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991.
992.
Vanessa Orsi Gordo Leonilson KS Herval Helder VA Galeti Yara Galv?o Gobato Maria JSP Brasil Gilmar E Marques Mohamed Henini Robert J Airey 《Nanoscale research letters》2012,7(1):592
We have studied the polarized resolved photoluminescence of n-type GaAs/AlAs/GaAlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. Under resonant tunneling conditions, we have observed two emission lines attributed to neutral (X) and negatively charged excitons (X−). We have observed a voltage-controlled circular polarization degree from the quantum well emission for both lines, with values up to −88% at 15 T at low voltages which are ascribed to an efficient spin injection from the 2D gases formed at the accumulation layers. 相似文献
993.
Angelo Zinellu Salvatore Sotgia Maria Franca Usai Luca Deiana Ciriaco Carru 《European Journal of Lipid Science and Technology》2006,108(5):444-447
Lipoprotein(a) [Lp(a)] is a recognized risk factor for atherosclerotic cardiovascular disease. It is made of a lipoprotein particle containing apoB100 linked by a single disulfide bridge to apolipoprotein(a), a glycosylated protein with a variable mass. Some authors suggest that oxidative modification could explain the contribution of Lp(a) in the development of atheromatous lesions in a comparable way to low‐density lipoproteins (LDL). Recently, the use of capillary electrophoresis to measure the variations in the relative electrophoretic mobility (REM) of LDL subjected to copper oxidation has been proposed. The aim of this work is to employ this method also to monitor the copper‐induced oxidative modification of Lp(a). Migration of Lp(a) was monitored by absorption at 200 nm in a 50 mmol/L tricine, 100 mmol/L methylglucamine, pH 9.7 run buffer. Contrary to the conventional slab gel methods, our procedure provides a rapid and reproducible means to measure the electrophoretic mobility of Lp(a) (migration time <10 min with a CV% <0.5). 相似文献
994.
Konrad Grob Angelo Maria Giuffr Ugo Leuzzi Biagio Mincione 《European Journal of Lipid Science and Technology》1994,96(8):286-290
Recognition of adulteration by other oils via direct analysis of the minor components (“sterol fraction”) is shown for olive oil. 10 % of various oils were admixed, the free alcohols silylated and the minor components analyzed by on-line coupled LC-GC-FID. For most oils, even smaller additions can be recognized. Admixed oils can no longer be determined, however, if their minor components have been removed by strong raffination. Bleaching of rapeseed oil with 7% of earth at 180 °C, in fact, completely removed free and esterified sterols. 相似文献
995.
Pâmela Maria Moreira Fonseca Paulo Luiz De Sá Júnior Walter Miyakawa Álvaro José Damião L.H. Moreira da Silva Melo Renato Amaro Zângaro 《臭氧:科学与工程》2019,41(3):242-249
Ozonated water has been demonstrated to induce significant results in terms of the elimination of microorganisms. The present study assessed the damage to Streptococcus mutans after exposure to ozonated water; the ozone generator was adjusted to provide an outlet concentration of 60 mg/L, the samples were submitted to different ozonation times 1, 2, 4, 6, and 10 mi. Scanning electron microscopy and atomic force images were obtained to identify damage to the bacteria, followed by reactive oxygen species (ROS) evaluation and microbial viability. The results showed a significant reduction in viability and the images evidenced the generation of gaps on the microbial wall and surface layer alterations. Ozone can induce significant damage to S. mutans, thus suggesting that the use of ozonated water to prevent carious lesion formation is extremely promising. 相似文献
996.
Dr. Elena Marchesi Dr. Nicola Chinaglia Dr. Massimo L. Capobianco Dr. Paolo Marchetti Tzu-En Huang Hao-Cheng Weng Dr. Jih-Hwa Guh Dr. Lih-Ching Hsu Dr. Daniela Perrone Dr. Maria Luisa Navacchia 《ChemMedChem》2019,14(7):779-787
A series of hybrid compounds based on natural products—bile acids and dihydroartemisinin—were prepared by different synthetic methodologies and investigated for their in vitro biological activity against HL-60 leukemia and HepG2 hepatocellular carcinoma cell lines. Most of these hybrids presented significantly improved antiproliferative activities with respect to dihydroartemisinin and the parent bile acid. The two most potent hybrids of the series exhibited a 10.5- and 15.4-fold increase in cytotoxic activity respect to dihydroartemisinin alone in HL-60 and HepG2 cells, respectively. Strong evidence that an ursodeoxycholic acid hybrid induced apoptosis was obtained by flow cytometric analysis and western blot analysis. 相似文献
997.
Maarten Sijm Julianna Siciliano de Araújo Alba Ramos Llorca Dr. Kristina Orrling Lydia Stiny An Matheeussen Prof. Dr. Louis Maes Prof. Dr. Iwan J. P. de Esch Dr. Maria de Nazaré Correia Soeiro Dr. Geert Jan Sterk Prof. Dr. Rob Leurs 《ChemMedChem》2019,14(18):1662-1668
Chagas disease is becoming a worldwide problem; it is currently estimated that over six million people are infected. The two drugs in current use, benznidazole and nifurtimox, require long treatment regimens, show limited efficacy in the chronic phase of infection, and are known to cause adverse effects. Phenotypic screening of an in-house library led to the identification of 2,2′-methylenebis(5-(4-bromophenyl)-4,4-dimethyl-2,4-dihydro-3H-pyrazol-3-one), a phenyldihydropyrazolone dimer, which shows an in vitro pIC50 value of 5.4 against Trypanosoma cruzi. Initial optimization was done by varying substituents of the phenyl ring, after which attempts were made to replace the phenyl ring. Finally, the linker between the dimer units was varied, ultimately leading to 2,2′-methylenebis(5-(3-bromo-4-methoxyphenyl)-4,4-dimethyl-2,4-dihydro-3H-pyrazol-3-one (NPD-0228) as the most potent analogue. NPD-0228 has an in vitro pIC50 value of 6.4 against intracellular amastigotes of T. cruzi and no apparent toxicity against the human MRC-5 cell line and murine cardiac cells. 相似文献
998.
Dr. Sónia Teixeira Dr. Miguel M. Santos Prof. Ricardo Ferraz Prof. Cristina Prudêncio Prof. Maria H. Fernandes Prof. João Costa-Rodrigues Dr. Luís C. Branco 《ChemMedChem》2019,14(20):1767-1770
Novel ionic liquids and organic salts based on mono- or dianionic zoledronate and protonated superbases, choline and n-alkylmethylimidazolium cations, were prepared and characterized by spectroscopic and thermal analyses. Most of the prepared salts display amorphous structures and very high solubility in water and saline solutions, especially the dianionic salts. Among the zoledronate-based ionic compounds, those containing choline [Ch] and methoxyethylmethylimidazolium [C3OMIM] cations appear to have significant cytotoxicity against human osteosarcoma cells (MG63) and low toxicity toward healthy skin fibroblast cells. Because osteosarcoma is a bone pathology characterized by an increase in bone turnover rate, the results presented herein may be a promising starting point for the development of new ionic pharmaceutical drugs against osteosarcoma. 相似文献
999.
Poly(l ‐lactic acid) (PLLA) is a biodegradable and biocompatible thermoplastic polyester produced from renewable sources, widely used for biomedical devices, in food packaging and in agriculture. It is a semicrystalline polymer, and as such its properties are strongly affected by the developed semicrystalline morphology. As a function of the crystallization temperature, PLLA can form different crystal modifications, namely α′‐crystals below about 120 °C and α‐crystals at higher temperatures. The α′ modification is therefore of special importance as it may be the preferred polymorph developing at processing‐relevant conditions. It is a metastable modification which typically transforms into the more stable α‐crystals on annealing at elevated temperature. The structure, kinetics of formation and thermodynamics of α′‐ and α‐crystals of PLLA are reviewed in this contribution, together with the effect of α′‐/α‐crystal polymorphism on the properties of PLLA. © 2018 Society of Chemical Industry 相似文献
1000.
Nathana L. Cristofoli Carlos Alexandre R. Lima Maria Margarida C. Vieira Kátia S. Andrade 《分离科学与技术》2019,54(4):580-590
Cajazeira leaves (Spondias mombin) have their highlighted use as antioxidant and natural antimicrobial, which justifies the objective of this work to evaluate the biological activities of different extracts. In order to evaluate the antioxidant and antimicrobial potentials of the cajazeira leaves, extractions at low pressure and high pressure were performed. The low pressure extractions (PLE) were carried out using Soxhlet (SOX) and tip ultrasound, using different solvents. Supercritical fluid extraction (SFE) was evaluated at temperature of 40?60°C and pressure of 150?300 bar besides extraction with cosolvent. Higher yields were obtained with the use of more polar solvents at LPE. The extracts obtained by SOX with ethanol and others polar solvents presented the best TPC values and antioxidant activity. The extracts at LPE with hexane and ethyl acetate and SFE presented better antimicrobial activity. Through liquid chromatography of high efficiency, it was possible to identify compounds with recognized biological activity, like ellagic acid, gallic acid and catechin. 相似文献