Solvent Mediated Assembly of Nanoparticles Confined in Mesoporous Alumina

The controlled self-assembly of thiol stabilized gold nanocrystals in a mediating solvent and confined within mesoporous alumina was probed in situ with small angle x-ray scattering. The evolution of the self-assembly process was controlled reversibly via regulated changes in the amount of solvent condensed from an undersaturated vapor. Analysis indicated that the nanoparticles self-assembled into cylindrical monolayers within the porous template. Nanoparticle nearest-neighbor separation within the monolayer increased and the ordering decreased with the controlled addition of solvent. The process was reversible with the removal of solvent. Isotropic clusters of nanoparticles were also observed to form temporarily during desorption of the liquid solvent and disappeared upon complete removal of liquid. Measurements of the absorption and desorption of the solvent showed strong hysteresis upon thermal cycling. In addition, the capillary filling transition for the solvent in the nanoparticle-doped pores was shifted to larger chemical potential, relative to the liquid/vapor coexistence, by a factor of 4 as compared to the expected value for the same system without nanoparticles.Comment: 9 pages, 9 figures, appeared in Phys. Rev.

Amorphization of embedded Cu nanocrystals by ion irradiation

While bulk crystalline elemental metals cannot be amorphized by ion irradiation in the absence of chemical impurities, the authors demonstrate that finite-size effects enable the amorphization of embedded Cu nanocrystals. The authors form and compare the atomic-scale structure of the polycrystalline, nanocrystalline, and amorphous phases, present an explanation for the extreme sensitivity to irradiation exhibited by nanocrystals, and show that low-temperature annealing is sufficient to return amorphized material to the crystalline form

TRANSVERSE SUSCEPTIBILITY STUDIES OF RECORDING MEDIA

A highly sensitive transverse susceptometer has been developed for the investigation of magnetic recording media. The susceptometer was based on the design of Pareti and Turilli[4] with modifications to the solenoid and sensing coils. The modifications have resulted in an improvement in the signal to baseline ratio of a factor of 525, and a reduction in random noise. The increase in the sensitivity of the susceptometer allowed the investigation of Advanced Metal Particle (AMP) tapes and the measurement of the imaginary component of the transverse susceptibility (TS) proposed by Papusoi[5]. Also, a modification was developed which allowed the investigation of the non-linear TS, proposed by Chantrell et al[7]. The work reported for the latter two techniques was the first experimental demonstration of these measurements on magnetic recording media. Samples of Co-y-Fe203, Cr02, mixed y-Fe203 / Cr02 and AMP tapes were investigated, as were y- Fe201, Cr0 2 and AMP powders. The investigations suggested that the incoherent reversal mode was dominant in the systems containing Cr02, with coherent reversal dominant in the remaining systems. The anisotropy peaks measured using the non-linear IS were found to be less dependent on sample texture than those of the traditional linear measurement. In particular the anisotropy peaks of the non-linear TS for incoherently reversing systems appeared to be independent of texture and it was proposed that these were a direct measure of the anisotropy field distribution, although independent verification was not performed. The determination of magnetic coating thickness after Sollis and Bissell[6] was extended to allow the measurement of AMP tapes. A computer model was developed to investigate the error in the technique due to the particulate nature of the coating. The results of the model indicated that the error increased as coating thickness and volume packing fraction decreased. Correction factors were determined for MP3 and MP4 particle based systems. The detection of the imaginary component of TS and its close agreement with the theoretical predictions of Papusoi suggested that the dassification of TS as a 'stiffness' method of anisotropy field determination might be in error

Deterministic and stochastic descriptions of gene expression dynamics

A key goal of systems biology is the predictive mathematical description of gene regulatory circuits. Different approaches are used such as deterministic and stochastic models, models that describe cell growth and division explicitly or implicitly etc. Here we consider simple systems of unregulated (constitutive) gene expression and compare different mathematical descriptions systematically to obtain insight into the errors that are introduced by various common approximations such as describing cell growth and division by an effective protein degradation term. In particular, we show that the population average of protein content of a cell exhibits a subtle dependence on the dynamics of growth and division, the specific model for volume growth and the age structure of the population. Nevertheless, the error made by models with implicit cell growth and division is quite small. Furthermore, we compare various models that are partially stochastic to investigate the impact of different sources of (intrinsic) noise. This comparison indicates that different sources of noise (protein synthesis, partitioning in cell division) contribute comparable amounts of noise if protein synthesis is not or only weakly bursty. If protein synthesis is very bursty, the burstiness is the dominant noise source, independent of other details of the model. Finally, we discuss two sources of extrinsic noise: cell-to-cell variations in protein content due to cells being at different stages in the division cycles, which we show to be small (for the protein concentration and, surprisingly, also for the protein copy number per cell) and fluctuations in the growth rate, which can have a significant impact.Comment: 23 pages, 5 figures; Journal of Statistical physics (2012

Fluphenazine decanoate (depot) and enanthate for schizophrenia

Background: Intramuscular injections (depot preparations) offer an advantage over oral medication for treating schizophrenia by reducing poor compliance. The benefits gained by long-acting preparations, however, may be offset by a higher incidence of adverse effects. Objectives: To assess the effects of fluphenazine decanoate and enanthate versus oral anti-psychotics and other depot neuroleptic preparations for individuals with schizophrenia in terms of clinical, social and economic outcomes. Search methods: We searched the Cochrane Schizophrenia Group's Trials Register (February 2011 and October 16, 2013), which is based on regular searches of CINAHL, BIOSIS, AMED, EMBASE, PubMed, MEDLINE, PsycINFO, and registries of clinical trials. Selection criteria: We considered all relevant randomised controlled trials (RCTs) focusing on people with schizophrenia comparing fluphenazine decanoate or enanthate with placebo or oral anti-psychotics or other depot preparations. Data collection and analysis: We reliably selected, assessed the quality, and extracted data of the included studies. For dichotomous data, we estimated risk ratio (RR) with 95% confidence intervals (CI). Analysis was by intention-to-treat. We used the mean difference (MD) for normal continuous data. We excluded continuous data if loss to follow-up was greater than 50%. Tests of heterogeneity and for publication bias were undertaken. We used a fixed-effect model for all analyses unless there was high heterogeneity. For this update. we assessed risk of bias of included studies and used the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to create a 'Summary of findings' table. Main results: This review now includes 73 randomised studies, with 4870 participants. Overall, the quality of the evidence is low to very low.Compared with placebo, use of fluphenazine decanoate does not result in any significant differences in death, nor does it reduce relapse over six months to one year, but one longer-term study found that relapse was significantly reduced in the fluphenazine arm (n = 54, 1 RCT, RR 0.35, CI 0.19 to 0.64, very low quality evidence). A very similar number of people left the medium-term studies (six months to one year) early in the fluphenazine decanoate (24%) and placebo (19%) groups, however, a two-year study significantly favoured fluphenazine decanoate (n = 54, 1 RCT, RR 0.47, CI 0.23 to 0.96, very low quality evidence). No significant differences were found in mental state measured on the Brief Psychiatric Rating Scale (BPRS) or in extrapyramidal adverse effects, although these outcomes were only reported in one small study each. No study comparing fluphenazine decanoate with placebo reported clinically significant changes in global state or hospital admissions.Fluphenazine decanoate does not reduce relapse more than oral neuroleptics in the medium term (n = 419, 6 RCTs, RR 1.46 CI 0.75 to 2.83, very low quality evidence). A small study found no difference in clinically significant changes in global state. No difference in the number of participants leaving the study early was found between fluphenazine decanoate (17%) and oral neuroleptics (18%), and no significant differences were found in mental state measured on the BPRS. Extrapyramidal adverse effects were significantly less for people receiving fluphenazine decanoate compared with oral neuroleptics (n = 259, 3 RCTs, RR 0.47 CI 0.24 to 0.91, very low quality evidence). No study comparing fluphenazine decanoate with oral neuroleptics reported death or hospital admissions.No significant difference in relapse rates in the medium term between fluphenazine decanoate and fluphenazine enanthate was found (n = 49, 1 RCT, RR 2.43, CI 0.71 to 8.32, very low quality evidence), immediate- and short-term studies were also equivocal. One small study reported the number of participants leaving the study early (29% versus 12%) and mental state measured on the BPRS and found no significant difference for either outcome. No significant difference was found in extrapyramidal adverse effects between fluphenazine decanoate and fluphenazine enanthate. No study comparing fluphenazine decanoate with fluphenazine enanthate reported death, clinically significant changes in global state or hospital admissions. Authors' conclusions: There are more data for fluphenazine decanoate than for the enanthate ester. Both are effective antipsychotic preparations. Fluphenazine decanoate produced fewer movement disorder effects than other oral antipsychotics but data were of low quality, and overall, adverse effect data were equivocal. In the context of trials, there is little advantage of these depots over oral medications in terms of compliance but this is unlikely to be applicable to everyday clinical practice.Full Tex

Genome Analysis, Metabolic Potential, and Predatory Capabilities of Herpetosiphon llansteffanense sp. nov.

Herpetosiphon spp. are ubiquitous, chemoheterotrophic, filamentous gliding bacteria with the ability to prey on other microbes through a “wolf pack” mechanism. The genus currently comprises four known species (H. aurantiacus, H. geysericola, H. giganteus, and H. gulosus), which produce antimicrobial secondary metabolites such as siphonazole. As part of a study isolating myxobacterial wolf pack predators, we serendipitously isolated a novel environmental strain (CA052B) from the edge of a stream at Llansteffan, United Kingdom, which was identified as a member of the Herpetosiphon genus. A lawn culture method was utilized to analyze the predatory activity of CA052B against 10 prey organisms of clinical relevance. CA052B was found to prey on Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Enterococcus faecalis, Bacillus subtilis, and Candida albicans. Purified CA052B outer membrane vesicles also exhibited killing activity against the prey organisms when tested by flow cytometry. 16S rRNA sequencing of CA052B showed 98 to 99% identity with other Herpetosiphon species members. Comparing the genome of CA052B with the publicly available genomes of H. aurantiacus and H. geysericola revealed average nucleotide identities of only 84% and 91%, respectively, whereas the genome-to-genome distance calculation showed sequence identities of 28.2% and 46.6%, respectively. Biochemical characterization also revealed distinctions between CA052B and both H. gulosus and H. giganteus. Thus, strain CA052BT (= DSM 107618T = NBRC 113495T) is proposed to be the type strain of a novel species, Herpetosiphon llansteffanense sp. nov. The genome sequence of CA052B also revealed diverse secondary metabolite biosynthetic clusters, encouraging further exploration of its antibiotic production potential

Caspase-1 causes truncation and aggregation of the Parkinson's disease-associated protein α-synuclein

The aggregation of α-synuclein (aSyn) leading to the formation of Lewy bodies is the defining pathological hallmark of Parkinson's disease (PD). Rare familial PD-associated mutations in aSyn render it aggregation-prone; however, PD patients carrying wild type (WT) aSyn also have aggregated aSyn in Lewy bodies. The mechanisms by which WT aSyn aggregates are unclear. Here, we report that inflammation can play a role in causing the aggregation of WT aSyn. We show that activation of the inflammasome with known stimuli results in the aggregation of aSyn in a neuronal cell model of PD. The insoluble aggregates are enriched with truncated aSyn as found in Lewy bodies of the PD brain. Inhibition of the inflammasome enzyme caspase-1 by chemical inhibition or genetic knockdown with shRNA abated aSyn truncation. In vitro characterization confirmed that caspase-1 directly cleaves aSyn, generating a highly aggregation-prone species. The truncation-induced aggregation of aSyn is toxic to neuronal culture, and inhibition of caspase-1 by shRNA or a specific chemical inhibitor improved the survival of a neuronal PD cell model. This study provides a molecular link for the role of inflammation in aSyn aggregation, and perhaps in the pathogenesis of sporadic PD as well

A new hammer to crack an old nut : interspecific competitive resource capture by plants is regulated by nutrient supply, not climate

Peer reviewedPublisher PD

Patents and Industrialisation. An Historical Overview of the British Case, 1624-1907

A Report to the Strategic Advisory Board on Intellectual Property Policy (SABIP), U