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11.
Septic spline is used for the numerical solution of the sixth-order linear, special case boundary value problem. End conditions for the definition of septic spline are derived, consistent with the sixth-order boundary value problem. The algorithm developed approximates the solution and their higher-order derivatives. The method has also been proved to be second-order convergent. Three examples are considered for the numerical illustrations of the method developed. The method developed in this paper is also compared with that developed in [M. El-Gamel, J.R. Cannon, J. Latour, A.I. Zayed, Sinc-Galerkin method for solving linear sixth order boundary-value problems, Mathematics of Computation 73, 247 (2003) 1325–1343], as well and is observed to be better. 相似文献
12.
M. M. Eid M. A. Badawy M. A. H. Ghazala Yehia A. Ibrahim 《Journal of heterocyclic chemistry》1983,20(6):1709-1711
Synthesis of several derivatives of thieno[2,3-e]-1,2,4-triazines has been achieved via the action of phosphorus pentasulfide on 6-vinyl- or 6-acylmethyl-5-oxo-1,2,4-triazine derivatives. During these investigations interesting synthetically useful functions for phosphorus pentasulfide in pyridine were observed, among which the deamination of certain N-amino heterocycles is unprecedented. 相似文献
13.
Subuhi Khan Mustafa Walid Al-Saad Ghazala Yasmin 《Applied mathematics and computation》2010,217(5):2169-2183
In this paper, the concepts and the formalism associated with monomiality principle and Sheffer sequences are used to introduce family of Hermite-based Sheffer polynomials. Some properties of Hermite-Sheffer polynomials are considered. Further, an operational formalism providing a correspondence between Sheffer and Hermite-Sheffer polynomials is developed. Furthermore, this correspondence is used to derive several new identities and results for members of Hermite-Sheffer family. 相似文献
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Self-phase modulation signatures of neuronal activity 总被引:1,自引:0,他引:1
Fischer MC Liu HC Piletic IR Escobedo-Lozoya Y Yasuda R Warren WS 《Optics letters》2008,33(3):219-221
We use phase-sensitive detection of spectral hole refilling to demonstrate strong novel intrinsic nonlinear signatures of neuronal activation in hippocampal brain slices. The ability to gain access to this fundamentally new intrinsic contrast with modest power levels suggests a new approach to in vivo neural imaging. We expect that we can extrapolate our method to high spatial and temporal resolution in deep tissue while retaining the noninvasive character. 相似文献
16.
Novel Schiff base ligand based on the condensation of 4,6-diacetyl resorcinol with 2-amino-4-methylthiazole in addition to its metal complexes with Cr (III), Mn (II), Fe (III), Co (II), Ni (II), Cu (II), Zn (II) and Cd (II) ions have been synthesized. The structure, electronic properties, and thermal behaviour of Schiff base and its metal complexes have been studied by elemental analysis, mass, 1H NMR, IR spectra, thermal analysis, and theoretically by density function theory. The ligand acted as mononegative bidentate (NO) ligand and all complexes showed octahedral geometry except Cu (II) showed tetrahedral geometry as indicated from the spectral and magnetic studies. The Cu (II), Zn (II) and Cd (II) complexes were non electrolytes while the rest of the complexes were electrolytes. The antibacterial plus anticancer activities of the parent Schiff base and its metal complexes were screened. In addition, the molecular docking study was performed to explore the possible ways for binding to Crystal Structure of Human Astrovirus capsid protein (5ibv) receptor. 相似文献
17.
Ghazala Riaz Amtul Bari Tabinda Adeel Mahmood Mehvish Mumtaz Abdul Qadir 《Analytical letters》2018,51(8):1245-1263
The current study assessed the spatiotemporal variations and human health surveillance associated with organochlorine pesticide (OCP) contamination in water, sediments, and fish from Chenab River, Pakistan. The OCP determinations were performed using high-performance liquid chromatography with a reverse-phase C18 column. The total OCP levels ranged from 13.33 to 274.59?ng/L in water, 4.63 to 239.11?ng/g in sediments, and 23.79 to 387.12?ng/g in fish species. The overall pattern of mean OCP concentrations followed the order as ΣDDTs?>?Σendosulfan?>?aldrin and OCP pollution pattern among the headworks were Khanki Barrage?>?Qadirabad Barrage?>?Trimmu Barrage?>?Marala Barrage in all three environmental matrixes during both seasons. The estimated daily intake (EDI) for ∑OCPs was found to be 22.44?ng/kg/day. The hazard ratios calculated to assess the carcinogenic risk indicated that the values for ∑DDT and aldrin at the 95th percentile concentrations were greater than one, indicating the probability of carcinogenic risk occurrence of one in million populations due to fish consumption. Therefore, these high levels of OCPs and carcinogenic risk through fish consumption highlight the needs of immediate elimination of OCPs from riverine environment of Chenab River and we recommend long-term monitoring-based freshwater ecological studies to be conducted in the study area. 相似文献
18.
We report a simple and highly stereocontrolled strategy toward the total synthesis of isoprostanes based on a bicyclic alpha,beta-epoxy ketone intermediate 6. Bicyclo[3.3.0]octene scaffold permitted stereodirection of reagents allowing stereoselective epoxidation, diastereoselective ketone reduction, and regioselective epoxide opening otherwise not accessible with a simple cyclopentene framework. 相似文献
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Study of the Degradation Kinetics of Carvedilol by Use of a Validated Stability-Indicating LC Method
Mohammad Rizwan Mohammed Aqil Adnan Azeem Yasmin Sultana Sushama Talegaonkar Asgar Ali 《Chromatographia》2009,70(7-8):1283-1286
The objectives of this investigation were to establish a validated stability-indicating LC method for assay of carvedilol and to study the degradation behaviour of the drug under different ICH-recommended stress conditions. Chromatographic separation was achieved on a C18 column with 55:45 (%, v/v) acetonitrile–0.02 m phosphate buffer, pH 3.5, as mobile phase at a flow rate of 1.0 mL min?1; detection was by UV absorbance at 242 nm. The method was validated for linearity, precision, accuracy, robustness, specificity, and sensitivity, with the bulk drug. The drug was subjected to forced degradation and peaks of all the degradation products were well resolved from that of the pure drug, with significantly different retention times, which indicates the specificity and stability-indicating properties of the method. First-order degradation kinetics of carvedilol were observed under acidic and alkaline conditions. When the utility of the method was verified by analysis of the drug in marketed tablets and a nano-emulsion formulation, the assay was found to be 98.60–99.61 and 99.52–99.87, respectively. These results indicate the method can be successfully used for routine analysis of carvedilol in the bulk drug and in pharmaceutical dosage forms. 相似文献