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In Recirculating Aquaculture Systems (RAS), nitrifying bacteria in biofilters are responsible for converting toxic substances such as organic nitrogen, NH+4-N, and NO-2-N in the culture water into less toxic NO-3-N. However, the high dissolved oxygen concentration and low carbon-to-nitrogen ratio in the system limit the denitrification performance of the biofilters, leading to the accumulation of NO-3-N. This accumulation not only poses a threat to the health of cultured animals but also presents challenges for the compliant discharge of aquaculture tailwater. This study employs an internal recirculating biological denitrification device to treat marine RAS wastewater and investigates water quality changes under different Hydraulic Loading Rate (HLR) conditions, specifically setting HLR at 1 m³/(m²·d), 2 m³/(m²·d), and 3 m³/(m²·d). At the end of each experimental stage, samples of PCL and K3 fillers from the device were collected for high-throughput sequencing to analyze the characteristics of their microbial communities and the results of functional gene predictions. The results indicate that during stable operation of the device, the average removal rate of NO-3-N was highest at 67. 31%±3. 03% when the HLR was 2 m³/(m²·d). The removal load of NO-3-N increased with the rise of HLR, reaching 55. 38±6. 13 g·N/(m³·d) at an HLR of 3 m³/(m²·d). During the stable operation of the device, no accumulation of NH+4-N, NO-2-N, and COD was detected in the effluent, with the main denitrification area located in the inner circle of the device. At the phylum level, Proteobacteria was the dominant bacterial phylum in both PCL and K3 samples. At the genus level, the denitrifying unclassified_f__ Rhodobacteraceae and Ruegeria dominated the biofilms on both types of fillers. The abundance of unclassified_ f__Rhodobacteraceae in the PCL samples increased with the increase in HLR, whereas the abundance of Ruegeria increased as the HLR decreased. Functional gene prediction results indicated that the abundance of nitrate reductase (EC 1. 7. 99. 4), nitrite reductase (EC 1. 7. 2. 1), nitric oxide reductase (EC 1. 7. 2. 5), and nitrous oxide reductase (EC 1. 7. 2. 4) involved in denitrification significantly increased with the rise in HLR. In conclusion, this study demonstrates that the biological denitrification device performs best at an HLR of 2 m³/(m²·d). It is recommended to consider this design in practical production and focus on colonizing and cultivating the two efficient denitrifying bacteria, unclassified_f__Rhodobacteraceae and Ruegeria, in the device. This research provides important references for optimizing the hydraulic load rate design of biological denitrification devices and offers new insights for further studies on denitrification efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Laser Technology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fujian Agricultural Science & Technology is the property of Fujian Agricultural Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Southwest China Journal of Agricultural Sciences is the property of Editorial Department of Southwest China Journal of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Water Conservancy & Electric Power Technology & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: In clinical work, some diabetic patients often have tooth loss. If the tooth loss is not timely repaired, it will lead to the elongation of the maxillary teeth, resulting in the reduction of the vertical occlusal gap, early occlusal contact, occlusal interference, and even tooth extraction. OBJECTIVE: To observe the expression of receptor for advanced glycation end products (RAGE) and bone sialoprotein (BSP) in periapical tissue of diabetic mice during tooth occlusal elongation, and explore the effect of diabetes on periapical tissues. METHODS: Totally 120 male C57BL mice were divided randomly into diabetic group (n=40), negative control group (n=40) and blank control group (n=40). Animal models of type II diabetes were established in the diabetic group by intraperitoneal injection of 70 mg/kg streptozotocin. The negative control group was intraperitoneally injected with the same amount of sodium citrate solution, while the blank control group was not disposed. After modeling, 30 mice randomly were selected from each group to extract the right maxillary molars. Then, the mice were further divided into five subgroups of 0, 3, 6, 9 and 12 days (n=6 per group). The mice were killed respectively according to the time specified by each group to obtain their right mandibles. The mRNA and protein expression levels of RAGE and BSP in periapical tissue were detected by real-time PCR and immunohistochemistry, respectively. RESULTS AND CONCLUSION: Real-time PCR results indicated significantly higher RAGE and lower BSP relative mRNA expression levels in the diabetic group than the blank and negative control groups (P < 0.05), while there was no significant difference between blank and negative control groups (P > 0.05). With the time extension of tooth extraction, the relative expression levels of two genes in the three groups both showed a trend of continuous growth. In the diabetic group, the expression levels increased obviously from 3 to 6 days, while in the blank and negative control groups, the expression levels raised apparently from 6 to 9 days. The increase trend of RAGE mRNA relative expression in the diabetic group was more obvious than that in the blank and negative control groups, while the increase trend of BSP mRNA relative expression did the opposite. Immunohistochemical staining results showed that the positive rates of RAGE and BSP in the periapical tissue of the three groups increased with the time prolongation of tooth extraction. The positive rate of RAGE was significantly higher in the diabetic group than the blank and negative control groups at each time after tooth extraction (P < 0.05). The positive rate of BSP was significantly lower in the diabetic group than the blank and negative control groups at 6, 9 and 12 days after tooth extraction (P < 0.05). There was no significant difference in the positive rate of RAGE and BSP between the blank and negative control groups (P > 0.05). To conclude, the expressions of RAGE and BSP in the periapical tissues of diabetic mice increased gradually with the time extension of tooth extraction, while he growth rate and expression of BSP were lower in the diabetic group than the negative and blank control groups. These indicate that diabetes may inhibit the expression of BSP. However, the high expression level of RAGE may be related to the accelerated damage to periapical tissue and delayed tissue reconstruction in diabetes. [ABSTRACT FROM AUTHOR]

In order to reveal the diversity and influencing factors of soil bacterial community, it takes the rhizosphere soil of Lilium pumilum DC. in Gaobai Mountain demonstration Base in Zichang City, Shaanxi Province as the main research material. High-throughput sequencing technique was used to determine the bacterial community in different soil collected. The results showed that a total of 575510 effective sequences of bacteria were obtained by culture-free method, including 30 phyla, 90 classes, 147 orders, 242 families and 391 genera. The dominant bacteria phyla were Actinobacteria (38.56%-46.12%), Proteobacteria (16.67%-26.55%) and Chloroflexi (9.45%-18.57%), Acidobacteria (2.96%-5.26%) and Bacteroidetes (2.04%-5.76%). The dominant bacteria classes were Alphaproteobacteria (32.44%-38.52%), α-Metamorphosis (15.47%-25.89%), Acidimicrobiia (2.39%-7.59%), Thermomicrobia (3.43%-5.55%) and Chlorobacter (2.14%-4.29%). Redundancy analysis showed that environmental factors could explain 61.86% of the changes in bacterial communities at the genus level. Organic matter, available potassium and available phosphorus were the main factors affecting the diversity of bacterial community composition in the rhizosphere soil of Lilium pumilum. The results showed that the diversity of bacterial community in the rhizosphere soil of Lilium pumilum was rich, and the cultivation pattern would affect the difference of bacterial community composition in Lilium pumilum rhizosphere soil. This study can provide reference for the further development of Lilium pumilum strain resources. [ABSTRACT FROM AUTHOR]

To investigate the protective effect of melatonin on myocardial ischemia reperfusion injury(IRI) by regulating Akt/FOXO4/BIM signaling pathway and its mechanism. Methods Myocardial IRI model was established, and cells were divided into the control group (CTRL group), the ischemia reperfusion group (IRI group), the melatonin treatment group (IRI+MEL group) and the Akt inhibitor group (IRI+MEL+MK2206 group). MTT method was used to detect the cell survival rate. The level of released LDH was measured with microplate reader. Flow cytometry was used to detect cell apoptosis. PCR method was used to detect the inflammatory gene levels of interleukin 6 (IL-6), tumor necrosis factor α (TNF- α) and monocyte chemotactic protein-1 (MCP-1). Western blot assay was used to detect the protein expression changes of p-Akt, p-FOXO4 and BIM. Results Compared with the CTRL group, the cell survival rate decreased and LDH content increased, the early stage and total apoptosis rates were increased, expression levels of IL-6, TNF-α and MCP-1 genes were increased, p-Akt protein expression decreased, and p-FOXO4 and BIM protein expression levels increased in the IRI group (P＜0.05). Compared with the IRI group, melatonin therapy increased the cell survival rate and p-Akt protein expression, decreased LDH content, cell apoptosis, IL-6, TNF- α, MCP-1 gene level and p-FOXO4 and BIM protein expression (P＜0.05). Compared with the IRI+MEL group, MK2206 partially reversed the protective effect of melatonin on IRI cardiomyocytes (P＜0.05). Conclusion Melatonin has protective effect on ischemia reperfusion injured myocardial cells, and its mechanism may be related to the regulation of Akt/FOXO4/BIM signaling pathway to reduce apoptosis and cell inflammation. [ABSTRACT FROM AUTHOR]

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Synthetic Crystals is the property of Journal of Synthetic Crystals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Tianjin Medical Journal is the property of Tianjin Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Clinical Nursing in Practice is the property of Journal of Clinical Nursing in Practice (Editorial Board, Shanghai Jiao Tong University Press) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Application Research of Computers / Jisuanji Yingyong Yanjiu is the property of Application Research of Computers Edition and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Fujian Agricultural Science & Technology is the property of Fujian Agricultural Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Art Panorama is the property of Art Panorama Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

以新型冠状病毒肺炎疫情防控期间上海港对于港口高风险岗位人员集中居住管理的探索和实践为例, 分 析港口高风险岗位人员集中居住管理在疫情防控中发挥的作用, 并探讨其对于疫情防控工作的启示. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective To investigate the mechanism of FUNDC1 affecting high glucose injured H9c2 cardiomyocyte apoptosis by regulating mitochondrial fission. Methods H9c2 cardiomyocytes were cultured in vitro, and the high glucoseinduced injury model of cells was established. After cell transfection or AMPK activation by AICAR, the cells were divided into the control (CTRL) group, the high glucose injury (HG) group, the HG with transfected shRNA-NC (HG+shRNA-NC) group, the HG with transfected FUNDC1 shRNA (HG+shRNA-FUNDC1) group and the HG with AICAR (HG+AICAR) group. MTT method was used to detect the cell survival rate. The level of released LDH was measured with microplate reader. The structure of mitochondria was observed by laser confocal microscope. The proteins expression levels of mitochondrial dynamin-related protein1 (DRP1), fission protein 1 (FIS1), Bcl-2 associated X protein (Bax), Blymphocytoma- 2 (Bcl-2), cleaved cysteine-containing aspartate-spicific protease 3 (Cleaved Caspase-3), FUNDC1 and GAPDH were detected by Western blot assay. Results Compared with the CTRL group, the cell survival rate decreased, and the protein levels of DRP1-cyto and Bcl-2 were also decreased, the release of LDH and the protein expression levels of DRP1-mito, FIS1, Bax and Cleaved Caspase-3 increased in the HG group (P＜0.05). Compared with the HG group, knocking down FUNDC1 increased the cell survival rate and the protein levels of DRP1-cyto and Bcl-2, decreased the release of LDH and the protein expression levels of DRP1-mito, FIS1, Bax and Cleaved Caspase-3 (P＜0.05). There was no difference in each index between the HG group and the HG+shRNA-NC group (P＞0.05). The mitochondria were mainly linear structure in the CTRL group, and the mitochondria were mainly pucta structure in the HG group and the HG+shRNANC group. Compared with the HG group, the mitochondrial linear structure increased and the puncta structure decreased in the HG+shRNA-FUNDC1 group. Compared with the CTRL group, the protein expression level of FUNDC1 increased in the HG group (P＜0.05). Compared with the HG group, the protein level of FUNDC1 significantly decreased in the HG+AICAR group (P＜0.05). Conclusion FUNDC1 affects H9c2 cardiomyocyte apoptosis induced by high glucose through regulating mitochondrial fission, and AMPK signaling pathway is involved in this process. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Health Resources is the property of Health Development & Policy Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Health Resources is the property of Health Development & Policy Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Water Conservancy & Electric Power Technology & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Clinical Nursing in Practice is the property of Journal of Clinical Nursing in Practice (Editorial Board, Shanghai Jiao Tong University Press) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Original basic research is a key driving force for the development of science and technology, as well as the source of the new round of scientific and technological revolution and industrial transformation. To further encourage and support originality and innovation, the National Natural Science Foundation of China (NSFC) implemented the original exploratory program as one of its priorities for deepening reform. In this paper, the concept and characteristics of original basic research are analyzed, and the funding orientation of foreign major science funding agencies on original basic research projects is investigated. This study further discusses the connotation and positioning of the original basic research, and puts forward specific suggestions for promoting the discovery and identification of original ideas and optimizing the application and review management of the original exploratory program. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Functional Materials / Gongneng Cailiao is the property of Chongqing Functional Materials Periodical Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to obtain a more reliable similarity matrix and make it contain the exact number of connected branches, this paper proposed a new sparse subspace clustering algorithm. The algorithm used the K nearest neighbor idea to find reliable neighbors from the local. In the aspect of distance metric, the algorithm selected the geodesic distance for calculation, and considered the geometric structure of the data in the high-dimensional space, which made the neighbor relationship of the data more reasonable. At the same time, using the Ky Fan theorem, the adaptive matrix adjusted the parameters so that the similar matrix contained the exact number of connected branches. In addition, the algorithm broke the conventional two-step mode, and simultaneously performed similar matrix learning and spectral clustering process, which closely linked data similarity and segmentation, further strengthening the mining and utilization of data structure information. The results of the experiments on artificial datasets, image datasets and real datasets show that the algorithm is effective. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Management & Technology Discussion is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: To investigate the relationship between cytochrome P4502C19 (CYP2C19) gene polymorphism and platelet reactivity in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS) after clopidogrel administration, and to evaluate the prognostic value of the genotypes. Methods: Totally 462 NSTE-ACS patients receiving PCI were successively included; according to the different genotypes of CYP2C19, they were divided into the extensive metabolism (EM) group (CYP2C19 * 1/ * 1), intermediate metabolism (IM) group (CYP2C19 * 1/ * 2, CYP2C19 * 1/ * 3) and poor metabolism (PM) group (CYP2C19 * 2/ * 2, CYP2C19 * 2/ * 3). Platelet reactivity after clopidogrel administration was evaluated by the platelet reactive index (PRI) measured by flow cytometry and platelet aggregation rate (PAG) measured by light transmittance aggregometry. All patients were followed up for 2 years; all-cause death, stent restenosis, acute stent thrombosis, and acute myocardial infarction were defined as major adverse cardiovascular events (MACE), and Cox regression analysis was performed to evaluate the predictive ab山ty of genotypes, PRI, P AG, and other indicators on MACE. Results: There were 158 cases of EM type, 246 cases of IM type, and 58 cases of PM type. The PRI values were 48. 6 士 10.5, 56.7 士 12.6, and 65.3 士 11.4, respectively; the PAG were 67. 4 士 8.5, 71. 9 士 8.2, and 78.4土6.1, respectively. There were statistical significant differences in PRI and PAG among the three groups (both P < 0. 01). The incidence rates of MACE in the three groups were 2. 5%, 9. 8% and 43. 1 %, respectively. When we compared the three groups in pairs, statistical differences were found among them (P <0. 01). Cox regression analysis indicated that PRI (HR: 1. 05, 95% Cl: 1. 03 -1. 07, P <0. 01) and CYP2C19 genotypes (HR: 1. 84, 95% Cl: 1. 09 -3. 12, P < 0. 05) were independent predictors for MACE. Conclusion: The CYP2C19 genotypes are associated with platelet reactivity of NSTE-ACS patients after clopidogrel administration, and PM genotype can be used as a prognostic indicator of poor prognosis in NSTE-ACS patients. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Application Research of Computers / Jisuanji Yingyong Yanjiu is the property of Application Research of Computers Edition and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Low frequency cyclic loading tests were conducted on six concrete columns with reinforcements splicing by grout-filled coupling sleeves and two cast-in-situ concrete columns, in which the nominal yield strength of longitudinal reinforcements and stirrups were both 500 MPa. Failure patterns, hysteretic curves, skeleton curves, displacement ductility, energy dissipation capacity and bearing capacity were analyzed. The influences of axial compression ratio, arrangement of stirrups and strength of grouting material on the seismic behavior were also investigated. The research results show that the displacement ductility, energy dissipation capacity and bearing capacity of the precast concrete columns are similar to those of cast-in-situ concrete columns. Meanwhile, sleeves of precast concrete columns have formed the rigid zone, top of which is seriously damaged. The interface of precast concrete columns with low axial compression ratio is also destroyed, which results in the obvious pinching of hysteretic loops. For the precast concrete columns with high axial compression ratio, the core concrete will also be crushed after the spalling of the concrete cover. The average value of displacement ductility coefficient for precast concrete columns is merely 2.20，but that of ultimate displacement drift ratio is up to 1/31. [ABSTRACT FROM AUTHOR]

Copyright of Shandong Medical Journal is the property of Shandong Medical Health Newspapers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)