568 research outputs found
Online matching in regular bipartite graphs
In an online problem, the input is revealed one piece at a time. In every time step, the online algorithm has to produce a part of the output, based on the partial knowledge of the input. Such decisions are irrevocable, and thus online algorithms usually lead to nonoptimal solutions. The impact of the partial knowledge depends strongly on the problem. If the algorithm is allowed to read binary information about the future, the amount of bits read that allow the algorithm to solve the problem optimally is the socalled advice complexity. The quality of an online algorithm is measured by its competitive ratio, which compares its performance to that of an optimal offline algorithm. In this paper we study online bipartite matchings focusing on the particular case of bipartite matchings in regular graphs. We give tight upper and lower bounds on the competitive ratio of the online deterministic bipartite matching problem. The competitive ratio turns out to be asymptotically equal to the known randomized competitive ratio. Afterwards, we present an upper and lower bound for the advice complexity of the online deterministic bipartite matching problem.Postprint (author's final draft
Synthesis of 0D to 3D hybrid-carbon nanomaterials carrying platinum(0) nanoparticles : towards the electrocatalytic determination of methylparabens at ultra-trace levels
A generic synthetic methodology has been applied for functionalizing four conducting carbon nanoallotropes, such as 0D carbon nanohorns (CNHs), 1D carbon nanotubes (CNTs), 2D reduced graphene oxide (rGO) and 3D graphite (GP) with platinum(0) nanoparticles (Pt-NP), and exploited towards the electrocatalytic determination of methylparaben (MeP), which has been classified as a potential endocrine-disrupting chemical. After an accurate physical, electrochemical and electroanalytical characterization, the hybrid Pt-NP@CNTs yields detection limits at nM levels, rather than the μM levels obtained with the rest of carbon homologous because of the optimum carbon/nanoparticle composition ratio. The proposed electrochemical sensing system has also been successfully validated by comparison with the standard bench-top chromatographic tool (HPLC), demonstrating its feasibility for MeP quantification in real cosmetic samples at ultra-trace levels. According to the outstanding performance of the hybrid Pt-NP@CNTs electrochemical platform, it can be regarded as a potential alternative to the conventional HPLC technique for the development of rapid, straightforward, cost-effective, reproducible and highly sensitive electrochemical sensors to be exploited in pharmacological, biomedical and environmental field
Variability of blood eosinophil count and prognosis of COPD exacerbations
MPOC; Eosinofília; ExacerbacióEPOC; Eosinofilia; ExacerbaciónCOPD; Eosinophilia; ExacerbationBackground
Eosinophils in peripheral blood are one of the emerging biomarkers in chronic obstructive pulmonary disease (COPD) patients. However, when analysing the relationship between peripheral eosinophilia and COPD prognosis, highly variable results are obtained. The aim of our study is to describe the serum eosinophilia levels in COPD patients and to analyse their relationship to prognosis following hospital admission.
Methods
A prospective observational study was conducted from 1 October 2016 to 1 October 2018 in the following Spanish centres: Salnés County Hospital in Vilagarcía de Arousa, Arquitecto Marcide Hospital in Ferrol and the University Hospital Complex in Santiago de Compostela. The patients were classified using three cut-off points of blood eosinophil count (BEC): 150 cells/µL, 300 cells/µL, and 400 cells/µL; in addition, the peripheral BEC was analysed on admission.
Results
615 patients were included in the study, 86.2% male, mean age 73.9 years, and mean FEV1 52.7%. The mean stay was 8.4 days, and 6% of all patients were readmitted early. No significant relationship was observed between the BEC, neither in the stable phase nor in the acute phase, and hospital stay, readmissions, deaths during admission, the need for intensive care, or the condition of frequent exacerbator.
Conclusion
The results of our study do not seem to support the usefulness of BEC as a COPD biomarker.This paper has not been funded by any project or scholarship
Unraveling Bicuspid Aortic Valve Enigmas by Multimodality Imaging: Clinical Implications
Aortic aneurysm; Bicuspid aortic valve; Computed tomographyAneurisma aòrtic; Vàlvula aòrtica bicúspide; Tomografia computadaAneurisma aórtico; Válvula aórtica bicúspide; Tomografía computadaMultimodality imaging is the basis of the diagnosis, follow-up, and surgical management of bicuspid aortic valve (BAV) patients. Transthoracic echocardiography (TTE) is used in our clinical routine practice as a first line imaging for BAV diagnosis, valvular phenotyping and function, measurement of thoracic aorta, exclusion of other aortic malformations, and for the assessment of complications such are infective endocarditis and aortic. Nevertheless, TTE is less useful if we want to assess accurately other aortic segments such as mid-distal ascending aorta, where computed tomography (CT) and magnetic resonance (CMR) could improve the precision of aorta size measurement by multiplanar reconstructions. A major advantage of CT is its superior spatial resolution, which affords a better definition of valve morphology and calcification, accuracy, and reproducibility of ascending aorta size, and allows for coronary artery assessment. Moreover, CMR offers the opportunity of being able to evaluate aortic functional properties and blood flow patterns. In this setting, new developed sequences such as 4D-flow may provide new parameters to predict events during follow up. The integration of all multimodality information facilitates a comprehensive evaluation of morphologic and dynamic features, stratification of the risk, and therapy guidance of this cohort of patients
Add-on inhaled budesonide in the treatment of hospitalised patients with COVID-19 : a randomised clinical trial
SARS-CoV-2 vaccines have been extremely effective to reduce the incidence of severe COVID19 [1-3], but effective and safe treatments of the acute infection are still limited [4, 5]. An uncontrolled pulmonary inflammatory response to SARS-CoV-2 is considered a key pathogenic mechanism of COVID19 progression [6], so systemic dexamethasone is recommended in severe cases [5, 7]. On the other hand, in very mild patients at home inhaled corticosteroids (ICS) may prevent disease progression [8-11]. Whether ICS prevent disease progression too in patients hospitalised because of COVID19 has not been explored before. Accordingly, we designed an investigator-initiated, open-label, randomised clinical trial (RCT) to explore the efficacy of adding inhaled budesonide to usual care to prevent disease progression in patients hospitalised because of COVID19 pneumonia. We also monitored carefully the safety of this intervention since there are concerns about the use of systemic corticosteroids in other viral (influenza) lung infections [12]
Who smokes in Europe? Data from 12 European countries in the TackSHS survey (2017-2018)
Background: Population data on tobacco use and its determinants require continuous monitoring and careful inter-country comparison. We aimed to provide the most up-to-date estimates on tobacco smoking from a large cross-sectional survey, conducted in selected European countries. Methods: Within the TackSHS Project, a face-to-face survey on smoking was conducted in 2017-2018 in 12 countries: Bulgaria, England, France, Germany, Greece, Ireland, Italy, Latvia, Poland, Portugal, Romania, and Spain, representing around 80% of the 432 million European Union (EU) adult population. In each country, a representative sample of around 1,000 subjects aged 15 years and older was interviewed, for a total of 11,902 participants. Results: Overall, 25.9% of participants were current smokers (31.0% of men and 21.2% of women, P < 0.001), while 16.5% were former smokers. Smoking prevalence ranged from 18.9% in Italy to 37.0% in Bulgaria. It decreased with increasing age (compared to <45, multivariable odds ratio [OR] for ≥65 year, 0.31; 95% confidence interval [CI], 0.27-0.36), level of education (OR for low vs high, 1.32; 95% CI, 1.17-1.48) and self-rated household economic level (OR for low vs high, 2.05; 95% CI, 1.74-2.42). The same patterns were found in both sexes. Conclusions: These smoking prevalence estimates represent the most up-to-date evidence in Europe. From them, it can be derived that there are more than 112 million current smokers in the EU-28. Lower socio-economic status is a major determinant of smoking habit in both sexes
The problematic use of Information and Communication Technologies (ICT) in adolescents by the cross sectional JOITIC study
Background: The emerging field of Information and Communications Technology (ICT) has brought about new interaction styles. Its excessive use may lead to addictive behaviours. The objective is to determine the prevalence of the problematic use of ICT such as Internet, mobile phones and video games, among adolescents enrolled in mandatory Secondary Education (ESO in Spanish) and to examine associated factors. Methods: Cross sectional, multi-centric descriptive study. Population: 5538 students enrolled in years one to four of ESO at 28 schools in the Vallès Occidental region (Barcelona, Spain). Data collection: self-administered socio-demographic and ICT access questionnaire, and validated questionnaires on experiences related to the use of the Internet, mobile phones and video games (CERI, CERM, CERV). Results: Questionnaires were collected from 5,538 adolescents between the ages of 12 and 20 (77.3 % of the total response), 48.6 % were females. Problematic use of the Internet was observed in 13.6 % of the surveyed individuals; problematic use of mobile phones in 2.4 % and problematic use in video games in 6.2 %. Problematic Internet use was associated with female students, tobacco consumption, a background of binge drinking, the use of cannabis or other drugs, poor academic performance, poor family relationships and an intensive use of the computer. Factors associated with the problematic use of mobile phones were the consumption of other drugs and an intensive use of these devices. Frequent problems with video game use have been associated with male students, the consumption of other drugs, poor academic performance, poor family relationships and an intensive use of these games. Conclusions: This study offers information on the prevalence of addictive behaviours of the Internet, mobile phones and video game use. The problematic use of these ICT devices has been related to the consumption of drugs, poor academic performance and poor family relationships. This intensive use may constitute a risk marker for ICT addictio
Waist to height ratio and cardiovascular risk factors in elderly individuals at high cardiovascular risk
Introduction: Several anthropometric measurements have been associated with cardiovascular disease, type-2 diabetes
mellitus and other cardiovascular risk conditions, such as hypertension or metabolic syndrome. Waist-to-height-ratio has
been proposed as a useful tool for assessing abdominal obesity, correcting other measurements for the height of the
individual. We compared the ability of several anthropometric measurements to predict the presence of type-2 diabetes,
hyperglycemia, hypertension, atherogenic dyslipidemia or metabolic syndrome.
Materials and Methods: In our cross-sectional analyses we included 7447 Spanish individuals at high cardiovascular risk,
men aged 55–80 years and women aged 60–80 years, from the PREDIMED study. Logistic regression models were fitted to
evaluate the odds ratio of presenting each cardiovascular risk factor according to various anthropometric measures. The
areas under the receiver-operating characteristic curve (AUC) were used to compare the predictive ability of these
measurements.
Results: In this relatively homogeneous cohort with 48.6% of type-2 diabetic individuals, the great majority of the studied
anthropometric parameters were significantly and positively associated with the cardiovascular risk factors. No association
was found between BMI and body weight and diabetes mellitus. The AUCs for the waist-to-height ratio and waist
circumference were significantly higher than the AUCs for BMI or weight for type-2 diabetes, hyperglycemia, atherogenic
dyslipidemia and metabolic syndrome. Conversely, BMI was the strongest predictor of hypertension.
Conclusions: We concluded that measures of abdominal obesity showed higher discriminative ability for diabetes mellitus,
high fasting plasma glucose, atherogenic dyslipidemia and metabolic syndrome than BMI or weight in a large cohort of
elderly Mediterranean individuals at high cardiovascular risk. No significant differences were found between the predictive
abilities of waist-to-height ratio and waist circumference on the metabolic disease
Effect of a Nutritional and Behavioral Intervention on Energy-Reduced Mediterranean Diet Adherence Among Patients With Metabolic Syndrome: Interim Analysis of the PREDIMED-Plus Randomized Clinical Trial
Key PointsQuestionWhat is the effect of a nutritional and behavioral intervention focused on encouraging an energy-reduced Mediterranean diet and physical activity on the dietary pattern of participants after 12 months? FindingsIn this preliminary analysis of an ongoing randomized clinical trial involving 6874 participants, an intervention focused on encouraging an energy-reduced Mediterranean diet and promoting physical activity, compared with advice to follow an energy-unrestricted Mediterranean diet, resulted in a significant increase in a measure of diet adherence, the 17-item energy-reduced Mediterranean diet score, at 12 months (4.7 points vs 2.5 points; score range, 0-17; minimal clinically important difference, 1 point). MeaningA nutritional and behavioral intervention focused on encouraging an energy-reduced Mediterranean diet and physical activity led to a significant improvement in a measure of diet adherence at 12 months. Further evaluation of the effects on long-term cardiovascular and other health outcomes is needed. ImportanceHigh-quality dietary patterns may help prevent chronic disease, but limited data exist from randomized trials about the effects of nutritional and behavioral interventions on dietary changes. ObjectiveTo assess the effect of a nutritional and physical activity education program on dietary quality. Design, Setting, and ParticipantsPreliminary exploratory interim analysis of an ongoing randomized trial. In 23 research centers in Spain, 6874 men and women aged 55 to 75 years with metabolic syndrome and no cardiovascular disease were enrolled in the trial between September 2013 and December 2016, with final data collection in March 2019. InterventionsParticipants were randomized to an intervention group that encouraged an energy-reduced Mediterranean diet, promoted physical activity, and provided behavioral support (n=3406) or to a control group that encouraged an energy-unrestricted Mediterranean diet (n=3468). All participants received allotments of extra-virgin olive oil (1 L/mo) and nuts (125 g/mo) for free. Main Outcomes and MeasuresThe primary outcome was 12-month change in adherence based on the energy-reduced Mediterranean diet (er-MedDiet) score (range, 0-17; higher scores indicate greater adherence; minimal clinically important difference, 1 point). ResultsAmong 6874 randomized participants (mean [SD] age, 65.0 [4.9] years; 3406 [52%] men), 6583 (96%) completed the 12-month follow-up and were included in the main analysis. The mean (SD) er-MedDiet score was 8.5 (2.6) at baseline and 13.2 (2.7) at 12 months in the intervention group (increase, 4.7 [95% CI, 4.6-4.8]) and 8.6 (2.7) at baseline and 11.1 (2.8) at 12 months in the control group (increase, 2.5 [95% CI, 2.3-2.6]) (between-group difference, 2.2 [95% CI, 2.1-2.4]; P<.001). Conclusions and RelevanceIn this preliminary analysis of an ongoing trial, an intervention that encouraged an energy-reduced Mediterranean diet and physical activity, compared with advice to follow an energy-unrestricted Mediterranean diet, resulted in a significantly greater increase in diet adherence after 12 months. Further evaluation of long-term cardiovascular effects is needed. Trial Registrationisrctn.com Identifier: ISRCTN89898870 This preliminary exploratory analysis of the ongoing PREDIMED-Plus randomized trial reports dietary adherence among Spanish community-dwelling participants with metabolic syndrome randomized to an energy-reduced Mediterranean diet, physical activity, and behavioral support vs an energy-unrestricted Mediterranean diet alone
Circulating carotenoids are associated with favorable lipid and fatty acid profiles in an older population at high cardiovascular risk
Carotenoid intake has been reported to be associated with improved cardiovascular health, but there is little information on actual plasma concentrations of these compounds as biomarkers of cardiometabolic risk. The objective was to investigate the association between circulating plasma carotenoids and different cardiometabolic risk factors and the plasma fatty acid profile. This is a cross-sectional evaluation of baseline data conducted in a subcohort (106 women and 124 men) of an ongoing multi-factorial lifestyle trial for primary cardiovascular prevention. Plasma concentrations of carotenoids were quantified by liquid chromatography coupled to mass spectrometry. The associations between carotenoid concentrations and cardiometabolic risk factors were assessed using regression models adapted for interval-censored variables. Carotenoid concentrations were cross-sectionally inversely associated with serum triglyceride concentrations [-2.79 mg/dl (95% CI: -4.25, -1.34) and -5.15 mg/dl (95% CI: -7.38, -2.93), p-values = 0.0002 and <0.00001 in women and men, respectively], lower levels of plasma saturated fatty acids [-0.09% (95% CI: -0.14, -0.03) and -0.15 % (95% CI: -0.23, -0.08), p-values = 0.001 and 0.0001 in women and men, respectively], and higher levels of plasma polyunsaturated fatty acids [(0.12 % (95% CI: -0.01, 0.25) and 0.39 % (95% CI: 0.19, 0.59), p-values = 0.065 and 0.0001 in women and men, respectively] in the whole population. Plasma carotenoid concentrations were also associated with higher plasma HDL-cholesterol in women [0.47 mg/dl (95% CI: 0.23, 0.72), p-value: 0.0002], and lower fasting plasma glucose in men [-1.35 mg/dl (95% CI: -2.12, -0.59), p-value: 0.001]. Keywords: Mediterranean diet; PREDIMED-plus study; cardiovascular health; liquid chromatography; mass spectrometry; plasma carotenoids
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