Hoffa fracture is an uncommon injury. In the literature, lateral condylar Hoffa fracture is mentioned as a more common injury pattern than medial condylar Hoffa fracture. The mechanism of injury and method of treatmen...Hoffa fracture is an uncommon injury. In the literature, lateral condylar Hoffa fracture is mentioned as a more common injury pattern than medial condylar Hoffa fracture. The mechanism of injury and method of treatment is not very well described in the literature. We are present- ing a rare case of comrninuted medial condylar Hoffa frac- ture with ipsilateral patellar fracture. The mechanism of in-jury has not been described in the literature. Lag screw fixation, which is the most acceptable method of treatment, is not possible due to comminution. We explain the pos- sible mechanism of injury and fix the fracture with L-but- tress plate.展开更多
Objective: To improve the results of the treatment of unstable types of intertrochanteric fractures of the femur (ITFF) by internal fixation. Methods: A L trapezoid compression plate system (L TCP) was designed and co...Objective: To improve the results of the treatment of unstable types of intertrochanteric fractures of the femur (ITFF) by internal fixation. Methods: A L trapezoid compression plate system (L TCP) was designed and compared to the AO/ASIF angle plates of 95° and 130° (L AP) with mechanical tests. An Evans Type Ⅲ model was made, the simulation electrical test with loading on single and both legs were done. The results demonstrated that the stability of the L TCP fixation was significantly greater, and the stress concentration at the upper screw hole was relevantly smaller than that of L AP. From June 1986 to June 1998, 82 patients of ITFF were treated with L TCP fixation. The average age was 67.4 years old (26 91). Seventy four of those fractures were unstable. Fifty eight patients were treated with open reduction, and 24 cases were treated by closed reduction and limited open (only lateral aspect of upper femur was exposed) fixation with L TCP under X ray monitoring. Results: Sixty six patients were followed up for 6 69 months. Complications, including 3 wound infection, 1 non union, 3 coxa varus and 2 implant breakage (9 complications of 7 cases), all occurred in the open reduction group. No complication was found in the closed reduction group. Conclusions: In the treatment of ITFF, the results of closed reduction and limited open fixation with L TCP is significantly better than that of open reduction and fully exposed fixation.展开更多
Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during initial substrate preorganization s...Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during initial substrate preorganization step, oxidosqualene cyclases （OSCs） are roughly segregated into protosteryl cation group that mainly catalyzes tetracyclic products and dammarenyl cation group which mostly generates pentacyclic products. However, in contrast to well-studied cascade of ring-forming reactions, little is known about the mechanism underlying the initial sub- strate folding process. Previously, we have identified a cucurbitadienol synthase （Bi） and its null allele bi （C393Y） from cucumber. By integration of homology modeling, residue coevolution and site-directed mutagenesis, we discover that four covarying amino acids including C393 constitute a dynamic domain that may be involved in substrate folding process for Bi. We also reveal a group of co-conserved residues that closely associated with the segregation of plant OSCs. These residues may act col- laboratively in choice of specific substrate folding inter- mediate for OSCs. Thus, engineer plant OSCs from into five-ringed producer. our findings open a door to four-ringed skeleton catalysts展开更多
文摘Hoffa fracture is an uncommon injury. In the literature, lateral condylar Hoffa fracture is mentioned as a more common injury pattern than medial condylar Hoffa fracture. The mechanism of injury and method of treatment is not very well described in the literature. We are present- ing a rare case of comrninuted medial condylar Hoffa frac- ture with ipsilateral patellar fracture. The mechanism of in-jury has not been described in the literature. Lag screw fixation, which is the most acceptable method of treatment, is not possible due to comminution. We explain the pos- sible mechanism of injury and fix the fracture with L-but- tress plate.
文摘Objective: To improve the results of the treatment of unstable types of intertrochanteric fractures of the femur (ITFF) by internal fixation. Methods: A L trapezoid compression plate system (L TCP) was designed and compared to the AO/ASIF angle plates of 95° and 130° (L AP) with mechanical tests. An Evans Type Ⅲ model was made, the simulation electrical test with loading on single and both legs were done. The results demonstrated that the stability of the L TCP fixation was significantly greater, and the stress concentration at the upper screw hole was relevantly smaller than that of L AP. From June 1986 to June 1998, 82 patients of ITFF were treated with L TCP fixation. The average age was 67.4 years old (26 91). Seventy four of those fractures were unstable. Fifty eight patients were treated with open reduction, and 24 cases were treated by closed reduction and limited open (only lateral aspect of upper femur was exposed) fixation with L TCP under X ray monitoring. Results: Sixty six patients were followed up for 6 69 months. Complications, including 3 wound infection, 1 non union, 3 coxa varus and 2 implant breakage (9 complications of 7 cases), all occurred in the open reduction group. No complication was found in the closed reduction group. Conclusions: In the treatment of ITFF, the results of closed reduction and limited open fixation with L TCP is significantly better than that of open reduction and fully exposed fixation.
基金supported by funding from the National Natural Science Foundation of China (31401886)the Agricultural Science and Technology Innovation Program
文摘Sterols and triterpenes are structurally diverse bioactive molecules generated through cyclization of linear 2,3-oxidosqualene. Based on carbocationic intermediates generated during initial substrate preorganization step, oxidosqualene cyclases （OSCs） are roughly segregated into protosteryl cation group that mainly catalyzes tetracyclic products and dammarenyl cation group which mostly generates pentacyclic products. However, in contrast to well-studied cascade of ring-forming reactions, little is known about the mechanism underlying the initial sub- strate folding process. Previously, we have identified a cucurbitadienol synthase （Bi） and its null allele bi （C393Y） from cucumber. By integration of homology modeling, residue coevolution and site-directed mutagenesis, we discover that four covarying amino acids including C393 constitute a dynamic domain that may be involved in substrate folding process for Bi. We also reveal a group of co-conserved residues that closely associated with the segregation of plant OSCs. These residues may act col- laboratively in choice of specific substrate folding inter- mediate for OSCs. Thus, engineer plant OSCs from into five-ringed producer. our findings open a door to four-ringed skeleton catalysts
