Background Safe and effective vaccines are urgently needed to end the COVID-19 pandemic caused by SARS-CoV-2 infection. We aimed to assess the preliminary safety, tolerability, and immunogenicity of an mRNA vaccine ARCoV, which encodes the SARS-CoV-2 spike protein receptor-binding domain (RBD). Methods This single centre, double-blind, randomised, placebo-controlled, dose-escalation, phase 1 trial of ARCoV was conducted at Shulan (Hangzhou) hospital in Hangzhou, Zhejiang province, China. Healthy adults aged 18–59 years negative for SARS-CoV-2 infection were enrolled and randomly assigned using block randomisation to receive an intramuscular injection of vaccine or placebo. Vaccine doses were 5 μg, 10 μg, 15 μg, 20 μg, and 25 μg. The first six participants in each block were sentinels and along with the remaining 18 participants, were randomly assigned to groups (5:1). In block 1 sentinels were given the lowest vaccine dose and after a 4-day observation with confirmed safety analyses, the remaining 18 participants in the same dose group proceeded and sentinels in block 2 were given their first administration on a two-dose schedule, 28 days apart. All participants, investigators, and staff doing laboratory analyses were masked to treatment allocation. Humoral responses were assessed by measuring anti-SARS-CoV-2 RBD IgG using a standardised ELISA and neutralising antibodies using pseudovirus-based and live SARS-CoV-2 neutralisation assays. SARS-CoV-2 RBD-specific T-cell responses, including IFN-γ and IL-2 production, were assessed using an enzyme-linked immunospot (ELISpot) assay. The primary outcome for safety was incidence of adverse events or adverse reactions within 60 min, and at days 7, 14, and 28 after each vaccine dose. The secondary safety outcome was abnormal changes detected by laboratory tests at days 1, 4, 7, and 28 after each vaccine dose. For immunogenicity, the secondary outcome was humoral immune responses: titres of neutralising antibodies to live SARS-CoV-2, neutralising antibodies to pseudovirus, and RBD-specific IgG at baseline and 28 days after first vaccination and at days 7, 15, and 28 after second vaccination. The exploratory outcome was SARS-CoV-2-specific T-cell responses at 7 days after the first vaccination and at days 7 and 15 after the second vaccination. This trial is registered with www.chictr.org.cn (ChiCTR2000039212). Findings Between Oct 30 and Dec 2, 2020, 230 individuals were screened and 120 eligible participants were randomly assigned to receive five-dose levels of ARCoV or a placebo (20 per group). All participants received the first vaccination and 118 received the second dose. No serious adverse events were reported within 56 days after vaccination and the majority of adverse events were mild or moderate. Fever was the most common systemic adverse reaction (one [5%] of 20 in the 5 μg group, 13 [65%] of 20 in the 10 μg group, 17 [85%] of 20 in the 15 μg group, 19 [95%] of ...

Sweet sorghum (Sorghum bicolor L. Moench) is a promising crop for biofuel and forage production, having strong resilience to multiple stresses and being capable of thriving on marginal land. The main goals in sweet sorghum improvement are to increase biomass and sugar yield. We validated quantitative trait loci (QTLs) controlling plant height, biomass, juice weight and Brix with 181 recombinant inbred lines derived from a cross between Shihong137, a dwarf grain sorghum, and L-Tian, a tall sweet sorghum, under four environments. Seven QTLs for plant height, stem and leaf fresh weight, stem fresh weight and juice weight could be repeatedly identified across four environments. However, three of those major QTLs, qPH7-2, qSLFW9 and qSFW9, had strong epistatic effect. Many QTLs related to biomass production were co-localised with previously known height QTLs, suggesting that plant height is a major trait regulating biomass production. However, qSFW1-2, qSLFW6-1, and qSLFW6-2 were mapped to positions with no known height QTL. We also identified and validated stable qBrix2 across environments. This study provided a genetic basis for integrated approaches, including plant height, to improve sweet sorghum biomass and sugar production.

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In order to obtain the maximum characteristic intensity of the up-conversion luminescence in GdTaO₄:RE/Yb(RE=Tm, Er) series, we established the regression equation between the luminescent intensity of the phosphors and the rare earth doping concentration upon the 980 nm laser excitation based on the experimental optimization design. The Tm³⁺/Yb³⁺ doping samples were combined with the uniform design and quadratic general rotation combination design, meanwhile the Er³⁺/Yb³⁺ doping samples were optimized by the uniform design and cubic orthogonal phosphor step by step. The relationship between concentration and luminous intensity was analyzed. The results showed that the concentration changes of RE³⁺ (RE=Tm, Er) and Yb³⁺ had a significant effect on luminous intensity, and there were extreme points of luminescent intensity in the test space. By solving the regression equation, we gained the optimal doping concentrations. The optimal samples were also prepared by high-temperature solid state method. The XRD diffraction patterns of the optimal samples are analyzed. The results show that the samples are pure phase, the doping of Li⁺ flux will inhibit the generation of reaction impurity phase, and the doping of rare earth will shift the diffraction peak to a high angle without changing the peak shape. The relationship between excitation power and luminescent intensity is analyzed. The results show that the blue light emission of Tm³⁺/Yb³⁺ co-doping phosphor is a three-photon process, and the green light emission of Er³⁺/Yb³⁺ co-doping phosphor is a two-photon process. The relationship between sample temperature and luminescent intensity is analyzed. The luminescent intensity of the sample decreases with the increasing of the temperature, indicating temperature quenching. Finally, the quenching activated energy of the sample is calculated.