载紫杉醇聚乳酸-羟基乙酸纳米粒的体外释药研究

以生物可降解材料聚乳酸-羟基乙酸(PLGA)为载体制备了载紫杉醇纳米粒,重点考察了纳米粒的体外释放特性.采用乳化-溶剂挥发法制备了载紫杉醇PLGA纳米粒,其平均粒径为200nm,载药量为21%,包封率为89.44%;体外释药符合Higuchi方程:Q=3.8796t1/2+30.4649(r=0.9397),同时载紫杉醇纳米粒具有一定的缓释作用.     

壳聚糖包覆二氧化硅纳米粒及其作为蛋白载体的研究

通过壳聚糖在二氧化硅纳米粒表面的沉积制备了壳聚糖包覆的二氧硅（CS@SiO2）。采用BSA作为模型蛋白,研究了CS@SiO2作为蛋白载体的可能性。结果表明,CS@SiO2可有效吸附BSA且可控释放被吸附的BSA。     

具有癌症诊疗潜力的多功能核壳纳米粒

采用乳化-溶剂挥发法制备了同时携载Mn3O4纳米粒和CuS白蛋白纳米粒的诊疗一体化多功能核壳纳米粒,可用于磁共振造影成像手段指引下的肿瘤光热消融,实现癌症的高效诊治.首先用高温热解法制备出粒径均一、分散性较好的Mn3O4纳米粒,并通过蛋白模板法制备CuS白蛋白纳米粒,之后采用可降解性聚乳酸-羟基乙酸共聚物(PLGA)作为载体,通过超声乳化法制备同时携载Mn3O4和CuS纳米粒的核壳纳米粒(Mn3O4/PLGA@CuS),并进行理化性质表征及诊疗一体化性能评价.结果表明:紫外-可见-近红外分光光度计测定结果显示该纳米粒被成功制备,其在近红外区具有较强吸收;核壳纳米粒的平均粒径为160 nm,粒径分布较为均匀;体外磁共振造影成像结果显示随着纳米粒中Mn离子浓度的升高,其造影增强效果也明显提升,显示其具有Mn离子浓度依赖的磁共振成像效果,纵向弛豫率为1.351 mM-1·s-1;在785及980 nm激光辐照下,该核壳纳米粒均显示出良好的光热升温效果.成功制备了具有良好的磁共振造影成像性能和显著的光热升温效应的核壳纳米粒,有望应用于肿瘤的诊疗一体化.     

山核桃仁鞣质叶酸-PEG修饰纳米粒的制备和性能研究

为了提高山核桃仁鞣质的肿瘤靶向性,增强其抗肿瘤活性,采用薄膜分散法制备山核桃仁鞣质叶酸-PEG修饰纳米粒,通过核磁共振、透射电镜等方法对纳米粒的结构、粒径和粒径分布、形态、稳定性、包封率以及肿瘤靶向性进行了初步研究。结果表明,山核桃仁鞣质叶酸-PEG修饰纳米粒平均粒径为166.8nm;包封率为74.5%,粒子呈大小均匀的球形;放置50d纳米粒粒径和包封率变化轻微,具有很好的稳定性;叶酸-PEG修饰纳米粒小鼠尾静脉注射后0.25,1和4h肿瘤分布分别为20.8%,36.2%和50.2%,具备明显的肿瘤靶向作用。     

pH值响应性透明质酸纳米粒的制备及作为阿霉素载体的研究

通过化学交联法合成组氨酸修饰透明质酸耦合物(His-HA),制备载阿霉素纳米粒,分析其pH值响应性和抗肿瘤特征.研究显示,随着pH值的降低(7.4～5.5),纳米粒的粒径增大(230～780nm),zeta电位升高,载药纳米粒的体外释放量增加.细胞毒性实验显示粒径＜300nm的载药纳米粒具更高的毒性.细胞摄入实验表明,阿霉素通过受体介导的胞吞和载药纳米粒的胞外释放两种途径被细胞摄入.以上研究显示组氨酸修饰透明质酸纳米粒具有显著的pH值响应性,具备作为阿霉素药物载体的应用前景.     

叶酸靶向介孔二氧化硅纳米粒的制备及其缓释研究

纳米药物缓释系统由于具有抗药性小、毒副作用低、治疗效果好等优点，得到研究者们的广泛关注。首先以双键修饰的介孔二氧化硅纳米粒为基质，叶酸和丙烯酰基-β-环糊精单体(β-CD-A)为功能单体，N,N′-亚甲基双丙烯酰胺(MBA)为交联剂，通过自由基聚合法制备了叶酸靶向药物载体MSNs@P(CD-co-FA)。然后采用浸渍法对姜黄素进行载药吸附。结果表明：MSNs@P(CD-co-FA)的最佳载药浓度为300mg/L,对姜黄素的平衡吸附量为81.7mg/g,最佳载药时间为10h。体外释药结果显示，MSNs@P(CD-co-FA)在24h时累计释放率为11.24%。     

蛋白质印迹羧化多壁碳纳米管/CaAlg水凝胶膜及其修饰的电化学传感器

文中以牛血清白蛋白(BSA)为模板、海藻酸钠(NaAlg)为功能单体，掺杂羧化多壁碳纳米管，经CaCl₂溶液交联制备了BSA分子印迹羧化多壁碳纳米管/海藻酸钙(CMWCNTs/CaAlg)复合水凝胶膜(MIP)，同时不用模板制备了非印迹膜(NIP)，研究了CMWCNTs含量对膜力学性能的影响；膜厚度、洗脱液pH值对BSA吸附性能的影响。研究了MIP膜的吸附选择性。结果表明，当CMWCNTs的质量为NaAlg的2%时，水凝胶膜同时具备良好的抗溶胀性能和力学性能。膜厚度控制在0.2 mm，洗脱液pH值为7.4时，MIP膜对BSA的吸附量最大，为35.04 mg/g。将MIP膜负载于裸碳电极表面，循环伏安法和差分脉冲伏安法测试表明，MIP膜修饰电极对BSA表现出较高的选择识别性。     

TiO2纳米管阵列膜对牛血清白蛋白的吸附与脱附

采用电化学阳极氧化法以含氟的乙二醇溶液为电解液阳极氧化纯钛制备出排列规则的高长径比TiO2纳米管阵列膜,并用扫描电镜(SEM)、比表面积仪表征了TiO2纳米管阵列膜的形貌和比表面积。结果表明,所制得的TiO2纳米管阵列的管径约180nm,管长可达230μm,比表面积约59.8m2/g。以牛血清白蛋白(BSA)为药物蛋白分子的模型,并研究了TiO2纳米管阵列膜对BSA的吸附和脱附行为,考察了溶液pH值、BSA初始浓度和溶液离子强度对BSA吸附的影响与吸附态的BSA在不同pH值的PBS溶液中的释放行为。结果表明,BSA分子在其等电点(pH值=4.8)附近较容易吸附到TiO2纳米管上,吸附量随着BSA初始浓度的增加而增加,较高的离子强度会降低BSA的吸附,碱性条件下吸附态的BSA容易从TiO2纳米管上脱附,并由于纳米管的扩散限制效益呈现一定程度的缓释。     

膨胀石墨基镍/炭复合物(英文)

NiO粒子修饰的压缩膨胀石墨(EGNiO)浸以煤焦油沥青,经550℃裂解,继而800℃水蒸气活化,制得Ni/C复合物块体。应用TEM考察了复合物中含Ni纳米粒的微结构排列方式。以N2吸附测定分析了复合物的比表面积和孔隙度。以2,2,3—三甲基戊烷脱氢裂解模型反应评估了复合物的催化活性并与EGNiO常规H2处理获得的参照物的活性做了比较。     

羟基磷灰石微纳结构对蛋白吸附的影响

本研究采用水热反应法, 在不同浓度环己烷六羧酸(H6E)模板调控作用下, 合成了具有不同表面微纳结构的羟基磷灰石(HAP)微粒, 并采用XRD、BET、FTIR和SEM对其进行表征。对HAP微粒进行了牛血清白蛋白(BSA)、纤维蛋白原(FN)和溶菌酶(LYS)的吸附及释放实验。结果表明: H6E能够在HAP微粒表面构建微纳结构, 不同微纳结构对不同蛋白质具有选择性吸附作用; 在H6E浓度为50 mmol/L的合成条件下制备的中空结构HAP微粒(HAP50)其载蛋白后体外释放具有明显的蛋白缓释性能。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.