Neurological manifestations of SARS-CoV-2 infection in hospitalised children and adolescents in the UK: a prospective national cohort study

Background: The spectrum of neurological and psychiatric complications associated with paediatric SARS-CoV-2 infection is poorly understood. We aimed to analyse the range and prevalence of these complications in hospitalised children and adolescents. Methods: We did a prospective national cohort study in the UK using an online network of secure rapid-response notification portals established by the CoroNerve study group. Paediatric neurologists were invited to notify any children and adolescents (age <18 years) admitted to hospital with neurological or psychiatric disorders in whom they considered SARS-CoV-2 infection to be relevant to the presentation. Patients were excluded if they did not have a neurological consultation or neurological investigations or both, or did not meet the definition for confirmed SARS-CoV-2 infection (a positive PCR of respiratory or spinal fluid samples, serology for anti-SARS-CoV-2 IgG, or both), or the Royal College of Paediatrics and Child Health criteria for paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS). Individuals were classified as having either a primary neurological disorder associated with COVID-19 (COVID-19 neurology group) or PIMS-TS with neurological features (PIMS-TS neurology group). The denominator of all hospitalised children and adolescents with COVID-19 was collated from National Health Service England data. Findings: Between April 2, 2020, and Feb 1, 2021, 52 cases were identified; in England, there were 51 cases among 1334 children and adolescents hospitalised with COVID-19, giving an estimated prevalence of 3·8 (95% CI 2·9–5·0) cases per 100 paediatric patients. 22 (42%) patients were female and 30 (58%) were male; the median age was 9 years (range 1–17). 36 (69%) patients were Black or Asian, 16 (31%) were White. 27 (52%) of 52 patients were classified into the COVID-19 neurology group and 25 (48%) were classified into the PIMS-TS neurology group. In the COVID-19 neurology group, diagnoses included status epilepticus (n=7), encephalitis (n=5), Guillain-Barré syndrome (n=5), acute demyelinating syndrome (n=3), chorea (n=2), psychosis (n=2), isolated encephalopathy (n=2), and transient ischaemic attack (n=1). The PIMS-TS neurology group more often had multiple features, which included encephalopathy (n=22 [88%]), peripheral nervous system involvement (n=10 [40%]), behavioural change (n=9 [36%]), and hallucinations at presentation (n=6 [24%]). Recognised neuroimmune disorders were more common in the COVID-19 neurology group than in the PIMS-TS neurology group (13 [48%] of 27 patients vs 1 [<1%] of 25 patients, p=0·0003). Compared with the COVID-19 neurology group, more patients in the PIMS-TS neurology group were admitted to intensive care (20 [80%] of 25 patients vs six [22%] of 27 patients, p=0·0001) and received immunomodulatory treatment (22 [88%] patients vs 12 [44%] patients, p=0·045). 17 (33%) patients (10 [37%] in the COVID-19 neurology group and 7 [28%] in the PIMS-TS neurology group) were discharged with disability; one (2%) died (who had stroke, in the PIMS-TS neurology group). Interpretation: This study identified key differences between those with a primary neurological disorder versus those with PIMS-TS. Compared with patients with a primary neurological disorder, more patients with PIMS-TS needed intensive care, but outcomes were similar overall. Further studies should investigate underlying mechanisms for neurological involvement in COVID-19 and the longer-term outcomes. Funding: UK Research and Innovation, Medical Research Council, Wellcome Trust, National Institute for Health Research

Effect of precursor solution stirring time on the electrochromic performance of tungsten oxide films

Tungsten oxide (WO3) is an n-type semiconductor with a wide range of transparent electronic applications such as smart windows, rear-view displays and gas sensors. In this work, WO3 films were prepared on tin doped indium oxide (ITO) coated glasses by utilising the sol–gel spin-coating method. The effect of WO3 precursor solution stirring time (3, 10 and 24 h) on the electrochromic (EC) properties of WO3 films was investigated. The optical transmittance of the WO3 films in the visible range decreased as precursor stirring time was increased. The WO3 films subjected to 3 and 10 h of stirring had a large optical modulation compared to the WO3 films subjected to 24 h of stirring. CV results showed higher coloration current in WO3 films subjected to 3 h stirring which is an indication of faster intercalation kinetics. Moreover, it had fast switching time and high coloration efficiency of 34.8 cm2 C–1

Towards an All-Solid-State Electrochromic Device: A Review of Solid-State Electrolytes and the Way Forward

In order to curb high electricity usage, especially in commercial buildings, smart windows, also known as “switchable” or “smart” glasses, have attracted a significant amount of attention in an effort to achieve energy savings in eco-friendly buildings and transportation systems. Smart windows save energy by regulating the input of solar heat and light and hence cutting down air-conditioning expenses, while maintaining indoor comfort. This is achieved by electrochromism, which is defined as the reversible colour change in electrochromic (EC) materials from transparent to dark blue and vice versa under a small applied voltage. Recent state-of-the-art electrochromic devices (ECD) adopt liquid-based electrolytes as the main source of energy for basic operations. While this has resulted in much success in ECDs as reported in past studies, there remain several drawbacks to this aspect, such as liquid electrolyte leakage and evaporation, not to mention safety concerns related to the harmful nature of electrolyte materials. This paper aims to review the recent advances in various solid electrolytes that are potential solutions to the mentioned problems

Sodium and potassium doped P-type ZnO films by sol-gel spin-coating technique

Zinc oxide (ZnO) is a promising material in a variety of applications including sensors, transistors and solar cells. Many researchers studied N-type ZnO films and reported enhanced properties. On the other hand, P-type ZnO films were rarely attempted due to the self-compensation effect. Success in achieving P-type ZnO films is important as it will pave the way for more advanced complementary devices. In this work, P-type sodium and potassium doped ZnO films were fabricated on glass substrates with doping concentration between 0 and 25 at.%. The influences of doping concentration on surface morphology, structural, optical and electrical properties were investigated using atomic force microscopy, X-ray diffraction spectroscopy, energy-dispersive X-ray spectroscopy, ultraviolet–visible (UV–Vis) spectrophotometer, photoluminescence spectroscopy and Hall-effect electrical transport measurement system. The distinctive behavior of P-type ZnO films with different doping concentrations will be discussed

Effect of film thickness on electrochromic performance of sol-gel deposited tungsten oxide (WO3)

In recent year, considerable interest has been addressed towards the high energy usage in buildings for indoor comfort due to the less energy efficient windows. Electrochromic (EC) smart window is a new technology that is capable of changing from transparent to opaque and has the potential in energy saving applications. Tungsten oxide (WO3) is a transition metal oxide with a wide range of applications which include electrochromic (EC) smart windows, displays and rear-view mirrors. In EC smart windows, WO3 is the key element where it is responsible for the colouring and bleaching of the device. Therefore the properties of WO3 will affect the EC performance. In this work, WO3 films were deposited on tin doped indium oxide (ITO) coated glasses via the sol-gel spin-coating technique. The WO3 film thicknesses were varied by means of number of deposited layers. The film thickness, morphological, structural, optical and EC properties were characterised by using step profilometer, scanning electron microscopy (SEM), X-ray diffraction (XRD) spectroscopy, ultraviolet-visible (UV-Vis) spectrophotometer and cyclic voltammetry (CV) and chronoamperometry (CA) measurements, respectively

Electrochromic properties of WO3 films based on lithium iodide and lithium perchlorate polymer electrolyte

Electrochromic (EC) window is a novel intelligent window technology which functions by switching between transparent and opaque states thereby allowing the energy saving, healthy and comfort living environment within residential and commercial building premises. In general, each layer is important in ensuring the smooth operation of an EC window. In particular, the electrolyte layer is one of the more important layers due to the fact that its material composition will directly impact the operation of the EC window. In this work, WO3 films were fabricated using sol-gel spin-coated technique on indium tin oxide (ITO) coated glasses. Lithium iodide in polyethylene glycol (PEG:LiI) and lithium perchlorate in propylene carbonate (PC:LiClO4) were used as polymer electrolytes. Subsequently, the EC performance of WO3 films using the mentioned polymer electrolytes were examined by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The optical properties of the WO3 films were measured by using the ultraviolet-visible (UV–vis) spectrophotometer. The electrolytes based on PEG:LiI and PC:LiClO4 have been the mainstream electrolytes with variant EC performance, and yet, the direct comparison of these polymers electrolytes were not explored. Therefore, the current work here is important to outline the characteristics of these electrolytes in determining the EC performance on WO3 films

Electrochromic properties of WO3 films based on lithium iodide and lithium perchlorate polymer electrolyte

Electrochromic (EC) window is a novel intelligent window technology which functions by switching between transparent and opaque states thereby allowing the energy saving, healthy and comfort living environment within residential and commercial building premises. In general, each layer is important in ensuring the smooth operation of an EC window. In particular, the electrolyte layer is one of the more important layers due to the fact that its material composition will directly impact the operation of the EC window. In this work, WO3 films were fabricated using sol-gel spin-coated technique on indium tin oxide (ITO) coated glasses. Lithium iodide in polyethylene glycol (PEG:LiI) and lithium perchlorate in propylene carbonate (PC:LiClO4) were used as polymer electrolytes. Subsequently, the EC performance of WO3 films using the mentioned polymer electrolytes were examined by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. The optical properties of the WO3 films were measured by using the ultraviolet-visible (UV-Vis) spectrophotometer. The electrolytes based on PEG:LiI and PC:LiClO4 have been the mainstream electrolytes with variant EC performance, and yet, the direct comparison of these polymers electrolytes were not explored. Therefore, the current work here is important to outline the characteristics of these electrolytes in determining the EC performance on WO3 films

Post-annealing effect on the electrochromic properties of WO3 films

The idea of Internet of Things (IoT) has brought about the innovation of smart materials and devices which affect our everyday life. One of the technologies associated to the IoT is the electrochromic (EC) smart windows and the key material is tungsten oxide (WO3). WO3 is considered as the best candidate due to its superior EC properties for example high optical modulation and high colouration efficiency. In this work, the structural properties of WO3 films were manipulated by varying the post annealing temperature between 27 °C and 450 °C. The WO3 films annealed at different temperature were characterised for their structural, morphological, optical and EC properties using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), optical transmittance study, cyclic voltammetry (CV) and chronoamperometry (CA) measurements. The effect of post annealing temperature will be analysed and investigated which is important for smart window performance optimisation