Zinc oxide nanoparticles (ZnO NPs) stand as among the most significant metal oxide nanoparticles in trigger the formation of reactive oxygen species (ROS) and induce apoptosis. Nevertheless, the ...utilization of ZnO NPs has been limited by the shallowness of short-wavelength light and the constrained production of ROS. To overcome these limitations, a strategy involves achieving a red shift towards the near-infrared (NIR) light spectrum, promoting the separation and restraining the recombination of electron-hole (e
-h
) pairs. Herein, the hybrid plasmonic system Au@ZnO (AZ) with graphene quantum dots (GQDs) doping (AZG) nano heterostructures is rationally designed for optimal NIR-driven cancer treatment. Significantly, a multifold increase in ROS generation can be achieved through the following creative initiatives: (i) plasmonic Au nanorods expands the photocatalytic capabilities of AZG into the NIR domain, offering a foundation for NIR-induced ROS generation for clinical utilization; (ii) elaborate design of mesoporous core-shell AZ structures facilitates the redistribution of electron-hole pairs; (iii) the incorporation GQDs in mesoporous structure could efficiently restrain the recombination of the e
-h
pairs; (iv) Modification of hyaluronic acid (HA) can enhance CD44 receptor mediated targeted triple-negative breast cancer (TNBC). In addition, the introduced Au NRs present as catalysts for enhancing photothermal therapy (PTT), effectively inducing apoptosis in tumor cells. The resulting HA-modified AZG (AZGH) exhibits efficient hot electron injection and e
-h
separation, affording unparalleled convenience for ROS production and enabling NIR-induced PDT for the cancer treanment. As a result, our well-designed mesoporous core-shell AZGH hybrid as photosensitizers can exhibit excellent PDT efficacy.
In order to improve the antibacterial performance of natural palygorskite, spindle-like ZnO/palygorskite (ZnO/PAL) nanocomposites with controllable growth of ZnO on the surface of PAL were prepared ...in the presence of non-ionic surfactants using an easy-to-operate hydrothermal method. The obtained ZnO/PAL nanocomposites have a novel and special spindle-shaped structure and good antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), and are also low cost. The minimum inhibitory concentrations of ZnO/PAL nanocomposites toward E. coli and S. aureus reached 1.5 and 5 mg/mL, respectively.
Core-shell silica microspheres with a nanocellulose derivative in the hybrid shell were successfully prepared as a chiral stationary phase by a layer-by-layer self-assembly method. The hybrid shell ...assembled on the silica core was formed using a surfactant as template by the copolymerization reaction of tetraethyl orthosilicate and the nanocellulose derivative bearing triethoxysilyl and 3,5-dimethylphenyl groups. The resulting nanocellulose hybrid core-shell chiral packing materials (CPMs) were characterized and packed into columns, and their enantioseparation performance was evaluated by high performance liquid chromatography. The results showed that CPMs exhibited uniform surface morphology and core-shell structures. Various types of chiral compounds were efficiently separated under normal and reversed phase mode. Moreover, chloroform and tetrahydrofuran as mobile phase additives could obviously improve the resolution during the chiral separation processes. CPMs still have good chiral separation property when eluted with solvent systems with a high content of tetrahydrofuran and chloroform, which proved the high solvent resistance of this new material.
A simple capillary electrophoresis (CE) method that using β-cyclodextrin (β-CD) as buffer modifier has been developed for the detection of ten amino acids of jujube from five different geographical ...origins. The CE methodology was optimized through the variation of type, pH and concentration of the buffer solution, concentration of the additive β-CD, applied voltage, injection time and wavelength of the UV detection. It was found that the best separation of ten kinds of amino acids was achieved within less than 6 min under the optimum separation conditions: 50 mmol L-1 pH 9.5 borate-phosphate buffer with 5.0 mmol L-1 β-CD, 15 kV applied voltage, 25 °C column temperature, 210 nm detection wavelength, and 5 s injection time. This method showed good repeatability with RSD values of 1.4-3.4% for peak area, and 1.4-4.7% for migration time, when β-CD was used as buffer modifier. Under the optimum conditions, the method has been successfully applied to the detection of actual jujube samples, which also verifies the effectiveness and practicability of the method. Recovery of real samples was in ranging of 90%-105%, which proved the feasibility of the method. It also proved that the method was successfully applied to the quantitative analysis of amino acids of interest in plant samples.
The genus Arthrobacter is a source of many natural products that are critical in the development of new medicines. Here, we isolated a novel carotenoid from Arthrobacter sp. QL17 and characterized ...its properties. The carotenoid was extracted with methanol, and purified by column chromatography and semi-preparative HPLC. Based on micrOTOF-Q and NMR analyses, the pigment was chemically characterized as 2,2′-(((1E,3E,5E,7E,9E,11E,13E,15E,17E,19E)-3,7,14,18-tetramethylicosa-1,3,5,7,9,11,13,15,17,19-decaene-1,20-diyl)bis(2,2,4-trimethylcyclohex-3-ene-3,1-diyl)) bis(ethan-2-yl-1-ylidene))bi(propane-1,3-diol), and named arthroxanthin. The biological activities of arthroxanthin were evaluated with DPPH, ABTS and MTT assays. Arthroxanthin exhibited excellent radical scavenging properties, as shown for 2, 20-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-n-(3,2-ethyl-benzothiazole-6-sulfonic acid) ammonium salt (ABTS), respectively, with IC50s of 69.8 and 21.5 µg/mL. It also showed moderate anticancer activities against HepG2, Hela, MDAB-231, SW480, and MKN-45 with IC50 values of 107.6, 150.4, 143.4, 195.9, and 145.5 μg/mL, respectively. Therefore, arthroxanthin derived from Arthrobacter sp. QL17 may be a potent antioxidant and anticancer agent for food and pharmaceutical use.
As an important carrier of urban water and gas transmission,buried pipelines play an indispensable role in the normal operation of cities. Due to the impact of soil environmental corrosion,buried ...pipelines can be easily destroyed under sudden earthquakes,resulting in environmental pollution and waste of resources. In this paper,on the basis of the stochastic corrosion process,a systematical research was conducted to study the seismic response law of multi-aged buried steel pipes. Considering the randomness of buried pipeline corrosion,a stochastic corrosion occurrence model based on homogeneous Markov process was established. According to the influences of different corrosion environments,a comprehensive corrosion model in an acidic environment and a local corrosion model in nearneutral and alkaline environments were established. Based on the accelerated corrosion and tensile tests of steel standard specimens,a Mechanical Property Deterioration Model of steel and a time-varying constitutive model of buried st
Despite the separation efficiency of capillary electrophoresis (CE) is much higher than other chromatographic methods, it is sometimes difficult to perfectly separate the complex ingredients in ...biological samples. One possible and simple way to develop the separation effect in CE is to add some modifiers in the running buffer. In this paper, the suitable running buffer modifiers were explored to simultaneously separate and detect six typical flavonoids (apigenin, luteolin, kaempferol, quercetin, (+)-catechin and (−)-epicatechin) which are the main active ingredients in chrysanthemum by capillary zone electrophoresis with amperometric detection (CZE-AD). It was found that when β-cyclodextrin (β-CD) and the mixture of methanol and ethanol were used as running buffer modifiers, a baseline separation of the six analytes could be accomplished in less than 20
min and the detection limits were as low as 10
−7 or 10
−8
g
ml
−1. Other factors affecting the CZE separation, such as working potential, pH value and ionic strength of running buffer, separation voltage and sample injection time were extensively investigated. Under the optimum conditions, a successful practical application on the determination of chrysanthemum samples confirmed the validity and practicability of this method.
In general capillary zone electrophoresis (CZE) separation models, o-, m-, and p-phenylenediamine isomers can be separated in a weak acidic running buffer for their pKa values being 4.52, 5.64, 6.04, ...respectively, while o-, m-, and p-dihydroxybenzene isomers can be separated in a weak basic buffer for their pKa values being 9.40, 9.40 and 10.04, respectively. So, it is hard to find a suitable running buffer at a fixed pH in normal CZE for simultaneous separation of these two groups of positional isomers. In this paper, a novel method based on alternately running two different pH buffers in CZE coupled with amperometric detection (CZE-AD) was designed to simultaneously determine these two groups of positional isomers. It is found that when two different pH running buffers were employed alternately under appropriate order and time, the six analytes could be separated perfectly in less than 20 min and the detection limits were as low as 10⁻⁷ mol/L. Furthermore, the effects of working electrode potential, pH and concentration of running buffer, separation voltage and injection time on CZE-AD were investigated. Experimental results demonstrated that the introduced method was practical to simultaneously determine two groups of positional isomers with different pKa and had some advantages of high sensitivity, good repeatability and small sample requirement.
PDF
