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1.
María Constanza Luciardi María Amparo Blzquez María Rosa Alberto Elena Cartagena Mario Eduardo Arena 《Molecules (Basel, Switzerland)》2021,26(10)
The chemical composition of three Citrus limon oils: lemon essential oil (LEO), lemon terpenes (LT) and lemon essence (LE), and their influence in the virulence factors production and motility (swarming and swimming) of two Pseudomonas aeruginosa strains (ATCC 27853 and a multidrug-resistant HT5) were investigated. The main compound, limonene, was also tested in biological assays. Eighty-four compounds, accounting for a relative peak area of 99.23%, 98.58% and 99.64%, were identified by GC/MS. Limonene (59–60%), γ-terpinene (10–11%) and β-pinene (7–15%) were the main compounds. All lemon oils inhibited specific biofilm production and bacterial metabolic activities into biofilm in a dose-dependent manner (20–65%, in the range of 0.1–4 mg mL−1) of both strains. Besides, all samples inhibited about 50% of the elastase activity at 0.1 mg mL−1. Pyocyanin biosynthesis decreases until 64% (0.1–4 mg mL−1) for both strains. Swarming motility of P. aeruginosa ATCC 27853 was completely inhibited by 2 mg mL−1 of lemon oils. Furthermore, a decrease (29–55%, 0.1–4 mg mL−1) in the synthesis of Quorum sensing (QS) signals was observed. The oils showed higher biological activities than limonene. Hence, their ability to control the biofilm of P. aeruginosa and reduce the production of virulence factors regulated by QS makes lemon oils good candidates to be applied as preservatives in the food processing industry. 相似文献
2.
Alicia Baldessari Constanza P. Mangone Eduardo G. Gros 《Helvetica chimica acta》1998,81(12):2407-2413
A series of acyloxy derivatives of pyridoxine ( 1 ) have been prepared by transesterification reactions of 1 and ethyl carboxylates, catalyzed by several lipases. Moreover, acetylated derivatives of 1 were selectively deacetylated by enzymatic catalysis in organic media. 相似文献
3.
Constanza Rubio Daniel Tarrazó-Serrano Oleg V. Minin Antonio Uris Igor V. Minin 《Physics letters. A》2019,383(5):396-399
In this letter, the improvement in focus by the use of a pupil mask produced in an acoustic mesoscale cuboid particle filled with CO2 is reported. Thereby, the result shows that the pupil mask increases the sound intensity and also increases the resolution (or a reduction of the full width at half maximum, FWHM) in focus compared to the non-masked one. These results are important because they confirm the effect of abnormal amplitude apodization for a one-wavelength dimension acoustic lens and demonstrate that it is possible to improve sound focusing of a cuboid gas-filled lens with one wavelength dimension. This is the smallest size of an acoustic lens ever considered in this type of literature, with side dimensions of the cube equal to one wavelength and a diameter to focus ratio of 2.5, the sound amplification in focus is 5.4 dB at 4125 Hz, with the resolution near to the diffraction limit. 相似文献
4.
Email: csfvega{at}dm.uba.ar
Received on August 17, 2006; Accepted on September 8, 2007 Necessary conditions are proved for optimal control problemsinvolving an infinite horizon and terminal conditions at infinitywhose states are governed by Volterra integral equations withnon-linear time delay. 相似文献
5.
Stefano Polesello Fabio Lovati Anna Rizzolo Constanza Rovida 《Journal of separation science》1993,16(9):555-559
To improve the aroma characterization of various strawberry cultivars, we tested supercritical fluid extraction (SFE) to determine its suitability for the extraction of aroma compounds from fresh fruit, comparing SFE results with traditional solvent extraction with dichloromethane. Using SFE it was possible to recover the majority of the aroma compounds which can be also found in the solvent extract; patterns related to variety and degree of maturation were preserved. Our results showed, however, that SFE is more selective and was able to recover the ‘character impact’ compound of wild strawberry. Our findings from the odor analysis of furaneol standard emphasize the importance of using a more selective extraction procedure, and always combining instrumental detection with sensory analysis. 相似文献
6.
Journal of Statistical Physics - We consider the d-dimensional fractional Anderson model $$(-\Delta )^\alpha + V_\omega $$ on $$\ell ^2({\mathbb {Z}}^d)$$ where $$0<\alpha \leqslant 1$$.... 相似文献
7.
Cárdenas C Bidon-Chanal A Conejeros P Arenas G Marshall S Luque FJ 《Journal of computer-aided molecular design》2010,24(12):1035-1051
Knowledge of the 3D structure of the binding groove of major histocompatibility (MHC) molecules, which play a central role
in the immune response, is crucial to shed light into the details of peptide recognition and polymorphism. This work reports
molecular modeling studies aimed at providing 3D models for two class I and two class II MHC alleles from Salmo salar (Sasa), as the lack of experimental structures of fish MHC molecules represents a serious limitation to understand the specific
preferences for peptide binding. The reliability of the structural models built up using bioinformatic tools was explored
by means of molecular dynamics simulations of their complexes with representative peptides, and the energetics of the MHC-peptide
interaction was determined by combining molecular mechanics interaction energies and implicit continuum solvation calculations.
The structural models revealed the occurrence of notable differences in the nature of residues at specific positions in the
binding groove not only between human and Sasa MHC proteins, but also between different Sasa alleles. Those differences lead to distinct trends in the structural features that mediate the binding of peptides to both
class I and II MHC molecules, which are qualitatively reflected in the relative binding affinities. Overall, the structural
models presented here are a valuable starting point to explore the interactions between MHC receptors and pathogen-specific
interactions and to design vaccines against viral pathogens. 相似文献
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Constanza G. Quintana Fernanda Ocayo Raul Guajardo Maturana John J. Hurtado Alvaro Muñoz-Castro 《International journal of quantum chemistry》2020,120(2):e26068
Superatomic clusters offer useful templates displaying distinctive physical and chemical characteristics. Here, we explore the [M@Au8(PPh3)8]n+ (M = Au, n = 3; Pd, Pt, n = 2) robust framework to gain an understanding of the nature of the inclusion of mercury atoms at Au4 faces, leading to [M@Au8Hgx(PPh3)8]n+ (x = 1, 2). Our results show a weak interaction of about 25 kcal mol−1 per Hg atom, which is mainly of electrostatic character, followed by orbital and London dispersion-type interactions. This weak interaction can be understood as the formation of host-guest species, for which the inherent electronic and optical properties of the [M@Au8(PPh3)8] cluster along the series do not vary to a large extent. This demonstrates that, in [M@Au8Hgx(PPh3)8], each Hg can be considered an inclusion atom rather than a dopant element, where the parent cluster is able to act as a Lewis acid host. Furthermore, the viable formation of such species can serve as useful examples to stimulate future experimental characterization of inclusion complexes involving related superatomic structures with available open faces. 相似文献