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In this study, a novel drug delivery system (MSN-PEG-Hypericin) was successfully fabricated using tetraethyl orthosilicate and 3-aminopropyltriethoxysilane as raw materials, and the PEGylation of the prepared aminated mesoporous silica and grafting of hypericin onto the carrier were further conducted to obtain MSN-PEG-Hypericin. The successful preparation of MSN-PEG-Hypericin was characterized by several physical-chemical techniques. Furthermore, the MSN-PEG-Hypericin system increased the ability of hypericin to generate reactive oxygen species (ROS) in vitro. The cytotoxicity assay and hemolysis analysis showed that MSN-PEG-Hypericin had good biocompatibility. For antibacterial studies, the irradiation time and incubation time of photodynamic therapy (PDT) for S. aureus and E. coli were respectively 8 min and 8 h, and the concentrations of hypericin were 2.5 and 5 μg/mL. The result of triphenyl tetrazolium chloride assay indicated that MSN-PEG-Hypericin had stronger photodynamic antibacterial activity than free hypericin, and S. aureus was more sensitive to PDT than E. coli, which was related to their cell structural differences. The antibacterial mechanism study indicated that the generated ROS could destroy the bacterial structures and cause bacterial death due to the leakage of the contents. The MSN-PEG-Hypericin system prepared in this study had potential application prospects in the antibacterial field. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this article is to examine the efficacy of oxytocin in treating core symptoms of autism spectrum disorder (ASD) with children. Methods: A systematic literature search was conducted to identify randomized controlled trials (RCTs) of oxytocin for the treatment of core symptoms in children with ASD. The search included studies published between January 1, 1999 and March 15, 2023, that were randomized, single or double-blinded, and included a placebo control group. Standard screening rules were applied to select relevant studies, resulting in the inclusion of five RCTs involving 486 children with ASD. Results: Ultimately, a total of five RCTs, involving 486 children with ASD, were included in the review using standard screening rules.One of the included studies demonstrated a statistically significant improvement in Social Responsiveness Scale (SRS) and Repetitive Behavior Scale-Revised (RBS) scores when children with ASD were treated with oxytocin (24 IU/2 days for 6 weeks). The improvement in core symptoms persisted at the 6-month follow-up. The meta-analysis findings suggested that oxytocin might have a moderate effect in improving the core symptom of narrow interests and repetitive stereotyped behaviors in children with ASD. Conclusion: While the therapeutic value of oxytocin in treating core symptoms of ASD in children is not fully established, the results of this meta-analysis indicate a potential moderate effect. However, further studies with larger sample sizes and more robust RCTs are needed to directly demonstrate the efficacy of oxytocin. Future research should also focus on effect size and outcome evaluation accuracy while minimizing bias in RCT experiments. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2)-based nanostructures are highly desirable for applications such as chemical and biological sensing, photo/electrochemical catalysis, and energy storage due to their unique physical and chemical properties. In this work, MoS2 core-shell nanoparticles were first prepared through the liquid-phase processing of bulk MoS2 by a femtosecond laser. The core of prepared nanoparticles was incompletely and weakly crystalline MoS2; the shell of prepared nanoparticles was highly crystalline MoS2, which wrapped around the core layer by layer. The femtosecond laser simultaneously achieved liquid-phase ablation and light exfoliation. The formation mechanism of the core-shell nanoparticles is to prepare the nanonuclei first by laser liquid-phase ablation and then the nanosheets by light exfoliation; the nanosheets will wrap the nanonuclei layer by layer through van der Waals forces to form core-shell nanoparticles. The MoS2 core-shell nanoparticles, because of Mo−S bond breakage and recombination, have high chemical activity for chemical catalysis. Afterward, the nanoparticles were used as a reducing agent to directly prepare three-dimensional (3D) Au-MoS2 micro/nanostructures, which were applied as surface-enhanced Raman spectroscopy (SERS) substrates to explore chemical sensing activity. The ultrahigh enhancement factor (1.06×1011), ultralow detection limit (10−13 M), and good SERS adaptability demonstrate highly sensitive SERS activity, great ability of ultralow concentration detection, and ability to detect diverse analytes, respectively. This work reveals the tremendous potential of 3D Au-MoS2 composite structures as excellent SERS substrates for chemical and biological sensing. [ABSTRACT FROM AUTHOR]

A melamine phosphate borate flame retardant was prepared through a solvothermal method and characterized by Fourier transform infrared spectroscopy, scanning electron microscope, element analysis, and X-ray photoelectron spectroscopy. The incorporation of melamine phosphate borate into the phenolic foams toughened by polyethylene glycol results in an increase in limiting oxygen index and a decrease in peak heat release rate, smoke, and CO and CO2production. The mechanical tests reveal that the incorporation of melamine phosphate borate leads to a further improvement in flexural strength and compressive strength, and a decrease in the pulverization ratios of the toughened foams. Moreover, the thermal stability of the toughened PF foams containing melamine phosphate borate was studied. [ABSTRACT FROM AUTHOR]

The Mo-doped WSe2 nanolamellars have been successfully prepared via solid-state thermal (750 °C) reaction between micro-sized W, Mo with Se powders under inert atmosphere in a closed reactor and characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that the morphologies of the as-prepared products changed from microplates to nanolamellars to aggregations composed of nanoparticles with the doping of Mo powders. And the sizes of crystallites evidently reduced while the contents of dopant increased within a certain limit (1 wt.%-7 wt.%). The tribological properties of the as-prepared products as additives in HVI750 base oil were investigated by UMT-2 multispecimen tribotester. The friction coefficient of the base oil containing Mo-doped WSe2 nanolamellars was lower and more stable than that of WSe2 nanolamellars. A combination of rolling friction, sliding friction, and stable tribofilm on the rubbing surface could further explain the good friction and wear properties of Mo-WSe2 nanoparticles as additives than that of WSe2. [ABSTRACT FROM AUTHOR]

Flavonoids belong to a class of plant secondary metabolites that have a polyphenol structure. Flavonoids show extensive biological activity, such as antioxidative, anti-inflammatory, anti-mutagenic, anti-cancer, and antibacterial properties, so they are widely used in the food, pharmaceutical, and nutraceutical industries. However, traditional sources of flavonoids are no longer sufficient to meet current demands. In recent years, with the clarification of the biosynthetic pathway of flavonoids and the development of synthetic biology, it has become possible to use synthetic metabolic engineering methods with microorganisms as hosts to produce flavonoids. This article mainly reviews the biosynthetic pathways of flavonoids and the development of microbial expression systems for the production of flavonoids in order to provide a useful reference for further research on synthetic metabolic engineering of flavonoids. Meanwhile, the application of co-culture systems in the biosynthesis of flavonoids is emphasized in this review. [ABSTRACT FROM AUTHOR]