78 research outputs found

    Cooling electrons by magnetic-field tuning of Andreev reflection

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    A solid-state cooling principle based on magnetic-field-driven tunable suppression of Andreev reflection in superconductor/two-dimensional electron gas nanostructures is proposed. This cooling mechanism can lead to very large heat fluxes per channel up to 10^4 times greater than currently achieved with superconducting tunnel junctions. This efficacy and its availability in a two-dimensional electron system make this method of particular relevance for the implementation of quantum nanostructures operating at cryogenic temperatures.Comment: 4 pages, 4 figures, published versio

    Prevalence of the Absence of Cirrhosis in Subjects with NAFLD-Associated Hepatocellular Carcinoma

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    Background. Hepatocellular carcinoma (HCC) is most commonly considered as a complication of cirrhosis. However, an increasing number of HCC in subjects with non-alcoholic fatty liver disease (NAFLD) without cirrhosis is being reported. We conducted a meta-analysis to assess the prevalence of the absence of cirrhosis in NAFLD-associated HCC. Methods. Four databases were searched until March 2021 (CRD42021242969). The original articles included were those reporting data on the presence or absence of cirrhosis among at least 50 subjects with NAFLD-associated HCC. The number of subjects with absent cirrhosis in each study was extracted. For statistical pooling of data, a random-effects model was used. Subgroup analyses according to the continent, target condition and reference standard for the diagnosis of cirrhosis were conducted. Results. Thirty studies were included, evaluating 13,371 subjects with NAFLD-associated HCC. The overall prevalence of cases without cirrhosis was 37% (95%CI 28 to 46). A higher prevalence was reported in Asia versus Europe, North America and South America (45, 36, 37 and 22%, respectively) as well as in studies adopting histology only as the reference standard for the diagnosis of cirrhosis versus histology and other modalities (e.g., radiology, endoscopy, biochemistry or overt clinical findings) (53 and 27%, respectively). No difference was found between studies including subjects with non-alcoholic steatohepatitis (NASH) only, versus NAFLD with or without NASH (p = 0.385). One in three subjects with NAFLD-associated HCC presented without cirrhosis. This should be reflected in future guidelines and surveillance programs adapted to allow for the early detection of these cancers too

    Non Alcoholic Fatty Liver Disease Is Positively Associated with Increased Glycated Haemoglobin Levels in Subjects without Diabetes

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    Screening for non-alcoholic fatty liver disease (NAFLD) is key step for primary management of fatty liver in the clinical setting. Excess weight subjects carry a greater metabolic risk even before exhibiting pathological patterns, including diabetes. We characterized the cross-sectional relationship between routine circulating biomarkers and NAFLD in a large sample of diabetes-free subjects with overweight or obesity, to elucidate any independent relationship. A population sample of 1232 consecutive subjects with a body mass index of at least 25 kg/m(2), not receiving any drug or supplemental therapy, was studied. Clinical data and routine biochemistry were analyzed. NAFLD was defined using the validated fatty liver index (FLI), classifying subjects with a score >= 60% as at high risk. Due to extreme skewing of variables of interest, resampling matching for age and sex was performed. Our study population was characterized by a majority of females (69.90%) and a prevalence of NAFLD in males (88.90%). As a first step, propensity score matching was explicitly performed to balance the two groups according to the FLI cut-off. Based on the resulting statistical trajectories, corroborated even after data matching, we built two logistic regression models on the matched population (N = 732) to verify any independent association. We found that each unit increase of FT3 implicated a 50% increased risk of NAFLD (OR 1.506, 95%CI 1.064 to 2.131). When including glycated haemoglobin (HbA1c) in the model, free-triiodothyronine (FT3) lost significance (OR 1.557, 95%CI 0.784 to 3.089) while each unit increase in HbA1c (%) indicated a significantly greater NAFLD risk, by almost two-fold (OR 2.32, 95%CI 1.193 to 4.512). Glucose metabolism dominates a key pathway along the hazard trajectories of NAFLD, turned out to be key biomarker in monitoring the risk of fatty liver in diabetes-free overweight subjects. Each unit increase in HbA1c (%) indicated a significantly greater NAFLD risk, by almost two-fold, in our study

    Video-Laparoscopic versus Open Surgery in Obese Patients with Colorectal Cancer: A Propensity Score Matching Study

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    Background: Minimally invasive surgery in obese patients is still challenging, so exploring one more item in this research field ranks among the main goals of this research. We aimed to compare short-term postoperative outcomes of open and video-laparoscopic (VL) approaches in CRC obese patients undergoing colorectal resection. Methods: We performed a retrospective analysis of a surgical database including 138 patients diagnosed with CRC, undergoing VL (n = 87, 63%) and open (n = 51, 37%) colorectal surgery. As a first step, propensity score matching was performed to balance the comparison between the two intervention groups (VL and open) in order to avoid selection bias. The matched sample (N = 98) was used to run further regression models in order to analyze the observed VL surgery advantages in terms of postoperative outcome, focusing on hospitalization and severity of postoperative complications, according to the Clavien–Dindo classification. Results: The study sample was predominantly male (N = 86, 62.3%), and VL was more frequent than open surgery (63% versus 37%). The two subgroup results obtained before and after the propensity score matching showed comparable findings for age, gender, BMI, and tumor staging. The specimen length and postoperative time before discharge were longer in open surgery (OS) patients; the number of harvested lymph nodes was higher than in VL patients as well (p < 0.01). Linear regression models applied separately on the outcomes of interest showed that VL-treated patients had a shorter hospital stay by almost two days and about one point less Clavien–Dindo severity than OS patients on average, given the same exposure to confounding variables. Tumor staging was not found to have a significant role in influencing the short-term outcomes investigated. Conclusion: Comparing open and VL surgery, improved postoperative outcomes were observed for VL surgery in obese patients after surgical resection for CRC. Both postoperative recovery time and Clavien–Dindo severity were better with VL surgery

    A family history of type 2 diabetes as a predictor of fatty liver disease in diabetes-free individuals with excessive body weight

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    Comprehensive screening for non-alcoholic fatty liver disease (NAFLD) may help prompt clinical management of fatty liver disease. A family history, especially of diabetes, has been little studied as a predictor for NAFLD. We characterized the cross-sectional relationship between a family history of type 2 diabetes (FHT2D) and NAFLD probability in 1185 diabetes-free Apulian (Southern-Italy) subjects aged > 20 years with overweight or obesity not receiving any drug or supplementation. Clinical data and routine biochemistry were analysed. NAFLD probability was defined using the fatty liver index (FLI). A first-degree FHT2D was assessed by interviewing subjects and assigning a score of 0, 1, or 2 if none, only one, or both parents were affected by type 2 diabetes mellitus (T2DM). Our study population featured most females (70.9%, N = 840), and 48.4% (N = 574) of the sample had first-degree FHT2D. After dividing the sample by a FHT2D, we found a higher BMI, Waist Circumference (WC), and diastolic blood pressure shared by FHT2D subjects; they also showed altered key markers of glucose homeostasis, higher triglyceride levels, and worse liver function. FLI scores were significantly lower in subjects without a first-degree FHT2D. After running logistic regression models, a FHT2D was significantly associated with the NAFLD probability, even adjusting for major confounders and stratifying by age (under and over 40 years of age). A FHT2D led to an almost twofold higher probability of NAFLD, regardless of confounding factors (OR 2.17, 95% CI 1.63 to 2.89). A first-degree FHT2D acts as an independent determinant of NAFLD in excess weight phenotypes, regardless of the age group (younger or older than 40 years). A NAFLD risk assessment within multidimensional screening might be useful in excess weight subjects reporting FHT2D even in the absence of diabetes

    Performance of Fatty Liver Index in Identifying Non-Alcoholic Fatty Liver Disease in Population Studies. A Meta-Analysis

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    Background. Fatty liver index (FLI) is a non-invasive tool used to stratify the risk of non-alcoholic fatty liver disease (NAFLD) in population studies; whether it can be used to exclude or diagnose this disorder is unclear. We conducted a meta-analysis to assess the prevalence of NAFLD in each FLI class and the performance of FLI in detecting NAFLD. Methods. Four databases were searched until January 2021 (CRD42021231367). Original articles included were those reporting the performance of FLI and adopting ultrasound, computed tomography, or magnetic resonance as a reference standard. The numbers of subjects with NAFLD in FLI classes <30, 30–60, and 60, and the numbers of subjects classified as true/false positive/negative when adopting 30 and 60 as cut-offs were extracted. A random-effects model was used for pooling data. Results. Ten studies were included, evaluating 27,221 subjects without secondary causes of fatty liver disease. The prevalence of NAFLD in the three FLI classes was 14%, 42%, and 67%. Sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio for positive results, likelihood ratio for negative results, and diagnostic odds ratio were 81%, 65%, 53%, 84%, 2.3, 0.3, and 7.8 for the lower cut-off and 44%, 90%, 67%, 76%, 4.3, 0.6, and 7.3 for the higher cut-off, respectively. A similar performance was generally found in studies adopting ultrasound versus other imaging modalities. Conclusions. FLI showed an adequate performance in stratifying the risk of NAFLD. However, it showed only weak evidence of a discriminatory performance in excluding or diagnosing this disorder

    Liver Fibrosis and 8-Year All-Cause Mortality Trajectories in the Aging Cohort of the Salus in Apulia Study

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    Age is a major contributor to the liver fibrosis rate and its adverse health-related outcomes, including mortality, but older populations are still under-explored. We investigated multimorbidity and inflammatory biomarkers in relation to the increasing liver fibrosis risk to delineate 8-year all-cause mortality trajectories in 1929 older adults from the population-based Salus in Apulia Study. Liver fibrosis risk was assumed using the fibrosis-4 (FIB-4) score, assigned to three liver fibrosis risk groups (low, intermediate, high). In the secondary analyses, the APRI score was also calculated to allow for comparisons. Male subjects (prevalence difference: −13.49, 95% confidence interval (CI): −18.96 to −8.03), a higher multimorbidity burden (effect size, ES: −0.14, 95% CI: −0.26 to −0.02), a higher prevalence of physical frailty (ES: 6.77, 95% CI: 0.07 to 13.47), and a more pronounced inflammatory pattern as indicated by tumor growth factor-α circulating levels (ES: −0.12, 95% CI: −0.23 to −0.01) were significantly more common in the highest-risk FIB-4 score group. Liver function characterized by lipid profile and platelet levels worsened with increasing FIB-4 risk score. The 8-year risk of death was nearly double in subjects in the highest-risk FIB-4 score group, even after controlling for possible confounders. Furthermore, a steeper mortality curve was clearly observed for FIB-4 scores as compared with the APRI scoring system with respect to liver fibrosis risk. In conclusion, using a scoring tool based on simple routine biomarkers to detect liver fibrosis risk may enhance biological knowledge of age-related outcomes of chronic liver disease and be helpful in the clinical setting to identify subjects at risk for adverse health-related outcomes, including mortality

    Predictors of Long-Term Outcomes of Video-Laparoscopic Versus Open Surgery in Obese Patients with Colorectal Cancer: A Propensity Score Matching Study

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    Background: Minimally invasive methods in colorectal surgery offer unquestionable advantages, especially in the context of obesity. The current study addresses the lack of scientific evidence on the long-term oncologic safety of video-laparoscopic (VL) approaches in excess-weight CRC patients undergoing surgery. Methods: We retrospectively analyzed a surgical database consisting of 138 CRC patients undergoing VL (n = 87, 63%) and open CRC surgery (n = 51, 37%). To reduce selection bias, a propensity score matching was applied as a preliminary step to balance the comparison between the two surgery groups, i.e., VL and open surgery. Data from patients treated by the same surgeon were used.to minimize bias. Additional Cox regression models were run on the matched sample (N = 98) to explore the observed benefits of VL surgery in terms of overall and cancer-free survival. The nonparametric Kaplan-Meier method was used to compare the two surgical approaches and assess the likelihood of survival and cancer relapse. Results: The study sample was mostly male (N = 86, 62.3%), and VL outnumbered open surgery (63% versus 37%). Both before and after the matching, the VL-allocated group showed better overall survival (p < 0.01) with comparable cancer-free survival over more than five years of median observation time (66 months). Kaplan Meier survival probability curves corroborated the VL significant protective effect on survival (HR of 0.32; 95% CI: 0.13 to 0.81) even after adjusting for major confounding factors (age, gender, comorbidity index, BMI, tumor localization, tumor staging, tumor grading, clearance, CRM). Findings on oncologic performance by tumor relapse were comparable but lacked significance due to the small number of events observed. Conclusions: Comparing CRC surgical approaches, VL allocation showed comparable cancer-free survival but also a better performance on overall mortality than open surgery over more than five years of median observation
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