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1.
Food Chem ; 363: 130319, 2021 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-34139519

RESUMEN

A high quality chocolate requires not only a shiny surface, a crunchy and pleasant texture, but also a proper resistance to blooming. All these characteristics are influenced by the physical and chemical properties of the components, which are directly related to their crystalline structure. Some works found that the proportion of cocoa butter (CB), cocoa butter equivalent (CBE) and milk fatty acid (AMF) tend to strongly delay the blooming when mixing them. The goal of our research is to determine how the choice of adding CBE to the mixture delays chocolate blooming. ESI/MALDI-HRMS, X-ray, DSC, MIR and Raman investigations were used to analyze the structure features and the vibrational modes of CB and CBE. The comparison of these experimental results between CB and CBE made it possible to highlight markers of differentiation between CB and CBE which seems to explain the impact of CBE in the chocolate blooming. Part of these triglycerides remains in form IV instead. The presence of the latter seems to be a key parameter that favors the transformation deceleration to the form VI, which is responsible for the fat bloom development.


Asunto(s)
Cacao , Espectrometría Raman , Grasas de la Dieta/análisis , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Triglicéridos
2.
Mol Ecol ; 18(14): 2937-44, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19538342

RESUMEN

Clonal reproduction may facilitate the spread of invasive species by reducing the minimum population size necessary for successful establishment. We used microsatellite markers to reconstruct the composition of founding populations in two regional (Central Africa and Hawaii) and 23 local (near a Gabonese oilfield) invasions of the facultatively parthenogenetic little fire ant. Central Africa had a single dominant queen clone, which appears to have initiated the regional infestation, and then produced numerous other clones by rare sexual reproduction. This interpretation of the data was also supported by the genotype of a worker from the first collection in Africa (Gabon 1913). We found only a single queen clone in Hawaii, likewise indicating a single-clone introduction, most likely from an earlier infestation in Florida. Single-clone introductions also gave rise to the vast majority (92%) of local infestations at our oilfield study site. These results suggest the unusual, largely clonal, reproductive strategy of the little fire ant may enhance its success as an invasive species. However, the occasional sexual production of novel genotypes after the initial introduction may provide genetic flexibility that overcomes shortcomings of pure clonality.


Asunto(s)
Hormigas/fisiología , Genotipo , Repeticiones de Microsatélite , África Central , Alelos , Animales , Hormigas/genética , Femenino , Marcadores Genéticos , Hawaii , Masculino , Partenogénesis/genética , Densidad de Población , Análisis de Secuencia de ADN
3.
Food Chem ; 267: 187-195, 2018 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-29934155

RESUMEN

Raman spectroscopy was used to characterize the polymorphs and liquid state of anhydrous milk fat, with emphasis placed on the thermal evolution of the ester carbonyl stretching modes (1800-1700cm-1) and the comparative study of the Raman-active CC (1660cm-1) and CH (3000-2700cm-1) vibrational modes. Specific Raman signatures in the crystalline phase were found and attributed to the coexistence of two groups of triglycerides. This was confirmed using differential scanning calorimetry and X-ray diffraction methods. In the ester carbonyl band, the effect of changing temperature on both the number of modes and new defined intensity ratios was studied and enabled polymorph discrimination. CH stretching signals increased with polymorph stability, indicating the dominance of antisymmetric CH methylene vibrations as the anhydrous milk fats crystal lattice became more ordered. The change in intensity of the CH stretching bands as a function of temperature was used to probe the order-disorder transition.


Asunto(s)
Grasas/química , Leche/química , Temperatura , Animales , Rastreo Diferencial de Calorimetría , Cristalización , Espectrometría Raman , Difracción de Rayos X
4.
Chem Phys Lipids ; 200: 11-23, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27318039

RESUMEN

The present paper discuss the structural and vibrational properties of polyoxyethylene glycol glycerides (Gelucire 50/13) during the hydration with increasing water from 0% to 80%. The Gelucire 50/13 used as sustained release matrix forming agent in pharmaceutical applications and it was essentially studied by Small and Wide Angle X-ray Scattering (SWAXS), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy according to the rate of hydration. The hydration behavior of this amphiphilic excipient has been investigated in the spectral range 4000-0cm-1 in Raman spectroscopy, and 4000-600cm-1 in FTIR. At increasing water contents Gelucire 50/13 forms successive bicontinuous to micellar supramolecular structures, and the vibrational changes were directly correlated with this conformational changes of the Gelucire structure. Overall, Raman and IR spectroscopy clearly demonstrated that the different functional groups studied could be characterized independently, allowing for the understanding of their role in Gelucire polymorphism.


Asunto(s)
Grasas/química , Aceites/química , Grasas/síntesis química , Aceites/síntesis química , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Agua/química , Difracción de Rayos X
5.
Chem Phys Lipids ; 134(2): 119-29, 2005 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-15784230

RESUMEN

A study of the vibrational behavior of five saturated monoacid triacylglycerides is performed by Raman spectroscopy at room temperature in the 3100-500 cm(-1) spectral range. The splitting of the CO stretching mode leads to conclude on the existence of two or three geometries of CO in the "knot" group OCO. The CO stretching mode seems to be a good tool for distinguishing the polymorphic forms of the studied triglycerides. The assignments of the different CH stretching modes are performed in the 1500-500 cm(-1) spectral range. The I(2845)/I(2880) (in the CH stretching spectral region) and I(1445)/I(1296) intensity ratios (between the maximal intensity I(1445) of the CH(2) scissoring mode and the maximal intensity I(1296) of the skeletal vibration of (CH(2))(n) in-phase twist) seem to depend on the type of polymorphic forms of these molecules.


Asunto(s)
Espectrometría Raman/métodos , Triglicéridos/química , Triacetina/química
6.
Eur J Radiol ; 8(2): 115-7, 1988 May.
Artículo en Inglés | MEDLINE | ID: mdl-3383856

RESUMEN

CT scans of two patients with acute fatty liver of pregnancy were reviewed in conjunction with the clinical evolution of this uncommon and potentially fatal disorder. In each of the CT scans, liver density measurements were less than those of the spleen. While the findings are non-specific, in the proper clinical context they are highly suggestive and may be the sole method of diagnosis, as these patients often have coagulation problems which rule out liver biopsy. It is an important diagnosis, as the high maternal and fetal mortality rates appear to be considerably reduced by early foetal delivery.


Asunto(s)
Hígado Graso/diagnóstico por imagen , Complicaciones del Embarazo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Enfermedad Aguda , Adulto , Hígado Graso/etiología , Femenino , Humanos , Embarazo
7.
J Radiol ; 68(3): 193-8, 1987 Mar.
Artículo en Francés | MEDLINE | ID: mdl-3598935

RESUMEN

Acute fatty liver of pregnancy is a disease of the third trimester, generally considered to be rare and to have a grave prognosis. Histologically the characteristic fine droplet steatosis usually produces distinct vacuolization. Successful treatment depends on accurate diagnosis and early delivery. Computed tomography is of value in the diagnosis of fatty liver through liver and spleen attenuation value measurements. We reviewed 4 cases of acute fatty liver of pregnancy. Computed tomography was performed in two cases and was very helpful in the diagnosis of this condition.


Asunto(s)
Hígado Graso/diagnóstico por imagen , Complicaciones del Embarazo/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Enfermedad Aguda , Adulto , Femenino , Humanos , Embarazo , Tercer Trimestre del Embarazo
8.
Arch Pediatr ; 19(5): 488-92, 2012 May.
Artículo en Francés | MEDLINE | ID: mdl-22463955

RESUMEN

We report on a boy, born on term, presenting with a weight loss and a persistent failure to thrive after 10 days despite a normal behavior under bottle-feeding. The clinical examination was normal and biological assessment revealed hyponatremia with hyponatriuria, normal kaliemia and elevated aldosterone values, leading to type I pseudohypoaldosteronism diagnosis. Treatment with salt supplementation allowed growth improvement. The diagnosis was confirmed by the identification of a mutation in the mineralocorticoid receptor. This change was also found in several family members.


Asunto(s)
Insuficiencia de Crecimiento/etiología , Insuficiencia de Crecimiento/genética , Seudohipoaldosteronismo/complicaciones , Seudohipoaldosteronismo/genética , Humanos , Recién Nacido , Masculino , Linaje
13.
C R Seances Soc Biol Fil ; 179(3): 327-30, 1985.
Artículo en Francés | MEDLINE | ID: mdl-2935228

RESUMEN

Phenotypic analysis with monoclonal antibodies showed that OKT8+ T cells represent the main cell population of the periparasitic mononuclear cell infiltrate in the liver of 7 patients with alveolar echinococcosis. A significant decrease of the OKT8+ subpopulation had been previously demonstrated in the peripheral blood mononuclear cells of these patients. The results obtained in this study suggest an intrahepatic homing for these particular T cells. However, functional analysis of these cells is required in order to assess the physiopathological significance of these observations.


Asunto(s)
Equinococosis Pulmonar/patología , Hígado/patología , Monocitos/citología , Anticuerpos Monoclonales , Humanos , Monocitos/inmunología , Fenotipo
14.
C R Seances Soc Biol Fil ; 179(6): 782-7, 1985.
Artículo en Francés | MEDLINE | ID: mdl-2939929

RESUMEN

Biological parameters of immediate type hypersensitivity were assessed in 19 patients with alveolar echinococcosis. Serum total IgE concentrations were higher than normal values in 12 patients, and parasite-specific IgE were present in 9 patients. A significant relationship was observed between these two parameters. Evolution of specific IgE during a 1-year period appeared to correlate with surgical removal of parasitic material; it did not correlate with the clinical evolution in patients treated with mebendazole. Specific basophil fixed-IgE were demonstrated using both a basophil degranulation test and a histamine release test in the 19 patients under study, including serologically negative and circulating specific IgE-negative patients.


Asunto(s)
Basófilos/inmunología , Equinococosis Pulmonar/inmunología , Inmunoglobulina E/análisis , Equinococosis Pulmonar/sangre , Equinococosis Pulmonar/terapia , Humanos , Factores de Tiempo
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