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91.
Bin Li Haoyu Liu Muhammad Amin Lindsay A. Wegiel Lynne S. Taylor Kevin J. Edgar 《Cellulose (London, England)》2013,20(4):2137-2149
Naringenin (Nar) is an important bioactive flavonoid with poor organic solubility and oral bioavailability. It is highly promising for treatment of conditions including diabetes, hyperlipidemia, and hepatitis C infection. Amorphous solid dispersion (ASD) of Nar is an appealing way to enhance its solubility, and carboxylated cellulose esters are attractive polymers for this purpose because of their ability to stabilize drugs against crystallization in both solid and solution phases, while restricting drug release to the pH of the small intestine (ca. 6.8). We demonstrate that ASDs of Nar can be formed using such carboxylated cellulose derivatives as cellulose acetate adipate propionate (CAAdP), carboxymethylcellulose acetate butyrate (CMCAB) and hydroxypropylmethylcellulose acetate succinate (HPMCAS). We compare Nar solution concentrations and release profiles from these cellulosic ASDs to those from pure crystalline Nar, and to Nar ASD in poly(vinylpyrrolidinone) (PVP). We show that all polymers in this study form ASDs with Nar, that the PVP ASDs release Nar at both gastric (1.2) and small intestine (6.8) pH, and that the cellulosic polymers release Nar selectively at neutral pH. Solution concentrations of Nar are significantly enhanced from these ASDs. These preliminary studies indicate that HPMCAS, CAAdP, and CMCAB are practical ASD polymers for Nar due to their ability to generate and stabilize high solution concentrations, and their pH-triggered drug release. 相似文献
92.
New types of carboxyl-terminated hyperbranched polyesters (HBPEs) with aromatic-aliphatic structure were synthesized by single step-melt polycondensation of adipic acid (as A2 monomer) and phloroglucinol (as B3 monomer) as a core via A2 + B3 approach, at three different monomer mole ratios (A2/B3 = 1: 1, 1.5: 1, 2: 1, respectively). FTIR spectroscopy indicated that the polymers contained hydroxyl groups, ester bonds, benzene ring, methyl and methylene groups, which were in agreement with the expected HBPEs. The HBPEs have inherent viscosities about 0.24 to 0.27 dL/g. The degree of branching of the HBPEs was estimated to be 0.45–0.49% by 1H-NMR and 13C-NMR measurements. The melting temperature of HBPE-1, HBPE-2 and HBPE-3 were 154, 155 and 160°C respectively measured by differential scanning calorimetry (DSC). The synthesized polymers were thermally stable; the thermogravimetric analysis (TGA) measurement revealed that HBPEs had 10% weight loss at 310°C in nitrogen. 相似文献
93.
Oxidation of cyclohexene and styrene with sodium periodate and tetra‐n‐butylammonium periodate (TBAP) catalyzed by MnT(3‐MePy)P(OAc), MnT(4‐SO3)PP(OAc) and MnTPP(OAc) has been studied in water, methanol, acetonitrile and dichloromethane as solvents. The results show significant dependence of the product distribution on the type of solvent and the electronic nature of the aryl substituents introduced at the porphyrin periphery. While the oxidation of cyclohexene and styrene in the presence of MnT(3‐MePy)P(OAc) and MnTPP(OAc) in water (also in methanol) gave the corresponding epoxides as nearly the sole product, performing the reactions in the presence of MnT(4‐SO3)PP(OAc) yielded the products of allylic oxidation, cyclohexene‐2‐ol and cyclohexene‐2‐one and acetophenone as the major products. In the case of styrene, performing the reaction in the presence of MnT(4‐SO3)PP(OAc), MnT(3‐MePy)P(OAc) and MnTPP(OAc) in acetonitrile gave a mixture of styrene oxide and acetophenone as the products. Under the same conditions, the oxidation of cyclohexene afforded cyclohexene oxide as approximately the exclusive product. Furthermore, the oxidation of olefins in dichloromethane gave the corresponding epoxide as the exclusive products. The product distributions observed in the protic and aprotic solvents were used to provide indirect evidence on the relative contribution and reactivity of high valent manganese oxo and periodato Mn(III) porphyrin species to the oxidation reactions. 相似文献
94.
Fazaeli Yousef Hosseini Mohammad Amin Shahabinia Fatemeh Feizi Shahzad 《Journal of Radioanalytical and Nuclear Chemistry》2019,320(1):201-207
Journal of Radioanalytical and Nuclear Chemistry - Porphyrins and 68Ga have emerged as novel synergic options for PET applications so the idea of preparation of a novel porphyrin complex using this... 相似文献
95.
Waseem Sharaf Saeed Hamad Abdullah Al-Lohedan Abdel-Basit Mohammed Al-Odayni Abdulaziz Ali Alghamdi Ahmad Abdulaziz Al-Owais 《Journal of Dispersion Science and Technology》2019,40(1):128-139
An n-butyl bromide/sodium dodecyl sulfate/n-butanol/water microemulsion system was chosen as a model of an organohalide-containing microemulsion. Two systems were prepared using the Bourayne method: a water-rich system and an n-butyl-bromide-rich system. The destabilization of this micro-organized system and the phase separation were investigated. This microemulsion, in which the oil phase in the feed is the lower layer, was successfully destabilized using the pervaporation technique with polydimethylsiloxane and poly(vinyl alcohol) membranes. In this way, different factors governing the separation process were investigated such as the mass transfer and the effect of time and operating temperature on the microemulsion destabilization. 相似文献
96.
Saeed Bahadorikhalili Samira Ansari Haleh Hamedifar Leila Ma'mani Mohsen Babaei Rahim Eqra Mohammad Mahdavi 《应用有机金属化学》2019,33(4)
In this paper, a novel catalyst is introduced based on the immobilization of palladium on modified magnetic graphene oxide nanoparticles. The catalyst is characterized by several methods, including transmission electron microscopy, scanning electron microscopy, X‐ray fluorescence, vibrating‐sample magnetometer, Fourier transform‐infrared and dynamic light scattering (DLS) analysis. The activity of the catalyst was investigated in the synthesis of 4(3H)‐quinazolinones via Pd‐catalyzed carbonylation‐cyclization of N‐(2‐bromoaryl) benzimidamides by Mo (CO)6. The Mo (CO)6 is used as a carbon monoxide source for performing the reaction under mild conditions. The catalyst showed good reusability, and no change in activity was observed after 10 cycles of recovery. 相似文献
97.
98.
99.
Abdo A Saeed F Hamza H Ahmed A Salim N 《Journal of computer-aided molecular design》2012,26(3):279-287
Query expansion is the process of reformulating an original query to improve retrieval performance in information retrieval
systems. Relevance feedback is one of the most useful query modification techniques in information retrieval systems. In this
paper, we introduce query expansion into ligand-based virtual screening (LBVS) using the relevance feedback technique. In
this approach, a few high-ranking molecules of unknown activity are filtered from the outputs of a Bayesian inference network
based on a single ligand molecule to form a set of ligand molecules. This set of ligand molecules is used to form a new ligand
molecule. Simulated virtual screening experiments with the MDL Drug Data Report and maximum unbiased validation data sets
show that the use of ligand expansion provides a very simple way of improving the LBVS, especially when the active molecules
being sought have a high degree of structural heterogeneity. However, the effectiveness of the ligand expansion is slightly
less when structurally-homogeneous sets of actives are being sought. 相似文献
100.
An economic process for manufacturing of molten carbonate fuel cells was developed. This process consisted of fabricating
the matrix by simply cutting it from a highly porous part with the geometry like an insulator brick, brush painting of the
cathode layer followed by sintering and deposition of anode layer through thermal spray process. In order to manage the electrolyte
content in the matrix and electrodes, coating of outer surfaces of the produced matrix with alumina slurry provided the required
pores with small size at the interfaces with the electrodes. The polarization curves of the cells with alumina slurry coating
and without it were not significantly different. The produced layer with small pores at the matrix outer surfaces caused the
vaporization of the molten carbonate salt electrolyte to be reduced from 22.9% to 14.4% of initially infiltrated in salt weight
content within 100 h of heat treating at 650 °C. This is at the same time to have the benefit of larger supply of electrolyte
due to the application of highly porous matrix. 相似文献