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以苯甲酸及其衍生物为第一配体、丁二酸为第二配体,在非水性溶剂条件下合成了6种新的铽三元荧光配合物。利用元素分析、EDTA配位滴定分析、红外光谱和紫外吸收光谱分析对目标物的组成与结构进行了表征,并研究了其发光性能和热稳定性。结果表明:丁二酸的引入显著地加强了各第一配体向中心铽离子传递能量的能力,其传递能量的顺序为:对氯苯甲酸>间氯苯甲酸>大茴香酸>对甲基苯甲酸>苯甲酸>对羟基苯甲酸。目标配合物与其相对应的二元配合物比较荧光强度有了显著的提高。  相似文献   

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Hyaluronic Acid: Its Role in Voice   总被引:8,自引:0,他引:8  
The extracellular matrix (ECM), once regarded simply as a structural scaffold, is now recognized as an important modulator of cellular behavior and function. One component that plays a prominent role in this process is hyaluronic acid (HA)--a molecule found in many different tissues. Research into the roles of HA indicates that it plays a key role in tissue viscosity, shock absorption, and space filling. Specifically, research into the role of HA in laryngology indicates that it has profound effects on the structure and viscosity of vocal folds. This article provides an introduction to the structure and biological functions of HA and its importance in voice. In addition, an overview of the pharmaceutical applications of HA is discussed.  相似文献   

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In order to develop a scaffolding material for tissue regeneration, porous matrices containing varying composites of collagen and hyaluronic acid (HA) (from 1:0 to 0:1) were fabricated using a freeze-drying method. The effect of the composition on the morphology, hydrophilicity, swelling behavior, mechanical properties, and in vitro cytotoxicity was investigated. The results showed that all the scaffolds had an interconnected pore structure with sufficient pore size for use as a support for the growth of fibroblasts. The addition of HA improved the swelling property, but reduced the compressive strength. The contact angle decreased with increasing HA content. In in vitro cytotoxicity tests using fibroblastic cells, the collagen/HA scaffolds showed no toxicity. All these results suggest that collagen/HA composite scaffolds are a potential candidate for tissue engineering scaffolds.  相似文献   

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Porous hydrogel blends composed of various weight ratios of hyaluronic acid (HA) and gelatin (Gel) were fabricated by a freeze-drying method. The 1-ethyl-3(3-dimethylaminopropyl) carbodiimide (EDC) was used as a crosslinker to improve their biostability. The effect of the component and crosslinker content on the morphology, swelling ratio (SR), and mechanical properties were investigated. The results indicated that after chemical crosslinking the hydrogel showed a smoother and denser surface with less pores and a crosssection with smaller pores than that without crosslinking. The crosssection morphologies of the HA/Gel hydrogels changed from a sheet-like appearance to a fiber-like appearance with increasing HA content. The addition of HA improved the swelling property, but reduced the compressive strength. As the crosslinker content increased, the SR decreased; however, the compressive strength of the HA/Gel hydrogels increased. All these results suggest that HA/Gel hydrogel crosslinked by EDC is a potential candidate for tissue engineering scaffolds.  相似文献   

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由柠檬酸出发,经过转化制备柠檬酸酐,与壬基酚聚氧乙烯醚反应制备柠檬酸壬基酚聚氧乙烯醚单酯,再与二乙醇胺反应合成了一种具有防锈、润滑双重性能的水基合成切削液新型添加剂-柠檬酸壬基酚聚氧乙烯醚单酯二乙醇酰胺。采用红外光谱法对原料、中间体及最终产物进行了测试。根据1 736.14 cm-1酯中CO双键伸缩振动的特征吸收峰,1 642.39 cm-1酰胺中CO双键伸缩振动的吸收峰,可知所得到的产物为柠檬酸壬基酚聚氧乙烯醚单酯二乙醇酰胺,说明所采用的合成的工艺路线是可行的。  相似文献   

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A simple approach is reported to engineer biodegradable and biocompatible nanoporous hyaluronic acid particles (NPHAs) with a characteristic sponge‐like morphology and uniform size. These NPHAs can be synthesized using the concomitant cross‐linking of hyaluronic acid and the cross‐linking agent precipitation. The nanoporous architecture of NPHAs prevents the rapid enzymatic degradation of hyaluronic acid and controls the erosion of microparticles in physiological conditions. Once injected into an intra‐articular body cavity of healthy mice, these NPHAs reside at the point‐of‐delivery for an extended time period, exhibiting a sustained release of hyaluronic acid. In addition, in vivo studies indicate the persistence of NPHAs in the knee joints with neither accumulation into major organs, nor any local or systemic side‐effect. The use of NPHAs is emphasized as reservoirs of hyaluronic acid, effectively providing an innovative and safe platform for prolonging the favorable effects displayed by hyaluronic acid on joints affected by osteoarthritis.  相似文献   

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首次合成丁二酸-1,10-菲啰啉稀土配合物,并运用光谱法研究配合物与DNA之间的作用机制,为新型抗癌药物的设计开发提供依据。以1,10-菲啰啉(phen)和丁二酸(SA)为配体构筑了3种稀土(La3+,Nd3+,Eu3+)配合物,采用元素分析、红外和紫外光谱及热重分析对配合物性质进行表征测试,确定其化学组成为(RE)2(SA)(phen)·2H2O(RE=La,Nd,Eu)。同时,通过光谱法探讨了这3种配合物分别与DNA作用的机理以及稀土离子种类对作用强度的影响。配合物与DNA作用时,可观察到较明显的吸收峰红移和较大的减色效应现象,同时,中性红(NR)荧光竞争实验发现配合物都能不同程度地猝灭NR-DNA体系的荧光。这3种配合物对DNA均具有较强的插入作用,作用强度为:La(Ⅲ)Nd(Ⅲ)Eu(Ⅲ)。计算了DNA与配合物的结合比、结合常数及一些热力学参数,得出DNA与Eu配合物、Nd配合物、La配合物的结合比分别为4∶1,2∶1和8∶1,Δr Gm0、Δr Sm0,表明这3种配合物与DNA之间的反应均能够自发进行,且作用是熵驱动的。  相似文献   

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以柠檬酸、乙酸酐、壬基酚聚氧乙烯醚和二乙醇胺为原料,经过原料精制、中间体和产物的合成等一系列过程,得到了一种具有防锈、润滑双重性能的水基合成切削液新型添加剂-柠檬酸壬基酚聚氧乙烯醚单酯二乙醇酰胺。采用红外光谱法对合成样品中酰胺进行定量分析,利用谱图中1 642.39 cm-1处酰胺中CO双键伸缩振动的特征吸收峰,选择硫氰酸钾作为内标物,以朗伯-比尔定律为理论依据,从而建立了直接红外光谱法测定柠檬酸壬基酚聚氧乙烯醚单酯二乙醇酰胺含量的方法。实验测定内标工作曲线为A=0.007 6m+0.325 6相关系数r2=0.999 7,通过对方法重现性和回收率的考查,得到了较为满意的结果。该法是确定合成柠檬酸壬基酚聚氧乙烯醚单酯二乙醇酰胺产品的反应程度和控制产品质量的一种必要手段,证明了由柠檬酸合成柠檬酸壬基酚聚氧乙烯醚单酯二乙醇酰胺的工艺路线是可行的。  相似文献   

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Epidermal growth factor (EGF) is widely recognized to be involved in the regenerative process, but only a few studies document its effect on acute wounds when EGF release is sustained over a period of time by encapsulation in an emulsion‐based hydrogel. Among hydrogels, hyaluronic acid (HA) is a promising carrier because it is biodegradable and known to bind to the components of the Extracellular Matrix (ECM) which undergoes remodeling during regeneration. Coupled with EGF in microparticulates, it may serve to directly deliver the cytokine to the impaired ECM to stimulate cells for ECM remodeling. In this study, a very simple and effective way is demonstrated to produce EGF‐conjugated HA microspheres for the purpose of targeted and sustained EGF delivery to damaged ECM in acute wounds. This approach is advantageous due to its simplicity which may serve to accelerate research in wound regeneration and relevant drug discovery.  相似文献   

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Mononuclear Ru(II)Polypyridyl complexes of type [Ru(A)2BPIIP] (ClO4)2.2H2O, where BPIIP?=?2-(3-(4-bromophenyl)isoxazole-5-yl)-1 H-imidazo [4,5-f] [1, 10] phenanthroline and A?=?bpy?=?bipyridyl (1), phen?=?1,10 Phenanthroline (2), dmb?=?4, 4' -dimethyl 2, 2'- bipyridine (3) & dmp?=?4,4'-dimethyl-1,10 –Ortho Phenanthroline (4), were synthesized and their antibacterial activity were examined. The synthesized complexes were characterized and their interaction with DNA was studied using Computational and Biophysical methods (Absorption, emission methods, and viscosity). Molecular modelling studies were carried out for molecular geometry and electronic properties (Frontier molecular orbital HOMO—LUMO). The electrostatic potential surface contours for the complexes were analysed to give their nucleophilic level of sensitivity. The study reveals that the Ru(II) Polypyridyl complexes bind to DNA preponderantly by intercalation. The results recommend that the phen and dmp complex have more effective binding ability than the bpy and dmb, indicating the role of the ancillary ligand in determining their specificity for DNA binding. Further molecular docking studies suggested an octahedral geometry and bind to DNA by preferential binding to Guanine. The docking study additionally sustains the binding constant data acquired with the absorption and emission techniques.The results reveal that the nature of the ancillary Ligand plays a considerable role for the intercalation of the Ru(II) polypyridyl complex to DNA, which subsequently influences the antibacterial activity. Biological studies conducted on Gram‐Negative (E.coli and K.pneumonia) and Gram-Positive (S. aureus and E. faecalis) bacteria establish that complex 1 and 2 were considerably active against S. aureus and E. coli.

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酸性黄是经过重氮化和偶合反应合成的一种偶氮染料,对它进行了IR、1H-NMR和元素分析的表征.进一步研究它的光致发光性质,结果表明:它的荧光发射为黄绿色光,其发射光谱有明显的溶剂效应,并且随着溶剂极性(乙酰乙酸乙酯、乙醇、吡啶和N,N-二甲基甲酰胺)的增大荧光光谱向长波方向移动(即发生红移);温度和过渡金属离子对它的荧光光谱有较大的影响.  相似文献   

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