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1.
一种可生物降解纤维——聚乳酸纤维   总被引:12,自引:0,他引:12  
本文综述了可生物降解纤维———聚乳酸纤维的特性、合成和纺丝方法及生物降解性能的评定方法。  相似文献
2.
密闭体系中乳酸的固相缩聚   总被引:9,自引:0,他引:9  
研究在真空密闭、存在脱水剂的条件下聚乳酸固相缩聚工艺的可行性,得到了分子量达25万的聚乳酸;实验研究了催化剂浓度,预聚体粒度和反应时间对缩聚过程的影响,表明降解副反应仍然是控制聚乳酸最终分子量的重要因素。  相似文献
3.
对采用“两步模压法”制备的β-偏磷酸钙(β-CMP)晶须/聚乳酸(PLLA)复合骨折内固定材料进行细胞安全性研究,为其应用提供生物学依据。将成骨细胞与复合材料共孵育,用四甲基偶氮唑盐微量酶反应比色法(MTT)法分析成骨细胞的增殖情况,并通过倒置显微镜和SEM观察成骨细胞在复合材料上的粘附、生长情况。β-CMP/PLLA复合材料对成骨细胞黏附、生长没有抑制作用而且能促进成骨细胞的增殖。β-CMP/PLLA复合材料具有良好的细胞相容性。  相似文献
4.
PLLA纳米纤维编织缝合线的制备及生物相容性研究   总被引:2,自引:2,他引:0  
以PLLA为原料,采用静电纺丝和圆盘定向收集得到具有有序排列的纳米纤维束,并将其编织成线,得到PLLA纳米纤维缝合线.对新型可吸收PLLA缝线的微观形貌、血液相容性、细胞毒性进行了性能表征,并测试了其力学性能.结果表明,纳米纤维在一定的圆盘转速下表现出较好的定向性,力学性能良好.缝线在溶血试验中溶血率<5%,符合医用材料的溶血要求.MTT实验结果表明缝线材料无细胞毒性,且显示出较高的增殖率,说明新型可吸收PLLA纳米纤维缝线具有良好的生物相容性和安全性.  相似文献
5.
To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissueengineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, i.e. solventcasting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behaviorof the porous scaffold, e.g. weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP,the particle size of β-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporatedinto the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold weredetermined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Resultsshow that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strengthneeded for surgery. RMSCs seeding on porous PLLA/#0;  相似文献
6.
干湿纺聚乳酸纤维的体外降解性能   总被引:1,自引:0,他引:1  
选用干湿法纺丝制得的聚乳酸(PLLA)纤维,通过一定的编织工艺制成织物。将织物置于37℃、pH=7.4的磷酸缓冲溶液中进行体外降解。通过对织物失重率、力学性能和纤维分子量及分布、结晶度以及表面形态的测定,对干湿纺PLLA纤维的水解机理进行了探讨,发现干湿法纺丝工艺可促进PLLA纤维的体外降解速率。  相似文献
7.
结晶温度对左旋聚乳酸的晶体改性和晶体形貌的影响   总被引:1,自引:0,他引:1  
徐阳  孙志丹  陈晓浪  郭刚  张志斌  胡书春 《功能材料》2012,43(16):2138-2141
以左旋聚乳酸(PLLA)为原料,制备了无定型PLLA膜及无定型PLLA在不同温度下等温结晶的样品。利用红外光谱(FT-IR)、X射线衍射(XRD)和偏光显微镜(POM)分析了结晶温度的改变对PLLA样品的晶体改性及晶体形貌的影响。研究结果表明,结晶温度的改变对PLLA样品的晶体结构、晶型转变及晶粒形貌特征产生了较大的影响。当结晶温度低于100℃时,PLLA主要以无序的α’-晶型存在;随着结晶温度的增加,PLLA的晶体结构和晶型开始转变,当结晶温度超过120℃后,PLLA主要以α-晶型的形式存在;而当结晶温度在100~120℃范围内,则形成的是α’-与α-晶型PLLA的混合形式存在。另一方面,POM照片测试结果表明,随着结晶温度的升高,PLLA的晶体形貌发生了改变,晶粒尺寸随温度的增加而增加,结晶速度增加,晶粒数量减少,PLLA晶体由α’-向α-晶型发生了转变。  相似文献
8.
The intention of this study was to surface modify the poly-L-lactic acid (PLLA) film and evaluate the effects of the surfaces on the growth of vascular smooth muscle cells (VSMCs) in vitro. Collagen and hyaluronic acid (HA) were utilized as polycation and polyanion in this study. Layer-by-layer (LBL) self-assembly technique was used to lead to the formation of multilayer moleculer on the poly-L-lactic acid (PLLA) film surfaces. Collagen/HA layers was overcasted coating on the PLLA surface after the activation layers by poly-(ethyleneimine) (PEI). The structure and morphology of the multilayer molecular were examined by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrophotometer and atomic force microscope (AFM), respectively. The ATR-FTIR analysis illuminated the presence of collagen on the PLLA surface. The AFM results showed the multilayer appeared on PLLA surface. The VSMCs were adopted to evaluate the cyto-compatibility of the modified PLLA films. It was found that the viability of VSMCs on the modified PLLA films were greater than that on original PLLA films and tissue culture plastic after ten days culture (p < 0.05). Scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM) data also confirmed the homogeneous results. These data suggest that collagen/HA coat can be successfully adopted in the surface modification of PLLA film through LBL technique, and also can enhance its cell compatibility.  相似文献
9.
To develop a novel degradable poly (L-lactic acid)/β-tricalcium phosphate (PLLA/β-TCP) bioactive materials for bone tissue engineering, β-TCP powder was produced by a new wet process. Porous scaffolds were prepared by three steps, I.e. Solvent casting, compression molding and leaching stage. Factors influencing the compressive strength and the degradation behavior of the porous scaffold, e.g. Weight fraction of pore forming agent-sodium chloride (NaCl), weight ratio of PLLA: β-TCP, the particle size ofβ-TCP and the porosity, were discussed in details. Rat marrow stromal cells (RMSC) were incorporated into the composite by tissue engineering approach. Biological and osteogenesis potential of the composite scaffold were determined with MTT assay, alkaline phosphatase (ALP) activity and bone osteocalcin (OCN) content evaluation. Results show that PLLA/β-TCP bioactive porous scaffold has good mechanical and pore structure with adjustable compressive strength needed for surgery. RMSCs seeding on porous PLLA/β-TCP composite behaves good seeding efficacy, biocompatibility and osteoinductive potential. Osteoprogenitor cells could well penetrate into the material matrix and begin cell proliferation and osteogenic differentiation. Osseous matrix could be formed on the surface of the composite after culturing in vitro. It is expected that the PLLA/β-TCP porous composites are promising scaffolds for bone tissue engineering in prosthesis surgery.  相似文献
10.
Water-repellent surfaces were fabricated on blend sheets of poly(l-lactic acid)/poly(butylene succinate) with various blending ratios by the successive processing; (1) plasma etching, followed by (2) the hydrophobic plasma polymer coating. Rough morphology was formed effectively on the mosaic structured surface of blend sheets via the oxidative etching, and advanced water repellency was achieved after the thin membrane coating was synthesized with a hydrophobic plasma polymer coating by use of hexamethyldisiloxane or hexamethyldisilazane. High water repellency is expressed through the columnar hair-like structured model, where the air-water surface interaction in the voids is taken into account.  相似文献
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