排序方式: 共有19条查询结果,搜索用时 15 毫秒
1.
In this study,a promising strategy has been developed to promote bone regeneration by combining antioxidant activities and osteoimmunomodulatory properties.Herein,an L-arginine/nanofish bone(Arg/NFB) nanocomplex has been prepared and evaluated in vitro and in vivo.The Arg/NFB nanocomplex possesses good antioxidant activities and could modulate the polarization of non-activated macrophage into different types and induce the secretion of pre-inflammato ry,anti-inflammatory,osteogenic as well as angiogenic cytokines.Additionally,the regulated immune microenvironment can enhance the osteogenic differentiation of mouse embryo osteoblast precursor cells(MC3 T3-E1) and angiogenic capacity of human umbilical vein endothelial cells(HUVECs),leading to the improved formation of mineralized nodules,alkaline phosphatase activity and angiogenic effects.In vivo results with cranial defect models reveal that the treatment of Arg/NFB nanocomplex exhibited significant improvement of new bone formation and angiogenesis.All the results demonstrate Arg/NFB nanocomplex with antioxidant activities and osteoimmunomodulatory properties could be a new idea for developing the next generation of bone regeneration biomaterials. 相似文献
2.
Rui‐Ting Gao Dan He Lijun Wu Kan Hu Xianhu Liu Yiguo Su Lei Wang 《Angewandte Chemie (International ed. in English)》2020,59(15):6213-6218
Increasing long‐term photostability of BiVO4 photoelectrode is an important issue for solar water splitting. The NiOOH oxygen evolution catalyst (OEC) has fast water oxidation kinetics compared to the FeOOH OEC. However, it generally shows a lower photoresponse and poor stability because of the more substantial interface recombination at the NiOOH/BiVO4 junction. Herein, we utilize a plasma etching approach to reduce both interface/surface recombination at NiOOH/BiVO4 and NiOOH/electrolyte junctions. Further, adding Fe2+ into the borate buffer electrolyte alleviates the active but unstable character of etched‐NiOOH/BiVO4, leading to an outstanding oxygen evolution over 200 h. The improved charge transfer and photostability can be attributed to the active defects and a mixture of NiOOH/NiO/Ni in OEC induced by plasma etching. Metallic Ni acts as the ion source for the in situ generation of the NiFe OEC over long‐term durability. 相似文献
3.
Metal ion-promoted fabrication of melanin-like poly(L-DOPA) nanoparticles for photothermal actuation
Wang Xianheng Yang Lei Yang Peng Guo Wancai Zhang Quan-Ping Liu Xianhu Li Yiwen 《中国科学:化学(英文版)》2020,63(9):1295-1305
Melanin-inspired polymers are currently the focus of growing interest for a wide range of applications ranging from energy to biomedical area. Whilst researchers have made numerous attempts to prepare and utilize polydopamine nanoparticles(PDA NPs), they have made limited progress in developing and discovering another typical functional mimic of natural melanin, poly(levodopa)(P(L-DOPA)) NPs, probably due to the lack of facile synthetic strategies towards satisfactory structural and functional control of melanin-like NPs. Herein, we reported a one-pot preparation method towards P(L-DOPA) NPs with good yields and controllable size/property in an aqueous solution assisted by various metal ions(i.e., Ni(II), Mg(II), Ca(II), Fe(III), Mn(II), Co(II), Zn(II) and Cd(II)). Interestingly, the resulting P(L-DOPA) NPs exhibited enhanced light absorption and photothermal behaviors compared with well-established PDA NPs, which can be employed to further fabricate kinds of photothermal composite actuators with promising performances such as folding, switching, and forward-moving. This study offers a facile and robust way to synthesize new synthetic melanins beyond PDA, and facilitates further functional discovery and evolution of melanin-inspired polymers and composites. 相似文献
4.
Jia Yan Ting Wang Siyao Qiu Zhilong Song Wangqin Zhu Xianhu Liu Jiabiao Lian Chenghua Sun Huaming Li 《Journal of Energy Chemistry》2022,(2):548-555
Two-dimensional carbon nitride(2 D-C3 N4)nanosheets are promising materials in photocatalytic water splitting,but still suffer from easy agglomeration and fast photogene rated electron-hole pairs recombination.To tackle this issue,herein,a hierarchical Nb2 O5/2 D-C3 N4 heterostructure is precisely constructed and the built-in electric field between Nb2O5 and 2 D-C3 N4 can provide the driving force to separate/transfer the charge carriers efficiently.Moreover,the strongly Lewis acidic Nb2O5 can adsorb TEOA molecules on its surface at locally high concentrations to facilitate the oxidation reaction kinetics under irradiation,resulting in efficient photogene rated electrons-holes separation and exceptional photocatalytic hydrogen evolution.As expected,the champion Nb2O5/2 D-C3N4 heterostructure achieves an exceptional H2 evolution rate of 31.6 mmol g-1 h-1,which is 213.6 times and 4.3 times higher than that of pristine Nb2O5 and2 D-C3N4,respectively.Moreover,the champion heterostructure possesses a high apparent quantum efficiency(AQE)of 45.08%atλ=405 nm and superior cycling stability.Furthermore,a possible photocatalytic mechanism of the energy band alignment at the hetero-interface is proposed based on the systematical characterizations accompanied by density functional theory(DFT)calculations.This work paves the way for the precise construction of a high-quality heterostructured photocatalyst with efficient charge separation to boost hydrogen production. 相似文献
5.
研究了以壳聚糖为基准物、浊度法测定超滤膜截留率的方法。以氢氧化钠为沉淀剂,用浊度法分别对6种不同相对分子质量的壳聚糖浓度进行检测,探讨了壳聚糖相对分子质量与氢氧化钠浓度等因素对浊度的影响。结果表明,壳聚糖含量在25~1 000 mg/L范围内与浊度呈现良好的线性关系,线性相关系数r~2≥0.996,检出限在2.1~4.8mg/L之间,样品加标回收率为82.1%~122%。测量结果的相对标准偏差为0.75%~8.7%(n=6)。该法快速、简便,可为超滤膜研究、生产、改性及应用等提供理论指导。 相似文献
6.
7.
吲哚酚显色底物是由作为产色原的吲哚酚或其取代物与酶底物间接缩合而成,其合成主要包括中间体乙酸1-乙酰基-吲哚-3-基酯的合成及其与酶底物的衍生物缩合两部分。中间体可以通过以取代苯胺、邻氨基苯甲酸、邻氯苯甲酸等为起始物合成,而其再与酶底物的衍生物如乙酰溴代糖、酰卤、三氯氧磷、氯磺酸等反应可得到相应的各种显色底物。吲哚酚显色底物应用于微生物检测,依据特异性酶与相应底物的特异性反应,一般通过显色培养基技术来实现,不同的显色底物针对的酶及其应用于检测的微生物会有所不同。 相似文献
8.
Xianhu Liu Changyan Zhang Kun Dai Guoqiang Zheng Chuntai Liu Changyu Shen 《先进技术聚合物》2013,24(2):270-272
As a part of continuous efforts to systematically understand the morphological development in water‐assisted injection molding, high density polyethylene with different molecular weights was molded in this study. Unexpectedly, it was found that shish kebab with high lamellar and molecular orientations was formed in the sample with a lower molecular weight (LMW) rather than in the higher one, especially in the water channel layer. Present finding is obviously inconsistent with the general consensus, that is, higher molecular weight (HMW) polymer is much easier to form preferential orientation in flow field than LMW one. Such anomalous phenomenon is explained by the fact that even though melts experienced the same processing, lower shear rate is practically achieved in HMW sample due to its high viscosity. The result indicates that the flow history in industrial processing method is far from that in laboratory one. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
9.
Bobo Zou Ting Wang Shengyuan Li Rong Kang Guochun Li Sherif A.El-Khodary Dickon H.L.Ng Xianhu Liu Jingxia Qiu Yan Zhao Jiabiao Lian Huaming Li 《Journal of Energy Chemistry》2021,(6):109-117
A new intercalation-type anode material is reported herein to improve the lithium storage kinetics for high-rate lithium ion capacitors.The crystal structure of... 相似文献
10.
A Two‐Dimensional Zirconium Carbide by Selective Etching of Al3C3 from Nanolaminated Zr3Al3C5 下载免费PDF全文
Jie Zhou Xianhu Zha Fan Y. Chen Qun Ye Prof. Per Eklund Prof. Shiyu Du Prof. Qing Huang 《Angewandte Chemie (International ed. in English)》2016,55(16):5008-5013
The room‐temperature synthesis of a new two‐dimensional (2D) zirconium‐containing carbide, Zr3C2Tz MXene is presented. In contrast to traditional preparation of MXene, the layered ternary Zr3Al3C5 material instead of MAX phases is used as source under hydrofluoric acid treatment. The structural, mechanical, and electronic properties of the synthesized 2D carbide are investigated, combined with first‐principles density functional calculations. A comparative study on the structrual stability of our obtained 2D Zr3C2Tz and Ti3C2Tz MXenes at elevated temperatures is performed. The obtained 2D Zr3C2Tz exhibits relatively better ability to maintain 2D nature and strucural integrity compared to Ti‐based Mxene. The difference in structural stability under high temperature condition is explained by a theoretical investigation on binding energy. 相似文献