Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has caused the global pandemic. The virus is rapidly evolving, characterized by the emergence of several major variants. Stable prefusion ...spike protein (Pre) is the immunogen in current vaccines but is limited in protecting against different variants. Here, the immune responses induced by the relatively conserved stem subunit (S2) of spike protein versus Pre are investigated. Pre generates the most robust neutralization responses against SARS‐CoV‐2 variants in vesicular stomatitis virus pseudovirus‐based assessment but elicits less antibody‐dependent cellular cytotoxicity (ADCC) activity than S2. By contrast, S2 induces the most balanced immunoglobulin G (IgG) antibodies with potent and broad ADCC activity although produces weaker neutralization. The immunogenicity of S2 and Pre improves by incorporating the two proteins into double‐layered protein nanoparticles. The resulting protein nanoparticles Pre/S2 elicit higher neutralizing antibodies than Pre alone, and stronger ADCC than S2 alone. Moreover, nanoparticles produce more potent and balanced serum IgG antibodies than the corresponding soluble protein mixture, and the immune responses are sustained for at least four months after the immunization. Thus, the double‐layered protein nanoparticles have the potential to be developed into broader SARS‐CoV‐2 vaccines with excellent safety profiles.
The double‐layer protein nanoparticles constructed from stem subunit (S2) and prefusion spike protein (Pre) induce potent antibody‐dependent cellular cytotoxicity antibodies and neutralize antibodies. Moreover, with a more balanced immunoglobulin G isotype antibody, long‐lasting immune responses, and excellent safety profiles, the nanoparticles have the potential to be developed into broader severe acute respiratory syndrome coronavirus 2 vaccines.
In this communication, we propose an inverse design method based on spectral analysis (IDMBSA) for achieving desired far-field radiation pattern through aperture field design. The aperture field ...obtained through IDMBSA can be utilized for array synthesis and sparse array design, and it can also serve as a design objective for existing aperture field implementation methods. IDMBSA combined with the coordinate transformation enables the fulfillment of design requirements for arbitrary phaseless radiation pattern and polarization needs. Nonlinearity introduced by phaseless is addressed with a multiobjective optimization (MOO) algorithm. Compared to traditional array synthesis methods, IDMBSA significantly reduces the number of optimization variables by using modal expansion and further reduces the computational burden by utilizing analytical solutions. The inherent smoothness of the aperture field obtained through IDMBSA allows for direct application in existing aperture field implementation methods, facilitating the direct design of radiating devices with arbitrary far-field radiation pattern. Simulations were conducted to explore IDMBSA's application in array synthesis, sparse arrays, and dual-polarization independent design, and the results show the practicability of IDMBSA and its wide application prospect.
Summary
During meiosis, recombination‐mediated pairing and synapsis of homologous chromosomes begin with programmed DNA double‐strand breaks (DSBs). In yeast and mice, DSBs form in a tethered ...loop–axis complex, in which DSB sites are located within chromatin loops and tethered to the proteinaceous axial element (AE) by DSB‐forming factors. In plants, the molecular connection between DSB sites and chromosome axes is poorly understood.
By integrating genetic analysis, immunostaining technology, and protein–protein interaction studies, the putative factors linking DSB formation to chromosome axis were explored in maize meiosis.
Here, we report that the AE protein ZmASY1 directly interacts with the DSB‐forming protein ZmPRD3 in maize (Zea mays) and mediates DSB formation, synaptonemal complex assembly, and homologous recombination. ZmPRD3 also interacts with ZmPRD1, which plays a central role in organizing the DSB‐forming complex. These results suggest that ZmASY1 and ZmPRD3 may work as a key module linking DSB sites to chromosome axes during DSB formation in maize.
This mechanism is similar to that described in yeast and recently Arabidopsis involving the homologs Mer2/ZmPRD3 and HOP1/ZmASY1, thus indicating that the process of tethering DSBs in chromatin loops to the chromosome axes may be evolutionarily conserved in diverse taxa.
An anisotropic complementary metantenna (ACMA) is proposed for the integration of low sidelobe radiation and low in-band co-polarized (IBCP) scattering with the aid of characteristic mode analysis ...(CMA). With the guidance of CMA, the proposed ACMA evolving from a conventional metantenna (MTA) not only generates a coding phase distribution for low scattering but also restores broadside radiation modes like a uniform MTA. With the IBCP conditions set to <inline-formula> <tex-math notation="LaTeX">x </tex-math></inline-formula>-polarization and the band around 9 GHz, the ACMA is constructed by mixing two types of double-layer anisotropic complementary metasurface (MTS) unit cells. Two desired characteristic modes of ACMA are simultaneously excited by a substrate integrated waveguide (SIW) cavity through dual bow-tie slots. Both the simulation and experiments demonstrate that the proposed ACMA achieves both the <inline-formula> <tex-math notation="LaTeX">x </tex-math></inline-formula>-polarized broadside radiation with sidelobe level below −18.9 dB and IBCP scattering levels below −17.8 dB over the frequency range from 8.87 to 9.78 GHz.
We demonstrate herein a mixed solvent containing organic amines and water for the solution processing of CuSeCN and apply it as the hole-transport material for stable and efficient inverted ...perovskite solar cells for the first time. The obtained CuSeCN film is characterized with X-ray diffraction spectrum, X-ray photoelectron spectroscopy, scanning electron microscope, and current-potential characteristics. High-quality perovskite film can be formed on the CuSeCN film obtained from the spin-coating of CuSeCN solution in a mixture solvent of H2O, ethanolamine (ETA), ethylenediamine (EDA), diethanolamine (DTA) with volume ratio of 2:6:1:1. The CuSeCN-based perovskite solar cell yields power conversion efficiency of 15.61% at forward scan and 15.97% at reverse scan with negligible hysteresis and good stability. As compared to the typically used thioether-based solvents for the solution processing of CuSCN, the mixture solvent proposed in this work is less volatile and much cheaper, which is critical for practical applications of perovskite solar cells.
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•CuSeCN is first used in p-i-n perovskite solar cells as the hole-transport material.•Mixed organic amine solvents are developed for the solution processing of CuSeCN.•The CuSeCN-based perovskite solar cell yields efficiency of 15.61%.•The CuSeCN-based perovskite solar cell shows small hysteresis and good stability.
A previously unknown, water-soluble polysaccharide, named DOTP-B, was isolated from the roots of the plant Dioscorea opposita Thunb, a well-known edible and medicinal plant in China. DOTP-B was found ...to be neutral in charge, with an average molecular weight of 5623 Da. Monosaccharide composition analysis by GC–MS revealed that DOTP-B was a hetero-polysaccharide consisting of glucose and galactose at a molar ratio of 14.6:1.0. Structural features of DOTP-B were investigated with a combination of chemical and instrumental methods, including complete acid hydrolysis, periodate oxidation, methylation, GC–MS, FTIR and several NMR spectra. Highly correlated results demonstrated that the main chain of DOTP-B consisted of →4)-α-d-glc(1 → residues, with about 6% internal →6)-β-d-gal(1 → residues. The antioxidant activity of DOTP-B was also evaluated as the EC50 values against DPPH and PTIO radicals were 2.1 ± 0.1 mg/mL and 1.6 ± 0.1 mg/mL, respectively. Therefore, the polysaccharide DOTP-B could be possibly developed as a promising natural antioxidant for application in medical and food industries.
The nickel‐catalyzed intermolecular cycloadditions of benzocyclobutenones with 1,3‐dienes developed by Martin and co‐workers are featured with the exclusive proximal C−C bond cleavage and a high ...chemoselectivity of the 4+4 over the 4+2 cycloaddition. In this report, the detailed reaction mechanism and the origins of the selectivities were investigated by means of density functional theory calculations. The results show that the reaction is initiated by a C−C oxidative addition of the benzocyclobutenone to form the five‐membered nickelacycles. A subsequent exo 1,4‐insertion/C−C reductive elimination and an endo 1,4‐insertion/C−C reductive elimination lead to the 4+4 and 4+2 cycloaddition products, respectively. The 1,4‐insertion of the 1,3‐diene into the Ni−C bond was calculated to be the rate‐ and selectivity‐determining step of the reaction. The calculations reproduced quite well the experimentally observed exclusive proximal C−C bond cleavage and the high chemoselectivity of the 4+4 over the 4+2 cycloaddition. In particular, it was found that the steric repulsion between the phosphine ligand and the α‐substituent of the benzocyclobutenone has a dramatic impact on the 1,4‐insertion, which enables the experimentally observed selectivities.
Different ways: DFT calculations were performed to investigate the nickel‐catalyzed intermolecular cycloadditions of benzocyclobutenones with 1,3‐dienes (see scheme). The steric repulsion between the phosphine ligand and the α‐substituent of the benzocyclobutenone has a dramatic impact on the 1,4‐insertion, which enables the observed exclusive proximal C−C bond cleavage and the high chemoselectivity for the 4+4 cycloaddition.
Smart garments for monitoring physiological and biomechanical signals of the human body are key sensors for personalized healthcare. However, they typically require bulky battery packs or have to be ...plugged into an electric plug in order to operate. Thus, a smart shirt that can extract energy from human body motions to run body-worn healthcare sensors is particularly desirable. Here, we demonstrated a metal-free fiber-based generator (FBG) via a simple, cost-effective method by using commodity cotton threads, a polytetrafluoroethylene aqueous suspension, and carbon nanotubes as source materials. The FBGs can convert biomechanical motions/vibration energy into electricity utilizing the electrostatic effect with an average output power density of ∼0.1 μW/cm2 and have been identified as an effective building element for a power shirt to trigger a wireless body temperature sensor system. Furthermore, the FBG was demonstrated as a self-powered active sensor to quantitatively detect human motion.
