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Respiratory syncytial virus (RSV) causes lower respiratory tract diseases and bronchiolitis in children and elderly individuals. There are no effective drugs currently available to treat RSV infection. In this study, we report that Licochalcone A (LCA) can inhibit RSV replication and mitigate RSV‐induced cell damage in vitro, and that LCA exerts a protective effect by reducing the viral titer and inflammation in the lungs of infected mice in vivo. We suggest that the mechanism of action occurs through pathways of antioxidant stress and inflammation. Further mechanistic results demonstrate that LCA can induce nuclear factor erythroid 2‐related factor 2 (Nrf2) translocation into the nucleus, activate heme oxygenase 1 (HO‐1), and inhibit reactive oxygen species‐induced oxidative stress. LCA also works to reverse the decrease in I‐kappa‐B‐alpha (IкBα) levels caused by RSV, which in turn inhibits inflammation through the associated nuclear factor kappa B and tumor necrosis factor‐α signaling pathways. The combined action of the two cross‐talking pathways protects hosts from RSV‐induced damage. To conclude, our study is the first of its kind to establish evidence of LCA as a viable treatment for RSV infection. [ABSTRACT FROM AUTHOR]

Constructing van der Waals (vdW) heterostructures provides an effective and feasible method for 2D materials to improve their properties and extend their possible applications. Using first-principles calculations, we explored the atomic and electronic structures of Janus In2SeX (X = S or Te) and revealed the existence of a vertical internal intrinsic electric field in these Janus monolayers. Then, we stacked the pristine InSe and Janus In2SeX (X = S or Te) with black phosphorus (BP) vertically to construct vdW heterostructures with a mismatch of less than 5% and systematically investigated their interface atomic structures and possible applications in photovoltaics. The calculation results reveal that the constructed vdW heterostructures can be synthesized experimentally, and the type-II band alignment can be found in all vdW heterostructures, which is independent of the internal electric field of Janus monolayers, the built-in dipole at the interface between two domains, and the number of layers. In addition, the vdW heterostructures show stronger light absorption compared to monolayer individuals, and the type-II band alignment can help the photo-excited carriers to separate and achieve an excellent photovoltaic power conversion efficiency of up to about 21% in these heterostructures. These extraordinary results suggest that these vdW heterostructures have great potential for more efficient solar photovoltaic applications. [ABSTRACT FROM AUTHOR]

Electrostatic control and van der Waals integration are useful methods for 2D materials to help modulate their properties. Here, we constructed nine types of monolayer and multilayer Janus structures based on group-III monochalcogenides and investigated their atomic and electronic structures from first-principles calculations. We found the existence of an intrinsic electric field at Janus structures by comparing their average vacuum electron potentials at two surfaces. Careful charge analyses reveal that the electric field at monolayer Janus structures is mainly due to the dipole of the bond that connects group-III elements of weaker negativity and group-VI elements of stronger negativity. The E-filed at multilayer Janus structures maintains owing to the superposition of dipole at each layer when layer numbers (LN) are not very large, and the electric field starts to reduce when LN is large enough and obvious charge transfer happens between two surfaces of Janus multilayers. Electronic structure calculations at Janus structures demonstrate that the electric field can hardly modulate the charge density population in the monolayer case, while the electric field will significantly bend the bands in multilayer cases and make the charge density of the valence band maximum and the conduction band minimum always located at two separating surfaces, which promotes electron–hole to separate. Furthermore, we investigated the band alignment of isolated monolayer pristine group-III monochalcogenides and isolated Janus group-III monochalcogenides of monolayer, bilayer, and trilayer, and constructed van der Waals (vdW) heterostructures with one pristine monolayer and one Janus monolayer. The results show that the surface termination of Janus structures at the interface can significantly influence the band offset and electronic structures of vdW heterostructures. These results can not only provide a new understanding of the intrinsic electric field of monolayer and multilayer 2D Janus structures but also give a guide that uses electrostatic to modulate the properties of group-III monochalcogenides and other 2D materials. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rice blast, caused by Magnaporthe oryzae, is a destructive disease threatening the production of staple foods worldwide. Quinone outside inhibitors (QoIs) are a group of chemicals exhibiting excellent activity against a majority of plant pathogens, with the disadvantage that pathogens can easily develop resistance to QoIs. RESULTS: Here, we investigated the activity of picoxystrobin against M. oryzae, which showed a great inhibitory effect on 100 strains of M. oryzae with half‐maximal effective concentrations (EC50) ranging from 0.0251 to 0.1337 μg ml−1. The EC50 values showed a continuous unimodal distribution that was identical to the normal distribution, suggesting the potency of our study to represent baseline sensitivity. In addition, nine resistant mutants were obtained by exposing M. oryzae to a high dosage of picoxystrobin in the laboratory; all of them showed cross‐resistance to the other five QoI fungicides. Although some mutants showed a decreased resistance factor after ten successive cultures on fungicide‐free medium, the resistance to picoxystrobin was still inheritable. Amino acid substitution of G143S was detected in eight of nine picoxystrobin‐resistant mutants, and G143A was detected in only one of nine mutants. A fitness penalty was found in the mutants carrying G143S rather than G143A. CONCLUSION: Our findings suggested that M. oryzae had a mid to high risk of resistance to picoxystrobin. Considering this, we should be vigilant to the resistance risk and apply picoxystrobin sensibly in the field. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Supercritical carbon dioxide (scCO2)–assisted annealing process has demonstrated promising prospects in the toughness enhancement of polymers. Herein, this effective method was adopted to toughen a biodegradable polymer, poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV). Significantly, the greatly improved tensile toughness and impact toughness of PHBV were achieved. It is noted that the 26 times enhancement in tensile toughness and 2.4 times improvement in impact toughness were obtained for the sample treated at annealing temperature of 90°C and saturation pressure of 10 MPa. More importantly, the toughness mechanism was further explored via various characterizations. It is indicated that the increment in the toughness of PHBV after scCO2‐assisted annealing was closely related to the perfection of microstructure sample and the appearance of micro‐voids. [ABSTRACT FROM AUTHOR]

Copy number variation (CNV) may have phenotypic effects by altering the expression level of the gene(s) or regulatory element(s) contained. It is believed that CNVs play pivotal roles in controlling plant architecture and other traits in plant. However, the effects of CNV contributing to special traits remain largely unknown. Here we report a CNV involved in rice architecture by modulating tiller number and leaf angle. In the genome of Oryza sativa ssp. japonica cv. Nipponbare, we found a locus Loc_Os08g34249 is derived from a 13,002-bp tandem duplication in the nearby region of OsMTD1 , a gene regulating tillering in rice. Further survey of 230 rice cultivars showed that the duplication occurred in only 13 japonica rice cultivars. Phenotypic investigation indicated that this CNV region may contribute to tiller number. Moreover, we revealed that OsMTD1 not only influences rice tiller number and leaf angle, but also represses pri-miR156f transcription in the CNV region. Intriguingly, this CNV performs function through both the dosage and position effects on OsMTD1 and pri-miR156f. Thus, our work identified a CNV and revealed a molecular regulatory basis for its effects on plant architecture, implying this CNV may possess importance and application potential in molecular breeding in rice. [ABSTRACT FROM AUTHOR]

A highly reliable high-performance liquid chromatography method was developed and validated for determining quality of extracts from the leaves ofDipsacus sativus(Linn.) Honck. Under optimum conditions, the chromatography profile of eight compounds was collected, with compound saponarin as marker. The analysis results indicated that saponarin and isovitexin were the main active components. Pharmacological experiments proved that extracts from the leaves showed significant antioxidant activity. This work could serve to validate the usefulness of high-performance liquid chromatography analyses in traditional Chinese medicine. [ABSTRACT FROM PUBLISHER]

Drug administration via buccal mucosa is an attractive drug delivery strategy due to good patient compliance, prolonged localized drug effect, and avoidance of gastrointestinal drug metabolism and first-pass elimination. Buccal drug delivery systems need to maintain an intimate contact with the mucosa lining in the wet conditions of the oral cavity for long enough to allow drug release and absorption. For decades, mucoadhesive polymers such as chitosan (CS) and its derivatives have been explored to achieve this. In this study, inspired by the excellent wet adhesion of marine mussel adhesive protein, we developed a buccal drug delivery system using a novel catechol-functionalized CS (Cat-CS) hydrogel. We covalently bonded catechol functional groups to the backbone of CS, and crosslinked the polymer with a non-toxic crosslinker genipin (GP). We achieved two degrees of catechol conjugation (9% and 19%), forming Cat9-CS/GP and Cat19-CS/GP hydrogels, respectively. We confirmed covalent bond formation during the catechol functionalization and GP crosslinking during the gel formation. The gelation time and the mechanical properties of Cat-CS hydrogels are similar to those of CS only hydrogels. Catechol groups significantly enhanced mucoadhesion in vitro (7 out of the 10 Cat19-CS hydrogels were still in contact with porcine mucosal membrane after 6 h, whereas all of the CS hydrogels lost contact after 1.5 h). The new hydrogel systems sustained the release of lidocaine for about 3 h. In-vivo, we compared buccal patches made of Cat19-CS/GP and CS/GP adhered to rabbit buccal mucosa. We were able to detect lidocaine in the rabbit's serum at concentration about 1 ng/ml only from the Cat19-CS patch, most likely due to the intimate contact provided by mucoadhesive Cat19-CS/GP systems. No inflammation was observed on the buccal tissue in contact with any of the patches tested. These results show that the proposed catechol-modified CS hydrogel is a promising mucoadhesive and biocompatible hydrogel system for buccal drug delivery. [ABSTRACT FROM AUTHOR]

Fluxapyroxad, a broad-spectrum and high-efficiency succinate dehydrogenase inhibitor (SDHI) fungicide, can control plant pathogens on many crops. However, no data about the fungicidal activity of fluxapyroxad against Stemphylium solani and its resistance risk are available. In this study, the mycelial growth inhibition method was used to determine the sensitivity of 99 S. solani strains to fluxapyroxad. The EC 50 values ranged from 0.0183 to 0.3017 μg/mL, with an average EC 50 value of 0.0839 ± 0.0051 μg/mL. The results indicated that fluxapyroxad exhibited an excellent inhibitory efficacy against S. solani. Six resistant mutants were obtained by laboratory fungicide taming. The resistance ratio of each mutant was greater than 50 and the resistance of the mutants to fluxapyroxad was steadily inheritable through 10 successive culture transfers to fungicide-free PSA plates. We found that fluxapyroxad resistance not only affected mycelial growth in S. solani , but was also temperature dependent. Moreover, fluxapyroxad resistance caused markedly decreased virulence of S. solani on detached tomato leaves, indicating that the resistant mutants suffered a fitness penalty. Cross-resistance analysis showed that no cross-resistance was observed between fluxapyroxad and fludioxonil, iprodione, azoxystrobin or fluazinam, while a positive cross-resistance was observed between fluxapyroxad and pydiflumetofen. We concluded that the resistance of S. solani to fluxapyroxad was moderate risk. Therefore, fluxapyroxad is recommended as a potential candidate for controlling tomato gray leaf spot caused by S. solani. • Fluxapyroxad exhibited an excellent in vitro antifungal activity against Stemphylium solani. • The resistance of Stemphylium solani to fluxapyroxad was classified as moderate risk. • There was a positive cross-resistance between fluxapyroxad and pydiflumetofen against Stemphylium solani. • Fluxapyroxad is recommended as a potential candidate for controlling tomato gray leaf spot caused by Stemphylium solani. [ABSTRACT FROM AUTHOR]

Chitosan (CH), partially N-deacetylatedchitin, is a biodegradable and biocompatible polymer that has showngreat potential in drug delivery and tissue engineering applications.Although bioadhesive, CH has limited mucoadhesion in wet conditionsdue to weak interactions with biological surfaces. DOPA (3,4-dihydroxy-l-phenylalanine), a catechol-containing molecule naturally presentin marine mussel foot proteins, has been shown to increase the mucoadhesionof several polymers. We report here a simple and bioinspired approachto enhance CH mucoadhesion in wet conditions by preparing mixed hydrogelsincluding CH and different catechol-containing compounds, namely DOPA,hydrocaffeic acid (HCA), and dopamine (DA). We characterized the hydrogelsfor their swelling, release kinetics of the catechol compounds, andmucoadhesive strength to rabbit small intestine. The swelling of thehydrogels was pH dependent with maximum swelling at pH 1. The hydrogelswelling was higher in the presence of the DOPA and DA but lower inthe presence of HCA. HCA/CH hydrogel also showed the slowest catecholrelease, most likely due to electrostatic interactions between CHand HCA. Lower hydrogel swelling and slower HCA release resulted inincreased mucoadhesion: HCA/CH showed more than 2-fold enhancementof mucoadhesion to rabbit small intestine compared to CH alone. Sinceit is known that catechol compounds can be oxidized, we analyzed theoxidation of DOPA, HCA, and DA at different pH values and its effecton mucoadhesion. We found that oxidation occurring before contactwith the intestinal mucosa did not improve mucoadhesion, while oxidationoccurring during the contact further increased the mucoadhesion ofHCA/CH hydrogels. These results show that mucoadhesion of CH hydrogelscan be increased with a simple bioinspired approach, which has thepotential to be applied to other polymers since it does not requireany chemical modification. [ABSTRACT FROM AUTHOR]

This study intended to investigate the role of microRNA-27b (miR-27b) in proliferation of oral squamous cell carcinoma (OSCC) cells and to explore the potential molecular mechanism. Cell proliferation was detected by MTT assay. The expression levels of miR-27b, Frizzled7 ( FZD7 ), cyclin D1 and c-myc were detected by quantitative real time polymerase chain reaction (qRT-PCR). The protein expression level of FZD7 was detected by western blot analysis. The relationship between miR-27b and FZD7, and the activity of Wnt signaling pathway were determined using luciferase reporter assay. The miR-27b expression in OSCC cell lines was significantly decreased compared with control. Overexpression of miR-27b remarkably inhibited OSCC cell proliferation. Additionally, miR-27b could target and inhibit FZD7 expression and decrease the activity of Wnt signaling pathway.miR-27b could inhibit OSCC cell proliferation through inhibiting FZD7 and FZD7-mediated Wnt signaling pathway. [ABSTRACT FROM AUTHOR]