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1.
Yi-Wen Chiu Sangwon Suh Stephan Pfister Stefanie Hellweg Annette Koehler 《The International Journal of Life Cycle Assessment》2012,17(1):16-24
Purpose
Though the development of biofuel has attracted numerous studies for quantifying potential water demand applying life cycle thinking, the impacts of biofuel water consumption still remain unknown. In this study, we aimed to quantify ecological impact associated with corn-based bioethanol water consumption in Minnesota in responding to different refinery expansion scenarios by applying a life cycle impact assessment method. 相似文献2.
Jo-Anne M.D. Murray Catherine Dunnett Meriel J.S. Moore-Colyer Annette C. Longland 《Animal Feed Science and Technology》2012,171(2-4):192-204
A series of in vitro experiments were conducted to assess three fibrolytic enzyme preparations as potential feed additives in equine diets. The three fibrolytic enzyme preparations were a concentrated cellulase (E1), an acid cellulase (E2) and a concentrated xylanase (E3). The enzymes were evaluated on their ability to modify the cell wall fraction of high-temperature dried lucerne (HTL) under various experimental conditions including differences in temperature, pH, incubation period, substrate levels and particle size to enable selection of the enzyme preparation most effective in the hydrolysis of lucerne. Results showed enzyme activities (as measured by reducing sugar assays) to be greatest at 50 °C, pH 5 and over an incubation period of greater than 20 h. E1 exhibited the greatest effect on total monosaccharide release from the HTL compared to E2 and E3. Moreover, dry matter (DM) and total non-starch polysaccharide (TNSP) losses were also greater in HTL treated with E1 compared to E2 and E3. Therefore, since the cell wall fraction of HTL contained substantial amounts of cellulose, the enzyme with the highest cellulase activity (Enzyme 1) was most effective in hydrolysing the cell walls of HTL. Consequently, it would appear that the application of exogenous fibrolytic enzyme preparations to forages requires the chemical characterisation of the target forage to enable selection of enzymes that are (a) most suitable to degrade the cell wall components of the candidate forage and (b) effective under field conditions. 相似文献
3.
Monoclonal antibodies have been generated against a cross-link-containing derivative of alpha polymer (alpha XLCNBr), isolated following CNBr digestion of fibrin [Sobel, J. H., Ehrlich, P. H., Birken, S., Saffran, A. J., & Canfield, R. E. (1983) Biochemistry (preceding paper in this issue)]. One cloned cell line (F-102) was chosen for characterization based on its apparent specificity for the A alpha-chain region A alpha 518-584 (CNBr X). A second line (F-103) was selected because of its anti-A alpha 241-476 (CNBr VIII) properties. These two regions of the A alpha chain have previously been implicated as major contributors to the cross-linking process that leads to alpha-polymer formation. Radioimmunoassays have been developed, employing the immunoglobulins produced by clones F-102 and F-103. These assays have been applied, in conjunction with high-performance liquid chromatography purified tryptic and chymotryptic derivatives of CNBr VIII and CNBr X, to localize the respective determinants involved in antibody binding. In each case, virtually full immunoreactivity was exhibited by both the CNBr fragment and a single tryptic or chymotryptic peptide originating from it. These findings indicate that sequence-specific, rather than conformational, determinants were operative in the generation of antibodies F-102 and F-103. The epitope recognized by F-102 was localized to the region of A alpha 540-554, while the F-103 binding site resided within A alpha 259-276. When these radioimmunoassays were applied to study the relative immunoreactivity exhibited by a variety of fibrinogen derivatives, the results obtained support earlier suggestions that the COOH-terminal portion of the A alpha chain contains regions of random conformation. 相似文献
4.
Annette Graham 《Free radical research》1998,28(6):611-621
Compelling evidence suggests that low-density lipoprotein (LDL) is oxidized by cells within the arterial intima and that, once oxidized, it is profoundly atherogenic. The precise mechanism(s) by which cells promote the oxidation of LDL in vivo are not known; in vitro, however, oxidation of LDL can be enhanced by a number of differing mechanisms, including reaction with free and protein-bound metal ions, thiols, reactive oxygen species, lipoxygenase, myeloperoxidase and peroxynitrite. This review is concerned with the mechanisms by which cells enhance the oxidation of LDL in the presence of transition metals; in particular, the regulation, pro- and anti-oxidant consequences, and mechanism of action of cellular thiol production are examined, and contrasted with thiol-independent oxidation of LDL in the presence of transition metals. 相似文献
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Rebecca C. Schreiber Stacey A. Vaccariello Kristen Boeshore Annette M. Shadiack Richard E. Zigmond 《Developmental neurobiology》2002,53(1):68-79
Transecting the axons of neurons in the adult superior cervical ganglion (SCG; axotomy) results in the survival of most postganglionic neurons, the influx of circulating monocytes, proliferation of satellite cells, and changes in neuronal gene expression. In contrast, transecting the afferent input to the SCG (decentralization) results in nerve terminal degeneration and elicits a different pattern of gene expression. We examined the effects of decentralization on macrophages in the SCG and compared the results to those previously obtained after axotomy. Monoclonal antibodies were used to identify infiltrating (ED1+) and resident (ED2+) macrophages, as well as macrophages expressing MHC class II molecules (OX6+). Normal ganglia contained ED2+ cells and OX6+ cells, but few infiltrating macrophages. After decentralization, the number of infiltrating ED1+ cells increased in the SCG to a density about twofold greater than that previously seen after axotomy. Both the densities of ED2+ and OX6+ cells were essentially unchanged after decentralization, though a large increase in OX6+ cells occurred after axotomy. Proliferation among the ganglion's total non‐neuronal cell population was examined and found to increase about twofold after decentralization and about fourfold after axotomy. Double‐labeling experiments indicated that some of these proliferating cells were macrophages. After both surgical procedures, the percentage of proliferating ED2+ macrophages increased, while neither procedure altered the proliferation of ED1+ macrophages. Axotomy, though not decentralization, increased the proliferation of OX6+ cells. Future studies must address what role(s) infiltrating and/or resident macrophages play in regions of decentralized and axotomized neurons and, if both are involved, whether they play distinct roles. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 68–79, 2002 相似文献
9.
We have developed a procedure for Vibratome (Oxford Laboratories) sections that is particularly valuable for providing uniformly thick, well preserved CNS tissue sections for morphometric applications. 相似文献
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