Hierarchically porous cellulose-based carbon aerogels with N-doped skeletons and encapsulated iron-based catalysts for efficient tetracycline catalytic degradation.

Three-dimensional interpenetrating and hierarchically porous carbon material is an efficient catalyst support in water remediation and it is still a daunting challenge to establish the relationship between hierarchically porous structure and catalytic degradation performance. Herein, a highly porous silica (SiO2)/cellulose-based carbon aerogel with iron-based catalyst (FexOy) was fabricated by in-situ synthesis, freeze-drying and pyrolysis, where the addition of SiO2 induced the hierarchically porous morphology and three-dimensional interpenetrating sheet-like network with nitrogen doping. The destruction of cellulose crystalline structure by SiO2 and the iron-catalyzed breakdown of glycosidic bonds synergistically facilitated the formation of electron-rich graphite-like carbon skeleton. The unique microstructure is confirmed to be favorable for the diffusion of reactants and electron transport during catalytic process, thus boosting the catalytic degradation performance of carbon aerogels. As a result, the catalytic degradation efficiency of tetracycline under light irradiation by adding only 5 mg of FexOy/SiO2 cellulose carbon aerogels was as high as 90 % within 60 min, demonstrating the synergistic effect of photocatalysis and Fenton reaction. This ingenious structure design provides new insight into the relationship between hierarchically porous structure of carbon aerogels and their catalytic degradation performance, and opens a new avenue to develop cellulose-based carbon aerogel catalysts with efficient catalytic performance.

Toward Excellent Energy Storage Performance via Well-Aligned and Isolated Interfaces in Multicomponent Polypropylene-Based All-Organic Polymer Dielectric Films.

Polypropylene (PP) serves as an excellent commercialized polymer dielectric film owing to its high breakdown strength, excellent self-healing ability, and flexibility. However, its low dielectric constant causes the large volume of the capacitor. Constructing multicomponent polypropylene-based all-organic polymer dielectric films is a facile strategy for achieving high energy density and efficiency simultaneously. Thereinto, the interfaces between the components become the key factors that determine the energy storage performance of the dielectric films. In this work, we propose to fabricate high-performance polyamide 513 (PA513)/PP all-organic polymer dielectric films via the construction of abundant well-aligned and isolated nanofibrillar interfaces. Laudably, a significant enhancement in the breakdown strength is achieved from 573.1 MV/m of pure PP to 692.3 MV/m with 5 wt % of PA513 nanofibrils. Besides, a maximum discharge energy density of about 4.4 J/cm2 is realized with 20 wt % of PA513 nanofibrils, which is about 1.6-folds higher than pure PP. Simultaneously, the energy efficiency of samples with modulated interfaces maintains higher than 80% up to 600 MV/m, which is much higher than pure PP of about 40.7% at 550 MV/m. This work provides a new strategy to fabricate high-performance multicomponent all-organic polymer dielectric films on an industrial scale.

Intraperitoneal injection of thalidomide alleviates early osteoarthritis development by suppressing vascular endothelial growth factor expression in mice.

Vascular endothelial growth factor (VEGF) is expressed in articular cartilage and increases in expression levels have been associated with the progression of osteoarthritis (OA). Thalidomide is a drug that has been reported to inhibit angiogenesis and reduce VEGF production by downregulating VEGF expression. The objective of the present study was to determine whether intraperitoneal administration of thalidomide may attenuate early OA development in mice. Male C57BL/6 mice (10­weeks­old) were randomly assigned into the destabilization of the medial meniscus (Dmm) with thalidomide treatment (Dmm+Th), Dmm and Sham groups equally. An OA model was induced surgically in Dmm+Th and Dmm groups, and mice of the Dmm+Th group were subsequently treated with an intraperitoneal injection of thalidomide (200 mg/kg/day). At 2 and 4 weeks following surgery, the pathological alterations in cartilage samples were assessed qualitatively by hematoxylin and eosin staining and Safranin O/Fast green staining, and quantitatively by the Osteoarthritis Research Society International scoring system. The mRNA expression levels of matrix metalloproteinase­13 (MMP­13) and VEGF were measured by reverse transcription­quantitative polymerase chain reaction. The protein expression levels of MMP­13 and VEGF were detected by immunofluorescence and immunohistochemistry, respectively. The production of VEGF in serum was evaluated via an ELISA assay. Pathological scores were significantly higher in the Dmm and the Dmm+Th groups than those in the Sham group; however, the Dmm+Th group exhibited markedly less severe pathological changes compared with the Dmm group. Compared with the Sham group, the mRNA and protein expression levels of VEGF and MMP­13 in the Dmm and the Dmm+Th groups were significantly increased. The Dmm+Th group exhibited significantly decreased expression levels of VEGF and MMP­13, as well as significantly decreased serum VEGF concentration compared with the Dmm group. Thus, the results of the present study demonstrated that intraperitoneal administration of thalidomide may alleviate the development of early OA by suppressing VEGF expression in mice and may have potential as a novel therapy for the treatment of OA.

[The effect of 5-fluorouracil on enriching cancer stem cells of hepatoma cell line BEL-7402].

OBJECTIVE: To investigate the effect of 5-FU (5-fluorouracil) on enriching cancer stem cells of HCC cell line BEL-7402 and the biological characteristics of enriched cells. METHODS: The enriching concentration of 5-FU was determined by CCK-8 (cell counting kit-8). Flow Cytometry was used to determine the changes in cell cycle and positive expression ratio of surface marker CD56, CD54, EpCAM and CD133. The self-renewal and differentiation of positive cells were tested by colony formation assay, and were compared with the control group. RESULTS: Enriching concentration of 5-FU was determined as 10 µg/ml with 48 h incubation. After enrichment, G0/G1 phase cells increased from 57.50 %+/-0.98% to 68.70%+/-3.41% (P<0.05). Whereas S phase cells decreased from 40.26%+/-4.12% to 31.80%+/-4.15% (P<0.01); G2/M phase cells disappeared in experimental group, and was 5.80%+/-1.87% in control group (P<0.01). The proportion of the cell cycle changed with significant statistical differences. Meanwhile, positive rate of cell surface makers CD56, CD54, EpCAM and CD133 increased from 0.57%+/-0.12%, 8.10%+/-6.79%, 0.3%+/-0.01% and 3.20%+/-0.99% to 4.13%+/-0.06%, 50.08%+/-1.69%, 0.55%+/-0.07% and 10.51%+/-1.13%, respectively. The difference was significant (P<0.05). The colony forming ratio of CD56, CD54, EpCAM and CD133 negative cells and positive cells were 2.11%+/-0.21%, 3.32%+/-0.31%; 0.86%+/-0.101%, 2.40%+/-0.52 %; 7.19%+/-0.56%, 7.73%+/-0.71%; 2.70%+/-0.26%, 5.75%+/-0.81%, respectively, and significant differences were found between (P<0.05). CONCLUSION: 5-fluorouracil enriched the cancer stem cell population in HCC cell line BEL-7402. CD56 and CD54 can be used as important surface markers in research of liver cancer stem cells.