负载氯喹的骨靶向纳米颗粒打破肿瘤细胞增殖与骨吸收之间的恶性循环

肿瘤细胞增殖与骨吸收之间的恶性循环加剧了骨肿瘤的进展和转移风险.为此,我们设计并制备了聚乙二醇-阿仑膦酸钠修饰的聚多巴胺(PPA)纳米粒子,并在其表面负载自噬抑制剂氯喹(CQ),期望利用该治疗载体(PPA/CQ)打破肿瘤细胞增殖与骨吸收之间的恶性循环,从而有效地治疗骨肿瘤.实验证明,PPA/CQ可以有效地富集到骨组织,...     

银铜共掺羟基磷灰石仿生涂层的制备与抗菌性能

为了增强医用镁合金表面羟基磷灰石（HA）涂层的抗菌性能,使用微波水相法在壳聚糖中间层表面制备了银铜共掺 HA（AgCuHA）仿生涂层。使用 XRD,SEM,EDS,TEM、光学轮廓仪和接触角测定仪分析了 AgCuHA 仿生涂层的物相、表面形貌、化学组成、晶体结构、表面粗糙度和亲水性;应用平板涂布法和 CCK-8 法测试了涂层的抗菌性能和细胞活力。结果表明,AgCuHA 涂层由富含纳米缺陷的纳米锥自下而上构建,形成一种仿生微/纳米拓扑结构;亲水性仿生涂层不但展现了高抗菌性能,而且可抑制镁合金的快速降解,具有良好细胞相容性。     

长江口北槽泥沙起动流速研究

在大量实测资料分析、室内水槽试验和现场坐底观测试验的基础上,对长江口北槽泥沙起动流速特性进行了分析研究。首先分析了北槽河床质实测资料,明确了北槽中段河床组成特性。通过北槽天然沙的室内水槽试验研究了天然沙在浅水区的起动特性。通过北槽现场坐底观测的实测结果分析了北槽实际的泥沙起动特征,其中泥沙起动状态主要通过近底泥沙浓度变化和床面冲淤变化的判定。在以上实测资料的基础上分析了北槽的泥沙起动规律,推荐了在浅水区和深水区适宜的泥沙起动流速经验公式。     

黄浦江上游水源地突发性水污染事故应急处置预案探讨

阐述了水源地突发污染事件的概念、特点及其对于供水安全和城市经济社会系统安全运行的重要意义.论述了城市水源地突发污染事件应急研究的主要内容;以上海市黄浦江上游水源地为例,探讨了突发性污染事件应急处置体系的构建,并提出了相应的政策建议。     

WWER -1000型核电站N-16监测系统探测效率的模拟计算

主要针对核电站蒸汽发生器传热管破损的氮-16监测系统工程实践中遇到的探测效率无法用常规计算和实验得出的困难,以WWER - 1000堆型为基础,建立了光子与NaI探测器介质作用的简化数学物理模型,采用EGS5蒙特卡罗程序对探测器效率进行了数值计算.计算结果与工程设计资料提供的数据符合较好,为今后研究几何位置变更与探测效...     

Facile fabrication of nano-hydroxyapatite/silk fibroin composite via a simplified coprecipitation route

Nano-hydroxyapatite/silk fibroin (n-HA/SF) composite was successfully fabricated based on a simplified coprecipitation route. In detail, the degummed SF was first dissolved in CaCl₂ aqueous/ethanol solution without desalting procedure, and then (NH₄)₂HPO₄ solution and NH₄OH were dropped into the above solution to form n-HA/SF composite. The structure and morphology of n-HA/SF composite were investigated by Transmission electron microscopy, Fourier transform infrared spectrometry, energy dispersive X-Ray spectrum, X-ray diffraction, and thermogravimetric analyses. Results indicate that the inorganic phase is carbonate-substituted HA with low crystallinity and similar to the crystals of human bone. The HA crystals have diameter of around 20–30 nm and length of about 200–500 nm. The content of SF in the composite is about 30%, and the two phases bonded each other strongly. In addition, a formation mechanism of n-HA/SF was proposed.     

Coarsening of needle-shaped apatite crystals in SiO2 • Al2O3 • Na2O • K2O • CaO • P2O5 • F glass

Coarsening of needle-shaped apatite crystals was studied in a SiO2 Al2O3 Na2O K2O CaO P2O5 F glass. Crystal numbers and size distributions were measured by image analysis of electron micrographs obtained from slightly etched fractures of powder compacts sintered from differently annealed glass powders. Results indicate that the growth of apatite needles is controlled by diffusion-limited Ostwald ripening. Thus, the mean needle diameter and length increase with t1/3 while the crystal number decreases with t–1 due to a constant volume fraction of apatite. An invariant reduced size distribution could be found for the diameters. The measurement of needle lengths is affected by several difficulties (e.g. random needle orientation).     

Low temperature fabrication of high strength porous calcium phosphate and the evaluation of the osteoconductivity

Porous NaO₂–MgO–CaO–P₂O₅ bioglass doped beta-tri-calcium phosphate (β-TCP) bioceramic possessing high mechanical properties and well pore structure with high porosity and high pore connectivity has been prepared through dipping method with the porous polyurethane as the pore forming template. The sintering mechanism and the mechanical properties of the bioglass doped β-TCP scaffold have been investigated by the X-ray diffraction (XRD) analysis, Scanning electron microscope (SEM) and thermal differential analysis (DTA). The scaffold’s in vivo osteoconductivity has been evaluated by implantation of scaffolds into the femurs of New Zealand rabbits. The results show that the porous structure can achieve the densification process at a low temperature about 950°C by a solid solution sintering mechanism and hence dense macropore scaffold with a compressive strength of 4.32 MPa when the porosity is 75% has been obtained. The in vivo test shows that the Na₂O–MgO–CaO–P₂O₅ bioglass doped porous β-TCP bioceramic has a relatively fast bone formation after implantation; after 1 month implantation new deposited bone tissue has been detected on the strut of the porous scaffold and degraded particles also has been found on the surface of the new formed bone. After 6 months implantation the porous scaffold has been thoroughly covered with new formed bone. Results show that the Na₂O–MgO–CaO–P₂O₅ bioglass doped porous β-TCP bioceramic is potential bone tissue engineering scaffold for orthopedic use.     

Dissolution behavior and bioactivity study of glass ceramic scaffolds in the system of CaO–P2O5–Na2O–ZnO prepared by sol–gel technique

Three-dimensional glass ceramic scaffolds from the system CaO–P₂O₅–Na₂O–ZnO have been prepared by coating polyurethane foams with sol–gel derived glass slurry. Main phase catena hexaphosphate (Ca₄P₆O₁₉), minor phases calcium pyrophosphate (β-Ca₂P₂O₇) and calcium metaphosphate (β-Ca(PO₃)₂) were detected in the prepared glass ceramics. In order to assess the potential use in hard tissue engineering, the dissolution and precipitation behavior of the glass ceramics was investigated in vitro after soaking in simulated body fluid (SBF) for different periods of time, and the bioactivity and biocompatibility studies were conducted using mouse MC3T3-E1. Ca₄P₆O₁₉ phase showed a good chemical durability in SBF solution over the period time of soaking. However, there were small quantities of apatite-like deposits formed on the surfaces after soaking 28 days, exhibiting a poor ability of inducing calcification in SBF. In vitro cell culture, a high degree of cell adhesion and spreading was achieved and large number of mineralized deposits composed of Ca, P and Zn were detected in these porous scaffolds. These results confirmed the biocompatibility and bioactivity of the glass ceramics and the positive effects on mouse MC3T3-E1 cell behavior although no continuous apatite layer was formed on scaffold surfaces after soaking in SBF, and also demonstrated that Zn doped this glass ceramics could strongly stimulate the formation of mineralized deposits in vitro culture of MC3T3-E1 cells.     

地铁车厢灯光自适应控制研究

解决地铁节电问题一直是国内外大力研究的课题。而行驶在高架以及地面段的地铁列车具有天然的采光资源——自然光。根据这一现状,提出一种自适应调节车厢内灯具照度的方法,来达到节约地铁车厢内照明用电的目的。针对自然光随机性高,变化频率快,以及地铁运行时外界环境干扰大的问题,提出采用数字滤波器结合模糊控制的方法,将经巴特沃斯低通滤波器滤除高频干扰的车厢内照度信号传输给模糊控制器,通过模糊控制器的逻辑推理判断处理,实现了地铁车厢灯光自适应地调节车厢内灯具的照度,节约了地铁车厢照明用电。