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51.
Alessandro DAlessandro Daniele Ballestrieri Lorenzo Strani Marina Cocchi Caterina Durante 《Molecules (Basel, Switzerland)》2021,26(13)
Basil is a plant known worldwide for its culinary and health attributes. It counts more than a hundred and fifty species and many more chemo-types due to its easy cross-breeds. Each species and each chemo-type have a typical aroma pattern and selecting the proper one is crucial for the food industry. Twelve basil varieties have been studied over three years (2018–2020), as have four different cuts. To characterize the aroma profile, nine typical basil flavour molecules have been selected using a gas chromatography–mass spectrometry coupled with an olfactometer (GC–MS/O). The concentrations of the nine selected molecules were measured by an ultra-fast CG e-nose and Principal Component Analysis (PCA) was applied to detect possible differences among the samples. The PCA results highlighted differences between harvesting years, mainly for 2018, whereas no observable clusters were found concerning varieties and cuts, probably due to the combined effects of the investigated factors. For this reason, the ANOVA Simultaneous Component Analysis (ASCA) methodology was applied on a balanced a posteriori designed dataset. All the considered factors and interactions were statistically significant (p < 0.05) in explaining differences between the basil aroma profiles, with more relevant effects of variety and year. 相似文献
52.
J.G. Guy M. Suk I. Dhar S. Tuli G. Borreani F. Marchetto G. Rinaudo 《Nuclear Physics B》1979,155(2):320-332
Inclusive data for the production of γ rays and π0 are presented from an experiment with a 4 GeV/cπ+ beam, using a track-sensitive target. The results are compared with data at other energies and with π+and π? distributions. 相似文献
53.
[reaction: see text] Deoxymannojirimycin (2) and swainsonine (4) have been synthesized from each enantiomer of the same bicyclic carbamate precursor 7. The key intermediate was prepared by a simple and efficient three-step synthesis involving RCM of the diene 8, which in turn is easily accessible in any configuration from enantiomerically enriched 2,3-epoxy-4-penten-1-ol 9. 相似文献
54.
The dependence of the elution volume of NaCl samples is discussed as a function of the volume and concentration injected and of the ionic strength of the eluent. The same is done with two fractions of polystyrene sulphonic acid in the sodium form. It is concluded that the exclusion depends directly on the screening parameter proportional to for NaCl and that a steric parameter has to be added with polyelectrolytes, depending on the molecular weight and on the ionic strength of the eluent. The behaviour is directly correlated to the pore size distribution in the gel. 相似文献
55.
Coluccio ML Ciardelli G Bertoni F Silvestri D Cristallini C Giusti P Barbani N 《Macromolecular bioscience》2006,6(6):403-411
The preparation of an enzymatic controlled drug release system from blends of PVA/starch/alphaA, in the form of films, is described. It was shown that alphaA hydrolyses the starch within these films, resulting in a time-dependent change of the porosity in the matrix. Films were characterized by calorimetric analysis to study the interactions between the enzyme and the polymeric constituents at the molecular level. The presence of alphaA, in fact, influenced the PVA crystallization in the blends. Release tests and permeability experiments were carried out to evaluate the transport properties of the films. An increase in porosity and permeability was observed by increasing alphaA content (16-28 wt.-%). Films loaded with theophylline and caffeine were also prepared to analyze drug release properties of the matrix. Drug release kinetics were coherent with the measured changes in porosity: at higher alphaA concentrations the amount of released drug increased under the influence of diffusion and erosion processes. The results obtained are promising for the realization of drug delivery devices for a rapid release or for the release of poorly soluble drugs which usually remain entrapped in the matrix.SEM images of a PVA/starch/alphaA film before (A) and after (B) the erosion. 相似文献
56.
Caterina Rinaudo Mario Allegrina Elisa Fornero Maya Musa Alessandro Croce Donata Bellis 《Journal of Raman spectroscopy : JRS》2010,41(1):27-32
Histological sections of a patient affected by an important respiratory disease were analysed firstly by optical microscope(OM)—crossed polarisers—to identify the presence of incorporated inorganic particles, with particular attention to the fibrous ones. Then, the particles/fibres that were found were studied both with micro‐Raman spectroscopy and variable‐pressure scanning electron microscopy with energy‐dispersive spectroscopy (VP‐SEM/EDS). The two techniques allowed the in situ characterisation of the inorganic phases without disintegration of the organic matter. Micro‐Raman spectroscopy was able to identify the vibrating chemical groups of the mineral phase associated with the inorganic grain while the crystalline structure was preserved by the biological system. The VP‐SEM/EDS characterisation, defining the elemental chemical composition of the analysed particle/fibre, allowed confirmation of the mineral phase deducible from spectroscopic data or its identification with certainty when the spectroscopic data were not exhaustive. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
57.
Gaggelli E Janicka-Klos A Jankowska E Kozlowski H Migliorini C Molteni E Valensin D Valensin G Wieczerzak E 《The journal of physical chemistry. B》2008,112(1):100-109
Alzheimer's disease is a fatal neurodegenerative disorder involving the abnormal accumulation and deposition of peptides (amyloid-beta, Abeta) derived from the amyloid precursor protein. Here, we present the structure and the Zn2+ binding sites of human and rat Abeta(1-28) fragments in water/sodium dodecyl sulfate (SDS) micelles by using 1H NMR spectroscopy. The chemical shift variations measured after Zn2+ addition at T>310 K allowed us to assign the binding donor atoms in both rat and human zinc complexes. The Asp-1 amine, His-6 Ndelta, Glu-11 COO-, and His-13 Nepsilon of rat Abeta28 all enter the metal coordination sphere, while His-6 Ndelta, His-13, His-14 Nepsilon, Asp-1 amine, and/or Glu-11 COO- are all bound to Zn2+ in the case of human Abeta28. Finally, a comparison between the rat and human binding abilities was discussed. 相似文献
58.
Gaggelli E Grzonka Z Kozłowski H Migliorini C Molteni E Valensin D Valensin G 《Chemical communications (Cambridge, England)》2008,(3):341-343
The interaction between Cu(II) and the rat amyloid beta (1-28) fragment in micellar solutions at pH 7.5 was investigated by CD and NMR spectroscopy; the proton-copper distances were used in restrained molecular dynamics simulations to obtain a structural model of the Cu(II) complex. 相似文献
59.
Corsaro C Spooren J Branca C Leone N Broccio M Kim C Chen SH Stanley HE Mallamace F 《The journal of physical chemistry. B》2008,112(34):10449-10454
Proton nuclear magnetic resonance (1H NMR) experiments have been performed to measure the spin-lattice, T1, and spin-spin, T2, relaxation times of the three functional groups in water/methanol mixtures at different methanol molar fractions (XMeOH=0, 0.04, 0.1, 0.24, 0.5, 1) as a function of temperature in the range 205 K相似文献
60.
In developing countries, subsistence gold mining entails mixing metallic mercury with crushed sediments to extract gold. In this approach, the gold−mercury amalgam is heated to evaporate mercury and obtain gold. Thus, the highly volatile mercury can be absorbed through inhalation, resulting in adverse health effects. Urinalysis can be used to detect mercury, which is excreted in urine and feces, and correlate exposure with toxic effects. The current gold standard analytical methods are based on fluorescence or inductively coupled plasma mass spectrometry methods, but are expensive, time consuming, and are not easily accessible in countries where testing is needed. In this work, we report on a miniature electrochemical sensor that can rapidly detect mercury in urine at levels well below the US Biological Exposure Index (BEI) limit of 50 ppb (μg/L). The sensor is based on a thin-film gold electrode and anodic stripping voltammetry electroanalytical approach. The sensor successfully detected mercury at trace levels in urine, with a limit of detection of ∼15 ppb Hg in the linear range of 20–80 ppb. With the low-cost disposable sensors and portable instrumentation, it is well suited for point-of-care applications. 相似文献