83 research outputs found

    An alternative 3D inversion method for magnetic anomalies with depth resolution

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    This paper presents a new method to invert magnetic anomaly data in a variety of non-complex contexts when a priori information about the sources is not available. The region containing magnetic sources is discretized into a set of homogeneously magnetized rectangular prisms, polarized along a common direction. The magnetization distribution is calculated by solving an underdetermined linear system, and is accomplished through the simultaneous minimization of the norm of the solution and the misfit between the observed and the calculated field. Our algorithm makes use of a dipolar approximation to compute the magnetic field of the rectangular blocks. We show how this approximation, in conjunction with other correction factors, presents numerous advantages in terms of computing speed and depth resolution, and does not affect significantly the success of the inversion. The algorithm is tested on both synthetic and real magnetic datasets

    A Multidisciplinary Study of the DPRK Nuclear Tests

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    The Democratic People Republic of Korea announced two underground nuclear tests carried out in their territory respectively on October 9th, 2006 and May 25th, 2009. The scarce information on the precise location and the size of those explosions has stimulated various kinds of studies, mostly based on seismological observations, by several national agencies concerned with the Nuclear Test Ban Treaty verification. We analysed the available seismological data collected through a global high-quality network for the two tests. After picking up the arrival times at the various stations, a standard location program has been applied to the observed data. If we use all the available data for each single event, due to the different magnitude and different number of available stations, the locations appear quite different. On the contrary, if we use only the common stations, they happen to be only few km apart from each other and within their respective error ellipses. A more accurate relative location has been carried out by the application of algorithms such as double difference joint hypocenter determination (DDJHD) and waveform alignment. The epicentral distance between the two events obtained by these methods is 2 km, with the 2006 event shifted to the ESE with respect to that of 2009. We then used a dataset of VHR TerraSAR-X satellite images to detect possible surface effects of the underground tests. This is the first ever case where these highly performing SAR data have been used to such aim. We applied InSAR processing technique to fully exploit the capabilities of SAR data to measure very short displacements over large areas. Two interferograms have been computed, one co-event and one post-event, to remove possible residual topographic signals. A clear displacement pattern has been highlighted over a mountainous area within the investigated region, measuring a maximum displacement of about 45 mm overall the relief. Hypothesizing that the 2009 nuclear test had been carried out close to the area where the displacement has been observed through the DInSAR technique, its relation with the epicenter location obtained through seismological processing has been discussed as a possible alternative hypothesis with respect to the preferred solutions reported by the nuclear explosion database (NEDB). The distance of about 10 km between the two places can be considered acceptable in light of the possible systematic location shifts commonly observed in the seismological practice over a global scale. The difference between the m b magnitudes of the two tests could reflect differences in geological conditions of the two test sites, even if the yield of the two explosions had been the same

    Antiphospholipid antibodies and heart failure with preserved ejection fraction. The multicenter athero-aps study

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    Background. The prevalence of heart failure with preserved ejection fraction (HFpEF) in patients with antiphospholipid syndrome (APS) is unknown. Methods. A prospective multicenter cohort study including 125 patients was conducted: 91 primary APS (PAPS), 18 APS-SLE, and 16 carriers. HFpEF was diagnosed according to the 2019 European Society of Cardiology criteria: patients with ≥5 points among major and minor functional and morphological criteria including NT-ProBNP > 220 pg/mL, left atrial (LA) enlargement, increased left ventricular filling pressure. Results. Overall, 18 (14.4%) patients were diagnosed with HFpEF; this prevalence increased from 6.3% in carriers to 13.2% in PAPS and 27.8% in APS-SLE. Patients with HFpEF were older and with a higher prevalence of hypertension and previous arterial events. At logistic regression analysis, age, arterial hypertension, anticardiolipin antibodies IgG > 40 GPL (odds ratio (OR) 3.43, 95% confidence interval (CI) 1.09–10.77, p = 0.035), anti β-2-glycoprotein-I IgG > 40 GPL (OR 5.28, 1.53– 18.27, p = 0.009), lupus anticoagulants DRVVT > 1.25 (OR 5.20, 95% CI 1.10–24.68, p = 0.038), and triple positivity (OR 3.56, 95% CI 1.11–11.47, p = 0.033) were associated with HFpEF after adjustment for age and sex. By multivariate analysis, hypertension (OR 19.49, 95% CI 2.21–171.94, p = 0.008), age (OR 1.07, 95% CI 1.00–1.14, p = 0.044), and aβ2GPI IgG > 40 GPL (OR 8.62, 95% CI 1.23–60.44, p = 0.030) were associated with HFpEF. Conclusion. HFpEF is detectable in a relevant proportion of APS patients. The role of aPL in the pathogenesis and prognosis of HFpEF needs further investigation.publishersversionpublishe

    Prevalence of Different Subtypes of Serrated Polyps and Risk of Synchronous Advanced Colorectal Neoplasia in Average-Risk Population Undergoing First-Time Colonoscopy

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    OBJECTIVES: A growing body of evidence indicates that patients with sessile serrated adenoma/polyp (SSA/P) and traditional serrated adenoma (TSA) are at risk for subsequent malignancy. Despite increasing knowledge on histological categorization of serrated polyps (SPs) data are lacking on the actual prevalence and the association of each SP subtype with advanced colorectal neoplasia. METHODS: We prospectively determined the prevalence of different SP subtypes and evaluate the association with synchronous advanced neoplasia in asymptomatic average-risk subjects undergoing first-time colonoscopy. All retrieved polyps were examined by two independent pathologists. Serrated lesions were classified into hyperplastic polyps (HP), SSA/P (without and with cytological dysplasia, SSA/P/DIS), and TSA, and were screened for BRAF and K-ras mutations. RESULTS: Among 258 polyps detected in 985 subjects, the proportion of SSA/P and TSA was 8.9% and 1.9% with an overall prevalence of 2.3% and 0.6%, respectively. SSA/Ps were small without significant difference in their location between proximal and distal colon; TSA were predominantly left-sided. BRAF mutation was common in SSA/Ps and K-ras mutation was present in all TSA. Independent predictors of advanced neoplasia were male sex (odds ratio (OR)=2.0, 95% confidence interval (CI) 1.0-4.0), increasing age (OR=4.5, 95% CI 1.5-13.4 for 50-69 years and OR=9.9, 95% CI 3.1-31.5 for >70 years), current smoking (OR=2.0, 95% CI 1.3-6.8), >3 tubular adenoma (OR=3.6, 95% CI 1.9-6.4), and SSA/P (OR=6.0, 95% CI 1.9-19.5). CONCLUSIONS: The substantial prevalence of BRAF-mutated SSA/P and the independent association with synchronous advanced colorectal neoplasia in asymptomatic average-risk subjects support the overall impact of the serrated pathway on colorectal cancer (CRC) risk in general population. The endoscopic characteristics of SSA/P emphasize the need of high-quality colonoscopy as a key factor for an effective CRC screening progra

    Low-grade endotoxemia and risk of recurrent thrombosis in primary antiphospholipid syndrome. The multicenter ATHERO-APS study.

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    Low-grade endotoxemia is associated with systemic inflammation, enhanced oxidative stress and cardiovascular events in different clinical settings, but its possible role as "second hit" in patients with primary antiphospholipid syndrome (PAPS) has never been investigated. To evaluate the relationship between plasma lipopolysaccharide (LPS) levels, oxidative stress markers and risk of thrombosis in the prospective multicenter ATHERO-APS study. Baseline LPS, soluble NADPH-oxidase 2-derived peptide (sNOX-dp), H2O2 production, hydrogen peroxide breakdown activity (HBA), and nitric oxide (NO) bioavailability were compared in 97 PAPS, 16 non-thrombotic aPL carriers and 21 controls (CTRL) matched for age and sex. Correlations among laboratory variables were explored by Rho Spearman's correlation (rS). Cox-regression analysis was performed to assess the association between LPS and risk for a composite outcome of cardiovascular death, venous and arterial thromboembolism. In the whole cohort (median age 51 years (IQR 43-60), 72 % female), PAPS demonstrated higher levels of LPS, sNOX-dp and H2O2 and lower levels of NO and HBA compared to non-thrombotic aPL carriers and CTRL. LPS levels were inversely correlated with HBA (rS: -0.295, p = 0.001) and NO (rS: -0.322, p 23.1 pg/ml) had a 5-fold increased risk of composite outcome compared to those with LPS below the median, after adjustment for sex, age, diabetes, and global antiphospholipid syndrome score. Low-grade endotoxemia is associated with an increased oxidative stress and a higher risk of thrombosis in PAPS. Its prognostic value in carriers needs to be investigated in larger cohorts

    The actin-bundling protein Fascin is overexpressed in inflammatory bowel disease and may be important in tissue repair

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    <b>Background</b> Fascin is associated with increased cell motility in colorectal tumours but is absent from the normal colonic epithelium. We examined the expression of fascin in inflammatory bowel disease (IBD) and its location at regions undergoing restitution and regeneration. Tissue repair is essential for disease remission and we sought to determine the effects of therapeutic modalities on fascin expression and function using an in vitro model.<p></p> <b>Methods</b> Immunohistochemistry was performed on colonic tissue from IBD patients to determine changes in fascin expression and distribution. A human colorectal epithelial cell line was treated with 5-aminosalicylate (a common treatment for IBD), or sodium butyrate to determine the effect on fascin expression and cell motility.<p></p> <b>Results</b> Fascin overexpression was observed in both ulcerative colitis and Crohn's colitis and expression correlated with disease severity. Immunoreactivity was more intense and widespread in Crohn's compared to ulcerative colitis. Interestingly, highly expressing foci were consistently observed at the edges of ulcers where flattened, motile epithelial cells are actively involved in restitution, and also in areas of mucosal regeneration. 5-aminosalicylate reduced fascin expression in colorectal epithelial cells and inhibited their motility. Conversely, sodium butyrate increased fascin expression and stimulated cell motility in the same cells.<p></p> <b>Conclusions</b> Our data shows that fascin is overexpressed in inflammatory bowel disease and its location is indicative of a role in tissue repair. Our in vitro studies show that different therapeutic modalities may have converse effects on fascin expression and may have significant consequences for disease remission and the clinical management of IBD

    Antiphospholipid Antibodies and Heart Failure with Preserved Ejection Fraction. The Multicenter ATHERO-APS Study

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    The prevalence of heart failure with preserved ejection fraction (HFpEF) in patients with antiphospholipid syndrome (APS) is unknown. A prospective multicenter cohort study including 125 patients was conducted: 91 primary APS (PAPS), 18 APS-SLE, and 16 carriers. HFpEF was diagnosed according to the 2019 European Society of Cardiology criteria: patients with ≥5 points among major and minor functional and morphological criteria including NT-ProBNP > 220 pg/mL, left atrial (LA) enlargement, increased left ventricular filling pressure. Overall, 18 (14.4%) patients were diagnosed with HFpEF; this prevalence increased from 6.3% in carriers to 13.2% in PAPS and 27.8% in APS-SLE. Patients with HFpEF were older and with a higher prevalence of hypertension and previous arterial events. At logistic regression analysis, age, arterial hypertension, anticardiolipin antibodies IgG > 40 GPL (odds ratio (OR) 3.43, 95% confidence interval (CI) 1.09-10.77, p = 0.035), anti β-2-glycoprotein-I IgG > 40 GPL (OR 5.28, 1.53-18.27, p = 0.009), lupus anticoagulants DRVVT > 1.25 (OR 5.20, 95% CI 1.10-24.68, p = 0.038), and triple positivity (OR 3.56, 95% CI 1.11-11.47, p = 0.033) were associated with HFpEF after adjustment for age and sex. By multivariate analysis, hypertension (OR 19.49, 95% CI 2.21-171.94, p = 0.008), age (OR 1.07, 95% CI 1.00-1.14, p = 0.044), and aβ2GPI IgG > 40 GPL (OR 8.62, 95% CI 1.23-60.44, p = 0.030) were associated with HFpEF. HFpEF is detectable in a relevant proportion of APS patients. The role of aPL in the pathogenesis and prognosis of HFpEF needs further investigation

    The Sex-Specific Detrimental Effect of Diabetes and Gender-Related Factors on Pre-admission Medication Adherence Among Patients Hospitalized for Ischemic Heart Disease: Insights From EVA Study

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    Background: Sex and gender-related factors have been under-investigated as relevant determinants of health outcomes across non-communicable chronic diseases. Poor medication adherence results in adverse clinical outcomes and sex differences have been reported among patients at high cardiovascular risk, such as diabetics. The effect of diabetes and gender-related factors on medication adherence among women and men at high risk for ischemic heart disease (IHD) has not yet been fully investigated.Aim: To explore the role of sex, gender-related factors, and diabetes in pre-admission medication adherence among patients hospitalized for IHD.Materials and Methods: Data were obtained from the Endocrine Vascular disease Approach (EVA) (ClinicalTrials.gov Identifier: NCT02737982), a prospective cohort of patients admitted for IHD. We selected patients with baseline information regarding the presence of diabetes, cardiovascular risk factors, and gender-related variables (i.e., gender identity, gender role, gender relations, institutionalized gender). Our primary outcome was the proportion of pre-admission medication adherence defined through a self-reported questionnaire. We performed a sex-stratified analysis of clinical and gender-related factors associated with pre-admission medication adherence.Results: Two-hundred eighty patients admitted for IHD (35% women, mean age 70), were included. Around one-fourth of the patients were low-adherent to therapy before hospitalization, regardless of sex. Low-adherent patients were more likely diabetic (40%) and employed (40%). Sex-stratified analysis showed that low-adherent men were more likely to be employed (58 vs. 33%) and not primary earners (73 vs. 54%), with more masculine traits of personality, as compared with medium-high adherent men. Interestingly, women reporting medication low-adherence were similar for clinical and gender-related factors to those with medium-high adherence, except for diabetes (42 vs. 20%, p = 0.004). In a multivariate adjusted model only employed status was associated with poor medication adherence (OR 0.55, 95%CI 0.31–0.97). However, in the sex-stratified analysis, diabetes was independently associated with medication adherence only in women (OR 0.36; 95%CI 0.13–0.96), whereas a higher masculine BSRI was the only factor associated with medication adherence in men (OR 0.59, 95%CI 0.35–0.99).Conclusion: Pre-admission medication adherence is common in patients hospitalized for IHD, regardless of sex. However, patient-related factors such as diabetes, employment, and personality traits are associated with adherence in a sex-specific manner

    Catenins and their associated proteins in colorectal cancer

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    Colorectal cancer is the second most common cause of cancer mortality in the western world. Colorectal cancer has been well studied, and the genetic steps involved in the adenoma to carcinoma sequence have been well elucidated. The first genetic alteration, found in 85% of adenomas, are mutations in the adenomatous polyposis coli (MC) gene. However, the consequences of this and the exact function of APC in the colon is not fully understood. It has been suggested that APC could function through its regulation of Bcatenin, an ubiquitous cytoskeletal protein with multiple binding specificities resulting in diverse functions including cell growth, adhesion, and migration. Any change in these associations may play a role in colorectal cancer development and progression
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