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61.
Claudio Arato E. Kendall Pye Gordon Gjennestad 《Applied biochemistry and biotechnology》2005,123(1-3):871-882
Processes that produce only ethanol from lignocellulosics display poor economics. This is generally overcome by constructing
large facilities having satisfactory economies of scale, thus making financing onerous and hindering the development of suitable
technologies. Lignol Innovations has developed a biorefining technology that employs an ethanol-based organosolv step to separate
lignin, hemicellulose components, and extractives from the cellulosic fraction of woody biomass. The resultant cellulosic
fraction is highly susceptible to enzymatic hydrolysis, generating very high yields of glucose (>90% in 12–24h) with typical
enzyme loadings of 10–20 FPU (filter paper units)/g. This glucose is readily converted to ethanol, or possibly other sugar
platform chemicals, either by sequential or simultaneous saccharification and fermentation. The liquor from the organosolv
step is processed by well-established unit operations to recover lignin, furfural, xylose, acetic acid, and a lipophylic extractives
fraction. The process ethanol is recovered and recycled back to the process. The resulting recycled process water is of a
very high quality, low BOD5, and suitable for overall system process closure. Significant benefits can be attained in greenhouse gas (GHG) emission reductions,
as per the Kyoto Protocol. Revenues from the multiple products, particularly the lignin, ethanol and xylose fractions, ensure
excellent economics for the process even in plants as small as 100 mtpd (metric tonnes per day) dry woody biomass input—a
scale suitable for processing wood residues produced by a single large sawmill. 相似文献
62.
63.
During direct liquid introduction (DLI) liquid chromatography-mass spectrometry (LC-MS), the detectability of acetone is shown to be predictable, based on consideration of the gas-phase acidities and basicities of solvents methanol and acetonitrile and modifiers formic acid and ammonium formate. Consequently, ion formation in DLI LC-MS resembles gas-phase chemical ionization processes; since the order of acidities is altered in solution, solution ionization must be much less important than gas-phase. Ion populations could be predicted on the basis of gas-phase proton affinities and acidities: acetone could be detected in all solvent mixture by positive ions, but it was not readily detected by negative ions when acid was also present. In solvents without additives it was always detected. 相似文献
64.
Allen I. Cohen
Louis Gordon
《Talanta》1961,7(3-4):195-211Studies have been made of the distribution behaviour of tracers with alkaline earth sulphates, using the technique of precipitation from homogeneous solution. The co-precipitation of strontium with barium sulphate and of lead, lanthanum, and yttrium, separately, with barium sulphate, and with strontium sulphate, were investigated. Although there was qualitative correlation between the observed values of the distribution coefficient and the theoretical solubility product ratios for each of the binary systems studied, the divergence between theory and observation was so great that it seems unlikely that there is any quantitative correlation. 相似文献
65.
An improved high-performance liquid chromatographic method for the simultaneous determination of caffeine and its N-demethylated metabolites in plasma is described. Excellent resolution of all components is provided by reversed-phase chromatography using a mobile phase consisting of 1% acetic acid-methanol (83:17) at a flow-rate of 2.7 ml/min, in conjunction with a Waters Assoc. Nova-Pak C18 column which was protected by a Waters Assoc. Guard-Pak precolumn module containing a Guard-Pak CN cartridge. Rapid extraction of caffeine and the dimethylxanthines from plasma was achieved using reversed-phase octadecylsilane bonded-silica columns (Bond-Elut C18). With only 100 microliters of sample, plasma levels in the region of 50 ng/ml for the dimethylxanthines and 100 ng/ml for caffeine can be determined using ultraviolet detection at 273 nm. The method has been used for measuring umbilical cord plasma samples to provide information regarding foetal exposure to caffeine and its metabolites and is also suitable for therapeutic drug monitoring of caffeine and theophylline levels in the treatment of neonatal apnoea. 相似文献
66.
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68.
THE SYNERGISTIC ACTION OF ULTRAVIOLET AND X RADIATION ON MUTANTS OF ESCHERICHIA COLI K-12 总被引:1,自引:0,他引:1
Abstract— Prior UV irradiation increased the X-ray sensitivity of wild-type E. coli K-12. This synergistic effect of combined UV and X irradiation was also observed, but to a reduced extent, in uvrA, uvrB, uvrC , and polA mutants, but was absent in exrA, recA, recB , or recC mutants of E. coli K-12. Alkaline sucrose gradient studies demonstrated that the wand err gene-controlled, growth-medium-dependent (Type III) repair of X-ray-induced DNA single-strand breaks was inhibited by prior UV irradiation. This inhibition probably explains the synergistic effect of these two radiations on survival. 相似文献
69.
Smith K. D. Klasson K. T. Clausen Ackerson E. C. Gaddy J. L. 《Applied biochemistry and biotechnology》1991,28(1):787-796
Applied Biochemistry and Biotechnology - The results of this study support the hypothesis that several organisms that are capable of utilizing CO are also capable of degrading CO-like compounds,... 相似文献
70.
INDUCIBLE POSTREPLICATION REPAIR IS RESPONSIBLE FOR MINIMAL MEDIUM RECOVERY IN UV-IRRADIATED Escherichia coliK–12 总被引:1,自引:0,他引:1
Abstract— Ultraviolet (UV)-irradiated Escherichia coli K–12 uvrA cells showed higher survival if plated on minimal growth medium rather than on rich growth medium, i.e., they showed minimal medium recovery (MMR). A 2-hour treatment of UV-irradiated cells with rifampicin inhibited the subsequent expression of MMR, and produced a large reduction in survival. We have recently isolated a new mutant ( mmrA1 ) that does not show MMR. The mmrA mutation protected UV-irradiated uvrA cells from the effect of rich growth medium on survival, but not from the effect of rifampicin on survival. DNA daughter-strand gap (DSG) repair in UV-irradiated (4 J/m2 ) uvrA cells was inhibited to the same degree whether rich growth medium was added immediately after irradiation or after 10 min of postirradiation incubation in minimal growth medium. However, chloramphenicol added immediately after irradiation greatly reduced this repair; there was less reduction if it was added 10 min after UV irradiation. These findings suggest that MMR is an inducible repair phenomenon, and that rich growth medium inhibits this repair process itself rather than its induction. 相似文献