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971.
Osama A. Fouad Abd El Rahman S. Khder Qilin Dai M. Samy El-Shall 《Journal of nanoparticle research》2011,13(12):7075-7083
Nanostructured zinc oxide (ZnO) nanobelts and aluminum oxide (Al2O3) nanoribbons have been grown successfully from the vapor phase. XRD results confirmed the purity and the high quality of
the formed crystalline materials. TEM images showed that ZnO nanostructures grew in the commonly known tetrapod structure
with nanobelts separated from the tetrapods with an average width range of 10–30 nm and a length of about 500 nm. Al2O3 nanostructures grew in the form of nanoribbons with an average width range of 20–30 nm and a length of up to 1 μm. The catalytic
oxidation of CO gas into CO2 gas over the synthesized nanostructures is also reported. Higher catalytic activity was observed for Pd nanoparticles loaded
on the ZnO nanobelts (100% conversion at 270 °C) and Al2O3 nanoribbons (100% conversion at 250 °C). The catalytic activity increased in the order Cu < Co < Au < Pd for the metal-loaded
nanostructures. The preparation methods could be applied for the synthesis of novel nanostructures of various materials with
novel properties resulting from the different shapes and morphologies. 相似文献
972.
Niken Taufiqurrahmi Abdul Rahman Mohamed Subhash Bhatia 《Journal of nanoparticle research》2011,13(8):3177-3189
Nanocrystalline zeolites with crystal size smaller than 100 nm are potential replacement for conventional zeolite catalysts
due to their unique characteristics and advantages. In this study, the synthesis of nanocrystalline zeolite Y (FAU) and nanocrystalline
zeolite beta (BEA) under hydrothermal conditions is reported. The effect of crystal size on the physico-chemical characteristics
of the zeolite, Y (FAU), and beta (BEA) is reported. The properties of nanocrystalline zeolites Y and Beta with crystal size
around 50 nm are compared with the microcrystalline zeolite Y and microcrystalline zeolite beta, respectively. The performance
of the nanocrystalline zeolite as a catalyst was investigated in the cracking of used palm oil for the production of biofuel.
The nanocrystalline zeolite catalytic activity was compared with the activity of microcrystalline zeolite in order to study
the effect of crystal size on the catalytic activity. Both nanocrystalline zeolites gave better performance in terms of conversion
of used palm oil as well as selectivity for the formation of gasoline fraction. The increase in surface area and improved
accessibility of the reactant in nanocrystalline zeolites enhanced the cracking activity as well as the desired product selectivity. 相似文献
973.
D. D. DiJulio J. Cederkall C. Fahlander A. Ekström P. Golubev K. Mattsson D. Rudolph G. de Angelis S. Aydin A. Y. Deo E. Farnea G. Farrelly K. Geibel C. He J. Iwanicki R. Kempley N. Marginean R. Menegazzo D. Mengoni R. Orlandi Z. Podolyak F. Recchia P. Reiter E. Sahin J. Smith P. A. Söderström D. A. Torres G. M. Tveten C. A. Ur J. J. Valiente-Dobón A. Wendt M. Zielińska 《The European Physical Journal A - Hadrons and Nuclei》2011,47(2):1-7
974.
975.
Detection of pyridaben residue levels in hot pepper fruit and leaves by liquid chromatography–tandem mass spectrometry: effect of household processes 下载免费PDF全文
Sung‐Woo Kim A. M. Abd El‐Aty Md. Musfiqur Rahman Jeong‐Heui Choi Ok‐Ja. Choi Gyu‐Seek Rhee Moon‐Ik Chang Heejung Kim Morad D. N. Abid Sung Chul Shin Jae‐Han Shim 《Biomedical chromatography : BMC》2015,29(7):990-997
Following quick, easy, cheap, effective, rugged and safe (QuEChERS) and LC/MS/MS analysis, pyridaben residual levels were determined in unprocessed and processed hot pepper fruit and leaves. The linearities were satisfactory with determination coefficients (R2) in excess of 0.995 in processed and unprocessed pepper fruit and leaves. Recoveries at various concentrations were 79.9–105.1% with relative standard deviations ≤15%. The limits of quantitation of 0.003–0.012 mg/kg were very low compared with the maximum residue limits (2–5 mg/kg) set by the Ministry of Food and Drug Safety, Republic of Korea. The effects of various household processes, including washing, blanching, frying and drying under different conditions (water volume, blanching time and temperature) on residual concentrations were evaluated. Both washing and blanching (in combination with high water volume and time factor) significantly reduced residue levels in hot pepper fruit and leaves compared with other processes. In sum, the developed method was satisfactory and could be used to accurately detect residues in unprocessed and processed pepper fruit and leaves. It is recommended that pepper fruit/leaves be blanched after washing before being consumed to protect consumers from the negative health effects of detected pesticide residues. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
976.
Mohammad Nasir Uddin Md. Shaharier Amin Md. Saifur Rahman Sonia Khandaker Wahhida Shumi Md. Atiar Rahman Sheikh Mahbubur Rahman 《应用有机金属化学》2021,35(1)
Symmetrical bis‐Schiff bases (LH 2) have been synthesized by the condensation of 1,6‐hexanediamine (hn) and carbonyl or dicarbonyl. One of the synthesized Schiff bases has been subjected to the molecular docking for the prediction of their potentiality against coronavirus (SARS‐CoV‐2). Molecular docking revealed that tested Schiff base possessed high binding affinity with the receptor protein of SARS CoV‐2 compared with hydroxychloroquine (HCQ). The ADMET analysis showed that ligand is non‐carcinogenic and less toxic than standard HCQ. Schiff bases acting as dibasic tetra‐dentate ligands formed titanium (IV) complexes of the type [TiL(H2O)2Cl2] or [TiL(H2O)2]Cl2 being coordinated through ONNO donor atoms. Ligands and complexes were characterized by the elemental analysis and physicochemical and spectroscopic data including FTIR, 1H NMR, mass spectra, UV‐Visible spectra, molar conductance, and magnetic measurement. Optimized structures obtained from quantum chemical calculations supported the formation of complexes. Antibacterial, antifungal, and anti‐oxidant activity assessments have been studied for synthesized ligands and complexes. 相似文献
977.
978.
Sanim Rahman Dr. Vered Wineman-Fisher Dr. Péter R. Nagy Dr. Yasmine Al-Hamdani Prof. Alexandre Tkatchenko Prof. Sameer Varma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(42):11005-11014
Lysine methylation can modify noncovalent interactions by altering lysine's hydrophobicity as well as its electronic structure. Although the ramifications of the former are documented, the effects of the latter remain largely unknown. Understanding the electronic structure is important for determining how biological methylation modulates protein−protein binding, and the impact of artificial methylation experiments in which methylated lysines are used as spectroscopic probes and protein crystallization facilitators. The benchmarked first-principles calculations undertaken here reveal that methyl-induced polarization weakens the electrostatic attraction of amines with protein functional groups – salt bridges, hydrogen bonds and cation-π interactions weaken by as much as 10.3, 7.9 and 3.5 kT, respectively. Multipole analysis shows that weakened electrostatics is due to the altered inductive effects, which overcome increased attraction from methyl-enhanced polarizability and dispersion. Due to their fundamental nature, these effects are expected to be present in many cases. A survey of methylated lysines in protein structures reveals several cases in which methyl-induced polarization is the primary driver of altered noncovalent interactions; in these cases, destabilizations are found to be in the 0.6–4.7 kT range. The clearest case of where methyl-induced polarization plays a dominant role in regulating biological function is that of the PHD1-PHD2 domain, which recognizes lysine-methylated states on histones. These results broaden our understanding of how methylation modulates noncovalent interactions. 相似文献
979.
Paris E. Georghiou Shofiur Rahman Ahmad Alrawashdeh Abdullah Alodhayb Gopikishore Valluru Kiran Sagar Unikela 《Supramolecular chemistry》2020,32(5):325-333
ABSTRACT A new bimodal triazole-bridged pyrene-appended calix[4]arene 2g has been synthesised and characterised and complexation studies showed that the binding of Cd2+ and Zn2+ occurs as demonstrated by enhanced monomer and declining excimer emission fluorescence spectral changes. With several other metal ions, quenching of both monomer and excimer emissions occurred. The observed monomer formation in the fluorescence spectra seen with Zn2+ and Cd2+ is possibly linked not just to the diminished parallel orientations of the pyrene rings but with the magnitude of the resulting HOMO-LUMO gaps and other parameters measured by DFT calculations. 相似文献
980.
Omidinia Eskandar Shahbazmohammadi Hamid MohseniPour Zeinab Mahdizadeh Rahman 《Applied biochemistry and biotechnology》2019,188(2):498-513
Applied Biochemistry and Biotechnology - Empirical modeling the partition behavior and recovery of a recombinant Pseudomonas putida POS-F84 proline dehydrogenase (ProDH) in aqueous two-phase... 相似文献