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141.
The momentum distribution of protons in the hydration shell of a globular protein has been measured through deep inelastic neutron scattering at 180 and 290 K, below and above the crossover temperature Tc=1.23Tg, where Tg=219 K is the glass transition temperature. It is found that the mean kinetic energy of the water hydrogens shows no temperature dependence, but the measurements are accurate enough to indicate a sensible change of momentum distribution and effective potential felt by protons, compatible with the transition from a single to a double potential well. This could support the presence of tunneling effects even at room temperature, playing an important role in biological function. 相似文献
142.
S Bruni E Cariati F Cariati F A Porta S Quici D Roberto 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2001,57(7):1417-1426
For fluorescent compounds, the combined use of absorption and emission solvatochromic data allows to estimate indirectly the cavity radius of the molecule in solution, a very critical parameter in the application of the solvatochromic method for the determination of the quadratic hyperpolarizability beta of dipolar molecules. For two test compounds, trans-4-[4-(dimethylamino)styryl]pyridine (DASP) and 5-dimethylamino-1,10-phenanthroline (DAPHEN), the beta values so obtained are compared with those obtained by the EFISH (Electric Field Induced Second-Harmonic generation) technique. For DAPHEN, the versatility of the method described in this work in the presence of more than one electronic transition contributing to the non-linear optical response is demonstrated. 相似文献
143.
144.
Giovanna Bruni Franco Sartor Vittorio Berbenni Chiara Milanese Mariarosa Maietta Dionigio Franchi Amedeo Marini 《Journal of Thermal Analysis and Calorimetry》2012,108(1):381-388
In this study, we present a full thermal characterization of antidepressant paroxetine and summarize the results for another
drug which treats depression: GW597599B. The main aim is to analyze how the thermodynamic and structural properties of these
compounds are modified when the two drugs are mixed in the solid state. We begin by putting into evidence how dehydration
and melting concur in shaping the calorimetric curves of paroxetine under different experimental conditions. Equipped with
this knowledge, we are able to interpret the thermal response of the physical mixtures paroxetine:GW597599B, in terms of partial
eutectic formation and simple superposition of contribution from the two compounds. 相似文献
145.
146.
Vittorio Berbenni Chiara Milanese Giovanna Bruni Alessandro Girella Amedeo Marini 《Journal of Thermal Analysis and Calorimetry》2012,110(2):831-837
Simultaneous TG?CDSC measurements have been used to study the solid state reaction in the system SnC2O4?C4MgCO3·Mg(OH)2·xH2O (Sn:Mg?=?0.5). The results obtained with physically prepared mixture and with mixture mechanically activated by high-energy milling are compared. Synthesis of the compound Mg2SnO4 has been attempted starting from both type of mixture: Mg2SnO4 forms by annealing the activated mixture at temperatures between 850 and 1,000?°C while it can hardly be obtained from physical mixtures even by thermal treatment at temperature as high as 1,300?C1,350?°C. Mg2SnO4 prepared by annealing the activated mixture has been characterized by diffuse reflectance FT-IR spectroscopy, modulated temperature differential scanning calorimetry, scanning electron microscopy, and specific surface area measurements (B.E.T. method). 相似文献
147.
Chiara Zaffino Giulia Dulcedo Bedini Giorgio Mazzola Vittoria Guglielmi Silvia Bruni 《Journal of Raman spectroscopy : JRS》2016,47(5):607-615
High‐performance liquid chromatography (HPLC) is still, today, the technique of choice for the analysis of natural dyes in artistic objects and historical textiles, particularly in association with photodiode array (PDA) detection. In the last two decades, surface‐enhanced Raman spectroscopy (SERS) gained also increasing importance for these investigations thanks to its sensitivity and limited requirements in terms of sample quantity. In favor of SERS, its high specificity in molecular recognition typical of vibrational spectroscopy should be mentioned, whereas this non‐separative technique is obviously disadvantaged in the analyses of mixed chromophores, as is often the case of many natural dyes and also of tints obtained by the combined use of different colorants. An optimized experimental setup combining the two techniques, HPLC‐PDA and SERS, is proposed in the present work, allowing online SERS detection of different dyeing compounds eluted from the HPLC column. Examples are presented concerning some of the colorants most widely used in history, such as morin and luteolin for yellow dyes, alizarin, purpurin, laccaic, kermesic, and carminic acids for red ones, and indigotin for blue tints. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
148.
Chiara Zaffino Silvia Bruni Bianca Russo Roberto Pilu Chiara Lago Gian Maria Colonna 《Journal of Raman spectroscopy : JRS》2016,47(3):269-276
The aim of the present study was to provide experimental procedures for the identification of anthocyanin‐based dyes used in antiquity. In particular, we assessed the possibility to identify anthocyanins, both in plant extracts and in dyed textiles, by means of surface‐enhanced Raman spectroscopy (SERS), a very chemically specific technique that is moreover sensitive to the changes in structures of molecules, phenomena that occur extensively in the chemistry of anthocyanins. The choice of the plant sources (bilberry, elderberry, sumac, purple corn and hollyhock) was based on their attested use in history as dyeing matters. Suitable extraction and pre‐treatment procedures were optimized both for plant sources (berries, cob glumes and flowers) and textiles dyed with such sources in the laboratory, followed by SERS analyses at different pH values. Finally, special attention was paid to the well‐known instability of anthocyanins: dyed wool samples were exposed to artificial aging in order to verify the possibility to identify such molecules also in faded textiles. The achievement of reliable surface‐enhanced Raman spectra from these samples encourages us to suggest the protocol for the analysis of historical objects. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
149.
Maria Elena Bruni 《4OR: A Quarterly Journal of Operations Research》2006,4(4):343-346
This is a summary of the main results presented in the author’s PhD thesis, supervised by D. Conforti and P. Beraldi and defended on March 2005. The thesis, written in English, is available from the author upon request. It describes one of the very few existing implementations of a method for solving stochastic mixed integer nonlinear programming problems based on deterministic global optimization. In order to face the computational challenge involved in the solution of such multi-scenario nonconvex problems, a branch and bound approach is proposed that exploits the peculiar structure of stochastic programming problem. 相似文献
150.
Elena Biasibetti Natascia Bruni Mauro Bigliati Maria Teresa Capucchio 《Natural product research》2018,32(17):2107-2110
Atopic dermatitis affects 3–15% of the general dog population and it has been diagnosed by veterinarians up to 58% of dogs affected with skin disease. It is usually a life-long pathology which can be controlled, but it can be seldom cured. The present investigation describes a case study in which lactoferricin and verbascoside are part of a formulation to obtain a dermatological lotion for canine dermatitis treatment. The study was an open-label trial design of two-week treatment. Thirty-eight dogs (23 females and 15 males), with atopic dermatitis and secondary bacterial or yeast overgrowth have been included. During treatment period the total clinical score progressively decreased associated with an improvement in clinical signs. No adverse effects were reported in any of the treated dogs. The present research suggests that daily applications of tested emulsion are effective in reducing bacterial overgrowth and clinical signs in skin folds and atopic dermatitis. 相似文献