Metal-Substituted Microporous Aluminophosphates

This chapter aims to present the zeotypes aluminophosphates (AlPOs) as a complementary alternative to zeolites in the isomorphic incorporation of metal ions within all-inorganic microporous frameworks as well as to discuss didactically the catalytic consequences derived from the distinctive features of both frameworks. It does not intend to be a compilation of either all or the most significant publications involving metal-substituted microporous aluminophosphates. Families of AlPOs and zeolites, which include metal ion-substituted variants, are the dominant microporous materials. Both these systems are widely used as catalysts, in particular through aliovalent metal ions substitution. Here, some general description of the synthesis procedures and characterization techniques of the MeAPOs (metal-contained aluminophosphates) is given along with catalytic properties. Next, some illustrative examples of the catalytic possibilities of MeAPOs as catalysts in the transformation of the organic molecules are given. The oxidation of the hardly activated hydrocarbons has probably been the most successful use of AlPOs doped with the divalent transition metal ions Co2+, Mn2+, and Fe2+, whose incorporation in zeolites is disfavoured. The catalytic role of these MeAPOs is rationalized based on the knowledge acquired from a combination of the most advanced characterization techniques. Finally, the importance of the high specificity of the structure-directing agents employed in the preparation of MeAPOs is discussed taking N,N-methyldicyclohexylamine in the synthesis of AFI-structured materials as a driving force. It is shown how such a high specificity could be predicted and how it can open great possibilities in the control of parameters as critical in catalysis as crystal size, inter-and intracrystalline mesoporosity, acidity, redox properties, incorporation of a great variety of heteroatom ions or final environment of the metal site (surrounding it by either P or Al)

Past, Present, and Future X-Ray and Gamma-Ray Missions

X- and -ray astronomy began in the early sixties of the last century with balloons flights, sounding rocket experiment and satellites. Long before space satellite detected X- and -rays emitted by cosmic sources, scientists had known that the Universe should be producing these photons. In this chapter we provided an overview of past and present missions that has made the X- and -ray astronomy an integral part of astronomical research, and prospects of future developments

Cerebral angiitis in four patients with chronic GVHD

There is growing evidence that GVHD affects the central nervous system (CNS). In this study, we describe the long-term follow-up of four allogeneic BM recipients who developed cerebral angiitis-like disease probably due to GVHD. The patients developed focal neurological signs, cognitive deficits and/or coma in association with GVHD, 2–18 years after transplantation, following reduction of immunosuppressive therapy. Magnetic resonance imaging was variable, showing generalized brain atrophy, ischemic lesions or leukoencephalopathy. Diagnosis of cerebral angiitis was confirmed by histopathological analysis of bioptic brain tissue and response to immunosuppressive therapy. By means of immunohistochemistry and immunofluorescence, perivascular lymphomononuclear cerebral infiltrates were shown to express the adhesion receptor, CD11a, and the chemokine receptor, CCR5. Our findings imply that GVHD should be considered in the differential diagnosis of noninfectious angiitis-like disease of the CNS in long-term survivors after allogeneic BMT. Infiltrating cells, in analogy to typical target organs of GVHD such as skin or liver, expressed CD11a and CCR5. These findings could be of etiopathological, diagnostic and therapeutic relevance

Neurological complications of hematopoietic stem cell transplantation (HSCT): a retrospective study in a HSCT center in Brazil Complicações neurológicas do transplante de células tronco hematopoiéticas (TCTH): estudo retrospectivo em um centro de TCTH no Brasil

We present the neurological complications evaluated in a series of 1000 patients who underwent hematopoietic stem cell transplantation (HSCT). Central nervous system (CNS) neurological complications, particularly brain hemorrhages, were the most common, followed by seizures and CNS infections. An unusual neurological complication was Wernicke's encephalopathy. Less frequent neurological complications were metabolic encephalopathy, neuroleptic malignant syndrome, reversible posterior leukoencephalopathy syndrome, brain infarct and movement disorders. The most common neurological complication of the peripheral nervous system was herpes zoster radiculopathy, while peripheral neuropathies, inflammatory myopathy and myotonia were very rarely found.<br>Apresentamos as complicações neurológicas avaliadas em uma série de 1000 pacientes submetidos ao transplante de células tronco hematopoiéticas (TCTH). As complicações neurológicas do sistema nervoso central foram as mais encontradas, particularmente as hemorragias encefálicas, seguidas por crises convulsivas e por infecções. Uma complicação peculiar foi a encefalopatia de Wernicke. Menos freqüentemente foram encontrados casos de encefalopatia metabólica, síndrome maligna neuroléptica, leucoencefalopatia posterior reversível, infarto cerebral e os distúrbios do movimento. Entre as complicações neurológicas do sistema nervoso periférico a mais encontrada foi a radiculopatia pelo herpes zoster, enquanto que raramente se observaram casos de polineuropatias periféricas, miopatia inflamatória e de miotonia