Scanning inverse spin Hall effect spectrometer by shorted coaxial probes.

In this work, a scanning inverse spin Hall effect measurement system based on a shorted coaxial resonator has been built, which provides a high throughput method to characterize spin transport properties. The system is capable of performing spin pumping measurements on patterned samples within an area of 100 × 100 mm2. Its capability was demonstrated with Py/Ta bilayer stripes deposited on the same substrate with different thicknesses of Ta. The results show that the spin diffusion length is about 4.2 nm with a conductivity of about 7.5 × 105 Ω-1 m-1, which leads to the conclusion that the intrinsic mechanism of spin relaxation of Ta is the Elliott-Yafet interactions. The spin Hall angle of Ta is estimated to be about -0.014 at room temperature. The setup developed in this work provides a convenient, efficient, and nondestructive way to obtain the spin and electron transportation characteristics of the spintronic materials, which will fertilize this community by developing new materials and figuring out their mechanism.

S-Trimer, a COVID-19 subunit vaccine candidate, induces protective immunity in nonhuman primates.

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.

Preoperative red cell distribution width predicts postoperative cognitive dysfunction after coronary artery bypass grafting.

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.

Nonstereoselective foliar absorption and translocation of cycloxaprid, a novel chiral neonicotinoid, in Chinese cabbage.

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.

Optogenetic Modulation and Reprogramming of Bacteriorhodopsin-Transfected Human Fibroblasts on Self-Assembled Fullerene C60 Nanosheets.

Fullerenes have unique biocompatibility and photoelectric properties and are candidate materials for biomedical applications. Several cell membrane proteins in nature such as bacteriorhodopsin also have photoelectric properties. Highly expressible bacteriorhodopsin (HEBR) is a novel light-sensitive opsin that has the potential to trigger neural activities through optogenetic modulation. Here, HEBR plasmids are delivered to human fibroblasts and the cells are exposed to C60 fullerene self-assembled 2D nanosheets. Results show that the above approach combined with light stimulation (3 s duration and three times per day) may promote reprogramming and differentiation of human fibroblasts into neural-like cells in 7 d without any neural induction medium. The special photoelectric properties of fullerenes as culture substrates and transfected HEBR on the cell membrane may provide a new optogenetic platform for regulating the location (C60 nanosheet) and time (frequency of light illumination) for human fibroblasts to become neural-like cells, and may be applied to improve neural regeneration in the future.

Upconversion fluorescence immunoassay for imidaclothiz by magnetic nanoparticle separation.

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 NaYF4/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 (IC50), limit of detection (LOD, IC10), and the linear assay range (IC10-IC90) 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.

Simultaneous Determination of ß-Cypermethrin and Its Metabolite 3-Phenoxybenzoic Acid in Microbial Degradation Systems by HPLC-UV.

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 ß-cypermethrin (ß-CY) and its degradation product 3-phenoxybenzoic acid (3-PBA) by liquid chromatograph-mass spectrometry. Few studies on the simultaneous determination of ß-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 ß-CY and 3-PBA simultaneously in microbial degradation systems. In this study, a novel ß-CY degrading strain, Bacillus licheniformis B-1, was isolated from a tea garden soil, utilizing ß-CY as a growth substrate. Good linear relationships between ß-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 ß-CY and 3-PBA, respectively, and the corresponding limits of quantification were 0.21 and 0.34 µg/mL, respectively. Spiking recoveries for ß-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 ß-CY and 3-PBA in microbial degradation systems.