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排序方式: 共有316条查询结果,搜索用时 31 毫秒
81.
Journal of Plant Diseases and Protection - Weed species within arable farming systems act as a source of food and provide habitat for various taxa at higher trophic levels. Using field experiments... 相似文献
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Hamilton SR Bobrowicz P Bobrowicz B Davidson RC Li H Mitchell T Nett JH Rausch S Stadheim TA Wischnewski H Wildt S Gerngross TU 《Science (New York, N.Y.)》2003,301(5637):1244-1246
We report the humanization of the glycosylation pathway in the yeast Pichia pastoris to secrete a human glycoprotein with uniform complex N-glycosylation. The process involved eliminating endogenous yeast glycosylation pathways, while properly localizing five active eukaryotic proteins, including mannosidases I and II, N-acetylglucosaminyl transferases I and II, and uridine 5'-diphosphate (UDP)-N-acetylglucosamine transporter. Targeted localization of the enzymes enabled the generation of a synthetic in vivo glycosylation pathway, which produced the complex human N-glycan N-acetylglucosamine2-mannose3-N-acetylglucosamine2 (GlcNAc2Man3GlcNAc2). The ability to generate human glycoproteins with homogeneous N-glycan structures in a fungal host is a step toward producing therapeutic glycoproteins and could become a tool for elucidating the structure-function relation of glycoproteins. 相似文献
84.
Schermelleh L Carlton PM Haase S Shao L Winoto L Kner P Burke B Cardoso MC Agard DA Gustafsson MG Leonhardt H Sedat JW 《Science (New York, N.Y.)》2008,320(5881):1332-1336
Fluorescence light microscopy allows multicolor visualization of cellular components with high specificity, but its utility has until recently been constrained by the intrinsic limit of spatial resolution. We applied three-dimensional structured illumination microscopy (3D-SIM) to circumvent this limit and to study the mammalian nucleus. By simultaneously imaging chromatin, nuclear lamina, and the nuclear pore complex (NPC), we observed several features that escape detection by conventional microscopy. We could resolve single NPCs that colocalized with channels in the lamin network and peripheral heterochromatin. We could differentially localize distinct NPC components and detect double-layered invaginations of the nuclear envelope in prophase as previously seen only by electron microscopy. Multicolor 3D-SIM opens new and facile possibilities to analyze subcellular structures beyond the diffraction limit of the emitted light. 相似文献
85.
Rajendran L Schneider A Schlechtingen G Weidlich S Ries J Braxmeier T Schwille P Schulz JB Schroeder C Simons M Jennings G Knölker HJ Simons K 《Science (New York, N.Y.)》2008,320(5875):520-523
beta-Secretase plays a critical role in beta-amyloid formation and thus provides a therapeutic target for Alzheimer's disease. Inhibitor design has usually focused on active-site binding, neglecting the subcellular localization of active enzyme. We have addressed this issue by synthesizing a membrane-anchored version of a beta-secretase transition-state inhibitor by linking it to a sterol moiety. Thus, we targeted the inhibitor to active beta-secretase found in endosomes and also reduced the dimensionality of the inhibitor, increasing its local membrane concentration. This inhibitor reduced enzyme activity much more efficiently than did the free inhibitor in cultured cells and in vivo. In addition to effectively targeting beta-secretase, this strategy could also be used in designing potent drugs against other membrane protein targets. 相似文献
86.
We consider estimation of the magnitude of incidental fisheries ‘bycatch’ for two petrel species, sooty shearwaters (Puffinus griseus) and short-tailed shearwaters (Puffinus tenuirostris). There are clear statistical advantages in estimating bycatch for abundant species such as these, and our results may also guide the conservation and management of rarer species. We used fisheries statistics and observer data to estimate retrospectively the total numbers of sooty and short-tailed shearwaters bycatch in seven large-scale pelagic North Pacific driftnet fisheries between 1952 and 2001. Sensitivity analysis greatly simplified estimation of uncertainty by identifying four driftnet fisheries to be of particular importance in determining the magnitude and precision of the estimated bycatch totals. We estimated that between 1.0 and 12.8 million (95% CI) sooty shearwaters were killed by driftnets between 1952 and 2001. For short-tailed shearwaters we estimated between 4.6 and 21.2 million (95% CI) over the same period. More precise estimation was hampered by the paucity of available observer data, lack of reported detail and inconsistencies among data sources. Estimates may be strongly biased because some dead birds are misidentified or drop out of nets before hauling, or because some records were of live captures that were subsequently released. Improved estimation of overall take and its impact on populations of seabirds requires standardisation of reporting, allowance for potential sampling bias, as well as a clearer definition of the sampling unit and underlying bycatch probability distribution model, and knowledge of potential compensatory changes in population parameters. 相似文献
87.
1THEPHILIPPINERICESITUA TIONDuringthelastdecade (1991- 2 0 0 0 ) ,annualgrowthin productionslightlyimprovedto 2 3%from 2 2 %duringthepreviousdecade (1981-1990 ) .Duringthelastdecade (1991- 2 0 0 0 ) ,annu algrowthinproductionslightlyimprovedto 2 3%from 2 2 %duringthe previousdecade (1981-1990 ) .Notwithstandingthesteadyincreaseinriceproduction ,thecountryremainedanetriceim porter .In 2 0 0 1,palay (paddy) productioninthecountryhit 12 95Mmtoraround 9 11Mmtofrice .However,inthes… 相似文献
88.
Jennifer Eiermann BVSc Kristin Kirkby-Shaw DVM MS PhD DACVS-SA DACVSMR CCRT Richard B. Evans PhD Sebastian C. Knell Dr med vet DECVS Michael P. Kowaleski DVM DACVS DECVS Philipp A. Schmierer Dr med vet DECVS Mary S. Bergh DVM DACVS DACVSMR Jason Bleedorn DVM MS DACVS Laura C. Cuddy MVB MS DACVS-SA DECVS DACVSMR DECVSMR MRCVS Nina R. Kieves DVM DACVS-SA DACVSMR CCRT Peter Lotsikas DVM DACVS DACVSMR Antonio Pozzi DVM MS DACVS DECVS DACVSMR 《Veterinary surgery : VS》2020,49(1):80-87
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Lena Vogt Veronica Duckwitz Sebastian P. Arlt Peggy Haimerl Alexander Bartel Claudia Hautzinger Stephan Birk Sebastian Haase Mechthild Ladwig-Wiegard Marcus G. Doherr 《Reproduction in domestic animals》2020,55(Z2):81-89
Virtual patients have become an interesting alternative in medical education. Due to increasing demands regarding theoretical and clinical teaching and to improve an interdisciplinary approach, a new blended learning concept including virtual patients was developed and implemented in the veterinary curriculum of the Freie Universität Berlin. In the presented project, three virtual patients from the field of canine reproduction were developed. They focus on pregnancy diagnosis with suspected luteal insufficiency, pyometra and benign prostatic hyperplasia, respectively. The results of an evaluation by veterinary students of the 7th semester showed a high acceptance of virtual patients in a blended learning reproduction module in the interdisciplinary lectures. Students especially preferred videos, such as video lectures, hands-on videos and animations as well as a glossary for background information, to successfully and autonomously work on a virtual case. The content covered by the new modules that were developed in the context of this project is part of a spiral curriculum; they will be revised and enhanced during the clinical year. 相似文献