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481.
Pooja Singh Othman Sulaiman Rokiah Hashim P. F. Rupani Leh Cheu Peng 《Reviews in Environmental Science and Biotechnology》2010,9(2):141-151
Biopulping can be an alternative to the traditional methods of pulping. Biopulping use fungi that are known to be able to degrade wood as well as lignin constituent of wood. Amongst these white
rot fungi are the most proficient biodegrader. The fungus is non sporulating and is a selective lignin degrader. It colonizes
either on living or dead wood and decomposes all wood polymers including lignin and extractives making it to be extremely
potential to be used in biopulping. The process of biopulping reduces the utilization of chemical in pulping industry and
help in decreasing the environmental hazard caused by normal pulping. The present review deals with diverse aspects of biopulping
and their ecological as well as economic significances. 相似文献
482.
Effect of nicotine on extracellular levels of neurotransmitters assessed by microdialysis in various brain regions: Role of glutamic acid 总被引:12,自引:0,他引:12
We studied the effect of local administration of nicotine on the release of monoamines in striatum, substantia nigra, cerebellum, hippocampus, cortex (frontal, cingulate), and pontine nucleus and on the release of glutamic acid in striatum of rats in vivo, using microdialysis for nicotine administration and for measuring extracellular amine and glutamic acid levels. Following nicotine administration the extracellular concentration of dopamine, increased in all regions except cerebellum; serotonin increased in cingulate and frontal cortex; and norepinephrine increased in substantia nigra, cingulate cortex, and pontine nucleus. Cotinine, the major nicotine metabolite, had no effect at similar concentrations. The cholinergic antagonists mecamylamine and atropine, the dopaminergic antagonists haloperidol and sulpiride, and the excitatory amino acid antagonist kynurenic acid all inhibited the nicotine-induced increase of extracellular dopamine in the striatum. The fact that kynurenic acid almost completely prevented the effects of nicotine, and nicotine at this concentration produced a 6-fold increase of glutamic acid release, suggests that the effect of nicotine is mainly mediated via glutamic acid release. 相似文献
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Sulaiman Ali Alharbi Milton Wainwright Tahani Awad Alahmadi Hashim Bin Salleeh Asmaa A. Faden Arunachalam Chinnathambi 《Saudi Journal of Biological Sciences》2014,21(4):289-293
What would have happened had Alexander Fleming not discovered penicillin in 1928? Perhaps the obvious answer is that, someone else would have discovered penicillin during 1930s and the Oxford group, would still have purified it sometime in the early 1940s. Here, however, in this counterfactual account of the penicillin story, it is argued that without Fleming, penicillin might still be undiscovered and the antibiotic age would never have dawned. As a result, many of the recent developments in medicine, such as organ transplantation, might have been delayed or, at best, made more hazardous. Penicillin might have come onto the scene a few years later but, had Fleming overlooked the discovery, it seems certain that penicillin would not have saved countless Allied lives, during and after D-Day. Instead of having enjoyed fifty and more years of the antibiotic age, it is argued here, that we would have had to rely upon highly developed sulphonamides, so-called “supasulfas”, and other chemically-derived antibacterial drugs. Indeed, it might be the case that, even well into this new millennium, the antibiotic age has yet to dawn, and medicine is still waiting for someone to chance upon penicillin. Here we discuss what might have happened had Fleming not discovered penicillin and come to the conclusion that the medical armoury available today would have been far different and might have relied solely upon highly developed varieties of sulphonamides or similar, synthetic, non-antibiotic antibacterial agents. 相似文献
487.
The melting of base pairs is a ubiquitous feature of RNA structural transitions, which are widely used to sense and respond to cellular stimuli. A recent study employing solution nuclear magnetic resonance (NMR) imino proton exchange spectroscopy provides a rare base-pair-specific view of duplex melting in the Salmonella FourU RNA thermosensor, which regulates gene expression in response to changes in temperature at the translational level by undergoing a melting transition. The authors observe “microscopic” enthalpy–entropy compensation—often seen “macroscopically” across a series of related molecular species—across base pairs within the same RNA. This yields variations in base-pair stabilities that are an order of magnitude smaller than corresponding variations in enthalpy and entropy. A surprising yet convincing link is established between the slopes of enthalpy–entropy correlations and RNA melting points determined by circular dichroism (CD), which argues that unfolding occurs when base-pair stabilities are equalized. A single AG-to-CG mutation, which enhances the macroscopic hairpin thermostability and folding cooperativity and renders the RNA thermometer inactive in vivo, spreads its effect microscopically throughout all base pairs in the RNA, including ones far removed from the site of mutation. The authors suggest that an extended network of hydration underlies this long-range communication. This study suggests that the deconstruction of macroscopic RNA unfolding in terms of microscopic unfolding events will require careful consideration of water interactions. 相似文献
488.
A. R. Zulkafli M. N. A. Amal S. Shohaimi A. Mustafa A. H. Ghani S. Hashim M. I. Anuar S. Ayub 《Zeitschrift fur angewandte Ichthyologie》2016,32(1):167-168
This study reports the length–weight relationships (LWR) of 15 fish species from Tembeling River, Pahang, Malaysia. The river flows adjacent to the National Park, Pahang, and supplies fishes for local consumption. In addition, this river also functions as a main water body for protection and breeding of commercial fish species. A total of eight LWRs were unknown to FishBase, and five new maximum lengths were identified from the study. 相似文献
489.
Ahmad Nazmi Rosli Maizathul Akmam Abu Bakar Vannajan Sanghiran Lee Sharifuddin Md Zain Mohd Rais Ahmad Ninie Suhana Abdul Manan Yatimah Alias Pei Meng Woi 《Journal of molecular modeling》2014,20(9):1-13
Amino acids are constituents of proteins and enzymes which take part almost in all metabolic reactions. Glutamic acid, with an ability to form a negatively charged side chain, plays a major role in intra and intermolecular interactions of proteins, peptides, and enzymes. An exhaustive conformational analysis has been performed for all eight possible forms at B3LYP/cc-pVTZ level. All possible neutral, zwitterionic, protonated, and deprotonated forms of glutamic acid structures have been investigated in solution by using polarizable continuum model mimicking water as the solvent. Nine families based on the dihedral angles have been classified for eight glutamic acid forms. The electrostatic effects included in the solvent model usually stabilize the charged forms more. However, the stability of the zwitterionic form has been underestimated due to the lack of hydrogen bonding between the solute and solvent; therefore, it is observed that compact neutral glutamic acid structures are more stable in solution than they are in vacuum. Our calculations have shown that among all eight possible forms, some are not stable in solution and are immediately converted to other more stable forms. Comparison of isoelectronic glutamic acid forms indicated that one of the structures among possible zwitterionic and anionic forms may dominate over the other possible forms. Additional investigations using explicit solvent models are necessary to determine the stability of charged forms of glutamic acid in solution as our results clearly indicate that hydrogen bonding and its type have a major role in the structure and energy of conformers. 相似文献
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