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61.
Letizia Pellegrini Shengkun Zhu 《Journal of Optimization Theory and Applications》2018,177(3):788-810
The scalar finite-dimensional case has been discussed in the first part of this work series, which aims at exploiting the image space analysis to establish a general regularity condition for constrained extremum problems. Based on this preliminary result, the present paper dedicates itself to further study the regularity conditions for vector constrained extremum problems in a Euclidean space. The case of infinite-dimensional image will be the subject of a subsequent paper. 相似文献
62.
Chiodo L Salazar M Romero AH Laricchia S Della Sala F Rubio A 《The Journal of chemical physics》2011,135(24):244704
Atomic clusters of TiO(2) are modeled by means of state-of-the-art techniques to characterize their structural, electronic and optical properties. We combine ab initio molecular dynamics, static density functional theory, time-dependent density functional theory, and many body techniques, to provide a deep and comprehensive characterization of these systems. TiO(2) clusters can be considered as the starting seeds for the synthesis of larger nanostructures, which are of technological interest in photocatalysis and photovoltaics. In this work, we prove that clusters with anatase symmetry are energetically stable and can be considered as the starting seeds to growth much larger and complex nanostructures. The electronic gap of these inorganic molecules is investigated, and shown to be larger than the optical gap by almost 4 eV. Therefore, strong excitonic effects appear in these systems, much more than in the corresponding bulk phase. Moreover, the use of various levels of theory demonstrates that charge transfer effects play an important role under photon absorption, and therefore the use of adiabatic functionals in time dependent density functional theory has to be carefully evaluated. 相似文献
63.
Dr. Matthew P. Conley Ruben M. Drost Dr. Mathieu Baffert Dr. David Gajan Prof. Dr. Cornelis Elsevier Dr. W. Trent Franks Prof. Dr. Hartmut Oschkinat Laurent Veyre Alexandre Zagdoun Dr. Aaron Rossini Dr. Moreno Lelli Dr. Anne Lesage Dr. Gilles Casano Dr. Olivier Ouari Prof. Dr. Paul Tordo Prof. Dr. Lyndon Emsley Prof. Dr. Christophe Copéret Dr. Chloé Thieuleux 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(37):12234-12238
64.
Marianna Carbone M. Letizia Ciavatta Gianluca De Rinaldis Francesco CastelluccioErnesto Mollo Margherita Gavagnin 《Tetrahedron》2014
The re-investigation of the Mediterranean opisthobranch Thuridilla hopei resulted in the isolation and chemical characterization of three novel nor-diterpene aldehydes, nor-thuridillonals 2–4, structurally related to co-occurring already reported thuridillins. Analogous with the thuridillins, the new molecules were thought to derive from the same dietary precursor epoxylactone 1. 相似文献
65.
J. Derbali F. AbdelMalek S. S. A. Obayya H. Bouchriha R. Letizia 《Optical and Quantum Electronics》2011,42(8):463-472
The development of technology in photonic crystal (PC) structures has seen rapid progress. Using PCs in biosensing area may
open new venues to achieve single molecule detection, and high resolution scanning. A novel PC sensor with improved performances,
in terms of size, compactness and sensitivity is presented in this paper. The sensing element consists of dielectric cylinders
with varying radius introduced along <01> and <10> directions of the crystal. The results show that the peak wavelength shifts
to the high frequency region when only six cylinders are filled with analytes. Also, the peaks show a larger shift compared
to the structure obtained using the entire PC waveguide as sensing region. The proposed sensor shows a better sensitivity
to water than other analytes, where the peak wavelength tends to shift towards the low frequency region. 相似文献
66.
Ester Sara Di Filippo Letizia Giampietro Barbara De Filippis Marwa Balaha Vincenzo Ferrone Marcello Locatelli Tiziana Pietrangelo Angela Tartaglia Rosa Amoroso Stefania Fulle 《Molecules (Basel, Switzerland)》2020,25(23)
The increased risk of illness and disability is related to the age inevitable biological changes. Oxidative stress is a proposed mechanism for many age-related diseases. The crucial importance of polyphenol pharmacophore for aging process is largely described thanks to its effects on concentrations of reactive oxygen species. Resveratrol (3,5,4′-trihydroxy-trans-stilbene, RSV) plays a critical role in slowing the aging process but has a poor bioavailabity after oral intake. In this present work, a series of RSV derivatives was designed, synthesized, and evaluated as potential antioxidant agents. These derivatives contain substituents with different electronic and steric properties in different positions of aromatic rings. This kind of substituents affects the activity and the bioavailability of these compounds compared with RSV used as reference compound. Studies of Log P values demonstrated that the introduction of halogens gives the optimum lipophilicity to be considered promising active agents. Among them, compound 6 showed the higher antioxidant activity than RSV. The presence of trifluoromethyl group together with a chlorine atom increased the antioxidant activity compared to RSV. 相似文献
67.
Reversed‐phase high‐performance liquid chromatography method with fluorescence detection to screen nitric oxide synthases inhibitors
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Cristina Maccallini Mauro Di Matteo Alessandra Ammazzalorso Alessandra D'Angelo Barbara De Filippis Sara Di Silvestre Marialuigia Fantacuzzi Letizia Giampietro Assunta Pandolfi Rosa Amoroso 《Journal of separation science》2014,37(12):1380-1385
Nitric oxide synthase (NOS) inhibitors are potential drug candidates due to the critical role of an excessive production of nitric oxide in a range of diseases. At present, the radiometric detection of l ‐[3H]‐citrulline produced from l ‐[3H]‐arginine during the enzymatic reaction is one of the most accepted methods to assess the in vitro activity of NOS inhibitors. Here we report a fast, easy, and cheap reversed‐phase high‐performance liquid chromatography method with fluorescence detection, based on the precolumn derivatization of l ‐citrulline with o‐phthaldialdehyde/N‐acetyl cysteine, for the in vitro screening of NOS inhibitors. To evaluate enzyme inhibition by the developed method, N‐[3‐(aminomethyl)benzyl]acetamidine, a potent and selective inhibitor of inducible NOS, was used as a test compound. The half maximal inhibitory concentration obtained was comparable to that derived by the well‐established radiometric assay. 相似文献
68.
In this paper, we have reported an immunoassay with time-resolved revelation system for ampicillin in raw milk samples. Immunological methods appear to be a promising approach in the analysis of β-lactam compounds, because they do not need previous sample pre-treatments. In fact, β-lactam ring is not very stable in extensive sample pre-treatment procedures requested in conventional analytical techniques. Specimens were collected from lactating cows bred in various conditions and assayed for the fat contents. Ampicillin was assayed in samples with different fat concentrations. The assay was performed using ampicillin-specific polyclonal antibody raised in rabbit; the immunogen was synthesized using bovine thyroglobulin conjugated to ampicillin by glutaraldehyde reaction; as fluorescent marker we used goat anti-rabbit IgG conjugated with a chelating molecule complexed with Eu3+. Bovine serum albumin (BSA) conjugated with ampicillin was synthesized and used to prepare a solid phase on polystyrene microtiter plates. The use of a lanthanide chelate as label allowed to achieve 1 ng mL−1 sensitivity, which is four times more sensitive than limits requested from European Community. Fat contents did not affect the assay performance. 相似文献
69.
Maria Letizia Ciavatta M. Pilar Lopez-Gresa Rosario Nicoletti Ernesto Mollo Guido Cimino 《Tetrahedron》2008,64(22):5365-5369
Chemical investigation of the culture broth of the fungus Eutypella scoparia ICB-OBX, isolated from the marine pulmonate mollusc Onchidium sp., led to the finding of novel compounds 1 and 2, structurally related to angiotensin II binding inhibitors cytosporins, along with unrelated known nitrogen metabolites (compounds 3-5). The structure and the relative stereochemistry of the novel metabolites were assigned mainly by a detailed analysis of two-dimensional NMR techniques whereas the absolute stereochemistry was proposed by modified Mosher's method. Compound 2 contains an unusual cyclic carbonate functionality that is rare among natural products. 相似文献
70.