Identifying the presence of magnetite in an ensemble of iron-oxide nanoparticles: a comparative neutron diffraction study between bulk and nanoscale.

Scientific interest in iron-oxides and in particular magnetite has been renewed due to the broad scope of their fascinating properties, which are finding applications in electronics and biomedicine. Specifically, iron oxide nanoparticles (IONPs) are gathering attraction in biomedicine. Their cores are usually constituted by a mixture of maghemite and magnetite phases. In view of this, to fine-tune the properties of an ensemble of IONPs towards their applications, it is essential to enhance mass fabrication processes towards the production of monodisperse IONPs with controlled size, shape, and stoichiometry. We exploit the vacancy sensitivity of the Verwey transition to detect the presence of magnetite. Here we provide direct evidence for the Verwey transition in an ensemble of IONPs through neutron diffraction. This transition is observed as a variation in the Fe magnetic moment at octahedral sites and, in turn, gives rise to a change of the net magnetic moment. Finally, we show this variation as the microscopic ingredient driving the characteristic kink that hallmarks the Verwey transition in thermal variation of magnetization.

FOXM1 allows human keratinocytes to bypass the oncogene-induced differentiation checkpoint in response to gain of MYC or loss of p53.

Tumour suppressor p53 or proto-oncogene MYC is frequently altered in squamous carcinomas, but this is insufficient to drive carcinogenesis. We have shown that overactivation of MYC or loss of p53 via DNA damage triggers an anti-oncogenic differentiation-mitosis checkpoint in human epidermal keratinocytes, resulting in impaired cell division and squamous differentiation. Forkhead box M1 (FOXM1) is a transcription factor recently proposed to govern the expression of a set of mitotic genes. Deregulation of FOXM1 occurs in a wide variety of epithelial malignancies. We have ectopically expressed FOXM1 in keratinocytes of the skin after overexpression of MYC or inactivation of endogenous p53. Ectopic FOXM1 rescues the proliferative capacity of MYC- or p53-mutant cells in spite of higher genetic damage and a larger cell size typical of differentiation. As a consequence, differentiation induced by loss of p53 or MYC is converted into increased proliferation and keratinocytes displaying genomic instability are maintained within the proliferative compartment. The results demonstrate that keratinocyte oncogene-induced differentiation is caused by mitosis control and provide new insight into the mechanisms driving malignant progression in squamous cancer.

Interacting Superparamagnetic Iron(II) Oxide Nanoparticles: Synthesis and Characterization in Ionic Liquids.

Interacting superparamagnetic iron(II) oxide nanoparticles (NPs) with sizes of 5.3 ± 1.6 nm were prepared by simple decomposition of [Fe(COT)2] (COT = 1,3,5,7-cyclooctatetraene) with 5 bar of H2 in 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI·NTf2) ionic liquid (IL). The static and dynamic magnetic characterization revealed a superparamagnetic behavior with weak dipolar interactions of these NPs. In situ structural studies by X-ray absorption spectroscopy demonstrated that they consist of nanostructured FeO. This approach is an appropriate method to prepare and stabilize nanostructured FeO particles, where the presence of an IL proved to be fundamental to suppress the aggregation and usual overoxidation of the FeO NPs.

Interplay between microstructure and magnetism in NiO nanoparticles: breakdown of the antiferromagnetic order.

The possibility of tuning the magnetic behaviour of nanostructured 3d transition metal oxides has opened up the path for extensive research activity in the nanoscale world. In this work we report on how the antiferromagnetism of a bulk material can be broken when reducing its size under a given threshold. We combined X-ray diffraction, high-resolution transmission electron microscopy, extended X-ray absorption fine structure and magnetic measurements in order to describe the influence of the microstructure and morphology on the magnetic behaviour of NiO nanoparticles (NPs) with sizes ranging from 2.5 to 9 nm. The present findings reveal that size effects induce surface spin frustration which competes with the expected antiferromagnetic (AFM) order, typical of bulk NiO, giving rise to a threshold size for the AFM phase to nucleate. Ni(2+) magnetic moments in 2.5 nm NPs seem to be in a spin glass (SG) state, whereas larger NPs are formed by an uncompensated AFM core with a net magnetic moment surrounded by a SG shell. The coupling at the core-shell interface leads to an exchange bias effect manifested at low temperature as horizontal shifts of the hysteresis loop (~1 kOe) and a coercivity enhancement (~0.2 kOe).

Magnetic ionic plastic crystal: choline[FeCl4].

A novel organic ionic plastic crystal (OIPC) based on a quaternary ammonium cation and a tetrachloroferrate anion has been synthesized with the intention of combining the properties of the ionic plastic crystal and the magnetism originating from the iron incorporated in the anion. The thermal analysis of the obtained OIPC showed a solid-solid phase transition below room temperature and a high melting point above 220 °C, indicating their plastic crystalline behaviour over a wide temperature range, as well as thermal stability up to approximately 200 °C. The magnetization measurements show the presence of three-dimensional antiferromagnetic ordering below 4 K. The results from electrochemical characterization display a solid-state ionic conduction sufficiently high and stable (between 10(-2.7) and 10(-3.6) S cm(-1) from 20 to 180 °C) for electrochemical applications.

La alimentación y sus perversiones. Anorexia, vigorexia,bulimia y obesidad / No disponible

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Long-range magnetic ordering in magnetic ionic liquid: Emim[FeCl4].

Up to now most of the magnetic ionic liquids containing tetrachloroferrate ion FeCl(4) have evidenced a paramagnetic temperature dependence of the magnetic susceptibility, with only small deviations from the Curie law at low temperatures. However, we report on the physical properties of 1-ethyl-3-methylimidazolium tetrachloroferrate Emim[FeCl(4)], that clearly shows a long-range antiferromagnetic ordering below the Néel temperature T(N)≈3.8 K. In addition, the field dependence of the magnetization measured at 2 K is characterized by a linear behaviour up to around 40 kOe, while above this field the magnetization becomes saturated with a value of 4.3 µ(B)/Fe, which is near the expected fully saturated value of 5 µ(B)/Fe for an Fe(3+) ion.

Pancreatitis autoinmune. A propósito de un caso / Autoimmune pancreatitis. Related to a case

La pancreatitis autoinmune es una reciente entidad a tener en cuenta en el diagnóstico diferencial de pancreatits crónica-masa pancreática. La presencia de estenosis difusa e irregular del Wirsung, junto con niveles elevados de IgG4, presencia de determinados autoanticuerpos e infiltración linfoplasmocitaria de páncreas son la clave del diagnóstico. La sospecha diagnóstica precoz y la colaboración multidisciplinar es vital en estos casos, ya que puede evitar cirugía innecesaria, puesto que el diagnóstico diferencial se establece con entidades entre las que se encuentra cáncer de páncreas, pancreatitis crónica, cirrosis biliar primaria o colangitis esclerosante primaria. Además, la pancreatitis autoinmune tiene excelente respuesta a tratamiento esteroideo, con resolución completa de parámetros clínicos, analíticos y radiológicos, como ocurría en nuestro paciente. Debido al escaso número de casos descritos en la Literatura, sería necesario la elaboración de estudios con seguimiento largo plazo para conocer pronóstico y frecuencia de asociación a otras patologías

Autoimmune pancreatitis is an entity that has recently been included in the differential diagnosis of chronic pancreatitis-pancreatic mass. The presence of diffuse, irregular Wirsung’s duct stenosis, together with high levels of IgG4, the existence of certain autoantibodies and lymphoplasmacytic infiltration of the pancreas are key factors in the diagnosis. An early diagnostic suspicion and multidisciplinary collaboration are vital in these cases to avoid unnecessary surgery as the differential diagnosis is established with such entities as pancreas cancer, chronic pancreatitis, primary biliary cirrhosis or primary sclerosing cholangitis. Autoimmune pancreatitis has an excellent response to steroid therapy, with complete resolution of clinical, analytical and radiological parameters, as occurred in our patient. The very few cases reported sofar suggest the need for the elaboration of long-term follow-up studies to determine the prognosis and frequency of its association with other diseases

[Autoimmune pancreatitis. Related to a case]. / Pancreatitis autoinmune. A propósito de un caso.

Autoimmune pancreatitis is an entity that has recently been included in the differential diagnosis of chronic pancreatitis-pancreatic mass. The presence of diffuse, irregular Wirsung's duct stenosis, together with high levels of IgG4, the existence of certain autoantibodies and lymphoplasmacytic infiltration of the pancreas are key factors in the diagnosis. An early diagnostic suspicion and multidisciplinary collaboration are vital in these cases to avoid unnecessary surgery as the differential diagnosis is established with such entities as pancreas cancer, chronic pancreatitis, primary biliary cirrhosis or primary sclerosing cholangitis. Autoimmune pancreatitis has an excellent response to steroid therapy, with complete resolution of clinical, analytical and radiological parameters, as occurred in our patient. The very few cases reported so far suggest the need for the elaboration of long-term follow-up studies to determine the prognosis and frequency of its association with other diseases.

Principios activos autorizados en España en 2006 (2ª parte) / Active Principles authorized in Spain in 2006 (2ª part)

Como continuación de nuestro trabajo publicado con anterioridad de igual título como parte 1ª [Sanidad Militar 2007;64(2):118-127], presentamos el resto de fármacos que han sido comercializados en nuestro país durante el pasado año 2006, con atención a sus diversas características, algunas de ellas reflejadas en su ficha técnica, y otras comentadas para complementar su conocimiento (AU)

As a continuation of our previous article published with the same title as first part [Sanidad Militar 2007;64(2):118-127], we present the other drugs that have been commercialized in our country during 2006. They are presented in accordance with their different characteristics, some of them described in the technical data sheet and other commented in order to complement their knowledge. The active principles that we present in this second part represent, as has already been stated previously, a reduced contribution from the innovation point of view. However for certain patients or group of patients, and in concrete circumstances, they may represent a specific solution for a case that might have a worse outlook without this contribution. The drugs that we present in order to complete those commercialized during 2006 are the following (AU)

Principios activos autorizados en España en 2006 (I. ª parte) / No disponible

Cada año la Agencia Española de Medicamentos evalúa la documentación correspondiente a los fármacos que le son presentados con propuesta para su registro y aprobación. Otros fármacos lo hacen a través de la Agencia Europea. En nuestro país se han autorizado veinticuatro principios activos durante el pasado año 2006. Se presentan y comentan los datos correspondientes a aquellos considerados por los autores de mayor interés. Tres principios son considerados como «Innovación excepcional», y uno más es considerado «Innovación importante ». El resto presentan mejoras menores aunque en determinadas circunstancias o en pacientes específicos pueden llegar a ser la alternativa de mayor interés (AU)

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Prevención del suicidio en los ancianos, suicidio-homicidio, ampliado y asistido / Prevention of suicide in the elderly, suicide-homicide, extended and assisted

El suicidio es el acontecimiento más trágico de la vida; es un problema de salud en todo el mundo y su prevención motivo de creciente interés.En la población anciana el suicidio es más frecuente, alcanzando el máximo entre los 75 y los 85 años. La etiología es multifactorial ya que elementos biológicos, psicológicos y sociales contribuyen a este aumento. Los factores de riesgo para el suicidio son: vivir solo o tener pobre apoyo social, trastornos psíquicos sobre todo depresión o abuso de sustancias, conflictos familiares, enfermedad física, institucionalización, incapacidad y la existencia de intentos anteriores. Una proporción elevada de los ancianos que realizan un intento de sucidio han visitado al médico el mes previo, pero pocos reciben tratamiento psiquiátrico y menos aún son enviados al psiquiatra. En los últimos tiempos diversos y dramáticos casos de sucidio-homicidio y de suicidio ampliado se han producido entre ancianos en nuestro país. Se hacen algunas sugerencias para identificar los factores de riesgo, incluyendo los socioeconómicos, para prevenir que se lleve a cabo (AU)

Bulimia de inicio en la menopausia / Bulimia at the menopausal age

La bulimia nerviosa se caracteriza por la presencia de atracones recurrentes y conductas purgativas conpensatorias o ayuno prolongado. Afecta generalmente a mujeres jóvenes y es raro su inicio en edades avanzadas. Se expone el caso de una mujer de 50 años que comienza con un cuadro de bulimia nerviosa dos años antes, coincidiendo con la menopausia. La bulimia tiene relación con la sintomatología afectiva y la menopausia se asocia con más frecuencia de síntomas depresivos lo que se atribuye a los cambios en los niveles de estrógenos a nivel cerebral. Se analiza el posible efecto antidepresivo de los estrógenos y la relación entre factores hormonales y los trastornos afectivos (AU)

Trastornos de la conducta alimentaria en el varón: etiología y rasgos clínicos / Eating disorders in males: etiology and clinical features

Los trastornos de la conducta alimentaria en el varón son menos frecuentes que en las mujeres y la información acerca de ellos es limitada. El estereotipo de que estos cuadros son típicos de mujeres puede contribuir a que estén infradiagnosticados y puede limitar una comprensión adecuada de los mismos. En este trabajo se analizan la etiología y características clínicas de estos cuadros; factores biológicos, psicológicos y socioculturales que favorecen su presentación, así como aspectos epidemiológicos de los distintos subgrupos (AU)

Craneofaringioma y trastorno de la conducta alimentaria: a propósito de dos casos / Craniopharyngioma and eating disorders: report of two cases

Se describen dos casos de mujeres que, tras ser intervenidas de un craneofa ringioma, presentan como secuela hiperfagia intensa y obesidad mórbida. Se analizan las características de ambos casos, similitudes y diferencias, consecuencias en la evolución de la enfermedad y pronóstico previsto. Se comentan algunos factores biológicos implicados en la hiperfagia que pueden estar influyendo en la presentación de la sintomatología y su relación con la bulimia (AU)

De senectute / De senectute

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