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1.
【目的】针对柑橘中常用的农药,采用QuEChERS方法和超高效液相色谱-三重四极杆串联质谱,系统研究了其测定过程中的基质效应。【方法】柑橘样品利用乙酸-乙腈溶液(V∶V=1∶99)提取、GCB净化,采用甲醇-0.1%甲酸水溶液(含1 mmol·L-1乙酸铵)作为流动相,正离子多反应监测(MRM)模式,基质外标法定量,可以有效地减弱基质效应。【结果】10种农药在柑橘中主要是以基质抑制为主,其基质效应范围为-18%~4%,在0.1~100 ng·mL-1内线性关系良好,相关系数(r)大于0.999,检出限为0.08~0.30μg·kg-1,回收率为70.5%~102%,相对标准偏差(RSD)为3.32%~5.76%。【结论】该方法快速简便、净化效果好,适合柑橘中常见农药的快速测定。 相似文献
2.
以西瓜‘中选1号’品种为试材,研究了与播前启动肥配套的播后不同施肥种类、施肥浓度及施肥频率对西瓜幼苗生长发育及壮苗形成的影响,通过测定茎粗度、全株干质量等形态指标及叶绿素含量、根系活力等生理指标,筛选出西瓜穴盘育苗播后灌溉施肥较优处理为:子叶平展至2片真叶平展时12-2-14、20-10-20两种肥料交替使用,施肥浓度为100 mg·kg-1N;2片真叶平展至4片真叶平展时12-2-14、20-10-20两种肥料交替施用,施肥浓度为200 mg·kg-1N;4片真叶平展至6片真叶平展时12-2-14、20-20-20两种肥料交替施用,施肥浓度为300 mg·kg-1N,3个阶段施肥频率均为1次肥、2次水。西瓜幼苗表现为壮苗指数增加、叶绿素含量升高和根系活力增强,分别比其他处理提高了5.14%16.83%、2.71%16.83%、2.71%6.09%、5.41%6.09%、5.41%10.05%。 相似文献
3.
建立了平菇中16种有机磷农药残留量的测定方法。平菇中16种有机磷农药残留用乙腈萃取后,采用石英毛细管柱DB-17分离、气相色谱-火焰光度检测器(GC-FPD)进行测定。在平菇样品中添加农药浓度为0.1 mg.kg-1～0.2mg.kg-1时,平均回收率为75.2%～105%,相对标准偏差为1.4%～9.9%,检出限为0.004 mg.kg-1～0.03 mg.kg-1,方法具有操作简单、分析速度快、准确度和精密度高等优点。 相似文献
4.
以白喉乌头不同部位为试材，采用无水乙醇超声波法提取乌头碱，利用分光光度计于231 nm波长条件下测定吸收度，计算总生物碱的含量，从而建立不同产地白喉乌头不同部位总生物碱的含量测定方法，以期为乌头的开发利用提供参考依据。结果表明：乌头碱在0.000 4～0.002 0 mg·L-1浓度范围内线性关系良好，回归方程Y=0.179 5X+0.511 72,r=0.999 4,精密度良好，RSD=3.2%（n=3）;样品溶液显色2 h内稳定，RSD=2.14%（n=3）,测定的重现性良好，RSD=1.49%（n=3）;平均加样回收率为99.886%,RSD=1.27%（n=3）,平均含量0.063 7 mg·g-1,RSD=0.716%（n=3）。 相似文献
5.
《中国瓜菜》2019,(2):18-22
建立了气相色谱-串联质谱测定香菇中25种有机磷农药残留的检测方法。样品用氯化钠、乙腈提取,C18分散固相萃取净化。采用EI源电离多反应监测(MRM)模式进行检测,基质标准溶液校正,外标法定性、定量。分别讨论了氯化钠加入先后顺序对提取效果的影响和C18的用量对净化效果的影响。结果表明,25种化合物色谱峰分离度高,在各自的线性范围内线性关系良好(r2>0.99),在3个添加水平下的平均回收率为70.7%～116.6%,相对标准偏差(RSD)为4.4%～14.0%,方法的定量限为0.002～0.010 mg·kg-1。该方法简单、快速,能保证批量样品连续检测的稳定性,适用于香菇样品中多种有机磷类农药残留的同时检测。 相似文献
6.
以海南三七的芽和假茎基部为试材,采用组织培养的方法,研究了不同激素浓度的培养基对芽增殖以及愈伤组织的诱导、增殖和分化的影响,以期为直接和间接植株组培快繁体系的建立提供参考依据。结果表明：在“以芽繁芽”的直接再生体系中,芽增殖最佳培养基为MS+6-BA 2.0 mg·L-1+NAA 0.1 mg·L-1。在以愈伤组织诱导与植株再生的间接再生体系中,假茎基部作为外植体接种在MS+6-BA 2.0 mg·L-1+2,4-D 1.0 mg·L-1的愈伤诱导培养基上愈伤诱导率最高,40 d后可达78.43%;愈伤增殖最适培养基为MS+6-BA 1.0 mg·L-1+2,4-D 2.0 mg·L-1,愈伤分化的最佳培养基为MS+6-BA 4.0 mg·L-1+NAA 0.6 mg·L-1,分化率可以达到66.67%;将组培苗移栽至基质中,成活率90%以上。海南三七直接和间接快繁体系的建立,为其工厂化生产、遗传育种及特定药用成... 相似文献
7.
《果树学报》2010,(3)
以富士、红星、金冠、国光苹果果实为试材,对分光光度法测定苹果果实总黄酮含量的条件进行了优化。结果表明,标准品以儿茶素为宜;检测波长以500nm为宜;氯化铝、硝酸铝和硫酸铝均可作显色剂;与25℃和40℃相比,4℃下显色更加稳定;显色反应体系中乙醇浓度以8%为宜。在优化后的条件下测定苹果果实总黄酮含量,黄酮浓度在50～300mg·L-1内有良好的线性关系,相关系数在0.999以上;儿茶素在果皮中的添加回收率为100.8%～104.9%(添加3804～6410mg·L-1),在果肉中的添加回收率为101.7%～105.0%(添加500mg·kg-1或1000mg·kg-1);方法RSD小于5.0%。 相似文献
8.
以太行菊叶片、叶柄、茎尖和茎段为试材,采用MS培养基,在其中添加不同的激素对太行菊的不同外植体进行培养,研究了濒临灭绝的太行菊再生植株的方法。结果表明:太行菊的叶片、叶柄作为外植体诱导出愈伤组织的诱导率分别为44.44%和44.11%,所需时间较长,而茎尖、茎段作为外植体诱导愈伤组织诱导率分别为48.44%和68.75%,培养时间较短。茎段最适合作为诱导愈伤组织的繁殖材料。为了使茎段能更好的诱导出愈伤组织,课题组又对诱导茎段愈伤组织的激素浓度组合进行了研究,A组:MS+6-BA 1.0 mg·L-1+NAA 0.5 mg·L-1+2,4-D 0.1 mg·L-1,B组:MS+6-BA 1.0 mg·L-1+NAA 1.0 mg·L-1+2,4-D 0.1 mg·L-1,C组:MS+6-BA 2.0 mg·L-1+NAA 0.5 mg·L-1+2,4-D 0.1 mg·L-1,D组:MS+6-BA 2.0 mg·L-1+NAA 1.0 mg·L-1+2,4-D 0.1 mg·L-1。试验表明,C组激素浓度组合最适合太行菊茎段的愈伤组织诱导。35 d后愈伤组织不再增加后进行继代培养,45 d后将植株转移至生根培养基1/2MS+NAA 0.12 mg·L-1中进行生根培养。 相似文献
9.
以大花蕙兰‘大凤’(Cymbidium hybridium‘Dafeng’)与豆瓣兰‘太极圣梅’(C.serratum var.Goeringii‘Taijishengmei’)F1代原球茎、根状茎为试材,采用在1/2MS培养基中添加不同植物激素的方法,研究了不同植物激素对大花蕙兰‘大凤’与豆瓣兰‘太极圣梅’F1代原球茎与根状茎增殖和分化的影响,以期为兰属植物高效繁育提供参考依据。结果表明：以1/2MS+香蕉80.0 g·L-1+碳粉0.5 g·L-1为基本培养基,加入TDZ 1.0 mg·L-1和NAA 0.2 mg·L-1最有利于根状茎增殖,增殖率达到343.33%;基本培养基加6-BA 2.0 mg·L-1和NAA 0.3 mg·L-1有利于根状茎分化,分化率达到83.33%。原球茎的增殖最佳配方为基本培养基加TDZ 1.0 mg·L-1和NAA 0.2 mg·L-1 相似文献
10.
以芦笋花粉粒培养获得的胚状体为试材，在其形成的不定芽中，以MS+蔗糖30 g·L-1+琼脂粉8 g·L-1为基本培养基，添加不同质量浓度嘧啶醇(0、0.05、0.10、0.50、1.00、2.00 mg·L-1)和NAA(0、0.05、0.10、0.20、0.50、1.00 mg·L-1),研究了嘧啶醇和NAA浓度对不同基因型再生植株生长的影响，以期优化和提高芦笋植株体外扩繁效率。结果表明：培养基添加0.50 mg·L-1嘧啶醇处理的再生植株净生长高度、茎数分别增加1.05 cm和1.0根，根系变长，侧根增多；MS培养基添加0.50 mg·L-1嘧啶醇和0.20 mg·L-1 NAA后再生植株净生长高度、茎数分别增加1.60 cm和2.0根，根系生长旺盛；并且0.50 mg·L-1嘧啶醇和0.20 mg·L-1 NAA对芦笋胚状体再生植株的促进作用无基因型的显著差异。综上，在MS培养基中添加... 相似文献
11.
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
12.
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
13.
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
14.
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
15.
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
16.
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
17.
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
18.
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
19.
20.
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