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61.
Phillips KM Ruggio DM Ashraf-Khorassani M 《Journal of agricultural and food chemistry》2005,53(24):9436-9445
Phytosterols were quantified in nuts and seeds commonly consumed in the United States. Total lipid extracts were subjected to acid hydrolysis and then alkaline saponfication, and free sterols were analyzed as trimethylsilyl derivatives by capillary GC-FID and GC-MS. Delta5-Avenasterol was quantified after alkaline saponification plus direct analysis of the glucoside. Sesame seed and wheat germ had the highest total phytosterol content (400-413 mg/100 g) and Brazil nuts the lowest (95 mg/100 g). Of the products typically consumed as snack foods, pistachio and sunflower kernel were richest in phytosterols (270-289 mg/100 g). beta-Sitosterol, Delta5-avenasterol, and campesterol were predominant. Campestanol ranged from 1.0 to 12.7 mg/100 g. Only 13 mg/100 g beta-sitosterol was found in pumpkin seed kernel, although total sterol content was high (265 mg/100 g). Phytosterol concentrations were greater than reported in existing food composition databases, probably due to the inclusion of steryl glycosides, which represent a significant portion of total sterols in nuts and seeds. 相似文献
62.
Outeiro TF Kontopoulos E Altmann SM Kufareva I Strathearn KE Amore AM Volk CB Maxwell MM Rochet JC McLean PJ Young AB Abagyan R Feany MB Hyman BT Kazantsev AG 《Science (New York, N.Y.)》2007,317(5837):516-519
The sirtuins are members of the histone deacetylase family of proteins that participate in a variety of cellular functions and play a role in aging. We identified a potent inhibitor of sirtuin 2 (SIRT2) and found that inhibition of SIRT2 rescued alpha-synuclein toxicity and modified inclusion morphology in a cellular model of Parkinson's disease. Genetic inhibition of SIRT2 via small interfering RNA similarly rescued alpha-synuclein toxicity. Furthermore, the inhibitors protected against dopaminergic cell death both in vitro and in a Drosophila model of Parkinson's disease. The results suggest a link between neurodegeneration and aging. 相似文献
63.
Amieva MR Vogelmann R Covacci A Tompkins LS Nelson WJ Falkow S 《Science (New York, N.Y.)》2003,300(5624):1430-1434
Helicobacter pylori translocates the protein CagA into gastric epithelial cells and has been linked to peptic ulcer disease and gastric carcinoma. We show that injected CagA associates with the epithelial tight-junction scaffolding protein ZO-1 and the transmembrane protein junctional adhesion molecule, causing an ectopic assembly of tight-junction components at sites of bacterial attachment, and altering the composition and function of the apical-junctional complex. Long-term CagA delivery to polarized epithelia caused a disruption of the epithelial barrier function and dysplastic alterations in epithelial cell morphology. CagA appears to target H. pylori to host cell intercellular junctions and to disrupt junction-mediated functions. 相似文献
64.
Convergent domestication of cereal crops by independent mutations at corresponding genetic Loci 总被引:1,自引:0,他引:1
Paterson AH Lin YR Li Z Schertz KF Doebley JF Pinson SR Liu SC Stansel JW Irvine JE 《Science (New York, N.Y.)》1995,269(5231):1714-1718
Independent domestication of sorghum, rice, and maize involved convergent selection for large seeds, reduced disarticulation of the mature inflorescence, and daylength-insensitive flowering. These similar phenotypes are largely determined by a small number of quantitative trait loci (QTLs) that correspond closely in the three taxa. The correspondence of these QTLs transcends 65 million years of reproductive isolation. This finding supports models of quantitative inheritance that invoke relatively few genes, obviates difficulties in map-based cloning of QTLs, and impels the comparative mapping of complex pheno-types across large evolutionary distances, such as those that separate humans from rodents and domesticated mammals. 相似文献
65.
Irvine R 《Science (New York, N.Y.)》2007,316(5826):845-846
66.
The Caenorhabditis elegans excretory canal is composed of a single elongated and branched cell that is tunneled by an inner lumen of apical character. Loss of the exc-4 gene causes a cystic enlargement of this intracellular tube. exc-4 encodes a member of the chloride intracellular channel (CLIC) family of proteins. EXC-4 protein localizes to various tubular membranes in distinct cell types, including the lumenal membrane of the excretory tubes. A conserved 55-amino acid domain enables EXC-4 translocation from the cytosol to the lumenal membrane. The tubular architecture of this membrane requires EXC-4 for both its formation and maintenance. 相似文献
67.
Scherer SW Cheung J MacDonald JR Osborne LR Nakabayashi K Herbrick JA Carson AR Parker-Katiraee L Skaug J Khaja R Zhang J Hudek AK Li M Haddad M Duggan GE Fernandez BA Kanematsu E Gentles S Christopoulos CC Choufani S Kwasnicka D Zheng XH Lai Z Nusskern D Zhang Q Gu Z Lu F Zeesman S Nowaczyk MJ Teshima I Chitayat D Shuman C Weksberg R Zackai EH Grebe TA Cox SR Kirkpatrick SJ Rahman N Friedman JM Heng HH Pelicci PG Lo-Coco F Belloni E Shaffer LG Pober B Morton CC Gusella JF Bruns GA Korf BR 《Science (New York, N.Y.)》2003,300(5620):767-772
68.
Crackower MA Kolas NK Noguchi J Sarao R Kikuchi K Kaneko H Kobayashi E Kawai Y Kozieradzki I Landers R Mo R Hui CC Nieves E Cohen PE Osborne LR Wada T Kunieda T Moens PB Penninger JM 《Science (New York, N.Y.)》2003,300(5623):1291-1295
Meiosis is a critical stage of gametogenesis in which alignment and synapsis of chromosomal pairs occur, allowing for the recombination of maternal and paternal genomes. Here we show that FK506 binding protein (Fkbp6) localizes to meiotic chromosome cores and regions of homologous chromosome synapsis. Targeted inactivation of Fkbp6 in mice results in aspermic males and the absence of normal pachytene spermatocytes. Moreover, we identified the deletion of Fkbp6 exon 8 as the causative mutation in spontaneously male sterile as/as mutant rats. Loss of Fkbp6 results in abnormal pairing and misalignments between homologous chromosomes, nonhomologous partner switches, and autosynapsis of X chromosome cores in meiotic spermatocytes. Fertility and meiosis are normal in Fkbp6 mutant females. Thus, Fkbp6 is a component of the synaptonemal complex essential for sex-specific fertility and for the fidelity of homologous chromosome pairing in meiosis. 相似文献
69.
Actor network theory and supply chainmanagement theory provide suggestive researchdirections for understanding regional agri-foodnetworks.
These theories claim that relationshipsbased upon trust and cooperation are critical to thestrength and vitality of the network.
This means thatexploring and detailing these relationships among thesuppliers, producers, workers, processors, brokers,wholesalers,
and retailers within specific regionalgeographies of these networks are critical forfurthering cooperation and trust. Key
areas ofcooperation include resource sharing andapprenticeship programs. Employing food networks as akey unit of contextual
analysis will deepen ourunderstanding of how to enhance their resiliency andvibrancy. Important questions can be raised about
thedifference gender makes for farmers, brokers,entrepreneurs, and workers in local food networks. 相似文献
70.
Wing SL Harrington GJ Smith FA Bloch JI Boyer DM Freeman KH 《Science (New York, N.Y.)》2005,310(5750):993-996
Rapid global warming of 5 degrees to 10 degrees C during the Paleocene-Eocene Thermal Maximum (PETM) coincided with major turnover in vertebrate faunas, but previous studies have found little floral change. Plant fossils discovered in Wyoming, United States, show that PETM floras were a mixture of native and migrant lineages and that plant range shifts were large and rapid (occurring within 10,000 years). Floral composition and leaf shape and size suggest that climate warmed by approximately 5 degrees C during the PETM and that precipitation was low early in the event and increased later. Floral response to warming and/or increased atmospheric CO2 during the PETM was comparable in rate and magnitude to that seen in postglacial floras and to the predicted effects of anthropogenic carbon release and climate change on future vegetation. 相似文献