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排序方式: 共有178条查询结果,搜索用时 15 毫秒
1.
Seyedeh Hoda Jazayeri Amir Amiri-Yekta Salahadin Bahrami Hamid Gourabi Mohammad Hossein Sanati Mohammad Reza Khorramizadeh 《Applied biochemistry and biotechnology》2018,185(4):986-1003
The rapid growth of global biopharmaceutical market in the recent years has been a good indication of its significance in biotechnology industry. During a long period of time in recombinant protein production from 1980s, optimizations in both upstream and downstream processes were launched. In this regard, one of the most promising strategies is expression vector engineering technology based on incorporation of DNA opening elements found in the chromatin border regions of vectors as well as targeting gene integration. Along with these approaches, cell line engineering has revealed convenient outcomes in isolating high-producing clones. According to the fact that more than 50% of the approved therapeutic proteins is being manufactured in mammalian cell lines, in this review, we focus on several approaches and developments in vector and cell line engineering technologies in mammalian cell culture. 相似文献
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Antibacterial and antibiofilm activity of nanochelating based silver nanoparticles against several nosocomial pathogens 下载免费PDF全文
Seyedeh Mahsan Hoseini‐Alfatemi Abdollah Karimi Shahnaz Armin Saideh Fakharzadeh Fatemeh Fallah Somayeh Kalanaky 《应用有机金属化学》2018,32(5)
The emergence of multi‐drug resistant (MDR) bacteria and dynamic pattern of infectious diseases demand to develop alternative and more effective therapeutic strategies. Silver nanoparticles (AgNPs) are among the most widely commercialized engineered nanomaterials, because of their unique properties and increasing use for various applications in nanomedicine. This study for the first time aimed to evaluate the antibacterial and antibiofilm activities of newly synthesized nanochelating based AgNPs against several Gram‐positive and ‐negative nosocomial pathogens. Nanochelating technology was used to design and synthesize the AgNPs. The cytotoxicity was tested in human cell line using the MTT assay. AgNPs minimal inhibitory concentration (MIC) was determined by standard broth microdilution. Antibiofilm activity was assayed by a microtiter‐plate screening method. The two synthesized AgNPs including AgNPs (A) with the size of about 20‐25 nm, and AgNPs (B) with 30‐35 nm were tested against Staphylococcus aureus, Staphylococcus epidermidis, Acinetobacter baumannii, and Pseudomonas aeruginosa. AgNPs exhibited higher antibacterial activity against Gram‐positive strains. AgNPs were found to significantly inhibit the biofilm formation of tested strains in concentration 0.01 to 10 mg/mL. AgNPs (A) showed significant effective antibiofilm activity compared to AgNPs (B). In summary, our results showed the promising antibacterial and antibiofilm activity of our new nanochelating based synthesized AgNPs against several nosocomial pathogens. 相似文献
4.
Sherif Zein El Abedin 《Journal of Solid State Electrochemistry》2012,16(2):775-783
The electrochemical behaviors of pure Al, Al–6%Si, Al–3%Cu, and Al–3.7%Cu–0.9%Mg–0.8%Pb–0.6%Fe alloys were investigated in
the chloroaluminate ionic liquids 1-butyl-3-methylimidazolium chloride [BMIm]Cl/AlCl3 (40/60 mol%) and 1-ethyl-3-methylimidazolium chloride [EMIm]Cl/AlCl3 (40/60 mol%). Electrolytic extraction of copper from Al–Cu alloys in the employed ionic liquids was explored. The alloys
were anodically dissolved in the ionic liquids and then pure copper was recovered under potentiostatic conditions. Due to
the large difference between the deposition potentials of Cu and Al, pure Cu can be obtained without Al contamination. Electrorefining
of Al–3%Cu and Al–6%Si alloys was also investigated in [BMIm]Cl/AlCl3 (40/60 mol%) at room temperature. High purity aluminum deposits were obtained with significantly low energy consumption of
about 2 kWh/kg of Al. 相似文献
5.
Seyedeh Parinaz Akhlaghi Richard C. Berry Kam C. Tam 《Cellulose (London, England)》2013,20(4):1747-1764
A novel drug delivery system based on two of the most abundant natural biopolymers was developed by modifying the surface of oxidized cellulose nanocrystal (CNC) with chitosan oligosaccharide (CSOS). First, the primary alcohol moieties of CNC were selectively oxidized to carboxyl groups using the 2,2,6,6-tetramethylpiperidine-1-oxyl radical catalyst. The amino groups of CSOS were then reacted with carboxylic acid groups on oxidized CNC (CNC-OX) via the carbodiimide reaction using N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide as coupling agents. Successful grafting of CSOS to CNC-OX was confirmed by infrared spectroscopy, thermogravimetry, potentiometric titration, and zeta potential measurements. The grafting resulted in a conversion of ~90 % carboxyl groups on CNC-OX and the degree of substitution was 0.26. CNC–CSOS nanoparticles showed a binding efficiency of 21.5 % and a drug loading of 14 % w/w. A drug selective electrode was used to directly measure the concentration of procaine hydrochloride released from CNC–CSOS particles. The in vitro drug release was studied at pH 8 and the nanoparticles revealed a fast release of up to 1 h, which can be used as biocompatible and biodegradable drug carriers for transdermal delivery applications. 相似文献
6.
The changes in the local and global dynamics of azide-labelled lysozyme compared with that of the wild type protein are quantitatively assessed for all alanine residues along the polypeptide chain. Although attaching -N to alanine residues has been considered to be a minimally invasive change in the protein it is found that depending on the location of the alanine residue, the local and global changes in the dynamics differ. For Ala92, the change in the cross-correlated motions are minimal, whereas attaching -N to Ala90 leads to pronounced differences in the local and global correlations as quantified by the cross-correlation coefficients of the C atoms. We also demonstrate that the spectral region of the asymmetric azide stretch distinguishes between alanine attachment sites, whereas changes in the low frequency, far-infrared region are less characteristic. 相似文献
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A.S. Ismail S. Zein El Abedin O. Höfft F. Endres 《Electrochemistry communications》2010,12(7):909-911
In this letter we report on the decomposition of the bis (trifluoromethylsulfonyl) amide (TFSA) anion under quite mild electrochemical conditions. The results show clearly that the TFSA anion can easily be decomposed during anodic oxidation of copper in the ionic liquid 1-butyl-1-methylpyrrolidinium bis (trifluoromethylsulfonyl) amide [BMP] TFSA at 70 °C leading to the formation of CuF2. At room temperature, however, no significant decomposition was obtained. Therefore, one has to be very careful in applying ionic liquids based on TFSA anions under anodic conditions at elevated temperature as the TFSA anion might decompose, depending on the anode material. 相似文献
9.
Ramin Ghorbani-Vaghei Seyedeh Mina Malaekehpour 《Central European Journal of Chemistry》2010,8(5):1086-1089
N,N,N,’N’-Tetrabromobenzene-1,3-disulfonamide [TBBDA] is found to be a reusable catalyst for efficient synthesis of various amidoalkyl
naphthols from β-naphthol, aromatic aldehydes and urea in good to high yields under solvent-free conditions.
相似文献
10.
A novel, cost‐effective, and simple electrocatalyst based on a Pt‐modified glassy carbon electrode (GCE), using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, is reported. Am‐phiphilic... 相似文献