Search

An integrated and research-focused laboratory experiment is developed to introduce the "antenna effect" occurring in luminescent lanthanide complexes to students. Students synthesized a lanthanide metal-organic framework (Ln-MOF) with the formula of [Eu(BTPCA)(H O)]·2DMF·nH[Subscript 2]O (Eu-BTPCA, H[subscript 3]BTPCA = 1,1',1?-(1,3,5-triazine-2,4,6-triyl)tripiperidine-4-carboxylic acid) by the solvothermal method and characterized its structure by powder X-ray diffraction. They then measured the luminescence spectrum of Eu-BTPCA and compared it with that of EuCl[subscript 3]. Finally, students performed the luminescent sensing studies to metal ions. This experiment lets students gain the first-hand experience of solvothermal syntheses of MOFs and introduces essential scientific research approaches to students as well as exposes students to modern instrumental techniques for chemical research. Most importantly, through this experiment and its outcomes analyses, students can better understand the "antenna effect" and witness its application in metal ion luminescent sensing.

An effective method to eliminate grain boundary resistance of crystalline vanadoborate electrolyte was developed. This method involved the addition of glycerol to result in the formation of many hydrogen bonds between crystal grains, facilitating a rapid transfer of protons across grain boundaries. Using this method, the intrinsic conduction of vanadoborate electrolyte was fully reflected in its bulk materials, valuable for advancing our understanding of vanadoborate electrolytes and for promoting the application of these electrolytes. [ABSTRACT FROM AUTHOR]

The rheological characteristics of four polymer melts polystyrene (PS), poly (methyl methacrylate) (PMMA), polypropylene (PP) and high density polyethylene (HDPE) were investigated using a double capillary rheometer under the die diameter from 1. 5 mm to 0. 5 mm. The effects of temperature on shear viscosity and the effects of temperature and shear rate on non-Newton exponent of melts were discussed when the die diameter was 0. 5 mm. The results show that the shear viscosity of four polymer melts decreases with the increase of shear rate at 10² -104 s-1. The shear viscosity of PS and PMMA increases with the decrease of die diameter, but that of PP and HDPE decreases with the decrease of die diameter,and small differences of shear viscosity under various die diameters are observed with the increase of shear rate. When the die diameter is 0. 5 mm, Arrhenius equation is found to be suitable to describe the relations between shear viscosity and temperature for four polymer melts. The non-Newton exponent of four polymer melts increases with the increase of temperature and decreases with the increase of shear rate. [ABSTRACT FROM AUTHOR]

Objective: To discuss the significance of DOG1, CD117 and PDGFRA in the diagnosis of gastrointestinal stromal tumors (GISTs), and analyze their correlations with clinicopathological features and risk ranking., Method: DOG1, CD117 and PDGFRA were detected with IHC Envision ldpe-g-nvp in 63 GISTs and 43 cases of non-GISTs, and analyzed for relations with clinicopathological factors (gender, age, location, tumor size, mitotic phase, histology) and risk degree., Results: The positive expression rate of DOG1, CD117 and PDGFRA in GISTs was 84.1% (53/63), 90.5% (57/63), 53.2% (33/63), respectively. Among the 6 CD117 negative cases, all were DOG1 positive and 5 were PDGFRA positive. Rates in patients with non-GISTs was 11.6%, 16.3%, 6.98%, respectively. Expression of DOG1 and PDGFRA demonstrated no significant variation with gender, age, position, tumor size, mitotic phase, histology, and risk rank. However, CD117 was related with position and histology (P=0.008 and P=0.045), those in the mesentery having a higher positive rate than those derived from stomach, small intestine, colon and rectum (50.0% vs 94.7%, P=0.008). Furthermore CD117 was also highly expressed in spindle and epithele types., Conclusions: DOG1 had a good sensitivity and specificity as a kind of newly discovered marker, especially for KIT negative GISTs. However, DOG1, CD117 and PDGFRA cannot be used for assessing the rish of patients.