甘草酸脂质体的制备及小鼠体内肝靶向效率的评价

目的 制备甘草酸脂质体,评价其在小鼠肝脏中的靶向性。方法 以薄膜分散-超声法制备甘草酸脂质体,于小鼠尾静脉给药,RP-HPLC法测定肝脏和血液中不同时间的药物浓度。以甘草酸注射剂为对照,通过相对摄取率(re)、靶向效率(te )和峰浓度比(Ce )3个参数来评价脂质体的肝靶向效率。 结果 甘草酸脂质体肝脏相对摄取率re=1.4;甘草酸脂质体肝靶向效率te =0.092;甘草酸注射液te =0.059,肝脏中Ce=1.59,血液中Ce=0.99。结论：与甘草酸注射剂相比,甘草酸脂质体有明显的肝靶向性。     

Fracture Models and Effect of Fibers on Fracture Properties of Cementitious Composites—A Review

Cementitious composites have good ductility and pseudo-crack control. However, in practical applications of these composites, the external load and environmental erosion eventually form a large crack in the matrix, resulting in matrix fracture. The fracture of cementitious composite materials causes not only structural insufficiency, but also economic losses associated with the maintenance and reinforcement of cementitious composite components. Therefore, it is necessary to study the fracture properties of cementitious composites for preventing the fracture of the matrix. In this paper, a multi-crack cracking model, fictitious crack model, crack band model, pseudo-strain hardening model, and double-K fracture model for cementitious composites are presented, and their advantages and disadvantages are analyzed. The multi-crack cracking model can determine the optimal mixing amount of fibers in the matrix. The fictitious crack model and crack band model are stress softening models describing the cohesion in the fracture process area. The pseudo-strain hardening model is mainly applied to ductile materials. The double-K fracture model mainly describes the fracture process of concrete. Additionally, the effects of polyvinyl alcohol (PVA) fibers and steel fibers (SFs) on the fracture properties of the matrix are analyzed. The fracture properties of cementitious composite can be greatly improved by adding 1.5–2% PVA fiber or 4% steel fiber (SF). The fracture property of cementitious composite can also be improved by adding 1.5% steel fiber and 1% PVA fiber. However, there are many problems to be solved for the application of cementitious composites in actual engineering. Therefore, further research is needed to solve the fracture problems frequently encountered in engineering.     

Effect of the Branching Pattern of Hydrophobic Dendrons on the Core Structure of Linear‐Dendritic Copolymer Micelles

Hydrophobic dendrons based on different branching patterns, viz. 3,5‐di‐ and 3,4,5‐trisubstituted phenyl rings, consist of the same backbone but exhibit different sizes, shapes, and hydrophobic densities. These dendrons are attached to poly(ethylene glycol) and the core pro­perties of the copolymer micelles are investigated in tetrahydrofuran (THF)/water mixtures by neutron scattering. Two polymers with intermediate hydrophobicity are studied further with variations in the solvent composition and the temperature. The aggregation numbers for 3,4,5‐based dendron copolymers are lower, with more THF molecules of solvation compared with the 3,5‐based dendron copolymer, the difference being greater at higher generations due to different molecular shapes. The micellar core size increases in small steps with dendron size so that dye encapsulation is tuned.

     

Dielectric Properties of Dual-Frequency Reactive Mesogens before and after Photopolymerization

The dielectric properties of reactive mesogens before and after photopolymerization were investigated. Commercially available nematic reactive mesogens (RMS03-013C, Merck) were measured and found to be dual-frequency liquid crystals. The property arose from the δ-relaxation process that was caused by rotational fluctuations parallel to the molecule’s long axis. After polymerization, the polymerized reactive mesogens still exhibited this dual-frequency property. The result was attributed to the β-relaxation process which arose from rotational fluctuations of localized parts of the main chain. The sign change of the dielectric anisotropy with increasing frequency after polymerization was opposite to the sign change before polymerization.     

Development,characterisation and efficacy evaluation of biochemical fungicidal formulations for postharvest control of anthracnose (Colletotrichum gloeosporioides Penz) disease in mango

The objectives of the study are to develop and characterise formulations with volatile molecules in an emulsifiable concentrate form, for their antimicrobial properties and to evaluate their efficacies against Colletotrichum gloeosporioides Penz., to control anthracnose in mangoes after harvest. Results showed EC39 and EC40 among formulations were characterised for their excellent emulsification properties, the droplet size of 192.34?±?0.48?nm and 227.4?±?0.71?nm and Zeta potential of ?52.5?±?2.76?mv and ?48.84?±?2.62?mv, respectively, with better storage stability at 10?±?20?°C and RH 80?±?5%. In vitro assay, 100% inhibition of visual spore germination by 0.15% and 0.2% MIC value for EC39 and EC40, respectively Studies on the efficacy of their fungicide properties also indicated the IC50 value of 0.161% and 0.162% for EC39 and EC40 respectively for mycelial growth inhibition. In vivo testing too, EC39 and EC40 effectively controlled anthracnose incidence in mango in a dosage-dependent manner.     

模拟口腔环境下温控型镍钛弓丝力学性能的实验研究

目的研究温控型镍钛弓丝在不同温度人工唾液环境下的力学性能变化,为临床合理、有效地使用温控型镍钛弓丝提供参考。方法利用Instron万能材料力学实验机在25、33、37、60 ℃人工唾液中对4种温控型镍钛弓丝进行改良部分牙弓托槽弯曲实验。将4种温控型镍钛弓丝加载挠曲至3 mm后卸载,绘制弓丝卸载的载荷-挠曲曲线,计算卸载至2.5 mm与0.5 mm之间的卸载刚度,结果采用单因素方差分析法进行统计分析。结果随着温度的升高,4种弓丝的卸载力值均有不同程度的升高;同种弓丝的卸载刚度在25、33、37 ℃时十分接近,而在60 ℃时卸载刚度均有明显增大。结论在本实验条件下,4种温控型镍钛弓丝表现出不同的力学性能,但均表现出临床所需的超弹性与形状记忆效应,也均表现出明显的温度敏感性。     

LLA/GA/ε-CL摩尔比对三元共聚物性能的影响

辛酸亚锡为催化剂,采用本体开环聚合方法,合成了一组不同摩尔比的L-丙交酯/乙交酯/ε-己内酯(LLA/GA/CL)三元共聚物。通过GPC、1H-NMR、DSC和XRD测试,研究了摩尔比对共聚物分子量及其分布、热性能和结晶性能的影响。结果表明共聚物组成摩尔比与投料摩尔比基本一致,共聚物玻璃化转变温度(Tg)随LLA和CL含量增加分别呈现升高和降低趋势,并且当LLA含量增加至77 mol%,即LLA/GA摩尔比85∶15时,共聚物表现出明显的部分结晶性。     

Bioceramic materials in endodontics

During the past two decades, a number of major advances have been made in the field of bioactive ceramics used for endodontic treatment. This article reviews the physico-chemical and biological properties of bioceramic materials and the application of bioceramic technology to endodontics. Bioceramic materials, with their biocompatible nature and excellent physico-chemical properties, are widely used in endodontic applications. They can function as cements, root repair materials, root canal sealers and filling materials, which have the advantages of enhanced biocompatibility, potential increased root strength following obturation, antibacterial properties and sealing ability. New bioceramic materials have demonstrated the ability to overcome some of the significant limitations of earlier generations of endodontic materials. Most bioceramic materials have been shown to be biocompatible and have good physico-chemical characteristics, therefore having a potential use in clinical endodontics. Although in vitro studies on the use of bioceramic materials in endodontics have given encouraging results, randomized and double-blind clinical studies of sufficient length with these materials are needed to confirm long-term success following their use.     

注射用益气复脉(冻干)的质量标志物研究

注射用益气复脉(冻干)是由红参、麦冬和五味子3味药材精制而成,临床上主要用于治疗冠心病劳累型心绞痛气阴两虚证及冠心病所致慢性左心功能不全II、III级气阴两虚证。根据质量标志物概念,从物质基础、药效、网络药理、药动学及药性等方面对注射用益气复脉(冻干)质量标志物进行预测分析,初步确定人参皂苷Rb1、Rg1、Rf、Rh1、Rc、Rb2、Ro、Rg3及麦冬皂苷C、麦冬苷元-3-O-α-L-吡喃鼠李糖基-(1→2)-β-D-吡喃葡萄糖苷、偏诺皂苷元-3-O-α-L-吡喃鼠李糖基-(1→2)-β-D-吡喃木糖基-(1→4)-β-D-吡喃葡萄糖苷、果糖、五味子醇甲13个成分为质量标志物,并以此为核心建立全程质量控制体系。基于质量标志物对注射用益气复脉(冻干)进行质控方法研究,可以为中药注射剂质量评价提供新的研究思路。     

蛋白酶抑制剂茚地那韦的知识产权保护状况和风险分析

通过对蛋白酶抑制剂茚地那韦国内外知识产权保护状况的初步分析,以及茚地那韦国际和国内的申请量、申请地区、申请人、保护状况和期限等方面统计,可见国外原研企业对于茚地那韦专利申请已逐年下降,但目前专利仍对该药有一定的保护力度,该药在合成方法、衍生物、新剂型、新用途等方面尚有较大的研发和保护空间,相关医药企业仍可从这些方面对该药进行研究改进或创新.