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291.
292.
Dijo Damien Kalaivanan Nagarajan Ashish Raj Mahesh Hariharan Manikoth M. Shaijumon 《Liver Transplantation》2017,7(20)
Organic rechargeable batteries gain huge scientific interest owing to the design flexibility and resource renewability of the active materials. However, the low reduction potentials still remain a challenge to compete with the inorganic cathodes. This study demonstrates a simple and efficient approach to tune the redox properties of perylene diimides (PDIs) as high voltage cathodes for organic‐based sodium‐ion batteries (SIBs). With appropriate electron‐withdrawing groups as substituents on perylene diimides, this study shows a remarkable tunability in the discharge potential from 2.1 to 2.6 V versus Na+/Na with a sodium intake of ≈1.6 ions per molecule. Further, this study explores tuning the shape of the voltage profiles by systematically tuning the dihedral angle in the perylene ring and demonstrates a single plateau discharge profile for tetrabromo‐substituted perylene diimide (dihedral angles θ1 & θ2 = 38°). Detailed structural analysis and electrochemical studies on substituted PDIs unveil the correlation between molecular structure and voltage profile. The results are promising and offer new avenues to tailor the redox properties of organic electrodes, a step closer toward the realization of greener and sustainable electrochemical storage devices. 相似文献
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295.
Jong Wan Bae Seunghee Shin S. Mohan Raj Song Eun Lee Sun-Gu Lee Yong-Joo Jeong Sunghoon Park 《Biotechnology and Bioprocess Engineering》2008,13(1):69-76
A recombinant Escherichia coli (pBAB1) containing styrene monooxygenase (SMO) was developed for the conversion of styrene to enantiopure (S)-styrene oxide that is an important chiral building block in organic synthesis. The styAB genes encoding SMO was cloned into a multicopy plasmid under the tightly regulated promoter of bacterial l-arabinose operon which is inducible by l-arabinose. The recombinant showed that expression level of StyA protein and whole-cell SMO activities were varied depending
on the concentration of the inducer l-arabinose. The maximum SMO activity was 108 U/g cdw when the cells were induced with 0.2% l-arabinose. SDS-PAGE and Western blot analyses indicated that whole-cell SMO activity was strongly correlated with the expression
level of StyA protein. Organic-aqueous two-phase experiment could yield 50 mM enantiopure (S)-styrene oxide in organic phase in 18 h, but the recombinant SMO activity was unstable during the reaction. The expression
of styAB under the control of l-arabinose promoter was significantly repressed in the presence of glucose. 相似文献
296.
In view of rising prices of crude oil due to increasing fuel demands, the need for alternative sources of bioenergy is expected
to increase sharply in the coming years. Among potential alternative bioenergy resources, lignocellulosics have been identified
as the prime source of biofuels and other value-added products. Lignocelluloses as agricultural, industrial and forest residuals
account for the majority of the total biomass present in the world. To initiate the production of industrially important products
from cellulosic biomass, bioconversion of the cellulosic components into fermentable sugars is necessary. A variety of microorganisms
including bacteria and fungi may have the ability to degrade the cellulosic biomass to glucose monomers. Bacterial cellulases
exist as discrete multi-enzyme complexes, called cellulosomes that consist of multiple subunits. Cellulolytic enzyme systems
from the filamentous fungi, especially Trichoderma reesei, contain two exoglucanases or cellobiohydrolases (CBH1 and CBH2), at least four endoglucanases (EG1, EG2, EG3, EG5), and
one β-glucosidase. These enzymes act synergistically to catalyse the hydrolysis of cellulose. Different physical parameters
such as pH, temperature, adsorption, chemical factors like nitrogen, phosphorus, presence of phenolic compounds and other
inhibitors can critically influence the bioconversion of lignocellulose. The production of cellulases by microbial cells is
governed by genetic and biochemical controls including induction, catabolite repression, or end product inhibition. Several
efforts have been made to increase the production of cellulases through strain improvement by mutagenesis. Various physical
and chemical methods have been used to develop bacterial and fungal strains producing higher amounts of cellulase, all with
limited success. Cellulosic bioconversion is a complex process and requires the synergistic action of the three enzymatic
components consisting of endoglucanases, exoglucanases and β-glucosidases. The co-cultivation of microbes in fermentation
can increase the quantity of the desirable components of the cellulase complex. An understanding of the molecular mechanism
leading to biodegradation of lignocelluloses and the development of the bioprocessing potential of cellulolytic microorganisms
might effectively be accomplished with recombinant DNA technology. For instance, cloning and sequencing of the various cellulolytic
genes could economize the cellulase production process. Apart from that, metabolic engineering and genomics approaches have
great potential for enhancing our understanding of the molecular mechanism of bioconversion of lignocelluloses to value added
economically significant products in the future.
JIMB 2008: BioEnergy - Special issue. 相似文献
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298.
We describe a method for imaging individual mRNA molecules in fixed cells by probing each mRNA species with 48 or more short, singly labeled oligonucleotide probes. This makes each mRNA molecule visible as a computationally identifiable fluorescent spot by fluorescence microscopy. We demonstrate simultaneous detection of three mRNA species in single cells and mRNA detection in yeast, nematodes, fruit fly wing discs, and mammalian cell lines and neurons. 相似文献
299.
Raj Kumar Koiri Surendra Kumar Trigun Santosh Kumar Dubey Santosh Singh Lallan Mishra 《Biometals》2008,21(2):117-126
Metal complex–protein interaction is an evolving concept for determining cellular targets of metallodrugs. Lacatate dehydrogenase
(LDH) is critically implicated in tumor growth and therefore, considered to be an important target protein for anti-tumor
metal complexes. Due to efficient biocompatibility of copper (Cu2+) and zinc (Zn2+), we synthesized CubpyAc2 · H2O (Cu-bpy) and ZnbpyAc2 · H2O (Zn-bpy; where bpy = 2,2′ bipyridine, Ac = CH3COO−) complexes and evaluated their interaction with and modulation of LDH in mouse tissues. The increasing concentration of both
the complexes showed a significant shift in UV–Vis spectra of LDH. The binding constant data (Kc = 1 × 103 M−1 for Cu-bpy and 7 × 106 M−1 for Zn-bpy) suggested that Zn-bpy-LDH interaction is stronger than that of Cu-bpy-LDH. LDH modulating potential of the complexes
were monitored by perfusing the mice tissues with non-toxic doses of Cu-bpy and Zn-bpy followed by activity measurement and
analysis of LDH isozymes on non-denaturing polyacrylamide gel electrophoresis (PAGE). As compared to the control sets, Cu-bpy
caused a significant decline (P < 0.05–0.001) in the activity of LDH in all the tissues studied. However, Zn-bpy showed inhibition of LDH only in liver (P < 0.01), kidney (P < 0.001) and heart (P < 0.01), but with no effect in spleen, brain and skeletal muscle tissues. PAGE analysis suggested that all the five LDH isozymes
are equally sensitive to both the complexes in the respective tissues. The results suggest that Cu- and Zn-bpy are able to
interact with and inhibit LDH, a tumor growth supportive target protein at tissue level. 相似文献
300.
Wright CM Chovatiya RJ Jameson NE Turner DM Zhu G Werner S Huryn DM Pipas JM Day BW Wipf P Brodsky JL 《Bioorganic & medicinal chemistry》2008,16(6):3291-3301
The Hsp70 molecular chaperones are ATPases that play critical roles in the pathogenesis of many human diseases, including breast cancer. Hsp70 ATP hydrolysis is relatively weak but is stimulated by J domain-containing proteins. We identified pyrimidinone-peptoid hybrid molecules that inhibit cell proliferation with greater potency than previously described Hsp70 modulators. In many cases, anti-proliferative activity correlated with inhibition of J domain stimulation of Hsp70. 相似文献