Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin thre...Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC), tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results: An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.展开更多
AIM： To evaluate whether multiple determinations of intramucosal pH （pHi） in acute pancreatitis （AP） patients could provide additional information of the disease severity during early hospitalization. METHODS： T...AIM： To evaluate whether multiple determinations of intramucosal pH （pHi） in acute pancreatitis （AP） patients could provide additional information of the disease severity during early hospitalization. METHODS： Twenty-one patients suffering from acute pancreatitis were monitored by gastric tonometry in the first 72 h after hospital admission. RESULTS： In the survivor group （n = 15） the initially low phi values returned to normal level （pHi ≥ 7.32） within 48 h （median pHi： d 1： 7.21; d 2： 7.32; d 3： 7.33）. In contrast, pHi values in the non-survivor group n = 6） were persistently either below or in the low normal range （median pHi 7.12; 7.12; 7.07 respectively）, but pHi differences between the two groups reached significance only after 24 h （P 〈 0.01）. Mucosal acidosis detected at any time during the monitored period was associated with the emergence of single or multiple organ dysfunction （P 〈 0.01）. CONCLUSION： Prolonged gastric mucosal acidosis was associated with remote organ dysfunction and failure in Acute Pancreatitis, however, correlation with the fatal outcome became significant only 24 h after admission. Due to its non-invasive nature gastric tonometry may supplement the pro-inflammatory markers to achieve a multi-faceted monitoring of the disease.展开更多
The first floating platform concept design work for South China Sea is undergoing in DMAR's office now. This tension leg platform has potential to become the first advanced floating production platform project. Pr...The first floating platform concept design work for South China Sea is undergoing in DMAR's office now. This tension leg platform has potential to become the first advanced floating production platform project. Project execution is always a challenge for floating system. This paper focuses on the critical elements of project execution for tension leg platform,and studies potential implications to future oil and gas exploration in South China Sea. There are many factors affecting successful execution of floating system project,including technical issues, engineering management,interface management,etc. There are also failure examples of project execution in the industry. The author has participated 28 large detailed projects and has gained extensive experience on floating projects,with ample hands-on project experiences. A detailed tension leg platform project study example and discussions in depth are presented for future project execution in China deepwater development.展开更多
The focal mechanisms of 62 moderate-small earthquakes since 1980 in the ＂ Huoshan seismic window＂ region are calculated with the method developed recently by Snoke, combining the use of the first motion of P, SV and...The focal mechanisms of 62 moderate-small earthquakes since 1980 in the ＂ Huoshan seismic window＂ region are calculated with the method developed recently by Snoke, combining the use of the first motion of P, SV and SH waves with their amplitude ratios. Based on these abundant focal mechanisms, the mean tectonic stress field in the ＂Huoshan seismic window＂ region is inverted with the average stress tensor method, and the result shows that the ＂Huoshan seismic window＂ region is horizontally compressed in the near EW direction and horizontally dilated in the near NS direction, which is in accord with statistical results of focal mechanism parameters. We estimate the difference （also referred to as consistency parameter 0） between the force axis direction of the focal mechanism solution and the mean stress tensor, then further analyze the variation characteristics of 0 versus time, and the relationship with moderately strong earthquakes in the east China region. The result indicates that 0 in the ＂ Huoshan seismic window＂ region is in good correspondence with moderately strong earthquakes in the East China region. When 0 is lower than the mean value, corresponding moderately strong earthquakes may occur in the East China region.展开更多
文摘Objective: To compare the biomechanical basis of 3 different internal fixation methods: nitinol patellar concentrator (NT-PC), tension band and wire circle in treating patellar fractures. Methods: The epoxy resin three dimensional photoelasticity patellar models were made by precise moulding, and were fixated by nitinol patellar concentrator (NT-PC), tension band and wire circle respectively. The patellar models with frozen stress stripes were put into the polarized light field and the stress distributions were compared. As for the model fixated by NT-PC, by dividing layer, photographing and tracing, we used the iterative method to calculate the stress value of every internal node of the epoxy resin patellar model, and the character of stress was analyzed. Results: An overall stress field was yielded when the patellar model was fixated by NT-PC, and the stripes were more than that of tension band model and wire circle model, which have only few stress stripes in the fixated layers. Further analysis indicated that there were continuous fixated stresses in the facies articularis and distal pole of patella, and the character of stresses produced by NT-PC were mainly in longitudinal direction, then in transverse direction. The shearing stresses were small. Conclusion: The initiative and continuous memorial stress of NT-PC and its overall stress distribution character are the essence of NT-PC distinguished with tension band and wire circle in treating patellar fractures. The stress character produced by NT-PC is good for the stability of fracture site and prompts fracture healing.
基金Supported by the Hungarian National Scientific Research Fund (OTKA), No. T 016630, and the Hungarian Ministry of Health(ETT), No. 276/2001
文摘AIM： To evaluate whether multiple determinations of intramucosal pH （pHi） in acute pancreatitis （AP） patients could provide additional information of the disease severity during early hospitalization. METHODS： Twenty-one patients suffering from acute pancreatitis were monitored by gastric tonometry in the first 72 h after hospital admission. RESULTS： In the survivor group （n = 15） the initially low phi values returned to normal level （pHi ≥ 7.32） within 48 h （median pHi： d 1： 7.21; d 2： 7.32; d 3： 7.33）. In contrast, pHi values in the non-survivor group n = 6） were persistently either below or in the low normal range （median pHi 7.12; 7.12; 7.07 respectively）, but pHi differences between the two groups reached significance only after 24 h （P 〈 0.01）. Mucosal acidosis detected at any time during the monitored period was associated with the emergence of single or multiple organ dysfunction （P 〈 0.01）. CONCLUSION： Prolonged gastric mucosal acidosis was associated with remote organ dysfunction and failure in Acute Pancreatitis, however, correlation with the fatal outcome became significant only 24 h after admission. Due to its non-invasive nature gastric tonometry may supplement the pro-inflammatory markers to achieve a multi-faceted monitoring of the disease.
文摘The first floating platform concept design work for South China Sea is undergoing in DMAR's office now. This tension leg platform has potential to become the first advanced floating production platform project. Project execution is always a challenge for floating system. This paper focuses on the critical elements of project execution for tension leg platform,and studies potential implications to future oil and gas exploration in South China Sea. There are many factors affecting successful execution of floating system project,including technical issues, engineering management,interface management,etc. There are also failure examples of project execution in the industry. The author has participated 28 large detailed projects and has gained extensive experience on floating projects,with ample hands-on project experiences. A detailed tension leg platform project study example and discussions in depth are presented for future project execution in China deepwater development.
基金funded by the Youth Program of Earthquake Scientific Research Fund of Anhui Province(20120704)Contract Subject of Earthquake Administration of Anhui Province(201210)
文摘The focal mechanisms of 62 moderate-small earthquakes since 1980 in the ＂ Huoshan seismic window＂ region are calculated with the method developed recently by Snoke, combining the use of the first motion of P, SV and SH waves with their amplitude ratios. Based on these abundant focal mechanisms, the mean tectonic stress field in the ＂Huoshan seismic window＂ region is inverted with the average stress tensor method, and the result shows that the ＂Huoshan seismic window＂ region is horizontally compressed in the near EW direction and horizontally dilated in the near NS direction, which is in accord with statistical results of focal mechanism parameters. We estimate the difference （also referred to as consistency parameter 0） between the force axis direction of the focal mechanism solution and the mean stress tensor, then further analyze the variation characteristics of 0 versus time, and the relationship with moderately strong earthquakes in the east China region. The result indicates that 0 in the ＂ Huoshan seismic window＂ region is in good correspondence with moderately strong earthquakes in the East China region. When 0 is lower than the mean value, corresponding moderately strong earthquakes may occur in the East China region.
