402 research outputs found

    Geographical and environment-related variations of essential oils in isolated populations of Thymus richardii Pers. in the Mediterranean basin

    Full text link
    Composition of essential oils of different populations of Thymus richardii grex of six localities from Bosnia-Herzegovina (Konjic, Borci), Spain (Majorca, Ibiza, Valencia) and Italy (Marettimo, Sicily) were determined by GC/FID and GC/MS. The main constituents in most of the samples were aromatic monoterpenes corresponding to non-phenolic cyclic compounds (p-cymene, gamma-terpinene). The highest monoterpene concentrations were found in the Bosnian samples (70%), and the lowest in samples from the Balearic Islands ( 50%) in samples from Majorca with beta-bisabolene (>40%) being the principal constituent. Discriminant analysis (LDA) shows the differentiation of two chemotypes: A (phenol chemotype), with p-cymene and gamma-terpinene as characteristic compounds and B, with beta-bisabolene and carvacrol, as major and significative compounds. The occurrence of the chemotypes was related to summer positive precipitation and to deep of soils.Llorens, L.; Llorens Molina, JA.; Agnello, S.; Boira Tortajada, H. (2014). Geographical and environment-related variations of essential oils in isolated populations of Thymus richardii Pers. in the Mediterranean basin. Biochemical Systematics and Ecology. 56:246-254. doi:10.1016/j.bse.2014.05.0072462545

    Multivariate calibration applied to simultaneous chemiluminiscence determination of Cobalt and Chromium

    Full text link
    The final publication is available at http://doi.org/ 10.1007/s00216-002-1637-8[EN] The simultaneous determination of chromium and cobalt in water samples has been studied. Chemiluminescence registers based on the luminol-hydrogen peroxide reaction have obtained by a batch procedure. PLS algorithms have employed to model the time-response (formation and destruction of emitter). The influence of the presence of two metals and the non-linearity relationship between response and concentration have been evaluated in the signal. Different experimental designs and the selection of variables have been tested. The calibration set has been selected based on two criteria: unicomponent and/or bicomponent standard solutions and the slope calculated from linear univariate calibration. The response has been modelled providing high percentages of explained variance, robust models and low prediction errors. The proposed methodology has been validated using test standard solutions and a standard reference material of fresh water. Accurate results have proved the advantages of this method for the simultaneous determination of chromium and cobalt in water samples.The authors are grateful to the DGICYT (Project no PB 97–1387) for financial support. S.M.Ll. and L.A.T.G. express their gratitude to Ministerio de Educación y Cultura (Spain) for the predoctoral grant.Campins-Falcó, P.; Tortajada-Genaro, LA.; Meseguer-Lloret, S.; Bosch-Reig, F. (2002). Multivariate calibration applied to simultaneous chemiluminiscence determination of Cobalt and Chromium. Analytical and Bioanalytical Chemistry. 374(7-8):1223-1229. https://doi.org/10.1007/s00216-002-1637-8S122312293747-

    Influence of water sample storage protocols in chemiluminescence detection of trace elements by batch or FI modes

    Full text link
    [EN] This paper shows the influence of different sample storage protocols, on the chemiluminescence signal of some metal ions. The storage protocols studied were: acid addition (HCl or HNO3) and no reagent addition to filtered and refrigerated (T=4 °C) samples. Light emission was produced for the chemiluminescence reaction between luminol and hydrogen peroxide in buffer carbonate conditions (pH 10.8) catalysed by Cr(III), Co(II) and Cu(II). Batch and/or flow modes in different conditions were tested. Fe(II), Fe(III), Ni(II) and Mn(II) did not give chemiluminescence in the studied conditions. A parallel study of sensitivity and selectivity was performed. Then the presence or absence of the masking agent EDTA, added to samples or used in the carrier stream, is assayed. If the samples are acidified with HNO3, a previous neutralisation is needed using batch mode. The determination of Cr(III) is independent of storage protocol by flow injection (FI) method; however, the determination of Co(II) or Cu(II) or total determination of three metals requires the conditioning of standards. Detection limits achieved are ranged between 0.5 and 2 ¿g l¿1. For batch mode, detection limits are better for unacidified samples and worse for carbonate-neutralised samples. The influence of storage protocols was validated using standard metal mixtures and calibration solutions. The use of standard reference material (SRM© 1640) (Trace elements in natural water) corroborates the previous statements and validates the accuracy of the different approaches underlined. This paper demonstrates that it is possible to determine Cr(III) selectively in natural waters.The authors are grateful to the DGICYT (Project No. PB 97-1387) for financial support. Y.M.M., S.M.L. and L.A.T.G. express their gratitude to Ministerio de Educación y Cultura (Spain) for the predoctoral grant.Molliner Martínez, Y.; Meseguer-Lloret, S.; Tortajada-Genaro, LA.; Campins-Falcó, P. (2003). Influence of water sample storage protocols in chemiluminescence detection of trace elements by batch or FI modes. Talanta. 60(1):257-268. https://doi.org/10.1016/S0039-9140(03)00068-7S25726860

    A guide to avoid method bias of chromium(III, VI) chemiluminescence determination by luminol-hydrogen peroxide reaction. Application to unknown water samples

    Full text link
    This is an Author's Accepted Manuscript of an article published in International Journal of Environmental & Analytical Chemistry, 83, 5, 405-416. DOI: 10.1080/0306731031000101383 © Taylor & Francis, available online at: http://doi.org/10.1080/0306731031000101383[EN] Cr(III) and/or Cr(VI) determinations based on light emission produced by luminol oxidation by hydrogen peroxide in basic aqueous solution catalyzed by Cr(III) were studied in order to diagnose and/or avoid method bias. The calibration step was optimized, and the usefulness of the method for speciating chromium was tested. The use of the standard addition method in the linear interval concentration range made it possible to diagnose the accuracy of the method for real samples. Good results were obtained for several real water samples containing chromium at different concentrations. The proposed protocol made the method traceable with an appropriate certified reference material and with the reference method.The authors are grateful to the DGICYT (Project n PB 97-1387) and to the Generalitat Valenciana (GR-0036) for financial support.Meseguer-Lloret, S.; Campins-Falcó, P.; Tortajada-Genaro, LA.; Blasco-Gómez, F. (2003). A guide to avoid method bias of chromium(III, VI) chemiluminescence determination by luminol-hydrogen peroxide reaction. Application to unknown water samples. International Journal of Environmental & Analytical Chemistry. 83(5):405-416. https://doi.org/10.1080/0306731031000101383S40541683

    Genotyping of single nucleotide polymorphisms related to attention-deficit hyperactivity disorder

    Full text link
    Pharmacological treatment of several diseases, such as attention-deficit hyperactivity disorder (ADHD), presents marked variability in efficiency and its adverse effects. The genotyping of specific single nucleotide polymorphisms (SNPs) can support the prediction of responses to drugs and the genetic risk of presenting comorbidities associated with ADHD. This study presents two rapid and affordable microarray-based strategies to discriminate three clinically important SNPs in genes ADRA2A, SL6CA2, and OPRM1 (rs1800544, rs5569, and rs1799971, respectively). These approaches are allele-specific oligonucleotide hybridization (ASO) and a combination of allele-specific amplification (ASA) and solid-phase hybridization. Buccal swab and blood samples taken from ADHD patients and controls were analyzed by ASO, ASA, and a gold-reference method. The results indicated that ASA is superior in genotyping capability and analytical performance.This research has been funded through projects FEDER MINECO INNPACTO IPT-2011-1132-010000, CTQ/2013/45875R, and PrometeoII/2014/040 (GVA).Tortajada-Genaro, LA.; Mena-Mollá, S.; Niñoles Rodenes, R.; Puigmule, M.; Viladevall, L.; Maquieira Catala, Á. (2016). Genotyping of single nucleotide polymorphisms related to attention-deficit hyperactivity disorder. Analytical and Bioanalytical Chemistry. 408(9):2339-2345. https://doi.org/10.1007/s00216-016-9332-3S233923454089Cortese S. The neurobiology and genetics of Attention-Deficit/Hyperactivity Disorder (ADHD): what every clinician should know. Eur J Paediatr Neurol. 2012;16:422–33.Contini V, Rovaris DL, Victor MM, Grevet EH, Rohde LA, Bau CH. Pharmacogenetics of response to methylphenidate in adult patients with attention-deficit/hyperactivity disorder (ADHD): a systematic review. Eur Neuropsychopharmacol. 2013;23:555–60.Gardiner SJ, Begg EJ. Pharmacogenetics, drug-metabolizing enzymes, and clinical practice. Pharmacol Rev. 2006;58(3):521–90.Abul-Husn NS, Obeng AO, Sanderson SC, Gottesman O, Scott SA. Implementation and utilization of genetic testing in personalized medicine. Pharmacogenomics Pers Med. 2014;7:227.Altman RB, Flockhart D, Goldstein DB, editors. Principles of pharmacogenetics and pharmacogenomics. Cambridge: Cambridge University Press; 2012.Hawi Z, Cummins TDR, Tong J, Johnson B, Lau R, Samarrai W, et al. The molecular genetic architecture of attention deficit hyperactivity disorder. Mol Psychiatry. 2015;20:289–97.Limaye N. Pharmacogenomics, Theranostics and Personalized Medicine-the complexities of clinical trials: challenges in the developing world. Appl Transl Genomics. 2013;2:17–21.Manolio TA, Chisholm RL, Ozenberger B, Roden DM, Williams MS, Wilson R, et al. Implementing genomic medicine in the clinic: the future is here. Genet Med. 2013;15:258–67.Kim S, Misra A. PharmGKB: the Pharmacogenomics Knowledge Base. Annu Rev Biomed Eng. 2007;9:289–320.Lucarelli F, Tombelli S, Minunni M, Marrazza G, Mascini M. Electrochemical and piezoelectric DNA biosensors for hybridisation detection. Anal Chim Acta. 2008;609:139–59.Knez K, Spasic D, Janssen KP, Lammertyn J. Emerging technologies for hybridization based single nucleotide polymorphism detection. Analyst. 2014;139:353–70.Choi JY, Kim YT, Byun JY, Ahn J, Chung S, Gweon DG, et al. Integrated allele-specific polymerase chain reaction–capillary electrophoresis microdevice for single nucleotide polymorphism genotyping. Lab Chip. 2012;12:5146–54.Ragoussis J. Genotyping Technologies for Genetic Research. Annu Rev Genomics Hum Genet. 2009;10:117–33.Sethi D, Gandhi RP, Kuma P, Gupta KC. Chemical strategies for immobilization of oligonucleotides. Biotechnol J. 2009;4:1513–29.Bañuls MJ, Morais SB, Tortajada-Genaro LA, Maquieira A. Microarray Developed on Plastic Substrates. Microarray Technology: Methods and Applications, 2016; 37-51.Tortajada-Genaro LA, Rodrigo A, Hevia E, Mena S, Niñoles R, Maquieira A. Microarray on digital versatile disc for identification and genotyping of Salmonella and Campylobacter in meat products. Anal Bioanal Chem. 2015;407:7285–94.Kieling C, Genro JP, Hutz MH, Rohde LA. A current update on ADHD pharmacogenomics. Pharmacogenomics. 2010;11:407–19.Kim BN, Kim JW, Cummins TD, Bellgrove MA, Hawi Z, Hong SB, et al. Norepinephrine genes predict response time variability and methylphenidate-induced changes in neuropsychological function in attention deficit hyperactivity disorder. J Clin Psychopharmacol. 2013;33:356–62.Carpentier PJ, Arias Vasquez A, Hoogman M, Onnink M, Kan CC, Kooij JJS, et al. Shared and unique genetic contributions to attention deficit/hyperactivity disorder and substance use disorders: A pilot study of six candidate genes. Eur Neuropsychopharmacol. 2013;23:448–57.Zhang Y, Haraksingh R, Grubert F, Abyzov A, Gerstein M, Weissman S, et al. Child development and structural variation in the human genome. Child Dev. 2013;84:34–48.Asari M, Watanabe S, Matsubara K, Shiono H, Shimizu K. Single nucleotide polymorphism genotyping by mini-primer allele-specific amplification with universal reporter primers for identification of degraded DNA. Anal Biochem. 2009;386:85–90.Choi JY, Kim YT, Ahn J, Kim KS, Gweon DG, Seo TS. Integrated allele-specific polymerase chain reaction–capillary electrophoresis microdevice for single nucleotide polymorphism genotyping. Biosens Bioelectron. 2012;35:327–34.Konstantou JK, Ioannou PC, Christopoulos TK. Dual-allele dipstick assay for genotyping single nucleotide polymorphisms by primer extension reaction. Eur J Hum Genet. 2009;17:105–11.Sebastian T, Cooney CG, Parker J, Qu P, Perov A, Golova JB, et al. Integrated amplification microarray system in a lateral flow cell for warfarin genotyping from saliva. Clin Chim Acta. 2014;429:198–205

    Hepatitis a among men who have sex with men in Barcelona, 1989-2010: insufficient control and need for new approaches

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Men who have sex with men (MSM) are a known group at risk for hepatitis A and outbreaks among this group are frequent. In Barcelona, vaccination for MSM has been recommended since 1994. In 1998 a vaccination campaign among preadolescents was implemented and an immunization program in gay bathhouses began in 2004. Objective: to asses the incidence of hepatitis A in adults in Barcelona from 1989 to 2010 and to evaluate the outbreaks among MSM including all genotypes involved.</p> <p>Methods</p> <p>All cases of acute hepatitis A among young adults notified to the Public Health Agency of Barcelona from 1989 to 2010 were included for analyses. We calculated the annual incidence rate and the incidence ratio male-to-female (M:F) as a marker for MSM. Spearman's coefficient was used to evaluate trends. We also evaluated the outbreaks among MSM and compared their characteristics using Chi-squared and ANOVA test. Fragment amplification of the VP1/P2A region was used for genetic analysis.</p> <p>Results</p> <p>The median annual incidence for the period of study was 4.7/100000 among females and 11.7/100000 among males. The rate of hepatitis A for adult woman decreased over time (Spearman' coefficient = -0.63, <it>p </it>= 0.002), whereas there was no decrease for adult men (Spearman' coefficient = 0.097, <it>p </it>= 0.67). During the study period the M:F ratio increased (Spearman' coefficient = 0.73, <it>p </it>< 0.001).</p> <p>Three large outbreaks among MSM were detected. When comparing outbreaks, there was a decrease in the percentage of bathhouse users (from 47% to 19%, <it>p </it>= 0.0001) and sex workers (from 6.5% to 0%) while the percentage of HIV infected individuals did not change significantly (range: 21%-28%, <it>p </it>= 0.36). The isolated strains were closely related to those circulating in Europe.</p> <p>Conclusions</p> <p>Annual incidences remain high among MSM without tendency to decrease. More strategies which effectively reach the whole MSM community are needed.</p

    Population-based identification of H α-excess sources in the Gaia DR2 and IPHAS catalogues

    Get PDF
    We present a catalogue of point-like H α-excess sources in the Northern Galactic Plane. Our catalogue is created using a new technique that leverages astrometric and photomeric information from Gaia to select H α-bright outliers in the INT Photometric H α Survey of the Northern Galactic Plane (IPHAS), across the colour-absolute magnitude diagram. To mitigate the selection biases due to stellar population mixing and to extinction, the investigated objects are first partitioned with respect to their positions in the Gaia colour-absolute magnitude space, and Galactic coordinates space, respectively. The selection is then performed on both partition types independently. Two significance parameters are assigned to each target, one for each partition type. These represent a quantitative degree of confidence that the given source is a reliable H α-excess candidate, with reference to the other objects in the corresponding partition. Our catalogue provides two flags for each source, both indicating the significance level of the H α-excess. By analysing their intensity in the H α narrow band, 28 496 objects out of 7474 835 are identified as H α-excess candidates with a significance higher than 3. The completeness fraction of the H α outliers selection is between 3 and 5 per cent. The suggested 5σ conservative cut yields a purity fraction of 81.9 per cent.MM acknowledges the support by the Spanish Ministry of Science, Innovation and University (MICIU/FEDER, UE) through grant RTI2018-095076-B-C21, and the Institute of Cosmos Sciences University of Barcelona (ICCUB, Unidad de Excelencia ‘María de Maeztu’) through grant CEX2019-000918-M

    Microbial β-glucosidases from cow rumen metagenome enhance the saccharification of lignocellulose in combination with commercial cellulase cocktail

    No full text
    Background A complete saccharification of plant polymers is the critical step in the efficient production of bio-alcohols. Beta-glucosidases acting in the degradation of intermediate gluco-oligosaccharides produced by cellulases limit the yield of the final product. Results In the present work, we have identified and then successfully cloned, expressed, purified and characterised 4 highly active beta-glucosidases from fibre-adherent microbial community from the cow rumen. The enzymes were most active at temperatures 45–55°C and pH 4.0-7.0 and exhibited high affinity and activity towards synthetic substrates such as p-nitrophenyl-beta-D-glucopyranoside (p NPbetaG) and p NP-beta-cellobiose, as well as to natural cello-oligosaccharides ranging from cellobiose to cellopentaose. The apparent capability of the most active beta-glucosidase, herein named LAB25g2, was tested for its ability to improve, at low dosage (31.25 units g-1 dry biomass, using p NPbetaG as substrate), the hydrolysis of pre-treated corn stover (dry matter content of 20%; 350 g glucan kg-1 dry biomass) in combination with a beta-glucosidase-deficient commercial Trichoderma reseei cellulase cocktail (5 units g-1 dry biomass in the basis of p NPbetaG). LAB25g2 increased the final hydrolysis yield by a factor of 20% (44.5 ± 1.7% vs. 34.5 ± 1.5% in control conditions) after 96–120 h as compared to control reactions in its absence or in the presence of other commercial beta-glucosidase preparations. The high stability (half-life higher than 5 days at 50°C and pH 5.2) and 2–38000 fold higher (as compared with reported beta-glucosidases) activity towards cello-oligosaccharides may account for its performance in supplementation assays. Conclusions The results suggest that beta-glucosidases from yet uncultured bacteria from animal digestomes may be of a potential interest for biotechnological processes related to the effective bio-ethanol production in combination with low dosage of commercial cellulases

    Of cattle, sand flies and men : a systematic review of risk factor analyses for South Asian visceral leishmaniasis and implications for elimination

    Get PDF
    Background: Studies performed over the past decade have identified fairly consistent epidemiological patterns of risk factors for visceral leishmaniasis (VL) in the Indian subcontinent. Methods and Principal Findings: To inform the current regional VL elimination effort and identify key gaps in knowledge, we performed a systematic review of the literature, with a special emphasis on data regarding the role of cattle because primary risk factor studies have yielded apparently contradictory results. Because humans form the sole infection reservoir, clustering of kala-azar cases is a prominent epidemiological feature, both at the household level and on a larger scale. Subclinical infection also tends to show clustering around kala-azar cases. Within villages, areas become saturated over a period of several years; kala-azar incidence then decreases while neighboring areas see increases. More recently, post kalaazar dermal leishmaniasis (PKDL) cases have followed kala-azar peaks. Mud walls, palpable dampness in houses, and peridomestic vegetation may increase infection risk through enhanced density and prolonged survival of the sand fly vector. Bed net use, sleeping on a cot and indoor residual spraying are generally associated with decreased risk. Poor micronutrient status increases the risk of progression to kala-azar. The presence of cattle is associated with increased risk in some studies and decreased risk in others, reflecting the complexity of the effect of bovines on sand fly abundance, aggregation, feeding behavior and leishmanial infection rates. Poverty is an overarching theme, interacting with individual risk factors on multiple levels. Conclusions: Carefully designed demonstration projects, taking into account the complex web of interconnected risk factors, are needed to provide direct proof of principle for elimination and to identify the most effective maintenance activities to prevent a rapid resurgence when interventions are scaled back. More effective, short-course treatment regimens for PKDL are urgently needed to enable the elimination initiative to succeed
    corecore