To overcome the shortcomings of conventional plasma arc welding （ PAW）, the ＇ controlled pulse key-holing＇ strategy is proposed and the keyhole PAW experiment system is developed. ＇The efflux plasma voltage signa...To overcome the shortcomings of conventional plasma arc welding （ PAW）, the ＇ controlled pulse key-holing＇ strategy is proposed and the keyhole PAW experiment system is developed. ＇The efflux plasma voltage signal is detected in realtime to characterize the keyhole size and dimension. The welding current waveform for controlled pulse key-holing strategy is implemented, and two slow-decreasing slopes are added at the dropping point from peak current to base current to further reduce both heat input and arc force so that the controllability of keyhole dynamics is improved. Two kinds of PAW tests are conducted, anti the different parameters of the controlled pulse current and the relevant efflux plasma voltage are measured in real-time to investigate ihe effects of welding current waveform parameters on the key-holing condition.展开更多
Laparoscopic surgery has many advantages over open surgery.At the same time,it is not without its risks.In this review,we discuss steps that could enhance the safety of laparoscopic surgery.Some of the important safet...Laparoscopic surgery has many advantages over open surgery.At the same time,it is not without its risks.In this review,we discuss steps that could enhance the safety of laparoscopic surgery.Some of the important safety considerations are ruling out pregnancy in women of the childbearing age group;advanced discussion with the patient regarding unexpected intraoperative situations,and ensuring appropriate equipment is available.Important perioperative safety considerations include thromboprophylaxis;antibiotic prophylaxis;patient allergies;proper positioning of the patient,stack,and monitor(s);patient appropriate pneumoperitoneum;ergonomic port placement;use of lowest possible intra-abdominal pressure;use of additional five-millimetre(mm)ports as needed;safe use of energy devices and laparoscopic staplers;low threshold for a second opinion;backing out if unsafe to proceed;avoiding hand-over in the middle of the procedure;ensuring all planned procedures have been performed;inclusion of laparoscopic retrieval bags and specimens in the operating count;avoiding 10-15 mm ports for placement of drains;appropriate port closures;and use of long-acting local anaesthetic agents for analgesia.Important postoperative considerations include adequate analgesia;early ambulation;careful attention to early warning scores;and appropriate discharge advice.展开更多
This study was designed to compare the approaches and efficacies of two different ways of neurosurgical management for spontaneous putaminal hemorrhage(SPH):computed tomographic-guided aspiration(CTGA)and the key-hole...This study was designed to compare the approaches and efficacies of two different ways of neurosurgical management for spontaneous putaminal hemorrhage(SPH):computed tomographic-guided aspiration(CTGA)and the key-hole approach(KHA).The indications of the two approaches are also explored.From September 2001 to 2003,a total of 1077 cases of SPH distributed in 135 hospitals all over the mainland of China were included for analysis.All cases had three-month follow-up data.The study was designed in a single-blinded manner to compare the efficacies of the different approaches.There were 563 cases in the CTGA group,165 in the KHA group,and 217 cases in the conventional open craniotomy(COC)group.In the CTGA and KHA groups,the mortalities at one month after operation(M1m)were 17.9% and 18.3%,respectively,while the mortalities at three months after operation(M3m)were 19.4% and 19.4%,respectively(P>0.05).The postoperative complications due to CTGA(23.7%)were not significantly different from those due to KHA(25.7%)(P=0.420).The M3m of patients with Glasgow coma scale(GCS)h8 was 3.45 and 4.0 times as much as those with GCS>8,respectively.The M3m of patients with complications was 3.92 times as much as those without complications.The M3m of patients with hemorrhage volume ≥70 mL was 2.67 times as much as those<70 mL.The CTGA is not better than KHA in the treatment of SPH in terms of a more favorable outcome or less mor tality and morbidity,but CTGA could be the first choice for those with bleeding volumes ≤50mL,while KHA is the first choice for those with bleeding volumes>50 mL.展开更多
基金Acknowledgement The authors are grateful to the financial support for this research from the National Natural Science Foundation of China （Key Program Grant No. 50936003）.
文摘To overcome the shortcomings of conventional plasma arc welding （ PAW）, the ＇ controlled pulse key-holing＇ strategy is proposed and the keyhole PAW experiment system is developed. ＇The efflux plasma voltage signal is detected in realtime to characterize the keyhole size and dimension. The welding current waveform for controlled pulse key-holing strategy is implemented, and two slow-decreasing slopes are added at the dropping point from peak current to base current to further reduce both heat input and arc force so that the controllability of keyhole dynamics is improved. Two kinds of PAW tests are conducted, anti the different parameters of the controlled pulse current and the relevant efflux plasma voltage are measured in real-time to investigate ihe effects of welding current waveform parameters on the key-holing condition.
文摘Laparoscopic surgery has many advantages over open surgery.At the same time,it is not without its risks.In this review,we discuss steps that could enhance the safety of laparoscopic surgery.Some of the important safety considerations are ruling out pregnancy in women of the childbearing age group;advanced discussion with the patient regarding unexpected intraoperative situations,and ensuring appropriate equipment is available.Important perioperative safety considerations include thromboprophylaxis;antibiotic prophylaxis;patient allergies;proper positioning of the patient,stack,and monitor(s);patient appropriate pneumoperitoneum;ergonomic port placement;use of lowest possible intra-abdominal pressure;use of additional five-millimetre(mm)ports as needed;safe use of energy devices and laparoscopic staplers;low threshold for a second opinion;backing out if unsafe to proceed;avoiding hand-over in the middle of the procedure;ensuring all planned procedures have been performed;inclusion of laparoscopic retrieval bags and specimens in the operating count;avoiding 10-15 mm ports for placement of drains;appropriate port closures;and use of long-acting local anaesthetic agents for analgesia.Important postoperative considerations include adequate analgesia;early ambulation;careful attention to early warning scores;and appropriate discharge advice.
文摘This study was designed to compare the approaches and efficacies of two different ways of neurosurgical management for spontaneous putaminal hemorrhage(SPH):computed tomographic-guided aspiration(CTGA)and the key-hole approach(KHA).The indications of the two approaches are also explored.From September 2001 to 2003,a total of 1077 cases of SPH distributed in 135 hospitals all over the mainland of China were included for analysis.All cases had three-month follow-up data.The study was designed in a single-blinded manner to compare the efficacies of the different approaches.There were 563 cases in the CTGA group,165 in the KHA group,and 217 cases in the conventional open craniotomy(COC)group.In the CTGA and KHA groups,the mortalities at one month after operation(M1m)were 17.9% and 18.3%,respectively,while the mortalities at three months after operation(M3m)were 19.4% and 19.4%,respectively(P>0.05).The postoperative complications due to CTGA(23.7%)were not significantly different from those due to KHA(25.7%)(P=0.420).The M3m of patients with Glasgow coma scale(GCS)h8 was 3.45 and 4.0 times as much as those with GCS>8,respectively.The M3m of patients with complications was 3.92 times as much as those without complications.The M3m of patients with hemorrhage volume ≥70 mL was 2.67 times as much as those<70 mL.The CTGA is not better than KHA in the treatment of SPH in terms of a more favorable outcome or less mor tality and morbidity,but CTGA could be the first choice for those with bleeding volumes ≤50mL,while KHA is the first choice for those with bleeding volumes>50 mL.
