707 research outputs found
Thermal stability and decomposition kinetics of NdNiO3− δ at 1 bar of O2
Despite the interest in rare-earth nickelates for applications, their processing under 1 bar of oxygen pressure is still challenging. In this work, we report the co-precipitation synthesis, thermal stability and thermally driven decomposition of NdNiO3 phase, in order to determine the synthesis parameters towards a pure perovskite phase. We concluded that using a 1% molar excess of Nd during preparation and posterior annealing at around 900 °C at 1 bar of O2 yields an almost pure NdNiO3−δ phase (with a hexagonal Nd2O3 phase below 0.6% molar), with an oxygen deficiency of δ = 0.082 ± 0.001. The decomposition of the NdNiO3−δ phase into Nd4Ni3O10 and NiO was found to start above 900 °C. On further heating, above 1050 °C, the Nd4Ni3O10 decomposes into Nd2NiO4 and NiO phases. Structural parameters and Raman spectra are provided for the NdNiO3, Nd4Ni3O10 and Nd2NiO4 compounds.The authors would like to acknowledge Fundacao para a Ciencia e Tecnologia (FCT) through projects NORTE/01/0145/FEDER/028538, CERN/FIS-PAR/0005/2017, CERN/FIS-TEC/0003/2019, PTDC/FIS-MAC/29454/2017 and when appropriate co-financed by FEDER under PT2020 Partnership Agreement: CQVR: UIDB/QUI/00616/2020; IFIMUP-IN: Norte-070124-FEDER-000070; NECL: NORTE-01-0145-FEDER-022096, UID/NAN/50024/2019. P. Machado and J. Oliveira acknowledge FCT through Ph.D. Grants SFRH/BD/108509/2015 and SFRH/BD/146886/2019 respectively. A special acknowledgment is made to CEMUP for XPS measurements
Depresión posparto y satisfacción con la relación de pareja: impacto longitudinal en una muestra brasileña
O objetivo deste trabalho foi verificar a relação entre a satisfação conjugal e a depressão pós-parto e o impacto destas variáveis nos níveis de satisfação conjugal e depressão futuros, em uma amostra brasileira. Estudos revelam que o conflito conjugal é um antecedente importante no desenvolvimento da depressão e que a depressão pós-parto influencia significativamente a satisfação conjugal. Métodos: Este estudo longitudinal com 99 mulheres brasileiras utilizou análises de regressão múltipla para verificar a associação entre a satisfação conjugal e a depressão. A sintomatologia depressiva foi avaliada pelo instrumento Self-Reporting Questionnaire (SRQ-20). A satisfação conjugal foi verificada a partir de itens sobre a percepção de satisfação conjugal das participantes. Os dados foram coletados 4 meses e 2 anos após o parto. Os dados longitudinais possibilitaram a análise cronológica da interação entre as duas variáveis. Resultados e Conclusões: Os resultados indicam que o modelo teórico que estabelece a relação entre conflito conjugal e depressão é também apropriado para casais brasileiros, sugerindo a utilização potencial da terapia de casal no tratamento da depressão pós-parto no Brasil.This study examined the relationship between marital satisfaction and postpartum depression as well as the impact of postpartum depression and marital satisfaction on later relational characteristics among Brazilian couples. Studies have shown that marital satisfaction is an important antecedent to depression and that postpartum depression has an influence on marital satisfaction. Methods: A longitudinal study using multiple regression to test the association between marital satisfaction and depression was conducted among Brazilian women. Depressive symptomatology was assessed using the Self-Reporting Questionnaire 20 and marital satisfaction using an instrument developed by the researchers to test the individuals’ perception of their marital quality. Data were collected at 4 months and 2 years after childbirth. The longitudinal data allowed researchers to chronologically analyze the interaction of key variables. Results and Conclusions: Results showed that the model established between marital satisfaction and depression is appropriate for Brazilian couples as well as for postpartum women. This study highlights the potential impact of marital treatment on postpartum depression in Brazil.El objetivo de este trabajo fué verificar la relación existente entre la satisfacción con la relación de pareja y la depresión pos-parto y el impacto de esas variables en los niveles de satisfacción con la relación de pareja y depresión futuros, en una muestra brasileña. Estudios revelan que el conflicto de pareja és un antecedente importante en el desarollo de depresión y que la depresión pos-parto provoca influencia significativa en la relación de pareja. Métodos: Este estudio longitudinal con 99 mujeres brasileñas hizo uso de análisis de regresión multiple para estudiar la asociación entre la satisfacción en la relación de pareja y la depresión. Los sintomas depresivos fueron evaluados por el instrumento Self-Reporting Questionnaire (SRQ-20). La satisfacción con la relación de pareja fué verificada utilizando datos sobre la percepción de satisfacción de las participantes. Los datos fueron obtenidos 4 meses y 2 años después del parto. Resultados y Conclusiones: Los resultados indican que el modelo teórico que establece la relación entre conflicto de pareja y depresión és tambien apropriado para parejas brasileña s y sugiere la posibilidad de utilización de la terapia de pareja en el tratamiento de la depresión pos-parto en Brasil
Ehrlich ascites tumor-bearing mice treated with aqueous ethanol plant extract from Euphorbia tirucalli showed signs of systemic toxicity
Purpose: To evaluate the antitumor effect of a latex extract from Euphorbia tirucalli Linn. (Euphorbiaceae) and its toxicity.Methods: Aqueous ethanol and petroleum ether extracts were obtained through maceration. .Maximum tolerated dose was determined in healthy mice. Antitumor activity was measured in Ehrlich ascites tumor-bearing mice treated with the extract through intraperitoneal injection (62.5, 125 or 250 mg/kg) every 48 h (four doses). Efficacy was assessed by weight gain, abdominal circumference, volume of ascitic fluid and packed tumor cells, tumor cell viability and survival. Toxicity indicators were serum glucose, triglycerides, total proteins, activity of alanine and aspartate aminotransferases and mass of heart, spleen, kidney and liver. A hemolysis assay was also performed.Results: Doses of 62.5 and 125 mg/kg caused no antitumor activity, while 250 mg/kg dose reduced weight gain (3-fold), abdominal circumference and volume of ascitic fluid (> 50 %) and packed cells (50 %), but lowered tumor cell viability (40 %). However, mice treated with the extract survived for a shorter time than control mice. Furthermore, the 250 mg/kg dose caused cardiac atrophy, splenomegaly and fasting hyperglycemia. The extract caused hemolysis, and the half-maximal effective concentration (EC50) was 1.6 (0.9 – 2.7) mg/mL.Conclusion: Euphorbia tirucalli extract inhibits Ehrlich ascites tumor in mice, but the therapeutic dose is also harmful to non-tumor tissues.Keywords: Euphorbia tirucalli, Ehrlich ascites tumor-bearing mice, Antitumor, Toxicity, Cardiac atrophy, Splenomegal
Signals: I. Survey description
SIGNALS, the Star formation, Ionized Gas, and Nebular Abundances Legacy Survey, is a large observing programme designed to investigate massive star formation and H II regions in a sample of local extended galaxies. The programme will use the imaging Fourier transform spectrograph SITELLE at the Canada–France–Hawaii Telescope. Over 355 h (54.7 nights) have been allocated beginning in fall 2018 for eight consecutive semesters. Once completed, SIGNALS will provide a statistically reliable laboratory to investigate massive star formation, including over 50 000 resolved H II regions: the largest, most complete, and homogeneous data base of spectroscopically and spatially resolved extragalactic H II regions ever assembled. For each field observed, three datacubes covering the spectral bands of the filters SN1 (363–386 nm), SN2 (482–513 nm), and SN3 (647–685 nm) are gathered. The spectral resolution selected for each spectral band is 1000, 1000, and 5000, respectively. As defined, the project sample will facilitate the study of small-scale nebular physics and many other phenomena linked to star formation at a mean spatial resolution of ∼20 pc. This survey also has considerable legacy value for additional topics, including planetary nebulae, diffuse ionized gas, and supernova remnants. The purpose of this paper is to present a general outlook of the survey, notably the observing strategy, galaxy sample, and science requirements
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at , 2.76 and 7 TeV
Measurements of the sphericity of primary charged particles in minimum bias
proton--proton collisions at , 2.76 and 7 TeV with the ALICE
detector at the LHC are presented. The observable is linearized to be collinear
safe and is measured in the plane perpendicular to the beam direction using
primary charged tracks with GeV/c in . The
mean sphericity as a function of the charged particle multiplicity at
mid-rapidity () is reported for events with different
scales ("soft" and "hard") defined by the transverse momentum of the leading
particle. In addition, the mean charged particle transverse momentum versus
multiplicity is presented for the different event classes, and the sphericity
distributions in bins of multiplicity are presented. The data are compared with
calculations of standard Monte Carlo event generators. The transverse
sphericity is found to grow with multiplicity at all collision energies, with a
steeper rise at low , whereas the event generators show the
opposite tendency. The combined study of the sphericity and the mean with multiplicity indicates that most of the tested event generators
produce events with higher multiplicity by generating more back-to-back jets
resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with
tune PERUGIA-2011 exhibits a noticeable improvement in describing the data,
compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16,
published version, figures from
http://aliceinfo.cern.ch/ArtSubmission/node/308
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