345 research outputs found
Oxygen reduction in an acid medium : electrocatalysis by CoNPc(1,2) impregnated on a carbon black support; effect of loading and heat treatment
O2 reduction in an acid medium has been investigated on a transition metal macrocycle, CoNPc(1,2), impregnated on a carbon black support with a high dibutylphthalate adsorption value, using a rotating disk electrode and voltammetry techniques described previously, combined with X-ray photoelectron spectroscopy measurements. Optimal activity was found for a bilayer coverage (n = 2) at 17%-18% w/w loading. Heat treatment seems to be beneficial for n 3: it increases the overall number N of exchanged electrons and improves the electrode wetting. For the most active samples, mixed Co(II)/Co(III) valencies were displayed
Oxygen reduction in acid media on supported iron naphthalocyanine: Effect of isomer configuration and pyrolysis
O2 reduction in H2SO4 medium has been investigated on FeNPc impregnations on Norit BrX by the rotating disk electrode technique. Important differences in activity and stability were found between the 1,2- and 2,3-FeNPc isomers (pyrolysed or not). XPS analyses show, for the most inactive sample, strong demetallation and nitrogen losses. This phenomenon can be attributed to the differences in flexibility between the FeNPc isomers, which influences their stabilization on the substrate
Oxygen reduction in acid media: influence of the heat treatment on the FeNPc(1–20 isomer mixture impregnated on carbon blacks and active charcoals
Oxygen reduction with the aid of a number of FeNPc(1–2) impregnated carbon supports in sulphuric acid solutions has been investigated.\ud
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Loading of the carbon samples amounted to about 10 wt.%. After a 10 day stay in the aerated solutions the samples were investigated with rotating disk electrode and X-ray photoelectron spectroscopy techniques. The most active and stable samples correspond to mono- or submonolayers of FeNPc deposited on high dibutylphthalate adsorption carbon blacks. Comparison with data obtained previously on Norit BrX impregnations emphasizes the rôle of the electron density on the inner nitrogen atoms rather than that on the iron centres
Wet-Chemical Synthesis of 3D Stacked Thin Film Metal-Oxides for All-Solid-State Li-Ion Batteries.
By ultrasonic spray deposition of precursors, conformal deposition on 3D surfaces of tungsten oxide (WO₃) negative electrode and amorphous lithium lanthanum titanium oxide (LLT) solid-electrolyte has been achieved as well as an all-solid-state half-cell. Electrochemical activity was achieved of the WO₃ layers, annealed at temperatures of 500 °C. Galvanostatic measurements show a volumetric capacity (415 mAh·cm-3) of the deposited electrode material. In addition, electrochemical activity was shown for half-cells, created by coating WO₃ with LLT as the solid-state electrolyte. The electron blocking properties of the LLT solid-electrolyte was shown by ferrocene reduction. 3D depositions were done on various micro-sized Si template structures, showing fully covering coatings of both WO₃ and LLT. Finally, the thermal budget required for WO₃ layer deposition was minimized, which enabled attaining active WO₃ on 3D TiN/Si micro-cylinders. A 2.6-fold capacity increase for the 3D-structured WO₃ was shown, with the same current density per coated area
The caregiver’s experience of childhood cancer treatment in South Africa
Background: This study explored the treatment-related, financial and psychological experiences of caregivers during cancer treatment of their children in South Africa’s (SA) public and private sectors. Methods: In this exploratory study, three focus groups were conducted with caregivers of children undergoing cancer treatment in SA’s public healthcare sector. A fourth small focus group with two parents in the private sector was conducted online. A mixed-methods approach was employed using a combination of thematic analysis and grounded theory. Results: Of the 20 public sector caregivers, many expressed frustration at the number of visits to primary healthcare clinics before being referred. Caregivers had difficulties coping with and accepting the diagnosis, alongside managing continued care for the child and other children at home. Support received by family and community members was varied. Financial strain was an important concern. The two private sector parents indicated greater levels of support and no financial hardship, but expressed similar levels of emotional stress. Conclusion: These caregiver experiences indicate that improvements are urgently needed in the recognition of childhood cancer symptoms at primary healthcare level in SA. They also highlight a need for increased financial support from government through social grants, travel allowances and nutritional support
Analysis of mouse brain transcriptome after experimental Duvenhage virus infection shows activation of innate immune response and pyroptotic cell death pathway
Rabies is an important neglected disease, characterized by invariably fatal encephalitis. Several studies focus on understanding the pathogenic mechanisms of the prototype lyssavirus rabies virus (RABV) infection, and little is known about the pathogenesis of rabies caused by other lyssaviruses. We sought to characterize the host response to Duvenhage virus infection and compare it with responses observed during RABV infection by gene expression profiling of brains of mice with the respective infections. We found in both infections differentially expressed genes leading to increased expression of type I interferons (IFNs), chemokines, and proinflammatory cytokines. In addition several genes of the IFN signaling pathway are up-regulated, indicating a strong antiviral response and activation of the negative feedback mechanism to limit type I IFN responses. Furthermore we provide evidence that in the absence of significant neuronal apoptotic death, cell death of neurons is mediated via the pyroptotic pathway in both infections. Taken together, we have identified several genes and/or pathways for both infections that could be used to explore novel approaches for intervention strategies against rabies
Evaluation of alignment of the reimbursement medicines list for children in Albania with the WHO essential medicines list for children
Background: The WHO Essential Medicine List for Children was released on the 30th anniversary of the general Essential Medicine List in 2007, to recognise special needs for medicines in children, and to promote the inclusion of paediatric medicines in national procurement programmes. This study aimed to investigate the alignment of the medicines included in the Albanian reimbursement medicines list of the Mandatory Healthcare Insurance Fund (AMHIF) and the Essential Medicine List for Children. Methods: A quantitative evaluation was performed to compare the paediatric medicines included in the 2022 list of the AMHIF and the 2021 WHO Essential Medicine List for Children. In addition, vaccines in the Albanian vaccination programmes for children were compared to the ones listed on the WHO Essential Medicine List for Children. Results: Both lists had a total of 284 active ingredients in common, whereas 14 of 24 vaccines were found to be in common in the Essential Medicine List for Children list and the Albanian vaccination programmes. Conclusions: This is the first study in Albania to investigate the alignment of the WHO EMLc and AMHIF list. In case of the same active ingredient there were many deviations in terms of dosage form, strength and indication
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