Microspheres of essential oil in polylactic acid and poly(methyl methacrylate) matrices and their blends

This study is focussed on micro-encapsulation of essential oils in polylactic acid (PLA) and a poly(methyl methacrylate) (PMMA) matrix as well as blends of the same. Microspheres were prepared by the solvent evaporation technique and characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infra-red spectroscopy (FTIR). The encapsulation efficiencies and release profiles of the essential oils were studied by gas chromatography mass spectrometry (GC-MS) and head-space solid-phase microextraction GC-MS, respectively. Furthermore, the microspheres were tested for antibacterial activity against both Gram-negative and Gram-positive bacterial strains.

The results showed that the microspheres compositions (PLA/PMMA ratio) have significant effect on their characteristics. The process adopted for preparing the microspheres promoted formation of spherical particles at the sizes of 1.5–9.5?µm. The highest encapsulation efficiency of the prepared microspheres was observed in systems consisting of linalool (81.10?±?10.0?wt. % for PLA system and 76.0?±?3.3?wt. % for PMMA system). Confirmation was also made that the release rate of the microspheres was affected by the size of the same.     

辛味中药在治疗消渴证中的应用价值及中药五味理论现代研究的思考

辛味是中药五味学说中的重要性味之一,通常具有“发散”“行气”和“行血”的作用,且辛味中药在传统医学临床应用中占有较大比例。结合中药辛味的功效内涵及传统中医理论对消渴证的认识,阐述辛味中药与消渴证治疗之间的内在联系,总结辛味中药对“消渴三消”的治疗意义与价值。并在此基础上,对中药五味理论的现代研究趋势和发展方向进行思考,为同行研究提供参考。     

Exploration of D022-Type Al3TM(TM = Sc,Ti, V,Zr, Nb,Hf, Ta): Elastic Anisotropy,Electronic Structures,Work Function and Experimental Design

The structural properties, elastic anisotropy, electronic structures and work function of D0₂₂-type Al₃TM (TM = Sc, Ti, V, Y, Zr, Nb, La, Hf, Ta) are studied using the first-principles calculations. The results indicate that the obtained formation enthalpy and cohesive energy of these compounds are in accordance with the other calculated values. It is found that the Al₃Zr is the most thermodynamic stable compound. The mechanical property indexes, such as elastic constants, bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, and Vickers hardness are systematically explored. Moreover, the calculated universal anisotropic index, percent anisotropy and shear anisotropic factors of D0₂₂-type Al₃TM are analyzed carefully. It demonstrates that the shear modulus anisotropy of Al₃La is the strongest, while that of Al₃Ta is the weakest. In particular, the density of states at Fermi level is not zero, suggesting that these phases have metal properties and electrical conductivity. More importantly, the mechanisms of correlation between hardness and Young’s modulus are further explained by the work function. Finally, the experimental design proves that D0₂₂-Al₃Ta has an excellent strengthening effect.     

Sensitive skin: correlation with skin surface microrelief appearance

BACKGROUND/PURPOSE: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief. METHODS: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)). RESULTS: A significant correlation was found between intensity of symptoms in stingers and ISI (r(s)=-0.47; P<0.001). CONCLUSION: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition.     

Physical laws of cholesterol gallstone fragmentation

Efficient fragmentation is the most important prerequisite for successful treatment of gallstones by extracorporeally induced shock waves. No data are available on the amount of energy necessary for stone disintegration and on the threshold energy below which no further fragmentation occurs. We therefore performed an in vitro investigation on human cholesterol gallstones to elucidate physical laws governing shock-wave lithotripsy. First, the focal pressure of the lithotripter was measured to calculate the energy traversing a stone. Second, 96 gallstones from 16 gall bladders were analysed with respect to physicochemical composition, radiological features and ultrasound before fragmentation was performed. Energy for stone disintegration was constant within each stone family but varied between 4.6 J mL^?1 and 36.8 J mL^?1 in different families. This energy correlated linearly with stone volume. None of the radiological and physicochemical factors revealed a clear-cut correlation of the different energies necessary for similar stone disintegration. The threshold energy differed between 0.26 mJ and 1.04 mJ per pulse. In conclusion, stone volume was the best parameter predicting stone fragmentation. However, in cholesterol stones with a similar composition the required energy per volume varies considerably together with the threshold energy. Radiological and ultrasound parameters appear to be of minor importance in explaining these differences.     

Synthesis and Properties of Haptens for the Development of Radioimmunoassays for Thioridazine,Mesoridazine, and Sulforidazine

For the separate development of radioimmunoassay procedures for thioridazine and its two major active metabolites, mesoridazine and sulforidazine, three haptens, respectively, 2-methylthio-, 2-methylsulfinyl-, and 2-methylsulfonyl-substituted 10-[2-[l-(2-carboxyethyl)-2-piperidinyl]ethyl]-10H-phenothiazine, were synthesized and characterized. Thioridazine hapten was coupled to bovine serum albumin, whereas the haptens for mesoridazine and sulforidazine were coupled to porcine thyroglobulin. The number of hapten residues per mole of carrier protein was determined in each case by an ultraviolet spectrophotometric method. Polyclonal antibodies to each hapten–protein conjugate were obtained in rabbits, and titers of the antisera were checked by evaluating their binding characteristics to the appropriate tritiated analyte. A hapten for the ring sulfoxide metabolite of thioridazine was also synthesized.     

复合矫治弓丝接头的力学性能及接头组织观察

目的　测试复合矫治弓丝接头的机械性能及分析接头、接头断口变化。方法　测试复合矫治弓丝接头的拉伸强度、剪切强度、扭转强度、弯曲形变残余角,TiNi形状记忆合金丝超弹性,扫描电镜观察及分析接头、断口组织变化。结果　复合矫治弓丝接头抗拉伸强度为32 0～36 0MPa ,剪切强度为2 2 0～2 5 0MPa ,抗扭转强度为30～4 0N·m、断裂时扭转角度不小于1 4 4 0°,弯曲形变残余角为1 2～1 7°;钎焊异质接头中TiNi形状记忆合金丝超弹性几乎没有破坏;接头钎料与TiNi形状记忆合金界面不存在扩散层,与不锈钢丝界面之间有一较宽的扩散层,接头断裂多发生在钎料与TiNi形状记忆合金超弹界面处,部分发生在钎缝中心。结论　复合矫治弓丝机械性能符合正畸临床要求,可应用于临床。     

冬凌草甲素亚微乳的制备及其特性表征

目的：制备冬凌草甲素亚微乳，并对其理化性质进行表征。方法：采用高压均质法制备冬凌草甲素亚微乳，并对其粒径、Zeta电位、黏度等性质进行表征。结果：冬凌草甲素亚微乳为白色不透明乳状液体，载药量1 g·L^-1，平均粒径(138.87±0.60) nm，Zeta电位(47.27±2.31) mV，pH(6.02±0.03)，黏度(1.78±0.015) MPa·s。结论：本实验所制得的冬凌草甲素亚微乳理化性质较稳定，工艺简单，可为冬凌草甲素亚微乳制剂的制备提供研究依据。     

Oral administration of methylergometrine shows a late and unpredictable effect on the non-pregnant human menstruating uterus

Objective: To study the pharmacodynamic and pharmacokinetic properties of oral and intravenous methylergometrine upon uterine motility during menstruation. Study-design: Intra-uterine pressure was measured in six volunteers with a fluid-filled sponge-tipped catheter during menstruation. Methylergometrine was given orally (0.5 mg) or intravenously (0.2 mg) in a cross-over design. Results: After intravenous administration, a fast increase of the frequency of uterine contractions and basal tone occurred with a decrease of amplitude, lasting at least 30 min. Oral administration had a late and less marked effect on uterine motility. An intravenous dose administered 24 h after an oral dose had no effect on uterine motility. Pharmacokinetic data, such as the maximum plasma concentration (C_max), the time at which C_max is reached (t_max) and the half-life of absorption (t_1/2abs) also demonstrated large individual variations after oral administration. Conclusion: Oral administration of methylergometrine had an unpredictable and late effect on uterine motility on the menstruating uterus, probably due to an unpredictable bioavailability, in contrast with the fast and predictable effect after intravenous administration.