Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies a...Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies available to promote nerve regeneration.Tacrolimus accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery.The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure.Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days.Size and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible byproducts.Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic delivery.Given its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.展开更多
Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of CO_(2).However,their potential is hindered by constraints such as limited light absorp-tion and slug...Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of CO_(2).However,their potential is hindered by constraints such as limited light absorp-tion and sluggish electron transfer and separation,impacting the overall efficiency of the photocatalytic process.In this study,TiO_(2)nanocrystals,modified with Ptx+,underwent laser etching were encapsulated within the traditional MOF-ZIF-8 framework.This enhanced the adsorption capabilities for CO_(2)reactants and solar light,while also facilitating directed electron transfer and the separation of photogenerated charges.The finely-tuned catalyst demonstrates impressive CH_(4) selectivity at 9.5%,with yields of 250.24μmol g^(-1)h^(-1)for CO and 25.43μmol g^(-1)h^(-1)for CH_(4),utilizing water as a hole trap and H^(+)source.This study demonstrates the viability of achieving characteristics related to the separation of photogen-erated charges in TiO_(2)nanocrystals through laser etching and MOF composite catalysts.It offers novel perspectives for designing MOF-based catalysts with enhanced performance in artificial photosynthesis.展开更多
目的:探讨端粒酶新核心亚单位(WD40-encoding RNA antisense to p53,WRAP53)又名端粒酶卡哈尔体蛋白1(telomerase cajal body protein 1,TCAB1)在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)组织中的表达,分析其与患者临床病理特...目的:探讨端粒酶新核心亚单位(WD40-encoding RNA antisense to p53,WRAP53)又名端粒酶卡哈尔体蛋白1(telomerase cajal body protein 1,TCAB1)在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)组织中的表达,分析其与患者临床病理特征及预后的关系。方法:收集28例PTC患者的癌及癌周正常新鲜组织标本,应用实时荧光定量聚合酶链反应法(quantitative real-time polymerase chain reaction,qPR-PCR)及免疫组织化学法分别检测WRAP53 mRNA及蛋白在PTC及周围正常组织中的表达,收集117例PTC术后患者的临床数据及对应的癌组织的石蜡切片进行免疫组化检测,分析其蛋白表达水平与甲状腺乳头状癌患者的临床病理特征的相关性,最后应用蛋白质表达图谱(The Human Protein Atlas,HPA)数据库探究WRAP53与PTC预后之间的关系。结果:qPR-PCR及免疫组化结果提示WRAP53在PTC中较正常组织高表达(P<0.05)。与WRAP53低表达的PTC患者相比,WRAP53高表达的PTC患者肿瘤直径更长,更易出现淋巴结转移(P<0.05)。HPA数据库显示WRAP53高表达的PTC患者的生存率差于WRAP53低表达的PTC患者(P=0.041)。结论:通过本次研究表明,WRAP53在PTC组织中表达较周围正常组织升高,且其高表达与PTC增殖、淋巴结转移及不良预后相关。WRAP53可能是治疗PTC新的潜在靶点。展开更多
The centrifugal pump is a prevalent power equipment widely used in different engineering patterns,and the impeller blade wrap angle significantly impacts its performance.A numerical investigation was conducted to anal...The centrifugal pump is a prevalent power equipment widely used in different engineering patterns,and the impeller blade wrap angle significantly impacts its performance.A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of 69.This study investigates six impellermodels that possess varying blade wrap angles(95°,105°,115°,125°,135°,and 145°)that were created while maintaining the same volute and other geometrical characteristics.The investigation of energy loss was conducted to evaluate the values of total and entropy generation rates(TEG,EGR).The fluid-structure interaction was considered numerically using the software tools ANSYS Fluent and ANSYSWorkbench.The elastic structural dynamic equation was used to estimate the structural response,while the shear stress transport k–ωturbulence model was utilized for the fluid domain modeling.The findings suggest that the blade wrap angle has a significant influence on the efficiency of the pump.The impeller featuring a blade wrap angle of 145°exhibits higher efficiency,with a notable increase of 3.76%relative to the original model.Variations in the blade wrap angle impact the energy loss,shaft power,and pump head.The model with a 145°angle exhibited a maximum equivalent stress of 14.8MPa and a total deformation of 0.084 mm.The results provide valuable insights into the intricate flow mechanism of the centrifugal pump,particularly when considering various blade wrap angles.展开更多
A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functio...A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functions of the main components are explained.Then after a comprehensive analysis of data transmission and a job life cycle model,a novel proactive file transmission and job management mechanism is devised to enhance the software architecture,and the command line programs are wrapped into web services in such a way that they can efficiently transmit files,supply instant status feedback and automatically manage the jobs.Experiments show that the proposed approach achieves higher performance with less memory usage compared to the related work, and the usability is also improved.This work has already been put into use in a production system of scientific computing and the data processing efficiency of the system is greatly improved.展开更多
WRAP(Water Rights Analysis Package)水权分析模型是基于水资源优先分配制度来模拟和预测一个或多个流域内水资源使用及管理的模型。作者首次将WRAP水权分析模型应用于北京通州区,以1956～2007年通州区相关资料作为模型的计算数据,模...WRAP(Water Rights Analysis Package)水权分析模型是基于水资源优先分配制度来模拟和预测一个或多个流域内水资源使用及管理的模型。作者首次将WRAP水权分析模型应用于北京通州区,以1956～2007年通州区相关资料作为模型的计算数据,模拟与计算结果表明:通州地区的天然年径流总体趋势基本保持不变,调度径流呈微弱增长趋势,两者的年际变差均逐渐剧烈;历年的径流消耗量总体趋势亦基本不变,但回归流呈逐渐增长趋势;研究区内多年平均水量保证率为59.9%,工业用水、城镇生活用水和农村生活用水呈上升趋势,而农业用水量总体呈下降趋势。展开更多
目的:探讨抑制p53的反义转录本WRAP53α基因表达对顺铂(cisplatin,CDDP)诱导人骨肉瘤U-2OS细胞凋亡的影响。方法:不同浓度的CDDP处理U-2OS细胞后,MTT法检测细胞的增殖率;不同浓度CDDP处理36 h和10μmol/L CDDP处理不同时间以及si WRAP5...目的:探讨抑制p53的反义转录本WRAP53α基因表达对顺铂(cisplatin,CDDP)诱导人骨肉瘤U-2OS细胞凋亡的影响。方法:不同浓度的CDDP处理U-2OS细胞后,MTT法检测细胞的增殖率;不同浓度CDDP处理36 h和10μmol/L CDDP处理不同时间以及si WRAP53转染后,实时荧光定量PCR和蛋白质印迹法检测U-2OS细胞中WARAP53α和p53 m RNA及p53蛋白的表达水平;FCM法检测CDDP单独处理及si WRAP53转染后联合CDDP处理组U-2OS细胞的凋亡率。结果:CDDP处理后,U-2OS细胞的增殖率低于未处理的对照组(P<0.05),且呈浓度依赖性。CDDP处理后,U-2OS细胞中WRAP53αm RNA的表达水平明显高于未处理的空白对照组(P<0.05),且呈浓度和时间依赖性;p53 m RNA及p53蛋白的表达水平高于空白对照组(P<0.05)。si WRAP53转染后,WRAP53α和p53 m RNA及p53蛋白的表达水平低于空白对照组(P<0.05)。CDDP单独给药组U-2OS细胞凋亡率高于si WRAP53α转染联合CDDP处理组(P<0.05),2组细胞的凋亡率均高于空白对照组(P<0.05)。结论:CDDP可抑制U-2OS细胞的增殖,诱导WRAP53α和p53 m RNA及p53蛋白的表达;干扰WRAP53α基因的表达可下调p53的表达水平,并逆转CDDP诱导的细胞凋亡。展开更多
The existing research on improving the hydraulic performance of centrifugal pumps mainly focuses on the design method and the parameter optimization. The traditional design method for centrifugal impellers relies more...The existing research on improving the hydraulic performance of centrifugal pumps mainly focuses on the design method and the parameter optimization. The traditional design method for centrifugal impellers relies more on experience of engineers that typically only satisfies the continuity equation of the fluid. In this study, on the basis of the direct and inverse iteration design method which simultaneously solves the continuity and motion equations of the fluid and shapes the blade geometry by controlling the wrap angle, three centrifugal pump impellers are designed by altering blade wrap angles while keeping other parameters constant. The three-dimensional flow fields in three centrifugal pumps are numerically simulated, and the simulation results illustrate that the blade with larger wrap angle has more powerful control ability on the flow pattern in impeller. The three pumps have nearly the same pressure distributions at the small flow rate, but the pressure gradient increase in the pump with the largest wrap angle is smoother than the other two pumps at the design and large flow rates. The pump head and efficiency are also influenced by the blade wrap angle. The highest head and efficiency are also observed for the largest angle. An experiment rig is designed and built to test the performance of the pump with the largest wrap angle. The test results show that the wide space of its efficiency area and the stability of its operation ensure the excellent performance of the design method and verify the numerical analysis. The analysis on influence of the blade wrap angle for centrifugal pump performance in this paper can be beneficial to the optimization design of the centrifugal pump.展开更多
In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously aff...In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously affects online shape detecting precision of cold strip. Based on the latest intelligent shape meter developed by Yanshan University, using PSO-BP neural network and actual working condition datum, the cold strip online dynamic wrapping angle compensation model is established, and successfully applied in 1250 mm 6-high cold mill, remarkable results are achieved. The error between calculated values and measured values of total tensions is within 3 %展开更多
基金supported by the German Research Foundation(DA 2255/1-1to SCD)+4 种基金a SickKids Research Training Competition(RESTRACOMP)Graduate Scholarship(to KJWS)an Ontario Graduate Scholarship(to KJWS)a grant from Natural Sciences and Engineering Research Council of Canada(NSERC)(to KJWS)a Kickstarter grant from the Institute of Biomedical Engineering(BME)at the University of Toronto(to KJWS)the Abe Frank Fund from the Riley’s Children Foundation(GHB)。
文摘Axonal regeneration following surgical nerve repair is slow and often incomplete,resulting in poor functional recovery which sometimes contributes to lifelong disability.Currently,there are no FDA-approved therapies available to promote nerve regeneration.Tacrolimus accelerates axonal regeneration,but systemic side effects presently outweigh its potential benefits for peripheral nerve surgery.The authors describe herein a biodegradable polyurethane-based drug delivery system for the sustained local release of tacrolimus at the nerve repair site,with suitable properties for scalable production and clinical application,aiming to promote nerve regeneration and functional recovery with minimal systemic drug exposure.Tacrolimus is encapsulated into co-axially electrospun polycarbonate-urethane nanofibers to generate an implantable nerve wrap that releases therapeutic doses of bioactive tacrolimus over 31 days.Size and drug loading are adjustable for applications in small and large caliber nerves,and the wrap degrades within 120 days into biocompatible byproducts.Tacrolimus released from the nerve wrap promotes axon elongation in vitro and accelerates nerve regeneration and functional recovery in preclinical nerve repair models while off-target systemic drug exposure is reduced by 80%compared with systemic delivery.Given its surgical suitability and preclinical efficacy and safety,this system may provide a readily translatable approach to support axonal regeneration and recovery in patients undergoing nerve surgery.
文摘Composites derived from metal-organic frameworks(MOFs)show promise as catalysts for the photocat-alytic reduction of CO_(2).However,their potential is hindered by constraints such as limited light absorp-tion and sluggish electron transfer and separation,impacting the overall efficiency of the photocatalytic process.In this study,TiO_(2)nanocrystals,modified with Ptx+,underwent laser etching were encapsulated within the traditional MOF-ZIF-8 framework.This enhanced the adsorption capabilities for CO_(2)reactants and solar light,while also facilitating directed electron transfer and the separation of photogenerated charges.The finely-tuned catalyst demonstrates impressive CH_(4) selectivity at 9.5%,with yields of 250.24μmol g^(-1)h^(-1)for CO and 25.43μmol g^(-1)h^(-1)for CH_(4),utilizing water as a hole trap and H^(+)source.This study demonstrates the viability of achieving characteristics related to the separation of photogen-erated charges in TiO_(2)nanocrystals through laser etching and MOF composite catalysts.It offers novel perspectives for designing MOF-based catalysts with enhanced performance in artificial photosynthesis.
文摘目的:探讨端粒酶新核心亚单位(WD40-encoding RNA antisense to p53,WRAP53)又名端粒酶卡哈尔体蛋白1(telomerase cajal body protein 1,TCAB1)在甲状腺乳头状癌(papillary thyroid carcinoma,PTC)组织中的表达,分析其与患者临床病理特征及预后的关系。方法:收集28例PTC患者的癌及癌周正常新鲜组织标本,应用实时荧光定量聚合酶链反应法(quantitative real-time polymerase chain reaction,qPR-PCR)及免疫组织化学法分别检测WRAP53 mRNA及蛋白在PTC及周围正常组织中的表达,收集117例PTC术后患者的临床数据及对应的癌组织的石蜡切片进行免疫组化检测,分析其蛋白表达水平与甲状腺乳头状癌患者的临床病理特征的相关性,最后应用蛋白质表达图谱(The Human Protein Atlas,HPA)数据库探究WRAP53与PTC预后之间的关系。结果:qPR-PCR及免疫组化结果提示WRAP53在PTC中较正常组织高表达(P<0.05)。与WRAP53低表达的PTC患者相比,WRAP53高表达的PTC患者肿瘤直径更长,更易出现淋巴结转移(P<0.05)。HPA数据库显示WRAP53高表达的PTC患者的生存率差于WRAP53低表达的PTC患者(P=0.041)。结论:通过本次研究表明,WRAP53在PTC组织中表达较周围正常组织升高,且其高表达与PTC增殖、淋巴结转移及不良预后相关。WRAP53可能是治疗PTC新的潜在靶点。
文摘The centrifugal pump is a prevalent power equipment widely used in different engineering patterns,and the impeller blade wrap angle significantly impacts its performance.A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of 69.This study investigates six impellermodels that possess varying blade wrap angles(95°,105°,115°,125°,135°,and 145°)that were created while maintaining the same volute and other geometrical characteristics.The investigation of energy loss was conducted to evaluate the values of total and entropy generation rates(TEG,EGR).The fluid-structure interaction was considered numerically using the software tools ANSYS Fluent and ANSYSWorkbench.The elastic structural dynamic equation was used to estimate the structural response,while the shear stress transport k–ωturbulence model was utilized for the fluid domain modeling.The findings suggest that the blade wrap angle has a significant influence on the efficiency of the pump.The impeller featuring a blade wrap angle of 145°exhibits higher efficiency,with a notable increase of 3.76%relative to the original model.Variations in the blade wrap angle impact the energy loss,shaft power,and pump head.The model with a 145°angle exhibited a maximum equivalent stress of 14.8MPa and a total deformation of 0.084 mm.The results provide valuable insights into the intricate flow mechanism of the centrifugal pump,particularly when considering various blade wrap angles.
基金The National Natural Science Foundation of China(No.60573117)the National Basic Research Program of China(973 Program)(No.2007CB310805)
文摘A web service wrapping approach for command line programs,which are commonly used in scientific computing,is proposed.First,software architecture for a basic web service wrapper implementation is given and the functions of the main components are explained.Then after a comprehensive analysis of data transmission and a job life cycle model,a novel proactive file transmission and job management mechanism is devised to enhance the software architecture,and the command line programs are wrapped into web services in such a way that they can efficiently transmit files,supply instant status feedback and automatically manage the jobs.Experiments show that the proposed approach achieves higher performance with less memory usage compared to the related work, and the usability is also improved.This work has already been put into use in a production system of scientific computing and the data processing efficiency of the system is greatly improved.
文摘WRAP(Water Rights Analysis Package)水权分析模型是基于水资源优先分配制度来模拟和预测一个或多个流域内水资源使用及管理的模型。作者首次将WRAP水权分析模型应用于北京通州区,以1956～2007年通州区相关资料作为模型的计算数据,模拟与计算结果表明:通州地区的天然年径流总体趋势基本保持不变,调度径流呈微弱增长趋势,两者的年际变差均逐渐剧烈;历年的径流消耗量总体趋势亦基本不变,但回归流呈逐渐增长趋势;研究区内多年平均水量保证率为59.9%,工业用水、城镇生活用水和农村生活用水呈上升趋势,而农业用水量总体呈下降趋势。
文摘目的:探讨抑制p53的反义转录本WRAP53α基因表达对顺铂(cisplatin,CDDP)诱导人骨肉瘤U-2OS细胞凋亡的影响。方法:不同浓度的CDDP处理U-2OS细胞后,MTT法检测细胞的增殖率;不同浓度CDDP处理36 h和10μmol/L CDDP处理不同时间以及si WRAP53转染后,实时荧光定量PCR和蛋白质印迹法检测U-2OS细胞中WARAP53α和p53 m RNA及p53蛋白的表达水平;FCM法检测CDDP单独处理及si WRAP53转染后联合CDDP处理组U-2OS细胞的凋亡率。结果:CDDP处理后,U-2OS细胞的增殖率低于未处理的对照组(P<0.05),且呈浓度依赖性。CDDP处理后,U-2OS细胞中WRAP53αm RNA的表达水平明显高于未处理的空白对照组(P<0.05),且呈浓度和时间依赖性;p53 m RNA及p53蛋白的表达水平高于空白对照组(P<0.05)。si WRAP53转染后,WRAP53α和p53 m RNA及p53蛋白的表达水平低于空白对照组(P<0.05)。CDDP单独给药组U-2OS细胞凋亡率高于si WRAP53α转染联合CDDP处理组(P<0.05),2组细胞的凋亡率均高于空白对照组(P<0.05)。结论:CDDP可抑制U-2OS细胞的增殖,诱导WRAP53α和p53 m RNA及p53蛋白的表达;干扰WRAP53α基因的表达可下调p53的表达水平,并逆转CDDP诱导的细胞凋亡。
基金supported by National Natural Science Foundation of China(Grant Nos.51176088,51179090)National Basic Research Program of China(973 Program,Grant No.2009CB724304)+1 种基金General Financial Grant from the China Postdoctoral Science Foundation(Grant No.2011M500315)Open Research Fund Program of State Key Laboratory of Hydroscience and Engineering of China(Grant No.sklhse-2012-E-02)
文摘The existing research on improving the hydraulic performance of centrifugal pumps mainly focuses on the design method and the parameter optimization. The traditional design method for centrifugal impellers relies more on experience of engineers that typically only satisfies the continuity equation of the fluid. In this study, on the basis of the direct and inverse iteration design method which simultaneously solves the continuity and motion equations of the fluid and shapes the blade geometry by controlling the wrap angle, three centrifugal pump impellers are designed by altering blade wrap angles while keeping other parameters constant. The three-dimensional flow fields in three centrifugal pumps are numerically simulated, and the simulation results illustrate that the blade with larger wrap angle has more powerful control ability on the flow pattern in impeller. The three pumps have nearly the same pressure distributions at the small flow rate, but the pressure gradient increase in the pump with the largest wrap angle is smoother than the other two pumps at the design and large flow rates. The pump head and efficiency are also influenced by the blade wrap angle. The highest head and efficiency are also observed for the largest angle. An experiment rig is designed and built to test the performance of the pump with the largest wrap angle. The test results show that the wide space of its efficiency area and the stability of its operation ensure the excellent performance of the design method and verify the numerical analysis. The analysis on influence of the blade wrap angle for centrifugal pump performance in this paper can be beneficial to the optimization design of the centrifugal pump.
基金Item Sponsored by National Science and Technology Support Plan of China(2007BAF02B10)Natural Science Foundation of Hebei Province of China(E2011203004)
文摘In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously affects online shape detecting precision of cold strip. Based on the latest intelligent shape meter developed by Yanshan University, using PSO-BP neural network and actual working condition datum, the cold strip online dynamic wrapping angle compensation model is established, and successfully applied in 1250 mm 6-high cold mill, remarkable results are achieved. The error between calculated values and measured values of total tensions is within 3 %
