Magnetic phases evolution in the LaMn1-xFexO3+y system

We have investigated the crystal structure and magnetic properties for polycrystalline samples of LaMn1-xFexO3+y, in the whole range x=0.0 to x=1.0, prepared by solid state reaction in air. All samples show the ORT-2 orthorhombic structure that suppresses the Jahn-Teller distortion, thus favoring a ferromagnetic (FM) superexchange (SE) interaction between Mn^{3+}-O-Mn^{3+}. For x=0.0 the oxygen excess (y ~ 0.09) produces vacancies in the La and Mn sites and generates a fraction around 18% of Mn^{4+} ions and 82% of the usual Mn^{3+} ions, with possible double exchange interaction between them. The Fe doping in this system is known to produce only stable Fe^{3+} ions. We find an evolution from a fairly strong FM phase with a Curie temperature T_{C} ~ 160 K, for x=0.0, to an antiferromagnetic (AFM) phase with T_{N} = 790 K, for x=1.0, accompanied by clear signatures of a cluster-glass behavior. For intermediate Fe contents a mixed-phase state occurs, with a gradual decrease (increase) of the FM (AFM) phase, accompanied by a systematic transition broadening for 0.2 < x < 0.7. A model based on the expected exchange interaction among the various magnetic-ion types, accounts very well for the saturation-magnetization dependence on Fe doping.Comment: 27 pages, 9 figure

Inflationary Models Driven by Adiabatic Matter Creation

The flat inflationary dust universe with matter creation proposed by Prigogine and coworkers is generalized and its dynamical properties are reexamined. It is shown that the starting point of these models depends critically on a dimensionless parameter $\Sigma$, closely related to the matter creation rate $\psi$. For $\Sigma$ bigger or smaller than unity flat universes can emerge, respectively, either like a Big-Bang FRW singularity or as a Minkowski space-time at $t=-\infty$. The case $\Sigma=1$ corresponds to a de Sitter-type solution, a fixed point in the phase diagram of the system, supported by the matter creation process. The curvature effects have also been investigated. The inflating de Sitter is a universal attractor for all expanding solutions regardless of the initial conditions as well as of the curvature parameter.Comment: 25 pages, 2 figures(available from the authors), uses LATE

Phenolic compounds and organic acids evaluation on red grapes used for winemaking in the Northeast of Brazil.

Monitoring maturation to determine harvest time is very important to determine the enological potential and the quality characteristics and typicality of the wines (Borghezan et al., 2011). Considering that there is no cold weather in the São Francisco Valley, it is possible to scale and production of two harvests per year. This study aimed to determine the chemical composition of the ?Syrah? and ?Tempranillo? grapes, during maturation. Sixty plants were used for each cultivar, divided into three blocks

Coronary artery aneurysm: case report

<p>Abstract</p> <p>Introduction</p> <p>Aneurysms of the left main coronary artery are rare with an incidence of 0.1% in large angiographic series. The majority are atherosclerotic in origin. Other causes include connective tissue disorders, trauma, vasculitis, congenital, mycotic and idiopathic. The primary complication is myocardial ischemia or infarction, with rupture being rare. Treatment options include anticoagulation, custom made covered stents, reconstruction, resection, and exclusion with bypass.</p> <p>Case Presentation</p> <p>A 66 year-old man was referred for evaluation of a 2 × 2 centimeter saccular aneurysm originating from the distal left main coronary artery. There was associated calcification and mild stenosis of the LM. The workup was prompted by a non-ST elevation myocardial infarction suffered following a laparotomy for a ruptured appendix. The past medical history was pertinent for hypertension, hyperlipidemia, and a left carotid endarterectomy.</p> <p>Cardiopulmonary bypass with hyperkalemic cardioplegic arrest was utilized. The aneurysm was exposed in the atrioventricular groove. The aneurysm was resected and oversewn. Calcification precluded patch angioplasty. The patient then underwent coronary bypass grafting with the left internal thoracic artery placed to the left anterior descending artery and a reversed greater saphenous vein graft to an obtuse marginal branch of the circumflex artery. The postoperative course was uneventful and discharge to home occurred on the fourth postoperative day. Surgical pathology confirmed an atheromatous coronary artery aneurysm.</p> <p>Conclusion</p> <p>Left main coronary artery aneurysms in adult patients are predominantly atherosclerotic in origin. The clinical presentation is that of myocardial ischemia, likely from associated embolism. Rupture is rare. Operative treatment is exclusion and revascularization.</p

Short sisal fiber reinforced recycled concrete block for one-way precast concrete slabs

This work is dedicated to the assessment of the structural performance of a new lightweight block for one-way precast concrete slabs made of short sisal fiber reinforced concrete (SSFRC) containing natural and recycled aggregate. The influence of the sisal fibers and recycled aggregate on the physical and mechanical properties was assessed experimentally, with clear benefits of fiber reinforcement on the post-cracking flexural capacity, while the higher water absorption of recycled aggregates had favorable impact on the compressive strength mainly in the FRC. Flexural tests were carried out on SSFRC blocks, as well as on ceramic and expanded polystyrene (EPS) blocks used commercially. The SSFRC blocks presented higher load and deflection capacity with much more ductile behavior, and with a geometry favorable for the passage of infrastructures. Slab panels including SSFRC, ceramic and EPS blocks were tested under four point bending configuration to assess the benefits of the new SSFRC block in quasi-real slab conditions. The results of these tests demonstrated the best structural performance of the SSFRC blocks over the other considered commercial solutions, not only in terms of initial stiffness, but also for the load at serviceability limit deflection conditions (average increase of 23%) and yield initiation (average increase of 38%); The observed continuous crack pattern crossing the SSFRC blocks and the main precast RC beams demonstrated the potentialities of these blocks to contribute for the structural performance of this type of slabs. Material nonlinear finite element simulations were carried out to derive, by inverse analysis, the values of the fracture mode I parameters of SSFRC. This multidirectional smeared crack model was also used to simulate the behavior of the composite materials and the SSFRC blocks, and the obtained level of accuracy has demonstrated the adequacy of the adopted inverse analysis strategy. A Finally, a parametric study was carried out to preview the potentialities of these new SSFRC blocks for this structural application, having been verified that a SSFRC block of 12 mm thickness and 250 mm height, of about 10 kg, is capable of accomplishing the standard recommendations, constituting a competitive and efficient solution for this market segment.The present study is part of the activities carried out by theAuthors within the PVE Program (Project 047/2012) funded bythe Brazilian agency CAPES. The first author acknowledges the sup-port of the CAPES (EST-SENIOR BEX 2579/2015-04), CNPq andFAPESB. The second author acknowledges the supported bySUPERCONCRETE- Marie Sklodowska-Curie Actions, Research andInnovation Staff Exchange (RISE), proposal 645704.info:eu-repo/semantics/publishedVersio

In Vivo Effects of Cagaita (Eugenia dysenterica, DC.) Leaf Extracts on Diarrhea Treatment

Eugenia dysenterica is a plant typically found in the Cerrado biome and commonly used in popular medicine due to its pharmacological properties, which include antidiarrheal, skin healing, and antimicrobial activities. The effects of ethanolic extract, aqueous extract and infusion of E. dysenterica leaves on intestinal motility and antidiarrheal activity were evaluated using ricin oil-induced diarrhea in rats. At doses of 400 and 800 mg·Kg−1, the ethanolic extract decreased intestinal motility while the other extracts showed no significant effects. Moreover, serum levels of chloride, magnesium, and phosphorus were also measured in rats. Histopathologic and enzymatic analyses were also performed to investigate any toxic effect. Animals treated with infusion, ethanolic extract, ricin oil, and loperamide presented morphological alterations in the small intestine, such as mucosa lesion, epithelial layer damage, and partial loss and/or morphological change of villi. Furthermore, the liver showed congestion and hydropic degeneration. Serum levels of alanine aminotransferase increased significantly in all treatments, but none rose above reference values. In summary, our results suggest that compounds present in leaves of E. dysenterica may have therapeutic benefits on recovery from diarrhea despite their toxic effects

Balanço de nutrientes de diferentes espécies arbóreas com potencial para reflorestamento.

0 presente trabalho tem como objetivos determinar a biomassa das espécies Swietenia macrophylla, Carapa guianensis, Cedrela odorata, Dipterix odorata, Hymenea courbaril, Ceiba pentandra, Virola surinamensis e Tabebuia heptaphylla em diferentes sistemas de plantacão (monocultivo, sistema agroflorestal misto e enriquecimento de linhas de capoeira), as respectivas exigencias nutricionais, o acumulo de nutrientes nas diferentes partes da planta, bem como estudar o consumo de água e a dinâmica de crescimento (principalmente a formacão de madeira)