3,074 research outputs found

    Comparison of ductile damage models during scratch tests - a numerical study

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    The ‘wear mode diagram’ has been commonly used to classify the deformation regime of the soft work-piece during scratching, into three modes: ploughing, wedge formation and cutting. The scratch test is usedto evaluate wear modes and material removal associated with wear. There are different damage models in the literature used for the description of material behaviour after damage initiation under different loadingconditions. However, there has been little analysis to compare damage models during scratch test conditions. The first aim of this work is first to use a finite element modelling package (Abaqus/Explicit) to build a 3Dmodel to capture deformation modes during scratching with indenters with different attack angles. Three different damage models are incorporated into the model and patterns of damage initiation and propagation arecompared with experimental results from the literature. This work highlights the role of the damage model in accurately capturing wear modes and material removal during two body sliding interactions

    Towards precision medicine in bariatric surgery prescription

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    Obesity is a complex, multifactorial and chronic disease. Bariatric surgery is a safe and effective treatment intervention for obesity and obesity-related diseases. However, weight loss after surgery can be highly heterogeneous and is not entirely predictable, particularly in the long-term after intervention. In this review, we present and discuss the available data on patient-related and procedure-related factors that were previously appointed as putative predictors of bariatric surgery outcomes. In addition, we present a critical appraisal of the available evidence on which factors could be taken into account when recommending and deciding which bariatric procedure to perform. Several patient-related features were identified as having a potential impact on weight loss after bariatric surgery, including age, gender, anthropometrics, obesity co-morbidities, eating behavior, genetic background, circulating biomarkers (microRNAs, metabolites and hormones), psychological and socioeconomic factors. However, none of these factors are sufficiently robust to be used as predictive factors. Overall, there is no doubt that before we long for precision medicine, there is the unmet need for a better understanding of the socio-biological drivers of weight gain, weight loss failure and weight-regain after bariatric interventions. Machine learning models targeting preoperative factors and effectiveness measurements of specific bariatric surgery interventions, would enable a more precise identification of the causal links between determinants of weight gain and weight loss. Artificial intelligence algorithms to be used in clinical practice to predict the response to bariatric surgery interventions could then be created, which would ultimately allow to move forward into precision medicine in bariatric surgery prescription

    Neck and supraclavicular lymphadenopathy secondary to 9-valent human papillomavirus vaccination

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    We present two clinical cases of lymphadenopathy after vaccination with the human papillomavirus (HPV) 9-valent vaccine: an asymptomatic 11-year-old boy with inferior cervical and supraclavicular lymphadenopathy, and a 13-year-old girl who presented with lymphadenopathy. In both cases, medical history was unremarkable and there was no recent infection, or other clinical findings. Both adolescents had received the HPV 9-valent vaccine in the previous week. In the first case, blood tests, ultrasonography and biopsy were performed, while in the second, a watchful waiting strategy was adopted. In both cases, the lymphadenopathy resolved spontaneously. The boy received the second dose of the vaccine 6 months later and lymphadenopathy reappeared. The Naranjo scale was applied, classifying the events as definite (in the case of the boy) and probable (girl) adverse drug reactions. The vaccine is safe, but recognising this minor adverse event is important to prevent unnecessary investigation and reduce patient and parental anxiety.info:eu-repo/semantics/publishedVersio

    Apoptosis regulation in adrenocortical carcinoma

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    Apoptosis evading is a hallmark of cancer. Tumor cells are characterized by having an impaired apoptosis signaling, a fact that deregulates the balance between cell death and survival, leading to tumor development, invasion and resistance to treatment. In general, patients with adrenocortical carcinomas (ACC) have an extremely bad prognosis, which is related to disease progression and significant resistance to treatments. In this report, we performed an integrative review about the disruption of apoptosis in ACC that may underlie the characteristic poor prognosis in these patients. Although the apoptosis has been scarcely studied in ACC, the majority of the deregulation phenomena already described are anti-apoptotic. Most importantly, in a near future, targeting apoptosis modulation in ACC patients may become a promising therapeutic.The work was supported by the Foundation for Science and Technology (FCT) (PTDC/MEC-ONC/31384/2017). Unit for Multidisciplinary Research in Biomedicine (UMIB) is funded by grants from FCT (UID/Multi/00215/2013)

    Chronic pancreatitis in children: treat like an adult?

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    A 15-year-old boy with a medical background of obesity, familial hyperlipidemia and acute recurrent pancreatitis, presented to emergency department reporting a 3-day course of periumbilical abdominal pain and nausea. Pain was noticed on epigastric palpation. Laboratory evaluation revealed leucocytosis, neutrophilia and pancreatic enzymes elevation more than three times the upper limit of normal. An acute recurrence of pancreatitis was diagnosed, was admitted to the hospital, being discharged after 5 days. Four days after, he was readmitted because of symptoms recurrence. Elevation of transaminases, gamma-glutamyltransferase (GGT) and direct bilirubin were noticed. Pancreatic enzymes still elevated but lower than in the previous episode. An endoscopic ultrasound revealed a Wirsung with a cephalic stricture and diffuse structural abnormalities suggestive of chronic pancreatitis. The patients was submitted to endotherapy with several sessions of endoscopic retrograde cholangiopancreatography including stenting and pancreatoscopy with marked clinical and imaging improvement. A genetic variant was identified.info:eu-repo/semantics/publishedVersio

    Renal Dysfunction Phenotypes in Patients Undergoing Obesity Surgery

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    Obesity surgery candidates are at an increased risk of kidney injury, but pre-operative evaluation usually neglects kidney function assessment. This study aimed to identify renal dysfunction in candidates for bariatric surgery. To reduce the sources of bias, subjects with diabetes, prediabetes under metformin treatment, neoplastic or inflammatory diseases were excluded. Patients' (n = 192) average body mass index was 41.7 +/- 5.4 kg/m(2). Among these, 51% (n = 94) had creatinine clearance over 140 mL/min, 22.4% (n = 43) had proteinuria over 150 mg/day and 14.6% (n = 28) albuminuria over 30 mg/day. A creatinine clearance higher than 140 mL/min was associated with higher levels of proteinuria and albuminuria. Univariate analysis identified sex, glycated hemoglobin, uric acid, HDL and VLDL cholesterol as being associated with albuminuria, but not with proteinuria. On multivariate analysis, glycated hemoglobin and creatinine clearance as continuous variables were significantly associated with albuminuria. In summary, in our patient population prediabetes, lipid abnormalities and hyperuricemia were associated with albuminuria, but not with proteinuria, suggesting different disease mechanisms might be implicated. Data suggest that in obesity-associated kidney disease, tubulointerstitial injury precedes glomerulopathy. A significant proportion of obesity surgery candidates present clinically relevant albuminuria and proteinuria along with renal hyperfiltration, suggesting that routine pre-operative assessment of these parameters should be considered

    Identification of a serum biomarker panel for the differential diagnosis of cholangiocarcinoma and primary sclerosing cholagnitis

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    The non-invasive differentiation of malignant and benign biliary disease is a clinical challenge. Carbohydrate antigen 19-9 (CA19-9), leucine-rich α2-glycoprotein (LRG1), interleukin 6 (IL6), pyruvate kinase M2 (PKM2), cytokeratin 19 fragment (CYFRA21.1) and mucin 5AC (MUC5AC) have reported utility for differentiating cholangiocarcinoma (CCA) from benign biliary disease. Herein, serum levels of these markers were tested in 66 cases of CCA and 62 cases of primary sclerosing cholangitis (PSC) and compared with markers of liver function and inflammation. Markers panels were assessed for their ability to discriminate malignant and benign disease. Several of the markers were also assessed in pre-diagnosis biliary tract cancer (BTC) samples with performances evaluated at different times prior to diagnosis. We show that LRG1 and IL6 were unable to accurately distinguish CCA from PSC, whereas CA19-9, PKM2, CYFRA21.1 and MUC5AC were significantly elevated in malignancy. Area under the receiver operating characteristic curves for these individual markers ranged from 0.73–0.84, with the best single marker (PKM2) providing 61% sensitivity at 90% specificity. A panel combining PKM2, CYFRA21.1 and MUC5AC gave 76% sensitivity at 90% specificity, which increased to 82% sensitivity by adding gamma-glutamyltransferase (GGT). In the pre-diagnosis setting, LRG1, IL6 and PKM2 were poor predictors of BTC, whilst CA19-9 and C-reactive protein were elevated up to 2 years before diagnosis. In conclusion, LRG1, IL6 and PKM2 were not useful for early detection of BTC, whilst a model combining PKM2, CYFRA21.1, MUC5AC and GGT was beneficial in differentiating malignant from benign biliary disease, warranting validation in a prospective trial

    Glycated hemoglobin and incident type 2 diabetes in singaporean Chinese adults: The Singapore Chinese Health Study

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    Background: The American Diabetes Association recently included glycated hemoglobin in the diagnostic criteria for diabetes, but research on the utility of this biomarker in Southeast Asians is scant. The aim of this study was to evaluate the association between percent HbA1c and incident diabetes in an Asian population of adult men and women without reported diabetes. Methods: Data analysis of 5,770 men and women enrolled in the Singapore Chinese Health Study who provided a blood sample at the follow-up I visit (1999-2004) and had no cancer and no reported history of diabetes or cardiovascular disease events. Diabetes was defined as self-report of physician diagnosis, identified at the follow-up II visit (2006-2010). Results: Hazard ratios (and 95%confidence intervals) for incident diabetes by 5 categories of HbA1c were estimated with Cox regression models and continuous HbA1c with cubic spline analysis. Compared to individuals with an HbA1c ≤ 5.7% (≤39 mmol/mol), individuals with HbA1c 5.8-5.9% (40-41 mmol/mol), 6.0-6.1% (42-43 mmol/mol), 6.2-6.4% (44-47 mmol/mol), and ≥ 6.5% (≥48 mmol/mol) had significantly increased risk for incident diabetes during followup. In cubic spline analysis, levels below 5.7% HbA1c were not significantly associated with incident diabetes. Conclusions: Our study found a strong and graded association with HbA1c 5.8% and above with incident diabetes in Chinese men and women

    Croup and COVID‐19

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    Are SADI-S and BPD/DS bariatric procedures identical twins or distant relatives?-A case report

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    Given the common anatomical features and similar short-term weight loss outcomes, Biliopancreatic Diversion with Duodenal Switch (BPD/DS) and Single-Anastomosis Duodenoileal bypass with Sleeve gastrectomy (SADI-S) are considered identical bariatric procedures, apart from technical complexity being lower for SADI-S. In the absence of prospective randomized trials or long-term comparative studies the rationale for choosing between procedures is hampered. Post-bariatric hormonal profiles could contribute to understand the underlying mechanisms and potentially be used as a decision aid when choosing between procedures. The main aim of this study was to compare the outcomes of BPD/DS and SADI-S, in genetically identical individuals exposed to similar environmental factors. Two identical twin (T) female patients, one submitted to BPD/DS (T_BPD/DS) and another to SADIS-S (T_SADI-S) were followed up to one year after surgery. Before surgery and at 3, 6 and 12 months after surgery, both patients underwent mixed meal tolerance tests (MMTT) to evaluate postprandial glucose, glucagon and GLP-1 response. In addition, 3 months after surgery, glucose dynamics were assessed using a Flash Glucose Monitoring (FGM) system for 14 days. The percentage of total weight loss (%TWL) was higher for T_BPD/DS compared to T_SADI-S (34.03 vs 29.03 %). During MMTT, T_BPD/DS presented lower glucose, glucagon, insulin and C-peptide excursions at all timepoints when compared to SADI-S; along with a greater percentage of time within the low glucose range (55.97 vs 39.93 %) and numerically lower glucose variability indexes on FGM (MAG change:0.51 vs 0.63 mmol/lxh- 1). In patients with the same genetic background, BPD/DS was shown to result in greater weight loss than SADI-S. The differences in glucose and enteropancreatic hormone profiles observed after BPD/DS and SADI-S suggest that different mechanisms underlie weight loss
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