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Determination of L-norvaline and L-tryptophan in dietary supplements by nano-LC using an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11- dihydroquinidine-silica hybrid monolithic column

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Journal of Pharmaceutical Analysis 2020年第1期10卷 70-77页

作者： Dongsheng Xu elena sanchez-Lopez Qiqin Wang Zhengjin Jiang mar.a Luisa marina Departamento de Química Analítica Química Física e Ingeniería QuímicaUniversidad de AlcalaCtra.Madrid-Barcelona Km.33.60028871Alcala de Henares(Madrid)Spain Institute of Pharmaceutical Analysis College of PharmacyJinan UniversityGuangzhou510632China Department of Pharmacy and Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine&New Drug Research Jinan UniversityGuangzhou510632China Instituto de Investigacion Química“Andres M.del Río”(IQAR) Universidad de AlcalaCtra.Madrid-Barcelona Km.33.60028871Alcala de Henares(Madrid)Spain

An analytical methodology based on an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine(MQD)-silica hybrid monolithic column was developed for the enantioseparation of 9-fluorenylmethoxycarbonyl(FMOC)derivatized amino acids by nano-liquid *** mobile phase was optimized including the apparent pH,content of ACN,and concentration of the buffer to obtain a satisfactory enantioresolution performance.27 FMOC derivatized amino acids including 19 protein and 8 non-protein amino acids were tested,and 19 out of them were enantiomerically discriminated obtaining baseline separation for 11 of *** characteristics of the method were evaluated for norvaline and tryptophan in terms of linearity,precision,accuracy,limits of detection(LOD)and quantitation(LOQ)showing good performance to be applied to the enantiomeric determination of these amino acids in dietary *** and LOQ values were 9.3 and 31 mM for norvaline enantiomers and 7.5 and 25 mM for tryptophan enantiomers,*** contents of D-norvaline and D-tryptophan were below their respective LODs in all the analyzed *** of L-tryptophan and L-norvaline showed good agreement with the labeled contents except for one sample which did not show presence of L-norvaline,contrary to the label indication.

关键词： 9-Fluorenylmethoxycarbonyl Amino acids Chiral separation Nano-LC Quinidine-silica hybrid monolithic column

Chemical Characterisation of the Industrial Residues of the Pineapple (Ananas comosus)

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Journal of Agricultural Chemistry and Environment 2014年第2期3卷 53-56页

作者： mar.a elena sánchez pardo mar.a elena Ramos Cassellis Rosalva Mora Escobedo Epifanio Jiménez García Benemérita Universidad Autónoma de Puebla Av.San Claudio y 18 sur Edif.106 Ciudad Universitaria Puebla Pue.3ExHacienda san Juan Molino km 1.5 carretera Estatal Tecuexcomac-Tepetitla México Instituto Politécnico Nacional Escuela Nacional de Ciencias Biológicas Prolongación de Carpio y Plan de Ayala S/N Col. Sto. Tomás. C.P. 11340 México D.F. México

In Mexico pineapple processing produces industrial residues with a high concentration of dietary fibre. The aim of this study was to quantify the constituents of the fibrous residues from the industrial processing of ... 详细信息

关键词： Pineapple Total Dietary Fibre Hemicelluloses Cellulose Lignin Pectin

Cellular automata model for traffic flow with safe driving conditions

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Chinese Physics B 2014年第5期23卷 216-226页

作者： mar.a elena Lárraga Luis Alvarez-Icaza Instituto de Ingeniería Universidad Nacional Autónoma de México04510Coyoacán D.F.México

In this paper, a recently introduced cellular automata （CA） model is used for a statistical analysis of the inner micro-scopic structure of synchronized traffic flow. The analysis focuses on the formation and dissolution of clusters or platoons of vehicles, as the mechanism that causes the presence of this synchronized traffic state with a high flow. This platoon formation is one of the most interesting phenomena observed in traffic flows and plays an important role both in manual and automated highway systems （AHs）. simulation results, obtained from a single-lane system under periodic boundary conditions indicate that in the density region where the synchronized state is observed, most vehicles travel together in pla- toons with approximately the same speed and small spatial distances. The examination of velocity variations and individual vehicle gaps shows that the flow corresponding to the synchronized state is stable, safe and highly correlated. Moreover, results indicate that the observed platoon formation in real traffic is reproduced in simulations by the relation between vehicle headway and velocity that is embedded in the dynamics definition of the CA model.

关键词： traffic flow models synchronized traffic cellular automata platoons formation

Clinico-radiological dissociation in multiple sclerosis: Future prospects

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World Journal of Neuroscience 2013年第3期3卷 147-153页

作者： elena Zapata-Arriaza mar.a Díaz-sánchez Neurology service University Hospital Virgen del Rocio Sevilla Spain

Magnetic resonance imaging (MRI) has significantly contributed to our capabilities of diagnosis multiple sclerosis (Ms) since it is able to detect demyelinating lesions in almost 100% of patients. However, there are modest correlations between irreversible disability and white matter lesion load, as measured by T2-weighted MRI scans, which represents the clinicoradiological paradox of Ms. We report the case of a patient with Ms and few neurological manifestations despite extensive T2 visible morphologic abnormalities. The use of non-conventional MRI techniques, which are more specific in the analysis of the pathological substrate of demyelinating lesions and normal appearing brain matter (both white and gray matter), might assist us to overcome this limitation of conventional MRI.

关键词： Multiple sclerosis Disability Progression Magnetic Resonance Imaging Diffusion-Tensor Imaging Proton Magnetic Resonance spectroscopic Imaging

Upper gastrointestinal endoscopic findings in celiac disease at diagnosis:A multicenter international retrospective study

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World Journal of Gastroenterology 2022年第43期28卷 6157-6167页

作者： Juan Pablo stefanolo Fabiana Zingone Carolina Gizzi Ilaria marsilio mar.a Luján Espinet Edgardo Gustavosmecuol mark Khaouli mar.a Laura Moreno mar.a I Pinto-sánchez sonia Isabel Niveloni elena F Verdú Carolina Ciacci Julio César Bai small Bowel section Dr.C.Bonorino Udaondo Gastroenterology HospitalBuenos Aires 1264Argentina Department of surgery Oncology and GastroenterologyUniversity of PaduaPadova 35124Italy Gastroenterology Unit Azienda Ospedale UniversitàPadova 35128Italy Department of Medicine SurgeryDentistryScuola Medica SalernitanaUniversity of SalernoSalerno 84081Italy Department of Medicine Farncombe Family Digestive Health Research InstituteMcMaster UniversityHamilton L8S 4K1Canada Research Institutes Universidad del SalvadorBuenos Aires 1020Argentina

BACKGROUND Gastroduodenal endoscopy and biopsy following positive specific serology is considered the gold standard to diagnose celiac disease(CeD)in *** upper endoscopy helps detect comorbid conditions is *** To investigate the prevalence of non-celiac endoscopic findings in patients in whom endoscopy was performed to confirm CeD *** This is an observational,descriptive,multicenter,retrospective study that reports endoscopic findings obtained in adult patients enrolled in local registries from four tertiary *** collected data reported on first endoscopy,indicated for investigation of *** of CeD was performed by histology(≥marsh 2type mucosal damage)and specific *** European and one North American center included biopsy-confirmed CeD following positive serology.A fourth center(south America)included symptomatic patients undergoing endoscopy,irrespective of CeD *** latter cohort included a non-CeD control *** A total of 1328 patients(80%female;35 years median age)were enrolled,of whom 95.6%had positive specific *** 135 patients,endoscopy revealed 163 abnormalities unrelated to CeD(prevalence:10.1%).Erosive reflux esophagitis(6.4%),gastric erosions(2.0%),and suspicion of esophageal metaplasia(1.2%)were the most common ***-confirmed Barrett’s esophagus was infrequent(0.2%).No endoscopic cancer was *** patients(≥51 years of age)had a higher prevalence of endoscopic findings than those≤50(Psouth American cohort,CeD was associated with a lower rate(8.2%)of comorbid endoscopic findings compared with controls(29.1%;Psted multivariate analysis of this cohort,having CeD was associated with a 72%reduction in the risk of any endoscopic abnormality(Psymptoms was associated with a 37%reduction in the risk of finding at least one endoscopic lesion(PsION In this large multicenter study,young adults w

关键词： Celiac disease Upper gastrointestinal endoscopy Concomitant endoscopic lesions Malignancies Multicenter study

Hypolipidemic Activity of Microwave-Dehydrated Mango (Mangifera indicaL.) Powder in Mice Fed a Hypercholesterolemic Diet

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Journal of Biomedical science and Engineering 2014年第10期7卷 809-817页

作者： Obed Osorio-Esquivel Vianney Cortés-Viguri Leticia Garduñ o-siciliano Alicia Ortiz-Moreno mar.a elena sánchez-pardo Department of Biochemical Engineering National School of Biological Sciences National Polytechnic Institute Mexico City Mexico Department of Physiology National School of Biological Sciences National Polytechnic Institute Mexico City Mexico

The effect of dietary supplementation with mango (Mangifera indica L.) powder obtained by microwave dehydration was studied in normal and hypercholesterolemic mice. The phenolic profiles in methanolic extracts and antioxidant activities were determined using high-performance liquid chromatography and DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTs (2,2'-azino-bis-3-ethyl-benzothiazoline-6-sulphonic acid) assays, respectively. The total phenolic content of microwave-dehydrated mango powder was 1451.7 ± 26.7 μggallic acid equivalents/g dry weight. The main phenolic compounds identified were gallic acid, epicatechin, ferulic acid, and catechin. The anti-oxidant activity was 14.6% higher in microwave-dehydrated mango powder than in conventional mango powder. Mice were fed a hypercholesterolemic diet (1 g cholesterol/100g over 7 days). The hypercholesterolemic mice whose diets were supplemented with microwave-dehydrated mango powder showed a significant decrease (P ≤ 0.05) in total serum cholesterol compared to the hypercholesterolemic mice and the mice fed with conventional dehydrated mango powder. We observed a significant increase (P ≤ 0.05) in HDL-c levels in the microwave-dehydrated mango powder group mice (12.4 ± 1.3 mmol/L) compared to the hypercholesterolemic group (8.6 ± 1.4 mmol/L) and the conventional-dehydrated mango powder group (10.9 ± 1.3 mmol/L). The mice provided with microwave-dehydrated mango powder had significantly lower (P ≤ 0.05) levels of serum LDL-c (36.0%) and total cholesterol (43.3%) compared to the mice in hypercholesterolemic group. Notably, the atherogenic index was 72% lower in the microwave-dehydrated mango powder group compared to the hypercholesterolemic group. These results suggest that the biocompounds, such as polyphenols and dietary fiber, found in mango pulp might improve the lipid profile in mice fed a hypercholesterolemic diet.

关键词： Hypolipidemic Activity Microwave-Dehydrated Mango Powder Hypercholesterolemic Diet Phenolic Profiles

Microwave Dried Carrot Pomace as a source of Fiber and Carotenoids

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Food and Nutrition sciences 2013年第10期4卷 1037-1046页

作者： marcela Hernández-Ortega Guy Kissangou Hugo Necoechea-Mondragón mar.a elena sánchez-pardo Alicia Ortiz-Moreno Coordinación de Cooperación Académica Edificio de la Secretaría Académica Instituto Politécnico Nacional México City México. Departamento de Ingeniería Bioquímica Escuela Nacional de Ciencias Biológicas Instituto Politécnico Nacional México City México

Carrot pomace is a major by-product obtained during the industrial juice extraction process, which is discarded contributing to environmental pollution. This residue is rich in fiber, and contains high amounts of carotenoids and phenolic compounds that could contribute to its application as functional ingredient, improving the quality of foods and helping to reduce the environmental problem. In this study, carrot pomace powders obtained by microwave or hot air drying were incorporated into cookies in order to improve their phytochemical content. Cookies were prepared using a traditional cookie recipe substituting 30% of the wheat flour for either of the carrot pomace powders. Fiber, carotenoids and phenolic compounds were determined;image analysis and acceptability of the cookies were also conducted. The substitution of 30% of wheat flour for carrot pomace powders increased 3.7 fold the total dietary fiber of cookies, from 7.13 g/100gto26.44 g/100g;accounting the 7.4% of fiber daily intake with the consumption of one cookie (7 g). A similar pattern was found in the content of carotenoids and phenolic compounds. Carrot pomace dried with microwaves had the highest amount of these bioactive compounds. β-carotene, epicatechin, gallic and ferulic acids were identified in cookies with microwave carrot pomace powder. The cookies incorporated with carrot pomace powders exhibited improved antioxidant properties because of the increase in the phytochemical content. Acceptable cookies with appealing orange color were obtained. The results indicated that the replacement of wheat flour for carrot pomace powders yielded dietary fiber enriched cookies with improved carotenoid content.

关键词： Carrot Pomace Microwave Drying Fiber Carotenoids Phenolic Compounds Antioxidant Activity Cookie

Grasslands Response to Livestock Grazing Intensity in the Austral Pampas(Argentina):Testing the Intermediate Disturbance Hypothesis

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Phyton-International Journal of Experimental Botany 2024年第8期93卷 2037-2050页

作者： Ana elena de Villalobos mar.a Andrea Long Grupo de Investigación en Ecosistemas de Pastizal(GIEP) CERZOSCONICETBahía Blanca8000Argentina Departamento de Biología Bioquímica y FarmaciaUniversidad Nacional del SurBahía Blanca8000Argentina

Livestock grazing has a significant impact on natural grasslands,with approximately one-third of the world’s land area dedicated to this *** 20%of global grasslands are highly degraded due to overgrazing,affecting their productivity and conservation *** practices are required to ensure sustainable livestock production that supports *** Intermediate Disturbance Hypothesis(IDH)suggests that environments with moderate levels of disturbance exhibit a higher species *** grazing can reduce the dominance of certain species,thereby enhancing plant ***,concerns arise regarding the increase of exotic and unpalatable species under moderate grazing levels,complicating grassland conservation *** impact of livestock grazing on the functional structure of grasslands depends on factors such as grazing intensity,livestock species,and environmental *** in grazing intensity may increase specific and functional diversity under moderate grazing,potentially masking the presence of invasive exotic *** the Austral Pampas(Pampean phytogeographic province,Buenos Aires,Argentina),grasslands face various pressures from domestic livestock grazing that endanger their integrity if not properly ***,our study aims to investigate potential differences in species richness and diversity,functional diversity,exotic plant abundance,and the number and distribution of plant functional groups across varying grazing *** IDH is utilized as a tool to regulate livestock pressure for grassland *** and functional diversity indices were used to assess the impact of grazing on grassland *** grazing increased species and functional diversity,while intensively grazed or ungrazed areas showed reduced *** presence influenced the balance between native and exotic plants,with ungrazed areas having higher native plant abundance and grazed areas exhibiti

关键词： Natural grasslands grazing effects disturbance specific and functional diversity

Intense Visible Photoluminescence from C46H22N8O4KM (M = Co, Fe, Pb) Derivatives Thin Films

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Advances in Materials Physics and Chemistry 2011年第3期1卷 57-63页

作者： mar.a elena sánchez Juan Carlos Alonso Jerry Nathan Reider 不详

strong visible photoluminescence (PL) at room temperature is obtained from thermal-evaporated thin solid films of Metallophthalocyanine (M = Co, Fe, Pb) and double potassium salt from 1,8 dihydroxyan-thraquinone. The PL of all the investigated samples is observed with the naked eye in a bright background. The deconvolution of the normalized PL spectra shows that each PL spectrum is composed of four emission bands which peak at approximately the same energies of 2.1, 2.2 and 2.4 eV and whose intensities and widths depend upon the structure of the complexes. FTIR and ellipsometry are employed to investigate the structural differences among the films. The optical absorption of the films is also investigated to evaluate the changes in the electronic structure of these metal organic compounds, with respect to other metalphtalocya-nines thin films. Our results suggest that the visible PL comes from radiative transitions between energy lev-els associated to the double potassium salt coordination to the metallic ion in the phthalocyanine.

关键词： Thin Films Optical Properties Photoluminescence