2,386 research outputs found

    Comparing weak versions of separability

    Get PDF
    Our aim is to investigate spaces with sigma-discrete and meager dense sets, as well as selective versions of these properties. We construct numerous examples to point out the differences between these classes while answering questions of Tkachuk [30], Hutchinson [17] and the authors of [8]

    Surface-enhanced Raman spectroscopy in 3D electrospun nanofiber mats coated with gold nanorods

    Full text link
    Nanofibers functionalized by metal nanostructures and particles are exploited as effective flexible substrates for SERS analysis. Their complex three-dimensional structure may provide Raman signals enhanced by orders of magnitude compared to untextured surfaces. Understanding the origin of such improved performances is therefore very important for pushing nanofiber-based analytical technologies to their upper limit. Here we report on polymer nanofiber mats which can be exploited as substrates for enhancing the Raman spectra of adsorbed probe molecules. The increased surface area and the scattering of light in the nanofibrous system are individually analyzed as mechanisms to enhance Raman scattering. The deposition of gold nanorods on the fibers further amplifies Raman signals due to SERS. This study suggests that Raman signals can be finely tuned in intensity and effectively enhanced in nanofiber mats and arrays by properly tailoring the architecture, composition, and light-scattering properties of the complex networks of filaments.Comment: 29 pages, 9 figures, 1 Tabl

    Association between Resistin Levels and All-Cause and Cardiovascular Mortality: A New Study and a Systematic Review and Meta-Analysis.

    Get PDF
    CONTEXT: Studies concerning the association between circulating resistin and mortality risk have reported, so far, conflicting results. OBJECTIVE: To investigate the association between resistin and both all-cause and cardiovascular (CV) mortality risk by 1) analyzing data from the Gargano Heart Study (GHS) prospective design (n=359 patients; 81 and 58 all-cause and CV deaths, respectively); 2) performing meta-analyses of all published studies addressing the above mentioned associations. DATA SOURCE AND STUDY SELECTION: MEDLINE and Web of Science search of studies reporting hazard ratios (HR) of circulating resistin for all-cause or CV mortality. DATA EXTRACTION: Performed independently by two investigators, using a standardized data extraction sheet. DATA SYNTHESIS: In GHS, adjusted HRs per one standard deviation (SD) increment in resistin concentration were 1.28 (95% CI: 1.07-1.54) and 1.32 (95% CI: 1.06-1.64) for all-cause and CV mortality, respectively. The meta-analyses included 7 studies (n=4016; 961 events) for all-cause mortality and 6 studies (n=4,187: 412 events) for CV mortality. Pooled HRs per one SD increment in resistin levels were 1.21 (95% CI: 1.03-1.42, Q-test p for heterogeneity<0.001) and 1.05 (95% CI: 1.01-1.10, Q-test p for heterogeneity=0.199) for all-cause and CV mortality, respectively. At meta-regression analyses, study mean age explained 9.9% of all-cause mortality studies heterogeneity. After adjusting for age, HR for all-cause mortality was 1.24 (95% CI: 1.06-1.45). CONCLUSIONS: Our results provide evidence for an association between circulating resistin and mortality risk among high-risk patients as are those with diabetes and coronary artery disease

    New molecular tool for a quick and easy detection of apple scab in the field

    Get PDF
    Venturia inaequalis, an agent of apple scab, is the most important pathogen of Malus x domestica. Control measures against this pathogen rely on intensive phytosanitary programs based on predictive models to identify the meteorological conditions conducive to the primary infection. The detection of the pathogen in field, both in naturally infected symptomatic and asymptomatic leaves, is desirable. Loop-mediated isothermal amplification (LAMP) assays are profitable molecular diagnostic tools for the direct detection of pathogens in field. A LAMP assay for V. inaequalis has been designed on the elongation factor 1-alpha sequence. The validation of the LAMP assay was carried out following the international EPPO standard PM 7/98 in terms of specificity, sensitivity, repeatability and reproducibility. Specificity testing was performed using target and non-target species, such as phylogenetically related Venturia species and other pathogens commonly found in apple, resulting in positive amplification only for the target with a time to positive ranging from 20 to 30 min. Sensitivity testing was performed with serial dilutions of DNA of the target and by artificial inoculation of young apple leaves. The reliability of the LAMP assay as an early-detection tool and its user-friendly application make it suitable for the diagnosis of apple scab in the field

    Metagenomics approaches for the detection and surveillance of emerging and recurrent plant pathogens

    Get PDF
    Globalization has a dramatic effect on the trade and movement of seeds, fruits and vegetables, with a corresponding increase in economic losses caused by the introduction of transboundary plant pathogens. Current diagnostic techniques provide a useful and precise tool to enact surveillance protocols regarding specific organisms, but this approach is strictly targeted, while metabarcoding and shotgun metagenomics could be used to simultaneously detect all known pathogens and potentially new ones. This review aims to present the current status of high-throughput sequencing (HTS) diagnostics of fungal and bacterial plant pathogens, discuss the challenges that need to be addressed, and provide direction for the development of methods for the detection of a restricted number of related taxa (specific surveillance) or all of the microorganisms present in a sample (general surveillance). HTS techniques, particularly metabarcoding, could be useful for the surveillance of soilborne, seedborne and airborne pathogens, as well as for identifying new pathogens and determining the origin of outbreaks. Metabarcoding and shotgun metagenomics still suffer from low precision, but this issue can be limited by carefully choosing primers and bioinformatic algorithms. Advances in bioinformatics will greatly accelerate the use of metagenomics to address critical aspects related to the detection and surveillance of plant pathogens in plant material and foodstuffs
    corecore