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171.
Fernando Aguilar Fatima E.M. Alaoui Jos J. Segovia Miguel A. Villaman Eduardo A. Montero 《Fluid Phase Equilibria》2009,284(2):106-113
Experimental excess molar enthalpies of the ternary systems dibutyl ether (DBE) + 1-butanol + benzene and the corresponding binary systems at T = 298.15 K and T = 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich-Kister equation and the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations. 相似文献
172.
Marc Montana Vincent Montero Omar Khoumeri Patrice Vanelle 《Molecules (Basel, Switzerland)》2021,26(16)
Background. The past decades have seen numerous efforts to develop new antitubercular agents. Currently, the available regimens are lengthy, only partially effective, and associated with high rates of adverse events. The challenge is therefore to develop new agents with faster and more efficient action. The versatile quinoxaline ring possesses a broad spectrum of pharmacological activities, ensuring considerable attention to it in the field of medicinal chemistry. Objectives. In continuation of our program on the pharmacological activity of quinoxaline derivatives, this review focuses on potential antimycobacterial activity of recent quinoxaline derivatives and discusses their structure—activity relationship for designing new analogs with improved activity. Methods. The review compiles recent studies published between January 2011 and April 2021. Results. The final total of 23 studies were examined. Conclusions. Data from studies of quinoxaline and quinoxaline 1,4-di-N-oxide derivatives highlight that specific derivatives show encouraging perspectives in the treatment of Mycobacterium tuberculosis and the recent growing interest for these scaffolds. These interesting results warrant further investigation, which may allow identification of novel antitubercular candidates based on this scaffold. 相似文献
173.
Belén Montero Carmen Ramírez Maite Rico Araceli Torres Jesús Cano Joaquín López 《Macromolecular Symposia》2008,267(1):74-78
A novel inorganic-organic hybrid material, belonging to the family of polyhedral oligomeric silsesquioxanes (POSS), was used to reduce the trend of a conventional epoxy-amine system to undergo combustion. The mixtures with different percentages in weight of POSS, and equal number of equivalents between of epoxy and amino groups were tested by thermogravimetic analysis (TGA) in both, argon and oxygen atmospheres. The results indicated that the char/ceramic yield values increase with the content of POSS and therefore, fire resistance is enhanced. Activation energies of degradation processes were obtained by Kissinger-Akahira-Sunose method. An empirical kinetic model satisfactorily explained the degradation mechanism of different blends. 相似文献
174.
The miscibility of a thermoplastic, polystyrene (PS), with the precursors of several epoxy-amine systems has been studied thermodynamically and experimentally. The epoxy-amine systems were different only in the origin of amino groups, which were provided by a monoamine (MA) and a diamine (DA) in different proportions. Cloud-point curves (CPC) at conversion zero were reported for five modified systems with different MA-DA proportion. All CPCs showed an UCST behaviour. CPC shifted to lower temperatures when the ratio of MA/DA in the system increased, meaning that the MA produces an increase in the miscibility of the system. A model based on the Flory-Huggins theory was used for the thermodynamic analysis, in which the dependence of interaction parameter on temperature and composition, χ(T,ϕ), and the polydispersity of components were considered. A general equation for χ(T,ϕ) also depending on the MA-DA proportion was reached and used to obtain the phase diagram of the different systems. A high level of agreement between theoretical and experimental CPCs was obtained. 相似文献
175.
Eleonora Casula Maria Manconi Jos Antonio Vzquez Tania Belen Lopez-Mendez Jos Luis Pedraz Esteban Calvo Antonio Lozano Marco Zaru Andreia Ascenso Maria Letizia Manca 《Molecules (Basel, Switzerland)》2021,26(21)
The extract of Cardiospermum halicacabum L. (C. halicacabum) obtained from flower, leaf and vine was loaded into modified phospholipid vesicles aiming at obtaining sprayable, biocompatible and effective nasal spray formulations for the treatment of nasopharyngeal diseases. Penetration enhancer-containing vesicles (PEVs) and hyalurosomes were formulated, and stabilized by adding a commercial gelatin from fish (20 mg/mL) or chondroitin sulfate from catshark cartilages (Scyliorhinus canicula, 20 mg/mL). Cryo-TEM images confirmed the formation of spherical vesicles, while photon correlation spectroscopy analysis disclosed the formation of small and negatively-charged vesicles. PEVs were the smaller vesicles (~100 nm) along with gelatin-hyalurosomes (~120 nm), while chondroitin-PEVs and chondroitin-hyalurosomes were larger (~160 nm). Dispersions prepared with chondroitin sulfate were more homogeneous, as the polydispersity index was ~0.15. The in vitro analysis of the droplet size distribution, average velocity module and spray cone angle suggested a good spray-ability and deposition of formulations in the nasal cavity, as the mean diameter of the droplets was in the range recommended by the Food and Drug Administration for nasal targets. The spray plume analysis confirmed the ability of PEVs, gelatin-PEVs, hyalurosomes and gelatin-hyalurosomes to be atomized in fine droplets homogenously distributed in a full cone plume, with an angle ranging from 25 to 30°. Moreover, vesicles were highly biocompatible and capable of protecting the epithelial cells against oxidative damage, thus preventing the inflammatory state. 相似文献
176.
Rubio Montero M. P. Carrasco Lourtau A. M. Jurado Vargas M. Durán Valle C. J. 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):451-461
Journal of Radioanalytical and Nuclear Chemistry - In the pyrolysis process carried out to obtain charcoal from plants, a concentration of the radionuclides found in trace amounts in the raw... 相似文献
177.
178.
We make a comparative study of the different asymptotic forms of the dynamical mass in quantum chomodynamics. Using the effective potential for composite operator we can determine which one of those dynamical mass correspond to a chiral-symmetry breaking à 1 a Nambu-Goldstone. 相似文献
179.
180.