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71.
Reyhaneh Hoseinpoor Seyed Latif Mousavi Gargari Iraj Rasooli Masoumeh Rajabibazl Bahareh Shahi 《Applied biochemistry and biotechnology》2014,172(6):3079-3091
Manipulation of clinically significant antibodies can effectively improve the processes of diagnosis and treatment. Affinity maturation process has a significant role in improvement of antibodies efficiency. Error-prone PCR technique is one of the proposed methods for improvement of the affinity of antibodies. In the present research, a method was applied to camel heavy-chain antibody (VHH, nanobody) raised against UreC subunit of urease enzyme from Helicobacter pylori. This VHH was used as a starting molecule to construct a highly diversified phage displayed VHH library. The constructed library of nanobody mutants was subjected to several rounds of panning against UreC antigen. High-affinity mutant was selected. Our VHH (HMR23) showed 1.5-fold higher binding activity than the parental VHH. In addition, the mutant VHH presented a better performance in inhibition of urease activity at low concentrations retaining its specificity and thermal stability. 相似文献
72.
Phillip Zellner Tyler Shake Ali Sahari Bahareh Behkam Masoud Agah 《Analytical and bioanalytical chemistry》2013,405(21):6657-6666
In this study, we report the first off-chip passivated-electrode, insulator-based dielectrophoresis microchip (OπDEP). This technique combines the sensitivity of electrode-based dielectrophoresis (eDEP) with the high-throughput and inexpensive device characteristics of insulator-based dielectrophoresis (iDEP). The device is composed of a permanent, reusable set of electrodes and a disposable, polymer microfluidic chip with microposts embedded in the microchannel. The device operates by capacitively coupling the electric fields into the microchannel; thus, no physical connections are made between the electrodes and the microfluidic device. During operation, the polydimethylsiloxan (PDMS) microfluidic chip fits onto the electrode substrate as a disposable cartridge. OπDEP uses insulting structures within the channel as well as parallel electrodes to create DEP forces by the same working principle that iDEP devices use. The resulting devices create DEP forces which are larger by two orders of magnitude for the same applied voltage when compared to off-chip eDEP designs from literature, which rely on parallel electrodes alone to produce the DEP forces. The larger DEP forces allow the OπDEP device to operate at high flow rates exceeding 1 mL/h. In order to demonstrate this technology, Escherichia coli (E. coli), a known waterborne pathogen, was trapped from water samples. Trapping efficiencies of 100 % were obtained at flow rates as high as 400 μL/h and 60 % at flow rates as high as 1200 μL/h. Additionally, bacteria were selectively concentrated from a suspension of polystyrene beads. Figure
Selective E. coli trapping in the cartridge based OπDEP device. 相似文献
73.
Bahareh DabirmaneshKhosro Khajeh Jafar AkbariHanieh Falahati Somayeh DaneshjooAkbar Heydari 《Journal of Molecular Liquids》2011,161(3):139-143
The use of ionic liquids to replace organic solvents in biocatalytic processes has recently gained much attention. Despite the wide applications of oxidoreductases, there are few reports of their catalyzed reaction in ionic liquid. We have investigated the influence of four water miscible ionic liquids on the activity, stability and structure of the mesophilic alcohol dehydrogenase from yeast. Upon changes in ionic liquids concentration, both activity and stability of the enzyme were affected. As the concentration of ionic liquids increased, Km increased while kcat decreased. Associated conformational changes caused by ILs (150 mM) were monitored using fluorescence technique. Finally, the effects of ILs cations and anions on the enzyme activity and stability in aqueous IL mixtures were discussed. 相似文献
74.
A new synthetic receptor has selective and strong interactions with glucose, directing towards future diabetes management. These studies pave the way to design future selective receptors that can potentially be modified with combinations of urea walls having multiple H-binding sites to generate hydrophilic affinities, and the incorporation of promising aromatic systems for hydrophobic π-interactions with glucose CH. 相似文献
75.
76.
Lawal Monsurat M. Sanusi Zainab K. Govender Thavendran Tolufashe Gideon F. Maguire Glenn E. M. Honarparvar Bahareh Kruger Hendrik G. 《Structural chemistry》2019,30(1):409-417
Structural Chemistry - We give an account of a one-step concerted catalytic mechanism of HIV-1 protease (PR) hydrolysis of its natural substrate using a hybrid QM/MM method. The mechanism is a... 相似文献
77.
Mohammad Hossein Habibi Bahareh Karimi 《Journal of Thermal Analysis and Calorimetry》2014,115(1):419-423
A sol–gel route to synthesize copper oxide nanoparticles with an average size of ca. 63 nm from copper acetate precursor and monoethanolamine as the capping agent is reported. Structural characterization showed the formation of a cubic phase for CuO. The effect of annealing temperature on formation of crystalline phases was investigated. Characterization of the products was performed using thermo-gravimetric analysis, X-ray diffraction, field emission scanning electron microscopy, and diffuse reflectance. The results showed that there are significant differences in the morphological, crystallographic, structural, and optical properties of the nanostructures prepared at different annealing temperatures. The optical properties and band gap of CuO nanoparticles were studied by UV–Vis spectroscopy. According to the results of the optical measurements, the band gap is estimated to be 1.41 eV. These results showed that the band gap energy changed with increase of annealing temperature, which can be attributed to the change in grain size of the samples. 相似文献
78.
Yasmine Abtahi 《Research in Mathematics Education》2018,20(1):1-13
In this article, I use the Vygotskian concept of the Zone of Proximal Development (ZPD) to examine the learning experience of two grade seven pupils as they attempted to solve an addition of fractions problem using fraction strips. The aim is to highlight how tools can facilitate the enactment of a ZPD, within which the tool provides the guidance. Viewing the ZPD as a zone that allows for the emergence of various forms of guided talk and actions, I present a detailed analysis of a short video-recording of the pupils’ participation in a tool-mediated problem-solving activity. I show how their knowing of the concept of fractions and their perceptions of the affordances of the fraction strips marked what they said and did. I conclude by suggesting that the ZPD emerges through participation and interaction, not only between individuals but also between individuals and tools. 相似文献
79.
We introduce and study strict, uniform, and compact-open locally convex topologies on an algebra \({\mathcal {B}},\) by the fundamental system of seminorms of a locally convex subalgebra \(({\mathcal {A},p}_\alpha )\). Moreover, we investigate when \({\mathcal {B}}\) is a locally convex algebra with respect to these topologies. Furthermore, we generalize an essential result related to derivations, from Banach to the Fréchet case. Finally we provide a useful example in this field. 相似文献
80.
Let G be a locally compact group, ω be a weight function on G and 1 < p < ∞. Here, we give a sufficient condition for that the weighted L
p
-space L
p
(G, ω) is a Banach algebra. Also, we get some necessary conditions on G and the weight function ω for L
p
(G, ω) to be a Banach algebra. As a consequence, we show that if G is abelian and L
p
(G, ω) is a Banach algebra, then G is σ-compact. 相似文献