排序方式: 共有159条查询结果,搜索用时 406 毫秒
21.
Tashrifi Zahra Mohammadi-Khanaposhtani Mohammad Hamedifar Haleh Larijani Bagher Ansari Samira Mahdavi Mohammad 《Molecular diversity》2020,24(4):1385-1431
Molecular Diversity - 2-Amino-3-cyano-4H-chromenes are structural core motifs that received increasing attention in the last years due to their interesting potential pharmacological properties. In... 相似文献
22.
The highly reactive alkylaminofurochromenone intermediate, produced from the reaction between 3-formylchromones and alkyl isocyanides, was trapped by monocyclic unsaturated acyl compounds such as maleic anhydride or maleimide derivatives to yield new types of organic fluorophores 4-(alkylamino)-1H-furo[3,4-b]xanthene-1,3,10-triones or 4-(alkylamino)chromeno[2,3-f]isoindole-1,3,10(2H)-triones, which exhibited strong sky blue emission in solution. The reaction is very simple from an experimental point-of-view and allows the creation of a fused benzene ring with concomitant formation of three new C–C bonds in a single operation. 相似文献
23.
Khalili B Jajarmi P Eftekhari-Sis B Hashemi MM 《The Journal of organic chemistry》2008,73(6):2090-2095
New 2-alkyl-5-aryl-(1H)-pyrrole-4-ol derivatives were synthesized via three-component reaction of beta-dicarbonyl compounds with arylglyoxals in the presence of ammonium acetate in water at room temperature. 相似文献
24.
Amirheidari Bagher Seifi Mohammad Abaszadeh Mehdi 《Research on Chemical Intermediates》2016,42(4):3413-3423
Research on Chemical Intermediates - Magnetically separable Fe3O4 nanoparticles were used as an environmental friendly catalyst for the synthesis of mono- and bis-tetrahydro-4H-chromene and mono-... 相似文献
25.
Younes Ghasemi Sara Rasoul-Amini Mohammad Hossein Morowvat Mohammad Bagher Ghoshoon Mohammad Javad Raee Soraya Khoubani Narges Negintaji Fatemeh Nouri Rezvan Parvizi 《Chemistry of Natural Compounds》2009,45(6):824-828
A unicellular microalga, Chlorella vulgaris, was isolated from rice field and applied in the biotransformation experiment
of hydrocortisone (1). This strain has not been previously tested for hydrocortisone bioconversion. Fermentation was carried out in BG-11 medium
supplemented with 0.05% substrate at 25°C for 14 days incubation. The products obtained were chromatographically purified
followed by their characterization using spectroscopic methods. 11β,17α,20β,21-Tetrahydroxypregn-4-en-3-one (2), 11β,17β-dihydroxyandrost-4-en-3-one (3), and 11β-hydroxyandrost-4-ene-3,17-dione (4) were the main bioproducts in the hydrocortisone bioconversion. Bioreaction characteristics observed were 20-ketone reduction
for accumulation of compound 2 and side chain degradation of the substrate to prepare compounds 3 and 4. Time course study showed the accumulation of the product 2 from the second day of the fermentation and 3 as well as 4 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also
amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of
PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of six strains of Chlorella
vulgaris. 相似文献
26.
Sepideh Ebrahimi Reza Sabbaghi-Nadooshan Mohammad Bagher Tavakoli 《Optical and Quantum Electronics》2018,50(4):196
In this paper, an optical waveguide has been developed based on the (Deoxyribonucleic acid) DNA core as a multi-slab structure by switching characteristic at 300 THz. We show that how the DNA with various electrical characteristics can be considered as a reconfigurable material which is placed between two optical metal layers. Therefore, we can control the current and voltage density values based on the divergence of the DNA types as an optical switch. Moreover, we can select the Au and Ag for the metal coat. In this research, we demonstrate that the Ag/DNA/Ag and Au/DNA/Ag have better performance in switching qualification than Au/DNA/Au model as a conventional structure. This DNA core waveguide has a switchable feature which cannot be found at any conventional plasmonic waveguide. The FDTD time domain is used for simulating the waveguide and the current density is considered as an ON/OFF switch. We carry out parametric studies for the physical dimensions of the waveguide and illustrate that how we can improve the switching characteristic. Moreover, we have checked the coupling effect between the transmission lines and defined the figure of merit for switching quality. This structure can be considered as an optical memristor and optical “YES” gate which couldn’t be obtained by other graphene waveguide while it became feasible based on DNA switching feature. 相似文献
27.
For charged black holes in Ho?ava–Lifshitz gravity, a second order phase transition takes place in extended phase space where the cosmological constant is taken as thermodynamic pressure. We relate the second order nature of phase transition to the fact that the phase transition occurs at a sharp temperature and not over a temperature interval. Once we know the continuity of the first derivatives of the Gibbs free energy, we show that all the Ehrenfest equations are readily satisfied. We study the effect of the perturbation of the cosmological constant as well as the perturbation of the electric charge on thermodynamic stability of Ho?ava–Lifshitz black hole. We also use thermodynamic geometry to study phase transition in extended phase space. We investigate the behavior of scalar curvature of Weinhold, Ruppeiner, and Quevedo metric in extended phase space of charged Ho?ava–Lifshitz black holes. It is checked if these curvatures could reproduce the result of specific heat for the phase transition. 相似文献
28.
Mohammad Bagher Majnooni Bahareh Mohammadi Ronak Jalili Gholamreza Bahrami 《液相色谱法及相关技术杂志》2016,39(19-20):877-881
A new high-performance liquid chromatographic method is described for the determination of fatty acids in seed oils. The method was based on precolumn derivatization with 9-fluorenylmethyl chloroformate as a labeling agent and fluorescence detection. Fatty acids were extracted from the samples and subjected to derivatization with the reagent at 60°C for 10?min. The chromatographic separation of 14 fatty acids (C10–C22) was achieved on a combined loading compression octadecyl sulfate (CLC-ODS) column with a run time of 30?min. Three-step gradient elution of a mobile phase consisted of acetonitrile and water was used, and the signal was monitored at excitation and emission wavelengths of 265 and 315?nm, respectively. The method indicated favorable sensitivity and reproducibility for fatty acids’ derivatives. The detection limits, at a signal-to-noise ratio of 3, were 0.01–0.05?µg/ml and relative standard deviations (RSDs) were less than 0.27%. Excellent linear responses were observed with coefficients of 0.9995. This method was applied to quantify fatty acids in white, brown, and black sesame seeds’ oil. 相似文献
29.
Optical imaging is an emerging method for bio-imaging. The advantages of this imaging provide non-ionizing and safe radiation, non-invasive and functional medical imaging. Due to diffusion of photons inside biological tissues, its image processing is complicated. So in spite of these advantages, this imaging method has not been progressed like ultrasound imaging and magnetic resonance imaging (MRI). Also, the penetration depth of photons inside biological phantom is low. To overcome this problem, the complicated diffusion of photons through tissue must be modeled. The diffuse equation can be applied to simulate photons through turbid media like biological tissues. In this paper, the diffuse equation is used to study propagation of diffuse photons. The green function method is applied to solve this equation, and then the optical properties of abnormalities in breast phantom are estimated. This fast method can be applied for image processing. 相似文献
30.
Nasli Esfahani Anita Iraji Aida Alamir Amir Moradi Shahram Asgari Mohammad Sadegh Hosseini Samanesadat Mojtabavi Somayeh Nasli-Esfahani Ensieh Faramarzi Mohammad Ali Bandarian Fatemeh Larijani Bagher Hamedifar Haleh Hajimiri Mir Hamed Mahdavi Mohammad 《Molecular diversity》2022,26(4):1995-2009
Molecular Diversity - A novel series of phenoxymethybenzoimidazole derivatives (9a-n) were rationally designed, synthesized, and evaluated for their α-glycosidase inhibitory activity. All... 相似文献