Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator facilities.An RFQ with a high frequency of 714 MHz dedicated to compact pro...Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator facilities.An RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medi-cal applications is designed in this study.The RFQ is designed to accelerate proton beams from 50 keV to 4 MeV within a short length of 2 m and can be matched closely with the downstream drift tube linac to capture more particles through a preliminary optimization.To develop an advanced RFQ,challenging techniques,including fabrication and tuning method,must be evaluated and verified using a prototype.An aluminium prototype is derived from the conceptual design of the RFQ and then redesigned to confirm the radio frequency performance,fabrication procedure,and feasibility of the tuning algorithm.Eventually,a new tuning algorithm based on the response matrix and least-squares method is developed,which yields favorable results based on the prototype,i.e.,the errors of the dipole and quadrupole components reduced to a low level after several tuning iterations.Benefiting from the conceptual design and techniques obtained from the prototype,the formal mechanical design of the 2-m RFQ is ready for the next manufacturing step.展开更多
AIM:To compare the effectiveness of needle-free incision suture closure with butterfly tape and traditional secondary suturing techniques in treating incision infection.METHODS:Two hundred and twenty-three patients wi...AIM:To compare the effectiveness of needle-free incision suture closure with butterfly tape and traditional secondary suturing techniques in treating incision infection.METHODS:Two hundred and twenty-three patients with incision infection following hepatobiliary surgery at a tertiary hospital were randomly divided into three groups:90 patients were closed by needle-free incision suture closure,which gradually closed the incision wound when drainage from incision infection was visibly decreased and healthy granulation tissues had grown;79 patients were closed by butterfly bandage;another 54 patients were closed by traditional secondary suturing technique.Healing time of incision infection was calculated from the beginning of dressing change to the healing of the incision.RESULTS:Healing time in the needle-free incision suture closure group(24.2±7.2 d)was significantly shorter than that in the butterfly bandage group(33.3±11.2 d)and the traditional secondary suturing group(36.2±15.3 d)(P<0.05).Healing time in the butterfly bandage group appeared to be slightly shorter than that in the secondary suture group,but the difference was not statistically significant(P>0.05).CONCLUSION:Needle-free incision suture closure could gradually close the infection wound at the same time of drainage and dressing change,thereby shortening the healing time.展开更多
基金This work was supported by National Natural Science Foundation of China(No.12222513).
文摘Radio frequency quadrupoles(RFQs),which are crucial components of proton injectors,significantly affect the performance of proton accelerator facilities.An RFQ with a high frequency of 714 MHz dedicated to compact proton injectors for medi-cal applications is designed in this study.The RFQ is designed to accelerate proton beams from 50 keV to 4 MeV within a short length of 2 m and can be matched closely with the downstream drift tube linac to capture more particles through a preliminary optimization.To develop an advanced RFQ,challenging techniques,including fabrication and tuning method,must be evaluated and verified using a prototype.An aluminium prototype is derived from the conceptual design of the RFQ and then redesigned to confirm the radio frequency performance,fabrication procedure,and feasibility of the tuning algorithm.Eventually,a new tuning algorithm based on the response matrix and least-squares method is developed,which yields favorable results based on the prototype,i.e.,the errors of the dipole and quadrupole components reduced to a low level after several tuning iterations.Benefiting from the conceptual design and techniques obtained from the prototype,the formal mechanical design of the 2-m RFQ is ready for the next manufacturing step.
基金Supported by National Nature Science Foundation of China,No.30801111 and No.30972923Science and Technology Sup-port Project of Sichuan Province No.14ZC1337,No.14ZC1335 and No.2014SZ0002-10
文摘AIM:To compare the effectiveness of needle-free incision suture closure with butterfly tape and traditional secondary suturing techniques in treating incision infection.METHODS:Two hundred and twenty-three patients with incision infection following hepatobiliary surgery at a tertiary hospital were randomly divided into three groups:90 patients were closed by needle-free incision suture closure,which gradually closed the incision wound when drainage from incision infection was visibly decreased and healthy granulation tissues had grown;79 patients were closed by butterfly bandage;another 54 patients were closed by traditional secondary suturing technique.Healing time of incision infection was calculated from the beginning of dressing change to the healing of the incision.RESULTS:Healing time in the needle-free incision suture closure group(24.2±7.2 d)was significantly shorter than that in the butterfly bandage group(33.3±11.2 d)and the traditional secondary suturing group(36.2±15.3 d)(P<0.05).Healing time in the butterfly bandage group appeared to be slightly shorter than that in the secondary suture group,but the difference was not statistically significant(P>0.05).CONCLUSION:Needle-free incision suture closure could gradually close the infection wound at the same time of drainage and dressing change,thereby shortening the healing time.
