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Search Results: 1 - 10 of 4177 matches for " QingFang Miao "
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Generation and antitumor effects of an engineered and energized fusion protein VL-LDP-AE composed of single-domain antibody and lidamycin
QingFang Miao,BoYang Shang,ZhiGang Ouyang,XiaoYun Liu,YongSu Zhen
Science China Life Sciences , 2007, DOI: 10.1007/s11427-007-0058-5
Abstract: Type IV collagenase plays a pivotal role in invasion, metastasis and angiogenesis of tumor. Single domain antibodies are attractive as tumor-targeting vehicle because of their much smaller size compared with antibody molecules produced by conventional methods. Lidamycin (LDM) is a potent enediyne-containing antitumor antibiotic. In this study an engineered and energized fusion protein VL-LDP-AE composed of lidamycin and VL domain of mAb 3G11 directed against type IV collagenase was prepared using a novel two-step method. First a VL-LDP fusion protein was constructed by DNA recombination. Secondly VL-LDP-AE was obtained by molecular reconstitution. In MTT assay, VL-LDP-AE showed potent cytotoxicity to HT-1080 cells and KB cells with IC 50 values of 8.55×10 12 and 1.70×10 11 mol/L, respectively. VL-LDP-AE showed antiangiogenic activity in chick chrorioallantoic membrane (CAM) assay and tube formation assay. In in vivo experiments, VL-LDP-AE was proved to be more effective than free LDM against the growth of subcutaneously transplanted hepatoma 22 in mice. Drugs were given intravenously on day 3 and 10 after tumor transplantation. Compared in terms of maximal tolerated doses, VL-LDP-AE at 0.25 mg/kg suppressed the tumor growth by 89.5%, LDM at 0.05 mg/kg by 69.9%, and mitomycin at 1 mg/kg by 35%. Having a molecular weight of 25.2 kDa, VL-LDP-AE was much smaller than other reported antibody-based drugs. The results suggested that VL-LDP-AE would be a promising candidate for tumor targeting therapy. And the 2-step approach could serve as a new technology platform for making a series of highly potent engineered antibody-based drugs for a variety of cancers.
Antitumor effects of an engineered and energized fusion protein consisting of an anti-CD20 scFv fragment and lidamycin
Hong Fang,QingFang Miao,ShengHua Zhang,Xin Cheng,DongSheng Xiong,YongSu Zhen
Science China Life Sciences , 2011, DOI: 10.1007/s11427-011-4143-4
Abstract: Antibody-based fusion proteins are the next generation of antibody therapies for cancer and other diseases. CD20 antigen, which is overexpressed on cell membranes in nearly 95% of cases of B-cell Non-Hodgkin’s Lymphoma, is an attractive target for the therapy of B-lymphoid malignancies. Lidamycin (LDM) is a potent enediyne-containing antitumor antibiotic that now has entered phase II clinical trials. In this study, we prepared an engineered fusion protein, scFv-LDP, consisting of an anti-CD20 scFv fragment and the apoprotein LDP of LDM using DNA recombination. After purification and refolding, scFv-LDP was found to bind specifically to CD20-positive lymphoma cells using ELISA and indirect immunofluorescent cytochemical staining assays. The energized fusion protein scFv-LDP-AE was obtained using molecular reconstitution of the active chromophore AE of LDM and scFv-LDP. MTT assay revealed potent cytotoxicity of scFv-LDP-AE to CD20-positive Raji and Daudi cells, with IC50 values of 1.21×10 11 and 6.24×10 11 mol L 1, respectively. An in vivo subcutaneous xenograft model of CD20-positive B cell lymphoma in BALB/c (nu/nu) mice was also utilized. Drugs were given intravenously on day 14 and 21 after tumor transplantation. In terms of maximal tolerated doses, scFv-LDP-AE at 0.3 mg kg 1 suppressed tumor growth by 79.3%, and LDM at 0.05 mg kg 1 by 68.6% (P<0.05). Results suggested scFv-LDP-AE could be a potential candidate for tumor-targeting therapy.
Generation and antitumor effects of an engineered and energized fusion protein VL-LDP-AE composed of single-domain antibody and lidamycin
MIAO QingFang,SHANG BoYang,OUYANG ZhiGang,LIU XiaoYun &,ZHEN YongSu,

中国科学C辑(英文版) , 2007,
Abstract: Type IV collagenase plays a pivotal role in invasion, metastasis and angiogenesis of tumor. Single domain antibodies are attractive as tumor-targeting vehicle because of their much smaller size compared with antibody molecules produced by conventional methods. Lidamycin (LDM) is a potent enediyne-containing antitumor antibiotic. In this study an engineered and energized fusion protein VL-LDP-AE composed of lidamycin and VL domain of mAb 3G11 directed against type IV collagenase was prepared using a novel two-step method. First a VL-LDP fusion protein was constructed by DNA recombination. Secondly VL-LDP-AE was obtained by molecular reconstitution. In MTT assay, VL-LDP-AE showed potent cytotoxicity to HT-1080 cells and KB cells with IC 50 values of 8.55×10 12 and 1.70×10 11 mol/L, respectively. VL-LDP-AE showed antiangiogenic activity in chick chrorioallantoic membrane (CAM) assay and tube formation assay. In in vivo experiments, VL-LDP-AE was proved to be more effective than free LDM against the growth of subcutaneously transplanted hepatoma 22 in mice. Drugs were given intravenously on day 3 and 10 after tumor transplantation. Compared in terms of maximal tolerated doses, VL-LDP-AE at 0.25 mg/kg suppressed the tumor growth by 89.5%, LDM at 0.05 mg/kg by 69.9%, and mitomycin at 1 mg/kg by 35%. Having a molecular weight of 25.2 kDa, VL-LDP-AE was much smaller than other reported antibody-based drugs. The results suggested that VL-LDP-AE would be a promising candidate for tumor targeting therapy. And the 2-step approach could serve as a new technology platform for making a series of highly potent engineered antibody-based drugs for a variety of cancers. Supported by the National High Technology Research and Development Program of China (863 Program)(Grant No. 2006AA02A255)
Suspensions Derived from Anaerobically Fermented Tilapia Offal Inhibit Fusarium oxysporum f. sp. cubense in Banana  [PDF]
Yuhan Zhou, Yuelian Liu, Qingfang Lv
Agricultural Sciences (AS) , 2018, DOI: 10.4236/as.2018.911105
Abstract: Effective control strategies are lacking for Fusarium wilt of banana crops worldwide. Here, the inhibitory efficacy of suspensions derived from Tilapia offal by anaerobic fermentation against Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4) was evaluated. Two anaerobic fermentation methods were used: 1) natural fermentation of offal (NF) and 2) fermentation of offal supplemented with 5% lime (LF). The suspensions were applied in three treatments: Plate assay, pot system, and in the field. The inhibition rate and disease index were determined. The results showed that the inhibition was significantly greater for LF than for NF on plates. In pot system and in the field, the disease index was lower for the LF group than for the NF group and was significantly lower than that of the control. Therefore, suspensions derived from anaerobically fermented offal provide a new control method for Fusarium wilt in banana.
The Syllable''''s Role in Language Production
音节在语言产生中的作用

Zhang Qingfang,
张清芳

心理科学进展 , 2005,
Abstract: 综述了音节在语言产生中的作用。首先简单介绍了音节的概念;然后介绍了两类语言产生理论关于音节存储和音节如何起作用的不同观点;第三,从实验研究的主要范式和主要问题两个方面分析了目前在语言产生领域对音节的研究成果及存在的问题。主要的研究范式有:掩蔽启动范式、重复启动范式、内隐启动范式和图画-词汇干扰实验范式。研究的主要问题有:音节是否是言语产生中的功能单位,音节在言语产生中是如何起作用的,以及音节启动效应的发生位置。最后根据汉语音节的特点,分析了汉语词汇产生中对音节的研究以及今后的研究趋势。
PfsR Is a Key Regulator of Iron Homeostasis in Synechocystis PCC 6803
Dan Cheng, Qingfang He
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0101743
Abstract: Iron is an essential cofactor in numerous cellular processes. The iron deficiency in the oceans affects the primary productivity of phytoplankton including cyanobacteria. In this study, we examined the function of PfsR, a TetR family transcriptional regulator, in iron homeostasis of the cyanobacterium Synechocystis PCC 6803. Compared with the wild type, the pfsR deletion mutant displayed stronger tolerance to iron limitation and accumulated significantly more chlorophyll a, carotenoid, and phycocyanin under iron-limiting conditions. The mutant also maintained more photosystem I and photosystem II complexes than the wild type after iron deprivation. In addition, the activities of photosystem I and photosystem II were much higher in pfsR deletion mutant than in wild-type cells under iron-limiting conditions. The transcripts of pfsR were enhanced by iron limitation and inactivation of the gene affected pronouncedly expression of fut genes (encoding a ferric iron transporter), feoB (encoding a ferrous iron transporter), bfr genes (encoding bacterioferritins), ho genes (encoding heme oxygenases), isiA (encoding a chlorophyll-binding protein), and furA (encoding a ferric uptake regulator). The iron quota in pfsR deletion mutant cells was higher than in wild-type cells both before and after exposure to iron limitation. Electrophoretic mobility shift assays showed that PfsR bound to its own promoter and thereby auto-regulated its own expression. These data suggest that PfsR is a critical regulator of iron homeostasis.
Assessment of Environmental Stresses for Enhanced Microalgal Biofuel Production – An Overview
Dan Cheng,Qingfang He
Frontiers in Energy Research , 2014, DOI: 10.3389/fenrg.2014.00026
Abstract: Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates) tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.
Study about Economic Growth Quality in Transferred Representative Areas of Midwest China  [PDF]
Jun He, Yi Yu, Qingfang Liu, Yujuan Zhang
American Journal of Industrial and Business Management (AJIBM) , 2013, DOI: 10.4236/ajibm.2013.32019
Abstract:

Malmquist productivity index (output based) and stochastic frontier production model are used to calculate the total factor productivity and decomposition index of 21 cities in transferred representative area and Shanghai. This paper also uses Tobit model to reveal influencing factors of production efficiency, taking Anhui Province as an example. The result shows that, growth of total factor productivity has been mainly brought by technology progress. Reducing of technology efficiency can hinder its growth. Development gap between Midwest China and developed areas owns to technology efficiency gap. The efficiency has a positive correlation with share of state-owned enterprise total in industrial output value, opening degree, human resources level and infrastructure level. At the same time, it negatively correlates with the share of government spending in GDP. The efficiency is uncorrelated with export and the proportion of science and technology spending accounts for fiscal expenditure.

Pruned Volterra Models with Memory Effects for Nonlinear Power Amplifiers  [PDF]
Pengpeng Li, Qingfang Zhang, Ping Wang, Zhongshan Xie, Bing Liu
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53B2102
Abstract:

In this letter, a novel model is proposed for modeling the nonlinearity and memory effects of power amplifiers. The classical Volterra model is modified through a function of the sum of nonlinearity order with sum of memory length. The parameters of this model can be extracted in digital domain since the model is analyzed based on the envelope signals. The model we proposed enables a substantial reduction in the number of coefficients involved, and with excellent accuracy.

Application of Hierarchical Model in Non-Life Insurance Actuarial Science  [PDF]
Guiming Miao
Modern Economy (ME) , 2018, DOI: 10.4236/me.2018.93025
Abstract: Loss data structures in non-life insurance businesses are increasingly complex, and the tendency of correlation and heterogeneity is gradually presented. Hierarchical model can breakthrough limitation that the traditional rate determination method only analyzes the loss data of the same insurance policy; meanwhile, the accuracy of complex structure data prediction is improved. This paper, using a hierarchical generalized linear model, studies the non-life rate determination of multi-year loss data and takes auto insurance data for empirical analysis. The research results show that GLMM’s fitting degree is greatly improved compared with GLM, considering the random effects. It can more effectively reflect different risk individual differences and also reveal the heterogeneity and correlation of risk individual loss during multiple insurance periods.
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