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1.
Fatemeh F. Bamoharram Majid M. Heravi Mina Roshani Ali Gharib Manouchehr Jahangir 《中国化学会会志》2007,54(4):1017-1020
Synthesis of aspirin at room temperature via O‐acetylation of salicylic acid in the presence of Preyssler type heteropolyacids has been investigated in order to contribute toward clean technology, which is the most important need of the society. All of the catalysts are recyclable and reusable. 相似文献
2.
Rabia Hassan Farzana Nazir Mah Roosh Arshemah Qaisar Uzma Habib Abdulrahim A. Sajini Mudassir Iqbal 《Molecules (Basel, Switzerland)》2022,27(19)
Ionic liquids (ILs) have emerged as active pharmaceutical ingredients because of their excellent antibacterial and biological activities. Herein, we used the green-chemistry-synthesis procedure, also known as the metathesis method, to develop three series of ionic liquids using 1-methyl-3-butyl imidazolium, butyl pyridinium, and diethyldibutylammonium as cations, and bromide (Br−), methanesulfonate (CH3SO3−), bis(trifluoromethanesulfonyl)imide (NTf2−), dichloroacetate (CHCl2CO2−), tetrafluoroborate (BF4−), and hydrogen sulfate (HSO4−) as anions. Spectroscopic methods were used to validate the structures of the lab-synthesized ILs. We performed an agar well diffusion assay by using pathogenic bacteria that cause various infections (Escherichia coli; Enterobacter aerogenes; Klebsiella pneumoniae; Proteus vulgaris; Pseudomonas aeruginosa; Streptococcus pneumoniae; Streptococcus pyogenes) to scrutinize the in vitro antibacterial activity of the ILs. It was established that the nature and unique combination of the cations and anions were responsible for the antibacterial activity of the ILs. Among the tested ionic liquids, the imidazolium cation and NTf2− and HSO4− anions exhibited the highest antibacterial activity. The antibacterial potential was further investigated by in silico studies, and it was observed that bis(trifluoromethanesulfonyl)imide (NTf2−) containing imidazolium and pyridinium ionic liquids showed the maximum inhibition against the targeted bacterial strains and could be utilized in antibiotics. These antibacterial activities float the ILs as a promising alternative to the existing antibiotics and antiseptics. 相似文献
3.
Sharpless KE Lindstrom RM Nelson BC Phinney KW Rimmer CA Sander LC Schantz MM Spatz RO Thomas JB Turk GC Wise SA Wood LJ Yen JH 《Journal of AOAC International》2010,93(4):1262-1274
Standard Reference Material (SRM) 1849 Infant/Adult Nutritional Formula has been issued by the National Institute of Standards and Technology (NIST) as a replacement for SRM 1846 Infant Formula, issued in 1996. Extraction characteristics of SRM 1846 have changed over time, as have NIST's analytical capabilities. While certified mass fraction values were provided for five constituents in SRM 1846 (four vitamins plus iodine), certified mass fraction values for 43 constituents are provided in SRM 1849 (fatty acids, elements, and vitamins) and reference mass fraction values are provided for an additional 43 constituents including amino acids and nucleotides, making it the most extensively characterized food-matrix SRM available from NIST. 相似文献
4.
Mixed ammonium-transition metal salts with formula of (NH4)xMyHzPMo12O40 (M = Ni2+, Co2+ or Fe 3+) denoted as MPMo12 have been investigated for the oxidation of propane, with molecular oxygen, at temperature range between 380℃ and 420℃ after in-situ pre-treatment performed at two heating rate of 5 or 9℃/min. They were characterized by BET method, XRD, UV-Vis and IR techniques. The catalysts were found to be active in the propane oxidation and selective to propene or acrolein, in particular for samples pre-t... 相似文献
5.
In this paper, a decentralized adaptive control scheme for multi-robot coverage is proposed. This control method is designed based on centroidal Voronoi configuration integrated with robust adaptive fuzzy control techniques. We consider simple single integrator mobile robots used for covering dynamical environments, where an adaptive fuzzy logic system is used to approximate the unknown parts of control law. A robust coverage criterion is used to attenuate the adaptive fuzzy approximation error and measurement noises to a prescribed level. Therefore, the robots motion is forced to obey solutions of a coverage optimization problem. The advantages of the proposed controller can be listed as robustness to external disturbances, computation uncertainties, and measurement noises, while applicability on dynamical environments. A Lyapunov-function based proof is given of robust stability, i.e. convergence to the optimal positions with bounded error. Finally, simulation results are demonstrated for a swarm coverage problem simultaneous with tracking mobile intruders. 相似文献
6.
The reaction of trimethylsilyl trifluoromethanesulfonate (trimethylsilyl triflate, TMSOTf) with imines leads to the formation of N-trimethylsilyliminium salts which react efficiently with soft nucleophiles to form secondary amines. 相似文献
7.
Nucleophilic aromatic substitution of fluorobenzoates and fluorophenylnitriles with weakly basic heterocycles readily occur. This synthetic methodology is utillized to produce potent angiotensin-II antagonists. 相似文献
8.
The beta dose response and Optically Stimulated Luminescence (OSL) signal stability characteristics of human tooth enamel deproteinated by hydrazine reagent under blue photon stimulation are reported. Removal of the protein organic component of tooth enamel resulted in a higher OSL sensitivity and slower fading of OSL signals. The effect of chemical sample preparation on the enamel sample sensitivity is discussed and further steps to make this deproteinization treatment suitable for in vitro dose reconstruction studies are suggested. 相似文献
9.
Khatoon Rabia Uddin Riaz Khurshid Salman Anwar Faiza Iqbal Saba Baloch Parwaiz Ahmed Khan Attaullah 《Journal of Analytical Chemistry》2022,77(5):611-617
Journal of Analytical Chemistry - A reliable, easy, and reproducible method was developed for the quantification of λ-cyhalothrin and malathion residues in desert locust. For the extraction, a... 相似文献
10.
Qamar Adnan Anwar Zahid Ali Hassan Shaukat Rabia Imran Shahid Arshad Attique Ali Hafiz Muhammad Korakianitis Theodosios 《Journal of Thermal Analysis and Calorimetry》2022,147(1):23-46
Journal of Thermal Analysis and Calorimetry - Nanofluids have recently attracted attention of many researchers due to their growing potential applications in heat transfer devices. They possess... 相似文献