BACKGROUND A one-stage laparoscopic operation has recently been considered a favorable option for the management of patients with Hirschsprung's disease(HD)due to its superior cosmetic results.One-stage transanal ...BACKGROUND A one-stage laparoscopic operation has recently been considered a favorable option for the management of patients with Hirschsprung's disease(HD)due to its superior cosmetic results.One-stage transanal endorectal pull-through for the treatment of rectosigmoid HD has been widely used in newborns without complications.However,enterostomy is required in some HD cases for enterocolitis and dilated colon.Our transumbilical enterostomy(TUE)and twostage laparoscopy-assisted anorectoplasty were effective and achieved a similar cosmetic effect to one-stage laparoscopy on the abdominal wall in patients with anorectal malformation,but the effect in patients with HD is unclear.AIM To evaluate the safety,efficacy and cosmetic results of TUE in two-stage laparoscopy-assisted pull-through for HD.METHODS From June 2013 to June 2018,53 patients(40 boys,13 girls;mean age at enterostomy:5.5±2.2 mo)who underwent enterostomy and two-stage laparoscopy-assisted pull-through for HD with stoma closure were reviewed at our institution.Two enterostomy approaches were used:TUE in 24 patients,and conventional abdominal enterostomy(CAE)in 29 patients.Eleven patients with rectosigmoid HD had severe preoperative enterocolitis or a dilated colon.26 patients had long-segment HD,and 16 patients had total colonic aganglionosis(TCA).The patients with left-sided HD underwent the two-stage laparoscopic Soave procedure,and the patients with right-sided HD and TCA underwent the laparoscopic Duhamel procedure.Demographics,enterostomy operative time,complications and cosmetic results were respectively evaluated.RESULTS There were no differences between the groups with respect to gender,age at enterostomy,weight and clinical type(P>0.05).No conversion to open technique was required.Two patients experienced episodes of stomal mucosal prolapse in the TUE group and 1 patient in the CAE group(8.33%vs 3.45%,P>0.05).No parastomal hernia was observed in either of the two groups.Wound infection at the stoma was seen in 1 case in the TUE group,and 2 cases in the CAE group(4.17%vs 6.90%,P>0.05).No obstruction was noted in any of the patients in the TUE group,whereas obstruction was found in 1 patient in the CAE group.Enterocolitis was observed in 3 and 5 patients in the TUE and CAE group,respectively(12.50%vs 17.24%,P>0.05).There was no significant difference between the TUE group and CAE group in terms of the incidence of soiling and constipation(P>0.05).The cosmetic result using the scar score in the TUE group was better than that in the CAE group(6.83±0.96 vs 13.32±1.57,P<0.05).CONCLUSION TUE is a safe and feasible method for the treatment of HD,and the staged enterostomy and two-stage laparoscopy-assisted pull-through achieved a similar cosmetic effect to the one-stage laparoscopic procedure.展开更多
The paper proposes a novel zero current transition (ZCT) push pull forward converter. The auxiliary resonant cell is in parallel with the main circuit and the zero current switching (ZCS) range of the main and the aux...The paper proposes a novel zero current transition (ZCT) push pull forward converter. The auxiliary resonant cell is in parallel with the main circuit and the zero current switching (ZCS) range of the main and the auxiliary switches of the proposed converter are entirely achieved. The resonant capacitor achieves high voltage by operating the auxiliary cell. The auxiliary switch turns on before the main switches turn off, the high voltage of resonant capacitor blanks off the rectifier, and then the curr...展开更多
The application areas of conventional push pull converters are limited because of high voltage stress of switches (twice of input voltage). This paper presents a novel zero voltage and zero current switching (ZCS)...The application areas of conventional push pull converters are limited because of high voltage stress of switches (twice of input voltage). This paper presents a novel zero voltage and zero current switching (ZCS) PWM push pull three level converter in which the voltage stress of switches is input voltage. With phase shifted modulation strategy, the leading switches can only realize zero voltage switching (ZVS), and the lagging switches can realize ZCS when block capacitor and block diodes are added. Using the strategy, the converter overcomes the drawbacks presented by the conventional push pull converter, such as magnetic aberration, large switch loss, and voltage spike on switches, so it can get higher efficiency, and a wider application area. The operating principle of the new converter is analyzed and verified on a 600 W, 50 kHz experimental prototype. Several zero voltage and zero current switching PWM push pull three level converters are proposed.展开更多
针对 WAP不同于有线 Internet的特点研究新的信息获取模式具有重要的意义 .本文在对比分析 PUSH和PUL L 两种信息获取模式的基础上 ,提出了更有效的 PU SH/ PU L L 集成应用模式 ,详细阐述了 WAP针对 PUSH定义的实体、相关协议及其实体...针对 WAP不同于有线 Internet的特点研究新的信息获取模式具有重要的意义 .本文在对比分析 PUSH和PUL L 两种信息获取模式的基础上 ,提出了更有效的 PU SH/ PU L L 集成应用模式 ,详细阐述了 WAP针对 PUSH定义的实体、相关协议及其实体分布体系 ,重点探讨了 PUSH机制的实现方法 .本文所提出的集成应用思想 ,通过最后给出的展开更多
基金Supported by the Public Welfare Research and Special Fund of the National Health and Family Planning of China,No.201402007
文摘BACKGROUND A one-stage laparoscopic operation has recently been considered a favorable option for the management of patients with Hirschsprung's disease(HD)due to its superior cosmetic results.One-stage transanal endorectal pull-through for the treatment of rectosigmoid HD has been widely used in newborns without complications.However,enterostomy is required in some HD cases for enterocolitis and dilated colon.Our transumbilical enterostomy(TUE)and twostage laparoscopy-assisted anorectoplasty were effective and achieved a similar cosmetic effect to one-stage laparoscopy on the abdominal wall in patients with anorectal malformation,but the effect in patients with HD is unclear.AIM To evaluate the safety,efficacy and cosmetic results of TUE in two-stage laparoscopy-assisted pull-through for HD.METHODS From June 2013 to June 2018,53 patients(40 boys,13 girls;mean age at enterostomy:5.5±2.2 mo)who underwent enterostomy and two-stage laparoscopy-assisted pull-through for HD with stoma closure were reviewed at our institution.Two enterostomy approaches were used:TUE in 24 patients,and conventional abdominal enterostomy(CAE)in 29 patients.Eleven patients with rectosigmoid HD had severe preoperative enterocolitis or a dilated colon.26 patients had long-segment HD,and 16 patients had total colonic aganglionosis(TCA).The patients with left-sided HD underwent the two-stage laparoscopic Soave procedure,and the patients with right-sided HD and TCA underwent the laparoscopic Duhamel procedure.Demographics,enterostomy operative time,complications and cosmetic results were respectively evaluated.RESULTS There were no differences between the groups with respect to gender,age at enterostomy,weight and clinical type(P>0.05).No conversion to open technique was required.Two patients experienced episodes of stomal mucosal prolapse in the TUE group and 1 patient in the CAE group(8.33%vs 3.45%,P>0.05).No parastomal hernia was observed in either of the two groups.Wound infection at the stoma was seen in 1 case in the TUE group,and 2 cases in the CAE group(4.17%vs 6.90%,P>0.05).No obstruction was noted in any of the patients in the TUE group,whereas obstruction was found in 1 patient in the CAE group.Enterocolitis was observed in 3 and 5 patients in the TUE and CAE group,respectively(12.50%vs 17.24%,P>0.05).There was no significant difference between the TUE group and CAE group in terms of the incidence of soiling and constipation(P>0.05).The cosmetic result using the scar score in the TUE group was better than that in the CAE group(6.83±0.96 vs 13.32±1.57,P<0.05).CONCLUSION TUE is a safe and feasible method for the treatment of HD,and the staged enterostomy and two-stage laparoscopy-assisted pull-through achieved a similar cosmetic effect to the one-stage laparoscopic procedure.
文摘The paper proposes a novel zero current transition (ZCT) push pull forward converter. The auxiliary resonant cell is in parallel with the main circuit and the zero current switching (ZCS) range of the main and the auxiliary switches of the proposed converter are entirely achieved. The resonant capacitor achieves high voltage by operating the auxiliary cell. The auxiliary switch turns on before the main switches turn off, the high voltage of resonant capacitor blanks off the rectifier, and then the curr...
文摘The application areas of conventional push pull converters are limited because of high voltage stress of switches (twice of input voltage). This paper presents a novel zero voltage and zero current switching (ZCS) PWM push pull three level converter in which the voltage stress of switches is input voltage. With phase shifted modulation strategy, the leading switches can only realize zero voltage switching (ZVS), and the lagging switches can realize ZCS when block capacitor and block diodes are added. Using the strategy, the converter overcomes the drawbacks presented by the conventional push pull converter, such as magnetic aberration, large switch loss, and voltage spike on switches, so it can get higher efficiency, and a wider application area. The operating principle of the new converter is analyzed and verified on a 600 W, 50 kHz experimental prototype. Several zero voltage and zero current switching PWM push pull three level converters are proposed.
文摘针对 WAP不同于有线 Internet的特点研究新的信息获取模式具有重要的意义 .本文在对比分析 PUSH和PUL L 两种信息获取模式的基础上 ,提出了更有效的 PU SH/ PU L L 集成应用模式 ,详细阐述了 WAP针对 PUSH定义的实体、相关协议及其实体分布体系 ,重点探讨了 PUSH机制的实现方法 .本文所提出的集成应用思想 ,通过最后给出的
