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Khoja Asif Hussain Anwar Mustafa Shakir Sehar Mehran Muhammad Taqi Mazhar Arslan Javed Adeel Amin Nor Aishah Saidina 《Research on Chemical Intermediates》2020,46(8):3817-3833
Research on Chemical Intermediates - The excess emission of greenhouse gases (GHGs) such as CO2 and CH4 is posing an acute threat to the environment, and efficient ways are being sought to utilize... 相似文献
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Habib Aqsa Iqbal Muhammad Adnan Bhatti Haq Nawaz Shahid Muhammad 《Transition Metal Chemistry》2019,44(5):431-443
Transition Metal Chemistry - A series of bidendate 5,6-dimethyl benzimidazolium-based N-heterocyclic carbene (NHC) proligands and their silver complexes were synthesized. The synthetic approaches... 相似文献
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Aqsa Habib Mansoureh Nazari V. Muhammad Adnan Iqbal Haq Nawaz Bhatti M.B. Khadeer Ahmed A.M.S. Abdul Majid 《Journal of Saudi Chemical Society》2019,23(7):795-808
The promising biomedical applications of silver complexes stimulated the researchers to test these compounds against cancer. The present research work was designed to achieve this goal. In this work, a series of 5-methyl benzimidazole based N-Heterocyclic carbene ligands and respective silver(I) complexes were synthesized and tested on cancer cell lines to assess their anticancer activity. Unsymmetrically substituted benzimidazole was found unique in its reactivity and generation of a single product during NHC ligand formation was only possible after two successive alkylations with same alkyl halide. The corresponding Ag(I)-NHC adducts were obtained by in situ deprotonation of the NHC ligands. Synthesized compounds were characterized by various physcio-chemical and spectroscopic methods. Single crystal X-ray diffraction study of complex 7 revealed its mononuclear structure. Preliminary in vitro anticancer study of azolium salts and respective Ag(I)-NHC complexes against human breast cancer (MDA-MB-231), colon cancer (HCT-116) and normal endothelial cells (EA.hy926) cells revealed that all the compounds are more cytotoxic to cancer cells than normal cells and the complexes are relatively more potent compared to the corresponding NHC ligands. It was found that increased chain length and presence of methyl substituent on benzimidazole ring enhance the biopotency of Ag(I)-NHC complexes. The synthesized compounds were further studied for pro-apoptotic mechanism of action via Rhodamine 123 test. The tested compounds were found to induce apoptosis via extrinsic mitochondrial pathway. 相似文献
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Effect on Landau damping rates for non-Maxwellian distribution function consisting of two electron populations 下载免费PDF全文
In many physical situations where a laser or electron beam passes through a dense plasma, hot low-density electron populations can be generated, resulting in a particle distribution function consisting of a dense cold population and a small hot population. Presence of such low-density electron distributions can alter the wave damping rate. Kinetic model is employed to study the Landau damping of Langmuir waves when a small hot electron population is present in the dense cold electron population with non-Maxwellian distribution functions. Departure of plasma from Maxwellian distributions significantly alters the damping rates as compared to the Maxwellian plasma. Strong damping is found for highly non-Maxwellian distributions as well as plasmas with higher dense and hot electron population. Existence of weak damping is also established when the distribution contains broadened flat tops at the low energies or tends to be Maxwellian. These results may be applied in both experimental and space physics regimes. 相似文献
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Zahoor Qadir Samra Sadaf Shabir Zainab Rehmat Mariam Zaman Aqsa Nazir Nadia Dar Muhammad Amin Athar 《Applied biochemistry and biotechnology》2010,162(3):671-686
Human serum paraoxonase 1 (PON1) is known as an antioxidant and is also involved in the detoxification of many compounds.
In this study, a novel purification strategy was employed to purify the PON1 by using cholesterol-conjugated magnetic nanoparticles.
Magnetic nanoparticles were synthesized and conjugated with cholesterol through diazotized p-aminohippuric acid. In Fourier transform infrared spectrum of cholesterol-p-aminohippuric acid-Fe3O4 nanoparticles, the appearance of peaks at 3,358.3, 1,645 cm−1, and at 2,334.9 cm−1 confirmed the conjugation. The molecular weight of purified PON1 was nearly 45 kDa on sodium dodecyl sulfate (SDS)–polyacrylamide
gel electrophoresis (PAGE), and isoelectric point was 5.3. The specific activity was 438 U mg−1 protein, and the purification fold was 515 with 73% yield. The K
m values were 1.3 and 0.74 mM with paraoxon and phenyl acetate, respectively. Western blot of 2D-PAGE confirmed the homogeneity
and stability of the enzyme. Mg+2, Mn+2, glycerol, (NH4)2SO4, PEG 6000, Triton X-100, and phenylmethylsulfonyl fluoride did not show any effect on activity. Pb+2, Co+2, Zn2+, ethanol, β-mercaptoethanol, and acetone reduced the activity while Ni2+, Cd2+, Cu2+, iodoacetic acid, SDS, dimethylformamide, DMSO inhibited the activity. In vitro enzyme activity was slightly reduced by acetyl
salicylic and acetaminophen and reduced 50% with amino glycosides and ampicillin antibiotics at concentrations of 0.6 and
30 mg ml−1, respectively. This is the first report for the synthesis of cholesterol-conjugated magnetic nanoparticles for simple purification
of PON1 enzyme. 相似文献
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Effect on Landau damping rates for a non-Maxwellian distribution function consisting of two electron populations 下载免费PDF全文
In many physical situations where a laser or electron beam passes through a dense plasma,hot low-density electron populations can be generated,resulting in a particle distribution function consisting of a dense cold population and a small hot population.Presence of such low-density electron distributions can alter the wave damping rate.A kinetic model is employed to study the Landau damping of Langmuir waves when a small hot electron population is present in the dense cold electron population with non-Maxwellian distribution functions.Departure of plasma from Maxwellian distributions significantly alters the damping rates as compared to the Maxwellian plasma.Strong damping is found for highly nonMaxwellian distributions as well as plasmas with a higher density and hot electron population.Existence of weak damping is also established when the distribution contains broadened flat tops at the low energies or tends to be Maxwellian.These results may be applied in both experimental and space physics regimes. 相似文献
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Sumera Zaib Rubina Munir Muhammad Tayyab Younas Naghmana Kausar Aliya Ibrar Sehar Aqsa Noorma Shahid Tahira Tasneem Asif Hashem O. Alsaab Imtiaz Khan 《Molecules (Basel, Switzerland)》2021,26(21)
Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of dementia worldwide. The limited pharmacological approaches based on cholinesterase inhibitors only provide symptomatic relief to AD patients. Moreover, the adverse side effects such as nausea, vomiting, loss of appetite, muscle cramps, and headaches associated with these drugs and numerous clinical trial failures present substantial limitations on the use of medications and call for a detailed insight of disease heterogeneity and development of preventive and multifactorial therapeutic strategies on urgent basis. In this context, we herein report a series of quinoline-thiosemicarbazone hybrid therapeutics as selective and potent inhibitors of cholinesterases. A facile multistep synthetic approach was utilized to generate target structures bearing multiple sites for chemical modifications and establishing drug-receptor interactions. The structures of all the synthesized compounds were fully established using readily available spectroscopic techniques (FTIR, 1H- and 13C-NMR). In vitro inhibitory results revealed compound 5b as a promising and lead inhibitor with an IC50 value of 0.12 ± 0.02 μM, a 5-fold higher potency than standard drug (galantamine; IC50 = 0.62 ± 0.01 μM). The synergistic effect of electron-rich (methoxy) group and ethylmorpholine moiety in quinoline-thiosemicarbazone conjugates contributes significantly in improving the inhibition level. Molecular docking analysis revealed various vital interactions of potent compounds with amino acid residues and reinforced the in vitro results. Kinetics experiments revealed the competitive mode of inhibition while ADME properties favored the translation of identified inhibitors into safe and promising drug candidates for pre-clinical testing. Collectively, inhibitory activity data and results from key physicochemical properties merit further research to ensure the design and development of safe and high-quality drug candidates for Alzheimer’s disease. 相似文献
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Sehar Iqbal Zegeling Paul Andries 《Computational Mathematics and Mathematical Physics》2019,59(12):2057-2079
Computational Mathematics and Mathematical Physics - In this paper, a higher order nonuniform grid strategy is developed for solving singularly perturbed convection-diffusion-reaction problems with... 相似文献