196 research outputs found

    Assessment of iron and nitrates concentration in drinking water, in the district of Bragança, Portugal between 2012 and 2013

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    Water is an essential resource for life. It is a crucial factor for all living beings’ survival thus, it is necessary to promote means to obtain drinking water for human consumption.1 The water intended for human consumption, according to the World Health Organization (WHO),is quality water as soon as it does not cause a significant threat to human health during its consumption.2 The diseases related to the contamination of water for human consumption constitute a very high responsibility and importance to the Public Health. The nitrates have a high solubility and may reach the groundwater in the deep layers of the soil by processes as leaching, particularly in areas with intensive farming and livestock. High concentrations of nitrates can be very harmful to human health since they can be easily converted into nitrites which concentrations cannot exceed the parametric value of 50 mg/L in water for human consumption (Dec. Law n.º 306/2007). The greater effect of nitrite in human health is your involvement in the oxidation of hemoglobin (Hb) to methemoglobin (MetHb). High concentrations of nitrates cause severe methaemoglobinemia in infants and adults. The methemoglobinemia is a rare condition caused by excessive conversion of hemoglobin (Hb) in methemoglobin (MetHb), being unable to bind and transport oxygen.3The iron exists in low concentrations in natural waters and usually its presence results of processes such as leaching of soils or industrial pollution. The presence of iron in the water can consequently cause the corrosion of metal pipes or the use of iron salts as agents of coagulation/flocculation in water treatment and the parametric value of iron is 200μg/L (Dec. Law n.º 306/2007) in water for human consumption.The objective of this study was to evaluate the concentration of nitrate and iron in drinking water in the district of Bragança in order to identify the sampling point that keeps concentrations of these ions above the parametric values.The collection of drinking water samples in the district of Bragança occurred between the years of 2012 and 2013, with subsequent spectrophotometric determination of nitrate and iron concentration, in the Public Health Laboratory of Bragança (PHLB).Samples with concentrations above the parametric values were identified: above 200 μg/L to iron and above 50 mg/L to nitrates (Dec, Law n.º 306/2007). The collected data was statistically treated in program Microsoft Office - Excel and the analysis of the data was carried out using the normal distribution with levels of confidence of 95 %. In the year 2012 were collected 624 samples and 8.8% of these were outside the parametric values with 8.7% corresponding to samples with values of increased iron and 0.1% corresponding to increased nitrate’s values. In the year 2013 it was collected 1208 samples in which 8.9% were above the parametric values stipulated, from which 8.6% corresponded to samples with increased concentrations of iron and 0.3% corresponded to samples with nitrate levels above the parametric values. Two regions exhibited a greater number of samples with concentrations above the established limits for the parameters studied in this work. One of the regions had 15.9% of the samples above the established limits and the other had 12.6%.Individuals that consumed this water with high levels of iron and nitrates may be associated with several potential health threat

    Assessment of iron and nitrates concentration in drinking water, in the district of Bragança, Portugal between 2012 and 2013

    Get PDF
    Water is an essential resource for life. It is a crucial factor for all living beings’ survival thus, it is necessary to promote means to obtain drinking water for human consumption.1 The water intended for human consumption, according to the World Health Organization (WHO),is quality water as soon as it does not cause a significant threat to human health during its consumption.2 The diseases related to the contamination of water for human consumption constitute a very high responsibility and importance to the Public Health. The nitrates have a high solubility and may reach the groundwater in the deep layers of the soil by processes as leaching, particularly in areas with intensive farming and livestock. High concentrations of nitrates can be very harmful to human health since they can be easily converted into nitrites which concentrations cannot exceed the parametric value of 50 mg/L in water for human consumption (Dec. Law n.º 306/2007). The greater effect of nitrite in human health is your involvement in the oxidation of hemoglobin (Hb) to methemoglobin (MetHb). High concentrations of nitrates cause severe methaemoglobinemia in infants and adults. The methemoglobinemia is a rare condition caused by excessive conversion of hemoglobin (Hb) in methemoglobin (MetHb), being unable to bind and transport oxygen.3The iron exists in low concentrations in natural waters and usually its presence results of processes such as leaching of soils or industrial pollution. The presence of iron in the water can consequently cause the corrosion of metal pipes or the use of iron salts as agents of coagulation/flocculation in water treatment and the parametric value of iron is 200μg/L (Dec. Law n.º 306/2007) in water for human consumption

    Tunable kinetic proofreading in a model with molecular frustration

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    In complex systems, feedback loops can build intricate emergent phenomena, so that a description of the whole system cannot be easily derived from the properties of the individual parts. Here we propose that inter-molecular frustration mechanisms can provide non trivial feedback loops which can develop nontrivial specificity amplification. We show that this mechanism can be seen as a more general form of a kinetic proofreading mechanism, with an interesting new property, namely the ability to tune the specificity amplification by changing the reactants concentrations. This contrasts with the classical kinetic proofreading mechanism in which specificity is a function of only the reaction rate constants involved in a chemical pathway. These results are also interesting because they show that a wide class of frustration models exists that share the same underlining kinetic proofreading mechanisms, with even richer properties. These models can find applications in different areas such as evolutionary biology, immunology and biochemistry

    Portuguese recommendations for the use of biological and targeted synthetic diseasemodifying antirheumatic drugs in patients with rheumatoid arthritis – 2020 update

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    Objective: To update the recommendations for the treatment of rheumatoid arthritis (RA) with biological and targeted synthetic disease-modifying antirheumatic drugs (bDMARDs and tsDMARDs), endorsed by the Portuguese Society of Rheumatology (SPR). Methods: These treatment recommendations were formulated by Portuguese rheumatologists taking into account previous recommendations, new literature evidence and consensus opinion. At a national meeting, in a virtual format, three of the ten previous recommendations were re-addressed and discussed after a more focused literature review. A first draft of the updated recommendations was elaborated by a team of SPR rheumatologists from the SPR rheumatoid arthritis study group, GEAR. The resulting document circulated among all SPR rheumatologists for discussion and input. The level of agreement with each of all the recommendations was anonymously voted online by all SPR rheumatologists. Results: These recommendations cover general aspects such as shared decision, treatment objectives, systematic assessment of disease activity and burden and its registry in Reuma.pt. Consensus was also achieved regarding specific aspects such as initiation of bDMARDs and tsDMARDs, assessment of treatment response, switching and definition of persistent remission. Conclusion: These recommendations may be used for guidance of treatment with bDMARDs and tsDMARDs in patients with RA. As more evidence becomes available and more therapies are licensed, these recommendations will be updated.info:eu-repo/semantics/publishedVersio

    Real time contrast enhanced ultrasonography in detection of liver metastases from gastrointestinal cancer

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    Background: Contrast enhanced ultrasound (CEUS) is an imaging technique which appeared on the market around the year 2000 and proposed for the detection of liver metastases in gastrointestinal cancer patients, a setting in which accurate staging plays a significant role in the choice of treatment. Methods: A total of 109 patients with colorectal (n = 92)or gastric cancer prospectively underwent computed tomography (CT) scan and conventional US evaluation followed by real time CEUS. A diagnosis of metastases was made by CT or, for lesions not visibile at CT, the diagnosis was achieved by histopathology or by a malignant behavior during follow-up. Results: Of 109 patients, 65 were found to have metastases at presentation. CEUS improved sensitivity in metastatic livers from 76.9% of patients (US) to 95.4% (p < 0.01), while CT scan reached 90.8% (p = n.s. vs CEUS, p < 0.01 vs US). CEUS and CT were more sensitive than US also for detection of single lesions (87 with US, 122 with CEUS, 113 with CT). In 15 patients (13.8%), CEUS revealed more metastases than CT, while CT revealed more metastases than CEUS in 9 patients (8.2%) (p = n.s.). Conclusion: CEUS is more sensitive than conventional US in the detection of liver metastases and could be usefully employed in the staging of patients with gastrointestinal cancer. Findings at CEUS and CT appear to be complementary in achieving maximum sensitivity. © 2007 Piscaglia et al; licensee BioMed Central Ltd

    Cultura de Inovação: Conceitos e Modelos Teóricos

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    This study portrays the state of the art in scientific literature on the culture of innovation, with the objective of characterizing its meaning and especially describing different theoretical models that seek to understand how it occurs in an organizational environment. To enrich the analysis, research results show the relationship between organizational culture and innovation. The literature review was carried out in 2011 using the following databases: Coordination for the Improvement of Higher Education Personnel (CAPES), Proquest and Directory of Open Access Journals (DOAJ). The keywords used were the expression culture of innovation and the joint terms culture and innovation, only full articles were included in the research. Culture of innovation articles that were cited in the papers identified in the literature search were also considered. The analysis consisted of 40 articles, based on the predefined criteria, and showed that this is a topic of interest for researchers in different world regions. It is a complex theme determined by factors with a systemic character. There is a predominance of quantitative research and strong evidence of a relationship between organizational culture and innovation, which requires further research to test the theoretical models proposed by these different authors
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