A method for determining chloramphenicol (CAP) in both propolis and propolis-derived dietary supplements was developed by utilizing high performance liquid chromatography-tandem mass spectrometry ...(HPLC-MS/MS). The flavones in the samples were removed with a lead acetate solution and ammonia, and the fat-soluble interferences, such as beewax and vegetable oils, were removed with
-hexane after the sample dissolved in ethanol. Tert-butyl methyl ether was used as the back-extraction solvent to reduce co-extracting compounds, such as polyethylene glycol 400 (PEG 400) and glycerol, which are common adjuvants of dietary supplements, and some polar interferences. CAP was detected by HPLC-MS/MS and quantified by the internal standard method. The calibration curve showed a good linearity in the range of 0.20-50.0 μg/L. The limits of detection and the limits of quantification were 0.03 and 0.1 μg/kg, respectively. The recoveries in four different matrices at three spiked levels were in the 86.0%-114.4% range with the relative standard deviations from 0.3% to 4.9%. With the advantages of excellent universality, ease of operation, high sensitivity, and strong anti-interference capability, the proposed method was suitable for the determination of CAP in both propolis and propolis-derived dietary supplements.
Biofeedback is a way to learn how to regulate body function and control through a series of training sessions. Using biofeedback training in sports science to adjust the level of sports arousal can ...also enhance athletes’ control ability. In this article, literature is used to explain the overview of biofeedback training, its application in sports science, problems and prospects.
Shot blasting on a tube steel of TP304H can greatly improve the oxidation resistance at 650–770 °C in water vapor and an appropriate blasting intensity reached the best result. SEM and EPMA analysis ...indicated that the structure of the oxide scale turned from multi-layer to monolayer after blasting and Cr
2O
3 is predominant. The untreated sample characterized in multi-layer oxide was composed of Fe in the outer layer and Fe and Cr underneath. For blasted one, the increase of diffusion rate of Cr and the decrease of effective diffusion energy of scale led to a uniform Cr-rich oxide layer, which was dense and protective and the oxidation resistance was increased.
The repeated impact test is an attractive method to evaluate different properties of hard coatings serving under the conditions subjected to cyclic loads. The main parameter leading to the failure of ...coatings has been attributed to the contacting load. However, the dynamic impact loading is characterized in the impact wave, which is much more severe than that of static loading, thus the load calculated by finite element method using the static stress is invalid. In this paper, the impact tests revealed two distinguished failure modes for CrN–Cu coatings: cohesive and interfacial. The primary mechanism for the coating failure is interfacial at low loading forces. The failure mode can change from adhesive to cohesive at the same loading force but with increasing velocity of the ball. It was shown that the applied kinetic energy absorbed and transformed to the plastic deformation energy has a strong relationship to the coating failure. Thus, the energy-cycles relation is a more suitable index to indicate the damage resistance of coatings.
Phototherapy has great application prospects in superficial tumors, such as melanoma, esophageal cancer, and breast carcinoma, owing to the advantages of noninvasiveness, high spatiotemporal ...selectivity, and less side effects. However, classical phototherapies including photodynamic and photothermal therapy still need to settle the bottleneck problems of poor efficacy, inevitable thermal damage, and a high rate of postoperative recurrence. In this study, we developed a nanocomposite with excellent optical properties and immune-stimulating properties, termed PBP@CpG, which was obtained by functionalizing black phosphorus (BP) with polydopamine and further adsorbing CpG. Benefiting from the protection of polydopamine against BP, ideal light absorption, and photoacoustic conversion properties, PBP@CpG not only enables precisely delineation of the tumor region with photoacoustic imaging but also powerfully disrupts the plasma membrane and cytoskeleton of tumor cells with a photoacoustic cavitation effect. In addition, we found that the photoacoustic cavitation effect was also capable of inducing immunogenic cell death and remarkably strengthening the antitumor immune response upon cooperating with immune adjuvant CpG. Therefore, PBP@CpG was expected to provide a promising nanoplatform for optical theranostics and herald a new strategy of photoimmunotherapy based on the photoacoustic cavitation effects and immunostimulatory effect.
Transportation facilitates the flow of tourists generating tourist flows, which produce flow effects on the spatial scale. By analyzing the evolution of tourist flows in Zhangjiajie by various modes ...of transportation over a long time series, the results show that the degree of development of the destination transportation network affects the dominance of the tourism node. Specifically, in the “train period”, Zhangjiajie, Changsha, Fenghuang, and Jishou core destinations become dominant with the “Matthew Effect”. In the “road period”, Jishou and Mengdonghe destinations decline, with the “Filtering Effect”. In the “high-speed railway period”, Zhangjiajie and Changsha are connected with more distant origins, and the “Diffusion Effect” occurs. It is worth noting that the development of high-speed rail has created a substitution effect for trains over long distances, and self-driving has created a substitution effect for trains over short and medium distances.
A bacteria strain Citrobacter W4 isolated from the microalgae sewage culture system showed flocculating activity against Chlorella pyrenoidosa. In this work, operation parameters under outdoor ...conditions were optimized. When the bacterial-algal ratio was 4:1, G value was 26.30 s−1, and harvesting time was 6 h, the harvesting efficiency achieved 87.37 ± 2.96% without ions addition and pH adjustment. The microbial community structure analysis showed Citrobacter W4 was dominant in the harvesting process. Flocculating active substances were on the surface and metabolites of Citrobacter W4. The main component of bacteria flocculating active substances was protein. Polysaccharides and carboxylic acid also promoted flocculation. The flocculation mechanisms were mainly adsorption bridging, net catching, and sweeping, not electric neutralization. The quality of FAMEs was improved after flocculation. The cost of 1 kg dried microalgae flocculated by Citrobacter W4 was $1.35. The novel flocculating bacteria showed the potential to harvest microalgae cost-effectively and environmentally friendly.
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•The harvesting efficiency achieved 87.37% flocculated by Citrobacter W4.•Protein was the main component of bacteria flocculating active substances.•Citrobacter W4 flocculated by adsorption bridging, net catching and sweeping.
For the fabrication of engineered tissue constructs by three-dimensional (3D) bioprinting technology, the cell viability will be significantly affected by the shear stress during extrusion process ...and the exposure of light for cross-linking. Microgels with independently controlled compartments were demonstrated to provide protection for cells encapsulation. Here, we proposed to prepare the core-shell structured microgels for cells encapsulation to prevent the cell damage from the shear stress in extrusion-based 3D printing processes. The core-shell structured microgels with core layer of type I collagen and shell layer of alginate were prepared using a one-step innovational microfluidics technology through a multichannel microfluidic device. In the microfluidic parameters, acetic acid concentration and flow rate ratios of water phase to oil phase were found to evidently affect the morphology of microgels and viability of encapsulated cells. Methacrylated silk fibroin (SilMA) and methacrylated gelatin (GelMA) were synthesized and blended with cell-laden microgels as bioinks to fabricate the 3D-printed constructs. The increasing content of SilMA would decrease the pore size and increase the compression property of SilMA/GelMA hydrogels. Importantly, the microgels-containing SilMA/GelMA construct ensure the improved cell proliferation as compared to the SilMA/GelMA counterpart. Furthermore, the in vivo experiments demonstrated that Microgels-15%SilMA/GelMA construct exhibited good biocompatibility and better bone formation performance compared with 15%SilMA/GelMA construct. Therefore, the strategy of preparing cell-laden microgels based on microfluidic technology to improve the survival rate of cells in the bioprinting process can be available and effective in development of tissue engineered constructs.
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•Core-shell structured microgels were prepared through multi-channel microfluidic chips.•Morphology and particle size of monodisperse microgels could be adjusted.•3D-printed constructs with cell-laden microgels showed improved cell viability.•Cell-laden microgels-embedded constructs exhibited better bone formation performance.
Purpose: Photothermal therapy (PTT) is a promising anticancer treatment that involves inducing thermal ablation and enhancing antitumor immune responses. However, it is difficult to completely ...eradicate tumor foci through thermal ablation alone. Additionally, the PTT elicited antitumor immune responses are often insufficient to prevent tumor recurrence or metastasis, due to the presence of an immunosuppressive microenvironment. Therefore, combining photothermal and immunotherapy is believed to be a more effective treatment approach as it can modulate the immune microenvironment and amplify the post-ablation immune response. Methods: Herein, the indoleamine 2, 3-dioxygenase-1 inhibitors (1-MT) loaded copper (I) phosphide nanocomposites (Cu.sub.3P/1-MT NPs) are prepared for PTT and immunotherapy. The thermal variations of the Cu.sub.3P/1-MT NPs solution under different conditions were measured. The cellular cytotoxicity and immunogenic cell death (ICD) induction efficiency of Cu.sub.3P/1-MT NPs were analyzed by cell counting kit-8 assay and flow cytometry in 4T1 cells. And the immune response and antitumor therapeutic efficacy of Cu.sub.3P/1-MT NPs were evaluated in 4T1-tumor bearing mice. Results: Even at low energy of laser irradiation, Cu.sub.3P/1-MT NPs remarkably enhanced PTT efficacy and induced immunogenic tumor cell death. Particularly, the tumor-associated antigens (TAAs) could help promote the maturation of dendritic cells (DCs) and antigen presentation, which further activates infiltration of CD8.sup.+ T cells through synergistically inhibiting the indoleamine 2, 3-dioxygenase-1. Additionally, Cu.sub.3P/1-MT NPs decreased the suppressive immune cells such as regulatory T cells (Tregs) and M2 macrophages, indicating an immune suppression modulation effect. Conclusion: Cu.sub.3P/1-MT nanocomposites with excellent photothermal conversion efficiency and immunomodulatory properties were prepared. In addition to enhanced the PTT efficacy and induced immunogenic tumor cell death, it also modulated the immunosuppressive microenvironment. Thereby, this study is expected to offer a practical and convenient approach to amplify the antitumor therapeutic efficiency with photothermal-immunotherapy. Keywords: copper (I) phosphide (Cu.sub.3P), photothermal therapy, IDO-1 inhibitors, immunotherapy
Agriculture provides humanity with the most basic products to sustain life and raw materials for production, closely linking human society and nature together. The sustainable development of ...agriculture, an inevitable choice to maintain long-term social stability, steady economic growth, and ecological security, is the key to the coordinated development of the economy, society, and environment in developing Central Asia economies. We attempted to evaluate the trend of agricultural sustainability in Central Asia between 2002 and 2017 by adopting analytic hierarchy process and entropy weight method in this study. It was found that the overall sustainability level of regional agriculture is rising, which is mainly driven by economic progress, with social and ecological dimensions contributing much less. Accordingly, we advanced four suggestions: enhancing water productivity, optimizing planting techniques, improving agricultural cooperatives, and promoting digital land management to boost the agricultural sustainability of the region.
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