167 research outputs found

    Superradiant anomaly magnification in evolution of vector bosonic condensates bounded by a Kerr black hole with near-horizon reflection

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    Ultralight vector particles can form evolving condensates around a Kerr black hole (BH) due to superradiant instability. We study the effect of near-horizon reflection on the evolution of this system; by matching three pieces of asymptotic expansions of the Proca equation in Kerr metric and considering the leading order in the electric mode, we present explicit analytical expressions for the corrected energy level shifts and the superradiant instability rates. Particularly, in high-spin BH cases, we identify an anomalous situation where the superadiance rate is temporarily increased by the reflection parameter R\mathcal{R}, which also occurs in the scalar scenario, but is largely magnified in vector condensates due to a faster growth rate in dominant mode; we constructed several featured quantities to illustrate this anomaly, and formalized the magnification with relevant correction factors, which may be of significance in future studies of gravitational waveforms of this monochromatic type. In addition, the duration of superradiance for the whole evolution is prolonged with a delay factor, which is calculated to be (1+R)/(1R)(1+\mathcal{R})/({1-\mathcal{R}}) approximately

    Molecular cloning, expression pattern of Trypsin gene and association analysis with growth traits in Penaeus monodon

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    A novel TRY homolog was cloned in Penaeus monodon by RACE technology, named PmTry (GenBank: KP998480). The PmTry cDNA was 916 bp, which encodes 266 amino acids with a predicted molecular weight of 28.38 KDa and an isoelectric point of 4.58. Homologous analysis indicated that PmTry shared 42%~91% similarity with other species. The phylogenetic tree showed that PmTry was closely related to Fenneropenaeus chinensis. Tissue expression profiles showed that PmTry was highest expressed in the hepatopancreas and the lowest expressed in the eyestalk nerve. It was expressed in the whole growth stage of P. monodon, but the relative expression level of each stage was significantly different. In addition, PmTry-524 and PmTry-798 were particularly related to growth traits of P. monodon by genotype. The SNP markers may provide a basis for genetic selection and breed improvement studies in P. monodon

    Bowman Birk Inhibitor Concentrate and Oral Leukoplakia: A Randomized Phase IIb Trial

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    Oral premalignancy serves as an ideal model for study of chemopreventive agents. Although 13-cis-retinoic acid showed reversal of oral premalignancy, toxicity, and reversal of clinical response after cessation of therapy obviated its widespread use. A search for nontoxic agents with cancer preventive activity led us to evaluate Bowman Birk Inhibitor (BBI) formulated as BBI Concentrate (BBIC). We previously reported encouraging results in a phase IIa trial of BBIC in patients with oral leukoplakia with measurable clinical responses and favorable biomarker changes. On the basis of these results, we undertook a randomized, placebo controlled phase IIb trial with patients receiving BBIC or placebo for 6 months, with assessment of clinical response and change in lesion area as primary end point and an intent-to-treat analysis. One hundred and thirty two subjects were randomized; and 89 subjects completed six months on study drug or placebo. Both placebo and BBIC showed a statistically significant decrease in mean lesion area of 17.1% and 20.6%, respectively, and partial or greater clinical responses of 30% and 28% respectively. No significant difference between placebo and study drug arms was observed. Histologic review, review of photographs of lesions, and comparison of serum neu protein and oral mucosal cell protease activity also did not show significant differences between study arms. Probable reasons for these negative results were considered, are discussed, and include a placebo with non-BBIC clinical activity and reduced pharmacokinetic availability of the second batch of BBIC. This experience should be a strong cautionary note to those considering Green chemoprevention. © 2013 AACR

    Charge separation: From the topology of molecular electronic transitions to the dye/semiconductor interfacial energetics and kinetics

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    Charge separation properties, that is the ability of a chromophore, or a chromophore/semiconductor interface, to separate charges upon light absorption, are crucial characteristics for an efficient photovoltaic device. Starting from this concept, we devote the first part of this book chapter to the topological analysis of molecular electronic transitions induced by photon capture. Such analysis can be either qualitative or quantitative, and is presented here in the framework of the reduced density matrix theory applied to single-reference, multiconfigurational excited states. The qualitative strategies are separated into density-based and wave function-based approaches, while the quantitative methods reported here for analysing the photoinduced charge transfer nature are either fragment-based, global or statistical. In the second part of this chapter we extend the analysis to dye-sensitized metal oxide surface models, discussing interfacial charge separation, energetics and electron injection kinetics from the dye excited state to the semiconductor conduction band states

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Neurotensin Receptor 1 Gene (NTSR1) Polymorphism Is Associated with Working Memory

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    BACKGROUND: Recent molecular genetics studies showed significant associations between dopamine-related genes (including genes for dopamine receptors, transporters, and degradation) and working memory, but little is known about the role of genes for dopamine modulation, such as those related to neurotensin (NT), in working memory. A recent animal study has suggested that NT antagonist administration impaired working memory in a learning task. The current study examined associations between NT genes and working memory among humans. METHODS: Four hundred and sixty healthy undergraduate students were assessed with a 2-back working memory paradigm. 5 SNPs in the NTSR1 gene were genotyped. 5 ANOVA tests were conducted to examine whether and how working memory differed by NTSR1 genotype, with each SNP variant as the independent variable and the average accuracy on the working memory task as the dependent variable. RESULTS: ANOVA results suggested that two SNPs in the NTSR1 gene (rs4334545 and rs6090453) were significantly associated with working memory. These results survived corrections for multiple comparisons. CONCLUSIONS: Our results demonstrated that NTSR1 SNP polymorphisms were significantly associated with variance in working memory performance among healthy adults. This result extended previous rodent studies showing that the NT deficiency impairs the working memory function. Future research should replicate our findings and extend to an examination of other dopamine modulators

    Continuous nanobelts of nickel oxide–cobalt oxide hybrid with improved capacitive charge storage properties

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    This paper reports the synthesis of continuous nanobelts, whose thickness is less than half of its pore diameter, of a material hybrid composing of nanograins of nickel oxide and cobalt oxide by electrospinning technique and their capacitive charge storage properties. While the constituent binary metal oxides (NiO and Co3O4) formed solid cylindrical nanofibers the hybrid and a stoichiometric compound in the Ni-Co-O system, i.e., spinel-type NiCo2O4, formed as thin nanobelts due to the magnetic interaction between nickel and cobalt ions. The nanobelts showed six-fold larger surface area, wider pores, and impressive charge storage capabilities compared to the cylindrical fibres. The hybrid nanobelts showed high specific capacitance (CS ~ 1250 F g− 1 at 10 A g− 1 in 6 M KOH) with high capacity retention, which is appreciably larger than found for the stoichiometric compound (~ 970 F g− 1 at 10 A g− 1). It is shown that the hybrid nanobelts have lower internal resistance (1.3 Ω), higher diffusion coefficient (4.6 × 10− 13 cm2 s− 1) and smaller relaxation time (0.03 s) than the benchmark materials studied here
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