Twelve-month observational study of children with cancer in 41 countries during the COVID-19 pandemic

Introduction Childhood cancer is a leading cause of death. It is unclear whether the COVID-19 pandemic has impacted childhood cancer mortality. In this study, we aimed to establish all-cause mortality rates for childhood cancers during the COVID-19 pandemic and determine the factors associated with mortality. Methods Prospective cohort study in 109 institutions in 41 countries. Inclusion criteria: children <18 years who were newly diagnosed with or undergoing active treatment for acute lymphoblastic leukaemia, non-Hodgkin's lymphoma, Hodgkin lymphoma, retinoblastoma, Wilms tumour, glioma, osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and neuroblastoma. Of 2327 cases, 2118 patients were included in the study. The primary outcome measure was all-cause mortality at 30 days, 90 days and 12 months. Results All-cause mortality was 3.4% (n=71/2084) at 30-day follow-up, 5.7% (n=113/1969) at 90-day follow-up and 13.0% (n=206/1581) at 12-month follow-up. The median time from diagnosis to multidisciplinary team (MDT) plan was longest in low-income countries (7 days, IQR 3-11). Multivariable analysis revealed several factors associated with 12-month mortality, including low-income (OR 6.99 (95% CI 2.49 to 19.68); p<0.001), lower middle income (OR 3.32 (95% CI 1.96 to 5.61); p<0.001) and upper middle income (OR 3.49 (95% CI 2.02 to 6.03); p<0.001) country status and chemotherapy (OR 0.55 (95% CI 0.36 to 0.86); p=0.008) and immunotherapy (OR 0.27 (95% CI 0.08 to 0.91); p=0.035) within 30 days from MDT plan. Multivariable analysis revealed laboratory-confirmed SARS-CoV-2 infection (OR 5.33 (95% CI 1.19 to 23.84); p=0.029) was associated with 30-day mortality. Conclusions Children with cancer are more likely to die within 30 days if infected with SARS-CoV-2. However, timely treatment reduced odds of death. This report provides crucial information to balance the benefits of providing anticancer therapy against the risks of SARS-CoV-2 infection in children with cancer

Effects of the position substrate upon the structural behaviour, electrical and optical properties of zinc-oxide films used in solar cells

The preparation by the rf sputtering technique and characterisation of ZnO thin films used as windows in solar cells are described. The electrical behaviour and structural spectra clearly show an important effect of the substrate position with respect to the target. In fact, among all the studied substrate positions, only the samples facing the target are randomly oriented having the mixed orientation (100), (002) and (101). All the others have the c(002)-axis orientation. The scanning electron-microscope observations confirm the X-ray analysis results. The last samples have a resistivity as low as 10-3 [Omega]cm while the randomly-oriented, ones have a large resisivity of about 102-103 [Omega]cm These latter show, in their transmittance characteristics, a slight shift towards higher wavelengths. However, no effect is noticed when the other samples are optically assessed. Consequently, the optical gap is found to be about 3.38 eV for the conducting films and 3.3 eV for the ones having a higher resistivity. The average transmittance in the visible range is around 85-90% for all the samplesZinc oxide X-ray diffraction Electrical properties and measurements Optical properties

The tin precursors and hydrogen peroxide effects on spray-deposited SnO

The oxide semiconductor compounds such as SnO2, In2O3, ITO, ZnO and others brought about a new attention for the metal-insulator-semiconductor structures as photovoltaic converters because of the high values of transmission and conductivity and the possibility of metal replacement in above-mentioned structures. The characteristics of the solar cells based on these oxide semiconductor compounds can be improved with conductivity increasing of the transparent semiconductor films and that is why the purpose of this paper is obtaining of F-doped tin oxide thin films, preparation of SnO2:F-Si solar cells and studying of their properties. The F-doped tin oxide thin films were prepared by spray pyrolysis technique [1–8]. This method was chosen because of the simplicity of the apparatus and relatively low cost. Aqueous solutions containing 0.1 M (TT, BTT or DTD) and 0.07 M NH4F (in the case of doping with F) have been sprayed by an atomizer on Si or glass substrates, heated up to 420 °C by maintaining the spray liquid volume, the spray time and the pressure of the carrier gas. Spray pyrolysis deposition of transparent and conductive SnO2 is a low-cost and very flexible technique applicable to solar cells. For SnO2, the drawback is that polycrystalline films are only obtained at relatively high deposition temperatures, largely above 450 °C. This constraint may cause damage to the photovoltaic junction. In the present work, it will be demonstrated that the photovoltaic parameters can be influenced by adding small amounts of hydrogen peroxide (H2O2) to the source solution

Electroluminescence AC powder displays based upon ZnS:Tm, Li

The preparation and characterisation of an inorganic blue-emitting alternate-current electrolumenescent (ACEL) cell based upon ZnS:Tm, Li phosphor powder are described. Electroluminescent and photoluminescent spectra clearly show a dominant blue-emission band peaking at 2.6 eV (477 nm) originated from 1G4-->3H6 transition. Advantages and drawbacks of the powder-based ACEL cell have been discussed in comparison with a ACEL thin-film based upon a similar material. The near-infra-red band (801 nm, 1.55 eV, 3F4-->3H6) seen in thin-film structure was significantly suppressed in these types of devices.Luminescence Optical properties Phosphorus X-ray diffraction

Multiphoton absorption in Er3+ doped fibres

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