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101.
An analytical expression is proposed to the Kirkwood-Fr?hlich dipole orientation correlation parameter g. This parameter,
which has been considered as a relevant guide to understanding the structuredness of supercritical fluids, had been always
determined numerically. The advantage of the used protocol: the BPES, is to yield continuous and integrable expressions which
can be easily incorporated in analytical models. The results have been compared to several precedent studies. 相似文献
102.
Merve Şamlı Oguz Bayraktar Figen Korel 《Journal of inclusion phenomena and macrocyclic chemistry》2014,80(1-2):37-49
In this study, cyclodextrin inclusion complexes with rutin were prepared via co-precipitation method. Stability constant and solubility energy of beta-cyclodextrin complex were calculated as 262 M?1 and 1,737 kJ mol?1, respectively. Aqueous solubility of rutin was increased with inclusion complex of beta-cyclodextrin. The effect of temperature on both aqueous solubility of free rutin, and its inclusion complex was also studied. Characterization of cyclodextrin complexes were conducted with UV–Vis spectrophotometry, Fourier transform infrared spectroscopy, X-ray diffractometry, differential scanning calorimetry, thermal gravimetric analysis, nuclear magnetic resonance spectroscopy and scanning electron microscopy techniques. Characterization results supported formation of inclusion complexes. Dissolution profiles of rutin, physical mixture and inclusion complex of rutin were observed at 37 °C. Dissolution results proved the effect of cyclodextrin addition on solubility rate of rutin. After loading rutin and its complexes into silk fibroin based films, release tests were performed at 37 °C in neutral pH conditions for 24 h. Most of the rutin were released from silk fibroin films within the first 5 h and the rest of it was released slowly (sustained release). Electron microscope analyses showed that films had homogenous and dense morphologies. These results revealed that silk fibroin is useful for preparing bioactive films loaded with natural compounds and for modifying their release behaviour at physiological conditions. 相似文献
103.
Necmettin Yildirim Mehmet Çiftçi Ö. İrfan Küfrevioğlu 《Journal of mathematical chemistry》2002,31(1):121-130
This paper describes a general methodology to handle closed multi enzyme systems using mixture of symbolic (which depends on the Gröbner Basis technique) and numerical computation methods. The applicability of the proposed method has been examined for the closed three-enzyme system of rabbit heart creatine kinase (EC 2.7.3.2), yeast hexokinase (EC 2.7.1.1) and human erythrocyte glucose 6-phosphate dehydrogenase (EC 1.1.1.49) using experimental data. 相似文献
104.
We have studied the superconducting properties of MgB2 from first-principles under isotropic, uniaxial, and biaxial compressions. We find that the in-plane boron phonons near the zone-center are very anharmonic and strongly coupled to the planar B σ bands near the Fermi level. This mode is found to be the key to quantitatively explain the observed high Tc, the total isotope effect and the pressure dependence of Tc. We propose that a stringent test on the hole and phonon based theories of the superconductivity in MgB2 would be a measurement of the biaxial ab-compression dependence of Tc. 相似文献
105.
H. Akat Y. Yildirim F. Yurt Lambrecht O. Yilmaz M. Balcan Y. Duman 《Journal of Radioanalytical and Nuclear Chemistry》2008,275(2):387-393
Gabapentin (GBP) is an anticonvulsant and is widely used in the treatment of epilepsy. In this study, GBP and an allyl derivative
of GBP were radioiodinated with 131I using the iodogen method; then their radiopharmaceutical potential in rats and rabbits was investigated. The radiochemical
purity of 131I-GBP and its derivatives was determined by RTLC. The labeling yield was 95±2%. Biological evaluation was performed in normal
rats and rabbits. Labeled compounds were intravenously injected into two rabbits via the ear vein after anesthetizing. The
dynamic and static scintigrams were obtained using a gamma camera at different time. Then the labeled compounds were administered
intravenously into the rats. The distribution was studied by counting the radioactivity in the removed organs. The results
of biodistribution in the rats showed the clearance of 131I-ALGBP was faster than 131I-GBP. On the other hand, the uptake of 131I-ALGBP in the brain was higher than 131I-GBP at 60 minutes. 相似文献
106.
A convenient procedure for the preparation of oxazole and pyrrole derivatives is described. 2-Amino-1,3-oxazol-2-ones 3a,b were first synthesized from the cyclocondensation reactions of cyanamide (2) with 4-ethoxycarbonyl-5-aryl-2,3-furandione 1a,b, and then new pyrrol-2-ones 5 were synthesized from the reaction of the compounds 3 with various aromatic amines 4. 相似文献
107.
The newly synthesized thirteen disazo dyes containing imidazole and pyrazole cycles (3a-3m) were carried out by diazotization reaction of 5-amino-4-arylazo-3-methyl-1H-pyrazoles (2a-2m) and coupling reaction with 1-methyl imidazole. Structures of synthesized azo dyes were characterized by UV–Vis, FT-IR, 1H-NMR, elemental analysis and their solvatochromic properties were studied in DMSO, DMF, methanol, acetic acid and chloroform. In addition, the antimicrobial activities of dyes against twelve pathogenic bacteria were examined in detail and all dyes showed antimicrobial activity against different bacterial strains. 相似文献
108.
Chen G Kierzek R Yildirim I Krugh TR Turner DH Kennedy SD 《The journal of physical chemistry. B》2007,111(24):6718-6727
The Watson-Crick-like isoG-isoC (iGiC) pair, with the amino and carbonyl groups transposed relative to the Watson-Crick GC pair, provides an expanded alphabet for understanding interactions that shape nucleic acid structure. Here, thermodynamic stabilities of tandem GA pairs flanked by iGiC pairs are reported along with the NMR structures of the RNA self-complementary duplexes (GCiGGAiCGCA)2 and (GGiCGAiGCCA)2. A sheared GA pairing forms in (GCiGGAiCGCA)2, and an imino GA pairing forms in (GGiCGAiGCCA)2. The structures contrast with the formation of tandem imino and sheared GA pairs flanked by GC pairs in the RNA self-complementary duplexes (GCGGACGC)2 and (GGCGAGCC)2, respectively. In both iGiC duplexes, Watson-Crick-like hydrogen bonds are formed between iG and iC, and iGiC substitutions result in less favorable loop stability. The results provide benchmarks for testing computations of molecular interactions that shape RNA three-dimensional structure. 相似文献
109.
110.
In this study, first, polyethyleneimine was acrylated and mixed with polyvinyl alcohol solution to prepare photo‐crosslinked polyethyleneimine (PEI)‐based nanofibers by utilizing ultraviolet and electrospinning technique at the same time. For CO2 permeability testing, same formulations were prepared by using solvent casting technique and exposed to ultraviolet light to have polyethyleneimine‐based membrane films. The chemical structures of the nanofibers were characterized by Fourier transform infrared spectroscopy. The thermal properties of nanofibers were examined by thermal gravimetric analysis and differential scanning calorimeter. The morphology of nanofibers was investigated by scanning electron microscopy. CO2 permeabilities of samples were also measured. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献