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661.
Rabin Neupane Saloni Malla Mariam Sami Abou-Dahech Swapnaa Balaji Shikha Kumari Digambar Kumar Waiker N. S. Hari Narayana Moorthy Piyush Trivedi Charles R. Ashby Jr. Chandrabose Karthikeyan Amit K. Tiwari 《Molecules (Basel, Switzerland)》2021,26(15)
A novel series of 4-anilinoquinazoline analogues, DW (1–10), were evaluated for anticancer efficacy in human breast cancer (BT-20) and human colorectal cancer (CRC) cell lines (HCT116, HT29, and SW620). The compound, DW-8, had the highest anticancer efficacy and selectivity in the colorectal cancer cell lines, HCT116, HT29, and SW620, with IC50 values of 8.50 ± 2.53 µM, 5.80 ± 0.92 µM, and 6.15 ± 0.37 µM, respectively, compared to the non-cancerous colon cell line, CRL1459, with an IC50 of 14.05 ± 0.37 µM. The selectivity index of DW-8 was >2-fold in colon cancer cells incubated with vehicle. We further determined the mechanisms of cell death induced by DW-8 in SW620 CRC cancer cells. DW-8 (10 and 30 µM) induced apoptosis by (1) producing cell cycle arrest at the G2 phase; (2) activating the intrinsic apoptotic pathway, as indicated by the activation of caspase-9 and the executioner caspases-3 and 7; (3) nuclear fragmentation and (4) increasing the levels of reactive oxygen species (ROS). Overall, our results suggest that DW-8 may represent a suitable lead for developing novel compounds to treat CRC. 相似文献
662.
We report the diffusion coefficient and viscosity of popular rigid water models: two non-polarizable ones (SPC/E with three sites, and TIP4P/2005 with four sites) and a polarizable one (Dang-Chang, four sites). We exploit the dependence of the diffusion coefficient on the system size (Yeh and Hummer 2004 J. Phys. Chem. B 108 15873) to obtain the size-independent value. This also provides an estimate of the viscosity of all water models, which we compare to the Green-Kubo result. In all cases, a good agreement is found. The TIP4P/2005 model is in better agreement with the experimental data for both diffusion and viscosity. The SPC/E and Dang-Chang models overestimate the diffusion coefficient and underestimate the viscosity. 相似文献
663.
We describe a low-temperature thermodynamic model for dynamic nuclear polarization (DNP) via continuous-wave partial saturation of electron spin resonance (ESR) lines that are both homogeneously and inhomogeneously broadened. It is a variant of a reasoning proposed by Borghini, which in turn used Redfield’s thermodynamic treatment of saturation. Our variant is furthermore based on Provotorov’s insight that under partial saturation of a coupled-spin system two distinct spin temperatures should appear in a thermodynamical theory. We apply our model to DNP results obtained at a temperature of 1.2?K and in magnetic fields of 3.35 and 5?T on 1-13C labeled sodium acetate dissolved in a frozen D2O/ethanol-d6 solution doped with the free radical TEMPO. 相似文献
664.
This paper gives three principal results: One, population pulsations are responsible for both the multiwavelength and the chaotic single-wavelength instabilities of single-mode operation in unidirectional ring lasers containing homogeneously-broadened media. Two, in appropriate limits the Fourier expansion method for treating three-frequency operation in saturation spectroscopy is equivalent to the linear stability analyses in laser theory and optical bistability. Three, inclusion of population pulsations significantly increases the instability range over that predicted by Casperson for single-mode bad-cavity lasers containing inhomogeneously-broadened media. 相似文献
665.
A series of model complexes for the type III site, in oxidised hemocyanin, containing Cu2(μ-0Ph)3+ core have been synthesised using a heptadentate ligand (H3L) formed from the Schiff base condensation of triethylenetetramine and salicylaldehyde. The ligand provides one imine and
one inbuilt imidazole nitrogen and two phenolic oxygen donors with both five- and six-membered chelate rings to each metal
centre. In the pentacoordinated complexes [Cu2(L)X]·nH2O, a third exogenous bridging ligand is present. The TG curve indicates the loss of lattice water molecules between 70 and
125°C. The residue after decomposition is CuO above 550°C. Theg values of theX-band EPR spectrum of [Cu2L(μ-OAc)]·2H2O in methanol glass (77 K) are typical of a variety of bridged copper(II) dimers. The copper-copper magnetic interaction is
dependent on the presence and nature of X in these complexes. 相似文献
666.
Laser-induced thermal stresses on steel surface 总被引:1,自引:0,他引:1
Bekir Sami Yilbas Muhammad Sami Shahzada Zaman Shuja 《Optics and Lasers in Engineering》1998,30(1):25-37
In laser heat treatment of steels, a thin surface layer of austenite forms during heating and subsequent phase change process in the cooling period. However, thermal stress develops due to high-temperature gradient attainment in the surface vicinity which in turn results in microcrack development at the surface. The present study is carried out to compute the temperature profiles due to step input pulse laser radiation and determine the resulting thermal stresses. The study is extended to include three-step input pulses having the same energy content. This provides the comparison for the influence of the pulse length on the resulting thermal stresses. To validate the theoretical predictions, an experiment is conducted to irradiate the AISI 4142 steel surface by an Nd–YAG laser. Microphotography and EDS analysis of the heated regions are carried out. It is found that considerable thermal stress is eveloped at the workpiece surface due to attainment of high-temperature gradient in this region. In addition, microcracks are observed at the surface of the irradiated spot. 相似文献
667.
Sami M. Al-Jaber 《International Journal of Theoretical Physics》1998,37(4):1289-1298
Some aspects of the N-dimensional hydrogen atomare discussed. The complete solution for the energyeigenfunctions is presented and the radial distributionfunction is examined. Degeneracy of energy levels, expectation values (<1/r> and<1/r2>), and the virial theorem areconsidered. It is shown that the effect of the effectivepotential manifests itself in some of the aspects beinginvestigated. 相似文献
668.
This work describes the development of a method for analyzing pesticide residues in olive oil by GC-MS and HPLC-MS. Pesticides were separated from the oily matrix by size-exclusion chromatography. After extraction, 20 pesticides were separated and analyzed by GC-MS and 11 others HPLC-MS in electrospray mode. The development of this method enabled us to identify and quantify the pesticides of interest. 相似文献
669.
Ahmad S. Shawali M. Sami S. Mourad Sherif Cyril Prknyi 《Journal of heterocyclic chemistry》1980,17(5):877-880
α-Aroyl-N-arylhydrazidoyl bromides 1 react with 2-aminopyridine in ethanol and give 2-aryl-3-arylazo-imidazo[1,2-α]pyridines 2 in 60-75% yield. The reaction of 1 with 3-phenyl-5-aminopyrazole in ethanol leads to 2,6-diaryl-3-arylazo-1H-pyrazolo[1,5-b]imidazoles 3 in almost quantitative yield. Also, 1 react with anthran-ilic acid in the presence of triethylamine giving 3-arylamino-2-aroyl-4-(3H)quinazolinones 4 in 80-85% yield. The structures of the products were assigned and confirmed on the basis of their elemental analysis and electronic absorption, infrared and nmr spectra. 相似文献
670.
Salon MC Abdelmouleh M Boufi S Belgacem MN Gandini A 《Journal of colloid and interface science》2005,289(1):249-261
The hydrolysis of three alkoxysilane coupling agents, gamma-methacryloxypropyltrimethoxysilane (MPS), gamma-aminopropyltriethoxysilane (APS), and gamma-diethylenetriaminopropyltrimethoxysilane (TAS), was carried out in an ethanol/water (80/20) solution and followed by 1H, 13C, and 29Si NMR spectroscopy, which showed that its rate increased in the order MPS < APS < TAS. The formation of the silanol groups was followed by their self-condensation to generate oligomeric structure. APS and MPS only gave soluble products, whereas colloidal particles precipitated in the medium when TAS was hydrolyzed. Pristine and hydrolyzed MPS were then adsorbed onto a cellulose substrate and thereafter a thermal treatment at 110-120 degrees C under reduced pressure was applied to the modified fibers to create permanent bonding of the coupling agent at their surface. 相似文献