反相气相色谱法测定溶剂在PBMA中的无限稀释活度系数

用反相气相色谱方法测定了１６种溶剂在聚甲基丙烯酸丁酯（ＰＢＭＡ）中３４３￣４３３Ｋ范围内的无限稀释活度系数,并用周浩等的高分子溶液分子热力学模型对实验结果进行了关联,结果令人满意。     

高效液相色谱法对PHEMA液体栓塞材料中单体残留的超痕量分析

应用高效液相色谱法测定了聚甲基丙烯酸-β-羟乙酯(PHEMA)液体栓塞材料中的单体甲基丙烯酸-β-羟乙酯(HEMA)残留量。采用色谱柱Aichrom Bond-1 C18(4.6 mm×250 mm,5μm)进行分离,流动相为乙腈-水(30∶70);检测波长为220 nm;进样量为20μL。单体在质量浓度为0.1~4.0 mg/L的范围,峰面积与单体浓度线性关系良好,相关系数0.9992,检测下限为0.01 mg/L。当试样加标浓度为0.5,2.0,4.0 mg/L时,加标回收率在99.5%~102.0%之间,RSD≤2%。     

溶剂解吸气相色谱同时测定工作场所中甲基丙烯酸甲酯和丙烯酸正丁酯的方法研究

目的建立工作场所空气中甲基丙烯酸甲酯和丙烯酸正丁酯气相色谱直接测定的方法。方法采用活性炭管吸附空气中甲基丙烯酸甲酯和丙烯酸正丁酯,二硫化碳解吸后进气相色谱（FID）测定。结果甲基丙烯酸甲酯和丙烯酸正丁酯的保留时间分别为0．544、1．143min;线性范围分别为1～300、0．5～250μg／ml;回归方程分别为Y=4．533＋9．189X、y=7．788＋12．244x;相关系数（r）分别为0．9995,0．9996;检出限分别为0．2、0．1μg/ml;最低检出浓度分别为0．13、0．07mg／m3（采样体积1．5L计）：平均解吸效率分别为96．26％、96．21％;样品在室温下至少可保存15d。结论该方法适合工作场所空气中甲基丙烯酸甲酯和丙烯酸正丁酯气相色谱同时测定。     

正丁基缩水甘油醚、环氧树脂6101~#的肝脏毒性及其联合毒性的实验研究

本文着重研究了正丁基缩水甘油醚(501~#)、环氧树脂6101~#的肝脏毒性。体外试验结果表明:501~#可使大鼠肝匀浆GSH含量降低、脂质过氧化增加,但对细胞色素P450无明显影响。6101~#可使细胞色素P450含量降低,但对脂质过氧化无明显影响。大鼠亚急性毒性试验结果表明:501~#对血滤波GSH、GSSG、GPT、血糖、肝脏GSH、GSSG、细胞色素P450均无明显影响。肝脏指数增大,但病理学检查无异常发现。501~#与6101~#联用在体外对肝匀浆脂质过氧化呈相加作用,但在体内对大鼠肝脏细胞色素P450无联合作用。结论认为:501~#、6101~#在一般接触情况下,不会引起明显的肝脏毒性。     

Synthesis and characterization of copolymers of methylmethacrylate and 2-hydroxyethyl methacrylate for the aqueous solubilization of Paclitaxel

The aim of the present work is the modification of a hydrophobic polymeric macromolecule, polymethylmethacrylate, by introducing hydrophilic moieties of 2-hydroxyethyl methacrylate within the polymer chain. Synthesis, characterization, and drug delivery control capabilities exerted on a highly hydrophobic drug (Paclitaxel) are illustrated. In particular, the dependency of the drug delivery kinetic on the fraction of hydrophilic units inserted in the copolymer chain was studied. Results showed that it is possible to have an increase of the kinetic delivery introducing hydrophilic units. In addition, a double control, diffusive and due to the relaxation of the molecules, on drug delivery was obtained.     

Occupational contact dermatitis in 2 dental technicians

2 dental technicians, both with chronic hand eczema, reported worsening from the use of 2 products containing methyl methacrylate, employed in manufacturing acrylic prostheses. Patch tests in both patients gave positive reactions to methyl methacrylate, ethylene glycol dimethacrylate and products employed in manufacturing acrylic prostheses (2% and 5% pet.). On the basis of results subsequently obtained from patch tests carried out with pieces of glove interposed between the skin and the allergens (methyl methacrylate and products employed), we advised our patients still to use latex gloves during work. Follow-up after 1 year showed complete regression of the dermatitis in 1 case and considerable improvement in the other.     

Biologically active polymers: synthesis and antimicrobial activity of modified glycidyl methacrylate polymers having a quaternary ammonium and phosphonium groups

Polymers with antibacterial activity have been synthesized by chemical modification of poly(glycidyl methacrylate). The glycidyl methacrylate was polymerized by the free radical polymerization technique. The poly(glycidyl methacrylate) was hydrolyzed and was chloroacetylated using chloroacetyl chloride. The chloroacetylated product was modified to yield polymers with either quaternary ammonium or phosphonium salts. The antimicrobial activity of the modified glycidyl methacrylate polymers has been examined against a variety of test microorganisms by the cut plug and the viable cell counting methods using shake flask of ten times diluted nutrient broth medium. All three polymers obtained were inhibitory to the growth of Gram negative bacteria (Escherichia coli, Pseudomones aeruginosa, Shigella sp. and Salmonella typhae) and Gram positive bacteria (Bacillus subtilis and B. cereus) as well as the fungus (Trichophytun rubrum). It was found that the growth inhibitory effect varied according to the structure of the polymer and the composition of the active group and increased with increasing the concentration of the polymer. The tested polymers showed more antimicrobial activity against Gram negative bacteria and the fungus, whereas were less active against Gram positive bacteria.     

甲基丙烯酸甲酯纳米SiO2颗粒原位分散效果的初步探讨

目的：探索SiO2纳米颗粒在甲基丙烯酸甲酯单体中分散工艺，减少纳米颗粒的团聚。方法：利用手混，机混（间断机混或连续机混）等方法，将纳米SiO2颗粒分散于甲基丙烯酸甲酯单体中后，在高倍光学显微镜下观察颗粒分散情况，并与粉体聚合制成标准试件，通过测试相同浓度下的抗弯强度及拉伸强度进行统计学分析，对几种分散方法进行比较。结果：3种分散方法所制备纳米SiO2／MMA单体中可视颗粒长径在200nm以上，SiO2／PMMA纳米复合材料的抗弯强度和抗拉强度进行方差分析，3种方法的分散方法无差异。结论：手混法和机混法都可以作为在甲基丙烯酸甲酯单体中分散纳米SiO2的方法，但纳米颗粒的问题有待于进一步探索。     

甲基丙烯酸环氧丙酯的致突变性和致癌性研究

甲基丙烯酸环氧两酯(GMA)是我们研究组近年发现的致突变物。GMA在Ames试验和小鼠骨髓微核试验得到阳性结果,GMA可与DNA共价结合,在体外淋巴细胞培养诱导UDS和抑制DNA复制。GMA对雄性小鼠生殖细胞也有遗传毒性。我们研究了GMA诱导的PBR322质粒TcR基因的限制酶酶谱,HPLC谱和DNA序列。结果提示,某些限制酶的酶切位点发生位移,GMA诱发缺失和插入,并存在序列专一性和热点。而且,我们发现GMA诱发叙利亚金黄地鼠胚胎细胞的恶性转化。     

甲基丙烯酸环氧丙酯诱导16HBE细胞恶性转化相关m6A修饰异常mRNA的分析

目的： 检测甲基丙烯酸环氧丙酯（GMA）诱导16HBE细胞恶性转化相关mRNA的m⁶A甲基化修饰水平,筛选出m⁶A修饰的mRNA并进行功能注释。方法： GMA（8 μg/mL）重复染毒16HBE细胞后,收集GMA染毒组和DMSO对照组的第30代细胞,采用高通量人类表观转录组芯片检测16HBE细胞恶性转化相关mRNA的m⁶A修饰水平,应用Visual Studio Code软件进行m⁶A修饰mRNA的筛选,并利用Omicshare工具对这些mRNA进行GO富集分析和KEGG通路分析。结果： 与对照组细胞比较,GMA诱导的恶性转化16HBE细胞中m⁶A修饰水平异常的mRNA共有454个,其中高甲基化水平mRNA 334个,低甲基化水平mRNA 120个;表达水平异常的mRNA共有434个,其中高表达mRNA 236个,低表达mRNA 198个。m⁶A修饰的mRNA有45个,GO富集分析结果显示上述mRNA主要富集于SNAP受体活性、SNARE结合、SNARE复合体等生物学过程,KEGG通路分析主要富集于囊泡运输中的SNARE相互作用、非同源末端连接、苯丙氨酸代谢等通路。结论： m⁶A修饰mRNA可能在GMA诱导16HBE恶性转化过程发挥重要作用。