组织工程真皮替代物的构建及在创伤修复中的作用

以双层胶原-壳聚糖海绵为支架构建组织工程真皮替代物并研究其在大鼠创伤愈合中的作用.将双层胶原-壳聚糖海绵支架埋植于SD大鼠皮下以考察其组织相容性;将SD大鼠皮肤中分离的成纤维细胞种植在支架上体外构建人工真皮替代物,并将该替代物移植到SD大鼠皮肤缺损处以修复创面.皮下埋植实验显示支架植入早期有炎症反应,但一周后炎症反应逐渐减轻,而且有成纤维细胞和毛细血管的侵入.皮肤移植实验结果显示:术后第7天和第14天实验组创面表皮再生和肉芽组织增生比对照组更快更明显;第14天和第21天实验组创面面积明显小于对照组(p<0.05).因此以双层胶原-壳聚糖海绵为支架构建的组织工程真皮替代物具有良好的生物相容性,并能促进皮肤创面的愈合,可以作为人工真皮替代物用于皮肤缺损的修复.     

以组织工程技术构建活性双层人工皮肤

用冷冻干燥胶原凝胶方法制备胶原海绵,经戊二醛交联处理,作为活性双层人工皮肤的支架;以幼儿包皮为细胞来源获得真皮成纤维细胞和皮肤角质细胞,体外扩增后作为种子细胞;在胶原海绵上接种成纤维细胞和角质细胞,体外构建活性双层人工皮肤。研究结果表明,人工真皮内的成纤维细胞生长良好,并且有人纤粘连蛋白类生物活性物质存在,活性双层人工皮肤表皮层有类似干天然皮肤表皮层的组织结构。     

胶原支架材料的制备与表征

分别采用真空高温脱水和化学交联剂1-乙基-3-(3-二甲基氨基丙基)-碳化二亚胺处理经冷冻干燥后的胶原海绵材料,制备组织工程支架,讨论反应条件对胶原性能的影响,测定胶原支架的力学强度和降解特性.结果发现,不同的处理方法都能保持胶原海绵的三维多孔结构,孔隙率可达到90%;真空高温脱水获得的胶原海绵材料力学强度较小,但断裂伸长率略大;碳化二亚胺交联胶原海绵材料力学强度相对较高,抗张强度为380 kPa左右.胶原海绵交联后,降解速率显著小于未经交联的胶原材料.细胞培养试验表明成纤维细胞可以在支架材料上正常生长.两种交联方法处理胶原海绵,其细胞生长行为差异无显著性,适合于作为组织工程支架.     

EDC/NHS交联对胶原物理化学性能的影响

为了提高胶原的物理化学性能,采用1-乙基-3-(3-二甲基氨丙基)-碳化二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)交联剂对胶原进行交联,考察了不同交联剂浓度对胶原物理化学性能的影响,并通过红外、差示扫描量热分析(DSC)、吸水率、膨胀动力学、抗酶解性能、扫描电镜(SEM)等技术手段对胶原交联前后的性能进行表征.研究结果表明,胶原经EDC/NHS交联后,热稳定性、形态稳定性增强,抵抗酶解的能力显著增加,胶原的显微结构由交联前的无序状态变为紧密有序的结构.说明EDC/NHS交联可有效改善胶原的物理化学性能.     

响应曲面法优化β-葡萄糖苷酶固定化的研究

以黑曲霉β-葡萄糖苷酶作为研究对像,采用交联-包埋的试验方法,以酶活力回收率作为评价的指标,选取海藻酸钠、壳聚糖、海藻酸钠-壳聚糖为载体,对β-葡萄糖苷酶固定化效果进行比较,结果显示海藻酸钠-壳聚糖固定化效果最好.再进行固定化条件单因素响应曲面试验,得到的最优条件为,海藻酸钠-壳聚糖的混合载体中海藻酸钠溶液的质量分数为1.91%、壳聚糖-醋酸溶液的质量分数为1.94%,温度为40.20℃,交联时间为0.98 h.此时酶活力为112 400 IU/m L,酶活力回收率为66.18%.经过三次回收试验,酶活力回收率分别为65.61%、64.48%、64.16%.     

壳聚糖多孔支架的制备与生物学性质

用一种蛋白改性壳聚糖,通过冷冻干燥方法制备三维多孔支架,对支架材料的细胞毒性、贴壁率和细胞增殖等生物学特性进行评价.结果显示,采用-20,-70,-196 ℃不同温度预冻后冻干,可以制成孔结构不同的支架材料.通过冻干法制备的蛋白改性壳聚糖多孔支架对细胞没有毒性,L929细胞和人成纤维细胞可以在支架表面和内部正常生长和增殖,角质细胞在材料表面可以正常老化、角质化.     

胶原-壳聚糖复合支架体外三维培养神经干细胞

采用冷冻干燥法制备了胶原-壳聚糖复合支架并通过层粘连蛋白（LN）进行结构修饰,测定其物理性能特征,建立了胎鼠海马神经干细胞（NSCs）的三维培养体系,同时考察了NSCs与胶原-壳聚糖复合支架的生物相容性．孔径、孔隙率、吸水率、降解率等参数的比较表明,体积比为7：3的复合支架更适合于体外细胞培养的要求,并且NSCs在经LN修饰后支架材料上的接种率得到明显提高;激光共聚焦显微镜及扫描电镜观察表明,NSCs能够在胶原-壳聚糖复合支架内良好地生长、增殖及分化．这些结果为NSCs的进一步临床移植应用,以及治疗神经系统疾病的新药筛选和机理研究等奠定了坚实的实验基础．     

印迹与交联壳聚糖吸附水中微量Cr（VI）的对比试验研究

本研究以壳聚糖为原料,戊二醛为交联剂,分别采用直接交联的方法和分子印迹技术制备交联壳聚糖和Cr(Ⅵ)印迹壳聚糖,并对这两种吸附剂对Cr(Ⅵ)的吸附性能进行了研究,考察了pH、反应时间、吸附剂投加量、Cr(Ⅵ)初始浓度、温度对Cr(Ⅵ)去除率的影响.实验结果表明:酸性环境有利于壳聚糖类吸附剂对Cr(Ⅵ)的吸附,pH为6.0时吸附效果最佳.交联壳聚糖和印迹壳聚糖对Cr(Ⅵ)的吸附速率在前20 min较快,90 min即可达到吸附平衡.对30 mg/L 的Cr(Ⅵ)溶液,交联壳聚糖与印迹壳聚糖对Cr(Ⅵ)的去除率随投加量增加而增加,在投加量为3.5 g/L时,对Cr(Ⅵ)的去除率最高可达到92.4%和97.8%.相同实验条件下,印迹壳聚糖对Cr(Ⅵ)的吸附较交联壳聚糖有明显提高,其幅度最高可达7.3%.     

印迹与交联壳聚糖吸附水中微量Cr(Ⅵ)的对比试验研究

本研究以壳聚糖为原料,戊二醛为交联剂,分别采用直接交联的方法和分子印迹技术制备交联壳聚糖和Cr(Ⅵ)印迹壳聚糖,并对这两种吸附剂对Cr(Ⅵ)的吸附性能进行了研究,考察了pH、反应时间、吸附剂投加量、Cr(Ⅵ)初始浓度、温度对Cr(Ⅵ)去除率的影响.实验结果表明:酸性环境有利于壳聚糖类吸附剂对Cr(Ⅵ)的吸附,pH为6.0时吸附效果最佳.交联壳聚糖和印迹壳聚糖对Cr(Ⅵ)的吸附速率在前20 min较快,90 min即可达到吸附平衡.对30 mg/L的Cr(Ⅵ)溶液,交联壳聚糖与印迹壳聚糖对Cr(Ⅵ)的去除率随投加量增加而增加,在投加量为3.5 g/L时,对Cr(Ⅵ)的去除率最高可达到92.4%和97.8%.相同实验条件下,印迹壳聚糖对Cr(Ⅵ)的吸附较交联壳聚糖有明显提高,其幅度最高可达7.3%.     

壳聚糖金属螯合亲和吸附剂的制备

目的 研究利用壳聚糖为载体、戊二醛为交联剂、亚氨基二乙酸(IDA)为螯合配基制备金属螯合亲和吸附剂的条件.方法 戊二醛对壳聚糖进行交联,环氧氯丙烷法进行载体活化和螯合配基的偶联.键合IDA后与Cu2+螯合.结果 采用0.22 mL/g(壳聚糖)戊二醛对壳聚糖进行交联.交联壳聚糖加入0.4 mol/L NaOH与体积分数为0.5的二甲亚砜的混合溶液中,充分搅匀,25℃下缓慢滴加1.2 mL(体积分数为0.3)的环氧氯丙烷,升温至40℃,170 r/min下振荡反应3h进行活化.之后,以4.26 g/g(壳聚糖)浓度的IDA进行连接反应,65℃下反应18 h.结论 采用优化条件制备的金属螯合亲和吸附剂对Cu2+有较大螯合量,可用作固定化金属亲和层析的固定相.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to