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排序方式: 共有75条查询结果,搜索用时 15 毫秒
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This study attempts to determine global warming impact (GWI) of imported wood pellets from the Southern United States for electricity production in The Netherlands. An attempt is also made to determine GWI of utilizing produced wood pellets within the state of Florida for electricity generation instead of exports. A life-cycle approach is adopted to determine overall GWIs of both the cases. Economic objectives of forest landowners are also incorporated to determine biomass (pulpwood and harvesting residues) availability from a hectare of slash pine plantation. The GWI of a unit of electricity produced at a power plant located at Geertruidenberg, The Netherlands and Gainesville, Florida was 296.4 and 177.5 g of carbon dioxide equivalent greenhouse gas, respectively. An overall saving of 72.6% in greenhouse gas emissions was estimated for every kilowatt-hour of electricity generated using imported wood pellets in The Netherlands when compared with coal-based electricity. This value was found to be 82.4% if produced wood pellets are utilized within Florida for electricity generation instead of exports. A need exists to evaluate the potential of other feedstocks for wood pellet production like understory forest biomass. Additionally, macroeconomic and ecological impacts of utilizing forest biomass for wood pellet production needs to be quantified. 相似文献
23.
Mihai Bogdan Preda Ana‐Mihaela Lupan Carmen Alexandra Neculachi Livia Ioana Leti Ioana Madalina Fenyo Sinziana Popescu Evelyn Gabriela Rusu Catalina Iolanda Marinescu Maya Simionescu Alexandrina Burlacu 《Journal of cellular and molecular medicine》2020,24(18):10889-10897
Subcutaneous transplantation of mesenchymal stromal cells (MSC) emerged as an alternative to intravenous administration because it avoids the pulmonary embolism and prolongs post‐transplantation lifetime. The goal of this study was to investigate the mechanisms by which these cells could affect remote organs. To this aim, murine bone marrow–derived MSC were subcutaneously transplanted in different anatomical regions and the survival and behaviour have been followed. The results showed that upon subcutaneous transplantation in mice, MSC formed multicellular aggregates and did not migrate significantly from the site of injection. Our data suggest an important role of hypoxia‐inducible signalling pathways in stimulating local angiogenesis and the ensuing modulation of the kinetics of circulating cytokines with putative protective effects at distant sites. These data expand the current understanding of cell behaviour after subcutaneous transplantation and contribute to the development of a non‐invasive cell‐based therapy for distant organ protection. 相似文献
24.
Effect of oxygen tension on human peripheral blood leukocytes: lysosomal enzyme release and metabolic responses during phagocytosis 总被引:2,自引:0,他引:2 下载免费PDF全文
JL Skosey DC Chow S Nusinow J May V Gestautas Y Niwa 《The Journal of cell biology》1981,88(2):358-363
We found that nonlethal lysosomal enzyme release from human peripheral blood leukocytes during phagocytosis of opsonized zymosan in vitro was modified by the oxygen tension under which the cells were incubated; with decreasing Po(2), zymosan-induced release of lysosomal enzymes was potentiated. The effect on enzyme release could not be attributed secondarily to an effect on phagocytosis, because, as others have reported, Po(2) had little effect on that response. Metabolic responses that accompany phagocytosis were also modified by oxygen tension. Stimulation of oxidation by way of the pentose cycle was further enhanced by increasing Po(2). Conversely, anaerobic glycolysis was promoted by decreasing oxygen tension. ATP levels fell as a function of time and concentration of phagocytic stimulus, mirroring lysosomal enzyme release as modified by Po(2). Cyclic AMP levels fell during phagocytosis and lysosomal enzyme release, a change that could act to facilitate lysosomal enzyme release. However, the fall in nucleotide level was greatest with highest Po(2) (i.e., when lysosomal enzyme release was least). The inverse relationship between oxidative metabolism and enzyme release suggested that a product of oxidative metabolism might adversely influence enzyme release. Sulfhydryl antioxidants (Cysteine, glutathione) and scavengers of oxygen-derived reactants (superoxide dismutase, catalase, benzoate, hypoxanthine, xanthine, histidine, azide) all potentiated zymosan- stimulated enzyme release. These findings are consistent with the interpretation that one or more factors (e.g., superoxide anion, hydrogen peroxide, hydroxyl radical, singlet oxygen), generated in association with the burst of oxidative metabolism which accompanies phagocytosis, acts to inhibit lysosomal enzyme release. 相似文献
25.
Bratosin D Estaquier J Slomianny C Tissier JP Quatannens B Bulai T Mitrofan L Marinescu A Trandaburu I Ameisen JC Montreuil J 《Biochimie》2004,86(3):183-192
Batracian Rana esculenta erythrocytes cell death induced by either calcium influx, or staurosporine, involves typical apoptotic phenotype. Our data reveal: (i) a drastic modification of the cell morphology with loss of the ellipsoidal form as assessed by phase contrast microscopy and scanning electron microscopy; (ii) an exposure of the phosphatidylserine residues in the outer leaflet of the cell membrane; (iii) a caspase-3-like activity; (iv) a mitochondrial membrane potential (Delta Psi m) loss; and (v) a chromatin condensation and fragmentation. Erythrocyte chromatin condensation and fragmentation are prevented by caspase and calpain peptide inhibitors. These inhibitors also prevent Delta Psi m loss supporting the idea that mitochondria is a central sensor for Rana erythrocytes cell death. Our observations highlight the conservation of the programmed cell death machinery in erythrocytes across kingdom. 相似文献
26.
Concentric electrodes have been fabricated from 304 stainless steel in which a small anode (0.031 cm2) and large cathode (4.87 cm2) are induced by the application of a current density of 11A cm–2 at the anode. It has previously been shown that reproducible pitting and maintenance of a galvanic current occurs only in the presence of a consortium of bacteria containing sulphate-reducing bacteria (SRB). Actively corroding systems that had maintained a galvanic current for at least 24 h after the applied current was removed were treated with inhibitors of the SRB. The only inhibitor tested which had any marked effect on the galvanic current was sodium molybdate which is a known inhibitor of corrosion as well as SRB. 相似文献
27.
The montane forests of northern Mozambique’s isolated massifs are inhabited by numerous range-restricted and threatened bird species, but until recently were extremely little-known. We report on a first avifaunal survey of the isolated montane habitats of Mt Mecula (1 442 m), Niassa National Reserve, notable as the only currently protected montane area in northern Mozambique. Mount Mecula’s moist forest is small (approximately 136 ha in total) and patchy, and although known botanically to have some montane affinities, was found to support an avifauna more typical of riparian forests of medium to low altitude. The only montane forest species recorded was Lemon Dove Aplopelia larvata. Other montane elements included Vincent’s Bunting Emberiza (capensis) vincenti, one of six species recorded new to the Niassa National Reserve list. Overall, it appears that despite its intermediate location, Mt Mecula does not represent a biogeographical ‘stepping stone’ for montane forest bird species. This probably owes to its remoteness from the Eastern Arc Mountains of Tanzania to the north and the massifs of other parts of northern Mozambique, to the south and west. 相似文献
28.
Angela CM Luyf Barbera DC van Schaik Michel de Vries Frank Baas Antoine HC van Kampen Silvia D Olabarriaga 《BMC bioinformatics》2010,11(1):598
Background
Bioinformatics is confronted with a new data explosion due to the availability of high throughput DNA sequencers. Data storage and analysis becomes a problem on local servers, and therefore it is needed to switch to other IT infrastructures. Grid and workflow technology can help to handle the data more efficiently, as well as facilitate collaborations. However, interfaces to grids are often unfriendly to novice users. 相似文献29.
30.
Ornella J Rullo Jennifer MP Woo Miriam F Parsa Alice DC Hoftman Paul Maranian David A Elashoff Timothy B Niewold Jennifer M Grossman Bevra H Hahn Maureen McMahon Deborah K McCurdy Betty P Tsao 《Arthritis research & therapy》2013,15(1):R18