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Jia Zhu, Lei Xiang, Yazhou Zhou and Juan Yang

Abstract

Cotton-like CoS cluster has been successfully synthesized via a simple one-step hydrothermal route assisted by diethylenetriamine (DETA) as a ligand and structure-directing agent. The structure and morphology of the product were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM) and N2 adsorption-desorption isotherm. The CoS sample which has a hexagonal phase without any impurities possesses a microscopic morphology made by cotton-like clusters. The as-fabricated CoS as a supercapacitor electrode presents desirable supercapacitive performance with a high specific capacitance (664 F∙g-1 at 0.5 A∙g-1), remarkable rate capability and excellent cycling stability (85.7 % specific capacitance retention after 1000 cycles), making it applicable as an electrode for high-performance supercapacitors.

Open access

Xiao-ming Li, Jia-yue Yin, Hao-jun Xu, Chengqiong Bi, Li Zhu, Xiao-dong Deng and Lei-nan Ma

Open access

Xiao-ming Li, Jia-yue Yin, He-zuo Qu, Cheng-qiong Bi, Hao-jun Xu and Li Zhu

Open access

Taichao Su, Hongyu Zhu, Hongan Ma, Shangsheng Li, Meihua Hu, Xiaolei Li, Fengrong Yu, Yongjun Tian and Xiaopeng Jia

Abstract

In this paper, crack-free bulk thermoelectric material Zn4Sb3 was prepared rapidly by high pressure and high temperature (HPHT) method. Near a single-phase Zn4Sb3 specimen was obtained using nominal stoichiometric powder mixtures, which were indexed by powder X-ray diffraction. The temperature-dependent thermoelectric properties including the Seebeck coefficient and electrical resistivity were studied. The maximum power factor of Zn4Sb3 specimen prepared by HPHT reaches 10.8 μW/(cmK2) at 637 K, which is comparable to the published data. The results show that the HPHT offers potential processing route to produce the thermoelectric material Zn4Sb3 quickly and effectively.

Open access

Chaoqi Yin, Chengqun Luo, Jianda Zhou, Quanyong He, Xie Zhu, Ping Li, Tiefu Chen, Hao Peng, Yangcheng Xu and Jia Chen

Abstract

Background: Previous study suggests that high mobility group box 1 (HMGB1) can be a potential late inflammatory mediator. However, whether heat shock factor 1 (HSF1) regulate HMGB1 expression via binding to heat shock element (HSE) is not known.

Objective:We investigated the role of HSF1 in the transcriptional regulation of HMGB1 protein.

Methods: A probe that included HMGB1 promoter region containing HSE was synthesized for electrophoretic mobility shift assay (EMSA) to determine the binding of HSF1 and HSE in the promoter region of HMGB1 gene. Mutant mouse HMGB1 promoter was prepared by PCR amplification on a template of wild-type plasmid DNA with site-directed mutant primers. The mutant DNA fragments were also inserted into a corresponding plasmid. In addition, luciferase reporter plasmids of HMGB1 promoter were constructed to transfect RAW264.7 cells. After that, luciferase activity was measured to assay the effects of the HSF1 transfection on the promoter activity.

Results: EMSA result showed a retardation strap after the coculture of biotin labeled HSF1 binding fragment and nuclear protein extracts. The retardation phenomenon could be competed by unlabeled probe and not by unlabeled mutant probe. A super retardation strap was present after adding HSF1 monoclonal antibody. After the HSE core sites was mutated, the relative luciferase activity of the mutant plasmid decreased by 4.26 folds compared with that in the wild-type (23.54±1.68 vs.100.25±3.26, p <0.01). EMSA assay also confirmed that there were HSF1 binding sites HSE (-668bp~-651bp) in the promoter region of HMGB1. The mutation of the core base of HSF1 binding sites decreased the transcriptional activity of HMGB1.

Conclusion: HSF1 can bind to the promoter region HSE (-668bp~-651bp) of HMGB1, which down-regulates the expression of HMGB1.