1,811 research outputs found

    Impaired placental perfusion and major fetal cardiac defects

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    Objectives: To investigate the relationship between fetal congenital heart defects (CHD) and placental perfusion assessed by uterine artery pulsatility index (UtA-PI) in relation to development of preeclampsia (PE). Methods: This was a prospective screening study in singleton pregnancies at 19-24 weeks’ gestation. Transvaginal ultrasound was used to measure the UtA-PI and the values were converted into multiples of the normal median (MoM). Median MoM values in pregnancies with fetuses with isolated major CHD were compared to those without CHD in relation to development of PE. Results: The 91,407 singleton pregnancies fulfilling the entry criteria included 206 (0.23%) with isolated major fetal CHD and 91,201 without CHD. The prevalence of PE was 4.4% in those with CHD and 2.7% in those without CHD (RR 1.6, 95% CI 0.84-3.04; p=0.150); the respective values for preterm-PE, with delivery at <37 weeks’ gestation, were 2.4% and 0.7%, (RR 3.4, 95% CI 1.42-8.09; p=0.006). In the total population, the median UtA-PI MoM was significantly higher in those that developed PE compared to those without PE (1.22, IQR 0.94-1.57 vs. 1.00, IQR 0.84-1.19; p<0.0001) and in the PE group the median UtA-PI MoM was inversely related to gestational age at delivery (r=-0.458; p<0.0001). The same pattern of inverse relationship between UtA-PI MoM and gestational age at delivery with PE was observed in pregnancies with and without CHD, but in the CHD group, compared to those without CHD, UtA-PI was significantly higher both in pregnancies with and in those without PE. Conclusions: In both pregnancies with and without fetal CHD that develop PE impedance to flow in the uterine arteries is increased and this increase is particularly marked in those with preterm-PE. The prevalence of preterm-PE is more than 3 times higher in pregnancies with than without fetal major CHD and the prevalence of major CHD in pregnancies with preterm-PE is also more than 3 times higher than in those without PE. However, >97% of pregnancies with fetal CHD do not develop preterm-PE and >99% of pregnancies with preterm-PE are not associated with fetal CHD

    Fetal major cardiac defects and placental dysfunction at 11-13 weeks' gestation

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    Objectives: To investigate the relationship between fetal major cardiac defects and markers of placental perfusion and function. Methods: This was a prospective screening study in singleton pregnancies at 11-13 weeks’ gestation. Uterine artery pulsatility index (UTPI), serum pregnancy associated plasma protein-A (PAPP-A) and placental growth factor (PLGF) were measured and the values were converted into multiples of the normal median (MoM). Median MoM values in fetuses with isolated major cardiac defects were compared to those in fetuses without major defects. Results: The 50,094 singleton pregnancies fulfilling the entry criteria included 49,898 pregnancies with a normal cardiac anatomy and 196 (0.39%) with major congenital cardiac defects; 73 (37.2%) with conotruncal defects, 63 (32.1%) with left ventricular outflow tract (LVOT) defects and 60 (30.6%) with valvular defects. In the group of cardiac defects, compared to controls, there was lower median PAPP-A MoM (0.81 vs 1.00, p<0.0001) and PLGF MoM (0.78 vs 1.00, p<0.0001) but no significant difference in UTPI MoM (1.01 vs 1.00, p=0.162). Conclusions: In pregnancies with isolated major cardiac defects there is evidence of placental dysfunction in the absence of impaired placental perfusion

    Laryngeal myxoma: a case report and review of the literature

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    Myxomas are a rare benign neoplasm of uncertain mesenchymal cell origin, typically involving the heart. Laryngeal myxomas are uncommon, and are usually misdiagnosed as laryngeal polyp. To the best of our knowledge, there are only nine reported cases in the English literature. We report a case of a laryngeal myxoma presenting clinically as a left vocal cord polyp in a 77 year old male, and review the literature related to this rare entity

    A family of kojic acid derivatives aimed to remediation of Pb2+ and Cd2+

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    The present work analyzes the complex formation ability towards Pb2+ and Cd2+ of a series of kojic acid derivatives that join the chelating properties of the pyrone molecules and those of polyamines, with the aim of evaluating how the different effects of oxygen and nitrogen coordinating groups act on the stability of metal complexes. Experimental research is carried out using potentiometric and spectrophotometric techniques supported by 1H and 13C NMR spectroscopy and DFT calculations. Actually, a different coordination mechanism toward Pb2+ and Cd2+ was proved: in the case of Pb2+, coordination takes place exclusively via the oxygen atoms, while the contribute of the nitrogen atoms appears relevant in the case of Cd2+. Lead complexes of all the studied ligands are characterized by significantly stronger stability than those of cadmium. Finally, on the basis of the measured complex formation stabilities, some of the proposed molecules seems promising effective ligands for lead and cadmium ion decorporation from polluted soils or waste waters

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

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    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

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    The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

    Combined search for the quarks of a sequential fourth generation

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    Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

    Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

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    A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

    Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

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    A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets
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