固体胆红素自由基的电子自旋共振研究

本文用电子自旋共振法(ESR)对各种来源的胆红素进行了研究,发现固体胆红素极易以稳定的自由基形式存在,并对该自由基的本质、结构特征及形成机理进行了探讨。结果表明胆红素自由基是由结合态的超氧自由基及半醌自由基构成,自由基再生动力学曲线属零级反应;微量过渡金属离子在胆红素超氧自由基形成及存在过程中起着重要作用。本文研究结果提示,胆红素的药理及毒理性质可能与其自由的性质有着密切关系,提出胆红素并非只是代谢的最终废弃物,而极可能是体内的活性氧自由基阱,是内源性细胞保护剂。     

用电子自旋共振谱研究我国一些煤的自由基

本文用电子自旋共振谱(ESR)研究了我国十种不同变质程度的煤。电子自旋共振最重要的参数是g值、自由基的浓度、线宽和线形。用这些参数与煤中的碳、氧等元素相关联,发现ESR参数与煤的变质程度有密切关系。     

三苯基硅自由基的电子自旋共振研究

有机硅自由基的电子自旋共振(ESR)的研究一直十分活跃,Bock等已做了大量工作。然而,对于三苯基硅自由基的ESR研究报道却甚少。采用X射线辐照单晶生成的三苯基硅自由基的ESR谱并未获得理想的超精细结构谱,而采用三苯基硅烷与二苯甲酮热反应仅获得Ph_2COSiPh_3自由基的ESR谱。本文报道在氯仿溶液中,用无水三氯化铝与三苯基硅醇或三苯基硅烷在室温下反应,获得三苯基硅烷正离子自由基(Ph_3Si~+)ESR的研究结果,并进行计算机模拟。     

MAQO和它的环糊精包结物的电子自旋共振研究

报导2-甲基-3乙酰基喹喔啉1，4-二氧化物（MAQO）和它与α-环糊精（α-CD），β-环糊精（β-CD）包结物在室温下应用紫外光（λ＝360nm）进行原位光化学反应生成自由基的电子自旋共振研究结果，推断MAQO在紫外光作用下首先生成激发态（MAQO）*，然后进一步发生光化学反应导致N＝C双键转移而生成氮氧自由基并为ESR所检测到．从ESR检测结果猜想，在非含氢溶剂中是生成较稳定的且又相距很远的氮氧双自由基；而在含氢溶剂中，由于发生夺氢反应而生成稳定的氮氧单自由基．当MAQO－α－CD包结物在含氢溶剂中发生光化学反应时亦生成氮氧单自由基；但其ESR谱的超精细结构（hfs）和线宽均发生了变化，推断环糊精包结在MAQO分子苯环一端，受环糊精的微环境空间阻碍效应．     

铜(Ⅱ)-羟肟络合物的电子自旋共振谱研究

本文报导芳香族羟肟铜(Ⅱ)络合物的电子自旋共振(ESR)谱的研究。讨论了这类配位体上取代基的电子效应对络合物中铜(Ⅱ)的超精细分裂常数A_(Cu)值的影响,以及A_(Cu)值与这些配位体萃取铜的分配系数的关系。     

激光光散射和电子自旋共振技术研究十二烷基硫酸钠与聚乙烯吡咯烷酮的相互作用

应用动态激光光散射(DLS)和电子自旋共振(ESR)测定研究了单长链表面活性剂十二烷基硫酸钠(SDS)与聚乙烯吡咯烷酮(PVP)相互作用.DLS测定结果表明:SDS在水中形成动力学半径约为61 nm的胶束聚集体,PVP在水中卷曲成动力学半径约为12 nm的线圈,DLS确定的SDS临界胶束浓度(cmc)为6.4×10^-3 mol·L^-1, PVP-SDS具有强的相互作用,PVP分子缠绕在SDS胶束聚集体的周围,屏蔽了SDS胶束聚集体表面碳氢基团与连续水相的接触;ESR结果表明:自由基探针5-doxyl stearic acid在SDS形成胶束聚集体后,从一个较强极性的连续相转变到较小极性的胶束聚集体内核中,胶束聚集体内核的微粘度较纯水的大,SDS与PVP复合聚集体的微观粘度较SDS胶束溶液的大,ESR确定SDS的cmc为6.8×10^-3 mol·L^-1.     

电子自旋共振光谱在研究血红素蛋白及其模拟化合物中的应用

介绍电子自旋共振（ＥＳＲ）的基本原理，及ＥＳＲ在血红素蛋白及其模拟化合物铁卟啉的结构、性能、中心铁离子的状态等研究中的应用，以及用ＥＳＲ参数进行晶体场合分析的方法。     

导电聚合物膜修饰电极的研究Ⅲ: 杂多酸掺杂聚吡咯膜电极的电子自旋共振(ESR)特性研究

本文通过对不同条件下的Co(W_2O_7)_6~(10-)和CuW_(12)O_(40)~(6-)掺杂聚吡膜ESR谱线的分析并以相同条件下NO_3~-掺杂聚吡咯膜作为参照,表明杂聚阴离子不仅起着中和电性的作用,而且与聚吡咯分子链相作用形成某种加合物,它影响聚吡咯的电结构,这种加合物在过正或过负的电位下均不稳定.首次发现在CuW_(12)O_(40)~(6-)掺杂的干态聚吡咯膜具有Dysonian线型,表明膜中其它电结构的存在.     

纳米雄黄与脂质体仿生膜的相互作用研究

本工作以卵磷脂与胆固醇组成的磷脂小单层脂质体（small unilamelarvesicles,suv）作为仿生膜的简单模型,采用表面等离子共振技术（SPR）、荧光偏振、拉曼（Raman）光谱、核磁共振（NMR）及原子力显微镜（AFM）研究纳米雄黄与SUV仿生膜的相互作用,证实了磷脂是纳米雄黄作用的关键靶分子．随纳米雄黄结合,SUV仿生膜的相对粘度聃值增大,膜的流动性减小．Raman光谱数据计算表明,作用后膜的纵向有序性参数s。。及横向有序性参数Slat值增大,说明纳米雄黄的结合使磷脂膜的脂酰基链全反式构型比例上升,膜的流动性减小．由Raman光谱和引PNMR结果推测,磷脂极性头部是纳米雄黄与磷脂的主要结合位点。AFM实时观测,纳米雄黄通过在膜表面打“孔”或“洞”的方式,损坏磷脂膜．     

硫杂蒽酮类光引发剂的电子自旋共振研究

本文采用ESR手段对五种硫杂蒽酮类光引发剂2-甲基硫杂蒽酮(MTX)2,4-二甲基硫杂蒽酮(DMTX)、1,2,4-三甲基硫杂蒽酮(TMTX)、2-甲氧基硫杂蒽酮(MOTX),2-戊氧基硫杂蒽酮(AOTX)和三乙胺引发体系进行了研究,提出了该类光引发剂和三乙胺暗反应的机理。     

Antibody modified Bovine Serum Albumin microspheres for targeted delivery of anticancer agent Gemcitabine

Inhibition of the EGFR signaling pathway is one of the attractive therapeutic targets for pancreatic cancer as recent studies demonstrated that EGFR is over‐expressed in pancreatic cancer. In this article we have demonstrated the design of targeted drug delivery system containing Bovine Serum Albumin (BSA) microspheres as delivery vehicle, gemcitabine as anticancer drug and anti‐EGFR (epidermal growth factor receptor) monoclonal antibody as targeting agent. The conjugated BSA microspheres were characterized by several physico‐chemical techniques such as scanning electron microscope, optical microscopy, fluorescent microscopy etc. Administration of these BSA microspheres containing gemcitabine and anti‐EGFR (BSA‐Gem‐EGFR) shows significant inhibition of pancreatic cancer cells (AsPC1) compared to the cells treated with only BSA microspheres, BSA with gemcitabine (BSA‐Gem), and free gemcitabine. This strategy could be used as a generalized approach for the treatment of pancreatic cancer along with other cancers which overexpress EGFR on cell surface. Copyright © 2012 John Wiley & Sons, Ltd.     

一种乙肝病毒表面抗原和其单克隆抗体相互作用的SERS研究

利用银纳米粒子的表面增强拉曼散射（SERS）效应，研究了乙肝病毒表面抗原 （HBsAg)和其鼠源单克隆抗体（单抗，Ab-HBsAg)的相互作用。SERS光谱结果表明 ，Ab-HBsAg分子主要通过位于非抗原结合部位的去质子化羧基（COO）^-实现与银 纳米粒子的结合。HBsAg与Ab-HBsAg相互作用形成免疫复合物后，HBsAg分子上的色 氨酸（Trp)残基特征振动完全消失，表明Trp残基位于HBsAg抗原分子的活性区，是 HBsAg与Ab-HBsAg相互作用的重要位点。     

亚油酸酰化胰岛素的制备及飞行质谱分析

胰岛素侧链氨基的酰化是胰岛素化学修饰较常用的方法。天然胰岛素分子中有三个裸露的氨基,即G lyA1、PheB1的α-氨基和LysB29的ε-氨基,都可作为胰岛素化学修饰的位点。酰化试剂通常经由N-羟基琥珀酰亚胺酯对胰岛素进行修饰。N-羟基琥珀酰亚胺酯可由羧酸与N-羟基琥珀酰亚胺(HOS     

脂质体中竹红菌乙素光谱特征和荧光环境效应

竹红菌乙素(HB)是一种新型的茈琨类光疗药物,临床研究表明对一些皮肤疾病和微血管疾病有很好疗效。HB的水溶性差,采用具有两亲性质的脂质体将HB分子进行包装,使药物与血液相容可以实现药物的可控释放和靶向给药。本文报导了HB被脂质体包裹后在脂双层中的光谱特征和荧光光谱的环境效应。     

Electroformation and collection of giant liposomes on an integrated microchip

In this work, a microchip was developed for the electroformation and collection of giant liposomes. On the chip, a reactor chamber array was expressly designed so that the influences of multiple parameters could be explored rapidly and efficiently to screen for a suitable condition. Furthermore, in order to overcome the difficulty in the collection of giant liposomes, a tailor-made collection chamber was also integrated on this chip.     

Glutathione and pH‐responsive fluorescent nanogels for cell imaging and targeted methotrexate delivery

Cancer is one of the health problems that lead to death in the world, and nanotechnology was shown to have a unique potential to improve the therapeutic efficacy of anticancer agents. The nanosized drug delivery systems (DDSs) have been offered for targeting tumor tissue because of enhanced drug bioavailability and long circulation time. In this context, we reported a facial approach to prepare a novel pH and glutathione‐responsive nanogel. After that, the nanocarriers coupled with highly fluorescent quantum dots were developed. Then methotrexate (MTX) was loaded into and on the surface of nanogels by ionic interaction so that the triggered MTX release ability of the synthesized nanocarriers was verified through the assessment of in vitro drug release at simulated tumor tissue condition. The improved efficiency of the developed nanogels and their targeted performance via conjugation of MTX (as target ligand of folate receptors) were investigated through the various cell cytotoxicity studies such as 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay, 4′6‐diamidino‐2‐phenylindole (DAPI) staining, and flow cytometry. The results of various cell cytotoxicity studies concluded that the developed smart nanogels have many promising abilities for the targeted MTX delivery to cancer tissues.     

Role of silica coated magnetic nanoparticle on cell flocculation,lipid extraction and linoleic acid production from Chlorella pyrenoidosa

Abstract

In the present work, it has been observed that magnetic (Fe₃O₄) – silica core- shell nanoparticles helps in flocculation of Chlorella pyrenoidosa cells with simultaneous production of linoleic acid. The mean particle size in Dynamic light scattering (DLS) of the silica coated magnetic nanoparticle was estimated 444.7?nm. The characterization of nanoparticles was also performed by X-ray diffraction technique (XRD). Apart from flocculation, it has been observed that in presence of magnetic silica core- shell nanoparticles the amount of lipid obtained was four times than that of control. On the contrary, in presence of these nanoparticles, linoleic acid (18:2) has been produced in Chlorella pyrenoidosa cells almost by 80% whereas, it has been noticed only 8.73% in control. This is the first report where the linoleic acid has been obtained as major component of microalgal fatty acid methyl esters (FAME) having important application in nutraceuticals and pharmaceutical sectors.     

Effect of conjugated linoleic acid grafting on the hemocompatibility of polyacrylonitrile membrane

Polyacrylonitrile (PAN) membrane was hydrolyzed with NaOH_(aq) and grafted with conjugated linoleic acid (CLA) via esterification with 1,3‐propanediol. The resulting CLA grafted PAN membranes were characterized using Fourier transform infrared spectrometry (FT‐IR) and X‐ray photoelectronic spectroscopy (XPS). The effects of CLA grafting on the blood coagulation, platelet aggregation, and oxidative stress were evaluated using human blood. The complete blood count (CBC) and coagulation time (CT) was evaluated in vitro for hemocompatibility. After CLA grafting, the proliferation of human umbilical vein endothelial cells (HUVECs) on the membranes were improved. In addition, the production of reactive oxygen species (ROS) was measured by the chemiluminescence (CL) method to evaluate the oxidative stress. The results showed that the CLA‐grafted PAN membrane could keep the CBC values more stable than unmodified PAN membrane. The CLA‐grafted PAN membranes also showed longer CT. CLA‐grafted PAN membrane could keep the CL counts of hydrogen peroxide and superoxide values more stable than unmodified PAN membrane. These results suggest that a CLA‐grafted PAN membrane could offer protection for patients against oxidative stress and would be helpful for reducing the dosage of anticoagulant during hemodialysis. Copyright © 2006 John Wiley & Sons, Ltd.     

季铵盐表面活性剂与卵磷脂囊泡相互作用的研究

采用动态光散射、ζ电势等方法研究了季铵盐二聚表面活性剂(C₁₂-8-C₁₂•2Br)和十二烷基三甲基溴化铵(DTAB)在卵磷脂囊泡中的增溶作用. C₁₂-8-C₁₂•2Br使囊泡粒径增大, 促进脂双层向胶团的转变, 过程明显分为三个阶段; 而DTAB与囊泡的作用则相对缓和, 72 h内未见明显变化. 此外, 用亲水头基总体积的大小, 讨论了这两种表面活性剂在脂质体中的吸附行为, 并对实验现象加以解释说明.