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•A stable cobalt doped CuO NPs as reduction catalyst is synthesized by a thermal route.•Cobalt doping resulted in decrease in particle size of CuO NPs.•Positron annihilation lifetime ...spectroscopy revealed cobalt at grain boundaries of CuO.•Reduction of 4-NP to 4-AP in less than 3min using 2mg/L Co doped CuO catalyst.•Catalytic reduction explained by hydride transfer mechanism.
We present here a simple thermal route for synthesizing 5.1wt% cobalt doped CuO nanoparticles (NPs) as the optimized composition of the best heterogeneous CuO catalyst for catalytic reduction of toxic 4-nitrophenol to industrially beneficial 4-aminophenol. The reduction is completed in merely 3min in the presence of 8mM NaBH4 as reducing agent. The optimized catalyst dose was 2mg/L for converting 0.12mM 4-nitrophenol and the corresponding rate constant (k) for reduction reaction was 43.8×10−3s−1 per mg of catalyst. The catalytic reduction reaction was monitored by UV–vis spectroscopy method and by HPLC analysis. The mechanism is discussed in the light of hydride transfer phenomenon facilitated by large surface area and positive surface charge of the cobalt doped CuO nanoparticles. The cobalt doping resulted in: (a) increasing surface area due to decrease in particle size of the CuO NPs to 10nm, measured by HRTEM; (b) improve stability of the cobalt doped CuO NPs. The cobalt dopant occupied the grain boundaries of CuO to reduce the particle size as derived from positron annihilation lifetime spectroscopy. The X-ray photoelectron spectroscopy analysis of unused catalyst and the spent catalyst revealed occurrence of Co2+ and Co3+ states at the surface. While the X-ray diffraction studies of spent catalyst confirmed the inhibition of reduction of the surface CuO to metallic copper in the presence of NaBH4, attributable to cobalt doping. It was concluded that cobalt doping led to stable and efficient CuO NPs as catalyst for reduction reaction.
ABSTRACT
Polymyositis and dermatomyositis are inflammatory myopathies that differ in their clinical features, histopathology, response to treatment, and prognosis. Although their clinical pictures ...differ, they both present with symmetrical, proximal muscle weakness. Treatment relies mainly upon empirical use of corticosteroids and immunosuppressive agents. A deeper understanding of the molecular pathways that drive pathogenesis, careful phenotyping, and accurate disease classification will aid clinical research and development of more efficacious treatments. In this review we address the current knowledge of the epidemiology, clinical characteristics, diagnostic evaluation, classification, pathogenesis, treatment, and prognosis of polymyositis and dermatomyositis. Muscle Nerve 51:638–656, 2015
Combinatorial synthesis via a continuous composition spread is an excellent route to develop thin-film libraries as it is both time- and cost-efficient. Creating libraries of functional, ...multicomponent, complex oxide films requires excellent control over the synthesis parameters combined with high-throughput analytical feedback. A reliable, high-throughput, in-situ characterization analysis method is required to meet the crucial need to rapidly screen materials libraries. Here, we report on the combination of two in-situ techniques-(a) Reflection high-energy electron diffraction (RHEED) for heteroepitaxial characterization and a newly developed compositional analysis technique, low-angle x-ray spectroscopy (LAXS), to map the chemical composition profile of combinatorial heteroepitaxial complex oxide films deposited using a continuous composition spread method via pulsed laser deposition. This is accomplished using a unique state-of-the-art combinatorial growth system with a fully synchronized four-axis mechanical substrate stage without shadow masks, alternating acquisition of chemical compositional data using LAXS at various different positions on the Formula: see text 41 mm Formula: see text 41 mm range and sequential deposition of multilayers of SrTiOFormula: see text and Formula: see text on a 2-inch (50.8 mm) Formula: see text wafer in a single growth run. Rutherford backscattering spectrometry (RBS) is used to calibrate and validate the compositions determined by LAXS. This study shows the feasibility of combinatorial synthesis of heteroepitaxial, functional complex oxide films at wafer-scale via two essential in-situ characterization tools-RHEED for structural analysis or heteroepitaxy and LAXS for compositional characterization. This is a powerful technique for development of new films with optimized heteroepitaxy and composition.
An agricultural waste-derived rice husk ash (RHA) as a source of silica was synthesized using a conventional low-cost method and subsequently used as a reinforcing agent to develop epoxy/RHA ...composites for microelectronic applications. The chemical composition and phase analysis of as-synthesized RHA was performed using x-ray fluorescence (XRF) spectroscopy and x-ray diffraction (XRD) techniques, respectively. The thermal, thermomechanical and dielectric properties of the epoxy/RHA composites were determined. The dispersion of RHA and the interfacial bonding between RHA and epoxy was studied using scanning electron microscopy (SEM). The addition of RHA in epoxy enhanced the glass transition temperature (
T
g
) of the composites significantly and all the composites showed better thermal stability than neat epoxy. The coefficient of thermal expansion (CTE) of the epoxy resin was reduced by 29.2% after the addition of 18.81 vol.% RHA. The storage modulus of epoxy/RHA composites was significantly enhanced up to 55.3% compared to neat epoxy. As compare to neat epoxy the composite with 18.81 vol.% RHA loading showed 44.7% improvement in microhardness. The dielectric constant of the epoxy decreased when the RHA was incorporated into it however epoxy/RHA composites exhibited insignificant change in dissipation factor compared to neat epoxy.
Background
Prior studies have demonstrated improved disease‐specific survival of mycosis fungoides (MF) patients over the last 50 years.
Objective
To analyse patterns of survival and incidence from ...1973 to 2016 and determine whether apparent improvements in MF‐specific survival are due to lead‐time bias rather than improvements in treatment.
Methods
We performed an analysis of 10 155 patients diagnosed with MF from 1973 to 2016 in the United States cancer registries of SEER‐18. We also performed a literature review of papers including stage data for unselected populations of MF patients prior to 2000.
Results
Incidence of MF increased from 3.0 per million person‐years in the 1970s to 5.9 in the 2010s. For all cohorts, non‐Hodgkin lymphoma (including MF) was the leading cause of death. Survival analysis demonstrated marked improvement in disease‐specific and overall survival from the 1970s to 2010s. Based on systematic review of the literature, 32%–73% of patients diagnosed prior to 2000 were diagnosed with early‐stage disease, as opposed to 81% of patients in the SEER 2000–2016 cohort (P < 0.035 for all cohorts).
Conclusions
Although there have been improvements in MF‐related survival over the last 50 years, these may reflect improvements in our ability to diagnose early‐stage disease rather than improved treatment.
Background
Patients with mycosis fungoides (MF) are at increased risk of developing non‐Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL), lung cancer, bladder cancer and melanoma. The characteristics of ...patients developing these malignancies have not been specifically delineated. In addition, there are no established guidelines for screening MF patients for second malignancies.
Materials/Methods
We identified 742 patients with MF who developed second malignancies in the Surveillance Epidemiology and End Result‐18 database.
Results
The majority of second malignancy patients were white and male, mean age 55–67 years at diagnosis of MF, and mean age 61–72 years at diagnosis of second malignancy. The majority of patients diagnosed with second malignancies had early stage MF. MF patients with NHL, lung cancer, and bladder cancer tended to be diagnosed at earlier stages of the second malignancy than patients without MF and demonstrated better 5‐year overall survival. There was no improvement in stage at diagnosis or survival for MF patients who were diagnosed with melanoma compared to patients without MF.
Conclusions
Improvements in survival in MF/NHL, MF/lung cancer and MF/bladder cancer patients may reflect differences in disease biology secondary to having MF or the importance of increased contact with the healthcare system. MF/melanoma data suggest that patients require regular pigmented‐lesion‐focused skin examinations. Tools for screening include regular lymph node examinations, pigmented‐lesion‐focused examinations and detailed review of systems questions. Smoking cessation counseling is key intervention in this population, as is ensuring that all age‐ and sex‐specific cancer screenings are up‐to‐date (e.g. lung cancer screening, mammography, and colonoscopy). The utility of regular imaging for second malignancy screening and lab testing such as routine urinalysis requires additional study and expert consensus.
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