100 resultados para Combustion reactions
Resumo:
Based on Heider’s theory I persumed that personal attitudes are stronger predictors of emotional responses to others’ outcomes than deservingness evaluation. I manipulated outcome, attitude and deservingness experimentally, and measured specific emotions. It appeared deservingness to play a secondary role in eliciting joy and sorrow when interpersonal attitudes were involved.
Resumo:
More than 40 years after the agrarian reform, Peru is experiencing a renewed process of concentration of land ownership in the hands of large-scale investors, favoring the development of a sugar cane production cluster along the northern coast. The expansion of the agricultural frontier by means of large irrigation projects – originally developed to benefit medium- and small-scale farmers – is carried out today in order to be sold to large-scale investors for the production of export crops. In the region of Piura the increasing presence of large-scale biofuel investors puts substantial pressure on land and water resources, not only changing the use of and access to land for local communities, but also generating water shortages vis-à-vis the multiple water demands of local food producers. The changes in land relations and the agro-ecosystem, the altering food production regime as well as the increasing proletarization of smallholders, is driving many locals – even those which (initially) welcomed the investment – into resistance activities against the increasing control of land, water and other natural resources in the hands of agribusinesses. The aim of this presentation is to discuss the contemporary political, social and cultural dynamics of agrarian change along the northern Peruvian coast as well as the «reactions from below» emanating from campesino communities, landless laborers, brick producers, pastoralists as well as other marginalized groups. The different strategies, forms and practices of resistance with the goal of the «protection of the territory» shall be explored as well as the reasons for their rather scattered occurrence and the lack of alliances on the land issue. This input shall make a contribution to the on-going debate on individual and communal property rights and the question of what is best in terms of collective defense against land grabbing.
Resumo:
We report the synthesis and characterization of colored ZnO-based powders via solution combustion reaction of urea and zinc nitrate hexahydrate in varying molar ratios between 1:1 and 10:1. Among other techniques, we employ X-ray diffraction, nuclear magnetic resonance, and Raman spectroscopy to characterize the products. Within a narrow range of reactant ratios, we reproducibly find an unidentified, crystalline precursor phase related to isocyanuric acid next to ZnO. Finally, we complement our investigations by performing Prompt Gamma Activation Analysis (PGAA) on selected products in order to directly determine elemental bulk compositions and compare these with X-ray photoelectron spectroscopy (XPS) measurements. Our data show traces of nitrogen mainly on the surface of the particles, and thus we question the solution combustion method as a reliable synthesis toward N-doped ZnO. Furthermore, we exclude nitrogen as being responsible for the appearance of the four controversially discussed Raman bands superimposed onto the spectrum of pure ZnO (at 275, 510, 582, and 643 cm–1) and show that the combination of PGAA and XPS is an excellent and complementary method to obtain information about the distribution of the elements in question.
Resumo:
4-Aryl-1,1,1-trifluorobut-3-en-2-ones ArCH[double bond, length as m-dash]CHCOCF3 (CF3-enones) react with arenes in excess of Brønsted superacids (TfOH, FSO3H) to give, stereoselectively, trans-1,3-diaryl-1-trifluoromethyl indanes in 35-85% yields. The reaction intermediates, the O-protonated ArCH[double bond, length as m-dash]CHC(OH(+))CF3 and the O,C-diprotonated ArHC(+)CH2C(OH(+))CF3 species, have been studied by means of (1)H, (13)C, (19)F NMR, and DFT calculations. Both types of the cations may participate in the reaction, depending on their electrophilicity and electron-donating properties of the arenes. The formation of CF3-indanes is a result of cascade reaction of protonated CF3-enones to form chemo-, regio- and stereoselectively three new C-C bonds. The obtained trans-1,3-diaryl-1-trifluoromethyl indanes were investigated as potential ligands for cannabinoid receptors CB1 and CB2 types. The most potent compound showed sub-micromolar affinity for both receptor subtypes with a 6-fold selectivity toward the CB2 receptor with no appreciable cytotoxicity toward SHSY5Y cells.
Resumo:
"Flare-up" reactions are late manifestations of severe T-cell-mediated drug hypersensitivity reactions. Management is anti-inflammatory treatment and avoiding unnecessary medicines. Symptoms like fever, lymph node swelling, and blood count abnormalities may lead to confusion with bacterial infections. For prompt recognition it is important to keep the differential diagnosis in mind.
Resumo:
BACKGROUND AND OBJECTIVES The distinction of oral lichenoid reactions from oral lichen planus may be difficult in a clinical setting. Our aims were to ascertain the utility of patch testing to confirm the association of oral lichenoid reactions with dental restorations and to identify the benefits of replacement of restorations, primarily made of amalgam. METHODS Patients seen in an oral medicine unit over a 10-year period diagnosed with oral lichenoid reactions, with oral lichen planus resistant to treatment or with atypical lichenoid features were included in this study. All had been subjected to skin patch testing. Histopathology reports blinded to patch test results were scrutinized. Patch-test-positive subjects were advised to have their restorations replaced. All were followed up to determine disease resolution for at least 3 months thereafter. RESULTS Among 115 patients, 67.8% patients reacted positive to a dental material and nearly a quarter to mercury or amalgam. No correlation was found between pathology and skin patch testing results (P = 0.44). A total of 87 patients were followed up in clinic, and among 26 patch-test-positive patients who had their amalgam fillings replaced, moderate to complete resolution was noted in 81%. CONCLUSIONS Skin patch testing is a valuable tool to confirm clinically suspected oral lichenoid reactions. Pathology diagnoses of oral lichenoid reactions did not correlate with patch test results. Prospective studies are needed to ascertain that a clinically suspected oral lichenoid reaction with a positive patch test result may resolve after the replacement of amalgam fillings.
Resumo:
Therapists having a positive influence on patients is a common view of psychotherapy. There is, however, an influence of patients on therapists too, which has received less attention. The more restricted and rigid patients are, the more limited the interpersonal behavior of others with which the get along well. In line with social psychological, interpersonal and clinical models they try to bring the therapist into an interpersonal position which suits them well. With 60 patients, common strategies have been rated: Good mood, Positive feedback, Negative feedback, Agenda setting, Provoking a response from the therapist, Negative reports about third persons, Fait accompli, Supplication, Self-promotion, Avoidance of contents, und Emotional avoidance. The rating procedure, frequencies, and therapist reactions upon these patient strategies will be reported
Resumo:
Giardia lamblia is an intestinal protozoan parasite infecting humans and various other mammalian hosts. The most important clinical signs of giardiasis are diarrhoea and malabsorption. Giardia lamblia is able to undergo continuous antigenic variation of its major surface antigen, named VSP (variant surface protein). While intestinal antibodies, and more specifically anti-VSP IgA antibodies, were proven to be involved in modulating antigenic variation of the parasite the participation of the local antibody response in control of the parasite infection is still controversial. Conversely, previous studies based on experimental infections in mice showed that cellular immune mechanisms are essential for elimination of the parasite from its intestinal habitat. Furthermore, recent data indicated that inflammatory mast cells have a potential to directly, or indirectly, interfere in duodenal growth of G. lamblia trophozoites. However, this finding was challenged by other reports, which did not find a correlation between intestinal inflammation and resistance to infection. Since intestinal infiltration of inflammatory cells and/or CD8+T-cells were demonstrated to coincide with villus-shortening and crypt hyperplasia immunological reactions were considered to be a potential factor of pathogenesis in giardiasis. The contribution of physiological factors to pathogenesis was essentially assessed in vitro by co-cultivation of G. lamblia trophozoites with epithelial cell lines. By using this in vitro model, molecular (through surface lectins) and mechanical (through ventral disk) adhesion of trophozoites to the epithelium was shown to be crucial for increased epithelial permeability. This phenomenon as well as other Giardia-induced intestinal abnormalities such as loss of intestinal brush border surface area, villus flattening, inhibition of disaccharidase activities, and eventually also overgrowth of the enteric bacterial flora seem to be involved in the pathophysiology of giardiasis. However, it remains to be elucidated whether at least part of these pathological effects are causatively linked to the clinical manifestation of the disease.