针对舰艇编队航渡过程中的多架舰载反潜直升机前出执行伴随反潜作战问题进行研究。通过分析潜射鱼雷射距,建立了理想条件与编队规避机动两种情况下的鱼雷攻击阵位模型,从而得出伴随反潜区的阵位配置。在此基础上,对编队航渡过程中的多...针对舰艇编队航渡过程中的多架舰载反潜直升机前出执行伴随反潜作战问题进行研究。通过分析潜射鱼雷射距,建立了理想条件与编队规避机动两种情况下的鱼雷攻击阵位模型,从而得出伴随反潜区的阵位配置。在此基础上,对编队航渡过程中的多机伴随反潜方法进行了分析,并建立了伴随反潜兵力需求与探测概率模型。最后仿真计算了潜射鱼雷发射阵位,以及反潜兵力数量、探测次数、伴随反潜区大小对发现概率的影响。结果表明,伴随反潜区配置在编队前方20 n mile处,大小为20 n mile×30 n mile,反潜直升机数量3架为宜。展开更多
AIM:To evaluate the safety and effectiveness of twostage vs single-stage management for concomitant gallstones and common bile duct stones.METHODS:Four databases,including PubMed,Embase,the Cochrane Central Register o...AIM:To evaluate the safety and effectiveness of twostage vs single-stage management for concomitant gallstones and common bile duct stones.METHODS:Four databases,including PubMed,Embase,the Cochrane Central Register of Controlled Trials and the Science Citation Index up to September 2011,were searched to identify all randomized controlled trials(RCTs).Data were extracted from the studies by two independent reviewers.The primary outcomes were stone clearance from the common bile duct,postoperative morbidity and mortality.The secondary outcomes were conversion to other procedures,number of procedures per patient,length of hospital stay,total operative time,hospitalization charges,patient acceptance and quality of life scores.RESULTS:Seven eligible RCTs [five trials(n = 621) comparing preoperative endoscopic retrograde cholangiopancreatography(ERCP)/endoscopic sphincterotomy(EST) + laparoscopic cholecystectomy(LC) with LC + laparoscopic common bile duct exploration(LCBDE);two trials(n = 166) comparing postoperative ERCP/EST + LC with LC + LCBDE],composed of 787 patients in total,were included in the final analysis.The metaanalysis detected no statistically significant difference between the two groups in stone clearance from the common bile duct [risk ratios(RR) =-0.10,95% confidence intervals(CI):-0.24 to 0.04,P = 0.17],postoperative morbidity(RR = 0.79,95% CI:0.58 to 1.10,P = 0.16),mortality(RR = 2.19,95% CI:0.33 to 14.67,P = 0.42),conversion to other procedures(RR = 1.21,95% CI:0.54 to 2.70,P = 0.39),length of hospital stay(MD = 0.99,95% CI:-1.59 to 3.57,P = 0.45),total operative time(MD = 12.14,95% CI:-1.83 to 26.10,P = 0.09).Two-stage(LC + ERCP/EST) management clearly required more procedures per patient than single-stage(LC + LCBDE) management.CONCLUSION:Single-stage management is equivalent to two-stage management but requires fewer procedures.However,patient's condition,operator's expertise and local resources should be taken into account in making treatment decisions.展开更多
Objective:Hepatocellular carcinoma (HCC) is among the most common and rapidly increasing cancers in Pakistan.There is currently no standard management for advanced HCC.The aim of the study was to assess response rate ...Objective:Hepatocellular carcinoma (HCC) is among the most common and rapidly increasing cancers in Pakistan.There is currently no standard management for advanced HCC.The aim of the study was to assess response rate and toxicity of concomitant gemcitabine and external radiation therapy (ERT) in locally advanced HCC.Methods:Sixty patients were enrolled.Gemcitabine,70 mg/m2 was given weekly during ERT.ERT was delivered with 60Co beam up to 30.6 Gy,1.8 Gy/fraction.Tumor response was assessed by computed tomography (CT) at eight weeks.Complete and partial response (CR and PR),progressive and stable disease (PD and SD) were assessed.Hematological,gastrointestinal and hepatic toxicities were assessed weekly.Results:No CR was seen.PR,SD and PD were seen in 33%,40% and 27% of patients respectively.Grade 3/4 toxicity for total leukocyte count and platelets was observed in 7% and 27% patients.Grade 3/4 toxicity for liver failure,bilirubin,aspartate aminotransferase,alanine aminotransferase and alkaline phosphatase was seen in 35%,28%,38%,24% and 43% patients respectively.Conclusion:The study showed that concomitant gemcitabine and ERT is a feasible option with moderate toxicity in advanced HCC.展开更多
Adjoint-based optimization method is a hotspot in turbomachinery.First,this paper presents principles of adjoint method from Lagrange multiplier viewpoint.Second,combining a continuous route with thin layer RANS equat...Adjoint-based optimization method is a hotspot in turbomachinery.First,this paper presents principles of adjoint method from Lagrange multiplier viewpoint.Second,combining a continuous route with thin layer RANS equations,we formulate adjoint equations and anti-physical boundary conditions.Due to the multi-stage environment in turbomachinery,an adjoint interrow mixing method is introduced.Numerical techniques of solving flow equations and adjoint equations are almost the same,and once they are converged respectively,the gradients of an objective function to design variables can be calculated using complex method efficiently.Third,integrating a shape perturbation parameterization and a simple steepest descent method,a frame of adjoint-based aerodynamic shape optimization for multi-stage turbomachinery is constructed.At last,an inverse design of an annular cascade is employed to validate the above approach,and adjoint field of an Aachen 1.5 stage turbine demonstrates the conservation and areflexia of the adjoint interrow mixing method.Then a direct redesign of a 1+1 counter-rotating turbine aiming to increase efficiency and apply constraints to mass flow rate and pressure ratio is taken.展开更多
文摘针对舰艇编队航渡过程中的多架舰载反潜直升机前出执行伴随反潜作战问题进行研究。通过分析潜射鱼雷射距,建立了理想条件与编队规避机动两种情况下的鱼雷攻击阵位模型,从而得出伴随反潜区的阵位配置。在此基础上,对编队航渡过程中的多机伴随反潜方法进行了分析,并建立了伴随反潜兵力需求与探测概率模型。最后仿真计算了潜射鱼雷发射阵位,以及反潜兵力数量、探测次数、伴随反潜区大小对发现概率的影响。结果表明,伴随反潜区配置在编队前方20 n mile处,大小为20 n mile×30 n mile,反潜直升机数量3架为宜。
文摘AIM:To evaluate the safety and effectiveness of twostage vs single-stage management for concomitant gallstones and common bile duct stones.METHODS:Four databases,including PubMed,Embase,the Cochrane Central Register of Controlled Trials and the Science Citation Index up to September 2011,were searched to identify all randomized controlled trials(RCTs).Data were extracted from the studies by two independent reviewers.The primary outcomes were stone clearance from the common bile duct,postoperative morbidity and mortality.The secondary outcomes were conversion to other procedures,number of procedures per patient,length of hospital stay,total operative time,hospitalization charges,patient acceptance and quality of life scores.RESULTS:Seven eligible RCTs [five trials(n = 621) comparing preoperative endoscopic retrograde cholangiopancreatography(ERCP)/endoscopic sphincterotomy(EST) + laparoscopic cholecystectomy(LC) with LC + laparoscopic common bile duct exploration(LCBDE);two trials(n = 166) comparing postoperative ERCP/EST + LC with LC + LCBDE],composed of 787 patients in total,were included in the final analysis.The metaanalysis detected no statistically significant difference between the two groups in stone clearance from the common bile duct [risk ratios(RR) =-0.10,95% confidence intervals(CI):-0.24 to 0.04,P = 0.17],postoperative morbidity(RR = 0.79,95% CI:0.58 to 1.10,P = 0.16),mortality(RR = 2.19,95% CI:0.33 to 14.67,P = 0.42),conversion to other procedures(RR = 1.21,95% CI:0.54 to 2.70,P = 0.39),length of hospital stay(MD = 0.99,95% CI:-1.59 to 3.57,P = 0.45),total operative time(MD = 12.14,95% CI:-1.83 to 26.10,P = 0.09).Two-stage(LC + ERCP/EST) management clearly required more procedures per patient than single-stage(LC + LCBDE) management.CONCLUSION:Single-stage management is equivalent to two-stage management but requires fewer procedures.However,patient's condition,operator's expertise and local resources should be taken into account in making treatment decisions.
文摘Objective:Hepatocellular carcinoma (HCC) is among the most common and rapidly increasing cancers in Pakistan.There is currently no standard management for advanced HCC.The aim of the study was to assess response rate and toxicity of concomitant gemcitabine and external radiation therapy (ERT) in locally advanced HCC.Methods:Sixty patients were enrolled.Gemcitabine,70 mg/m2 was given weekly during ERT.ERT was delivered with 60Co beam up to 30.6 Gy,1.8 Gy/fraction.Tumor response was assessed by computed tomography (CT) at eight weeks.Complete and partial response (CR and PR),progressive and stable disease (PD and SD) were assessed.Hematological,gastrointestinal and hepatic toxicities were assessed weekly.Results:No CR was seen.PR,SD and PD were seen in 33%,40% and 27% of patients respectively.Grade 3/4 toxicity for total leukocyte count and platelets was observed in 7% and 27% patients.Grade 3/4 toxicity for liver failure,bilirubin,aspartate aminotransferase,alanine aminotransferase and alkaline phosphatase was seen in 35%,28%,38%,24% and 43% patients respectively.Conclusion:The study showed that concomitant gemcitabine and ERT is a feasible option with moderate toxicity in advanced HCC.
文摘Adjoint-based optimization method is a hotspot in turbomachinery.First,this paper presents principles of adjoint method from Lagrange multiplier viewpoint.Second,combining a continuous route with thin layer RANS equations,we formulate adjoint equations and anti-physical boundary conditions.Due to the multi-stage environment in turbomachinery,an adjoint interrow mixing method is introduced.Numerical techniques of solving flow equations and adjoint equations are almost the same,and once they are converged respectively,the gradients of an objective function to design variables can be calculated using complex method efficiently.Third,integrating a shape perturbation parameterization and a simple steepest descent method,a frame of adjoint-based aerodynamic shape optimization for multi-stage turbomachinery is constructed.At last,an inverse design of an annular cascade is employed to validate the above approach,and adjoint field of an Aachen 1.5 stage turbine demonstrates the conservation and areflexia of the adjoint interrow mixing method.Then a direct redesign of a 1+1 counter-rotating turbine aiming to increase efficiency and apply constraints to mass flow rate and pressure ratio is taken.
