排序方式: 共有71条查询结果,搜索用时 31 毫秒
61.
Smriti Singh Dan Eugen Demco Khosrow Rahimi Radu Fechete Jos Carlos Rodriguez‐Cabello Martin Mller 《Macromolecular rapid communications》2016,37(2):181-186
The investigation of the coacervation (self‐aggregation) behavior of biomicrogels which can potentially be used as drug carriers is an important topic, because self‐aggregation can not only cause loss of activity, but also toxicity and immunogenicity. To study this effect microgels from elastin‐like recombinamer are synthesized using miniemulsion technique. The existence of coacervation for such microgels, at different concentrations and temperatures, is studied and proved by cryo‐field emission scanning clectron microscopy (cryo‐FESEM), cryo‐transmission electron microscopy (cryo‐TEM), and by a novel 1H high‐resolution magic angle sample spinning (HRMAS), nuclear magnetic resonance (NMR) spectroscopy, and relaxometry methods. The findings by 1H HRMAS NMR spectroscopy and relaxometry show simultaneous processes of volume phase temperature transition and coacervation with different sensitivity for hydrophobic and hydrophilic amino acid side‐chains in the microgel. The coacervation process is more evidential by the behavior of glycine α‐CH2, 1H NMR peak as compared to the proline β‐CH2.
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In this paper, we provide an exact analysis of a discrete-time queueing system driven by a discrete autoregressive model of order 1 (DAR(1)) characterized by an arbitrary marginal batch size distribution and a correlation coefficient. Closed-form expressions for the probability generating function and mean queue length are derived. It is shown that the system performance is quite sensitive to the correlation of the arrival process. In addition, a comparison with traditional Markovian processes shows that arrival processes of DAR(1) type exhibit larger queue length as compared with the traditional Markovian processes when the marginal densities and correlation coefficients are matched. 相似文献
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Saadi Samadi Khosrow Jadidi Mojgan Samadi Akram Ashouri Behrouz Notash 《Tetrahedron》2019,75(7):862-867
A new type of amido-oxazoline ligands was conveniently synthesized from inexpensive and commercially available materials in high yields and enantiomeric excesses. The corresponding chiral copper complexes with this class of ligands [C2 symmetric S,S-bis(amido-oxazoline-Cu(II) complex] were synthesized accordingly. The ORTEP diagram of ligand 6a and complex 6a-copper were compared and characterization of the complex confirmed the involvement of both dentate parts of the ligands, the oxygen and nitrogen atoms, in complexation with copper. The utilization of this amido-oxazoline ligands in the copper-catalyzed enantioselective esterification of allylic CH bonds of cyclic olefins with tert-butyl-4-nitrobenzoperoxoate resulted in the highest activities, yields (up to 95%) and enantioselectivities (up to 96%) in the presence of HZSM-5 zeolite. These new findings highlight the protocol as one of the most attractive and useful methods for the oxidation of the asymmetric allylic CH bond of cycloalkenes compared to other methodologies reported in the literature. 相似文献
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Khosrow Laali Robert J. Gerzina Christine M. Flajnik Cynthia M. Geric Ann Marie Dombroski 《Helvetica chimica acta》1987,70(3):607-611
The effectiveness of copper(II) triflate (copper(II) trifluoromethanesulfonate) as a new dehydrating reagent for a variety of alcohols has been demonstrated. Based on several control experiments, a possible mechanism is suggested. 相似文献
66.
Jadidi K Gharemanzadeh R Mehrdad M Darabi HR Khavasi HR Asgari D 《Ultrasonics sonochemistry》2008,15(2):124-128
Novel pyrrolizidines (1) were synthesized from 1,3-dipolar cycloaddition of azomethine ylides and dipolarophiles (4). The reactions were highly diastereoselective and regioselective and were carried out under reflux and ultrasonic condition at room temperature. In general, milder conditions and moderate improvements in rates and reaction times were observed when ultrasonic condition was used. The products were obtained in high yields, and their structures were determined by (1)H and (13)C NMR spectral data and X-ray diffraction. 相似文献
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Hossein Reza Darabi Khosrow Jadidi Ali Reza Mohebbi Laleh Faraji Kioumars Aghapoor Shant Shahbazian 《Supramolecular chemistry》2013,25(3):327-333
The bromination/dehydrobromination of stilbenophanes as a practical, simple and efficient strategy is applied to the synthesis of tolanophanes 1a (n = 2) and 1b (n = 4). The method is significantly superior to the reported methods. A careful conformational study on a novel tolanophane 1b showed that the relative stability of its conformers is directly linked to both twist angle between the two arene rings and the orientation of the alkoxy groups. The strong interaction between 1b and CDCl3 at ? 60°C is an unusual feature that is attributed to high restriction in its molecular motion. 相似文献
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A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions. 相似文献
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Khosrow Khodabakhshi Marianne Gilbert Saeed Fathi Philip Dickens 《Journal of Thermal Analysis and Calorimetry》2014,115(1):383-391
This work was part of a major project aiming to produce polyamide 6 parts using an additive manufacturing process. This is by manufacturing 3D parts layer by layer. The influence of heating strategy (heating rate, cooling rate and maximum temperature) on anionic polymerisation of caprolactam in a small-scale was investigated by means of differential scanning calorimetry (DSC). The relationship between heating rate and the polymerisation–crystallisation processes was determined. Two different catalyst/activator compositions were used to study the influence of a di-functional activator on polymerisation. Results showed that unlike cooling rate, the heating rate and maximum heating temperature had a major effect on the final properties of polymer such as crystallinity, monomer conversion and polymer chains regularity. Using a di-functional activator resulted in slowing down the crystallisation process due to the enhanced rate of branching. 相似文献