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1.
Talanta ; 226: 122095, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676652

RESUMO

This paper presents a new analytical approach for element concentration determination in samples containing significant concentrations of dissolved and suspended interferences. The proposed system enables to segregate of the complex matrix, species of interest from other interferences with a minimum requirement of reagents and energy. For this purpose, a new cleanup chamber design was implemented with cationic and anionic resins employed under membrane form and the tangential flow of the solution avoided the drawbacks commonly attributed to the packed and fluidized bed columns, such as the formation of preferred paths, increasing hydrodynamic pressure and clogging. The element concentration determination was colorimetrically performed with an automatic flow analysis system. The strategy was validated with the concentration determination of calcium and phosphorus in raw sugarcane juice. Quantification limit of 0.48 to calcium and 1.13 mg L-1 to phosphorus, linear range between 1 and 50 mg L-1, with RSD of 0.50 and 1.50% (n = 11) respectively.

2.
Public Health ; 187: 150-156, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32979606

RESUMO

OBJECTIVES: The Global Matrix of report card grades on physical activity serves as a public health awareness tool by summarising the status of child and youth physical activity prevalence and action. The objectives were to: (1) provide a detailed examination of the evidence informing the 'School' and 'Community and Environment' indicators across all participating European Global Matrix 3.0 countries; (2) explore the comparability of the grades for these two indicators across Europe; (3) detail any limitations or issues with the methods used to assign grades; and (4) provide suggestions on how future grading of the indicators could be improved. STUDY DESIGN: A comparative review of published methods on the grading of Global Matrix 3.0 indicators across European countries. METHODS: Key documents relating to the European countries involved in the 2018 Global Matrix 3.0 were collated and a template used to extract data for both the 'School' and 'Community and Environment' indicators. RESULTS: Seventeen of the 20 European Report Card countries (85%) had a grade for schools, and 15 countries (75%) had a grade for community and environment. All countries considered between one and five factors when assigning the grade for these indicators. There were wide disparities in the number and sources of evidence used to assign the grades for both indicators, limiting the comparability of the evidence between different countries. CONCLUSION: To enable comparability, the authors recommend moving towards an agreed standardised set of metrics for grading each indicator. Furthermore, it would be useful to develop and share common tools, methods and instruments to collect data in a uniform way across countries, where possible. Such action will ultimately make the Global Matrix a more robust and useful tool for the future.


Assuntos
Meio Ambiente , Exercício Físico , Promoção da Saúde/métodos , Características de Residência , Adolescente , Criança , Europa (Continente) , Política de Saúde/tendências , Humanos , Masculino , Saúde Pública
3.
J Anal Methods Chem ; 2020: 8865849, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32724704

RESUMO

Salicylic acid (SA) is an important stress signaling phytohormone and plays an essential role in physiological processes in plants. SA fractionation has been carried out batchwise, which is not compatible with the high analytical demand in agronomical studies and increases susceptibility to analytical errors. In this context, a novel flow-batch sample preparation system for SA fractionation on fresh plant leaves was developed. It was based on microwave-assisted extraction with water and conversion of the conjugated species to free SA by alkaline hydrolysis. Free and total SA were quantified by fluorimetry after separation by sequential injection chromatography in a C18 monolithic column. The proposed procedure is directly applicable to plant leaves containing up 16 mg kg-1 SA, with a limit of detection of 0.1 mg kg-1 of SA, coefficient of variation of 3.0% (n = 10), and sampling rate of 4 samples h-1. The flow-batch sample preparation system was successfully applied to SA fractionation in sugarcane, corn, and soybean leaves without clogging or increasing in backpressure. The proposed approach is simple, less time-consuming, and more environmentally friendly in comparison to batchwise procedures.

4.
J Sep Sci ; 43(7): 1232-1239, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31926120

RESUMO

Salicylic acid is an emerging environmental contaminant, usually found at ng/L concentrations in natural waters. Its quantification usually involves liquid chromatography-tandem mass spectrometry, which requires complex and costly instrumentation as well as time-consuming sample pretreatment, typically involving large solvent volumes. In this work, sequential injection chromatography was exploited to develop a fast, green, cost-effective, and highly sensitive procedure for fluorimetric determination of salicylic acid in natural waters. Analyte preconcentration directly on the chromatographic column (on-column preconcentration) was exploited to improve detectability, yielding an enrichment factor of 122 (1.75 mL of sample) and takes only 8.5 min per determination. A detection limit of 20 ng/L, a linear response range from 0.06 to 5.00 µg/L, coefficients of variation lower than 3.0% (n = 10), and recoveries within 86 and 114% were estimated. The procedure was applied for the analyses of freshwater samples and results agreed with those obtained by liquid chromatography-tandem mass spectrometry at the 95% confidence level. The proposed procedure encompasses in-line concentration, isolation/separation, and detection, without the need for sample clean-up, thus minimizing the consumption of organic solvents and risk of analyte losse.


Assuntos
Poluentes Ambientais/análise , Água Doce/química , Ácido Salicílico/análise , Poluentes Químicos da Água/análise , Fluorometria
5.
Public Health ; 163: 87-94, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30107297

RESUMO

OBJECTIVES: The media is a substantial vehicle for conveying public health messages to the public. This study examined the extent to which the publication of special issues in a high-impact medical journal in 2012 and 2016 generated media interest in physical activity and health in the UK and explored the main issues that were reported. STUDY DESIGN: This is a systematic narrative review of print media. METHODS: Relevant print news articles were identified by searching Factiva and Google News. The timeframe of each search was 2 weeks, using the publication date of each special issue as the anchor point. Overall, 20 articles were included in the analysis for 2012 and 37 articles for 2016. RESULTS: The news media coverage was encouraging for the profile of physical activity and health. In 2012 and 2016, common themes included the benefits of physical activity and the risks of being inactive, comparisons between mortality rates from physical inactivity and smoking and the recommended volume of physical activity to benefit health. CONCLUSIONS: The profile given to an issue through prestigious scientific publication is one of the levers for community attention and policy change. Efforts are needed to further use the media for improving policy, practice and public awareness, which are antecedents to population health change.


Assuntos
Exercício Físico , Fator de Impacto de Revistas , Jornalismo Médico , Meios de Comunicação de Massa/estatística & dados numéricos , Publicações Periódicas como Assunto , Humanos , Reino Unido
6.
Talanta ; 168: 303-306, 2017 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-28391858

RESUMO

An advanced strategy involving concentric tubes is proposed for fast and controlled heating (or cooling) of the reaction medium in flow analysis. Different temperatures are set by sequentially circulating two thermostated water streams through the outer larged bore (2.0mm i.d.) silicone tube, which acted as a water-jacket of the inner (0.8mm i.d.) PTFE tube, and directing the sample zone to flow through it. Each end of the outer tube is connected to a three-way valve that selects the stream to flow inside it. For 25-85cm tube lengths and a 12.0mLmin-1 flow rate, the time interval required for temperature attainment, and the uniformity of temperature along the tube were evaluated. For the 85-cm tube, low differences in temperatures along the coil (1.1-8.7°C) and between programmed and attained values (2.3-13.4°C) were noted within a wide range of pre-set temperatures (15-75°C). The feasibility of the innovation in flow analysis was demonstrated in a model system relying on the iodide-nitrite reaction. The strategy allows fast (15-120s) thermostating of the reaction medium in a versatile and simple way, and is especially attractive when two controlled temperatures are set during the analytical course. Potentialities and limitations of the innovation are discussed.

7.
Phys Rev E ; 94(2-2): 026102, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27627424

RESUMO

We reply to the "Comment on 'Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic mirrors.' " We believe the comment misrepresents our papers, and fails to provide a plausible resolution to the conflict between theory and experiment.

8.
Phys Rev E ; 93(2): 022108, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26986289

RESUMO

We examine the conditions of validity for the Lifshitz-Matsubara sum formula for the Casimir pressure between magnetic metallic plane mirrors. As in the previously studied case of nonmagnetic materials [Guérout et al., Phys. Rev. E 90, 042125 (2014)], we recover the usual expression for the lossy model of optical response, but not for the lossless plasma model. We also show that the modes associated with the Foucault currents play a crucial role in the limit of vanishing losses, in contrast to expectations.

9.
Anal Chim Acta ; 902: 123-128, 2016 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-26703261

RESUMO

The feasibility of implementing tracer-monitored titrations in a flow system is demonstrated. A dye tracer is used to estimate the instant sample and titrant volumetric fractions without the need for volume, mass or peak width measurements. The approach was applied to spectrophotometric flow titrations involving variations of sample and titrant flow-rates (i.e. triangle programmed technique) or concentration gradients established along the sample zone (i.e. flow injection system). Both strategies required simultaneous monitoring of two absorbing species, namely the titration indicator and the dye tracer. Mixing conditions were improved by placing a chamber with mechanical stirring in the analytical path aiming at to minimize diffusional effects. Unlike most of flow-based titrations, the innovation is considered as a true titration, as it does not require a calibration curve thus complying with IUPAC definition. As an application, acidity evaluation in vinegars involving titration with sodium hydroxide was selected. Phenolphthalein and brilliant blue FCF were used as indicator and dye tracer, respectively. Effects of sample volume, titrand/titrant concentrations and flow rates were investigated aiming at improved accuracy and precision. Results were reliable and in agreement with those obtained by a reference titration procedure.

10.
Talanta ; 143: 419-430, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26078179

RESUMO

In flow analysis, use of a steady and pulseless flow was considered essential for ensuring a reproducible handling of the flowing sample. To this end, peristaltic and syringe pumps have been the propelling device in the vast majority of the flow analysers. Recently, the number of applications involving pulsed flow has been increasing. Most of them refer to use of solenoid pumps, the essence of the so-called multi-pumping flow systems. This review critically discusses the characteristics, potentialities and limitations of the pulsed flow systems, emphasizing the main advantageous characteristics of the streams involved, such as high radial mass transference and good mixing of the fluids. Diverse contributions ranging from instrumentation development to analytical applications are presented.


Assuntos
Análise de Injeção de Fluxo , Análise de Injeção de Fluxo/instrumentação , Análise de Injeção de Fluxo/métodos
11.
Hum Reprod ; 30(1): 28-36, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25376459

RESUMO

STUDY QUESTION: Which embryo score variables are most powerful for predicting live birth after single embryo transfer (SET) at the early cleavage stage? SUMMARY ANSWER: This large prospective study of visual embryo scoring variables shows that blastomere number (BL), the proportion of mononucleated blastomeres (NU) and the degree of fragmentation (FR) have independent prognostic power to predict live birth. WHAT IS KNOWN ALREADY: Other studies suggest prognostic power, at least univariately and for implantation potential, for all five variables. A previous study from the same centre on double embryo transfers with implantation as the end-point resulted in the integrated morphology cleavage (IMC) score, which incorporates BL, NU and EQ. STUDY DESIGN, SIZE AND DURATION: A prospective cohort study of IVF/ICSI SET on Day 2 (n = 6252) during a 6-year period (2006-2012). The five variables (BL NU, FR, EQ and symmetry of cleavage (SY)) were scored in 3- to 5-step scales and subsequently related to clinical pregnancy and LBR. PARTICIPANTS/MATERIALS, SETTING, METHODS: A total of 4304 women undergoing IVF/ICSI in a university-affiliated private fertility clinic were included. Generalized estimating equation models evaluated live birth (yes/no) as primary outcome using the embryo variables as predictors. Odds ratios with 95% confidence intervals and P-values were presented for each predictor. The C statistic (i.e. area under receiver operating characteristic curve) was calculated for each model. Model calibration was assessed with the Hosmer-Lemeshow test. A shrinkage method was applied to remove bias in c statistics due to over-fitting. MAIN RESULTS AND THE ROLE OF CHANCE: LBR was 27.1% (1693/6252). BL, NU, FR and EQ were univariately highly significantly associated with LBR. In a multivariate model, BL, NU and FR were independently significant, with c statistic 0.579 (age-adjusted c statistic 0.637). EQ did not retain significance in the multivariate model. Prediction model calibration was good for both pregnancy and live birth. We present a ranking tree with combinations of values of the BL, NU and FR embryo variables for optimal selection of the embryo/s to transfer, providing a revised IMC score. The five embryo variables had similar effects over all age groups. LIMITATIONS, REASONS FOR CAUTION: Limitations of the present study are those inherent for real-time visual scoring, including risks of inter-observer variation and the hazards of fixed time-point scoring procedures in a dynamic process. The study is restricted to Day-2 transfers. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge this is the largest prospective, SET study performed with the explicit aim of constructing an evidence-based embryo score for the ranking and selection of early cleavage stage embryos. In line with previous research, our data suggest that the symmetry of cleavage variable may be omitted when scoring embryos in the early cleavage stage. We suggest that, following validation in other populations, the revised IMC score may be used when international standards for embryo scoring are discussed. STUDY FUNDING/COMPETING INTEREST: Carl von Linné Clinic, Uppsala and the Department of Women's and Children's Health and the Family Planning Fund in Uppsala, Uppsala University, Uppsala, Sweden financed this study. There are no competing interests to declare.


Assuntos
Blastômeros/citologia , Nascido Vivo , Transferência Embrionária , Desenvolvimento Embrionário , Feminino , Fertilização in vitro , Humanos , Modelos Logísticos , Análise Multivariada , Razão de Chances , Gravidez , Estudos Prospectivos
12.
Artigo em Inglês | MEDLINE | ID: mdl-25375456

RESUMO

We carefully reexamine the conditions of validity for the consistent derivation of the Lifshitz-Matsubara sum formula for the Casimir pressure between metallic plane mirrors. We recover the usual expression for the lossy Drude model but not for the lossless plasma model. We give an interpretation of this new result in terms of the modes associated with the Foucault currents, which play a role in the limit of vanishing losses, in contrast to common expectations.

13.
Analyst ; 139(15): 3666-82, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24886858

RESUMO

The main contributions of Brazilian researchers to the field of flow analysis are reviewed, with an emphasis on historical developments, conceptual aspects, system design, and analytical applications. Contributions after the advent of flow injection analysis are highlighted. Novel approaches (e.g. zone merging, zone sampling, zone trapping, multi-site detection, and multi-commutation), flow modalities (e.g. monosegmented flow analysis, flow-batch analysis, multi-pumping flow analysis), as well as the pioneering implementation of different detection techniques (e.g. potentiometry, turbidimetry, flame atomic absorption spectrometry, inductively coupled plasma-optical emission spectrometry, and gravimetry) and analytical steps (e.g. titrations, membrane-less gas diffusion, and electrolytic dissolution) are highlighted. Strategies to improve analytical figures of merit and the use of the flow analyser as a tool for teaching purposes are also discussed. Contributions from Brazilian workers in the context of system miniaturization, "green" chemistry, analysis of complex samples, novel strategies and materials for in-line analyte separation/concentration, and proposals for expert systems are also highlighted. The large-scale analysis of samples of agronomical, environmental, industrial, and clinical relevance is emphasized.

14.
Artigo em Inglês | MEDLINE | ID: mdl-23251870

RESUMO

OBJECTIVE: To examine whether treatment with armodafinil for 6 weeks affected patient-reported overall functioning and daily quality of life compared with placebo in patients with excessive sleepiness associated with shift work disorder. METHOD: This 6-week, multicenter, randomized, double-blind, placebo-controlled, parallel-group study was conducted in 45 sleep centers across the United States between February and October 2010. Patients included in the study were 18 to 65 years of age and diagnosed with excessive sleepiness associated with shift work disorder on the basis of the International Classification of Sleep Disorders: Diagnostic and Coding Manual, Second Edition and DSM-IV-TR criteria. These patients also experienced late-in-shift sleepiness between 4 AM and 8 AM (Karolinska Sleepiness Scale score ≥ 6) and were functionally impaired (Global Assessment of Functioning score < 70). Patients were administered 150 mg of armodafinil or placebo on nights worked, and efficacy measures included changes in patient-reported overall functioning (modified Sheehan Disability Scale [SDS-M]) and daily quality of life (10-question Functional Outcomes of Sleep Questionnaire [FOSQ-10]). RESULTS: Patients treated with armodafinil had significantly greater improvement in SDS-M composite scores at final visit (last observation carried forward) (-6.8 vs -4.5, respectively, P = .0027) than those receiving placebo. Although the armodafinil group, compared to the placebo group, showed a greater improvement in total FOSQ-10 score from baseline to final visit (+3.4 vs +2.7, respectively, P = .0775), a statistically significant improvement was observed only at week 6 (+3.6 vs +2.7, respectively, P = .0351). CONCLUSIONS: These findings are consistent with our previous report on clinician-rated measures of efficacy by demonstrating that armodafinil improves patient-rated functioning in patients with shift work disorder. Additionally, the current findings show for the first time that armodafinil may have benefits on quality of life after 6 weeks of treatment. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01080807.

15.
Talanta ; 102: 53-8, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23182574

RESUMO

A flow system with zone merging and zone trapping in the main reactor was proposed. The sample and reagent inserted aliquots merge together and the resulting zone is directed towards a displaceable reactor inside which its most concentrated portion is trapped. After the pre-set TRAP period, the handled sample is released towards detection. A comparison with an analogous flow system exploiting zone stopping revealed the superior characteristics of sampling rate and system operation; moreover, the sample inserted volume plays little influence on sampling rate. The system was applied to the spectrophotometric determination of cobalt in pastures, and enhanced figures of merit (sampling rate=18 h(-1); peak height r.s.d.=0.7%, detection limit=0.046 µg L(-1) Co; reagent consumption=330 µg of Tiron per measurement; 98%

Assuntos
Cobalto/análise , Poaceae/química , Sal Dissódico do Ácido 1,2-Di-Hidroxibenzeno-3,5 Dissulfônico/química , Catálise , Peróxido de Hidrogênio/química , Indicadores e Reagentes/química , Oxirredução , Hidróxido de Sódio/química , Espectrofotometria/métodos
17.
J Occup Environ Med ; 53(12): 1460-5, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22104981

RESUMO

OBJECTIVE: This study examined the effect of armodafinil on late-in-shift clinical condition, wakefulness, and overall functioning of patients with shift work disorder. METHODS: Patients with clinically diagnosed shift work disorder received armodafinil or placebo on nights worked for 6 weeks. Patients included in the study experienced late-in-shift sleepiness between 4 AM and 8 AM (Karolinska Sleepiness Scale ≥6) and were functionally impaired (Global Assessment of Functioning <70). Efficacy was determined by improvements in clinical condition (Clinical Global Impression-Change), late-in-the-shift Karolinska Sleepiness Scale score, and overall Global Assessment of Functioning score. Tolerability was assessed. RESULTS: Patients receiving armodafinil showed significant improvements in late-in-shift clinical condition, wakefulness, and global functioning, compared to placebo at final visit. Armodafinil was generally well tolerated. CONCLUSIONS: Armodafinil improved clinical condition and wakefulness late in the night shift of patients with shift work disorder. Overall patient functioning was also improved.


Assuntos
Compostos Benzidrílicos/uso terapêutico , Estimulantes do Sistema Nervoso Central/uso terapêutico , Transtornos do Sono do Ritmo Circadiano/tratamento farmacológico , Adulto , Compostos Benzidrílicos/efeitos adversos , Estimulantes do Sistema Nervoso Central/efeitos adversos , Distúrbios do Sono por Sonolência Excessiva/tratamento farmacológico , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modafinila , Vigília/efeitos dos fármacos , Adulto Jovem
18.
Talanta ; 85(1): 259-63, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21645697

RESUMO

A novel strategy for accomplishing zone trapping in flow analysis is proposed. The sample and the reagent solutions are simultaneously inserted into convergent carrier streams and the established zones merge together before reaching the detector, where the most concentrated portion of the entire sample zone is trapped. The main characteristics, potentialities and limitations of the strategy were critically evaluated in relation to an analogous flow system with zone stopping. When applied to the spectrophotometric determination of nitrite in river waters, the main figures of merit were maintained, exception made for the sampling frequency which was calculated as 189 h(-1), about 32% higher relatively to the analogous system with zone stopping. The sample inserted volume can be increased up to 1.0 mL without affecting sampling frequency and no problems with pump heating or malfunctions were noted after 8-h operation of the system. In contrast to zone stopping, only a small portion of the sample zone is halted with zone trapping, leading to these beneficial effects.


Assuntos
Monitoramento Ambiental/métodos , Análise de Injeção de Fluxo/métodos , Espectrofotometria/métodos , Nitritos/análise , Rios/química
19.
Br J Sports Med ; 45(3): 203-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20484314

RESUMO

OBJECTIVE: To develop and test a new single-item physical activity screening tool, suitable for assessing respondents' eligibility for behaviour change interventions. DESIGN: Two single-item assessment tools were developed, one using a "past week" recall period, the other using a "past month" recall period. A quota sampling system was used to recruit 480 adults from across England, Scotland and Wales. Half the sample completed the past-week question and half completed the past-month version. Test-retest reliability was assessed over a 2- to 5-day period. Concurrent validity was assessed using the Global Physical Activity Questionnaire and the UK Active People Survey. All surveys were completed via telephone interviews. RESULTS: Both versions of the single-item instrument demonstrated strong reproducibility (r=0.72-0.82), using Spearman's rank correlation coefficients. The past-week recall question showed strong agreement in the classification of respondents meeting the current physical activity recommendation (kappa=0.63, 95% CI 0.54 to 0.72).Concurrent validity over the past week compared to the Global Physical Activity Questionnaire was modest (r=0.53) and slightly weaker for the past month compared to the Active People Survey (r=0.33-0.48). CONCLUSION: Both versions of the new single-item measure performed as well as other short physical activity tools in terms of reliability and concurrent validity. Criterion validity testing of the single-item measure is recommended to establish its ability to assess objectively measured physical activity levels. In addition, further research to assess the responsiveness of the single-item measure in detecting changes in physical activity will inform its usefulness in programme evaluation.


Assuntos
Exercício Físico/fisiologia , Inquéritos e Questionários/normas , Adolescente , Adulto , Feminino , Humanos , Masculino , Rememoração Mental , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Adulto Jovem
20.
Femina ; 38(9)set. 2010.
Artigo em Português | LILACS | ID: lil-570111
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