731 research outputs found
Multiple gestation epidemiology--15 years survey
Between January of 1987 and December of 2001 were born 1243 twins related to 609 multiple pregnancies, in Maternidade Bissaya-Barreto. Data were grouped in periods of three years and several parameters were studied. The rate of multiple gestation has increased probably due to the contribution of the assisted conception techniques, and to the increase of the number of multiple fetal pregnancies (two or more) and to the increase of the mother age. These more frequent obstetric problems were preterm birth, gestational hypertension and abnormal sonographic data of fetal growth. The average age of delivery was 34 weeks and the birth weight has decreased. The most important factors for neonatal morbidity were hyaline membranous disease, intraventricular haemorrhage and the twin-twin transfusion syndrome. The neonatal mortality decreased in the last studied period
Hypercalcemic crisis associated with primary hyperparathyroidism during pregnancy
Primary hyperparathyroidism is a rare occurrence in pregnancy with significant risks to the mother and the foetus, witch is related to the level of serum calcium. A 41-year-old women, gravida 2, para 1, presented at 22 weeks gestation with nausea, vomiting and mild cognitive dysfunction associated with hypercalcemic crisis. The hypercalcemia was observed to be related to parathyroid hyperplasia that was surgically removed. Complete resolution of her symptomatology and hypercalcemia occurred postoperatively. The pregnancy was complicated with transient hypertension. A small for gestational age healthy male infant was delivered at term with no neonatal complications related with this pathology
Anoxia- and hypoxia-induced expression of LDH-A* in the Amazon Oscar, Astronotus crassipinis
Adaptation or acclimation to hypoxia occurs via the modulation of physiologically relevant genes, such as erythropoietin, transferrin, vascular endothelial growth factor, phosphofructokinase and lactate dehydrogenase A. In the present study, we have cloned, sequenced and examined the modulation of the LDH-A gene after an Amazonian fish species, Astronotus crassipinis (the Oscar), was exposed to hypoxia and anoxia. In earlier studies, we have discovered that adults of this species are extremely tolerant to hypoxia and anoxia, while the juveniles are less tolerant. Exposure of juveniles to acute hypoxia and anoxia resulted in increased LDH-A gene expression in skeletal and cardiac muscles. When exposed to graded hypoxia juveniles show decreased LDH-A expression. In adults, the levels of LDH-A mRNA did not increase in hypoxic or anoxic conditions. Our results demonstrate that, when given time for acclimation, fish at different life-stages are able to respond differently to survive hypoxic episodes
RG-improved single-particle inclusive cross sections and forward-backward asymmetry in production at hadron colliders
We use techniques from soft-collinear effective theory (SCET) to derive
renormalization-group improved predictions for single-particle inclusive (1PI)
observables in top-quark pair production at hadron colliders. In particular, we
study the top-quark transverse-momentum and rapidity distributions, the
forward-backward asymmetry at the Tevatron, and the total cross section at
NLO+NNLL order in resummed perturbation theory and at approximate NNLO in fixed
order. We also perform a detailed analysis of power corrections to the leading
terms in the threshold expansion of the partonic hard-scattering kernels. We
conclude that, although the threshold expansion in 1PI kinematics is
susceptible to numerically significant power corrections, its predictions for
the total cross section are in good agreement with those obtained by
integrating the top-pair invariant-mass distribution in pair invariant-mass
kinematics, as long as a certain set of subleading terms appearing naturally
within the SCET formalism is included.Comment: 55 pages, 14 figures, 6 table
AIDS in adults 50 years of age and over: characteristics, trends and spatial distribution of the risk
Heavy colored resonances in top-antitop + jet at the LHC
The LHC is the perfect environment for the study of new physics in the top
quark sector. We study the possibility of detecting signals of heavy
color-octet vector resonances, through the charge asymmetry, in top-antitop+jet
events. Besides contributions with the top-antitop pair in a color-singlet
state, the asymmetry gets also contributions which are proportional to the
color factor f_{abc}^2. This process is particularly interesting for
extra-dimensional models, where the inclusive charge asymmetry generated by
Kaluza-Klein excitations of the gluon vanishes at the tree level. We find that
the statistical significance for the measurement of such an asymmetry is
sizable for different values of the coupling constants and already at low
energies
Esquistossomose hepatoesplênica cirúrgica: histopatologia hepatica e endoscopia digestiva alta em crianças comparadas a adultos
Irradiation-Induced Deinococcus radiodurans Genome Fragmentation Triggers Transposition of a Single Resident Insertion Sequence
Stress-induced transposition is an attractive notion since it is potentially important in creating diversity to facilitate adaptation of the host to severe environmental conditions. One common major stress is radiation-induced DNA damage. Deinococcus radiodurans has an exceptional ability to withstand the lethal effects of DNA–damaging agents (ionizing radiation, UV light, and desiccation). High radiation levels result in genome fragmentation and reassembly in a process which generates significant amounts of single-stranded DNA. This capacity of D. radiodurans to withstand irradiation raises important questions concerning its response to radiation-induced mutagenic lesions. A recent study analyzed the mutational profile in the thyA gene following irradiation. The majority of thyA mutants resulted from transposition of one particular Insertion Sequence (IS), ISDra2, of the many different ISs in the D. radiodurans genome. ISDra2 is a member of a newly recognised class of ISs, the IS200/IS605 family of insertion sequences
Cytogenetic divergence between two sympatric species of Characidium (Teleostei, Characiformes, Crenuchidae) from the Machado River, Minas Gerais, Brazil
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