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761.
A carbon‐paste electrode modified with 2,7‐bis(ferrocenyl ethyl)fluoren‐9‐one and carbon nanotubes was used for the sensitive voltammetric determination of levodopa (LD). The electrochemical response characteristics of the modified electrode toward LD, uric acid (UA) and folic acid (FA) were investigated. The results showed an efficient catalytic activity of the electrode for the electrooxidation of LD, which leads to lowering its overpotential by more than 320 mV. The modified electrode exhibits an efficient electron mediating behavior together with well‐separated oxidation peaks for LD, UA and FA. Also, the modified electrode was used for determination of LD in some real samples. 相似文献
762.
Matin-Alsadat Mostaan Jamal Davoodi Hadi Alizadeh Mohsen Yarifard 《The European Physical Journal B - Condensed Matter and Complex Systems》2018,91(10):260
In this paper, we study the tensile behavior of cylindrical rutile TiO2 nanowires, employing molecular dynamics (MD) simulation technique. The third-generation charge optimized many-body (COMB3) has been used for interatomic potential modeling. The influence of temperature and nanowire diameter on Young’s modulus is investigated. Our simulations exhibit the anisotropic behavior of Young’s modulus as a function of diameter for different crystallographic orientations. Although our results are in good accord with the existing results in [1 0 0] direction, Young’s modulus adds up monotonically with increasing the cross-sectional diameter of nanowire in [0 0 1] direction. It is found that Young’s modulus of the nanowires are lower (higher) than the bulk value for [0 0 1] ([1 0 0]) direction. Furthermore, simulation results also indicate that Young’s modulus of rutile TiO2 nanowire increases as a function of temperature for a given diameter, unexpectedly. The obtained results may be useful in the field of nanotechnology for optimizing mechanical performance to gain specific applications. 相似文献
763.
Wave propagation modeling as a vital tool in seismology can be done via several different numerical methods among them are finite-difference, finite-element, and spectral-element methods (FDM, FEM and SEM). Some advanced applications in seismic exploration benefit the frequency domain modeling. Regarding flexibility in complex geological models and dealing with the free surface boundary condition, we studied the frequency domain acoustic wave equation using FEM and SEM. The results demonstrated that the frequency domain FEM and SEM have a good accuracy and numerical efficiency with the second order interpolation polynomials. Furthermore, we developed the second order Clayton and Engquist absorbing boundary condition (CE-ABC2) and compared it with the perfectly matched layer (PML) for the frequency domain FEM and SEM. In spite of PML method, CE-ABC2 does not add any additional computational cost to the modeling except assembling boundary matrices. As a result, considering CE-ABC2 is more efficient than PML for the frequency domain acoustic wave propagation modeling especially when computational cost is high and high-level absorbing performance is unnecessary. 相似文献
764.
Hongwei Ge Kui Zhang Huan Yu Ji Yue Long Yu Xinfeng Chen Tianxin Hou Khalid A. Alamry Hadi M. Marwani Suhua Wang 《Journal of fluorescence》2018,28(6):1405-1412
This paper reported a dual-mode probe for D-penicillamine on the basis of pH-mediated gold nanoparticles aggregation and fluorescence resonance energy transfer (FRET) from carbon dots. D-penicillamine is a zwitterionic compound and has different forms depending on specific pH ranges. The thiol group of D-penicillamine has high affinity towards the surface of gold nanoparticles and can replace other surface ligands. When pH values were close to its isoelectrical point (pH(I)), the D-penicillamine capped gold nanoparticles aggregated through hydrogen bonding or electrostatic interactions, resulting in the releasing of carbon dots from gold nanoparticles. The dual-mode probe consisted of fluorescent carbon dots and gold nanoparticles, and the fluorescence of carbon dots was quenched by the attached gold nanoparticles due to the FRET. Then, the fluorescence can be recovered in presence of D-penicillamine due to the gold nanoparticles aggregation in specific pH range. Under the optimum conditions, the probe has linear response for D-penicillamine in the 0.25–1.5 μM concentration range with a detection limit of 0.085 μM. This method provides a potential application in sensitive detection of D-penicillamine. 相似文献
765.
Abdollah Ardebili Mohammad Hassan Pouriayevali Sahar Aleshikh Marziyeh Zahani Mehdi Ajorloo Ahdieh Izanloo Abolghasem Siyadatpanah Hadi Razavi Nikoo Polrat Wilairatana Henrique Douglas Melo Coutinho 《Molecules (Basel, Switzerland)》2021,26(22)
The treatment of viral disease has become a medical challenge because of the increasing incidence and prevalence of human viral pathogens, as well as the lack of viable treatment alternatives, including plant-derived strategies. This review attempts to investigate the trends of research on in vitro antiviral effects of curcumin against different classes of human viral pathogens worldwide. Various electronic databases, including PubMed, Scopus, Web of Science, and Google Scholar were searched for published English articles evaluating the anti-viral activity of curcumin. Data were then extracted and analyzed. The forty-three studies (published from 1993 to 2020) that were identified contain data for 24 different viruses. The 50% cytotoxic concentration (CC50), 50% effective/inhibitory concentration (EC50/IC50), and stimulation index (SI) parameters showed that curcumin had antiviral activity against viruses causing diseases in humans. Data presented in this review highlight the potential antiviral applications of curcumin and open new avenues for further experiments on the clinical applications of curcumin and its derivatives. 相似文献
766.
767.
控制反应条件如表面活性剂的组成、加入量或反应时间,可以制得不同形态、相结构且具有上转换发光(UCL)的氟钪纳米晶(NCs)。改变表面活性剂油酸(OA)/油胺(OM)的比例有利于晶体结构从立方相ScF_3∶Yb,Er转变为具有上转换发光性能增强的正交相KSc_2F_7∶Yb,Er纳米晶,而纳米晶的形态会发生从小到大的转变。改变掺杂元素的种类及含量,在980 nm光激发下,KSc_2F_7纳米晶的上转换发光可以从蓝色变到白色,再到主要发射紫色光。 相似文献