bluuebunny/crossref_metadata_2025 huggingface dataset:
How environmental conditions, phenological periods, and production endowment affect lychee yield
Authors: Qi Wen'e , Tang Wenzhu (David) , Yan Fafa (Monica)
Published: March 2023

The increasingly revealed effects of climate change threaten tropical fruit production. Considerable production loss and unstable yield has been observed in China and other regions with similar climate condition. Accordingly, this paper aims to explore the impacts of environmental conditions, phenological periods, and production endowments on a tropical fruit yield, namely lychee, by using the extended Cobb–Douglas model. Lychee (Litchi chinensis Sonn.) is chosen as the focus of this study given it is one of the most climate‐sensitive tropical fruits which have important contributions to the health, economy, and culture in South China. The growth‐span was divided into four phenological periods, namely: exposure period, heading period, flowering period and maturing period. A two‐way fixed effect model is employed for county‐level mixed‐frequency panel data. This data comprises lychee yield, environmental conditions (mean temperature, minimum temperature, and precipitation), production endowments (labor input, capital input, and technical input), and phenological periods in 39 main producing counties in China from 2011 to 2019. The key conclusions of interest are (1) higher minimum temperature results in larger lychee yield, (2) higher minimum temperature in the earlier phenological period has larger positive impact on lychee yield, and (3) higher growth in technical input causes lower lychee yield, and an explanation is provided. Heterogeneity analysis further implies various effects of the minimum temperature influencing lychee yield. The minimum temperature has a significant positive effect on lychee yield in non‐coastal and non‐western counties, especially in earlier phenological periods.
An Image Detection–Memory–Recognition Artificial Visual Unit Based on Dual‐Gate Phototransistors
Authors: Wang Bo , Zhang Yichi , You Jie , Yang Maolong , Han Zhao , Lin Dongdong , Liu Maliang , Zhang Ningning , Jiang Zuimin , Guo Hui , Zhang Jincheng , Wang Liming , Hu Huiyong
Published: March 2023

Optoelectronic synapses integrating sensing–memory–processing functions have great advantages in neuromorphic computing for visual information processing and complex learning, recognition, and memory in an energy‐efficient manner. Herein, a light‐induced bidirectional response is demonstrated in the proposed WSe2/MoS2 junction field‐effect transistor (JFET) with an extra Ge back gate. The WSe2/MoS2 JFET exhibits high responsivity and detectivity owing to effective modulation by the top junction and back dielectric gates. The unique bidirectional photoresponse and interfacial state storage properties of the device result in significant synaptic excitatory effects under visible light stimulation and remarkable synaptic inhibitory effects under infrared illumination. Optical storage with visible light and optical erasure with infrared light can be achieved in the device based on its synaptic behavior. The conductance changes under different types of illumination can be used to mimic the weight update in a neural network for image recognition. A high accuracy exceeding 98% was achieved in handwritten digit recognition. This visible and infrared dual‐band phototransistor, which integrates image perception, memory, and recognition functionalities, provides a promising solution for self‐driving, surveillance, computer vision, and biomedical imaging applications.
Optical‐Nanofiber‐Enabled Gesture‐Recognition Wristband for Human–Machine Interaction with the Assistance of Machine Learning
Authors: Wang Shipeng , Wang Xiaoyu , Wang Shan , Yu Wen , Yu Longteng , Hou Lei , Tang Yao , Zhang Zhang , Yao Ni , Cao Chuan , Dong Hao , Zhang Lei , Bao Hujun
Published: March 2023

The metaverse, where the virtual and real world are fused, is currently under rapid development. Immersive and vivid experience in the metaverse requires human–machine interaction devices that, unlike those currently available, are simultaneously imperceptible, convenient to use, inexpensive, and safe. Herein, an optical‐nanofiber‐based gesture‐recognition wristband that can accurately recognize gestures and be used to interact with a robotic hand is proposed and realized. Requiring only three optical‐nanofiber‐based pressure sensors, the wristband is simple in structure, convenient to use, and remarkably imperceptible to the user. With the assistance of a machine‐learning algorithm, a maximum recognition accuracy of 94% is achieved for testers with different physiques. A robotic hand can be remotely controlled by the wristband through gestures. The wristband has broad application prospects and is a promising solution for advanced human–machine‐interaction devices. An interactive preprint version of the article can be found here: https://doi.org/10.22541/au.167022827.77928491/v1.
In Situ Reconfigurable Continuum Robot with Varying Curvature Enabled by Programmable Tensegrity Building Blocks
Authors: Zhang Jie , Shi Junhao , Huang Junhai , Wu Qihuan , Zhao Yuwen , Yang Jinzhao , Rajabi Hamed , Wu Zhigang , Peng Haijun , Wu Jianing
Published: March 2023

Reconfigurable continuum robots exhibit programmable interaction capability, enabling them to cope with challenges poorly addressed by conventional rigid robots. However, the regulation of the module type and/or sequence may result in time‐consuming and labor‐intensive problems. Therefore, in situ reconfiguration schemes are required to develop in a simple yet robust solution for continuum robot design. Herein, inspired by the structure characteristics of the seahorse tail, an original template based on a tensegrity building block (TBB) for creating an in situ reconfigurable continuum robotic paradigm is proposed. As the length of the stretchable struts in the TBB could be programmed, five typical homologous types from the template are derived. Then, ten TBBs into a continuum robot are assembled and the multi‐body dynamic framework is employed to develop a mechanical model for predicting the profile after deformation. Theoretical predictions demonstrate that the robotic shape can be customized in situ by switching the type of TBBs, without disassembling the robot. Furthermore, the tailored continuum robotic configurations are applied to conformally interact with the varying‐curvature objects. The experimental results suggest that the proposed programmable template offers a facile and rapid reconfiguration scheme for the continuum robots, which greatly improves the robotic interaction capability.
Does the immune system of milk increase activity for infants experiencing infectious disease episodes in Kilimanjaro, Tanzania?
Authors: Wander Katherine , Fujita Masako , Mattison Siobhán , Gauck Megan , Duris Margaret , Kiwelu Ireen , Mmbaga Blandina T.
Published: March 2023

Introduction

Multiple studies have reported that milk immune content increases for infants experiencing infectious disease (ID) episodes, suggesting that the immune system of milk (ISOM) offers enhanced protection when needed to combat ID.

Methods

To test the hypothesis that ISOM content and/or activity increases during an infant's ID episode, we characterized milk secretory immunoglobulin A (sIgA; a major ISOM constituent) and in vitro interleukin‐6 (IL‐6) responses to Salmonella enterica and Escherichia coli, as system‐level biomarkers of ISOM activity, in a prospective study among 96 mother–infant dyads in Kilimanjaro, Tanzania.

Results

After control for covariates, no milk immune variables (sIgA, Coef: 0.03; 95% CI −0.25, 0.32; in vitro IL‐6 response to S. enterica, Coef: 0.23; 95% CI: −0.67, 1.13; IL‐6 response to E. coli, Coef: −0.11; 95% CI: −0.98, 0.77) were associated with prevalent ID (diagnosed at the initial participation visit). Among infants experiencing an incident ID (diagnosed subsequent to the initial participation), milk immune content and responses were not substantially higher or lower than the initial visit (sIgA, N: 61; p: 0.788; IL‐6 response to S. enterica, N: 56; p: 0.896; IL‐6 response to E. coli, N: 36; p: 0.683); this was unchanged by exclusion of infants with ID at the time of initial participation.

Conclusion

These findings are not consistent with the hypothesis that milk delivers enhanced immune protection when infants experience ID. In environments with a high burden of ID, dynamism may be less valuable to maternal reproductive success than stability in the ISOM.
Copper‐Catalyzed [3+2] Annulation of Pyridinium Ylides with α‐CF3 Ketones: Synthesis of Functionalized 2‐Fluoroindolizines
Authors: Shu Shiming , Wang Leilei , Lv Leiyang , Li Zhiping
Published: March 2023

A copper‐catalyzed [3+2] annulation of the in situ generated pyridinium ylides with α‐CF3 ketones was realized, in which α‐CF3 ketones first acted as the synthetic equivalents of unstable fluoroalkynones. With this protocol, a series of functionalized 2‐fluoroindolizines were afforded in moderate to good yields under ambient conditions with air as the oxidant.
Genetic associations with age at dementia onset in the PSEN1 E280A Colombian kindred
Authors: Cochran Jesse Nicholas , Acosta‐Uribe Juliana , Esposito Bianca T. , Madrigal Lucia , Aguillón David , Giraldo Margarita M. , Taylor Jared W. , Bradley Joseph , Fulton‐Howard Brian , Andrews Shea J. , Acosta‐Baena Natalia , Alzate Diana , Garcia Gloria P. , Piedrahita Francisco , Lopez Hugo E. , Anderson Ashlyn G. , Rodriguez‐Nunez Ivan , Roberts Kevin , Dominantly Inherited Alzheimer Network  , Absher Devin , Myers Richard M. , Beecham Gary W. , Reitz Christiane , Rizzardi Lindsay F. , Fernandez Maria Victoria , Goate Alison M. , Cruchaga Carlos , Renton Alan E. , Lopera Francisco , Kosik Kenneth S.
Published: March 2023

INTRODUCTION

Genetic associations with Alzheimer's disease (AD) age at onset (AAO) could reveal genetic variants with therapeutic applications. We present a large Colombian kindred with autosomal dominant AD (ADAD) as a unique opportunity to discover AAO genetic associations.

METHODS

A genetic association study was conducted to examine ADAD AAO in 340 individuals with the PSEN1 E280A mutation via TOPMed array imputation. Replication was assessed in two ADAD cohorts, one sporadic early‐onset AD study and four late‐onset AD studies.

RESULTS

13 variants had p<1×10−7 or p<1×10−5 with replication including three independent loci with candidate associations with clusterin including near CLU. Other suggestive associations were identified in or near HS3ST1, HSPG2, ACE, LRP1B, TSPAN10, and TSPAN14.

DISCUSSION

Variants with suggestive associations with AAO were associated with biological processes including clusterin, heparin sulfate, and amyloid processing. The detection of these effects in the presence of a strong mutation for ADAD reinforces their potentially impactful role.
Dopant‐free NiOx Nanocrystals: A Low‐cost and Stable Hole Transport Material for Commercializing Perovskite Optoelectronics
Authors: Zhang Hong , Zhao Chenxu , Yao Jianxi , Choy Wallace C. H.
Published: March 2023

Advancing inverted (p‐i‐n) perovskite solar cells (PSCs) is critical for commercial applications given their compatibility with different bottom cells for tandem photovoltaics, low‐temperature processability (≤100 °C), and promising operational stability. Although inverted PSCs have achieved an efficiency of over 25 % using doped or expensive organic hole transport materials (HTMs), their synthesis cost and stability still cannot meet the requirements for their commercialization. Recently, dopant‐free and low‐cost non‐stoichiometric nickel oxide nanocrystals (NiOx NCs) have been extensively studied as a low‐cost and effective HTM in perovskite optoelectronics. In this minireview, we summarize the synthesis and surface‐functionalization methods of NiOx NCs. Then, the applications of NiOx NCs in other perovskite optoelectronics beyond photovoltaics are discussed. Finally, we provide a perspective for the future development of NiOx NCs for the commercialization of perovskite optoelectronics.
Experimental study combined with density functional theory and molecular dynamics simulation on the mechanism of glucose alcoholysis reaction
Authors: Jia Yu , Zhao Haoran , Chen Yihang , Liang Xuanyu , Tao Hongge , Xu Guizhuan , Chang Chun
Published: March 2023

The reaction characteristics and mechanism of carbohydrates is important in exploring and developing suitable technology for biofuels and biochemical production from lignocellulosic biomass. In this study, experiments combined with density functional theory (DFT) calculation and molecular dynamics (MD) simulation were used to investigate the glucose alcoholysis reaction mechanism catalyzed by extremely low concentrated sulfuric acid. The effects of temperature and tetrahydrofuran (THF) on the distribution of the product in the alcoholysis process of high‐concentration glucose were investigated. DFT calculation results showed that the addition of THF in ethanol can decrease the energy barrier of glucose degradation. Meanwhile, the MD simulation indicated that the catalyst tends to localize more around the glucose molecular, which was beneficial to the glucose degradation in ethanol. Combining the experimental and theoretical results, plausible glucose alcoholysis reaction pathways were proposed in this work. It was found that when temperature was lower than 190°C, the three main pathways were glucose conversion into ethyl glucoside (EDGP); glucose conversion into 1,6‐anhydro‐β‐d‐glucopyranose (LG), then further to levoglucosone (LGO), furans, or 1,4:3,6‐dianhydro‐α‐d‐glucopyranose (DGP); and glucose conversion to fructose. However, at higher temperatures (190 and 220°C), the main reaction pathways were, glucose conversion into LG, LGO, and ethyl levulinate (EL); glucose conversion into fructose, 5‐hydroxymethylfurfural (HMF), 5‐ethoxymethylfurfural (EMF), and EL; and glucose conversion into humins. DFT, MD simulation, and experimental results showed that the addition of THF is beneficial for the EDGP formation from high concentration glucose catalyzed by Brønsted acid.
Doubly cross‐linked polymer gels with ultra‐high‐thermal stability for hydrofracking
Authors: Chen Hao , Lv Yongli , Zhang Sheng , Yin Hongyao , Feng Yujun
Published: March 2023

Cross‐linked polymer gels have been commonly utilized in the hydraulic fracturing process for stimulating oil and gas production; however, their weak thermal stability still impedes their more broadly use. Here we report doubly cross‐linked polymer gel consists of a high‐viscosity friction reducer (HVFR), poly‐(acrylamide‐co‐acrylic acid‐co‐2‐acrylamido‐2‐methyl‐1‐propane‐sulfonic acid), and crosslinkers zirconium ion (Zr4+) and polyethyleneimine (PEI). The mixture solution of HVFR/Zr4+/PEI can be gelled spontaneously via heating to form double cross‐linked polymer gel due to the formation of physical and chemical crosslinks. The electrostatic interactions of Zr4+ and carboxylate moieties from HVFR to form first physically cross‐linked network at low temperature; the transamidation reaction between amide groups of HVFR and primary amines of PEI to generate second chemically cross‐linked network at high temperature. More significantly, the physical and chemical crosslinks can work synergistically to improve thermal stability of double cross‐linked polymer gel as compared to single cross‐linked polymer gel counterparts, which is capable of reaching fluid service temperatures up to 190°C. The double cross‐linked polymer gel features delayed crosslinking performance, the physically cross‐linked reaction of HVFR and Zr4+ occurs at approximately 52°C, while the onset of chemical crosslink of HVFR and PEI can be tuned from 154 to 180°C. Moreover, double cross‐linked polymer gel provides a high viscosity at ultra‐high temperatures, with remarkable heat‐ and shear‐resistance as well as proppant carrying capacity in hydrofracking process. The double cross‐linked polymer gel also can be completely broken with no apparent residues. This double cross‐linked polymer gel may provide a new approach for polymer gels used in ultra‐high‐temperature reservoirs.
Differentiable Imaging: A New Tool for Computational Optical Imaging
Authors: Chen Ni , Cao Liangcai , Poon Ting‐Chung , Lee Byoungho , Lam Edmund Y.
Published: March 2023

The field of computational imaging has made significant advancements in recent years, yet it still faces limitations due to the restrictions imposed by traditional computational techniques. Differentiable programming offers a solution by combining the strengths of classical optimization and deep learning, enabling the creation of interpretable model‐based neural networks. Through the integration of physics into the modeling process, differentiable imaging, which employs differentiable programming in computational imaging, has the potential to overcome challenges posed by sparse, incomplete, and noisy data. As a result, it has the potential to play a key role in advancing the field of computational imaging and its various applications.
N‐Heterocyclic Imine‐Supported Bimetallic Cu(II) Catalyst for Azide‐Alkyne Cycloaddition: Solvent‐free, Reductant‐free, ppm‐level Catalysis to Access 1,4‐Disubstituted Triazoles
Authors: Revathi Shanmugam , Ghatak Tapas
Published: March 2023

In this article, we present a unique bimetallic paddle wheel copper(II) complex with the molecular formula [Cu2C42H54N6O8]. Several characterization tools have been employed to analyze this complex including single‐crystal X‐ray diffraction, HRMS, FTIR, and UV‐vis spectroscopy. This copper(II) complex excels admirably as a catalytic system in parts‐per‐million level (ppm) loading for the azide‐alkyne ‘click’ reaction under solvent‐free conditions, allowing for the quantitative conversion of numerous 1,4‐disubstituted 1,2,3‐triazole. The specially designed coordinated ligand (perimidin‐2‐imine) in the Cu(II) complex accelerates the reaction rate significantly during the oxidative homocoupling reaction (OHC) and acts as a base for Cu‐coordinated alkyne deprotonation. It has been demonstrated that the catalyst loading of 2.5 ppm is adequate to catalyze the cycloaddition of benzyl azide to phenylacetylene, leading to the extremely high turnover number of 120000 and a turnover frequency of 5000 h−1. Synergistic evidence from stoichiometric reactions and experimental results provides insights into the plausible mechanism for the reaction. Each copper atom contributes to the outcome of the proposed reaction, one by bonding to the acetylide and the other by activating the azide as part of a bimetallic synergistic pathway.
Organic transformations of isocyanides classified by their activation strategies
Authors: Kim Jungwon , Hong Soon Hyeok
Published: March 2023

Isocyanides have been extensively utilized in organic synthesis to construct valuable chemical structures. Classical Ugi 4‐component reaction is the robust method to access diversely functionalized peptoids. By using well‐established cyclization techniques, a variety of nitrogen heterocycles from commercially accessible compounds have been efficiently synthesized. Several transition metal‐catalyzed processes have been developed to utilize isocyanide as a useful carbonyl nitrogen synthon. Recently developed synthetic methods, such as C–H bond activation and visible‐light photocatalysis, have been adopted to the isocyanide chemistry to enhance the efficiency, availability, and novelty of the chemical processes. This review summarizes the reactivity of isocyanide classified by the activation modes of electrophilic, nucleophilic, and radical species, together with the seminal discoveries and recent advances in the past 10 years.
Construction and analysis of evaluation model for medical students' innovation competency based on research‐oriented biochemistry and molecular biology course in China
Authors: Fan Guanhua , Huang Zijian , Sun Hong , Li Zihua , Wu Xiaoman , Li Congsen , Lin Chunbiao , Zhan Weijie , Li Zibo , Zheng Chunwen , Xie Weijie , Zou Haiying , Wu Bingli , Fang Wangkai , Xu Liyan , Yang Mianhua , Zheng Shaoyan , Li Enmin
Published: March 2023

Presently, a variety of policies and measures has implemented to enhance the scientific research and innovation ability of medical students, but in the process of practice, there are many problems, such as they lack of independent topic selection ability, weak scientific research skills, lack of autonomous learning ability, the research results are simple and ineffective, limited teacher guidance time and so on. This paper attempted to build an effective model for the promotion of medical students' scientific research and innovation ability, in order to establish an efficacy evaluation model of the “Medical students' Innovative Scientific Research Program.” Undergraduates, graduate assistants, and tutors were interviewed with the Behavioral Event Interview technique, and a questionnaire of efficacy evaluation characteristics concluded from the interviews was formed. The questionnaire was conducted on medical students in the Medical students' Innovative Scientific Research Program, and the constructed model was analyzed using reliability analysis, validity analysis, and variation analysis. At the same time, the experimental teaching models are summarized and combed, and compared with other methods such as independent sample test. The results show the model could effectively evaluate the efficacy of the Medical students' Innovative Scientific Research Program and its teaching model is effective in cultivating medical students' learning and scientific research ability. It can provide theoretical support and practical reference for the evaluation and reform of the teaching modes related to the cultivation of scientific and innovative ability of medical students.
An agile, data‐driven approach for target selection in rTMS therapy for anxiety symptoms: Proof of concept and preliminary data for two novel targets
Authors: Young Isabella M. , Taylor Hugh M. , Nicholas Peter J. , Mackenzie Alana , Tanglay Onur , Dadario Nicholas B. , Osipowicz Karol , Davis Ethan , Doyen Stephane , Teo Charles , Sughrue Michael E.
Published: March 2023

Introduction

Data‐driven approaches to transcranial magnetic stimulation (TMS) might yield more consistent and symptom‐specific results based on individualized functional connectivity analyses compared to previous traditional approaches due to more precise targeting. We provide a proof of concept for an agile target selection paradigm based on using connectomic methods that can be used to detect patient‐specific abnormal functional connectivity, guide treatment aimed at the most abnormal regions, and optimize the rapid development of new hypotheses for future study.

Methods

We used the resting‐state functional MRI data of 28 patients with medically refractory generalized anxiety disorder to perform agile target selection based on abnormal functional connectivity patterns between the Default Mode Network (DMN) and Central Executive Network (CEN). The most abnormal areas of connectivity within these regions were selected for subsequent targeted TMS treatment by a machine learning based on an anomalous functional connectivity detection matrix. Areas with mostly hyperconnectivity were stimulated with continuous theta burst stimulation and the converse with intermittent theta burst stimulation. An image‐guided accelerated theta burst stimulation paradigm was used for treatment.

Results

Areas 8Av and PGs demonstrated consistent abnormalities, particularly in the left hemisphere. Significant improvements were demonstrated in anxiety symptoms, and few, minor complications were reported (fatigue (n = 2) and headache (n = 1)).

Conclusions

Our study suggests that a left‐lateralized DMN is likely the primary functional network disturbed in anxiety‐related disorders, which can be improved by identifying and targeting abnormal regions with a rapid, data‐driven, agile aTBS treatment on an individualized basis.
Continuity of care and advanced prostate cancer
Authors: Jayadevappa Ravishankar , Guzzo Thomas , Vapiwala Neha , Malkowicz Stanley Bruce , Gallo Joseph J. , Chhatre Sumedha
Published: March 2023

Background

Continuity of care is an important element of advanced prostate cancer care due to the availability of multiple treatment options, and associated toxicity. However, the association between continuity of care and outcomes across different racial groups remains unclear.

Objective

To assess the association of provider continuity of care with outcomes among Medicare fee‐for‐service beneficiaries with advanced prostate cancer and its variation by race.

Design

Retrospective cohort study using Surveillance, Epidemiology, and End Results (SEER)‐Medicare data.

Subjects

African American and white Medicare beneficiaries aged 66 or older, and diagnosed with advanced prostate cancer between 2000 and 2011. At least 5 years of follow‐up data for the cohort was used.

Measures

Short‐term outcomes were emergency room (ER) visits, hospitalizations, and cost during acute survivorship phase (2‐year post‐diagnosis), and mortality (all‐cause and prostate cancer‐specific) during the follow‐up period. We calculated continuity of care using Continuity of Care Index (COCI) and Usual Provider Care Index (UPCI), for all visits, oncology visits, and primary care visits in acute survivorship phase. We used Poisson models for ER visits and hospitalizations, and log‐link GLM for cost. Cox model and Fine‐Gray competing risk models were used for survival analysis, weighted by propensity score. We performed similar analysis for continuity of care in the 2‐year period following acute survivorship phase.

Results

One unit increase in COCI was associated with reduction in short‐term ER visits (incidence rate ratio [IRR] = 0.65, 95% confidence interval [CI] 0.64, 0.67), hospitalizations (IRR = 0.65, 95% CI 0.64, 0.67), and cost (0.64, 95% CI 0.61, 0.66) and lower hazard of long‐term mortality. Magnitude of these associations differed between African American and white patients. We observed comparable results for continuity of care in the follow‐up period.

Conclusions

Continuity of care was associated with improved outcomes. The benefits of higher continuity of care were greater for African Americans, compared to white patients. Advanced prostate cancer survivorship care must integrate appropriate strategies to promote continuity of care.
Development of a Novel Tool To Demystify Drug Distribution at Tissue‐Blood Barriers
Authors: Hughes Elizabeth A. , Zieliński Rafał , Ray Ashley E. , Priebe Waldemar , Douglass Junior Eugene F.
Published: March 2023

Tissue endothelial cells express ABC‐transporter enzymes that change the concentration of small molecules within different tissue compartments. These “blood‐tissue barriers” have been shown to directly affect the efficacy and toxicity of anticancer, antimicrobial, psychiatric, and anti‐epileptic drugs. Currently this phenomenon is best studied for the blood‐brain barrier, but remains enigmatic for most other tissues. In addition, canonical pharmacokinetic theory specifically assumes an equal concentration of free drug within all tissue compartments. Inspired by Lipinski's “rule of 5,” we here clarify current knowledge on drug–tissue distribution by: 1) curating the in‐vivo literature on 73 drugs across 23 tissues and 2) developing two graphical web‐based applications to visually describe and interpret data. Thesecurated in‐vivo datasetandvisualization toolsenabled us to achieve new insights into the logic of the barrier‐tissue organization and showed remarkable correspondence to whole‐body imaging of radiolabeled molecules.
Anodically‐Generated Alkyl Radicals Derived from Carboxylic Acids as Reactive Intermediates for Addition to Alkenes
Authors: Ding Haoran , Orazov Marat
Published: March 2023

Electrochemically driven C−C coupling has the potential to reduce the cost and environmental impact of some organic syntheses currently accomplished through thermochemical methods. Here, we use electrochemical oxidation of carboxylic acids as a source of reactive carbon‐centered radicals that enable radical addition to alkenes in the anode boundary layer. We demonstrate an optimization of reaction conditions to suppress the thermodynamically favored, but synthetically undesirable radical self‐coupling in favor of radical addition to styrene. In methanol solvent, 88 % selectivity and 72 % Faradaic efficiency for targeted functionalized benzenes are achieved. For low current densities, iridium anodes outperform platinum, gold, palladium, and glassy carbon anodes. With constant potential or constant current electrolyses, the deposition of organic by‐products on the catalyst surface leads to anode passivation. We show that periodic cathodic current pulses effectively regenerate the catalyst. Lastly, we confirm the role of free radicals in the reaction mechanism with a radical trap.
Experimental and Computational Aspects of Electrochemical Reflection Anisotropy Spectroscopy: A Review
Authors: Guidat Margot , Löw Mario , Kölbach Moritz , Kim Jongmin , May Matthias M.
Published: March 2023

Electrode/electrolyte interfaces play a crucial role in many electrochemical energy conversion and storage technologies. Hence, a deep understanding of the interfacial structure, energetic alignment and processes is of high relevance and has triggered the development of a number of in situ and operando techniques. One approach for gaining information about the change in surface chemistry and structure on an atomic scale is reflection anisotropy spectroscopy (RAS). This review presents and discusses the continuing effort to develop RAS as an in situ optical probe for solid‐liquid interfaces under applied potentials. Experimental and computational basic principles are presented and key challenges of electrochemical RAS are highlighted. Furthermore, we exemplarily demonstrate the potential of the method for spectroelectrochemistry, focusing on indium phosphide‐ and gold‐aqueous electrolyte interfaces as exemplary case studies, and outline research directions for battery systems.
Single‐atomic Co‐B2N2 sites anchored on carbon nanotube arrays promote lithium polysulfide conversion in lithium–sulfur batteries
Authors: Wang Zhifeng , Yan Yajing , Zhang Yongguang , Chen Yanxu , Peng Xianyun , Wang Xin , Zhao Weimin , Qin Chunling , Liu Qian , Liu Xijun , Chen Zhongwei
Published: March 2023

Due to low cost, high capacity, and high energy density, lithium–sulfur (Li–S) batteries have attracted much attention; however, their cycling performance was largely limited by the poor redox kinetics and low sulfur utilization. Herein, predicted by density functional theory calculations, single‐atomic Co‐B2N2 site‐imbedded boron and nitrogen co‐doped carbon nanotubes (SA‐Co/BNC) were designed to accomplish high sulfur loading, fast kinetic, and long service period Li–S batteries. Experiments proved that Co‐B2N2 atomic sites can effectively catalyze lithium polysulfide conversion. Therefore, the electrodes delivered a specific capacity of 1106 mAh g−1 at 0.2 C after 100 cycles and exhibited an outstanding cycle performance over 1000 cycles at 1 C with a decay rate of 0.032% per cycle. Our study offers a new strategy to couple the combined effect of nanocarriers and single‐atomic catalysts in novel coordination environments for high‐performance Li–S batteries.
Orientational Control of Circularly Polarized Luminescence from Pyrene Clusters by Using a DNA Scaffold
Authors: Kashida Hiromu , Ito Yuka , Kakuta Takahiro , Ogoshi Tomoki , Asanuma Hiroyuki
Published: March 2023

Invited for the cover of this issue is the group of Hiromu Kashida and Hiroyuki Asanuma at Nagoya University and co‐workers. The image depicts the orientation dependence of circularly polarized luminescent. Read the full text of the article at 10.1002/chem.202300182.
Preparation and chromatographic performance of chiral peptide‐based stationary phases for enantiomeric separation
Authors: Ma Zhengyue , Shang Panpan , Liu Delu , Nie Yangyang , Liu Yanli , Guo Xinyuan , Wei Benben , Bai Ligai , Qiao Xiaoqiang
Published: March 2023

This study presents the development of three new chiral stationary phases. They are based on silica modified with peptides containing phenylalanine and proline. Successful analyses and characterizations were conducted using Fourier transform infrared spectra, elemental analysis, and thermogravimetric analysis. After this, the enantioselective performance of the three chiral peptide‐based columns was evaluated. The evaluation used 11 racemic compounds under normal‐phase high performance liquid chromatography mode. Optimized enantiomeric separation conditions were established. Under these conditions, the enantiomers of flurbiprofen and naproxen were successfully separated on CSP‐1 column: the separation factor of these was 1.27 and 1.21, respectively. In addition, the reproducibility of the CSP‐1 column was also investigated. The results of the investigation illustrated that the stationary phases have good reproducibility (RSD = 0.73%, n = 5).
Fluorescent Silk Obtained by Feeding Silkworms with Fluorescent Materials†
Authors: Wu Zhao‐Fan , Sun Zhao‐Nan , Xiong Huan‐Ming
Published: March 2023

Comprehensive Summary

Fluorescent silk has potential application in many fields such as bioimaging, tissue engineering scaffolds, luminescent marks, and dazzling fabrics. Among the methods to endow natural silk with fluorescent properties, feeding silkworms with fluorescent additives is facile, low‐cost and environment friendly, which has the prospect of large‐scale production. In this paper, we reviewed the research progress for this aim in the past ten years, and summarized the unified characteristics for the substances that can enter the silk gland by digestive tract of silkworms. The advantages and disadvantages of various fluorescent materials for this application are compared in detail. And the future research directions are suggested to overcome the shortcomings of the present research.
Meningitis caused by the varicella vaccine virus in 17 immunized children and adolescents from the United States, Europe, and Japan
Authors: Grose Charles , Bonthius Daniel J.
Published: March 2023

The varicella vaccination program has an excellent safety record. The vaccine virus, like its wild‐type counterpart, can enter latency and later reactivate as herpes zoster. A lesser known but serious adverse event following reactivation is varicella vaccine meningitis. We investigate that adverse event. We performed a literature search using the PubMed and Google Scholar search engines to locate all published cases of varicella vaccine meningitis. We continued the search through January 2023. We found 17 cases of varicella vaccine meningitis. The first case was published in 2003, and the last case was published in 2023. The children lived in the United States, Greece, Germany, Switzerland, and Japan. Among the 17 cases, 14 were immunocompetent; nine of the 17 were adolescents. One potential risk factor was the administration of corticosteroids three to four weeks before the onset of meningitis. Varicella vaccine meningitis is a rare but one of the more serious adverse events that occurs several years following varicella vaccination. In immunocompetent children, this complication is treatable with a single course of intravenous acyclovir after hospitalization.
Distributed and deep vertical federated learning with big data
Authors: Liu Ji , Zhou Xuehai , Mo Lei , Ji Shilei , Liao Yuan , Li Zheng , Gu Qin , Dou Dejing
Published: March 2023

In recent years, data are typically distributed in multiple organizations while the data security is becoming increasingly important. Federated learning (FL), which enables multiple parties to collaboratively train a model without exchanging the raw data, has attracted more and more attention. Based on the distribution of data, FL can be realized in three scenarios, that is, horizontal, vertical, and hybrid. In this article, we propose to combine distributed machine learning techniques with vertical FL and propose a distributed vertical federated learning (DVFL) approach. The DVFL approach exploits a fully distributed architecture within each party in order to accelerate the training process. In addition, we exploit homomorphic encryption to protect the data against honest‐but‐curious participants. We conduct extensive experimentation in a large‐scale cluster environment and a cloud environment in order to show the efficiency and scalability of our proposed approach. The experiments demonstrate the good scalability of our approach and the significant efficiency advantage (up to 6.8 times with a single server and 15.1 times with multiple servers in terms of the training time) compared with baseline frameworks.
Determining the Conformational Stability of a Protein from Urea and Thermal Unfolding Curves
Authors: Thurlkill Richard L. , Trevino Saul R. , Scholtz J. Martin , Grimsley Gerald R.
Published: March 2023

This article contains protocols for determining the conformational stability of a globular protein from either urea or thermal unfolding curves. Circular dichroism is the optical spectroscopic technique most commonly used to monitor protein unfolding. These protocols describe how to analyze data from an unfolding curve to obtain the thermodynamic parameters necessary to calculate conformational stability, and how to determine differences in stability between protein variants. Curr. Protoc. Protein Sci. 71:28.4.1‐28.4.14. © 2023 Wiley Periodicals LLC.

Basic Protocol 1: Determining protein conformational stability from urea‐induced unfolding curves

Support Protocol 1: Preparing a urea stock solution

Support Protocol 2: Analyzing urea unfolding curves

Basic Protocol 2: Determining the conformational stability of a protein from thermal unfolding curves

Support Protocol 3: Analyzing thermal unfolding curves

Support Protocol 4: Determining differences in conformational stability for protein variants
The effect of preparation design on the fracture resistance and adaptation of the CEREC ceramic endocrowns
Authors: Jalali Samar , Jalali Hamid , Kharazi Fard Mohammad Javad , Abdolrahmani Ali , Alikhasi Marzieh
Published: March 2023

Objective

The purpose of this experimental in vitro study was to assess the effect of having one or two intact axial walls on the improvement of the fracture resistance, and marginal and internal adaptation of computer‐aided design/computer‐aided manufacturer fabricated ceramic endocrowns.

Materials and Methods

Thirty‐six endodontically treated mandibular molars were divided into three groups (n = 12). Group A, represented teeth that all of their axial walls were reduced till they all had 3 mm height. In group B, the buccal wall had 5 mm height and the others were reduced to 3 mm. Specimens of the group C had 5‐mm‐height buccal and one 5 mm‐height proximal wall, with all other walls of 3 mm height. All teeth were scanned using intraoral scanner, and endocrowns were milled from zirconia lithium silicate ceramics blocks. The marginal and internal discrepancy of restorations were evaluated with the replica technique. Fracture resistance was also measured after cementation and modes of failure were observed. One‐way analysis of variance and Tukey HSD multiple comparisons were used to analyze the data (α = .5).

Results

Significant differences were observed within the groups in terms of the axial discrepancy (p = .022); group A had significantly higher amounts of axial discrepancy compared to group B (p = .001) and group C (p = .003). Preservation of the intact axial walls did not result in a statistically significant decrease in marginal (p = .21) and pulpal (p = .31) discrepancy values. Also, concerning the fracture resistance no significant difference was observed among the groups (p = .51).

Conclusion

Preservation of at least one of the axial walls could reduce the amount of the axial discrepancy and, therefore, improves the adaptation of the restoration. However, based on this study, it did not improve fracture resistance.
Hydrogen Production and Carbon Capture by Gas‐Phase Methane Pyrolysis: A Feasibility Study
Authors: Lott Patrick , Mokashi Manas B. , Müller Heinz , Heitlinger Dominik J. , Lichtenberg Sven , Shirsath Akash B. , Janzer Corina , Tischer Steffen , Maier Lubow , Deutschmann Olaf
Published: March 2023

Invited for this month′s cover is the research group of Olaf Deutschmann and the team of Patrick Lott at the Karlsruhe Institute of Technology. The Cover image shows how an electrically heated reactor converts methane from natural gas or biogas into gaseous hydrogen and elemental carbon by means of high‐temperature pyrolysis. The transfer of this technology into industrial applications can be a valuable contribution towards a decarbonization of the chemical industry and the establishment of a hydrogen economy. The Research Article itself is available at 10.1002/cssc.202201720.
CMOS linear voltage‐controlled positive/negative floating resistance configuration and its application in realising a voltage controllable all‐pass filter
Authors: Senani Raj , Rai Manish , Singh Abdhesh Kumar
Published: March 2023

This letter presents a general CMOS linear voltage‐controlled resistance (VCR) configuration, which can be configured as a voltage‐controlled floating positive resistance (VCFPR) and a voltage‐controlled floating negative resistance (VCFNR) by a simple artifice of changing two connections. The validity of this configuration has been demonstrated by SPICE simulations using 0.18‐μm CMOS process parameters. As an illustration of the utility of the proposed configuration, an application in which both VCFPR and VCFNR are utilised to realise a voltage tuneable all pass filter has been presented whose workability too has been demonstrated by SPICE simulations.
Callicarpa stoloniformis (Lamiaceae), a new species from Southeast China based on morphological characters and phylogenetic evidence
Authors: Ma Zhonghui , Su Xiangxiu , Cai Huimin , Su Zhiwei , Chen Bin
Published: March 2023

Callicarpa stoloniformis sp. nov. (Lamiaceae) is described as a new species from Fujian Province of China on the basis of both morphological and molecular data. The new species is morphologically most close to C. hainanensis. However, it can be distinguished from the latter by its unique procumbent life form, adventitious roots at nodes, papery leaves, cup‐shaped or campanulate calyx, truncate or shallow fissure calyx lobes, and smaller fruits. In addition, the new species is also similar with C. basitruncata, a species only known from the original description and the photograph of holotype, but it can differ from the latter by its procumbent shrub, purple terete branchlets with apparent linear lenticels, adventitious roots at nodes, and papery larger leaves with prominently cordate leaf base. Original photographs, illustration, distribution map, and a comparative morphological table, as well as an identification key of the related taxa are provided.
Nocturnal emergence facilitated by thermally‐induced hatching in the Chinese softshell turtle, Pelodiscus sinensis
Authors: Zhu Qingjun , Lin Liu , Kong Fei , Zhang Ting , Shi Hai‐Tao
Published: March 2023

The coincidence of hatching and emergence events with favorable conditions is crucial for turtle survival. Nocturnal emergence has been widely documented across marine and freshwater turtles, and has long been suggested as an adaptive behavior that reduces risks of heat stress and predation. To our knowledge, however, studies related to nocturnal emergence have mainly focused on the post‐hatching behaviors of turtles, and very few experimental studies have been performed to investigate the effects of hatching time on the distribution of emergence times over the course of a day. Here, we visually monitored the activity of the Chinese softshell turtle (Pelodiscus sinensis)—a shallow‐nesting freshwater turtle—from hatching to emergence. Our study provides evidence for the novel finding that (i) the timing of synchronous hatching events in P. sinensis coincides with the time of day when nest temperatures decrease, (ii) the synchrony between hatching and emergence may further facilitate their nocturnal emergence, and (iii) synchronous behaviors of hatchlings in the nest may be effective in reducing the risk of hatchling predation, and predation is more likely to occur in the asynchronous hatching groups. This study suggests that the hatching of shallow‐nesting P. sinensis in response to temperature changes in the nest might be an adaptive nocturnal emergence strategy.
Effect of circulating ceramides on adiposity and insulin resistance in patients with type 2 diabetes: An observational cross‐sectional study
Authors: Ofori Emmanuel K. , Buabeng Alfred , Amanquah Seth D. , Danquah Kwabena O. , Amponsah Seth K. , Dziedzorm Wormenor , Dogodzi Francis K. , Adusu‐Donkor Laurinda X. , Bernard Segla K. , Asare‐Anane Henry
Published: March 2023

Introduction

Insulin resistance (IR) is one of the common chronic metabolic disorders in Africa and elsewhere. Accumulation of lipids in the body may be due to an imbalance in the metabolism of lipids, glucose and proteins. Ceramides are a sphingolipid class of lipids that are biologically active and vital in the production of more complex lipids. Circulating ceramides are thought to have a role in the development of obesity‐related IR, although the precise involvement remains unclear.

Aim

To investigate the impact of circulating ceramide on IR and body adiposity in people with and without type 2 diabetes mellitus (T2DM).

Methodology

The study was observational and cross‐sectional. There were a total of 84 volunteers with T2DM and 75 nondiabetics (control). The participants' ages, body mass indexes (BMI), waist circumferences, and blood pressure (BP) were among the clinical parameters assessed. Ceramide levels, fasting plasma glucose (FPG), lipids, basal insulin levels and glycated haemoglobin (HbA1c) were also measured. Additionally, the homeostatic model assessment for IR (HOMA‐IR) and beta cell function (HOMA‐β) were computed.

Results

T2DM and control participants had different mean values for anthropometric parameters, BP, FPG, HbA1c, lipids, insulin, HOMA‐IR, HOMA‐β and ceramide levels (p < .05 for all). HOMA‐IR, HOMA‐β and cardiovascular risk were significant correlates with ceramide levels in the T2DM group (r = 0.24; −0.34; 0.24, p < .05, respectively). Further, FPG (OR = 1.83, p = .01) and ceramide (OR = 1.05, p = .01) levels were significant predictors of IR in the case group.

Conclusion

Patients with T2DM exhibited high ceramide concentrations, which, when combined with high FPG, were associated with IR. The consequences of circulating ceramides in health and disease; however, merit further research.
Backpropagation Neural Network‐Based Prediction Model for Fuel Cell Thermal Management System
Authors: He Liange , Xin Yajie , Zhang Yan , Li Pengpai , Yang Yuanyin
Published: March 2023

The temperature prediction of fuel cell thermal management systems (FCTMS) has been the focus of research in fuel cell vehicle. Herein, a prediction model of FCTMS based on the backpropagation neural network is proposed. Predictive models are applied to fuel cell TMSs for predicting temperature changes within the system. First, the fuel cell TMS is established based on Amesim software and verified by using experimental data. Then a prediction model is established based on the simulation data of the system model. After the validation calculation, the highest accuracy of the stack temperature prediction was found, with a relative error of 0.75%. The heat sink outlet temperature prediction accuracy is the worst, with a relative error of 4.3%. The mean square error of the overall output of the prediction model is 0.043, and the mean absolute percentage error of the three results is 0.23%, 0.48%, and 0.16%. Both are below 5%. Therefore, the prediction model has more precise prediction performance, which helps the parameter study and control decision setting of FCTMS.