Melting and Equilibrium Shape of Icosahedral Gold Nanoparticles

We use molecular dynamics simulations to study the melting of gold icosahedral clusters of a few thousand atoms. We pay particular attention to the behavior of surface atoms, and to the equilibrium shape of the cluster. We find that although the surface of the cluster remains ordered up to the melting T_m, the increasing mobility of vertex and edge atoms significantly soften the surface structure, leading to inter- and intra-layer diffusion, and shrinking of the average facet size, so that the average shape of the cluster is nearly spherical at melting.Comment: 4 pages, 4 figures - replaced with final published versio

Polymorphism in TGFB1 is associated with worse non-relapse mortality and overall survival after stem cell transplantation with unrelated donors.

Transforming growth factor beta-1, encoded by the TGFB1 gene, is a cytokine that plays a central role in many physiological and pathogenic processes. We have sequenced TGFB1 regulatory region and assigned allelic genotypes in a large cohort of hematopoietic stem cell transplantation patients and donors. In this study, we analyzed 522 unrelated donor-patient pairs and examined the combined effect of all the common polymorphisms in this genomic region. In univariate analysis, we found that patients carrying a specific allele, 'p001', showed significantly reduced overall survival (5-year overall survival 30.7% for p001/ p001 patients vs. 41.6% others; P=0.032) and increased non-relapse mortality (1-year nonrelapse mortality: 39.0% vs. 25.4%; P=0.039) after transplantation. In multivariate analysis, the presence of a p001/ p001 genotype in patients was confirmed as an independent factor for reduced overall survival [hazard ratio=1.53 (1.04-2.24); P=0.031], and increased non-relapse mortality [hazard ratio=1.73 (1.06-2.83); P=0.030]. In functional experiments we found a trend towards a higher percentage of surface transforming growth factor beta-1-positive regulatory T cells after activation when the cells had a p001 allele (P=0.07). Higher or lower production of transforming growth factor beta-1 in the inflammatory context of hematopoietic stem cell transplantation may influence the development of complications in these patients. Findings indicate that TGFB1 genotype could potentially be of use as a prognostic factor in hematopoietic stem cell transplantation risk assessment algorithms

Adverse Childhood Life Events and Postpartum Psychosis in Bipolar Disorder

Background Women with bipolar disorder are at increased risk of postpartum psychosis. Adverse childhood life events have been associated with depression in the postpartum period, but have been little studied in relation to postpartum psychosis. In this study we investigated whether adverse childhood life events are associated with postpartum psychosis in a large sample of women with bipolar I disorder. Methods Participants were 432 parous women with DSM-IV bipolar I disorder recruited into the Bipolar Disorder Research Network (www.BDRN.org). Diagnoses and lifetime psychopathology, including perinatal episodes, were obtained via a semi-structured interview (Schedules for Clinical Assessment in Neuropsychiatry; Wing et al., 1990) and case-notes. Adverse childhood life events were assessed via self-report and case-notes, and compared between women with postpartum psychosis (n=208) and those without a lifetime history of perinatal mood episodes (n=224). Results There was no significant difference in the rate of any adverse childhood life event, including childhood sexual abuse, or in the total number of adverse childhood life events between women who experienced postpartum psychosis and those without a lifetime history of perinatal mood episodes, even after controlling for demographic and clinical differences between the groups. Limitations Adverse childhood life events were assessed in adulthood and therefore may be subject to recall errors. Conclusions We found no evidence for an association between adverse childhood life events and the occurrence of postpartum psychosis. Our data suggest that, unlike postpartum depression, childhood adversity does not play a significant role in the triggering of postpartum psychosis in women with bipolar disorder

The Luminosity Function and stellar Mass to Light ratio of the massive globular cluster NGC2419

We used archival Hubble Space Telescope WFC3 images to obtain the Luminosity Function of the remote globular cluster NGC2419 from two magnitudes above the Horizontal Branch level down to \sim3.0 magnitudes below the Turn Off point (to M_I\sim6.4), approximately covering the range of initial stellar masses 0.5 M_sun<= m <= 0.9 M_sun. The completeness-corrected Luminosity Function does not display any change of shape over the radial range covered by the WFC3 data, out to ~6 core radii (r_c), or, equivalently, to ~2 half-light radii. The Luminosity Function in this radial range is also identical to that obtained from ground based data at much larger distances from the cluster centre (12r_c<= R<= 22r_c), in the magnitude range in which the two distributions overlap (M_I<= 4.0). These results support the conclusion by Dalessandro et al. that there is no significant mass segregation among cluster stars, hence the stellar mass-to-light ratio remains constant with distance from the cluster centre. We fitted the observed Luminosity Function with theoretical counterparts with the proper age and metallicity from different sets of stellar evolution models and we consistently derive a total V band mass-to-light ratio 1.2<= M/L_V<= 1.7, by extrapolating to the Hydrogen burning limit, with a best-fit value M/L_V=1.5 +/- 0.1. On the other hand, assuming that there are no cluster stars with m 0.8. These estimates provide useful constraints for dynamical models of the cluster that were forced to consider the stellar mass-to-light ratio as a (nearly) free parameter.Comment: Accepted for publication by MNRAS. Pdftex, 13 pages, 9 figure

Diluting the material forming the second generation stars in Globular Clusters: the contribution by unevolved stars

In this short communication we consider the possibility that stars less evolved than the polluters are the source of the dilution needed to explain the observed composition of second-generation globular cluster (GC) stars and the Na-O and Mg-Al anticorrelations. If these stars can lose 0.5-1% of their mass during the relevant epochs, there is enough diluting material to produce the observed anticorrelations. In this case, the original mass of proto-GCs was several tens times higher than the current mass of GCs. While not strictly impossible, this is a stringent hypothesis that needs more support. Should this scenario be found true, then the link between the primordial (first-generation) population in GC and the field population would be very strong.Comment: Accepted for publication on Astronomy and Astrophysic

Reprogramming the diseased brain

Direct conversion of astrocytes to dopamine neurons in vivo offers fresh optimism for the development of improved Parkinson's therapie

Physiotherapist-led suprascapular nerve blocks for persistent shoulder pain: Evaluation of a new service in the UK.

INTRODUCTION: This service evaluation explored and reported findings from a new physiotherapist-led service offering suprascapular nerve blocks (SSNBs) to patients with persistent shoulder pain. METHODS: We collected data before the SSNB injection and at the 6-weeks and 6-month follow-up from consecutive patients with persistent shoulder pain being treated by physiotherapists or an anaesthetist. Outcomes were patient-reported pain (numerical rating scale [NRS 0 to 10]), patient-specific functional score (PSFS) and health-related quality of life [the EuroQol five dimensions questionnaire (EQ5D-5 L)]. Exploratory analyses compared baseline and follow-up scores within each clinician delivery group (physiotherapists, anaesthetist). RESULTS: Forty patients (mean age 57 years [standard deviation {SD} 12]; 63% female) received an SSNB from a physiotherapist, eight patients (mean age 59 years [SD 11]; female 88%) received an SSNB from an anaesthetist. At the 6-week follow-up, the physiotherapy group showed a mean reduction in pain (on the NRS): 2.2 (95% confidence interval [CI] 1.3 to 3.0) and an improvement in function (on the PSFS): -1.3 (95% CI -1.9 to -0.4). Similar changes were found in those treated by the anaesthetist (pain: 1.3 [95% CI -1.18 to 3.80]; function: -1.4 (95% CI -3.18 to 0.35]). Very small changes, that were not statistically significant, were found in EQ5D-5 L scores. At the 6-month follow-up, the mean reduction in pain (NRS) was maintained at 2.0 (95% CI 0.99 to 2.95) for the physiotherapy group. CONCLUSION: The results provide early, exploratory evidence that patients with persistent shoulder pain treated by physiotherapists using palpation-guided SSNBs achieve clinically important changes in pain and function in the short and medium term