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This study presented the influence of two types of clay: kaolin (Kao) and red clay (RC) on the chemical and physical properties of ceramic specimens when galvanic sludge (GS) is incorporated to encapsulate heavy metals. Samples were obtained of GS from the industrial district of Manaus - Amazonas State, Brazil, and kaolin (Kao), and red clay (RC) from the Central Amazon. A fourth sample was prepared by mixing GS, Kao, and RC in the ratio 1:1:8 (GS + Kao + RC). This mixture was ground, and ceramic specimens were prepared, and heat treated at 950 °C and 1200 °C for three hours for phase detection, compressive strength, leaching of Fe, Ni and Cr metals and life cycle assessment. Galvanic sludge, Kao, and RC were also, and heat treated to at 950 °C and 1200 °C for three hours, obtaining GS950, GS1200, Kao950, Kao1200, RC950, and RC1200. The samples were submitted to XRF, XRD, Rietveld refinement, Mössbauer spectroscopy, TG/DTG/DSC, and SEM. The results show that the formation of nickel oxide and a spinel solid solution of the type Fe 3+ {Fe 1-y 3+ ,Fe 1-x 2+ ,Ni x 2+ ,Cr y 3+ }O 4 (in which [] = tetrahedral site, {} octahedral site) occurs in GS1200, which is caused by sulfate decomposition to SO 2 . At 1200 °C, heavy metals are encapsulated, forming other phases such as nickel silicate and hematite. Life cycle assessment was used to verify the sustainability and value of GS in clay for making bricks, and it indicated that the production of ceramics is feasible, reduces the use of clays, and is sustainable., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Tricuspid valve repair during mitral valve replacement surgery remains a controversial topic. The risk-benefit ratio in some populations remains uncertain, especially in rheumatic heart disease patients. Therefore, we aimed to evaluate the impact of concomitant tricuspid repair on surgical mortality in patients undergoing cardiac surgery due to rheumatic mitral valve disease who have moderate to severe functional tricuspid regurgitation., Methods: This is a prospective cohort study from January 1, 2017, to December 30, 2022. All patients over 18 years of age who underwent cardiac surgery to correct rheumatic mitral valve disease with concomitant moderate to severe tricuspid regurgitation were included. The primary outcome was a surgical death. In an exploratory analysis, clinical and echocardiographic data were obtained 2 years after the procedure., Results: Of the 144 patients included, 83 (57.6%) underwent tricuspid valve repair. The mean age was 46.2 (±12.3) years with 107 (74.3%) female individuals, the median left ventricular ejection fraction was 61.0% (55-67), and systolic pulmonary artery pressure (sPAP) was 55.0 mmHg (46-74), with 45 (31.3%) individuals with right ventricular dysfunction. The total in-hospital mortality was 15 (10.4%) individuals, and there was no difference between the groups submitted or not to tricuspid repair: 10 (12.0%) vs. 5 (7.5%); p = 0.46, respectively. There was an association with one variable independently: the sPAP value, relative risk 1.04 (1.01-1.07), p = 0.01. The estimated cut-off value of sPAP that indicates higher early mortality through the receiver operating characteristic curve (area 0.70, p = 0.012) was 73.5 mmHg., Conclusions: Performing tricuspid repair in individuals who were undergoing cardiac surgery to correct rheumatic mitral valve disease was not associated with increased surgical mortality. Our results suggest the safety of tricuspid repair even in this high-risk population, reinforcing the recommendations in current guidelines., Competing Interests: The authors report no conflict of interest., (© 2024 The Author(s).)

Background: Left atrial (LA) volume indexing for body surface area (BSA) may underestimate LA size in obese and overweight people. Since LA volume is a risk marker for some cardiovascular events, it is suggested that indexing for height would be an alternative more appropriate method. The aims of this study were to find normal and the best cutoff values for LA volume indexed for height in our population., Methods: Echocardiograms from 2018 to 2021 were reviewed and patients without known cardiac disease and completely normal echocardiograms that had the left atrial volume (LAvol) measured by biplane Simpson's method were included. LAvol was indexed by BSA (ml/m 2 ), by height (LAvol/m), by height raised to exponent 2.7 (ml/ m 2.7 ) and by height squared (ml/h 2 )., Results: A total of 545 patients, 50.5 ± 13.4 y., 335 females (61,5%) were analyzed. There were 145 normal weight (26.6%), 215 overweight (39.4%), 154 obese (28.3%) and 31 low weight (5.7%) patients. To establish normal values we included only the normal weight group and considered normal values from 2SD below to 2SD above the mean. Mean and normal values were: LAvol/h 26.0 ±4.5, 17 - 35 ml/m, LAvol/ht 2 16 ± 2.8, 10.4 - 21.6 ml/ ht 2 and LAvol/ht 2.7 11.4 ± 2.2, 7.0 - 15.8 ml/m 2.7 . The normal LAvol/ht 2.7 differed between male and female (11.4 ± 2.4 and 12.8 ± 2.6, p < 0.001). LA diameter, LAvol, LAvol/h, LAvol/h 2 and LAvol/ht 2.7 increased progressively from low-weight, normal weight, overweight and obese patients (p< 0.0001), but not LAvol/BSA. When indexing LAvol for height, for height 2 and for height 2.7 20.8%, 22.7% and 21.4% of the obese patients, respectively, were reclassified as enlarged LA, and 7.4%, 8.8% and 8.4% of the overweight patients as well. Using ROC curve analysis, LAvol/h 2 had the highest AUC ant the best predictive value to identify LA enlargement and LAvol/BSA the worst one., Conclusions: Normal values for LAvol indexed for height by three different methods are described in normal individuals. We reinforce that LAvol indexation for BSA underestimates LA size in obese and overweight patients and in these groups, specially, indexing for height 2 is probably the best method to evaluate LAvol.

The objective of this study was to establish the best parameters to correct for matrix effects in the chemical analysis of a siliceous geologic material rich in metallic elements of high economic value, such as La, Ce, Nd, Sm, and Gd (rare earth elements), using empirical influence coefficients applied to wavelength dispersive X-ray fluorescence (WDXRF). At present, this material is considered waste derived from the extraction of tin from cassiterite, a special ore from which niobium and tantalum are also processed. In this study, a reliable methodology for the analysis of rare earth elements in a siliceous matrix using the WDXRF technique was developed. This procedure may be useful in promoting industrial processes for chemical control in solid matrices, as the usual techniques are only possible in liquid media and require acid dissolution., (Copyright © 2019 Elsevier B.V. All rights reserved.)

This study covers the evaluation of the structure and the capacity in adsorbing orthophosphate ions of kaolinites collected from sampling sites in Manaus (Brazil). The kaolinites were obtained using physical fractioning (sieving/siphoning) techniques and chemical treatment with HCl, H2SO4, H2O2 and KCl. The investigation of the kaolinite lattices involved the Hinckley and Plançon indexes determined from X-ray diffraction data, Fourier transformed infrared spectroscopy, scanning electron microscopy and Mössbauer spectroscopy. The absorption capacity of orthophosphate ions was calculated by Freundlich and Langergren isotherms. A transitional state was observed in the crystallographic structure from kaolinites because of the isomorphic substitution of Al3+ by Fe3+. This isomorphic substitution occurs accompanied by the optical pleochroism behavior, but it also reduces the mean particle sizes and increases the number of structural defects and magnetic properties of these kaolinites. Mössbauer spectroscopy showed that the substituting Fe3+ preferentially occupies octahedral sites. In the kaolinite lattices there are different octahedral sites of Al bounded by cis-OH-Fe3+ and trans-OH-Fe3+ octahedral sites. The kaolinite from the Kao1 sample has a higher number of cis-OH-Fe3+ from octahedral sites and is able to adsorb higher contents of orthophosphate ions than those from samples Kao2 and Kao3.

Objective: Near-death experiences have been defined as profound psychological events that may occur to a person while close to death or in a situation of extreme physical or emotional distress. These experiences seem to have an important effect on the patients' mental health and may occur in several situations despite their cultural and religious beliefs., Case Description: The present case report describes the positive impact of a near-death experience (Greyson scale > 7) followed by religious conversion on the mental health of a former prisoner., Comments: Investigation of the role of near-death experiences by the scientific community could shed light on the coping mechanisms and moral/ethical transformations that take place in these individuals.

This paper reports on the speciation study and the Hg redox behavior in Amazon soils not influenced by gold mining and collected near Manaus, AM, Brazil. The samples were incubated by adding Hg(0) and HgCl(2) to dry soil. Solid phase Hg speciation analysis was carried out using a Hg thermodesorption technique with the aim of distinguishing elemental Hg(0) from Hg(II) binding forms. In the first case, we observed the conversion of Hg(0) to Hg(II) binding forms in the range of 28-68% and a correlation between the percent of oxidation and OM content. Samples incubated with Hg(II) showed the formation of Hg(I) and/or Hg(0) in the range of 19-69%. The lowest values corresponded to the samples with the lowest clay contents. The kinetics of conversion of Hg(0) as well as HgCl(2) were roughly fitted to the two first order reactions, a fast one and a slow one. It was not possible to evaluate differences between sampling sites and types of soils, but the mean half-life of the first order reaction obtained by the addition of Hg(II) was slower (t(1/2)=365d) than the one obtained by the addition of Hg(0) (t(1/2)=148d). Previous studies have shown the predominance of organically bound Hg in these samples. Thus, the kinetic difference between Hg oxidation and reduction in combination with the efficient retention processes by OM may explain the high background values found in Amazon soils.

In order to investigate the content and distribution of Hg in soils from Amazon areas not impacted by gold mining activities, the concentration and granulometric distribution of Hg were determined in three different types of soils. Hg speciation data were obtained by a thermodesorption atomic spectrometry system and the role of physico-chemical and mineralogical characteristics on Hg content were also studied. Hg concentrations found in the soil fraction <2000 microm were similar to values found in other Amazon areas without anthropogenic sources. The fine fraction (<53 microm) of podzolized soils had a higher Hg content than clayey soils. Multivariate analysis shows that there are marking differences between Spodosols of two distinct areas (fine fraction Hg contents up to 10-fold as high) indicating the importance of pedogenic processes. All statistical data analysis indicated that organic matter plays an important role in Hg accumulation in the types of soils studied. Thermodesorption analysis revealed the presence of only Hg2+, and the predominance of organically bound Hg in the majority of the studied samples.

Objective: To evaluate the immediate results of percutaneous mechanical mitral commissurotomy., Methods: Thirty patients underwent percutaneous mechanical mitral commissurotomy performed with a Cribier's metallic valvulotome from 8/11/99 to 2/4/00. Mean age was 30.7 years, and 73.3% were women. With regards to functional class, 63.3% were class III, and 36.7% were class IV. The echocardiographic score had a mean value of 7.5+/- 1.8., Results: The mitral valve area increased from 0.97+/-0.15cm2 to 2.16+/-0.50cm2 (p>0.0001). The mean diastolic gradient decreased from 17.9+/-5.0mmHg to 3.2+/-1.4mmHg. The mean left atrial pressure decreased from 23.6+/-5.4mmHg to 8.6+/-3.1mmHg, (p>0.0001). Systolic pressure in the pulmonary artery decreased from 52.7+/-18.3mmHg to 32.2+/-7.4mmHg. Twenty-nine cases were successful. One patient developed severe mitral regurgitation. Interatrial septal defect was observed and one patient. One patient had cardiac tamponade due to left ventricular perforation. No deaths occurred., Conclusion: This method has proven to be safe and efficient in the treatment of rheumatic mitral stenosis. The potential advantage is that it can be used multiple times after sterilization, which decreases procedural costs significantly.

The authors studied a series of 100 patients submitted to direct myocardial revascularization before 40 years of age. One hundred and seventy-three saphenous vein by-passes and 4 mammary artery left descending coronary artery anastomoses were performed. There was no operative mortality and the late mortality was 2%. The period of postoperative clinical evaluation of the patients varied from 12 to 60 months (mean 32.0 months).

Six cases of coronary artery fistulae surgically treated are presented. All patient but one was male; the ages varied from 4 to 44 years. The fistulae originated from the left coronary artery in three cases from the right in two cases and from both arteries in one case. The draining heart chambers were the right atrium in three, the right ventricle in two and the pulmonary artery in one case. Associated lesions were present in three cases. One patient died on the early postoperative period and the evolution was satisfactory in five cases.