1,782 research outputs found
Arachnoid cyst spontaneous rupture
Arachnoid cysts are benign congenital cerebrospinal fluid collections, usually asymptomatic and diagnosed incidentally in children or adolescents. They may become symptomatic after enlargement or complications, frequently presenting with symptoms of intracranial hypertension. We report an unusual case of progressive refractory headache in an adult patient due to an arachnoid cyst spontaneous rupture. Although clinical improvement occurred with conservative treatment, the subdural hygroma progressively enlarged and surgical treatment was ultimately needed. Spontaneous rupture is a very rare complication of arachnoid cysts. Accumulation of cerebrospinal fluid accumulation in the subdural space causes sustained intracranial hypertension that may be life-threatening and frequently requires surgical treatment. Patients with arachnoid cysts must be informed on their small vulnerability to cyst rupture and be aware that a sudden and severe headache, especially if starting after minor trauma or a Valsalva manoeuvre, always requires medical evaluation.info:eu-repo/semantics/publishedVersio
A Deductive Verification Platform for Cryptographic Software
In this paper we describe a deductive verification platform for the CAO language. CAO is a domain-specific language for cryptography. We show that this language presents interesting challenges for formal verification, not only in the rich mathematical type system that it introduces, but also in the cryptography-oriented language constructions that it offers. We describe how we tackle these problems, and also demonstrate that, by relying on the Jessie plug-in included in the Frama-C framework, the development time of such a complex verification tool could be greatly reduced. We base our presentation on real-world examples of CAO code, extracted from the open-source code of the NaCl cryptographic library, and illustrate how various cryptography-relevant security properties can be verified
Optimizing high-volume ultrasonic melt degassing using synchronized kinematic translation
Ultrasonic vibration is a physical processing technique that has been gathering support as an environmentally friendly approach to degas light alloy melts. Since metallic sonotrodes promote melt inclusions due to erosion, ceramic sonotrodes have also been shown as a viable solution for ultrasonic melt degassing in industrial scales. This study shows that resonant ceramic sonotrodes are characterized by a complex low-amplitude radial eigen mode, while particle image velocimetry reveals that their efficiency depends on the angular direction. An approach based on synchronized kinematic translation was designed to optimize the degassing efficiency in ultrasonic approaches, assuring its angle with higher cavitation is always facing the center of the crucible. Results show that this approach can reach lower degassing thresholds (Hmin ¼ 0.13 ml/100 g Al) at higher degassing rates, relatively to both Argon inflation (Hmin ¼ 0.22 ml/100 g Al) and static Ultrasound (Hmin ¼ 0.18 ml/100 g Al) methods. An enhanced grain refinement further supports the hypothesis that promoting a synchronized kinematic translation enhances the ultra sonic degassing efficiency. Considering these results, this approach is suggested as a reliable route to implement efficient ultrasonic degassing techniques in industrial light alloy melt treatment.This work was supported by PTDC/EMEEME/30967/2017 and NORTE-0145-FEDER-030967, co-financed by the European Regional Development Fund (ERDF), through the Operational Programme for Competitiveness and Internationalization (COMPETE 2020), under Portugal 2020, and by the Fundação para a Ciencia e a Tecnologia e FCT I.P. national funds. Also, this work was supported by Portuguese FCT, under the reference project UIDB/04436/2020 and Stimulus of Scientific Employment Application CEECIND/03991/2017
Avaliação de cultivares de soja no município de Querência-MT.
bitstream/item/39593/1/COT36-98.pd
Demographics and outcomes of hepatitis B and D: A 10-year retrospective analysis in a Swiss tertiary referral center.
Hepatitis B virus (HBV) is a major global health challenge with approximately 250-350 million chronically infected individuals. An improved understanding of the demographic features and outcomes of chronic HBV infection and hepatitis D virus (HDV) infection in low-endemic areas may improve prevention, early identification and management both at individual and community levels. Here, we retrospectively analyzed the demographic and clinical characteristics, treatment rates and outcomes of adult patients with chronic HBV infection with or without HDV coinfection examined at Lausanne University Hospital, Switzerland over a 10-year period.
We analyzed the medical records of all adult patients with chronic HBV and HDV infection examined in our center between 2007 and 2016. Liver-related outcome was defined as the occurrence of cirrhosis, hepatocellular carcinoma, liver transplantation or liver-related death. Analyses were performed using logistic regression and results were reported as odds ratio (OR) and 95% confidence interval (CI).
Of 672 consecutive patients, 421 (62.6%) were male, median age was 36 years (interquartile range, 28-46 years), and 233 (34.7%) were of African origin. The prevalence of HDV coinfection was 7.1% and the proportion of anti-HDV-positive patients with detectable HDV RNA was 70.0%. In multivariate analysis, HDV coinfection was the strongest predictor for liver-related outcome (OR 6.06, 95% CI 2.93-12.54, p<0.001), followed by HBeAg positivity (OR 2.47, 95% CI 1.30-4.69, p = 0.006), age (OR per 10-year increase 2.03, 95% CI 1.63-2.52, p<0.001) and sex (OR for female 0.39, 95% CI 0.22-0.71, p = 0.002). The predictive accuracy of the multivariate model was high (receiver operator characteristic area under the curve 0.81).
This retrospective study underscores the importance of migration in the epidemiology of chronic hepatitis B in low-endemic areas. HDV coinfection, HBeAg positivity and age predicted liver-related outcomes while female sex had a protective effect
Fibrosis-4 Index as an Independent Predictor of Mortality and Liver-Related Outcomes in NAFLD.
Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and its prevalence continues to rise. Fibrosis-4 index (FIB-4) has been shown to be a prognostic marker of liver-related outcomes in patients with NAFLD. We analyzed data from TriNetX global federated research network, combining data on 30 million patients. Patients were categorized into three diagnostic groups: NAFLD, nonalcoholic steatohepatitis (NASH), and at risk of NASH. Primary outcome was all-cause mortality, and secondary outcomes included progression to NASH, development of cirrhosis, end-stage liver disease, hepatocellular carcinoma (HCC), and liver transplantation. A total of 442,277 subjects (1.5% of the cohort) were assessed, and 81,108 were retained for analysis. Median follow-up was 34.8 months (interquartile range 12.2). FIB-4 was < 1.3 in 52.3% patients and ≥ 2.67 in 11.4% patients. In multivariate analysis, FIB-4 ≥ 2.67 was significantly and independently associated with all-cause mortality (hazard ratio [HR] 2.49, 95% confidence interval [CI] 2.20-2.82, P < 0.001) as well as with progression to NASH (HR 5.78, 95% CI 4.72-7.07, P < 0.001), cirrhosis (HR 2.04, 95% CI 1.86-2.24, P < 0.001), end-stage liver disease (HR 1.86, 95% CI 1.68-2.05, P < 0.001), HCC (HR 3.66, 95% CI 2.71-4.94, P < 0.001), and liver transplantation (HR 7.98, 95% CI 4.62-13.79, P < 0.001). Conclusion: In a real-world nationwide database, FIB-4 ≥ 2.67 was a strong predictor of both all-cause mortality and liver-related adverse outcomes independently of the baseline diagnostic group and common risk factors. Our findings indicate that FIB-4 could play a role as a risk-stratification tool for a population health approach. Significant underdiagnosis of both NAFLD/NASH and NASH cirrhosis in electronic medical records was observed
Effect of hybrid ultrasonic and mechanical stirring on the distribution of m-SiCp in A356 alloy
The present study details the micro-scale silicon carbide particle (m-SiCp) homogeneous distribution in an A356 alloy through hybrid ultrasonic-stirring melt treatment under different operation conditions. Ultrasonically excited fluids were studied by particle image velocimetry to estimate the efficiency of the acoustic streaming in different distances to the sonotrode. Distinct particle approaches to introduce the melt and stirring techniques were performed to determine a successful route to promote a homogenous distribution of reinforcement particles. Results showed that the addition of m-SiCp in the semisolid state significantly improved particle wettability, preventing rapid sedimentation. The combination of ultrasonic induced streaming and mechanical stirring is an effective tool for the homogeneous distribution of m-SiCp along the casting specimen.:This work was supported by PTDC/EMEEME/30967/2017 and NORTE-0145-FEDER-030967, co-financed by
the European Regional Development Fund (ERDF), the Operational Program for Competitiveness and
Internationalization (COMPETE 2020), under Portugal 2020, and by the Fundação para a Ciência e a
Tecnologia—FCT I.P. national funds. Additionally, this work was supported by the Portuguese FCT under the
reference project UIDB/04436/2020 and the Stimulus of Scientific Employment Application CEECIND/03991/2017
Project-based learning in a mechanical engineering course: A new proposal based on student's views
The evolution of learning in higher education is nowadays evident. Several discussions and studies have been performed about new methodologies that can disrupt the way the classes are taught in universities. In this context, Project-Based Learning (PBL) is the most emphasized. In the Mechanical Engineering course at the University of Minho (UM), the Integration Project (IP) courses apply a PBL methodology, being these classes the differentiating element of the Integrated Master in Mechanical Engineering (IMME) compared with other Portuguese universities. However, even if the innovative aspect of this approach is recognized nationally, the opinions between students and Professors, about the structure and organization of this class, are still divided. In that sense, this work presents a new proposal for the IP courses in which the opinion of students and successful models implemented in international universities are considered. This study analyses the best PBL methodologies implemented in Engineering courses and presents a PBL model actually implemented at the IMME. This information is combined with the student's views obtained from a survey conducted at the Department of Mechanical Engineering (DEM), regarding the actual PBL model. Through this study, a new proposal for the IP courses is presented. This proposal intends to provide an effective answer to the necessity of the students, using successful tools and methodologies to improve the teaching and learning process in the IMME course. Through this proposal, it is expected to increase the learning process and motivation of the students making them better prepared for a productive profession.The first author would like to express her gratitude for the support given by the Portuguese Foundation for Science and Technology (FCT) and the MIT Portugal Program. This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 (ALGORITMI Center) and R&D Units Project Scope UIDP/04077/2020 (METRICS Center)
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