IgG Seroconversion and Pathophysiology in Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

We investigated the dynamics of seroconversion in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. During March 29–May 22, 2020, we collected serum samples and associated clinical data from 177 persons in London, UK, who had SARS-CoV-2 infection. We measured IgG against SARS-CoV-2 and compared antibody levels with patient outcomes, demographic information, and laboratory characteristics. We found that 2.0%–8.5% of persons did not seroconvert 3–6 weeks after infection. Persons who seroconverted were older, were more likely to have concurrent conditions, and had higher levels of inflammatory markers. Non-White persons had higher antibody concentrations than those who identified as White; these concentrations did not decline during follow-up. Serologic assay results correlated with disease outcome, race, and other risk factors for severe SARS-CoV-2 infection. Serologic assays can be used in surveillance to clarify the duration and protective nature of humoral responses to SARS-CoV-2 infection

Construction status and prospects of the Hyper-Kamiokande project

The Hyper-Kamiokande project is a 258-kton Water Cherenkov together with a 1.3-MW high-intensity neutrino beam from the Japan Proton Accelerator Research Complex (J-PARC). The inner detector with 186-kton fiducial volume is viewed by 20-inch photomultiplier tubes (PMTs) and multi-PMT modules, and thereby provides state-of-the-art of Cherenkov ring reconstruction with thresholds in the range of few MeVs. The project is expected to lead to precision neutrino oscillation studies, especially neutrino CP violation, nucleon decay searches, and low energy neutrino astronomy. In 2020, the project was officially approved and construction of the far detector was started at Kamioka. In 2021, the excavation of the access tunnel and initial mass production of the newly developed 20-inch PMTs was also started. In this paper, we present a basic overview of the project and the latest updates on the construction status of the project, which is expected to commence operation in 2027

Prospects for neutrino astrophysics with Hyper-Kamiokande

Hyper-Kamiokande is a multi-purpose next generation neutrino experiment. The detector is a two-layered cylindrical shape ultra-pure water tank, with its height of 64 m and diameter of 71 m. The inner detector will be surrounded by tens of thousands of twenty-inch photosensors and multi-PMT modules to detect water Cherenkov radiation due to the charged particles and provide our fiducial volume of 188 kt. This detection technique is established by Kamiokande and Super-Kamiokande. As the successor of these experiments, Hyper-K will be located deep underground, 600 m below Mt. Tochibora at Kamioka in Japan to reduce cosmic-ray backgrounds. Besides our physics program with accelerator neutrino, atmospheric neutrino and proton decay, neutrino astrophysics is an important research topic for Hyper-K. With its fruitful physics research programs, Hyper-K will play a critical role in the next neutrino physics frontier. It will also provide important information via astrophysical neutrino measurements, i.e., solar neutrino, supernova burst neutrinos and supernova relic neutrino. Here, we will discuss the physics potential of Hyper-K neutrino astrophysics

Radiation hard true single-phase-clock logic for high-speed circuits in 28 nm CMOS

True Single-Phase-Clock (TSPC) dynamic logic is widely used in high-speed circuits such as high-speed SERDES (Serializer/Deserializer) and frequency dividers. TSPC flip-flops (FF) are known for their high operational speed and low power consumption, compared to static FFs. Due to the relatively high leakage currents in modern CMOS processes, the use of leakage protection techniques of the storage nodes in TSPC must be considered, especially at high radiation doses. In this paper, the limitations originating from Total Ionization Dose (TID)-induced subthreshold leakage currents are analysed and radiation-hardening-by-design (RHBD) circuit techniques are proposed. Additionally, Single Event Upsets (SEU) are investigated by quantifying the critical charge of the leakage protected TSPC FF. The results are compared to both the static and the TSPC FF without leakage mitigation

IgG Seroconversion and Pathophysiology in Severe Acute Respiratory Syndrome Coronavirus 2 Infection

We investigated the dynamics of seroconversion in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. During March 29–May 22, 2020, we collected serum samples and associated clinical data from 177 persons in London, UK, who had SARS-CoV-2 infection. We measured IgG against SARS-CoV-2 and compared antibody levels with patient outcomes, demographic information, and laboratory characteristics. We found that 2.0%–8.5% of persons did not seroconvert 3–6 weeks after infection. Persons who seroconverted were older, were more likely to have concurrent conditions, and had higher levels of inflammatory markers. Non-White persons had higher antibody concentrations than those who identified as White; these concentrations did not decline during follow-up. Serologic assay results correlated with disease outcome, race, and other risk factors for severe SARS-CoV-2 infection. Serologic assays can be used in surveillance to clarify the duration and protective nature of humoral responses to SARS-CoV-2 infection

Proposal for A Water Cherenkov Test Beam Experiment for Hyper-Kamiokande andFuture Large-scale Water-based Detectors

Here we propose a 50 ton scale Water Cherenkov test experiment (WCTE) to be deployed in an East Area test beam line. The experiment will include a secondary target located just upstream of the experiment in order to produce very low energy particle fluxes, including charged pions. The WCTE program will be carried out with the following objectives. We will operate and understand the performance of new detector technologies such as multi-PMTs, and in a possible future phase, dichroicon wavelength-separating cones and water-based liquid scintillator in a fully integrated detector. We will study the performance of a <1 kiloton scale water Cherenkov detector with known particle fluxes, and test and develop calibration systems necessary for accurate modeling of a detector of this size. We will measure important physics processes for the modeling of water Cherenkov detector responses, including high-angle Cherenkov light production, pion scattering and absorption, and secondary neutron production in hadron scattering. We aim to start operation of the water Cherenkov test experiment in 2022