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71.
Sangeeta Kumari Aundrea Roman Arshad Khan 《Journal of polymer science. Part A, Polymer chemistry》1996,34(14):2975-2980
The experimental UV-vis spectrum of the glycogen-iodine (GI) complex shows certain features remarkably similar to that of the amylopectin-iodine (API) complex [J. Polymer. Chem. 32, 2257 (1994)], suggesting a strong similarity between the API and the GI structures. As in the API complex, a nearly linear polyiodine unit, I4, at an interiodine distance of around 3 Å is expected to exist within the helix of 11 anhydroglucose units (AGUs). There are several other spectral features that suggest the presence of another similar but more loosely bound iodine species with a longer interiodine distance of 3.1 Å. These findings suggest the involvement of two different types of glycogen chains in binding iodine molecules. © 1996 John Wiley & Sons, Inc. 相似文献
72.
Muhammad Omer Iqbal Muhammad Masood Ahmed Shafia Arshad Usman Javaid Imran Ahmad Khan Majid Manzoor Shumaila Andleeb Romana Riaz Shaukat Hussain Munawar Zahid Manzoor Asma Mumtaz 《Molecules (Basel, Switzerland)》2022,27(3)
Alhagi camelorum (AC) is an old plant with a significant therapeutic value throughout Africa, Asia, and Latin America. The overuse of cisplatin (Cis > 50 mg/m2) is associated with observed nephrotoxicity, ototoxicity, gastrotoxicity, myelosuppression, and allergic reactions. Remedial measures are needed for the protection of nephrotoxicity against cisplatin. Thus, we investigated the nephroprotective effects of AC plant extract to prevent cisplatin-induced nephrotoxicity in albino Wistar rats. The presence of polyphenols, phenolic compounds, tannins, and saponins was revealed during phytochemical investigation, and a significantly intense antioxidant activity was recorded. There were no toxicological symptoms in the treated rats, and no anatomical, physiological, or histological abnormalities were found compared to the control rats. The results of correcting cisplatin-induced nephrotoxicity revealed that the extract has a significant ability to treat kidney damage, with most parameters returning to normal after only three weeks of therapy. It is concluded that co-administration of cisplatin with AC extract showed exceptional nephroprotective effects at a dose of 600 mg/kg for Cis-induced nephrotoxicity. 相似文献
73.
Danish Muhammad Akhtar Arusa Ashfaq Muhammad Arshad Muhammad Nadeem Asiri Abdullah M. 《Journal of chemical crystallography》2021,51(4):543-552
Journal of Chemical Crystallography - In this paper, we report new sulfonamide derivatives, 4-((2,4-dichlorophenylsulfonamido)methyl)cyclohexanecarboxylic acid (1), ethyl... 相似文献
74.
Dr. Alan E. Enciso Dr. Francesca Lorandi Arshad Mehmood Dr. Marco Fantin Dr. Grzegorz Szczepaniak Prof. Dr. Benjamin G. Janesko Prof. Dr. Krzysztof Matyjaszewski 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):15020-15030
A facile and efficient two-step synthesis of p-substituted tris(2-pyridylmethyl)amine (TPMA) ligands to form Cu complexes with the highest activity to date in atom transfer radical polymerization (ATRP) is presented. In the divergent synthesis, p-Cl substituents in tris(4-chloro-2-pyridylmethyl)amine (TPMA3Cl) were replaced in one step and high yield by electron-donating cyclic amines (pyrrolidine (TPMAPYR), piperidine (TPMAPIP), and morpholine (TPMAMOR)) by nucleophilic aromatic substitution. The [CuII(TPMANR2)Br]+ complexes exhibited larger energy gaps between frontier molecular orbitals and >0.2 V more negative reduction potentials than [CuII(TPMA)Br]+, indicating >3 orders of magnitude higher ATRP activity. [CuI(TPMAPYR)]+ exhibited the highest reported activity for Br-capped acrylate chain ends in DMF, and moderate activity toward C−F bonds at room temperature. ATRP of n-butyl acrylate using only 10–25 part per million loadings of [CuII(TPMANR2)Br]+ exhibited excellent control. 相似文献
75.
M. Arshad A. H. Qureshi K. Masud N. K. Qazi 《Journal of Thermal Analysis and Calorimetry》2007,89(2):595-600
The production of bulk high T
c superconducting phase (2223) by EDTA-gel (ethylenediaminetetraacetic acid) techniques has been investigated. It is shown
that close control of pH is necessary for the production of a well-complexed precursor which allows subsequent decomposition
in two stages at 300 and 800°C. The problem of carbonate formation was investigated experimentally and solved. Precursors
are characterised by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) and the sintering behaviour
was monitored by dilatometry. At least three different phases Bi2Sr2Cax−1CuxO8+y (BSCCO); where x=1, 2, 3 were identified within superconducting pellets using XRD, named as Bi2Sr2CuO7 (2201), Bi2Sr2CaCu2O9 (2212) and Bi2Sr2Ca3O10 (2223). The superconducting properties of the sintered samples were studied by vibrating sample magnetometer (VSM). Transition
to a superconducting state around 80 K appeared in samples (sintered at 845°C) containing the Bi2Sr2Ca1Cu2Oy (2212) phase. Liquid phase sintering of the samples aided the formation of Bi2Sr2Ca2Cu3Ox (2223) phase at high temperature (860°C), which showed a superconducting transition temperature of 108 K. 相似文献
76.
Heather Davis Walter Skrzypek Arshad Khan 《Journal of polymer science. Part A, Polymer chemistry》1994,32(12):2267-2274
The iodine binding capacity (IBC) of amylopectin (AP, from potatoes) is determined to be around 0.38% (w/w) of the total AP in the solution. The mass of iodine bound comprises about 13.6% of the mass of AP involved with the complex, suggesting that with every four iodine atoms bound there are 23 anhydroglucose residues (AGU). Since our previous study indicates that four iodine atoms within the helix of 11 AGUs form a chromophore unit in the API complex, only 48% of the AGUs (11 out of 23) in the AP molecule are directly involved with the iodine. The heat of reaction for the API complex formation is determined to be around ?47 kJ/mol of I–I units bound and is significantly lower in magnitude than that of the amylose-iodine (AI) complex [Biopolymers, 31 , 57 (1991)]. A possible mechanism has been proposed for the formation of AI and API complexes with fixed compositions. © 1994 John Wiley & Sons, Inc. 相似文献
77.
MUHAMMAD Nadeem Arshad HASSAN M.Faidallah ABDULLAH M.Asiri OSMAN I.Osman FAISAL M.S.Aqlan 《结构化学》2019,(3)
Pyridinone derivatives are of great interest in medicinal chemistry where they were found to be potent to various diseases. Their metal complexes added more value to their applications. Here, we have synthesized two 2-pyridinone derivatives(3-cyano-4-(4-hydroxy-3-methoxyphenyl)-6-phenyl-2(1 H)-pyridinone and 3-cyano-4-chlorophenyl-6-(4-tolyl)-2(1 H)-pyridinone) using one-pot multicomponent system. They were well characterized using spectroscopic techniques like nuclear magnetic resonance(NMR-1 H 13 C), Fourier transform infrared(FT-IR) and UV/Vis spectroscopy. The final structures were determined using single-crystal X-ray diffraction technique which helps us to determine their geometries. Density functional theory(DFT) and time-dependent density functional theory(TD-DFT) with suitable basis-sets of calculations have correctly simulated these spectroscopic parameters. The intramolecular charge transfer(ICT) of both substrates has been discussed using natural bond orbital(NBO) technique. Molecular electrostatic potential(MEP) surfaces showed their reactive locations for intermolecular charge transfer. Compared to p-nitroaniline(pNA), both substrates were shown to have substantial molecular hyperpolarizability. 相似文献
78.
Gopinath Subash C. B. Perumal Veeradasan Balakrishnan S.R. Md Arshad M. K. Lakshmipriya Thangavel Haarindraprasad R. Hashim Uda 《Mikrochimica acta》2017,184(11):4425-4431
Microchimica Acta - The authors describe an impedimetric nanosensor for aptamer-mediated detection of ATP. A triangular junction of polysilicon substrate is used as a transducer. The aptamer was... 相似文献
79.
80.
Xiao-Jing Liu Chun-Hua Cui Hui-Hui Li Yong Lei Tao-Tao Zhuang Meng Sun Muhammad Nadeem Arshad Hassan A. Albar Tariq R. Sobahi Shu-Hong Yu 《Chemical science》2015,6(5):3038-3043
Hollow alloyed nanoparticles (NPs) represent one kind of promising fuel cell electrocatalyst. However, the formation of single-cavity hollow structures by a dealloying process is quite challenging owing to the random leaching/dissolution of transition metals, surface passivation and the limited diffusion distance of the noble metals. Here we present a facile method to prepare hollow PtPdCu NPs derived from monodisperse alloy NPs by an acetic acid-assisted dealloying process. Here, acetic acid not only acts as a chemical etching agent but also plays an important role in the removal of the residual surfactants for colloidal NPs. Our findings rectify the current knowledge that hollow alloyed NPs cannot be prepared by a dealloying strategy and provide further understanding of the dealloying process in a ternary system. Such unique hollow ternary PtPdCu NPs exhibit outstanding durability and improved catalytic activity toward the oxygen reduction reaction. 相似文献