1,875 research outputs found

    Poder Calorífico da Casca de Arroz, Caroço de Pêssego, Serragem de Eucalipto e de seus Produtos de Pirólise

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    The Higher Heating Value (HHV) of rice husks, peach stones andeucalyptus sawdust was determined, as well as of the resulting bio-oils andresidual chars from low temperature conversion process. Products yields forbio oils varied from 16 to 26%, and for solid residue, from 38 to 48%. HHV of3,900, 2,600 and 4,100 cal/g were measured for rice husks biomass, its residualchar and bio-oil; 4,100, 5,800 and 4,000 cal/g, for eucalyptus sawdust, its charand bio oil; 3.,400, 3,200 e 3,900 cal/g, for peach stones, its char and bio oil,respectively. These values show that biomasses and pyrolysis products canbe considered as renewable energy sources, clean and neutral to global warming.Determinou-se o poder calorífico superior (PCS) das biomassas:casca de arroz, caroço de pêssego, serragem de eucalipto, e dos bioóleos eresíduos carbonosos correspondentes, obtidos por conversão térmica a baixatemperatura. Rendimentos de bioóleo entre 16% e 26%, e, de resíduo carbonoso,entre 38% e 48%, foram obtidos na pirólise. Valores de Poder Calorífico de3.900, 2.600 e 4.100 cal/g foram medidos para a casca de arroz, seu carvão e óleode pirólise; 4.100, 5.800 e 4.000 cal/g, para serragem de eucalipto, seu carvão eóleo de pirólise; 3.400, 3.200 e 3.900 cal/g, para caroço de pêssego, seu carvãoe bioóleo, respectivamente. Estes valores demonstram que as biomassas e osseus produtos de pirólise podem ser considerados fontes renováveis de energia,limpas e neutras quanto ao fenômeno de aquecimento global.Palavras chave: biomassa, pirólise, poder calorífico superior

    Careers of highly educated self-initiated expatriates : observations from studies among Finnish business professionals

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    This chapter reviews existing literature about the careers of self-initiated expatriates and analyzes the different studies carried out among university level educated Finnish business professionals. A series of studies carried out among members of the Finnish Association of Business School Graduates during the last 15 years was cross-analyzed. The studies are based on three surveys and further interviews among their expatriate members (1999, 2004 and a follow-up study in 2012) also involving SIEs. Therefore, this chapter provide an overview of what we know about the careers of Finnish SIEs and show evidence of (1) their career motives, (2) the role of family considerations in the career decision making of SIEs, (3) the development of career capital and social capital during SIE-experiences, and also (4) longer-term career impacts of SIE-experiences. Based on the literature review and analysis of above mentioned studies we highlight the gaps in in the knowledge about SIEs and suggest areas where further research is needed.fi=vertaisarvioitu|en=peerReviewed

    Nitric oxide production and monoamine oxidase activity in cancer patients during interferon-α therapy

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    Both increased and decreased nitric oxide (NO) synthesis have been reported in patients treated with interferon-α (IFN-α). Animal studies showed that IFN-α administration results in increased levels of biogenic amines, subsequent activation of monoamine oxidases (MAOs), and finally in a change in NO production due to the H2O2 generated by MAOs. We examined the potential relationship between NO production in plasma and MAO-B activity in platelets of 43 cancer patients during 8 weeks of treatment with IFN-α. NO synthesis was quantitated by measuring both the ratio of citrulline and arginine (CIT/ARG-ratio) and total nitrite/nitrate (NOx) levels. Compared to baseline, MAO activity and NOx increased, while the CIT/ARG-ratio decreased. No associations were found between NOx, MAO and CIT/ARG-ratio. Only few associations were observed between changes in the biochemical parameters and changes in psychopathology induced by IFN-α, of which the association between changes in CIT and lassitude was the most consistent. The results suggest that peripheral NO production and MAO activity are unrelated to each other, and that peripheral changes in these biochemical parameters induced by IFN-α are unlikely to contribute to definite psychiatric disturbance

    Aldehyde dehydrogenase inhibition as a pathogenic mechanism in Parkinson disease

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    Parkinson disease (PD) is a neurodegenerative disorder particularly characterized by the loss of dopaminergic neurons in the substantia nigra. Pesticide exposure has been associated with PD occurrence, and we previously reported that the fungicide benomyl interferes with several cellular processes potentially relevant to PD pathogenesis. Here we propose that benomyl, via its bioactivated thiocarbamate sulfoxide metabolite, inhibits aldehyde dehydrogenase (ALDH), leading to accumulation of the reactive dopamine metabolite 3,4-dihydroxyphenylacetaldehyde (DOPAL), preferential degeneration of dopaminergic neurons, and development of PD. This hypothesis is supported by multiple lines of evidence. (i) We previously showed in mice the metabolism of benomyl to S-methyl N-butylthiocarbamate sulfoxide, which inhibits ALDH at nanomolar levels. We report here that benomyl exposure in primary mesencephalic neurons (ii) inhibits ALDH and (iii) alters dopamine homeostasis. It induces selective dopaminergic neuronal damage (iv) in vitro in primary mesencephalic cultures and (v) in vivo in a zebrafish system. (vi) In vitro cell loss was attenuated by reducing DOPAL formation. (vii) In our epidemiology study, higher exposure to benomyl was associated with increased PD risk. This ALDH model for PD etiology may help explain the selective vulnerability of dopaminergic neurons in PD and provide a potential mechanism through which environmental toxicants contribute to PD pathogenesis

    Immunization with Single-Cycle SIV Significantly Reduces Viral Loads After an Intravenous Challenge with SIVmac239

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    Strains of simian immunodeficiency virus (SIV) that are limited to a single cycle of infection were evaluated for the ability to elicit protective immunity against wild-type SIVmac239 infection of rhesus macaques by two different vaccine regimens. Six animals were inoculated at 8-week intervals with 6 identical doses consisting of a mixture of three different envelope variants of single-cycle SIV (scSIV). Six additional animals were primed with a mixture of cytoplasmic domain-truncated envelope variants of scSIV and boosted with two doses of vesicular stomatitis virus glycoprotein (VSV G) trans-complemented scSIV. While both regimens elicited detectable virus-specific T cell responses, SIV-specific T cell frequencies were more than 10-fold higher after boosting with VSV G trans-complemented scSIV (VSV G scSIV). Broad T cell recognition of multiple viral antigens and Gag-specific CD4+ T cell responses were also observed after boosting with VSV G scSIV. With the exception of a single animal in the repeated immunization group, all of the animals became infected following an intravenous challenge with SIVmac239. However, significantly lower viral loads and higher memory CD4+ T cell counts were observed in both immunized groups relative to an unvaccinated control group. Indeed, both scSIV immunization regimens resulted in containment of SIVmac239 replication after challenge that was as good as, if not better than, what has been achieved by other non-persisting vaccine vectors that have been evaluated in this challenge model. Nevertheless, the extent of protection afforded by scSIV was not as good as typically conferred by persistent infection with live, attenuated SIV. These observations have potentially important implications to the design of an effective AIDS vaccine, since they suggest that ongoing stimulation of virus-specific immune responses may be essential to achieving the degree of protection afforded by live, attenuated SIV

    New cellular tools reveal complex epithelial–mesenchymal interactions in hepatocarcinogenesis

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    To enable detailed analyses of cell interactions in tumour development, new epithelial and mesenchymal cell lines were established from human hepatocellular carcinoma by spontaneous outgrowth in culture. We obtained several hepatocarcinoma (HCC)-, B-lymphoblastoid (BLC)-, and myofibroblastoid (MF)-lines from seven cases. In-depth characterisation included cell kinetics, genotype, tumourigenicity, expression of cell-type specific markers, and proteome patterns. Many functions of the cells of origin were found to be preserved. We studied the impact of the mesenchymal lines on hepatocarcinogenesis by in vitro assays. BLC- and MF-supernatants strongly increased the DNA replication of premalignant hepatocytes. The stimulation by MF-lines was mainly attributed to HGF secretion. In HCC-cells, MF-supernatant had only minor effects on cell growth but enhanced migration. MF-lines also stimulated neoangiogenesis through vEGF release. BLC-supernatant dramatically induced death of HCC-cells, which could be largely abrogated by preincubating the supernatant with TNFβ-antiserum. Thus, the new cell lines reveal stage-specific stimulatory and inhibitory interactions between mesenchymal and epithelial tumour cells. In conclusion, the new cell lines provide unique tools to analyse essential components of the complex interplay between the microenvironment and the developing liver cancer, and to identify factors affecting proliferation, migration and death of tumour cells, neoangiogenesis, and outgrowth of additional malignancy

    Cross-Border Mobility of Self-Initiated and Organizational Expatriates

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    Globalization in the late twentieth and early twenty-first centuries has been marked by an increase in cross-border mobility of the highly skilled. Though self-initiated expatriation is a widespread phenomenon, it has received relatively little attention in the academic literature. Furthermore, large-scale studies that track self-initiated and organizational expatriates together, over time and across geographies, are noticeably absent from the literature. Consequently, our understanding of these two forms of mobility is relatively limited. This study, which is the first large-scale analysis of the trends in and patterns of the mobility of organization-initiated expatriates and self-initiated expatriates, attempts to fill this gap by analyzing the mobility patterns of 55,915 highly skilled individuals who made 76,660 cross-border moves between 1990 and 2006. Specifically, we analyze patterns of geographic mobility and then examine the rate, duration, and direction of self-initiated and organizational expatriation over time. Finally, we consider demographic differences in mobility between the two groups
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