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The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health concern. The development of vaccines with high immunogenicity and safety is crucial for controlling the global COVID-19 pandemic and preventing further illness and fatalities. Here, we report the development of a SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the spike (S) protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG and neutralizing antibodies in three animal models: BALB/c mouse, Syrian hamster, and a non-human primate (Macaca leonina). In addition, a viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. Nanocovax did not induce any adverse effects in mice (Mus musculus var. albino) and rats (Rattus norvegicus). These preclinical results indicate that Nanocovax is safe and effective.

This study investigates a practical design for a switched beam planar antenna that can be implemented as a compact, low-cost switchable and/or reconfigurable beam antenna array. The antenna consists of a four-port antenna array, which is based on L-shaped quarter-wavelength slot antenna elements. This type of antenna array is a planar structure and its maximum directional radiation beam pattern presents in an azimuth plane covering 3608. The antenna array operates based on the 'ON' or 'OFF' states of PIN diodes in each individual slot antenna element and the combined signals from the four-port output. Therefore by properly controlling the state of the PIN diodes, the antenna exposes its characteristics of switchable/ reconfigurable beam patterns in the F-plane. To validate the proposed design, a small smart, switched-beam antenna operating at 2.7 GHz in multiple input-multiple output applications is simulated and fabricated.

Textile‐reinforced concrete (TRC) is a combination of small‐grain high‐performance concrete (HPC) and high‐strength textile reinforcement. TRC enables thin layers and has high tensile and compressive strengths. In this paper, TRC was used for the face layers and combined with a core of lightweight expanded polystyrene concrete (EPC) to create lightweight sandwich beams without special joint reinforcement to connect the layers. The experimental testing of the loadbearing behaviour of this kind of sandwich beam, along with the influence of the shear span‐to‐depth ratio (a/d) as observed during three‐ and four‐point bending tests, will be summarized. The failure behaviour of the sandwich beams is influenced by the shear span‐to‐depth ratio, the type of bending test and the tensile capacity of the TRC layer. A diagonal tension failure occurred in experimental beams with 2.6 ≤ a/d ≤ 5.2 in three‐point bending tests and 3.1 ≤ a/d ≤ 4.1 in four‐point tests. The shear strength of the beams could be conservatively estimated according to the current European standards.

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