We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagati...We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagation were compared in our investigation.The results show that flowing water results in drops of seepage pressure,development of penetration radii in the upstream side and drops of propagation area during the same period,compared with grouting in static water.The propagation area in static water is always round before grouts reach the joint boundaries.However,the propagation shape changes from round to an elliptic shape for grouting into a fracture with flowing water.A theoretical model for the grout penetration radius in a fracture considering flowing velocity was developed and validated by our experimental results.These results are helpful in improving understanding of fracture grouting mechanism and in guiding engineering practices.展开更多
Purpose： To explore the advantages of palmar approach with Kirschner-wire （K-wire） fixation in the treatment of children＇s distal radius extension type fracture, Methods： Thirty patients, average age of 8.5 years...Purpose： To explore the advantages of palmar approach with Kirschner-wire （K-wire） fixation in the treatment of children＇s distal radius extension type fracture, Methods： Thirty patients, average age of 8.5 years ranging from 5 to 13 years, with distal radius extension type fracture and undergoing a failed manual reposition in our hospital were included, and treated by palmar approach with K-wire fixation between May 2014 and December 2017. Among these patients （21 male and 9 female）, 5 patients had chronic injuries over 10 days, and 6 patients had fracture of the distal radius epiphysis. The time between injury and treatment ranged from 1 to 30 days. Among them, 11 patients with right-sided fractures and 19 patients with left-sided fractures were operated via the palmar longitudinal incision approach. Results： The results were evaluated after an average of 18 months ranging from 5 to 36 months after operation. The recovery time of fracture was from 4 to 8 weeks and all incisions were primary healing with an average of 6 weeks. Nonunion, delayed union, early closure of distal radial epiphysis, and wrist varus/valgus deformity were not found in all the cases. Based on Gartland and Wereley wrist score assessment undertaken three months after operation, excellent scores were achieved in 24 cases, good scores in 3 cases, acceptable scores in 3 cases. Conclusion： The palmar approach with K-wire fixation via a front longitudinal incision in the treatment of children＇s distal radius extension type fracture has following advantages： （1） easy to reposition for both fresh and old fractures; （2） less damage to surrounding tissues and epiphysis; （3） quick recovery. It is suitable to treat children＇s distal radius extension type fracture.展开更多
Purpose： To study the effects of surgical and nonoperative treatment on wrist function in patients with distal radius fracture. Methods： In total, 97 patients treated for distal radius fracture in the Department of ...Purpose： To study the effects of surgical and nonoperative treatment on wrist function in patients with distal radius fracture. Methods： In total, 97 patients treated for distal radius fracture in the Department of Orthopedic Trauma at the People＇s Hospital of Peking University from Jan. 2010 to Jun. 2016 were selected for outpatient follow-up, including manipulative reduction and dorsal splint fixation in 24 cases, bivalve cast fixation in 19 cases and open reduction and internal fixation in 54 cases. Evaluation was based on Sartiento＇s modification of the Gartland and Werley score. Efficacy was assessed with wrist pain as the focus. Results： The wrist function scores of the surgical group were better than nonoperative groups. There was no significant difference in wrist function scores between the dorsal splint group and the bivalve cast group. The ulnar wrist pain incidence had no significant difference in surgical and nonoperative groups. The displace rate in dorsal splint group was higher than other groups. Conclusion： The overall effect of surgical treatment of distal radius fracture is better than nonoperative treatment. The ulnar wrist pain incidence has no significant difference in these groups. Dorsal splint fixation is more prone to displace than bivalve cast fixation.展开更多
The recognition and binding of proteins through the "fly-casting" mechanism are important biological processes. In this paper, a physical model for fly-casting binding is described based on the capillarity t...The recognition and binding of proteins through the "fly-casting" mechanism are important biological processes. In this paper, a physical model for fly-casting binding is described based on the capillarity theory for protein chains. It is found that the capture radius for the fly-casting binding process is maximized at the transition temperature at which the free energy of the monomeric extended state of the protein equals that of the folded state. The factors related to the folding barrier or binding affinity do not change the condition needed to realize the optimization for fly-casting processes. These results will aid in the comprehensive understanding of binding processes.展开更多
基金Financial support for this work,provided by the National Natural Science Foundation of China(Nos.40772192 and 41072237)the State Key Laboratort of Geomechanics and Deep Underground Engineering(No.SKLGDUEK0903)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20100095110015)
文摘We present a series of experimental tests on chemical grouting into a fracture with flowing and static water,using a transparent fracture grouting experimental device.Variations of seepage pressure and grout propagation were compared in our investigation.The results show that flowing water results in drops of seepage pressure,development of penetration radii in the upstream side and drops of propagation area during the same period,compared with grouting in static water.The propagation area in static water is always round before grouts reach the joint boundaries.However,the propagation shape changes from round to an elliptic shape for grouting into a fracture with flowing water.A theoretical model for the grout penetration radius in a fracture considering flowing velocity was developed and validated by our experimental results.These results are helpful in improving understanding of fracture grouting mechanism and in guiding engineering practices.
文摘Purpose： To explore the advantages of palmar approach with Kirschner-wire （K-wire） fixation in the treatment of children＇s distal radius extension type fracture, Methods： Thirty patients, average age of 8.5 years ranging from 5 to 13 years, with distal radius extension type fracture and undergoing a failed manual reposition in our hospital were included, and treated by palmar approach with K-wire fixation between May 2014 and December 2017. Among these patients （21 male and 9 female）, 5 patients had chronic injuries over 10 days, and 6 patients had fracture of the distal radius epiphysis. The time between injury and treatment ranged from 1 to 30 days. Among them, 11 patients with right-sided fractures and 19 patients with left-sided fractures were operated via the palmar longitudinal incision approach. Results： The results were evaluated after an average of 18 months ranging from 5 to 36 months after operation. The recovery time of fracture was from 4 to 8 weeks and all incisions were primary healing with an average of 6 weeks. Nonunion, delayed union, early closure of distal radial epiphysis, and wrist varus/valgus deformity were not found in all the cases. Based on Gartland and Wereley wrist score assessment undertaken three months after operation, excellent scores were achieved in 24 cases, good scores in 3 cases, acceptable scores in 3 cases. Conclusion： The palmar approach with K-wire fixation via a front longitudinal incision in the treatment of children＇s distal radius extension type fracture has following advantages： （1） easy to reposition for both fresh and old fractures; （2） less damage to surrounding tissues and epiphysis; （3） quick recovery. It is suitable to treat children＇s distal radius extension type fracture.
文摘Purpose： To study the effects of surgical and nonoperative treatment on wrist function in patients with distal radius fracture. Methods： In total, 97 patients treated for distal radius fracture in the Department of Orthopedic Trauma at the People＇s Hospital of Peking University from Jan. 2010 to Jun. 2016 were selected for outpatient follow-up, including manipulative reduction and dorsal splint fixation in 24 cases, bivalve cast fixation in 19 cases and open reduction and internal fixation in 54 cases. Evaluation was based on Sartiento＇s modification of the Gartland and Werley score. Efficacy was assessed with wrist pain as the focus. Results： The wrist function scores of the surgical group were better than nonoperative groups. There was no significant difference in wrist function scores between the dorsal splint group and the bivalve cast group. The ulnar wrist pain incidence had no significant difference in surgical and nonoperative groups. The displace rate in dorsal splint group was higher than other groups. Conclusion： The overall effect of surgical treatment of distal radius fracture is better than nonoperative treatment. The ulnar wrist pain incidence has no significant difference in these groups. Dorsal splint fixation is more prone to displace than bivalve cast fixation.
基金supported by the National Basic Research Program of China (Grant No.2007CB814806)the National Natural Science Foundation of China (Grant Nos.10974088,10834002 and 10774069)the Natural Science Foundation of Jiangsu Province (Grant No.BK2009008)
文摘The recognition and binding of proteins through the "fly-casting" mechanism are important biological processes. In this paper, a physical model for fly-casting binding is described based on the capillarity theory for protein chains. It is found that the capture radius for the fly-casting binding process is maximized at the transition temperature at which the free energy of the monomeric extended state of the protein equals that of the folded state. The factors related to the folding barrier or binding affinity do not change the condition needed to realize the optimization for fly-casting processes. These results will aid in the comprehensive understanding of binding processes.
