Systematic review and meta-analysis of mortality and digoxin use in atrial fibrillation

Background: There is growing controversy regarding the association between digoxin and mortality in atrial fibrillation (AF). The aim of this analysis was to systematically review digoxin use and risk of mortality in patients with AF. Methods: MEDLINE, EMBASE, GoogleScholar, CINAHL, meeting abstracts, presentations, and Cochrane central databases were searched from inception through December 2014, without language restrictions. For a study to be selected, it had to report the risk of mortality associated with digoxin use in AF patients as an outcome measure. Data were extracted by 2 independent authors. Evidence tables were created. Results: A total of 16 studies (6 post hoc analyses of randomized controlled trials) with 111,978 digoxin users and 389,643 non-digoxin users were included. In a random effects model, patients treated with digoxin had a 27% increased risk of all-cause mortality (pooled HR 1.27; 95% CI 1.19–1.36) and 21% increased risk of cardiovascular mortality (pooled HR 1.21; 95% CI 1.12–1.30) compared with those who did not use digoxin. In a random effects model, the association of digoxin with all-cause mortality was stronger for AF patients without heart failure (pooled HR 1.47; 95% CI 1.25–1.73) than AF patients with heart failure (pooled HR 1.21; 95% CI 1.07–1.36, interaction p = 0.06). Conclusions: Digoxin use in AF is associated with increased risk of all-cause and cardiovascular mortalities. The effect size was larger for AF patients without heart failure than AF patients with heart failure. The study suggests further directed analyses to study the effect that is suggested by this meta-analysis, especially in AF without heart failure.

FACTORS AFFECTING METFORMIN AND CLOMIPHENE’S REPRODUCTIVE EFFICACY IN PCOS WOMEN

Polycystic Ovarian Syndrome (PCOS) is a heterogeneous multifactorial disorder in which the ovarian dysfunction is the main cause of an ovulatory infertility. Metformin and Clomiphene Citrate (CC) are two effective drugs to induce ovulation in these patients. The study aimed to ascertain the effect of obesity, serum insulin and free testosterone levels on fertility success with metformin and CC as first line approaches in PCOS. This clinical study was a retrospective multicenter cohort study conducted in nine gynecology and endocrinology clinics. It included (61) PCOS women, aged (18-32) years, having desire to conceive, and free from the study medications for more than six months. Patients were divided to metformin receiving and CC receiving groups. Main outcomes of measure were; pregnancy rate, and improvement in PCOS as detected by ultrasound on their second visit. Results showed that CC was more effective in non-obese users (P0.05). Overall improvement was affected by Serum Free Testosterone (SFT) in both study groups (P\u3e0.05). Metformin was effective regardless of patient’s SFT levels, while CC was effective in patients with high SFT levels. There was a significant association between obesity and pregnancy rate in metformin users (P0.05). However, CC was less effective than metformin in overall improvement (OR=0.53, P\u3e0.05,) suggesting metformin as the possible drug of choice regardless to obesity, serum insulin and SFT levels

Measurement of Magnetic Moment at the Atomic Scale in a High TC Molecular Based Magnet

The molecular-based magnet Cs^(I) [Ni^(II) Cr^(III) (CN)6]-2H2O is a ferromagnetic with a Curie temperature TC ) 90 K. Its structure consists of face-centered cubic lattice of Ni^(II) ions connected by Cr(CN)6 entities. We have recorded X-ray magnetic circular dichroism (XMCD) at nickel L2,3 edges. It clearly evidences that nickel(II) is in a high-spin configuration and ferromagnetically coupled to the surrounding Cr^(III) . Through ligand field multiplet calculations, we have determined the total magnetic moment carried by Ni^(II) . Special attention has been paid to the magnetic anisotropy that complicates the calculation of the cross section for a powder. By using sum rules derived for XMCD, it has been possible to extract the orbital and spin contributions to the total magnetic moment. A somewhat too small magnetic moment is found on nickel. A complete calculation taking into account the multiplet coupling effect and the covalent hybridization allowed to determine the precise ground state of nickel and showed that hybridization cannot be responsible for the experimental low nickel magnetic moment. The origin of this effect is discussed

Nuevas tendencias en la determinación de la autenticación de aceite de maíz.

HPLC analysis of triacylglycerols and minor components, such as free and acylated sterols, and sterylglycosides, tocopherols and ¡soprenoid alcohols, have been employed for establishing oil authenticity. GLC analysis of the whole sterols as their TMS - derivatives has been also conducted. Genuine oils, namely, rapeseed, sunflower and corn oil as well as corn oil admixtures with the two oils were analyzed. Triacylglycerols and tocopherols were directly determined in the oils whereas the four sterol in lipids (free and acylated sterols and sterylglycosides) and isoprenoid alcohols were isolated and derivatized into their anthroyi nitrile derivatives. It was concluded that the analysis of minor components in combination with triacylglycerols is more advantageous for authentication of corn oil. However, ¡soprenoid alcohols are more decisive in this respect. Natural variability of the components in the oils from different origins can modify the detection limits.Para establecer la autenticación del aceite se ha utilizado la cromatografía líquida de alta eficacia de triacilgliceroles y componentes menores tales como los esteróles y esterilglicosidos libres y acilados, tocoferoles y alcoholes isoprenicos. También se ha llevado a cabo el análisis por cromatografía gas-líquido de los esteróles totales así como de sus derivados silanizados. Se analizaron aceites genuinos de colza, girasol y maíz así como mezclas de aceites de maíz con los otros dos aceites. Se determinaron directamente los triacilgliceroles y tocoferoles en los aceites mientras que los cuatro lipidos esterólicos (esteróles y esterilglicosidos libres y acilados) y alcoholes isoprenicos se aislaron y se transformaron en sus antroil nitril derivados. Se concluyó que el análisis de los componentes menores en combinación con el de los triacilgliceroles es más ventajoso para la autenticación del aceite de maíz. Sin embargo a este respecto son más decisivos los alcoholes isoprenicos. La variabilidad natural de los componentes en los aceites de diferentes orígenes puede modificar los límites de decisión

Numerical Study of a Mixed Ising Ferrimagnetic System

We present a study of a classical ferrimagnetic model on a square lattice in which the two interpenetrating square sublattices have spins one-half and one. This model is relevant for understanding bimetallic molecular ferrimagnets that are currently being synthesized by several experimental groups. We perform exact ground-state calculations for the model and employ Monte Carlo and numerical transfer-matrix techniques to obtain the finite-temperature phase diagram for both the transition and compensation temperatures. When only nearest-neighbor interactions are included, our nonperturbative results indicate no compensation point or tricritical point at finite temperature, which contradicts earlier results obtained with mean-field analysis.Comment: Figures can be obtained by request to [email protected] or [email protected]

Magnetic Behavior of a Mixed Ising Ferrimagnetic Model in an Oscillating Magnetic Field

The magnetic behavior of a mixed Ising ferrimagnetic system on a square lattice, in which the two interpenetrating square sublattices have spins +- 1/2 and spins +-1,0, in the presence of an oscillating magnetic field has been studied with Monte Carlo techniques. The model includes nearest and next-nearest neighbor interactions, a crystal field and the oscillating external field. By studying the hysteretic response of this model to an oscillating field we found that it qualitatively reproduces the increasing of the coercive field at the compensation temperature observed in real ferrimagnets, a crucial feature for magneto-optical applications. This behavior is basically independent of the frequency of the field and the size of the system. The magnetic response of the system is related to a dynamical transition from a paramagnetic to a ferromagnetic phase and to the different temperature dependence of the relaxation times of both sublattices.Comment: 10 figures. To be published in Phys.Rev

Parameterized vertex deletion problems for hereditary graph classes with a block property

For a class of graphs P, the Bounded P-Block Vertex Deletion problem asks, given a graph G on n vertices and positive integers k and d, whether there is a set S of at most k vertices such that each block of G − S has at most d vertices and is in P. We show that when P satisfies a natural hereditary property and is recognizable in polynomial time, Bounded P-Block Vertex Deletion can be solved in time 2O(k log d)nO(1), and this running time cannot be improved to 2o(k log d)nO(1), in general, unless the Exponential Time Hypothesis fails. On the other hand, if P consists of only complete graphs, or only K1,K2, and cycle graphs, then Bounded P-Block Vertex Deletion admits a cknO(1)-time algorithm for some constant c independent of d. We also show that Bounded P-Block Vertex Deletion admits a kernel with O(k2d7) vertices. © Springer-Verlag GmbH Germany 2016

Magnetic Behaviour of Disordered Ising Ferrimagnet in High Magnetic Field

The magnetic behaviour of a disordered ferrimagnetic system Ap B1-p where both A and B represent the magnetic atoms with respective spin SA = 1/2 and SB = 1 in presence of high magnetic field is treated theoretically.Assuming the magnetic interaction can be described through Ising Hamiltonian the approximate free energy is obtained using the cluster-variational method. The field dependence of the magnetization is then obtained for different concentration p and exchange parameters (JAA, JBB and JAB). For p = 0.5,the magnetization M in ferrimagnetic state and in absence of compensation temperature Tcm vanishes at TC.Field induced reversal of M is found at switching temperature TS (<TC) which is decreasing function of field H.A maximum in M is found above TS and the maximum value of M increases with field.In ferrimagnetic state M increases almost linearly at high H region. For system with large ferromagnetic JAA,the compensation temperature Tcm is increasing function of JBB and JAB .The decrease in compensation temperature is linear at small field and tends to saturate at higher field.The sharpness of the magnetization reversal is increased with H.For fully compensated state of the system with p = 2/3,the magnetization in presence of H also exhibits switching behaviour at TS .For p = 0.2 the field induced reversal of magnetization occurs more sharply.The orientational switching of the sublattice magnetization MA and MB with field increases the Zeeman energy and is the origin of magnetization reversal at TsComment: 12 pages,9 Figure