189 research outputs found

    Gallium arsenide photodetectors for imaging in the far ultraviolet region

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    The aim of the present work is to systematically investigate the response and stability of commercial GaAs devices in the 200–400 nm UV range with a view to establishing their potentiality in imaging devices. The irradiation results of GaAs detectors with various geometries are presented and discussed. The detectors were reverse biased in fully depleted condition and in partially depleted condition (5 V reverse bias) in order to investigate the possibilities of integration with the standard bias values of read-out-integrated circuits. The results show that fabrication technology for nondedicated devices is still immature

    (1)H-NMR analysis provides a metabolomic profile of patients with multiple sclerosis

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    OBJECTIVE: To investigate the metabolomic profiles of patients with multiple sclerosis (MS) and to define the metabolic pathways potentially related to MS pathogenesis. METHODS: Plasma samples from 73 patients with MS (therapy-free for at least 90 days) and 88 healthy controls (HC) were analyzed by (1)H-NMR spectroscopy. Data analysis was conducted with principal components analysis followed by a supervised analysis (orthogonal partial least squares discriminant analysis [OPLS-DA]). The metabolites were identified and quantified using Chenomx software, and the receiver operating characteristic (ROC) curves were calculated. RESULTS: The model obtained with the OPLS-DA identified predictive metabolic differences between the patients with MS and HC (R2X = 0.615, R2Y = 0.619, Q2 = 0.476; p < 0.001). The differential metabolites included glucose, 5-OH-tryptophan, and tryptophan, which were lower in the MS group, and 3-OH-butyrate, acetoacetate, acetone, alanine, and choline, which were higher in the MS group. The suitability of the model was evaluated using an external set of samples. The values returned by the model were used to build the corresponding ROC curve (area under the curve of 0.98). CONCLUSION: NMR metabolomic analysis was able to discriminate different metabolic profiles in patients with MS compared with HC. With the exception of choline, the main metabolic changes could be connected to 2 different metabolic pathways: tryptophan metabolism and energy metabolism. Metabolomics appears to represent a promising noninvasive approach for the study of M

    Prognostic value of high-sensitivity cardiac troponin I early after coronary artery bypass graft surgery

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    Background: The diagnosis of periprocedural myocardial infarction (PMI) after coronary artery bypass graft (CABG) is based on biochemical markers along with clinical and instrumental findings. However, there is not a clear cutoff value of high-sensitivity cardiac troponin (hs-cTn) to identify PMI. We hypothesized that isolated hs-cTn concentrations in the first 24&nbsp;h following CABG could predict cardiac adverse events (in-hospital death and PMI) and/or left ventricular ejection fraction (LVEF) decrease. Methods: We retrospectively enrolled all consecutive adult patients undergoing CABG, alone or in association with other cardiac surgery procedures, over 1&nbsp;year. Hs-cTn I concentrations (Access, Beckman Coulter) were serially measured in the post-operative period and analyzed according to post-operative outcomes. Results: 300 patients were enrolled; 71.3% underwent CABG alone, 33.7% for acute coronary syndrome. Most patients showed hs-cTn I values superior to the limit required by the latest guidelines for the diagnosis of PMI. Five patients (1.7%) died, 8% developed a PMI, 10.6% showed a LVEF decrease ≥ 10%. Hs-cTn I concentrations did not significantly differ with respect to death and/or PMI whereas they were associated with LVEF decrease ≥ 10% (p value &lt; 0.005 at any time interval), in particular hs-cTn I values at 9–12&nbsp;h post-operatively. A hs-cTn I cutoff of 5556&nbsp;ng/L, a value 281 (for males) and 479 (for females) times higher than the URL, at 9–12&nbsp;h post-operatively was identified, representing the best balance between sensitivity (55%) and specificity (79%) in predicting LVEF decrease ≥ 10%. Conclusions: Hs-cTn I at 9–12&nbsp;h post-CABG may be useful to early identify patients at risk for LVEF decrease and to guide early investigation and management of possible post-operative complications

    Urinary metabolomic analysis to identify preterm neonates exposed to histological chorioamnionitis : A pilot study

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    Objective Chorioamnionitis is a leading cause of preterm birth worldwide, with higher incidence at lower gestational ages. An early and reliable diagnosis of histological chorioamnionitis (HCA) in preterm infants may be helpful in guiding postnatal management, especially the administration of prophylactic antibiotics to prevent early-onset sepsis. The main aim of this study was to investigate metabolomic analysis of urines collected in the first 24 hours of life as diagnostic tool of HCA. Methods Gestational age-, birth weight-, delivery mode- and sex- matched (1:2) preterm neonates (< 35 weeks\u2019 gestation) born to mothers with or without HCA were enrolled from an observational study. Gas chromatography-mass spectrometry (GC-MS)-based metabolomic analysis was performed on urine samples non-invasively collected in the first 24 hours of life. Univariate analysis, partial least square discriminant analysis (PLS-DA) and its associated variable importance in projection (VIP) score were performed. The most affected metabolic pathways were examined by Metabolite Sets Enrichment Analysis (MSEA). Results Fifteen cases (mean GA 30.2 \ub1 3.8 weeks, mean BW 1415 \ub1 471.9 grams) and 30 controls (mean GA 30.2 \ub1 2.9 weeks, mean BW 1426 \ub1 569.8 grams) were enrolled. Following univariate analysis, 29 metabolites had a significantly different concentration between cases and controls. The supervised PLS-DA model confirmed a separation between the two groups. Only gluconic acid, an oxidation product of glucose, was higher in cases than in controls. All other VIP metabolites were more abundant in the control group. Glutamate metabolism, mitochondrial electron transport chain, citric acid cycle, galactose metabolism, and fructose and mannose degradation metabolism were the most significantly altered pathways (P < 0.01). Conclusions For the first time, urinary metabolomics was able to discriminate neonates born to mothers with and without HCA. The identification of specifically altered metabolic pathways may be helpful in understanding metabolic derangement following chorioamnionitis

    Biodegradable composite porous poly(dl-lactide-co-glycolide) scaffold supports mesenchymal stem cell differentiation and calcium phosphate deposition

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    In recent decades, tissue engineering strategies have been proposed for the treatment of musculoskeletal diseases and bone fractures to overcome the limitations of the traditional surgical approaches based on allografts and autografts. In this work we report the development of a composite porous poly(dl-lactide-co-glycolide) scaffold suitable for bone regeneration. Scaffolds were produced by thermal sintering of porous microparticles. Next, in order to improve cell adhesion to the scaffold and subsequent proliferation, the scaffolds were coated with the osteoconductive biopolymers chitosan and sodium alginate, in a process that exploited electrostatic interactions between the positively charged biopolymers and the negatively charged PLGA scaffold. The resulting scaffolds were characterized in terms of porosity, degradation rate, mechanical properties, biocompatibility and suitability for bone regeneration. They were found to have an overall porosity of 3c85% and a degradation half time of 3c2\u2009weeks, considered suitable to support de novo bone matrix deposition from mesenchymal stem cells. Histology confirmed the ability of the scaffold to sustain adipose-derived mesenchymal stem cell adhesion, infiltration, proliferation and osteo-differentiation. Histological staining of calcium and microanalysis confirmed the presence of calcium phosphate in the scaffold sections

    Surgical treatment of primitive gastro-intestinal lymphomas: a systematic review

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    Primitive Gastrointestinal Lymphomas (PGIL) are uncommon tumours, although time-trend analyses have demonstrated an increase. The role of surgery in the management of lymphoproliferative diseases has changed over the past 40 years. Nowadays their management is centred on systemic treatments as chemo-/radio- therapy. Surgery is restricted to very selected indications, always discussed in a multidisciplinary setting. The aim of this systematic review is to evaluate the actual role of surgery in the treatment of PGIL

    Phase I Randomised Clinical Trial of an HIV-1CN54, Clade C, Trimeric Envelope Vaccine Candidate Delivered Vaginally

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    We conducted a phase 1 double-blind randomised controlled trial (RCT) of a HIV-1 envelope protein (CN54 gp140) candidate vaccine delivered vaginally to assess immunogenicity and safety. It was hypothesised that repeated delivery of gp140 may facilitate antigen uptake and presentation at this mucosal surface. Twenty two healthy female volunteers aged 18–45 years were entered into the trial, the first receiving open-label active product. Subsequently, 16 women were randomised to receive 9 doses of 100 µg of gp140 in 3 ml of a Carbopol 974P based gel, 5 were randomised to placebo solution in the same gel, delivered vaginally via an applicator. Participants delivered the vaccine three times a week over three weeks during one menstrual cycle, and were followed up for two further months. There were no serious adverse events, and the vaccine was well tolerated. No sustained systemic or local IgG, IgA, or T cell responses to the gp140 were detected following vaginal immunisations. Repeated vaginal immunisation with a HIV-1 envelope protein alone formulated in Carbopol gel was safe, but did not induce local or systemic immune responses in healthy women

    Accumulation of neutral lipids in peripheral blood mononuclear cells as a distinctive trait of Alzheimer patients and asymptomatic subjects at risk of disease

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    <p>Abstract</p> <p>Background</p> <p>Alzheimer's disease is the most common progressive neurodegenerative disease. In recent years, numerous progresses in the discovery of novel Alzheimer's disease molecular biomarkers in brain as well as in biological fluids have been made. Among them, those involving lipid metabolism are emerging as potential candidates. In particular, an accumulation of neutral lipids was recently found by us in skin fibroblasts from Alzheimer's disease patients. Therefore, with the aim to assess whether peripheral alterations in cholesterol homeostasis might be relevant in Alzheimer's disease development and progression, in the present study we analyzed lipid metabolism in plasma and peripheral blood mononuclear cells from Alzheimer's disease patients and from their first-degree relatives.</p> <p>Methods</p> <p>Blood samples were obtained from 93 patients with probable Alzheimer's disease and from 91 of their first-degree relatives. As controls we utilized 57, cognitively normal, over-65 year-old volunteers and 113 blood donors aged 21-66 years, respectively. Data are reported as mean ± standard error. Statistical calculations were performed using the statistical analysis software Origin 8.0 version. Data analysis was done using the Student t-test and the Pearson test.</p> <p>Results</p> <p>Data reported here show high neutral lipid levels and increased ACAT-1 protein in about 85% of peripheral blood mononuclear cells freshly isolated (<it>ex vivo</it>) from patients with probable sporadic Alzheimer's disease compared to about 7% of cognitively normal age-matched controls. A significant reduction in high density lipoprotein-cholesterol levels in plasma from Alzheimer's disease blood samples was also observed. Additionally, correlation analyses reveal a negative correlation between high density lipoprotein-cholesterol and cognitive capacity, as determined by Mini Mental State Examination, as well as between high density lipoprotein-cholesterol and neutral lipid accumulation. We observed great variability in the neutral lipid-peripheral blood mononuclear cells data and in plasma lipid analysis of the subjects enrolled as Alzheimer's disease-first-degree relatives. However, about 30% of them tend to display a peripheral metabolic cholesterol pattern similar to that exhibited by Alzheimer's disease patients.</p> <p>Conclusion</p> <p>We suggest that neutral lipid-peripheral blood mononuclear cells and plasma high density lipoprotein-cholesterol determinations might be of interest to outline a distinctive metabolic profile applying to both Alzheimer's disease patients and asymptomatic subjects at higher risk of disease.</p

    CYP17, GSTP1, PON1 and GLO1 gene polymorphisms as risk factors for breast cancer: an Italian case-control study

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    <p>Abstract</p> <p>Background</p> <p>Estrogens, environmental chemicals with carcinogenic potential, as well as oxidative and carbonyl stresses play a very important role in breast cancer (BC) genesis and progression. Therefore, polymorphisms of genes encoding enzymes involved in estrogen biosynthesis pathway and in the metabolic activation of pro-carcinogens to genotoxic intermediates, such as cytochrome P450C17α (CYP17), endogenous free-radical scavenging systems, such as glutathione S-transferase (GSTP1) and paraoxonase 1 (PON1), and anti-glycation defenses, such as glyoxalase I (GLO1), could influence individual susceptibility to BC. In the present case-control study, we investigated the possible association of CYP17 A1A2, GSTP1 ILE105VAL, PON1 Q192R or L55M, and GLO1 A111E polymorphisms with the risk of BC.</p> <p>Methods</p> <p>The above-said five polymorphisms were characterized in 547 patients with BC and in 544 healthy controls by PCR/RFLP methods, using DNA from whole blood. To estimate the relative risks, Odds ratios and 95% confidence intervals were calculated using unconditional logistic regression after adjusting for the known risk factors for BC.</p> <p>Results</p> <p>CYP17 polymorphism had no major effect in BC proneness in the overall population. However, it modified the risk of BC for certain subgroups of patients. In particular, among premenopausal women with the A1A1 genotype, a protective effect of later age at menarche and parity was observed. As to GSTP1 and PON1 192 polymorphisms, the mutant Val and R alleles, respectively, were associated with a decreased risk of developing BC, while polymorphisms in PON1 55 and GLO1 were associated with an increased risk of this neoplasia. However, these findings, while nominally significant, did not withstand correction for multiple testing.</p> <p>Conclusion</p> <p>Genetic polymorphisms in biotransformation enzymes CYP17, GSTP1, PON1 and GLO1 could be associated with the risk for BC. Although significances did not withstand correction for multiple testing, the results of our exploratory analysis warrant further studies on the above mentioned genes and BC.</p

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