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This paper investigates the thermal and irradiation-dependent dehydration and kinetics occurring in Na2SO4.10H2O (mirabilite) and MgSO4.7H2O (epsomite) at room conditions by using powder X-ray thermodiffraction. An improved version of a first optically stimulated X-ray diffractometer prototype was used. Specific software for the thermodiffraction study was developed (XPowder PLUS) and a filter inserted between the lamp (heating system) and the sample. The results show that these salts are thermal and irradiation sensitive. The temperature and kinetic rates of the salt conversions differed depending on direct exposure to high-intensity radiation (photodehydration) or whether the radiation was blocked by the filter (thermodehydration). In general, radiation-induced dehydration triggers the transformation at lower temperature and accelerates the kinetic reaction more than when the filter is used. Mirabilite dehydration starts with the initial radiation impacts, unlike epsomite. Thermodehydration and photodehydration of mirabilite is a non-isothermal reaction occurring through an amorphous-mediated step. Radiation damage in epsomite leads to isothermal dehydration, whereas non-isothermal dehydration occurs when epsomite is thermally damaged. In both cases, no amorphous material was observed. Because of the weaker bond between cation and oxygen atom in mirabilite, its thermal and radiation stability is lower than in epsomite. These results have important implications for the prevention of salt weathering of porous materials found in the cultural heritage.

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The thermal dehydration of epsomite (MgSO4*7H2O) crystals grown in the presence and absence of organic additives (phosphonates, carboxylic acids, and polyacrylic acid derivatives) was studied by means of thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray thermodiffraction (XRTD), and environmental scanning electron microscopy (ESEM). In situ XRTD analyses (in air, 30% relative humidity) show an -->epsomite hexahydrite (MgSO4*6H2O) transition at 25-38 degrees C, followed by formation of amorphous phase(s) at T > 43-48 degrees C, and MgSO4 crystallization at approximately 300 degrees C. Kinetic parameters (E(alpha) and A) were determined for the main dehydration step (25-160 degrees C), which corresponds to a MgSO4*7H2O-->MgSO4*H2O transition, by applying two isoconversional methods to nonisothermal TG data obtained at different heating rates (beta= 1, 3, and 5 K*min-1). In situ, hot-stage ESEM observations of the thermal dehydration of epsomite crystals are consistent with the nonisothermal kinetic study and, along with XRTD results, allow us to propose a dehydration mechanism which includes an early nucleation and growth event, followed by the advancement of the reaction interface (3D phase boundary reaction). Both E(alpha) and A values increase in the presence of the most effective crystallization inhibitors tested. H-bonding between additives and epsomite crystal surfaces is consistent with Fourier transform infrared spectroscopy (FTIR) and may account for this effect. The increase of E(alpha) values can be related to the excess energy required to break additive-water bonds in the reactant. These results are likely to further our understanding of the interaction mechanisms between salt hydrates and organic additives which act as growth inhibitors/modifiers.

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En este trabajo estudiamos las interacciones de la flunarizina con polietilenglicol 4000 en dispersiones sólidas preparadas siguiendo el método de disolución propuesto por Sekiguchi y Obi. Como elementos de comparación se han utilizado mezclas físicas de ambos componentes, preparados en las mismas proporciones de fármaco/polímero: 10/ 90, 20/80, 30/70, 40/60, 50/50,60/40 y 80/20.Las propiedades fisicoquímicas de las dispersiones sólidas y mezclas físicas se investigan mediante espectroscopía infrarroja, difracción de rayos X, calorimetría diferencial de barrido y solubilidad en equilibrio. Los espectros de infrarrojo indican que no ha habido interacción química entre la flunarizina y el PEG. Los difractogramas muestran que a determinadas proporciones, el PEG se introduce en la estructura de la flunarizina y los estudios térmicos parecen indicar la formación de una mezcla eutéctica a la proporción 28,96 por ciento de flunarizina y 71,04 por ciento de PEG 4000. Todas las muestras presentan una solubilidad superior a la del fármaco puro y en ambos tipos de muestras el incremento es mayor al aumentar la proporción de polímero. El análisis de comparación múltiple aplicado independientemente a las dispersiones sólidas y mezclas físicas, indica que no existe diferencia estadísticamente significativa (p<0,05) entre las muestras de proporciones 30/70, 40/60. 50/50 y 60/40, pero sí hay diferencias entre éstas y las de proporciones 10/90, 20/80 y 80/20 (AU)

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OBJECTIVE: To report the case of a female with Mammary Angiosarcoma. SETTING: Breast Unit of Oncology Service from Hospital General de México. CASE REPORT: A 28 year old female patient was noted to have a left painless breast mass with reddish-violaceous macular lesions in the overlaying skin in upper quadrants, which she had initially discovered 2 years previously. The patient described a progressive breast enlargement. Mammography showed dense tissue without focal mass. A contrast-enhanced Magnetic Resonance of left breast was performed, and 10.5 x 8.5 cm enhancing vascular mass with irregular borders that occupied the entire superior portion of the breast was identified, the mass extended to the pectoral fascia but no evidence of muscle invasion. An incisional Biopsy of the breast mass was performed and the biopsy was interpreted as low grade Mammary Angiosarcoma. Left Simple Mastectomy with partial pectoral resection was performed; and final histopathologic result was intermediate grade Mammary Angiosarcoma. Immunohistochemistry was positive for Factor VIII, Anti Ulex Europeaus and CD 31. CONCLUSION: High index suspect is mandatory for an opportune diagnosis and treatment of Angiosarcoma. Magnetic resonance has a potential role in guiding clinical management.

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Schistosoma mansoni infection is frequent in certain areas of the world in which it is endemic. It is characterised by colonic and hepatic lesions. Gastrointestinal hemorrhages due to rupture of esophageal varices in case of hepatic involvement or moderate rectal bleeding due to colonic involvement may also be observed. We report a case of colonic Schistosoma mansoni infection presenting exclusively with recurrent episodes of serious gastrointestinal hemorrhage without hepatic lesions. All diagnostic investigations were negative. The diagnosis was only established on histological examination of the operative left hemicolectomy carried out with the utmost emergency for the serious recurrent hemorrhage. Histological examination revealed the presence of mucosal micro-ulcers, capillary neovascularization in the submucosa and serosa, and the presence of fibrous nodules and giant cell granulomas surrounding the eggs of Schistosoma mansoni in the serosa. This case is original by its clinical presentation and the difficulty to diagnose the Schistosomiasis.

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The reactions of K2PdCl4 with meso-diaminosuccinic acid (H2dasa) in 0.1 M HCl or its diethyl ester dihydrochloride Et2dasa.2HCl in neutralized aqueous solution yield cis-[Pd(H2dasa)Cl2](I) and cis-[Pd(Et2dasa)Cl2](II), respectively. These products were characterized by elemental analysis, IR spectroscopy, and TG-DTA thermal analysis. The crystal of II is monoclinic, space group C2/c (a = 14.292(5), b = 14.636(5), c = 13.435(5) A, beta = 98.08(2) degrees, Z = 8, R = 0.041 and wR = 0.06). The Pd(II) atom exhibits a roughly square planar coordination with two Pd-N bonds (Et2dasa) (2.014(2) and 2.049(7) A) and two cis-imposed Pd-Cl bonds (2.294(2) and 2.303(2) A). Compound I reacts with 2,2'-bipyridine in neutral aqueous solution to give [Pd(2,2'-bipy)(dasa)].3H2O(III) in a process of cis-chloride substitution by 2,2'-bipy as a model N-heterocyclic chelating entity. The molecular and crystal structure of III is also reported. It was observed that both cis-dichloro-Pd(II) complexes having Pd(H2dasa) (acidic) and Pd-(Et2dasa)(esterified) chelate entities induce conformational changes in the covalent closed circular (ccc) form of pUC8 plasmid. Both compounds were assayed for antitumor activity in vitro against MDA-MB 468 and HL-60 human cancer cell lines. The results show that compounds I and II have values of ID50 lower than those of K2PdCl4, and also lower than those of diaminoacid ligands (meso-diaminosuccinic acid and meso-diaminosuccinate diethyl ester). Thus it is likely that the imposed cis-coordination of the chelating H2dasa or Et2dasa to the Pd(II) center increases the biological activity of these palladium(II) complexes.

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