1,002 research outputs found

    EXPERIMENTAL STUDY AND ANALYTICAL METHOD OF PARTIALLY CONCRETE-FILLED STEEL BRIDGE PIERS UNDER BI-DIRECTIONAL DYNAMIC LOADING

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    From past large earthquake, it has been recognized that the highway steel bridge piers in urban areas play a very important role in the social lifeline system. The seismic design specification of steel bridge piers introduced in the current Japan allows independent, longitudinal, and transverse forces. To date the seismic performance of steel bridge piers has been widely studied through static cyclic loading tests, pseudo-dynamic loading tests, and numerical analysis in a single lateral direction under constant axial force. However, the actual seismic waves consist of three-directional components and the seismic response of bridge piers is simultaneously affected by the two horizontal components. It is difficult to properly evaluate the seismic performance of bi-directional horizontal seismic motions through single-directional loading tests because of the complex behavior of local buckling and inelastic behavior caused in the component plates of the pier at the ultimate state. To clarify the seismic performance of partially concrete-filled steel bridge piers subjected to bi-directional seismic loading, the performance of partially concrete-filled steel bridge piers under actual earthquake conditions was investigated using 20 square section specimens through cyclic static loading tests and single-and bi-directional hybrid loading tests in this study. Three acceleration records of two horizontal NS and EW direction components in three different ground types, obtained during the 1995 Kobe Earthquake, were adopted during the dynamic tests. The experimental results clarified that the maximum displacement and residual displacement under actual earthquake conditions cannot be correctly estimated by conventional single-directional loading test results in medium and soft ground types, and the filled-in concrete can effectively improve the seismic resistance performance in sufficiently high concrete filled steel bridge piers. In this study, an analytical model consisting of a concentrated mass and a rigid bar with multiple springs located at the base was developed to simulate the hysteretic behavior of partially concrete-filled steel bridge piers subjected to single- or bi-directional ground motions. In order to describe the complicated nonlinear behavior of each spring element accurately, a series of approximate curves whose parameters were determined by results of single-directional static cyclic loading tests had been adopted. To examine the validity of the proposed model, the results due to the simulation were compared with those of static cyclic tests, single- and bi-directional hybrid tests. By comparison, it is demonstrated that the proposed multiple-spring model can predict well the hysteretic behavior of partially concrete-filled thin-walled steel bridge piers with square cross-section

    Investigation of Noncovalent Complexes Between β-Cyclodextrin and Polyamide Acids Containing N-Methylpyrrole and N-Methylimidazole by Electrospray Ionization Mass Spectrometry

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    Electrospray ionization (ESI) mass spectrometry was utilized to investigate noncovalent complexes between β-cyclodextrin (β-CD) and five novel polyamide acids containing N-methylpyrrole and N-methylimidazole. The 1:1 binding mode was specified by examining the binding stoichiometry from ESI mass spectra. It found that polyamide acids with β-CD have binding affinities in the order: ImImImβCOOH > ImPyImβCOOH > ImPyPyβCOOH > PyPyPyβCOOH > NO2PyPyPyβCOOH. The method gives, simultaneously, the binding constants between β-CD and polyamide acids based on a novel linear equation

    A Curve Approximated Hysteresis Model for Steel Bridge Columns

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    In this paper,a curve approximated hysteresis model for SDF analysis is proposed to predict the nonlinear response of bridges supported by steel columns with suitable scope of severe damaged deterioration domain. Instead of multiple straight lines,a series of curves are adopted to precisely describe complicated force-displacement hysteresis behavior of the column. The P-δ effect, hardeing effect in unloading-reloading hysteresis loops, deterioration of strength and stiffness are taken into account. Parameters of proposed hysteresis model for three types of steel pier specimens used in this study are calibrated by six static cyclic tests. To verify the accuracy of the proposed model, eleven pseudo-dynamic tests are conducted. By comparing the simulation and the test results,the differences between the predicted nonlinear seismic response using the proposed model and pseudo-dynamic tests are found to be, averagely, 5% in maximum response displacement,22% in residual displacement and 4% in the amount of energy dissipation

    Transcriptome analysis of epithelioma papulosum cyprini cells after SVCV infection

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    BACKGROUND: Spring viraemia of carp virus (SVCV) has been identified as the causative agent of spring viraemia of carp (SVC) and it has caused significant losses in the cultured common carp (Cyprinus carpio) industry. The molecular mechanisms that underlie the pathogenesis of the disease remain poorly understood. In this study, deep RNA sequencing was used to analyse the transcriptome and gene expression profile of EPC cells at progressive times after SVCV infection. This study addressed the complexity of virus–cell interactions and added knowledge that may help to understand SVCV. RESULTS: A total of 33,849,764 clean data from 36,000,000 sequence reads, with a mean read length 100 bp, were obtained. These raw data were assembled into 88,772 contigs. Of these contigs, 19,642 and 25,966 had significant hits to the NR and Uniprot databases where they matched 17,642 and 13,351 unique protein accessions, respectively. At 24 h post SVCV infection (1.0 MOI), a total of 623 genes were differentially expressed in EPC cells compared to non-infected cells, including 288 up-regulated genes and 335 down-regulated genes. These regulated genes were primarily involved in pathways of apoptosis, oxidative stress and the interferon system, all of which may be involved in viral pathogenesis. In addition, 8 differentially expressed genes (DEGs) were validated by quantitative PCR. CONCLUSIONS: Our findings demonstrate previously unrecognised changes in gene transcription that are associated with SVCV infection in vitro, and many potential cascades identified in the study clearly warrant further experimental investigation. Our data provide new clues to the mechanism of viral susceptibility in EPC cells. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2164-15-935) contains supplementary material, which is available to authorized users

    The rise of urbanism and exchange network: reconstruction of a 4000-year local history of Xinjiang, northwestern China

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    Urbanization is one of the milestones in the development of human society. Many regions in the southern parts of ‘the old world’ demonstrating an early emergence of agriculture also witnessed the flourishing of some of the earliest cities. Recent, yet still sparse, archaeological evidence appears to indicate a relatively later time for early urbanism in central Eurasia. However, given its vital geographic location and cultural nexus between East and West, more attention should be paid to the sedentary communities and their cities in oases amid the vast droughty desert, particularly in light of the rapidly increasing number of publications on early pastoralism and related communication routes along mountain chains and rivers. This study reveals the trajectory of urbanization and its role in the establishment of an exchange network in Xinjiang’s oasis region via reconstruction of the chronological sequence of the local societal history of the Baiyang River Basin along the southern piedmont of the Eastern Tianshan Mountains. A thorough archaeological investigation and refined radiocarbon dating programme was carried out and coupled with information from historical documentation within a Bayesian statistical framework. The results indicate three pulses of local urbanization during: the Early Iron Age, Tang–Yuan period, and Qing Dynasty, respectively. Combining this with evidence from other parts of Xinjiang, we re-evaluate the role of oasis urbanism in the promotion of trans-regional exchange

    Insulin Resistance and Oxidative Stress: In Relation to Cognitive Function and Psychopathology in Drug-Naive, First-Episode Drug-Free Schizophrenia

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    Objective: The present study aimed to examine whether insulin resistance and oxidative stress are associated with cognitive impairment in first-episode drug-free schizophrenia (SZ) patients. Methods: Ninety first-episode SZ patients and 70 healthy controls were enrolled. Fasting insulin (FINS) and markers of oxidative stress [oxidized glutathione (GSSG), superoxide dismutase (SOD), nitric oxide (NO) and uric acid (UA) levels] were measured in serum before pharmacological treatment was initiated. Psychiatric symptoms and cognitive function were assessed with the Positive and Negative Syndrome Scale (PANSS) and MATRICS Consensus Cognitive Battery (MCCB), respectively. In addition, the homeostatic model assessment of insulin resistance (HOMA-IR) was also studied. Results: HOMA-IR and serum levels of GSSG and NO were significantly higher in SZ patients than in healthy controls (P \u3c 0.001), while the serum levels of SOD were significantly lower than in healthy controls (P \u3c 0.001). HOMA-IR, GSSG and NO levels were significantly correlated to the total cognitive function scores of the patient group (r = -0.345,-0.369,-0.444, respectively, P \u3c 0.05). But these factors were not co-related to the cognitive functions in the healthy control group. And, levels of SOD, UA were not associated with the total cognitive function scores in both the patient and the healthy control groups. NO was positively correlated with general pathological and the total score in the PANSS, and was negatively correlated with six cognitive domains (r = -0.316 to -0.553, P \u3c 0.05). Conclusions: The levels of insulin resistance and oxidative stress are elevated, and correlated with the severity of cognitive impairment in drug-naive, first-episode SZ patients. Treatment approaches targeting on reducing insulin resistance and oxidative stress may improve cognitive function in SZ patients

    The influence of gold mining wastes on the migration-transformation behavior and health risks of arsenic in the surrounding soil of mined-area

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    Understanding the characteristic heavy metals and their migration-transformation behavior in mining areas is essential for the prevention and control of mining pollution. This study selected a gold mine in the Anqing-Guichi ore-cluster region in the Middle-Lower Yangtze metallogenic belt as the research area, the concentrations, and migration-transformation mechanisms of metalloid As and typical heavy metals (Cd, Zn, Pb, Cu, Cr, and Ni) in gold mining wastes (mine tailings and sewage sludge) and the surrounding soil (farmland soil and soil a mining area) were investigated. The results showed that the concentration of As was high in both mining wastes and soils, and the geo-accumulation index values of As in soils ranging from 1.44–6.70, indicated that As pollution was severe in the soil. Besides, a close correlation between the concentration of As and the content of iron was observed by XRF analysis, in conjunction with SEM observations, most As-bearing phases are embedded in Fe, O, and Si compounds. According to EDS and XPS results, the Fe-O-As particle was suggested to be Fe-(oxy)hydroxides with absorbed or co-precipitated As. Furthermore, the arsenic phase observed in the soils were consistent with the weathering oxidation products in the tailings, demonstrating that the mineral particles in the tailings could migrate into soils via atmospheric transport, rainwater leaching, surface runoff, etc., and consequently result in heavy metal accumulation. The sequential chemical extraction result showed that the residual state of As in the soil exceeded 60%, and As posed no risk to low risk according to the Risk assessment code result. However, due to the high concentration and high mobility of arsenic, its environmental impact cannot be ignored even if its bio-accessibility in mined area soil is low

    A Truncated IL‐17RC Peptide Ameliorates Synovitis and Bone Destruction of Arthritic Mice

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134880/1/adhm201600668_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134880/2/adhm201600668-sup-0001-S1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134880/3/adhm201600668.pd

    Profile and clinical implication of circular RNAs in human papillary thyroid carcinoma

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    Background Differently expressed circular RNAs (circRNAs) have been reported to play a considerable role in tumor behavior; however, the expression profile and biological function of circRNAs in papillary thyroid carcinoma (PTC) remains unknown. Thus, the study was aimed to characterize the circRNA expression profile to comprehensively understand the biological behavior of PTC. Methods We investigated the expression profile of circRNAs using circRNA microarray in three pairs of PTC and adjacent normal tissues. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) was used to validate eight candidate circRNAs in 40 paired PTC tumors and adjacent normal samples. Next, we employed a bioinformatics tool to identify putative miRNA and circRNA-associated downstream genes, followed by constructing a network map of circRNA-miRNA-mRNA interactions and exploring the potential role of the candidate circRNAs. Results In total, 206 up- and 177 downregulated circRNAs were identified in PTC tissues (fold change >1.5; P < 0.05). The expression levels of eight candidate circRNAs confirmed by qRT-PCR were significantly different between the PTC and normal samples. The downstream genes of candidate circRNAs participated in various biological processes and signaling pathways. The most up and downregulated circRNAs were hsa_circRNA_007148 and hsa_circRNA_047771. The lower expression level of hsa_circRNA_047771 was associated BRAFV600 mutation, lymph node metastasis (LNM), as well as with advanced TNM stage (all P < 0.05). The higher expression level of hsa_circRNA_007148 was significantly correlated with LNM (P < 0.05). The areas under receiver operating curve were 0.876 (95% CI [0.78–0.94]) for hsa_circRNA_047771 and 0.846 (95% CI [0.75–0.96]) for hsa_circRNA_007148. Discussion The study suggests that dysregulated circRNAs play a critical role in PTC pathogenesis. PTC-related hsa_circRNA_047771 and hsa_circRNA_007148 may serve as potential diagnostic biomarkers and prognostic predictors for PTC patients

    Transcriptomics yields valuable information regarding the response mechanisms of Chinese Min pigs infected with PEDV

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    Porcine epidemic diarrhea virus (PEDV) causes porcine epidemic diarrhea (PED), a highly infectious disease, which has resulted in huge economic losses for the pig industry. To date, the pathogenic and immune response mechanism was not particularly clear. The purpose of this study was to investigate the pathogenic and immune responses of pigs infected with PEDV.In this study, 12 Min pigs were randomly selected without taking colostrum. At 3 days old, eight piglets were infected with 1 mL of PEDV solution (10 TCID50/ml), and the remaining four piglets were handled by 1 mL of 0.9% normal saline. Within the age of 7 days old, four piglets died and were considered as the death group. Correspondingly, four alive individuals were classified into the resistance group. Tissues of the duodenum, jejunum, ileum, colon, cecum, and rectum of piglets in the three groups were collected to measure the PEDV content. Additionally, the jejunum was used for the measurements and analyses of Hematoxylin-eosinstaining (HE), immunohistochemical sections, and transcriptomics. The phenotypes of Min piglets infected with PEDV showed that the viral copy numbers and jejunal damage had significant differences between the death and resistance groups. We also observed the transcriptome of the jejunum, and the differentially expressed (DE) analysis observed 6,585 DE protein-coding genes (PCGs), 3,188 DE long non-coding RNAs (lncRNAs), and 350 DE microRNAs (miRNAs), which were mainly involved in immune response and metabolic pathways. Furthermore, the specific expressed molecules for each group were identified, and 97 PCGs,108 lncRNAs, and 51 miRNAs were included in the ceRNA-regulated networks. By weighted gene co-expression network analysis (WGCNA) and transcription factor (TF) prediction, 27 significant modules and 32 significant motifs (E-value &lt; 0.05) annotated with 519 TFs were detected. Of these TFs, 53 were DE PCGs. In summary, the promising key PCGs, lncRNAs, and miRNAs related to the pathogenic and immunological response of pigs infected with PEDV were detected and provided new insights into the pathogenesis of PEDV
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