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  1. Article: Simultaneous and individual quantitative estimation of Salmonella, Shigella and Listeria monocytogenes on inoculated Roma tomatoes (Lycopersicon esculentum var. Pyriforme) and Serrano peppers (Capsicum annuum) using an MPN technique

    Cabrera-Díaz, E / A. Castillo / D.G. González-Aguilar / J. Sánchez-Camarena / J.A. Muñiz-Flores / L. Martínez-Chávez / N.E. Martínez-Gonzáles / P. Gutiérrez-González / S.M. Arvizu-Medrano

    Food microbiology. 2018 Aug., v. 73

    2018  

    Abstract: ... of three strains of Salmonella, Shigella or L. monocytogenes, or by simultaneous inoculation of three ... analysis of variance (p < 0.05) and LSD multiple rang test. There were differences (p < 0.05) in recovery ... of simultaneous and individual bacteria inoculated (individual > simultaneous), type of bacteria (Salmonellaâ ...

    Abstract Simultaneous and individual enumeration of Salmonella, Shigella and Listeria monocytogenes was compared on inoculated Roma tomatoes and Serrano peppers using an Most Probable Number (MPN) technique. Samples consisting of tomatoes (4 units) or peppers (8 units) were individually inoculated with a cocktail of three strains of Salmonella, Shigella or L. monocytogenes, or by simultaneous inoculation of three strains of each pathogen, at low (1.2–1.7 log CFU/sample) and high (2.2–2.7 log CFU/sample) inocula. Samples were analyzed by an MPN technique using universal pre-enrichment (UP) broth at 35 °C for 24 ± 2 h. The UP tubes from each MPN series were transferred to enrichment and plating media following adequate conventional methods for isolating each pathogen. Data were analyzed using multifactorial analysis of variance (p < 0.05) and LSD multiple rang test. There were differences (p < 0.05) in recovery of simultaneous and individual bacteria inoculated (individual > simultaneous), type of bacteria (Salmonella > Shigella and L. monocytogenes), type of sample (UP broth > pepper and tomato), and inoculum level (high > low). The MPN technique was effective for Salmonella on both commodities. Shigella counts were higher on tomatoes compared to peppers, (p < 0.05), and for L. monocytogenes on peppers (p < 0.05).
    Keywords analysis of variance ; bacteria ; Capsicum annuum ; data analysis ; factor analysis ; inoculum ; Listeria monocytogenes ; most probable number technique ; pathogens ; peppers ; Salmonella ; Shigella ; Solanum lycopersicum var. lycopersicum ; tomatoes
    Language English
    Dates of publication 2018-08
    Size p. 282-287.
    Publishing place Elsevier Ltd
    Document type Article
    ZDB-ID 50892-5
    ISSN 1095-9998 ; 0740-0020
    ISSN (online) 1095-9998
    ISSN 0740-0020
    DOI 10.1016/j.fm.2018.02.009
    Database NAL-Catalogue (AGRICOLA)

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  2. Article: Matrix-effect free quantitative liquid chromatography mass spectrometry analysis in complex matrices using nanoflow LC with integrated emitter tip and high dilution factors

    Moreno-González, David / Jaime Alcántara-Durán / Bienvenida Gilbert-López / Juan F. García-Reyes / Antonio Molina-Díaz

    Journal of chromatography. 2017,

    2017  

    Abstract: Matrix effects are probably the Achilles heel of most quantitative liquid chromatography mass spectrometry (LC–MS) methods based on electrospray ionization. This work reports the evaluation of matrix effects in challenging matrices such as food ... ...

    Abstract Matrix effects are probably the Achilles heel of most quantitative liquid chromatography mass spectrometry (LC–MS) methods based on electrospray ionization. This work reports the evaluation of matrix effects in challenging matrices such as food extracts, human urine or wastewater at different dilution factors using nanoflow liquid chromatography-high resolution mass spectrometry (LC–MS). For this purpose, a suite of representative low-molecular weight compounds such as pesticides, drugs of abuse, sport drugs or environmental contaminants were selected. The approach is based on the use of reversed-phase C18 nano columns furnished with an integrated emitter tip. The nanoflow LC system was combined with full-scan high resolution mass spectrometry using a HRMS (orbitrap) instrument operated at a resolution of 70000. The sensitivity achieved with this configuration enables the implementation of high dilution factors (e.g. 1:20, 1:50 or beyond). When combining nanoflow LC–MS analysis with such high dilution factors (e.g. 1:50), signal suppression was negligible in most cases, so that matrix-matched standards may eventually be skipped, simplifying laboratory workflows by using external calibration in demanding applications such as drug analysis in urine, environmental contaminants in wastewater or pesticide testing in food, thus, eliminating the need for standard addition, matrix-matched calibration or isotopically-labelled standards.
    Keywords humans ; illicit drugs ; ionization ; liquid chromatography ; mass spectrometry ; pesticides ; pollution ; reports ; sports ; urine ; wastewater
    Language English
    Size p. .
    Publishing place Elsevier B.V.
    Document type Article
    Note Pre-press version
    ZDB-ID 218139-3
    ISSN 0021-9673 ; 0378-4355 ; 0376-737X
    ISSN 0021-9673 ; 0378-4355 ; 0376-737X
    DOI 10.1016/j.chroma.2017.09.006
    Database NAL-Catalogue (AGRICOLA)

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  3. Article: Evaluation of nanoflow liquid chromatography high resolution mass spectrometry for pesticide residue analysis in food

    Moreno-González, David / Patricia Pérez-Ortega / Bienvenida Gilbert-López / Antonio Molina-Díaz / Juan F- García-Reyes / Amadeo R. Fernández-Alba

    Journal of chromatography. 2017,

    2017  

    Abstract: This article reports on the evaluation of nanoflow liquid chromatography-mass spectrometry (LC-MS) for pesticide residue analysis in food. The approach is based on the use of reversed-phase C18nano columns with an integrated emitter, so that separation, ... ...

    Abstract This article reports on the evaluation of nanoflow liquid chromatography-mass spectrometry (LC-MS) for pesticide residue analysis in food. The approach is based on the use of reversed-phase C18nano columns with an integrated emitter, so that separation, ionization and detection are performed minimizing dead volumes. The use of nanoflow not only increases ionization efficiency and minimizes ionization suppression but also boost sensitivity compared to analytical-scale LC-MS methods The nanoflow LC system was combined with full-scan high resolution mass spectrometry using a Q-Exactive Orbitrap instrument. The analytical performance was assessed for over 60 representative pesticides in five representative commodities (tomato, baby food, orange, fruit-based jam and olive oil). The sensitivity achieved with this configuration enables the implementation of high dilution factors (eg. 1:20, 1:50 or beyond) in pesticide residue workflows without compromising sensitivity, featuring limits of quantitation in the low ng Kg−1 range. Using this dilution factors, signal suppression was found negligible in most cases (<10% in most cases, especially with 1:50 dilution), so that matrix-matched standards may be skipped, thus simplifying laboratory workflows. The robustness of the nanoflow LC system and its capability to withstand long analytical runs was also evaluated. Appropriate precision in terms of peak area and retention time was obtained at different concentration levels for over 125 injections without any instrument servicing. The main benefits of the nanoflow liquid chromatography approach are the high sensitivity gain and the outstanding reduction in matrix effects thanks to the high sample dilution factors that can be implemented, along with the substantial reduction in solvent usage.
    Keywords food contamination ; infant foods ; ionization ; jams ; liquid chromatography ; mass spectrometry ; olive oil ; oranges ; pesticide residues ; pesticides ; solvents ; tomatoes
    Language English
    Size p. .
    Publishing place Elsevier B.V.
    Document type Article
    Note Pre-press version
    ZDB-ID 218139-3
    ISSN 0021-9673 ; 0378-4355 ; 0376-737X
    ISSN 0021-9673 ; 0378-4355 ; 0376-737X
    DOI 10.1016/j.chroma.2017.07.019
    Database NAL-Catalogue (AGRICOLA)

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  4. Article: Nickelocene as precursor of microporous organometallic-derived carbon and nickel oxide-carbon nanocomposite

    González-García, P / D. Ávila-Brande / D. Arenas-Esteban / E. Urones-Garrote / L.C. Otero-Díaz

    Journal of Colloid And Interface Science. 2016,

    2016  

    Abstract: ... the characteristics D and G bands. The peak positions, the ratio of their intensities (ID/IG) and full width at half ... and micro-nanostructure, has been followed from 200 to 900 °C. Conventional ... electron energy-loss spectroscopy shows sp2 carbon bonding content higher than 95% and mass density in the range of 1.0 – 1.6 g ...

    Abstract Microporous flower-like and spherical carbon particles, made of graphene-like layers, have been obtained via chlorination of nickelocene (Ni(C5H5)2). Their mechanism of formation, in terms of morphology and micro-nanostructure, has been followed from 200 to 900 °C. Conventional transmission electron microscopy and high-resolution-TEM observations allow determining that their structure is made of highly disordered graphene-like layers. The Raman spectrum of the high temperature sample exhibits the characteristics D and G bands. The peak positions, the ratio of their intensities (ID/IG) and full width at half maximum suggest a high degree of disorder in the nanostructures. The calculated in-plane correlation length of these graphene-like layers is 1.15 nm. In all the carbon particles, electron energy-loss spectroscopy shows sp2 carbon bonding content higher than 95% and mass density in the range of 1.0 – 1.6 g/cm3. Textural studies show Type I adsorption isotherms with surface area of 922 m2/g for the sample produced at 900 °C. In addition, the basic hydrothermal treatment of the sample chlorinated at 600°C yields a composite material with NiO nanoparticles well dispersed within the carbon matrix.
    Keywords carbon ; chlorination ; hot water treatment ; nanocomposites ; nanoparticles ; nickel ; porous media ; sorption isotherms ; spectroscopy ; surface area ; temperature ; transmission electron microscopy
    Language English
    Size p. .
    Publishing place Elsevier Inc.
    Document type Article
    Note Pre-press version
    ZDB-ID 241597-5
    ISSN 1095-7103 ; 0021-9797
    ISSN (online) 1095-7103
    ISSN 0021-9797
    DOI 10.1016/j.jcis.2016.11.034
    Database NAL-Catalogue (AGRICOLA)

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  5. Article: Plant diversity partitioning in Mediterranean croplands: effects of farming intensity, field edge, and landscape context

    Concepción, Elena D / Federico Fernández-González / Mario Díaz

    Ecological applications. 2012 Apr., v. 22, no. 3

    2012  

    Abstract: Farmland biodiversity is affected by factors acting at various spatial scales. However, most studies to date have focused on the field or farm scales that only account for local (α) diversity, and these may underestimate the contribution of other ... ...

    Abstract Farmland biodiversity is affected by factors acting at various spatial scales. However, most studies to date have focused on the field or farm scales that only account for local (α) diversity, and these may underestimate the contribution of other diversity components (β diversity) to total (γ) farmland diversity. In this work, we aimed to identify the most suitable management options and the scale at which they should be implemented to maximize benefits for diversity. We used a multi‐scale additive partitioning approach, with data on plant diversity from 640 plots in 32 cereal crop fields from three agricultural regions of central Spain that differed in landscape configuration. We analyzed the relative contribution to overall plant diversity of different diversity components at various spatial scales and how these diversity components responded to a set of local (application of agri‐environment schemes [AES] and position within the field) and landscape (field size and landscape connectivity and composition) factors. Differences in species composition among regions and then among fields within regions contributed most to overall plant diversity. Positive edge effects were found on all diversity components at both the field‐ and regional scales, whereas application of AES benefited all diversity components only at the field scale. Landscape factors had strong influences on plant diversity, especially length of seminatural boundaries, which increased species richness at both the field and the regional scales. In addition, positive effects of percentage of nonproductive land‐uses in the landscape were found on all diversity components at the regional scale. Results showed that components that contributed most to overall plant diversity were not benefited by current AES. We conclude that agri‐environmental policies should incorporate and prioritize measures aimed at the maintenance of seminatural boundaries and patches of nonproductive habitats within agricultural landscapes, through landscape planning, cross‐compliance, or high nature‐value farmland programs. These options will help to conserve overall plant diversity at regional scales, as well as the spillover of plant species from such seminatural elements into crops, especially in Mediterranean areas that still harbor extensive farming and relatively complex landscapes.
    Keywords agri-environmental policy ; cropland ; crops ; edge effects ; extensive farming ; farms ; habitat connectivity ; landscapes ; planning ; species diversity ; Mediterranean region ; Spain
    Language English
    Dates of publication 2012-04
    Size p. 972-981.
    Publishing place Ecological Society of America
    Document type Article
    Note JOURNAL ARTICLE
    ZDB-ID 1074505-1
    ISSN 1939-5582 ; 1051-0761
    ISSN (online) 1939-5582
    ISSN 1051-0761
    DOI 10.1890/11-1471.1
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: Evasion of Early Antiviral Responses by Herpes Simplex Viruses

    Paula A. Suazo / Francisco J. Ibañez / Angello R. Retamal-Díaz / Marysol V. Paz-Fiblas / Susan M. Bueno / Alexis M. Kalergis / Pablo A. González

    Mediators of Inflammation, Vol

    2015  Volume 2015

    Keywords Pathology ; RB1-214 ; Medicine ; R
    Language English
    Publishing date 2015-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article: Application of Focused Ultrasound-Assisted Extraction for the Quantification of Persistent Organic Pollutions in Liver Tissue of Giant Toad (Rhinella marina)

    Flores-Ramírez, R / G. Espinosa-Reyes / V. G. Cilia-López / D. J. González-Mille / M. Rodríguez-Aguilar / L. Díaz de León-Martínez / F. Díaz-Barriga

    Bulletin of environmental contamination and toxicology. 2017 Feb., v. 98, no. 2

    2017  

    Abstract: ... between 1.7 and 4.8 and 3.5–7.5 ng/mL, respectively. Recovery rates were among 79%–116% for POPs ...

    Abstract A simple and rapid focused ultrasound extraction method was developed for the determination of Persistent Organic Pollutants (POPs) in liver tissue obtained of giant toad (Rhinella marina) using a gas chromatography coupled to a mass detector with electron impact ionization. The performed method for POPs, was validated in fortified matrix, showing linearity from the LOQ up to 100 ng/mL; LODs and LOQs for each compound were between 1.7 and 4.8 and 3.5–7.5 ng/mL, respectively. Recovery rates were among 79%–116% for POPs determined. Finally, the method was applied in liver samples of giant toads found in a malarial area in Mexico. The sensitivity of the proposed method was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.
    Keywords Bufo marinus ; gas chromatography ; ionization ; liver ; persistent organic pollutants ; toads ; ultrasonic treatment ; Mexico
    Language English
    Dates of publication 2017-02
    Size p. 204-211.
    Publishing place Springer US
    Document type Article
    ZDB-ID 6895-0
    ISSN 1432-0800 ; 0007-4861
    ISSN (online) 1432-0800
    ISSN 0007-4861
    DOI 10.1007/s00128-016-2009-y
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Foods contributing to vitamin B6, folate, and vitamin B12 intakes and biomarkers status in European adolescents: The HELENA study

    Iglesia, Iris / Theodora Mouratidou / Marcela González-Gross / Inge Huybrechts / Christina Breidenassel / Javier Santabárbara / Ligia-Esperanza Díaz / Lena Hällström / Stefaan De Henauw / Frédéric Gottrand / Anthony Kafatos / Kurt Widhalm / Yannis Manios / Denes Molnar / Peter Stehle / Luis A. Moreno

    European journal of nutrition. 2017 June, v. 56, no. 4

    2017  

    Abstract: ... ₂ intakes and biomarkers in adolescents. METHODS: In total 2189 individuals participating ... soups/bouillon (females) determined the most folate intakes and biomarkers. Considering vitamin B₁â ...

    Institution on the behalf of HELENA study group
    Abstract PURPOSE: To examine the association between food groups consumption and vitamin B₆, folate and B₁₂ intakes and biomarkers in adolescents. METHODS: In total 2189 individuals participating in the cross-sectional Healthy Lifestyle in Europe by Nutrition in Adolescence study met the eligibility criteria for analysis of dietary intakes (46 % males) and 632 for biomarker analysis (47 % males). Food intakes were assessed by two non-consecutive 24-h recalls. Biomarkers were measured by chromatography and immunoassay. Food groups which best discriminated participants in the extreme tertiles of the distribution of vitamins were identified by discriminant analyses. Food groups with standardised canonical coefficients higher or equal to 0.3 were selected as valid discriminators of vitamins intake and biomarkers extreme tertiles. Linear mixed model elucidated the association between food groups and vitamins intakes and biomarkers. RESULTS: Vitamin B₆ intakes and biomarkers were best discriminated by meat (males and females), margarine and mixed origin lipids only in males and breakfast cereals (females). Breakfast cereals (males), and fruits, margarine and mixed origin lipids, vegetables excluding potatoes, breakfast cereals, and soups/bouillon (females) determined the most folate intakes and biomarkers. Considering vitamin B₁₂ intakes and biomarkers, meat, and white and butter milk (males and females), snacks (males), and dairy products (females) best discriminated individual in the extremes of the distribution. Fewer associations were obtained with mixed model for biomarkers than for vitamins intakes with food groups. CONCLUSIONS: Whereas B-vitamin intakes were associated with their food sources, biomarkers did with overall food consumption. Low-nutrient-density foods may compromise adolescents’ vitamin status.
    Keywords adolescence ; adolescents ; biomarkers ; breakfast cereals ; buttermilk ; chromatography ; females ; folic acid ; food groups ; food intake ; fruits ; immunoassays ; lifestyle ; lipids ; males ; margarine ; meat ; potatoes ; pyridoxine ; snacks ; soups ; statistical models ; vitamin B12 ; vitamin status ; Europe
    Language English
    Dates of publication 2017-06
    Size p. 1767-1782.
    Publishing place Springer Berlin Heidelberg
    Document type Article
    ZDB-ID 1466536-0
    ISSN 1436-6215 ; 1436-6207
    ISSN (online) 1436-6215
    ISSN 1436-6207
    DOI 10.1007/s00394-016-1221-1
    Database NAL-Catalogue (AGRICOLA)

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  9. Article ; Online: Suitability of Biomorphic Silicon Carbide Ceramics as Drug Delivery Systems against Bacterial Biofilms

    J. Serra / M. Landin / P. González / R. Seoane / A. Pérez-Estévez / P. Díaz-Rodríguez

    ISRN Pharmaceutics, Vol

    2013  Volume 2013

    Keywords Pharmacy and materia medica ; RS1-441 ; Medicine ; R ; DOAJ:Pharmacy and materia medica ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2013-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article: Temporal carbon dynamics over the rotation period of two alternative management systems in Mediterranean mountain Scots pine forests

    Moreno-Fernández, Daniel / Eugenio Díaz-Pinés / Ignacio Barbeito / Mariola Sánchez-González / Fernando Montes / Agustín Rubio / Isabel Cañellas

    Forest ecology and management. 2015 July 15, v. 348

    2015  

    Abstract: Forests play an important role in the mitigation of global warming, acting as carbon sinks. However, the effects of forest management on the carbon pools over the rotation period in Mediterranean areas are scarcely understood. The objective of this work ... ...

    Abstract Forests play an important role in the mitigation of global warming, acting as carbon sinks. However, the effects of forest management on the carbon pools over the rotation period in Mediterranean areas are scarcely understood. The objective of this work is to assess the way in which two alternative management systems; one more intensive and the other more moderate (with less severe harvesting and more spread over time) affect the carbon stocks in the living tree biomass, coarse woody debris, forest floor and mineral soil in Mediterranean forests. For this purpose, two chronosequences were established covering the whole rotation period in two Pinus sylvestris L. forests. We conducted four forest inventories over a period of 15years, measuring the diameter and the height of all the trees higher than 1.3m in order to calculate the carbon stored in the living parts of the tree. Soil pits were excavated and we collected soil samples to estimate the soil organic carbon. We found that the temporal trends for living tree biomass were similar in both forests. However, the total living tree carbon stored at the end of the rotation period was greater in the forest with the longer rotation period and lighter thinning regime (345.5Mgha−1 of carbon) than in the intensively-managed forest (223.8Mgha−1 of carbon). On average, more carbon was found to be stored in the forest floor under the more intensive management system, whereas more carbon was present in the first 20cm of mineral soil under the moderate management system. Moreover, in each forest, the carbon stocks of the forest floor and in the uppermost cm of the soil remained constant over the rotation period. Therefore, management systems with longer rotation periods and moderate harvesting intensities are recommended to increase carbon fixation in Mediterranean forests.
    Keywords Pinus sylvestris ; biomass ; carbon ; carbon dioxide fixation ; carbon sinks ; chronosequences ; coarse woody debris ; coniferous forests ; forest inventory ; forest litter ; forest management ; global warming ; harvesting ; management systems ; mineral soils ; soil organic carbon ; soil sampling ; trees ; Mediterranean region
    Language English
    Dates of publication 2015-0715
    Size p. 186-195.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 751138-3
    ISSN 0378-1127
    ISSN 0378-1127
    DOI 10.1016/j.foreco.2015.03.043
    Database NAL-Catalogue (AGRICOLA)

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