The U.S. COVID-19 vaccination program, which commenced in December 2020, has been instrumental in preventing morbidity and mortality from COVID-19 disease. Safety monitoring has been an essential ...component of the program. The federal government undertook a comprehensive and coordinated approach to implement complementary safety monitoring systems and to communicate findings in a timely and transparent way to healthcare providers, policymakers, and the public. Monitoring involved both well-established and newly developed systems that relied on both spontaneous (passive) and active surveillance methods. Clinical consultation for individual cases of adverse events following vaccination was performed, and monitoring of special populations, such as pregnant persons, was conducted. This report describes the U.S. government’s COVID-19 vaccine safety monitoring systems and programs used by the Centers for Disease Control and Prevention, the U.S. Food and Drug Administration, the Department of Defense, the Department of Veterans Affairs, and the Indian Health Service. Using the adverse event of myocarditis following mRNA COVID-19 vaccination as a model, we demonstrate how the multiple, complementary monitoring systems worked to rapidly detect, assess, and verify a vaccine safety signal. In addition, longer-term follow-up was conducted to evaluate the recovery status of myocarditis cases following vaccination. Finally, the process for timely and transparent communication and dissemination of COVID-19 vaccine safety data is described, highlighting the responsiveness and robustness of the U.S. vaccine safety monitoring infrastructure during the national COVID-19 vaccination program.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Point-of-care (POC) methods currently available for detecting SARS-CoV-2 infections still lack accuracy. Here, we report the development of a highly sensitive electrochemical immunoassay capable of ...quantitatively detecting the presence of the SARS-CoV-2 virus in patient nasopharyngeal samples using stencil-printed carbon electrodes (SPCEs) functionalized with capture antibodies targeting the SARS-CoV-2 nucleocapsid protein (N protein). Samples are added to the electrode surface, followed by horseradish peroxidase (HRP)-conjugated detection antibodies also targeting the SARS-CoV-2 N protein. The concentration of the virus in samples is quantified using chronoamperometry in the presence of 3,3′5,5′-tetramethylbenzidine. Limits of detection equivalent to less than 50 plaque forming units/mL (PFU/mL) were determined with virus sample volumes of 20 μL. No cross-reactivity was detected with the influenza virus and other coronavirus N proteins. Patient nasopharyngeal samples were tested as part of a proof-of-concept clinical study where samples were also tested using the gold-standard real-time quantitative polymerase chain reaction (RT-qPCR) method. Preliminary results from a data set of 22 samples demonstrated a clinical specificity of 100% (n = 9 negative samples according to RT-qPCR) and a clinical sensitivity of 70% for samples with RT-PCR cycle threshold (Ct) values under 30 (n = 10) and 100% for samples with Ct values under 25 (n = 5), which complies with the World Health Organization (WHO) criteria for POC COVID-19 diagnostic tests. Our functionalized SPCEs were also validated against standard plaque assays, and very good agreement was found between both methods (R 2 = 0.9993, n = 6), suggesting that our assay could be used to assess patient infectivity. The assay currently takes 70 min from sampling to results.
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IJS, KILJ, NUK, PNG, UL, UM
A significant improvement in the power conversion efficiency (PCE) and the environmental stability of n-Graphene/p-Si solar cells is indicated through effective n-doping of graphene, using low work ...function oxide capping layers. AlO x , deposited through atomic layer deposition, is particularly effective for such doping and in addition serves as an antireflection coating and a cell encapsulating layer. It is shown that the related charge transfer doping and interfacial engineering was crucial to achieve a record PCE of 12.5%. The work indicates a path forward, through work function engineering, for further efficiency gains in Gr-based solar cells.
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IJS, KILJ, NUK, PNG, UL, UM
Over the last few years, the SARS-CoV-2 pandemic has made the need for rapid, affordable diagnostics more compelling than ever. While traditional laboratory diagnostics like PCR and well-plate ELISA ...are sensitive and specific, they can be costly and take hours to complete. Diagnostic tests that can be used at the point-of-care or at home, like lateral flow assays (LFAs) are a simple, rapid alternative, but many commercially available LFAs have been criticized for their lack of sensitivity compared to laboratory methods like well-plate ELISAs. The Capillary-Driven Immunoassay (CaDI) device described in this work uses microfluidic channels and capillary action to passively automate the steps of a traditional well-plate ELISA for visual read out. This work builds on prior capillary-flow devices by further simplifying operation and use of colorimetric detection. Upon adding sample, an enzyme-conjugated secondary antibody, wash steps, and substrate are sequentially delivered to test and control lines on a nitrocellulose strip generating a colorimetric response. The end user can visually detect SARS-CoV-2 antigen in 15–20 min by naked eye, or results can be quantified using a smartphone and software such as ImageJ. An analytical detection limit of 83 PFU/mL for SARS-CoV-2 was determined for virus in buffer, and 222 PFU/mL for virus spiked into nasal swabs using image analysis, similar to the LODs determined by traditional well-plate ELISA. Additionally, a visual detection limit of 100 PFU/mL was determined in contrived nasal swab samples by polling 20 untrained end-users. While the CaDI device was used for detecting clinically relevant levels of SARS-CoV-2 in this study, the CaDI device can be easily adapted to other immunoassay applications by changing the reagents and antibodies.
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•Developed a device that steps of a traditional ELISA from 1 user step.•Device detects SARS-CoV-2 nucleocapsid protein at similar LOD to an ELISA.•Able to visually detect clinically relevant levels of SARS-CoV-2 in 20 min.•Aspects of the device can be adjusted to detect other diseases.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The COVID-19 pandemic focused attention on a pressing need for fast, accurate, and low-cost diagnostic tests. This work presents an electrochemical capillary driven immunoassay (eCaDI) developed to ...detect SARS-CoV-2 nucleocapsid (N) protein. The low-cost flow device is made of polyethylene terephthalate (PET) and adhesive films. Upon addition of a sample, reagents and washes are sequentially delivered to an integrated screen-printed carbon electrode for detection, thus automating a full sandwich immunoassay with a single end-user step. The modified electrodes are sensitive and selective for SARS-CoV-2 N protein and stable for over 7 weeks. The eCaDI was tested with influenza A and Sindbis virus and proved to be selective. The eCaDI was also successfully applied to detect nine different SARS-CoV-2 variants, including Omicron.
The COVID-19 pandemic pushed the demand for readily available monitoring tools, leading to the development of electrochemical point-of-care devices. This work presents an electrochemical ...capillary-driven immunoassay (eCaDI) device based on polyethylene terephthalate (PET) and adhesive films featuring a screen-printed carbon electrode (SPCE) for the detection of SARS-CoV-2 nucleocapsid (N) protein in clinical samples. The SPCE was modified with protein A and capture antibodies (Ab1) to ensure biomolecule immobilization and enhance sensitivity to detect N protein. The eCaDI automates an enzyme-linked immunosorbent assay (ELISA) through sequential reagent delivery, allowing for one-step sample addition. This process involves capturing the N protein by Ab1, followed by the automated delivery of HRP-labelled antibody and 3,3’,5,5’-tetramethylbenzidine (TMB) followed by electrochemical detection through TMB reduction. The SPCEs are sensitive and selective for SARS-CoV-2 N protein and stable for four weeks. Inactivated virus was used to determine a limit of detection (LOD) of 627 PFU/mL. The results obtained through immunoassay on eCADI were consistent with those of the RT-PCR method, showing a coefficient of determination (R2) of 0.816 for 27 nasal swab samples from SARS-CoV-2 infected individuals. The developed eCADI is an alternative to conventional ELISA, given the device's low cost (less than $1), low consumption of samples and reagents, low waste generation, and short analysis time (5 min). Moreover, the immunoassay has shown potential for diagnosing COVID-19 in decentralized areas.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A numerical model that describes the transport of mobile ionic species in metal–insulator–semiconductor (MIS) and photovoltaic (PV) devices subject to temperature and voltage stress is presented. The ...finite element method (FEM) is used to solve the Nernst–Planck equation while imposing Poisson's equation self‐consistently as a restriction for the electrostatic potential. This allows the contribution of the ionic species to the potential to be taken into account. Using a variational formulation eases the implementation of diverse boundary conditions, including the incorporation of segregation kinetics at the device interfaces. Segregation across the dielectric–semiconductor interface is relevant to modeling the electronic device degradation in systems where contamination reaches the semiconductor. The model in closed systems with no‐flux boundary conditions is validated first. In the limiting case of low contamination levels with respect to the gate bias, the FEM solution matches analytically derived approximations. Then, the implementation is broadened to include an open boundary at the dielectric–semiconductor interface to account for leakage of ions. The predicted time dependence of the flatband voltage in Na‐contaminated MIS test structures agrees well with measurements. The model successfully captures the role of long‐range ion transport at concentrations of relevance to electronic and PV device instability and neuromorphic computing.
A framework to model the transport kinetics of ions in metal–insulator–semiconductor devices and solar cells is described. The finite element method is used to solve the Nernst–Planck equation self‐consistently with Poisson's equation to account for the electrostatic potential arising from the sodium ion distribution. This formulation enables analysis and discussion of the segregation of sodium in the insulating layer.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Hyperspectral (HS) measurement is among the most useful tools in agriculture for early disease detection. However, the cost of HS cameras that can perform the desired detection tasks is ...prohibitive-typically fifty thousand to hundreds of thousands of dollars. In a previous study at the Agricultural Research Organization’s Volcani Institute (Israel), a low-cost, high-performing HS system was developed which included a point spectrometer and optical components. Its main disadvantage was long shooting time for each image. Shooting time strongly depends on the predetermined integration time of the point spectrometer. While essential for performing monitoring tasks in a reasonable time, shortening integration time from a typical value in the range of 200 ms to the 10 ms range results in deterioration of the dynamic range of the captured scene. In this work, we suggest correcting this by learning the transformation from data measured with short integration time to that measured with long integration time. Reduction of the dynamic range and consequent low SNR were successfully overcome using three developed deep neural networks models based on a denoising auto-encoder, DnCNN and LambdaNetworks architectures as a backbone. The best model was based on DnCNN using a combined loss function of
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and Kullback–Leibler divergence on images with 20 consecutive channels. The full spectrum of the model achieved a mean PSNR of 30.61 and mean SSIM of 0.9, showing total improvement relatively to the 10 ms measurements’ mean PSNR and mean SSIM values by 60.43% and 94.51%, respectively.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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