Epoxyeicosatrienoic acid: the signal transduction

Cytochrome P450 monoxygenase converts arachionic acid to four epoxyeicosatrienoic acid regiosomes: 5, 6-EET (epoxyeicosatrienoic acid); 8, 9-EET; 11, 12-EET and 14, 15-EET. Recent studies show that EETs are involved in signal transduction. EETs open Ca²⁺-sensit ive K⁺ channel and inhibit Na⁺ channel, Ca²⁺-sensitive Cl^- channel and so on. What is more, EETs have been demonstrated to activate PP60^c-src and initiate a tyrosine kinase cascade that mediates mitogenic effects.     

多肉植物塑化标本制作研究

本文从“永生花”的存在提出“永生多肉”的想法，既保存其鲜活性，又不让它丧失独特的肉感美，本研究探讨了多肉植物固色、塑化和环氧树脂AB胶包埋的工艺，建立了适合多肉植物的标本制作方法。主要不同叶片厚度的多肉植物利用硫酸铜溶液浸泡法及干燥法进行固色，结果显示10%硫酸铜溶液固色96h，对叶片中、厚型绿色多肉效果最佳，硅胶干燥法适合叶片薄型多肉植物。按25%-50%-75%-100%的浓度梯度PEG200脱水塑化，每个浓度24h，效果最好。最后以环氧树脂AB胶结合UV胶进行定型包埋。     

Ehe 桐油酸酐及桐酸酸酐合成工艺优化研究

考察不同溶剂、物料比、反应时间、反应温度对酸值的影响,通过正交实验优化出两种酸酐合成的最佳工艺分别为:①桐油:顺丁稀二酸酐=20:5.5 ,反应时间90min,反应温度115℃,不加溶剂;②桐酸:顺丁稀二酸酐=10:2.6,反应时间90min,反应温度140℃,不加溶剂.用红外光谱比较两者的结构.用不同酸值的两种酸酐固化环氧树脂,测试胶化时间,结果为酸值越大,胶化时间越短;游离酸值越小,胶化时间越短.     

松香松节油在环氧树脂及固化剂中的应用进展

综述了国内外在利用松香、松节油合成与改性环氧树脂、固化剂方面的研究现状,以及其应用方面的进展。     

Synthesis of a base-stock for electrical insulating fluid based on palm kernel oil

This report presents a method for synthesizing base-stock for green industrial product from a vegetable oil with a high composition of unsaturated fatty acids. Epoxy methyl ester of palm kernel oil was synthesized from laboratory purified palm kernel oil using a two-step reaction and the products were used as a base-stock for green electrical insulation fluid. Epoxidized palm kernel oil was first prepared through epoxidation reaction involving purified palm kernel oil, acetic acid and hydrogen peroxide in the presence of amberlite as catalyst which lasted for 4 h. It was then followed by transesterification reaction involving the epoxidized product and methanol in the presence of sodium hydroxide as catalyst to synthesize the corresponding epoxy methyl ester. The thermal and electrical breakdown properties of the epoxy methyl ester demonstrated significantly improved properties for its use as raw material for bio-based industrial products such as electrical insulation fluids.     

环氧生漆在水曲柳木材上的涂饰工艺研究

主要研究了天然环氧生漆在水曲柳木材表面的涂饰工艺。通过正交试验的方法,研究了基材平整度、涂膜质量和干燥时间对最终涂膜性能的影响,涂膜性能测试包括涂膜硬度、附着力、抗冲击强度等力学性能和涂膜光泽度。通过研究发现三种因素中涂膜质量对涂膜附着力的影响最显著。在单因素试验中设定基材打磨采用180#砂纸,干燥时间为12 h,试验结果显示:当生漆涂膜质量为10 g时,环氧生漆涂膜的综合性能表现较好,其中涂膜硬度为3B,附着力2级,抗冲击强度是35 kg·cm。     

Acoustic emission on failure analysis of rubber-modified epoxy resin

Rubber-modified epoxy resins have been employed as adhesive and matrix materials for glass and corbon-fiber composites. The behavior of fracture around a crack tip for rubber-modified epoxy resin is investigated through the acoustic emission (AE) analysis of compact tension specimens. Damage zone and rubber particles distributed around a crack tip were observed by a polarized optical microscope and an atomic force microscope (AFM). The damage zone in front of pre-crack tip in rubber-modified specimen (15 wt% rubber) began to form at about 13 % level of the fracture load and grew in size until 57 % load level. After that, the crack propagated in a stick-slip manner. Based on time-frequency analysis of AE signals and microscopic observation of damage zone, it was thought that AE signals with frequency bands of 0.15–0.20 MHz and 0.20–0.30 MHz were generated from cavitation in the damage zone and crack propagation, respectively.     

Preparation of anion-exchange resins from pine sulfuric acid lignin,one of the acid hydrolysis lignins

To utilize acid hydrolysis lignin effectively, chemical conversion to anion-exchange resin was investigated by two methods. Sulfuric acid lignin (SAL) was selected as a typical acid hydrolysis lignin in this experiment. Because it is less reactive, SAL was phenolated with sulfuric acid catalyst to yield reactive phenolized SAL (P-SAL) with p-hydroxyphenyl nuclei. One method was the restricted resinification of P-SAL followed by the Mannich reaction with formaldehyde and dimethylamine to yield a weakly basic anion-exchange resin with an ion-exchange capacity of 2.4mEq/g. Another method was to react resinified P-SAL with glycidyltrimethylammonium chloride to yield a strongly basic anion-exchange resin with an ion-exchange capacity of 2.0mEq/g. The reaction of a simple P-SAL model compound with an epoxide suggested that the phenolic hydroxyl group of the p-hydroxyphenyl nucleus had slightly higher reactivity than that of the guaiacyl nucleus.Part of this report was presented at the 47th Lignin Symposium, Fukuoka, October 2002     

正丁醇开环环氧菜籽油制备脂肪酸多元醇的研究

以菜籽油为原料,首先合成环氧菜籽油,再由合成的环氧菜籽油与正丁醇在对甲苯磺酸作催化剂的条件下,通过开环加成反应制备高羟值菜籽油多元醇。研究了水用量、正丁醇用量、反应时间、反应温度等因素对合成反应的影响,并对产物的羟值和黏度进行测试。结果表明,当水用量为50g,正丁醇用量为1mol,反应温度为70℃,反应时间为60min时,菜籽油多元醇的羟值相对较高。最后,对高羟值产物进行了红外（IR）分析。     

Experimental study on structure,mechanical properties and biocompatibility of artificial biological ligament in vitro and in vivo

AIM: To detect the structure, mechanical properties and biocompatibility of an artificial biological ligament (ABL), and to explore the feasibility of reconstructing the anterior cruciate ligament (ACL) with ABL. METHODS: By means of treating porcine tendon with epoxy cross-linking fixation, diversified antigen minimization process, mechanic enhancement modification and surface activating process, the ABL samples were fabricated in a goat implantation model. The in vivo and in vitro performances of ABL were analyzed by histological examination, scanning electron microscopy, cell culture and mechanical tests before and after animal implantation. RESULTS: The appearance of ABL was similar to that of the normal human ligament. Histological examination showed that the ABL was cell-free collagen fibers. Electron microscope examination revealed that the ABL was composed of hair-looking and fiber-like objects running uniformly in a certain direction and closely parallel-arranged. After cultured with xenogenic marrow matrix cells on the surface of ABL for 3 weeks, the cells adhered to the ABL and the matrix apposition around the cells was observed. No cells were found inside the ABL. The average diameter of ABL was 5 mm and the mechanical test at a speed of 100 mm/min showed the average tensile limit of 927.19 N and the tension-resistant strength of 47.22 N/mm, which were closed to the corresponding parameters of normal goat's ACL. Twelve weeks after the replacement of goat ACL with ABL, the synovial membrane was observed to cover with the ingrowths of small blood vessels on the surface of the implant. Fifty weeks after the replacement, the ABL material was partially replaced by regenerated host ligament-like tissue. The direct connection mode of ligament-fibro cartilage-calcified cartilage-bone was established around the ABL material fibers in the bone tunnel close to the joint surface. CONCLUSION: ABL has acceptable biomechanical properties, superior biocompatibility and promising prospect for clinical applications.