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991.
Journal of High Energy Physics - We prove using invariance under the modular S− and ST −transformations that every unitary two-dimensional conformal field theory (CFT) having only... 相似文献
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Mercedes Salazar Hernández Carmen Salazar Hernández Alfredo Gutiérrez Fuentes Enrique Elorza Marcelino Carrera-Rodríguez María J. Puy Alquiza 《Journal of Sol-Gel Science and Technology》2014,71(3):514-521
Silica was obtained from rice husk, this type of silica is also known as SiO2-rice, was investigated as drug delivery for the folic acid. The SiO2-rice was obtained from calcinations at 600 °C and its textural properties were compared with mesoporous silica (MS). The maximum folic acid adsorption on SiO2-rice was at the 18 % weight, while MS adsorbs 19 % weight. An important pH effect on the drug released was observed; both silicas released around 35 % of acid folic at pH 7, while at pH 3 only 3 % of the drug was released. Differential Thermal Analyzer analysis suggests that the folic acid was not crystallized into the porous of the silica; therefore, it is possible that the drug was trapped within the complex network of pores preventing their full release. However, the drug released for 400 μg of folic acid, a commercial dose, indicated that until 93 % of drug could be released for the silicas at pH of 5.5; a minor desorption was observed by commercial tablet. 相似文献
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Synthesis and characterization of tributyltin derivatives from 4‐oxo‐4‐(arylamino)butanoic acids and their in vitro biological activity against cervical cancer cell lines
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Irma Rojas‐Oviedo Carlos Camacho‐Camacho Luis Sánchez‐Sánchez Jorge Cárdenas Hugo López‐Muñoz Hugo Eugenio‐Robledo Israel Velázquez Rubén Alfredo Toscano 《应用有机金属化学》2014,28(12):884-891
Uterine (cervix and corpus) cancer is one of the major causes of mortality in women in Mexico. Organotin carboxylated derivatives have shown high cytotoxic activity against various cell lines of human origin. We describe the synthesis of three new tri‐n‐butyltin derivatives from 4‐oxo‐4‐(arylamino)butanoic acids; their structures were confirmed using spectral data (1H NMR, 13C NMR, 119Sn NMR and infrared), elemental analyses, mass spectrometry and X‐ray diffraction. All the tri‐n‐butyltin carboxylates exhibit 1 J (119/117Sn–13C) coupling satellites in solution and lie in the range 357 to 339 Hz, suggesting a tetrahedral geometry around the tin atom. The polymeric structures of two of the derivatives and the monomeric structure of another were confirmed using X‐ray crystallography. Using succinic anhydride as raw material, five N‐substituted succinamic acid compounds were synthesized by the acylation reaction with aniline, 4‐nitroaniline, 4‐nitro‐3‐(trifluoromethyl)aniline, 2‐amino‐5‐nitrothiazole and 4‐aminoantipyrine. From these compounds, five tin derivatives were prepared and their in vitro anti‐proliferative effect on HeLa, CaSki and ViBo cell lines was screened. All of the compounds showed potency against all three strains and null or low cytotoxic activity (necrotic) as well. The most potent of our derivatives as an anti‐proliferative agent against the three cell lines was tributylstannyl 4‐oxo‐4‐[(3‐trifluoromethyl‐4‐nitrophen‐1‐yl)amino]butanoate, exhibiting an IC50 value of 0.43 μM against the HeLa cell line. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Wastewaters and by-products generated in the winemaking process are important and inexpensive sources of value-added compounds that can be potentially reused for the development of new products of commercial interest (i.e., functional foods). This research was undertaken in order to evaluate the potential of nanofiltration (NF) membranes in the recovery of anthocyanins and monosaccharides from a clarified Carménère grape marc obtained through a combination of ultrasound-assisted extraction and microfiltration. Three different flat-sheet nanofiltration (NF) membranes, covering the range of molecular weight cut-off (MWCO) from 150 to 800 Da, were evaluated for their productivity as well as for their rejection towards anthocyanins (malvidin-3-O-glucoside, malvidin 3-(acetyl)-glucoside, and malvidin 3-(coumaroyl)-glucoside) and sugars (glucose and fructose) in selected operating conditions. The selected membranes showed differences in their performance in terms of permeate flux and rejection of target compounds. The NFX membrane, with the lowest MWCO (150–300 Da), showed a lower flux decay in comparison to the other investigated membranes. All the membranes showed rejection higher than 99.42% for the quantified anthocyanins. Regarding sugars rejection, the NFX membrane showed the highest rejection for glucose and fructose (100 and 92.60%, respectively), whereas the NFW membrane (MWCO 300–500 Da) was the one with the lowest rejection for these compounds (80.57 and 71.62%, respectively). As a general trend, the tested membranes did not show a preferential rejection of anthocyanins over sugars. Therefore, all tested membranes were suitable for concentration purposes. 相似文献