Experimental and Numerical Investigation of the Effect of Blast-induced Vibration from Adjacent Tunnel on Existing Tunnel

Hua-bing Zhao,Yuan Long,Xing-hua Li,Liang Lu 대한토목학회 2016 KSCE JOURNAL OF CIVIL ENGINEERING Vol.20 No.1

Since the new tunnel is close to existing tunnel, the vibration wave induced by blasting endangers the safety and stabilization of the surrounding rock and the lining of existing tunnel. In the tunnel blasting vibration monitoring and safety prediction, Peak Particle Velocity (PPV) and vibration frequency are used widely as safety standards. To investigate the effect of blast-induced vibration from adjacent tunnel on existing tunnel, field monitoring experiments and a numerical method that is Finite Element Method (FEM) were adopted to study the blasting vibration velocity and vibration frequency of existing tunnel. Combined blasting vibration velocity with vibration frequency, the paper studied axial and radial blasting vibration velocity distributions and the corresponding Power Spectral Density (PSD) distributions of the existing tunnel under the effect of blast-induced vibration from adjacent subway tunnel. And the parameters of constitutive model and blasting loads were also discussed. It is shown that field monitoring experiment and numerical simulation can optimize blasting excavation program and provide a reference for other similar engineering projects.

Modulation of Drug Resistance in Ovarian Cancer Cells by Inhibition of Protein Kinase C-alpha (PKC-α) with Small Interference RNA (siRNA) Agents

Zhao, Li-Jun,Xu, Heng,Qu, Jun-Wei,Zhao, Wan-Zhou,Zhao, Yi-Bing,Wang, Jin-Hua Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Objective: To determine whether silence of $PKC-{\alpha}$ expression by small interference RNA (siRNA) might regulate MDR1 expression and reverse chemoresistance of ovarian cancer. Methods: We measured gene and protein expression of MDR1 and $PKC-{\alpha}$ in ovarian cancer cells and assessed their correlation with cell drug resistance. We also examined whether blocking $PKC-{\alpha}$ by RNA interference (RNAi) affected MDR1 expression and reversed drug resistance in drug sensitivity tests. Results: The drug resistance cell lines, OV1228/DDP and OV1228/Taxol, had higher gene and protein expression of MDR1 and $PKC-{\alpha}$ than their counterpart sensitive cell line, OV1228. SiRNA depressed $PKC-{\alpha}$ gene protein expression, as well as MDR1 and protein expression and improved the drug sensitivity in OV1228/DDP and OV1228/Taxol cells. Conclusion: These results indicated that decreasing $PKC-{\alpha}$ expression with siRNA might be an effective method to improve drug sensitivity in drug resistant cells with elevated levels of $PKC-{\alpha}$ and MDR1. A new siRNA-based therapeutic strategy targeting $PKC-{\alpha}$ gene could be designed to overcome the chemoresistance of ovarian cancer.

Values of Three Different Preoperative Regimens in Comprehensive Treatment For Young Patients with Stage Ib2 Cervical Cancer

Zhao, Yi-Bing,Wang, Jin-Hua,Chen, Xiao-Xiang,Wu, Yu-Zhong,Wu, Qiang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4

Objective: To compare the clinical efficacy of concurrent chemoradiotherapy, neoadjuvant chemotherapy, and intracavity brachytherapy in comprehensive treatment for young patients with stage Ib2 cervical cancer. Methods: One hundred and twelve young patients with stage Ib2 cervical cancer were enrolled retrospectively in our hospital from January 2003 to June 2005. They were categorized into three groups according to preoperative regimens, including the concurrent chemoradiotherapy group (Group 1, n=38), the neoadjuvant chemotherapy (Group 2, n=49), and the intracavity brachytherapy group (Group 3, n=25). Radical hysterectomy was performed following these regimens. Chemotherapy and radiotherapy were given according to pelvic lymph node metastasis, deep cervical stromal invasion, intravascular cancer emboli, histological grading, vaginal stump and positive surgical margin. Results: The cancer disappearance and superficial muscle invasion rates were statistically significantly better in the concurrent chemoradiotherapy group than in the other two groups (P<0.01). No statistically significant difference was noted in the deep muscle invasion rate, surgical time and intraoperative blood loss among three groups, but significantly more postoperative complications occurred in the concurrent chemoradiotherapy group. The 2-year pelvic recurrence was statistically significantly lower in the concurrent chemoradiotherapy group compared to other two groups, while the 5-year survival was higher. Conclusion: Concurrent chemoradiotherapy is efficacious for young patients with stage Ib2 cervical cancer.

Continuous DC-CIK Infusions Restore CD8⁺ Cellular Immunity, Physical Activity and Improve Clinical Efficacy in Advanced Cancer Patients Unresponsive to Conventional Treatments

Zhao, Yan-Jie,Jiang, Ni,Song, Qing-Kun,Wu, Jiang-Ping,Song, Yu-Guang,Zhang, Hong-Mei,Chen, Feng,Zhou, Lei,Wang, Xiao-Li,Zhou, Xin-Na,Yang, Hua-Bing,Ren, Jun,Lyerly, Herbert Kim Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Background: There are few choices for treatment of advanced cancer patients who do not respond to or tolerate conventional anti-cancer treatments. Therefore this study aimed to deploy the benefits and clinical efficacy of continuous dendritic cell-cytokine induced killer cell infusions in such patients. Materials and Methods: A total of 381 infusions (from 67 advanced cases recruited) were included in this study. All patients underwent peripheral blood mononuclear cell apheresis for the following cellular therapy and dendritic cells-cytokine induced killer cells were expanded in vitro. Peripheral blood T lymphocyte subsets were quantified through flow cytometry to address the cellular immunity status. Clinical efficacy and physical activities were evaluated by RECIST criteria and Eastern Cooperative Oncology Group scores respectively. Logistic regression model was used to estimate the association between cellular infusions and clinical benefits. Results: An average of $5.7{\pm}2.94{\times}10^9$ induced cells were infused each time and patients were exposed to 6 infusions. Cellular immunity was improved in that cytotoxic $CD8^+CD28^+$ T lymphocytes were increased by 74% and suppressive $CD8^+CD28^-$ T lymphocytes were elevated by 16% (p<0.05). Continuous infusion of dendritic cells-cytokine induced killer cells was associated with improvement of both patient status and cellular immunity. A median of six infusions were capable of reducing risk of progression by 70% (95%CI 0.10-0.91). Every elevation of one ECOG score corresponded to a 3.90-fold higher progression risk (p<0.05) and 1% increase of $CD8^+CD28^-$ T cell proportion reflecting a 5% higher risk of progression (p<0.05). Conclusions: In advanced cancer patients, continuous dendritic cell-cytokine induced killer cell infusions are capable of recovering cellular immunity, improving patient status and quality of life in those who are unresponsive to conventional cancer treatment.

Time-varying H∞ Control for Discrete-time Switched Systems with Admissible Edge-dependent Average Dwell Time

Rui-Hua Wang,Bing-Xin Xue,Jing-Bo Zhao 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.8

The problem of H∞ control for discrete-time switched systems is investigated via admissible edgedependent average dwell time (AED-ADT) method in this paper. By virtue of a convex combination of positive definite matrices, a novel multiple piecewise convex Lyapunov function (MPCLF) is designed, which can relax the restricted conditions of Lyapunov functions at switching points and interval interior points. Based on the MPCLF approach, the time-varying H∞ state feedback controllers, guaranteeing that the corresponding closed-loop system is globally uniformly exponentially stable (GUES) with a prescribed H∞ performance, are established for the considered switched system. Finally, three numerical examples are provided to illustrate the effectiveness of the proposed approaches.

Microstructure and viscoelastic behavior of waterborne polyurethane/cellulose nanofiber nanocomposite

Hui Zhao,Kui-Can Li,Wei Wu,Qing Li,Yan Jiang,Bing-Xu Cheng,Chong-Xing Huang,Hua-Nan Li 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.110 No.-

Cellulose nanofiber (CNF) has been widely used to reinforce the mechanical properties of waterbornepolyurethane (WPU). There are, however, few works that focus on structure, rheological behavior, andcreep resistance of WPU/CNF composites. To fill this research gap, in this work, the m-CNF was obtainedby c-aminopropyltriethoxysilane modification to improve the interfacial strength of CNF and WPU, andthen it was introduced into the polyurethane matrix. Structure characterization of WPU/m-CNFnanocomposites is performed using Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction(XRD), Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The obtainedresults show that with the increase of m-CNF, the hydrogen bonding index (HBI) increased, which meanta significant improvement in the mechanical properties. The tensile strength improved by 480%. Moreover, with the increase of m-CNF content, the viscosity, storage modulus, and loss modulus of thedispersions increased and showed more obvious shear-thinning behavior. In addition, m-CNF improvedthe thermal stability and creep resistance of WPU. The creep strain of WPU decreased from 3% to 0.2%. This work offers a simply feasible way to prepare environmental friendly green nanocomposites.

The production technology and properties of an aluminum alloy processed by equal channel angular pressing

Jun Zhao,Chang-Hua Zhang,Chen-Bing Xu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.2

Distribution of equivalent stress and equivalent strain was analyzed in the ECAP process based on material flow laws. Simulation results showed that severe plastic deformation occurred at the corner of the cavity, indicating a stress concentration at the equal channel angle. Distribution of stress and strain at the same section was not uniform. Equivalent stresses on the surface at the inside corner of the part were larger. Experimental results showed that forming speed and lubrication conditions had a great influence on quality of parts. The parts were in good condition with no wrinkle and rupture after ten ECAP passes. EBSD analyses showed that the original coarse grains were refined and uniformly distributed, and the average grain size of the cross section was about 620 nm after ten ECAP passes. With increasing the number of ECAP passes, the proportion of small angle grain boundaries decreased gradually and the ratio of large angle grain boundaries increased. Tensile strength and hardness increased sharply, while the elongation decreased sharply after the first ECAP pass. With succeeding the ECAP passes, the tensile strength, hardness and the elongation all increased slowly.

Clinical Application of Endoscopic Inguinal Lymph Node Resection after Lipolysis and Liposuction for Vulvar Cancer

Wu, Qiang,Zhao, Yi-Bing,Sun, Zhi-Hua,Ni, Jing,Wu, Yu-Zhong,Shao, Heng-Hua,Qu, Jun-Wei,Huang, Xin-En Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Aim: To examine lymph nodes obtained after lipolysis and liposuction of subcutaneous fat of the inguinal region of female vulvar cancer patients to explore the feasibility of clinical application. Methods: The field of operation was on the basis of the range of the conventional resection of inguinal lymph nodes. We injected lipolysis liquid fanwise, started liposuction after 15-20 minutes; then the subcutaneous fatty tissue was sucked out clearly by suction tube. We selected the first puncture holes located on 2-3 cm part below anterior superior spine, the others respectively being located 3cm and 6cm below the first for puncturing into the skin, imbedding a trocar to intorduce $CO_2$ gas and the specular body, and excise the lymph nodes by ultrasonic scalpel. The surgical field chamber was set with negative pressure drainage and was pressured with a soft saline bag after surgery. Results: A lacuna emerged from subcutaneous of the inguinal region after lipolysis and liposuction, with a wide fascia easily exposed at the bottom where lymph nodes could be readily excised. The number of lymph nodes of ten patients excised within the inguinal region on each side was 4-18. The excised average number of lymph nodes was 11 when we had mature technology. Conclusion: Most of adipose tissue was removed after lipolysis and liposuction of subcutaneous tissue of inguinal region, so that the included lymph nodes were exposed and easy to excise by endoscope. This surgery avoided the large incision of regular surgery of inguinal region, the results indicating that this approach is feasible and safe for used as an alternative technology.

Mechanistic Analysis of Taxol-induced Multidrug Resistance in an Ovarian Cancer Cell Line

Wang, Ning-Ning,Zhao, Li-Jun,Wu, Li-Nan,He, Ming-Feng,Qu, Jun-Wei,Zhao, Yi-Bing,Zhao, Wan-Zhou,Li, Jie-Shou,Wang, Jin-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.9

Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.

Dynamic and Damage Characteristics of Mortar Composite under Impact Load

Qing Li,Tong-de Zhao,Chen Huang,Bing-bing Yu,Zheng-Hua Gao,Kai Wang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.3

In the process of underground construction, it is common to spray concrete on the working surface, which will form a concrete-rock composite structure, to achieve the expected reinforcement effect. Compared with pure concrete or rock structures, composite structures have different mechanical properties, energy evolution and damage characteristics. Understanding the dynamic mechanics and damage characteristics of composite structures under impact loads is important to the safety of underground engineering construction. First, dynamic compression tests on different grades of mortar-sandstone composite specimens were carried out by using a Hopkinson pressure bar system to discuss the effect of impact velocities on the mechanical properties and failure modes of composite specimens. The results show that the dynamic peak stress, strain energy density and fragmentation block of the mortar-sandstone composite have an obvious strain rate effect. With an increase in impact velocity, the internal cracks of the sample do not have sufficient time to expand, and the energy absorbed by the sample leads to the continuous initiation of new cracks in the sample, resulting in an increasing damage degree of composite specimens. The increase in mortar strength can significantly increase the peak stress, improve the load-bearing capacity of the sample, and reduce the degree of sample damage. At the same impact velocity, the fragmentation degree of the mortar sample is more severe than that of sandstone, and the mortar sample is broken into powder debris, while the sandstone is broken into fragments. In addition, according to the failure properties of the composite sample, the mortar and sandstone samples are described by different damage models, and the dynamic damage constitutive model of the mortar-sandstone composite is established based on the overlay principle. The dynamic test results were fitted. The research shows that the fitting curves of the model are well fitted with the test curves and that the model accurately reflects the changes in the mechanical parameters of the composite specimens.