排序方式: 共有69条查询结果,搜索用时 265 毫秒
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Niloofar Tavakoli-Hoseini Majid M. HeraviFatemeh F. Bamoharram Abolghasem DavoodniaMitra Ghassemzadeh 《Journal of Molecular Liquids》2011,163(3):122-127
Under solvent-free conditions and in the presence of 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate [MIM(CH2)4SO3H][HSO4], a Brønsted acidic ionic liquid, the reaction of aromatic aldehydes with 4-hydroxycoumarin has been investigated. A wide range of aromatic aldehydes easily undergoes condensation with 4-hydroxycoumarin to afford biscoumarins with good purity in excellent yields. However, reaction of 2-hydroxybenzaldehyde with 4-hydroxycoumarin gave, not the corresponding biscoumarin, but a tetracyclic compound, 7-(2-hydroxy-4-oxo-4H-chromen-3-yl)-6H,7H-chromeno[4,3-b]chromen-6-one, in high yield. 相似文献
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An efficient, environmentally friendly procedure for the synthesis of amidoalkyl naphthols through the one‐pot, three‐component reaction of β‐naphthol, aryl aldehydes, and acetamide in the presence of a carbon‐based solid acid under thermal solvent‐free conditions is described. The beneficial fea-tures of this new synthetic approach include short reaction time, high yields, clean reaction profiles, and a simple work‐up procedure. Furthermore, the catalyst can be readily recycled and reused four times without obvious significant loss of activity. The structure of the catalyst was confirmed by Fourier transform infrared spectroscopy, N2 adsorption/desorption analysis, and X‐ray diffraction. 相似文献
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An efficient and eco-friendly procedure for one-pot synthesis of β-amino carbonyl compounds by three-component reaction of aromatic aldehydes, acetophenone, and aromatic amines via a Mannich type reaction using a stable tightly bound complex, titanium tetrachloride incorporated crosslinked polystyrene copolymer (PS/TiCl4), as a water tolerant, recoverable, and reusable polymeric Lewis acid catalyst in ethanol at room temperature is reported. The complex of the polystyrene and TiCl4 provides a shelf-stable acidic, water tolerant material, and it is not easily hydrolyzed by water. Our findings thus show a novel and improved modification of the Mannich type reaction in terms of mild reaction conditions, clean reaction profiles, applicability to various substrates using a simple workup procedure which makes this reaction an interesting alternative to previously applied procedures. The recyclability of the catalyst makes this protocol environmentally benign. 相似文献
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Yahya S. Beheshtiha Mina Saeedi Narges Karimi Masumeh Zakeri Niloofar Tavakoli-Hossieni 《合成通讯》2013,43(8):1216-1223
1,2-Disubstituted benzimidazoles and quinoxalines have been synthesized in the presence of Br?nsted acid ionic liquid, [(CH2)4SO3HMIM][HSO4], in water at ambient temperature. 相似文献
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The weighted canonical correlation regression technique is employed for reconstruction of reflectance spectra of surface colors
from the related XYZ tristimulus values of samples. Flexible input data based on applying certain weights to reflectance and
colorimetric values of Munsell color chips has been implemented for each particular sample which belongs to Munsell or GretagMacbeth
Colorchecker DC color samples. In fact, the colorimetric and spectrophotometric data of Munsell chips are selected as fundamental
bases and the color difference values between the target and samples in Munsell dataset are chosen as a criterion for determination
of weighting factors. The performance of the suggested method is evaluated in spectral reflectance reconstruction. The results
show considerable improvements in terms of root mean square error (RMS) and goodness-of-fit coefficient (GFC) between the
actual and reconstructed reflectance curves as well as CIELAB color difference values under illuminants A and TL84 for CIE1964
standard observer. 相似文献
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Mohammad T. Baei A. S. Ghasemi E. Tazikeh Lemeski Alireza Soltani Niloofar Gholami 《Journal of Cluster Science》2016,27(4):1081-1096
Density functional theory calculations were performed to understand the electronic properties of C24, B12N12, B12P12, and (6, 0) BNNT interacted with N2O molecule in the presence and absence of an external electric field using the B3LYP method and 6-31G** basis set. The adsorption of N2O from O-side on the surface of (6, 0) BNNT has high sensitivity in comparison with B12N12 nano-cage. The adsorption energy of N2O (O-side) on the sidewalls of B12N12 and BNNT in the presence of an electric field are ?21.01 and ?15.48 kJ mol?1, respectively. Our results suggest that in the presence of an electric field, the B12N12 nano-cage is the more energetically notable upon the N2O adsorption than (6, 0) BNNT, C24, and B12P12. Whereas, our results indicate that the electronic property of BNNT is more sensitive to N2O molecule at the presence of an electric field than B12N12 nano-cage. It is anticipated that BNNT could be a favorable gas sensor for the detection of N2O molecule. 相似文献
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Ahmad Ahmeda Akram Zangeneh Roozbeh Javad Kalbasi Niloofar Seydi Mohammad Mahdi Zangeneh Sanaz Mansouri Samaneh Goorani Rohallah Moradi 《应用有机金属化学》2020,34(4):e5358
The purpose of this experiment was the green synthesis of silver nanoparticles from aqueous extracts of Ziziphora clinopodioides Lam (AgNPs@Ziziphora) and assessment of their cytotoxicity, antioxidant, antibacterial, antifungal, and cutaneous wound-healing effects. These nanoparticles were characterized using ultraviolet–visible spectroscopy (UV–Vis), X-ray diffraction (XRD), field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX), atomic force microscopy (AFM), and transmission electron microscopy (TEM). UV–Vis, TEM, and FESEM analyses indicated that the size of Ag nanoparticles (AgNPs) depended on Z. clinopodioides and AgNO3 concentrations. In vitro biological experiments indicated that AgNPs@Ziziphora has excellent antioxidant potential against DPPH, antifungal effects against Candida guilliermondii, Candida krusei, Candida glabrata, and Candida albicans, and antibacterial activities against Staphylococcus aureus, Bacillus subtilis, Streptococcus pneumonia, Salmonella typhimurium, Pseudomonas aeruginosa, and Escherichia coli O157:H7. Also, these nanoparticles did not exhibit cytotoxicity property against human umbilical vein endothelial cells (HUVECs). An in vivo biological test revealed that AgNPs@Ziziphora ointment significantly (p ≤ 0.01) increased the levels of wound contracture, blood vessels, hydroxyl proline, hexuronic acid, hexosamine, fibrocytes, fibroblasts, and fibrocyte/fibroblast ratio and significantly (p ≤ 0.01) decreased the wound area, and levels of total cells, neutrophils, and lymphocytes than other groups in rats. The results of UV–Vis, XRD, FESEM-EDX, AFM, and TEM confirmed that the aqueous extract of Z. clinopodioides can be used to produce silver nanoparticles with significant antioxidant, antimicrobial, and cutaneous wound-healing properties without any cytotoxicity. 相似文献
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Niloofar Seydi Sania Saneei Ali R. Jalalvand Mohammad Mahdi Zangeneh Akram Zangeneh Reza Tahvilian Elham Pirabbasi 《应用有机金属化学》2019,33(11)
The application of nanotechnologies to medicine, or nanomedicine, which has already demonstrated its tremendous impact on the pharmaceutical and biotechnology industries, is rapidly becoming a major driving force behind ongoing developments in the antimicrobial and wound healing fields. This study confirms the potential of Allium eriophyllum Boiss aqueous extract for the green synthesis of titanium nanoparticles (TiNPs). Also, we reveal the antioxidant, cytotoxicity, cutaneous wound healing, antifungal and antibacterial properties of TiNPs. These nanoparticles were characterized using Fourier transform infrared (FT‐IR) and UV–visible spectroscopies, X‐ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (SEM). FT‐IR findings suggested molecular interactions of compounds in the plant were the sources of reducing power, reducing titanium ions to TiNPs. In XRD analysis, 22.8 nm was measured for the crystal size of the nanoparticles. SEM and TEM images indicated a uniform spherical morphology and average diameters of 22 nm. 2,2‐Diphenyl‐1‐picrylhydrazyl experiments were conducted to assess the antioxidant activities, which indicated similar antioxidant potentials for TiNPs and butylated hydroxytoluene. In the antimicrobial part of this study, agar diffusion experiments were done to determine the antibacterial and antifungal characteristics. TiNPs had antifungal activities against Candida guilliermondii, C. krusei, C. albicans and C. glabrata and antibacterial potentials against Gram‐negative bacteria (Pseudomonas aeruginosa, Salmonella typhimurium and Escherichia coli O157:H7) and Gram‐positive bacteria (Staphylococcus aureus, Streptococcus pneumoniae and Bacillus subtilis). Also, these nanoparticles did not have any cytotoxicity against human umbilical vein endothelial cells. In in vivo experiments, TiNP ointment significantly decreased (p ≤ 0.01) wound area, total cells, macrophages, neutrophils and lymphocytes and notably increased (p ≤ 0.01) wound contracture, vessels, hydroxyproline, hexosamine, hexuronic acid, fibrocytes and fibrocyte/fibroblast ratio in rats. The results of FT‐IR, UV, XRD, TEM and SEM analyses confirm that aqueous extract of A. eriophyllum leaves can be used to yield TiNPs with notable antioxidant, antibacterial, antifungal and cutaneous wound healing potentials without any cytotoxicity. Further clinical trials are necessary for confirmation of these remedial properties of TiNPs in humans. 相似文献