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A Hint Frequency Based Approach to Enhancing the I/O Performance of Multilevel Cache Storage Systems

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Journal of Computer Science & Technology 2017年第2期32卷 312-328页

作者： xiao-dong meng Chen-Tao Wu Min-Yi Guo Jie Li xiao-Yao Liang Bin Yao Long Zheng Department of Computer Science and Engineering Shanghai Jiao Tong University Shanghai 200240 China

With the enormous and increasing user demand, I/O performance is one of the primary considerations to build a data center. Several new technologies in data centers, such as tiered storage, prompt the widespread usage of multilevel cache techniques. In these storage systems, the upper level storage typically serves as a cache for the lower level, which forms a distributed multilevel cache system. However, although many excellent multilevel cache algorithms have been proposed to improve the I/O performance, they still have potential to be enhanced by investigating the history information of hints. To address this challenge, in this paper, we propose a novel hint frequency based approach （HFA）, to improve the overall multilevel cache performance of storage systems. The main idea of HFA is using hint frequencies （the total number of demotions/promotions by employing demote/promote hints） to efficiently explore the valuable history information of data blocks among multiple levels. HFA can be applied with several popular multilevel cache algorithms, such as Demote, Promote and Hint-K. Simulation results show that, compared with original multilevel cache algorithms such as Demote, Promote and Hint-K, HFA can improve the I/O performance by up to 20% under different I/O workloads.

关键词： storage system multilevel cache hint I/O performance

Metformin attenuates motility,contraction,and fibrogenic response of hepatic stellate cells in vivo and in vitro by activating AMP-activated protein kinase

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World Journal of Gastroenterology 2018年第7期24卷 819-832页

作者： Zhen Li Qian Ding Li-Ping Ling Ying Wu dong-xiao meng xiao Li Chun-Qing Zhang Department of Gastroenterology Shandong Provincial Hospital Affiliated to Shandong UniversityJinan 250021Shandong ProvinceChina Shandong Provincial engineering and technological research center for liver disease prevention and control Jinan 250021Shandong ProvinceChina

AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot *** Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.

关键词： hepatic stellate cell intrahepatic vascular resistance angiogenesis contraction liver fibrosis adenosine monophosphate-activated protein kinase

早期帕金森病患者胃排空障碍在胃肠超声造影中的表现

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广东医学 2024年第4期45卷 510-515页

作者：董晓梦李斌陈连祥宋晓文王洪财苏毅鹏滨州医学院附属医院神经内科山东滨州256603 滨州医学院附属医院超声医学科山东滨州256603

目的研究早期帕金森病患者的非运动症状—胃排空障碍在胃肠超声造影中的表现。方法对32例门诊及住院的、诊断为早期帕金森病(HY分级Ⅰ~Ⅱ期)并存在胃排空障碍(包括恶心呕吐、早饱、餐后持续性上腹胀满等症状)的患者(PD组)和同期30例健... 详细信息

目的研究早期帕金森病患者的非运动症状—胃排空障碍在胃肠超声造影中的表现。方法对32例门诊及住院的、诊断为早期帕金森病(HY分级Ⅰ~Ⅱ期)并存在胃排空障碍(包括恶心呕吐、早饱、餐后持续性上腹胀满等症状)的患者(PD组)和同期30例健康体检者(对照组)进行胃肠超声造影检查,记录并测量两组入组者在饮入胃肠造影剂后的不同时间点(0~120 min)的胃窦收缩幅度(ACA)、胃窦收缩频率(ACF)、胃动力指数(GMI)、胃排空率(GER)、胃排空时间(GET)、胃壁增厚率、胃蠕动波速度等胃动力参数。结果PD组患者在各时间点的ACA、ACF、GMI及GER值均低于对照组(P<0.01,P<0.05);胃窦排空时间大于对照组(P均<0.01);30 min时PD组胃壁增厚率及胃蠕动波速度均低于对照组(均P<0.01)。结论早期帕金森病患者的胃排空障碍可借助胃肠超声造影得到有效评估。

关键词：早期帕金森病胃排空障碍胃肠超声造影

A simple model for two-proton radioactivity

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Chinese Physics C 2024年第10期48卷 247-255页

作者： Jie-dong Jiang xiao Liu dong-meng Zhang Ming Li Xi-Jun Wu xiao-Hua Li School of Nuclear Science and Technology University of South ChinaHengyang 421001China School of Math and Physics University of South ChinaHengyang 421001China National Exemplary Base for International Sci&Tech.Collaboration of Nuclear Energy and Nuclear Safety University of South ChinaHengyang 421001China Cooperative Innovation Center for Nuclear Fuel Cycle Technology&Equipment University of South ChinaHengyang 421001China Key Laboratory of Low Dimensional Quantum Structures and Quantum Control Hunan Normal UniversityChangsha 410081China

In this work,considering the preformation factor of the emitted two protons in parent nucleus S_(2p) and the effect of the parent nucleus deformation,based on the Wentzel-Kramers-Brillouin approximation and Bohr-Sommerfeld quantization condition,we improve a simple phenomenological model proposed by Bayrak[***.G:47,025102(2020)]to systematically study 2p radioactivity *** model contains two adjustable parameters V_(0) and a_(β),which are related to the depth of nuclear potential and effect of *** calculated results show that this model can effectively reproduce the experimental data with a corresponding root-mean-square(RMS)standard deviation of σ=*** comparison,we include the Gamow-like model(GLM)proposed by Liu et al.[***.C 45,044110(2021)],generalized liquid drop model(GLDM)proposed by Cui et al.[***.C 101,014301(2020)],effective liquid drop model(ELDM)proposed by *** et al.[***.B 774,14(2017)],two-potential approach with Skyrme-Hartree-Fock(TPASHF)proposed by Pan et al.[***.C 45,124104(2021)],phenomenological model with a screened electrostatic barrier(SEB)propoesed by Zou et al.[***.C 45,104101(2021)],unified fission model(UFM)proposed by Xing et al.[***.C 45,124105(2021)],Coulomb and proximity potential model for deformed nuclei(CPPMDN)proposed by Santhosh[***.C 104,064613(2021)],two-parameter empirical formula proposed by Liu et al.[***.C 45,024108(2021)],and four-parameter empirical formula proposed by Sreeja et al.[***.J.A 55,33(2019)].In addition,we use this model to 2p predict the radioactive half-lives of some possible potential nuclei whose 2p radioactivity are energetically allowed or observed but not yet quantified in NUBASE2020.

关键词： two-proton radioactivity half-lives Wentzel-Kramers-Brillouin approximation

Dynamic shielding of bacterial outer membrane vesicles for safe and efficient chemo-immunotherapy against tumors

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Nano Research 2024年第2期17卷 836-847页

作者： Shuping Li Xin Li Jiaqi meng Weier Bao Shuang Wang Peng Ye xiao-dong Gao Wei Wei Key Laboratory of Carbohydrate Chemistry and Biotechnology Ministry of Education School of BiotechnologyJiangnan UniversityWuxi 214122China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China

Bacterial outer membrane vesicles(OMVs)are potent immunostimulants of regulating the tumor microenvironment(TME)for immunotherapy,and can be used to deliver ***,the severe systemic inflammatory response triggered by OMVs upon intravenous(i.v.)injection has limited their ***,we developed a safe and effective strategy by conjugating doxorubicin-loaded serum albumin(SA-DOX,AD)onto the surface of OMVs using a matrix metalloproteinase(MMP)-cleavable peptide linker(cL).This approach enabled the dynamic shielding of OMVs to reduce the systemic side effects while simultaneously enhancing the anti-tumor effects through ***,the resulting OMV-cL-AD formulation exhibited significantly enhanced accumulation at the tumor site after ***,facilitated by the SA decoration on the OMVs ***,the shield on the OMV-cL-AD was cleaved by the over-expressed MMP in the TME,leading to the release of both OMVs and *** process provided OMV-induced immunotherapy and DOX-induced chemotherapy,resulting in synergistic tumor *** conclusion,our work demonstrated the potential of OMV-cL-AD as an effective immunochemotherapy strategy that can prolong the survival time of mice without inducing side effects.

关键词： outer membrane vesicles doxorubicin tumor microenvironment immunotherapy chemotherapy

On Minor Left Prime Factorization Problem for Multivariate Polynomial Matrices

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Journal of Systems Science & Complexity 2024年第3期37卷 1295-1307页

作者： LU dong WANG Dingkang xiao Fanghui School of Mathematics Southwest Jiaotong UniversityChengdu 610031China KLMM Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China MOE-LCSM School of Mathematics and StatisticsHunan Normal UniversityChangsha 410081China

A new necessary and sufficient condition for the existence of minor left prime factorizations of multivariate polynomial matrices without full row rank is *** key idea is to establish a relationship between a matrix and any of its full row rank *** on the new result,the authors propose an algorithm for factorizing matrices and have implemented it on the computer algebra system *** examples are given to illustrate the effectiveness of the algorithm,and experimental data shows that the algorithm is efficient.

关键词： Free modules Grobner bases minor left prime(MLP) multivariate polynomial matrices polynomial matrix factorizations

Visible-light-activated aziridination reaction enables simultaneous resolving of C=C bond location and the sn-position isomers in lipids

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Chinese Chemical Letters 2024年第4期35卷 481-485页

作者： Qiongqiong Wan Yanan xiao Guifang Feng Xin dong Wenjing Nie Ming Gao Qingtao meng Suming Chen The Institute for Advanced Studies Renmin Hospital of Wuhan UniversityWuhan UniversityWuhan 430072China

There is a close relationship between the biological functions of lipids and their structures, and various isomers greatly increases the complexity of lipid structures. The C=C bond location and sn-position are two of the essential attributes that determine the structures of unsaturated lipids. However, simultaneous identification of both attributes remains challenging. Here, we develop a visible-light-activated aziridination reaction system, which enables the dual-resolving of the C=C bond location and sn-position isomerism of in lipids when combines with liquid chromatography-mass spectrometry(LC-MS). Based on the derivatization of C=C bonds with Ph I=NTs, their location in lipids could be easily identified by tandem MS. Especially, the sn-position isomers of unsaturated phosphatidylcholine(PC) can be separated and quantified by LC-MS after the derivatization. By using the proposed method, the significant changes of the sn-position isomers ratios of PC in mouse brain ischemia were revealed. This study offers a powerful tool for deep lipid structural biology.

关键词： Aziridination Lipid isomers C=C bond location sn-Position Mass spectrometry

Direct numerical simulation of shock wave/boundary layer interaction controlled by steady microjet in a compression ramp

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Chinese Journal of Aeronautics 2024年第10期37卷 83-102页

作者： Ruoye xiao dong SUN Jian YU School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China State Key Laboratory of Aerodynamics Mianyang 621000China

Shock wave/boundary layer interaction in a 24°turning angle of the compression ramp at Mach number 2.9 controlled by steady microjet is investigated using direct numerical *** different jet spacings which are termed as sparse,moderate and dense are considered,and the induced vortex system and shock structures are compared.A moderate jet spacing configuration is found to generate counter-rotating vortex pairs that transport high-momentum fluid towards the vicinity of wall and strengthen the boundary layer to resist separation,reducing the separation *** dense jet spacing configuration creates a larger momentum deficit region,reducing the friction downstream of the *** of pressure and pressure gradient reveals that dense jet spacing configuration reduces the intensity of separation *** impact of varying jet spacings on the turbulent kinetic energy transport mechanism is also investigated by decomposing the budget terms in the transport ***,the spectral characteristics of the separation region are studied using power spectral density and dynamic mode decomposition methods,revealing that moderate jet spacing configuration suppresses low-frequency fluctuations in the separation region.

关键词： Shock wave/boundary layer interaction Compression ramp Steady microjet Different jet spacings Direct numerical simulation

A systematic framework of constructing surrogate model for slider track peeling strength prediction

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Science China Technological Sciences 2024年第10期67卷 3261-3274页

作者： dong XingJian CHEN Qian LIU WenBo WANG dong PENG ZhiKe meng Guang State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong University KEIPER Seating Mechanisms Co. Ltd. Department of Industrial Engineering and Management Shanghai Jiao Tong University

Peeling strength can comprehensively reflect slider track safety and is crucial in car seat safety assessments. Current methods for determining slider peeling strength are primarily physical testing and numerical simulation. However, these methods encounter the potential challenges of high costs and overlong time consumption which have not been adequately addressed. Therefore, the efficient and low-cost surrogate model emerges as a promising solution. Nevertheless, currently used surrogate models suffer from inefficiencies and complexity in data sampling, lack of robustness in local model predictions, and isolation between data sampling and model prediction. To overcome these challenges, this paper aims to set up a systematic framework for slider track peeling strength prediction, including sensitivity analysis, dataset sampling, and model prediction. Specifically, the interpretable linear regression is performed to identify the sensitivity of various geometric variables to peeling strength. Based on the variable sensitivity, a distance metric is constructed to measure the disparity of different variable groups. Then, the sparsity-targeted sampling(STS) is proposed to formulate a representative dataset. Finally, the sequentially selected local weighted linear regression(SLWLR) is designed to achieve accurate track peeling strength prediction. Additionally, a quantitative cost assessment of the supplementary dataset is proposed by utilizing the minimum adjacent sample distance as a mediator. Experimental results validate the efficacy of sequential selection and the weighting mechanism in enhancing localization ***, the proposed SLWLR method surpasses similar approaches and other common surrogate methods in terms of prediction performance and data quantity requirements, achieving an average absolute error of 3.3 kN in the simulated test dataset.

关键词： slider track peeling strength surrogate model sensitivity analysis data sampling local weighted linear regression