Development of self-centring energy-dissipative rocking columns equipped with SMA tension braces

Yan-Wen Li,Michael C.H. Yam,Ping Zhang,Ke Ke,Yan-Bo Wang 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.5

Energy-dissipative rocking (EDR) columns are a class of seismic mitigation device capable of dissipating seismic energy and preventing weak-story failure of moment resisting frames (MRFs). An EDR consists of two hinge-supported steel columns interconnected by steel dampers along its height. Under earthquakes, the input seismic energy can be dissipated by plastic energy of the steel dampers in the EDR column. However, the unrecoverable plastic deformation of steel dampers generally results in residual drifts in the structural system. This paper presents a proof-of-concept study on an innovative device, namely self-centring energy-dissipative rocking (SC-EDR) column, aiming at enabling self-centring capability of the EDR column by installing a set of shape memory alloy (SMA) tension braces. The working mechanism of the SC-EDR column is presented in detail, and the feasibility of the new device is carefully examined via experimental and numerical studies considering the parameters of the SMA bar diameter and the steel damper plate thickness. The seismic responses including load carrying capacities, stress distributions, base rocking behaviour, source of residual deformation, and energy dissipation are discussed in detail. A rational combination of the steel damper and the SMA tension braces can achieve excellent energy dissipation and self-centring performance.

Design of Micro Biopsy Device for Wireless Autonomous Endoscope

Wen-Wen Chen,Guo-Zheng Yan,Hua Liu,Ping-Ping Jiang,Zhi-Wu Wang 한국정밀공학회 2014 International Journal of Precision Engineering and Vol. No.

Well-established technology that provides assistance from outside the patient may soon give way to alternative approaches that bythe wireless robotic mechanisms inside the patient through natural orifices. For this study, two kinds of micro biopsy mechanisms weredeveloped for capsule endoscope which could traverse the gut environment automatically. This mobility allows the biopsy device tomove to the area of interest to sample specific tissues. Based on the medical and mechanism considerations, we concerned on designprecise biopsy jaw with sufficient cutting force, and the biopsy process should be safe, repeatable and visible. The lead-screw linkagesystem that actuated jaw of biopsy allowing for large force production. Using one micro-motor, the biopsy process was carried outquickly by three motions: stretching to sampling point; bite and cutting off; withdrawing into capsule body with the sample. With thecontrol and vision system, the biopsy process could compete automatically. The robot was capable of traversing in the gut environmentwirelessly and had been successfully used to biopsy gut tissue in vitro. In addition, experimental analysis of the biopsy mechanismshowed good results towards more elaborate tissue manipulation in the future.

Expression Level of Valosin Containing Protein is Associated with Prognosis of Primary Orbital MALT Lymphoma

Zhu, Wen-Wen,Kang, Li,Gao, Ya-Ping,Hei, Yan,Dong, Jie,Liu, Yu,Xiao, Li-Hua,Yang, Guang Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Objective: To investigate whether the expression level of valosin-containing protein (VCP) is correlated with the prognosis of primary orbital mucosa-associated lymphoid tissue (MALT) lymphoma. Methods: VCP expression in 58 samples from primary orbital MALT lymphoma patients was determined by immunohistochemisty using monoclonal antibodies. Correlations between VCP expression level and prognosis were clarified by statistical analysis. Results: It was found that the percentage of VCP positive cells in samples of primary orbital MALT lymphoma ranged from 32% to 95%. The samples were divided into two groups (level 1 and level 2) according to the median value (45%) of the percentage of VCP positive cells. It was found that the expression level of VCP was significantly correlated with recurrence (P=0.003) and tumor size (P=0.008). At the same time, the 5-year disease-free and overall survival rate of patients of level 1 was significantly better than that of level 2 (P=0.001; P=0.032). There was no observed correlation between the expression level of VCP and other clinical features. Conclusion: VCP could be a useful marker for predicting the prognosis of primary orbital MALT lymphoma.

Applicability Analysis of Microseismic Technology in Tunnel Water Inrush Monitoring

Yan-hao Chen,Shuai Cheng,Li-Ping Li,Jun-yan Yang,Hong-liang Liu,Wen-feng Tu 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.7

Water inrush disaster is one of the most serious geological disasters in tunnel construction. There are still some problems in the existing researches, such as the activity information of surrounding rock is difficult to obtain, the mechanism of water inrush disaster is unclear, the correlation between water inrush disaster and microseismic (MS) information is missing, which have caused the water inrush disaster to be passively controlled. Combining with the practical experience of tunnel engineering, the application problems of MS technology in tunnel engineering is summarized, which provides ideas for monitoring of surrounding rock activity. The formation mechanism of water inrush disaster caused by rock mass fracturing and filling medium instability has been revealed. The MS characteristics of the water inrush channel in different water inrush disasters have also been revealed. The MS response characteristics of water inrush and rockburst disasters are compared, which provides guidance for the improvement of MS monitoring technology and the analysis of effective MS information. The compression failure test of limestone under saturated and natural conditions is carried out. The results show that the presence of water weakens the ability of rock to store energy. The acoustic emission (AE) phenomenon is weaker in the process of saturated limestone failure, which increases the difficulty of AE monitoring. The number of AE events of natural limestone and saturated limestone shows a slow increase to a sudden increase in the process stress loading, which can be regarded as an important precursor of rock failure.

Protective Effects of Silibinin and Its Possible Mechanism of Action in Mice Exposed to Chronic Unpredictable Mild Stress

( Wen Jing Yan ),( Ying Chun Tan ),( Ji Cheng Xu ),( Xian Ping Tang ),( Chong Zhang ),( Peng Bo Zhang ),( Ze Qiang Ren ) 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.3

Silibinin, a natural flavonoid antioxidant isolated from extracts of the milk thistle herb, has recently been identified as having antihepatotoxic and anticancer properties. In this paper, we investigated the effects of silibinin on behavior and neuroplasticity in mice subjected to chronic unpredictable mild stress (CUMS). After 5 consecutive weeks of CUMS, the mice were treated with silibinin (100 mg/kg, 200 mg/kg and 400 mg/kg by oral gavage) for 3 consecutive weeks. The results showed that silibinin administration significantly alleviated the CUMS-induced depressive-like behavior, including the total number of squares crossed and the frequency of rearing in the open field test, the immobility time in the tail suspension test and the forced swimming test. Furthermore, silibinin treatment increased the levels of brain-derived neurotrophic factor (BDNF), serotonin (5-HT) and norepinephrine (NE) in the prefrontal cortex and hippocampus. Our study provides new insight into the protective effects of silibinin on the depressive status of CUMS mice, specifically by improving neuroplasticity and neurotransmission.

Association between the MDM2 T309G Polymorphism and Leukemia Risk: a Meta-analysis

Yan, Yu-Lan,Han, Feng,Tan, Wen-Min,Wu, Cui-Ping,Qin, Xi Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16

Several studies have suggested associations between MDM2 (mouse double minute 2 homolog) polymorphisms and leukemia risk, but they reported contradictory results. For better understanding of the effect of MDM2 T309G polymorphism on leukemia risk, we performed a meta-analysis. All eligible studies were identified through a search of PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature (CBM) databases before May 2014. Assessment of associations between the MDM2 T309G polymorphism and leukemia risk was conducted by odds ratios (ORs) and 95% confidence intervals (95% CIs). Finally, a total of 11 publications covering 12 case-control studies with 2, 362 cases and 5, 562 controls concerning MDM2 T309G polymorphism with respect to leukemia were included in the meta-analysis. Significant associations were found between MDM2 T309G polymorphism and leukemia risk in four models in overall populations (G vs T: OR=1.29, 95% CI=1.11-1.49, p=0.001; GG vs TT: OR=1.67, 95% CI=1.21-2.30, p=0.002; GG vs TG/TT: OR=1.56, 95% CI=1.21-2.00, p=0.001; GG/TG vs TT: OR=1.28, 95% CI=1.05-1.57, p=0.015). In the sub-group analysis according to ethnicity, increased leukemia risks were observed in three genetic models among Asians but not Caucasians. In conclusion, the results of our meta-analysis suggest that the MDM2 T309G polymorphism can increase the risk of leukemia, especially among Asian populations.

Down-regulation of Protease-activated Receptor 4 in Lung Adenocarcinoma is Associated with a More Aggressive Phenotype

Jiang, Ping,Yu, Guo-Yu,Zhang, Yong,Xiang, Yang,Hua, Hai-Rong,Bian, Li,Wang, Chun-Yan,Lee, Wen-Hui,Zhang, Yun Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

The role of protease-activated receptors (PARs) in lung tumors is controversial. Although PAR4 is preferentially expressed in human lung tissues, its possible significance in lung cancer has not been defined. The studies reported herein used a combination of clinical observations and molecular methods. Surgically resected lung adenocarcinomas and associated adjacent normal lung tissues were collected and BEAS-2B and NCI-H157 cell lines were grown in tissue culture. PAR4 expression was evaluated by RT-PCR, RT-qPCR, Western blotting and immunohistochemistry analysis. The results showed that PAR4 mRNA expression was generally decreased in lung adenocarcinoma tissues as compared with matched noncancerous tissues (67.7%) and was associated with poor differentiation (p=0.017) and metastasis (p=0.04). Western blotting and immunohistochemical analysis also showed that PAR4 protein levels were mostly decreased in lung adenocarcinoma tissues (61.3%), and were also associated with poor differentiation (p=0.035) and clinical stage (p=0.027). Moreover, PAR4 expression was decreased in NCI-H157 cells as compared with BEAS-2B cells. In conclusion, PAR4 expression is significantly decreased in lung adenocarcinoma, and down-regulation of PAR4 is associated with a more clinically aggressive phenotype. PAR4 may acts as a tumor suppressor in lung adenocarcinoma.

Phylogenetic Diversity and Antifungal Activity of Endophytic Fungi Associated with Tephrosia purpurea

( Ze Ping Luo ),( Hai Yan Lin ),( Wen Bing Ding ),( Hua Liang He ),( You Zhi Li ) 한국균학회 2015 Mycobiology Vol.43 No.4

Sixty-one endophytic fungus strains with different colony morphologies were isolated from the leaves, stems and roots of Tephrosia purpurea with colonization rates of 66.95%, 37.50%, and 26.92%, respectively. Based on internal transcribed spacer sequence analysis, 61 isolates were classified into 16 genera belonging to 3 classes under the phylum Ascomycota. Of the 61 isolates, 6 (9.84%) exhibited antifungal activity against one or more indicator plant pathogenic fungi according to the dual culture test. Isolate TPL25 had the broadest antifungal spectrum of activity, and isolate TPL35 was active against 5 plant pathogenic fungi. Furthermore, culture filtrates of TPL25 and TPL35 exhibited greater than 80% growth inhibition against Sclerotinia sclerotiorum. We conclude that the endophytic fungal strains TPL25 and TPL35 are promising sources of bioactive compounds.

Experimental and Numerical Investigations on the Spherical Steel Bearing Capacity of New Anti-Separation Design

Lei Yan,Xiao-Ying Gou,Xin Zhang,Yu Jiang,Xing-Wen Ran,Ping Zhang 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.2

To solve the issues of slippage and dislodging caused by insufficient grout compactness in railway bridge spherical steel bearings, a novel kind of anti-separation spherical steel bearing is presented. Firstly, a comparative test model was meticulously designed and constructed for the bearing-stone assembly, encompassing both the traditional spherical steel bearing and the innovative anti-separation spherical steel bearing. Next, mechanical performance testing and finite element simulation analysis were completed. Finally, an empirical equation for the vertical load-strain fitting of the bearing was established. The results demonstrate that, under the maximum vertical static load, the convex spherical crown anti-separation design of the new anti-dislodging bearing is not sensitive to the bearing performance of the bearing-bedding stone combination. All indexes also meet the specifications. Under the action of cyclic load, the error of each parameter between finite element analysis and test results is less than 7%, which shows that the new anti- separation spherical bearing has higher bearing capacity and better fatigue resistance; the fitted value of the established bearing vertical load-strain calculation formula is in agreement with the test value by more than 0.95, which can predict whether the new anti-separation bearing fails.

Random vibration analysis of train-slab track-bridge coupling system under earthquakes

Zhi-ping Zeng,Xian-feng He,Yan-gang Zhao,Zhi-wu Yu,Ling-kun Chen,Wen-tao Xu,Ping Lou 국제구조공학회 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.54 No.5

This study aimed to investigate the random vibration characteristic of train-slab track-bridge interaction system subjected to both track irregularities and earthquakes by use of pseudo-excitation method (PEM). Each vehicle subsystem was modeled by multibody dynamics. A three-dimensional rail-slabgirder-pier finite element model was created to simulate slab track and bridge subsystem. The equations of motion for the entire system were established based on the constraint condition of no jump between wheel and rail. The random load vectors of equations of motion were formulated by transforming track irregularities and seismic accelerations into a series of deterministic pseudo-excitations according to their respective power spectral density (PSD) functions by means of PEM. The time-dependent PSDs of random vibration responses of the system were obtained by step-by-step integration method, and the corresponding extreme values were estimated based on the first-passage failure criterion. As a case study, an ICE3 high-speed train passing a fifteen-span simply supported girder bridge simultaneously excited by track irregularities and earthquakes is presented. The evaluated extreme values and the PSD characteristic of the random vibration responses of bridge and train are analyzed, and the influences of train speed and track irregularities (without earthquakes) on the random vibration characteristic of bridge and train are discussed.