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排序方式: 共有205条查询结果,搜索用时 15 毫秒
11.
Sadegh Rostamnia 《Comptes Rendus Chimie》2013,16(11):1042-1046
EtOAc-dispersed magnetic nanoparticles (DMNPs) of γ-Fe2O3 represent a straightforward and green catalyst for the rapid three-component synthesis of 5-oxo-2-thioxo-3-thiophenecarboxylate derivatives as rhodanine skeletons via a single-pot domino process. The rhodanines were prepared over magnetic nanoparticles of γ-Fe2O3 without any salt or additives. Dispersed nano-γ-Fe2O3 have many advantages, such as stability in air, reusability, reactions with high efficiency, simple separation with magnetic external field from mixture reactions, chemical stability, and also low toxicity. 相似文献
12.
Hassan Keypour Ahmad Ali Dehghani-Firouzabadi Majid Rezaeivala Sadegh Salehzadeh 《合成通讯》2013,43(7):1136-1142
A new Schiff base cryptand (L) has been prepared via [2 + 2] condensation of 1,3,5-tris(2-formylphenoxymethyl)benzene (1) with 1,3,5-tris(aminomethyl)benzene trishydrochloride (2) in the presence of Ba(II) ion. The analytical data show that the Ba(II) cation is not retained by the product. Thus it seems that the role of the Ba(II) ion is to organize the transition state preceding the formation of the cryptand. 相似文献
13.
Seyyed Hossein Miraghaie Ashkan Zandi Zahra Davari Mohamad Sadegh Mousavi-kiasary Zohre Saghafi Ali Gilani Yasin Kordehlachin Fatemeh Shojaeian Amir Mamdouh Zahra Heydari Farid Abedin Dorkoosh Babak Kaffashi Mohammad Abdolahad 《Macromolecular bioscience》2023,23(9):2300181
Pure positive electrostatic charges (PPECs) show suppressive effect on the proliferation and metabolism of invasive cancer cells without affecting normal tissues. PPECs are used for the delivery of drug-loaded polymeric nanoparticles (DLNs) capped with negatively charged poly(lactide-co-glycolide) (PLGA) and Poly(vinyl-alcohol) PVA into the tumor site of mouse models. The charged patch is installed on top of the skin in the mouse models' tumor region, and the controlled selective release of the drug is assayed by biochemical, radiological, and histological experiments on both tumorized models and normal rats' livers. It is found that DLNs synthesized by PLGA show great attraction to PPECs due to their stable negative charges, which would not degrade immediately in blood. The burst and drug release after less than 48h of this synthesized DLNs are 10% and 50%, respectively. These compounds can deliver the loaded-drug into the tumor site with the assistance of PPECs, and the targeted-retarded release will take place. Hence, local therapy can be achieved with much lower drug concentration (conventional chemotherapy [2 mg kg−1] versus DLNs-based chemotherapy [0.75 mg kg−1]) with negligible side effects in non-targeted organs. PPECs have many potential clinical applications for advanced-targeted chemotherapy with the lowest discernible side effects. 相似文献
14.
Ali Shokuhi Rad Sadegh Mehdi Aghaei Elaheh Aali Majid Peyravi Mohsen Jahanshahi 《应用有机金属化学》2018,32(2)
The interactions of the nucleobases thymine (C5H6N2O2) and uracil (C4H4N2O2) with Cr‐doped C20 fullerene (C19Cr) are investigated by performing density functional theory calculations. The adsorption of these nucleobases on C19Cr leads to two distinct geometries (P1 and P2) differing in the orientation of the nucleobases. The interaction of the nucleobases with the C19Cr nanocluster is highly exothermic, revealing that they are chemically adsorbed on C19Cr. The results show that the binding energy of the thymine–C19Cr complex is slightly higher than that of the uracil–C19Cr complex. In addition, the P2 geometry is more stable compared to P1 due to the higher binding energy in the former configuration. However, based on the results of natural bond orbital and frontier molecular orbitals analyses, the C19Cr nanocage has higher reactivity with the nucleobases in P1 geometry in comparison with P2 due to the larger charge transfer and orbital hybridization in the former geometry. Moreover, the band gap of the C19Cr nanocage decreases after interaction with the nucleobases, and interestingly the impact is more pronounced for P1 geometry, confirming the higher sensitivity of C19Cr to the nucleobases in P1 geometry. Our findings reveal the promising potential of C19Cr as an organometallic carrier for nucleobases thymine and uracil. 相似文献
15.
Masoumeh Taei Foroozan Hasanpour Mohammad Dinari Nasrin Sohrabi Mohammad Sadegh Jamshidi 《中国化学快报》2017,28(2):240-247
In this study,Au nanoparticles/poly 5-[(2-hydroxynaphthalen-l-yl)diazenyl]isophthalic acid film modified glassy carbon electrode(AuNPs/poly(NDI)/GCE) has shown excellent electrocatalytic activity toward the oxidation of adrenaline(ADR),paracetamol(PAC),and tryptophan(Trp).The bare glassy carbon electrode(GCE) fails to separate the oxidation peak potentials of these molecules,while the poly(NDI) film modified electrode can resolve them.Electrochemical impedance spectroscopy(EIS)indicates that the charge transfer resistance of the bare electrode decreases as 5-[(2-hydroxynaphthalen-l-yl)diazenyl]isophthalic acid is electropolymerized on the bare electrode.Furthermore,EIS exhibits enhancement of electron transfer kinetics between analytes and the electrode after electrodeposition of Au nanoparticles.Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 0.01-680.0 μmol L~1 for ADR,0.05-498.0 μmol L~1 for PAC,and 3.0-632.0 μmol L~1 for Trp;with detection limits(S/N = 3) of 0.009 μmol L~1,0.005 μmol L~1,and 0.09 μmol L~1 for ADR,PAC,and Trp,respectively.The proposed method has been successfully applied for simultaneous determination of ADR,PAC,and Trp in biological samples. 相似文献
16.
Abdolali Alizadeh Sadegh Rostamnia Qasem Oskueyan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1779-1784
Heterocyclic systems 4,5-dihydrothiazol-2-ylamine derivatives are synthesized via an intramolecular thioiminoformamide annulation reaction. 相似文献
17.
Seyyed Javad Sabounchei Sadegh SalehzadehMarjan Hosseinzadeh Fateme Akhlaghi BagherjeriHamid Reza Khavasi 《Polyhedron》2011,30(15):2486-2492
The reaction of the new ambidentate ylide, Ph3PCHCOCH2COOC2H5 (EAPPY), with HgX2 (X = Cl, Br and I) in equimolar ratios using methanol as the solvent leads to binuclear complexes of the type [EAPPY·HgX2]2 (X = Cl (1), Br (2) and I (3)). Single crystal X-ray analysis reveals the presence of a centrosymmetric dimeric structure containing the ylide and HgX2 (X = Br or I). The IR and NMR data of the product [(EAPPY)·HgCl2]2 (1), formed by the reaction of mercury(II) chloride with the same ylide, are similar to those of 2 and 3. Analytical data indicate a 1:1 stoichiometry between the ylide and Hg(II) halide in each of the three products. Theoretical studies indicate that the nature of the R group in ylides of the type Ph3PCHCOR has a weak effect on the Hg-C(ylide) bond length in binuclear Hg2L2I4 complexes. 相似文献
18.
The system, Pd(OAc)2/imidazolium salts (L2), was found as an efficient catalyst in the Heck coupling reaction of olefins with aryl halides and Suzuki reactions of various aryl halides with aryl boronic acids under aerobic condition. This catalytic system demonstrates great tolerance to a wide range of groups on all substrates of aryl halides, alkenes and aryl boronic acids. 相似文献
19.
Heterocyclic skeleton building blocks to afford dihydropyrimidinones and dihydropyridines based on neat adducts of diketene,alcohols and aldehydes via silica sulfuric acid(SSA) catalyzed ring opening of diketene in four-component Biginelli-type and Hantzsch-type reactions are presented. 相似文献
20.
In this paper,an axial dispersion mathematical model is developed to simulate a three-phase slurry bubble column reactor for direct synthesis of dimethyl ether(DME) from syngas.This large-scale reactor is modeled using mass and energy balances,catalyst sedimentation andsingle-bubble as well as two-bubbles class flow hydrodynamics.A comparison between the two hydrodynamic models through pilot plantexperimental data from the literature shows that heterogeneous two-bubbles flow model is in better agreement with the experimental data thanhomogeneous single-bubble gas flow model.Also,by investigating the heterogeneous gas flow and axial dispersion model for small bubblesas well as the large bubbles and slurry(i.e.including paraffins and the catalyst) phase,the temperature profile along the reactor is obtained.Acomparison between isothermal and non-isothermal reactors reveals no obvious performance difference between them.The optimum values ofreactor diameter and height were obtained at 7 m and 50 m,respectively.The effects of operating variables on the axial catalyst distribution,DME productivity and CO conversion are also investigated in this research. 相似文献