Marker-free GFP transgenic tobacco plants were constructed based on Cre/lox site-specific recombination system. A GFP gene was introduced into the tobacco genome using the Bar gene as a linked selectable marker flanke...Marker-free GFP transgenic tobacco plants were constructed based on Cre/lox site-specific recombination system. A GFP gene was introduced into the tobacco genome using the Bar gene as a linked selectable marker flanked by recombination sites in a directed orientation. The Bar gene expression box was subsequently excised from the plant genome by a strategy of Cre gene retransformation. After removal of the Cre-NPT Ⅱ locus by genetic segregation through self-cross, plants that incorporated only the GFP transgene were obtained. Transgenic tobacco plants mediated by Agrobacterium tumefaciens were obtained, which resisted herbicide Basta and GFP expressed well, then the Cre gene was subsequently introduced into 5 plants of them, respectively, by retransformation. The leaf disks from Cre transgenic plants were used to test the resistance to Basta on the medium with 8 mg L-1 of PPT. The results showed that few discs were able to regenerate normally, and the excision at 76-100% efficiency depended on individual retransformation events. Evidence for a precise recombination event was confirmed by cloning the nucleotides sequence surrounding the lox sites of the Basta sensitive plants. The result indicated that the excision event in the recombination sites was precise and conservative, without loss or alteration of any submarginal nucleotides of the recombination sites. Bar gene excised plants were selfpollinated to allow segregation of the GFP gene from the Cre-NPT Ⅱ locus. The progenies from self-pollinated plants were scored for Kan senstivity, then the segregation of GFP gene from Cre-NPT Ⅱ locus in the Kan senstive plants were confirmed by PCR analysis subsequently. Hence, constructing marker-free transgenic tobacco plants by Cre/lox sitespecific recombination system was reliable, and the strategy presented here should be applicable to other plants for the construction of marker-free transgenic plants as well.展开更多
Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and p...Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and products formation from the oxidation of the primary and the secondary hydroxyl groups are understood by combining the model calculations and DFT calculations, aiming to discriminate the corresponding dominant Pt active sites. The Pt(100) facet is demonstrated to be the dominant active sites for the glycerol conversion and the products formation from the two routes. The insights revealed here could shed new light on fundamental understanding of the Pt particle size effects and then guiding the design and optimization of Pt-catalyzed base-free oxidation of glycerol toward targeted products.展开更多
Full thickness skin grafts and composite grafts are a workhorse in reconstructive surgery of nose and ear defects whether they are originated from trauma, cancer surgery or burns. The reliability of these grafts has b...Full thickness skin grafts and composite grafts are a workhorse in reconstructive surgery of nose and ear defects whether they are originated from trauma, cancer surgery or burns. The reliability of these grafts has been proved with an established clinical use and morbidity to the donor site is minimal if harvesting and donor site selection if appropriate. Use of double or multiple grafts to reconstruct a complex defect of the nose has not been described and our report is meaningful for the fact that it describes a further use of the surgical concept of grafting.展开更多
砂土液化是常见的地震灾害,目前应用于研究砂土液化动力特性的室内试验以及模型试验还不能全面反映土体液化全过程。计算流体动力学(computational fluid dynamics,CFD)与离散元法(discrete element method,DEM)耦合模拟方法能够准确地...砂土液化是常见的地震灾害,目前应用于研究砂土液化动力特性的室内试验以及模型试验还不能全面反映土体液化全过程。计算流体动力学(computational fluid dynamics,CFD)与离散元法(discrete element method,DEM)耦合模拟方法能够准确地模拟各类水土耦合问题。通过二次开发的CFD-DEM流固耦合模块实现离散元软件PFC3D与计算流体力学软件OpenFOAM之间的力学信息交互,利用颗粒水下自由沉降验证该方法的可行性。利用PFC3D软件模拟室内循环三轴试验标定出具有真实饱和砂土动力特性的数值砂样。根据已有的参数信息以及耦合模拟方法建立了饱和砂土的场地液化模型。模拟结果表明,离散元法能够复现室内砂土液化试验,标定参数可应用于场地液化模拟;单颗粒沉降速度与理论解一致验证了CFD-DEM耦合方法的准确性;峰值加速度0.25g下不同深度处土体均会发生液化,液化时超孔压比无法达到1,超孔压累计值由浅层往深层递增;液化后土体强度自下而上逐渐恢复,再固结的场地土体结构呈现均匀化发展趋势。展开更多
Exploration and characterization of grafting productions by experimental methods are often cumbersome or sometimes impossible.Therefore,quantum chemistry calculations were performed to characterize the graft sites of ...Exploration and characterization of grafting productions by experimental methods are often cumbersome or sometimes impossible.Therefore,quantum chemistry calculations were performed to characterize the graft sites of epoxy resin.According to the Gibbs free energy criterion of the second law of thermodynamic,the reported graft sites were confirmed,and more important,some unreported graft sites were found.In addition,method of increasing the number of graft sites was studied in this article.展开更多
Aim:To assess the efficacy and limitation of free/total prostate-specific antigen ratio(f/tPSA)at a single institution in Japan,focusing on the avoidance of pointless prostate biopsies.Methods:In total,631 men between...Aim:To assess the efficacy and limitation of free/total prostate-specific antigen ratio(f/tPSA)at a single institution in Japan,focusing on the avoidance of pointless prostate biopsies.Methods:In total,631 men between 44 and 93 years old(mean 69.8 years)with elevated PSA underwent power-Doppler ultrasoundgraphy-guided transrectal 10-core prostate biopsies at Niigata Cancer Center Hospital,and their histological features were investigated with total PSA (tPSA)and f/tPSA.Results:PCa was detected in 126 of 134 patients(94.3%)with tPSA of 26 ng/mL or higher.The detection rate was 59.4% for tPSA of 21-25 ng/mL,followed by 39.2% for 16-20 ng/mL,30.0% for 11-15 ng/mL, 20.0% for 4.1-10 ng/mL and 7.6% for≤4.0 ng/mL,f/tPSA of the PCa group was significantly lower than that of non-malignamt disorders in any tPSA ranges(mean 0.122 vs.0.160,P<0.001).Receiver-operating characteristics analyses showed that f/tPSA(AUC:0.664)performed more valuably than tPSA(AUC:0.559)in patients with tPSA between 3.0-10 ng/mL(P<0.01).Although f/tPSA of 0.250 for the cut-off value might miss 1.8% PCa patients,it potentially spares 9.2% of unnecessary biopsies.Conclusion:f/tPSA is more valuable compared with tPSA alone for the prediction of the occurrence of PCa.We recommend 0.250 as the cut-off value for f/tPSA in PCa screening for Asian men having so-called grey-zone tPSA.(Asian J Androl 2006 Jul;8:429-434)展开更多
基金the National Natural Science Foundation of China (30200185)the Science Foundation of Committee of Education of Chongqing Municipality,China (030208)
文摘Marker-free GFP transgenic tobacco plants were constructed based on Cre/lox site-specific recombination system. A GFP gene was introduced into the tobacco genome using the Bar gene as a linked selectable marker flanked by recombination sites in a directed orientation. The Bar gene expression box was subsequently excised from the plant genome by a strategy of Cre gene retransformation. After removal of the Cre-NPT Ⅱ locus by genetic segregation through self-cross, plants that incorporated only the GFP transgene were obtained. Transgenic tobacco plants mediated by Agrobacterium tumefaciens were obtained, which resisted herbicide Basta and GFP expressed well, then the Cre gene was subsequently introduced into 5 plants of them, respectively, by retransformation. The leaf disks from Cre transgenic plants were used to test the resistance to Basta on the medium with 8 mg L-1 of PPT. The results showed that few discs were able to regenerate normally, and the excision at 76-100% efficiency depended on individual retransformation events. Evidence for a precise recombination event was confirmed by cloning the nucleotides sequence surrounding the lox sites of the Basta sensitive plants. The result indicated that the excision event in the recombination sites was precise and conservative, without loss or alteration of any submarginal nucleotides of the recombination sites. Bar gene excised plants were selfpollinated to allow segregation of the GFP gene from the Cre-NPT Ⅱ locus. The progenies from self-pollinated plants were scored for Kan senstivity, then the segregation of GFP gene from Cre-NPT Ⅱ locus in the Kan senstive plants were confirmed by PCR analysis subsequently. Hence, constructing marker-free transgenic tobacco plants by Cre/lox sitespecific recombination system was reliable, and the strategy presented here should be applicable to other plants for the construction of marker-free transgenic plants as well.
基金financially supported by the Natural Science Foundation of China (21776077)the Shanghai Natural Science Foundation (17ZR1407300 and 17ZR1407500)+5 种基金the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learningthe Shanghai Rising-Star Program (17QA1401200)the Open Project of State Key Laboratory of Chemical Engineering (SKLChe-15C03)the State Key Laboratory of Organic– Inorganic Composites (oic-201801007)the Fundamental Research Funds for the Central Universities (222201718003)the 111 Project of the Ministry of Education of China (B08021)
文摘Understanding the nature of Pt active sites is of great importance for the structure-sensitive base-free oxidation of glycerol. In the present work, the remarkable Pt particle size effects on glycerol conversion and products formation from the oxidation of the primary and the secondary hydroxyl groups are understood by combining the model calculations and DFT calculations, aiming to discriminate the corresponding dominant Pt active sites. The Pt(100) facet is demonstrated to be the dominant active sites for the glycerol conversion and the products formation from the two routes. The insights revealed here could shed new light on fundamental understanding of the Pt particle size effects and then guiding the design and optimization of Pt-catalyzed base-free oxidation of glycerol toward targeted products.
文摘Full thickness skin grafts and composite grafts are a workhorse in reconstructive surgery of nose and ear defects whether they are originated from trauma, cancer surgery or burns. The reliability of these grafts has been proved with an established clinical use and morbidity to the donor site is minimal if harvesting and donor site selection if appropriate. Use of double or multiple grafts to reconstruct a complex defect of the nose has not been described and our report is meaningful for the fact that it describes a further use of the surgical concept of grafting.
文摘砂土液化是常见的地震灾害,目前应用于研究砂土液化动力特性的室内试验以及模型试验还不能全面反映土体液化全过程。计算流体动力学(computational fluid dynamics,CFD)与离散元法(discrete element method,DEM)耦合模拟方法能够准确地模拟各类水土耦合问题。通过二次开发的CFD-DEM流固耦合模块实现离散元软件PFC3D与计算流体力学软件OpenFOAM之间的力学信息交互,利用颗粒水下自由沉降验证该方法的可行性。利用PFC3D软件模拟室内循环三轴试验标定出具有真实饱和砂土动力特性的数值砂样。根据已有的参数信息以及耦合模拟方法建立了饱和砂土的场地液化模型。模拟结果表明,离散元法能够复现室内砂土液化试验,标定参数可应用于场地液化模拟;单颗粒沉降速度与理论解一致验证了CFD-DEM耦合方法的准确性;峰值加速度0.25g下不同深度处土体均会发生液化,液化时超孔压比无法达到1,超孔压累计值由浅层往深层递增;液化后土体强度自下而上逐渐恢复,再固结的场地土体结构呈现均匀化发展趋势。
基金supported by the Program of Introducing Talents of Discipline to Universities(No.B08003).
文摘Exploration and characterization of grafting productions by experimental methods are often cumbersome or sometimes impossible.Therefore,quantum chemistry calculations were performed to characterize the graft sites of epoxy resin.According to the Gibbs free energy criterion of the second law of thermodynamic,the reported graft sites were confirmed,and more important,some unreported graft sites were found.In addition,method of increasing the number of graft sites was studied in this article.
文摘Aim:To assess the efficacy and limitation of free/total prostate-specific antigen ratio(f/tPSA)at a single institution in Japan,focusing on the avoidance of pointless prostate biopsies.Methods:In total,631 men between 44 and 93 years old(mean 69.8 years)with elevated PSA underwent power-Doppler ultrasoundgraphy-guided transrectal 10-core prostate biopsies at Niigata Cancer Center Hospital,and their histological features were investigated with total PSA (tPSA)and f/tPSA.Results:PCa was detected in 126 of 134 patients(94.3%)with tPSA of 26 ng/mL or higher.The detection rate was 59.4% for tPSA of 21-25 ng/mL,followed by 39.2% for 16-20 ng/mL,30.0% for 11-15 ng/mL, 20.0% for 4.1-10 ng/mL and 7.6% for≤4.0 ng/mL,f/tPSA of the PCa group was significantly lower than that of non-malignamt disorders in any tPSA ranges(mean 0.122 vs.0.160,P<0.001).Receiver-operating characteristics analyses showed that f/tPSA(AUC:0.664)performed more valuably than tPSA(AUC:0.559)in patients with tPSA between 3.0-10 ng/mL(P<0.01).Although f/tPSA of 0.250 for the cut-off value might miss 1.8% PCa patients,it potentially spares 9.2% of unnecessary biopsies.Conclusion:f/tPSA is more valuable compared with tPSA alone for the prediction of the occurrence of PCa.We recommend 0.250 as the cut-off value for f/tPSA in PCa screening for Asian men having so-called grey-zone tPSA.(Asian J Androl 2006 Jul;8:429-434)
