A gene sequence coding for the precursor of Galanthus nivalis agglutinin (GNA) was modified by site-directed mutagenesis to change very low usage bias codons to higher usage bias ones for improvement of the gene expre...A gene sequence coding for the precursor of Galanthus nivalis agglutinin (GNA) was modified by site-directed mutagenesis to change very low usage bias codons to higher usage bias ones for improvement of the gene expression in transgenic tobacco (Nicotiana tabacum L.) plants. Results from Western blot analysis of some of the transgenic tobacco plants showed that the expression level of GNA in plants transformed with the modified gene GNA34m reached 0.25% of total soluble proteins, while that of the GNA34 gene transgenic plants was 0.17%. Since the GNA expression level increased, the aphid resistance of GNA34m transgenic plants were also enhanced significantly as judged by a 71.0% aphid population inhibition in insect bioassay of GNA34m transformed plants and 63.7% for the plants transformed with the natural GNA34 gene.展开更多
The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simulator with 300mm diameter. It has been found that the regime transition occurs as the clear liquid height is equa...The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simulator with 300mm diameter. It has been found that the regime transition occurs as the clear liquid height is equal to the residual pressure drop on the trays. A convenient and accurate technique was proposed for determination of the regime transition point. Based on analysis of the transition process at a sieve hole, a new formula which can be used to correlate the experimental results was provided.展开更多
Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line ...Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45. Results We found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45. Conclusion NF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.展开更多
Objective：To investigate the influence of lumbar disc degeneration on the efficacy of lumbar fixed-point rotation manipulation in sitting position in treating lumbar intervertebral disc herniation（LIDH）.Methods：We...Objective：To investigate the influence of lumbar disc degeneration on the efficacy of lumbar fixed-point rotation manipulation in sitting position in treating lumbar intervertebral disc herniation（LIDH）.Methods：We simulated lumbar fixed-point rotation manipulation of sitting position using three finite element models including a normal model,a mild degeneration model and a moderate degeneration model of L3-5,in which the herniated disc was assumed at the left rear of L4 disc and the rotation manipulation was carried out on the right side.The displacement and stress at the left rear of L4 disc of the three models were analyzed.Results：When lumbar fixed-point rotation manipulation in sitting position was carried out,a displacement and stress were generated at the left rear of L4 intervertebral disc of the three models directing forward.The displacement and stress in degeneration models were less than those in the normal model,and the smallest values were found in the moderate degeneration model.From normal model to mild and then to the moderate degeneration model,the displacement decreased by 36% and 59%,and the stress decreased by 22.3% and 45.2%,respectively.Conclusion：The lumbar disc degeneration affects adversely the effectiveness of lumbar fixed-point rotation manipulation in sitting position in the treatment of LIDH.The severer the lumbar degeneration,the greater the influence.展开更多
The ability to knockdown the expression of an endogenous gene by RNAi has emerged as a powerful strategy for the rapid identification of specific gene functions. Vector-based constitutive expression of shRNA can resul...The ability to knockdown the expression of an endogenous gene by RNAi has emerged as a powerful strategy for the rapid identification of specific gene functions. Vector-based constitutive expression of shRNA can result in stable and efficient knockdown of target genes. However, constitutive expression of shRNA imposes major limitations when analyzing the fimction of genes whose expression is vital for the survival of an organism. Inducible RNAi systems can circumvent this limitation by enabling the inhibition of expression of an essential gene only when the inducing agent is present, and the level of knockdown of the essential gene can be controlled and adjusted by the concentration of inducing agent. In this review, we briefly summarize the recent development of various inducible RNAi systems and their potential applications in drug target validation.展开更多
文摘A gene sequence coding for the precursor of Galanthus nivalis agglutinin (GNA) was modified by site-directed mutagenesis to change very low usage bias codons to higher usage bias ones for improvement of the gene expression in transgenic tobacco (Nicotiana tabacum L.) plants. Results from Western blot analysis of some of the transgenic tobacco plants showed that the expression level of GNA in plants transformed with the modified gene GNA34m reached 0.25% of total soluble proteins, while that of the GNA34 gene transgenic plants was 0.17%. Since the GNA expression level increased, the aphid resistance of GNA34m transgenic plants were also enhanced significantly as judged by a 71.0% aphid population inhibition in insect bioassay of GNA34m transformed plants and 63.7% for the plants transformed with the natural GNA34 gene.
基金Supported by the National Natural Science Foundation of China(No.29170288)
文摘The transition from froth to spray regime on sieve trays was experimentally studied in an air/water simulator with 300mm diameter. It has been found that the regime transition occurs as the clear liquid height is equal to the residual pressure drop on the trays. A convenient and accurate technique was proposed for determination of the regime transition point. Based on analysis of the transition process at a sieve hole, a new formula which can be used to correlate the experimental results was provided.
基金Supported by National Natural Science Foundation of China (30130026, U0632005, 30721063)National Basic Research Program of China (973 Program) (2011CB964803)+1 种基金National Laboratory of Medical Molecular Biology grant (2060204)Beijing municipal government grant (YB20081002301)
文摘Objective To investigate whether α-hemoglobin stabilizing protein (AHSP), the α-globin-specific molecular chaperone, is regulated by erythroid transcription factor NF-E2. Methods We established the stable cell line with NF-E2p45 (the larger subunit of NF-E2) short hairpin RNA to silence its expression. Western blot, real-time polymerase chain reaction, and chromatin immunoprecipitation (ChIP) analysis were performed to detect the expression of AHSP, the histone modifications at AHSP gene locus, and the binding of GATA-1 at the AHSP promoter with NF-E2p45 deficiency. ChIP was also carried out in dimethyl sulfoxide (DMSO)-induced DS19 cells and estrogen-induced G1E-ER4 cells to examine NF-E2 binding to the AHSP gene locus and its changes during cell erythroid differentiation. Finally, luciferase assay was applied in HeLa cells transfected with AHSP promoter fragments to examine AHSP promoter activity in the presence of exogenous NF-E2p45. Results We found that AHSP expression was highly dependent on NF-E2p45. NF-E2 bound to the regions across AHSP gene locus in vivo, and the transcription of AHSP was transactivated by exogenous NF-E2p45. In addition, we observed the decrease of H3K4 trimethylation and GATA-1 occupancy at the AHSP gene locus in NF-E2p45-deficient cells. Restoration of GATA-1 in G1E-ER4 cells in turn led to increased DNA binding of NF-E2p45. Conclusion NF-E2 may play an important role in AHSP gene regulation, providing new insights into the molecular mechanisms underlying the erythroid-specific expression of AHSP as well as new possibilities for β-thalassemia treatment.
基金supported by Scientific Research Project for the Construction of Chinese Medicine Province of Administration of Traditional Chinese Medicine of Guangdong(No.20141063)~~
文摘Objective：To investigate the influence of lumbar disc degeneration on the efficacy of lumbar fixed-point rotation manipulation in sitting position in treating lumbar intervertebral disc herniation（LIDH）.Methods：We simulated lumbar fixed-point rotation manipulation of sitting position using three finite element models including a normal model,a mild degeneration model and a moderate degeneration model of L3-5,in which the herniated disc was assumed at the left rear of L4 disc and the rotation manipulation was carried out on the right side.The displacement and stress at the left rear of L4 disc of the three models were analyzed.Results：When lumbar fixed-point rotation manipulation in sitting position was carried out,a displacement and stress were generated at the left rear of L4 intervertebral disc of the three models directing forward.The displacement and stress in degeneration models were less than those in the normal model,and the smallest values were found in the moderate degeneration model.From normal model to mild and then to the moderate degeneration model,the displacement decreased by 36% and 59%,and the stress decreased by 22.3% and 45.2%,respectively.Conclusion：The lumbar disc degeneration affects adversely the effectiveness of lumbar fixed-point rotation manipulation in sitting position in the treatment of LIDH.The severer the lumbar degeneration,the greater the influence.
基金National Natural Science Foundation of China(Grant No.20852001)"985"Project Foundation(Grant No.985-2-126-121 )+1 种基金The Key Laboratory Grant(Grant No.20080104)National Basic Research Program of China(Grant No.973 Program,2010CB 12300)
文摘The ability to knockdown the expression of an endogenous gene by RNAi has emerged as a powerful strategy for the rapid identification of specific gene functions. Vector-based constitutive expression of shRNA can result in stable and efficient knockdown of target genes. However, constitutive expression of shRNA imposes major limitations when analyzing the fimction of genes whose expression is vital for the survival of an organism. Inducible RNAi systems can circumvent this limitation by enabling the inhibition of expression of an essential gene only when the inducing agent is present, and the level of knockdown of the essential gene can be controlled and adjusted by the concentration of inducing agent. In this review, we briefly summarize the recent development of various inducible RNAi systems and their potential applications in drug target validation.
