5,853 research outputs found

    A metabolomic approach to animal vitreous humor topographical composition: A pilot study

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    The purpose of this study was to evaluate the feasibility of a 1H-NMR-based metabolomic approach to explore the metabolomic signature of different topographical areas of vitreous humor (VH) in an animal model. Five ocular globes were enucleated from five goats and immediately frozen at 280uC. Once frozen, three of them were sectioned, and four samples corresponding to four different VH areas were collected: the cortical, core, and basal, which was further divided into a superior and an inferior fraction. An additional two samples were collected that were representative of the whole vitreous body. 1H-NMR spectra were acquired for twenty-three goat vitreous samples with the aim of characterizing the metabolomic signature of this biofluid and identifying whether any site-specific patterns were present. Multivariate statistical analysis (MVA) of the spectral data were carried out, including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Partial Least Squares Discriminant Analysis (PLS-DA). A unique metabolomic signature belonging to each area was observed. The cortical area was characterized by lactate, glutamine, choline, and its derivatives, N-acetyl groups, creatine, and glycerol; the core area was characterized by glucose, acetate, and scyllo-inositol; and the basal area was characterized by branched-chain amino acids (BCAA), betaine, alanine, ascorbate, lysine, and myo-inositol. We propose a speculative approach on the topographic role of these molecules that are mainly responsible for metabolic differences among the as-identified areas. 1H-NMR-based metabolomic analysis has shown to be an important tool for investigating the VH. In particular, this approach was able to assess in the samples here analyzed the presence of different functional areas on the basis of a different metabolite distribution.The purpose of this study was to evaluate the feasibility of a 1H-NMR-based metabolomic approach to explore the metabolomic signature of different topographical areas of vitreous humor (VH) in an animal model. Five ocular globes were enucleated from five goats and immediately frozen at -80°C. Once frozen, three of them were sectioned, and four samples corresponding to four different VH areas were collected: the cortical, core, and basal, which was further divided into a superior and an inferior fraction. An additional two samples were collected that were representative of the whole vitreous body. 1H-NMR spectra were acquired for twenty-three goat vitreous samples with the aim of characterizing the metabolomic signature of this biofluid and identifying whether any site-specific patterns were present. Multivariate statistical analysis (MVA) of the spectral data were carried out, including Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Partial Least Squares Discriminant Analysis (PLS-DA). A unique metabolomic signature belonging to each area was observed. The cortical area was characterized by lactate, glutamine, choline, and its derivatives, N-acetyl groups, creatine, and glycerol; the core area was characterized by glucose, acetate, and scyllo-inositol; and the basal area was characterized by branched-chain amino acids (BCAA), betaine, alanine, ascorbate, lysine, and myo-inositol. We propose a speculative approach on the topographic role of these molecules that are mainly responsible for metabolic differences among the as-identified areas. 1H-NMR-based metabolomic analysis has shown to be an important tool for investigating the VH. In particular, this approach was able to assess in the samples here analyzed the presence of different functional areas on the basis of a different metabolite distribution. © 2014 Locci et al

    Early amniotomy after cervical ripening for induction of labor: a systematic review and meta-analysis of randomized controlled trials

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    OBJECTIVE DATA: Timing of artificial rupture of membranes (ie, amniotomy) in induction of labor is controversial, because it has been associated not only with shorter labors, but also with fetal nonreassuring testing, at times necessitating cesarean delivery. The aim of this systematic review and metaanalysis of randomized trials was to evaluate the effectiveness of early amniotomy vs late amniotomy or spontaneous rupture of membranes after cervical ripening. STUDY: The search was conducted with the use of electronic databases from inception of each database through February 2019. Review of articles included the abstracts of all references that were retrieved from the search. STUDY APPRAISAL AND SYNTHESIS METHODS: Selection criteria included randomized clinical trials that compared early amniotomy vs control (ie, late amniotomy or spontaneous rupture of membranes) after cervical ripening with either Foley catheter or prostaglandins at any dose. The primary outcome was the incidence of cesarean delivery. The summary measures were reported as summary relative risk with 95% of confidence interval with the use of the random effects model of DerSimonian and Laird. RESULTS: Four trials that included 1273 women who underwent cervical ripening with either Foley catheter or prostaglandins and then were assigned randomly to either early amniotomy, late amniotomy, or spontaneous rupture of membranes (control subjects) were included in the review. Women who were assigned randomly to early amniotomy had a similar risk of cesarean delivery (31.1% vs 30.9%; relative risk, 1.05; 95% confidence interval, 0.71-1.56) compared with control subjects and had a shorter interval from induction to delivery of approximately 5 hours (mean difference, -4.95 hours; 95% confidence interval, -8.12 to -1.78). Spontaneous vaginal delivery was also reduced in the early amniotomy group, but only 1 of the included trials reported this outcome (67.5% vs 69.1%; relative risk, 0.78; 95% confidence interval, 0.66-0.93). No between-group differences were reported in the other obstetrics or perinatal outcomes. CONCLUSION: After cervical ripening, routine early amniotomy does not increase the risk of cesarean delivery and reduces the interval from induction to delivery

    Intrahepatic persistent fetal right umbilical vein: a retrospective study

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    Introduction: To appraise the incidence and value of intrahepatic persistent right umbilical vein (PRUV). Methods: This was a single-center study. Records of all women with a prenatal diagnosis of intrahepatic PRUV were reviewed. The inclusion criteria were women with gestational age greater than 13 weeks of gestation. Exclusion criteria were fetuses with situs abnormalities, due to the hepatic venous ambiguity, and extrahepatic PRUV. The primary outcome was the incidence of intrahepatic PRUV in our cohort. The secondary outcomes were associated malformations. Results: 219/57,079 cases (0.38%) of intrahepatic PRUV were recorded. The mean gestational age at diagnosis was 21.8 ± 2.9 weeks of gestations. PRUV was isolated in the 76.7%, while in 23.3% was associated with other major or minor abnormalities. The most common associated abnormalities were cardiovascular abnormalities (8.7%), followed by genitourinary abnormalities (6.4%), skeletal abnormalities (4.6%), and central nervous system abnormalities (4.1%). Within the cardiovascular abnormalities, the most common one was ventricular septal defect (six cases). Conclusion: In most cases PRUV is an isolated finding. Associated minor or major malformations are presented in the 23.3% of the cases, so this finding should prompt detailed prenatal assessment of the fetus, with particular regard to cardiovascular system

    Combustion synthesis of metal carbides: Part I. Model development

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    The definition of a rigorous theoretical framework for the appropriate physico-chemical description of self-propagating high-temperature synthesis (SHS) processes represents the main goal of this work which is presented in two sequential articles. In this article, a novel mathematical model to simulate SHS processes is proposed. By adopting a heterogeneous approach for the description of mass transfer phenomena, the model is based on appropriate mass and energy conservation equations for each phase present during the system evolution. In particular, it takes microstructural evolution into account using suitable population balances and properly evaluating the different driving forces from the relevant phase diagram. The occurrence of phase transitions is treated on the basis of the so-called enthalpy approach, while a conventional nucleation-and-growth mechanistic scenario is adopted to describe quantitatively the formation of reaction products. The proposed mathematical model may be applied to the case of combustion synthesis processes involving a low melting point reactant and a refractory one, as for the synthesis of transition metal carbides from pure metal and graphite. Thus, the model can be profitably used to gain a deeper insight into the microscopic elementary phenomena involved in combustion synthesis processes through a suitable combination of experimental and modeling investigations, as it may be seen in Part II of this wor

    Physics Behind Precision

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    This document provides a writeup of contributions to the FCC-ee mini-workshop on "Physics behind precision" held at CERN, on 2-3 February 2016.Comment: https://indico.cern.ch/event/469561

    Comparative use of aqueous humour 1H NMR metabolomics and potassium concentration for PMI estimation in an animal model

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    Estimation of the post-mortem interval (PMI) remains a matter of concern in the forensic scenario. Traditional and novel approaches are not yet able to fully address this issue, which relies on complex biological phenomena triggered by death. For this purpose, eye compartments may be chosen for experimental studies because they are more resistant to post-mortem modifications. Vitreous humour, in particular, has been extensively investigated, with potassium concentration ([K+]) being the marker that is better correlated with PMI estimation. Recently, a 1H nuclear magnetic resonance (NMR) metabolomic approach based on aqueous humour (AH) from an animal model was proposed for PMI estimation, resulting in a robust and validated regression model. Here we studied the variation in [K+] in the same experimental setup. [K+] was determined through capillary ion analysis (CIA) and a regression analysis was performed. Moreover, it was investigated whether the PMI information related to potassium could improve the metabolome predictive power in estimating the PMI. Interestingly, we found that a part of the metabolomic profile is able to explain most of the information carried by potassium, suggesting that the rise in both potassium and metabolite concentrations relies on a similar biological mechanism. In the first 24-h PMI window, the AH metabolomic profile shows greater predictive power than [K+] behaviour, suggesting its potential use as an additional tool for estimating the time since death

    Social enrichment reverses the isolation-induced deficits of neuronal plasticity in the hippocampus of male rats

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    Environmental enrichment is known to improve brain plasticity and protect synaptic function from negative insults. In the present study we used the exposure to social enrichment to ameliorate the negative effect observed in post weaning isolated male rats in which neurotrophic factors, neurogenesis, neuronal dendritic trees and spines were altered markedly in the hippocampus. After the 4 weeks of post-weaning social isolation followed by 4 weeks of reunion, different neuronal growth markers as well as neuronal morphology were evaluated using different experimental approaches. Social enrichment restored the reduction of BDNF, NGF and Arc gene expression in the whole hippocampus of social isolated rats. This effect was paralleled by an increase in density and morphology of dendritic spines, as well as in neuronal tree arborisation in granule cells of the dentate gyrus. These changes were associated with a marked increase in neuronal proliferation and neurogenesis in the same hippocampal subregion that were reduced by social isolation stress. These results further suggest that the exposure to social enrichment, by abolishing the negative effect of social isolation stress on hippocampal plasticity, may improve neuronal resilience with a beneficial effect on cognitive function

    Combustion synthesis of metal carbides: Part II. Numerical simulation and comparison with experimental data

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    Based on the general theoretical model proposed in Part I of this work [J. Mater. Res. 20, 1257 (2005)], a series of numerical simulations related to the self-propagating high-temperature synthesis in the Ti-C system is presented. A detailed and quantitative description of the various physical and chemical processes that take place during combustion synthesis processes is provided in Part II of this work. In particular, the proposed mathematical description of the system has been discussed by highlighting the relation between system macroscopic behavior obtained experimentally with the modeled phenomena taking place at the microscopic scale. Model reliability is tested by comparison with suitable experimental data being nucleation parameters adopted for the fitting procedure. The complex picture emerging as a result of the model sophistication indicates that the rate of conversion is essentially determined by the rate of nucleation and growth. In addition, comparison between model results and experimental data seems to confirm the occurrence of heterogeneous nucleation in product crystallization

    Metabolomics improves the histopathological diagnosis of asphyxial deaths: an animal proof-of-concept model

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    The diagnosis of mechanical asphyxia remains one of the most difficult issues in forensic pathology. Asphyxia ultimately results in cardiac arrest (CA) and, as there are no specific markers, the differential diagnosis of primitive CA and CA secondary to asphyxiation relies on circumstantial details and on the pathologist experience, lacking objective evidence. Histological examination is currently considered the gold standard for CA post-mortem diagnosis. Here we present the comparative results of histopathology versus those previously obtained by 1H nuclear magnetic resonance (NMR) metabolomics in a swine model, originally designed for clinical purposes, exposed to two different CA causes, namely ventricular fibrillation and asphyxia. While heart and brain microscopical analysis could identify the damage induced by CA without providing any additional information on the CA cause, metabolomics allowed the identification of clearly different profiles between the two groups and showed major differences between asphyxiated animals with good and poor outcomes. Minute-by-minute plasma sampling allowed to associate these modifications to the pre-arrest asphyxial phase showing a clear correlation to the cellular effect of mechanical asphyxia reproduced in the experiment. The results suggest that metabolomics provides additional evidence beyond that obtained by histology and immunohistochemistry in the differential diagnosis of CA
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