In silico optimization of actuation performance in dielectric elastomercomposites via integrated finite element modeling and deep learning

Dielectric elastomers(DEs)require balanced electric actuation performance and mechanical integrity under applied voltages.Incorporating high dielectric particles as fillers provides extensive design space to optimize concentration,morphology,and distribution for improved actuation performance and material modulus.This study presents an integrated framework combining finite element modeling(FEM)and deep learning to optimize the microstructure of DE composites.FEM first calculates actuation performance and the effective modulus across varied filler combinations,with these data used to train a convolutional neural network(CNN).Integrating the CNN into a multi-objective genetic algorithm generates designs with enhanced actuation performance and material modulus compared to the conventional optimization approach based on FEM approach within the same time.This framework harnesses artificial intelligence to navigate vast design possibilities,enabling optimized microstructures for high-performance DE composites.

电解液中Cu(111)晶面电溶解/沉积势垒施加电荷相关性的跨尺度计算

电化学沉积和电化学腐蚀的核心问题是不同电压/电荷作用下的电极/电解质界面行为,其控制量是溶解/沉积反应路径的势垒,但是势垒的测量和计算难度比较大。本文采用密度泛函和连续介质耦合方法研究了不同加载电荷面密度下平整表面和含阶梯表面的Cu(111)面薄板电极直接和间接溶解/沉积两种路径的能量形态。结果发现,不同加载电荷面密度下溶质Cu原子在Cu(111)面的表面扩散和溶解过程中初末态能量分别和最高过渡态能量存在简单的线性关系,符合经典的Brønsted-Evans-Polanyi关系。在直接/间接溶解和沉积过程中,势垒和加载的电荷面密度呈线性或二次函数关系。通过这些表达式可以直接从稳态能量计算溶解/沉积和表面扩散的势垒,也可以直接计算不同加载电荷面密度下的势垒,极大的降低实验和计算工作量。通过拟合公式计算出不同临界加载电荷面密度时的势垒大小可以得出:对于溶解过程中,随着加载电荷面密度逐渐增大至0.135|e|/Å2,阶梯处原子首先以直接溶解的方式进入到电解质溶液中;对于沉积过程,随着加载电荷面密度降低至0.105|e|/Å2,电沉积首先发生在平整表面,并可越过较低的表面扩散势垒移动至台阶处,表面扩散是速率控制步骤。当加载电荷面密度进一步减小为0.086|e|/Å2,此时的沉积方式以直接沉积到阶梯位置为主。

High-performance inverters based on ambipolar organic-inorganic heterojunction thin-film transistors

This work reports on the integration of organic and inorganic semiconductors as heterojunction active layers for high-performance ambipolar transistors and complementary metal-oxide-semiconductor(CMOS)-like inverters.Pentacene is employed as a p-type organic semiconductor for its stable electrical performance,while the solution-processed scandium(Sc)substituted indium oxide(ScInO)is employed as an n-type inorganic semiconductor.It is observed that by regulating the doping concentration of Sc,the electrical performance of the n-type semiconductor could be well controlled to obtain a balance with the electrical performance of the p-type semiconductor,which is vital for achieving high-performance inverters.When the doping concentration of Sc is 10 at.%,the CMOS-like logic inverters exhibit a voltage gain larger than 80 and a wide noise margin(53%of the theoretical value).The inverters also respond well to the input signal with frequency up to 500 Hz.

Air-coupled piezoelectric micromachined ultrasonic transducers for surface stain detection and imaging

This paper proposes an air-coupled piezoelectric micromachined ultrasonic transducer(PMUT)for detection and imaging of surface stains.A 508 kHz PMUT array is designed,fabricated,and characterized in terms of its electrical and acoustic properties,and it is used in a pulse echo validation test.Imaging of stains on metal blocks is successfully demonstrated.Compared with existing optical methods for stain detection,the proposed approach can work in a dark environment without color requirements.This work provides a new and promising route for the development of miniaturized stain detection systems.

Acoustofluidics-enhanced biosensing with simultaneously high sensitivity and speed

Simultaneously achieving high sensitivity and detection speed with traditional solid-state biosensors is usually limited since the target molecules must passively diffuse to the sensor surface before they can be detected.Microfluidic techniques have been applied to shorten the diffusion time by continuously moving molecules through the biosensing regions.However,the binding efficiencies of the biomolecules are still limited by the inherent laminar flow inside microscale channels.In this study,focused traveling surface acoustic waves were directed into an acoustic microfluidic chip,which could continuously enrich the target molecules into a constriction zone for immediate detection of the immune reactions,thus significantly improving the detection sensitivity and speed.To demonstrate the enhancement of biosensing,we first developed an acoustic microfluidic chip integrated with a focused interdigital transducer;this transducer had the ability to capture more than 91%of passed microbeads.Subsequently,polystyrene microbeads were pre-captured with human IgG molecules at different concentrations and loaded for detection on the chip.As representative results,~0.63,2.62,11.78,and 19.75 seconds were needed to accumulate significant numbers of microbeads pre-captured with human IgG molecules at concentrations of 100,10,1,and 0.1 ng/mL(~0.7 pM),respectively;this process was faster than the other methods at the hour level and more sensitive than the other methods at the nanomolar level.Our results indicated that the proposed method could significantly improve both the sensitivity and speed,revealing the importance of selective enrichment strategies for rapid biosensing of rare molecules.

piRT-IFC:Physics-informed real-time impedance flow cytometry for the characterization of cellular intrinsic electrical properties

Real-time transformation was important for the practical implementation of impedance flow cytometry.The major obstacle was the time-consuming step of translating raw data to cellular intrinsic electrical properties(e.g.,specific membrane capacitance C_(sm) and cytoplasm conductivityσ_(cyto)).Although optimization strategies such as neural network-aided strategies were recently reported to provide an impressive boost to the translation process,simultaneously achieving high speed,accuracy,and generalization capability is still challenging.To this end,we proposed a fast parallel physical fitting solver that could characterize single cells’C_(sm)andσ_(cyto)within 0.62 ms/cell without any data preacquisition or pretraining requirements.We achieved the 27000-fold acceleration without loss of accuracy compared with the traditional solver.Based on the solver,we implemented physics-informed real-time impedance flow cytometry(piRT-IFC),which was able to characterize up to 100,902 cells’C_(sm) andσ_(cyto)within 50 min in a real-time manner.Compared to the fully connected neural network(FCNN)predictor,the proposed real-time solver showed comparable processing speed but higher accuracy.Furthermore,we used a neutrophil degranulation cell model to represent tasks to test unfamiliar samples without data for pretraining.After being treated with cytochalasin B and N-Formyl-Met-Leu-Phe,HL-60 cells underwent dynamic degranulation processes,and we characterized cell’s C_(sm)andσ_(cyto)using piRT-IFC.Compared to the results from our solver,accuracy loss was observed in the results predicted by the FCNN,revealing the advantages of high speed,accuracy,and generalizability of the proposed piRT-IFC.

Dynamic Changes of ORF1ab and N Gene Ct Values in COVID-19 Omicron Inpatients of Different Age Groups—Beijing Municipality,China,November-December 2022

Introduction:In November 2021,the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron variant was identified as the variant of concern and has since spread globally,replacing other cocirculating variants.To better understand the dynamic changes in viral load over time and the natural history of the virus infection,we analyzed the expression of the open reading frames 1ab(ORF1ab)and nucleocapsid(N)genes in patients infected with Omicron.Methods:We included patients initially admitted to the hospital for SARS-CoV-2 infection between November 5 and December 25,2022.We collected daily oropharyngeal swabs for quantitative reverse transcriptase-polymerase chain reaction tests using commercial kits.We depicted the cycle threshold(Ct)values for amplification of ORF1ab and N genes from individual patients in age-specific groups in a time series.Results:A total of 480 inpatients were included in the study,with a median age of 59 years(interquartile range,42 to 78;range,16 to 106).In the<45-year-old age group,the Ct values for ORF1ab and N gene amplification remained below 35 for 9.0 and 11.5 days,respectively.In the≥80-year-old age group,the Ct values for ORF1ab and N genes stayed below 35 for 11.5 and 15.0 days,respectively,which was the longest among all age groups.The Ct values for N gene amplification took longer to rise above 35 than those for ORF1ab gene amplification.Conclusion:The time to test negative varied among different age groups,with viral nucleic acid shedding taking longer in older age groups compared to younger age groups.As a result,the time to resolution of Omicron infection increased with increasing age.

Si nanowire Bio-FET for electrical and label-free detection of cancer cell-derived exosomes

Exosomes are highly important in clinical diagnosis due to their high homology with their parental cells.However,conventional exosome detection methods still face the challenges of expensive equipment,low sensitivity,and complex procedures.Field effect transistors(FETs)are not only the most essential electronic component in the modern microelectronics industry but also show great potential for biomolecule detection owing to the advantages of rapid response,high sensitivity,and label-free detection.In this study,we proposed a Si nanowire field-effect transistor(Si-NW Bio-FET)device chemically modified with specific antibodies for the electrical and label-free detection of exosomes.The Si-NW FETs were fabricated by standard microelectronic processes with 45 nm width nanowires and packaged in a polydimethylsiloxane(PDMS)microfluidic channel.The nanowires were further modified with the specific CD63 antibody to form a Si-NW Bio-FET.The use of the developed Si-NW Bio-FET for the electrical and labelfree detection of exosomes was successfully demonstrated with a limit of detection(LOD)of 2159 particles/mL.In contrast to other technologies,in this study,Si-NW Bio-FET provides a unique strategy for directly quantifying and realtime detecting exosomes without labeling,indicating its potential as a tool for the early diagnosis of cancer.

Epidemiology of Animal Rabies—China,2010–2020

Introduction:Rabies is a fatal zoonotic infectious disease that poses a serious threat to public health in China.Since 2005,a National Animal Rabies Surveillance System has been operating to understand the rabies situation in animals in China with a view to control and eventually eliminate dog-mediated human rabies.Methods:From 2010,the brain tissues of dogs,livestock,and wild animals showing rabies-like clinical signs were collected and tested by the National Reference Laboratory(NRL)for Animal Rabies to analyze the epidemiological characteristics of rabies,including animal species,geographic distribution,and transmission sources.Over the same period,clinically suspected animal rabies cases were collected by Animal Disease Control Centers through the National Animal Disease Monitoring Information Platform(NADMIP)and then reported in the Veterinary Bulletin.Results:During 2010–2020,170 of 212 suspected animal rabies cases were submitted to and confirmed by NRL as rabies virus-positive.Of these confirmed cases dogs,especially free-roaming and ownerless dogs in rural areas,were major transmission hosts(71/170).A total of 51 infected dogs attacked humans with 45 biting more than one person.The dog cases were reported all year round,but with significantly more in spring and summer.The majority of livestock rabies cases(70/80)being caused by rabid wild foxes in Xinjiang and Inner Mongolia revealed that foxes play a pivotal role in animal rabies epizootics in the north and northwest of the country.Conclusion:Dogs were the main transmission sources of rabies in China,and along with the recent increase of rabies in foxes and other wildlife,presented an increasing threat to livestock and public health.

Grain boundary segregation and relaxation in nano-grained polycrystalline alloys

The present study carries out systematic thermodynamics analysis of Grain Boundary(GB)segregation and relaxation in NanoGrained(NG)polycrystalline alloys.GB segregation and relaxation is an internal process towards thermodynamic equilibrium,which occurs naturally in NG alloys without any applied loads,causes deformation and generates internal stresses.The analysis comprehensively investigates the multiple coupling effects among chemical concentrations and mechanical stresses in GBs and grains.A hybrid approach of eigenstress and eigenstrain is developed herein to solve the multiple coupling problem.The analysis results indicate that the GB stress and grain stress induced by GB segregation and relaxation can be extremely high in NG alloys,reaching the GPa level,which play an important role in the thermal stability of NG alloys,especially via the coupling terms between stress and concentration.The present theoretic analysis proposes a novel criterion of thermal stability for NG alloys,which is determined by the difference in molar free energy between a NG alloy and its reference single crystal with the same nominal chemical composition.If the difference at a temperature is negative or zero,the NG alloy is thermal stable at that temperature,otherwise unstable.

The evolving species concepts used for yeasts:from phenotypes and genomes to speciation networks

Here we review how evolving species concepts have been applied to understand yeast diversity.Initially,a phenotypic species concept was utilized taking into consideration morphological aspects of colonies and cells,and growth profiles.Later the biological species concept was added,which applied data from mating experiments.Biophysical measurements of DNA similarity between isolates were an early measure that became more broadly applied with the advent of sequencing technology,leading to a sequence-based species concept using comparisons of parts of the ribosomal DNA.At present phylogenetic species concepts that employ sequence data of rDNA and other genes are universally applied in fungal taxonomy,including yeasts,because various studies revealed a relatively good correlation between the biological species concept and sequence divergence.The application of genome information is becoming increasingly common,and we strongly recommend the use of complete,rather than draft genomes to improve our understanding of species and their genome and genetic dynamics.Complete genomes allow in-depth comparisons on the evolvability of genomes and,consequently,of the species to which they belong.Hybridization seems a relatively common phenomenon and has been observed in all major fungal lineages that contain yeasts.Note that hybrids may greatly differ in their post-hybridization development.Future in-depth studies,initially using some model species or complexes may shift the traditional species concept as isolated clusters of genetically compatible isolates to a cohesive speciation network in which such clusters are interconnected by genetic processes,such as hybridization.

Chemical Strain of Graphite-Based Anode during Lithiation and Delithiation at Various Temperatures

Electrochemical lithiation/delithiation of electrodes induces chemical strain cycling that causes fatigue and other harmful influences on lithium-ion batteries.In this work,a homemade in situ measurement device was used to characterize simultaneously chemical strain and nominal state of charge,especially residual chemical strain and residual nominal state of charge,in graphite-based electrodes at various temperatures.The measurements indicate that raising the testing temperature from 20℃ to 60℃ decreases the chemical strain at the same nominal state of charge during cycling,while residual chemical strain and residual nominal state of charge increase with the increase of temperature.Furthermore,a novel electrochemicalmechanical model is developed to evaluate quantitatively the chemical strain caused by a solid electrolyte interface(SEI)and the partial molar volume of Li in the SEI at different temperatures.The present study will definitely stimulate future investigations on the electro-chemo-mechanics coupling behaviors in lithium-ion batteries.

An efficient ionic liquid supported divergent assembly of 3,6-branched glucosamine-containing pentasaccharide

We utilized the glycosyl acceptor tagging method with ionic liquid support for synthesis of the core segment of Clostridium botulinum C2 toxin ligand through a divergent synthetic strategy without chromatographic purification.The total yield was 57.1% and the reaction was completed in 10 h.The efficient ionic liquid supported glycosylation and purification procedure was applied for the synthesis of branched glucosamine-containing oligosaccharides for the first time,which expanded the scope of ionic liquid supported synthesis of biologically important oligosaccharides.

MEMS ultrasonic transducers for safe,low-power and portable eye-blinking monitoring

Eye blinking is closely related to human physiology and psychology.It is an effective method of communication among people and can be used in human-machine interactions.Existing blink monitoring methods include videooculography,electro-oculograms and infrared oculography.However,these methods suffer from uncomfortable use,safety risks,limited reliability in strong light or dark environments,and infringed informational security.In this paper,we propose an ultrasound-based portable approach for eye-blinking activity monitoring.Low-power pulse-echo ultrasound featuring biosafety is transmitted and received by microelectromechanical system(MEMS)ultrasonic transducers seamlessly integrated on glasses.The size,weight and power consumption of the transducers are 2.5 mm by 2.5 mm,23.3 mg and 71μW,respectively,which provides better portability than conventional methods using wearable devices.Eye-blinking activities were characterized by open and closed eye states and validated by experiments on dfferent volunteers.Finally,real-time eye-blinking monitoring was successfully demonstrated with a response time less than 1 ms.The proposed solution paves the way for ultrasound-based wearable eye-blinking monitoring and offers miniaturization,light weight,low power consumption,high informational security and biosafety.

Chemical Strain of Graphite-Based Anode during Lithiation and Delithiation at Various Temperatures

Electrochemical lithiation/delithiation of electrodes induces chemical strain cycling that causes fatigue and other harmful influences on lithium-ion batteries.In this work,a homemade in situ measurement device was used to characterize simultaneously chemical strain and nominal state of charge,especially residual chemical strain and residual nominal state of charge,in graphite-based electrodes at various temperatures.The measurements indicate that raising the testing temperature from 20℃ to 60℃ decreases the chemical strain at the same nominal state of charge during cycling,while residual chemical strain and residual nominal state of charge increase with the increase of temperature.Furthermore,a novel electrochemicalmechanical model is developed to evaluate quantitatively the chemical strain caused by a solid electrolyte interface(SEI)and the partial molar volume of Li in the SEI at different temperatures.The present study will definitely stimulate future investigations on the electro-chemo-mechanics coupling behaviors in lithium-ion batteries.

Correction to:The evolving species concepts used for yeasts:from phenotypes and genomes to speciation networks

The name of the second author was incorrectly captured in the initial online publication,and due to an error at the proofs stage,several proof corrections had been left undone.The original online article has been corrected.