529 research outputs found
Great Books and Missionary Fictions
https://place.asburyseminary.edu/firstfruitspapers/1039/thumbnail.jp
Pressure-induced phase transition in the electronic structure of palladium nitride
We present a combined theoretical and experimental study of the electronic
structure and equation of state (EOS) of crystalline PdN2. The compound forms
above 58 GPa in the pyrite structure and is metastable down to 11 GPa. We show
that the EOS cannot be accurately described within either the local density or
generalized gradient approximations. The Heyd-Scuseria-Ernzerhof
exchange-correlation functional (HSE06), however, provides very good agreement
with experimental data. We explain the strong pressure dependence of the Raman
intensities in terms of a similar dependence of the calculated band gap, which
closes just below 11 GPa. At this pressure, the HSE06 functional predicts a
first-order isostructural transition accompanied by a pronounced elastic
instability of the longitudinal-acoustic branches that provides the mechanism
for the experimentally observed decomposition. Using an extensive Wannier
function analysis, we show that the structural transformation is driven by a
phase transition of the electronic structure, which is manifested by a
discontinuous change in the hybridization between Pd-d and N-p electrons as
well as a conversion from single to triple bonded nitrogen dimers. We argue for
the possible existence of a critical point for the isostructural transition, at
which massive fluctuations in both the electronic as well as the structural
degrees of freedom are expected.Comment: 9 pages, 12 figures. Revised version corrects minor typographical
error
Deviancy and Normative Training Processes in Experimental Groups of Delinquent and Nondelinquent Male Adolescents
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96268/1/ab21456.pd
Maternal mortality due to heart disease
A retrospective study on maternal mortality in pregnant women with cardiac disease over a period of eleven years (January 1979 to December 1989) was undertaken. The objetive was an analysis of the main aspects of this association. Cardiac disease was diagnosed in 694 patients (4.2%) of a total of 16,423 admitted to the Obstetrics Department of the Escola Paulista de Medicina. As for etiology, rheumatic disease (52.3%); Chagas's disease (19.3%) and congenital disease (8.1%) were the most frequent causes. There were 51 maternal deaths, according to FIGO's definition (1967), corresponding to a maternal mortality rate of 428.2/100,000 livebirths during the same period. Twelve of these maternal deaths were due to cardiac disease (maternal mortality rate of 100.8/100,000 livebirths). The statistical analysis identified the following aspects associated with maternal mortality among patients with cardiac disease: primigravida, lack of adequate prenatal care, and cardiac surgery performed previously to and/or during pregnancy. Congestive heart failure with pulmonary edema (41.7%) and thromboembolism (25.0%) were the most frequent causes of maternal death among patients with cardiac disease. The NYHA functional classification was not a good parameter for pregnancy prognosis: eleven patients (91.7%) were considered as belonging to the favorable group before they became pregnant. Most maternal deaths occurred during the first 72 hours after delivery. Therefore, this period was considered most critical for maternal mortality in patients with cardiac disease. No relation-ship was found among the factors: maternal age, race, marital status, delivery and maternal mortality among patients with cardiac disease. The effects of maternal death on the prognosis of the fetus and newborn were severe: 1/3 were undelivered; 1/2 premature liveborn, one fetus died during delivery and an other in the neonatal period. Thus a loss of 50.0% of the conceptuses occurred in this group.Realizou-se estudo retrospectivo da mortalidade materna por cardiopatia, no perÃodo de janeiro de 1979 a dezembro de 1989. Dentre um total de 16.423 internações, houve 694 gestantes com o diagnóstico de cardiopatia (4,2%). No mesmo perÃodo, ocorreram 51 óbitos maternos, correspondendo a um coeficiente de mortalidade materna de 428,2/100.000 nascidos vivos. Houve 12 óbitos maternos por cardiopatia. A análise estatÃstica permitiu a identificação de alguns fatores associados a maior risco de morte nas pacientes cardiopatas: primeira gravidez, primiparidade, ausência de assistência pré-natal, realização de cirurgia cardÃaca anterior à gravidez e/ou na gestação. O maior número de mortes ocorreu no puerpério. A classificação funcional (NYHA) não se constituiu em parâmetro seguro para avaliar o prognóstico materno, pois 91,7% dos casos de óbito foram incluÃdos no grupo considerado favorável (classes I e II) ao iniciar a gestação.Escola Paulista de Medicina Setor de Cardiopatia e Gravidez Departamento de TocoginecologiaUNIFESP, EPM, Setor de Cardiopatia e Gravidez Depto. de TocoginecologiaSciEL
Nonlinear Self-Duality in Even Dimensions
We show that the Born-Infeld theory with n complex abelian gauge fields
written in an auxiliary field formulation has a U(n,n) duality group. We
conjecture the form of the Lagrangian obtained by eliminating the auxiliary
fields and then introduce a new reality structure leading to a Born-Infeld
theory with n real fields and an Sp(2n,R) duality symmetry. The real and
complex constructions are extended to arbitrary even dimensions. The maximal
noncompact duality group is U(n,n) for complex fields. For real fields the
duality group is Sp(2n,R) if half of the dimension of space-time is even and
O(n,n) if it is odd. We also discuss duality under the maximal compact
subgroup, which is the self-duality group of the theory obtained by fixing the
expectation value of a scalar field. Supersymmetric versions of self-dual
theories in four dimensions are also discussed.Comment: LaTeX file, 29 pages, expanded discussion in Section
The Impact Of Cardiac Diseases During Pregnancy On Severe Maternal Morbidity And Mortality In Brazil.
To evaluate maternal heart disease as a cause or complicating factor for severe morbidity in the setting of the Brazilian Network for Surveillance of Severe Maternal Morbidity. Secondary data analysis of this multicenter cross-sectional study was implemented in 27 referral obstetric units in Brazil. From July 2009 to June 2010, a prospective surveillance was conducted among all delivery hospitalizations to identify cases of severe maternal morbidity (SMM), including Potentially Life-Threatening Conditions (PLTC) and Maternal Near Miss (MNM), using the new criteria established by the WHO. The variables studied included: sociodemographic characteristics, clinical and obstetric history of the women; perinatal outcome and the occurrence of maternal outcomes (PLTC, MNM, MD) between groups of cardiac and non-cardiac patients. Only heart conditions with hemodynamic impact characterizing severity of maternal morbidity were considered. 9555 women were included in the Network with severe pregnancy-related complications: 770 maternal near miss cases and 140 maternal death cases. A total of 293 (3.6%) cases were related to heart disease and the condition was known before pregnancy in 82.6% of cases. Maternal near miss occurred in 15% of cardiac disease patients (most due to clinical-surgical causes, p<0.001) and 7.7% of non-cardiac patients (hemorrhagic and hypertensive causes, p<0.001). Maternal death occurred in 4.8% of cardiac patients and in 1.2% of non-cardiac patients, respectively. In this study, heart disease was significantly associated with a higher occurrence of severe maternal outcomes, including maternal death and maternal near miss, among women presenting with any severe maternal morbidity.10e014438
Pregnancy follow-up and outcome in a patient with Takayasu's arteritis
We describe here the pregnancy follow-up and outcome in a patient with Takayasu's arteritis, with a detailed account of the complications during gestation and delivery and the impact of the disease on the newborn's health.No presente relato, que descreve a gestação de paciente portadora de arterite de Takayasu, serão avaliadas a interação dessa afecção com a gravidez e as intercorrências materno-fetais, do parto e do recém-nascido.Universidade Federal de São Paulo (UNIFESP)UNIFESPSciEL
Condensation of Hard Spheres Under Gravity: Exact Results in One Dimension
We present exact results for the density profile of the one dimensional array
of N hard spheres of diameter D and mass m under gravity g. For a strictly one
dimensional system, the liquid-solid transition occurs at zero temperature,
because the close-pakced density, , is one. However, if we relax this
condition slightly such that , we find a series of critical
temperatures T_c^i=mgD(N+1-i)/\mu_o with \mu_o=const, at which the i-th
particle undergoes the liquid-solid transition. The functional form of the
onset temperature, T_c^1=mgDN/\mu_o, is consistent with the previous result
[Physica A 271, 192 (1999)] obtained by the Enskog equation. We also show that
the increase in the center of mass is linear in T before the transition, but it
becomes quadratic in T after the transition because of the formation of solid
near the bottom
Percutaneous balloon mitral valvuloplasty in comparison with open mitral valve commissurotomy for mitral stenosis during pregnancy
OBJECTIVES We sought to compare the maternal and fetal outcomes of patients with severe mitral stenosis submitted to percutaneous balloon dilation Versus open mitral valve commissurotomy (MVC) during pregnancy.BACKGROUND Heart failure in patients with mitral stenosis complicating pregnancy is a common problem in developing countries. Since 1984, percutaneous dilation of the mitral valve using a balloon catheter has become a therapeutic alternative to open heart surgery. Although the efficacy of percutaneous mitral valve balloon dilation is well established, its results have never before been compared viith the results of commissurotomy during pregnancy.METHODS We compared the clinical and obstetric complications in 45 women who were treated with percutaneous mitral valve balloon dilation (group I, n = 21; from 1990 to 1995) or open MVC (group II, n = 24; from 1985 to 1990) for severe heart failure due to mitral stenosis during pregnancy.RESULTS in our study, percutaneous balloon dilation of the mitral. valve had a success rate of 95% (Gorlin formula) and 90.5% (echocardiographic pressure half-time method), as demonstrated by the final mitral valve area achieved. This improvement was followed by a marked decrease in the mitral valve gradient, left atrial pressure and mean pulmonary artery pressure. Patients in both groups had similar improvements in symptoms. Patients who underwent percutaneous balloon dilation had significantly fewer fetal complications, with a reduction in fetal and neonatal mortality (1 death in group I vs. 8 in group II, p = 0.025).CONCLUSIONS Percutaneous balloon mitral valvuloplasty is safe and effective and appears to be preferable for the fetus, compared with open MVC during pregnancy. (J Am Coil Cardiol 2001;37:900-3) (C) 2001 by the American College of Cardiology.Universidade Federal de São Paulo, Dept Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiovasc Surg, São Paulo, BrazilSt Vincents Hosp & Med Ctr, Comprehens Cardiovasc Ctr, New York, NY 10011 USAUniversidade Federal de São Paulo, Dept Cardiol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Cardiovasc Surg, São Paulo, BrazilWeb of Scienc
Arago (1810): the first experimental result against the ether
95 years before Special Relativity was born, Arago attempted to detect the
absolute motion of the Earth by measuring the deflection of starlight passing
through a prism fixed to the Earth. The null result of this experiment gave
rise to the Fresnel's hypothesis of an ether partly dragged by a moving
substance. In the context of Einstein's Relativity, the sole frame which is
privileged in Arago's experiment is the proper frame of the prism, and the null
result only says that Snell's law is valid in that frame. We revisit the
history of this premature first evidence against the ether theory and calculate
the Fresnel's dragging coefficient by applying the Huygens' construction in the
frame of the prism. We expose the dissimilar treatment received by the ray and
the wave front as an unavoidable consequence of the classical notions of space
and time.Comment: 16 pages. To appear in European Journal of Physic
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