Effect of Al doping on the optical phonon spectrum in Mg(1-x)Al(x)B(2)

Raman and infrared absorption spectra of Mg(1-x)Al(x)B(2) have been collected for 0<x<0.5 in the spectral range of optical phonons. The x-dependence of the peak frequency, the width and the intensity of the observed Raman lines has been carefully analized. A peculiar x-dependence of the optical modes is pointed out for two different Al doping ranges. In particular the onset of the high-doping structural phase previously observed in diffraction measurements is marked by the appearence of new spectral components at high frequencies. A connection between the whole of our results and the observed suppression of superconductivity in the high doping region is established

The radial arrangement of the human chromosome 7 in the lymphocyte cell nucleus is associated with chromosomal band gene density

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ Springer-Verlag 2008.In the nuclei of human lymphocytes, chromosome territories are distributed according to the average gene density of each chromosome. However, chromosomes are very heterogeneous in size and base composition, and can contain both very gene-dense and very gene-poor regions. Thus, a precise analysis of chromosome organisation in the nuclei should consider also the distribution of DNA belonging to the chromosomal bands in each chromosome. To improve our understanding of the chromatin organisation, we localised chromosome 7 DNA regions, endowed with different gene densities, in the nuclei of human lymphocytes. Our results showed that this chromosome in cell nuclei is arranged radially with the gene-dense/GC-richest regions exposed towards the nuclear interior and the gene-poorest/GC-poorest ones located at the nuclear periphery. Moreover, we found that chromatin fibres from the 7p22.3 and the 7q22.1 bands are not confined to the territory of the bulk of this chromosome, protruding towards the inner part of the nucleus. Overall, our work demonstrates the radial arrangement of the territory of chromosome 7 in the lymphocyte nucleus and confirms that human genes occupy specific radial positions, presumably to enhance intra- and inter-chromosomal interaction among loci displaying a similar expression pattern, and/or similar replication timing

Which criteria should be used for starting pharmacologic therapy for management of gestational diabetes in pregnancy? Evidence from randomized controlled trials

Introduction: There is inconclusive evidence to support any specific criteria for starting pharmacologic therapy after diet in women with gestational diabetes mellitus (GDM). We aimed to analyze the most used criteria for starting pharmacologic treatment for patients with GDM. Material and methods: Electronic databases were searched from their inception to September 2017. We included all the randomized controlled trials (RCTs) of GDM managed initially by diet and exercise reporting criteria for starting pharmacologic therapy. RCTs in women with pregestational diabetes were excluded. Data regarding glucose values used for starting pharmacologic therapy were extracted and carefully reviewed. Results: We included 15 RCTs (4307 women) in the meta-analysis. For fasting glucose target, 8/14 (57%) used a value lower or equal to 90 mg/dL and the remainder used values 50% of the values higher than the target values and another one (7%) used >30%. Conclusion: The majority of RCTs (87%) used very tight criteria of either 1 or 2 values over the target values in the 1 or 2-week period for starting pharmacologic treatment for patients with GDM; more than 50% used 2 values. Key Message Pharmacologic therapy should be considered in women with gestational diabetes when, despite an adequate diet and exercise, 1 or 2 blood glucose values are over the target values of 90mg/dL fasting or 120mg/dL 2-hour postprandial over 1 or 2 weeks

Cobalt ferrite nanoparticles under high pressure

We report by the first time a high pressure X-ray diffraction and Raman spectroscopy study of cobalt ferrite (CoFe2O4) nanoparticles carried out at room temperature up to 17 GPa. In contrast with previous studies of nanoparticles, which proposed the transition pressure to be reduced from 20–27 GPa to 7.5–12.5 GPa (depending on particle size), we found that cobalt ferrite nanoparticles remain in the spinel structure up to the highest pressure covered by our experiments. In addition, we report the pressure dependence of the unit-cell parameter and Raman modes of the studied sample. We found that under quasi-hydrostatic conditions, the bulk modulus of the nanoparticles (B0 = 204 GPa) is considerably larger than the value previously reported for bulk CoFe2O4 (B0 = 172 GPa). In addition, when the pressure medium becomes non-hydrostatic and deviatoric stresses affect the experiments, there is a noticeable decrease of the compressibility of the studied sample (B0 = 284 GPa). After decompression, the cobalt ferrite lattice parameter does not revert to its initial value, evidencing a unit cell contraction after pressure was removed. Finally, Raman spectroscopy provides information on the pressure dependence of all Raman-active modes and evidences that cation inversion is enhanced by pressure under non-hydrostatic conditions, being this effect not fully reversible.Fil: Saccone, Fabio Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Ferrari, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Errandonea, Daniel. Universidad de Valencia; EspañaFil: Florencia Grinblat. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Bilovol, Vitaliy. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnologías y Ciencias de la Ingeniería; ArgentinaFil: Agouram, S.. Universidad de Valencia; Españ

Peanut ball for decreasing length of labor: A systematic review and meta-analysis of randomized controlled trials

INTRODUCTION: Prolonged length of labor is associated with increased maternal and neonatal complications. Therefore, great attention has been given to interventions aimed at reducing the length of labor. One such intervention is the peanut ball, a large elongated exercise ball placed between a woman's legs during labor. OBJECTIVE: The aim of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to assess the effect of the use of peanut ball in reducing length of labor. STUDY DESIGN: Data sources: MEDLINE, EMBASE, Web of Sciences, Scopus, ClinicalTrial.gov, OVID and Cochrane Library were searched from inception until January 2019. SELECTION CRITERIA: Selection criteria included RCTs of laboring women with singleton gestations in cephalic presentation at term (≥37weeks) who were randomized to either use of peanut ball or control group (no peanut ball). DATA COLLECTION AND ANALYSIS: Four trials with 648 nulliparous and multiparous women in spontaneous or induced labor were identified and included. 330 women were randomized to the intervention (peanut ball between the knees during labor) and 318 women to the control. Summary measures were reported as mean difference (MD) with 95% of confidence interval (CI) using the random effects model of DerSimonian and Laird. The primary outcome was total length of labor. PROSPERO Registration Number: CRD42018082438 RESULTS: Total length of labor was 79min shorter in the peanut ball group, but this was not significant (MD -79.1 min, 95% CI -204.9, 46.7). Peanut ball use showed trends toward higher incidence of spontaneous vaginal deliveries (RR 1.1, 95% CI 1.0, 1.2) and lower incidence of cesarean deliveries (RR 0.8, 95% CI 0.6, 1.0). CONCLUSIONS: Peanut ball use was not associated with a significant decrease in total length of labor. Since there were trends toward reductions in length of labor, an increased incidence in spontaneous vaginal deliveries, and lower incidence of cesarean deliveries, more research is needed

A Superconductor Made by a Metal Heterostructure at the Atomic Limit Tuned at the "Shape Resonance": MgB2

We have studied the variation of Tc with charge density and lattice parameters in Mg1-xAlxB2 superconducting samples at low Al doping x<8%. We show that high Tc occurs where the chemical potential is tuned at a "superconducting shape resonance" near the energy Ec of the quantum critical point (QCP) for the dimensional transition from 2D to 3D electronic structure in a particular subband of the natural superlattice of metallic atomic boron layers. At the "shape resonance" the electrons pairs see a 2D Fermi surface at EF-w0 and a 3D Fermi surface at EF+wo, where wo is the energy cut off of the pairing interaction. The resonant amplification occurs in a narrow energy range where EF-Ec is in the range of 2wo.Comment: 16 page

New evidence on the link between ethnic fractionalization and economic freedom

Among the determinants of economic freedom, the presence of different ethnic groups within a country has sometimes been explored by the empirical literature, without conclusive evidence on the sign of the relation, its drivers, and the conditions under which it holds. This paper offers new evidence by empirically modelling how ethnic fragmentation is related to economic freedom, as measured by the Economic Freedom Index and by each of its numerous areas, components and sub-components. The results provide insights on the components driving the effect and, interestingly, detect notable differences between developed and developing countries

About females and males: continuity and discontinuity in flies

Through the decades of relentless and dedicated studies in Drosophila melanogaster, the pathway that governs sexual development has been elucidated in great detail and has become a paradigm in understanding fundamental cell-fate decisions. However, recent phylogenetic studies show that the molecular strategy used in Drosophila deviates in some important aspects from those found in other dipteran flies and suggest that the Drosophila pathway is likely to be a derivative of a simpler and more common principle. In this essay, I will discuss the evolutionary plasticity of the sex-determining pathway based on studies in the common housefly, Musca domestica. Diversification appears to primarily arise from subtle differences in the regulation of the key switch gene transformer at the top of the pathway. On the basis of these findings I propose a new idea on how the Drosophila pathway may have evolved from a more archetypal system such as in M. domestica. In essence, the arrival of an X counting mechanism mediated by Sex-lethal to compensate for X linked gene dose differences set the stage for an intimate coupling of the two pathways. Its precedent recruitment to the dosage compensation pathway allowed for an intervention in the regulation of transformer where it gradually and eventually' completely substituted for a need of transformer autoregulation

Heritability of Smoking Initiation and Nicotine Dependence

In contrast to other aspects of smoking behavior, little attention has been paid to the genetics of nicotine dependence. In this paper, three models (single liability dimension, independent liability dimension and combined model) have been applied to data on smoking initiation and nicotine dependence (n = 1572 Dutch twin pairs, mean age 30.5). A combined model best described the data. This model postulates a smoking initiation dimension and a nicotine dependence dimension, which are not independent. For both males and females, individual differences in smoking initiation were explained by genetic (44%), shared environmental (51%) and unique environmental (5%) influences. The nicotine dependence dimension was influenced only by genetic (75%) and unique environmental (25%) factors. The substantial impact of genetic factors on nicotine dependence emphasizes the need for further research to localize and identify specific genes and pathways involved in nicotine dependence. © 2005 Springer Science+Business Media, Inc