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Search Results: 1 - 10 of 93450 matches for " XU Zheng-Hong "
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Hydrothermal Synthesis of Iodine-Doped Nanoplates with Enhanced Visible and Ultraviolet-Induced Photocatalytic Activities
Jiang Zhang,Zheng-Hong Huang,Yong Xu,Feiyu Kang
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/915386
Abstract: The iodine-doped Bi2WO6 (I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420?nm) or ultraviolet light (<400?nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0 and were coadsorbed on the defect surface of Bi2WO6 in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies. 1. Introduction To decompose the organic pollutants existing in water and air, the advanced oxidation technique of photocatalysis was applied to deal with the serious environmental problems. Among all kinds of photocatalysts, the UV-induced TiO2 as an effective photocatalyst have been applied widely in the conversion of photon energy into chemical energy and the decomposition of organic pollutants in air and water. For example, the photocatalytic technology had been used to disinfect water utilizing the solar energy [1]. In earlier researches, to develop visible-light-driven photocatalysts, in the case of TiO2, the doping with nonmetal elements was regarded as a feasible modification to expand the photoresponsive range greatly and to inhibit the recombination of photoinduced electrons and holes efficiently [2–4]. In the past decades, the nitrogen-doped titanium dioxide was regarded as an effective case to improve the visible light photoresponsivity and to shift the optical absorption edge of TiO2 towards a lower energy, thereby increasing the photoactivity. Among these nonmetal dopants, iodine-doping was paid more attentions owing to altering the surface charge, shifting the photoresponse from UV to visible region and acting as a conduction-band electron scavenger capable of inhibiting the rapid recombination of photoinduced electron-hole pairs [5–17]. Bi2WO6 is thought to be a promising
Sol-Gel-Hydrothermal Synthesis of the Heterostructured - Composite with High-Visible-Light- and Ultraviolet-Light-Induced Photocatalytic Performances
Jiang Zhang,Zheng-Hong Huang,Yong Xu,Feiyu Kang
International Journal of Photoenergy , 2012, DOI: 10.1155/2012/469178
Abstract: The heterostructured TiO2/N-Bi2WO6 composites were prepared by a facile sol-gel-hydrothermal method. The phase structures, morphologies, and optical properties of the samples were characterized by using X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), and UV-vis diffuse reflectance spectroscopy. The photocatalytic activities for rhodamine B of the as-prepared products were measured under visible and ultraviolet light irradiation at room temperature. The TiO2/N-Bi2WO6 composites exhibited much higher photocatalytic performances than TiO2 as well as Bi2WO6. The enhancement in the visible light photocatalytic performance of the TiO2/N-Bi2WO6 composites could be attributed to the effective electron-hole separations at the interfaces of the two semiconductors, which facilitate the transfer of the photoinduced carriers.
Bioassay-Guided Isolation of DPP-4 Inhibitory Fractions from Extracts of Submerged Cultured of Inonotus obliquus
Yan Geng,Zhen-Ming Lu,Wei Huang,Hong-Yu Xu,Jin-Song Shi,Zheng-Hong Xu
Molecules , 2013, DOI: 10.3390/molecules18011150
Abstract: Inonotus obliquus is a medicinal mushroom used in Russian and Eastern European folk medicine for the treatment of gastrointestinal cancer, cardiovascular disease and diabetes. Previous studies in our laboratory have demonstrated that the mycelium powders of I. obliquus possess significant antihyperglycemic effects in a mouse model of diabetic disease induced by alloxan. However, the active ingredients of mycelium powders responsible for the diabetes activity have not been identified. This study aims to identify the active ingredients of I. obliquus mycelium powders by a bioassay-guided fractionation approach and explore the mechanism of action of these active ingredients by using a well-established DPP-4 (an important enzyme as a new therapeutic target for diabetes) inhibitory assay model. The results showed the chloroform extract of mycelium was potential inhibitory against DPP-4. Bioactivity guided fractionation led to the identification of 19 compounds using UPLC-Q-TOF-MS. Molecular docking between the compounds and DPP-4 revealed that compounds 5, 8, 9, 14, 15 may be the active components responsible for the DPP-4 inhibitory activity.
Poloxamer 188 Protects Neurons against Ischemia/Reperfusion Injury through Preserving Integrity of Cell Membranes and Blood Brain Barrier
Jin-Hua Gu, Jian-Bin Ge, Mei Li, Hai-Dong Xu, Feng Wu, Zheng-Hong Qin
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0061641
Abstract: Poloxamer 188 (P188), a multiblock copolymer surfactant, has been shown to protect against ischemic tissue injury of cardiac muscle, testes and skeletal muscle, but the mechanisms have not been fully understood. In this study, we explored whether P188 had a protective effect against cerebral ischemia/reperfusion injury and its underlying mechanisms. The in vivo results showed that P188 significantly reduced the infarct volume, ameliorated the brain edema and neurological symptoms 24 h after ischemia/reperfusion. In the long-term outcome study, P188 markedly alleviated brain atrophy and motor impairments and increased survival rate in 3 weeks of post stroke period. Additionally, P188 protected cultured hippucampal HT22 cells against oxygen–glucose deprivation and reoxygenation (OGD/R) injury. The ability in membrane sealing was assessed with two fluorescent membrane-impermeant dyes. The results showed that P188 treatment significantly reduced the PI-positive cells following ischemia/reperfusion injury and repaired the HT22 cell membrane rupture induced by Triton X-100. In addition, P188 inhibited ischemia/reperfusion-induced activation of matrix metalloproteinase (MMP)-9 and leakage of Evans blue. Therefore, the present study concludes that P188 can protect against cerebral ischemia/reperfusion injury, and the protection involves multi-mechanisms in addition to the membrane resealing.
Identification of L-Serine Producer SYPS-062 and the Effect of Different Carbon Source
产L-丝氨酸菌株SYPS-062的鉴定及碳源对发酵的影响

ZHANG Xiao-Mei,DOU Wen-Fang,XU Hong-Yu,XU Zheng-Hong,
张晓梅
,窦文芳,许泓瑜,许正宏

微生物学通报 , 2009,
Abstract: SYPS-062 was an L-serine producing strain stored by our lab, which could directly produce L-serine from sugar. According to morphology, physiological and biochemical identification and 16S rDNA sequence, SYPS-062 was identified as Corynebacterium glutamicum. And the effect of different carbon source for the SYPS-062 and Corynebacterium glutamicum ATCC13032 fermentation were studied. The experiment result showed that the sucrose was 60 g/L, the yield of L-serine and biomass reached the maximal value, 6.6 g/L and 8.1 g/L respectively.
Spectral Characteristics of Voltage Sensitive Dye di-4-ANEPPS in Perfusates
电压敏感染料di-4-ANEPPS在灌注液中的光谱特性

XU Zheng-hong,ZHANG Zhen-xi,WANG Jing,ZHANG Hong,
徐正红
,张镇西,王晶,张虹

光子学报 , 2008,
Abstract: 研究了电压敏感染料di-4-ANEPPS在溶液中的吸收光谱和荧光光谱特性.结果表明,染料的吸收峰在480 nm附近,加入钙阻断剂BDM不会影响染料的吸收峰位.染料在去离子水和新鲜台氏液中的荧光发射光谱峰位近似,而在灌注后的台氏液中染料的荧光峰位有蓝移现象.这些研究结果为心脏光学标测系统的设计提供了理论依据.
Effect of phosphoenolpyruvate carboxylase gene knock-out on physiological metabolism in Corynebacterium glutamicum V1
磷酸烯醇式丙酮酸羧化酶基因的敲除对于谷氨酸棒杆菌V1生理代谢的影响

QIU Ai-Mei,DOU Wen-Fang,LI Hui,XU Zheng-Hong,
仇爱梅
,窦文芳,李会,许正宏

微生物学通报 , 2012,
Abstract: Objective] In order to optimize precursor supply for L-valine biosynthesis,a Corynebacterium glutamicum V1 mutant with phosphoenolpyruvate carboxylase gene(pepc) in-frame deletion was constructed through crossover PCR and homologous recombination.The effect of pepc knock-out on physiological characteristics of the mutant was investigated.Methods] The upstream and downstream fragments of pepc were cloned from C.glutamicum V1 chromosome and ligated to integration vector.The mutant C.glutamicum V1-Δpepc was screened by homologous recombination.The physiological characteristics of the mutant were investigated by fermentation experiments and enzymes activity measurement of pyruvate carboxylase(PC),pyruvate dehydrogenase(PDH) and pyruvate kinase(PK).The mutant with pepc gene in-frame deletion was screened and confirmed by PCR and phosphoenolpyruvate carboxylase activity determination.Results] The pepc knock-out resulted in L-argine accumulation to 7.48 g/L and no accumulation of L-valine,which accompanied by increase of PDH activity and PC activity in C.glutamicum V1-Δpepc.The knock-out of pepc gene affected the metabolism of the strain to some extent.Conclusion] Blocking the anaplerotic pathway PEPC participated increased TCA cycle,leading to the increase of L-argine and decrease of amino acids with pyruvic acid as precursor,such as L-valine and alanine.
Advances in the Research on Microbial Phytases
微生物植酸酶研究进展

YANG Ping-Ping XU Zheng-Hong WANG Yan TAO Wen-Yi,
杨平平
,许正宏,王燕,陶文沂

微生物学通报 , 2004,
Abstract: Phytases are studied widely in plants and microorganisms. Interest in these enzymes has been stimulated by the fact that phytase has the advantage in forage, food process and medicine. This paper reviews recent trends on the production, purification, properties and gene of microbial phytases.
Identification of psychrotrophs SYP-A2-3 producing cold-adapted protease from the No.1 Glacier of China and study on its fermentation conditions
中国冰川1号产适冷蛋白酶耐冷菌的分离鉴定及产酶条件

SHI Jin-song WU Qi-fan XU Zheng-hong,TAO Wen-yi,
史劲松
,吴奇凡,许正宏,陶文沂

微生物学报 , 2005,
Abstract: The psychrotrophs SYP-A2-3 producing the cold-adapted protease has been isolated from the bacterial samples collected from the No. 1 Glacier of China and identified as Bacillus cereus according to its morphological and physiochemical characteristics and 16s rDNA gene sequence analysis. It could grow between 0 degree C and 38 degrees C while its optimal growth temperature was 25 degrees C and the optimal temperature for its protease production was 15 degrees C. The cold-adapted protease was identified as neutral metallo-protease, the molecular weight was 34.2 kD shown by SDS-PAGE, the optimal pH and temperature for activity was 7.0-8.5 and 42 degrees C, respectively. Various fermentation conditions of its protease production were also investigated. The results showed that casein was the best nitrogen source while glucose and starch were suitable carbon source for its protease production. The initial pH of fermentation broth ranged from 6.5 to 7.0 was optimal. Under optimized conditions, the protease activity produced by SYP-A2-3 could reach 3800 U/mL and 4800 U/mL conducted in shaking flask and 5 L stirred jar experiment, respectively.
Design of X-band backward wave oscillator with 10 GW output power
X波段10GW高功率返波管振荡器设计

Ma Qiao-Sheng,Jin Xiao,Xu Ming,Li Zheng-Hong,Wu Yang,
马乔生
,金晓,绪明,李正红,吴洋

物理学报 , 2011,
Abstract: An efficient high power relativistic backward wave oscillator (RBWO) is designed. To enhance the beam-wave conversion efficiency and output power, an overmoded slow wave structure (SWS) is used and an inner conductor is inserted into the SWS. When electron energy is 1.3 MeV while the beam current is 17 kA, the simulated output microwave power is 10.4 GW at 8.8 GHz frequency for the RBWO.
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