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671.
672.
Amedeo Marini Vittorio Berbenni Giovanna Bruni Piercarlo Mustarelli Ferdinando Giordano Marco Villa 《Journal of inclusion phenomena and macrocyclic chemistry》1995,22(3):221-234
A method to determine the composition and hydration state of the complexes formed in aqueous solution by cyclodextrins (CD) is presented and applied to the -CD/ketoprofen system; it is based on a combination of spectroscopic, calorimetric, and thermogravimetric analyses. The complexes have, on average and per -CD mole, more than eleven water molecules, which are present in completely different bound states. 相似文献
673.
Gelesky MA Umpierre AP Machado G Correia RR Magno WC Morais J Ebeling G Dupont J 《Journal of the American Chemical Society》2005,127(13):4588-4589
Stable Pd(0) and Rh(0) nanoparticles with small and narrow size distribution can be prepared from relative large and agglomerated transition-metal particles dispersed in 1-n-butyl-3methylimidazolium hexafluorophosphate ionic liquid by simple laser irradiation. The laser irradiation is a complementary method for the generation of stable metal colloids in ionic liquids and also for the regeneration of small-size nanoparticles that may result from their agglomeration after different applications. 相似文献
674.
Giovanna Pressi Roberto Dal Toso Renzo Dal Monte Giovanni Carturan 《Journal of Sol-Gel Science and Technology》2003,26(1-3):1189-1193
Ajuga reptans cells are cultivated and used for production of invertase. These plant cells are immobilized by a sol-gel SiO2 membrane, which is built up directly on the cell surface by exposure to a gaseous flow of silicon alcoxide precursors. The immobilization modifies the metabolic activity of cells, resulting in a 40-fold increase in invertase production with respect of free cells. Results concerning total release of proteins, cell growth and produced invertase activity are discussed, considering the absence of breeding, induced by SiO2 immobilization, the prominent factor promoting the observed exceptional increase in invertase productivity. 相似文献
675.
Ivana Fenoglio Dr. Giovanna Greco Dr. Stefano Livraghi Dr. Bice Fubini Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(18):4614-4621
Kept in the dark : The non‐photocatalytic generation of free radicals from fine and ultrafine TiO2 particles has been studied by means of a spin‐trapping/ESR spectroscopy technique (see figure). The amount and kind of free radicals generated depends on the crystalline structure, but not on the particle dimensions.
676.
Riccardo Di Corato Philomena Piacenza Mariarosaria Musarò Raffaella Buonsanti Pantaleo Davide Cozzoli Massimo Zambianchi Giovanna Barbarella Roberto Cingolani Liberato Manna Teresa Pellegrino 《Macromolecular bioscience》2009,9(10):952-958
Nanostructures displaying fluorescence and magnetic properties at the same time are potentially useful for achieving simultaneous bio‐separation and bio‐sensing (e.g., magnetic separation coupled with multiplexing optical detection of different tumour cell populations). Spherical nanobeads that display both fluorescent and magnetic features are reported; they are fabricated by grafting fluorescent oligothiophene molecules to an amphiphilic polymer that is then used to enwrap iron oxide nanoparticles, which acts as the magnetic domain. By tuning experimental conditions, control over the number of magnetic nanoparticles per bead and over the bead diameter (30–400 nm) was achieved. A cell separation efficiency of the level required for cell sorting applications is also reported.
677.
Laschi S Miranda-Castro R González-Fernández E Palchetti I Reymond F Rossier JS Marrazza G 《Electrophoresis》2010,31(22):3727-3736
In this work, the characterisation and the optimisation of hybridisation assays based on a novel, rapid and sensitive micro-analytical, gravity-driven, flow device is reported. This device combines a special chip containing eight polymer microchannels, with a portable, computer-controlled instrument. The device is used as a platform for affinity experiments using oligonucleotide-modified paramagnetic particles. In our approach, both hybridisation and labelling events are performed on streptavidin-coated paramagnetic microparticles functionalized with a biotinylated capture probe. Modified particles, introduced in the microchannel inlet of the chip, accumulate near the electrode surface by virtue of a magnetic holder. After hybridisation with the complementary sequence, the hybrid is labelled with an alkaline phosphatase conjugate. The electrochemical substrate for alkaline phosphatase revelation is p-aminophenyl phosphate. Solutions and reagents are sequentially passed through the microchannels, until enzyme substrate is added for in situ signal detection. Upon readout, the magnet array is flipped away, beads are removed by addition of regeneration buffer, and the so-regenerated chip is ready for further analysis. This protocol has been applied to the analytical detection of specific DNA sequences of Legionella pneumophila, with an RSD=8.5% and a detection limit of 0.33 nM. 相似文献
678.
Metadynamics Simulations Rationalise the Conformational Effects Induced by N‐Methylation of RGD Cyclic Hexapeptides 下载免费PDF全文
Cristina Paissoni Dr. Michela Ghitti Prof. Laura Belvisi Dr. Andrea Spitaleri Dr. Giovanna Musco 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):14165-14170
We combined metadynamics, docking and molecular mechanics/generalised born surface area (MM/GBSA) re‐scoring methods to investigate the impact of single and multiple N‐methylation on a set of RGD cyclopeptides displaying different affinity for integrin αIIbβ3. We rationalised the conformational effects induced by N‐methylation and its interplay with receptor affinity, obtaining good agreement with experimental data. This approach can be exploited before entering time‐consuming and expensive synthesis and binding experiments. 相似文献
679.
Paola Mura Giovanna Corti Francesca Maestrelli Marzia Cirri 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(3-4):307-313
The present work was performed to investigate the effect of chitosan, a well known hydrophilic polymer with both enhancer and solubilizing properties, on the solubilizing and complexing abilities of cyclodextrins towards drugs. With this aim, phase-solubility studies were carried out with a series of model drugs, both of acid and basic nature and with different water-solubility and lipophilicity values, in the presence of chitosan and cyclodextrin (ß- or hydroxypropyl-ß-cyclodextrin), both separately (binary systems) and in combination (ternary systems). Unexpectedly, differently from the favorable effect reported in literature for various hydrophilic polymers, the addition of chitosan to the cyclodextrin complexation medium caused a decrease in the cyclodextrin complexing power towards all the examined drugs, independent from their very different physicochemical properties. On the contrary, the influence of the polymer on the cyclodextrin solubilizing efficiency was found to be dependent on the type of drug and both positive, or negative or non-significant effects were observed. The overall results are explained in terms of a common basic mechanism due to the presence of chitosan–cyclodextrin interactions, which hindered the drug–cyclodextrin complex formation, thus causing the binding constant reduction; the simultaneous presence of drug–chitosan and/or chitosan–(drug–cyclodextrin complex) interactions, different from drug to drug, were considered responsible for the distinct (and sometimes opposite) effects observed in the drug solubilizing efficiency of ternary systems. 相似文献
680.
Alessia Tropea David Wilson Nicola Cicero Angela G. Potortì Giovanna L. La Torre Giacomo Dugo 《Natural product research》2016,30(9):1009-1016
Ethanol production by fermentation is strongly dependent on media composition. Specific nutrients, such as trace elements, vitamins and nitrogen will affect the physiological state and, consequently, the fermentation performance of the micro-organism employed. The purpose of this study has been to assess the highest ethanol production by a minimal medium, instead of the more complex nutrients supplementation used during alcoholic fermentation. All fermentation tests were carried out using a microwell plate reader to monitor the processes. Two Saccharomyces cerevisiae strains (NCYC 2826 and NCYC 3445) were tested using three nitrogen sources, supplied with different vitamin and salts. The results show that solutions made of urea phosphate, KCl, MgSO4·7H2O, Ca-panthothenate, biotin allowed an ethanol yield of 22.9 and 23.4 g/L for strain NCYC 2826 and NCYC 3445, respectively, representing 90 and 92% of the theoretical yield. All tests were carried out using glucose as common reference carbon source. 相似文献