52 research outputs found

    The polymorphism of 2-benzoyl-N,N-diethylbenzamide

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    The crystal structures of two new polymorphs of 2-benzoyl-N,N-diethylbenzamide were obtained after recrystallization trials with different solvents. The new forms II and III were monoclinic and crystallized in the same space group with similar a, b and c lengths but different β angles. The forms had no conformation differences within themselves; however, the long-range packing (> two unit cells) was not isostructural. In comparison with the previously published crystal structure, form I, different conformations and packing arrangements were observed. The new form II was thermally characterized and stable at room temperature, when heated up to its melting point and when cooled to −170 °C. Additionally, once form II was re-heated, a fourth form is observed after a phase transition from the monoclinic to the orthorhombic crystal systems, form IV

    Histological findings of autoimmune hepatitis

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    Histology of autoimmune hepatitis (AIH), chronic active hepatitis, is characterized by portal inflammation with interface hepatitis. Although the basic histology of AIH is similar to that of virus-related chronic hepatitis, hepatitic changes are usually prominent in AIH compared with chronic viral hepatitis. Clinicopathological diagnosis of AIH requires exclusion of other causes of liver disease, including hepatitis virus, alcohol, drugs, metabolic disorders, and other autoimmune diseases. At present, some criteria systems considering clinicopathological findings are proposed to categorize patients as having either definite or probably/atypical AIH. Among the pathological items of a simplified AIH scoring system of the International AIH Group, in addition to evident chronic hepatitis with interface hepatitis and hepatic rosette formation, emperipolesis, indicating the close immunological interaction of lymphocytes and hepatocytes, is noted but is sometimes difficult to evaluate. In addition to classical AIH, showing chronic active hepatitis, some AIH patients show a clinically acute hepatitis-like clinical course. These patients have mostly acute exacerbation from chronic active AIH, but acute-onset AIH cases, which histologically exhibit diffuse lobular hepatitis and/or confluent necrosis including perivenular zonal necrosis (zone 3 necrosis, centrizonal necrosis), are also encountered. © 2014 Springer Japan. All rights reserved.(Book Chapter

    Cyanobacterial lipopolysaccharides and human health – a review

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    Cyanobacterial lipopolysaccharide/s (LPS) are frequently cited in the cyanobacteria literature as toxins responsible for a variety of heath effects in humans, from skin rashes to gastrointestinal, respiratory and allergic reactions. The attribution of toxic properties to cyanobacterial LPS dates from the 1970s, when it was thought that lipid A, the toxic moiety of LPS, was structurally and functionally conserved across all Gram-negative bacteria. However, more recent research has shown that this is not the case, and lipid A structures are now known to be very different, expressing properties ranging from LPS agonists, through weak endotoxicity to LPS antagonists. Although cyanobacterial LPS is widely cited as a putative toxin, most of the small number of formal research reports describe cyanobacterial LPS as weakly toxic compared to LPS from the Enterobacteriaceae. We systematically reviewed the literature on cyanobacterial LPS, and also examined the much lager body of literature relating to heterotrophic bacterial LPS and the atypical lipid A structures of some photosynthetic bacteria. While the literature on the biological activity of heterotrophic bacterial LPS is overwhelmingly large and therefore difficult to review for the purposes of exclusion, we were unable to find a convincing body of evidence to suggest that heterotrophic bacterial LPS, in the absence of other virulence factors, is responsible for acute gastrointestinal, dermatological or allergic reactions via natural exposure routes in humans. There is a danger that initial speculation about cyanobacterial LPS may evolve into orthodoxy without basis in research findings. No cyanobacterial lipid A structures have been described and published to date, so a recommendation is made that cyanobacteriologists should not continue to attribute such a diverse range of clinical symptoms to cyanobacterial LPS without research confirmation

    Analyse électronique : oxydation des alliages Au-Cu - (Complément à un travail antérieur)

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    Les auteurs se reportent à leur travail antérieur et montrent que la modification « 0» observée lorsqu'on chauffe à l'air une feuille d'or contenant des traces de cuivre, est dûe à la formation superficielle d'un oxyde de cuivre CuO', très voisin de la ténorite
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