Preparation and Characterization of A Semi-interpenetrating Network Alkaline Anion Exchange Membrane

Yifu Wang,Heting Wan,Dan Wang,Jilin Wang,Lulu Wang,Ruijiang Feng 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

A series of semi-interpenetrating network (semi-IPN) anion exchange membranes (QCS/St-G8-2-8, Quaternized chitosan/styrene-[maleic alkylene group diethyl bis (octyl dimethyl chloro/bromide), abbreviated as G8-2-8] were prepared via in-situ polymerization by Styrene (St) and G8-2-8 in QCS casting solution. During the process of in-situ polymerization, linearblock polymers (St-G8-2-8) of Styrene and G8-2-8 was constructed, then was mixed with QCS casting solution, followed crosslinking the QCS by glutaraldehyde (GA). With the increasing content of linear block polymer, water uptake and swelling ratio of the composite membrane decreased; This kind of linear structure makes an order arrangement of quaternaryammonium groups which improves the OH− migration efficiency. At 70 oC, the M-30 composite membrane performs a high OH− conductivity of 8.20×10-2 S·cm-1, the methanol permeability is 3.23×10-6 cm-2·s-1 which is still lower than Nafion 115 of 2.42×10-6 cm-2·s-1, but M-30 shows a higher selectivity of 25.3 than Nafion 115 of 11.6. Furthermore, the membranes exhibited excellent thermal stability (≥150 oC), the tensile strength of the composite membrane is in the range of 14-25 MPa and elongation at break is in the range of 16-37 % at room temperature, as well as superior chemical stability in 1.0 M KOH solution for 250 h.

Design and Implementation of a Novel Horizontal AFM Probe Utilizing a Quartz Tuning Fork

Yifu Chen,Yingzi Li,Guanqiao Shan,Yingxu Zhang,Zhenyu Wang,Mubing Wang,Hua Li,Jianqiang Qian 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.1

This paper presents a new structure of a novel horizontal atomic force microscope probe utilizing a quartz tuning fork. The horizontal structure exhibits high resistance to environmental noise, and thus the probe can maintain good stability throughout the imaging work. The quartz tuning fork, which is utilized as a force sensor due to its simple mechanical structure and self-actuating and self-sensing characteristics, can significantly simplify the mechanical structure of the probe. The probe is divided into three parts: an approximation device, a force sensor, and a three-dimensional scanner. Each part is carefully designed to guarantee the imaging performance. It is verified that the proposed horizontal AFM probe is stable by conducting finite-element analysis, including modal analysis and noise analysis. Furthermore, the probe is fabricated and the experiments are performed to verify its stability. The proposed horizontal AFM probe combined with the existing control system in the frequency modulation succeeds in imaging within 25 μm × 25 μm and 20 μm × 20 μm ranges stably.

Facile hydrothermal synthesis of ultrahigh-aspect-ratio V2O5 nanowires for high-performance supercapacitors

Nannan Wang,Yifu Zhang,Tao Hu,Yunfeng Zhao,Changgong Meng 한국물리학회 2015 Current Applied Physics Vol.15 No.4

Ultrahigh-aspect-ratio V2O5 nanowires were successfully prepared using [VO(O2)2(OH2)]- as the starting material by a template-free hydrothermal route without the addition of organic surfactant or inorganic ions. The prepared samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmet-Teller (BET), cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). The results revealed that the peroxovanadium (V) complexes can be easily transformed to V2O5 nanowires by this hydrothermal route. The uniform nanowires were with width about 50 nm and length about dozens of micron. The BET analysis showed the V2O5 nanowires had a high specific surface area of 25.6 m2 g-1. The synthesized V2O5 nanowires performed a high capacitance of 351 F g-1 when used as supercapacitor electrode in 1 mol L-1 LiNO3.

Cloning and Functional Analysis of a cDNA Encoding Ginkgo biloba Farnesyl Diphosphate Synthase

Kexuan Tang,Peng Wang,Zhihua Liao,Liang Guo,Wenchao Li,Min Chen,Yan Pi,Yifu Gong,Xiaofen Sun 한국분자세포생물학회 2004 Molecules and cells Vol.18 No.2

Farnesyl diphosphate synthase (FPS; EC2.5.1.1/EC2. 5.1.10) catalyzes the synthesis of farnesyl diphosphate, and provides precursor for biosynthesis of sesquiterpene and isoprenoids containing more than 15 isoprene units in Ginkgo biloba. Here we report the cloning, characterization and functional analysis of a new cDNA encoding FPS from G. biloba. The full-length cDNA (designated GbFPS) had 1731 bp with an open reading frame of 1170 bp encoding a polypeptide of 390 amino acids. The deduced GbFPS was similar to other known FPSs and contained all the conserved regions of trans-prenyl chain-elongating enzymes. Structural modeling showed that GbFPS had the typical structure of FPS, the most prominent feature of which is the arrangement of 13 core helices around a large central cavity. Southern blot analysis revealed a small FPS gene family in G. biloba. Expression analysis indicated that GbFPS expression was high in roots and leaves, and low in stems. Functional complementation of GbFPS in an FPS-deficient strain confirmed that GbFPS mediates farnesyl diphosphate biosynthesis.

A Two-Dimensional Risk Assessment Method for Oil and Gas Pipelines Based on “Accident Probability–Reputation Loss”

Chen Xuefeng,Chen Wentao,Zhang Yifu,Peng Bin,Wang Yuling,Xu Mingwei 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.1

Oil and gas pipeline accidents not only caused personnel casualties, economic losses and environmental pollution but also brought great panic to the public. To provide accurate accident prevention strategies, risk assessment (RA) has been widely used in the oil and gas pipeline industry. It aims to quantify the potential risk due to unexpected eventualities. However, the current RA methods mainly pay attention to the tangible risk (such as the human safety risk, economic risk and environmental risk), and the intangible risk (such as reputation loss risk) is often neglected. This cannot refl ect the real risk for the oil and gas pipeline. To settle existing research limitation, a two-dimensional risk assessment method for oil and gas pipelines based on “accident probability–reputation loss” is proposed. The method mainly involves four steps, namely, risk identifi cation, probability calculation, consequence assessment and risk assessment. The proposed method is used to quantitatively assess a natural gas pipeline in central China. Its results indicate that pipeline risk is unacceptable due to the unacceptability of accident probability and various dimensions of risk. Therefore, this study can enrich and develop the current oil and gas pipeline RA method to refl ect the real risk of oil and gas pipeline accidents.

Glucosamine induces cell death via proteasome inhibition in human ALVA41 prostate cancer cell

Bao-Qin Liu,Hua-Qin Wang,Xin Meng,Chao Li,Yan-Yan Gao,Ning Li,Xiao-Fang Niu,Yifu Guan 생화학분자생물학회 2011 Experimental and molecular medicine Vol.43 No.9

Glucosamine, a naturally occurring amino monosaccharide,has been reported to play a role in the regulation of apoptosis more than half century. However the effect of glucosamine on tumor cells and the involved molecular mechanisms have not been thoroughly investigated. Glucosamine enters the hexosamine biosynthetic pathway (HBP) downstream of the rate-limiting step catalyzed by the GFAT (glutamine:fluctose-6-phosphate amidotransferase), providing UDPGlcNAc substrates for O-linked β-N-acetylglucosamine (O-GlcNAc) protein modification. Considering that O-GlcNAc modification of proteasome subunits inhibits its activity, we examined whether glucosamine induces growth inhibition via affecting proteasomal activity. In the present study, we found glucosamine inhibited proteasomal activity and the proliferation of ALVA41 prostate cancer cells. The inhibition of proteasomal activity results in the accumulation of ubiquitinated proteins, followed by induction of apoptosis. In addition, we demonstrated that glucosamine downregulated proteasome activator PA28γ and overexpression of PA28γ rescued the proteasomal activity and growth inhibition mediated by glucosamine. We further demonstrated that inhibition of O-GlcNAc abrogated PA28γ suppression induced by glucosamine. These findings suggest that glucosamine may inhibit growth of ALVA41 cancer cells through downregulation of PA28γ and inhibition of proteasomal activity via O-GlcNAc modification.

Molecular Cloning and Characterization of a Novel Stem-specific Gene from Camptotheca acuminata

Pi, Yan,Liao, Zhihua,Chai, Yourong,Zeng, Hainian,Wang, Peng,Gong, Yifu,Pang, Yongzhen,Sun, Xiaofen,Tang, Kexuan Korean Society for Biochemistry and Molecular Biol 2006 Journal of biochemistry and molecular biology Vol.39 No.1

In higher plants, P450s participate in the biosynthesis of many important secondary metabolites. Here we reported for the first time the isolation of a new cytochrome P450 cDNA that expressed in a stem-specific manner from Camptotheca acuminata (designated as CaSS), a native medicinal plant species in China, using RACE-PCR. The full-length cDNA of CaSS was 1735 bp long containing a 1530 bp open reading frame (ORF) encoding a polypeptide of 509 amino acids. Bioinformatic analysis revealed that CASS contained a heme-binding domain PFGXGRRXCX and showed homology to other plant cytochrome P450 monooxygenases and hydroxylases. Southern blotting analysis revealed that there was only one copy of the CaSS present in the genome of Camptotheca acuminata. Northern blotting analysis revealed that CaSS expressed, in a tissue-specific manner, highly in stem and lowly in root, leaf and flower. Our study suggests that CaSS is likely to be involved in the phenylpropanoid pathway.

Molecular Cloning and Characterization of a Novel Stem-specificGene from Camptotheca acuminata

Yan Pi,Hainian Zeng,Yongzhen Pang,Kexuan Tang,Zhihua Liao,Yourong Chai,Peng Wang,Yifu Gong,Xiaofen Sun 한국생화학분자생물학회 2006 BMB Reports Vol.39 No.1

Glucosamine induces cell death $via$ proteasome inhibition in human ALVA41 prostate cancer cell

Liu, Bao-Qin,Meng, Xin,Li, Chao,Gao, Yan-Yan,Li, Ning,Niu, Xiao-Fang,Guan, Yifu,Wang, Hua-Qin Korean Society for Biochemistry and Molecular Bion 2011 Experimental and molecular medicine Vol.43 No.9

Glucosamine, a naturally occurring amino monosaccharide, has been reported to play a role in the regulation of apoptosis more than half century. However the effect of glucosamine on tumor cells and the involved molecular mechanisms have not been thoroughly investigated. Glucosamine enters the hexosamine biosynthetic pathway (HBP) downstream of the rate-limiting step catalyzed by the GFAT (glutamine:fluctose- 6-phosphate amidotransferase), providing UDP-GlcNAc substrates for O-linked ${\beta}$-N-acetylglucosamine (O-GlcNAc) protein modification. Considering that O-GlcNAc modification of proteasome subunits inhibits its activity, we examined whether glucosamine induces growth inhibition $via$ affecting proteasomal activity. In the present study, we found glucosamine inhibited proteasomal activity and the proliferation of ALVA41 prostate cancer cells. The inhibition of proteasomal activity results in the accumulation of ubiquitinated proteins, followed by induction of apoptosis. In addition, we demonstrated that glucosamine downregulated proteasome activator $PA28{\gamma}$ and overexpression of $PA28{\gamma}$ rescued the proteasomal activity and growth inhibition mediated by glucosamine. We further demonstrated that inhibition of O-GlcNAc abrogated $PA28{\gamma}$ suppression induced by glucosamine. These findings suggest that glucosamine may inhibit growth of ALVA41 cancer cells through downregulation of $PA28{\gamma}$ and inhibition of proteasomal activity via O-GlcNAc modification.

Tunicamycin enhances TRAIL-induced apoptosis by inhibition of cyclin D1 and the subsequent downregulation of survivin

Hai-Yan Zhang,Zhen-Xian Du,Bao-Qin Liu,Yan-Yan Gao,Xin Meng,Yifu Guan,Wei-Wei Deng,Hua-Qin Wang 생화학분자생물학회 2009 Experimental and molecular medicine Vol.41 No.5

TNF-related apoptosis-inducing ligand (TRAIL) has been proposed as a promising cancer therapy that preferentially induces apoptosis in cancer cells, but not most normal tissues. However, many cancers are resistant to TRAIL by mechanisms that are poorly understood. In this study, we showed that tunicamycin, a naturally occurring antibiotic, was a potent enhancer of TRAIL-induced apoptosis through downregulation of survivin. The tunicamycin-mediated sensitization to TRAIL was efficiently reduced by forced expression of survivin, suggesting that the sensitization was mediated at least in part through inhibition of survivin expression. Tunicamycin also repressed expression of cyclin D1, a cell cycle regulator commonly overexpressed in thyroid carcinoma. Furthermore, silencing cyclin D1 by RNA interference reduced survivin expression and sensitized thyroid cancer cells to TRAIL; in contrast, forced expression of cyclin D1 attenuated tunicamycin-potentiated TRAIL-induced apoptosis via over-riding downregulation of survivin. Collectively, our results demonstrated that tunicamycin promoted TRAIL-induced apoptosis, at least in part, by inhibiting the expression of cyclin D1 and subsequent survivin. Of note, tunicamycin did not sensitize the differentiated thyroid epithelial cells to TRAIL-induced apoptosis. Thus, combined treatment with tunicamycin and TRAIL may offer an attractive strategy for safely treating resistant thyroid cancers. TNF-related apoptosis-inducing ligand (TRAIL) has been proposed as a promising cancer therapy that preferentially induces apoptosis in cancer cells, but not most normal tissues. However, many cancers are resistant to TRAIL by mechanisms that are poorly understood. In this study, we showed that tunicamycin, a naturally occurring antibiotic, was a potent enhancer of TRAIL-induced apoptosis through downregulation of survivin. The tunicamycin-mediated sensitization to TRAIL was efficiently reduced by forced expression of survivin, suggesting that the sensitization was mediated at least in part through inhibition of survivin expression. Tunicamycin also repressed expression of cyclin D1, a cell cycle regulator commonly overexpressed in thyroid carcinoma. Furthermore, silencing cyclin D1 by RNA interference reduced survivin expression and sensitized thyroid cancer cells to TRAIL; in contrast, forced expression of cyclin D1 attenuated tunicamycin-potentiated TRAIL-induced apoptosis via over-riding downregulation of survivin. Collectively, our results demonstrated that tunicamycin promoted TRAIL-induced apoptosis, at least in part, by inhibiting the expression of cyclin D1 and subsequent survivin. Of note, tunicamycin did not sensitize the differentiated thyroid epithelial cells to TRAIL-induced apoptosis. Thus, combined treatment with tunicamycin and TRAIL may offer an attractive strategy for safely treating resistant thyroid cancers.