region of IR, providing valuable insights for defining breeding zones and identifying more productive and stable seed production fields.