丝素组织工程支架的研究进展

随着组织工程学的兴起,丝素组织工程支架也已成为丝素生物材料研究的热点,以丝素为材料的多种形态的组织工程支架已用于各种细胞组织构建的研究。主要介绍丝素组织工程支架的制备,以及丝素组织工程支架用于骨、软骨、韧带和肌腱等细胞组织构建的研究进展,并展望丝素作为组织工程支架材料的研究发展趋势,以期为丝素组织工程支架的深入研究提供参考。     

溶胀剂U预处理对真丝织物性能及丝纤维结构的影响

为利用溶胀剂的膨化和分纤作用提高真丝织物的接枝增重率和改善织物的性能,采用不同浓度的溶胀剂U对真丝织物进行预处理,再以甲基丙烯酰胺(MAA)为单体,过硫酸钾(KPS)为引发剂对真丝织物接枝增重。选择体积分数为10%的溶胀剂U对真丝织物进行预处理,丝纤维直径由11.90μm增加至14.24μm,起到了较好的膨化和分纤作用,织物的强力、折皱回复角、白度损失也较小。与未进行预处理的真丝织物相比,用10%溶胀剂U预处理后真丝织物的接枝增重率提高,织物的强力、折皱回复角、白度得到改善。真丝织物经10%溶胀剂U预处理后进行丝纤维微观结构形貌表征:红外光谱(IR)显示丝纤维仍保持着β-折叠结构;扫描电子显微镜(SEM)观测到丝纤维表面覆盖的聚合物减少,横截面变粗,直径变大,出现分纤现象和微孔特征;X-射线衍射分析表明丝纤维的结晶度提高。     

Structure and properties of silk fibroin modified cotton

In this research, a novel cotton fiber with a silk fibroin (SF) coating was prepared by the oxidation of a cotton thread with sodium periodate and subsequent treatment in a solution of silk fibroin. The structures of both the oxidized cotton samples and the SF modified cotton samples were investigated by Fourier transform infrared (FT-IR) in combination with X-ray photoelectron spectroscopy (XPS) analysis. Other performances such as surface morphology and breaking strength were also studied. The results indicated that the weight of the oxidized cotton samples increased during SF treatment, while that of the un-oxidized cotton (pure cotton) samples reduced after SF treatment. Compared with the pure cotton samples, the oxidized cotton clearly showed a characteristic absorption band at 1730 cm⁻¹ due to the stretching vibration of the C=O double bond of the aldehyde group. After being treated with the SF solution, the oxidized cotton fiber showed a weakened characteristic absorption band at 1730 cm⁻¹ and a new absorption band at round 1540 cm⁻¹, suggesting the formation of C-N bond between aldehyde groups in the oxidized cotton and primary amines in the silk fibroin. The results were also confirmed by XPS analysis. Compared with the oxidized cotton samples, the SF treated cottons had relatively smooth surfaces, similar breaking strength, and the improved wrinkle recovery angles. The results in this research suggest that cotton based materials with protein coating can be achieved without using any other crosslinking agents by the method introduced.     

西北地区“丝绸之路”沿线10城市旅游竞争力浅析

基于前人的相关研究,选择西北地区丝绸之路沿线西安、乌鲁木齐等10个重要旅游城市为研究对象。首先对城市旅游竞争力的影响因素与评价指标进行分析,建立城市旅游竞争力的评价指标体系和层次结构模型,运用层次分析法确定指标权重。然后利用数学模型计算出丝绸之路沿线10城市旅游竞争力得分,据此建立诸旅游中心城市的等级体系,并分析了每个城市旅游的优、劣势,最后提出该10城市旅游发展的建议和对策。     

家蚕品种金秋及其杂交亲本的蛋白质表达谱分析

 【目的】探讨家蚕杂交育成品种及其亲本蛋白水平的差异,从蛋白水平分析育成品种的基因结构,为阐明杂交育种成败的分子机理创造条件。【方法】采用蛋白质组研究技术,分析杂交亲本及其育成品种的丝腺、血淋巴和中肠的蛋白质表达谱。【结果】3种组织器官中育成品种金秋与两个亲本的匹配蛋白斑点比例只达到70%左右,剩余30%左右是各个品种的特异蛋白斑点;在匹配蛋白斑点中,还有9%～24%的蛋白表现上调和下调。这些特异蛋白可能是两个亲本的基因在杂交育成品种中产生了互作而形成的新蛋白,也可能是对相同的蛋白进行了不同的修饰而获得的修饰蛋白。【结论】新品种的育成,除了汇集亲本的优良基因外,还有赖于基因互作产生的新功能蛋白的作用。     

中国真丝绸商品出口的国际竞争力分析

依据国际市场占有率(MS)、贸易竞争力指数(TC)和显示性比较优势指数(RCA)等3项指标数据,对我国真丝绸商品自入世以来的国际竞争力进行实证分析。以蚕丝类为代表的原料制品和以绸缎类为代表的半制成品在国际市场上具有较强竞争优势,其MS和TC指数都比较高,但是RCA指数却呈现下降趋势;以女衬衫、披肩以及领带为代表的丝绸二次制成品在国际市场上的竞争力相对较弱。实证结果说明我国依然处于蚕丝原料输出国的地位,利润空间较小的蚕丝类和绸缎类的出口占很大比例,而利润空间比较大的部分丝绸二次制成品的国际市场占有率则相对较小。提升我国真丝绸商品出口的国际竞争力,一方面要在中西部地区建立专业化、规模化的优质蚕茧生产基地,以保障高档真丝绸制成品的原料品质;另一方面要增强丝绸二次制成品生产企业在产品研发设计、生产技术、产品营销策划等方面的能力,以及改善生产设备,创建一批国际化的高档丝绸品牌,增加高附加值丝绸产品的出口量和出口额。     

不同辐照剂量和氛围下 60 Co-γ射线辐照蚕丝的电子自旋共振分析

在不同辐照剂量、不同辐照氛围下用60Co-γ射线辐照蚕丝纤维,通过电子自旋共振波谱(ESR)检测蚕丝纤维产生的自由基浓度,分析不同辐照条件对蚕丝纤维性能的影响。结果表明:在0~250 kGy剂量范围内,随辐照剂量的增加,60Co-γ射线辐照蚕丝产生的自由基浓度增加,但辐照剂量过大会使蚕丝纤维发生裂解而影响其性能,故辐照剂量应不超过50 kGy;与同剂量空气下辐照蚕丝纤维产生的自由基相比,在真空下辐照蚕丝纤维产生的自由基浓度增加,且主要为氨基己酸自由基,但随着辐照剂量的增加,真空和空气下辐照蚕丝纤维产生的自由基浓度差异变小。     

Analysis of green total factor productivity trend and its determinants for the countries along silk roads

In coping with increasing energy consumption and the consequential environmental pollution, green development is becoming an important part of social development. Since the inauguration of China’s Silk Road Economic Belt Initiative (BRI), economic cooperation between China and other countries along BRI has seen much growth. Therefore, it is of great significance to study the levels of green total factor productivity (GTFP) of the countries in the Silk Roads Economic Belt (B&R) and examine how these levels vary spatially and evolve temporally. In this paper, a panel regression analysis with DEA windows is used to study the spatiotemporal trends of the levels of GTFP. The results are: (1) The B&R countries have seen an increase in their overall levels of GTFP over time; (2) There are regional differences in the levels of GTFP, with higher efficiency in Western Asia and Central and Eastern Europe, and lower efficiency in Southeast and Central Asia; (3) The analysis of GTFP for countries in these regions shows that the efficiencies of most countries have been improving, with that of only a few countries have been decreasing; (4) By using regression analysis, we find that variables such as import, export, industrial structure, and urban affect the B&R countries with growing GTFP.     

丝素蛋白-氧化石墨烯多孔微球支架的制备及性能测试

为了拓展丝素蛋白(SF)在组织工程等生物医学领域的应用,采用微乳液-冷冻相分离技术制备丝素蛋白-氧化石墨烯(SF-GO)复合多孔微球支架,并通过傅里叶变换红外光谱(FTIR)、拉曼光谱(Raman)、扫描电子显微镜(SEM)及热重分析(DTG-TG)等方法对SF-GO复合支架的化学结构和形貌等理化性质进行分析表征。结果表明,宏观上SF微球支架和SF-GO复合微球支架均呈现为表面规则平滑的球形且粒径均匀,但SF-GO微球支架比SF微球支架有更大的微孔结构;加入氧化石墨烯后,微球支架的热稳定性能得到明显改善。体外细胞培养实验表明该微球支架有良好的生物相容性,且SF-GO复合微球支架比普通SF微球支架更能够促进骨髓间充质干细胞的黏附和增殖。     

冷冻干燥丝素粉末的性质

对丝素溶液经冷并干燥制得的丝素粉末的性质进行的研究表明,丝素溶液经冷冻干燥得到的丝素粉末易溶解于水,得到的溶液同一般丝素溶液一样能形成丝素凝胶和丝素膜,但丝素膜的强度有下降趋势,伸长度有增加趋势。对丝素粉末进行高温高湿处理后,丝素粉末的溶解性下降,溶解丝素粉末制得的丝素膜的强度、伸长度下降。