53 research outputs found

    IIT Hyderabad scientists convert fly ash into waterproofing material

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    Researchers from the Indian Institute of Technology Hyderabad (IIT H) have found that fly ash — waste byproduct of power plants that poses a threat to the environment — can be modified into a waterproofing material

    Biocompatible and antimicrobial multilayer fibrous polymeric wound dressing with optimally embedded silver nanoparticles

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    The demand for advanced, biocompatible wound dressings with antibacterial properties is increasing in order to treat people with severe skin wounds, such as burn victims or those suffering from ulcers. We have developed an ultrafine three-layer polymer nanofiber mesh using electrospinning that is able to kill bacteria (Escherichia coli; E. coli and Staphylococcus aureus; S. aureus) but also has cytocompatibility properties. The first layer was generated with polystyrene (PS) for strength and functions as a carrier layer. The second layer consisted of polycaprolactone (PCL) with silver nanoparticles (Ag NPs) that were added to the spinning solution, which had antibacterial properties. Finally, the third layer comprised of polyethylene oxide (PEO) acting as a hydrophilic, barrier layer that was also non-adhesive, with the potential to further assist in wound healing. Systematic physicochemical and biological characterization was performed including dynamic light scattering (DLS), UV spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), scanning electron microscopy (SEM), water contact angles, evaluation of antibacterial properties, and cell attachment and proliferation assays. The cumulative Ag ion release was optimized for a period up to 84 days in physiologically similar media at physiological temperature. Chemical, mechanical, and biological analysis demonstrated that incorporation of Ag NPs at higher quantities into the PCL fibers layer providing excellent antimicrobial activity with minimal toxicity at low concentration. The findings highlight the importance of optimizing the properties of Ag based antibacterial meshes to find the balance between high antibacterial activity and low toxicity

    The CMS Outer Hadron Calorimeter

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    The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with a outer calorimeter to ensure high energy shower containment in CMS and thus working as a tail catcher. Fabrication, testing and calibrations of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter has a very good signal to background ratio even for a minimum ionising particle and can hence be used in coincidence with the Resistive Plate Chambers of the CMS detector for the muon trigger

    Design, Performance, and Calibration of the CMS Hadron-Outer Calorimeter

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    The CMS hadron calorimeter is a sampling calorimeter with brass absorber and plastic scintillator tiles with wavelength shifting fibres for carrying the light to the readout device. The barrel hadron calorimeter is complemented with an outer calorimeter to ensure high energy shower containment in the calorimeter. Fabrication, testing and calibration of the outer hadron calorimeter are carried out keeping in mind its importance in the energy measurement of jets in view of linearity and resolution. It will provide a net improvement in missing \et measurements at LHC energies. The outer hadron calorimeter will also be used for the muon trigger in coincidence with other muon chambers in CMS

    Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world

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    Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic. Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality. Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States. Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis. Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection

    Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

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    Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

    N-doped MWCNTs from catalyst-free, direct pyrolysis of commercial glue

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    We report a unique, catalyst-free, direct pyrolysis process to obtain nitrogen-doped multiwall carbon nanotubes (N-MWCNTs). The process includes the polymerization of ethyl cyanoacrylate (ECA) based commercial super glue with aqueous NaCl solution. The resultant poly-ethyl cyanoacrylate (PECA)-NaCl composite was washed to remove NaCl and subsequently calcined at 1000 °C in an inert atmosphere to obtain carbon nanotubes. The field emission scanning electron microscopy and high-resolution transmission electron microscopy studies confirm that these are nitrogen-doped multiwall carbon nanotubes (N-MWCNTs) with diameters in the range of 80–110 nm. Compared to conventional MWCNTs, these nanotubes exhibit distinct multilayer stacking of carbon with short-range ordering with interlayer spacing slightly larger than graphitic carbon. XPS studies reveal the presence of doped nitrogen substituting for carbon atoms, whereas Raman spectroscopy data shows that these nitrogen-doped nanotubes exhibit nanocrystalline, graphitic carbon. Washing of PECA-NaCl composite results in the removal of NaCl leading to the unique porous PECA intermediate structure. These unique morphological changes and structural transformations of PECA in DI water along with the peculiar degradation behavior of PECA during the heat treatment process may be responsible for the formation of N-MWCNT

    Low temperature synthesis and characterization of single phase multi-component fluorite oxide nanoparticle sols

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    We report for the first time a simple, scalable approach for the synthesis of single-phase multi-component fluorite oxide nanoparticle sols: Gd0.2La0.2Y0.2Hf0.2Zr0.2O2 (GLYHZ) and Gd0.2La0.2Ce0.2Hf0.2Zr0.2O2 (GLCHZ) using chemical co-precipitation followed by peptization in acidic medium under mild conditions (≤80 °C). High resolution transmission electron microscopy (HRTEM) along with selected area electron diffraction (SAED) studies confirm fully crystalline single-phase cubic fluorite nanoparticles having a particle size of about 2–3 nm with a narrow size distribution was obtained. The powder X-ray diffraction (XRD) and Rietveld refinement studies of samples calcined at 500 °C for 4 hours confirm a single phase solid solution and a lack of secondary phases
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