The sweating process promotes toxigenic fungi expansion and increases the risk of combined contamination of mycotoxins in Radix Dipsaci

Sweating is one of the most important processing methods of Chinese medicinal herbs. However, the high temperature and humidity environment required for sweating Chinese medicinal herbs makes it very easy for fungi to breed, especially toxigenic fungi. The mycotoxins produced by these fungi will then contaminate the Chinese medicinal herbs. In this study, we explored the changes in mycobiota, toxigenic fungi, and mycotoxins with and without sweating in Radix Dipsaci (RD), a typical representative of traditional Chinese medicine that requires processing through sweating. We also isolated and identified the toxigenic fungi from RD, whether they were subjected to sweating treatment or not, and examined their toxigenic genes and ability. The results showed that the detection rate of mycotoxins (aflatoxins, ochratoxins, zearalenone, and T-2 toxin) in RD with sweating was 36%, which was 2.25-fold higher than that in RD without sweating. We also detected T-2 toxin in the RD with sweating, whereas it was not found in the RD without sweating. The sweating process altered the fungal composition and increased the abundance of Fusarium and Aspergillus in RD. Aspergillus and Fusarium were the most frequently contaminating fungi in the RD. Morphological and molecular identification confirmed the presence of key toxigenic fungal strains in RD samples, including A. flavus, A. westerdijkiae, F. oxysporum and F. graminearum. These four fungi, respectively, carried AflR, PKS, Tri7, and PKS14, which were key genes for the biosynthesis of aflatoxins, ochratoxins, zearalenone, and T-2 toxin. The toxigenic ability of these four fungal strains was verified in different matrices. We also found that A. flavus, A. westerdijkiae, and F. oxysporum were isolated in RD both with sweating and without sweating, but their isolation frequency was significantly higher in the RD with sweating than in the RD without sweating. F. graminearum was not isolated from RD without sweating, but it was isolated from RD with sweating. These findings suggest that the sweating process promotes the expansion of toxigenic fungi and increases the risk of combined mycotoxin contamination in RD

Perioperative probiotics attenuates postoperative cognitive dysfunction in elderly patients undergoing hip or knee arthroplasty: A randomized, double-blind, and placebo-controlled trial

BackgroundPostoperative cognitive dysfunction (POCD) is a common complication in elderly patients following surgery. The preventive and/or treatment strategies for the incidence remain limited.ObjectiveThis study aimed to investigate the preventive effect of perioperative probiotic treatment on POCD in elderly patients undergoing hip or knee arthroplasty.MethodsAfter obtaining ethical approval and written informed consent, 106 patients (age ≥60 years) were recruited, who scheduled elective hip or knee arthroplasty, from 16 March 2021 to 25 February 2022 for this randomized, double-blind, and placebo-controlled trial. They were randomly assigned with a 1:1 ratio to receive either probiotics or placebo treatment (four capsules, twice/day) from hospital admission until discharge. Cognitive function was assessed with a battery of 11 neuropsychological tests on the admission day and the seventh day after surgery, respectively.ResultsA total of 96 of 106 patients completed the study, and their data were finally analyzed. POCD occurred in 12 (26.7%) of 45 patients in the probiotic group and 29 (56.9%) of 51 patients in the placebo group (relative risk [RR], 0.47 [95% confidence interval [CI], 0.27 to 0.81]; P = 0.003). Among them, mild POCD occurred in 11 (24.4%) in the probiotic group and 24 (47.1%) in the placebo group (RR, 0.52 [95% CI, 0.29 to 0.94]; P = 0.022). No significant difference in severe POCD incidence was found between the two groups (P = 0.209). Compared with the placebo group, the verbal memory domain cognitive function was mainly improved in the probiotic group.ConclusionProbiotics may be used perioperatively to prevent POCD development and improve verbal memory performance in elderly patients receiving hip or knee arthroplasty.Clinical trial registrationwww.chictr.org.cn, identifier: ChiCTR2100045620

2D MXene Ti3C2Tx nanosheets in the development of a mechanically enhanced and efficient antibacterial dental resin composite

The bacterial accumulation at the margins of dental resin composites is a main cause of secondary caries, which may further lead to prosthodontic failure. In this regard, this study for the first time incorporated 2D MXene Ti3C2Tx nanosheets (NSs) into epoxy resin at different mass ratios (0, 0.5, 1.0, and 2.0 wt%) by solution blending and direct curing for dental applications. Compared to the pure resin, the as-fabricated MXene/resin composite not only exhibited improved mechanical and abrasive results but also displayed gradually improved antibacterial activity with MXene loading which was further enhanced by illumination in natural light due to the high photothermal efficiency of MXene. In addition, the cytotoxicity result demonstrated that the MXene-modified resin did not cause severe damage to normal cells. This novel MXene/resin nanocomposite could pave the way for new designs for high-performance, multifunctional nanocomposites to effectively protect dental health in daily life

Investigation of Mechanical Properties and Plastic Deformation Behavior of (Ti45Cu40Zr10Ni5)100−xAlx Metallic Glasses by Nanoindentation

The effect of Al addition on mechanical properties and plastic deformation behavior of (Ti45Cu40Zr10Ni5)100−xAlx (x = 0, 2, 4, 6 and 8) amorphous alloy ribbons have been investigated by nanoindentation. The hardness and elastic modulus do not simply increase with the increase of Al content. The alloy with 8 at.% Al exhibits the highest hardness and elastic modulus. The serrations or pop-in events are strongly dependent on the loading rate and alloy composition

Bismuth Quantum Dot (Bi QD)/Polydimethylsiloxane (PDMS) Nanocomposites with Self-Cleaning and Antibacterial Activity for Dental Applications

In the oral microenvironment, bacteria colonies are easily aggregated on the tooth-restoration surface, in the manner of a biofilm, which usually consists of heterogeneous structures containing clusters of a variety of bacteria embedded in an extracellular matrix, leading to serious recurrent caries. In this contribution, zero-dimensional (0D) bismuth (Bi) quantum dots (QDs) synthesized by a facile solvothermal method were directly employed to fabricate a Bi QD/polydimethylsiloxane (PDMS)-modified tooth by simple curing treatment. The result demonstrates that the as-fabricated Bi QD/PDMS-modified tooth at 37 °C for 120 min not only showed significantly improved hydrophobic performance with a water contact angle of 103° and 115° on the tooth root and tooth crown, respectively, compared to that (~20° on the tooth root, and ~5° on the tooth crown) of the pristine tooth, but also exhibited excellent antibacterial activity against S. mutans, superior biocompatibility, and biosafety. In addition, due to the highly photothermal effect of Bi QDs, the antibacterial activity of the as-fabricated Bi QD/PDMS-modified tooth could be further enhanced under illumination, even at a very low power density (12 mW cm−2). Due to the facile fabrication, excellent hydrophobicity, superior antibacterial activity, and biocompatibility and biosafety of the Bi QD/PDMS-modified tooth, it is envisioned that the Bi QD/PDMS-modified tooth with a fascinating self-cleaning and antibacterial performance can pave the way to new designs of versatile multifunctional nanocomposites to prevent secondary caries in the application of dental restoration

Tin Oxide (SnO₂) Nanoparticles: Facile Fabrication, Characterization, and Application in UV Photodetectors

Tin oxide (SnO2) nanomaterials are of great interest in many fields such as catalytic, electrochemical, and biomedical applications, due to their low cost, suitable stability characteristics, high photosensitivity, etc. In this contribution, SnO2 NPs were facilely fabricated by calcination of tin (II) oxalate in air, followed by a liquid-phase exfoliation (LPE) method. Size-selected SnO2 NPs were easily obtained using a liquid cascade centrifugation (LCC) technique. The as-obtained SnO2 NPs displayed strong absorption in the UV region (~300 nm) and exhibited narrower absorption characteristics with a decrease in NP size. The as-fabricated SnO2 NPs were, for the first time, directly deposited onto a poly(ethylene terephthalate) (PET) film with a regular Ag lattice to fabricate a flexible working electrode for a photoelectrochemical (PEC)-type photodetector. The results demonstrated that the SnO2-NP-based electrode showed the strongest photoresponse signal in an alkaline electrolyte compared with those in neutral and acidic electrolytes. The maximum photocurrent density reached 14.0 μA cm−2, significantly outperforming black phosphorus nanosheets and black phosphorus analogue nanomaterials such as tin (II) sulfide nanosheets and tellurene. The as-fabricated SnO2 NPs with relatively larger size had better self-powered photoresponse performance. In addition, the as-fabricated SnO2-NP-based PEC photodetector exhibited strong cycling stability for on/off switching behavior under ambient conditions. It is anticipated that SnO2 nanostructures, as building blocks, can offer diverse availabilities for high-performance self-powered optoelectronic devices to realize a carbon-neutral or carbon-free environment

Simply synthesized nitrogen-doped graphene quantum dot (NGQD)-modified electrode for the ultrasensitive photoelectrochemical detection of dopamine

Recently, nitrogen-doped graphene quantum dots (NGQDs), as a new type of quantum semiconductor and photoelectrochemical material, are promising candidates in photoelectric sensing, water splitting, and biological imaging and have various potential application prospects. In this work, NGQDs were prepared by a simple calcination method, and then a photoelectrochemical sensing platform based on the NGQDs electrode with superior photoelectrochemical activity was designed and fabricated for the detection of dopamine (DA). Benefitting from the quantum effect and size effect, NGQDs displayed an enhanced photocurrent effective within ultra-low detection limit (0.03 μm), wide detection range (0.03–450 and 450–9680 μm), and high sensitivity in detecting DA with the assistance of ultraviolet light irradiation. The NGQDs electrode also showed continuous and stable photocurrent densities after long-term experiment, indicating the excellent durability of NGQDs for DA detection

Zirconium and its stable isotopes in igneous systems

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