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Study on microstructure, microhardness, bioactivity, and biocompatibility of La2 O3 -containing bioceramic coating doping SiO2 fabricated by laser cladding.
Fu, Q, Liu, Q, Li, L, Li, X, Gu, H, Sheng, B, Yang, B
Journal of biomedical materials research. Part B, Applied biomaterials. 2020;(5):2099-2107
Abstract
To solve the lack of strength of calcium phosphate ceramic coatings in load-bearing applications, gradient Ca-P bioceramic coatings doped with La2 O3 and SiO2 are fabricated by laser cladding on Ti-6Al-4 V. The effect of SiO2 on microstructure, microhardness, bioactivity, and biocompatibility of coatings was investigated. The experimental results illustrate that the coating doped with La2 O3 and SiO2 has excellent metallurgical bonding. The XRD analysis confirms that the amount of hydroxyapatite and tricalcium phosphate in the coating reached maximum when doping amount of SiO2 is 10 wt %. SiO2 -doped coatings show a significantly higher bone-like apatite precipitation after immersion in SBF than that of other coatings. in vitro experiment also shows that coating with 10 wt % SiO2 is more suitable for the attachment and proliferation of MG63 cells, indicating that coating with 10 wt % SiO2 exhibits best bioactivity and biocompatibility. These results suggest that the addition of SiO2 improves the bonding strength, bioactivity, and biocompatibility of coatings.
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Magnetic biochar-based manganese oxide composite for enhanced fluoroquinolone antibiotic removal from water.
Li, R, Wang, Z, Zhao, X, Li, X, Xie, X
Environmental science and pollution research international. 2018;(31):31136-31148
Abstract
Magnetic biochar-based manganese oxide composite (MMB) and raw biochar (BC) were synthesized via pyrolysis at a temperature of 500 °C under anoxic conditions of potato stems and leaves, characterized, and successfully used for the removal of norfloxacin (NOR), ciprofloxacin (CIP), and enrofloxacin (ENR) as representative compounds of fluoroquinolone antibiotics (FQs). Characterization results suggested that Fe3O4 and MnOx are the dominant crystals in MMB. MMB possessed large surface area and pore volume than BC. Batch adsorption experiments showed that the maximum adsorption abilities of MMB for norfloxacin (NOR), ciprofloxacin (CIP), and enrofloxacin (ENR) were 6.94, 8.37, and 7.19 mg g-1. In comparison to BC, the adsorption abilities of MMB increased 1.2, 1.5, and 1.6 times for NOR, CIP, and ENR, respectively. The pseudo-second-order kinetic model and the Langmuir model correlated satisfactorily to the experimental data. Thermodynamic studies revealed that the adsorption processes were spontaneous and endothermic. The adsorption capacity of MMB decreased with increasing solution pH (between 3.0 and 10.0) and increasing ionic strength (0.001-0.1). The MMB with high FQ removal efficiency, easy separation, and desirable regeneration ability may have promising environmental applications for the removal of fluoroquinolone antibiotics from water environment.
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Magnetic solid phase extraction of sulfonamides based on carboxylated magnetic graphene oxide nanoparticles in environmental waters.
Gao, PS, Guo, Y, Li, X, Wang, X, Wang, J, Qian, F, Gu, H, Zhang, Z
Journal of chromatography. A. 2018;:1-10
Abstract
A magnetic nano-adsorbent material was prepared by functionalizing carboxylic group onto the granule surface of magnetic graphene oxide nanoparticles (CMGO), using in-situ co-precipitating method. The surface morphology was characterized by SEM and TEM. The CMGO was selected as the adsorbent for the magnetic solid phase extraction (MSPE) of sulfonamides (SAs) from environmental water samples, and the eluted analytes were determined by ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). A series of experimental parameters were optimized to improve the extraction efficiency such as amount of CMGO, extraction time, pH, ionic strength of the sample solution and desorption conditions. When the pH of water sample was 4.00, the extraction recoveries (ERs) for SAs were over 82.0% with 15.0 mg CMGO adsorption for 20 min. Under the optimized extraction conditions, linear range was obtained with coefficients of determination (R2)≥0.9983. The limits of detection for this proposed method were in the range of 0.49-1.59 ng/L, and the enrichment factors were 1320-1702 for eight SAs. The newly developed method was successfully applied to the analysis of trace SAs in real-world water samples, which provided satisfactory ERs in the range of 82.0-106.2% with RSDs less than 7.2%. Overall, it shows a great potential for the concentration of trace amine organic pollutions in complex matrices.
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Underlying mechanisms and effects of hydrated lime and selenium application on cadmium uptake by rice (Oryza sativa L.) seedlings.
Huang, G, Ding, C, Guo, F, Li, X, Zhang, T, Wang, X
Environmental science and pollution research international. 2017;(23):18926-18935
Abstract
A pot experiment was conducted to investigate the effects of selenium (Se) and hydrated lime (Lime), applied alone or simultaneously (Se+Lime), on growth and cadmium (Cd) uptake and translocation in rice seedlings grown in an acid soil with three levels of Cd (slight, mild, and moderate contamination). In the soil with 0.41 mg kg-1 Cd (slight Cd contamination), Se addition alone significantly decreased Cd accumulation in the root and shoot by 35.3 and 40.1%, respectively, but this tendency weakened when Cd level in the soil increased. However, Se+Lime treatment effectively reduced Cd accumulation in rice seedlings in the soil with higher Cd levels. The results also showed that Se application alone strongly increased Cd concentration in the iron plaque under slight Cd contamination, which was suggested as the main reason underlying the inhibition of Cd accumulation in rice seedlings. Se+Lime treatment also increased the ability of the iron plaques to restrict Cd uptake by rice seedlings across all Cd levels and dramatically decreased the available Cd concentration in the soil. These results suggest that Se application alone would be useful in the soil with low levels of Cd, and the effect would be enhanced when Se application is combined with hydrated lime at higher Cd levels.
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5.
[Effect of arsenic trioxide combined with adriamycin on the proliferation and apoptosis of human lymphoma cells].
Huang, R, Li, X, Huang, X, Yang, X, Li, W
Zhong nan da xue xue bao. Yi xue ban = Journal of Central South University. Medical sciences. 2009;(6):515-22
Abstract
OBJECTIVE To determine the effect of arsenic trioxide combined with adriamycin(ADM) on the proliferation and apoptosis of human lymphoma cells. METHODS Raji cells were divided into an experimental group and a control group, and the experimental group was further divided into 1 micromol/L As(2)O(3) group,2 micromol/L As(2)O(3) group, ADM group,1 micromol/L As(2)O(3) and ADM group,2 micromol/L As(2)O(3) and ADM group. Human lymphoma cells Raji were treated with As(2)O(3) combined with ADM. Wright-Giemsa dying assay was used to observe the apoptosis morphology of lymphoma cells. The proliferation of the cells treated with As(2)O(3) and adriamycin was detected by the method of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide(MTT). Flow cytometry(FCM) was used to detect the apoptosis rate of lymphoma and the fluorescene density in the lymphocytes. Effect of arsenic trioxide and adriamycin on the mutant p53 expression in Raji cells was detected by semi-quantitive RT-PCR. RESULTS Evident apoptotic morphological changes of Raji cells were observed 24 hours after treatment with As(2)O(3) or ADM. Compared with As(2)O(3) or ADM alone, As(2)O(3) combined with ADM could increase the inhibition ratio significantly (P<0.05), and the inhibition rate was related to the concentration and action time of As(2)O(3) (P<0.05). Compared with As(2)O(3) or ADM alone, As(2)O(3) combined with ADM could increase the apoptosis rate of lymphoma cells with obvious difference (P<0.05). Semi-quantitive and RT-PCR showed that the expression of mutant p53 in As(2)O(3) and ADM alone and combined groups was obviously less than that in the control (P<0.05). After the treatment with 1 micromol/L and 2 micromol/L As(2)O(3), the fluorescene density in the Raji cells was 18.53 and 18.12, 0.056 and 0.023 times increase respectively.There was no difference (P>0.05). CONCLUSION As(2)O(3) and ADM alone or combined can inhibit the proliferation, induce cell apoptosis, and downregulate the expression of mutant p53 in vitro. As(2)O(3) combined with ADM has synergistic anti-lymphoma cell effect in vitro. As(2)O(3) has no significant effect on the concentration of ADM on the Raji cells, but can enhance the chemosensitivity of Raji cells, and its mechanism may be that it can downregulate the expression of mutant p53.