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排序方式: 共有139条查询结果,搜索用时 484 毫秒
101.
102.
Sadik Elshani Pete Apgar Shaofen Wang C. M. Wai 《Journal of heterocyclic chemistry》1994,31(5):1271-1274
A series of new macrocyclic compounds containing one and two proton-ionizable triazole subcyclic units have been prepared and characterized. These triazolo-crowns containing benzo, tert-butylbenzo or cyclohexano lipophilic groups show varying solubilities in chloroform. The bistriazolo-crowns dissolved in chloroform are highly effective for extraction of lead, mercury, and gold from aqueous solutions. 相似文献
103.
Sadik Elshani Hong‐Sik Hwang Michael J. Pugia Jan Krzykawski Richard A. Bartsch 《Journal of heterocyclic chemistry》2003,40(3):443-450
Synthetic routes to twenty‐six new crown ether compounds with pendent amine, amide, O‐benzylhydrox‐amate, and urethane groups are reported. The new lariat ether compounds are based on sym‐dibenzo‐16‐crown‐5, sym‐dicyclohexano‐16‐crown‐5, and 14‐crown‐4 scaffolds. 相似文献
104.
In this paper, we formulate a nonlinear elasticity theory in which the ambient space is evolving. For a continuum moving in an evolving ambient space, we model time dependency of the metric by a time-dependent embedding of the ambient space in a larger manifold with a fixed background metric. We derive both the tangential and the normal governing equations. We then reduce the standard energy balance written in the larger ambient space to that in the evolving ambient space. We consider quasi-static deformations of the ambient space and show that a quasi-static deformation of the ambient space results in stresses, in general. We linearize the nonlinear theory about a reference motion and show that variation of the spatial metric corresponds to an effective field of body forces. 相似文献
105.
Terbium sensitized luminescence for the determination of fexofenadine in pharmaceutical formulations
Salma M.Z. Al-Kindy Khadija Al-Shamalani FakhrEldin O. Suliman Haidar A.J. Al-Lawati 《Arabian Journal of Chemistry》2019,12(8):2457-2463
A sensitive and specific luminescence method for the determination of Fexofenadine (FEX), in pharmaceutical formulations is reported. The method is based on the sensitization of terbium (Tb3+) by complex formation with FEX. The luminescence signal for Tb–FEX complex is greatly enhanced by the addition of triethylamine (ET3N) and zinc nitrate in methanol solution. Monitoring of the signal is accomplished when the instrument is in the phosphorescence mode with the excitation and emission wavelengths set at λex = 220 nm and λem = 550 nm respectively. Optimum conditions for the formation of the complex in methanol were 2.25 × 10?6 M of Tb3+, 5.00 × 10?6 M of Et3N and Zn2+ which allows for the determination of 10–800 ppb of FEX in the batch mode with a detection limit of 0.3 ppb. The proposed method was successfully applied for the determination of FEX in pharmaceutical formulations. 相似文献
106.
Marwa Enneffati Nadia Khadija Maaloul Bassem Louati Kamel Guidara Kamel Khirouni 《Optical and Quantum Electronics》2017,49(10):331
In this paper, NaCdPO4 orthophosphate was prepared by solid-state reaction technique at high temperature. Structural, vibrational and optical properties have been investigated. X-ray powder diffraction analysis revealed that the titled compound crystallizes in the orthorhombic system with Pmnb space group. Vibrational study by means of Raman and FTIR spectroscopies confirms the existence of the (PO4)3? functional group. Optical properties were recorded at room temperature using UV–visible spectroscopy in the spectral range (200–800) nm. The UV–Vis absorption bands are attributed to the charge transfer from the oxygen ligands to the central phosphate atom inside the PO4 3? groups. The optical absorbance was measured also to determinate the optical band gap using Kubelka–Munk function. The dispersion parameters (E0 and Ed) of this compound were estimated using the Wemple Di-Domenico model. 相似文献
107.
Ayoub Lafnoune Su-Yeon Lee Jin-Yeong Heo Khadija Daoudi Bouchra Darkaoui Salma Chakir Rachida Cadi Khadija Mounaji David Shum Haeng-Ran Seo Naoual Oukkache 《Molecules (Basel, Switzerland)》2022,27(7)
Hepatocellular carcinoma (HCC) is the most dominant primary liver cancer, which can be caused by chronic hepatitis virus infections and other environmental factors. Resection, liver transplantation, and local ablation are only a few of the highly effective and curative procedures presently accessible. However, other complementary treatments can reduce cancer treatment side effects. In this present work, we evaluated the activity of Moroccan scorpion venom Buthus occitanus and its fractions obtained by chromatography gel filtration against HCC cells using a 3D cell culture model. The venom was fractionated by gel filtration chromatography, each fraction and the crude venom was tested on normal hepatocytes (Fa2N-4 cells). Additionally, the fractions and the crude venom were tested on MCTSs (multicellular tumor spheroids), and this latter was generated by cultivate Huh7.5 cancer cell line with WI38 cells, LX2 cells, and human endothelial cells (HUVEC). Our results indicate that Buthus occitanus venom toxin has no cytotoxic effects on normal hepatocytes. Moreover, it is reported that F3 fraction could significantly inhibit the MCTS cells. Other Protein Separation Techniques (High-performance liquid chromatography) are needed in order to identify the most active molecule. 相似文献
108.
Tamim Rkia Mahdouk Kamal Otmani Samira Achgar Khadija 《Journal of Thermal Analysis and Calorimetry》2020,139(2):953-961
Journal of Thermal Analysis and Calorimetry - Phase relationships in the Al–Re binary system have been thermodynamically reassessed by using the CALPHAD technique to take into account the... 相似文献
109.
Touayba Ahl el haj El Mejdoubi Khalid Sadraoui Khadija Brahim Chafik El idrissi Sallek Brahim 《Kinetics and Catalysis》2022,63(6):707-715
Kinetics and Catalysis - Our work is around the heterogeneous catalysts based on phosphate. This is all the more important as Morocco has a significant wealth of world reserves of this mineral.... 相似文献
110.
Kandula Madhu Kumar Reddy Shaik Mahammad Sadik Kotha Peddanna Nemallapudi Bakthavatchala Reddy Gundala Sravya Zyryanov Grigory V 《Phosphorus, sulfur, and silicon and the related elements》2018,193(5):329-334
The synthesis of new α-aminophosphonates 4a-j (diethyl((dialkoxyphosphoryl)(phenyl)methyl)phosphoramidates) were achieved through a one pot simple and efficient method from the three-component condensation reaction (Kabachnik-Fields reaction) of diethyl phosphoramidate, aryl salicylaldehydes, and dialkyl phosphite by using microwave irradiation under solvent-free and catalyst-free conditions in good to excellent yields and short reaction times. The structures of the novel products were established by IR, 1H, 13C & 31P-NMR and Mass spectroscopy. All the synthesized compounds were screened their antimicrobial activity. 相似文献