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1.
An improved micropropagation protocol has been developed for teak (Tectona grandis). Nodal explants placed on MS medium supplemented with 22.2 M benzylaminopurine and then serially transferred to fresh medium after 12, 24, 48 and 72 h gave maximum culture establishment (76.8%). Establishment was reduced when explants were retained in the initial culture medium longer than 12 h. Explants collected in May showed maximum (76.8%) response. Placement of the explants on MS medium supplemented with 22.2 M benzylaminopurine and 0.57 M indole-3-acetic acid resulted in the maximum average number of shoots. In vitro raised micro shoots were rooted ex vitro by dipping in indole-3-butyric acid (9.8 mM) for 2 min followed by planting in polyethylene pots containing a soil:vermiculite (1:1 v/v) mixture. This treatment resulted in 77.9% survival of the plantlets. They were weaned in a glasshouse and finally moved to an agro-net shade house.  相似文献   
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The International Journal of Life Cycle Assessment - Producing biochar from forest residues can help resolve environmental issues by reducing forest fires and mitigating climate change. However,...  相似文献   
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Lactoperoxidase (LPO) is a hemeprotein catalyzing the oxidation of thiocyanate and I? into antimicrobials and small aromatic organics after being itself oxidized by H2O2. LPO is excreted by the lungs, mammary glands, found in saliva and tears and protects mammals against bacterial, fungal and viral invasion. The Fe(II) form binds CO which inactivates LPO like many other hemeproteins. We present the 3-dimensional structure of CO?CLPO at 2.0? resolution and infrared (IR) spectra of the iron-bound CO stretch from pH?3 to 8.8?at 1 cm?1 resolution. The observed Fe?CC?CO bond angle of 132° is more acute than the electronically related Fe(III), CN?CLPO with a Fe?CC?CN angle of 161°. The orientations of the two ligands are different with the oxygen of CO pointing towards the imidazole of distal His109 while the nitrogen of CN points away, the Fe(II) moves towards His109 while the Fe(III) moves away; both movements are consistent with a hydrogen bond between the distal His109 and CO, but not to the nitrogen of CN?CLPO. The IR spectra of CO?CLPO exhibit two major CO absorbances with pH dependent relative intensities. Both crystallographic and IR data suggest proton donation to the CO oxygen by His109 with a pK ?? 4; close to the pH of greatest enzyme turnover. The IR absorbance maxima are consistent with a first order correlation between frequency and Fe(III)/Fe(II) reduction potential at pH?7; both band widths at half-height correlate with electron density donation from Fe(II) to CO as gauged by the reduction potential.  相似文献   
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A directed evolution protocol was developed for glucose oxidase (GOx) from Aspergillus niger that mimics applications conditions and employs a well-known mediator, oxidized ferrocenemethanol, in a medium throughput screen (96-well plate format). Upon reduction, oxidized ferrocenemethanol shows a color change from blue to pale yellow that can be recorded at 625 nm. Under optimized screening conditions, a CV of less than 20% was achieved in 96-well microtiter plates. For validating the screening system, two mutant libraries of GOx were generated by standard error-prone PCR conditions (0.04 mM MnCl(2)) and Saccharomyces cerevisiae was employed as host for secreted GOx expression. Two screening of approximately 2000 GOx mutants yielded a double mutant (T30S I94V) with improved pH and thermal resistance. Thermal resistance at a residual activity of 50% was increased from 58 degrees C (wild type, WT) to 62 degrees C (T30S I94V) and pH stability was improved at basic pH (pH 8-11). K(m) for glucose remained nearly unchanged (20.8 mM WT; 21.3 mM T30S I94V) and k(cat) increased (69.5/s WT; 137.7/s T30S I94V).  相似文献   
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Neurochemical Research - Human/animal brain is a unique organ with substantially high metabolism but it contains no energy reserve that is the reason it requires continuous supply of O2 and energy...  相似文献   
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  总被引:1,自引:0,他引:1  
The hydropower reservoirs, considered as a green source of energy, are now found to emit significant quantities of greenhouse gas (GHG) to the atmosphere. This article attempts to predict the vulnerability of Tehri reservoir, India to GHG emissions using the GHG risk assessment tool (GRAT). The GRAT is verified with experimental GHG fluxes. The annual mean CO2 fluxes from diffusion, bubbling, and degassing were 425.93 ± 122.50, 4.81 ± 1.33, and 7.01 ± 2.77 mg m?2d?1, whereas CH4 fluxes were 23.11 ± 7.08, 4.79 ± 1.08, and 7.41 ± 4.50 mg m?2d?1, respectively, during 2011–12. The model found that Tehri reservoir emitted higher CO2 and CH4 (i.e., 790 mg m?2d?1 and 64 mg m?2d?1, respectively) in 2011, which came within vulnerability range causing more climate change impact. By the year 2015, it would scale down to medium risks necessitating no further assessment of GHG. Significant difference between predicted and experimental GHG emission are assessed, which may be due to insufficient data, spatial and temporal variations, decomposition of flooded biomass, limitation of GRAT model, and inadequate methodology. The study reveals that GHG emission from Tehri reservoir is less than predicted by the GRAT.  相似文献   
9.
Eye suppression,a novel function of teashirt,requires Wingless signaling   总被引:1,自引:0,他引:1  
teashirt (tsh) encodes a Drosophila zinc-finger protein. Misexpression of tsh has been shown to induce ectopic eye formation in the antenna. We report that tsh can suppress eye development. This novel function of tsh is due to the induction of homothorax (hth), a known repressor of eye development, and requires Wingless (WG) signaling. Interestingly, tsh has different functions in the dorsal and ventral eye, suppressing eye development close to the ventral margin, while promoting eye development near the dorsal margin. It affects both growth of eye disc and retinal cell differentiation.  相似文献   
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Lakes, especially shallow lakes, contribute disproportionately to greenhouse gas (GHG; particularly CO2 and CH4) emissions and have received global attention due to their high potential to contribute to global warming and future climate change. Recent studies have identified eutrophication as a critical factor in GHG emissions. However, the role of lake trophic state index (TSI) and the impact of important water quality parameters (WQP) such as pH, Chl-a, total nitrogen, total phosphorus and organic carbon on GHG emissions are still a subject of debate and an area of intense research. To further understand the relationship between GHG and lake eutrophication, datasets (GHG and WQP) from the scientific literature have been compiled, and statistical analyses of these secondary data were performed to determine the influence of eutrophication on GHG emissions. In this review, GHG emissions from Chinese lakes are quantified, and the important factors affecting these emissions are analysed systematically. The statistical analysis reveals that chlorophyll a and carbon (as TOC) are the key factors of lake eutrophication and have a significant effect on the GHG potential (mainly CH4 fluxes). In addition, the proposed mitigation measures could serve as a guide for scientists and young researchers to reduce future climatic risks.  相似文献   
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