稀土配合物Eu(pic)_3L·2H_2O的合成、荧光性质及与DNA作用方式研究

合成了苦味酸铕与N,N-二苄基-N′-苯基-1,1′-联萘-2,2′-二(氧杂乙酰胺)(L)的稀土配合物。经元素分析,IR,TG-DTA和摩尔电导率的表征,确定其组成为Eu(pic)3L.2H2O。测定了配合物在不同溶剂中的荧光强度,发现其荧光强度随溶剂配位能力增强而减弱。通过紫外吸收光谱、荧光发射光谱、粘度法,稳态荧光猝灭方法及其与溴化乙啶(EB)的竞争实验研究了配合物与ct-DNA的作用情况,结果显示,配合物与ct-DNA作用时,其紫外吸收产生明显增色效应,荧光强度增强;EB-DNA体系的荧光强度随配合物的加入迅速减弱;在ct-DNA存在下,配合物被猝灭剂K4[Fe(CN)6]的发光猝灭程度减小;配合物的加入使ct-DNA的粘度增加;实验结果证明,配合物与ct-DNA以插入方式结合,其结合常数Kq=2.665×104L.mol-1。     

手性Eu(Ⅲ)配合物的合成和作为ct-DNA荧光探针的研究

通过制备拆分剂氯化(8S,9R)-(-)-N-苄基辛可尼定,拆分了外消旋联萘酚得到其两种对映异构体,以手性联萘酚为原料分别合成了配体(R)-L和(S)-L及其相应的Eu(Ⅲ)配合物(R or S)-L-Eu(NO3)3,并测定了旋光度。分别研究了配合物(R or S)-L-Eu(NO3)3与ct-DNA的作用方式及键合常数,发现配合物与小牛胸腺DNA(ct-DNA)存在插入作用,且(R)-L-Eu3+配合物与ct-DNA的键合能力较强。由于ct-DNA对(R)-L-Eu3+配合物荧光的增敏作用,选择(R)-L-Eu3+配合物作为ct-DNA的手性荧光探针,在最佳实验条件下,其线性范围为0.11×10-5～0.55×10-5 mol·L-1,0.55×10-5～7.8×10-5 mol·L-1,检出限为5.85×10-7 mol·L-1。     

铕掺杂配合物的合成及其荧光性质研究

采用稀土掺杂的方法以Zn2+与Eu3+、配体对氯苯甲酸(CBA)、邻菲罗啉(Phen)合成铕掺杂配合物铕-锌-对氯苯甲酸-邻菲罗啉(Eu-Zn-CBA-Phen).经元素分析,推测其组成为:Eu1-xZnx(CBA)3-xPhen*H2O(x=0～0.8).红外光谱分析证实,铕与配体发生配位,而紫外与荧光光谱分析表明,随着Zn2+取代配合物中部分Eu3+,配合物的荧光强度明显增加,当掺杂Zn2+与Eu3+摩尔分数比为2∶3时,荧光强度达到最大值.同时还系统地考察了非稀土金属离子的加入对配合物荧光性能的影响和荧光增强机理.     

[RE(pic)L](pic)_2·6H_2O的合成、荧光性质及与DNA作用方式初探

合成了四种N,N’-二(2-氨基吡啶)-1,1’-联萘-2,2’-二(氧杂乙酰胺)(L)稀土配合物。通过元素分析、红外光谱、紫外光谱、热重分析和摩尔电导率的分析,确定配合物的组成为[RE(pic)L](pic)2.6H2O[RE=La(Ⅲ)、Eu(Ⅲ)、Tb(Ⅲ)、Sm(Ⅲ),pic为苦味酸根],稀土离子的配位数为8,在CH3OH溶液中属于2∶1型电解质,该系列配合物的荧光光谱表明,Eu(Ⅲ)配合物的荧光强度远大于Tb(Ⅲ)配合物,说明配体L的三重态能级与Eu3+的激发态能级匹配较好。通过电子吸收光谱、荧光光谱和粘度法对配合物和DNA之间的作用方式进行了初步研究,结果表明,配合物与DNA之间存在着插入作用。     

双苄基双亚砜高氯酸铕二元及三元配合物的合成及其与BSA的作用研究

合成并表征了双苄基双亚砜高氯酸铕二元及三元配合物,对配合物进行了稀土络合滴定、摩尔电导率和元素分析,配合物的组成为:[EuL2.5·(ClO4)](ClO4)2·3H2O和[Eu2L4·phen(ClO4)2](ClO4)4·12H2O(L=C6H5CH2SOCH2SOCH2C6H5)。配合物的荧光光谱表明,配合物均产生了Eu3+的特征荧光发射光谱,且三元配合物比二元配合物的荧光发射强度增强1.87倍。通过荧光光谱法,研究了稀土配合物与牛血清白蛋白(BSA)的相互作用。研究表明,双苄基双亚砜稀土二元、三元配合物-BSA体系的猝灭过程可能是静态猝灭,并且各配合物与BSA均具有较强的结合作用,能够被BSA储存和运输,因此,有望成为蛋白质荧光探针。     

Eu(Ⅲ)-β-NPA-HTTA二元、三元配合物的合成和光谱研究

为了获得高光效、高稳定性能的发光材料,探讨β-萘甲酸(β-NPA)化合物在发光材料方面的应用,合成了Eu(Ⅲ)与β-NPA及2-噻吩甲酰三氟丙酮(HTTA)形成的二元、三元荧光配合物。对所合成的配合物利用元素分析、紫外可见光谱、红外光谱、荧光光谱等手段进行了表征。对稀土配合物的结构与发光性能之间的关系进行了探讨。表征结构表明,两个配合物的组成分别为Eu(β-NPA)_3·3H_2O和Eu(β-NPA)(TTA)_2·2H_2O;紫外光谱研究表明,β-NPA与铕离子配位后整个体系的共轭程度增大,使得配合物的紫外吸收能力增强;荧光光谱研究显示,与铕离子反应后的配合物的配体β-NPA、2-HTTA能将吸收的能量有效地传递给铕离子,从而使配合物发射出强的铕离子的特征荧光,且两个配合物Eu(β-NPA)_3·3H_2O,Eu(β-NPA)(TTA)_2·2H_2O均以~5D_0→~7F_2跃迁的荧光发射最强。得到了两种高效的红色荧光配合物Eu(β-NPA)_3·3H_2O,Eu(β-NPA)(TTA)_2·2H_2O,它们可望成为制备鲜艳红色发光材料的侯选。     

系列Schiff配体及其Eu(Ⅲ),Tb(Ⅲ)配合物的合成、表征及荧光性质

为了研究Schiff类稀土配合物的组成和荧光性质,合成了N,N’-二(2-羟基-1-萘酚醛)-4,4’-二氨基二苯基甲烷(L1),N,N’-二(2-羟基-1-萘酚醛)-4,4’-二氨基二苯基甲烷(L2),N,N’-二(2-羟基-1-萘酚醛)-4,4’-二氨基二苯醚(L3)3种配体及其Eu(Ⅲ),Tb(Ⅲ)配合物。通过对配体和配合物的红外吸收、核磁共振、紫外吸收、元素分析、差热—热重、摩尔电导率及荧光光谱的测定分析了配合物的组成和性质。结果表明,配合物的组成为RE2(NO3)4.L4.2H2O(RE=Tb3+,Eu3+;L=L1,L2,L3),每个稀土离子与5个O、4个N配位,配位数为9,还有2个结晶水。室温下,Eu(Ⅲ),Tb(Ⅲ)配合物均有荧光发射,且Eu(Ⅲ)配合物发射出更强的Eu3+特征荧光,说明该类配体敏化Eu3+发光比Tb3+发光程度更大。     

桂皮酸-邻菲啰啉稀土配合物的合成及其与DNA作用研究

分别以轻、中和重稀土Pr、Eu、Gd、Dy、Lu为中心离子,以桂皮酸(Hcin)和邻菲啰啉(phen)为配体,合成了五种三元稀土配合物。经C、H、N元素分析和稀土络合滴定推测三元配合物的组成为REphen(cin)3(RE3+=Pr3+、Eu3+、Gd3+、Dy3+、Lu3+);红外光谱和紫外吸收光谱测试表明配合物中RE3+与桂皮酸的羧基氧原子及邻菲啰啉的两个氮原子配位成键。采用紫外吸收光谱法及粘度法研究了三元稀土配合物与小牛胸腺DNA(CT-DNA)的作用,结果表明配合物是以插入方式与DNA结合,配合物中的平面分子phen在一定程度上插入到了DNA的碱基对中,与DNA的键合常数随稀土原子序数增大而增大,表明离子半径小的重稀土配合物更容易插入到DNA的碱基对中。     

铕与5-氰基间苯二甲酸配合物的合成及发光性能

在水溶液中合成了铕与5-氰基间苯二甲酸配合物,它在紫外线辐照下能发出明亮的红光.元素分析表明,其组成为EuLCl·3H2O(L = C6H3CN(COO)22-),配合物的紫外吸收主要是配体的吸收;红外吸收光谱表明,配合物中Eu3+与羰基氧双齿螯合配位;荧光光谱表明,配合物具有良好的荧光性能,最佳激发波长为395nm,发射光谱为Eu3+ 的特征光谱,最强发射峰位于616nm,Eu3+处于无反演对称中心格位上,荧光发光机理属于M-M型.     

高氯酸稀土邻氨基苯甲酸配合物的固相合成及Tb3+的发光

应用固相反应法合成了稀土高氯酸盐与邻氨基苯甲酸的配合物。对配合物进行了组成分析及热谱分析,确定了配合物组成为[RE(LH)2(L)(ClO4)2]·6H2O(RE:Nd,Eu,Tb;LH:C6H4(NH2)COOH;L:C6H4(NH2)COO-)。通过IR光谱、紫外光谱及摩尔电导的测定推测了配位情况。溶解性实验表明配合物可溶于乙醇,但不溶于水。荧光光谱实验表明:固相反应合成Tb3 的高氯酸盐邻氨基苯甲酸的配合物具有良好的荧光性能。     

Phaeochromocytoma with myocarditis managed with alpha-methyl-p-tyrosine

A case of bilateral phaeochromocytoma with catecholamine-induced myocarditis is described. The two operations needed allowed comparison of the use of alpha-methyl-p-tyrosine alone and in conjunction with adrenergic blocks in the management of the patient. The combination of both drugs was particularly successful in the relief of symptoms and reduction of catecholamine metabolism as monitored by 4-hydroxy-3-methoxymandelic acid (HMMA) excretion. As myocarditis is a potentially fatal complication, further investigation of the combined use of alpha-methyl-p-tyrosine and adrenergic blocking drugs is suggested in the pre-operative management of patients with phaeochromocytoma.     

Factors related with compliance with tuberculosis chemoprophylaxis

OBJECTIVES: To determine therapeutic tolerance and compliance level with antituberculous chemoprophylaxis. PATIENTS AND METHODS: 587 patients were proposed for antituberculous chemoprophylaxis with isoniazid from January 1995 to June 1996 in Murcia (Spain). RESULTS: 3.6% of the patients gave up treatment because of hepatic intolerance and 73% completed the prophylaxis. Non-compliance related factors were: social risk factors (odds ratio [OR] = 9.31), previous history of allergies (OR = 2.87), previous personal history of tuberculosis-related events (OR = 0.49) and interaction between sex and age. CONCLUSIONS: Support and intervention measures directed to risk groups of a social origin deem to be needed. Control measures and information provided to middle-aged males, with particular emphasis to the first weeks of prophylaxis, should also be implemented.     

Communication with parents of children with cancer

The authors summarize the results of recent work evidencing the existence of latent merozoites during the course of the erythrocytic cycle of the rodent Plasmodia. These merozoites, unlike the majority of merozoites released at schizogony, do not penetrate immediately into the erythrocytes and remain latent for a variable length of time. The merozoites of each of the species or subspecies show marked peculiarities which are responsible for the characteristics of their cycle. The presence of latent merozoites free in the blood, the asynchronous development, and the resistance to chloroquine, are three closely related factors. Knowing that the merozoite is so far drug resistant, and that latent merozoites can maintain the infection for any length of time, it appears important to take into account these purely biological data, when studying the drug resistance of the human falciparum malaria.     

Surgical outcome in patients with epilepsy with occult vascular malformations treated with lesionectomy

PURPOSE: This retrospective study reports the long-term surgical outcome of patients with medically refractory epilepsy and vascular malformations who were treated with lesionectomy. A detailed analysis of surgical failures had been performed in an attempt to define predictors of surgical success and failure. METHODS: Fifteen patients with medically intractable epilepsy and angiographically occult vascular malformations (AOVMs) were treated surgically with lesionectomy at Duke University Medical Center. Lesionectomy consisted of removal of the AOVM and surrounding hemosiderin-stained brain only, without the use of electrocorticography (ECoG) to guide resection. RESULTS: Eleven (73%) patients are seizure free after lesionectomy. Three showed no significant improvement, and one patient died, presumably after a seizure. Age of onset, duration of seizures, age at resection, and gender did not affect outcome. All patients with neocortical AOVMs in whom EEG findings correlated with the site of the lesion were seizure free after lesional resection. Treatment failures were associated with the presence of multiple intracranial lesions, poorly localized or diffuse EEG findings, discordant positron emission tomography (PET) imaging, or with a lesion in close proximity to the limbic system. CONCLUSIONS: Lesionectomy, with removal of surrounding hemosiderin-stained brain, can be considered the procedure of choice in carefully selected patients with epilepsy with occult vascular malformations.