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The ongoing coronavirus disease 2019 (COVID-19) pandemic caused more than 96 million infections and over 2 million deaths worldwide so far. However, there is no approved vaccine available for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the disease causative agent. Vaccine is the most effective approach to eradicate a pathogen. The tests of safety and efficacy in animals are pivotal for developing a vaccine and before the vaccine is applied to human populations. Here we evaluated the safety, immunogenicity, and efficacy of an inactivated vaccine based on the whole viral particles in human ACE2 transgenic mouse and in non-human primates. Our data showed that the inactivated vaccine successfully induced SARS-CoV-2-specific neutralizing antibodies in mice and non-human primates, and subsequently provided partial (in low dose) or full (in high dose) protection of challenge in the tested animals. In addition, passive serum transferred from vaccine-immunized mice could also provide full protection from SARS-CoV-2 infection in mice. These results warranted positive outcomes in future clinical trials in humans. Supplementary Information The online version contains supplementary material available at 10.1007/s12250-021-00376-w.

The ongoing COVID-19 pandemic is causing huge impact on health, life, and global economy, which is characterized by rapid spreading of SARS-CoV-2, high number of confirmed cases and a fatality/case rate worldwide reported by WHO. The most effective intervention measure will be to develop safe and effective vaccines to protect the population from the disease and limit the spread of the virus. An inactivated, whole virus vaccine candidate of SARS-CoV-2 has been developed by Wuhan Institute of Biological Products and Wuhan Institute of Virology. The low toxicity, immunogenicity, and immune persistence were investigated in preclinical studies using seven different species of animals. The results showed that the vaccine candidate was well tolerated and stimulated high levels of specific IgG and neutralizing antibodies. Low or no toxicity in three species of animals was also demonstrated in preclinical study of the vaccine candidate. Biochemical analysis of structural proteins and purity analysis were performed. The inactivated, whole virion vaccine was characterized with safe double-inactivation, no use of DNases and high purity. Dosages, boosting times, adjuvants, and immunization schedules were shown to be important for stimulating a strong humoral immune response in animals tested. Preliminary observation in ongoing phase I and II clinical trials of the vaccine candidate in Wuzhi County, Henan Province, showed that the vaccine is well tolerant. The results were characterized by very low proportion and low degree of side effects, high levels of neutralizing antibodies, and seroconversion. These results consistent with the results obtained from preclinical data on the safety.

Multi-layer multi-pass (MLMP) welding of medium thickness plate is always the focus and difficulty of research and application. It is widely used in shipbuilding and pressure vessel manufacturing. This paper summarizes the research developments of MLMP in recent years, including welding technologies, advances and future prospects. In welding technology, some modified welding techniques are included, such as ASDAW. The welding simulation process is also discussed in detail. In automation part, the novel feature extraction methods based on different sensing techniques are summarized. Then, the emphasis is laid on the researches of recent years on path planning model and seam tracking techniques. At the end of this paper, summary is made and future prospects of application of advanced technology in intelligent robotic MLMP welding are given. And the promising development directions of MLMP are prospected in intelligent robotic welding of medium thickness plate.

Gas chromatography-mass spectrometry (GC-MS) is an important analytical technique for the analysis of organophosphorus pesticides in food products. Because of the complex matrices of food products, multiple preprocessing steps are required prior to performing the GC-MS analysis. Despite that, it is difficult to totally eliminate the interference of complex matrix background. In this work, we introduce an entropy minimization technique that can eliminate the need for comprehensive preprocessing steps to detect organophosphorus pesticides in a fortified orange juice sample. The pure mass spectra and extracted-ion chromatograms of the pesticides were extracted and reconstructed. The results achieved higher National Institute of Standard and Technology (NIST) match scores in comparison to the conventional background subtraction technique. Taken together, the entropy minimization technique is capable of providing rapid qualitative and quantitative analyses of complex GC-MS data. This technique is expected to have great potential for natural products and food analysis applications.

A major challenge for accurate GC-MS analysis is to achieve excellent chromatographic separation and a high signal-to-noise ratio. In fact, real-world samples are often contaminated with impurities that manifest as intense background noise in GC-MS data. Herein, a dynamic background noise removal system is developed based on an entropy minimization algorithm to extract pure mass spectra of straight-chain n-alkane components in a sample of hydrogenated jet fuel. This system is capable of extracting pure component spectra from overlapping peaks that are heavily superimposed by background noise without a priori information. The performance of the system surpasses that of the background subtraction method applied in Agilent ChemStation software. The robustness of the system to accurately analyse real-world samples is expected to simplify and revolutionise the application of GC-MS for chemical analysis.

Chemical profiling with gas chromatography/mass spectrometry (GC/MS) full-spectrum acquisition mode often leads to the discovery of known-unknown components. These are non-identified components which arise from the limitation of the data processing method or limited breadth of mass spectral libraries. The recent introduction of the NIST Hybrid Search sought to relieve the latter limitation by providing an improved class annotation technique. Herein, we demonstrate the importance of using a precise mass spectral reconstruction technique to increase the confidence of detecting the presence of known-unknowns and subsequently identifying them successfully with NIST Hybrid Search function. We compared the AMDIS algorithm against the rBTEM algorithm and found that the latter could more accurately reconstruct the mass spectra of co-eluting known-unknown components. This has a far-reaching implication to increase the number of identified compounds in GC/MS scan data.

Based on second-order cone programming, we present a new superdirective beamforming method with interferences and noise suppression for small aperture HF receive arrays. In the novel method, low side lobe level (SLL) and nulls are not only used to suppress interferences and noise, but also play an important part in overcoming the low array e-ciency brought by superdirective beamforming. According to the actual condition, the new method can present a good tradeofi between directive gain, array e-ciency, SLL, nulls and robustness against array uncertainty. Compared with the existing methods, it is more efiective in suppressing interference and noise. The superiority and validity of the proposed method can be illustrated by numerical results.

This study is aimed to evaluate the brain distribution of transforming growth factor-beta1 (TGF-beta1) following intranasal administration and the subsequent biological effects of TGF-beta1. Adult rats were given recombinant human TGF-beta1 (rhTGF-beta1) or vehicle solution intranasally. TGF-beta1 concentrations were significantly raised in several brain regions and the trigeminal nerve following intranasal delivery. The elevation appeared within 30 min and was sustained for at least 6 h, reaching its greatest level at 60 min. A concentration gradient in the central nervous system (CNS) regions was produced during the first 2 h after intranasal administration, with the OB presenting a significantly higher concentration than any other CNS regions. The nasally administered TGF-beta1 subsequently regulated gene expressions of its two receptors (TGF-beta receptor types I and II) in vivo, but did not affect mRNA level of TGF-beta1 itself. Our results suggest that TGF-beta1 can be transported into the CNS via the olfactory and trigeminal pathways, and may consequently exert its biological effects by regulating gene expressions of its receptors. Intranasal administration of neurotrophic factors may offer a potential strategy for treating some CNS disorders.