Paulo Joaquim Almeida

Impact of family environment and support on adherence, metabolic control, and quality of life in adolescents with diabetes

Background: Diabetes is a common disease in pediatric populations. Family functioning has been related to child adaptation to diabetes. Purpose: To determine the impact of family factors on diabetes, particularly the influence of family support and family environment on adherence to treatment, quality of life, and metabolic control in Portuguese adolescents with type 1 diabetes, taking in consideration age, sex, duration of disease, and social class. Method: This study used a cross-sectional design. A sample of 157 Portuguese diabetic patients filled disease-specific measures on adherence and quality of life and family functioning measures. Hypotheses were that family support and an organized family environment (high cohesion and low conflict) would be positively associated with better adherence, metabolic control, and quality of life. Results: This study’s results confirmed that adherence was predicted by family support for females and lower-class patients while metabolic control was predicted by family conflict for upper-class patients. Quality of life was predicted by lack of family conflict and family social support for both males and females as well as lower-class patients. Conclusion: The results highlight the importance of studying family variables in adolescents’ diabetes care within the wider cultural factors affecting the patient.

DETERMINATION OF GLYOXAL, METHYLGLYOXAL, AND DIACETYL IN SELECTED BEER AND WINE, BY HPLC WITH UV SPECTROPHOTOMETRIC DETECTION, AFTER DERIVATIZATION WITH o-PHENYLENEDIAMINE

The α-diketones glyoxal, methylglyoxal, and diacetyl were determined in selected beer and wine using a procedure involving the use of C18 solid phase extraction columns to remove interferences and derivatization of the compounds with o-phenylenediamine to form quinoxalines, which are separated by HPLC and detected using UV spectrophotometric detection. Interferences were more difficult to remove in the case of beer, due to the higher complexity of the matrix and because the concentrations of the compounds were lower (higher for methylglyoxal and lower for diacetyl, but all in the 10−7 M region). The determination was easier to implement in the case of wine as the typical concentrations of the compounds were about ten times higher, with methylglyoxal being the more abundant compound found.

Increased sensitivity of anodic stripping voltammetry at the hanging mercury drop electrode by ultracathodic deposition.

An improved approach to the anodic stripping voltammetric (ASV) determination of heavy metals, using the hanging mercury drop electrode (HMDE), is reported. It was discovered that using very cathodic accumulation potentials, at which the solvent reduction occurs (overpotential deposition), the voltammetric signals of zinc(II), cadmium(II), lead(II) and copper(II) increase. When compared with the classical methodology a 5 to 10-fold signal increase is obtained. This effect is likely due to both mercury drop oscillation at such cathodic potentials and added local convection at the mercury drop surface caused by the evolution of hydrogen bubbles.

Determination of E-2-nonenal by high-performance liquid chromatography with UV detection: Assay for the evaluation of beer ageing

The analysis of E-2-nonenal is of considerable interest for the brewery industry as this compound is claimed to be responsible for a paper/cardboard unpleasant flavour. Usually, the presence of E-2-nonenal can be noticed in aged beers at levels higher than 0.1 microg/l. In this work, an analytical method was developed to determine E-2-nonenal in beer involving steam distillation of beer followed by an extraction/concentration step using solid-phase extraction and determination of E-2-nonenal by HPLC with UV detection. Fastness and simplicity are the main advantages of the proposed method, when compared with other existing methodologies for the determination of E-2-nonenal in beer. Using the developed conditions, the interference of E-2-nonenal formed by degradation of its precursors during steam distillation is almost negligible. The presence of sulphur dioxide at legal levels does not interfere with the assay. The method was used in a comparative study of fresh and either naturally or forced aged beers. A much larger chromatographic peak was found near the peak of E-2-nonenal that correlates well with the peak of E-2-nonenal. Identification of the corresponding compound is currently under investigation, considering its future application on the evaluation of beer ageing.

Voltammetric studies of anthraquinone dyes adsorbed at a hanging mercury drop electrode using fast pulse techniques

Abstract Square wave voltammetric studies, involving adsorptive stripping methodology, of anthraquinone-based reactive dyes and of a typical anthraquinone dye Alizarin Red S are reported. The reduction of their anthraquinone moiety is reversible and fast and the sensitivity of these determinations can be improved if current sampling is made earlier after the pulse application. In order to try to modify the rate of the electrochemical process at the electrode, two approaches have been tested: the effect of adding surfactants and the influence of supporting electrolyte concentration. In both cases, a change in the results obtained is observed, owing, in the first case, to the modification of the electrode surface, and, in the second, to the importance of the resistance of the solution.

Determination of Carbonyl Compounds in Cork Agglomerates by GDME-HPLC-UV: Identification of the Extracted Compounds by HPLC-MS/MS

A new approach is proposed for the extraction and determination of carbonyl compounds in solid samples, such as wood or cork materials. Cork products are used as building materials due to their singular characteristics; however, little is known about its aldehyde emission potential and content. Sample preparation was done by using a gas-diffusion microextraction (GDME) device for the direct extraction of volatile aldehydes and derivatization with 2,4-dinitrophenylhydrazine. Analytical determination of the extracts was done by HPLC-UV, with detection at 360 nm. The developed methodology proved to be a reliable tool for aldehyde determination in cork agglomerate samples with suitable method features. Mass spectrometry studies were performed for each sample, which enabled the identification, in the extracts, of the derivatization products of a total of 13 aldehydes (formaldehyde, acetaldehyde, furfural, propanal, 5-methylfurfural, butanal, benzaldehyde, pentanal, hexanal, trans-2-heptenal, heptanal, octanal, and trans-2-nonenal) and 4 ketones (3-hydroxy-2-butanone, acetone, cyclohexanone, and acetophenone). This new analytical methodology simultaneously proved to be consistent for the identification and determination of aldehydes in cork agglomerates and a very simple and straightforward procedure.

Accelerated weathering of polypropylene geotextiles

Abstract This paper reports research about the durability of non-woven geotextiles when exposed to artificial weathering conditions [ultraviolet (UV) radiation, rain and dew] on a laboratory weatherometer. The geotextiles were specially manufactured from polypropylene fibers stabilized with different amounts of the additive Chimassorb 944 and the pigment carbon black. The degradation suffered by the geotextiles was evaluated by tensile tests and by scanning electron microscopy.

Determination of Chimassorb 944 in Polypropylene Geotextiles by HPLC-UV

This paper reports the development of a method for the determination of Chimassorb 944 (C944), in polypropylene geotextiles, by high performance liquid chromatography with ultraviolet detection. The C944 was removed from the geotextiles by an ultrasonic extraction and then separated in a NH2 column, followed by UV detection at 244 nm. Analytical validation showed that the method is accurate and precise. The developed methodology was applied for the determination of C944 in geotextiles exposed to artificial UV radiation and to natural weathering. To the best of our knowledge, this is the first method proposed for the determination of C944 in geotextiles.

Development of a partitioned liquid-liquid extraction- dispersive solid phase extraction procedure followed by liquid chromatography-tandem mass spectrometry for analysis of 3-monochloropropane-1,2-diol diesters in edible oils

A fast and effective method using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach which includes partitioned liquid-liquid extraction (PLLE) and dispersive solid phase extraction (dSPE) clean-up step for the determination of seven 3-monochloropropane-1,2-diol (3-MCPD) fatty acid diesters in vegetable oils is developed and validated according to the Food and Drug Administration (FDA) guidelines. Due to the complexity of the matrices, combination of silica based sorbents (Silica Strong Anion Exchange (Si-SAX), Supel™ QuE Z-Sep+ (Z-Sep+) and Primary Secondary Amine (PSA) were tested for lipid removal. The effect of several experimental factors on the efficiency of the extraction procedure was studied by a screening design 3422//16 and a response surface Doehlert design. The separation and determination was carried out by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The method provided suitable linearity (r2 > 0.9960), precision (relative standard deviation (RSD) lower than 10%) and accuracy, in terms of recovery. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 10 to 20 μg kg -1 and from 25 to 50 μg kg-1, respectively. The recoveries at three spiking levels of 100, 250, and 500 μg kg-1 were over the range of 71.4-122.9% with RSD lower than 13%. The method was successfully applied in edible oils and fatty food samples. The results provide valuable information to assess the risk of exposure to these foodborne contaminants.

Laboratory Evaluation of Interactions in the Degradation of a Polypropylene Geotextile in Marine Environments

The long-term behaviour of geosynthetics applied in coastal engineering structures can be adversely affected by many agents. This paper studies the resistance of a nonwoven polypropylene geotextile against some degradation agents present in marine environments and evaluates the existence of interactions between them. For that purpose, the geotextile was exposed to some laboratory degradation tests: immersion tests (in seawater, deionised water, and sodium chloride 35 g·L−1), thermooxidation, and artificial weathering. The geotextile was (1) exposed separately to each degradation test and (2) exposed successively to combinations of two or three degradation tests. The damage caused by the degradation tests was evaluated by monitoring the tensile properties of the geotextile. Based on the changes occurred in tensile strength, reduction factors were determined. The reduction factors obtained directly in the multiple exposures were compared with those obtained by the traditional methodology for the combined effect of the degradation agents. The results, among other findings, showed the existence of relevant interactions between the degradation agents and showed that the reduction factors obtained by the traditional methodology were unable to represent accurately (by underestimating) the degradation occurred in the geotextile.