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Rapid HPLC Method for Determination of Rebaudioside D in Leaves of Stevia rebaudiana Bertoni Grown in the Southeast of Mexico

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American Journal of Analytical Chemistry 2014年第13期5卷 813-819页

作者： Irma Aranda-González yolanda Moguel-Ordonez David Betancur-Ancona Facultad de Ingeniería Química Universidad Autónoma de YucatánMéridaMéxico Instituto Nacional de Investigaciones Forestales Agrícolas y Pecuarias(INIFAP)MococháMéxico

Stevia leaves contain glycosides on which biological activity and sweetening capacity has been reported. Besides the main glycosides—stevioside and rebaudioside A—there are minor glycosides that may contribute to the activity and thus it is important to quantify them. Rebaudioside D is one of the minor glycoside present in S. rebaudiana leaves and there are no reports of a validated method to quantify it. Therefore a simple and sensitive high performance liquid chromatography (HPLC) method was validated for the determination of rebaudioside D in leaves of Stevia rebaudiana B. grown in the southeast of México. HPLC method was performed using a C18 column (250 mm × 4.6 mm, 5 μm) and UV detector set at 210 nm. The mobile phase consisted of 32:68 (v/v) mixture of acetonitrile and sodium phosphate buffer (10 mmol/L, pH 2.6), set to a flow rate of 1.0 ml/min. The calculated parameters were: sensitivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy and precision. The retention time of rebaudioside D was found to be 3.47 min ± 0.04 (S.D.). The calibration curves were linear over the working range (25 - 150 μg/ml), with correlation coefficient ≥0.99 and determination coefficient ≥0.98. The calculated limit of detection (LOD) was 8.53 μg/ml, while the limit of quantitation (LOQ) was 25.85 μg/ml. The percent recoveries of fortified samples were 100% ± 10% and precision relative standard deviation was ≤2.79%. The criteria of validation showed accuracy, linearity, and precision;therefore the method is suitable for quantitative analysis of rebaudioside D in Stevia rebaudiana leaves. Rebaudioside D content (g/100g) in Morita II and Criolla varieties grown in the southeast of Mexico were 0.43 and 0.46, respectively with no significant differences (p > 0.05) between them.

关键词： Rebaudioside D Stevia Rebaudiana HPLC Validation

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Calibration and validation of FAO-AquaCrop model to estimate the total biomass and yacon root yield

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International Journal of Agricultural and Biological Engineering 2020年第3期13卷 123-128页

作者： Ramon Amaro de Sales Alexandre Cândido Xavier Evandro chaves de Oliveira Fábio Luiz de Oliveira Diego Mathias Natal da Silva Sávio da Silva Berilli Departament of Plant Science Federal University of ViçosaMinas GeraisBrazil Center of Agrarian Sciences and Engineering Federal University of Espirito SantoEspírito SantoBrazil Federal Institute of Education Science and Technology of Espírito Santo-Campus ItapinaEspírito SantoBrazil Federal Institute of Education Science and Technology of Southeast Minas Gerais-Campus ManhuaçuMinas GeraisBrazil

Due to the current water scarcity in the world,it is extremely important to improve the use of this natural and exhaustible resource in agriculture,by contributing to increase agricultural production and *** models of crop growth simulation were developed to predict the edaphoclimatic effects on crop *** models are calibrated and validated for a given region using the data generated from field ***,the objective of this study was to calibrate and validate the FAO AquaCrop model for yacon(Smallanthus sonchifolius)crop in a tropical *** experiment was conducted in an experimental area located in the municipality of Ibatiba,state of Espírito Santo(Brazil)during the years of 2013 and *** calibration was done using the Autumn planting and validation with the Winter and Spring *** the statistical analysis,the coefficient of determination,Willmott concordance index,bias for the systematic error,root mean square error and the mean absolute error to test the model performance were *** general,the FAO AquaCrop model predicted the root yield,total biomass and harvest index with acceptable accuracy,and with deviations of less than 6%for total and root *** planting of yacon showed a reduction in yield as well as total biomass.

关键词： Smallanthus sonchifolius root yield simulation modelling agrometeorology

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用硫羟阳离子表面活性剂处理后毛纤维的抗菌性

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国外纺织技术（纺织针织服装化纤染整） 2002年第6期 33-37页

作者： M.diz 朱华

在适宜的温度和湿度条件下,毛纤维会成为微生物生长和传播的媒介.这些微生物会使毛纤维产生损伤,使皮肤搔痒或感染.近来合成了一种新型高效的季胺表面活性剂,N,N-二甲基-N-十二烷基氨基乙酸半胱氨酸氢氯化物(DABM).DABM可以通过其硫羟... 详细信息

在适宜的温度和湿度条件下,毛纤维会成为微生物生长和传播的媒介.这些微生物会使毛纤维产生损伤,使皮肤搔痒或感染.近来合成了一种新型高效的季胺表面活性剂,N,N-二甲基-N-十二烷基氨基乙酸半胱氨酸氢氯化物(DABM).DABM可以通过其硫羟基团与经亚硫酸盐预处理的毛纤维中的半胱氨酸-S-磺酸酯残余物(邦特盐)作用,或与毛纤维胱氨酸二硫键作用,从而与毛纤维反应,形成不对称的二硫键.对于经亚硫酸氢盐预处理和未预处理的毛纤维,都使用DABM处理.

关键词：硫羟阳离子表面活性剂毛纤维抗菌性抗菌处理

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Alendronate disturbs femoral growth due to changes during immunolocalization of transforming growth factor-β1 and bone morphogenetic protein-2 in epiphyseal plate

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World Journal of Experimental Medicine 2020年第1期10卷 1-9页

作者： Juliana Souza Vieira Emanuelle Juliana Cunha Juliana Feltrin de Souza Luis Henrique Koeler chaves Jessica Lakes de Souza Allan Fernando Giovanini Clinical Dentistry University PositivoCuritibaPR 81280330Brazil Stomatology Department University Federal of ParanáCuritibaPR 80210-170Brazil

BACKGROUND The epiphyseal growth plate is an important anatomical segment localized on the ends of a long *** the abovementioned atractive reasons for alendronate’s use,few data on the effect of alendronate during epiphyseal growth *** Verify the effect of alendronate on the growth epiphyseal plate,and compare its effect with the size of the femur during the double-staining of the immunolocalization of transforming growth factor-β1(TGF-β1)and bone morphogenetic protein-2(BMP2)in endochondral ossifing in specimens that have received *** Forty newborn rats were randomly divided into two groups:a control group(were given applications of 1 mg/kg physiologic saline)and a group that received Alendronate(a dose of 2.5 mg/kg).These groups were then divided into two subgroups for euthanasia in two and 12 d of *** euthanasia,the femurs were removed,and the femoral bones were measured linearly between the apex of the greater trochanter until the lower intercondylar midlle face to verify the probable bone growth between 3 and 12 d in control and alednroanto treated ***,the surgical pieces were also sent to the histopathology laboratory to produce histological *** obtained slides were stained with hematoxylin and eosin to measure each of the cartilage zones in endochondral *** other slides were immunohistochemically tested for anti-TGF-β1 and BMP-2 antibodies to investigate the immunolocalization of these proteins in the epiphyseal plaque *** On the third day,some diferences between the control group and specimens treated with alendronate were ***,we found similarities in size between the femoral bones when we compared the control group with the specimens that received *** the 12^th day,the bone size of the mice receiving the drug was significantly smaller than those of the control *** results coincide with changes in the TGF-β1 and BMP-2 *** the speci

关键词： Alendronate Bone development Epiphyseal plate Bone morphogentic protein-2 Transforming growth factor-β1

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Carbon pool dynamics after variable retention harvesting in Nothofagus pumilio forests of Tierra del Fuego

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Ecological Processes 2023年第1期12卷 64-82页

作者： Jimena E.chaves Marie-Claire Aravena Acuña Julián Rodríguez-Souilla Juan M.Cellini Nolan J.Rappa María V.Lencinas Pablo L.Peri Guillermo J.Martínez Pastur Centro Austral de Investigaciones Científicas(CADIC) Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Houssay 200(9410)UshuaiaTierra del FuegoArgentina Laboratorio de Investigaciones en Maderas(LIMAD) Universidad Nacional de la Plata(UNLP)Diagonal 113469(1900)La PlataBuenos AiresArgentina Nature Conservation&Landscape Ecology University of FreiburgTennenbacherstrasse 479106 FreiburgGermany Instituto Nacional de Tecnología Agropecuaria(INTA) Universidad Nacional de la Patagonia Austral(UNPA)Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET)Cc 332(9400)Río GallegosSanta CruzArgentina

Background It is necessary to determine the implications for managing forest stands using variable retention harvesting for maintaining carbon and for calculating the effects of different harvesting practices on above-and below-ground carbon balance in forest *** this context,forest carbon management has gained more attention among managers and policy-makers during recent *** aim of this study was to determine carbon pool dynamics in different forest ecosystem components after variable retention harvesting(VRH)to characterize the ecological stability and quantify the recovery rate through the years-after-harvesting(YAH).Methods Carbon pool compartmentalization of 14 different components was determined in 60 harvested and primary unmanaged forests during the first 18 YAH in Tierra del Fuego(Argentina).We compared them using uni-and multi-variate methods,relativizing the outputs with primary unmanaged *** We determined the effectiveness to retain carbon components in post-harvested stands under different retention strategies(aggregated ***).The balance among carbon pool components changed between managed and unmanaged stands across the YAH,and was directly related to the impact *** retention improved the ecological stability of the harvested areas,where the below-ground components were more stable than the above-ground *** recovery rate was directly related to the post-harvesting natural dynamics of the *** studied period was not enough to fully recover the C levels of primary unmanaged for-ests,but VRH showed advantages to increase the C pools in the managed *** Promoting VRH can improve sustainable forestry at the landscape level and in the long term,generating positive synergies with biodiversity and the provision of ecosystem *** study provides important new insights into forest carbon management,in particular to setting standards in carbon projects and sets the ground

关键词： Carbon reservoir Temperate forest Ecological stability Recovery rate Forest carbon management

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