Magnetically-dressed CrSBr exciton-polaritons in ultrastrong coupling regime.

Over the past few decades, exciton-polaritons have attracted substantial research interest due to their half-light-half-matter bosonic nature. Coupling exciton-polaritons with magnetic orders grants access to rich many-body phenomena, but has been limited by the availability of material systems that exhibit simultaneous exciton resonances and magnetic ordering. Here we report magnetically-dressed microcavity exciton-polaritons in the van der Waals antiferromagnetic (AFM) semiconductor CrSBr coupled to a Tamm plasmon microcavity. Using angle-resolved spectroscopy, we reveal an exceptionally high exciton-photon coupling strength, up to 169 meV, demonstrating ultrastrong coupling that persists up to room temperature. By performing temperature-dependent spectroscopy, we show the magnetic nature of the exciton-polaritons in CrSBr microcavity as the magnetic order changes from AFM to paramagnetic. By applying an out-of-plane magnetic field, we achieve effective tuning of the polariton energy while maintaining the ultrastrong exciton-photon coupling strength. We attribute this to the spin canting process that modulates the interlayer exciton interaction.

Mesoporous Silica Nanoparticles Induce Intracellular Peroxidation Damage of Phytophthora infestans: A New Type of Green Fungicide for Late Blight Control.

Nanopesticides are considered to be a promising alternative strategy for enhancing bioactivity and delaying the development of pathogen resistance to pesticides. Here, a new type of nanosilica fungicide was proposed and demonstrated to control late blight by inducing intracellular peroxidation damage to Phytophthora infestans, the pathogen associated with potato late blight. Results indicated that the structural features of different silica nanoparticles were largely responsible for their antimicrobial activities. Mesoporous silica nanoparticles (MSNs) exhibited the highest antimicrobial activity with a 98.02% inhibition rate of P. infestans, causing oxidative stress responses and cell structure damage in P. infestans. For the first time, MSNs were found to selectively induce spontaneous excess production of intracellular reactive oxygen species in pathogenic cells, including hydroxyl radicals (•OH), superoxide radicals (•O2-), and singlet oxygen (1O2), leading to peroxidation damage in P. infestans. The effectiveness of MSNs was further tested in the pot experiments as well as leaf and tuber infection, and successful control of potato late blight was achieved with high plant compatibility and safety. This work provides new insights into the antimicrobial mechanism of nanosilica and highlights the use of nanoparticles for controlling late blight with green and highly efficient nanofungicides.

Construction of Function-Oriented Core-Shell Nanostructures in Hydrogen-Bonded Organic Frameworks for Near-Infrared-Responsive Bacterial Inhibition.

Exploration of effective ways to integrate various functional species into hydrogen-bonded organic frameworks (HOFs) is critically important for their applications but highly challenging. In this study, according to the "bottle-around-ship" strategy, core-shell heterostructure of upconversion nanoparticles (UCNPs) and HOFs was fabricated for the first time via a ligand-grafting stepwise method. The UCNPs "core" can effectively upconvert near-infrared (NIR) irradiation (980 nm) into visible light (540 nm and 653 nm), which further excites the perylenediimide-based HOF "shell" through resonance energy transfer. In this way, the nanocomposite inherits the high porosity, excellent photothermal and photodynamic efficiency, NIR photoresponse from two parent materials, achieving intriguing NIR-responsive bacterial inhibition toward Escherichia coli. This study may shed light on the design of functional HOF-based composite materials, not only enriching the HOF library but also broadening the horizon of their potential applications.

Effect of Bacillus thuringiensis biomass and insecticidal activity by cultivation with vegetable wastes.

Bacillus thuringiensis (Bt) has been regarded as a biopesticide with high efficiency and safety, while it still cannot be popularized and mass-produced because of its high production costs. In the present study, we aimed to develop a cost-effective biopesticide via the secondary use of discharged vegetable wastes as the raw fermentation medium, and the insecticidal activity of Bt strain prepared by this cheap cultivation approach was evaluated. The suitable carbon source, nitrogen source additives and optimal metal ions were screened by the single-factor test, and the optimal combination of additives was determined by orthogonal test and ANOVA analysis. We found that soluble starch (6 g l-1), soya bean meal (6 g l-1), Al3+ (0.4 g l-1) and Fe2+ (0.4 g l-1) were the optimal exogenous additives, and the optimal fermentation conditions were as follows: pH 7.0, temperature of 35°C and aeration of 80 ml/250 ml. Meanwhile, the bioactivity test results showed that the Bt strain prepared by cheap cultivation still exhibited a good insecticidal effect on Helicoverpa armigera compared with the standard LB medium. Collectively, our findings provided a new strategy for vegetable waste utilization with less environmental impact and reduced production cost.

Comparison of gefitinib-induced skin adverse reactions (SAR) in C57BL/6 and FVB/N mice.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as gefitinib, erlotinib, and afatinib, are widely used in clinical practice and remarkably effective in treatment of advanced non-small cell lung cancer. However, there are some adverse effects while taking EGFR-TKIs, among which skin adverse reactions (SAR) are the most common events. At present, the poor outcome of SAR and insufficient research on SAR models need to be addressed. In this study we focused on the SAR models to lay a foundation for mechanism researches. Gefitinib, one of the EGFR-TKIs, was used as SAR inducing agents. We chose C57BL/6 and FVB/N mice as experimental model and they were divided into four groups. The weight and skin moisture of mice were detected every 7 days, itching behavior and abnormal eyelids were tested at 35th day after gavage, and survival rate was also recorded. The weight of unit area hair, length of whiskers and inflammatory cells were evaluated after mice sacrificed. C57BL/6 animals treated with gefitinib showed significant differences in survival rate, weight of unit area hair, skin moisture changes, skin dryness, itching behavior, whisker irregular growth, abnormal eyelids, and inflammatory cells; FVB/N animals treated with gefitinib only showed significant differences in survival rate, whisker irregular growth and abnormal eyelids, compared with the control group, respectively. In this study, we compared the similarities and differences of gefitinib-induced SAR between C57BL/6 and FVB/N mice, which illustrated different patients probably showing different symptoms clinically and provided experimental basis for researching mechanism of EGFR-TKIs induced SAR.

Design of a Controlled-Release Delivery Composite of Antibacterial Agent Gatifloxacin by Spherical Silica Nanocarrier.

In this study, a spherical silica nanoparticle was explored as a gatifloxacin carrier synthesized by the chemical precipitation method. It was found that there was no new chemical bond formation during the loading process between gatifloxacin and silica, which implies that the binding was driven by physical interaction. In addition, the drug loading and encapsulation efficiency could be improved by appropriately increasing nano-silica content in the loading process. Meanwhile, the release rate of gatifloxacin after loading nano-silica was also improved, suggesting the successful design of a controlled-release delivery composite. The silica nanocarrier could significantly improve the antibacterial performance of Escherichia coli by 2.1 times, which was higher than the pure gatifloxacin. The 24 h bacteriostatic rate was higher than that of a simple mixture of silica nanoparticles and gatifloxacin. Strong reactive oxygen species (ROS) in GAT-SiO2 NPs suggests that ROS might be associated with bactericidal activity. The synergy between the physicochemical effect and ROS production of this material is proposed as the mechanism of its antibacterial activity, which can also be confirmed by the cell membrane damage observed under electron microscopy and DNA damage experiments. Collectively, our finding indicates that nano-silica microspheres could serve as a promising carrier for the sustained release of gatifloxacin, thereby providing a new carrier design scheme for the improvement of the antibacterial effect.