The retroviral vector （RCAS） has been widely used in avian system to study development and diseases, but is not suitable for mammals which do not produce the retrovirus receptor TVA. In this review, we trace the cur...The retroviral vector （RCAS） has been widely used in avian system to study development and diseases, but is not suitable for mammals which do not produce the retrovirus receptor TVA. In this review, we trace the current uses of RCAS-TVA approach in mammalian system with improved strategies, including generation of tv-a transgenic mice, use of soluble TVA receptor and retroviral receptor-ligand fusion proteins, improvement of RCAS vectors, and compare a series of mammalian models in variant studies of gene function, development, oncogenesis and gene therapy. All those studies demonstrate that the RCAS-TVA based mammalian models are powerful tools for understanding the mechanisms and target treating of human diseases.展开更多
Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid (PLGA) bearing a...Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid (PLGA) bearing anti-sense monocyte chemotactic protein-1 (A-MCP-l), a specific expression gene, and the package efficiency, release progress in vitro, and the size of the complex were determined. The possibility of the new vector was evaluated with genomic DNA PCR by transferring gene into cultured smooth muscle cells (SMC), cationic lipids as a control. For study in vivo, jugular vein-to-artery bypass grafting procedures were performed on 20 New Zealand white rabbits, of which 6 grafts were transferred with nanoparticle-A-MCP-1 (200 μg), 6 with A - MCP-1 (200 μ g) by cationic liposome, 4 with LNCX plasmid, and 4 as control. Fourteen days after the grafts were harvested, the expression of A-MCP-l and its effect on MCP-1 in vein grafts were detected by dot blot, and the morphologic evaluation of grafts was performed.Results. The package efficiency of the nanoparticle-DNA complex was 0. 9% , release progress in vitro lasted 2 weeks, and the size ranged from 150 to 300nm. SMC genomic DNA PCR showed that A-MCP-l gene could be successfully transfected into cells by nanoparticle. The study in vivo indicated that A-MCP-l mRNA was expressed in both local gene delivery groups, nanoparticle and liposome, meanwhile, MCP-1 expression in vein grafts was significantly inhibited and neointimal hyperplasia was notably reduced.Conclusion. Nanoparticle can act as a vector to transfect specific gene.展开更多
A field study on the behavior of three destructive piles in soft soils subjected to axial load was presented.All the three piles with different diameters were base-grouted and installed with strain gauges along the pi...A field study on the behavior of three destructive piles in soft soils subjected to axial load was presented.All the three piles with different diameters were base-grouted and installed with strain gauges along the piles.The complete load transfer behavior of the base-grouted pile was analyzed using measured results.Moreover,the thresholds of the relative pile-soil displacement for fully mobilizing skin frictions in different soils were investigated,and pile tip displacements needed to fully mobilize tip resistances were analyzed.The results of the full-scale loading tests show that the skin frictions are close to the ultimate values when the pile-soil relative displacements are 1%-3% of pile diameter,and the pile tip displacements needed to fully mobilize the tip resistances are about 1.3%-2.0% of pile diameter.The load transmission curve of the soils around the pile tip corresponds to a softening model when the pile is loaded to failure.展开更多
Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of t...Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of the sum of three principal strains was deduced to quantitatively investigate the infrared radiation characteristics in test. Two typical specimens,the three-point bending beam and the disc pressed in diameter,were tested and their principal strains were calculated by finite element method in order to obtain the temperature differences of infrared radiation. Numerical results are in a good agreement with test results,which verifies the validity of the formula of calculating temperature differences of infrared radiation and the model of quantitatively describing the infrared radiation characteristics of solid materials,and reveals the corresponding inner physical mechanism.展开更多
Objective:The aim of our study was to investigate the effect of Pin1 on the expression of MMP-2 and MMP-9 in human colorectal carcinoma SW620 cells. Methods: We constructed a eukaryotic expression vector of RNA interf...Objective:The aim of our study was to investigate the effect of Pin1 on the expression of MMP-2 and MMP-9 in human colorectal carcinoma SW620 cells. Methods: We constructed a eukaryotic expression vector of RNA interfering (shRNA) for Pin1 gene (pGenesil-1-Pin1), and then observed its expression in SW620 cells by Western blotting. The cells motility were tested by wound healing assay and Boyden chamber assay. The protein levels and activity of MMP-2 and MMP-9 were tested by Western blotting and Gelatin zymography in SW620 cells after transfected with pGenesil-1-PIN1. Results: pGenesil-1-PIN1 was successfully constructed, which was confirmed by sequencing. Silencing the Pin1 by RNAi significantly decreased the cells motility from 96.4±3.9 per field (×10 objective) to 52.7±4.4 per field (P<0.05, Student's t-test) for SW620 cells transfected with pGenesil-1-PIN1 (SW620/p-shRNA) in Boyden chamber assay, and reduced the MMP-2 and MMP-9 expressions and activity in SW620 cells. The protein relative levels of MMP-2 were 0.32±0.04 for SW620/p-shRNA, and 0.76±0.03 for SW620/p-Con; MMP-9 were 0.41±0.09 for SW620/p-shRNA, and 0.94±0.07 for SW620/p-Con (p<0.05). Conclusion: Inhibited Pin1 expression may contribute to the suppression of the invasive and metastatic capacity of colon cancer cells in vitro.展开更多
The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, ...The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, we accom- plish sustainably enhanced electrochemical performance for a SnO2/carbon LIB. 2-5 nm SnO2 nanoparticles are hydro- thermally grown in different nanoporous carbon frameworks, which are pristine, nitrogen- or oxygen-doped carbons. Compared with pristine and nitrogen-doped carbon hosts, the SnO2/oxygen-doped activated carbon （OAC） composite ex- hibits a higher discharge capacity of 1,122mAhg^-1 at 500 mA g^-1 after 320 cycles operation and a larger lithium storage capacity up to 680 mAhg-I at a high rate of 2,000 mA g^-1. The exceptional electrochemical performance originated from the oxygen groups, which could act as Lewis acid sites to attract electrons effectively from Sn during the charge process, thus accelerating reversible conversion of Sn to SnO2. Meanwhile, SnO2 nanoparticles are effectively bonded with carbon through such oxygen groups, thus preventing the electrochemical sintering and maintaining the cycling stability of the SnO2/OAC composite anode. The high electrochemical performance, low biomass cost, and facile preparation renders the SnO2/OAC composites a promising candidate for anode materials.展开更多
文摘The retroviral vector （RCAS） has been widely used in avian system to study development and diseases, but is not suitable for mammals which do not produce the retrovirus receptor TVA. In this review, we trace the current uses of RCAS-TVA approach in mammalian system with improved strategies, including generation of tv-a transgenic mice, use of soluble TVA receptor and retroviral receptor-ligand fusion proteins, improvement of RCAS vectors, and compare a series of mammalian models in variant studies of gene function, development, oncogenesis and gene therapy. All those studies demonstrate that the RCAS-TVA based mammalian models are powerful tools for understanding the mechanisms and target treating of human diseases.
基金This program was supported by the National Natural Sciences Foundation of China (No. 39870196).
文摘Objective. To evaluate the possibility and efficiency of nanoparticle as a new vector in specific gene transference.Methods. Nanoparticle-DNA complex was prepared with Poly- dl-lactic-co-glycolic acid (PLGA) bearing anti-sense monocyte chemotactic protein-1 (A-MCP-l), a specific expression gene, and the package efficiency, release progress in vitro, and the size of the complex were determined. The possibility of the new vector was evaluated with genomic DNA PCR by transferring gene into cultured smooth muscle cells (SMC), cationic lipids as a control. For study in vivo, jugular vein-to-artery bypass grafting procedures were performed on 20 New Zealand white rabbits, of which 6 grafts were transferred with nanoparticle-A-MCP-1 (200 μg), 6 with A - MCP-1 (200 μ g) by cationic liposome, 4 with LNCX plasmid, and 4 as control. Fourteen days after the grafts were harvested, the expression of A-MCP-l and its effect on MCP-1 in vein grafts were detected by dot blot, and the morphologic evaluation of grafts was performed.Results. The package efficiency of the nanoparticle-DNA complex was 0. 9% , release progress in vitro lasted 2 weeks, and the size ranged from 150 to 300nm. SMC genomic DNA PCR showed that A-MCP-l gene could be successfully transfected into cells by nanoparticle. The study in vivo indicated that A-MCP-l mRNA was expressed in both local gene delivery groups, nanoparticle and liposome, meanwhile, MCP-1 expression in vein grafts was significantly inhibited and neointimal hyperplasia was notably reduced.Conclusion. Nanoparticle can act as a vector to transfect specific gene.
基金Project(51078330) supported by the National Natural Science Foundation of China
文摘A field study on the behavior of three destructive piles in soft soils subjected to axial load was presented.All the three piles with different diameters were base-grouted and installed with strain gauges along the piles.The complete load transfer behavior of the base-grouted pile was analyzed using measured results.Moreover,the thresholds of the relative pile-soil displacement for fully mobilizing skin frictions in different soils were investigated,and pile tip displacements needed to fully mobilize tip resistances were analyzed.The results of the full-scale loading tests show that the skin frictions are close to the ultimate values when the pile-soil relative displacements are 1%-3% of pile diameter,and the pile tip displacements needed to fully mobilize the tip resistances are about 1.3%-2.0% of pile diameter.The load transmission curve of the soils around the pile tip corresponds to a softening model when the pile is loaded to failure.
基金Projects (10775018, 10702010, 50374073) supported by the National Natural Science Foundation of ChinaProject(2002CB412701) supported by the National Basic Research Program of China
文摘Based on the thermodynamics theory and physical micro-properties of solid materials subjected to external loading at room temperature,a formula of calculating temperature difference of infrared radiation in terms of the sum of three principal strains was deduced to quantitatively investigate the infrared radiation characteristics in test. Two typical specimens,the three-point bending beam and the disc pressed in diameter,were tested and their principal strains were calculated by finite element method in order to obtain the temperature differences of infrared radiation. Numerical results are in a good agreement with test results,which verifies the validity of the formula of calculating temperature differences of infrared radiation and the model of quantitatively describing the infrared radiation characteristics of solid materials,and reveals the corresponding inner physical mechanism.
基金Supported by a grant from the Science and Technology Project of Shanxi Province,China (No.2006031087-02)
文摘Objective:The aim of our study was to investigate the effect of Pin1 on the expression of MMP-2 and MMP-9 in human colorectal carcinoma SW620 cells. Methods: We constructed a eukaryotic expression vector of RNA interfering (shRNA) for Pin1 gene (pGenesil-1-Pin1), and then observed its expression in SW620 cells by Western blotting. The cells motility were tested by wound healing assay and Boyden chamber assay. The protein levels and activity of MMP-2 and MMP-9 were tested by Western blotting and Gelatin zymography in SW620 cells after transfected with pGenesil-1-PIN1. Results: pGenesil-1-PIN1 was successfully constructed, which was confirmed by sequencing. Silencing the Pin1 by RNAi significantly decreased the cells motility from 96.4±3.9 per field (×10 objective) to 52.7±4.4 per field (P<0.05, Student's t-test) for SW620 cells transfected with pGenesil-1-PIN1 (SW620/p-shRNA) in Boyden chamber assay, and reduced the MMP-2 and MMP-9 expressions and activity in SW620 cells. The protein relative levels of MMP-2 were 0.32±0.04 for SW620/p-shRNA, and 0.76±0.03 for SW620/p-Con; MMP-9 were 0.41±0.09 for SW620/p-shRNA, and 0.94±0.07 for SW620/p-Con (p<0.05). Conclusion: Inhibited Pin1 expression may contribute to the suppression of the invasive and metastatic capacity of colon cancer cells in vitro.
基金supported by the National High Technology Research and Development Program of China(2012AA053305 and 2014AA052501)the National Natural Science Foundation of China(21506224)
文摘The coupling between electrochemically active material and conductive matrix is vitally important for high efficiency lithium ion batteries （LIBs）. By introducing oxygen groups into the nanoporous carbon framework, we accom- plish sustainably enhanced electrochemical performance for a SnO2/carbon LIB. 2-5 nm SnO2 nanoparticles are hydro- thermally grown in different nanoporous carbon frameworks, which are pristine, nitrogen- or oxygen-doped carbons. Compared with pristine and nitrogen-doped carbon hosts, the SnO2/oxygen-doped activated carbon （OAC） composite ex- hibits a higher discharge capacity of 1,122mAhg^-1 at 500 mA g^-1 after 320 cycles operation and a larger lithium storage capacity up to 680 mAhg-I at a high rate of 2,000 mA g^-1. The exceptional electrochemical performance originated from the oxygen groups, which could act as Lewis acid sites to attract electrons effectively from Sn during the charge process, thus accelerating reversible conversion of Sn to SnO2. Meanwhile, SnO2 nanoparticles are effectively bonded with carbon through such oxygen groups, thus preventing the electrochemical sintering and maintaining the cycling stability of the SnO2/OAC composite anode. The high electrochemical performance, low biomass cost, and facile preparation renders the SnO2/OAC composites a promising candidate for anode materials.
