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《中国化学快报》2020,31(6):1654-1659
The carbon quantum dots(CQDs) and their functionalized materials are promising in biomedical field because of their unique properties;meanwhile,a growing concern has been raised about the potential toxicity of these modified materials in biosystem.In this study,we synthesized original CQDs and two common functionalized CQDs including N-doped CQDs(NCQDs) and folic acid-modified CQDs(FACQDs),and compared the toxicity and biocompatibility with each other in vitro and in vivo.L929,C6 and normal cell MDCK were selected to detect the adverse reaction of these materials in vitro.No acute toxicity or obvious changes were noted from in vitro cytotoxicity studies with the dose of these CQD materials increasing to a high concentration at 1 mg/mL.Among these materials,the FA-CQDs show a much lower toxicity.Moreover,in vivo toxicity studies were performed on the nude mice for 15 days.The experimental animals in 10 or 15 mg/kg groups were similar with animals treated by phosphate buffer solution(PBS) after 15 days.The results of the multifa rious biochemical parameters also suggest that the functionalized products of CQDs do not influence the biological indicators at feasible concentration.Our findings in vitro and in vivo through toxicity tests demonstrate that CQDs and their modified materials are safe for future biological applications. 相似文献
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Pristine multi-walled carbon nanotubes (MWNTs) were incorporated into poly(vinylidene fluoride) (PVDF), poly(methyl methacrylate) (PMMA), and PVDF/PMMA blends to achieve binary and ternary nanocomposites. MWNTs were more compatible with the PVDF matrix than with the PMMA-containing matrices. MWNT addition did not alter the development of α-form PVDF crystals in the binary/ternary composites. Nucleation and overall isothermal crystallization of PVDF were enhanced by the presence of MWNTs, and enhancements were optimal in the PVDF/MWNT binary composites. Avrami analysis revealed that addition of MWNTs led to more extensive athermal-type nucleation of PVDF, and that PMMA slightly decreased the crystal growth dimension of PVDF. The equilibrium melting temperature (Tm°) of PVDF increased in the binary composites but remained nearly constant in the ternary system. Thermal stability was enhanced in the binary/ternary composites, and enhancements were more evident in the air environment than in nitrogen. Rheological property measurements revealed that the intensely entangled chains of high-molecular weight PVDF dominated the rheological response of PVDF-included samples in the melt state. A (pseudo)network structure was developed in each of the PVDF-included samples as well as in the 1 phr MWNT-added PMMA/MWNT composite. The storage moduli of the PVDF, PMMA, and PVDF/PMMA:1/1 blend increased to 37%, 22% and 34%, respectively, at 40 °C after addition of 1 phr MWNT. 相似文献
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XIANG VAN ZENG XIANCHENG∗ CHENG SIQING LI YANTUAN XIE JIAQING 《Journal of Dispersion Science and Technology》2013,34(7):857-867
Abstract The hydrolysis of p-nirrophenyl picolinate (PNPP) catalyzed by the Cu(II) and Zn(H) complexes of d-glucosamine schiff base was investigated kinetically by observing the rates of the release of p-nitrophenol in the buffered micellor solution at different pit and 25°C. The scheme for reaction acting mode involving a ternary complex contain ligand, metal ion and substrate in micelle was establish and the reaction mechanisms were discussed The experimental results indicated that the complexes catalyzed efficiently the hydrolysis of PNPP, especially Zn(II) complex. The rate constant kN, which shows the catalytic reactivity of complexes, WBI determined to be 0.4251 s?1 far Cu(II) complex at pH 7 60 in micellar solution. The catalytic reactivity of Zn(II) complex were much larger than Cu(II) complex, the kN was determined to be 3.1914 s?1 at same pH value. 相似文献
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Julong Wu Xiaojun Li Bing Ma Maosheng Tian Shirong Li 《International journal of quantum chemistry》2011,111(14):3786-3792
The structure, electronic property, and infrared spectroscopy of endohedral metallofullerenes TM@C20 (TM = Ce and Gd) have been systematically investigated with the aid of the hybrid DFT‐B3LYP functional. It is found that in the endohedral metallofullerenes the average C? C bond lengths are obvious longer than those of empty cage. The frontier orbital analyses show that the endohedral metallofullerene Gd@C20 has the high‐thermodynamic stability. Natural population analysis also tells us that only in the Ce@C20, the Ce atom acts as an electron acceptor with the negative charges, and the 4f orbitals of Ce and Gd atoms have a significant contribution in the formation of chemical bonding. Additionally, the analyses of harmonic vibrational frequencies reveal that when the TM atoms are encapsulated into the C20 cage, the strongest absorption peaks are characterized by a mixture of TM?C bending and C? C stretching vibrations. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011 相似文献
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设p为素数,r≥0是整数.利用广义Fermat方程的深刻结论证明了:若3≤q<100,q≠31,则当p≥5时,超椭圆曲线yp=x(x+qr)上仅有平凡的有理点y=0;当q=5,11,23,29,41,47,59,83时,给出了该超椭圆曲线所有的有理点(x,y).特别地,当q=3且r=1时,证明了超椭圆曲线yp=x(x+3)仅在p=2时有非平凡的有理点(x,y),并给出了此时所有的非平凡有理点. 相似文献
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A new anisotropic potential is fitted to {\it ab initio} data. The close-coupling
approach is utilized to calculate state-to-state rotational excitation
partial wave cross sections for elastic and inelastic collisions of He atom
with HBr molecule based on the fitted potential. The calculation is
performed separately at the incident energies: 75, 100 and 200~meV.The
tendency of the elastic and inelastic rotational excitation partial wave
cross sections varying with total angular quantum number $J$ is obtained. 相似文献