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81.
Ahmad Khalid Raza Khan Suhail Ahmad Khan Sunil Mishra Tajuddin Khan Mohiuddin Ansari Badshah Hasan Khan 《International journal of quantum chemistry》2012,112(11):2371-2377
The quantitative structure activity relationship models of 22 testosterone derivatives have been made with the help of topological and quantum chemical parameters. The molecular modeling and geometry optimization have been carried out with CAChe Pro software. The calculations of topological and quantum chemical parameters have been done by MOPAC 2007. The statistical parameters are calculated by STATISTICA and SSP software. The study indicates that the topological parameters better predict the receptor binding affinity of testosterone derivatives, whereas quantum chemical parameters better predict androgenic potency of testosterone derivatives as indicated by correlation coefficient, standard error, standard error of estimation, p value, t value, and degree of freedom of the quantitative structure activity relationship (QSAR) models. The predicted activity values obtained by these QSAR models are close to observed activity. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 相似文献
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Raza M. A. Amin M. Muhammad G. Rashid A. Adnan A. 《Russian Journal of General Chemistry》2017,87(11):2678-2683
Russian Journal of General Chemistry - Herein we present the study of synthesis of novel bio-organometallic conjugates using 1,3-dipolar cycloaddition click reactions. Amino acid azides such as... 相似文献
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Muhammad Asad Anam Zulfiqar Rizwan Raza Minghui Yang Akhtar Hayat Naeem Akhtar 《Electroanalysis》2020,32(1):11-18
A novel electrode based on orange peel derived C‐dots decorated CuO nanorods (CR@C‐dot) modified lead pencil (LP) electrode has been fabricated for highly sensitive and selective monitoring of dopamine (DA). Prior to the functionalization with C‐dot, electrochemical efficacy of CR was evaluated and compared with CuO nano‐needles (CN) and nano‐spheres (CS). The morphology, surface area and composition of synthesized nanoparticles was confirmed through field emission scanning electron microscopy (FE‐SEM), N2‐adsorption‐desorption isotherm, X‐ray diffraction (XRD), Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS). Our results indicated that CR has high electrocatalytic activity compared to CN and CS by expositing greater fraction of catalytic active sites, large surface area and short diffusion pathways. The electrochemical efficacy of CR is further enhanced by decorating with orange peel derived C‐dots, which surprisingly lead to the integrations of surface‐active sites with current collectors with minimum resistance by acting as an electron transport mediator and providing more surface defects. The developed CR@C‐dot sensor enables highly sensitive and selective recognition of DA detection (0.0007 μM), over good linear range (5–2250 μM) with rapid response time. the developed CR@C‐dot sensor was successfully used to monitor the DA from deboned chicken, thus suggesting reliability of the developed electrode. 相似文献
87.
Syed Abdul Wadood Guo Boli Zhang Xiaowen Ali Raza Wei Yimin 《Journal of mass spectrometry : JMS》2020,55(1)
This study aimed to develop a potential analytical method to discriminate the Chinese winter wheat according to geographical origin and cultivars. A total of 90 wheat samples of 10 different wheat cultivars among three regions were examined by headspace solid phase microextraction coupled with gas chromatography‐mass spectrometry (GC‐MS). The peak areas of 32 main volatile compounds were selected and subjected to statistical analysis, which revealed significant differences among different regions and cultivars. Multivariate analysis of variance showed a significant influence of regions, wheat genotypes, and their interaction on the volatile composition of wheat. Principal component analysis of the aromatic profile showed better visualization for wheat geographical origins. Finally, a classification model based on the linear discriminant analysis was successfully constructed for the discrimination of regions and cultivars with the correct classification percentages of 90 and 100%, respectively. 相似文献
88.
Synthesis and surface engineering of magnetic nanoparticles for environmental cleanup and pesticide residue analysis: A review
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Ranjeet Kaur Abshar Hasan Nusrat Iqbal Samsul Alam Mahesh Kr Saini Syed Kalbe Raza 《Journal of separation science》2014,37(14):1805-1825
In recent years, water pollution and pesticide accumulation in the food chain have become a serious environmental and health hazard problem. Direct determination of these contaminants is a difficult task due to their low concentration level and the matrix interferences. Therefore, an efficient separation and preconcentration procedure is often required prior to the analysis. With the advancement in nanotechnology, various types of magnetic core–shell nanoparticles have successfully been synthesized and received considerable attention as sorbents for decontamination of diverse matrices. Magnetic core–shell nanoparticles with surface modifications have the advantages of large surface‐area‐to‐volume ratio, high number of surface active sites, no secondary pollutant, and high magnetic properties. Due to their physicochemical properties, surface‐modified magnetic core–shell nanoparticles exhibit high adsorption efficiency, high rate of removal of contaminants, and easy as well as rapid separation of adsorbent from solution via external magnetic field. Such facile separation is essential to improve the operation efficiency. In addition, reuse of nanoparticles would substantially reduce the treatment cost. In this review article, we have attempted to summarize recent studies that address the preconcentration methods of pesticide residue analysis and removal of toxic contaminants from aquatic systems using magnetic core–shell nanoparticles as adsorbents. 相似文献
89.
A. Gargaro F. De Luca E. De Vita G. H. Raza B. Maraviglia 《Colloids and surfaces. A, Physicochemical and engineering aspects》1998,140(1-3):321-324
A T1ρ filter for the NMR imaging of solid polymers is presented. T1ρ is the relaxation time in the rotating frame, which is sensitive to the molecular motion and whose spectral density falls in the range of slow dynamics, namely motion characterized by correlation times ranging between 10−2 and 10−5 s. The method allows one to obtain a good spatial resolution without the need of strong field gradients and without the effects related to the spatial encoding manipulation of the spin system. 相似文献
90.
Raza A. Tahir-Kheli 《Solid State Communications》1976,19(12):1213-1215
We construct a simple CPA for studying ferromagnets which simultaneously possess site and (isotropic) exchange bond disorders. We use the theory to study spin-wave stiffness in diluted ferromagnet with exchange amorphousness and analyze the structure of the interfaces between ferromagnetic, spin-glass and paramagnetic phases of such a system. 相似文献