218 research outputs found

    Long-term surveillance of SUDEP in drug-resistant epilepsy patients treated with VNS therapy.

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    Limited data are available regarding the evolution over time of the rate of sudden unexpected death in epilepsy patients (SUDEP) in drug-resistant epilepsy. The objective is to analyze a database of 40 443 patients with epilepsy implanted with vagus nerve stimulation (VNS) therapy in the United States (from 1988 to 2012) and assess whether SUDEP rates decrease during the postimplantation follow-up period. Patient vital status was ascertained using the Centers for Disease Control and Prevention's National Death Index (NDI). An expert panel adjudicated classification of cause of deaths as SUDEP based on NDI data and available narrative descriptions of deaths. We tested the hypothesis that SUDEP rates decrease with time using the Mann-Kendall nonparametric trend test and by comparing SUDEP rates of the first 2 years of follow-up (years 1-2) to longer follow-up (years 3-10). Our cohort included 277 661 person-years of follow-up and 3689 deaths, including 632 SUDEP. Primary analysis demonstrated a significant decrease in age-adjusted SUDEP rate during follow-up (S = -27 P = .008), with rates of 2.47/1000 for years 1-2 and 1.68/1000 for years 3-10 (rate ratio 0.68; 95% confidence interval [CI] 0.53-0.87; P = .002). Sensitivity analyses confirm these findings. Our data suggest that SUDEP risk significantly decreases during long-term follow-up of patients with refractory epilepsy receiving VNS Therapy. This finding might reflect several factors, including the natural long-term dynamic of SUDEP rate, attrition, and the impact of VNS Therapy. The role of each of these factors cannot be confirmed due to the limitations of the study

    Evolution of density perturbations in a realistic universe

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    Prompted by the recent more precise determination of the basic cosmological parameters and growing evidence that the matter-energy content of the universe is now dominated by dark energy and dark matter we present the general solution of the equation that describes the evolution of density perturbations in the linear approximation. It turns out that as in the standard CDM model the density perturbations grow very slowly during the radiation dominated epoch and their amplitude increases by a factor of about 4000 in the matter and later dark energy dominated epoch of expansion of the universe.Comment: 19 pages, 4 figure

    Evaluation of a Web-Based Training in Smoking Cessation Counseling Targeting U.S. Eye-Care Professionals

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    Background. Smoking causes blindness-related diseases. Eye-care providers are uniquely positioned to help their patients quit smoking. Aims. Using a pre-/postevaluation design, this study evaluated a web-based training in smoking cessation counseling targeting eye-care providers. Method. The training was developed based on the 3A1R protocol: “Ask about smoking, Advise to quit, Assess willingness to quit, and Refer to tobacco quitlines,” and made available in the form of a web-based video presentation. Providers (n = 654) at four academic centers were invited to participate. Participants completed pretraining, posttraining, and 3-month follow-up surveys. Main outcomes were self-reported improvement in their motivation, confidence, and counseling practices at 3-month follow-up. Generalized linear mixed models for two time-points (pretraining and 3-month) were conducted for these outcomes. Results. A total of 113 providers (54.0% males) participated in the study (17.7% response rate). At the 3-month evaluation, 9.8% of participants reported improvement in their motivation. With respect to the 3A1R, 8% reported improvement in their confidence for Ask, 15.5% for Advise, 28.6% for Assess, and 37.8% for Refer. Similarly, 25.5% reported improvement in their practices for Ask, 25.5% for Advise, 37.2% for Assess, and 39.4% for Refer to tobacco quitlines (p <.001 for all except for Refer confidence p =.05). Discussion. Although participation rate was low, the program effectively improved providers’ smoking cessation counseling practices. Conclusions. Including training in smoking cessation counseling in ophthalmology curriculums, and integrating the 3A1R protocol into the electronic medical records systems in eye-care settings, might promote smoking cessation practices in these settings

    Antikaon production in A+A collisions at SIS energies within an off-shell G-matrix approach

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    The production and propagation of antikaons -- described by dynamical spectral functions Ah(X,P,M2)A_h(X,\vec{P},M^2) as evaluated from a coupled channel GG-matrix approach -- is studied for nucleus-nucleus collisions at SIS energies in comparison to the conventional quasi-particle limit and the available experimental data using off-shell transport theory. We find that the KK^- spectra for 12C+12C^{12}C + ^{12}C and 58Ni+58Ni^{58}Ni + ^{58}Ni at 1.8 A\cdotGeV remain underestimated in the GG-matrix approach as in the on-shell quasi-particle approximation whereas the preliminary spectra for Au+AuAu + Au at 1.5 A\cdotGeV are well described in both limits. This also holds approximately for the KK^- rapidity distributions in semi-central collisions of Ni+NiNi+Ni at 1.93 A\cdotGeV. However, in all limits considered there is no convincing description of all spectra simultaneously. Our off-shell transport calculations, furthermore, demonstrate that the strongest in-medium effects should be found for low antikaon momenta in the center-of-mass frame, since the deceleration of the antikaons in the attractive Coulomb and nuclear potentials and the propagation to the on-shell mass induces a net shift and squeezing of the KK^- spectra to the low momentum regime.Comment: 44 pages, including 18 eps figures, to be published in Nucl. Phys.

    Antiflow of kaons in relativistic heavy ion collisions

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    We compare relativistic transport model calculations to recent data on the sideward flow of neutral strange K^0_s mesons for Au+Au collisions at 6 AGeV. A soft nuclear equation of state is found to describe very well the positive proton flow data measured in the same experiment. In the absence of kaon potential, the K^0 flow pattern is similar to that of protons. The kaon flow becomes negative if a repulsive kaon potential determined from the impulse approximation is introduced. However, this potential underestimates the data which exhibits larger antiflow. An excellent agreement with the data is obtained when a relativistic scalar-vector kaon potential, that has stronger density dependence, is used. We further find that the transverse momentum dependence of directed and elliptic flow is quite sensitive to the kaon potential in dense matter.Comment: 5 pages, Revtex, 4 figure

    Kaon properties in (proto)neutron stars

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    The modification on kaon and antikaon properties of in the interior of (proto-)neutron stars is investigated using a chiral SU(3) model. The parameters of the model are fitted to nuclear matter saturation properties, baryon octet vacuum masses, hyperon optical potentials and low energy a kaon-nucleon scattering lengths. We study the kaon/antikaon medium modification and explore the possibility of antikaon condensation in (proto-)neutron star matter at zero as well as finite temperature/entropy and neutrino content. The effect of hyperons on kaon and antikaon optical potentials is also investigated at different stages of the neutron star evolution.Comment: 17 pages including 4 figure

    Heavy flavor properties of jets produced in ppˉp\bar{p} interactions at sqrts=sqrt{s}= 1.8 TeV

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    We present a detailed examination of the heavy flavor properties of jets produced at the Fermilab Tevatron collider. The data set, collected with the Collider Detector at Fermilab, consists of events with two or more jets with transverse energy ET15E_T \geq 15 GeV and pseudo-rapidity η1.5|\eta| \leq 1.5. The heavy flavor content of the data set is enriched by requiring that at least one of the jets (lepton-jet) contains a lepton with transverse momentum larger than 8 GeV/c. Jets containing hadrons with heavy flavor are selected via the identification of secondary vertices. The parton-level cross sections predicted by the {\sc herwig} Monte Carlo generator program are tuned within theoretical and experimental uncertainties to reproduce the secondary-vertex rates in the data. The tuned simulation provides new information on the origin of the discrepancy between the bbˉb\bar{b} cross section measurements at the Tevatron and the next-to-leading order QCD prediction. We also compare the rate of away-jets (jets recoiling against the lepton-jet) containing a soft lepton (pT2p_T \geq 2 GeV/c) in the data to that in the tuned simulation. We find that this rate is larger than what is expected for the conventional production and semileptonic decay of pairs of hadrons with heavy flavor.Comment: 65 pages, 14 tables, 14 figures. To be submitted to Phys. Rev.

    Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus

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    A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk

    Estudo fitoquímico de folhas de Solanum lycocarpum A. St.-Hil (Solanaceae) e sua aplicação na alelopatia

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    (Phytochemistry of Solanum lycocarpum A.St.–Hil (Solanaceae) leaves and their application in allelopathy). Solanum lycocarpum A.St.-Hil (Solanaceae) is a typical shrub in the Cerrado of central Brazil. The allelopathic activity of aqueous extracts of the leaves and fruits of this species has already been proven in previous studies. The goal of this work was to verify the allelopathic activity of different leaf extracts of S. lycocarpum on the germination and growth of four target species. The leaves were collected, dried, triturated and submitted to two distinct methods of extraction: 1- liquid--liquid (ethyl acetate and dichloromethane) from the aqueous extract and 2- with solvents of increasing polarities (hexane, dichloromethane, ethyl acetate, acetone, methanol and water) directly from the leaves. Each extraction was made with ultrasound equipment for one hour, filtered and evaporated. From these extracts, solutions of 800, 400 and 200 ppm were prepared, and water and Logran® were used as positive and negative controls, respectively. Each solution, as well as the controls, was dissolved in DMSO for the bioassays. The target species used were lettuce, watercress, tomato and onion. To each plate, 20 seeds were added and 1 mL of the tested solutions (with 4 repetitions). The plates were incubated at 25 oC without light, and the shoots and roots of the seedlings were then measured and the percentage of germination and the inhibition of each extract were calculated. Tomato was the most sensitive to the extracts, followed by watercress, onion and lettuce. The extracts with stronger activity were AcOEt, acetone and the liquid-liquid extraction, indicating the fractions that may contain the active principles of the leaves in this species
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