To define the criteria of posterior selective thoracic fusion in patients with adolescent idiopathic scoliosis. Methods By reviewing the medical records and roentgenograms of 17 patients with adolescent idiopathic sco...To define the criteria of posterior selective thoracic fusion in patients with adolescent idiopathic scoliosis. Methods By reviewing the medical records and roentgenograms of 17 patients with adolescent idiopathic scoliosis who un-derwent posterior selective thoracic fusion, the curve type, Cobb angle, apical vertebral rotation and translation, trunk shift, and thoracolumbar kyphosis were measured and analyzed. Results There were 17 King type Ⅱ patients (PUMC type: Ⅱb1 13, Ⅱc3 4). The coronal Cobb angle of thoracic curve be-fore and after operation were 56.9°and 21.6° respectively, the mean correction rate was 60.1%. The coronal Cobb angle of lumbar curve before and after operation were 34.8° and 12.1° respectively, and the mean spontaneous correction rate was 64.8%. At final follow-up, the coronal Cobb angle of thoracic and lumbar curve were 23.5° and 15.2° respectively, there were no significant changes in the coronal Cobb angle, apical vertebral translation and rotation compared with that after operation. One patient had 12° of thoracolumbar kyphosis after operation, no progression was noted at final follow-up. There was no trunk decompensation or deterioration of the lumbar curve. In this group, 3.9 levels were saved compared with fusing both the th-oracic and lumbar curves. Conclusion Posterior selective thoracic fusion can be safely and effectively performed in King type Ⅱ patients with a mo-derate and flexible lumbar curve, which can save more mobile segments and at the same time can maintain a good coronal and sagittal balance.展开更多
The desulfurization performance of the UDS solvents was investigated at an industrial side-stream plant and was compared with that of MDEA solvent.A mass transfer performance model was employed for explaining the COS ...The desulfurization performance of the UDS solvents was investigated at an industrial side-stream plant and was compared with that of MDEA solvent.A mass transfer performance model was employed for explaining the COS absorption into different solvents.Meanwhile,the regeneration performance of the UDS solvents was evaluated in side-stream tests.Results indicate that under the conditions covering an absorption temperature of 40℃,a pressure of 8.0 MPa,and a gas to liquid volume ratio(V/L)of around 230,the H2S content in purified gas can be reduced to 4.2 mg/m3 and 0 by using solvents UDS-II and UDS-III,respectively.Moreover,the total sulfur content in both purified gases is less than 80 mg/m3.As a result,the UDS-III solvent shows by 30 percentage points higher in COS removal efficiency than MDEA.In addition,the total volume mass transfer coefficient of UDS solvent is found to be twice higher than that of MDEA.Furthermore,the UDS solvents exhibit satisfactory thermal stability and regeneration performance.展开更多
A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide(PLA) in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly...A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide(PLA) in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly(ethylene glycol) methyl ether acrylate(PEGA) and poly[poly(ethylene glycol) methyl ether acrylate](PPEGA, a comb-like copolymer), respectively. The results measured from phase contrast optical microscopy(PCOM) and differential scanning calorimetry(DSC) indicate that PLA and PEGA components are miscible, whereas PLA and PPEGA components are immiscible. The study of crystallization kinetics for PLA/PEGA and PLA/PPEGA blends by means of polarized optical microscopy(POM) and DSC indicates that both PEGA and PPEGA significantly increase the PLA spherulitic growth rates, G, although PLA/PPEGA blends are immiscible and the glass transition temperatures of PLA only have slight decreases. PPEGA component enhances nucleation for PLA crystallization as compared with PEGA component owing to the heterogeneous nucleation effect of PPEGA at the low composition of 20 wt%, while PLA crystallization-induced phase separation for PLA/PEGA blend might cause further nucleation at the high composition of 50 wt%. DSC measurement further demonstrates that isothermal crystallization kinetics can be relatively more enhanced for PLA/PPEGA blends than for PLA/PEGA blends. The "abnormal" enhancement in G for PLA in its immiscible blends can be explained by local interfacial interactions through the densely grafted PEGA side chains in the comb-like PPEGA, even though the whole blend system(PLA/PPEGA blends) represents an immiscible one.展开更多
文摘To define the criteria of posterior selective thoracic fusion in patients with adolescent idiopathic scoliosis. Methods By reviewing the medical records and roentgenograms of 17 patients with adolescent idiopathic scoliosis who un-derwent posterior selective thoracic fusion, the curve type, Cobb angle, apical vertebral rotation and translation, trunk shift, and thoracolumbar kyphosis were measured and analyzed. Results There were 17 King type Ⅱ patients (PUMC type: Ⅱb1 13, Ⅱc3 4). The coronal Cobb angle of thoracic curve be-fore and after operation were 56.9°and 21.6° respectively, the mean correction rate was 60.1%. The coronal Cobb angle of lumbar curve before and after operation were 34.8° and 12.1° respectively, and the mean spontaneous correction rate was 64.8%. At final follow-up, the coronal Cobb angle of thoracic and lumbar curve were 23.5° and 15.2° respectively, there were no significant changes in the coronal Cobb angle, apical vertebral translation and rotation compared with that after operation. One patient had 12° of thoracolumbar kyphosis after operation, no progression was noted at final follow-up. There was no trunk decompensation or deterioration of the lumbar curve. In this group, 3.9 levels were saved compared with fusing both the th-oracic and lumbar curves. Conclusion Posterior selective thoracic fusion can be safely and effectively performed in King type Ⅱ patients with a mo-derate and flexible lumbar curve, which can save more mobile segments and at the same time can maintain a good coronal and sagittal balance.
基金financial support from the National Key Science and Technology Project of China (2011ZX05017-005)the Fundamental Research Funds for the Central Universities (No.22A201514010)
文摘The desulfurization performance of the UDS solvents was investigated at an industrial side-stream plant and was compared with that of MDEA solvent.A mass transfer performance model was employed for explaining the COS absorption into different solvents.Meanwhile,the regeneration performance of the UDS solvents was evaluated in side-stream tests.Results indicate that under the conditions covering an absorption temperature of 40℃,a pressure of 8.0 MPa,and a gas to liquid volume ratio(V/L)of around 230,the H2S content in purified gas can be reduced to 4.2 mg/m3 and 0 by using solvents UDS-II and UDS-III,respectively.Moreover,the total sulfur content in both purified gases is less than 80 mg/m3.As a result,the UDS-III solvent shows by 30 percentage points higher in COS removal efficiency than MDEA.In addition,the total volume mass transfer coefficient of UDS solvent is found to be twice higher than that of MDEA.Furthermore,the UDS solvents exhibit satisfactory thermal stability and regeneration performance.
基金supported by the National Basic Research Program of China (2012CB025901)the National Natural Science Foundation of China (21174139)the Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences
文摘A significant enhancement in isothermal crystallization kinetics of biodegradable polylactide(PLA) in its immiscible blends can be accomplished through blending it with a comb-like copolymer. PLA was blended with poly(ethylene glycol) methyl ether acrylate(PEGA) and poly[poly(ethylene glycol) methyl ether acrylate](PPEGA, a comb-like copolymer), respectively. The results measured from phase contrast optical microscopy(PCOM) and differential scanning calorimetry(DSC) indicate that PLA and PEGA components are miscible, whereas PLA and PPEGA components are immiscible. The study of crystallization kinetics for PLA/PEGA and PLA/PPEGA blends by means of polarized optical microscopy(POM) and DSC indicates that both PEGA and PPEGA significantly increase the PLA spherulitic growth rates, G, although PLA/PPEGA blends are immiscible and the glass transition temperatures of PLA only have slight decreases. PPEGA component enhances nucleation for PLA crystallization as compared with PEGA component owing to the heterogeneous nucleation effect of PPEGA at the low composition of 20 wt%, while PLA crystallization-induced phase separation for PLA/PEGA blend might cause further nucleation at the high composition of 50 wt%. DSC measurement further demonstrates that isothermal crystallization kinetics can be relatively more enhanced for PLA/PPEGA blends than for PLA/PEGA blends. The "abnormal" enhancement in G for PLA in its immiscible blends can be explained by local interfacial interactions through the densely grafted PEGA side chains in the comb-like PPEGA, even though the whole blend system(PLA/PPEGA blends) represents an immiscible one.
