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。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

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.