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The aim of the present study was to establish a simple and reliable ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method and apply it for the determination of pharmacokinetics of moxidectin-loaded microspheres (MOX-MS) in rats. Plasma samples were processed using a simplified liquid–liquid extraction method and were separated using an Agilent Zorbax Eclipse Plus C18 column (50 mm × 2.1 mm, 1.8 μm) with a mobile phase consisting of a 10 mM ammonium formate solution with 0.1% formic acid (A) and acetonitrile (B) at a flow rate of 0.4 mL/min for 5 min. Avermectin B1a was used as an internal standard (IS). The sample was injected at a volume of 10 μL with a column temperature of 35 °C and detected in a positive ion mode. A good linear response across the concentration range of 1.00–200 ng/mL (r2 > 0.99) and a lower limit of quantification (LLOQ) of 1.00 ng/mL were achieved. The extraction recovery of moxidectin exceeded 94.1%, the matrix effect was between 91.2% and 96.2%, the accuracy ranged from 100.1 to 103.6%, and the relative standard deviation (RSD) did not exceed 15% for the intra- and inter-day accuracy and precision. The pharmacokinetic results showed that MOX-MS significantly decreased Cmax, prolonged T1/2, and improved bioavailability. The developed method significantly reduced the assay volume, shortened detection time, simplified sample processing methods and saved assay costs, which may contribute to the development of the new antiparasitic drug. [ABSTRACT FROM AUTHOR]

Anthropogenic activities in the environment affect the ecosystem and can play an important role in selecting and spreading antibiotic‐resistant bacteria (ARB) and genes (ARGs). The dairy farm environment may serve as a hotspot and reservoir for exchanging and spreading ARGs, but studies are scarce. Here, we investigated and characterized the extended‐spectrum β‐lactamase producing Escherichia coli strains recovered from the dairy farm environment co‐harboring blaOXA−1, catB3, and arr-3 genes. The isolates were identified and characterized by PCR, antimicrobial susceptibility testing, conjugation assay, whole genome sequencing (WGS), and multiple bioinformatics tools. Seven E. coli strains co‐harboring blaOXA−1, catB3, and arr-3 genes were identified which belonged to distinct sequence types (STs) and carried diverse plasmid replicon types. The conjugation assay revealed a successful transfer of blaOXA−1, catB3, and arr-3 genes into the recipient E. coli J53 with a co‐conjugation frequency ranging from (2.25 ± 0.3) × 10−4 to (3.85 ± 0.3) × 10−3. Bioinformatics analysis of WGS revealed the diversity of acquired ARGs, conferring resistance to aminoglycosides, beta‐lactams, quinolones, tetracyclines, macrolides, trimethoprim–sulfamethoxazole, phosphonic, phenicol, and rifamycin. The genetic environment analysis showed that aac(6′)‐Ib-cr-blaOXA−1‐catB3-arr-3-qacE1-sul1 was the common genetic backbone among the seven E. coli strains. Among the mobile genetic elements, insertion sequences were the predominant elements as compared to transposons. The phylogenetic analysis demonstrated a close relationship between the E. coli of this study and other strains of human–animal‐environment origin retrieved from the NCBI database. This study presented the whole genome‐based characterization of E. coli strains carrying the blaOXA−1‐catB3-arr-3 genes. It provided evidence that the dairy environment may harbor a variety of ARGs and act as a potential reservoir for their spread in the ecosystem. The results recommend the routine surveillance of ARGs carrying bacteria in dairy environments and the need for additional studies to understand the dissemination mechanism within One Health perspective to prevent their further spread. [ABSTRACT FROM AUTHOR]

As one of the most representative natural products among flavonoids, quercetin (QUE) has been reported to exhibit beneficial effects on gut health in recent years. In this study, we utilized a dextran sulfate sodium (DSS)-induced colitis mice model to explore the protective effects and underlying mechanisms of QUE on colitis. Our data demonstrated that QUE oral gavage administration significantly ameliorates the symptoms and histopathological changes associated with colitis. Additionally, the concentration of mucin-2, the number of goblet cells, and the expression of tight junction proteins (such as ZO-1, Occludin, and Claudin-1) were all found to be increased. Furthermore, QUE treatment regulated the levels of inflammatory cytokines and macrophage polarization, as well as the oxidative stress-related pathway (Nrf2/HO-1) and associated enzymes. Additionally, 16S rDNA sequencing revealed that QUE treatment rebalances the alterations in colon microbiota composition (inlcuding Bacteroidaceae, Bacteroides, and Odoribacter) in DSS-induced colitis mice. The analysis of network dynamics reveals a significant correlation between gut microbial communities and microenvironmental factors associated with inflammation and oxidative stress, in conjunction with the previously mentioned findings. Collectively, our results suggest that QUE has the potential to treat colitis by maintaining the mucosal barrier, modulating inflammation, and reducing oxidation stress, which may depend on the reversal of gut microbiota dysbiosis. [ABSTRACT FROM AUTHOR]

The early monitoring and inactivation of bacteria are of crucial importance in preventing the further spread of foodborne pathogens. Staphylococcus aureus (S. aureus), a prototypical foodborne pathogen, is widely present in the natural environment and has the capability to trigger a range of diseases at low concentrations. In this work, we designed Fe3O4@SiO2-Au core–shell–satellite nanocomposites (NCs) modified with aptamer for efficient capture, high-sensitivity surface-enhanced Raman scattering (SERS) detection, and photothermal therapy (PTT) against S. aureus. Fe3O4@SiO2-Au NCs with tunable Au nanocrystal nanogaps were prepared. By combining the finite-difference time-domain (FDTD) method and experimental results, we studied the electric field distribution of Fe3O4@SiO2-Au under different Au nanogaps and ultimately obtained the optimal SERS substrate FSA-60. The modification of aptamer on the surfaces of FSA-60 could be used for the specific capture and selective detection of S. aureus, achieving a detection limit of as low as 50 cfu/mL. Furthermore, Apt-FSA-60 possessed excellent photothermal properties, demonstrating the strong photothermal killing ability against S. aureus. Therefore, Apt-FSA-60 is a promising high-sensitivity SERS substrate and efficient photothermal agent and is expected to be widely applied and promoted in future disease prevention and treatment. [ABSTRACT FROM AUTHOR]

The escalating demand for enhanced therapeutic efficacy and reduced adverse effects in the pharmaceutical domain has catalyzed a new frontier of innovation and research in the field of pharmacy: novel drug delivery systems. These systems are designed to address the limitations of conventional drug administration, such as abbreviated half-life, inadequate targeting, low solubility, and bioavailability. As the disciplines of pharmacy, materials science, and biomedicine continue to advance and converge, the development of efficient and safe drug delivery systems, including biopharmaceutical formulations, has garnered significant attention both domestically and internationally. This article presents an overview of the latest advancements in drug delivery systems, categorized into four primary areas: carrier-based and coupling-based targeted drug delivery systems, intelligent drug delivery systems, and drug delivery devices, based on their main objectives and methodologies. Additionally, it critically analyzes the technological bottlenecks, current research challenges, and future trends in the application of novel drug delivery systems. [ABSTRACT FROM AUTHOR]

Remanufacturing is one of the most effective forms of the recycling economy, and the “Trade-in for Remanufacturing” (TIFR) program in China plays an important role in the development of remanufacturing. To understand this new business model of remanufacturing, the price and demand relationship of the NP and RP are examined in two periods, considering TIFR subsidy which is in practice in China. Comparing integrated optimization scheme and tiered optimization scheme, this paper then researches the pricing strategy with TIFR subsidy respectively, as multi-object optimization is employed in the latter scheme. Tiered optimization pricing is found to improve the old customer’s TIFR enthusiasm, balance the remanufacturing system and work better with TIFR subsidy through numerical experiments. This paper studies the impacts of subsidy rate, receptiveness to RP, and the mixture of them, then verifies the proposed model and gives an inspiration to the management of the new remanufacturing business model about TIFR subsidy.

Characterizing the electrical properties of hydrate-bearing sediments, especially resistivity, is essential for reservoir identification and saturation evaluation. The variation in electrical properties depends on the evolution of pore habits, which in turn are influenced by the hydrate growth pattern. To analyze the relationship between hydrate morphology and resistivity quantitatively, different micromorphologies of hydrates were simulated at the pore scale. This study was also conducted based on Maxwell's equations for a constant current field. During numerical simulation, three types of hydrate occurrence patterns (grain-cementing, pore-filling and load-bearing) and five types of distribution morphologies (circle, square, square rotated by 45°, ellipse and ellipse rotated by 90°) in the pore-filling mode were considered. Moreover, the effects of porosity, the conductivity of seawater, the size of the pore-throat and other factors on resistivity are also discussed. The results show that the variation in resistivity with hydrate saturation can be broadly divided into three stages (basically no effect, slow change and rapid growth). Compared with the grain-cementing and pore-filling modes, the resistivity of the load-bearing mode was relatively high even when hydrate saturation was low. For high hydrate-saturated sediments (Sh > 0.4), the saturation exponent n in Archie equation was taken as 2.42 ± 0.2. The size of the throat is furthermore the most critical factor affecting resistivity. This work shows the potential application prospects of the fine reservoir characterization and evaluation of hydrate-bearing sediments. [ABSTRACT FROM AUTHOR]

In the realm of automatic wire-traction micromanipulation systems, the alignment of the central axis of the coil with the rotation axis of the rotary stage can be a challenge, which leads to the occurrence of eccentricity during rotation. The wire-traction is conducted at a micron-level of manipulation precision on micron electrode wires; eccentricity has a significant impact on the control accuracy of the system. To resolve the problem, a method for measuring and correcting the coil eccentricity is proposed in this paper. First, models of radial and tilt eccentricity are established respectively based on the eccentricity sources. Then, measuring eccentricity is proposed by an eccentricity model and microscopic vision; the model is used to predict eccentricity, and visual image processing algorithms are used to calibrate model parameters. In addition, a correction based on the compensation model and hardware is designed to compensate for the eccentricity. The experimental results demonstrate the accuracy of the models in predicting eccentricity and the effectiveness of correction. The results show that the models have an accurate prediction for eccentricity that relies on the evaluation of the root mean square error (RMSE); the maximal residual error after correction was within 6 μm, and the compensation was approximately 99.6%. The proposed method, which combines the eccentricity model and microvision for measuring and correcting eccentricity, offers improved wire-traction micromanipulation accuracy, enhanced efficiency, and an integrated system. It has more suitable and wider applications in the field of micromanipulation and microassembly. [ABSTRACT FROM AUTHOR]