Effect of polyvinyl alcohol ligands on supported gold nano-catalysts: Morphological and kinetics studies

The effect of polyvinyl alcohol (PVA) stabilizers and gold nanoparticles supported on active carbon (AuNPs/AC) was investigated in this article. Polymers with different molecular weights and hydrolysis degrees have been synthesized and used, like the stabilizing agent of Au nano-catalysts obtained by the sol-immobilization method. The reduction of 4-nitrophenol with NaBH4 has been used as a model reaction to investigate the catalytic activity of synthesized Au/AC catalysts. In addition, we report several characterization techniques such as ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) in order to correlate the properties of the polymer with the metal nanoparticle size and the catalytic activity. A volcano plot was observed linking the catalytic performance with hydrolysis degree and the maximum of the curve was identified at a value of 60%. The Au:PVA-60 weight ratio was changed in order to explain how the amount of the polymer can influence catalytic properties. The effect of nitroaromatic ring substituents on the catalytic mechanism was examined by the Hammett theory. Moreover, the reusability of the catalyst was investigated, with little to no decrease in activity observed over five catalytic cycles. Morphological and kinetic studies reported in this paper reveal the effect of the PVA polymeric stabilizer properties on the size and catalytic activity of supported gold nanoparticles

FAK Mediates a Compensatory Survival Signal Parallel to PI3K-AKT in PTEN-Null T-ALL Cells

SummaryMutations and inactivation of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) are observed in 15%–25% of cases of human T cell acute lymphoblastic leukemia (T-ALL). Pten deletion induces myeloproliferative disorders (MPDs), acute myeloid leukemia (AML), and/or T-ALL in mice. Previous studies attributed Pten-loss-related hematopoietic defects and leukemogenesis to excessive activation of phosphatidylinositol 3-kinase (PI3K)/AKT/mTOR signaling. Although inhibition of this signal dramatically suppresses the growth of PTEN-null T-ALL cells in vitro, treatment with inhibitors of this pathway does not cause a complete remission in vivo. Here, we report that focal adhesion kinase (Fak), a protein substrate of Pten, also contributes to T-ALL development in Pten-null mice. Inactivation of the FAK signaling pathway by either genetic or pharmacologic methods significantly sensitizes both murine and human PTEN-null T-ALL cells to PI3K/AKT/mTOR inhibition when cultured in vitro on feeder layer cells or a matrix and in vivo

The bank lending channel: an empirical assessment of measures to stimulate bank lending in the European Union

This thesis first examines the role of banks in the transmission mechanism of monetary policy by focusing on the eight European new member States of Central and Eastern Europe over the 2004-2013 period. We specifically investigate the influence of monetary policy changes on bank lending activity and if this potential influence is contingent on bank characteristics, such as banks’ size, capital, liquidity, risk factor and market power. Moreover, we focus on the prospective role of banks in the monetary policy transmission mechanism in order to reveal any clear trends in banks’ lending behaviour during the 2008-2011 financial crisis. Secondly, we investigate the impact of a protracted period of low monetary policy rates on loosening of banks’ credit standards regarding enterprises, households and consumer loans through concentrating on the nine Eurozone countries involved since the initiation of the Euro area Bank Lending Survey in the three distinct time frames of pre- (2002Q4-2008Q3), mid- (2008Q4-2010Q4) and post- (2011Q1-2014:Q4) financial crisis. Furthermore, we test the fundamental concept of the risk taking channel by examining excessive risk-taking behaviour by banks in stressed vs. non-stressed countries of the Eurozone. In an additional analysis, the efficacy of the European Central Bank’s 3 year Long-Term Refinancing Operations is evaluated in great depth in order to determine whether banks’ credit standards have been softened and the degree to which demand for loans has increased. Thirdly, we explore the financing structure of bank lending constrained Small and Medium Sized Enterprises in the eleven Eurozone countries by utilising firm-level data over the period of 2009 to 2014. We estimate if bank lending constrained firms demonstrate relatively more usage or requests for alternative financing. Additionally, a comprehensive investigation is presented by unveiling the impact and determinants of various financing constraints including credit lines, bank loans, trade credit and other lending on Eurozone firms. Furthermore, the notion of discouraged borrowers originally formulated by Kon and Storey (2003) is empirically evaluated. Finally, we present the conclusion of our research by further outlining its limitations and prospective scope for future studie

"Delirium Day": A nationwide point prevalence study of delirium in older hospitalized patients using an easy standardized diagnostic tool

Background: To date, delirium prevalence in adult acute hospital populations has been estimated generally from pooled findings of single-center studies and/or among specific patient populations. Furthermore, the number of participants in these studies has not exceeded a few hundred. To overcome these limitations, we have determined, in a multicenter study, the prevalence of delirium over a single day among a large population of patients admitted to acute and rehabilitation hospital wards in Italy. Methods: This is a point prevalence study (called "Delirium Day") including 1867 older patients (aged 65 years or more) across 108 acute and 12 rehabilitation wards in Italian hospitals. Delirium was assessed on the same day in all patients using the 4AT, a validated and briefly administered tool which does not require training. We also collected data regarding motoric subtypes of delirium, functional and nutritional status, dementia, comorbidity, medications, feeding tubes, peripheral venous and urinary catheters, and physical restraints. Results: The mean sample age was 82.0 \ub1 7.5 years (58 % female). Overall, 429 patients (22.9 %) had delirium. Hypoactive was the commonest subtype (132/344 patients, 38.5 %), followed by mixed, hyperactive, and nonmotoric delirium. The prevalence was highest in Neurology (28.5 %) and Geriatrics (24.7 %), lowest in Rehabilitation (14.0 %), and intermediate in Orthopedic (20.6 %) and Internal Medicine wards (21.4 %). In a multivariable logistic regression, age (odds ratio [OR] 1.03, 95 % confidence interval [CI] 1.01-1.05), Activities of Daily Living dependence (OR 1.19, 95 % CI 1.12-1.27), dementia (OR 3.25, 95 % CI 2.41-4.38), malnutrition (OR 2.01, 95 % CI 1.29-3.14), and use of antipsychotics (OR 2.03, 95 % CI 1.45-2.82), feeding tubes (OR 2.51, 95 % CI 1.11-5.66), peripheral venous catheters (OR 1.41, 95 % CI 1.06-1.87), urinary catheters (OR 1.73, 95 % CI 1.30-2.29), and physical restraints (OR 1.84, 95 % CI 1.40-2.40) were associated with delirium. Admission to Neurology wards was also associated with delirium (OR 2.00, 95 % CI 1.29-3.14), while admission to other settings was not. Conclusions: Delirium occurred in more than one out of five patients in acute and rehabilitation hospital wards. Prevalence was highest in Neurology and lowest in Rehabilitation divisions. The "Delirium Day" project might become a useful method to assess delirium across hospital settings and a benchmarking platform for future surveys

Pediatric drug safety signal detection: a new drug-event reference set for performance testing of data-mining methods and systems

BACKGROUND: Better evidence regarding drug safety in the pediatric population might be generated from existing data sources such as spontaneous reporting systems and electronic healthcare records. The Global Research in Paediatrics (GRiP)-Network of Excellence aims to develop pediatric-specific methods that can be applied to these data sources. A reference set of positive and negative drug-event associations is required. OBJECTIVE: The aim of this study was to develop a pediatric-specific reference set of positive and negative drug-event associations. METHODS: Considering user patterns and expert opinion, 16 drugs that are used in individuals aged 0-18 years were selected and evaluated against 16 events, regarded as important safety outcomes. A cross-table of unique drug-event pairs was created. Each pair was classified as potential positive or negative control based on information from the drug's Summary of Product Characteristics and Micromedex. If both information sources consistently listed the event as an adverse event, the combination was reviewed as potential positive control. If both did not, the combination was evaluated as potential negative control. Further evaluation was based on published literature. RESULTS: Selected drugs include ibuprofen, flucloxacillin, domperidone, methylphenidate, montelukast, quinine, and cyproterone/ethinylestradiol. Selected events include bullous eruption, aplastic anemia, ventricular arrhythmia, sudden death, acute kidney injury, psychosis, and seizure. Altogether, 256 unique combinations were reviewed, yielding 37 positive (17 with evidence from the pediatric population and 20 with evidence from adults only) and 90 negative control pairs, with the remainder being unclassifiable. CONCLUSION: We propose a drug-event reference set that can be used to compare different signal detection methods in the pediatric population

Phosphorylated poly(vinyl alcohol) surface coatings as intumescent flame inhibitor for polymer matrix composites

Flammability is one of the main drawbacks affecting polymer matrix composites (PMCs), limiting metal replacement in several applications. Phosphorus compounds demonstrated a great ability in contrasting fire spreading. Here, phosphorylated poly(vinyl alcohol) (PPVA) has been synthesized and used as an intumescent flame inhibitor coating for carbon fiber reinforced polymer (CFRP) laminates. The synthesized PPVAs, with a phosphorylation degree up to 7.5 %wt, were investigated by spectroscopic (NMR and IR) and thermal (TGA and DSC) analyses. Moreover, thermal degradation kinetics was also rationalized by applying differential and integrals methods: the phosphorus catalytic effect combined with radicals-coupling behaviour deriving from the phosphorus species developed during the combustion has been highlighted, confirming the inhibitor role of PPVAs. Cone-calorimeter tests, simulating a small-scale fire scenario, were carried out on poly(vinyl alcohol)-coated and PPVA-coated materials prepared by solvent casting. Results highlight the anti-flame properties of PPVAs, especially as effective flame inhibitors: up to −58 % in the time of flame (TOF). Instead, poly(vinyl alcohol) coatings lead to an overall worsening of the material fire behaviour, highlighting the crucial role of phosphorous to reduce flammability. Such promising results pave the way for the use of PPVA coatings to reduce the fire risk of flammable composites making them safer

Electron diffraction study of the sillenites Bi12SiO20, Bi25FeO39 and Bi25InO39: Evidence of short-range ordering of oxygen-vacancies in the trivalent sillenites

We present an electron diffraction study of three sillenites, Bi12SiO20, Bi25FeO39, and Bi25InO39 synthesized using the solid-state method. We explore a hypothesis, inspired by optical studies in the literature, that suggests that trivalent sillenites have additional disorder not present in the tetravalent compounds. Electron diffraction patterns of Bi25FeO39 and Bi25InO39 show streaks that confirm deviations from the ideal sillenite structure. Multi-slice simulations of electron-diffraction patterns are presented for different perturbations to the sillenite structure - partial substitution of the M site by Bi3+, random and ordered oxygen-vacancies, and a frozen-phonon model. Although comparison of experimental data to simulations cannot be conclusive, we consider the streaks as evidence of short-range ordered oxygen-vacancies