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杏鲍菇多糖抗氧化作用研究 总被引：1，自引：0，他引：1
采用恒温水浴振荡方法提取杏鲍菇水溶性粗多糖,再经分离纯化得固体杏鲍菇多糖.以对氧自由基的清除率为评价指标,采用邻苯三酚自氧化法和邻二氮菲-Fe2+-H2O2氧化法研究了杏鲍菇多糖对氧自由基的清除能力.结果表明:杏鲍菇多糖对羟自由基和超氧阴离子自由基均有清除作用.在一定的多糖浓度范围内随着多糖浓度的增加对羟自由基和超氧阴离子自由基的清除作用亦增强,并呈良好的线性关系;杏鲍菇多糖浓度在0.7 mg/mL对羟自由基的清除率可达98.65％,对超氧阴离子自由基的清除率可达37.66％. 相似文献
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以鲜菌草与灵芝菌丝发酵得到的菌质为试材,采用单因素试验和正交实验对其多糖进行提取,研究了不同的料液比、提取时间、提取温度和提取次数对菌质多糖提取率的影响,获得最优化的提取条件;用Fenton体系和邻苯三酚自氧化体系研究了菌质多糖对羟自由基和超氧自由基清除率的影响。结果表明:影响鲜菌草与灵芝菌丝发酵菌质多糖提取得率的主次因素分别为提取温度料液比提取次数提取时间;最佳提取工艺条件为料液比1∶30g·mL~(-1)、温度100℃、提取时间4h、提取次数3次,以此最佳组合提取鲜菌草与灵芝菌丝发酵菌质多糖时,其得率为4.88%。鲜菌草与灵芝菌丝发酵菌质多糖对羟基自由基和超氧阴离子自由基有明显的清除作用,并且随着多糖浓度的增加,清除能力增强,表明鲜菌草与灵芝菌丝发酵菌质多糖对羟基自由基和超氧阴离子自由基的清除能力与多糖浓度有明显的量效关系。通过相关方程可以得到鲜菌草与灵芝菌丝发酵菌质多糖清除羟基自由基的EC_(50)值为0.461mg·mL~(-1),清除超氧阴离子自由基的EC_(50)值为0.864mg·mL~(-1)。 相似文献
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通过摇瓶液体发酵获得蛹虫草菌丝体,采用脱脂、水提醇沉、去蛋白、脱色素、透析和冷冻干燥等一系列手段提取蛹虫草菌丝体多糖。利用羟基自由基(·OH)、超氧阴离子自由基(O2-·)和1,1—二苯基-2-三硝基苯肼(DPPH)清除实验,评价蛹虫草菌丝体多糖体外抗氧化活性。结果显示,蛹虫草菌丝体多糖对3种自由基均表现出较强的清除效果,其中对DPPH的清除力相对最强。随着浓度上升,其抑制自由基的效果均增强,呈现剂量正相关。该多糖对3种不同自由基抑制作用的IC50值分别为7.01 mg·m L-1、19.90 mg·m L-1和3.51 mg·m L-1。蛹虫草菌丝体多糖表现出良好的体外抗氧化活性。 相似文献
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以L135、香66、808、日大4株香菇菌株为试材,采用苯酚-硫酸法、滤纸片扩散法及分光光度计法,研究了香菇胞外多糖含量、抑菌活性和抗氧化活性的差异,以期为香菇药食资源开发提供参考依据.结果表明:L135、808、香66、日大4株香菇的胞外多糖含量分别为(2.82±0.02)(1.61±0.04)(1.85±0.03)(2.22±0.06)mg·mL-1.当多糖质量浓度达到1.0mg·mL-1时,菌株香66的还原能力最强,菌株日大的ABTS+自由基清除率最高,其清除率为39.97％;菌株L135的DPPH自由基清除率最高,其EC50 值为3.53 mg·mL-1;菌株808的对羟自由基清除能力和抑菌活性最强. 相似文献
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为探索不同来源茯苓多糖的抗氧化活性,采用邻二氮菲-Fe2+氧化法、DPPH自由基分析法、邻苯三酚自氧化法分别考察了茯苓胞外多糖、胞内多糖和菌核多糖对羟基自由基(·OH)、DPPH自由基(DPPH·)和超氧阴离子自由基(O·2)的清除活性,采用傅里叶变换红外光谱分析法对其结构进行了初步分析。结果表明:不同来源的茯苓多糖均表现出3种自由基的清除活性,但茯苓胞内多糖的活性最佳,其对·OH、DPPH·和O·2的最大清除率分别为32.07%、90.12%和39.74%。红外光谱分析进一步验证了3种待测样品均为多糖,但茯苓胞内多糖在823cm-1处存在特征吸收峰,推测其结构中存在独特的甘露糖苷键。这些数据证实了茯苓多糖的抗氧化活性以及茯苓胞内多糖在抗氧化保健食品和药品研发领域的应用优势,为真菌多糖的深度开发提供了必要参考。 相似文献
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选取3株不同种属白腐菌（K1：灵芝属Ganoderma lueidum，B2：侧耳属Pleurots sp.，A3：香菇属Lentinula edodes），2种不同木质纤维素基质（玉米秸粉、稻草秸粉），对白腐菌在木质纤维素基质上固、液培养过程中产生的胞外羟自由基（·OH）清除能力进行了研究，并初步探析了可能的主效物质。结果表明：（1）白腐菌在木质纤维索基质上不同时期的培养物均具有胞外·OH清除能力，显示了该能力在白腐菌中的普遍性；且试验中香菇A3培养物的胞外·OH清除能力最高，玉米秸粉比稻草秸粉更利于白腐菌培养物产生胞外·OH清除效应。（2）对香菇A3进行玉米秸粉液体培养，第8d时胞外·OH清除率达峰值42．53％，清除·OH的主效物质为胞外粗多糖，其作用占胞外液·0H总清除率效果的75．4％。 相似文献
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AIM: Although endovascular radiotherapy inhibits neointimal hyperplasia, the exact alterations induced by β-particles irradiation remain to be elucidated. The objective of this study was to investigate the ability and the cellular mechanism of local β-particles emission from 188Re to inhibit vascular smooth muscle cells (SMCs). METHODS: The SMCs in vitro were irradiated by 188Re with single doses of 2.6 Gy-25.8 Gy. The effects of β-particles on SMCs, such as effective irradiate doses, the period of inhibition for SMCs proliferation, the changes of cell proliferation rate and DNA synthesis rate, cell cycle progression and related gene expression, were investigated by cell count, [3H]-TdR incorporation, cell cycle progression analysis, cell viability and immunocytochemistry, respectivecy. RESULTS: β-particles irradiation with dose of 5.2 Gy could inhibit significantly SMCs proliferation. At dose of 20.6 Gy DNA synthesis inhibitory rate was 92%, SMCs proliferation rate was only 3%. Renoval of 188Re did not abolish the inhibitory effects of β-particles on SMCs proliferation. The expression of P53 was up regulation and PCNA was down regulation after irradiation. CONCLUSION: β-particles from 188 Re was significantly effective and permanent in inhibiting SMCs proliferation, and inhibitory effect was in dose-dependet manner ED50was 5 Gy, the best dose to inhibit SMCs proliferation was 20 Gy. β-particles irradiation induced SMCs to occur G0/G1 arrest, damaged the ability of SMCs reproliferation and led to cell clonogenic death. P53 and PCNA had regulatiory effects on SMCs proliferation after β-particles irradiation. 相似文献
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多效唑对猕猴桃离体试管苗生长及内源激素的影响 总被引：18，自引：0，他引：18
多效唑（ＰＰ３３３）处理猕猴桃试管苗，降低了其生长强度；植株体内的ＧＡ３、ＩＡＡ和ＺＴ含量下降，ＡＢＡ的含量上升，乙烯释放率增加；并且能降低外源的ＧＡ３和ＩＡＡ促进生长的作用，而外源的ＧＡ３和ＩＡＡ又能不同程度地逆转多效唑的抑制作用，使植株恢复生长。 相似文献
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HU Zhi-cheng ZHU Jia-yuan ZHU Bin GUO Dong CHEN Bin ZHANG Kai HU Kun-hua LI Ming-tao TANG Bing 《园艺学报》2011,27(9):1802-1806
AIM: To investigate and screen the sensitive proteins in the formation mechanism of pathological scars by comparing the results of differential proteomic analysis between pathological scars and normal skin.METHODS: Two-dimensional gel electrophoresis was used to detect the protein expression profiles in 8 keloid patients, 8 hypertrophic scar patients and 3 matched normal skin patients.The proteins that showed differential expression of over 4-fold change were cut and analyzed by MALDI-TOF/TOF mass spectrometry.RESULTS: A two-dimensional protein profiling comparison between pathological scars and normal skin was successfully established.On average, 2 978 spots in keloid, 2 975 spots in hypertrophic scar and 3 053 spots in normal skin were identified using gel analysis software.Compared with normal skin, there were totally 36 differentially-expressed proteins in keloid and hypertrophic scar identified from the spots of over 4-fold change, including 16 proteins in both keloid and hypertrophic scar (8 up-regulated and 8 down-regulated), 11 only in keloid (9 up-regulated and 2 down-regulated) and 9 only in hypertrophic scar (4 up-regulated and 5 down-regulated).CONCLUSION: Proteomic analysis can identify the proteins with variance of pathological scars versus normal skin, thus providing probable new clues to reveal the formation mechanism of pathological scars. 相似文献
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Duncan Brean W. Boyle Shannon Breininger David R. Schmalzer Paul A. 《Landscape Ecology》1999,14(3):291-309
Historic landcover dynamics in a scrubby flatwoods (Tel-4) and scrub landscape (Happy Creek) on John F. Kennedy Space Center were measured using aerial images from 1943, 1951, 1958, 1969, 1979, and 1989. Landcover categories were mapped, digitized, geometrically registered, and overlaid in ARC/INFO. Both study sites have been influenced by various land use histories, including periods of range management, fire suppression, and fire management. Several analyses were performed to help understand the effects of past land management on the amount and spatial distribution of landcover within the study sites. A chi-squared analysis showed a significant difference between the frequency of landcover occurrence and management period. Markov chain models were used to project observed changes over a 100-year period; these showed current management practices being effective at Tel-4 (restoring historic landscape structure) and much less effective at Happy Creek. Documenting impacts of past management regimes on landcover has provided important insight into current landscape composition and will provide the basis for improving land management on Kennedy Space Center and elsewhere. 相似文献
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AIM: Previous studies performed with XBP-01 in vitro indicated that XBP-01 could inhibit vascular smooth muscle cells from being transformed into foam cell and could eliminate the atherosclerotic plaque in C57BL/6J mouse. This experiment is to investigate its mechanism of eliminating plaques in vitro. METHODS: The cultured porcine artery smooth muscle cells incubated with XBP-01 of 0.1 mg/L for 24 h after preincubated with oxidized low density lipoprotein of 15 mg/L for 72 h in vitro. The samples were analyzed by fluorescence microscope, confocal microscope system and flow cytometry. RESULTS: Apoptosis was triggered by being incubated with oxidized low density lipoprotein and this process was accelerated additionally by being incubated with XBP-01. CONCLUSION: XBP-01 can be effective in eliminating atherosclerotic plaque by accelerating the process in which oxidized low density lipoprotein induced smooth muscle cell apoptosis. 相似文献
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Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations
from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations,
dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture
or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near
Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between
November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation
was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme
temperatures (summer maximums, winter minimums). The correlation (r
2) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation
in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences
respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds
that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for
37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest
species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain
the patchy distribution of many species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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AIM: To detect the expression of cytoplasmic inhibitor of apoptosis protein 2 (c-IAP2) and growth arrest-specific gene 1 (GAS1) in Hodgkin's lymphoma (HL) and anaplastic large cell lymphoma (ALCL) and to investigate the role of two genes in the pathogenesis of HL and ALCL.METHODS: HE staining, the antibodies CD30, CD15, CD45RO and CD20 were used to screen the cases of HL and ALCL from 288 cases of lymphoma. The clarified HL and ALCL were subjected for immunohistochemical staining by SP and ABC methods to analyze the expression of c-IAP2 and GAS1. RESULTS: ①The positive rate of c-IAP2 in HL was 25/26(96.1%) while that in ALCL was 6/19(31.6%), there presented statistic significance between HL and ALCL groups(P<0.05), meanwhile the positive rate of GAS1 showed statistic significance between HL and ALCL groups(P<0.05). ②Two cases were showed to be a mixed type combined with large tumor cells of HL and relatively smaller tumor cells of ALCL.CONCLUSION: ①The different expression of c-IAP2 and GAS1 in HL and ALCL implied a different mechanism of oncogenesis and the different defects in the pathway of signal transduction of apoptosis in HL and ALCL;②Few cases showed an overlap and a likely transitional state between HL and ALCL; ③The different expressing manner of GAS1 and c-IAP2 in HL and ALCL implied the potential marks for the differential dignosis of two kinds of lymphoma. 相似文献
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Effects of patch attributes, barriers, and distance between patches on the distribution of a rock-dwelling rodent (Lagidium viscacia) 总被引：1，自引：0，他引：1
We tested whether size of habitat patches and distance between patches are sufficient to predict the distribution of the mountain
vizcacha Lagidium viscacia a large, rock-dwelling rodent of the Patagonian steppe Argentina, or whether information on other patch and landscape characteristics
also is required. A logistic regression model including the distance between rock crevices and depth of crevices, distance
between a patch and the nearest occupied patch, and whether or not there was a river separating it from the nearest occupied
patch was a better predictor of patch occupancy by mountain vizcachas than was a model based only on patch size and distance
between patches. Our results indicate that a simple metapopulation analysis based on size of habitat patches and distance
between patches may not provide an accurate representation of regional population dynamics if patches vary in habitat quality
independently of patch size and features in the matrix alter connectivity.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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β3-adrenergic receptor is the third subtype of β-adrenergic receptors. The genetic structure and pharmacological property of β3-adrenergic receptor are markedly distinguished from β1-and β2-adrenergic receptor subtypes. Recently studies show that myocardial β3-adrenergic receptor mediates negative inotropic effect through Gi-protein/NO/cGMP pathway, the expression of β3-adrenergic receptor and negative inotropic effect mediated by β3-adrenergic receptor are increased in heart failure. However, because of the low expression of β3-adrenergic receptor in the heart, the actual pathophysiological significance of β3-adrenergic receptor remains unknown. 相似文献