A novel design method for improving collapse resistances of multi-story steel frames with unequal spans using steel braces

Zheng Tan,Wei-hui Zhong,Bao Meng,Shi-chao Duan,Hong-chen Wang3,Xing-You Yao,Yu-hui Zheng 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.47 No.2

The bearing capacities resisted by the two-bay beams of multi-story planar frames with unequal spans under column removal scenarios differ considerably owing to the asymmetric stress on the left and right beams connected to the failed column and cause the potential for beams with larger span-to-depth ratios to be unable to exert effectively, which is disadvantageous for resisting the vertical load in unequal-span frame structures. To address this problem, the structural measure of adding braces to the weak bays of multi-story unequal-span frames was proposed, with the objective of achieving a coordinated stress state in two-bay beams with unequal spans, thereby improving the collapse resistance of unequal-span frame structures. Before conducting the numerical simulation, the modeling methods were verified by previous experimental results of two multi-story planar frames with and without steel braces. Thereafter, the effects of the tensile and compressive braces on the collapse behavior of the frame structures were elucidated. Then, based on the mechanical action laws of the braces throughout the collapse process, a detailed design method for improving the collapse resistance of unequal-span frame structures was proposed. Finally, the proposed design method was verified by using sufficient example models, and the results demonstrated that the design method has good application prospects and high practical value.

Thermo-mechanical strong coupling analysis on braking device of pipe belt conveyor

Yao Wang,Shujun Li,Wenjun Meng 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.3

In this study, the formula to calculate the impact factor of coupling (ξ) was proposed, considering the thermo-mechanical coupling problem of friction pairs for braking device during braking. First, a correlation between independent physical field parameters was provided by analyzing the interaction parameters of stress and temperature field. Next, the thermal analysis and thermo-mechanical strong coupling analysis were completed for friction pairs using heat transfer module and structural mechanics module of COMSOL multiphysics software on the basis of the actual operating situation of a pipe belt conveyor. The distribution and variation characteristics of the temperature and stress fields were studied with comparative analysis for braking friction pairs during braking. The mathematical expression on the impact factor of coupling (ξ) depending on braking time (t) was established. Finally, the model with thermo-mechanical strong coupling analysis was verified and compared with the thermal analysis model in terms of the measured surface temperature during braking. Simulation results revealed that the impact factor of coupling (ξ) decreased with braking time (t). However, the change rate of function initially decreased and then increased with time. An inflection point existed at t = 1.5396 s in the function ξ of t. In comparison with the small fluctuation of the simulations with thermal analysis model, the simulations with thermo-mechanical strong coupling analysis model were in good agreement with the trend of experimental results, and all the maximum relative errors were less than 4 %. Thus, the simulation with thermo-mechanical strong coupling analysis was more reliable than thermal analysis. This work could provide valuable insights in solving complex multiphysics coupling analysis.

Cordycepin protects against β-amyloid and ibotenic acid-induced hippocampal CA1 pyramidal neuronal hyperactivity

Yao, Li-Hua,Wang, Jinxiu,Liu, Chao,Wei, Shanshan,Li, Guoyin,Wang, Songhua,Meng, Wei,Liu, Zhi-Bin,Huang, Li-Ping The Korean Society of Pharmacology 2019 The Korean Journal of Physiology & Pharmacology Vol.23 No.6

Cordycepin exerts neuroprotective effects against excitotoxic neuronal death. However, its direct electrophysiological evidence in Alzheimer's disease (AD) remains unclear. This study aimed to explore the electrophysiological mechanisms underlying the protective effect of cordycepin against the excitotoxic neuronal insult in AD using whole-cell patch clamp techniques. ${\beta}$-Amyloid ($A{\beta}$) and ibotenic acid (IBO)-induced injury model in cultured hippocampal neurons was used for the purpose. The results revealed that cordycepin significantly delayed $A{\beta}$ + IBO-induced excessive neuronal membrane depolarization. It increased the onset time/latency, extended the duration, and reduced the slope in both slow and rapid depolarization. Additionally, cordycepin reversed the neuronal hyperactivity in $A{\beta}$ + IBO-induced evoked action potential (AP) firing, including increase in repetitive firing frequency, shortening of evoked AP latency, decrease in the amplitude of fast afterhyperpolarization, and increase in membrane depolarization. Further, the suppressive effect of cordycepin against $A{\beta}$ + IBO-induced excessive neuronal membrane depolarization and neuronal hyperactivity was blocked by DPCPX (8-cyclopentyl-1,3-dipropylxanthine, an adenosine $A_1$ receptor-specific blocker). Collectively, these results revealed the suppressive effect of cordycepin against the $A{\beta}$ + IBO-induced excitotoxic neuronal insult by attenuating excessive neuronal activity and membrane depolarization, and the mechanism through the activation of $A_1R$ is strongly recommended, thus highlighting the therapeutic potential of cordycepin in AD.

Resveratrol Exerts Dosage-Dependent Effects on the Self-Renewal and Neural Differentiation of hUC-MSCs

Wang, Xinxin,Ma, Shanshan,Meng, Nan,Yao, Ning,Zhang, Kun,Li, Qinghua,Zhang, Yanting,Xing, Qu,Han, Kang,Song, Jishi,Yang, Bo,Guan, Fangxia Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.5

Resveratrol (RES) plays a critical role in the fate of cells and longevity of animals via activation of the sirtuins1 (SIRT1) gene. In the present study, we intend to investigate whether RES could promote the self-renewal and neural-lineage differentiation in human umbilical cord derived MSCs (hUC-MSCs) in vitro at concentrations ranging from 0.1 to $10{\mu}M$, and whether it exerts the effects by modulating the SIRT1 signaling. Herein, we demonstrated that RES at the concentrations of 0.1, 1 and $2.5{\mu}M$ could promote cell viability and proliferation, mitigate senescence and induce expression of SIRT1 and Proliferating Cell Nuclear Antigen (PCNA) while inhibit the expression of p53 and p16. However, the effects were reversed by 5 and $10{\mu}M$ of RES. Furthermore, RES could promote neural differentiation in a dose-dependent manner as evidenced by morphological changes and expression of neural markers (Nestin, ${\beta}III-tubulin$ and NSE), as well as pro-neural transcription factors Neurogenin (Ngn)1, Ngn2 and Mash1. Taken together, RES exerts a dosage-dependent effect on the self-renewal and neural differentiation of hUC-MSCs via SIRT1 signaling. The current study provides a new strategy to regulate the fate of hUC-MSCs and suggests a more favorable in vitro cell culture conditions for hUCMSCs-based therapies for some intractable neurological disorders.

Room Temperature Fabrication of MIMCAPs via Aerosol Deposition

Wang, C.,Kim, H. J.,Meng, F. Y.,Kim, H. K.,Li, Y.,Yao, Z.,Kim, N. Y. IEEE 2016 IEEE electron device letters Vol.37 No.2

<P>We report the microwave dielectric properties of BaTiO3 thin films fabricated via aerosol deposition, which is capable of applying functional ceramic films to Si-based semiconductor fabrication at room temperature. As the starting powder, BaTiO3 powder with an average particle size of 300 nm afforded a dense thin film with a thickness of 500 nm as well as a smooth interface with the Pt/Ti/SiO2/Si substrate. In comparison, the interface roughness of BaTiO3 thin film was degraded (>100 nm) when BaTiO3 powder with an average particle size of 450 nm was used as the starting powder, owing to the excessive impact energy during film growth. Metal-insulator-metal capacitors were realized on a Si wafer via electron beam evaporation and inductively coupled plasma etching in order to determine the relative permittivity, loss tangent, and current-voltage characteristics. The average values of the relative dielectric permittivity and loss tangent of the BaTiO3 thin film were 78 and 0.03, respectively, in the frequency range of 1-6 GHz.</P>

Development of a Lateral Flow Strip-Based Recombinase Polymerase Amplification Assay for the Detection of Haemonchus contortus in Goat Feces

Yao-Dong Wu,Qi-Qi Wang,Meng Wang,Hany M. Elsheikha,Xin Yang,Min Hu,Xing-Quan Zhu,Min-Jun Xu 대한기생충학열대의학회 2021 The Korean Journal of Parasitology Vol.59 No.2

Haemonchosis remains a significant problem in small ruminants. In this study, the assay of recombinase polymerase amplification (RPA) combined with the lateral flow strip (LFS-RPA) was established for the rapid detection of Haemonchus contortus in goat feces. The assay used primers and a probe targeting a specific sequence in the ITS-2 gene. We compared the performance of the LFS-RPA assay to a PCR assay. The LFS-RPA had a detection limit of 10 fg DNA, which was 10 times less compared to the lowest detection limit obtained by PCR. Out of 24 goat fecal samples, LFS-RPA assay detected H. contortus DNA with 95.8% sensitivity, compared to PCR, 79.1% sensitivity. LFS-RPA assay did not detect DNA from other related helminth species and demonstrated an adequate tolerance to inhibitors present in the goat feces. Taken together, our results suggest that LFS-RPA assay had a high diagnostic accuracy for the rapid detection of H. contortus and merits further evaluation.

Evaluation and Optimization of Resource Allocation among Multiple Networks

( Dexiang Meng ),( Dongchen Zhang ),( Shoufeng Wang ),( Xiaoyan Xu ),( Wenwen Yao ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.10

Many telecommunication operators around the world have multiple networks. The networks run by each operator are always of different generations, such as 2G and 3G or even 4G systems. Each system has unique characters and specified requirements for optimal operation. It brings about resource allocation problem among these networks for the operator, because the budget of each operator is limited. However, the evaluation of resource allocation among various networks under each operator is missing for long, not to mention resource allocation optimization. The operators are dying for an algorithm to end their blind resource allocation, and the Resource Allocation Optimization Algorithm for Multi-network Operator (RAOAMO) proposed in this paper is what the operators want. RAOAMO evaluates and optimizes resource allocation in the view of overall cost for each operator. It outputs a resource distribution target and corresponding optimization suggestion. Evaluation results show that RAOAMO helps operator save overall cost in various cases.

Integrated Analysis Method of Thin-Walled Turbine Blade Precise Machining

Hui Wang,Lijiang Huang,Chao Yao,Meng Kou,Wenyu Wang,Bohao Huang,Weizhen Zheng 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

Conventional turbine blade machining technology has to face some challenges on production efficiency, quality and environmental impact. So a new machining technical solution for thin-walled turbine blade is presented. Technical problems associated with the precise machining of turbine blade are discussed in detail. On the basis of analysis with existing demerits, we propose a new fixture optimization and precise machining schema for turbine blade. In the proposed technical methodology, geometric locating tolerance analysis and FEM based structural deformation prediction methods are integrated into one framework to improve the machining performance of thin-walled turbine blade. An automatic machining station of turbine blade is also developed. Promising technical capability of this system is demonstrated and validated by real machining experiments.

Increased retinoic acid signaling decreases lung metastasis in salivary adenoid cystic carcinoma by inhibiting the noncanonical Notch1 pathway

Zhou Meng-jiao,Yang Jia-jie,Ma Ting-yao,Feng Ge-xuan,Wang Xue-lian,Wang Li-Yong,Ge Yu-ze,Gao Ran,Hong-liang Liu,Shan Lin,Kong Lu,Chen Xiao-hong 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

MYB-NFIB fusion and NOTCH1 mutation are common hallmark genetic events in salivary gland adenoid cystic carcinoma (SACC). However, abnormal expression of MYB and NOTCH1 is also observed in patients without MYB-NFIB fusion and NOTCH1 mutation. Here, we explore in-depth the molecular mechanisms of lung metastasis through single-cell RNA sequencing (scRNA-seq) and exome target capture sequencing in two SACC patients without MYB-NFIB fusion and NOTCH1 mutation. Twenty-five types of cells in primary and metastatic tissues were identified via Seurat clustering and categorized into four main stages ranging from near-normal to cancer-based on the abundance of each cell cluster in normal tissue. In this context, we identified the Notch signaling pathway enrichment in almost all cancer cells; RNA velocity, trajectory, and sub-clustering analyses were performed to deeply investigate cancer progenitor-like cell clusters in primary tumor-associated lung metastases, and signature genes of progenitor-like cells were enriched in the “MYC_TARGETS_V2” gene set. In vitro, we detected the NICD1-MYB-MYC complex by co-immunoprecipitation (Co-IP) and incidentally identified retinoic acid (RA) as an endogenous antagonist of genes in the “MYC_TARGETS_V2” gene set. Following this, we confirmed that all-trans retinoic acid (ATRA) suppresses the lung metastasis of SACC by correcting erroneous cell differentiation mainly caused by aberrant NOTCH1 or MYB expression. Bioinformatic, RNA-seq, and immunohistochemical (IHC) analyses of primary tissues and metastatic lung tissues from patients with SACC suggested that RA system insufficiency partially promotes lung metastasis. These findings imply the value of the RA system in diagnosis and treatment.

Timosaponin AIII induces apoptosis and autophagy in human melanoma A375-S2 cells

Ye Wang,Lei Xu,Li-Li Lou,Shao-Jiang Song,Guo-Dong Yao,Meng-Yao Ge,Toshihiko Hayashi,Shin-ichi Tashiro,Satoshi Onodera,Takashi Ikejima 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.1

Timosaponin AIII (AIII), a steroidal saponinisolated from Anemarrhena asphodeloides Bge. Our studyshowed that AIII induced both apoptosis and autophagy,and autophagy inhibited apoptosis in A375S2 cells. Furtherly,this study was carried out to investigate what kindof cytokines plays an important role in this process. Theresults revealed that AIII induced apoptosis through activatingc-Jun N-terminal protein kinase (JNK) or extracellularsignal related kinase (ERK) signaling pathway andgenerating NO. However, JNK or ERK inhibited autophagy,while NO had no effect on autophagy. Therefore,JNK, ERK or NO regulates two programmed death processesin different ways. AIII did not show obvious cytotoxiceffect on human peripheral blood mononuclear cells,which indicated that AIII has less side effects on normalcells, and could be considered as a leading compound fordeveloping novel anticancer drug.