2,319 research outputs found
Prenatal Arsenic Exposure is Associated with Decreased Mitochondrial DNA Copy Number and Increased Genomic Indicators of Reactive Oxygen Species in Newborn Cord Blood Leukocytes
To better understand the mechanisms of inorganic arsenic (iAs) toxicity during the prenatal period, mitochondrial DNA (mtDNA) copy number was examined in the Biomarkers of Exposure to ARsenic (BEAR) pregnancy cohort from GĂłmez Palacio, Mexico. Newborn cord blood and maternal whole blood leukocytes examined for mtDNA copy number were compared to iAs in maternal drinking water and total maternal urinary arsenic (U-tAs). Analysis of mtDNA and iAs exposure measures revealed a negative association between maternal U-tAs and newborn mtDNA content. Additional analysis of gene expression changes associated with mtDNA copy number identified 3 genes that are known to play a role in ROS protection, and 22 genes that have been shown to be altered by arsenic exposure. This study highlights mtDNA as a novel responder to prenatal arsenic exposure that may contribute to mechanisms of iAs toxicity in utero.Master of Scienc
Implementation of Industry 4.0 technology: New opportunities and challenges for maintenance strategy
Abstract Industry 4.0 is revolutionizing decision-making processes within the manufacturing industry. Maintenance strategies play a crucial role to improve progressively technical performances and economical savings. The introduction of Industry 4.0 technology results in relevant innovations able to condition maintenance policies. Moreover, innovative solutions can be introduced, such as "remote maintenance" and the "self-maintenance". In this paper, we investigate the state-of-the-art of technologies in a "smart factory" with the aim to understand how Industry 4.0 technologies are affecting maintenance policies and to discuss their implication in strategies. We found important trends in maintenance policies, such as "remote maintenance" and the attractive option of the "autonomous maintenance". This study represents the first comprehensive investigation in these research themes, and it desires to produce a broader insight and knowledge of current trends and main difficulties, highlighting critical aspects and disadvantages for the implementation of innovative policies
A real-time compensation method for MV voltage transducer for power quality analysis
Peer Reviewe
A New Strategy for As(V) Biosensing Based on the Inhibition of the Phosphatase Activity of the Arsenate Reductase from Thermus thermophilus
Arsenic (As) pollution is a widespread problem worldwide. In recent years, biosensors
based on enzymatic inhibition have been developed for arsenic detection, making the study of the
effect of inhibitors on the selected enzymatic activity crucial for their setup. The arsenate reductase of
Thermus thermophilus HB27, TtArsC, reduces As(V) into As(III), but is also endowed with phosphatase
activity. This work investigates the inhibitory effects of As(V) and As(III) on phosphatase activity
by taking advantage of a simple colorimetric assay; the results show that both of them are noncompetitive inhibitors affecting the Vmax but not the KM of the reaction. However, their Ki values
are different from each other (15.2 ± 1.6 µm for As(V) and 394.4 ± 40.3 µm with As(III)), indicating a
higher inhibitory effect by As(V). Moreover, the inhibition-based biosystem results to be selective for
As(V) since several other metal ions and salts do not affect TtArsC phosphatase activity; it exhibits a
sensitivity of 0.53 ± 0.03 mU/mg/µm and a limit of detection (LOD) of 0.28 ± 0.02 µm. The good
sensitivity and specificity for As(V) point to consider inhibition of TtArsC phosphatase activity for
the setup of a novel biosensor for the detection of As(V)
Extremophiles, a Nifty Tool to Face Environmental Pollution: From Exploitation of Metabolism to Genome Engineering
Insight into CAZymes of Alicyclobacillus mali FL18: Characterization of a New Multifunctional GH9 Enzyme
In the bio-based era, cellulolytic and hemicellulolytic enzymes are biocatalysts used in many industrial processes, playing a key role in the conversion of recalcitrant lignocellulosic waste biomasses. In this context, many thermophilic microorganisms are considered as convenient sources of carbohydrate-active enzymes (CAZymes). In this work, a functional genomic annotation of Alicyclobacillus mali FL18, a recently discovered thermo-acidophilic microorganism, showed a wide reservoir of putative CAZymes. Among them, a novel enzyme belonging to the family 9 of glycosyl hydrolases (GHs), named AmCel9, was identified; in-depth in silico analyses highlighted that AmCel9 shares general features with other GH9 members. The synthetic gene was expressed in Escherichia coli and the recombinant protein was purified and characterized. The monomeric enzyme has an optimal catalytic activity at pH 6.0 and has comparable activity at temperatures ranging from 40 °C to 70 °C. It also has a broad substrate specificity, a typical behavior of multifunctional cellulases; the best activity is displayed on β-1,4 linked glucans. Very interestingly, AmCel9 also hydrolyses filter paper and microcrystalline cellulose. This work gives new insights into the properties of a new thermophilic multifunctional GH9 enzyme, that looks a promising biocatalyst for the deconstruction of lignocellulose
Bioprospecting of Extremophilic Microorganisms to Address Environmental Pollution
Geothermal springs are rich in various metal ions due to the interaction between rock and water that takes place in the deep aquifer. Moreover, due to seasonality variation in pH and temperature, fluctuation in element composition is periodically observed within these extreme environments, influencing the environmental microbial communities. Extremophilic microorganisms that thrive in volcanic thermal vents have developed resistance mechanisms to handle several metal ions present in the environment, thus taking part to complex metal biogeochemical cycles. Moreover, extremophiles and their products have found an extensive foothold in the market, and this holds true especially for their enzymes. In this context, their characterization is functional to the development of biosystems and bioprocesses for environmental monitoring and bioremediation. To date, the isolation and cultivation under laboratory conditions of extremophilic microorganisms still represent a bottleneck for fully exploiting their biotechnological potential. This work describes a streamlined protocol for the isolation of thermophilic microorganisms from hot springs as well as their genotypical and phenotypical identification through the following steps: (1) Sampling of microorganisms from geothermal sites ("Pisciarelli", a volcanic area of Campi Flegrei in Naples, Italy); (2) Isolation of heavy metal resistant microorganisms; (3) Identification of microbial isolates; (4) Phenotypical characterization of the isolates. The methodologies described in this work might be generally applied also for the isolation of microorganisms from other extreme environments
Permeability properties of a three-cell type in vitro model of blood-brain barrier.
We previously found that RBE4.B brain capillary endothelial cells (BCECs) form a layer with blood-brain barrier (BBB) properties if co-cultured with neurons for at least one week. As astrocytes are known to modulate BBB functions, we further set a culture system that included RBE4.B BCECs, neurons and astrocytes. In order to test formation of BBB, we measured the amount of 3H-sucrose able to cross the BCEC layer in this three-cell type model of BBB. Herein we report that both neurons and astrocytes induce a decrease in the permeability of the BCEC layer to sucrose. These effects are synergic as if BCECs are cultured with both neurons and astrocytes for 5 days, permeability to sucrose decreases even more. By Western analysis, we also found that, in addition to the canonical 60 kDa occludin, anti-occludin antibodies recognize a smaller protein of 48 kDa which accumulates during rat brain development. Interestingly this latter protein is present at higher amounts in endothelial cells cultured in the presence of both astrocytes and neurons, that is in those conditions in which sucrose permeation studies indicate formation of BBB
Bone Mineral Density in Young Women on Methadone Substitution
Little is known about bone mineral density (BMD) in patients with heroin addiction and subsequent methadone substitution. The goal of this study was to compare bone mass density of young HIV-negative women on long-term methadone treatment to a local group of young healthy women. Eleven women (aged 20-29) with previous heroin dependence and current methadone substitution (20-140mg, median 60, daily) for 1.5-9 (median 3) years were compared to 30 healthy women (aged 20-28). Participants were examined with dual-energy X-ray absorptiometry of the lumbar spine (L2-L4), of the total proximal hip area, and of the femoral neck. Patients and controls had neither current nor lifetime underweight condition, had comparable ages at menarche, and did not differ significantly in current body mass index (21.9±4.0, respectively, 20.5±1.5kg/m2) in spite of a largely unhealthy lifestyle (cigarette, alcohol, and cocaine consumption in patients). Patients' total-hip parameters were marginally lower than those of controls (BMD P=0.054, T score P=0.049), whereas the femoral neck and lumbar spine parameters did not differ significantly between the two groups. Long-term methadone substitution in HIV-negative women seems to slightly affect bone mass densit
Synergistic effects of neurons and astrocytes on the differentiation of brain capillary endothelial cells in culture
Brain capillary endothelial cells form a functional barrier between blood and brain, based on the existence of tight junctions that limit paracellular permeability. Occludin is one of the major transmembrane proteins of tight junctions and its peripheral localization gives indication of tight junction formation. We previously reported that RBE4.B cells (brain capillary endothelial cells), cultured on collagen IV, synthesize occludin and correctly localize it at the cell periphery only when cocultured with neurons. In the present study, we describe a three-cell type-culture system that allowed us to analyze the combined effects of neurons and astrocytes on differentiation of brain capillary endothelial cells in culture. In particular, we found that, in the presence of astrocytes, the neuron-induced synthesis and localization of occludin is precocious as compared to cells cocultured with neurons only
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