62 research outputs found

    Wettability and corrosion of [NTf2] anion-based ionic liquids on steel and PVD (TiN, CrN, ZrN) coatings

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    Thewetting and corrosion behavior of three bis(trifluoromethylsulfonyl)imide-based ionic liquids: 1-Dodecyl-3- methylimidazolium bis(trifluoromethylsulfonyl)imide [C12MIM][NTf2], tributylmethylammonium bis(trifluoromethylsulfonyl)imide [N4441][NTf2] and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide [N1888][NTf2] are tested in this research. The surface tension was measured for temperatures of 293–353 K resulting in the expected linearly decreasing behavior with temperature increase. In addition, contact angle measurements were made on AISI 52100 steel and three coatings (TiN, CrN and ZrN) obtained by PVD technique, finding the regular behavior in hydrophobic (non-polar) systems: high contact angles led to high surface tensions. Complementary parameters like spreading parameter and polarity fraction were calculated to enhance the wetting evaluation of these ionic liquids. [N1888][NTf2]/TiN resulted as the best IL-surface combination for a good wettability, due to the higher dispersion of the charge on the large size cation in this IL and the higher values of total and polar component of the surface free energy for this coating. Finally, SEM-EDS analysis determined that [N1888][NTf2]/ZrN was the best option in order to avoid corrosion problems. The evaporation of water, present as impurity in the ionic liquids, was found the main reason because of corrosion did not occur in the tests carried out at 100 °C

    H3K4me1 marks DNA regions hypomethylated during aging in human stem and differentiated cells

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    In differentiated cells, aging is associated with hypermethylation of DNA regions enriched in repressive histone post-translational modifications. However, the chromatin marks associated with changes in DNA methylation in adult stem cells during lifetime are still largely unknown. Here, DNA methylation profiling of mesenchymal stem cells (MSCs) obtained from individuals aged 2 to 92 yr identified 18,735 hypermethylated and 45,407 hypomethylated CpG sites associated with aging. As in differentiated cells, hypermethylated sequences were enriched in chromatin repressive marks. Most importantly, hypomethylated CpG sites were strongly enriched in the active chromatin mark H3K4me1 in stem and differentiated cells, suggesting this is a cell type-independent chromatin signature of DNA hypomethylation during aging. Analysis of scedasticity showed that interindividual variability of DNA methylation increased during aging in MSCs and differentiated cells, providing a new avenue for the identification of DNA methylation changes over time. DNA methylation profiling of genetically identical individuals showed that both the tendency of DNA methylation changes and scedasticity depended on nongenetic as well as genetic factors. Our results indicate that the dynamics of DNA methylation during aging depend on a complex mixture of factors that include the DNA sequence, cell type, and chromatin context involved and that, depending on the locus, the changes can be modulated by genetic and/or external factors

    The spatial structure of lithic landscapes : the late holocene record of east-central Argentina as a case study

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    Fil: Barrientos, Gustavo. División Antropología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Catella, Luciana. División Arqueología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Oliva, Fernando. Centro Estudios Arqueológicos Regionales. Facultad de Humanidades y Artes. Universidad Nacional de Rosario; Argentin

    INCURVATA2 encodes the catalytic subunit of DNA polymerase α and interacts with genes involved in chromatin-mediated cellular memory in Arabidopsis thaliana

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    Cell type-specific gene expression patterns are maintained by the stable inheritance of transcriptional states through mitosis, requiring the action of multiprotein complexes that remodel chromatin structure. Genetic and molecular interactions between chromatin remodeling factors and components of the DNA replication machinery have been identified in Schizosaccharomyces pombe, indicating that some epigenetic marks are replicated simultaneously to DNA with the participation of the DNA replication complexes. This model of epigenetic inheritance might be extended to the plant kingdom, as we report here with the positional cloning and characterization of INCURVATA2 (ICU2), which encodes the putative catalytic subunit of the DNA polymerase a of Arabidopsis thaliana. The strong icu2-2 and icu2-3 insertional alleles caused fully penetrant zygotic lethality when homozygous and incompletely penetrant gametophytic lethality, probably because of loss of DNA polymerase activity. The weak icu2-1 allele carried a point mutation and caused early flowering, leaf incurvature, and homeotic transformations of sepals into carpels and of petals into stamens. Further genetic analyses indicated that ICU2 interacts with TERMINAL FLOWER2, the ortholog of HETEROCHROMATIN PROTEIN1 of animals and yeasts, and with the Polycomb group (PcG) gene CURLY LEAF. Another PcG gene, EMBRYONIC FLOWER2, was found to be epistatic to ICU2. Quantitative RT-PCR analyses indicated that a number of regulatory genes were derepressed in the icu2-1 mutant, including genes associated with flowering time, floral meristem, and floral organ identity. © 2007 American Society of Plant Biologists

    Application of untargeted volatile profiling to investigate the fate of aroma compounds during wine oral processing

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    We employed an untargeted volatile profiling approach in combination with spit off-odorant measurement procedure to investigate the fate of aroma compounds in mouth by determining how oral processing and intrinsic biological variables influence the overall volatile composition. A red wine before and after oral processing (expectorated wine), and control samples (expectorated water) were analyzed using GC-TOF-MS to determine as many volatile compounds as possible. We identified compounds in expectorated wines that originated in mouth from either an endogenous or exogenous source, while confirming that compounds might have metabolized by the action of salivary enzymes. Our data also show the changes in volatiles via hydrolysis from the corresponding molecules and may provide evidence of de novo formation of volatiles via transesterification reaction in mouth. While investigating the impact of intrinsic biological variables, we found age and gender specific differences in wine volatile composition due to oral processing and identified the key volatiles.This research was supported by the Spanish MINECO through the AGL201678936-R and PID 2019-11734RB-100 projects. M.P.-J. and C.M.-G. thank MINECO and CAM for their respective predoctoral and postdoctoral (Atracción de Talento CAM, 2019 T1/BIO13748) contracts. F.P and E.S would like to acknowledge financial contribution from The New Zealand Institute for Plant and Food Research Limited’s Strategic Science Investment Fund (SSIF) provided by the Ministry of Business, Innovation and Employment (MBIE).Peer reviewe

    A prospective cohort study of neurocognitive function in aviremic HIV-infected patients treated with 1 or 3 antiretrovirals

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    The evolution of neurocognitive performance in aviremic human immunodeficiency virus (HIV)– positive patients treated with <3 antiretrovirals is unknown. Methods. We prospectively included aviremic (≥1 year) HIV-positive patients, without concomitant major neurocognitive confounders, currently receiving boosted lopinavir or darunavir as monotherapy (n = 67) or triple antiretroviral therapy (ART) (n = 67) for ≥1 year. We evaluated neurocognitive function (7 domains) at baseline and after 1 year.We performed analysis of covariance to evaluate if 1 additional year of exposure tomonotherapy compared with triple ART had an effect on Global Deficit Score (GDS) changes after adjustment for potential confounders. We also compared the evolution of neurocognitive performance and impairment rates. Results. Intention-to-treat analysis showed that monotherapy did not influence 1-year GDS change after adjustment for significant confounders (age, ethnicity, duration of therapy, hepatitis C virus status, and HOMA-IR index); the adjusted effect was −0.04 (95% confidence interval, −.14 to .05; P = .38). Neurocognitive stability was observed with monotherapy and triple therapy (GDS crude mean change, −0.09 [95% confidence interval, −.16 to −.01] vs −0.08 [−.14 to −.02]), after 1 year of follow-up, similar proportions of patients changed neurocognitive status from impaired to unimpaired (monotherapy, 4 of 18 [22.2%]; triple therapy, 4 of 19 [21.1%]; P = .91) and vice versa (monotherapy, 5 of 44 [10.2%] and triple therapy, 3 of 45 [6.3%]; P = .48). Similar results were observed in an on-treatment analysis and with use of clinical ratings instead of GDS changes. Conclusions. The number of antiretrovirals included in the ART regimen does not seem to influence the evolution of neurocognitive function in HIV-infected patients with suppressed plasma viremia.8.886 JCR (2014) Q1, 9/148 Immunology, 2/78 Infectious diseases, 9/119 MicrobiologyUE

    Neurocognitive impairment in patients treated with protease inhibitor monotherapy or triple drug antiretroviral therapy.

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    In patients who remain virologically suppressed in plasma with triple-drug ART a switch to protease inhibitor monotherapy maintains high rates of suppression; however it is unknown if protease inhibitor monotherapy is associated to a higher rate of neurocognitive impairment.In this observational, cross-sectional study we included patients with plasma virological suppression (≥ 1 year) without concomitant major neurocognitive confounders, currently receiving for ≥ 1 year boosted lopinavir or darunavir as monotherapy or as triple ART. Neurocognitive impairment was defined as per the 2007 consensus of the American Association of Neurology. The association between neurocognitive impairment and protease inhibitor monotherapy, adjusted by significant confounders, was analysed.Of the 191 included patients--triple therapy: 96, 1-2 years of monotherapy: 40 and >2 years of monotherapy: 55--proportions (95% CI) with neurocognitive impairment were: overall, 27.2% (20.9-33.6); triple therapy, 31.6% (22.1-41.0); short-term monotherapy, 25.0% (11.3-38.7); long-term monotherapy: 21.4% (10.5-32.3); p = 0.38. In all groups, neurocognitive impairment was mildly symptomatic or asymptomatic by self-report. There were not significant differences in Global Deficit Score by group. In the regression model confounding variables for neurocognitive impairment were years on ART, ethnicity, years of education, transmission category and the HOMA index. Adjusted by these variables the Odds Ratio (95% CI) for neurocognitive impairment of patients receiving short-term monotherapy was 0.85 (0.29-2.50) and for long-term monotherapy 0.40 (0.14-1.15).Compared to triple drug antiretroviral therapy, monotherapy with lopinavir/ritonavir or darunavir/ritonavir in patients with adequate plasma suppression was not associated with a higher rate of asymptomatic neurocognitive impairment than triple drug ART

    Neurocognitive Impairment in Patients Treated with Protease Inhibitor Monotherapy or Triple Drug Antiretroviral Therapy

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    Background: In patients who remain virologically suppressed in plasma with triple-drug ART a switch to protease inhibitor monotherapy maintains high rates of suppression; however it is unknown if protease inhibitor monotherapy is associated to a higher rate of neurocognitive impairment. Methods: In this observational, cross-sectional study we included patients with plasma virological suppression (1year)withoutconcomitantmajorneurocognitiveconfounders,currentlyreceivingfor1 year) without concomitant major neurocognitive confounders, currently receiving for 1 year boosted lopinavir or darunavir as monotherapy or as triple ART. Neurocognitive impairment was defined as per the 2007 consensus of the American Association of Neurology. The association between neurocognitive impairment and protease inhibitor monotherapy, adjusted by significant confounders, was analysed. Results: Of the 191 included patients - triple therapy: 96, 1–2 years of monotherapy: 40 and .2 years of monotherapy: 55 - proportions (95% CI) with neurocognitive impairment were: overall, 27.2% (20.9–33.6); triple therapy, 31.6% (22.1–41.0); short-term monotherapy, 25.0% (11.3–38.7); long-term monotherapy: 21.4% (10.5–32.3); p = 0.38. In all groups, neurocognitive impairment was mildly symptomatic or asymptomatic by self-report. There were not significant differences in Global Deficit Score by group. In the regression model confounding variables for neurocognitive impairment were years on ART, ethnicity, years of education, transmission category and the HOMA index. Adjusted by these variables the Odds Ratio (95% CI) for neurocognitive impairment of patients receiving short-term monotherapy was 0.85 (0.29–2.50) and for long-term monotherapy 0.40 (0.14–1.15). Conclusions: Compared to triple drug antiretroviral therapy, monotherapy with lopinavir/ritonavir or darunavir/ritonavir in patients with adequate plasma suppression was not associated with a higher rate of asymptomatic neurocognitive impairment than triple drug ART.3.534 JCR (2013) Q1, 8/55 Multidisciplinary science
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