New Complex Crystals of Chiral Poly(L‐lactic acid) and Different Tactic Poly(methyl methacrylate)

Based on evidence from differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), and Fourier‐transform infrared (FTIR) spectroscopy, a new stereocomplex crystal (DSC T_m = 175 °C, with WAXD 2θ = 10.0° and 12.5°) is proven for the first time between structurally dissimilar chiral poly(L ‐lactic acid) (PLLA) and syndiotactic poly(methyl methacrylate) (sPMMA). There is a strong complexing capacity only between low molecular weight PLLA and sPMMA, in miscible state, at specific weight fractions (70:30). The complexing capacity is more significant when the mixtures are melt‐crystallized at T_c = 110 °C or lower, and the intensity of this complex can be further enhanced if it is annealed between 100 and 160 °C, below its T_m = 175 °C. The new complex crystal can be formed only between PLLA and sPMMA, but not with isotactic or atactic PMMA.     

Stable Polymerized Cholesteryl Methacrylate Liposomes for Vincristine Delivery

Preparation of stable polymerized liposomes as carriers for the delivery of anticancer drug was investigated. Cholesteryl methacrylate monomer was synthesized and liposomes containing the monomer were prepared by sonication method. The mono- meric liposomes were subsequently polymerized using aqueous redox initiators. Both monomeric and polymerized liposomes were characterized by FT-IR, FT-NMR, transmission electron microscopy and turbidity measurement. Liposomes containing cholesterol as control vesicles were also prepared for comparison study. The completion of polymerization of monomeric liposomes was confirmed by IR and NMR studies. The transmission electron micrographs showed the spherical shape of both monomeric and polymerized liposomes. The average particle size of monomeric and polymerized liposomes are 400 nm and 500 nm respectively. The turbidity measurement indicated that the polymerized liposomes are very stable when compared to monomeric and the control liposomes. Vincristine sulphate (VCR), an anti cancer drug was chosen as a model drug for incorporation in the above three types of liposomes. The percentage encapsulation of VCR was determined by solubilizing the liposome bilayers using Triton-X-100. In vitro release of the incorporated VCR from control, monomeric and polymerized liposomes was carried out in phosphate buffered saline, pH 7.4 and in 1% v/v human plasma at physiological condition. In both media, the polymerized liposomes released the drug in a sustained manner for longer period of time than the monomeric and control liposomes. These results demonstrated that the stable polymerized liposomes are good carriers for the prolonged release of anticancer drugs.     

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.     

聚甲基丙烯酸廿二烷酯在环己烷中静态和动态溶液性质的研究

利用光散射法,测定了带有长链侧基的聚甲基丙烯酸正廿二烷基酯在环己烷中稀溶液范围内(C相似文献   

Monoliths with chiral surface functionalization for enantioselective capillary electrochromatography

The state-of-the-art in CEC enantiomer separations with monolithic capillary columns is comprehensively reviewed. The various types of monolithic columns comprising in situ organic polymer monoliths, molecularly imprinted polymer (MIP) monoliths, silica monoliths and monoliths made from particles are discussed with a focus on materials’ synthesis, chemistry and properties as well as column aspects. Monolithic MIP-type porous layer open-tubular (PLOT) columns are treated herein as well. From this survey of the literature, the authors come to the conclusion that monolithic silica capillaries appear to become the preferred column type for CEC enantiomer separations of low-molecular drugs and other chiral pharmaceuticals or chemicals.     

异戊二烯-甲基丙烯酸甲酯的阴离子嵌段共聚合

在四氢呋喃(THF)与环己烷的混合溶剂中,以正丁基锂(n-BuLi)为引发剂,采用具有较大空间位阻和特定电荷环境的P配合物为添加剂,实现了异戊二烯(Ip)和甲基丙烯酸甲酯(MMA)的阴离子嵌段共聚。分别采用GPC、1H-NMR对聚合物的结构进行了分析表征。结果表明：随着THF与环己烷体积比的增大,单体的转化率呈现下降的趋势;同时空间位阻较大的P配合物的加入,堵塞了正、负离子对之间的部分通道,有效地抑制了MMA段聚合副反应的发生,在易于工业化的0 ℃之下成功合成了分子量分布窄(1.21)的聚异戊二烯聚甲基丙烯酸甲酯嵌段共聚物(PI-b-PMMA),并且共聚物中PI嵌段以3,4结构链节为主。     

甲基丙烯酸三氟乙酯与甲基丙烯酸异冰片酯共聚物的制备和性能

研究了甲基丙烯酸三氟乙酯（TFEMA）与甲基丙烯酸异冰片酯（IBDMA）在偶氮二异丁腈引发下的本体共聚合。重点研究了两种单体的竞聚率和不同单体组成制备得到的共聚物的性能。采用KT和FR两种作图法及YBR计算法对单体的竞聚率进行了计算和比较,结果表明,TFEMA与IBOMA的竞聚率分别为3693和0263。采用差示扫描量热法（DSC）、阿贝折光仪、紫外可见分光光度计分别测定了共聚物的玻璃化转变温度、折光指数和透光率。     

经皮中央纵向穿刺技术在治疗6例骶骨转移性肿瘤中的应用

目的探讨经皮中央纵向穿刺技术在治疗骶骨转移性肿瘤中应用的疗效。方法回顾性分析2009年9月至2011年10月,在C型臂X线引导下应用经皮中央纵向穿刺技术治疗骶骨转移性肿瘤6例的临床资料。结果 6例11个椎体均顺利完成,每椎平均手术时间21.3min。S1、S2、S3椎体平均注入骨水泥分别为4.2、2.8、2.0mL,骨水泥外漏1椎(S3),无神经损害并发症发生。术后3dVAS评分[(3.25±0.90)分]较术前[(6.25±1.09)分]明显下降(P<0.05)。结论通过中央纵向穿刺途径行经皮骶椎成形术具有安全有效、操作简单等特点。适于对骶骨转移性肿瘤的穿刺活检及强化治疗。     

Ablation Zones and Weight-Bearing Bones: Points of Caution for the Palliative Interventionalist

PurposeTo evaluate and classify underlying mechanisms of adverse outcomes after percutaneous computed tomography (CT)–guided cryoablation for palliation of painful musculoskeletal metastatic disease.Materials and MethodsData were collected for patients who underwent CT-guided percutaneous palliative cryoablation for painful musculoskeletal metastatic disease between January 2010 and December 2012. Cases with adverse outcomes or suboptimal response were identified and classified according to the Society of Interventional Radiology (SIR) classification system for complications by outcome and according to underlying mechanism of the outcome as delineated on follow-up examination.ResultsThere were 61 patients who received ablation for painful musculoskeletal metastatic disease. Six patients with adverse outcomes were identified. Two were minor complications (A, n = 1; B, n = 1), and four were major complications (C, n = 1; D, n = 3). Four patients incurred sequelae related to damage of ancillary structures included in the ablation zone, and two patients developed complete fractures after ablation of lesions in weight-bearing bones.ConclusionsComplete cryoablation of a painful musculoskeletal metastatic lesion may lead to ancillary damage of adjacent structures or fracture in weight-bearing bones.     

赝复体塑料支架表面的偶联剂处理对与硅橡胶粘接性能的影响

目的: 评估塑料基板(聚甲基丙烯酸甲酯)表面的偶联剂(A-304)处理对与SY-1型硅橡胶之间粘接性能的影响. 方法: 塑料义齿基板与SY-1型硅橡胶之间的粘接分别采用:硅橡胶粘接剂(GD-414)与偶联剂共同使用、只用粘接剂及只用偶联剂三组,按照国际标准分别对这三组二者之间的粘接强度进行测试,进行统计学分析. 结果: 这三组拉块强度从大到小依次为:硅橡胶粘接剂与偶联剂共同使用组,只用偶联剂组,只用粘接剂组. 结论: 硅橡胶偶联剂在硅橡胶与塑料基板的粘接中发挥着非常重要的作用,故临床中粘接时建议硅橡胶粘接剂与偶联剂共同使用可获得最大的粘接强度.