Output-only modal parameter identification of civil engineering structures

Wei-Xin Ren,Zhou-Hong Zong 국제구조공학회 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.17 No.3-4

The ambient vibration measurement is a kind of output data-only dynamic testing where the traffics and winds are used as agents responsible for natural or environmental excitation. Therefore an experimental modal analysis procedure for ambient vibration testing will need to base itself on output-only data. The modal analysis involving output-only measurements presents a challenge that requires the use of special modal identification technique, which can deal with very small magnitude of ambient vibration contaminated by noise. Two complementary modal analysis methods are implemented. They are rather simple peak picking (PP) method in frequency domain and more advanced stochastic subspace identification (SSI) method in time domain. This paper presents the application of ambient vibration testing and experimental modal analysis on large civil engineering structures. A 15 storey reinforced concrete shear core building and a concrete filled steel tubular arch bridge have been chosen as two case studies. The results have shown that both techniques can identify the frequencies effectively. The stochastic subspace identification technique can detect frequencies that may possibly be missed by the peak picking method and gives a more reasonable mode shapes in most cases.

Output-only modal parameter identification of civil engineering structures

Ren, Wei-Xin,Zong, Zhou-Hong Techno-Press 2004 Structural Engineering and Mechanics, An Int'l Jou Vol.17 No.3

The ambient vibration measurement is a kind of output data-only dynamic testing where the traffics and winds are used as agents responsible for natural or environmental excitation. Therefore an experimental modal analysis procedure for ambient vibration testing will need to base itself on output-only data. The modal analysis involving output-only measurements presents a challenge that requires the use of special modal identification technique, which can deal with very small magnitude of ambient vibration contaminated by noise. Two complementary modal analysis methods are implemented. They are rather simple peak picking (PP) method in frequency domain and more advanced stochastic subspace identification (SSI) method in time domain. This paper presents the application of ambient vibration testing and experimental modal analysis on large civil engineering structures. A 15 storey reinforced concrete shear core building and a concrete filled steel tubular arch bridge have been chosen as two case studies. The results have shown that both techniques can identify the frequencies effectively. The stochastic subspace identification technique can detect frequencies that may possibly be missed by the peak picking method and gives a more reasonable mode shapes in most cases.

IL-34 Aggravates Steroid-Induced Osteonecrosis of the Femoral Head via Promoting Osteoclast Differentiation

Wang Feng,Min Hong Sung,Shan Haojie,Yin Fuli,Jiang Chaolai,Zong Yang,Ma Xin,Lin Yiwei,Zhou Zubin,Yu Xiaowei 대한면역학회 2022 Immune Network Vol.22 No.3

IL-34 can promote osteoclast differentiation and activation, which may contribute to steroid-induced osteonecrosis of the femoral head (ONFH). Animal model was constructed in both BALB/c and IL-34 deficient mice to detect the relative expression of inflammation cytokines. Micro-CT was utilized to reveal the internal structure. In vitro differentiated osteoclast was induced by culturing bone marrow-derived macrophages with IL-34 conditioned medium or M-CSF. The relative expression of pro-inflammation cytokines, osteoclast marker genes, and relevant pathways molecules was detected with quantitative real-time RT-PCR, ELISA, and Western blot. Up-regulated IL-34 expression could be detected in the serum of ONFH patients and femoral heads of ONFH mice. IL-34 deficient mice showed the resistance to ONFH induction with the up-regulated trabecular number, trabecular thickness, bone value fraction, and down-regulated trabecular separation. On the other hand, inflammatory cytokines, such as TNF-α, IFN-γ, IL-6, IL-12, IL-2, and IL-17A, showed diminished expression in IL-34 deficient ONFH induced mice. IL-34 alone or works in coordination with M-CSF to promote osteoclastogenesis and activate ERK, STAT3, and non-canonical NF-κB pathways. These data demonstrate that IL-34 can promote the differentiation of osteoclast through ERK, STAT3, and non-canonical NF-κB pathways to aggravate steroid-induced ONFH, and IL-34 can be considered as a treatment target.

Analysis of the Relationship between MHC-DRB1 Gene Polymorphism and Hydatidosis in Kazakh Sheep

Li, Ren-Yan,Jia, Bin,Zhang, Wen-Ju,Zhao, Zong-Sheng,Shi, Guo-Qing,Shen, Hong,Peng, Qiang,Lv, Li-Min,Zhou, Qi-Wei,Du, Ying-Chun Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.9

The objective of this work was to analyze the relationship between ovine major histocompatibility complex (MHC) DRB1 gene polymorphism and genetic resistance to hydatidosis in Kazakh sheep. The Ovar (ovine MHC) class II DRB1 second exon was amplified by polymerase chain reaction (PCR) from DNA samples of 702 Kazakh sheep, including 302 sheep with hydatidosis and 400 health controls. PCR products were characterized by the restriction fragment length polymorphism (RFLP) technique using five restriction enzymes, i.e., MvaI, HaeIII, SacI, SacII and Hin1I, yielding 14 alleles and 28 genotypes. Comparing the frequency of genotypes in hydatidosis sheep with the control group, it was found that the genotype frequencies of MvaIbc, Hin1Iab, SacIIab, HaeIIIde, HaeIIIdf and HaeIIIdd in control sheep were significantly (p<0.01) higher than in hydatidosis sheep, indicating that a significant correlation existed between these genotypes and resistance to hydatidosis. Genotype frequencies of MvaIbb, SacIIaa, Hin1Ibb and HaeIIIef in sheep with hydatidosis were extremely significantly (p<0.01) higher than in the control group, and the genotype frequency of HaeIIIab was significantly higher (p<0.05), indicating that a marked correlation existed between these genotypes and susceptibility to hydatidosis. By way of analyzing haplotype with these resistant genotypes, the hydatidosis resistant haplotype MvaIbc-SacIIab-Hin1Iab of Kazakh sheep was screened out, and then verified through artificial hydatid infection in sheep. The results indicated that the infection rate of sheep with the resistant haplotype of hydatidosis was significantly lower (p<0.01) than without this resistant haplotype. It showed that the genic haplotype MvaIbc-SacIIab-Hin1Iab of Ovar-DRB1 exon 2 was the resistant haplotype of hydatidosis in Kazakh sheep.

Comparison of Prevention of NSAID-Induced Gastrointestinal Complications by Rebamipide and Misoprostol: A Randomized, Multicenter, Controlled Trial—STORM STUDY

Park, Soo-Heon,Cho, Chul-Soo,Lee, Oh-Young,Jun, Jae-Bum,Lin, San-Ren,Zhou, Li-Ya,Yuan, Yao-Zong,Li, Zhao-Shen,Hou, Xiao-Hua,Zhao, Hong-Chuan,Kachintorn, Udom,Kositchaiwat, Chomsri,Lertkupinit, Comson the Society for Free Radical Research Japan 2007 Journal of clinical biochemistry and nutrition Vol.40 No.2

<P>Nonsteroidal anti-inflammatory drugs (NSAIDs) have gastrointestinal side effects such as dyspepsia, peptic ulcer, hemorrhage, and perforation. Misoprostol and PPIs have been used to prevent NSAID-induced gastroduodenal injury. Rebamipide increases gastric mucus and stimulates the production of endogenous prostaglandins. The prophylactic effect of rebamipide on NSAID-induced gastrointestinal complications is unknown. The aim of this study was to compare NSAID-induced gastrointestinal complications in rebamipide- and misoprostol-treated groups. Patients were randomized to two groups and took a conventional NSAID plus rebamipide or misoprostol for 12 weeks. Gastric mucosal damage was evaluated by endoscopy at screening and the end of the study. The prevalences of active gastric ulcer were 7/176 (3.9%) in the rebamipide group and 3/156 (1.9%) in the misoprostol group. The prevalences of peptic ulcer were 8/176 (4.5%) in the rebamipide group and 7/156 (4.4%) in the misoprostol group. The cumulative incidences of peptic ulcer in the high-risk subgroup were 6/151 (4.0%) for rebamipide and 6/154 (3.9%) for misoprostol. In conclusion, rebamipide prevented NSAID-induced peptic ulcer as effectively as misoprostol in patients on long-term NSAID therapy. Rebamipide may be a useful therapeutic option for the prevention of NSAID-induced gastrointestinal ulcer because of its therapeutic effect and safety.</P>