掺杂稀土对铕、铽苯二甲酸-冠醚配合物发光的影响

合成了稀土Eu3+,Tb3+冠醚、对苯二甲酸高氯酸盐两个系列18种固态配合物。结果表明,配合物的组成为:Eu2LL′2(ClO4)4.4H2O、EuReLL′2(ClO4)4.nH2O、Tb2LL′2(ClO4)4.4H2O和TbReLL′2(ClO4)4.nH2O(Re:掺杂离子,n=2,3,4)。对苯二甲酸的羧基氧与稀土离子以对称螯合双齿配位;部分高氯酸在内界以单齿配位;配合物含有水分子。配合物的相对荧光光谱测定表明,相同配体的铽系列配合物的荧光强度明显强于铕系列。稀土离子Eu3+的5D0能级为17250cm-1,Tb3+的5D4能级为20430cm-1,而配体对苯二甲酸的三重态能级为25160cm-1,高于Eu3+和Tb3+离子的激发态能级,满足配合物分子内传能配体的三重态能级高于稀土离子发射能级的条件,可以提高Eu3+和Tb3+离子的特征荧光强度。但相对于Eu3+离子,对苯二甲酸的三重态能级与Tb3+离子的激发态能级(5D4)更匹配,更有利于能量的有效传递,因此,铽系列的荧光强度明显强于铕系列。Ho3+、Yb3+对Eu3+离子发光敏化作用最强,Ce3+、Sm3+、Dy3+、Er3+对Eu3+离子发光也有敏化作用,Pr3+、Nd3+离子对Eu3+离子的发光是猝灭的;Yb3+、Dy3+离子对Tb3+离子发光有较强敏化作用,而Ce3+、Pr3+、Nd3+、Sm3+、Ho3+、Er3+离子的掺入对Tb3+离子的发光是猝灭的。应用分子内能量传递过程对发光机理进行了探讨。

Synthesis,Characterization and Fluorescence Properties of Europium,Terbium Complexes with Biphenyl-4-Carboxylic Acid and o-Phenanthroline

Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen) L3·1/2H2O; Tb (phen) L3·H2O and Tb0.5 RE0.5(Phen)L3·1/2H2O. (RE = Y3+, La3+ and Gd3+; L = biphenyl 4-carboxylic acid; phen = o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE (III ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 + is raised by inert fluorescent rare earth ions (Y3+ , Gd3+ and La3+ ), but in Tb3+ hetero-nuclear rare earth complexes the intensity of Tb3+ ions are quenched by the inert fluorescent rare earth ions.

Synthesis and Fluorescence Properties of Europium, Terbium Doped Zn^(2+), Cd^(2+) and Cr^(3+) Complexes

Europium and terbium complexes with strong fluorescence intensity and long fluorescence lifetime were prepared. By replacing half of the europium or terbium ion with M （M = Zn^2＋, Cd^2＋, and Cr^3＋） using the doped method, and then incorporating it with 18-crown-6 ether and terephthalic acid, six heteronuclear samples EuZnLL＇Cl3·3H2O（1）, EuCdLL2＇Cl3·5H2O（2）, EuCrLL＇Cl4· 4H2O（3）, TbZnLL＇Cl3·4H2O（4）, TbCdLL＇2Cl3·4H2O（5）, and TbCrLL＇2Cl4 ·4H2O（6） （L = terephthalic acid, L＇= 18-Crown-6 ether） were obtained. The elemental analysis, molar conductivities, rare earth complexometry, Fourier Transform Infrared Spectroscopy （FT-IR）, ultraviolet （UV）, TGA, fluorescence intensity, and fluorescence lifetime of the samples were measured. The results showed that there were good luminescence properties for heteronuclear complexes （1）, （2）, （4）, and （5）, which were even stronger than those of the homonuclear complexes Eu2LL＇2Cl4·4H2O and Tb2LL＇2Cl4 ·4H2O, but the luminescence properties of EuCrLL＇Cl4·4H2O, TbCrLL＇Cl4·4H2O were very weak. A possible luminescence mechanism was suggested by the organic-inorganic doped mechanism and the law of intramolecular energy transfer.

Genotype frequency of gelatinase B C-1562 T polymorphism in coronary heart disease and myocardial infarction

Background One of the characteristics of atherosclerosis is a change in the content of extracellular matrix in the arterial wall. Gelatinase B, a member of the family of matrix metalloproteinase, can regulate extracellular matrix metabolismand play a role in the pathogenesis of atherosclerosis, coronary heart disease (CHD) and myocardial infarction (MI). Gelatinase B is polymorphic due to a C to T change at the position -1562 bp in the promoter region.Its relationship with gene product concentration in serum and its role in mediating the risk of CHD and MI in Germans is still unknown. Methods We enrolled 102 controls and 322 patients with angiographically documented CHD,including a sub-group of 173 patients with acute or chronic MI and 80 patients with acute coronary syndrome (ACS).All patients and controls were Germans and genotyped by polymerase chain reaction and digestion with SphI. Results We found that several classical risk factors for CHD and MI, including hypercholesterolemia and cigarette smoking,were significantly increased in CHD and MI patients compared with controls. Serum levels of gelatinase B and tissue inhibitor of metalloproteinase-1 were increased in the peripheral blood of patients with acute coronary syndrome. No significant differences in genotype or allelic frequencies between CHD, MI and control subjects of either men or women were found. Our search for a possible association of the polymorphisms with CHD and MI by logistic regression analysis was also negative. The serum concentrations of gelatinase B showed no differences between genotypes. Conclusions Our data showed that gelatinase B might provide an index of plaque activity in ACS, but gelatinase B protein was not affected by genotypes. Also, the T variant of gelatinase B was not associated with CHD or MI in Germans. (J Geriatr Cardiol 2004;1(2):114-118.)

Lobar lung transplantation from deceased donors: A systematic review

AIM To systematically review reports on deceased-donor-lobar lung transplantation(dd LLTx) and uniformly describe sizematching using the donor-to-recipient predicted-total lung-capacity(pT LC) ratio. METHODS We set out to systematically review reports on ddL LTx and uniformly describe size matching using the donorto-recipient pT LC ratio and to summarize reported oneyear survival data of ddL LTx and conventional-LTx. We searched in Pub Med, CINAHL via EBSCO, Cochrane Database of Systematic Reviews via Wiley(CDSR),Database of Abstracts of Reviews of Effects via Wiley(DARE), Cochrane Central Register of Controlled Trials via Wiley(CENTRAL), Scopus(which includes EMBASE abstracts), and Web of Science for original reports on ddL LTx. RESULTS Nine observational cohort studies reporting on 301 ddL LTx met our inclusion criteria for systematic review of size matching, and eight for describing one-year-survival. The dd LLTx-group was often characterized by high acuity;however there was heterogeneity in transplant indications and pre-operative characteristics between studies. Data to calculate the pT LC ratio was available for 242 ddL LTx(80%). The mean pT LCratio before lobar resection was1.25 ± 0.3 and the transplanted pT LCratio after lobar resection was 0.76 ± 0.2. One-year survival in the ddL LTxgroup ranged from 50%-100%, compared to 72%-88%in the conventional-LTx group. In the largest study ddL LTx(n = 138) was associated with a lower one-year-survival compared to conventional-LTx(n = 539)(65.1% vs84.1%, P < 0.001). CONCLUSION Further investigations of optimal donor-to-recipient size matching parameters for ddL LTx could improve outcomes of this important surgical option.

Fibroadhesive scarring of grafted collagen scaffolds interferes with implant–host neural tissue integration and bridging in experimental spinal cord injury

Severe traumatic spinal cord injury(SCI)results in a devastating and permanent loss of function,and is currently an incurable condition.It is generally accepted that future intervention strategies will require combinational approaches,including bioengineered scaffolds,to support axon growth across tissue scarring and cystic cavitation.Previously,we demonstrated that implantation of a microporous type-I collagen scaffold into an experimental model of SCI was capable of supporting functional recovery in the absence of extensive implant–host neural tissue integration.Here,we demonstrate the reactive host cellular responses that may be detrimental to neural tissue integration after implantation of collagen scaffolds into unilateral resection injuries of the adult rat spinal cord.Immunohistochemistry demonstrated scattered fibroblast-like cell infiltration throughout the scaffolds as well as the presence of variable layers of densely packed cells,the fine processes of which extended along the graft–host interface.Few reactive astroglial or regenerating axonal profiles could be seen traversing this layer.Such encapsulation-type behaviour around bioengineered scaffolds impedes the integration of host neural tissues and reduces the intended bridging role of the implant.Characterization of the cellular and molecular mechanisms underpinning this behaviour will be pivotal in the future design of collagen-based bridging scaffolds intended for regenerative medicine.