bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reconfigurable Multilevel Optical PUF by Spatiotemporally Programmed Crystallization of Supersaturated Solution
Authors: Kim Youngchan , Lim Jaemook , Lim Ji Hwan , Hwang Eunseung , Lee Hyunkoo , Kim Minwoo , Ha Inho , Cho Hyunmin , Kwon Jinhyeong , Oh Junho , Ko Seung Hwan , Pan Heng , Hong Sukjoon 
Published: March 2023

AbstractPhysical unclonable functions (PUFs) are emerging as an alternative to information security by providing an advanced level of cryptographic keys with non‐replicable characteristics, yet the cryptographic keys of conventional PUFs are not reconfigurable from the ones assigned at the manufacturing stage and the overall authentication process slows down as the number of entities in the dataset or the length of cryptographic key increases. Herein, a supersaturated solution‐based PUF (S‐PUF) is presented that utilizes stochastic crystallization of a supersaturated sodium acetate solution to allow a time‐efficient, hierarchical authentication process together with on‐demand rewritability of cryptographic keys. By controlling the orientation and the average grain size of the sodium acetate crystals via a spatiotemporally programmed temperature profile, the S‐PUF now includes two global parameters, that is, angle of rotation and divergence of the diffracted beam, in addition to the speckle pattern to produce multilevel cryptographic keys, and these parameters function as prefixes for the classification of each entity for a fast authentication process. At the same time, the reversible phase change of sodium acetate enables repeated reconfiguration of the cryptographic key, which is expected to offer new possibilities for a next‐generation, recyclable anti‐counterfeiting platform.
Preventing Vanishing Gradient Problem of Hardware Neuromorphic System by Implementing Imidazole‐Based Memristive ReLU Activation Neuron
Authors: Oh Jungyeop , Kim Sungkyu , Lee Changhyeon , Cha Jun‐Hwe , Yang Sang Yoon , Im Sung Gap , Park Cheolmin , Jang Byung Chul , Choi Sung‐Yool 
Published: March 2023

AbstractWith advances in artificial intelligent services, brain‐inspired neuromorphic systems with synaptic devices are recently attracting significant interest to circumvent the von Neumann bottleneck. However, the increasing trend of deep neural network parameters causes huge power consumption and large area overhead of a nonlinear neuron electronic circuit, and it incurs a vanishing gradient problem. Here, a memristor‐based compact and energy‐efficient neuron device is presented to implement a rectifying linear unit (ReLU) activation function. To emulate the volatile and gradual switching of the ReLU function, a copolymer memristor with a hybrid structure is proposed using a copolymer/inorganic bilayer. The functional copolymer film developed by introducing imidazole functional groups enables the formation of nanocluster‐type pseudo‐conductive filaments by boosting the nucleation of Cu nanoclusters, causing gradual switching. The ReLU neuron device is successfully demonstrated by integrating the memristor with amorphous InGaZnO thin‐film transistors, and achieves 0.5 pJ of energy consumption based on sub‐10 µA operation current and high‐speed switching of 650 ns. Furthermore, device‐to‐system‐level simulation using neuron devices on the MNIST dataset demonstrates that the vanishing gradient problem is effectively resolved by five‐layer deep neural networks. The proposed neuron device will enable the implementation of high‐density and energy‐efficient hardware neuromorphic systems.
Photochemical Precharging of Tungsten Trioxide for Enhanced Transmittance Modulation in Flexible Electrochromic Devices
Authors: Brändler Lisa , Niklaus Lukas , Schott Marco , Löbmann Peer 
Published: March 2023

AbstractUV irradiation is used to precharge sputtered tungsten trioxide (WO3) on polyethylene terephthalate enhancing the photochromic response with organic solvents. A comparison between the optical and electrochemical properties of photochemically and electrochemically charged WO3results in a correlation of the transmittance to the respective charge density. This allows for a precise control of the charge density in the precharging process monitored by UV–Vis spectroscopy. A proof‐of‐concept flexible electrochromic device combining precharged WO3(charge density: 20 mC cm−2) and Prussian blue (15 mC cm−2) exhibits a superior change in the visible light transmittance (τv) from 8% (dark) to 79% (bleached) and a coloration efficiency of 139 cm2 C−1at 716 nm.
Electro‐Reconfigurable Adaptive Microlens with Simultaneous Multidirectional Focal Adjustment and Zooming
Authors: Yoon Jae Uk , Han Dong‐Heon , Oh Seung‐Ju , Woo Insun , Park Hyeon‐Su , Bae Jin Woo 
Published: March 2023

AbstractElectrically reconfigurable lenses capable of focal adjustment and zooming require deformable adaptive optical components. However, existing electroactive optical devices that perform these functions are limited by fluid leakage or require complex mechanical parts. Although polyvinyl chloride (PVC) gel‐based lenses with variable focal lengths and zooming have recently been developed, focal adjustment can only be made in the horizontal axis. Herein, a PVC gel‐based adaptive microlens capable of controlling the focal length and focal point simultaneously in the vertical, horizontal, and diagonal directions without mechanical gears or liquid leakage is presented. By optimizing the characteristics of PVC gels plasticized with three different structured plasticizers, a PVC gel‐based adaptive microlens is fabricated. The produced microlens demonstrates the properties of multidirectional focal adjustment, variable focal length (+33.7 to −15.1 mm) at low input voltages (<300 V), excellent transparency (>90%), fast response (0.10 s at 100 V), silent operation, low power consumption (0.39 mW), and excellent potential for further miniaturization.
Addressing the Conflict between Mobility and Stability in Oxide Thin‐film Transistors
Authors: Liang Lingyan , Zhang Hengbo , Li Ting , Li Wanfa , Gao Junhua , Zhang Hongliang , Guo Min , Gao Shangpeng , He Zirui , Liu Fengjuan , Ning Ce , Cao Hongtao , Yuan Guangcai , Liu Chuan 
Published: March 2023

AbstractAmorphous oxide semiconductor thin‐film transistors (AOS TFTs) are ever‐increasingly utilized in displays. However, to bring high mobility and excellent stability together is a daunting challenge. Here, the carrier transport/relaxation bilayer stacked AOS TFTs are investigated to solve the mobility‐stability conflict. The charge transport layer (CTL) is made of amorphous In‐rich InSnZnO, which favors big average effective coordination number for all cations and more edge‐shared structures for better charge transport. Praseodymium‐doped InSnZnO is used as the charge relaxation layer (CRL), which substantially shortens the photoelectron lifetime as revealed by femtosecond transient absorption spectroscopy. The CTL and CRL with the thickness suitable for industrial production respectively afford minute potential barrier fluctuation for charge transport and fast relaxation for photo‐generated carriers, resulting in transistors with an ultrahigh mobility (75.5 cm2 V−1 s−1) and small negative‐bias‐illumination‐stress/positive‐bias‐temperature‐stress voltage shifts (−1.64/0.76 V). The design concept provides a promising route to address the mobility‐stability conflict for high‐end displays.
Trends and Prospects of Bulk and Single‐Atom Catalysts for the Oxygen Evolution Reaction
Authors: Iqbal Sarmad , Safdar Bushra , Hussain Iftikhar , Zhang Kaili , Chatzichristodoulou Christodoulos 
Published: March 2023

AbstractElectrolytic hydrogen is expected to play a key role in the production of green fuels and chemicals, while contributing to balancing consumption and supply in the future electricity grid relying largely on intermittent renewable sources for energy production. However, the oxygen evolution reaction (OER) is a major bottleneck in boosting conversion efficiency due to the sluggish kinetics of the four‐electron transfer process. Intensive research efforts are thus directed toward the development of advanced OER electrocatalysts. This review aims at bringing together recent advances in bulk and single‐atom electrocatalysts (SACs) for the OER. Starting from the established understanding of the OER mechanism, it offers an overview of state‐of‐the‐art materials for the OER, highlighting the current research directions and shortcomings of bulk electrocatalysts. The final part addresses the novel development of SACs, covering their OER performance as well as the established synthetic routes and advances in characterization techniques that shine light on the geometric and electronic configuration of SACs. The review of experimental findings is complimented with theoretical insights from density functional theory (DFT). The article concludes with a summary along with future opportunities to further improve the activity of SACs for the OER.
COVID‐19 and the economic recovery in South Asia: Economywide modeling scenarios for Bangladesh and Nepal
Authors: Dorosh Paul , Pauw Karl , Pradesha Angga , Thurlow James 
Published: March 2023

AbstractWe use economywide models to examine the economic recovery from COVID‐19 shocks in Bangladesh and Nepal during 2020–2026. Declining labor productivity, capital underutilization, consumption shifts, and international investment shocks had significant and differential sectoral and country‐level impacts in these countries. By 2026, GDP will be 6.9% and 13.9% lower in Bangladesh and Nepal, respectively, and the two countries will have an additional 3.3 million people in poverty compared to a no‐COVID baseline. Regaining economic and welfare losses will require substantial investments in key industrial, agricultural, and tourism sectors, although tough policy decisions will be required given high levels of public debt.
Re‐remembering the influence of randomized β‐carotene on cognitive decline
Authors: Kopec Rachel E. , Chasman Daniel I. , Okereke Olivia I. , Sesso Howard D. 
Published: March 2023

AbstractThe wave of individuals impacted by dementia continues to rise rapidly as worldwide lifespan increases. Dietary strategies to slow cognitive decline and prolong time to clinical dementia remain understudied, but with potentially powerful public health consequences. Indeed, previously conducted large, randomized, placebo‐controlled trials of micronutrients remain an under‐leveraged resource to study changes in cognitive performance. As a motivating example, we highlight an ancillary report from the Physicians’ Health Study, where subjects randomized to β‐carotene (a provitamin A carotenoid) had a more attenuated change in longitudinal global cognitive performance and verbal memory, as compared to subjects randomized to placebo. Despite mechanistic evidence from cell and animal studies supporting a vitamin A‐mediated role in the biology associated with cognition, limited follow‐up work has been conducted. We argue that dietary factors (including provitamin A) deserve a second look, leveraging multi‐omic approaches, to elucidate how they may mitigate cognitive decline and dementia risk.
Hemin as a General Static Dark Quencher for Constructing Heme Oxygenase‐1 Fluorescent Probes
Authors: Chen Fan , Zhang Baoxin , Ding Zhenjiang , Zhong Miao , Hou Yanan , Zhang Fang , Hu Guodong , Fang Jianguo 
Published: March 2023

AbstractThe development of small‐molecule probes suitable for live‐cell applications remains challenging yet highly desirable. We report the first fluorescent probe, RBH, for imaging the heme oxygenase‐1 (HO‐1) activity in live cells after discovering hemin as a universal dark quencher. Hemin works via a static quenching mechanism and shows high quenching efficiency (>97 %) with fluorophores across a broad spectrum (λex=400–700 nm). The favorable properties of RBH (e.g. long excitation/emission wavelengths, fast response rate and high magnitude of signal increase) enable its use for determining HO‐1 activity in complex biological samples. As HO‐1 is involved in regulating antioxidant defence, iron homeostasis and gasotransmitter carbon monoxide production, we expect RBH to be a powerful tool for dissecting its functions. Also, the discovery of hemin as a general static dark quencher provides a straightforward strategy for constructing novel fluorescent probes for diverse biological species.
Harnessing the Structure and Dynamics of the Squalene‐Hopene Cyclase for (−)‐Ambroxide Production**
Authors: Schneider Andreas , Curado Christian , Lystbaek Thomas B. , Osuna Sílvia , Hauer Bernhard 
Published: March 2023

AbstractTerpene cyclases offer enormous synthetic potential, given their unique ability to forge complex hydrocarbon scaffolds from achiral precursors within a single cationic rearrangement cascade. Harnessing their synthetic power, however, has proved to be challenging owing to their generally low catalytic performance. In this study, we unveiled the catalytic potential of the squalene‐hopene cyclase (SHC) by harnessing its structure and dynamics. First, we synergistically tailored the active site and entrance tunnel of the enzyme to generate a 397‐fold improved (−)‐ambroxide synthase. Our computational investigations explain how the introduced mutations work in concert to improve substrate acquisition, flow, and chaperoning. Kinetics, however, showed terpene‐induced inactivation of the membrane‐bound SHC to be the major turnover limitation in vivo. Merging this insight with the improved and stereoselective catalysis of the enzyme, we applied a feeding strategy to exceed 105 total turnovers. We believe that our results may bridge the gap for broader application of SHCs in synthetic chemistry.
High‐Throughput Optimization of Photochemical Reactions using Segmented‐Flow Nanoelectrospray‐Ionization Mass Spectrometry**
Authors: Sun Alexandra C. , Steyer Daniel J. , Robinson Richard I. , Ginsburg‐Moraff Carol , Plummer Scott , Gao Jinhai , Tucker Joseph W. , Alpers Dirk , Stephenson Corey R. J. , Kennedy Robert T. 
Published: March 2023

AbstractWithin the realm of drug discovery, high‐throughput experimentation techniques enable the rapid optimization of reactions and expedited generation of drug compound libraries for biological and pharmacokinetic evaluation. Herein we report the development of a segmented flow mass spectrometry‐based platform to enable the rapid exploration of photoredox reactions for early‐stage drug discovery. Specifically, microwell plate‐based photochemical reaction screens were reformatted to segmented flow format to enable delivery to nanoelectrospray ionization‐mass spectrometry analysis. This approach was demonstrated for the late‐stage modification of complex drug scaffolds, as well as the subsequent structure–activity relationship evaluation of synthesized analogs. This technology is anticipated to expand the robust capabilities of photoredox catalysis in drug discovery by enabling high‐throughput library diversification.
Metal‐Induced Planar Chirality of Soft‐Bridged Binuclear Platinum(II) Complexes: 100 % Phosphorescence Quantum Yields, Chiral Self‐Sorting, and Circularly Polarized Luminescence
Authors: Song Jintong , Xiao Hui , Zhang Bao , Qu Lang , Zhou Xiangge , Hu Ping , Xu Zong‐Xiang , Xiang Haifeng 
Published: March 2023

AbstractPtII complexes have attracted a great deal of interest due to their rich phosphorescent properties. However, these square‐planar PtII complexes are far more likely to encounter the problems of lack of metal‐induced chirality and emission “aggregation‐caused quenching”. Herein, soft‐bridged binuclear PtII complexes bearing metal‐induced planar chirality were synthesized and characterized. These soft bridging ligands with smaller conjugated system would help to not only improve solubility for synthesis and enantioseparation but also introduce point chirality from amino acid for highly efficient diastereoselectivity. Furthermore, the intramolecular Pt−Pt distances could be well regulated by soft bridging ligands, and consequently the phosphorescence quantum yield up to 100 % could be achieved by shortening intramolecular Pt−Pt distance for first time. These complexes can be used as emitters in highly efficient solution‐processed organic light‐emitting diodes.
Fast Isomerization Before Isomerization‐Hydroformylation: Probing the Neglected Period with A Novel Microfluidic Device
Authors: Guan Fanfu , Qian Yu , Zhang Peiqi , Zhang Runtong , Zhang Xumu , Wen Jialin 
Published: March 2023

AbstractBy combining the concept of flash chemistry and radial synthesis, a novel microreactor (Flashstop reactor) was designed to study isomerization process of hydroformylation by a Rh/tetraphosphite catalyst in a time scale of seconds. It was found that in the initial 313 seconds, 60–99 % of 1‐octene was isomerized to 2‐ and 3‐octenes before the formation of aldehydes. Within this period, two different types of isomerization reactions were observed. It was proposed that a monohydride complex without CO ligand accounts for the ultrafast isomerization in the initial 30 seconds. The isomerization rate with such monohydride species was calculated much faster than that with the well‐known H(CO)Rh(P−P) species. Both experimental and DFT computational studies were carried out to support this assumption. Fast transformations early on in catalytic cycles have been rarely studied due to the lack of proper tools. We believe that the Flashstop reactor is a powerful tool for analysis of kinetics in gas‐liquid biphasic reactions within a time scale of seconds to minutes.
Photoinduced Fluorescence Switching in Molecular Aggregates by Topological [2+2] Cycloaddition
Authors: Pan Guocui , Wu Zhiyuan , Liu Zhaoyang , Xu Bin , Tian Wenjing 
Published: March 2023

AbstractThe optical modulation of fluorescence characteristics in molecular aggregates, which mainly involves diverse molecular stacking and the consequent intermolecular interactions, remains a significant challenge for potential applications in optical anticounterfeiting, data storage, and imaging. Here we successfully realize in situ fluorescence switching in molecular aggregates of thianaphthene‐dioxide derivatives by topological [2+2] photocycloaddition, which represents a promising way to regulate the molecular stacking and alter photophysical processes. Notably, 2‐(3,5‐bis‐trifluoromethylphenyl)benzo[b]thiophene‐dioxide (BTO‐TF) in both crystal and powder forms exhibits a unique switching from an initial nonfluorescent state to a highly fluorescent state (ΦPL=0.46) upon UV irradiation, because of the destruction of the [2+2] cycloaddition process by volume expansion of the photodimer. Furthermore, we demonstrate such a [2+2] photocycloaddition can occur when 2‐(4‐carboxypheny)benzo[b]thiophene‐dioxide (BTO‐OH) is doped within selective polymer matrixes, and can be utilized for the visualization of macrophase separation in polymer blends.
Hand stencils and communal history: A case study from Auwim, East Sepik, Papua New Guinea
Authors: Tsang Roxanne , Katuk Sebastien , May Sally K. , Taçon Paul S.C. , Ricaut François‐Xavier , Leavesley Matthew G. 
Published: March 2023

ABSTRACTHand stencils directly represent modern humans in landscape settings around the world. Yet their social and cultural contexts are often overlooked due to the lack of ethnography associated with the artwork. This paper explores the hand stencils from Kundumbue and Pundimbung rock art sites, situated in the traditional boundaries of the Auwim people in the East Sepik Province of Papua New Guinea. Combining archaeological rock art analysis with ethnographic knowledge, we demonstrate that the hand stencils are a priority in each clan's place‐making practices, around which they construct the community's social narratives. Rock shelters and their rock art also show a form of communal history that is evoked through their production in contemporary settings, in addition to having been a form of esoteric magic in the past. We conclude that hand stencils can have multiple meanings over time and across space as a widespread cultural marker. However, aspects of the identities of individuals, groups and communities who created the now static hand imagery, remain in place.
Recent Advances in Rhodium‐Catalyzed Electrochemical C−H Activation
Authors: Kumar Vikash , Maayuri Rajaram , Mantry Lusina , Gandeepan Parthasarathy 
Published: March 2023

AbstractRhodium‐catalyzed C−H activation has emerged as a powerful tool for forging C−C and C‐heteroatom bonds. Nevertheless, the requirement of stoichiometric chemical oxidants for oxidative transformations significantly hampered the overall sustainability of the C−H activation transformations. The emergence of merging transition metal catalysis and electrochemistry, called metalla‐electrocatalysis provides an excellent opportunity to construct organic molecules efficiently and sustainably. This review highlights the recent developments of rhodium‐catalyzed electrochemical C−H activation transformations, challenges and opportunities for future developments.
A vehicle cloud control system considering communication quantization and stochastic delay
Authors: Pan JiAn , Xu Qing , Li KeQiang , Wang JianQiang 
Published: March 2023

AbstractA novel kind of networked feedback controller is designed for the vehicle cloud control system in the presence of both sensor‐controller/controller‐actuator delay and communication quantization. Firstly, the vehicle cloud control system with delayed and quantized communication is modeled using the lateral/longitudinal vehicle dynamic and Markovian jump linear system (MJLS) theory. Then, some efficient stabilization conditions in matrix inequalities forms are derived for the considered cloud‐controlled vehicles. Furthermore, a cone complementary linearization method is utilized to solve the nonlinear matrix inequalities involved in the stabilization conditions. Simulation tests on connected vehicle lateral and longitudinal control are conducted to verify the effectiveness of the analytical results. Compared with the commonly used constant‐parameter controllers, the proposed method is practical to design vehicle cloud controllers under stochastic delay and communication quantization scenarios, with known delay distribution. Lastly, the stability of the vehicle cloud control system is guaranteed under the infection of unreliable communication factors with the proposed control method.
A censored quantile regression approach for relative survival analysis: Relative survival quantile regression
Authors: Williamson John M. , Lin Hung‐Mo , Lyles Robert H. 
Published: March 2023

AbstractWe propose a censored quantile regression model for the analysis of relative survival data. We create a hybrid data set consisting of the study observations and counterpart randomly sampled pseudopopulation observations imputed from population life tables that adjust for expected mortality. We then fit a censored quantile regression model to the hybrid data incorporating demographic variables (e.g., age, biologic sex, calendar time) corresponding to the population life tables of demographically‐similar individuals, a population versus study covariate, and its interactions with the variables of interest. These latter variables can be interpreted as relative survival parameters that depict the differences in failure quantiles between the study participants and their population counterparts.