Intense photoluminescence emission at room temperature in calcium copper titanate powders

A study was undertaken about the structural and photoluminescent properties at room temperature of CaCu3Ti4O12 (CCTO) powders synthesized by a soft chemical method and heat treated between 300 and 800 °C. The decomposition of precursor powder was followed by thermogravimetric analysis (TG-DTA), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Fourier transform Raman (FT-Raman) and photoluminescence (PL) measurements. XRD analyses revealed that the powders annealed at 800 °C are becoming ordered and crystallize in the cubic structure. The most intense PL emission was obtained for the sample calcined at 700 °C, which is not highly disordered (300-500 °C) and neither completely ordered (800 °C). From the spectrum it is clearly visible that the lowest wavelength peak is placed around 480 nm and the highest wavelength peak at about 590 nm. The UV/vis absorption spectroscopy measurements showed the presence of intermediate energy levels in the band gap of structurally disordered powders. © 2012 Elsevier Ltd and Techna Group S.r.l.

Geografias do drama humano: leituras do espaço em São Bernardo, de Graciliano Ramos e Pedro Páramo, de Juan Rulfo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Conservação de sementes de taperebá (Spondias mombin L., Anacardiaceae)

Pós-graduação em Agronomia (Agricultura) - FCA

Geografias do drama humano: leituras do espaço em São Bernardo, de Graciliano Ramos, e Pedro Páramo, de Juan Rulfo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Application of continuous positive airway pressure in the delivery room: a multicenter randomized clinical trial

This study evaluated whether the use of continuous positive airway pressure (CPAP) in the delivery room alters the need for mechanical ventilation and surfactant during the first 5 days of life and modifies the incidence of respiratory morbidity and mortality during the hospital stay. The study was a multicenter randomized clinical trial conducted in five public university hospitals in Brazil, from June 2008 to December 2009. Participants were 197 infants with birth weight of 1000-1500 g and without major birth defects. They were treated according to the guidelines of the American Academy of Pediatrics (APP). Infants not intubated or extubated less than 15 min after birth were randomized for two treatments, routine or CPAP, and were followed until hospital discharge. The routine (n=99) and CPAP (n=98) infants studied presented no statistically significant differences regarding birth characteristics, complications during the prenatal period, the need for mechanical ventilation during the first 5 days of life (19.2 vs 23.4%, P=0.50), use of surfactant (18.2 vs 17.3% P=0.92), or respiratory morbidity and mortality until discharge. The CPAP group required a greater number of doses of surfactant (1.5 vs 1.0, P=0.02). When CPAP was applied to the routine group, it was installed within a median time of 30 min. We found that CPAP applied less than 15 min after birth was not able to reduce the need for ventilator support and was associated with a higher number of doses of surfactant when compared to CPAP applied as clinically indicated within a median time of 30 min.

Photoluminescence emission at room temperature in zinc oxide nano-columns

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Quando gestos não políticos são políticos: a tradução brasileira de Giovanni's Room, de James Baldwin, e a questão da homossexualidade

This work is part of a research project on the role of translations of African-American literature in Brazil and their relation to issues of identity, discourse and aesthetics. It analyzes the translation, by Affonso Blacheyre, of Giovanni's room (1956), by James Baldwin, which was published in 1967 in Brazil. Baldwin is revered for his role in the Civil Rights Movement, having produced works that portray the contradictions of a democratic, but, at the same time, racist society. Giovanni's room was first rejected by his publisher for addressing homosexuality. The text displayed on the book flaps of the translation praises Baldwin's "work with language", in contrast to his anti-racism in other works. The praise of aesthetics of Giovanni's room is noteworthy, in contrast with the absence of any remarks on its critique of the marginalization of homosexuality. The focus on the aesthetics of the work corresponded to characters speaking a more formal register in the translation. Discourses on identity strengthening were less apparent in the 60s in Brazil in comparison to nowadays. The emphasis on aesthetics represented a seemingly "non-political" gesture that made it less shocking in the context of military dictatorship prevalent in the country at the time.

Acute kidney injury in septic patients admitted to emergency clinical room: risk factors and outcome

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sepsis and AKI in clinical emergency room patients: the role of urinary NGAL

Few studies have investigated the predictive properties of urinary (u) NGAL as an AKI marker in septic population. This study evaluated the efficacy of uNGAL as predictor of AKI and death in septic patients admitted to the clinical emergency room (ER). We prospectively studied patients with sepsis admitted to the ER. Urine was analyzed for NGAL within the first 24 hours after admission (classified as NGAL1), between 24 and 48 h (NGAL2), and at moment of AKI diagnosis (NGAL3). Among 168 septic patients admitted to ER, 72% developed AKI. The uNGAL and its relationship with creatinine (Cr) were high in septic patients but statistically higher in those with sepsis and AKI. The uNGAL1 and uNGAL2, as well as uNGAL1/uCr1 and uNGAL2/uCr2, were good predictors for AKI (AUC-ROC 0.73, 0.70, 0.77, and 0.84, resp.). The uNGAL1 and uNGAL1/uCr1 were poor predictors for death (AUC-ROC 0.66 and 0.68, resp.), whereas uNGAL2 and uNGAL2/uCr2 were better predictors (AUC-ROC 0.70 and 0.81, resp.). The uNGAL is highly sensitive but nonspecific predictor of AKI and death in septic patients admitted into ER.

Pólis vs. Oikos: a investigação do papel feminino no drama grego

This work analyzes the consequences of the intersection between the two spheres polis and oikos. It does so by examining themes present in three plays: Medea, Agamemnon and Lysistrata. The focus of the analysis is the way in which the feminine characters react to conflicts of interests in their respective situations. To fully comprehend which values correspond to which mentioned institution, the work also necessarily investigates the socialization and functions of both genders in fifth-century Athenian society. The analysis of the feminine condition in the creation myth implies the importance of the misogynistic sense of that time, which culminated in the silencing, discrediting, and systemic repression of females. The role of women in society, instilled in all girls starting in early childhood, is to succeed in marriage and domestic permanence. This lies opposite the masculine role, which was focused outside of the family center and to environments relating to war and public life. Matrimony and family, traditional female values, were threatened when overlapping with male interests, such as unavoidable war or social ascension through a different matrimonial bond. Therefore, it is possible to affirm that the opposition evident in the definitions male vs. female indicates that, in certain contexts, the interests of each element cause the conflicts present in the chosen plays

Robust isothermal electric control of exchange bias at room temperature

Voltage-controlled spin electronics is crucial for continued progress in information technology. It aims at reduced power consumption, increased integration density and enhanced functionality where non-volatile memory is combined with highspeed logical processing. Promising spintronic device concepts use the electric control of interface and surface magnetization. From the combination of magnetometry, spin-polarized photoemission spectroscopy, symmetry arguments and first-principles calculations, we show that the (0001) surface of magnetoelectric Cr2O3 has a roughness-insensitive, electrically switchable magnetization. Using a ferromagnetic Pd/Co multilayer deposited on the (0001) surface of a Cr2O3 single crystal, we achieve reversible, room-temperature isothermal switching of the exchange-bias field between positive and negative values by reversing the electric field while maintaining a permanent magnetic field. This effect reflects the switching of the bulk antiferromagnetic domain state and the interface magnetization coupled to it. The switchable exchange bias sets in exactly at the bulk Néel temperature.