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1.
Clin Diabetes ; 40(3): 283-296, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35983416

RESUMO

This study analyzed patient-described barriers and facilitators related to diabetes management, focusing on how these differ by glycemia and across individual characteristics. A cross-sectional telephone survey was conducted with adult patients with diabetes in Alberta, Canada, asking two open-ended questions to describe the most helpful and difficult components of their diabetes management. Responses were analyzed using directed content analysis using the Theoretical Domains Framework as a template. The most frequently cited facilitator was care context and information, and the most frequently cited barriers were cognitive challenges and structural barriers, with patient-perceived barriers and facilitators varying by individual-level factors.

2.
J Environ Manage ; 218: 497-508, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29709818

RESUMO

This study reports on the assessment of the environmental sustainability of different management practices for an environmentally degraded site in Slovenia: the Old Zinc-Works in the town of Celje. Life Cycle Assessments (LCAs) were applied in order to evaluate possible trade-offs by comparing a proposed in situ remediation scenario with two other reclamation scenarios (scenario 2: incineration, metal extraction, underground disposal and reclamation of the site by refilling it with replacement material, and scenario 3: underground disposal and reclamation of the site by refilling it with replacement material) and with a no-action scenario. The results of the comparisons performed show that in the case of the in situ remediation scenario, the consumption of resources is smaller by a factor of 51 compared to that in the second scenario and by a factor of 7 compared to that in the third scenario. The impacts on human health and ecosystem quality are approximately 30 and 3.5 times less in the first scenario than in the second and third scenarios, respectively. Compared to the impact of the no-action scenario, the impact on human health of the in situ soil remediation scenario is approximately 6 times less, whereas its impact on the ecosystem is approximately 4 times less. The results confirmed that the in situ soil remediation scenario is the most sustainable practice from an environmental point of view. Its main advantage lies in the achieved conservation of natural resources. Despite the recovery of valuable metals (Zn, Pb, Cu, and Ni) from the bottom ash, the second scenario is significantly more environmentally burdensome compared to both the first and third scenarios. This outcome is due to the significantly high impacts related to the consumption of fuels needed to support the incineration of low-calorific contaminated soil and to electricity consumption. The present study demonstrates that the results of LCA studies, in addition to technological, economic and social indicators, yield important information about the sustainability of different management practices and therefore should be an important part of decision-making when approaching the reclamation of environmentally degraded sites.


Assuntos
Recuperação e Remediação Ambiental , Incineração , Poluentes do Solo , Poluição Ambiental , Humanos , Eslovênia , Solo
3.
Qual Life Res ; 25(1): 35-43, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26216584

RESUMO

PURPOSE: The EuroQol Valuation Technology (EQ-VT) uses traditional time trade-off (tTTO) for health states better than dead and lead-time TTO (LT-TTO) for states worse than dead to elicit a value (-1.0 to +1.0) for each health state. In the Canadian EQ-5D-5L Valuation study which used the EQVT platform, we observed an unexpected peak in frequency of "0" values and few negative values, particularly in the range of 0 to -0.5. To better understand this finding, we sought to explore respondents' thought processes while valuing a health state, and their understanding of the tTTO and LT-TTO exercises. METHODS: Qualitative semi-structured interviews were conducted with EQVT task respondents. Questions focused on valuations of health states as: (a) Same as dead in tTTO, (b) Worse than dead in tTTO but changed to same as dead in LT-TTO, (c) Worse than dead in LT-TTO, and (d) Worse than dead in LT-TTO with trading off all 10 years. Data were analyzed using content and thematic analysis. RESULTS: Mean age of participants (N = 70) was 40 ± 18.1 years, 60% female, and 76% Caucasian. Participants provided similar reasons for valuing a health state same as or worse than dead. Many participants expressed confusion about worse than dead valuations, distinction between same as and worse than dead, and the transition from tTTO to LT-TTO. A few indicated that the addition of 10 years of full health in the LT-TTO influenced their valuations. CONCLUSIONS: The transition from tTTO to LT-TTO in the EQVT was confusing to participants, whereby some health state valuations around this transition appeared to be arbitrary.


Assuntos
Atitude Frente a Saúde , Nível de Saúde , Qualidade de Vida/psicologia , Adulto , Canadá , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Fatores de Tempo , Trabalho
4.
Psychol Health Med ; 21(8): 945-53, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26899570

RESUMO

OBJECTIVE: More evidence from prospective studies is needed to determine 'if' and 'how' social cognitive constructs mediate behaviour change. In a longitudinal study, we aimed to examine potential social cognitive mediators of objectively measured physical activity (PA) behaviour among people with type 2 diabetes (T2D) who participated in a six-month PA intervention. METHODS: All participants from the proven effective Healthy Eating and Active Living for Diabetes in Primary Care Networks trial were included for this secondary analysis. Change in pedometer-derived daily step counts (baseline to six months) was the outcome of interest. Primary constructs of interest were from Social Cognitive Theory, however constructs from and Theory of Planned Behaviour were also tested in a mediating variable framework using a product-of-coefficients test. RESULTS: The sample (N = 198) had a mean age of 59.5 (SD 8.3) years, haemoglobin A1c 6.8% (SD 1.1), 50% women, BMI 33.6 kg/m(2) (SD 6.5), systolic pressure 125.6 mmHg (SD 16.2) and average daily steps were 5879 (SD 3130). Daily pedometer-determined steps increased for the intervention group compared to usual care control at six-months (1481 [SD 2631] vs. 336 [SD 2712]; adjusted p = .002). There was a significant action theory test effect for 'planning' (A = .21, SE = .10, p = .037), and significant conceptual theory test results for 'subjective norms' (B = 657, SE = 312, p = .037) and 'cons' (B = -664, SE = 270, p = .015). None of the constructs satisfied the criteria for mediation. CONCLUSIONS: We were unable to account for the effect of a pedometer-based PA intervention for people with T2D through our examination of mediators. Our findings are inconsistent with some literature concerning PA interventions in diabetes; this may be due to variability in measures used or in study populations.


Assuntos
Diabetes Mellitus Tipo 2/psicologia , Diabetes Mellitus Tipo 2/terapia , Terapia por Exercício/métodos , Avaliação de Resultados em Cuidados de Saúde/normas , Idoso , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade
5.
Environ Monit Assess ; 188(4): 234, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27000319

RESUMO

During capital and/or maintenance dredging operations, large amounts of material are produced. Instead of their discharge, dredged sediments may be a valuable natural resource if not contaminated. One of the possible areas of application is civil engineering. In the present work, the environmental status of seaport dredged sediment was evaluated in order to investigate its potential applicability as a secondary raw material. Sediments were analysed for element concentrations in digested samples, aqueous extracts and fractions from sequential extraction; for fluoride, chloride and sulphate concentrations in aqueous extracts; and for tributyltin (TBT). Granulometric and mineralogical compositions were also analysed. The elemental impact was evaluated by calculation of the enrichment factors. The total element concentrations determined showed moderate contamination of the dredged sediments as was confirmed also by their moderate enrichment factors, presumably as a result of industrial and port activities. Elemental concentrations in the aqueous extract were very low and therefore do not represent any hazard for the environment. The water-soluble element concentrations were under the threshold levels set by the EU Directive on the landfill of waste, on the basis of which the applicability of dredged sediments in civil engineering is evaluated, while the content of chloride and sulphate were above the threshold levels. It was found out that due to the large amounts of sediment available, civil engineering applications such as the construction of embankments and backfilling is the most beneficial recycling solution at present.


Assuntos
Sedimentos Geológicos/química , Poluentes da Água/análise , Monitoramento Ambiental , Sedimentos Geológicos/análise , Navios , Compostos de Trialquitina/análise
6.
Cardiovasc Ultrasound ; 13: 41, 2015 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-26340922

RESUMO

BACKGROUND: The risk stratification of patients with diabetes mellitus (DM) is a major objective for the clinicians, and it can be achieved by coronary flow velocity reserve (CFVR) or with coronary artery calcium score (CS). CS evaluates underlying coronary atherosclerotic plaque burden and CFVR estimates both presence of coronary artery stenosis and microvascular function. Consequently, CFVR may provide unique risk information beyond the extent of coronary atherosclerosis. AIM: Our aim is to assess joint prognostic value of CFVR and CS in asymptomatic DM patients. MATERIALS AND METHODS: We prospectively included 200 asymptomatic patients (45,5 % male, mean age 57,35 ± 11,25), out of which, there were 101 asymptomatic patients with DM and 99 asymptomatic patients without DM, but with one or more conventionally risk factors for coronary artery disease. We analyzed clinical, biochemical, metabolic, inflammatory parameters, CS by Agatston method, transthoracic Doppler echocardiography CFVR of left anterior descending artery and echocardiographic parameters. RESULTS: Total CS and CS LAD were significantly higher, while mean CFVR was lower in diabetics compared to the nondiabetics. During 1 year follow-up, 24 patients experienced cardio-vascular events (one cardiovascular death, two strokes, three myocardial infarctions, nine new onsets of unstable angina and nine myocardial revascularizations): 19 patients with DM and five non DM patients, (p = 0,003). Overall event free survival was significantly higher in non DM group, compared to the DM group (94,9 % vs. 81,2 %, p = 0,002 respectively), while the patients with CS ≥200 and CFVR <2 had the worst outcome during 1 year follow up in the whole study population as well as in the DM group. At multivariable analysis CFVR on LAD (HR 12.918, 95 % CI 3.865-43.177, p < 0.001) and total CS (HR 13.393, 95 % CI 1.675-107.119, p = 0.014) were independent prognostic predictors of adverse events in DM group of patients. CONCLUSION: Both CS and CFVR provide independent and complementary prognostic information in asymptomatic DM patients. When two parameters are analyzed together, the risk stratification ability improves, even when DM patients are analyzed together with non DM patients. As a result, DM patients with CS ≥200 and CFVR <2 had the worst outcome. Consequently, the use of two tests identified subset of patients who can derive the most benefit from the intensive prevention measures.


Assuntos
Calcinose/diagnóstico por imagem , Calcinose/mortalidade , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Complicações do Diabetes/mortalidade , Reserva Fracionada de Fluxo Miocárdico , Doenças Assintomáticas/mortalidade , Calcinose/complicações , Calcinose/fisiopatologia , Causalidade , Comorbidade , Doença da Artéria Coronariana/fisiopatologia , Complicações do Diabetes/diagnóstico por imagem , Complicações do Diabetes/fisiopatologia , Ecocardiografia/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Reprodutibilidade dos Testes , Medição de Risco/métodos , Sensibilidade e Especificidade , Sérvia , Índice de Gravidade de Doença , Taxa de Sobrevida
7.
Artigo em Inglês | MEDLINE | ID: mdl-36767380

RESUMO

The environmental properties of three geotechnical composites made by recycling wastes were investigated on a laboratory scale and in the field with the use of lysimeters designated for the revitalization of degraded mining sites. Composites were prepared by combining the mine waste with paper-mill sludge and foundry sand (Composite 1), with digestate from municipal waste and paper ash (Composite 2), and with coal ash, foundry slag and waste incineration bottom ash (Composite 3). The results of laboratory leaching tests proved that Composites 1 and 3 are environmentally acceptable, according to the legislative limits, as the potentially hazardous substances were immobilized, while in Composite 2, the legislative limits were exceeded. In the field lysimeters, the lowest rate of leaching was determined for optimally compacted Composites 1 and 3, while for Composite 2 the leaching of Cu was high. This study proved that optimally installed Composites 1 and 3 are environmentally acceptable for use in construction as an alternative to virgin materials, for the revitalization of degraded mining sites or, along with Composite 2, for closure operations with landfills. In this way, locally available waste streams are valorised and channelized into a beneficial and sustainable recycling practice.


Assuntos
Cinza de Carvão , Incineração , Esgotos , Instalações de Eliminação de Resíduos , Reciclagem/métodos , Resíduos Sólidos/análise
8.
Clin Anat ; 25(6): 767-72, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22271495

RESUMO

The aim of this study is to analyze the morphological differences of infrarenal aortic aneurysms and common iliac arteries that are important for endovascular management between patients of different body mass index using 64 slice multidetector row CT aortography. This was a multicenter study of 100 patients (50 Europeans and 50 Japanese). All patients had risk factors, manifest symptoms, and ultrasound verified aneurysmal dilation of the infrarenal aorta. All examinations were performed on the same CT platform using the same post-processing protocols. Due to the heterogeneity of the population, several statistical models were used. Significant differences were found in morphological parameters of infrarenal aorta in relation to BMI. In over one out of three patients with BMI less than 23, endovascular treatment is contraindicated due to the dimensions of the aneurysmal neck. Relative to BMI value, differences were found in transverse diameters of the medium part of the aneurysm and in the length of common iliac arteries. CT aortography performed on a 64 slice multidetector row CT platform provides precise and numerous data for the analysis of anatomical and pathological differences of infrarenal aortic aneurysms that are of crucial importance for the planning of treatment and the analysis of the differences relating to body habitus.


Assuntos
Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aortografia/normas , Aneurisma Ilíaco/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/etnologia , Aneurisma da Aorta Abdominal/cirurgia , Povo Asiático , Índice de Massa Corporal , Procedimentos Endovasculares , Europa (Continente)/epidemiologia , Feminino , Humanos , Aneurisma Ilíaco/etnologia , Aneurisma Ilíaco/cirurgia , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Tomografia Computadorizada Multidetectores , Cuidados Pré-Operatórios , Estudos Prospectivos , Valores de Referência , População Branca
9.
Materials (Basel) ; 15(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35329673

RESUMO

This paper presents an experimental investigation of the compressive behavior of high-strength self-compacting concrete exposed to temperatures up to 600 °C. Ten different concrete compositions were tested, in which part of the cement (by weight) was replaced by three different mineral additives (5-15% metakaolin, 20-40% fly ash and 5-15% limestone). The stress-strain curves, compressive strength, modulus of elasticity and strain at peak stress were evaluated from uniaxial compression tests. Scanning electron microscope micrographs were also taken to evaluate the damage caused by the high temperatures. A sharp decrease in mechanical properties and an increase in peak strain were observed already after 200 °C for all mixes tested. The different mineral additives used in this study affected the variations of residual compressive strength by 24% and peak strain by 38%, while the variations of residual modulus elasticity were 14%. Comparing the obtained results with the recommendations for compressive strength given in regulatory code EN 1992-1-2 for high strength concrete, it can be concluded that the strength loss observed in EN 1992-1-2 at temperatures up to 400 °C is too conservative. The Popovics model for the relationship between stress and strain provided a good approximation for the experimentally determined stress-strain curves at different temperatures.

10.
Toxics ; 10(1)2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35051052

RESUMO

Old metallurgical dumps across Europe represent a loss of valuable land and a potential threat to the environment, especially to groundwater (GW). The Javornik electric arc furnace (EAF) and ladle slag heap, situated in Slovenia, was investigated in this study. The environmental impact of the slag heap was evaluated by combining leaching characterization tests of landfill samples and geochemical modelling. It was shown that throughout the landfill the same minerals and sorptive phases control the leaching of elements of potential concern, despite variations in chemical composition. Although carbonation of the disposed steel slags occurred (molar ratio CO3/(Ca+Mg) = 0.53) relative to fresh slag, it had a limited effect on the leaching behaviour of elements of potential concern. The leaching from the slag heaps had also a limited effect on the quality of the GW. A site-specific case, however, was that leachates from the slag heap were strongly diluted, since a rapid flow of GW fed from the nearby Sava River was observed in the landfill area. The sampling and testing approach applied provides a basis for assessing the long-term impact of release and is a good starting point for evaluating future management options, including beneficial uses for this type of slag.

11.
Sci Rep ; 12(1): 15186, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36071144

RESUMO

Anion-exchange high performance liquid chromatography inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was used for simultaneous speciation of chromate, molybdate and arsenate. The repeatability of measurement tested for multielemental standard solution of chromate, molybdate and arsenate (50 ng mL-1 of Cr, Mo and As, pH 12) was ± 0.9%, ± 4.9% and ± 4.1%, respectively. Limits of quantification (LOQs) were low (0.53 ng mL-1 for chromate and arsenate and 1.03 ng mL-1 for molybdate, expressed as elemental concentrations). A wide linear concentration range (from LOQs to 500 ng mL-1) was obtained. The performances of this method enabled simultaneous speciation analysis in samples of water from lysimeters, in which three geotechnical composites, made of recycled waste, were installed in parallel in compacted and uncompacted, 20 times less dense form. The release of toxic chemical species of elements into lysimetric waters from each composite was studied. The results revealed that the degree of compaction and the composition of composites both have a significant influence on leaching of chromate, molybdate and arsenate. The study proved that multielemental speciation analysis is fast and cost-effective method for investigations of environmental impacts of materials, made from recycled waste, and can be used in other similar applications.


Assuntos
Arseniatos , Cromatos , Molibdênio , Água
12.
J Comput Assist Tomogr ; 35(4): 462-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21765302

RESUMO

AIM: The hypothesis of this multicentric study is performing a specific typification in the selection of grafts for the endoluminal treatment of an aneurysmally altered distal aorta based on mathematical information and the correlation of a number of morphological parameters diagnosed by 64-multidetector computed tomographic (CT) aortography. MATERIALS AND METHODS: The study is multicentric and encompassed 30 Asian and 30 European patients. Examinations were performed on the same type of 64- multidetector CT equipment and under same conditions of examination technique and postprocessing. Several statistical methods were applied to analyze the results. RESULTS: Statistically significant differences were found between Asian and European patients in the morphology of the central part of the aneurysm at the level of the abdominal aorta and the width and length of the iliac arteries. The principal cause of the most frequent complication observed was defined by a CT aortographic study. CONCLUSIONS: Computed tomographic aortographic quantification of significant parameters makes it possible to plan the exact dimensions of grafts in each individual case. Computed tomographic examinations make possible very exact measurements and positioning of the graft of the novel design proposed by the authors and expected to substantially reduce the incidence of complications.


Assuntos
Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aortografia/métodos , Tomografia Computadorizada por Raios X/métodos , Análise de Variância , Aneurisma da Aorta Abdominal/cirurgia , Ásia , Distribuição de Qui-Quadrado , Europa (Continente) , Feminino , Humanos , Masculino , Interpretação de Imagem Radiográfica Assistida por Computador , Estatísticas não Paramétricas
13.
J Environ Qual ; 40(4): 1153-61, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21712585

RESUMO

Electric arc furnace (EAF) steel slag can be used as an alternative high-quality material in road construction. Although asphalts with slag aggregates have been recognized as environmentally acceptable, there is a lack of data concerning the potential leaching of toxic Cr(VI) due to the highly alkaline media of EAF slag. Leaching of selected water extractable metals from slag indicated elevated concentrations of total chromium and Cr(VI). To estimate the environmental impacts of asphalt mixes with slag, leachability tests based on diffusion were performed using pure water and salt water as leaching agents. Compact and ground asphalt composites with natural aggregates, and asphalt composites in which the natural aggregates were completely replaced by slag were prepared. The concentrations of total chromium and Cr(VI) were determined in leachates over a time period of 6 mo. After 1 and 6 mo, the concentrations of some other metals were also determined in the leachates. The results indicated that chromium in leachates from asphalt composites with the addition of slag was present almost solely in its hexavalent form. However, the concentrations were very low (below 25 µg L) and did not represent an environmental burden. The leaching of other metals from asphalt composites with the addition of slag was negligible. Therefore, the investigated EAF slag can be considered as environmentally safe substitute for natural aggregates in asphalt mixes.


Assuntos
Monitoramento Ambiental , Hidrocarbonetos/análise , Resíduos Industriais/análise , Aço/análise , Poluentes Químicos da Água/análise , Cromo/análise , Cromo/química , Materiais de Construção/análise , Hidrocarbonetos/química , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/química
14.
Sci Rep ; 11(1): 22363, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34785758

RESUMO

This study introduces a novel geotechnical composite material comprising two types of fill material sourced from the paper industry-deinking paper sludge ash (DPSA) and deinking paper sludge (DPS). Five composites with different DPSA and DPS contents were investigated. Two composites were selected for further analyses. The technology and procedure for composite installation were implemented in field tests. The composites with 80% and 70% DPSA exhibited the elasticity required to withstand minor landslide slip deformations, in addition to achieving sufficiently high values of uniaxial compressive strength. The composites had a low maximum dry density value, which led to fewer settlements in the entire support structure. The enhanced shear characteristics can enable the construction of a thinner retaining wall. The delay between preparation and installation of the composites was further investigated. The field tests confirmed that the composites with 80% and 70% DPSA can be installed on the construction site 4 h and even 24 h after mixing. In 2018, a retaining wall structure with 70% DPSA and 30% DPS was successfully implemented near a railway line using conventional technology as followed-up research to the herein presented study. Results have been derived from work performed in the scope of the H2020 Paperchain project in which novel circular economy models centered on the valorization of the waste streams generated by the pulp and paper industry as secondary raw material for several resource-intensive sectors, including the construction sector, have been developed. Environmental benefits are savings in natural raw materials, reduction of landfill disposal as well as CO2 emission reduction.

15.
Eur J Prev Cardiol ; 28(13): 1452-1459, 2021 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-33611455

RESUMO

BACKGROUND: Coronary collateral circulation exerts protective effects on myocardial ischaemia due to coronary artery disease and can be promoted by exercise with heparin co-administration. Whether this arteriogenetic effect is accompanied by functional improvement of left ventricle during stress and lessening of angina symptoms remains unknown. AIMS: To evaluate the anti-ischaemic efficacy of heparin plus exercise in coronary artery disease. METHODS: In a prospective, single-centre, randomized, double-blind study we recruited 32 'no-option' patients (27 males; mean age 61 ± 8 years) with stable angina, exercise-induced ischaemia and coronary artery disease not suitable for revascularization. All underwent a two-week cycle of exercise (two exercise sessions per day, five days per week) and were randomized (n = 16 per group) to intravenous placebo (0.9% saline) versus unfractionated heparin (5.000 IU intravenously), 10 min prior to exercise. We assessed Canadian Cardiovascular Society angina class, stress electrocardiogram and echo parameters (wall motion score index) and computed tomography angiography for collaterals. RESULTS: After two-week cycle, Canadian Cardiovascular Society class statistically decreased in both groups (heparin plus exercise group: 2.6 ± 0.7 to 1.9 ± 0.7, p < 0.001, exercise group: 2.4 ± 0.7 to 2.1 ± 0.9, p = 0.046). Only the heparin plus exercise group improved time-to-ST segment depression (before 270, 228-327 s vs. after 339, 280-360 s, p = 0.012) and wall motion score index (before 1.38 ± 0.25 vs. after 1.28 ± 0.18, p = 0.005). By multi-slice computed tomography angiography, collaterals improved in 12/15 (80%) in the heparin plus exercise group versus 2/16 (12.5%) in the exercise group (p < 0.001). CONCLUSION: A two-week, 10-test cycle of heparin plus exercise is better than exercise in improving angina class, myocardial ischaemia and collaterals by computed tomography angiography.

16.
Anal Methods ; 12(39): 4769-4782, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32940268

RESUMO

Ammonium and selected anions were determined in wastewater samples with highly complex matrices by spectrophotometry using the reagent-kit method. For this purpose, the interferents of coloured compounds and S2-, SO32-, CO32- and Cl-, which are often present in wastewater samples, were systematically investigated in the spectrophotometric determination of ammonium, nitrate, chloride, sulphate, fluoride and phosphate. After this, innovative procedures for their removal were proposed. For sample decolourization, a DEAE column was used to determine ammonium, while a Florisil column was used for the colour removal and anions' determination. S2- and CO32- were eliminated from the samples by adding HCl or HNO3, which transformed them into gases H2S and CO2. The stepwise addition of CaCl2 to the sample, adjusted to pH 8, initiated the formation of CaSO3, which was removed by filtration. Cl- was removed by the addition of Ag2O, which formed a AgCl precipitate that was removed from the solution by filtration. The accuracy of the determination was tested with spike-recovery tests, which showed recoveries for the analytes in the spiked samples ranging from 95 to 105%. The repeatability of the measurements of nitrate, chloride, sulphate and phosphate in the wastewater samples was better than ±1%, while that for the ammonium and fluoride samples was ±2 and ±5%, respectively. The data from the present investigation revealed that the developed procedures for the decolourization and stepwise removal of interferents enabled accurate spectrophotometric determination of ammonium, nitrate, chloride, sulphate, fluoride and phosphate by using cuvette tests in complex wastewater and environmental water samples.

17.
Waste Manag ; 28(12): 2667-74, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18308534

RESUMO

The potential use of filter dust in asphalt composites for road construction was investigated. Filter dust contains high concentrations of metals, of which Cr(VI) and Pb are leached with water. Compact and ground asphalt composites with addition of 2% of filter dust by mass were studied. In order to evaluate their environmental impact, leachability tests were performed using water and salt water as leaching agents. The concentrations of Cr(VI) and Pb were determined in leachates over a time period of 182 days. The results indicated that Pb was not leached with leaching agents from asphalt composites. Cr(VI) was also not leached with leaching agents from compact asphalt composites. However, in ground asphalt composites, Cr(VI) was leached with water in concentrations up to 220 microg L(-1) and in salt water up to 150 microg L(-1). From the physico-mechanical and environmental aspects, filter dust can be used as a component in asphalt mixtures.


Assuntos
Cromo/química , Materiais de Construção/análise , Poeira/análise , Hidrocarbonetos/química , Filtração , Solubilidade , Fatores de Tempo , Poluentes Químicos da Água
18.
Sci Total Environ ; 634: 1259-1268, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29660878

RESUMO

Zero-valent iron nanoparticles (nZVI) exhibit great potential for the removal of metal contaminants from wastewater. After their use, there is a risk that nZVI will remain dispersed in remediated water and represent potential nano-threats to the environment. Therefore, the behaviour of nZVI after remediation must be explored. To accomplish this, we optimised a novel method using single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) for the sizing and quantification of nZVI in wastewater matrices. H2 reaction gas was used in MS/MS mode for the sensitive and interference-free determination of low concentrations of nZVI with a low size limit of detection (36nm). This method was applied to study the influence of different iron (Fe) loads (0.1, 0.25, 0.5 and 1.0gL-1) and water matrices (Milli-Q water, synthetic and effluent wastewater) on the behaviour of nZVI, their interactions with Cd2+ and the efficiency of Cd2+ removal. The aggregation and sedimentation of nZVI increased with settling time. Sedimentation was slower in effluent wastewater than in Milli-Q water or synthetic wastewater. Consequently, Cd2+ was more efficiently (86%) removed from effluent wastewater than from synthetic wastewater (73%), while its removal from Milli-Q water was inefficient (19%). The trace amounts of Cd2+ that remained in the remediated water were either dissolved or sorbed to residual nZVI. The results of the nanoremediation of effluent wastewater with varying Fe loads showed that sedimentation was faster at higher initial concentrations of nZVI. After seven days of settling, low concentrations of Fe remained in the effluent wastewater at Fe loads of 0.5gL-1 or higher, which could indicate that the use of nZVI in nanoremediation under the described conditions may not represent an environmental nano-threat. However, further studies are needed to assess the ecotoxicological impact of Fe-related NPs used for the nanoremediation of wastewaters.

19.
Environ Sci Pollut Res Int ; 24(1): 1030-1041, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27770323

RESUMO

The environmental acceptability of geotechnical composites made of treated municipal sewage sludge (SwS) and paper ash (PA) after two different curing periods has been investigated. The mineral composition of such composites, including their content of major oxides, is mainly influenced by the PA. The content of potentially toxic elements (PTEs) in the initial materials and in the composites varies considerably. In the SwS the Ba, Cd, Cr, Cu, Hg, Ni and Zn contents are above the legally permitted limits. The PTE content of PA are lower, but still somewhat above the permitted values for Ba and Cu. Mixing these two materials together resulted in a decrease in the PTE, but the Ba, Cu and Zn contents are still too high for agricultural application. However, leachates from composites that had been cured for 28 days are highly alkaline, and the As, Ba, Cd, Cr, Hg, Mo, Ni, Pb and Zn contents in them are well below the permitted values. The Cu contents (2.4 to 5.4 mg/kg) are above the permitted limit for inert material, but inside the range for non-hazardous material. In a leachate of composite which was prepared with fresh PA and a lower PA to SwS ratio, the Cu content was 1.4 mg/kg, since fresh PA is more reactive and therefore has a higher ability to immobilise Cu. Therefore, such mixtures can be utilised for covers and liners for sanitary landfills.


Assuntos
Cinza de Carvão/química , Materiais de Construção/análise , Poluentes Ambientais/análise , Metais Pesados/análise , Papel , Reciclagem/métodos , Esgotos/química , Materiais de Construção/normas , Eslovênia
20.
Contemp Clin Trials ; 61: 23-28, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28700892

RESUMO

BACKGROUND: Gestational diabetes mellitus (GDM) is a common complication in pregnancy and a significant risk factor for type 2 diabetes (T2D). Most women who have had GDM are not engaging in health behaviours known to reduce their risk for developing future T2D. The objective of this study is to evaluate the effectiveness of a lifestyle modification program targeting healthy eating and active living behaviours after a GDM pregnancy. METHOD: This trial will randomize 100 women to either a lifestyle modification program or a control condition. Those allocated to the Healthy Eating and Active Living for Diabetes and Gestational Diabetes Mellitus (HEALD-GDM), program will receive a previously developed and tested 24-week program led by an Exercise Specialist at a local recreational facility. The original HEALD program will be tailored for women with GDM through the provision of complementary childcare at HEALD-GDM sessions and theory-guided peer-led telephone support. Our primary outcome is the 6-month change in objectively derived average daily moderate and vigorous physical activity. DISCUSSION: Programs to increase physical activity in women with GDM should carefully consider and find ways to address known barriers specific to this population. We believe that our modified program may be successfully translated to women who have had GDM. CLINICAL TRIALS REGISTRATION: NCT02483949.


Assuntos
Diabetes Mellitus Tipo 2/prevenção & controle , Diabetes Gestacional/terapia , Dieta Saudável , Exercício Físico , Adolescente , Adulto , Pressão Sanguínea , Pesos e Medidas Corporais , Feminino , Hemoglobinas Glicadas , Estilo de Vida Saudável , Humanos , Lipídeos/sangue , Pessoa de Meia-Idade , Gravidez , Projetos de Pesquisa , Adulto Jovem
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