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Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

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Chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： Chi Zhang Rong liu Jing-Yuan liu Wen-wei Jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

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Remote-controlled dexamethasone-duration on eye-surface with a micelle-magnetic nanoparticulate co-delivery system for dry eye disease

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Acta Pharmaceutica Sinica B 2024年第8期14卷 3730-3745页

作者： Qinxiang Zheng Chaoxiang Ge Kexin Li Longxin Wang Xiaoyu Xia Xiao liu Rashid Mehmood Jianliang Shen Kaihui nan wei Chen Sen Lin National Engineering Research Center of Ophthalmology and Optometry Eye HospitalWenzhou Medical UniversityWenzhou 325027China National Clinical Research Center for Ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhou 325027China Zhejiang Engineering Research Center for Tissue Repair Materials Wenzhou InstituteUniversity of Chinese Academy of SciencesWenzhou 325000China School of Chemical Engineering UNSW SydneyHigh StreetBuilding E10KensingtonNSW 2052Australia Adult Cancer Program Lowy Cancer Research CentreUNSW SydneyCorner Botany&High StreetsKensingtonNSW 2052Australia

Dexamethasone(DEX)is used to treat ocular surface ***,regulating DEX duration in tears while preventing its absorption into the anterior chamber is critical for balancing its therapy effects and the side *** this study,a novel magnetic nanoparticle(MNP)-micelle(MC)codelivery system(MMDS)was *** MC moiety in the MMDS served as the carrier for DEX and the MNP part endowed the MMDS with magnetic-responsive *** extend its residency,the MMDS was magnetically attracted by an external magnet after instilling,which acted as a precorneal drug-depot enabling a sustainable release of DEX in *** combination of magnet treatment,the topical instillation of MMDS@DEX significantly prolonged the DEX-retention in tears and increased the DEX-concentration in the cornea and conjunctiva,as well as concurrently reduced the DEX-level in the aqueous humor,when compared with the commercial DEX eye drop *** combination of MMDS@DEX and magnet treatment exerted significantly better therapeutic effects against DED with smaller side effects than conventional treatments including DEX suspension,commercial DEX eye drops,as well as the MMDS@DEX treatment *** present work provided a new method for the effective delivery of DEX to ocular surface tissues while reducing its side effects,which will be beneficial to the treatments of a wide range of ocular surface diseases.

关键词： Magnetic nanoparticle Micelle Dexamethasone Eye drop Bioavailability Dry eye disease Cornea Conjunctiva

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Relationships Between Meteorological Factors and Mongolian Gerbils and Its Flea Burdens—Xilingol League,Inner Mongolia Autonomous Region,China,2012–2021

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China CDC weekly 2024年第23期6卷 547-552,I0012-I0018页

作者： Ke Li Zhenxu Wang Xiaohui wei Haoqiang Ji Meng Shang nan Chang Zihao Wang Chenran Guo Lei Xu Ning Zhao Qiyong liu National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases National Institute for Communicable Disease Control and PreventionChinese Center for Disease Control and PreventionBeijingChina School of Public Health Nanjing Medical UniversityNanjing CityJiangsu ProvinceChina Cheeloo College of Medicine Shandong UniversitySchool of Public HealthJinan CityShandong ProvinceChina Vanke School of Public Health Tsinghua UniversityBeijingChina

Introduction:Plague is a significant global infectious disease,its spread is linked to host and flea *** conditions can impact flea populations and host densities,hence influencing plague *** the connection between meteorological factors,flea populations,and rodent densities in Inner Mongolia’s natural plague foci can aid in predicting and managing plague ***:Monthly data on flea index,rodent density,meteorological factors,and normalized difference vegetation index(NDVI)were collected for the study *** additive modeling(GAM)was used to analyze the non-linear and lag effects of meteorological factors on flea index and rodent *** equation modeling(SEM)was employed to investigate the relationships among meteorological factors,NDVI,flea index,and rodent ***:GAM analysis revealed that temperature,precipitation,relative humidity,and NDVI had significant linear,non-linear,and time-lagged impacts on the density of Mongolian gerbils and the flea *** analysis indicated that meteorological factors could directly influence the density and flea index of Mongolian gerbils,or indirectly impact NDVI,subsequently influencing gerbil density and the flea ***:Meteorological factors primarily influence gerbil density and flea index indirectly by affecting NDVI and the relationship between flea index and gerbil *** study offers additional support for the significance of meteorological factors and NDVI in influencing the vector-rodent system,offering valuable insights for predicting and managing plague outbreaks.

关键词： meteorological offering humidity

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Computed tomography radiogenomics:A potential tool for prediction of molecular subtypes in gastric stromal tumor

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World Journal of Gastrointestinal Oncology 2024年第4期16卷 1296-1308页

作者： Xiao-nan Yin Zi-Hao Wang Li Zou Cai-wei Yang Chao-Yong Shen Bai-Ke liu Yuan Yin Xi-Jiao liu Bo Zhang Gastric Cancer Research Center West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Paediatric Surgery West China Hospital of Sichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Radiology West China HospitalSichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Gastrointestinal Surgery Sichuan University West China HospitalChengdu 610041Sichuan ProvinceChina

BACKGROUND Preoperative knowledge of mutational status of gastrointestinal stromal tumors(GISTs)is essential to guide the individualized precision *** To develop a combined model that integrates clinical and contrast-enhanced computed tomography(CE-CT)features to predict gastric GISTs with specific genetic mutations,namely KIT exon 11 mutations or KIT exon 11 codons 557-558 *** A total of 231 GIST patients with definitive genetic phenotypes were divided into a training dataset and a validation dataset in a 7:3 *** models were constructed using selected clinical features,conventional CT features,and radiomics features extracted from abdominal CE-CT *** models were developed:ModelCT sign,modelCT sign+rad,and model CTsign+rad+*** diagnostic performance of these models was evaluated using receiver operating characteristic(ROC)curve analysis and the Delong *** The ROC analyses revealed that in the training cohort,the area under the curve(AUC)values for model_(CT sign),model_(CT sign+rad),and modelCT_(sign+rad+clinic)for predicting KIT exon 11 mutation were 0.743,0.818,and 0.915,*** the validation cohort,the AUC values for the same models were 0.670,0.781,and 0.811,*** predicting KIT exon 11 codons 557-558 deletions,the AUC values in the training cohort were 0.667,0.842,and 0.720 for model_(CT sign),model_(CT sign+rad),and modelCT_(sign+rad+clinic),*** the validation cohort,the AUC values for the same models were 0.610,0.782,and 0.795,*** on the decision curve analysis,it was determined that the model_(CT sign+rad+clinic)had clinical significance and *** Our findings demonstrate that the combined modelCT_(sign+rad+clinic)effectively distinguishes GISTs with KIT exon 11 mutation and KIT exon 11 codons 557-558 *** combined model has the potential to be valuable in assessing the genotype of GISTs.

关键词： Gastrointestinal stromal tumor Radiomics Gene mutation Computed tomography Model

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Influence of powder oxidation on powder properties and formability in H13 hot-work steels processed by electron beam melting

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Journal of Iron and Steel Research International 2024年第4期31卷 924-932页

作者： wei liu Yan Wang Li-xiong Han Ying-kang wei Hui-ping Tang Shi-feng liu School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina School of Engineering Zhejiang University City CollegeHangzhou 310015ZhejiangChina

The oxygen content of metal powder is decisive for the recyclability of *** research on the effect of oxygen content on powder properties and material formability has practical significance for economical production with additive manufacturing while preventing the waste of ***,we deliberately oxidized the powder by baking at high temperature to increase the oxygen content in the powder and gave the calculation method of the oxygen content in the powder oxidation *** majority of oxygen element was found in the oxide particles in the powder and the oxide flm on the powder surface,which did affect the flowability of the *** is worth noting that the increase in the oxygen content does not change the phase of H13 steel,but it can promote the molten pool flow and obtain a smoother *** increase in the oxygen content in the powder is not the decisive factor for the formability and defects of the printed *** is the combined effect of the powder deformation,the increase in the oxygen content,and the impurity pollution after repeated use,which leads to the limitation of repeated utilization of the powder.

关键词： Additive manufacturing Electron beam melting H13 steel powder-Powder oxidation

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Transient Monte Carlo simulation of phonon transport in silicon nanofilms with the local heat source

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Science China(Technological Sciences) 2024年第7期67卷 2087-2098页

作者： LI JiaQi CAI JiuQing LI Rui liu ZhiChun liu wei School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan 430074China Wuhan Second Ship Design and Research Institute Wuhan 430205China

Accurate prediction of junction temperature is crucial for the efficient thermal design of silicon nano-devices. In nano-scale semiconductor devices, significant ballistic effects occur due to the mean free path of phonons comparable to the heat source size and device scale. We employ a three-dimensional non-gray Monte Carlo simulation to investigate the transient heat conduction of silicon nanofilms with both single and multiple heat sources. The accuracy of the present method is first verified in the ballistic and diffusion limits. When a single local heat source is present, the width of the heat source has a significant impact on heat conduction in the domain. Notably, there is a substantial temperature jump at the boundary when the heat source width is 10 *** increasing heat source width, the boundary temperature jump weakens. Furthermore, we observe that the temperature excitation rate is independent of the heat source width, while the temperature influence range expands simultaneously with the increase in heat source width. Around 500 ps, the temperature and heat flux distribution in the domain stabilize. In the case of dual heat sources, the hot zone is broader than that of a single heat source, and the temperature of the hot spot decreases as the heat source spacing increases. However, the mean heat flux remains unaffected. Upon reaching a spacing of 200 nm between the heat sources, the peak temperature in the domain remains unchanged once a steady state is reached. These findings hold significant implications for the thermal design of silicon nano-devices with local heat sources.

关键词： phonon transport Monte Carlo simulation transient heat conduction silicon nanofilms local heat source

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Aspirin suppresses hepatocellular carcinoma progression by inhibiting platelet activity

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World Journal of Gastrointestinal Oncology 2024年第6期16卷 2742-2756页

作者： Li-Jun Zhao Zhi-Yin Wang wei-Ting liu Li-Li Yu Hao-nan Qi Jie Ren Chen-Guang Zhang Hematology Laboratory The First Affiliated Hospital of Xinxiang Medical UniversityXinxiang 453100Henan ProvinceChina Xinxiang Key Laboratory of Tumor Microenvironment and Immunotherapy School of Medical TechnologyXinxiang Medical UniversityXinxiang 453003Henan ProvinceChina School of Public Health Xinxiang Medical UniversityXinxiang 453003Henan ProvinceChina

BACKGROUND Hepatocellular carcinoma(HCC)is the most common malignant liver disease in the ***(PLTs)are known to play a key role in the maintenance of liver homeostasis and the pathophysiological processes of a variety of liver *** is the most classic antiplatelet ***,the molecular mechanism of platelet action and whether aspirin can affect HCC progression by inhibiting platelet activity need further *** To explore the impact of the antiplatelet effect of aspirin on the development of *** Platelet-rich plasma,platelet plasma,pure platelet,and platelet lysate were prepared,and a coculture model of PLTs and HCC cells was ***-8 analysis,apoptosis analysis,Transwell analysis,and real-time polymerase chain reaction(RT-PCR)were used to analyze the effects of PLTs on the growth,metastasis,and inflammatory microenvironment of ***-PCR and Western blot were used to detect the effects of platelet activation on tumor-related signaling *** was used to block the activation and aggregation of PLTs both in vitro and in vivo,and the effect of PLTs on the progression of HCC RESULTS PLTs significantly promoted the growth,invasion,epithelial-mesenchymal transition,and formation of an inflammatory microenvironment in HCC *** PLTs promoted HCC progression by activating the mitogenactivated protein kinase/protein kinase B/signal transducer and activator of transcription three(MAPK/AKT/STAT3)signaling ***,aspirin inhibited HCC progression in vitro and in vivo by inhibiting platelet *** PLTs play an important role in the pathogenesis of HCC,and aspirin can affect HCC progression by inhibiting platelet *** results suggest that antiplatelet therapy has promising application prospects in the treatment and combined treatment of HCC.

关键词： Platelets Antiplatelet therapy Hepatocellular carcinoma Aspirin Antitumor

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NONMONOTONE LOCAL MINIMAX METHODS FOR FINDING MULTIPLE SADDLE POINTS

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Journal of Computational Mathematics 2024年第3期42卷 851-884页

作者： wei liu Ziqing Xie Wenfan Yi South China Research Center for Applied Mathematics and Interdisciplinary Studies South China Normal UniversityGuangzhou 510631China Key Laboratory of Computing and Stochastic Mathematics(Ministry of Education) Hunan Normal UniversityChangshaHunan 410081China Hunan Provincial Key Laboratory of Intelligent Information Processing and Applied Mathematics School of MathematicsHunan UniversityChangshaHunan 410082China

In this paper,by designing a normalized nonmonotone search strategy with the BarzilaiBorwein-type step-size,a novel local minimax method(LMM),which is a globally convergent iterative method,is proposed and analyzed to find multiple(unstable)saddle points of nonconvex functionals in Hilbert *** to traditional LMMs with monotone search strategies,this approach,which does not require strict decrease of the objective functional value at each iterative step,is observed to converge faster with less ***,based on a normalized iterative scheme coupled with a local peak selection that pulls the iterative point back onto the solution submanifold,by generalizing the Zhang-Hager(ZH)search strategy in the optimization theory to the LMM framework,a kind of normalized ZH-type nonmonotone step-size search strategy is introduced,and then a novel nonmonotone LMM is *** feasibility and global convergence results are rigorously carried out under the relaxation of the monotonicity for the functional at the iterative ***,in order to speed up the convergence of the nonmonotone LMM,a globally convergent Barzilai-Borwein-type LMM(GBBLMM)is presented by explicitly constructing the Barzilai-Borwein-type step-size as a trial step-size of the normalized ZH-type nonmonotone step-size search strategy in each ***,the GBBLMM algorithm is implemented to find multiple unstable solutions of two classes of semilinear elliptic boundary value problems with variational structures:one is the semilinear elliptic equations with the homogeneous Dirichlet boundary condition and another is the linear elliptic equations with semilinear Neumann boundary *** numerical results indicate that our approach is very effective and speeds up the LMMs significantly.

关键词： Multiple saddle points Local minimax method Barzilai-Borwein gradient method Normalized nonmonotone search strategy Global convergence

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Transition metal clusters with precise numbers of atoms anchored on graphdiyne as multifunctional electrocatalysts for OER/ORR/HER:a computational study

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Rare Metals 2024年第7期43卷 3107-3117页

作者： Xin-Yang liu Jing-wei liu Gang Li Jing-Xiang Zhao College of Chemistry and Chemical Engineering Harbin Normal UniversityHarbin 150025China

Subnanometer metal clusters play an increasingly important role in heterogeneous catalysis due to their high catalytic activity and *** this work,by means of the density functional theory(DFT) calculations,the catalytic activities of transition metal clusters with precise numbers of atoms supported on graphdiyne(TM_(1-4)@GDY,TM=V,Cr,Mn,Fe,Co,Ni,Cu,Ru,Rh,Pd,Ir,Pt) were investigated for oxygen evolution reactions(OER),oxygen reduction reactions(ORR) and hydrogen evolution reactions(HER).The computed results reveal that the Pd_(2),Pd_(4) and Pt_(1) anchored graphdiyne can serve as trifunctional catalysts for OER/ORR/HER with the overpotentials of 0.49/0.37/0.06,0.45/0.33/0.12 and 0.37/0.43/0.01 V,respectively,while Pd_(1) and Pt_(2)@graphdiyne can exhibit excellent catalytic performance for water splitting(OER/HER) with the overpotentials of 0.55/0.17 and 0.43/0.03 *** addition,Ni_(1) and Pd_(3) anchored GDY can perform as bifunctional catalysts for metal-air cells(OER/ORR) and fuels cells(ORR/HER) with the overpotentials of 0.34/0.32 and 0.42/0.04 V,***,by precisely controlling the numbers of atoms in clusters,the TM_(1-4) anchored graphdiyne can serve as promising multifunctional electrocatalysts for OER/ORR/HER,which may provide an instructive strategy to design catalysts for the energy conversation and storage devices.

关键词： Density functional theory Graphdiyne Single-cluster catalysts Multifunctional electrocatalysts Overpotential

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Changes in Spring Snow Cover over the Eastern and Western Tibetan Plateau and Their Associated Mechanism

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Advances in Atmospheric Sciences 2024年第5期41卷 959-973页

作者： Fangchi liu Xiaojing JIA wei DONG Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province School of Earth SciencesZhejiang UniversityHangzhouZhejiang 310058China

The spring snow cover(SC)over the western Tibetan Plateau(TP)(TPSC)(W_TPSC)and eastern TPSC(E_TPSC)have displayed remarkable decreasing and increasing trends,respectively,during 1985–*** current work investigates the possible mechanisms accounting for these distinct TPSC *** results indicate that the decrease in W_TPSC is primarily attributed to rising temperatures,while the increase in E_TPSC is closely linked to enhanced *** circulation analysis shows that the essential system responsible for the TPSC changes is a significant anticyclonic system centered over the northwestern *** anomalous descending motion and adiabatic heating linked to this anticyclone leads to warmer temperatures and consequent snowmelt over the western ***,anomalous easterly winds along the southern flank of this anticyclone serve to transport additional moisture from the North Pacific,leading to an increase in snowfall over the eastern *** analysis reveals that the anomalous anticyclone is associated with an atmospheric wave pattern that originates from upstream *** warming of the subtropical North Atlantic(NA)sea surface temperature(SST)induces an atmospheric pattern resembling a wave train that travels eastward across the Eurasian continent before reaching the ***,the decline in winter sea ice(SIC)over the Barents Sea exerts a persistent warming influence on the atmosphere,inducing an anomalous atmospheric circulation that propagates southeastward and strengthens the northwest TP anticyclone in ***,an enhancement of subtropical stationary waves has resulted in significant increases in easterly moisture fluxes over the coastal areas of East Asia,which further promotes more snowfall over eastern TP.

关键词： snow cover Tibetan Plateau long-term changes spring

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