10 research outputs found
Ultrastructural Characterization of Oil Bodies in Different Coffea Species
In the coffee seed, the lipid component known as coffee oil is stored in the endosperm tissue as an energy reserve for germination and post-germination growth. This coffee constituent is present in the form of subcellular spherical oil bodies ("oleosomes") in a typical size range of 0.2-2.5 \u3bcm. These particles are filled with an osmiophilic matrix of triglycerides, delimited by a single protein membrane, typical of oleaginous plant tissues. The object of this study is to characterize the morphology and distribution of oil bodies in different coffee species. In particular, we studied Indian samples of Coffea arabica, C. canephora, C. liberica, C. stenophylla and C. salvatrix. After appropriate fixation and preparation, the samples were examined and oil bodies characterized by optical microscopy and transmission electron microscopy. Oil bodies morphology, tissue distribution and size distribution were determined and several features of these subcellular structures were observed and discussed for the first time in the framework of a coffee inter-species comparative stud
Thermal expansion of the nuclear fuel-sodium reaction product Na3(U0.84(2),Na0.16(2))O4 - Structural mechanism and comparison with related sodium-metal ternary oxides
Na3.16(2)UV,VI0.84(2)O4 is obtained from the reaction of sodium with uranium dioxide under oxygen potential conditions typical of a sodium-cooled fast nuclear reactor. In the event of a breach of the steel cladding, it would be the dominant reaction product forming at the rim of the mixed (U,Pu)O2 fuel pellets. High-temperature X-ray diffraction measurements show that a distortion of the uranium environment in Na3.16(2)UV,VI0.84(2)O4 results in a strongly anisotropic thermal expansion. A comparison with several related sodium metallates Nan-2Mn+On-1 - including Na3SbO4 and Na3TaO4, whose crystal structures are reported for the first time - has allowed us to assess the role played in the lattice expansion by the Mn+ cation radius and the Na/M ratio. On this basis, the thermomechanical behavior of the title compound is discussed, along with those of several related double oxides of sodium and actinide elements, surrogate elements, or fission products.JRC.G.I.3-Nuclear Fuel Safet
Preliminary Characterization of MonofloralCoffeaspp. Honey: Correlation between Potential Biomarkers and Pollen Content
To determine the botanical origin of Coffea honey, a new method using proton nuclear magnetic resonance (1H
NMR) is proposed. Integration of the aromatic region of the NMR spectrum of Coffea honey diluted in deuterated water allowed
us to simultaneously quantify caffeine, theobromine, and trigonelline, as well as other compounds. The amounts of the three
markers listed are significantly higher than those previously reported for Citrus spp. honey: caffeine ranged from 15 to 98 mg/kg,
theobromine from 25 to 160 mg/kg, and trigonelline from 23 to 86 mg/kg. The concurrent presence of these three substances is
proposed as an indicator of the botanical origin of Coffea honey. Excellent correlation was found between these markers and the
relative amounts of Coffea pollen measured in the same samples
Correction: A polymeric membrane permeabilizer displaying densely packed arrays of crown ether lateral substituents
International audienceCorrection of Liu, M.; Bertova, A.; Illy, N.; Brissault, B.; Penelle, J.; Ondrias, K.; Barbier, V. “A Polymeric Membrane Permeabilizer Displaying Densely Packed Arrays of Crown Ether Lateral Substituents”, RSC Advances, 2012, 2, 8606-8609 (DOI: 10.1039/C2RA20548C)
A polymeric membrane permeabilizer displaying densely packed arrays of crown ether lateral substituents
Correction available: Liu, M.; Bertova, A.; Illy, N.; Brissault, B.; Penelle, J.; Ondrias, K.; Barbier, V. “Correction - A Polymeric Membrane Permeabilizer Displaying Densely Packed Arrays of Crown Ether Lateral Substituents”, RSC Advances, 2016, 6, 14222 (DOI: 10.1039/C6RA90009g).International audienceWe report the design, synthesis and evaluation of a novel macromolecular membrane permeabilizer displaying geminally substituted crown-ethers (18-crown-6) on every third carbon alongside the backbone. The polymer has a rather high affinity with potassium as well as permeabilization properties towards K+, Na+ and Ca2+, including single-channel behavior
Isocapnic hyperpnea with a portable device in Cystic Fibrosis: an agreement study between two different set-up modalities
Influence of synthetic pathway, molecular weight and side chains on properties of indacenodithiophene-benzothiadiazole copolymers made by direct arylation polycondensation
Atom-economic protocols for the synthesis of poly(indacenodithiophene-alt-benzothiadiazole) (PIDTBT) are presented in which all C-C coupling steps are achieved by direct arylation. Using two different synthetic pathways, PIDTBT copolymers with different side chains (hexylphenyl, octylphenyl, dodecyl, methyl/2-octyldodecylphenyl, 2-octyldodecylphenyl/2-octyldodecylphenyl) and molecular weight (MW) are prepared. Route A makes use of direct arylation polycondensation (DAP) of indacenodithiophene (IDT) and 4,7-dibromo-2,1,3-benzothiadiazole (BTBr2) leading to PIDTBT in high yields, with adjustable MW and without indications for structural defects. Route B starts from a polyketone precursor also prepared by DAP following cyclization. While route B allows introduction of asymmetric side chains at the IDT unit, polymer analogous cyclization gives rise to defect formation. The absorption coefficient of PIDTBT with alkylphenyl side chains made by route A increases with MW. Field-effect hole mobilities around similar to 10(-2) cm(2) V-1 s(-1) are molecular weight-independent, which is ascribed to a largely amorphous thin film morphology. PIDTBT with linear dodecyl side (C12) chains exhibits a bathochromic shift (20 nm), in agreement with theory, and more pronounced vibronic contributions to absorption spectra. In comparison to alkylphenyl side chains, C12 side chains allow for increased order in thin films, a weak melting endotherm and lower energetic disorder, which altogether explain substantially higher field-effect hole mobilities of similar to 10(-1) cm(2) V-1 s(-1)