COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection. It is currently unknown as to the correlation between the magnitude of neutralizing antibody (NAb) responses and the disease severity in COVID-19 patients. In a cohort of 59 recovered patients with disease severity including severe, moderate, mild, and asymptomatic, we observed the positive correlation between serum neutralizing capacity and disease severity, in particular, the highest NAb capacity in sera from the patients with severe disease, while a lack of ability of asymptomatic patients to mount competent NAbs. Furthermore, the compositions of NAb subtypes were also different between recovered patients with severe symptoms and with mild-tomoderate symptoms. These results reveal the tremendous heterogeneity of SARS-CoV-2-specific NAb responses and their correlations to disease severity, highlighting the needs of future vaccination in COVID-19 patients recovered from asymptomatic or mild illness.

InGaN – GaN multiple-quantum-well light-emitting diodes were fabricated on (101¯0) m plane GaN films grown on (101¯0) m plane 4H–SiC substrates. The [0001] axis of the epitaxial film is parallel to the [0001] axis of the substrate. The surface is striated, with features running perpendicular to the c axis and a maximum surface height difference of 45nm. Electroluminescence shows strong polarization anisotropy, with 7× more light emitted with polarization perpendicular to the c axis compared to parallel to the c axis. An Ahrrenius fit of the polarization ratio indicates that there is a 49meV difference in the energy gap between the two polarization states. This suggests that a high polarization ratio can be maintained at the high temperatures (>150°C) and drive current densities required for high-power light-emitting diode applications.

Severe bone damage from diseases, including extensive trauma, fractures, and bone tumors, cannot self-heal, while traditional surgical treatment may bring side effects such as infection, inflammation, and pain. As a new biomaterial with controllable mechanical properties and biocompatibility, hydrogel is widely used in bone tissue engineering (BTE) as a scaffold for growth factor transport and cell adhesion. In order to make hydrogel more suitable for the local treatment of bone diseases, hydrogel preparation methods should be combined with synthetic materials with excellent properties and advanced technologies in different fields to better control drug release in time and orientation. It is necessary to establish a complete method to evaluate the hydrogel’s properties and biocompatibility with the human body. Moreover, establishment of standard animal models of bone defects helps in studying the therapeutic effect of hydrogels on bone repair, as well as to evaluate the safety and suitability of hydrogels. Thus, this review aims to systematically summarize current studies of hydrogels in BTE, including the mechanisms for promoting bone synthesis, design, and preparation; characterization and evaluation methods; as well as to explore future applications of hydrogels in BTE.

High power light emitting diodes (LEDs) continue to increase in output flux with the best III‐nitride based devices today emitting over 150 lm of white, cyan, or green light. The key design features of such products will be covered with special emphasis on power packaging, flip‐chip device design, and phosphor coating technology. The high‐flux performance of these devices is enabling many new applications for LEDs. Two of the most interesting of these applications are LCD display backlighting and vehicle forward lighting. The advantages of LEDs over competing lighting technologies will be covered in detail.

COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection. It is currently unknown as to the correlation between the magnitude of neutralizing antibody (NAb) responses and the disease severity in COVID-19 patients. In a cohort of 59 recovered patients with disease severity including severe, moderate, mild and asymptomatic, we observed the positive correlation between serum neutralizing capacity and disease severity, in particular, the highest NAb capacity in sera from the patients with severe disease, while a lack of ability of asymptomatic patients to mount competent NAbs. Furthermore, the compositions of NAb subtypes were also different between recovered patients with severe symptoms and with mild-to-moderate symptoms. These results reveal the tremendous heterogeneity of SARS-CoV-2-specific NAb responses and their correlations to disease severity, highlighting the needs of future vaccination in COVID-19 patients recovered from asymptomatic or mild illness.