Nanoparticulation of probucol, a poorly water-soluble drug, using a novel wet-milling process to improve in vitro dissolution and in vivo oral absorption

To improve the dissolution and oral absorption properties of probucol, a novel wet-milling process using the ULTRA APEX MILL was investigated. The particle size of bulk probucol powder was 17.1 μm. However, after wet-milling with dispersing agents such as Gelucire 44/14, Gelucire 50/13, vitamin E-TPGS, and Pluronic F-108, the probucol particle sizes decreased to about 77-176 nm. Scanning electron microscopy (SEM) analysis also suggested that the probucol particles were successfully milled into the nanometer range. An in vitro dissolution study showed that the dissolution rates of all nanopowders were several folds higher than those of the corresponding mixed powders. When orally administered to rats, the AUC values of probucol nanopowders treated with Gelucire 44/14 and 50/13, and vitamin E-TPGS were about 3.06-3.54-folds greater than that of the bulk powder. Therefore, through this study, we have developed a new pharmaceutical technique to improve the dissolution rate and oral absorption of probucol using the ULTRA APEX MILL by wet-milling with various dispersing agents.     

表面活性剂与同离子效应对己内酰胺吸附的影响

通过向硫酸铵与己内酰胺混合物中添加阳离子表面活性剂、两性离子表面活性剂和同离子物质,研究了己内酰胺在硫酸铵晶体表面的吸附情况。实验结果表明：十二烷基三甲基氯化铵、十二烷基三甲基溴化铵、十六烷基三甲基氯化铵与氟阳离子表面活性剂能显著降低吸附量;硫酸钠、氯化铵、十二烷基甜菜碱和十六烷基三甲基溴化铵的加入,使己内酰胺在硫酸铵晶体表面的吸附量呈不规律的变化。在硫酸铵-母液-酰胺油体系中添加少量的十二烷基三甲基溴化铵可有效降低己内酰胺在硫酸铵颗粒表面的吸附量。     

管道内壁腐蚀的红外热像无损检测的数值模拟

红外热像无损检测技术以其独特的优点而得到广泛应用,检测前的仿真研究,可解决其检测设备红外热像仪使用成本较高的问题。笔者以存在内表面腐蚀的45钢管道检测为研究对象,以ANSYS软件为数值仿真研究平台,分析探讨了评判缺陷可检测性的指标体系,即最大温差、可检测持续时间及最佳检测时间,研究了缺陷大小和检测条件等因素对缺陷可检测性的影响。结果表明,该研究对管道内壁腐蚀的红外热像无损检测具有一定的参考意义。     

批判性地域主义视野下的少数民族民居建筑改造——以云南怒江流域干一它村傈僳族民居为例

在全球文化的“趋同”与地域文化符号化、表皮化的大背景下,以批判的地域主义为理论基础,重新审视该理论对我国少数民族直过区传统民居建筑的保护和传承的适应性发展。通过干一它村傈僳族传统民居建筑改造实践,提出回归本土居民的批判性思考,更多地关注民居建筑物理环境的舒适性、空间组织的地域适应性和地方依恋的地域载体,以弥补当下批判的地域主义实践在系统性考虑本土居民的需求上的缺失,探索传统民居建筑改造如何在传承中创新。     

Effects of Microalloying on the Impact Toughness of Ultrahigh-Strength TRIP-Aided Martensitic Steels

The effects of the addition of Cr, Mo, and/or Ni on the Charpy impact toughness of a 0.2 pct C-1.5 pct Si-1.5 pct Mn-0.05 pct Nb transformation-induced plasticity (TRIP)-aided steel with a lath-martensite structure matrix (i.e., a TRIP-aided martensitic steel or TM steel) were investigated with the aim of using the steel in automotive applications. In addition, the relationship between the toughness of the various alloyed steels and their metallurgical characteristics was determined. When Cr, Cr-Mo, or Cr-Mo-Ni was added to the base steel, the TM steel exhibited a high upper-shelf Charpy impact absorbed value that ranged from 100 to 120 J/cm² and a low ductile–brittle fracture appearance transition temperature that ranged from 123 K to 143 K (?150 °C to ?130 °C), while also exhibiting a tensile strength of about 1.5 GPa. This impact toughness of the alloyed steels was far superior to that of conventional martensitic steel and was caused by the presence of (i) a softened wide lath-martensite matrix, which contained only a small amount of carbide and hence had a lower carbon concentration, (ii) a large amount of finely dispersed martensite-retained austenite complex phase, and (iii) a metastable retained austenite phase of 2 to 4 vol pct in the complex phase, which led to plastic relaxation via strain-induced transformation and played an important role in the suppression of the initiation and propagation of voids and/or cleavage cracks.     

Electrochemical doping of pure single-walled carbon nanotubes used as supercapacitor electrodes

Pure single-walled carbon nanotubes (SWCNTs) with little bundling show an excellent capacitor performance attributable to the intrinsic nature of the SWCNTs, and possess unusual electrochemical properties characterized by a butterfly shaped cyclic voltammogram which differs from those for conventional activated carbon electrodes. Electrochemical doping in semi-conductor nanotubes occurred at the interface between the electrolyte and the SWCNT surface. In situ measurements showed a remarkable increase of electric conductivity with the polarization from the flat band potential. Because of the potential dependence, the capacitance of the SWCNT electrodes was higher at the higher charging potentials.     

Pre-treatment of sperm reduces success of ICSI in the pig

In pigs, although ICSI is a feasible fertilization technique, its efficiency is low. In general, injected pig sperm are insufficient to induce oocyte activation and embryonic development. Pretreatments for disrupting sperm membranes have been applied to improve the fertility of ICSI oocytes; however, we hypothesize that such pretreatment(s) may reduce the ability of the sperm to induce oocyte activation. We first evaluated the effects of sperm pretreatments (sonication (SO) to isolate the sperm heads from the tails, Triton X-100 (TX), and three cycles of repeated freezing/thawing (3×-FT) for disrupting sperm membranes) on the rate of pronucleus (PN) formation after ICSI. We found that oocytes injected with control (whole) sperm had higher rates of PN formation than those obtained after subjecting the sperm to SO, TX, and 3×-FT. The amounts of phospholipase Cζ (PLCζ), which is thought to be the oocyte-activating factor in mammalian sperm, in sperm treated by each method was significantly lower than that in whole untreated sperm. Furthermore, using immunofluorescence, it was found that in pig sperm, PLCζ was localized to both the post-acrosomal region and the tail area. Thus we demonstrated for the first time that sperm pretreatment leads to a reduction of oocyte-activating capacity. Our data also show that in addition to its expected localization to the sperm head, PLCζ is also localized in the tail of pig sperm, thus raising the possibility that injection of whole sperm may be required to attain successful activation in pigs.     

Polymer/polymer blend solar cells with 2.0% efficiency developed by thermal purification of nanoscale-phase-separated morphology

We have fabricated polymer/polymer blend solar cells consisting of poly(3-hexylthiophene) as the electron donor and poly{2,7-(9,9-didodecylfluorene)-alt-5,5-[4',7'-bis(2-thienyl)-2',1',3'-benzothiadiazole]} as the acceptor. The power conversion efficiency (PCE) was strongly dependent on solvents employed for spin coating. The best PCE of 2.0% was obtained for thermally annealed devices prepared from a chloroform solution, in contrast to devices fabricated from chlorobenzene and o-dichlorobenzene solutions. On the basis of the morphology-performance relationship in the polymer blends examined by atomic force microscopy and the photoluminescence quenching measurements, we conclude that the highly efficient performance is achieved by thermal purification of nanoscale-phase-separated domains formed by spin coating from chloroform.     

Estimation of mechanochemical dechlorination rate of poly(vinyl chlorde)

Poly(vinyl chloride) (PVC) was ground in air with CaO in the presence of quartz powder as a grinding aid by a small-scale planetary ball mill to investigate the relation of the dechlorination rate of PVC with the impact energy of the balls calculated from a computer simulation based on the Discrete Element Method under various conditions. Mechanochemical dechlorination proceeds as the grinding progresses and is improved with an increase in both the mill speed and the amount of balls introduced into the mill. The same trend can be seen in the relation between the specific normal impact energy of the balls and the rotational speed. The relationship between the observed dechlorination rate and the computed normal impact energy of the balls is linear, with a correlation coefficient of 0.965. This relationship can be used to estimate the dechlorination rate of PVC in a large-scale planetary ball mill.