SARS-CoV-2 is the underlying cause for the COVID-19 pandemic. Like most enveloped RNA viruses, SARS-CoV-2 uses a homotrimeric surface antigen to gain entry into host cells. Here we describe S-Trimer, ...a native-like trimeric subunit vaccine candidate for COVID-19 based on Trimer-Tag technology. Immunization of S-Trimer with either AS03 (oil-in-water emulsion) or CpG 1018 (TLR9 agonist) plus alum adjuvants induced high-level of neutralizing antibodies and Th1-biased cellular immune responses in animal models. Moreover, rhesus macaques immunized with adjuvanted S-Trimer were protected from SARS-CoV-2 challenge compared to vehicle controls, based on clinical observations and reduction of viral loads in lungs. Trimer-Tag may be an important platform technology for scalable production and rapid development of safe and effective subunit vaccines against current and future emerging RNA viruses.
A full understanding of the growth and distribution of tree roots is conducive to guiding precision irrigation, fertilization, and other agricultural work during agricultural production. Detecting ...tree roots with a ground-penetrating radar is a repeatable detection method that does no harm to the earth surface and tree roots. In this research, a rapid and accurate automatic detection was conducted on hyperbolic waveforms formed by root targets in B-scan images based on YOLOv5s. Following this, the regions of interest containing target hyperbolas were generated. Three or more coordinate points on the hyperbola were selected according to the three-point fixed circle (TPFC) method to locate the root system and estimate the root diameter. The results show that the accuracy of hyperbola detection using YOLOv5s was 96.7%, the recall rate was 86.6%, and the detection time of a single image was only 13 ms. In the simulation image, the TPFC method was used to locate the root system and estimate the root diameter through three different frequency antennas (500 MHz, 750 MHz, and 1000 MHz). A more accurate result was obtained when the antenna frequency was 1000 MHz, with the average distance error of root system positioning being 3.17 cm, and the slope and R2 of the linear fitting result between the estimated root diameter and the actual one being 1.029 and 0.987, respectively. Verified by the pre-buried root test and wilderness field test, both root localization and root diameter estimation in our research were proved to gain good results and conform to the rules found in simulation experiments. Therefore, we believe that this method can quickly and accurately detect the root system, locate and estimate the root diameter, and provide a new perspective for the non-destructive detection of the root system and the three-dimensional reconstruction of the root system.
With the rapid graying of China’s population, ensuring and improving the quality of life for Chinese elderly people has become an urgent issue. This paper explores the needs of elderly people in ...China from the perspective of their caregivers by applying machine learning approach upon social media posts related to elderly care and subsequently put forward strategies with respect to data mining findings. We obtain more than thirty thousand texts from the Douban discussion group named “One-Child Parent Retirement Exchange”; Latent Dirichlet Allocation (LDA) model is employed to extract topic and words, to analyze and categorize text into relevant elderly care. This study then utilizes SnowNLP module upon previous outcome to appraise the emotional bias of the caregivers. Our finding points out that the essential needs of Chinese elderly people are mental health needs, information needs and intergenerational needs; the emotional bias of children in supporting their parents was generally negative. At the end, our paper subsequently suggests strategies to satisfy the primary elderly caring needs while at the same time alleviating caregivers’ pressure.
We assessed the relationship between red blodd cell distribution width (RDW) and postoperative cognitive dysfunction (POCD) after coronary artery bypass grafting (CABG) in patients who usually had ...obvious hemodynamic changes. We enrolled 362 coronary heart disease patients who received CABG. POCD was assessed through neuropsychological examination at 21 days after operation. Demographics, history of diseases, blood biochemical parameters and perioperative data were collected. The receiver operating characteristic (ROC) curve was used to find the best cut-off value of RDW for diagnosis of POCD. Logistic regression was used to explore the relationship between RDW and POCD. The 21-day incidence of POCD in patients receiving CABG was 27.1% (98/362). The RDW of POCD patients was significantly higher than in the non-POCD patients (17.4 vs. 13.2). The sensitivity and specificity of RDW for predicting POCD were 82.7 and 64.8%, respectively. The POCD patients also tended to be older and had higher fasting plasma glucose, hypersensitive c-reactive protein, tumor necrosis factor-α, white blood cell levels and longer surgery time. No significant differences were found in other parameters. The 21-day neuropsychological test results were better in the POCD patients than the non-POCD patients. After adjustment of potential factors, the preoperative high RDW was still associated with an increased risk of POCD (odds ratio (OR) = 2.52, 95% confidence interval (CI): 1.28-4.31). Our study indicates that preoperative RDW is significantly elevated in POCD patients receiving CABG. The elevated preoperative RDW is associated with an increased risk of POCD and preoperative RDW can be an independent predictor of POCD.
Exploring traditional neonicotinoid pesticides substitutes has become one of the global scientific attentions because of their hazardous environmental impacts. Cycloxaprid (CYC) is considered to be a ...promising candidate alternative. But the environmental behaviors and fate of CYC in different planting system remain poorly understood. The accumulation of 14C-labeled CYC stereoisomers within different parts of Chinese cabbage (Brassica chinensis L.) was investigated, with a particular focus on the foliar absorption, translocation and stereoselectivity of CYC, during a laboratory trial. In general, the stereoisomers 14C-5R,8S-CYC and 14C-5S,8R-CYC, their metabolites, as well as the breakdown and reaction products can be transferred in both acropetal and basipetal directions. Most of the two stereoisomers absorbed by plants remained in the treated leaves, whereas a small amount was distributed to the roots. The amount of 14C in the stalks varied among the experimental time points. At 192 h after treatment (HAT), the detected radioactivity of both 14C-5R,8S-CYC and 14C-5S,8R-CYC in the leaves above the treated leaf (LATL) was higher than that in the leaves below the treated leaf (LBTL). However, the stereoisomers of CYC underwent nonstereoselective absorption and translocation in this trial. This information implies that racemic CYC and its metabolites should be a main research focus. Thus, the obtained results provide implications for a more accurate prediction about the risk assessment of CYC, which will be helpful for guiding its rational use as well as securing the ecological environment safety and human health.
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•Most of the two cycloxaprid stereoisomers absorbed by plants remained in the treated leaves.•Only a small amount was transported to the roots.•The detected radioactivity of both stereoisomers in the LATL was higher than that in the LBTL.•No significant difference in distribution was detected between the two stereoisomers.
The stereoisomers of 14C-labeled CYC underwent nonstereoselective absorption and translocation in Chinese cabbage.
In this paper, a microstrip resonator based on double split rings is used to build an electron spin resonance (ESR) measurement system. The resonator is optimized by the finite element ...electromagnetic simulation and the 3 dB bandwidth is 58.7 MHz. Due to the open structure of the resonator, large-size samples with high dielectric loss can be measured nondestructively. The ESR signal of 2,2-diphenyl-1-picrylhydrazyl (DPPH) powder with different quality is measured at room temperature, and the result indicated that the spin detection limit of this system can reach 9.66 ×1012 spins/Gs Hz1/2. It is demonstrated that the system can be used to characterize films deposited on different substrates such as silicon, glasses or ceramics regardless of its high frequency losses through the measurement of DPPH sample spin-coated on silicon and zerodur. Our system provides a convenient approach to research the defect of thin films and to characterize their performances within microwave frequency.
A sensitive fluorescence immunoassay for the detection of imidaclothiz was established by using magnetic nanoparticles (MNPs) as concentration elements and upconversion nanoparticles (UCNPs) as ...signal labels. The NaYF
4
/Yb,Er UCNPs and MNPs were conjugated with imidaclothiz monoclonal antibody and imidaclothiz antigen, respectively. Imidaclothiz could compete with the antigen-conjugated MNPs for binding to the antibody-conjugated UCNPs and resulted in a decreased fluorescence signal when the MNPs were separated by an external magnet. Under the optimal conditions, the concentration of imidaclothiz producing 50% inhibition of the signal (IC
50
), limit of detection (LOD, IC
10
), and the linear assay range (IC
10
–IC
90
) were 14.59, 0.74, and 0.74–289.30 ng mL
−1
, respectively. The immunoassay exhibited no obvious cross-reactivity with analogues of imidaclothiz except for imidacloprid, with 89.2% cross-reactivity. The average recoveries measured in paddy water, pear, soil, peach, rice, tomato, wheat, and pakchoi were 75.7–105.2%, and the relative standard deviations (RSDs) were less than 11.2%. In addition, the results of the immunoassay correlated well with that of high-performance liquid chromatography (HPLC) for authentic samples.
Graphical abstract
Development of an upconversion fluorescence immunoassay for the detection of imidaclothiz by using antibody-modified upconversion nanoparticles (UCNPs) as the detection probe and antigen-modified magnetic nanoparticles (MNPs) as the capture probe.
Fe2O3@C nanocomposites (denoted as FeC-n, n represents the weight percent of Fe(NO3)3·9H2O in the starting gel) have been fabricated by pyrolyzing Fe(NO3)3·9H2O impregnated starch gels. When the ...Fe(NO3)3·9H2O content was below 50wt.%, the products contained well dispersive and uniform γ-Fe2O3 nanoparticles that embedded in the carbon matrix. The particle sizes were positively related to the content of Fe(NO3)3·9H2O. The nanocomposites FeC-50 that contained 4.25nm nanoparticles exhibited an enhanced electrochemical performance within the voltage window of −1.3–0.4V in 6molL−1 KOH solutions. The symmetric capacitor of FeC-50 possessed a high specific capacitance (SC) of 267.2Fg−1 at 0.35Ag−1 with a high voltage of 1.4V.
► Fe2O3@C Nanocomposites were prepared by pyrolyzing Fe(NO3)3·9H2O impregnated starch gels. ► Iron oxides well dispersed in the carbon matrix and showed superfine grains as well as narrow size distribution. ► The particle size of iron oxides could be easily controlled by Fe(NO3)3·9H2O content in the starting gels. ► FeC−50 sample exhibited the highest specific capacitance of 267.2F·g−1. Normalizing this value to the iron oxide mass yielded 498.0F·g−1. ► The symmetric capacitor loading with FeC−50 had a high operating voltage (1.4V) and showed excellent cycling stability (only 8.3% fade within 5000 cycles).
The wide use of pesticides in agriculture is necessary to guarantee adequate food production worldwide. However, pesticide residues have caused global concern because of their potential health risk ...to consumers. In this study, we could identify β-cypermethrin (β-CY) and its degradation product 3-phenoxybenzoic acid (3-PBA) by liquid chromatograph–mass spectrometry. Few studies on the simultaneous determination of β-CY and its metabolites have been carried out so far; hence, we established a high-performance liquid chromatography method to determine the concentrations of both β-CY and 3-PBA simultaneously in microbial degradation systems. In this study, a novel β-CY degrading strain, Bacillus licheniformis B-1, was isolated from a tea garden soil, utilizing β-CY as a growth substrate. Good linear relationships between β-CY and 3-PBA were observed and the concentrations of reference solutions were between 0.50 and 60.00 µg/mL. Satisfactory stability and intra- and interday precision were obtained. The limits of detection were 0.06 and 0.13 µg/mL for β-CY and 3-PBA, respectively, and the corresponding limits of quantification were 0.21 and 0.34 µg/mL, respectively. Spiking recoveries for β-CY varied from 98.38 to 105.80%, with relative standard deviations (RSDs) varying from 1.49 to 3.93%. Spiking recoveries for 3-PBA varied from 99.59 to 101.20%, with RSDs varying from 0.58 to 3.64%. The proposed method has advantages of simplicity, rapidity, high accuracy, good separation and reproducibility; thus, it is ideally suitable for simultaneous determination of β-CY and 3-PBA in microbial degradation systems.
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