44 research outputs found
Bronchopulmonary Dysplasia: Comparison Between the Two Most Used Diagnostic Criteria
Objectives: To compare the Shennan\u27s and the consensus definition of Bronchopulmonary Dysplasia (BPD) from the National Institutes of Health (NIH) workshop and analyze specific risk factors associated with each definition.
Study design: Retrospective analysis of records of 274 infants admitted to a level IV intensive care unit. Infants were classified as having BPD or no BPD by both definitions. Differences in incidence and risk factors were analyzed. Statistical methods included descriptive statistics, comparative tests, and marginal logistic regression modeling.
Results: The estimated difference in prevalence was 32% [95% CI: (26%, 37%), (p \u3c 0.0001)] between both criteria. The prevalence of BPD was 80% higher based on the NIH criteria [RR = 1.80; 95% CI: (1.58, 2.06)]. Infants with no BPD by the Shennan definition were breathing room air with or without positive or continuous pressure support and were most likely to be discharged home on oxygen [OR = 4.47, 95% CI: (1.20, 16.61), p = 0.03]. Gestational age, birth weight, and 1-min Apgar score predicted BPD by both definitions. Chorioamnionitis increased the risk of BPD by the Shennan definition but was associated with lower risk by the NIH criteria. IUGR was associated with BPD by the Shennan definition and with severe BPD by the NIH criteria.
Conclusion: Compared to the Shennan\u27s definition, the NIH consensus identified 80% more infants with BPD and is a better predictor of oxygen requirement at discharge. Until a new better criteria is develop, the NIH consensus definition should be used across centers
EFFECT OF SULFACETAMIDE ON THE COMPOSITION OF CORROSION PRODUCTS FORMED ONTO CARBON STEEL SURFACE IN HYDROCHLORIC ACID
IUPAC name N- [(4-aminophenyl) sulfonyl] acetamide (APSA) on the corrosion of carbon steel in 1.0 M HCl solution has been investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and XPS analysis. The electrochemical measurements indicated that the presence of APSA in 1.0 M HCl solution decreases the corrosion current (i corr ) and increases the polarization rezistance (R p ). XPS surface analysis showed at this stage, in the absence of APSA, that the main product of corrosion is a non-stoichiometric Fe 3+ oxide/oxidehydroxide, consisting of a mixture of Fe 2 O 3 and FeO(OH), where FeO(OH) is the main phase. Moreover, in presence of inhibitor the surface layer consists of FeO(OH) rather than pure oxide, adsorbed molecules of sulfacetamide and inorganic compounds such as: sulfides, carbonates, sulphates, nitrates, which were obtained by electrochemical degradation of APSA. UV-Vis spectrophotometry and HPLC technique were performed to determine the medium composition before and after corrosion. The results showed a decrease of the inhibitor concentration in 1.0 M HCl solution after carbon steel corrosion, indicating an adsorption process between organic compound molecules from aqueous phase and the electrode surface and/or the electrochemical degradation of APSA
Bronchopulmonary Dysplasia: Comparison Between the Two Most Used Diagnostic Criteria
Objectives: To compare the Shennan's and the consensus definition of Bronchopulmonary Dysplasia (BPD) from the National Institutes of Health (NIH) workshop and analyze specific risk factors associated with each definition.Study design: Retrospective analysis of records of 274 infants admitted to a level IV intensive care unit. Infants were classified as having BPD or no BPD by both definitions. Differences in incidence and risk factors were analyzed. Statistical methods included descriptive statistics, comparative tests, and marginal logistic regression modeling.Results: The estimated difference in prevalence was 32% [95% CI: (26%, 37%), (p < 0.0001)] between both criteria. The prevalence of BPD was 80% higher based on the NIH criteria [RR = 1.80; 95% CI: (1.58, 2.06)]. Infants with no BPD by the Shennan definition were breathing room air with or without positive or continuous pressure support and were most likely to be discharged home on oxygen [OR = 4.47, 95% CI: (1.20, 16.61), p = 0.03]. Gestational age, birth weight, and 1-min Apgar score predicted BPD by both definitions. Chorioamnionitis increased the risk of BPD by the Shennan definition but was associated with lower risk by the NIH criteria. IUGR was associated with BPD by the Shennan definition and with severe BPD by the NIH criteria.Conclusion: Compared to the Shennan's definition, the NIH consensus identified 80% more infants with BPD and is a better predictor of oxygen requirement at discharge. Until a new better criteria is develop, the NIH consensus definition should be used across centers
Manganese(II) Complexes with Schiff Bases Immobilized on Nanosilica as Catalysts of the Reaction of Ozone Decomposition
In this article, we submit the description of synthesis and identification of manganese(II) complexes with pyrogenic nanosilica-immobilized (d av = 10 nm; S sp = 290 m2/g) hydroxyaldimine ligands (Mn(L)2/Si): salicilaldiminopropyl (L1); 5-bromosalicilaldiminopropyl (L2); 2-hydroxynaphtaldiminopropyl (L3); 2-hydroxy-3-methoxybenzaldiminopropyl (L4); 2-hydroxy-3,5-dichloroacetophenoniminopropyl (L5); and 4-hydroxy-3-methoxybenzaldiminopropyl (L6). The ligands and complexes were characterized by UV-VIS and IR spectrometry. Nanocomposites consisting of complexes Mn(L)2/Si showed a high catalytic activity in low-temperature ozone decomposition in the range of concentrations between 2.1 × 10−6 and 8.4 × 10−6 mol/l. The number of catalytic cycles increased for isostructural pseudotetrahedral complexes Mn(L)2/Si (L1–L5) in the following order: Mn(L3)2 >> Mn(L4)2 > Mn(L1)2 > Mn(L2)2 > Mn(L5)2. In the case of pseudooctahedral complexes with L6, the change of coordination polyhedral does not influence the kinetics and stoichiometric parameters of the reaction
Study of the Corrosion Resistance of Ni/CeO2 Composite Coatings Electrodeposited on Carbon Steel in Hydrochloric Acid
The phase formation of Ni-Ce composites onto a carbon steel electrode was investigated using electrochemical deposition. The anticorrosive properties of composite coating in 0.1 mol L–1 HCl solution were studied by Tafel polarization and electrochemical
impedance spectroscopy (EIS). Incorporation of CeO2 particles into the Ni matrices was found to improve corrosion resistance of pure Ni coatings. The values of protection efficiency obtained from Tafel polarization and EIS measurements are in good agreement,
reaching a maximum value of 57 %, at 0.1 g L–1 CeO2 containing electro-deposition bath. The surface morphologies and compositions of coatings were studied using scanning electron microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS). In case of electro-depositions from solution containing CeO2 (Fig. 3c) the layer uniformity is more apparent and the feature of a metalic nucleation, forming a matrix in which are embedded certain oxide particle is relatively nuanced
Corrosion Inhibition of Carbon Steel in Hydrochloric Acid Solution Using a Sulfa Drug
The corrosion inhibition of carbon steel in 1.0 mol L–1 HCl in the presence of an antibacterial sulfa drug Sulfathiazole, IUPAC name 4-amino-N-(1,3-thiazol-2-yl) benzene sulfonamide (TBSA) was investigated using mass loss and electrochemical measurements
such as: potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Surface chemistry was analyzed by X-ray photoelectron spectroscopy (XPS). For the study of the surface morphology scanning electron spectroscopy (SEM) was used. The results showed that TBSA acts as a corrosion inhibitor in 1.0 mol L–1 HCl solution by suppressing simultaneously the cathodic and anodic processes via adsorption on the carbon steel surface and that the inhibition efficiency increases with increasing concentration. XPS analysis revealed that the corrosion product consists of an
oxyhydroxide/oxide mixture and that the iron oxyhydroxide proportion is higher than the iron oxide proportion
Removal of methylene blue and methyl blue from wastewater by electrochemical degradation
Electrochemical degradation of such dyes as methylene blue (BM-ylene) and methyl blue (BM-yl)
was investigated using UV-Vis spectrophotometry, in order to be removed from the solutions, leading to
discoloration of wastewater obtained under simulated laboratory conditions. The electrochemical
degradation in the presence of SO4(-) ions, as well as in the presence of Cl(-) ions were compared for the
synthetic waters containing BM-ylene and BM-yl. The results showed that the fastest degradation and
discoloration of the BM-yl solution containing Cl(-) ions was achieved, with a high value for its color
removal (CR) of 89.7% obtained after 10 min