催化动力学荧光法测定中草药对羟基自由基的清除率

苯甲酸具有很弱的荧光,在Co2+的催化下,过氧化氢能氧化苯甲酸发出强的荧光。中草药提取物可以清除溶液中的·OH, 使产物的生成量减少, 从而使溶液的荧光增加程度降低。据此原理建立了一种测定中草药对羟基自由基清除率的催化动力学荧光新体系。当中草药的浓度为4.0 mg(干重)·mL-1时,测得紫花地丁、苍术和赤芍对羟基自由基的清除率分别为60.8%,40.1%和94.3%。该方法与分光光度法测定结果相比无显著性差异。     

新型L-氨基酸尾式卟啉及其锌(Ⅱ)配合物的合成与光谱性质

用L-氨基酸和5-[邻-(2-溴乙氧基)苯基]-10,15,20-三苯基卟啉为原料合成了三种新型L-氨基酸尾式卟啉及其锌(Ⅱ)配合物,通过元素分析、红外光谱、紫外光谱、化学分析和质谱等对其进行了结构表征。测试并研究了它们在4 000～400 cm-1范围内的傅里叶变换红外光谱,对主要谱带进行了经验归属。     

Tannic acid NPs – Synthesis and immobilization onto a solid surface in a one-step process and their antibacterial and anti-inflammatory properties

Tannic acid nanoparticles were synthesized from an aqueous solution without the use of stabilizers via a sonochemical process. In order to avoid the dissolution of the formed nanoparticles, the sonochemical reaction was performed in the presence of a cotton fabric: following their formation, the tannic acid nanoparticles were embedded into the cotton substrate in a one-step process. The bioactive properties of the tannic acid coated surface were examined towards the inhibition of myeloperoxidase and collagenase, two major enzymes related with inflammatory processes. In addition, the antibacterial activity of the tannic acid nanoparticles coated textiles was evaluated against Staphylococcus aureus and Pseudomonas aeruginosa.     

五种氨基酸钆络合物的ESR波谱

迄今未见任何稀土氨基酸络合物的ESR波谱报道,本文在合成Gd³⁺分别与甘氨酸、β-丙氨酸、谷氨酸、天冬氨酸和天冬酰胺五种氨基酸络合物的基础上,测定了不同温度下,水溶液、粉末及分子筛吸附样品的ESR谱,讨论了络合物中晶体场强,对称性及成键特性。     

Surfactant‐assisted specific‐acid catalysis of Diels–Alder reactions in aqueous media

Surfactant‐assisted specific‐acid catalysis (SASAC) for Diels–Alder reactions of dienophiles 1 and 4 with cyclopentadiene 2 in aqueous media at 32 °C was studied. This study showed that acidified anionic surfactants (pH 2) such as sodium dodecyl sulfate (SDS) and linear alkylbenzene sulfonic acid (LAS) accelerate Diels—Alder reactions. Conversely, under similar reaction conditions (pH 2) these reactions are inhibited by (acidified) cationic surfactants such as dodecyltrimethylammonium bromide (DTAB), dodecyldimethylammonium bromide (DDAB), and dodecylmethylammonium bromide (DMAB). A modest rate acceleration resulting from the surfactant hydrogen‐bonding capacity is also recorded for the Diels–Alder reaction of naphthoquinones ( 6 ) with cyclopentadiene ( 2 ) in aqueous media at 32 °C. Copyright © 2007 John Wiley & Sons, Ltd.     

FTIR法研究氨基酸稀土配合物与磷脂的相互作用

利用傅里叶变换红外光谱（ＦＴＩＲ）法研究了不同类型氨基酸及其配合物与二棕榈酰磷脂酰胆碱脂质体浇铸膜的相互作用。结果表明，在有氨基酸存在下，二棕榈酰磷脂酰胆碱的红外谱图没有明显的变化；氨基酸稀土配合物与磷脂极性头基团有静电相互作用，作用的程度随稀土离子、氨基酸及稀土同氨基酸配比的不同而有所不同。     

Tracer studies of anodic films formed on aluminium in malonic and oxalic acids

Using a tungsten-containing layer, incorporated into sputtering-deposited aluminium, as a tracer, the growth of porous anodic films in malonic and oxalic acid electrolytes has been investigated using transmission electron microscopy, Rutherford backscattering spectroscopy and nuclear reaction analysis. Comparisons were also made with films formed in phosphoric acid electrolyte, which have been studied previously. The findings reveal a distortion of the tracer layer within the barrier region of the porous films, evident as a lagging of the tracer beneath the pores relative to that in the adjacent cell wall region. Further, the films are significantly thicker than the layer of metal consumed during anodizing and display smooth-sided pores. The anodizing behaviours are consistent with a major role for field-assisted flow of film material within the barrier layer in the development of the pores.     

荧光法研究对-二甲氨甲基-杯[8]芳烃与二苯胺磺酸钠包结作用

用荧光法研究了水溶性对-二甲氨甲基-杯[8]芳烃与二苯胺磺酸钠的相互作用。发现当对-二甲氨甲基-杯[8]芳烃加入到二苯胺磺酸钠溶液时,二苯胺磺酸钠的荧光峰发生了明显的蓝移,荧光增强,可能的作用机理是二苯胺磺酸钠中的磺酸根与对-二甲氨甲基-杯[8]芳烃中带正电的氮原子之间有较强的静电作用,二苯胺磺酸钠进入了对-二甲氨甲基-杯[8]芳烃的疏水空腔。同时研究了几种有机溶剂对包结物的荧光强度的影响,初步探讨了其作用机理。     

FTIR-ATR技术考察TiO2膜对油酸的光催化氧化性能

采用Sol-Gel和PVD法在玻璃、陶瓷、铝片表面制备出TiO2膜,直接将食用油中的主成分油酸用溶剂稀释后均匀涂在膜表面,采用FTIR-ATR技术实现了对膜样品光催化自清洁性能的快速准确评价,并通过测量水的接触角评价了膜的亲水性。结果表明,Sol-Gel法和PVD法制备的TiO2/玻璃膜都具有较好的光致亲水性和光催化降解油酸性能,两者的亲水性没有明显差别,但前者的光催化活性稍优于后者。比较Sol-Gel法制备的TiO2/玻璃、TiO2/陶瓷和TiO2/铝片膜对油酸的光催化降解性能发现,光照3·5h后3个样品的降解率分别为92%,85%和46%,表明基底材料性质对TiO2膜的光催化活性有明显影响,镀在非导电性玻璃和陶瓷表面的TiO2膜比镀在导电性金属铝表面的TiO2膜对油酸有更高的光催化降解能力。     

Fluorescence Study of Dehydroabietic Acid-Based Bipolar Arylamine-Quinoxalines

The absorption and fluorescence spectra, lifetimes and quantum yields of a series of triarylaminequinoxaline bipolar compounds, with and without the bulky dehydroabietic acid group, have been studied in toluene solution. This bulky group is introduced to improve solubility and thermal properties of these systems. It is shown that this does not affect their spectral or photophysical behavior. The compounds show relatively strong fluorescence, with the emission maximum strongly dependent upon the substituents present. Oxidation potentials have also been determined in acetonitrile solution, and again indicate that introduction of the resin acid moiety has no effect on these properties.