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This article discusses a case of a 75-year-old female patient with COVID-19 who developed bilateral adrenal hemorrhage. The patient initially presented with fever and cough and was diagnosed with COVID-19 and normal adrenal glands. However, after two weeks, chest and abdominal CT scans showed increased infection in the lungs and bilateral adrenal hemorrhage. The patient was treated with hormones and discharged from the hospital after receiving hormonal, anticoagulant, hemostatic, and antiviral treatment. The article highlights that adrenal hemorrhage caused by COVID-19 is a rare complication that can lead to acute adrenal insufficiency. The pathogenesis of adrenal hemorrhage may involve vascular rupture bleeding, adrenal vascular endothelial cell injury, or immune response that destroys adrenal tissue. [Extracted from the article]

Antimicrobial resistance to currently available antibiotics requires innovation of antibiotics. Here, the authors identify a critical inhibitory site in an energy-producing enzyme, which can lead to rational design of antibiotics.

The nanosize effect on Ge diffusion (850≤T≤1000 °C) in polycrystalline Si layers is investigated. The Ge diffusion coefficients in microcrystalline and nanocrystalline Si layers made of 30 μm and 40 nm wide grains, respectively, are measured and compared. In the microcrystalline Si layer, the Ge diffusion coefficient in micrograin boundaries is measured using a conventional analytical solution of Fick’s equations corresponding to the Fisher model. In the nanocrystalline Si layer, the Ge diffusion coefficients in nanograins and in nanograin boundaries are measured via a method based on two-dimensional simulations using the Fisher model geometry. The diffusivities in nanograins and nanograin boundaries are one order of magnitude higher than in micrograins and micrograin boundaries, respectively. However, the nanosize effect appears to be different in grains and grain boundaries; despite that the activation energy for diffusion in 40 nm wide grains is at least 1 eV lower than in Si bulk. The activation energy in nanograin boundaries is about the same as in micrograin boundaries. [ABSTRACT FROM AUTHOR]

The severe nuclear accident at the Fukushima Daiichi Nuclear Power Plant (NPP) in Japan on March 11, 2011 had a huge impact on the world’s nuclear regulatory bodies and industry. This paper summarizes the lessons learned from the Fukushima Daiichi Nuclear Accident, which include inadequacy of sitespecific extreme external natural hazards evaluation, prolonged loss of power and ultimate heat sink, insufficiency of response and management of severe accident monitoring and mitigation means and etc. It is also important to aware of that the accident can occur simultaneously on several units at a multiunit plant. In the decade after the Fukushima nuclear accident, nuclear safety improvement actions and nuclear safety regulatory standard revisions were implemented by major nuclear power countries such as the United States, Japan, France, and China. In United States, the new regulation 10CFR 50.155 Mitigation of BeyondDesignBasis Events (MBDBE) was come into forces to further enhance the capability of NPP to address the BDBE. In Japan, a new independent regulatory body, Nuclear Regulatory Authority (NRA), was established and new safety standards were released in three aspects, including design basis safety standards, severe accident measures, and safety standards relative to earthquakes/tsunamis. In France, complementary safety assessments (CSAs) were performed on all nuclear facilities, the concept hardened safety core was prepared and longterm improvement measures are still undergoing. In China, comprehensive safety inspection and external hazard safety margin assessment on NPPs were carried out, the “Code on the Safety of Nuclear Power Plant Design” (HAF102) was revised in 2016, which is a highlevel requirement on design and new nuclear safety goal, safety philosophy, and safety requirements were established in general. In this paper, the nuclear safety philosophy and requirements were elaborated in detail in the fields of practical elimination of early or large radioactive release, category of accident conditions, defense-in-depth concept, mobile equipment configuration and etc. some of which are explicit in nuclear safety review practice while others may be needed to be further clarified. In summary, certain specific suggestions of NPP safety in the future were given with international requirements and practices, as well as the domestic NPP characteristics being considered. It is also recommended that the relevant safety guides and technical positions on specific requirements should be improved constantly, a complete and logical nuclear safety regulation regime should be established, a balanced combination of deterministic and probabilistic approaches should be adapted, the specific nuclear safety and assessment criteria should be consolidated in areas such as practical elimination of early or large radioactive release, the independence between all defenseindepth levels, design extension conditions with core melting, as well as the number and configuration of mobile equipment on the multipleunit plant site.

A numerical analysis of a compact microring resonator that was defined on a yttrium-aluminum-garnet (YAG) thin film bonded on top of a SiO2 cladding layer and operated at the wavelengths of approximately 1.064 and 1.6 μm was performed. The single-mode conditions of YAG waveguides at different waveguide geometries and their propagation losses at different SiO2 cladding layer thicknesses were systematically analyzed. The key design parameters of the microring resonator, such as gap size and ring radius, were simulated based on the 2.5-dimensional variational finite-difference time-domain method. This study could be helpful in understanding the mechanism of microring resonators defined on YAG thin films and fabricating integrated microlaser sources on YAG-on-insulators.

Under pressurized thermal shock (PTS), once crack initiation occurs in a reactor pressure vessel (RPV), the stress concentration around the crack tips may result in local instability and crack propagation. The temperature-dependent material properties are introduced into the finite element analysis model. According to the response of the transient temperature field and stress field near the crack tip region, the influence of PTS on the carrying capacity of the structure is demonstrated. Also, the process of crack initiation and propagation is simulated by using the extended finite element method (XFEM). The results show that the crack of mode I is easy to be initiated on the nozzle in the initial high temperature and high pressure working state. The effect of cladding on the RPV integrity is enhanced with the increase of crack size, and it mainly depends on the crack length. During the PTS transient, a discontinuity of stress exists near the cladding-base interface, and the cladding bears more loading than the base of the same size. As the unloading of the internal pressure, the stress does not decline due to the strong thermal shock. In the late stage of the PTS process, the internal pressure caused by repressurization poses a challenge to the strength of the structure. With the decrease of the base wall thickness, the allowable repressure value also gradually decreases. However, the increase of the base wall thickness causes the rise of thermal stress, and the allowable repressure load is not significantly improved. [ABSTRACT FROM AUTHOR]