Browsing by Author "Santos, L."
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- Application of experimental design methodology to optimize antibiotics removal by walnut shell based activated carbonPublication . Teixeira, Salomé; Delerue-Matos, Cristina; Santos, L.Three-level Box-Behnken experimental design with three factors (pH, temperature and antibiotic initial concentration) combined with response surface methodology (RSM) was applied to study the removal of Metronidazole and Sulfamethoxazole by walnut shell based activated carbon. This methodology enabled to identify the effects of the different factors studied and their interactions in the response of each antibiotic. The relationship between the independent variable (sorption capacity) and the dependent variables (pH, temperature and antibiotic concentration) was adequately modelled by second-order polynomial equation. The pH factor exerted a significant but distinct influence on the removal efficiency of both antibiotics. The removal of Metronidazole is favoured by increasing pH values, with the maximum value obtained for pH 8 - upper limit of the study domain; while Sulfamethoxazole displays a maximum value around 5.5, with a decrease in the extent of adsorption as the pH increases. The best conditions, predicted by the model, for the removal of the antibiotic Sulfamethoxazole (106.9 mg/g) are obtained at a temperature of 30 °C, initial concentration of 40 mg/L and a pH value of 5.5. For the antibiotic Metronidazole, the highest removal value (127 mg/g) is expected to occur at the maximum levels attributed to each of the factors (pH = 8, Cin = 40 mg/L, T = 30 °C). The results of isotherm experiments (at 20 °C and pH 6) displayed a good agreement with the models predictions. The maximum sorption capacity, estimated by the Langmuir model, was 107.4 mg/g for Metronidazole and 93.5 mg/g for Sulfamethoxazole.
- A health model based on the clinical practice of manual therapistsPublication . Santos, L.; Santos, P.C.; Cruz, E.B.The evolution of health models occurred along with the changes of the definition of health and rehabilitation but it is still unknown the predominant model of health that fits the clinical practice of physiotherapists who work in manual therapy. Creation of a questionnaire to assess the health model that fits the clinical practice of physiotherapists and after application, verify the knowledge of healthcare models, the degree of agreement between the health model in which physiotherapists based clinical practice and the attitudes and beliefs of physiotherapists in the face of biomedical and biopsychosocial orientation (PABS-PT) and verify the profile and attitudes and behaviors of physiotherapists are related to the health care model. Cross-sectional analytical quantitative study with 203 manual therapists. For the construction of the questionnaire were measured content validity and an accomplished pilot study of reliability. The questionnaire was available for 40 days. Data analysis used the chi-square test, the ordinal correlation coefficient of Spearman and descriptive analysis. Physiotherapists consider that clinical practice is based on the holistic model. This model and the biopsychosocial model is the best-known models, opposite to the ecological model. On the intervention, evaluation directed greater attention to physical symptoms, medical history and causes of the condition, report that work and give more importance to the biological and physical component. After reading the definition of health model, the holistic model stood out. By analyzing the attitudes and beliefs, who referred to the biomedical model as a basis, has increased awareness of the model itself. The choice of model is independent of the profile of physical therapists. Physiotherapists consider their clinical practice is based on the holistic model, however, maintain intervention and evaluation focused on the biomedical model.
- Human dermal exposure to galaxolide from personal care productsPublication . Correia, Patrícia; Cruz, Agostinho; Santos, L.; Alves, A.Musks are synthetic fragrances applied on personal care and household products as fixatives, by retarding the release of other fragrances with higher volatility. Galaxolide is the most used polycyclic musk since the 90th decade, and it has been detected in several environmental and biological matrices, particularly in human tissues and fluids. For exposure assessment purposes, large-monitoring data need to be obtained and rapid but reliable analytical techniques are requested. The main objective of this study is to develop and validate a new and fast analytical methodology to quantify galaxolide in personal care products and to apply this method to real matrices like skin care products (creams and lotions), shower products (soap bar), hair care products (shampoo and hair conditioner) and oral care products (toothpaste), to evaluate the human dermal exposure risk. A dispersive solid-phase extraction is proposed, using QuEChERS methodology, followed by HPLC with fluorescence detection. Some extraction parameters were studied, like the ratio of sample/solvent amounts, the homogenization time, the salt addition effect and the used sorbents. The validation parameters of the developed method were the following: a linearity range of 0.005-1.002 mg kg⁻¹ sample, a limit of detection of 0.001 mg kg⁻¹ sample, repeatability between 0.7% and 11.3% (variation coefficient of six standard injections), an intermediate precision of 2.5% (variation coefficient of six independent analysis of the same sample), mean recoveries ranging from 65% (soap bar) to 95% (body cream) and 3% of global uncertainty in most of the working range. The time of analysis, including the extraction steps, is 60 min, allowing a throughput of 4 samples h⁻¹ . Galaxolide was detected in all of the seven analysed products in concentrations ranging from 0.04 ± 0.01 mg kg⁻¹ sample (toothpaste) to 280.78 ± 8.19 mg kg⁻¹ sample (perfumed body cream), which may correspond to a significant estimated daily human dermal exposure of 904 μg day⁻¹.
- Indoor air quality in community health centers: a preliminary studyPublication . Santos, L.; Santos, J.; Rebelo, A.; Vieira Da Silva, ManuelaIndoor air quality (IAQ) in healthcare facilities is of great concern for both patients and staff. The aim of this study was to evaluate the IAQ in Community Health Centers. Total aerobic count and fungal load were assessed using a microbiological air sampler. The determination of the other parameters was per formed using real-time equipments. The average concentrations ranged between 161 CFU/m3 and 1423 CFU/m3 for fungi and between 147 CFU/m3 and 999 CFU/m3 for total aerobic count. Only three waiting rooms exceeded the concentration reference value for carbon dioxide. The concentration of particulate matter and carbon monoxide were above the limit value. In general, physical parameters are outside the comfort zones. These results demonstrate the need for on-going efforts to ensure adequate ventilation in Community Health Centers to maintain an acceptable IAQ. Therefore, it is essential to accomplish a long-term surveil lance of IAQ in this type of buildings