Coal-rock as a typical sedimentary rock has obvious stratification,namely it has transversely isotropic feature.Meanwhile,deformation leads to coal-rock mass having the characteristics of different porous and crack st...Coal-rock as a typical sedimentary rock has obvious stratification,namely it has transversely isotropic feature.Meanwhile,deformation leads to coal-rock mass having the characteristics of different porous and crack structures as well as local anisotropy.Equivalent axial and circumferential strain' formulas of the pure coal-rock mass specimen with a single crack were derived through the establishment of equivalent mechanical model of standard cylindrical coal-rock specimen,and have been widely used to a variety of media combined different structures containing multiple cracks.The complete stress strain curve of a real coal-rock specimen was obtained by the CTC test.Additionally,according to the comparison with the theoretical value,the theoretical mechanical model could well explain the deformation characteristics of coal-rock mass and verify its validity.Further,following features were analyzed:strain normalized coefficient and elastic modulus(Poisson's ratio) in vertical and parallel direction to the stratification,stratification angle,porosity,pore radius,normal and tangential stiffness of crack,and the relationship of different crack width with different tangential stiffness of crack.Through the analysis above,it substantiate this claim that the theoretical model with better reliability reflects the transversely isotropic nature of the coal-rock and the local anisotropy caused by the porous and cracks.展开更多
Objective: To review the evidence for tamsulosin as medical expulsive therapy in enhancing the effectiveness of distal ureteral stone clearance rate. Methods: We searched Pubmed/Medline, Embase, CBM and the Cochrane L...Objective: To review the evidence for tamsulosin as medical expulsive therapy in enhancing the effectiveness of distal ureteral stone clearance rate. Methods: We searched Pubmed/Medline, Embase, CBM and the Cochrane Library up to October 2011. All randomized controlled trials in which tamsulosin was evaluated with distal ureterolithiasis were eligible for the analysis. Outcome measure assessed was stone clearance rate. Two authors independently assessed study quality and extracted data. All data were analyzed using RevMan 5.1. Results: Thirteen studies involving 1067 participants met the inclusion criteria. Study duration ranged from 7 to 42 d. The pooled analysis showed an improvement of 41% in stone clearance rate of tamsulosin as medical expulsive therapy for distal ureteral calculi (RR=1.41, 95% CI=1.18 to 1.70). According to stone size (6 mm<size<10 mm, 5 mm<size<6 mm, size <5 mm), the pooling effects of tamsulosin were analyzed, with a higher stone expulsion rate obtained than control (RR=1.52, 1.75, 1.05, 95% CI=1.30 to 1.77, 1.25 to 2.45, 0.95 to 1.16, respectively). Adverse effects of tamsulosin, mainly retrograde ejaculation, dizziness and hypotension, were reported in 7 included trials. Conclusion: Treatment with tamsulosin appears to be a safe and effective medical expulsion therapy for distal ureterolithiasis. To make a definite clinical recommendation to use tamsulosin as medical expulsive treatment for distal ureteral calculi, high quality multicentric, randomized, double blinded, controlled trials are necessary to prove its efficacy.展开更多
文摘目的:检测GADD45α基因在膀胱癌中的表达情况及作用机制。方法:分别使用免疫组化、荧光定量PCR和Western blot实验检测GADD45α基因在膀胱癌组织中的表达情况;用慢病毒包装质粒上调膀胱癌细胞中GADD45α的表达后,流式细胞仪分析膀胱癌细胞周期比例分布情况和用Western blot实验检测细胞周期蛋白激酶水平变化情况。结果:膀胱癌组织中GADD45α的表达水平较癌旁正常组织的表达降低;上调膀胱癌细胞中GADD45α的表达后,与control细胞相比,高表达GADD45α细胞的克隆大小和数目皆明显下降(86±12.3 vs 134±13.5,P<0.05);升高GADD45α表达后,膀胱癌细胞G_(2)期比例升高至56.54%,而G_(1)期比例则由82.87%下降至40.8%,S期比例由17.13%下降至2.66%,膀胱癌细胞周期被阻滞在G_(2)/M期,伴随细胞周期蛋白激酶cdc2/cyclinB1的表达下降。结论:GADD45α在膀胱癌中表达下降,GADD45α通过抑制cdc2/cyclinB1的表达活性以阻滞膀胱癌细胞周期在G_(2)/M期,抑制膀胱癌细胞的增殖。
基金supported by the State Key Basic Research Project of China(No.2011CB201201)the National Natural Science Foundation of China(Nos.51134018 and 11172318)the Key Technologies R&D Program of China(No.2008BAB36B07)
文摘Coal-rock as a typical sedimentary rock has obvious stratification,namely it has transversely isotropic feature.Meanwhile,deformation leads to coal-rock mass having the characteristics of different porous and crack structures as well as local anisotropy.Equivalent axial and circumferential strain' formulas of the pure coal-rock mass specimen with a single crack were derived through the establishment of equivalent mechanical model of standard cylindrical coal-rock specimen,and have been widely used to a variety of media combined different structures containing multiple cracks.The complete stress strain curve of a real coal-rock specimen was obtained by the CTC test.Additionally,according to the comparison with the theoretical value,the theoretical mechanical model could well explain the deformation characteristics of coal-rock mass and verify its validity.Further,following features were analyzed:strain normalized coefficient and elastic modulus(Poisson's ratio) in vertical and parallel direction to the stratification,stratification angle,porosity,pore radius,normal and tangential stiffness of crack,and the relationship of different crack width with different tangential stiffness of crack.Through the analysis above,it substantiate this claim that the theoretical model with better reliability reflects the transversely isotropic nature of the coal-rock and the local anisotropy caused by the porous and cracks.
文摘Objective: To review the evidence for tamsulosin as medical expulsive therapy in enhancing the effectiveness of distal ureteral stone clearance rate. Methods: We searched Pubmed/Medline, Embase, CBM and the Cochrane Library up to October 2011. All randomized controlled trials in which tamsulosin was evaluated with distal ureterolithiasis were eligible for the analysis. Outcome measure assessed was stone clearance rate. Two authors independently assessed study quality and extracted data. All data were analyzed using RevMan 5.1. Results: Thirteen studies involving 1067 participants met the inclusion criteria. Study duration ranged from 7 to 42 d. The pooled analysis showed an improvement of 41% in stone clearance rate of tamsulosin as medical expulsive therapy for distal ureteral calculi (RR=1.41, 95% CI=1.18 to 1.70). According to stone size (6 mm<size<10 mm, 5 mm<size<6 mm, size <5 mm), the pooling effects of tamsulosin were analyzed, with a higher stone expulsion rate obtained than control (RR=1.52, 1.75, 1.05, 95% CI=1.30 to 1.77, 1.25 to 2.45, 0.95 to 1.16, respectively). Adverse effects of tamsulosin, mainly retrograde ejaculation, dizziness and hypotension, were reported in 7 included trials. Conclusion: Treatment with tamsulosin appears to be a safe and effective medical expulsion therapy for distal ureterolithiasis. To make a definite clinical recommendation to use tamsulosin as medical expulsive treatment for distal ureteral calculi, high quality multicentric, randomized, double blinded, controlled trials are necessary to prove its efficacy.
