2,447 research outputs found

    Monitoring Muscle Stem Cell Cultures with Impedance Spectroscopy

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    The aim of this work is to present a new circuit for the real-time monitoring the processes of cellular growth and differentiation of skeletal myoblast cell cultures. An impedance spectroscopy Oscillation-Based technique is proposed for the test circuit, converting the biological system into a voltage oscillator, and avoiding the use of very high performance circuitry or equipment. This technique proved to be successful in the monitoring of cell cultures growth levels and could be useful for determining the degree of differentiation achieved, of practical implications in tissue engineering.Ministerio de Economía y Competitividad TEC2013-46242-C3-1-

    The ZFHX1A gene is differentially autoregulated by its isoforms

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    The Zfhx1a gene expresses two different isoforms; the full length Zfhx1a-1 and a truncated isoform termed Zfhx1a-2 lacking the first exon. Deletion analysis of the Zfhx1a-1 promoter localized cell-specific repressors, and a proximal G-string that is critically required for transactivation. Transfection of Zfhx1a-1 cDNA, but not Zfhx1a-2, downregulates Zfhx1a-1 promoter activity. Mutation of an E2-box disrupted the binding of both Zfhx1a isoforms. Consistent with this, transfected Zfhx1a-1 does not regulate the transcriptional activity of the E-box mutated Zfhx1a-1 promoter. Competitive EMSAs and transfection assays show that Zfhx1a-2 can function as a dominant negative isoform since it is able to compete and displace Zfhx1a-1 from its binding site and overcome Zfhx1a-1 induced repression of the Zfhx1a-1 promoter in cells. Hence, the Zfhx1a-1 gene is autoregulated in part by negative feedback on its own promoter which is, in turn, modified by the availability of the negative dominant isoform Zfhx1a-2.Fil: Manavella, Pablo Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Roqueiro, Gonzalo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Darling, Douglas S.. University of Louisville; Estados UnidosFil: Cabanillas, Ana Maria de Los A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; Argentin

    Is the reputation of Eucalyptus plantations for using more water than Pinus plantations justified?

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    The effect of Eucalyptus plantations on water balance is thought to be more severe than for commercial alternatives such as Pinus species. Although this perception is firmly entrenched, even in the scientific community, only four direct comparisons of the effect on the water balance of a Eucalyptus species and a commercial alternative have been published. One of these, from South Africa, showed that Eucalyptus grandis caused a larger and more rapid reduction in streamflow than Pinus patula. The other three, one in South Australia and two in Chile, did not find any significant difference between the annual evapotranspiration of E. globulus and P. radiata after canopy closure. While direct comparisons are few, there are at least 57 published estimates of annual evapotranspiration of either a Eucalyptus or Pinus species. This paper presents a meta-analysis of these published data. Zhang et al. (2004) fitted a relationship between the crop factor and the climate wetness index to published data from catchment studies and proposed this approach for comparing land uses. We fitted the same model to the published data for Eucalyptus and Pinus and found that the single parameter of this model did not differ significantly between the two genera (p=0.48). This implies that for a given climate wetness index the two genera have similar annual water use. The residuals compared to this model were significantly correlated with soil depth for Eucalyptus, but this was not the case for Pinus. For Eucalyptus the model overestimates the crop factor on deep soils and underestimates the crop factor on shallow soils.</p

    Is the reputation of Eucalyptus plantations for using more water than Pinus plantations justified?

    Get PDF
    The effect of Eucalyptus plantations on water balance is thought to be more severe than for commercial alternatives such as Pinus species. Although this perception is firmly entrenched, even in the scientific community, only four direct comparisons of the effect on the water balance of a Eucalyptus species and a commercial alternative have been published. One of these, from South Africa, showed that Eucalyptus grandis caused a larger and more rapid reduction in streamflow than Pinus patula. The other three, one in South Australia and two in Chile, did not find any significant difference between the annual evapotranspiration of E. globulus and P. radiata after canopy closure. While direct comparisons are few, there are at least 57 published estimates of annual evapotranspiration of either the Eucalyptus or Pinus species. This paper presents a meta-analysis of these published data. Zhang et al. (2004) fitted a relationship between the vegetation evaporation efficiency and the climate wetness index to published data from catchment studies and proposed this approach for comparing land uses. We fitted this model to the published data for Eucalyptus and Pinus and found that the single parameter of this model did not differ significantly between the two genera (p = 0.48). This was also the case for all parameters of an exponential relationship between evapotranspiration and rainfall (p = 0.589) and a linear relationship between the vegetation evaporation index and rainfall (p = 0.155). These results provide strong evidence that, for a given climate wetness index, the two genera have similar annual water use. The residuals compared to the model of Zhang et al. (2004) were significantly correlated with soil depth for Eucalyptus, but this was not the case for Pinus. For Eucalyptus, the model overestimates the vegetation evaporation efficiency on deep soils and underestimates the vegetation evaporation efficiency on shallow soils

    Increased circulating microRNAs miR-342-3p and miR-21-5p in natural sheep prion disease

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    Scrapie is a transmissible spongiform encephalopathy (TSE), or prion disease, of sheep and goats. As no simple diagnostic tests are yet available to detect TSEs in vivo, easily accessible biomarkers could facilitate the eradication of scrapie agents from the food chain. To this end, we analysed by quantitative reverse transcription PCR a selected set of candidate microRNAs (miRNAs) from circulating blood plasma of naturally infected, classical scrapie sheep that demonstrated clear scrapie symptoms and pathology. Significant scrapie-associated increase was repeatedly found for miR-342-3p and miR-21-5p. This is the first demonstration, to our knowledge, of circulating miRNA alterations in any animal suffering from TSE. Genome-wide expression studies are warranted to investigate the true depth of miRNA alterations in naturally occurring TSEs, especially in presymptomatic animals, as the presented study demonstrates the potential feasibility of miRNAs as circulating TSE biomarkers

    Positive culture in allograft ACL-reconstruction: what to do?

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    The transmission of disease or infection from the donor to the recipient is always a risk with the use of allografts. We carried out a research study on the behavioural pattern of implanted allografts, which were initially stored in perfect conditions (all cultures being negative) but later presented positive cultures at the implantation stage. Because there is no information available on how to deal with this type of situation, our aim was to set guidelines on the course of action which would be required in such a case. We conducted a retrospective study of 181 patients who underwent an ACL reconstruction using BPTB allografts. All previous bone and blood cultures and tests for hepatitis B and C, syphilis and HIV were negative. An allograft sample was taken for culture in the operating theatre just before its implantation. The results of the cultures were obtained 3-5 days after the operation. We had 24 allografts with positive culture (13.25%) after the implantation with no clinical infection in any of these patients. Positive cultures could be caused by undetected contamination while harvesting, storing or during manipulation before implantation. The lack of clinical signs of infection during the follow-up of our patients may indicate that no specific treatment-other than an antibiotic protocol-would be required when facing a case of positive culture of a graft piece after its implantation

    Granulomas Following Subcutaneous Injection With Aluminum Adjuvant-Containing Products in Sheep

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    The use of vaccines including aluminum (Al)–based adjuvants is widespread among small ruminants and other animals. They are associated with the appearance of transient injection site nodules corresponding to granulomas. This study aims to characterize the morphology of these granulomas, to understand the role of the Al adjuvant in their genesis, and to establish the presence of the metal in regional lymph nodes. A total of 84 male neutered lambs were selected and divided into 3 treatment groups of 28 animals each: (1) vaccine (containing Al-based adjuvant), (2) adjuvant-only, and (3) control. A total of 19 subcutaneous injections were performed in a time frame of 15 months. Granulomas and regional lymph nodes were evaluated by clinicopathological means. All of the vaccine and 92.3% of the adjuvant-only lambs presented injection-site granulomas; the granulomas were more numerous in the group administered the vaccine. Bacterial culture in granulomas was always negative. Histologically, granulomas in the vaccine group presented a higher degree of severity. Al was specifically identified by lumogallion staining in granulomas and lymph nodes. Al median content was significantly higher (P <.001) in the lymph nodes of the vaccine group (82.65 µg/g) compared with both adjuvant-only (2.53 µg/g) and control groups (0.96 µg/g). Scanning transmission electron microscopy demonstrated aggregates of Al within macrophages in vaccine and adjuvant-only groups. In these two groups, Al-based adjuvants induce persistent, sterile, subcutaneous granulomas with macrophage-driven translocation of Al to regional lymph nodes. Local translocation of Al may induce further accumulation in distant tissues and be related to the appearance of systemic signs

    Investigation of the fusion process for B 10 + Au 197 at near-barrier energies

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    In a previous work, we presented data for the B10+Au197 system, corresponding to quasielastic and elastic scattering, Au197 inelastic excitation, and one neutron pickup transfer, measuring the angular distribution of scattered beam-like ejectiles at several energies around the Coulomb barrier. In this paper, we present data for the fusion process of the same system, at several energies around the Coulomb barrier, as well as new data for one neutron pickup and stripping transfer. In this case, we detected offline γ rays stemming from the β-delayed decay chain of fusion-evaporation residues and heavy transfer products. As in our previous work, we analyzed this data set with coupled reaction channels calculations using the São Paulo potential. We show that the coupling to the one neutron transfer channel is quite important to describe the fusion data at the sub-barrier energy region. We also provide a comparison of the experimental fusion cross sections obtained for B10+Au197 with data for several other systems involving the same target nucleus.Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET, Argentina) PIP00786COFondo para la Investigacin Cientfica y Tecnolgica (FONCYT, Argentina) PICT-2017-4088Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, Brazil) 2018/09998-8, 2019/07767-1, 2019/05769-7Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil) 302160/2018-3, 304056/2019-7Ministerio de Ciencia, Innovación y Universidades PGC2018-096994-B-C2

    Electrochemical conversion/combustion of a model organic pollutant on BDD anode: Role of sp3/sp2 ratio

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    In this work, it is presented critical evidence about the influence of sp3/sp2 ratio on the performance of electrochemical oxidation (combustion or conversion) of Rhodamine B (RhB), used as a model organic pollutant. Results demonstrate that the higher the content in diamond-carbon, the greater are the TOC and COD decay rates and hence the oxidation of organic to CO2. The evidence of chromatographic analysis also indicates that the oxidation carried out by the diamonds with lower content of sp3-carbon is softer, favoring electrochemical conversion of RhB instead of mineralization. This degradation pathway is followed because higher graphite content on BDD anode leads to a higher direct electrochemical activity. These results are of a paramount significance for the choice of electrodes that could guarantee high efficiencies in wastewater remediation processes; because they clearly indicate that the sp3-sp2 carbon ratio should be kept as higher as possible in order to deplete completely pollutants and intermediates from the waste
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