Showing papers by "Helena I. S. Nogueira published in 2018"
TL;DR: Foams and fibers were the most abundant type in São João da Madeira, while fibers and fragments were themost abundant in Aguincheira and Estarreja in water and sediment samples, respectively.
468 citations
TL;DR: The accumulation of plastics in aquatic systems constitutes an emerging scientific and societal concern, because of their ubiquity, high persistence and insufficient management by sewage and wastewater treatment processes as mentioned in this paper, and it constitutes a major concern.
70 citations
TL;DR: A strategy to fabricate SERS active substrates (Ag/ LCP) based on liquid-crystal polymer (LCP) textile fibers decorated with Ag nanoparticles (NPs) is developed, which can be an easy alternative to prepare simple, highly efficient and low-cost SERSactive filter membranes for water analysis.
47 citations
19 Apr 2018
TL;DR: These studies demonstrate that the parameters employed in the fabrication of the SERS substrates have a strong impact on the Raman signal enhancement and allow establishing improvements that translate to better performances of the substrates in the analyte detection.
Abstract: A series of nanocomposites based on polyamide (NL16, PA) filter membranes containing metal nanoparticles (NPs) have been prepared by filtration under reduced pressure of the metal colloids. The ensuing materials were then investigated as substrates for surface-enhanced Raman scattering (SERS) imaging studies envisaging the spectroscopic detection of vestigial organic pollutants dissolved in contaminated water. The organic dye crystal violet (CV) was used here as a model pollutant because it is a hazardous compound present in certain effluent waters. Moreover this compound is well-known for its strong SERS activity, which is clearly advantageous in the context of material development for SERS. Indeed, several preparative strategies were employed to prepare PA-based composites, and the impact on SERS detection was investigated. These include the use of chemical and morphological distinct plasmonic NPs (Ag, Au), a variable metal load and changing the order of addition of the analytical specimens. These studi...
29 citations
TL;DR: The hybrid nanomaterials were investigated as adsorbents for the uptake of tetracycline from aqueous solutions and subsequent detection using surface-enhanced Raman scattering (SERS).
Abstract: Magnetite nanoparticles (MNPs) decorated with gold nanostars (AuNSs) have been prepared by using a seed growth method without the addition of surfactants or colloidal stabilizers. The hybrid nanomaterials were investigated as adsorbents for the uptake of tetracycline (TC) from aqueous solutions and subsequent detection using surface-enhanced Raman scattering (SERS). Several parameters were investigated in order to optimize the performance of these hybrid platforms on the uptake and SERS detection of TC, including variable pH values and the effect of contact time on the removal of TC. The spatial distribution of TC and AuNS on the hybrid composites was accomplished by coupling SERS analysis with Raman imaging studies, allowing also for the determination of the detection limit for TC when dissolved in ultrapure water (10 nM) and in more complex aqueous matrices (1 μM). Attempts were also made to investigate the adsorption modes of the TC molecules at the surface of the metal NPs by taking into account the enhancement of the Raman bands in these different matrices.
28 citations
21 citations
TL;DR: Gil Goncalves et al. as discussed by the authors used the PT2020 Partnership Agreement with the Portuguese Foundation for Science and Technology (FCT/MCTES) for a research contract under the Program Investigator 2013 (IF/00917/2013/CP1162/CT0016) and TEMA-Centre for Mechanical Technology and Automation (UID/EMS/00481/2013), financed by national funds through the FCT and MEC.
16 citations
TL;DR: The present study analyzed the association between healthy sleep duration and risk of obesity in Portuguese children to study the consequences of irregular sleep duration at younger ages.
Abstract: OBJECTIVES The consequences of irregular sleep duration at younger ages remains uncertain, especially when we consider shorter and longer than recommended sleep durations. Therefore, the present study aimed to analyze the association between healthy sleep duration and risk of obesity in Portuguese children. METHODS The sample for this cross-sectional study comprised 8273 children (4183 females) aged 6-9 years. Height and weight were measured and body mass index (BMI) was calculated. Sleep habits and sedentary behaviors (i.e., TV viewing) were assessed by questionnaire. Logistic regressions were used. RESULTS After adjustments for confounders, males who have irregular sleep duration were 1.28 times more likely to be classified as overweight or obese than their counterparts who had normal sleep duration on weekdays. No associations between sleep duration and overweight/obesity risk were found for girls, neither on weekdays nor on the weekend. For both boys and girls, the final model showed a significant inverse association between overweight/obesity risk and the educational level of fathers (males: 95% CI 0.51 to 0.79, P < .001; females: 95% CI 0.57 to 0.87, P < .01). CONCLUSION Findings revealed that shorter and longer than recommended sleep duration was positively associated with risk of obesity in boys on weekdays. Furthermore, pediatric obesity risk could be highly influenced by the education level of fathers of both males and females. Future research should extend a similar design, using objective measures of sleep duration to confirm some of the afore-mentioned results.
14 citations
TL;DR: Increased body fat predicted high blood pressure (HBP) and the use of anthropometric indicators may be useful in screening for HBP among Portuguese schoolchildren.
Abstract: Objective The aim of the study was to estimate the prevalence of high blood pressure (HBP) and its association with anthropometric indicators of adiposity in Portuguese schoolchildren. Methods In this cross-sectional study, a nationally representative sample of 6-9-year-old children was analyzed. Weight and height (used to calculate body mass index [BMI]), blood pressure (BP), waist circumference (WC) and skinfold thickness (used to estimate body fat percentage [BFP]) were measured using standard techniques. BP was classified as high-normal BP or hypertension for values between the 90th and 95th percentiles or above the 95th percentile, respectively. A body adiposity index was calculated with principal component analysis using BMI, WC and BFP. Multinomial logistic regression models were used to estimate the strength of the association between anthropometric indicators and HBP. Results The prevalence of high-normal BP and hypertension was 4.5% and 3.7%, respectively. BP was positively correlated with all anthropometric indicators (p Conclusion Increased body fat predicted HBP. The use of anthropometric indicators may thus be useful in screening for HBP among Portuguese schoolchildren.
13 citations
TL;DR: Overall, the proportions of boys with overweight/obesity were significantly higher in the Socioeconomic Vulnerable Areas which comes in line with previous evidence.
12 citations
TL;DR: Findings revealed that eating out at snack bars may be a risk for children’s health because those who eat out at these food establishments have a 21% higher risk of being overweight than those peers who do not eat out in snack bars.
Abstract: The present study examined the association between childhood overweight, children's meals and eating out in three types of restaurants (traditional Portuguese food restaurant, fast-food restaurant and snack bar). A representative sample of Portuguese children (5706 boys; 5950 girls aged 6-11 years) was used for this analysis and an ethnographic study with 233 interviews of the owners of snack bars in Coimbra (Portugal). Weight and height were measured (body mass index was consequently calculated). A familial and nutritional questionnaire was filled out by parents. Logistic regressions were used. Findings revealed that eating out at snack bars may be a risk for children's health because those who eat out at these food establishments have a 21% higher risk of being overweight than those peers who do not eat out at snack bars. In conclusion, findings revealed a statistically significant association between overweight and eating out at snack bars in boys.
TL;DR: In this article, a large-area MoS 2 obtained by sulfurization of MoO 3 using chemical vapor deposition (CVD) at different Ar base pressures was found to be ∼50mbar (millibar).
TL;DR: Children who consumed daily soft-drinks were 1.52 times more likely to be obese, and 72% morelikely to be classified as overweight children, than other children aged 3–5 years.
Abstract: The relationship between dietary intake and overweight-risk was assessed in 4349 children aged 3-5 years. Eating and sedentary behaviours were assessed by questionnaire. Logistic regressions were used. Children who consumed daily soft-drinks were 1.52 times more likely to be obese, and 72% more likely to be classified as overweight children.
18 Apr 2018
TL;DR: A review of the development of SERS substrates based on polymer nanocomposites and their applications in different fields can be found in this paper, where the main focus is on SERS studies that have used a diversity of polymer based nanocom composites, highlighting certain properties of the materials that are relevant for the envisaged functionalities.
Abstract: Polymer based nanocomposites containing metal nanoparticles (e.g. Au, Ag) have gained increased attention as a new class of SERS (Surface Enhanced Raman Scattering) substrates for analytical platforms. On the other hand, the application of SERS using such platforms can also provide new insights on the properties of composite materials. In this chapter, we review recent research on the development of SERS substrates based on polymer nanocomposites and their applications in different fields. The fundamentals of SERS are briefly approached and subsequently there is a reference to the strategies of preparation of polymer based nanocomposites. Here the main focus is on SERS studies that have used a diversity of polymer based nanocomposites, highlighting certain properties of the materials that are relevant for the envisaged functionalities. A final section is devoted to the joint use of Raman imaging and SERS in nanocomposites development, a topic that presents a great potential still to be explored as shown by the recent research in this field.
29 Jun 2018
TL;DR: Evidence suggests that obesity might also be determined by environmental features such as the urbanization level of the place where people live and work, which leads to overweight and obesity.
Abstract: Enquadramento: A obesidade e um grave problema de saude publica em todo o mundo devido ao seu impacto negativo na saude dos individuos e aos altos custos para os sistemas de saude. O objetivo deste estudo foi avaliar a relacao entre a proporcao de populacao urbana e a prevalencia de obesidade em todo o mundo e em Portugal. Metodos: Trata-se de um estudo transversal que utilizou dados disponiveis gratuitamente quanto a percentagem de populacao urbana e prevalencia de obesidade, em nivel global e nacional. Os dados recolhidos foram organizados por pais, a nivel mundial e, por regioes em Portugal. Posteriormente, os dados foram mapeados e os resultados foram representados atraves de graficos de dispersao, com linha de regressao e o respetivo coeficiente de determinacao. Resultados: Os resultados deste estudo mostram que existe uma correlacao entre obesidade e urbanizacao (r = 0,502, p <0,01) em todo o mundo e em Portugal. Conclusoes: As evidencias sugerem que a obesidade podera ser determinada por caracteristicas ambientais, como o nivel de urbanizacao do local onde as pessoas vivem e trabalham. A populacao urbana tende a ser menos ativa e ingerir mais alimentos altamente caloricos, o que leva ao sobrepeso e a obesidade.