Spectrum of Neurological Manifestations of COVID-19 Data from a Tertiary Care Hospital.

Background: Coronavirus is a novel virus which has disrupted life in the past year. While it involves the lungs in the majority and this has been extensively studied, it involves other organ systems. More number of studies need to be focused on the extrapulmonary manifestations of the disease. Objective: To delineate the clinical manifestations of coronavirus disease 2019 (COVID-19) virus on the central and peripheral nervous systems and to assess the risk factors and the outcome of COVID-19 patients with neurological manifestations. Materials and Methods: All patients who were SARS-CoV-2 RNA polymerase chain reaction (PCR) positive were assessed, and detailed clinical history and laboratory findings were collected. Data was analyzed using percentage, mean, and frequency. Results: Out of 864 patients, 17 (N = 17, 1.96%) had neurological manifestations. Twelve out of 17 had comorbid conditions. Patients had diverse presentations ranging from acute cerebrovascular accident to paraplegia and encephalopathy. Ten (58.8%) patients presented with acute cerebrovascular accidents. Of the patients who developed stroke, five (50%) died. Conclusions: COVID-19 usually presents as a respiratory disease. The neurological manifestations of COVID-19 are not uncommon. One should be aware of a wide spectrum of neurological signs and symptoms of COVID-19 for early diagnosis and treatment for preventing mortality and morbidity.

Intra- and inter-nanocrystal charge transport in nanocrystal films.

The exploitation of semiconductor nanocrystal (NC) films in novel electronic and optoelectronic applications requires a better understanding of charge transport in these systems. Here, we develop a model of charge transport in NC films, based on a generalization of the concept of transport energy level ET to nanocrystal assemblies, which considers both intra- and inter-NC charge transfer processes. We conclude that the role played by each of these processes can be probed from temperature-dependent measurements of charge carrier density n and mobility µ in the same films. The model also enables the determination of the position of the Fermi energy level EF with respect to ET, an important parameter of charge transport in semiconductor materials, from the temperature dependence of n. Moreover, we provide support to an essentially temperature-independent intra-NC charge carrier mobility, considered in the transport level concept, and consequently the frequently observed temperature dependence of the overall mobility µ in NC films results from a temperature variation of the inter-NC charge transport processes. Importantly, we also conclude that the temperature dependence of conductivity in NC films should result in general from a combination of temperature variations of both n and µ. By applying the model to solution-processed Si NC films, we conclude that transport within each NC is similar to that in amorphous Si (a-Si), with charges hopping along band tail states located below the conduction band edge. For Si NCs, we obtain values of ET - EF of ∼0.25 eV. The overall mobility µ in Si NC films is significantly further reduced with respect to that typically found in a-Si due to the additional transport constraints imposed by inter-NC transfer processes inherent to a nanoparticulate film. Our model accounting for inter- and intra-NC charge transport processes provides a simple and more general description of charge transport that can be broadly applied to films of semiconductor NCs.