5,784 research outputs found

    Synthesis of titanate nanostructures using amorphous precursor material and their adsorption/photocatalytic properties

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    This paper reports on a new and swift hydrothermal chemical route to prepare titanate nanostructures (TNS) avoiding the use of crystalline TiO2 as starting material. The synthesis approach uses a commercial solution of TiCl3 as titanium source to prepare an amorphous precursor, circumventing the use of hazardous chemical compounds. The influence of the reaction temperature and dwell autoclave time on the structure and morphology of the synthesised materials was studied. Homogeneous titanate nanotubes with a high length/diameter aspect ratio were synthesised at 160^{\circ}C and 24 h. A band gap of 3.06\pm0.03 eV was determined for the TNS samples prepared in these experimental conditions. This value is red shifted by 0.14 eV compared to the band gap value usually reported for the TiO2 anatase. Moreover, such samples show better adsorption capacity and photocatalytic performance on the dye rhodamine 6G (R6G) photodegradation process than TiO2 nanoparticles. A 98% reduction of the R6G concentration was achieved after 45 minutes of irradiation of a 10 ppm dye aqueous solution and 1 g/L of TNS catalyst.Comment: 29 pages, 10 figures, accepted for publication in Journal of Materials Scienc

    Sacroiliac Joint Fusion – Impact of a New Image-Guidance Protocol on Safety and Complications

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    INTRODUCTION Low back pain is a common affliction impacting patients worldwide. The burden of low back pain on modern society in terms of direct costs associated with diagnosis and treatment, as well as indirect costs such as time missed from work for both patients and caregivers, is estimated to be as high as $100 billion annually in the United States alone.1,2 Up to 2-3% of physician visits are thought to be related to chronic low back pain.1,3 While the traditional focus of healthcare providers has been on lumbosacral pathology, sacroiliac joint dysfunction is an underappreciated and underdiagnosed cause of low back pain. Previous studies3-8 have suggested that 15-30% of chronic low back pain is due to pathology located in the sacroiliac joint. Historically, recognition of this pathology was difficult, limited by lack of standardized diagnostic criteria and disease-specific outcome measures. Traditional treatment focused on conservative therapy, such as physical therapy with focus on core and pelvic stability, orthoses, pain and anti-inflammatory medication, weight loss, intra- or peri-articular injections, and radiofrequency ablation.4,5,9-12 Early surgical intervention came in the form of morbid open approaches often utilizing iliac crest autografting. More recently, minimally invasive techniques for sacroiliac fusion have been developed that allow for significant sparing of muscle dissection, shorter operating room times and blood loss, reduced length of stay, and fewer complications.13-17 Such techniques are often performed with fluoroscopic guidance. However, three-dimensional sacral anatomy can be challenging to conceptualize on fluoroscopic imaging and several centers are now beginning to perform the procedure utilizing image-guidance with intraoperative CT data. This is particularly helpful in patients with transitional lumbosacral anatomy or those undergoing revision procedures. Complications such as pseudarthrosis and neural injuries, while rare, are often associated with need for revision surgery and poorer outcome.18,19 The transition to CT-based image-guidance aims to reduce such complications. The purpose of this study is to review our series of minimally invasive sacroiliac fusion with a focus on safety and complications, and to review differences in these parameters between patients undergoing fluoroscopic technique versus CT-based image-guidance

    Holographic Vitrification

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    We establish the existence of stable and metastable stationary black hole bound states at finite temperature and chemical potentials in global and planar four-dimensional asymptotically anti-de Sitter space. We determine a number of features of their holographic duals and argue they represent structural glasses. We map out their thermodynamic landscape in the probe approximation, and show their relaxation dynamics exhibits logarithmic aging, with aging rates determined by the distribution of barriers.Comment: 100 pages, 25 figure

    Novel role for the innate immune receptor toll-like receptor 4 (TLR4) in the regulation of the wnt signaling pathway and photoreceptor apoptosis

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    Recent evidence has implicated innate immunity in regulating neuronal survival in the brain during stroke and other neurodegenerations. Photoreceptors are specialized light-detecting neurons in the retina that are essential for vision. In this study, we investigated the role of the innate immunity receptor TLR4 in photoreceptors. TLR4 activation by lipopolysaccharide (LPS) significantly reduced the survival of cultured mouse photoreceptors exposed to oxidative stress. With respect to mechanism, TLR4 suppressed Wnt signaling, decreased phosphorylation and activation of the Wnt receptor LRP6, and blocked the protective effect of the Wnt3a ligand. Paradoxically, TLR4 activation prior to oxidative injury protected photoreceptors, in a phenomenon known as preconditioning. Expression of TNFα and its receptors TNFR1 and TNFR2 decreased during preconditioning, and preconditioning was mimicked by TNFα antagonists, but was independent of Wnt signaling. Therefore, TLR4 is a novel regulator of photoreceptor survival that acts through the Wnt and TNFα pathways. © 2012 Yi et al

    Guidance on noncorticosteroid systemic immunomodulatory therapy in noninfectious uveitis: fundamentals of care for uveitis (focus) initiative

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    Topic: An international, expert-led consensus initiative to develop systematic, evidence-based recommendations for the treatment of noninfectious uveitis in the era of biologics. Clinical Relevance: The availability of biologic agents for the treatment of human eye disease has altered practice patterns for the management of noninfectious uveitis. Current guidelines are insufficient to assure optimal use of noncorticosteroid systemic immunomodulatory agents. Methods: An international expert steering committee comprising 9 uveitis specialists (including both ophthalmologists and rheumatologists) identified clinical questions and, together with 6 bibliographic fellows trained in uveitis, conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol systematic reviewof the literature (English language studies from January 1996 through June 2016; Medline [OVID], the Central Cochrane library, EMBASE,CINAHL,SCOPUS,BIOSIS, andWeb of Science). Publications included randomized controlled trials, prospective and retrospective studies with sufficient follow-up, case series with 15 cases or more, peer-reviewed articles, and hand-searched conference abstracts from key conferences. The proposed statements were circulated among 130 international uveitis experts for review.Atotal of 44 globally representativegroupmembersmet in late 2016 to refine these guidelines using a modified Delphi technique and assigned Oxford levels of evidence. Results: In total, 10 questions were addressed resulting in 21 evidence-based guidance statements covering the following topics: when to start noncorticosteroid immunomodulatory therapy, including both biologic and nonbiologic agents; what data to collect before treatment; when to modify or withdraw treatment; how to select agents based on individual efficacy and safety profiles; and evidence in specific uveitic conditions. Shared decision-making, communication among providers and safety monitoring also were addressed as part of the recommendations. Pharmacoeconomic considerations were not addressed. Conclusions: Consensus guidelines were developed based on published literature, expert opinion, and practical experience to bridge the gap between clinical needs and medical evidence to support the treatment of patients with noninfectious uveitis with noncorticosteroid immunomodulatory agents

    Associations Between Methylation of Paternally Expressed Gene 3 (PEG3), Cervical Intraepithelial Neoplasia and Invasive Cervical Cancer.

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    Cytology-based screening for invasive cervical cancer (ICC) lacks sensitivity and specificity to discriminate between cervical intraepithelial neoplasia (CIN) likely to persist or progress from cases likely to resolve. Genome-wide approaches have been used to identify DNA methylation marks associated with CIN persistence or progression. However, associations between DNA methylation marks and CIN or ICC remain weak and inconsistent. Between 2008-2009, we conducted a hospital-based, case-control study among 213 Tanzania women with CIN 1/2/3 or ICC. We collected questionnaire data, biopsies, peripheral blood, cervical scrapes, Human papillomavirus (HPV) and HIV-1 infection status. We assessed PEG3 methylation status by bisulfite pyrosequencing. Multinomial logistic regression was used to estimate odds ratios (OR) and confidence intervals (CI 95%) for associations between PEG3 methylation status and CIN or ICC. After adjusting for age, gravidity, hormonal contraceptive use and HPV infection, a 5% increase in PEG3 DNA methylation was associated with increased risk for ICC (OR = 1.6; 95% CI 1.2-2.1). HPV infection was associated with a higher risk of CIN1-3 (OR = 15.7; 95% CI 5.7-48.6) and ICC (OR = 29.5, 95% CI 6.3-38.4). Infection with high risk HPV was correlated with mean PEG3 differentially methylated regions (DMRs) methylation (r = 0.34 p<0.0001), while the correlation with low risk HPV infection was weaker (r = 0.16 p = 0.047). Although small sample size limits inference, these data support that PEG3 methylation status has potential as a molecular target for inclusion in CIN screening to improve prediction of progression. Impact statement: We present the first evidence that aberrant methylation of the PEG3 DMR is an important co-factor in the development of Invasive cervical carcinoma (ICC), especially among women infected with high risk HPV. Our results show that a five percent increase in DNA methylation of PEG3 is associated with a 1.6-fold increase ICC risk. Suggesting PEG3 methylation status may be useful as a molecular marker for CIN screening to improve prediction of cases likely to progress

    Study of Bc+B_c^+ decays to the K+Kπ+K^+K^-\pi^+ final state and evidence for the decay Bc+χc0π+B_c^+\to\chi_{c0}\pi^+

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    A study of Bc+K+Kπ+B_c^+\to K^+K^-\pi^+ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0 fb1\mathrm{fb}^{-1} collected by the LHCb experiment in pppp collisions at centre-of-mass energies of 77 and 88 TeV. Evidence for the decay Bc+χc0(K+K)π+B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+ is reported with a significance of 4.0 standard deviations, resulting in the measurement of σ(Bc+)σ(B+)×B(Bc+χc0π+)\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+) to be (9.83.0+3.4(stat)±0.8(syst))×106(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm 0.8(\mathrm{syst}))\times 10^{-6}. Here B\mathcal{B} denotes a branching fraction while σ(Bc+)\sigma(B_c^+) and σ(B+)\sigma(B^+) are the production cross-sections for Bc+B_c^+ and B+B^+ mesons. An indication of bˉc\bar b c weak annihilation is found for the region m(Kπ+)<1.834GeV ⁣/c2m(K^-\pi^+)<1.834\mathrm{\,Ge\kern -0.1em V\!/}c^2, with a significance of 2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html, link to supplemental material inserted in the reference

    Association between air pollution and ventricular arrhythmias in high-risk patients (ARIA study): a multicentre longitudinal study

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    Summary Background Although the effects of air pollution on mortality have been clearly shown in many epidemiological and observational studies, the pro-arrhythmic effects remain unknown. We aimed to assess the short-term effects of air pollution on ventricular arrhythmias in a population of high-risk patients with implantable cardioverter-defibrillators (ICDs) or cardiac resynchronisation therapy defibrillators (ICD-CRT). Methods In this prospective multicentre study, we assessed 281 patients (median age 71 years) across nine centres in the Veneto region of Italy. Episodes of ventricular tachycardia and ventricular fibrillation that were recorded by the diagnostic device were considered in this analysis. Concentrations of particulate matter of less than 10 μm (PM 10 ) and less than 2·5 μm (PM 2·5 ) in aerodynamic diameter, carbon monoxide, nitrogen dioxide, sulphur dioxide, and ozone were obtained daily from monitoring stations, and the 24 h median value was considered. Each patient was associated with exposure data from the monitoring station that was closest to their residence. Patients were followed up for 1 year and then scheduled to have a closing visit, within 1 more year. This study is registered with ClinicalTrials.gov, number NCT01723761. Findings Participants were enrolled from April 1, 2011, to Sept 30, 2012, and follow-ups (completed on April 5, 2014) ranged from 637 to 1177 days (median 652 days). The incidence of episodes of ventricular tachycardia and ventricular fibrillation correlated significantly with PM 2·5 (p 10 . An analysis of ventricular fibrillation episodes alone showed a significant increase in risk of higher PM 2·5 (p=0·002) and PM 10 values (p=0·0057). None of the gaseous pollutants were significantly linked to the occurrence of ventricular tachycardia or ventricular fibrillation. In a subgroup analysis of patients with or without a previous myocardial infarction, only the first showed a significant association between particulate matter and episodes of ventricular tachycardia or ventricular fibrillation. Interpretation Particulate matter has acute pro-arrhythmic effects in a population of high-risk patients, which increase on exposure to fine particles and in patients who have experienced a previous myocardial infarction. The time sequence of the arrhythmic events suggests there is an underlying neurally mediated mechanism. From a clinical point of view, the results of our study should encourage physicians to also consider environmental risk when addressing the prevention of arrhythmic events, particularly in patients with coronary heart disease, advising them to avoid exposure to high levels of fine particulate matter. Funding There was no funding source for this study
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