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1.
Phys Med ; 53: 103-107, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30241744

RESUMO

OBJECTIVE: Number and complexity of interventional cardiology procedures have increased during last years and can result in patient skin dose high enough to cause deterministic skin effects. The aim of the work is to investigate the correlation between Peak Skin Dose (PSD) and the dosimetric indicators directly registered by the radiological equipment and provide the physicians a tool to identify patients at risk of deterministic effects and include them into a follow-up program. METHODS: PSD was measured in vivo using radiochromic Gafchromic XR-RV3 films, properly calibrated. DAP, Cumulative Dose at the interventional reference point (CD) and exposure time of each procedure were retrieved from the Radiation Dose Structured Reports created by an Allura Clarity Xper FD20 angiographic system. Linear correlation between PSD and both DAP and CD was investigated. RESULTS: 42 interventional cardiology procedures (16 CA and 26 PTCA) were involved in the study. The dosimetric indicators values for PTCA are generally higher than those for CA, due to the different levels of procedure complexity. Mean PSD values were (103 ±â€¯64) and (526 ±â€¯436) mGy for CA and PTCA procedures. For CA, we found strong correlation both between PSD and DAP (r = 0.753) and PSD and CD (r = 0.782). For PTCA, good correlation both for DAP (r = 0.648) and CD (r = 0.649) was found. CONCLUSIONS: DAP and CD show strong correlation with PSD measured with Gafchromic films during interventional procedures. The proposed method allows the physician to estimate patient's PSD from the dosimetric indicators that the radiological equipment display and record at the end of the procedure.


Assuntos
Cardiologia , Dosimetria Fotográfica , Doses de Radiação , Pele/efeitos da radiação , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
2.
J Hazard Mater ; 281: 70-76, 2015 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-25139286

RESUMO

Iron sulphate (FeSO4) and colloidal nano zero-valent iron (nZVI) as reducing agents were compared, with the aim of assessing their effectiveness in hexavalent chromium [Cr(VI)] removal from a contaminated industrial soil. Experiments were performed on soil samples collected from an industrial site where a nickel contamination, caused by a long-term productive activity, was also verified. The influence of reducing agents amount with respect to chromium content and the effectiveness of deoxygenation of the slurry were discussed. The soil was fully characterized before and after each test, and sequential extractions were performed to assess chemico-physical modifications and evaluate metals mobility induced by washing. Results show that both the reducing agents successfully lowered the amount of Cr(VI) in the soil below the threshold allowed by Italian Environmental Regulation for industrial reuse. Cr(VI) reduction by colloidal nZVI proved to be faster and more effective: the civil reuse of soil [Cr(VI)<2mg/kg] was only achieved using colloidal nZVI within 60min adopting a nZVI/Cr(VI) molar ratio of 30. The reducing treatment resulted in an increase in the amount of chromium in the oxide-hydroxide fraction, thus confirming a mechanism of chromium-iron hydroxides precipitation. In addition, a decrease of nickel (Ni) and lead (Pb) content in soil was also observed when acidic conditions were established.


Assuntos
Cromo/química , Compostos Ferrosos/química , Ferro/química , Nanopartículas Metálicas/química , Poluentes do Solo/química , Hidróxidos/química , Oxirredução , Óxidos/química
3.
Minerva Anestesiol ; 81(2): 195-204, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24739207

RESUMO

Cesarean delivery is a major surgical procedure, after which a woman can experience substantial postoperative discomfort or pain. Inadequate postoperative analgesia is one of the most common reasons for poor patient satisfaction following cesarean delivery. Although spinal or systemic opioids are currently the gold standard to achieve effective analgesia, they are often associated with side effects. In the last few years there has been growing interest in abdominal plane blocks, with promising data on their efficacy. The transversus abdominis plane (TAP) block is a regional analgesic technique which is gaining acceptance in postoperative analgesia for lower abdominal surgeries. In this systematic review of articles published as of 31 December 2013, we searched the principal medical databases for randomized controlled trials that assessed the efficacy of ultrasound (US)-guided TAP block following cesarean delivery and reported on postoperative opioid consumption and pain score, opioid-related side-effects and patient satisfaction. Although controversy surrounds the utility of US-guided TAP block in cesarean section, evidence suggests that when correctly executed as part of a multimodal analgesic regimen, TAP block may reduce postoperative opioid consumption and opioid-related side effects, improving postoperative pain control and patient satisfaction. Further studies are necessary to explore this field of research.


Assuntos
Cesárea/métodos , Bloqueio Nervoso/métodos , Dor Pós-Operatória/tratamento farmacológico , Músculos Abdominais , Adulto , Analgesia/métodos , Feminino , Humanos , Gravidez
4.
Int J Immunopathol Pharmacol ; 26(4): 961-4, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24355232

RESUMO

Multiple Chemical Sensitivity (MCS) is characterised by the appearance of numerous and sometimes severe symptoms, when subjects are in contact with various chemicals and medicinal substances. Currently there are no useful guidelines for managing clinical issues and, specifically, anaesthesia for patients with MCS. This case report describes anaesthesia management in a patient affected by clinically documented MCS and a latex allergy, a candidate for a laparoscopic cholecystectomy operation.


Assuntos
Anestesia Geral/métodos , Sensibilidade Química Múltipla/complicações , Colecistectomia Laparoscópica , Feminino , Humanos , Hipersensibilidade ao Látex/complicações , Pessoa de Meia-Idade
5.
Horm Res Paediatr ; 78(5-6): 297-303, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23257416

RESUMO

AIM: To investigate the role of ghrelin and obestatin in infancy. METHODS: We measured ghrelin and obestatin concentrations in blood samples of infants, lactating mothers, and in breast milk. RESULTS: The median (interquartile range) serum ghrelin concentrations were 922.11 (868.44) pg/ml in infants, 667.88 (942.78) pg/ml in lactating mothers, and 526.4 (439.86) pg/ml in breast milk. The serum obestatin levels were 844.87 (805.14) pg/ml in infants, 759.105 (855.55) pg/ml in lactating mothers, and 846.6 (472.07) pg/ml in breast milk. A positive correlation was found for serum ghrelin concentrations in breastfed infants and lactating mothers (p < 0.001, r = 0.789), serum ghrelin concentrations in breastfed infants and in breast milk (p < 0.001, r = 0.581), serum ghrelin concentrations in lactating mothers and in breast milk (p = 0.021, r = 0.450), and serum obestatin concentrations in breastfed infants and in lactating mothers (p = 0.047, r = 0.609). CONCLUSION: We report for the first time the serum obestatin concentrations in infants and confirm the presence of correlations between ghrelin and obestatin in lactating mothers and breast milk. The correlations found early in infants' life, when hormones begin to exert their effects on feeding behavior, suggest that they may be involved in these processes.


Assuntos
Grelina/sangue , Lactação/sangue , Leite Humano/química , Adulto , Estudos Transversais , Feminino , Humanos , Lactente , Fórmulas Infantis , Fenômenos Fisiológicos da Nutrição do Lactente , Dobras Cutâneas
6.
Acta Paediatr ; 101(10): 1058-62, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22646778

RESUMO

AIMS: The aims of the study were to determine human breast milk adiponectin concentration and to investigate its relationship with serum adiponectin concentration in lactating mothers and their infants and also to evaluate the relationship between serum adiponectin concentration and anthropometric parameters in nurses and infants. METHODS: We enrolled 60 healthy term breastfed (BF) infants and their lactating mothers. Adiponectin was determined by radioimmunoassay test in serum and by enzyme-linked immunosorbent assay test in human milk (HM). Infants' and mothers' anthropometric parameters were measured. RESULTS: Median (25‰, 75‰) adiponectin concentration in HM was 9.99 (3.59, 20.52) ng/mL. Serum adiponectin concentration in infants was 60.49 (45.76, 74.24) µg/mL and in lactating mothers 21.14 (12.61, 29.66) µg/mL. Adiponectin concentration in HM correlated positively with adiponectin in mothers' serum; r = 0.60 (p < 0.001) and in infants' serum r = 0.37 (p = 0.015). Adiponectin in HM correlated negatively with infants' age r = -0.3 (p = 0.04). Infants' serum adiponectin correlated negatively with their weight r = -0.35 (p = 0.005), length r = -0.35 (p = 0.006) and age r = -0.46 (p < 0.001) and mothers' serum adiponectin with their weight r = -0.37 (p = 0.02) and body mass index r = -0.45 (p = 0.004). CONCLUSIONS: The observed correlations between adiponectin in mothers, HM and BF infants may be suggestive for a metabolic link between nurses and infants through milk.


Assuntos
Adiponectina/sangue , Recém-Nascido/sangue , Lactação/metabolismo , Leite Humano/química , Adiponectina/metabolismo , Adulto , Aleitamento Materno , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Leite Humano/metabolismo , Radioimunoensaio , Adulto Jovem
7.
Eur J Clin Nutr ; 64(9): 972-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20588294

RESUMO

BACKGROUND/OBJECTIVES: Leptin is present in human milk, but it is not clear what the relationship between breast milk (BM) leptin levels and maternal and infant serum leptin concentrations is. The objective of this study was to evaluate the leptin concentration in BM and to investigate its relationship with infants' and mothers' anthropometric parameters and with serum leptin concentration in breast-fed (BF) infants and lactating mothers. SUBJECTS/METHODS: We enrolled 36 adequate for gestational age healthy, exclusively BF, term infants aged <6 months. Leptin concentration in serum and BM was determined by radioimmunoassay (RIA) test (human-leptin-RIA-sensitive, Mediagnost). Infants' and mothers' weights, lengths and body mass indexes (BMI) were measured. RESULTS: The median leptin concentration was 3.42 ng/ml (interquartile range (IR): 2.65) in BF infants' serum, 3.02 ng/ml (IR: 2.85) in mothers' serum (n=17) and 0.51 ng/ml (IR: 0.34) in BM (n=24). BM leptin concentrations were significantly lower than serum BF infant (P<0.001) and maternal (P<0.001) leptin levels. Infant serum leptin concentration correlated positively with infant weight (r=0.437, P=0.008) and BMI (r=0.561, P=0.004). Mother serum leptin levels correlated positively with weight (r=0.755, P<0.001) and BMI (r=0.661, P=0.007). No correlations were found between BM leptin and serum leptin concentrations in BF infants and mothers. CONCLUSIONS: We confirmed the presence of leptin in BM at a lower concentration than that found in infant and lactating mother serum. We observed a positive correlation between serum leptin levels in BF infants and their growth parameters.


Assuntos
Índice de Massa Corporal , Peso Corporal/fisiologia , Recém-Nascido/sangue , Leptina/análise , Leite Humano/química , Adulto , Aleitamento Materno , Estudos Transversais , Feminino , Idade Gestacional , Humanos , Lactente , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido/crescimento & desenvolvimento , Lactação/metabolismo , Leptina/sangue , Leptina/metabolismo , Masculino , Leite Humano/metabolismo , Mães
8.
Oncogene ; 28(23): 2276-88, 2009 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-19421145

RESUMO

The promyelocytic leukemia zinc-finger protein (PLZF) is a transcription factor and c-kit is a receptor tyrosine kinase associated with human disease, particularly in hematopoietic cells. MicroRNAs (miRs) are post-transcriptional regulators of gene expression, and c-kit has been described as a target of miRs-221 and -222 in erythropoiesis. In the present study, we identified c-kit as a target of PLZF in normal and leukemic cells. Particularly, in erythropoietic (E) culture of CD34(+) progenitors, PLZF is downregulated, whereas c-kit expression at both the mRNA and protein levels inversely increases during the first days of E differentiation. In functional experiments, PLZF transfection induces c-kit downregulation, inhibits E proliferation and delays differentiation, whereas PLZF knockdown induces opposite effects, independently of miRs-221 and -222 expression. The inverse correlation between PLZF and c-kit expression was found in normal CD34(+)38(+/-) hematopoietic progenitor/stem cells and in acute myeloid leukemias of M0/M1 French-American-British subtypes, suggesting that the control of PLZF on c-kit expression may be crucial at the level of the stem cell/progenitor compartment. Altogether, our data indicate a new mechanism of regulation of c-kit expression that involves a transcriptional control by PLZF in CD34(+) cells and early erythropoiesis.


Assuntos
Antígenos CD34/metabolismo , Eritropoese , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Proto-Oncogênicas c-kit/metabolismo , ADP-Ribosil Ciclase 1/metabolismo , Western Blotting , Linhagem Celular , Proliferação de Células , Ensaio de Desvio de Mobilidade Eletroforética , Citometria de Fluxo , Imunofluorescência , Regulação Neoplásica da Expressão Gênica , Humanos , Células K562 , Fatores de Transcrição Kruppel-Like/genética , Leucemia/genética , Leucemia/metabolismo , Leucemia/patologia , Luciferases/genética , Luciferases/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Microscopia de Contraste de Fase , Proteína com Dedos de Zinco da Leucemia Promielocítica , Proteínas Proto-Oncogênicas c-kit/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transfecção
9.
Acta Paediatr ; 97(6): 701-5, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18397349

RESUMO

UNLABELLED: Adiponectin, a protein hormone produced by adipocytes, is also found in breast milk, which in turn is implicated in childhood obesity prevention. Although a biological role for adiponectin has not been firmly established, clinical and experimental research indicates that it regulates lipid and glucose metabolism, affects foetal development, and exerts anti-inflammatory and antiatherogenic effects. CONCLUSION: This review demonstrates an emerging interest of paediatric research on adiponectin. A better understanding of adiponectin's bioactivity might clarify whether breast milk indeed prevents childhood obesity.


Assuntos
Adipócitos/metabolismo , Adiponectina/metabolismo , Proteção da Criança , Adiponectina/biossíntese , Aleitamento Materno , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Leptina , Leite Humano , Obesidade/metabolismo , Obesidade/prevenção & controle , Pediatria
10.
Eur Respir J ; 27(3): 529-41, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16507853

RESUMO

Circulating CD34+ cells are haemopoietic progenitors that may play a role in tissue repair. No data are available on circulating progenitors in chronic obstructive pulmonary disease (COPD). Circulating CD34+ cells were studied in 18 patients with moderate-to-severe COPD (age: mean+/-sd 68+/-8 yrs; forced expiratory volume in one second: 48+/-12% predicted) and 12 controls, at rest and after endurance exercise. Plasma concentrations of haematopoietic growth factors (FMS-like tyrosine kinase 3 (Flt3) ligand, kit ligand), markers of hypoxia (vascular endothelial growth factor (VEGF)) and stimulators of angiogenesis (VEGF, hepatocyte growth factor (HGF)) and markers of systemic inflammation (tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8) were measured. Compared with the controls, the COPD patients showed a three-fold reduction in CD34+ cell counts (3.3+/-2.5 versus 10.3+/-4.2 cells.microL-1), and a 50% decrease in AC133+ cells. In the COPD patients, progenitor-derived haemopoietic and endothelial cell colonies were reduced by 30-50%. However, four COPD patients showed progenitor counts in the normal range associated with lower TNF-alpha levels. In the entire sample, CD34+ cell counts correlated with exercise capacity and severity of airflow obstruction. After endurance exercise, progenitor counts were unchanged, while plasma Flt3 ligand and VEGF only increased in the COPD patients. Plasma HGF levels were higher in the COPD patients compared with the controls and correlated inversely with the number of progenitor-derived colonies. In conclusion, circulating CD34+ cells and endothelial progenitors were decreased in chronic obstructive pulmonary disease patients and could be correlated with disease severity.


Assuntos
Antígenos CD34 , Células Endoteliais , Células-Tronco Hematopoéticas , Doença Pulmonar Obstrutiva Crônica/sangue , Células-Tronco , Idoso , Contagem de Células , Células Endoteliais/imunologia , Células-Tronco Hematopoéticas/imunologia , Humanos , Pessoa de Meia-Idade , Células-Tronco/imunologia
11.
Medicina (B.Aires) ; Medicina (B.Aires);65(5): 430-430, 2005. ilus
Artigo em Espanhol | LILACS | ID: lil-445759
12.
Leukemia ; 18(11): 1864-71, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15385939

RESUMO

Interferon regulatory factor (IRF)-1 is a transcription factor controlling the expression of several genes, which are differentially induced depending on the cell type and signal. IRF-1 modulates multiple functions, including regulation of immune responses and host defence, cell growth, cytokine signalling and hematopoietic development. Here, we investigated the role of IRF-1 in granulocytic differentiation in mice with a null mutation in the IRF-1 gene. We show that IRF-1(-/-) bone marrow cells exhibit an increased number of immature granulocytic precursors, associated with a decreased number of mature granulocytic elements as compared to normal mice, suggestive of a defective maturation process. Clonogenetic analyses revealed a reduced number of CFU-G, CFU-M and CFU-GM colonies in IRF-1(-/-) mice, while the number of BFU-E/CFU-E colonies was unchanged. At the molecular level, the expression of CAAT-enhancer-binding protein (C/EBP)-epsilon, -alpha and PU.1 was substantially lower in the CD11b(+) cells from the bone marrow of IRF-1(-/-) mice as compared to cells from wild-type mice. These results, together with the fact that IRF-1 is markedly induced early during granulo-monocytic differentiation of CD34+ cells, highlight the pivotal role of IRF-1 in the early phases of myelopoiesis.


Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular , Proteínas de Ligação a DNA/fisiologia , Granulócitos/citologia , Monócitos/citologia , Mielopoese/fisiologia , Fosfoproteínas/fisiologia , Animais , Células da Medula Óssea/metabolismo , Proteína alfa Estimuladora de Ligação a CCAAT/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Antígeno CD11b/metabolismo , Ensaio de Unidades Formadoras de Colônias , Proteínas de Ligação a DNA/genética , Células Precursoras Eritroides , Granulócitos/metabolismo , Homozigoto , Fator Regulador 1 de Interferon , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/metabolismo , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo
13.
Artigo em Inglês | MEDLINE | ID: mdl-15137714

RESUMO

The oxidation of an atrazine solution obtained from a flushing treatment of a contaminated soil was investigated. Experimental tests were performed on an artificially contaminated standard soil. Atrazine was removed from the soil by flushing with an aqueous solution at 5% volume of ethanol. Oxidative Fenton-type treatment on the extracted solution was then performed in order to transform atrazine into its by-products. The influence of different concentration of ethanol on atrazine oxidation was studied. Results show that the oxidative treatment is strongly affected by the ethanol residual amount. The degradation mechanism of atrazine during oxidation with Fenton's reagent in the presence of ethanol was also investigated.


Assuntos
Atrazina/análise , Atrazina/química , Poluição Ambiental/prevenção & controle , Etanol/química , Herbicidas/análise , Herbicidas/química , Poluentes do Solo/análise , Solventes/química , Peróxido de Hidrogênio/química , Ferro/química , Oxidantes/química , Oxirredução , Movimentos da Água
14.
J Hazard Mater ; 99(3): 265-76, 2003 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-12758011

RESUMO

This paper presents a feasibility study in the field of the remediation of soils contaminated with atrazine. Experimental tests were performed on an artificially contaminated synthetic soil. Atrazine was removed from the soil by flushing with an aqueous solution at 5 vol.% of ethanol. Experimental tests of evaporation and Fenton's oxidation on the extracted solution were then performed in order to transform atrazine into its oxidation products. Tests were performed in the presence of a peroxide excess the ratio between Fe(2+) and H(2)O(2) was 1:10. Peroxide was first added in order to reduce the consumption of hydroxyl radicals by their reaction with the excess of Fe(2+). The degradation mechanism of atrazine during oxidation with Fenton's reagent in the presence of ethanol was investigated. Results showed that due to the non selective nature of Fenton's reagent a high consumption of reagent was needed to achieve a significant atrazine oxidation from solutions at 4.5 vol.% of ethanol. While at a Fe(2+) concentration of 3mM atrazine practically disappeared from pure aqueous solutions within 2h, a degradation yield of only 28.1% was observed in the presence of ethanol even when Fe(2+) concentration was 15 mM.


Assuntos
Atrazina/isolamento & purificação , Herbicidas/isolamento & purificação , Poluentes do Solo/isolamento & purificação , Atrazina/química , Herbicidas/química , Peróxido de Hidrogênio/química , Ferro/química , Oxidantes/química , Oxirredução
15.
Bioresour Technol ; 86(2): 193-200, 2003 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-12653287

RESUMO

The physical and biological mechanisms of attached-biomass growth were analyzed and a steady-state model was proposed to determine the soluble carbonaceous removal in an RBC unit for different organic loading rates in the reactor. The objective of the model was the prediction of the organic loading rate corresponding to the maximum removal capacity in the system. A system of equations was solved where the influent soluble carbonaceous substrate concentration was the main variable. Monod's rate law was used for the growth of microorganism: the soluble carbonaceous substrate was the limiting substrate. Endogenous decay was neglected. The influence of disk rotational speed on the RBC removal capacity was investigated, the disk rotational speed being a parameter acting on oxygen transfer in the biofilm. The criteria for the evaluation of the kinetic parameter in the model were proposed.


Assuntos
Reatores Biológicos , Carbono/metabolismo , Modelos Teóricos , Oxigênio/metabolismo , Bactérias , Biofilmes , Biomassa , Cinética , Dinâmica Populacional
16.
Sci Total Environ ; 299(1-3): 1-19, 2002 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-12462571

RESUMO

Traffic is the main source of platinum-group element (PGE) contamination in populated urban areas. There is increasing concern about the hazardous effects of these new pollutants for people and for other living organisms in these areas. Airborne and road dusts, as well as tree bark and grass samples were collected at locations in the European cities of Göteborg (Sweden), Madrid (Spain), Rome (Italy), Munich (Germany), Sheffield and London (UK). Today, in spite of the large number of parameters that can influence the airborne PGE content, the results obtained so far indicate significantly higher PGE levels at traffic sites compared with the rural or non-polluted zones that have been investigated (background levels). The average Pt content in airborne particles found in downtown Madrid, Göteborg and Rome is in the range 7.3-13.1 pg m(-3). The ring roads of these cities have values in the range 4.1-17.7 pg m(-3). In Munich, a lower Pt content was found in airborne particles (4.1 pg m(-3)). The same tendency has been noted for downtown Rh, with contents in the range 2.2-2.8 pg m(-3), and in the range 0.8-3.0 and 0.3 pg m(-3) for motorway margins in Munich. The combined results obtained using a wide-range airborne classifier (WRAC) collector and a PM-10 or virtual impactor show that Pt is associated with particles for a wide range of diameters. The smaller the particle size, the lower the Pt concentration. However, in particles

Assuntos
Poluentes Atmosféricos/análise , Exposição por Inalação , Compostos de Platina/análise , Saúde Pública , Emissões de Veículos/análise , Poluentes Atmosféricos/efeitos adversos , Cidades , Poeira , Monitoramento Ambiental , Europa (Continente) , Humanos , Tamanho da Partícula , Compostos de Platina/efeitos adversos , Medição de Risco , População Urbana , Emissões de Veículos/efeitos adversos
17.
Ann Chim ; 91(3-4): 145-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11381538

RESUMO

Wastewater containing a mixture of hypophosphites and phosphites was treated in order to assess the possibility of attaining high levels of phosphorus oxidation to phosphate. An initial series of tests based on chemical oxidation by means of Fenton's reagent demonstrated the feasibility of this process for solutions containing 250-750 mg/l of phosphorus. Removal yields of up to 98% were attained at pH 3.5 by using variable ratios of [H2O2]/[Fe2+]. The second series involved the electrolytic generation of Fenton's reagent at pH 2-2.5 through cathodic oxygen reduction. This demonstrated the possibility of obtaining quantitative yields for solutions containing 80-160 mg/l P with a constant [H2O2]/[Fe2+] ratio of 3.94. Economic comparison of the two processes showed that the operative cost of the electrochemical treatment is comparable to that of the chemical process.


Assuntos
Fosfitos/química , Fósforo/química , Poluentes Químicos da Água , Purificação da Água/métodos , Eletroquímica , Peróxido de Hidrogênio , Indicadores e Reagentes , Resíduos Industriais , Ferro , Nitratos , Oxirredução , Purificação da Água/economia
18.
J Am Coll Cardiol ; 28(4): 924-34, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8837570

RESUMO

OBJECTIVES: We sought to evaluate changes in RR interval variability during dipyridamole infusion and dipyridamole-induced myocardial ischemia. BACKGROUND: Myocardial ischemia and the autonomic nervous system can be mutually interdependent. Spectral analysis of RR interval variability is a useful tool in assessing autonomic tone. METHODS: We used a time variant autoregressive spectral estimation algorithm that could extract spectral variables even in the presence of nonstationary signals. Two groups were considered: group A (patients with ischemia, n = 15) with effort or mixed angina, angiographically assessed coronary artery disease and positive exercise and dipyridamole echocardiographic test results, and group B (control subjects, n = 10) with normal exercise and dipyridamole echocardiographic test results. We investigated the following variables: RR interval mean and variance, low frequency (LF) and high frequency (HF) power in normalized units, LF ratio (LF/LFbasal power), HF ratio (HF/HFbasal power) and LF/HF ratio. For each test epoch, we calculated for group A and group B the mean value +/- SE of all indexes considered. Differences due to an effect either of group (ischemic vs. control) or of time (including both drug and ischemia effects) were analyzed by using analysis of variance for repeated measurements. RESULTS: Dipyridamole injection was characterized by a reduction of all spectral components in negative test. The LF ratio was the only variable able to discriminate patients with ischemia from control subjects (p < 0.05), whereas a time effect was evident for both mean RR interval and high frequency power in normalized units (p < 0.05). The LF ratio decreased in group B from 1 +/- 0.00 (basal) to 0.31 +/- 0.22 (peak), and increased in group A from 1 +/- 0.00 to 15.41 +/- 6.59, respectively. Results of an unpaired t test comparing the peak values of the two groups were also statistically significant (p < 0.01). CONCLUSIONS: Our data show that time variant analysis of heart rate variability evidences an increase in the low frequency ratio that allows differentiation of positive from negative test results, suggesting that the electrocardiogram may contain ischemia information unrelated to ST-T variations, even if their enhancement requires a more complex data processing procedure.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Dipiridamol , Ecocardiografia , Frequência Cardíaca/efeitos dos fármacos , Isquemia Miocárdica/fisiopatologia , Vasodilatadores , Idoso , Algoritmos , Sistema Nervoso Autônomo/efeitos dos fármacos , Dipiridamol/farmacologia , Ecocardiografia/efeitos dos fármacos , Eletrocardiografia/efeitos dos fármacos , Teste de Esforço , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico por imagem , Processamento de Sinais Assistido por Computador , Vasodilatadores/farmacologia
19.
Clin Cardiol ; 19(3): 248-52, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8674265

RESUMO

HYPOTHESIS: Computer processing of the exercise electrocardiogram (ECG) has many advantages, but the reliability of the analysis algorithms is not easily evaluable. No standard annotated database, nor recommended practice for testing and reporting performance results is available: thus, performance evaluation of such devices can be accomplished only by using a set of unannotated recordings, obtained in clinical practice. We evaluated the accuracy of an original microcomputer-based exercise test analyzer comparing the ST computer output with the measurements obtained by two experienced cardiologists. METHODS: Six hundred ECG strips were randomly selected from the exercise test recordings of 60 patients. The ST shift (at J + 80 ms) was blindly assessed by two observers (with the aid of a calibrated lens) and compared with computer measurements. Correlation coefficients, linear regression equations, percent of discrepant measurements, and 95% confidence limits of the mean error were calculated for all leads, peripheral leads, precordial leads, and "stress-test" leads (II, III, aVF, V4, V5, V6). RESULTS: The computer did not analyze five samples on a total of 600 (0.83%) ECG strips because of excessive noise or signal loss, while 51 (8.5%) were considered unreadable by both observers and 67 (11.2%) were rejected by at least one observer. Correlation between the measurements taken by computer and observer(s) measurements was statistically significant (p < 0.001 for all lead groups), no systematic measurement bias was found, and the mean difference was lower than human eye resolution. CONCLUSIONS: Our algorithms provide results as good as those provided by trained cardiologists in measuring ST changes occurring during exercise test. However, this study did not evaluate whether computer improvement of the signal-to-noise ratio would allow accurate measurements even on cardiologists' uninterpretable ECG. This potential advantage of computer-assisted analysis could be assessed only by using a dedicated exercise test database, in which different patterns of noise are superimposed on noise-free recordings previously annotated for ST level.


Assuntos
Algoritmos , Eletrocardiografia , Teste de Esforço , Processamento de Sinais Assistido por Computador , Adulto , Idoso , Artefatos , Viés , Cardiologia , Eletrocardiografia/estatística & dados numéricos , Estudos de Avaliação como Assunto , Feminino , Frequência Cardíaca , Humanos , Sistemas de Informação , Modelos Lineares , Masculino , Microcomputadores , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Método Simples-Cego , Validação de Programas de Computador
20.
IEEE Trans Biomed Eng ; 40(2): 136-44, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8319964

RESUMO

A time-variant algorithm of autoregressive (AR) identification is introduced and applied to the heart rate variability (HRV) signal. The power spectrum is calculated from the AR coefficients derived from each single RR interval considered. Time-variant AR coefficients are determined through adaptive parametric identification with a forgetting factor which obtains weighed values on a running temporal window of 50 preceding measurements. Power spectrum density (PSD) is hence obtained at each cardiac cycle, making it possible to follow the dynamics of the spectral parameters on a beat-by-beat basis. These parameters are mainly the LF (low frequency) and the HF (high frequency) powers, and their ratio LF/HF. These together account for the balanced sympatho-vagal control mechanism affecting the heart rate. This method is applied to subjects suffering from transient ischemic attacks. The time variant spectral parameters suggest an early activation of LF component in the HRV power spectrum. It precedes by approximately 1.5-2 min the tachycardia and the ST displacement, generally indicative of the onset of an ischemic episode. The results suggest an arousal of sympathetic system before the acute attack.


Assuntos
Algoritmos , Eletrocardiografia Ambulatorial , Frequência Cardíaca , Ataque Isquêmico Transitório/complicações , Processamento de Sinais Assistido por Computador , Taquicardia/diagnóstico , Simulação por Computador , Estudos de Avaliação como Assunto , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Pessoa de Meia-Idade , Sistema Nervoso Simpático/fisiopatologia , Taquicardia/etiologia , Taquicardia/fisiopatologia , Nervo Vago/fisiopatologia
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