Excitation frequency, fastener stiffness and damping, and speed of the moving harmonic load on the dynamic response of the track structure

Liu Yan-qi,Zhang Yan,Song Chun-fang,Huangsen Gu,Longlong Xu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.1

The dynamic response of a track structure under a uniform-speed moving harmonic load is researched according to dynamic response characteristics of a periodic structure under moving harmonic load in the frequency domain. The track was assumed as a simple Euler beam model periodically supported by continuous discrete point, and mathematical model of the dynamic differential equation of vertical vibration for the track structure is built. Then, the analytical equation for the dynamic response of any point on the track structure is concluded in the frequency domain for the following research. The dynamic responses of the track structure under the uniform-speed moving harmonic load are investigated using the theory of infinite periodic structure. Finally, the effects of excitation frequency, fastener stiffness, fastener damping, and speed of the moving harmonic load on the dynamic response of the track structure are studied. Results indicate that the response peaks of the rail under moving harmonic load occur near the excitation frequency, and the dynamic response decreases rapidly in the area far from the excitation frequency. The response peaks of the rail will move slightly toward a high frequency with the increase in the excitation frequency. The increase in the fastener stiffness will lead to improvement of the dynamic response of the rail in the nonresonant region at a high frequency, equivalent to the high rigidity of the rail fastener and intense vibration of the rail. The changes in fastener damping exert no significant effect on the resonant peak and peak bandwidth of the system. The fastener damping plays a significant role in restraining the vibration at a high frequency. The strong vibration of the track structure can be effectively controlled by an increase in the damping.

Association of Single Nucleotide Polymorphisms in the Prostaglandin-endoperoxide Synthase 2 (PTGS2) and Phospholipase A₂ Group IIA (PLA2G2A) Genes with Susceptibility to Esophageal Squamous Cell Carcinoma

Liu, Fen,Wei, Wen-Qiang,Cormier, Robert T.,Zhang, Shu-Tian,Qiao, You-Lin,Li, Xin-Qing,Zhu, Sheng-Tao,Zhai, Yan-Chun,Peng, Xiao-Xia,Yan, Yu-Xiang,Wu, Li-Juan,He, Dian,He, Yan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.4

Background: The prostaglandin-endoperoxide synthase 2 (PTGS2) and phospholipase A2 group IIA (PLA2G2A) genes encode enzymes that are involved in arachidonic acid and prostaglandin biosynthesis. Dysregulation of both genes is associated with inflammation and carcinogenesis, including esophageal squamous cell carcinoma (ESCC). We therefore hypothesized that there is an association between single nucleotide polymorphisms (SNPs) in these genes and susceptibility to ESCC. Methods: We performed a gene-wide tag SNP-based association study to examine the association of SNPs in PTGS2 and PLA2G2A with ESCC in 269 patients and 269 healthy controls from Taihangshan Mountain, Henan and Hebei Provinces, the rural area of China which has the highest incidence of esophageal cancer in the world. Thirteen tag SNPs in PLA2G2A and 4 functional SNPs in PTGS2 were selected and genotyped using a high-throughput Mass Array genotyping platform. Results: We found a modest increased risk of ESCC in subjects with the PTGS2 rs12042763 AA genotype (OR=1.23; 95% CI, 1.00-3.04) compared with genotype GG. For PLA2G2A, a decreased risk of ESCC was observed in subjects with the rs11677 CT (OR=0.51, 95%CI, 0.29-0.85) or TT genotype (OR=0.51, 95%CI, 0.17-0.96) or the T carriers (CT+TT) (OR=0.52, 95%CI, 0.31-0.85) when compared with the CC genotype. Also for PLA2G2A, rs2236771 C allele carriers were more frequent in the control group (P=0.02). Subjects with the GC (OR=0.55, 95%CI, 0.33-0.93) or CC genotype (OR=0.38, 95% CI, 0.16-0.94) or the C carriers (GC+CC) (OR=0.52, 95%CI, 0.32-0.85) showed a negative association with ESCC susceptibility. Conclusions: Our results suggest that PTGS2 and PLA2G2A gene polymorphisms may modify the risk of ESCC development.

Fertility-Preserving Treatments in Patients with Gynecological Cancers: Chinese Experience and Literature Review

Liu, Chun-Yan,Li, Hua-Jun,Lin, Hua,Ling, Bin Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.12

We conducted a retrospectively reviewed of the literature published of patients underwent fertility-preserving treatments for cervical, endometrial and ovarian cancers using the WANFANG database in Chinese. A majority were retrospective studies and case reports. With cervical cancer, radical trachelectomy(RT) in combination with pelvic lymphadenectomy could preserve the fertility of patients with early stage IA1-IB1 cancers, Tumor size ${\leq}2cm$ should be emphasized as the indication of RT in considering of the higher recurrent rate in patients with tumor size >2cm. For endometrial cancers, there is much experience on it. Given accurate pretreatment assessment, hormonal therapy is feasible management option to preserve fertility in young patients with early stage lesions that limited to the endometrium and well differentiated. High dose progestin have been applied, oral medroxyprogesterone acetate (MPA), 250-500mg/day, megestrol acetate 160-480mg/day. Other therapies that have been used in a limited number of cases include GnRH analog, intrauterine devices (IUDS) containing progestogen, usually combination of these therapies. All patients should be followed up by ultrasound and/or MRI evaluation, and endometrial curettage at intervals of 3 months. With ovarian cancer, in China, fertilitypreserving surgery in patients with stage IA (grade G1) of epithelial ovarian tumor and patients with germ cell tumor and borderline ovarian tumor have been successfully performed.

Cadmium induces apoptosis in primary rat osteoblasts through caspase and mitogen-activated protein kinase pathways

Hong-Yan Zhao,Wei Liu,Yi Wang,Nannan Dai,Jian-Hong Gu,Yan Yuan,Xue-Zhong Liu,Jian-Chun Bian,Zong-Ping Liu 대한수의학회 2015 Journal of Veterinary Science Vol.16 No.3

Exposure to cadmium (Cd) induces apoptosis in osteoblasts (OBs); however, little information is available regarding the specific mechanismsof Cd-induced primary rat OB apoptosis. In this study, Cd reduced cell viability, damaged cell membranes and induced apoptosis in OBs. We observed decreased mitochondrial transmembrane potentials, ultrastructure collapse, enhanced caspase-3 activity, and increasedconcentrations of cleaved PARP, cleaved caspase-9 and cleaved caspase-3 following Cd treatment. Cd also increased the phosphorylationof p38-mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases (ERK)1/2 and c-jun N-terminal kinase (JNK) in OBs. Pretreatment with the caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, ERK1/2 inhibitor (U0126), p38 inhibitor(SB203580) and JNK inhibitor (SP600125) abrogated Cd-induced cell apoptosis. Furthermore, Cd-treated OBs exhibited signs of oxidativestress protection, including increased antioxidant enzymes superoxide dismutase and glutathione reductase levels and decreased formationof reactive oxygen species. Taken together, the results of our study clarified that Cd has direct cytotoxic effects on OBs, which are mediatedby caspase- and MAPK pathways in Cd-induced apoptosis of OBs.

Overexpression of Phospholipase A₂ Group IIA in Esophageal Squamous Cell Carcinoma and Association with Cyclooxygenase-2 Expression

Zhai, Yan-Chun,Dong, Bin,Wei, Wen-Qiang,He, Yan,Li, Xin-Qing,Cormier, Robert T.,Wang, Wei,Liu, Fen Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

Background: Esophageal cancer is one of the most frequently occurring malignancies and the seventh leading cause of cancer-related deaths in the world. The esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer worldwide. Materials and Methods: Our goal in this study was to detect phospholipase A2 Group IIA (PLA2G2A) and cyclooxygenase-2 (COX-2) immuno-expression in ESCC in a high-risk population in China. Results: Positive expression of PLA2G2A protein was observed in 57.2% (166/290) of the cases, while COX-2 was found in 257 of 290 samples (88.6%), both PLA2G2A and COX-2 being expressed in 153 cases (52.8%), with a significant agreement (Kappa=0.091, p=0.031).Overexpression of PLA2G2A was significantly correlated with the depth of invasion (p=0.001). Co-expression of PLA2G2A and COX-2 not only significantly correlated with the depth of invasion (p=0.004) but also with TNM stage (p=0.04). Conclusions: Our results showed that in patients with ESCC, PLA2G2A overexpression and PLA2G2A co-expression with COX-2 is significantly correlated with advanced stage. The biological role and pathophysiologic regulation of PLA2G2A and COX-2 overexpression in ESCC deserve further investigation.

Thalidomide Combined with Chemotherapy in Treating Patients with Advanced Colorectal Cancer

Huang, Xin-En,Yan, Xiao-Chun,Wang, Lin,Ji, Zhu-Qing,Li, Li,Liu, Meng-Yan,Qian, Ting,Shen, Hui-Ling,Gu, Han-Gang,Liu, Yong,Gu, Ming,Deng, Li-Chun Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Objective: To assess the safety and effectiveness of thalidomide (produced by CHANGZHOU PHARMACEUTICAL FACTORY CO.LTD) combined with chemotherapy in treating patients with advanced colorectal cancer. Method: A consecutive cohort of pretreated patients with advanced colorectal cancer were treated with thalidomide combined with chemotherapy. And chemotherapy for patients with advanced colorectal cancer were administered according to the condition of patients. Thalidomide was orally administered at a dosage of 50mg/day to 150mg/day before sleeping for at least 14 days. After at least 14 days of treatment, safety and side effects were evaluated. Results: There were 12 female and 3 male patients with advanced cancer recruited into this study, including 9 patients with colon, 6 patients with rectal cancer. The median age of patients was 57(41-82) years. Partial response was observed in 2 patients (2/15), and stable disease in 3 patients(3/15). Incidences of Grade 1 to 2 myelosuppression was observed in 1/15 patients, and Grade 1 to 2 elevation of hepatic enzyme was recorded in 1/15 patients. Adverse effects on the gastrointestinal tract were documented in 1/15 patients, and were Grade 1. No Grade 3-4 toxicities were diagnosed. No treatment related death was found. Conclusions: Thalidomide combined with chemotherapy was safe and mildly effective in treating patients with advanced colorectal cancer. However, further study should be conducted to clarify the effectiveness of this combination.

Comparison of Serum Tumor Associated Material (TAM) with Conventional Biomarkers in Cancer Patients

Shu, Jian,Li, Cheng-Guang,Liu, Yang-Chen,Yan, Xiao-Chun,Xu, Xu,Huang, Xin-En,Cao, Jie,Li, Ying,Lu, Yan-Yan,Wu, Xue-Yan,Liu, Jin,Xiang, Jin Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objective: To compare expression level of serum tumor associated materials (TAM) with several conventional serum tumor biomarkers, eg., carcinoembryonic antigen (CEA), carbohydrate antigen19-9 (CA19-9), carbohydrate antigen 15-3 (CA15-3), alpha-fetoprotein(AFP), in selected solid tumors. Methods: Patients diagnosed histologically or cytologically with liver, breast, esophageal, gastric, colorectal or pancreatic cancers were enrolled into this study. After diagnosis, the level of TAM was determined by chemical colorimetry, and levels of conventional tumor markers was measured by chemiluminescence methods. Results: A total of 560 patients were enrolled into this study. No statistically significant difference was detected in TAM and the above mentioned tumor biomarkers in terms of their positivity and negativity ( P>0. 05). Conclusions: Detection of TAM in liver, breast, esophageal, gastric, colorectal, and pancreatic cancer patients demonstrates a good accordance with CEA, CA199, CA153, and AFP, thus suggesting that further study is warranted to verify whether TAM could be a surrogate for these conventional biomarkers.

Senescence Effects of Angelica sinensis Polysaccharides on Human Acute Myelogenous Leukemia Stem and Progenitor Cells

Liu, Jun,Xu, Chun-Yan,Cai, Shi-Zhong,Zhou, Yue,Li, Jing,Jiang, Rong,Wang, Ya-Ping Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Leukemia stem cells (LSCs) play important roles in leukemia initiation, progression and relapse, and thus represent a critical target for therapeutic intervention. Hence, it is extremely urgent to explore new therapeutic strategies directly targeting LSCs for acute myelogenous leukemia (AML) therapy. We show here that Angelica sinensis polysaccharide (ASP), a major active component in Dong quai (Chinese Angelica sinensis), effectively inhibited human AML $CD34^+CD38^-$ cell proliferation in vitro culture in a dose-dependent manner while sparing normal hematopoietic stem and progenitor cells at physiologically achievable concentrations. Furthermore, ASP exerted cytotoxic effects on AML K562 cells, especially LSC-enriched $CD34^+CD38^-$ cells. Colony formation assays further showed that ASP significantly suppressed the formation of colonies derived from AML $CD34^+CD38^-$ cells but not those from normal $CD34^+CD38^-$ cells. Examination of the underlying mechanisms revealed that ASP induced $CD34^+CD38^-$ cell senescence, which was strongly associated with a series of characteristic events, including up-regulation of p53, p16, p21, and Rb genes and changes of related cell cycle regulation proteins P16, P21, cyclin E and CDK4, telomere end attrition as well as repression of telomerase activity. On the basis of these findings, we propose that ASP represents a potentially important agent for leukemia stem cell-targeted therapy.

Correlation Study of Knowledge and Behavior Regarding Breast Care among Female Undergraduate Students in China

Liu, Meng-Xue,Li, Jian,Geng, Yun-Long,Wang, Yan-Chun,Li, Jie,Chen, Yu-Juan,Ali, Gholam,Tarver, Siobhan L.,Wen, Yu-Feng,Sun, Wen-Jie Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.24

Background: This study aimed to understand the relationship between knowledge level and behavior on breast care in Chinese students, so as to provide strategies for improving the health education of breast care and subsequently for aiding in breast cancer prevention. Materials and Methods: A self-designed questionnaire was used to evaluate breast care knowledge level and characterize related behavior. Correlation analysis was conducted for the knowledge level and behavior. The study was carried out using 597 female undergraduate students in medical and non-medical colleges in Wuhu, China. Results: The average score of breast care knowledge was $5.32{\pm}1.68$ ($5.62{\pm}1.68$ and $5.00{\pm}1.68$ for medical and non-medical students, respectively), with a greater score value for sophomores ($5.59{\pm}1.72$) than freshmen ($5.18{\pm}1.65$). The average score of breast care behavior was $2.21{\pm}1.13$, again with a greater value in sophomores ($2.37{\pm}1.15$) than freshmen ($2.21{\pm}1.13$). A significant positive correlation (r=0.231, p<0.01) between knowledge scores and behavior scores was observed. In addition, various factors, including paying attention to breast care information, receiving breast self-examination guidance, TV program and Internet, were found to influence breast care knowledge. Conclusions: In general, female undergraduate students lack of self-awareness of breast care with a low rate of breast self-examination. It is necessary to carry out health education to improve early detection of breast cancer.

Comparative Study of Contrast-Enhanced Ultrasound Qualitative and Quantitative Analysis for Identifying Benign and Malignant Breast Tumor Lumps

Liu, Jian,Gao, Yun-Hua,Li, Ding-Dong,Gao, Yan-Chun,Hou, Ling-Mi,Xie, Ting Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.19

Background: To compare the value of contrast-enhanced ultrasound (CEUS) qualitative and quantitative analysis in the identification of breast tumor lumps. Materials and Methods: Qualitative and quantitative indicators of CEUS for 73 cases of breast tumor lumps were retrospectively analyzed by univariate and multivariate approaches. Logistic regression was applied and ROC curves were drawn for evaluation and comparison. Results: The CEUS qualitative indicator-generated regression equation contained three indicators, namely enhanced homogeneity, diameter line expansion and peak intensity grading, which demonstrated prediction accuracy for benign and malignant breast tumor lumps of 91.8%; the quantitative indicator-generated regression equation only contained one indicator, namely the relative peak intensity, and its prediction accuracy was 61.5%. The corresponding areas under the ROC curve for qualitative and quantitative analyses were 91.3% and 75.7%, respectively, which exhibited a statistically significant difference by the Z test (P<0.05). Conclusions: The ability of CEUS qualitative analysis to identify breast tumor lumps is better than with quantitative analysis.