81 research outputs found
The sealing step in aluminum anodizing: a focus on sustainable strategies for enhancing both energy efficiency and corrosion resistance
Increasing demands for environmental accountability and energy efficiency in industrial
practice necessitates significant modification(s) of existing technologies and development of new
ones to meet the stringent sustainability demands of the future. Generally, development of required
new technologies and appropriate modifications of existing ones need to be premised on in-depth
appreciation of existing technologies, their limitations, and desired ideal products or processes. In
the light of these, published literature mostly in the past 30 years on the sealing process; the second
highest energy consuming step in aluminum anodization and a step with significant environmental
impacts has been critical reviewed in this systematic review. Emphasis have been placed on the
need to reduce both the energy input in the anodization process and environmental implications.
The implications of the nano-porous structure of the anodic oxide on mass transport and chemical
reactivity of relevant species during the sealing process is highlighted with a focus on exploiting
these peculiarities, in improving the quality of sealed products. In addition, perspective is provided
on plausible approaches and important factors to be considered in developing sealing procedures
that can minimize the energy input and environmental impact of the sealing step, and ensure a more
sustainable aluminum anodization process/industry.in publicatio
Ages and metallicities of stellar clusters using S-PLUS narrow-band integrated photometry: the Small Magellanic Cloud
The Magellanic Clouds are the most massive and closest satellite galaxies of
the Milky Way, with stars covering ages from a few Myr up to 13 Gyr. This makes
them important for validating integrated light methods to study stellar
populations and star-formation processes, which can be applied to more distant
galaxies. We characterized a set of stellar clusters in the Small Magellanic
Cloud (SMC), using the .
This is the first age (metallicity) determination for 11 (65) clusters of this
sample. Through its 7 narrow bands, centered on important spectral features,
and 5 broad bands, we can retrieve detailed information about stellar
populations. We obtained ages and metallicities for all stellar clusters using
the Bayesian spectral energy distribution fitting code .
With a sample of clusters in the color range , for which
our determined parameters are most reliable, we modeled the age-metallicity
relation of SMC. At any given age, the metallicities of SMC clusters are lower
than those of both the Gaia Sausage-Enceladus disrupted dwarf galaxy and the
Milky Way. In comparison with literature values, differences are
log(age) and [Fe/H], which is
comparable to low-resolution spectroscopy of individual stars. Finally, we
confirm a previously known gradient, with younger clusters in the center and
older ones preferentially located in the outermost regions. On the other hand,
we found no evidence of a significant metallicity gradient.Comment: 12 pages, 11 figure
The association of myocardial strain with cardiac magnetic resonance and clinical outcomes in patients with acute myocarditis
IntroductionThe role of myocardial strain in risk prediction for acute myocarditis (AMC) patients, measured by cardiac magnetic resonance (CMR), deserves further investigation. Our objective was to evaluate the association between myocardial strain measured by CMR and clinical events in AMC patients.Material and methodsThis was a prospective single-center study of patients with AMC. We included 100 patients with AMC with CMR confirmation. The primary outcome was the composite of all-cause mortality, heart failure and AMC recurrence in 24 months. A subgroup analysis was performed on a sample of 36 patients who underwent a second CMR between 6 and 18 months. The association between strain measures and clinical events or an increase in left ventricular ejection fraction (LVEF) was explored using Cox regression analysis. Global peak radial, circumferential and longitudinal strain in the left and right ventricles was assessed. ROC curve analysis was performed to identify cutoff points for clinical event prediction.ResultsThe mean follow-up was 18.7 ± 2.3 months, and the composite primary outcome occurred in 26 patients. The median LVEF at CMR at baseline was 57.5% (14.6%). LV radial strain (HR = 0.918, 95% CI: 0.858–0.982, p = 0.012), LV circumferential strain (HR = 1.177, 95% CI: 1.046–1.325, p = 0.007) and LV longitudinal strain (HR = 1.173, 95% CI: 1.031–1.334, p = 0.015) were independently associated with clinical event occurrence. The areas under the ROC curve for clinical event prediction were 0.80, 0.79 and 0.80 for LV radial, circumferential, and longitudinal strain, respectively. LV longitudinal strain was independently correlated with prognosis (HR = 1.282, CI 95%: 1.022–1.524, p = 0.007), even when analyzed together with ejection fraction and delayed enhancement. LV and right ventricle (RV) strain were not associated with an increase in LVEF. Finally, when the initial CMR findings were compared with the follow-up CMR findings, improvements in the measures of LV and RV myocardial strain were observed.ConclusionMeasurement of myocardial strain by CMR can provide prognostic information on AMC patients. LV radial, circumferential and longitudinal strain were associated with long-term clinical events in these patients
Multimodality imaging methods and systemic biomarkers in classical low-flow low-gradient aortic stenosis: Key findings for risk stratification
ObjectivesThe aim of the present study is to assess multimodality imaging findings according to systemic biomarkers, high-sensitivity troponin I (hsTnI) and B-type natriuretic peptide (BNP) levels, in low-flow, low-gradient aortic stenosis (LFLG-AS).BackgroundElevated levels of BNP and hsTnI have been related with poor prognosis in patients with LFLG-AS.MethodsProspective study with LFLG-AS patients that underwent hsTnI, BNP, coronary angiography, cardiac magnetic resonance (CMR) with T1 mapping, echocardiogram and dobutamine stress echocardiogram. Patients were divided into 3 groups according to BNP and hsTnI levels: Group 1 (n = 17) when BNP and hsTnI levels were below median [BNP < 1.98 fold upper reference limit (URL) and hsTnI < 1.8 fold URL]; Group 2 (n = 14) when BNP or hsTnI were higher than median; and Group 3 (n = 18) when both hsTnI and BNP were higher than median.Results49 patients included in 3 groups. Clinical characteristics (including risk scores) were similar among groups. Group 3 patients had lower valvuloarterial impedance (P = 0.03) and lower left ventricular ejection fraction (P = 0.02) by echocardiogram. CMR identified a progressive increase of right and left ventricular chamber from Group 1 to Group 3, and worsening of left ventricular ejection fraction (EF) (40 [31–47] vs. 32 [29–41] vs. 26 [19–33]%; p < 0.01) and right ventricular EF (62 [53–69] vs. 51 [35–63] vs. 30 [24–46]%; p < 0.01). Besides, there was a marked increase in myocardial fibrosis assessed by extracellular volume fraction (ECV) (28.4 [24.8–30.7] vs. 28.2 [26.9–34.5] vs. 31.8 [28.9–35.5]%; p = 0.03) and indexed ECV (iECV) (28.7 [21.2–39.1] vs. 28.8 [25.4–39.9] vs. 44.2 [36.4–51.2] ml/m2, respectively; p < 0.01) from Group 1 to Group 3.ConclusionsHigher levels of BNP and hsTnI in LFLG-AS patients are associated with worse multi-modality evidence of cardiac remodeling and fibrosis
Delimiting the Origin of a B Chromosome by FISH Mapping, Chromosome Painting and DNA Sequence Analysis in Astyanax paranae (Teleostei, Characiformes)
Supernumerary (B) chromosomes have been shown to contain a wide variety of repetitive sequences. For this reason, fluorescent in situ hybridisation (FISH) is a useful tool for ascertaining the origin of these genomic elements, especially when combined with painting from microdissected B chromosomes. In order to investigate the origin of B chromosomes in the fish species Astyanax paranae, these two approaches were used along with PCR amplification of specific DNA sequences obtained from the B chromosomes and its comparison with those residing in the A chromosomes. Remarkably, chromosome painting with the one-arm metacentric B chromosome probe showed hybridization signals on entire B chromosome, while FISH mapping revealed the presence of H1 histone and 18S rDNA genes symmetrically placed in both arms of the B chromosome. These results support the hypothesis that the B chromosome of A. paranae is an isochromosome. Additionally, the chromosome pairs Nos. 2 or 23 are considered the possible B chromosome ancestors since both contain syntenic H1 and 18S rRNA sequences. The analysis of DNA sequence fragments of the histone and rRNA genes obtained from the microdissected B chromosomes showed high similarity with those obtained from 0B individuals, which supports the intraspecific origin of B chromosomes in A. paranae. Finally, the population hereby analysed showed a female-biased B chromosome presence suggesting that B chromosomes in this species could influence sex determinism.This research was funded by grants from the State of São Paulo Research Foundation (FAPESP) to DMZAS (2011/16825-3) and CO (2010/17009-2), grants from National Council for Research and Development (CNPq) to FF and by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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