Optimization hydrothermal synthesis conditions for nano-sized (Na0.5 Bi0.495 Nd0.005 )TiO3 particles by an orthogonal experiment and their luminescence performance.

By designing an orthogonal experiment with four factors and three levels, (Na0.5 Bi0.495 Nd0.005 )TiO3 (NBT-Nd) nanopowders were prepared using a hydrothermal method under different conditions to determine the optimum hydrothermal synthesis conditions. The synthesized NBT-Nd nanopowders were characterized using X-ray diffraction measurement, ultraviolet-visible spectra, photoluminescence spectra, and transmission electron microscopy to evaluate the orthogonal experimental conditions. The results showed that NBT-Nd powders with excellent crystalline and luminescence properties could be obtained at 160°C, with a 16 h reaction time, 8 mol·L-1 NaOH, and with 0.4489 g C19 H42 BrN. The optimized hydrothermal method-prepared NBT-Nd powder has a rather pure rhombohedral perovskite structure at room temperature, and exhibits an aggregated polycrystalline structure containing nanotubes and nano-sized particles. Under excitation of 247 nm light, strong fluorescence emissions are excited at 423 nm and 441 nm in the NBT-Nd powder that were generated by transitions of Nd3+ from 2 D5/2 to 4 I9/2 and from 4 G11/2 to 4 I9/2 , respectively. Through CIE1931 chromaticity calculation of the emission peaks, the NBT-Nd powder was shown to emit indigo blue fluorescent light.

Vitamin D inhibits the occurrence of experimental cerebral malaria in mice by suppressing the host inflammatory response.

In animal models of experimental cerebral malaria (ECM), neuropathology is associated with an overwhelming inflammatory response and sequestration of leukocytes and parasite-infected RBCs in the brain. In this study, we explored the effect of vitamin D (VD; cholecalciferol) treatment on host immunity and outcome of ECM in C57BL/6 mice during Plasmodium berghei ANKA (PbA) infection. We observed that oral administration of VD both before and after PbA infection completely protected mice from ECM. VD administration significantly dampened the inducible systemic inflammatory responses with reduced circulating cytokines IFN-γ and TNF and decreased expression of these cytokines by the spleen cells. Meanwhile, VD also resulted in decreased expression of the chemokines CXCL9 and CXCL10 and cytoadhesion molecules (ICAM-1, VCAM-1, and CD36) in the brain, leading to reduced accumulation of pathogenic T cells in the brain and ultimately substantial improvement of the blood-brain barriers of PbA-infected mice. In addition, VD inhibited the differentiation, activation, and maturation of splenic dendritic cells. Meanwhile, regulatory T cells and IL-10 expression levels were upregulated upon VD treatment. These data collectively demonstrated the suppressive function of VD on host inflammatory responses, which provides significant survival benefits in the murine ECM model.

Isolating Antipathogenic Fungal Coumarins from Coriaria nepalensis and Determining Their Primary Mechanism In Vitro.

Through bioassay-guided isolation, eight undescribed coumarins (1-8), along with six reported coumarins (9-14), were obtained from Coriaria nepalensis. The new structures were determined by using IR, UV, NMR, HRESIMS, and ECD calculations. The results of the biological activity assays showed that compound 9 exhibited broad spectrum antifungal activities against all tested fungi in vitro and a significant inhibitory effect on Phytophthora nicotianae with an EC50 value of 3.00 µg/mL. Notably, compound 9 demonstrated greater curative and protective effects against tobacco balack shank than those of osthol in vivo. Thus, 9 was structurally modified to obtain new promising antifungal agents, and the novel derivatives (17b, 17j, and 17k) exhibited better effects on Sclerotinia sclerotiorum than did lead compound 9. Preliminary mechanistic exploration illustrated that 9 could enhance cell membrane permeability, destroy the morphology and ultrastructure of cells, and reduce the exopolysaccharide content of P. nicotianae mycelia. Furthermore, the cytotoxicity results revealed that compound 9 exhibited relatively low cytotoxicity against HEK293 cell lines with an inhibition rate of 33.54% at 30 µg/mL. This research is promising for the discovery of new fungicides from natural coumarins with satisfactory ecological compatibility.

Recent advances in respiratory immunization: A focus on COVID-19 vaccines.

The development of vaccines has always been an essential task worldwide since vaccines are regarded as powerful weapons in protecting the global population. Although the vast majority of currently authorized human vaccinations are administered intramuscularly or subcutaneously, exploring novel routes of immunization has been a prominent area of study in recent years. This is particularly relevant in the face of pandemic diseases, such as COVID-19, where respiratory immunization offers distinct advantages, such as inducing systemic and mucosal responses to prevent viral infections in both the upper and lower respiratory tracts and also leading to higher patient compliance. However, the development of respiratory vaccines confronts challenges due to the physiological barriers of the respiratory tract, with most of these vaccines still in the research and development stage. In this review, we detail the structure of the respiratory tract and the mechanisms of mucosal immunity, as well as the obstacles to respiratory vaccination. We also examine the considerations necessary in constructing a COVID-19 respiratory vaccine, including the dosage form of the vaccines, potential excipients and mucosal adjuvants, and delivery systems and devices for respiratory vaccines. Finally, we present a comprehensive overview of the COVID-19 respiratory vaccines currently under clinical investigation. We hope this review can provide valuable insights and inspiration for the future development of respiratory vaccinations.