Experimental Studies on Progressive Collapse Behavior of RC Frame Structures: Advances and Future Needs

Wei?Jian Yi,Fan Yi,Yun Zhou 한국콘크리트학회 2021 International Journal of Concrete Structures and M Vol.15 No.4

In the recent two decades, the progressive collapse of reinforced concrete (RC) frame structures attracted unprecedented research interests in the structural engineering community. Experiments are regarded as an essential method in this field since actual cases can barely provide sufficient and effective data to support rigorous research. In this paper, prevailing experimental assumptions and configurations among over 100 series of experiments are quantitatively revealed by a bibliometric collection based on systematic search in an academic database. Since numerous experiments have been reported on the progressive collapse of RC frame structures, this paper subsequently presents a state-of-the-art review summarizing both experimental consensuses and controversies constituted by three main aspects: (a) static mechanisms, (b) dynamic behavior, and (c) threat-dependent research. The significance of secondary mechanisms, existing problems of dynamic effects, and potential flaws of the threat-independent assumption are discussed in detail with experimental findings. Future needs are emphasized on research targets, correlations between experiments and design, dynamic effects, threat-dependent issues, and retrofitting. These recommendations might help researchers or designers realize a more reliable and realistic progressive collapse design of RC frame structures in the future.

DNA methylation and mRNA expression of COL6A3 in antler mesenchyme of female and male reindeer

Jian‑Cheng Zhai,Ruo‑Bing Han,Sheng‑Nan Wang,Qiang‑Hui Wang,Yan‑Ling Xia,Wei‑Shi Liu,Ya‑Jie Yin,He‑Ping Li 한국유전학회 2019 Genes & Genomics Vol.41 No.9

Backgroud Reindeer is the only deer species that both male and female produce antlers, which provides a particularly interesting case in studying the differences between antlers of the two sexes. Alpha 3(VI) Collagen Gene (COL6A3), forms a microfibrillar network associated with the structural integrity and biomechanical properties, has been found to be one of the differentially expressed genes in antler mesenchyme of female and male reindeer. Objective and Methods The promoter sequence of reindeer COL6A3 gene was obtained using the cloning technology and analyzed by the bioinformatics methods. Bisulfite sequencing PCR (BSP) was used to detect the methylation status of the COL6A3 promoter in reindeer antler mesenchyme. Real-time quantitative PCR was used to detect COL6A3 expression in the antler mesenchyme of female and male reindeer. Results Sequence analysis revealed that the reindeer COL6A3 partial promoter sequence was 983 bp including the possible promoter region at + 105 bp to + 155 bp. Homology and phylogenetic analysis indicated that the COL6A3 promoter of reindeer had the closest genetic distance with Bos taurus, Capra hircus and Ovis aries. BSP results indicated that the methylation level of COL6A3 promoter in the female reindeer antler mesenchyme was significantly higher than in the male. Correlating with increased methylation status, we also found that COL6A3 mRNA expression in female reindeer antler mesenchyme was significantly lower than in the male. Conclusion The higher methylation level of the COL6A3 gene in female reindeer antler mesenchyme coincides with decreased COL6A3 mRNA expression, thereby affecting the transposon silencing mechanism and possibly contributing to apparent differences of antlers in female and male reindeer.

Inhibition of microRNA-214 promotes epithelial mesenchymal transition process and induces interstitial cystitis in postmenopausal women by upregulating Mfn2

Jian-Wei Lv,Wei Wen,Chen Jiang,Qi-Bo Fu,Yin-Jun Gu,Ting-Ting Lv,Zhen-Dong Li,Wei Xue 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Our study aims to investigate the roles that microRNA-214 (miR-214) plays in the epithelial mesenchymal transition (EMT) process and the development of interstitial cystitis (IC) in postmenopausal women by targeting Mitofusin 2 (Mfn2). IC bladder tissues and adjacent normal bladder tissues were collected from postmenopausal women. Immunohistochemistry (IHC) staining was conducted. The target relationship between miR-214 and Mfn2 was determined by a dual luciferase reporter gene assay. Adipose-derived mesenchymal stem cells (ADMSCs) were extracted from postmenopausal rats and assigned to the blank, mimics, miR-214 inhibitors, mimics negative control (NC), inhibitors NC, Mfn2 siRNA, miR-214 inhibitors and Mfn2 siRNA groups. Exosomes secreted by transfected ADMSCs were instilled into the bladders of postmenopausal rats. The expression of miR-214 and Mfn2 mRNA and EMT markers was assessed by qRT-PCR and western blotting. It was confirmed that Mfn2 was the target gene of miR-214 in IC. Compared with the normal bladder tissues, miR-214 decreased, but Mfn2 increased in IC bladder tissues. Compared with the blank group, the expression of miR-214 and the expression levels of N-cadherin, Fibronectin, Twist1, Snail and Vimentin mRNA and protein increased, whereas the expression levels of Mfn2, E-cadherin and ZO-1 mRNA and protein decreased in the miR-214 mimics and Mfn2 groups. The expression of MiR-214 and the expression levels of N-cadherin, Fibronectin, Twist1, Snail and Vimentin mRNA and protein decreased, whereas the expression levels of Mfn2, E-cadherin and ZO-1 mRNA and protein increased in the miR-214 inhibitors group. Our findings indicate that the inhibition of miR-214 promotes the EMT process and contributes to bladder wall fibrosis by up-regulating Mfn2, thus leading to the occurrence of IC in postmenopausal women.

Review of the Macrophya regia group (Hymenoptera: Tenthredinidae) from China with the descriptions of two new species

Ze‐Jian Li,Meng-Meng LIU,Meicai Wei,Chao-dong Zhu 한국곤충학회 2018 Entomological Research Vol.48 No.5

The Macrophya regia group is reviewed and five species are recognized from China, among them two new species, M. acutiserrula Li, Liu & Wei sp. nov. and M. frontalis Li, Liu & Zhu sp. nov., and three known species, M. regia Forsius 1930, M. maculoclypeatina Wei et al. 2003, and M. xiaoi Wei et al. 2003. A key to the Chinese species of the Macrophya regia group are provided.

Silencing of Lysyl Oxidase Gene Expression by RNA Interference Suppresses Metastasis of Breast Cancer

Liu, Jian-Lun,Wei, Wei,Tang, Wei,Jiang, Yi,Yang, Hua-Wei,Li, Jing-Tao,Zhou, Xiao Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Objective: The aim of this study was to investigate possible mechanisms of LOX gene effects on invasion and metastasis of breast cancer cells by RNA interference. Methods: LOX-RNAi-LV was designed, synthesized, and then transfected into a breast cancer cell line (MDA-MB-231). Expression of LOX, MMP-2 and MMP-9 was determined by real-time PCR, and protein expression of LOX by Western blotting. Cell migration and invasiveness were assessed with Transwell chambers. A total of 111 cases of breast cancer tissues, cancer-adjacent normal breast tissues, and 20 cases of benign lesion tissues were assessed by immunohistochemistry. Results: Expression of LOX mRNA and protein was suppressed, and the expression of MMP-2 and MMP-9 was significantly lower in the RNAi group than the control group (P<0.05), after LOX-RNAi-LV was transfection into MDA-MB-231 cells. Migration and invasion abilities were obviously inhibited. The expression of LOX protein in breast cancer, cancer-adjacent normal breast tissues and benign breast tumor were 48.6% (54/111), 26.1% (29/111), 20.0% (4/20), respectively, associations being noted with clinical stage, lymph node metastasis, tumor size and ER, PR, HER2, but not age. LOX protein was positively correlated with MMP-2 and MMP-9. Conclusion: LOX displayed an important role in invasion and metastasis of breast cancer by regulating MMP-2 and MMP-9 expression which probably exerted synergistic effects on the extracellular matrix (ECM).

Inhibition of cancer cell growth and migration by dihydroxynaphthyl aryl ketones

Wei Xiong,Yun-Feng Li,Shan Liu,Ting Chen,Hong-Tao Zhang,Zhi-Bin Yang,Ying-Ying Ding,De-Pei Gao,Guan-Shun Wang,Jian Dong,Jian Dong 대한독성 유전단백체 학회 2016 Molecular & cellular toxicology Vol.12 No.4

Dihydroxynaphthyl aryl ketones 1-5 exhibit activity as tubulin polymerization inhibitors by targeting the colchicine binding site of microtubules making them potential anticancer drugs. Therefore, analogues 1-5 have been evaluated for their cytotoxic activity against the cancer cell lines DU-145 (prostate), T24 (bladder) and MCF-7 (breast). notable differences in biological activity were observed for compounds 1-5, most likely related to the nature of the aryl substituent bonded to the carbonyl group. among the tested compounds, only compound 5 showed selectivity for cancer cells over healthy, non-transformed cells. T24 cancer cells treated with compound 5 presented a concentration-dependent decrease in cell proliferation and a loss of migration ability. The cytotoxicity of compounds 1-5 on the selected cell-based assays is discussed in terms of it lipophilicity and polarizability parameters.

Experimental Study on Sustained-release 5-Fluorouracil Implantation in Canine Peritoneum and Para-aortic Abdominalis

Wei, Guo,Nie, Ming-Ming,Shen, Xiao-Jun,Xue, Xu-Chao,Ma, Li-Ye,Du, Cheng-Hui,Wang, Shi-Liang,Bi, Jian-Wei Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Objective: To observe local and systemic toxicity after sustained-release 5-fluorouracil (5-Fu) implantation in canine peritoneum and para-aortic abdominalis and the changes of drug concentration in the local implanted tissue with time. Methods: 300 mg sustained-release 5-Fu was implanted into canine peritoneum and para-aorta abdominalis. Samples were taken 3, 5, 7 and 10 days after implantation for assessment of changes and systemic reactions. High performance liquid chromatography was applied to detect the drug concentrations of peritoneal tissue at different distances from the implanted site, lymphatic tissue of para-aortic abdominalis, peripheral blood and portal venous blood. Results: 10 days after implantation, the drug concentrations in the peritoneum, lymphatic tissue and portal vein remained relatively high within 5 cm of the implanted site. There appeared inflammatory reaction in the local implanted tissue, but no visible pathological changes such as cell degeneration and necrosis, and systemic reaction like anorexia, nausea, vomiting and fever. Conclusions: Sustained-release 5-Fu implantation in canine peritoneum and para-aortic abdominalis can maintain a relatively high tumour-inhibiting concentration for a longer time in the local implanted area and portal vein, and has mild local and systemic reactions. Besides, it is safe and effective to prevent or treat recurrence of gastrointestinal tumours and liver metastasis.

CircularRNA_104670 plays a critical role in intervertebral disc degeneration by functioning as a ceRNA

Jian Son,Hong-Li Wang,Ke-Han Song,Zhi-Wen Ding,Hai-Lian Wang,Xiao-Sheng Ma,Fei-Zhou Lu,Xin-Lei Xia,Ying-Wei Wang,Fei-Zou,Jian-Yuan Jiang 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

This study was carried out to explore the roles of circular RNAs (circRNAs) in nucleus pulposus (NP) tissues in intervertebral disc degeneration (IDD). Differentially expressed circRNAs in IDD and normal NP tissues were identified based on the results of microarray analysis. Bioinformatics techniques were employed to predict the direct interactions of selected circRNAs, microRNAs (miR), and mRNAs. CircRNA_104670 was selected as the target circRNA due to its large multiplier expression in IDD tissues. After luciferase reporter and EGFP/RFP reporter assays, we confirmed that circRNA_104670 directly bound to miR-17-3p, while MMP-2 was the direct target of miR-17-3p. The receiver-operating characteristic (ROC) curve showed that circRNA_104670 and miR-17-3p had good diagnostic significance for IDD (AUC circRNA_104670 = 0.96; AUC miRNA-17-3p = 0.91). A significant correlation was detected between the Pfirrmann grade and expression of circRNA_104670 (r = 0.63; p = 0.00) and miR-17-3p (r = −0.62; p = 0.00). Flow-cytometric analysis and the MTT assay showed that interfering with circRNA_104670 using small interfering RNA (siRNA) inhibited NP cell apoptosis (p < 0.01), and this inhibition was reduced by interfering with miR-17-3p. Interfering with circRNA_104670 suppressed MMP-2 expression and increased extracellular matrix (ECM) formation, which were also reduced by interfering with miR-17-3p. Finally, an MRI evaluation showed that circRNA_104670 inhibition mice had a lower IDD grade compared with control mice (p < 0.01), whereas circRNA_104670 and miRNA-17-3p inhibition mice had a higher IDD grade compared with circRNA_104670 inhibition mice (p < 0.05). CircRNA_104670 is highly expressed in the NP tissues of IDD and acts as a ceRNA during NP degradation.

Investigation of surface-piercing fixed structures with different shapes for Bragg reflection of water waves

Wei-Wei Ding,Zao-jian Zou,Jing-Ping Wu,Bai-Gang Huang 대한조선학회 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

Bragg reflection of water waves by three kinds of surface-piercing fixed structures with rectangular, cosinoidal and triangular shapes is studied. Boundary element method is used to analyze the wave scattering by these structures based on the linear wave theory. Results of reflection and transmission coefficients are validated by comparing with those available in literature. These structures with proper configurations are proved to be effective in attenuating waves by using Bragg reflection, and the triangular structures are found to be the best choices among the structures with same width and same area. Systematic calculations are then carried out for the triangular structures by varying the number, the draft, the width, the gap and the combination of width and gap of the structures to analyze their influences on the characteristics of Bragg reflection. The results are of reference values for design of the structures to attenuate waves based on the Bragg reflection.

Parameter Analysis of Progressive Collapse Simulation of Long-Span Spatial Grid Structures

Jian-peng Wei,Li-Min Tian,Ji-Ping Hao 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.6

To accurately simulate the collapse process of long-span spatial grid structures, certain key parameters should be treated carefully. In the present study, the eff ects of the strain rate and the damage and fracture parameters were analyzed. A numerical simulation shows the following information: (1) First, the Cowper-Symonds model is utilized to simulate the rate-dependent material properties, illustrating that the strain rate eff ect can be overlooked for a progressive collapse simulation. (2) Then, the constant failure strain method is used for a damage and fracture simulation. The fi rst fracture of the members is postponed, and the fi nal failure patterns are therefore quite diff erent with an increase in the initial damage-equivalent plastic strain. (3) And, the progressive collapse pattern is unaff ected while the fracture is delayed or prevented with a greater equivalent plastic strain of the fi nal failure. These results can provide a reference for determining the damage and fracture parameters. (4) Finally, the equivalent plastic strain of the initial damage is relevant to the stress triaxiality. After considering the stress triaxiality, there is a signifi cant diff erence compared with the constant failure strain model. The stress triaxiality must therefore be considered.