This work presents potential applications of low-cost fused deposition modeling 3D-printers to fabricate multiuse 3D-printed electrochemical cells for flow or batch measurements as well as the ...3D-printing of electrochemical sensing platforms. Electrochemical cells and sensors were printed with acrylonitrile butadiene styrene (ABS) and conductive graphene-doped polylactic acid (G-PLA) filaments, respectively. The overall printing operation time and estimated cost per cell were 6 h and $ 6.00, respectively, while the sensors were printed within minutes (16 sensor strips of 1 × 2 cm in 10 min at a cost of $ 1.00 each sensor). The cell performance is demonstrated for the amperometric detection of tert-butylhydroquinone, dipyrone, dopamine and diclofenac by flow-injection analysis (FIA) and batch-injection analysis (BIA) using different working electrodes, including the proposed 3D-printed sensor, which presented comparable electroanalytical performance with other carbon-based electrodes (LOD of 0.1 μmol L−1 for dopamine). Raman spectroscopy and scanning electron microscopy of the 3D-printed sensor indicated the presence of graphene nanoribbons within the polymeric matrix. Electrochemical impedance spectroscopy and heterogeneous electron transfer constants (k0) for the redox probe Ru(NH3)6+3 revealed that a glassy-carbon electrode presented faster electron transfer rates than the 3D-printed sensor; however, the latter presented lower LOD values for dopamine and catechol probably due to oxygenated functional groups at the G-PLA surface.
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•Low-cost fused deposition modeling (FDM) 3D-printers to produce cells and electrodes.•Multiuse cells for flow- (FIA) and batch-injection analysis (BIA) as well for batch condition.•Designs and printing conditions accessible for any FDM 3D-printers.•Graphene-doped PLA printed sensors for voltammetric and amperometric detection.•Electroanalytical performance similar to GCE modified with carbon nanomaterials.
In the fog computing paradigm, fog nodes are placed on the network edge to meet end-user demands with low latency, providing the possibility of new applications. Although the role of the cloud ...remains unchanged, a new network infrastructure for fog nodes must be created. The design of such an infrastructure must consider user mobility, which causes variations in workload demand over time in different regions. Properly deciding on the location of fog nodes is important to reduce the costs associated with their deployment and maintenance. To meet these demands, this paper discusses the problem of locating fog nodes and proposes a solution which considers time-varying demands, with two classes of workload in terms of latency. The solution was modeled as a mixed-integer linear programming formulation with multiple criteria. An evaluation with real data showed that an improvement in end-user service can be obtained in conjunction with the minimization of the costs by deploying fewer servers in the infrastructure. Furthermore, results show that costs can be further reduced if a limited blocking of requests is tolerated.
Epigenetic changes, particularly histone compaction modifications, have emerged as critical regulators in the epigenetic pathway driving endothelial cell phenotype under constant exposure to laminar ...forces induced by blood flow. However, the underlying epigenetic mechanisms governing endothelial cell behavior in this context remain poorly understood. To address this knowledge gap, we conducted in vitro experiments using human umbilical vein endothelial cells subjected to various tensional forces simulating pathophysiological blood flow shear stress conditions, ranging from normotensive to hypertensive forces. Our study uncovers a noteworthy observation wherein endothelial cells exposed to high shear stress demonstrate a decrease in the epigenetic marks H3K4ac and H3K27ac, accompanied by significant alterations in the levels of HDAC (histone deacetylase) proteins. Moreover, we demonstrate a negative regulatory effect of increased shear stress on HOXA13 gene expression and a concomitant increase in the expression of the long noncoding RNA, HOTTIP, suggesting a direct association with the suppression of HOXA13. Collectively, these findings represent the first evidence of the role of histone‐related epigenetic modifications in modulating chromatin compaction during mechanosignaling of endothelial cells in response to elevated shear stress forces. Additionally, our results highlight the importance of understanding the physiological role of HOXA13 in vascular biology and hypertensive patients, emphasizing the potential for developing small molecules to modulate its activity. These findings warrant further preclinical investigations and open new avenues for therapeutic interventions targeting epigenetic mechanisms in hypertensive conditions.
HIGHLIGHTS
In vitro methodologies are employed as an initial approach to identify biomarkers associated with elevated shear stress in hypertension
Mechanosignaling mediated by oscillatory shear stress necessitates the involvement of epigenetic modifications, particularly histone‐mediated chromatin compression
Enhanced shear stress levels lead to a reduction in the overall abundance of acetylation marks, specifically H3K4 and H3K27, in endothelial cells
HOXA13 does not play a crucial role in the development of mechanosignaling induced by high shear stress
The data demonstrates a positive Pearson correlation between the long noncoding RNA HOTTIP and HOXA13
During the morphological changes occurring in osteoblast differentiation, Sonic hedgehog (Shh) plays a crucial role. While some progress has been made in understanding this process, the epigenetic ...mechanisms governing the expression of Hh signaling members in response to bone morphogenetic protein 7 (BMP7) signaling in osteoblasts remain poorly understood. To delve deeper into this issue, we treated pre‐osteoblasts (pObs) with 100 ng/mL of BMP7 for up to 21 days. Initially, we validated the osteogenic phenotype by confirming elevated expression of well‐defined gene biomarkers, including Runx2, Osterix, Alkaline Phosphatase (Alp), and bone sialoprotein (Bsp). Simultaneously, Hh signaling‐related members Sonic (Shh), Indian (Ihh), and Desert (Dhh) Hedgehog (Hh) exhibited nuanced modulation over the 21 days in vitro period. Subsequently, we evaluated epigenetic markers, and our data revealed a notable change in the CpG methylation profile, considering the methylation/hydroxymethylation ratio. CpG methylation is a reversible process regulated by DNA methyltransferases and demethylases, including Ten‐eleven translocation (Tets), which also exhibited changes during the acquisition of the osteogenic phenotype. Specifically, we measured the methylation pattern of Shh‐related genes and demonstrated a positive Pearson correlation for GLI Family Zinc Finger 1 (Gli1) and Patched (Ptch1). This data underscores the significance of the epigenetic machinery in modulating the BMP7‐induced osteogenic phenotype by influencing the activity of Shh‐related genes. In conclusion, this study highlights the positive impact of epigenetic control on the expression of genes related to hedgehog signaling during the morphogenetic changes induced by BMP7 signaling in osteoblasts.
This work presents the association of cloud point extraction (CPE) and electroanalysis for the selective and sensitive determination of methyl parathion (MP) in honey. The CPE step provided the ...pre-concentration of MP from a complex sample, in which the optimized extraction parameters (Triton X-100 concentration of 0.75% w/v, NaCl concentration of 1.0% w/v and heating time of 30 min) were investigated using a factorial design (2
3
). The detection of MP was performed using a cathodically pre-treated boron-doped diamond (BDD) working electrode and square wave voltammetry (SWV), after a suitable dilution of the CPE extract in Britton-Robinson buffer pH 6.0 as the supporting electrolyte. MP presented three electrochemical processes over the BDD surface, but only the reduction peak at around −0.7 V was monitored for the MP determination (higher detectability). Improved reproducibility was reached by applying an
in situ
cleaning step (+2.0 V for 15 s) followed by a re-activation process (−2.0 V for 15 s) between measurements. Using the optimized variables, a linear range between 0.1 and 2.0 μmol L
−1
was obtained for MP with a limit of detection of 0.006 μmol L
−1
, a 6-fold lower value when compared with the value attained without the CPE step. The experimental enrichment factor of MP was 6.1. Also, the optimized CPE allowed the determination of MP in honey samples with good accuracy (recovery between 94 and 106%), which was not possible using direct detection (without CPE) due to the matrix interference. This is the first paper that demonstrates the combination of CPE and electroanalysis for the determination of an organic compound.
This work presents the association of cloud point extraction (CPE) and electroanalysis for the selective and sensitive determination of methyl parathion (MP) in honey.
X-ray structural determinations and computational studies were used to investigate halogen interactions in two halogenated oxindoles. Comparative analyses of the interaction energy and the ...interaction properties were carried out for Br···Br, C-H···Br, C-H···O and N-H···O interactions. Employing Møller–Plesset second-order perturbation theory (MP2) and density functional theory (DFT), the basis set superposition error (BSSE) corrected interaction energy (Eint(BSSE)) was determined using a supramolecular approach. The Eint(BSSE) results were compared with interaction energies obtained by Quantum Theory of Atoms in Molecules (QTAIM)-based methods. Reduced Density Gradient (RDG), QTAIM and Natural bond orbital (NBO) calculations provided insight into possible pathways for the intermolecular interactions examined. Comparative analysis employing the electron density at the bond critical points (BCP) and molecular electrostatic potential (MEP) showed that the interaction energies and the relative orientations of the monomers in the dimers may in part be understood in light of charge redistribution in these two compounds.
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•Chronic hyperglycemia impacts bone biology and changes in the bone ultrastructural organization.•Gene expression modulation of osteokines and their receptors in bone and brain ...tissue.•Epigenetic regulation of the osteokines Ocn and Lcn2 in the femur through DNA methylation.•Transcriptional repression of Fgfr1 and Gpr158 receptors in the Central Nervous System.
Diabetes mellitus (DM) is a chronic metabolic disease, mainly characterized by increased blood glucose and insulin dysfunction. In response to the persistent systemic hyperglycemic state, numerous metabolic and physiological complications have already been well characterized. However, its relationship to bone fragility, cognitive deficits and increased risk of dementia still needs to be better understood. The impact of chronic hyperglycemia on bone physiology and architecture was assessed in a model of chronic hyperglycemia induced by a single intraperitoneal administration of streptozotocin (STZ; 55 mg/kg) in Wistar rats. In addition, the bone-to-brain communication was investigated by analyzing the gene expression and methylation status of genes that encode the main osteokines released by the bone Fgf23 (fibroblast growth factor 23), Bglap (bone gamma-carboxyglutamate protein) and Lcn2 (lipocalin 2) and their receptors in both, the bone and the brain Fgfr1 (fibroblast growth factor receptor 1), Gpr6A (G-protein coupled receptor family C group 6 member A), Gpr158 (G protein-coupled receptor 158) and Slc22a17 (Solute carrier family 22 member 17). It was observed that chronic hyperglycemia negatively impacted on bone biology and compromised the balance of the bone-brain endocrine axis. Ultrastructural disorganization was accompanied by global DNA hypomethylation and changes in gene expression of DNA-modifying enzymes that were accompanied by changes in the methylation status of the osteokine promoter region Bglap and Lcn2 (lipocalin 2) in the femur. Additionally, the chronic hyperglycemic state was accompanied by modulation of gene expression of the osteokines Fgf23 (fibroblast growth factor 23), Bglap (bone gamma-carboxyglutamate protein) and Lcn2 (lipocalin 2) in the different brain regions. However, transcriptional regulation mediated by DNA methylation was observed only for the osteokine receptors, Fgfr1(fibroblast growth factor receptor 1) in the striatum and Gpr158 (G protein-coupled receptor 158) in the hippocampus. This is a pioneer study demonstrating that the chronic hyperglycemic state compromises the crosstalk between bone tissue and the brain, mainly affecting the hippocampus, through transcriptional silencing of the Bglap receptor by hypermethylation of Gpr158 gene.
The global increase in drug consumption exposes the growing need to develop new systems for the detection, capture, and treatment of bioactive molecules. Carbamazepine is one instance of such ...contaminants at the top of the ranking commonly found in sewage treatment systems. This work, therefore, presents a theoretical study of fullerene C
and its derivatives with substitutional doping with B, Al, Ga, Si, Ge, N and P, for the detection and capture of carbamazepine is aqueous medium. Solvation effects were included by means of the Polarizable Continuum Solvent method. The results indicate that doped fullerenes are sensitive for the detection of carbamazepine both in gaseous and aquatic environments. Investigation on the intermolecular interactions between the drug and the fullerene molecule were carried out, allowing the characterization of the interactions responsible for stabilizing the adsorption of carbamazepine to the fullerenes. The theoretical survey revealed that fullerenes doped with Al, Ga, Si and Ge chemically adsorb carbamazepine whereas for the case of fullerenes doped with other heteroatoms physisorption is responsible for the molecular recognition. Relying on DFT calculations, the fullerene derivatives C
Al, C
Si and C
Ga are the most suitable to act both as a sensor and to uptake carbamazepine in aquatic environments.
Modifications on shear stress‐based mechanical forces are associated with pathophysiological susceptibility and their effect on endothelial cells (EC) needs to be better addressed looking for ...comprehending the cellular and molecular mechanisms. This prompted us to better evaluate the effects of shear stress in human primary venous EC obtained from the umbilical cord, using an in vitro model to mimic the laminar blood flow, reaching an intensity 1–4 Pa. First, our data shows there is a significant up‐expression of phosphatidylinositol 3‐kinase (PI3K) in shear‐stressed cells culminating downstream with an up‐phosphorylation of AKT and up‐expression of MAPK‐ERK, concomitant to a dynamic cytoskeleton rearrangement upon integrin subunits (α4 and ß 3) requirements. Importantly, the results show there is significant involvement of nitric oxide synthase (eNOS), nNOS, and vascular endothelial growth factors receptor 2 (VEGFR2) in shear‐stressed EC, while cell cycle‐related events seem to being changed. Additionally, although diminution of 5‐hydroxymethylcytosine in shear‐stressed EC, suggesting a global repression of genes transcription, the promoters of PI3K and eNOS genes were significantly hydroxymethylated corroborating with their respective transcriptional profiles. Finally, to better address, the pivotal role of PI3K in shear‐stressed EC we have revisited these biological issues by wortmannin targeting PI3K signaling and the data shows a dependency of PI3K signaling in controlling the expression of VGFR1, VGFR2, VEGF, and eNOS, once these genes were significantly suppressed in the presence of the inhibitor, as well as transcripts from Ki67 and CDK2 genes. Finally, our data still shows a coupling between PI3K and the epigenetic landscape of shear‐stressed cells, once wortmannin promotes a significant suppression of ten‐11 translocation 1 (TET1), TET2, and TET3 genes, evidencing that PI3K signaling is a necessary upstream pathway to modulate TET‐related genes. In this study we determined the major mechanotransduction pathway by which blood flow driven shear stress activates PI3K which plays a pivotal role on guaranteeing endothelial cell phenotype and vascular homeostasis, opening novel perspectives to understand the molecular basis of pathophysiological disorders related with the vascular system.
Abstract Background Individuals with psychotic disorders experience disruptions to both the sleep and circadian components of the sleep/wake cycle. Recent evidence has supported a role of sleep ...disturbances in emerging psychosis. However, less is known about how circadian rhythm disruptions may relate to psychosis symptoms and prognosis for adolescents with clinical high-risk (CHR) syndromes. The present study examines circadian rest/activity rhythms in CHR and healthy control (HC) youth to clarify the relationships among circadian rhythm disturbance, psychosis symptoms, psychosocial functioning, and the longitudinal course of illness. Methods Thirty-four CHR and 32 HC participants were administered a baseline evaluation, which included clinical interviews, 5 days of actigraphy, and a sleep/activity diary. CHR ( n = 29) participants were re-administered clinical interviews at a 1-year follow-up assessment. Results Relative to HC, CHR youth exhibited more fragmented circadian rhythms and later onset of nocturnal rest. Circadian disturbances (fragmented rhythms, low daily activity) were associated with increased psychotic symptom severity among CHR participants at baseline. Circadian disruptions (lower daily activity, rhythms that were more fragmented and/or desynchronized with the light/dark cycle) also predicted severity of psychosis symptoms and psychosocial impairment at 1-year follow-up among CHR youth. Conclusions Circadian rhythm disturbances may represent a potential vulnerability marker for emergence of psychosis, and thus, rest/activity rhythm stabilization has promise to inform early-identification and prevention/intervention strategies for CHR youth. Future studies with longer study designs are necessary to further examine circadian rhythms in the prodromal period and rates of conversion to psychosis among CHR teens.
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