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Search Results: 1 - 10 of 120048 matches for " Qinhong Wang "
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Simultaneous Separation and Quantification of Iron and Transition Species Using LC-ICP-MS  [PDF]
Qinhong Hu
American Journal of Analytical Chemistry (AJAC) , 2011, DOI: 10.4236/ajac.2011.26077
Abstract: Using liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS), this work investigates the simultaneous separation and quantification of seven transition metal species (Fe, Mn, Co, Ni, Cu, Zn, and Cd), based on a separation scheme published by Dionex company that used the spectrophotometric method for quantification. The LC-ICP-MS method overcomes the shortcomings of conventional ferrozine approaches of measuring Fe(II) and total Fe by two separate runs and calculating Fe(III) by the difference of two runs. The advantage is particularly evident in that organo-iron species are found to be the predominant iron species in many natural waters, and the difference method cannot measure the concentration of Fe(III) because ferrozine will not complex with organo-iron species. In the work reported here, the LC-ICP-MS method is successfully applied to the separation of dissolved iron species, as well as six other divalent transition metals in tap water, deionized water, river water, hot springs, and groundwater samples.
LA-ICP-MS Calibrations for Intact Rock Samples with Internal Standard and Modified Constant-Sum Methods  [PDF]
Sheng Peng, Qinhong Hu
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.32024
Abstract: Laser ablation coupled with inductively coupled plasma-mass spectrometry (LA-ICP-MS) calibration was conducted with multiple spot analyses on eleven intact rock samples using both an internal standard (IS) method and a modified constant-sum (MCS) method. Methods were then compared for reported bulk elemental composition of the rocks. The MCS method was based on the sum of eight major elements, which is spatially more stable than one single major ele-ment as used in the IS method, and is quite constant among different rock samples. Calibrations were performed with standard reference materials NIST SRM 610, 612, 614, and 616. Little difference was found between using a single standard and a set of standards, because of the good linearity shown by the reference materials. Comparison of the two calibration methods shows that the MCS method produced better and more stable results than the IS method for heterogeneous samples. With the MCS method, approximately 94% to 95% of the total measurements are within the range of ±100% relative deviation, compared with 82% to 86% with the IS method. The IS method resulted insubstantial overestimations for some rock samples (e.g., 648% for Basalt BCR-2 using NIST SRM 610 as the calibration standard), while the largest deviation with the MCS method was 216% for U in Eagle Ford shale #80 sample. For Quartz latite QLO-1, a relative homogeneous sample, the IS method generated slightly better results than the MCS method. Regardless of method, spatially heterogeneous distribution of elements in the intact rock at the scale of the laser spot is considered to be the main reason for the large relative deviations seen in our work compared to published results.
The Alcohol Dehydrogenase System in the Xylose-Fermenting Yeast Candida maltosa
Yuping Lin,Peng He,Qinhong Wang,Dajun Lu,Zilong Li,Changsheng Wu,Ning Jiang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011752
Abstract: The alcohol dehydrogenase (ADH) system plays a critical role in sugar metabolism involving in not only ethanol formation and consumption but also the general “cofactor balance” mechanism. Candida maltosa is able to ferment glucose as well as xylose to produce a significant amount of ethanol. Here we report the ADH system in C. maltosa composed of three microbial group I ADH genes (CmADH1, CmADH2A and CmADH2B), mainly focusing on its metabolic regulation and physiological function.
Mono- or Double-Site Phosphorylation Distinctly Regulates the Proapoptotic Function of Bax
Qinhong Wang,Shi-Yong Sun,Fadlo Khuri,Walter J. Curran,Xingming Deng
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0013393
Abstract: Bax is the major multidomain proapoptotic molecule that is required for apoptosis. It has been reported that phosphorylation of Bax at serine(S) 163 or S184 activates or inactivates its proapoptotic function, respectively. To uncover the mechanism(s) by which phosphorylation regulates the proapoptotic function of Bax, a series of serine (S)→ alanine/glutamate (A/E) Bax mutants, including S163A, S184A, S163E, S184E, S163E/S184A (EA), S163A/S184E (AE), S163A/S184A (AA) and S163E/S184E (EE), were created to abrogate or mimic, respectively, either single or double-site phosphorylation. The compound Bax mutants (i.e. EA and AE) can flesh out the functional contribution of individual phosphorylation site(s). WT and each of these Bax mutants were overexpressed in Bax?/? MEF or lung cancer H157 cells and the proapoptotic activities were compared. Intriguingly, expression of any of Bax mutants containing the mutation S→A at S184 (i.e. S184A, EA or AA) represents more potent proapoptotic activity as compared to WT Bax in association with increased 6A7 epitope conformational change, mitochondrial localization/insertion and prolonged half-life. In contrast, all Bax mutants containing the mutation S→E at S184 (i.e. S184E, AE or EE) have a mobility-shift and fail to insert into mitochondrial membranes with decreased protein stability and less apoptotic activity. Unexpectedly, mutation either S→A or S→E at S163 site does not significantly affect the proapoptotic activity of Bax. These findings indicate that S184 but not S163 is the major phosphorylation site for functional regulation of Bax's activity. Therefore, manipulation of the phosphorylation status of Bax at S184 may represent a novel strategy for cancer treatment.
Molecular cloning, expression and biochemical property analysis of AtKP1, a kinesin gene from Arabidopsis thaliana
XuYan Li,HaiQing Wang,Tao Xu,QinHong Cao,DongTao Ren,GuoQin Liu
Chinese Science Bulletin , 2007, DOI: 10.1007/s11434-007-0196-y
Abstract: Kinesins are common in a variety of eukaryotic cells with diverse functions. A cDNA encoding a member of the Kinesin-14B subfamily is obtained using 3′-RACE technology and named AtKP1 (for Arabidopsis kinesin protein 1). This cDNA has a maximum open reading frame of 3.3 kb encoding a polypeptide of 1087 aa. Protein domain analysis shows that AtKP1 contains the motor domain and the calponin homology domain in the central and amino-terminal regions, respectively. The carboxyl-terminal region with 202 aa residues is diverse from other known kinesins. Northern blot analysis shows that AtKP1 is widely expressed at a higher level in seedlings than in mature plants. 2808 bp of the AtKP1 promoter region is cloned and fused to GUS. GUS expression driven by the AtKP1 promoter region shows that AtKP1 is mainly expressed in vasculature of young organs and young leaf trichomes, indicating that AtKP1 may participate in the differentiation or development of Arabidopsis thaliana vascular bundles and trichomes. A truncated AtKP1 protein containing the putative motor domain is expressed in E. coli and affinity-purified. In vitro characterizations indicate that the polypeptide has nucleotide-dependent microtubule-binding ability and microtubule-stimulated ATPase activity.
Potent Antitumor Activity Generated by a Novel Tumor Specific Cytotoxic T Cell
Zheng Wang, Pei Li, Qinhong Xu, Jun Xu, Xuqi Li, Xufeng Zhang, Qingyong Ma, Zheng Wu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066659
Abstract: Hepatocellular carcinoma is one of the most common malignant neoplasms in the world and is the main cause of death in patients with liver cirrhosis. Surgical intervention is not suitable for majority of hepatocellular carcinoma. Investigation of the effective targeting to the tumor cells is essential for both primary tumors and metastases. Tumor specific cytotoxic T lymphocytes (CTL) have been considered to be the attractive vehicles for delivering therapeutic agents toward various tumor diseases. This study was to explore the distribution pattern of CTL carrying the lentiviral vectors with the characteristic of adenoviral E1 gene under the control of the cell activation-dependent CD40 ligand promoter (Lenti/hCD40L/E1AB). Following transduction with adenoviral vectors containing chimeric type 5 and type 35 fiber proteins (Ad5/35-TRAIL), these CTLs produced infectious virus when exposed to HepG2 cells. We assessed the therapeutic ability of CTLs using MTT, Western blot and colony formation assay. The novel CTL harboring Lenti/hCD40L/E1AB and Ad5/35-TRAIL caused proliferation inhibition and significant apoptosis in hepatocellular carcinoma cell lines. Thus, the novel CTL may be useful for the development of gene therapy approaches to hepatocellular carcinoma.
Modification of the Warrants Pricing Model and Validation Analysis
Jinlong Chen,Qinhong Li
International Journal of Business and Management , 2009, DOI: 10.5539/ijbm.v3n2p63
Abstract: Based on the previous study in this article, modified Black-Sholes model was more suitable for the domestic warrants price, and calculated 6 warrants’ price in the listed time, It also confirmed the rationality of the model comparing the pricing theory with the actual market price. The result of the computation of the modified warrant price model shows that though in the warrant market the realistic price deviates from theoretical price, the deviations of realistic and theoretical prices is smaller from May, 2006 to May, 2007.

He Peng Lu Dajun Wang Qinhong,Shen An,Jiang Ning,

微生物学报 , 2001,
Abstract: Recombinant plasmid pVgb\|EX2 containing Vitreoscilla hemoglobin gene vgb and formaldehyde resistant gene SFA1 was constructed and transformed into D\|arabitol producing yeast strain Saccharomyces sp.X\|62.The fact that the amount of VHb in transformant cells was considerably higher than that in control cells indicated that gene vgb was expressed in transformant cells.D\|arabitol productivity and yield of fermentation by transformants were improved.The most improvement of D\|arabitol productivity in repeat experiments reached 27.3%.It appeared that the fermentation productivity of D\|arabitol was relative to the amount of VHb in cells under experimental conditions.
L鼠腹水肿瘤细胞 P核磁共振的研究

Zhang Naizhong,Wang Fengru,Ma Liying,Han Qinhong,Wang Junheng,Liu Xiuping,Wu Jiazhen,Zhou Shuhua,

生物化学与生物物理进展 , 1990,
Abstract: 用 31P核磁共振技术(31P-NMR)研究了L7811鼠腹水肿瘤细胞和615系鼠胸腺细胞(正常对照细胞)。结果发现在肿瘤晚期阶段,L7811腹水肿瘤细胞的含磷化合物未进入完全不活跃状态。此外,腹水肿瘤细胞的磷脂组成与含量亦有明显改变。因此, 31P-NMR谱可做为观察肿瘤细胞内能量生成和某些磷脂合成宏观动态过程的一项参考指标。
A Functional +61G/A Polymorphism in Epidermal Growth Factor Is Associated with Glioma Risk among Asians
Xin Xu, Lei Xi, Jie Zeng, Qinhong Yao
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041470
Abstract: Background Epidermal growth factor (EGF), a potent mitogenic protein, plays an important role in the development of cancers, including glioma. Previous studies showed that the EGF +61G/A polymorphism (rs4444903) may lead to an alteration in EGF production and/or activity, which can result in individual susceptibility to glioma. However, published data regarding the association between the +61G/A polymorphism and glioma risk was contradictory. Objective The aim of this study was to perform a meta-analysis of eligible studies to derive precise estimation of the association of EGF +61G/A with glioma risk. Methods We performed a pooled analysis of seven published studies that included 1,613 glioma cases and 2,267 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Results Overall, no significant associations between the EGF +61G/A polymorphism and glioma cancer risk were found for AA versus GG (OR = 0.95, 95% CI = 0.62–1.45), GA versus GG (OR = 0.94, 95% CI = 0.72–1.22), AA/GA versus GG (OR = 0.93, 95% CI = 0.70–1.23), and AA versus GA/GG (OR = 1.04, 95% CI = 0.77–1.39). However, in the stratified analysis by ethnicity, the EGF +61G/A polymorphism had a higher risk of glioma development among Asians, but a lower risk among Caucasians. Conclusions Taken together, the results suggest that the EGF +61G/A polymorphism may contribute to the susceptibility of glioma in different ethnic groups.
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