排序方式: 共有82条查询结果,搜索用时 15 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.
62.
Majid Rafipoor Farhad Salimi Khosrow Jarrahian Seyyed Saeed Ghorashi 《Journal of Dispersion Science and Technology》2014,35(1):56-63
In this research, polyacrylamide-based gels were made at 25°C and aged in an oven at 90°C for 24 hours. The bottle testing results indicated that gel composed of 15000 ppm partially hydrolyzed polyacrylamide (PHPA) and 2500 ppm chromium(III) acetate exhibited an acceptable strength. The strain sweep test results showed that elastic modulus is fixed on 6 Pa below strain of 100%. According to frequency test results, linear viscoelasticity region was observed at the frequency limits from 0.1 to 10 s?1. Moreover, elastic modulus decreased from 8 Pa at 25°C to 4 Pa at 90°C. Furthermore, gelation time for gelant with the same composition was obtained (14, 13, and 20 minutes) in sequence. 相似文献
63.
Javad Zolgharnein Ghasem Shahmoradi Khosrow Zamani Saeid Amani 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):99-103
The complexation reaction of phenylaza-15-crown-5, and 4-nitrobenzo-15-crown-5, benzo-15-crown-5 and dibenzopyrdino-18-crwon-6,
dibenzo-18-crown-6,dicyclohexyl-18-crown-6(cis and trans), and 18-crown-6 with Na+ ion in methanol have been studied by potentiometric method. The Na+ ion-selective electrode has been used both as indicator and reference electrode. The stoichiometry and stability constants
of complexes of these crown ethers with sodium ion were evaluated by MINIQUAD program. The major trend of stability of resulting
complexes of these macrocycle with Na+ ion varied in the order DCY18C6 > DB18C6 > 18C6 > DBPY18C6 > phenylaza-15C5 > benzo-15C5 > 4-nitrobenzo-15C5. The obtained
results in particular stability constant of complexes of DBPY18C6, phenylaza-15C5 and 4-nitrobenzo-15C5 with sodium ion in
comparison with other crowns ether are novel, and interesting. 相似文献
64.
Khosrow Jadidi Ramin Ghahremanzadeh Peiman Mirzaei Ayoob Bazgir 《Journal of heterocyclic chemistry》2011,48(5):1014-1018
A one‐pot, three‐component method for the efficient and simple synthesis of novel 2′‐amino‐8′,9′‐dihydro‐3′H‐spiro[indoline‐3,5′‐pyrimido[4,5‐b]quinoline]‐2,4′,6′(7′H,10′H)‐trione derivatives in aqueous media is reported. J. Heterocyclic Chem., (2011). 相似文献
65.
Nina Yu. Kostina Sebastien Blanquer Ognen Pop‐Georgievski Khosrow Rahimi Barbara Dittrich Anita Hcherl Jií Michlek Dirk W. Grijpma Cesar Rodriguez‐Emmenegger 《Macromolecular bioscience》2019,19(4)
Stereolithography‐assisted fabrication of hydrogels of carboxybetaine methacrylamide (CBMAA) and a α,ω‐methacrylate poly(d,l ‐lactide‐block‐ethylene glycol‐block‐ d,l ‐lactide) (MA‐PDLLA‐PEG‐PDLLA‐MA) telechelic triblock macromer is presented. This technique allows printing complex structures with gyroid interconnected porosity possessing extremely high specific area. Hydrogels are characterized by infrared spectroscopy (FTIR), X‐ray photoelectron spectroscopy (XPS), and laser scanning confocal microscopy (LSCM). The copolymerization with zwitterionic comonomer leads hydrogels with high equilibrium water content (EWC), up to 700% while maintaining mechanical robustness. The introduction of carboxybetaine yields excellent resistance to nonspecific protein adsorption while providing a facile way for specific biofunctionalization with a model protein, fluorescein isothiocyanate labeled bovine serum albumin (BSA). The homogeneous protein immobilization across the hydrogel pores prove the accessibility to the innermost pore volumes. The remarkably low protein adsorption combined with the interconnected nature of the porosity allowing fast diffusion of nutrient and waste product and the mimicry of bone trabecular, makes the hydrogels presented here highly attractive for tissue engineering. 相似文献
66.
Numerical Algorithms - The main aim of this research study is to present a new and efficient numerical method based on the second kind Chebyshev wavelets for solving the general form of distributed... 相似文献
67.
Jadidi Omid Firouzi Fatemeh Loucks John S. Park Yong Shin 《Computational Management Science》2022,19(3):375-394
Computational Management Science - In sourcing decisions, a buyer encounters three main issues. The first issue is the demand uncertainty that leads the buyer to find the optimal inventory level... 相似文献
68.
Khalil Faghihi Khosrow Zamani Azizollah Mirsamie Mohammad Reza Sangi 《European Polymer Journal》2003,39(2):247-254
Rapid and highly efficient synthesis of novel optically active poly(amide-imide)s (PAIs) 6(a-f) was achieved using microwave irradiation. These were made from the polycondensation reactions of 4,4′-carbonyl-bis(phthaloyl-l-alanine) diacid chloride [N,N′-(4,4′-carbonyldiphthaloyl)] bisalanine diacid chloride 5 with six different derivatives of hydantoin and thiohydantoin compounds 4(a-f) in the presence of a small amount of a nonpolar organic medium that acts as a primary microwave absorber. Hydantoin and thiohydantoin derivatives 4(a-e) were synthesis from the reactions between benzil or benzil derivatives 3(a-e) with urea and thiourea. 5,5-Dimethylhydantoin 4f was synthesis from the reactions between acetone cyanohydrin 3f and ammonium carbonate. The polycondensation proceeded rapidly, and was completed within 10 min giving a series of PAIs with an inherent viscosity about 0.25-0.45 dL/g. The resulting PAIs 6(a-f) were obtained in a high yield and were optically active and thermally stable. All of the above compounds were fully characterized by means of Fourier transform infrared spectroscopy, elemental analyses, inherent viscosity (ηinh), solubility tests and specific rotation. Thermal properties of the PAIs 6(a-f) were investigated using thermal gravimetric analysis. 相似文献
69.
Dr. Abdolhossein Miri Dr. Hakimeh Najafzadeh Dr. Majid Darroudi Dr. Mohammad Javad Miri Dr. Mohammad Amin Jadidi Kouhbanani Mina Sarani 《ChemistryOpen》2021,10(3):327-333
Iron oxide nanoparticles have attracted much attention because of their superparamagnetic properties and their potential applications in many fields such as magnetic storage devices, catalysis, sensors, superparamagnetic relaxometry (SPMR), and high-sensitivity biomolecule magnetic resonance imaging (MRI) for medical diagnosis and therapeutics. In this study, iron oxide nanoparticles (Fe2O3 NPs) have been synthesized using a taranjabin (camelthorn or persian manna) aqueous solution. The synthesized Fe2O3 NPs were identified through powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), field energy scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX), vibrating-sample magnetometer (VSM) and Raman technics. The results show that the nanoparticles have a hexagonal structure with 20 to 60 nm in size. The cytotoxic effect of the synthesized nanoparticles has been tested upon application against lung cancer cell (A549) lines. It was found that there is no cytotoxic activity at lower concentrations of 200 μg/mL. The ability of the synthesized nanoparticles for lead removal in wastewaters was tested. Results show that highest concentration of adsorbent (50 mg/L) has maximum removal efficiency (96.73 %). So, synthesized Fe2O3 NPs can be a good candidate to use as heavy metals cleaner from contaminated waters. 相似文献
70.
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