120 research outputs found

    The Relevance of Academic Libraries in the Twenty-First Century

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    The biggest challenge facing the library profession in the twenty-first century is staying relevant to its users. It is often stated that the Internet and Google have changed librarianship. This challenge, while significant, does not mean that libraries will go away. It is causing us to re-evaluate what we do, how we do it, and what role libraries have in the academy and in our culture at large. This column addresses some of the ways in which academic libraries can stay relevant throughout the twenty-first century

    Visible reconstruction by a circular holographic display from digital holograms recorded under infrared illumination

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    Cataloged from PDF version of article.A circular holographic display that consists of phase-only spatial light modulators is used to reconstruct images in visible light from digital holograms recorded under infrared (10.6 μm) illumination. The reconstruction yields a holographic digital video display of a three-dimensional ghostlike image of an object floating in space where observers can move and rotate around it. © 2012 Optical Society of Americ

    Liver biopsy-based validation, confirmation and comparison of the diagnostic performance of established and novel non-invasive non-alcoholic fatty liver disease indexes:Results from a large multi-center study

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    Background: Non-invasive tools (NIT) for non-alcoholic fatty liver disease (NAFLD) screening or diagnosis need to be thoroughly validated using liver biopsies.Purpose: To externally validate NITs designed to differentiate the presence or absence of liver steatosis as well as more advanced disease stages, to confirm fully validated indexes (n = 7 NITs), to fully validate partially validated indexes (n = 5 NITs), and to validate for the first time one new index (n = 1 NIT).Methods: This is a multi-center study from two Gastroenterology-Hepatology Departments (Greece and Australia) and one Bariatric-Metabolic Surgery Department (Italy). Overall, n = 455 serum samples of patients with biopsy-proven NAFLD (n = 374, including 237 patients with non-alcoholic steatohepatitis (NASH)) and Controls (n = 81) were recruited. A complete validation analysis was performed to differentiate the presence of NAFLD vs. Controls, NASH vs. NAFL, histological features of NASH, and fibrosis stages.Results: The index of NASH (ION) demonstrated the highest differentiation ability for the presence of NAFLD vs. Controls, with the area under the curve (AUC) being 0.894. For specific histological characterization of NASH, no NIT demonstrated adequate performance, while in the case of specific features of NASH, such as hepatocellular ballooning and lobular inflammation, ION demonstrated the best performance with AUC being close to or above 0.850. For fibrosis (F) classification, the highest AUC was reached by the aspartate aminotransferase to platelet ratio index (APRI) being ~0.850 yet only with the potential to differentiate the severe fibrosis stages (F3, F4) vs. mild or moderate fibrosis (F0–2) with an AUC > 0.900 in patients without T2DM. When we excluded patients with morbid obesity, the differentiation ability of APRI was improved, reaching AUC = 0.802 for differentiating the presence of fibrosis F2–4 vs. F0–1. The recommended by current guidelines index FIB-4 seemed to differentiate adequately between severe (i.e., F3–4) and mild or moderate fibrosis (F0–2) with an AUC = 0.820, yet this was not the case when FIB-4 was used to classify patients with fibrosis F2–4 vs. F0–1. Trying to improve the predictive value of all NITs, using Youden's methodology, to optimize the suggested cut-off points did not materially improve the results.Conclusions: The validation of currently available NITs using biopsy-proven samples provides new evidence for their ability to differentiate between specific disease stages, histological features, and, most importantly, fibrosis grading. The overall performance of the examined NITs needs to be further improved for applications in the clinic

    Liver biopsy-based validation, confirmation and comparison of the diagnostic performance of established and novel non-invasive non-alcoholic fatty liver disease indexes:Results from a large multi-center study

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    Background: Non-invasive tools (NIT) for non-alcoholic fatty liver disease (NAFLD) screening or diagnosis need to be thoroughly validated using liver biopsies.Purpose: To externally validate NITs designed to differentiate the presence or absence of liver steatosis as well as more advanced disease stages, to confirm fully validated indexes (n = 7 NITs), to fully validate partially validated indexes (n = 5 NITs), and to validate for the first time one new index (n = 1 NIT).Methods: This is a multi-center study from two Gastroenterology-Hepatology Departments (Greece and Australia) and one Bariatric-Metabolic Surgery Department (Italy). Overall, n = 455 serum samples of patients with biopsy-proven NAFLD (n = 374, including 237 patients with non-alcoholic steatohepatitis (NASH)) and Controls (n = 81) were recruited. A complete validation analysis was performed to differentiate the presence of NAFLD vs. Controls, NASH vs. NAFL, histological features of NASH, and fibrosis stages.Results: The index of NASH (ION) demonstrated the highest differentiation ability for the presence of NAFLD vs. Controls, with the area under the curve (AUC) being 0.894. For specific histological characterization of NASH, no NIT demonstrated adequate performance, while in the case of specific features of NASH, such as hepatocellular ballooning and lobular inflammation, ION demonstrated the best performance with AUC being close to or above 0.850. For fibrosis (F) classification, the highest AUC was reached by the aspartate aminotransferase to platelet ratio index (APRI) being ~0.850 yet only with the potential to differentiate the severe fibrosis stages (F3, F4) vs. mild or moderate fibrosis (F0–2) with an AUC > 0.900 in patients without T2DM. When we excluded patients with morbid obesity, the differentiation ability of APRI was improved, reaching AUC = 0.802 for differentiating the presence of fibrosis F2–4 vs. F0–1. The recommended by current guidelines index FIB-4 seemed to differentiate adequately between severe (i.e., F3–4) and mild or moderate fibrosis (F0–2) with an AUC = 0.820, yet this was not the case when FIB-4 was used to classify patients with fibrosis F2–4 vs. F0–1. Trying to improve the predictive value of all NITs, using Youden's methodology, to optimize the suggested cut-off points did not materially improve the results.Conclusions: The validation of currently available NITs using biopsy-proven samples provides new evidence for their ability to differentiate between specific disease stages, histological features, and, most importantly, fibrosis grading. The overall performance of the examined NITs needs to be further improved for applications in the clinic

    Liver biopsy-based validation, confirmation and comparison of the diagnostic performance of established and novel non-invasive non-alcoholic fatty liver disease indexes:Results from a large multi-center study

    Get PDF
    Background: Non-invasive tools (NIT) for non-alcoholic fatty liver disease (NAFLD) screening or diagnosis need to be thoroughly validated using liver biopsies.Purpose: To externally validate NITs designed to differentiate the presence or absence of liver steatosis as well as more advanced disease stages, to confirm fully validated indexes (n = 7 NITs), to fully validate partially validated indexes (n = 5 NITs), and to validate for the first time one new index (n = 1 NIT).Methods: This is a multi-center study from two Gastroenterology-Hepatology Departments (Greece and Australia) and one Bariatric-Metabolic Surgery Department (Italy). Overall, n = 455 serum samples of patients with biopsy-proven NAFLD (n = 374, including 237 patients with non-alcoholic steatohepatitis (NASH)) and Controls (n = 81) were recruited. A complete validation analysis was performed to differentiate the presence of NAFLD vs. Controls, NASH vs. NAFL, histological features of NASH, and fibrosis stages.Results: The index of NASH (ION) demonstrated the highest differentiation ability for the presence of NAFLD vs. Controls, with the area under the curve (AUC) being 0.894. For specific histological characterization of NASH, no NIT demonstrated adequate performance, while in the case of specific features of NASH, such as hepatocellular ballooning and lobular inflammation, ION demonstrated the best performance with AUC being close to or above 0.850. For fibrosis (F) classification, the highest AUC was reached by the aspartate aminotransferase to platelet ratio index (APRI) being ~0.850 yet only with the potential to differentiate the severe fibrosis stages (F3, F4) vs. mild or moderate fibrosis (F0–2) with an AUC > 0.900 in patients without T2DM. When we excluded patients with morbid obesity, the differentiation ability of APRI was improved, reaching AUC = 0.802 for differentiating the presence of fibrosis F2–4 vs. F0–1. The recommended by current guidelines index FIB-4 seemed to differentiate adequately between severe (i.e., F3–4) and mild or moderate fibrosis (F0–2) with an AUC = 0.820, yet this was not the case when FIB-4 was used to classify patients with fibrosis F2–4 vs. F0–1. Trying to improve the predictive value of all NITs, using Youden's methodology, to optimize the suggested cut-off points did not materially improve the results.Conclusions: The validation of currently available NITs using biopsy-proven samples provides new evidence for their ability to differentiate between specific disease stages, histological features, and, most importantly, fibrosis grading. The overall performance of the examined NITs needs to be further improved for applications in the clinic

    Advantages of the single delay model for the assessment of insulin sensitivity from the intravenous glucose tolerance test

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    The Minimal Model, (MM), used to assess insulin sensitivity (IS) from Intra-Venous Glucose-Tolerance Test (IVGTT) data, suffers from frequent lack of identifiability (parameter estimates with Coefficients of Variation (CV) less than 52%). The recently proposed Single Delay Model (SDM) is evaluated as a practical alternative

    Safety and efficacy of hydrothermal duodenal mucosal resurfacing in patients with type 2 diabetes: the randomised, double-blind, sham-controlled, multicentre REVITA-2 feasibility trial

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    Objective: Hydrothermal duodenal mucosal resurfacing (DMR) is a safe, outpatient endoscopic procedure. REVITA-2, a double-blind, superiority RCT, investigates safety and efficacy of DMR using the single catheter Revita system (Revita DMR [catheter and system], on glycaemic control and liver fat content in Type 2 Diabetes (T2D).Design: Eligible patients (HbA1c 59–86mmol/mol, BMI ≥24 and ≤40kg/m2, fasting insulin >48.6pmol/L, ≥1 oral antidiabetic medication) enrolled in Europe and Brazil. Primary endpoints were safety, change from baseline in HbA1c at 24 weeks, and liver magnetic resonance imaging proton-density fat fraction (MRI-PDFF) at 12 weeks. Results: Overall mITT (DMR N=56; sham N=52), 24-weeks post-DMR, median (IQR) HbA1c change was −10.4 (18.6) mmol/mol in DMR group versus −7.1 (16.4) mmol/mol in sham group (p=0.147). In patients with baseline liver MRI-PDFF >5% (DMR n=48; sham n=43), 12-week post-DMR liver-fat change was −5.4 (5.6)% in DMR group versus −2.9 (6.2)% in sham group (p=0.096). Results from prespecified interaction testing and clinical parameter assessment showed heterogeneity between European (DMR N=39; sham N=37) and Brazilian (DMR N=17; sham N=16) populations (p=0.063), therefore, results were stratified by region. In European mITT, 24-weeks post-DMR, median (IQR) HbA1c change was –6.6 mmol/mol (17.5 mmol/mol) versus –3.3 mmol/mol (10.9 mmol/mol) post-sham (p=0.033); 12-week post-DMR liver-fat change was –5.4% (6.1%) versus –2.2% (4.3%) post-sham (p=0.035). Brazilian mITT results trended towards DMR benefit in HbA1c, but not liver fat, in context of a large sham effect. In overall PP, patients with high baseline fasting plasma glucose ([FPG] ≥10 mmol/L) had significantly greater reductions in HbA1c post-DMR versus sham (p=0.002). Most adverse events were mild and transient. Conclusions: DMR is safe and exerts beneficial disease-modifying metabolic effects in T2D with or without non-alcoholic liver disease (NAFLD), particularly in patients with high FPG

    The trans-ancestral genomic architecture of glycemic traits

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    Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe
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