pinecone/core-2020-05-10-deduplication huggingface dataset:
Chiral capillary electrophoresis in food analysis

9 páginas, 5 figuras, 2 tablas.-- El pdf del artículo es la versión post-print.-- Review.This review article addresses the different chiral capillary electrophoretic methods used to study and characterize foods and beverages through the enantiomeric separation of different food compounds such as amino acids, pesticides, polyphenols, etc. This work intends to provide an updated overview on the main applications of such enantioselective procedures together with their main advantages and drawbacks in food analysis. Some foreseeable applications and developments of these chiral CZE, CEC and MEKC methods for food characterization are also discussed. Papers that were published within the period January 2003 to October 2009 are included, following the previous review on this topic by Simo et al. (Electrophoresis 2003, 24, 2431–2441).This work was supported by the following projects:\ud
2008IT0013 CSIC-CNR bilateral project, AGL2008-05108-\ud
C03-01 (Ministerio de Ciencia e Innovación) and CSD2007-\ud
00063 FUN-C-FOOD (Programa CONSOLIDER, Ministerio\ud
de Educación y Ciencia). M. H. thank Spanish Science and\ud
Innovation Ministry (MICINN) for a ‘‘Juan de la Cierva’’\ud
contract.Peer reviewe
Simultaneous detection of genetically modified organisms by multiplex ligation-dependent genome amplification and capillary gel electrophoresis with laser-induced fluorescence

11 páginas, 5 figuras, 2 tablas.-- El pdf del artículo es la versión revisada de autor.In this work, an innovative method useful to simultaneously analyze multiple genetically modified organisms is described. The developed method consists in the combination of multiplex ligation-dependent genome dependent amplification (MLGA) with CGE and LIF detection using bare-fused silica capillaries. The MLGA process is based on oligonucleotide constructs, formed by a universal sequence (vector) and long specific oligonucleotides (selectors) that facilitate the circularization of specific DNA target regions. Subsequently, the circularized target sequences are simultaneously amplified with the same couple of primers and analyzed by CGE-LIF using a bare-fused silica capillary and a run electrolyte containing 2-hydroxyethyl cellulose acting as both sieving matrix and dynamic capillary coating. CGE-LIF is shown to be very useful and informative for optimizing MLGA parameters such as annealing temperature, number of ligation cycles, and selector probes concentration. We demonstrate the specificity of the method in detecting the presence of transgenic DNA in certified reference and raw commercial samples. The method developed is sensitive and allows the simultaneous detection in a single run of percentages of transgenic maize as low as 1% of GA21, 1% of MON863, and 1% of MON810 in maize samples with signal-to-noise ratios for the corresponding DNA peaks of 15, 12, and 26, respectively. These results demonstrate, to our knowledge for the first time, the great possibilities of MLGA techniques for genetically modified organisms analysis.This work was supported by AGL2008-05108-C03-01\ud
(Ministerio de Ciencia e Innovación) and CSD2007-00063\ud
FUN-C-FOOD (Programa CONSOLIDER, Ministerio de\ud
Educacion y Ciencia) projects.Peer reviewe
Induced-charge electrophoresis near a wall

Induced-charge electrophoresis (ICEP) has mostly been analyzed for asymmetric particles in an infinite fluid, but channel walls in real systems further break symmetry and lead to dielectrophoresis (DEP) in local field gradients. Zhao and Bau (Langmuir 2007, 23, 4053) predicted that a metal (ideally polarizable) cylinder is repelled from an insulating wall in a DC field. We revisit this problem with an AC field and show that attraction to the wall sets in at high frequency and leads to an equilibrium distance, where DEP balances ICEP, although, in three dimensions, a metal sphere is repelled from the wall at all frequencies. This conclusion, however, does not apply to asymmetric particles. Consistent with the experiments of Gangwal et al. (Phys. Rev. Lett. 2008, 100, 058302), we show that a metal/insulator Janus particle is always attracted to the wall in an AC field. The Janus particle tends to move toward its insulating end, perpendicular to the field, but ICEP torque rotates this end toward the wall. Under some conditions, the theory predicts steady translation along the wall, perpendicular to the field, at an equilibrium tilt angle around 45°, consistent with the experiments, although improved models are needed for a complete understanding of this phenomenon.National Science Foundation (U.S.) (Contract No. DMS-0707641)Ecole supérieure de physique et de chimie (Paris, France
Genotyping of Saccharomyces cerevisiae strains by interdelta sequence typing using automated microfluidics

Amplification of genomic sequences flanked by delta elements of retrotransposons TY1 and TY2 is a reliable method for characterization of Saccharomyces cerevisiae strains. The aim of this study is to evaluate the usefulness of microfluidic electrophoresis (Caliper LabChip®) to assess the factors that affect interlaboratory reproducibility of interdelta sequence typing for S. cerevisiae strain delimitation. We carried out experiments in two laboratories, using varying combinations of Taq DNA polymerases and thermal cyclers. The reproducibility of the technique is evaluated using non-parametric statistical tests and we show that the source of Taq DNA polymerase and technical differences between laboratories have the highest impact on reproducibility, whereas thermal cyclers have little impact. We also show that the comparative analysis of interdelta patterns is more reliable when fragment sizes are compared, than when absolute and relative DNA concentrations of each band are considered. Interdelta analysis based on a smaller fraction of bands with intermediate sizes between 100 and 1000 bp yield the highest reproducibility.Fundação para a Ciência e Tecnologi
In-line preconcentration capillary zone electrophoresis for the analysis of haloacetic acids in water

Two in-line enrichment procedures (large volume sample stacking (LVSS) and field amplified sample injection (FASI)) have been evaluated for the capillary zone electrophoresis (CZE) analysis of haloacetic acids (HAAs) in drinking water. For LVSS, separation on normal polarity by using 20 mM acetic acid-ammonium acetate (pH 5.5) containing 20% acetonitrile as BGE was required. For FASI, the optimum conditions were 25 s hydrodynamic injection (3.5 kPa) of a water plug followed by 25 s electrokinetic injection (-10 kV) of the sample, and 200 mM formic acid-ammonium formate buffer at pH 3.0 as BGE. For both FASI and LVSS methods, linear calibration curves (r2>0.992), limit of detection (LOD) on standards prepared in Milli-Q water (49.1-200 µg/L for LVSS and 4.2-48 µg/L for FASI), and both run-to-run and day-to-day precisions (RSD values up to 15.8% for concentration) were established. Due to the higher sensitive enhancement (up to 310-fold) achieved with FASI-CZE this method was selected for the analysis of HAAs in drinking water. However, for an optimal FASI application sample salinity was removed by solid phase extraction (SPE) using Oasis WAX cartridges. With SPE-FASI-CZE, method detection limits in the range 0.05-0.8 µg/L were obtained, with recoveries, in general, higher than 90% (around 65% for monochloroacetic and monobromoacetic acids). The applicability of the SPE-FASI-CZE method was evaluated by analyzing a drinking tap water from Barcelona where seven HAAs were found at concentration levels between 3-13 µg/L
Determination of betaines in vegetable oils by capillary electrophoresis tandem mass spectrometry. Application to the detection of olive oil adulteration with seed oils.

The final publication is available at Springer via http://dx.doi.org/10.1002/elps.201100005A capillary electrophoresis-tandem mass spectrometry methodology enabling the\ud
simultaneous determination of betaines (glycine betaine, trigonelline, proline betaine and\ud
total content of carnitines) in vegetable oils was developed. Betaines were derivatized\ud
with butanol previous to their baseline separation in 10 min using a 0.1 M formic acid\ud
buffer at pH 2.0. Ion trap conditions were optimized in order to maximize selectivity and\ud
sensitivity. Analytical characteristics of the proposed method were established by\ud
evaluating its selectivity, linearity, precision (RSDs ranged from 4.8% to 10.7% for\ud
corrected peak areas), accuracy by means of recovery studies (from 80% to 99%) and\ud
LODs and LOQs at 0.1 ppb level. The method was applied to the determination of the\ud
selected betaines in seed oils and extra virgin olive oils. MS2 experiments provided the\ud
fingerprint fragmentation for all betaines studied in seed oils. In extra virgin olive oils,\ud
carnitines were not detected being possible to propose them as a feasible novel marker for\ud
the detection of adulterations of olive oils. Application of the developed method to the\ud
analysis of different mixtures of extra virgin olive oil with seed oil (between 2-10 %)\ud
enabled the detection and quantitation of the total content of carnitines. The results\ud
obtained show the high potential of the developed method for the authentication and\ud
quality control of olive oils.Authors thank the Spanish Ministry of Science and Innovation (project CTQ2009- 09022) and the Comunidad Autónoma of Madrid (Spain) and european funding from FEDER programme (project S2009/AGR-1464, ANALISYC-II). They also thank the University of Alcalá and the Comunidad Autónoma of Madrid for project CCG10- UAH/AGR-5950. Laura Sánchez-Hernández thanks the Comunidad Autónoma of Madrid for her research contract
Is metabolomics reachable? Different purification strategies of human colon cancer cells provide different CE-MS metabolite profiles

13 páginas, 3 figuras, 1 tabla.--El pdf del artículo es la versión de autor.In this work, four different metabolite purification approaches are investigated prior to metabolomics of human HT29 colon cancer cells. Namely, methanol deproteinization, ultrafiltration and two SPE methods using C18 and polymer-based cartridges were studied. The extracts were characterized via a metabolomic approach based on the application of CE TOF MS (CE-MS). CE-MS analysis time was less than 20 min per sample and allowed the simultaneous and reproducible analysis of more than 80 metabolites in a single run with a minimum consumption of sample and reagents. Metabolome analysis revealed in some cases important differences among the studied metabolite purification procedures. No significant differences were observed in the metabolite profile using C18 and polymer-based cartridges, or between ultrafiltration and methanol deproteinization. However, important differences were observed in the metabolomic profiles obtained from SPE and methanol deproteinization samples. These results demonstrate the crucial role of the metabolite purification strategy in metabolomics since it can bias (and in some cases mislead) the conclusions achieved by the metabolomic studyThis work was supported by AGL2008-05108-C03-01 and\ud
200870I185 (Ministerio de Ciencia e Innovación, Spain), and\ud
CSD2007-00063 FUN-C-FOOD (Programa CONSOLIDER,\ud
Ministerio de Educacion y Ciencia, Spain). C.I. thanks the\ud
Ministerio de Ciencia e Innovación for her FPI pre-doctoral\ud
fellowship.Peer reviewe
Rapid, automated measurement of dielectrophoretic forces using DEP-activated microwells.

Dielectrophoresis (DEP) is a physical effect that generates a force on polarisable particles experiencing a non-homogeneous electric field; studying the effect as a function of frequency allows the determination of the electrical properties of that particle, i.e. the electrical permittivity and conductivity. In the past, DEP-based techniques applied to the measurement of one or several cells at a time have been subject to many sources of noise, which result in an ambiguous or inaccurate result. However, improvements are possible by generating more information from the experiments. In this paper, we present a rapid automated system that measures the DEP spectrum from a large population of cells with a low level of noise using the microwell electrodes, based on a method of analysis that provides additional information about the electrical properties of the cells and a new theoretical approach was developed to obtain accurate, bias-free results in <5 min
Analysis of chiral amino acids in cerebrospinal fluid samples linked to different stages of Alzheimer disease

El pdf del artículo es la versión de autor.-- et al.Chiral micellar electrokinetic chromatography with laser-induced fluorescence detection (chiral-MEKC-LIF) was used to investigate D- and L-amino acid contents in cerebrospinal fluid (CSF) samples related to different Alzheimer disease (AD) stages. CSF samples were taken from (i) control subjects (S1 pool), (ii) subjects showing a mild cognitive impairment who remained stable (S2 pool), (iii) subjects showing an mild cognitive impairment that progressed to AD (S3 pool) and (iv) subjects diagnosed with AD (S4 pool). The optimized procedure only needed 10μL of CSF and it included sample cleaning, derivatization with FITC and chiral-MEKC-LIF separation. Eighteen standard amino acids were baseline separated with efficiencies up to 703000plates/m, high sensitivity (LODs in the nM range) and good resolution (values ranging from 2.6 to 9.5). Using this method, L-Arg, L-Leu, L-Gln, γ-aminobutyric acid, L-Ser, D-Ser, L-Ala, Gly, L-Lys, L-Glu and L-Asp were detected in all the CSF samples. S3 and S4 samples (i.e. AD subjects) showed significant lower amounts of L-Arg L-Lys, L-Glu and L-Asp compared to the non-AD S1 and S2 samples, showing in the S4 group the lowest amounts of L-Arg L-Lys, L-Glu and L-Asp. Moreover, γ-aminobutyric acid was significantly higher in AD subjects with the highest amount also found for S4. No significant differences were observed for the rest of amino acids including D-Ser. Based on the obtained chiral-MEKC-LIF data, it was possible to correctly classify all the samples into the four groups. These results demonstrate that the use of enantioselective procedures as the one developed in this work can provide some new light on the investigations of AD, including the discovery of new biomarkers related to different stages of AD. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.S.S. thanks Shota Rustaveli Georgia National Science Foundation for her Young Scientists Grant (Project 04/03). C.I. thanks the Ministerio de Ciencia e Innovación for her FPI predoctoral fellowship. This work was supported by: Projects AGL2008-05108-C03-01 and CONSOLIDER INGENIO 2010 CSD2007-00063 FUN-C-FOOD (Ministerio de Educación y Ciencia), Gun och Bertil Stohnes Stiftelse, Karolinska Institutets fund for geriatric research, Stiftelsen Gamla Tjanarinnor, Stiftelsen Dementia, Swedish Alzheimer Foundation, Swedish Brain Foundation, Ramon Areces Foundation and the regional agreement on medical training and clinical research (ALF) between Stockholm County Council and the Karolinska Institute.Peer Reviewe
Dielectrophoresis in microfluidics technology

Cataloged from PDF version of article.Dielectrophoresis (DEP) is the movement of a particle in a non-uniform electric field due
to the interaction of the particle’s dipole and spatial gradient of the electric field. DEP is a
subtle solution to manipulate particles and cells at microscale due to its favorable scaling
for the reduced size of the system. DEP has been utilized for many applications in
microfluidic systems. In this review, a detailed analysis of the modeling of DEP-based
manipulation of the particles is provided, and the recent applications regarding the
particle manipulation in microfluidic systems (mainly the published works between 2007
and 2010) are presented
Harnessing glycomics technologies: Integrating structure with function for glycan characterization

Glycans, or complex carbohydrates, are a ubiquitous class of biological molecule which impinge on a variety of physiological processes ranging from signal transduction to tissue development and microbial pathogenesis. In comparison to DNA and proteins, glycans present unique challenges to the study of their structure and function owing to their complex and heterogeneous structures and the dominant role played by multivalency in their sequence-specific biological interactions. Arising from these challenges, there is a need to integrate information from multiple complementary methods to decode structure–function relationships. Focusing on acidic glycans, we describe here key glycomics technologies for characterizing their structural attributes, including linkage, modifications, and topology, as well as for elucidating their role in biological processes. Two cases studies, one involving sialylated branched glycans and the other sulfated glycosaminoglycans, are used to highlight how integration of orthogonal information from diverse datasets enables rapid convergence of glycan characterization for development of robust structure–function relationships.National Institutes of Health (U.S.) (GM R37 GM057073-13)Singapore-MIT Alliance for Research and Technolog
Recent advances in the application of capillary electromigration methods for food analysis and Foodomics

The analysis of food components using capillary electromigration methods is reviewed in this work. Papers that were published from February 2009 to February 2011 are included following the previous review by Herrero et al. (Electrophoresis, 2010, 31, 205-228). The analysis of amino acids, biogenic amines, peptides, proteins, DNAs, carbohydrates, phenols, polyphenols, pigments, toxins, pesticides, vitamins, additives, small organic and inorganic ions and other compounds found in foods and beverages are reviewed, as well as those applications of CE for monitoring food interactions and food processing. The use of microchips, CE-MS and chiral-CE in food analysis is also discussed as well as other current and foreseen trends in this area of research including new developments in Foodomics. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.This work was supported by AGL2008-05108-C03-01 (Ministerio de Ciencia e Innovación, Spain), and CSD2007- 00063 FUN-C-FOOD (Programa CONSOLIDER, Ministerio de Educacion y Ciencia, Spain). M.C.-P. thanks the Ministerio de Ciencia e Innovación for her Juan de la Cierva contract (JCI- 2009-05297).Peer Reviewe
Recent approaches in sensitive enantioseparations by CE

The latest strategies and instrumental improvements for enhancing the detection sensitivity in chiral analysis by CE are reviewed in this work. Following the previous reviews by García-Ruiz et al. (Electrophoresis 2006, 27, 195-212) and Sánchez-Hernández et al. (Electrophoresis 2008, 29, 237-251; Electrophoresis 2010, 31, 28-43), this review includes those papers that were published during the period from June 2009 to May 2011. These works describe the use of offline and online sample treatment techniques, online sample preconcentration techniques based on electrophoretic principles, and alternative detection systems to UV-Vis to increase the detection sensitivity. The application of the above-mentioned strategies, either alone or combined, to improve the sensitivity in the enantiomeric analysis of a broad range of samples, such as pharmaceutical, biological, food and environmental samples, enables to decrease the limits of detection up to 10-12M. The use of microchips to achieve sensitive chiral separations is also discussed. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.The authors thank the Spanish Ministry of Science and Innovation (project CTQ2009-09022) and the Comunidad Autónoma of Madrid (Spain) and European funding from FEDER programme (project S2009/AGR-1464, ANALISYCII). They also thank the University of Alcalá and the Comunidad Autónoma of Madrid for project CCG10-UAH/AGR-5950. Laura Sánchez-Hernández thanks the Comunidad Autónoma of Madrid for her research contract. Maria Castro Puyana thanks the Spanish Ministry of Science and Innovation for her Juan de la Cierva contract (JCI-2009-05297).Peer Reviewe
Food authentication of commercially-relevant shrimp and prawn species: From classical methods to Foodomics

11 páginas, 2 figuras, 2 tablasAlthough seafood species identification has traditionally relied on morphological analysis, sometimes this is difficult to apply for the differentiation among penaeid shrimps owing to their phenotypic similarities and to the frequent removal of external carapace during processing. The objective of this review is to provide an updated and extensive overview on the molecular methods for shrimp and prawn species authentication, in which several omics approaches based on protein and DNA analysis are described. DNA-based methods include the amplification by PCR of different genes, commonly the mitochondrial 16S ribosomal RNA and cytochrome oxidase I genes. A recently described method based on RFLP coupled to PCR turned out to be particularly interesting for species differentiation and origin identification. Protein analysis methods for the characterization and detection of species-specific peptides are also summarized, emphasizing some novel proteomics-based approaches, such as phyloproteomics, peptide fragmentation, and species-specific peptide detection by HPLC coupled to multiple reaction monitoring (MRM) MS, the latter representing the fastest method described to date for species authentication in foodThis work was supported by the National Food Program of the INIA (Spanish Ministry for Education and Science) (Project CAL-03-030-C2–2) and by the PGIDIT Research Program in Marine Resources (Project 04RMA261004PR) of the Xunta de Galicia (Galician Council for Industry, Commerce and Innovation).Peer reviewe
Identification of potential complementary serum biomarkers to differentiate prostate cancer from benign prostatic hyperplasia using gel- and lectin-based proteomics analyses

Diagnosis of prostate cancer (PCa) is currently much reliant on the invasive and time-consuming transrectal ultrasound-guided biopsy of the prostate gland, particularly in light of the inefficient use of prostate-specific antigen as its biomarker. In the present study, we have profiled the sera of patients with PCa and benign prostatic hyperplasia (BPH) using the gel- and lectin-based proteomics methods and demonstrated the significant differential expression of apolipoprotein AII, complement C3 beta chain fragment, inter-alpha-trypsin inhibitor heavy chain 4 fragment, transthyretin, alpha-1-antitrypsin, and high molecular weight kininogen (light chain) between the two groups of patientsâ�� samples. Our data are suggestive of the potential use of the serum proteins as complementary biomarkers to effectively discriminate PCa from BPH, although this requires further extensive validation on clinically representative populations