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1.
Renew Sustain Energy Rev ; 133: 110343, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34234618

RESUMO

This paper offers perspectives on the development of low-carbon energy technology in Brazil, pinpointing changes that have occurred since our former publication in 2011. It takes a fresh approach in terms of how likely Brazil will achieve its Nationally Determined Contributions Commitments in the energy sector. Many countries have implemented national climate policies to accomplish their pledged NDC and contribute to the temperature objectives of the Paris Agreement on climate change. Based on official reports and databases of energy development projections in Brazil and the socioeconomic context, we discuss what can be expected for the future of the Brazilian energy sector, the probability of implementing selected technologies, and the prospects of reaching the NDC targets for 2025 and 2030. In addition, this paper provides an overview of the current stage of development of these technologies, main directions, and bottlenecks in Brazil. Analyses have shown that the Brazilian renewable matrix tends to remain significant, driven by the development of solar and mostly small hydroelectric power sources, as well as different types of biomass. In addition, the system will include the replacement of thermoelectric plants powered by diesel and fuel oil by natural gas plants. The prospects for Brazil's official energy plan for 2027 are aligned with the reference technology scenario, which represents the business as usual scenario. Despite this, low-carbon technologies could be implemented far beyond the NDC's goals, given the abundance of renewable natural resources in the country.

2.
Acta Cytol ; 45(3): 360-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11393067

RESUMO

OBJECTIVE: To assess the efficacy of conventional oral exfoliative cytology as a diagnostic tool in paracoccidioidomycosis. STUDY DESIGN: Cytologic smears and incisional biopsies were obtained from 10 patients with a clinical suspicion and oral manifestations of paracoccidioidomycosis. Cytologic smears and sections of the incisional biopsy underwent methenamine silver staining for fungi according to the Gomori-Grocott method. The dry glass slides were examined at 400 or 1,000 x magnification, and the presence and shape of yeasts of Paracoccidioides brasiliensis were investigated. RESULTS: Yeasts of the fungus P brasiliensis were clearly identified in cytologic smears and sections from incisional biopsies in all cases analyzed (100.0%). CONCLUSION: Cytology of oral samples proved an effective diagnostic method for the detection of paracoccidioidomycosis in humans.


Assuntos
Doenças da Boca/microbiologia , Paracoccidioides/citologia , Paracoccidioidomicose/microbiologia , Coloração e Rotulagem/métodos , Adulto , Biópsia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças da Boca/patologia , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/patologia
3.
Cell Mol Biol (Noisy-le-grand) ; 43(4): 589-96, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9220152

RESUMO

Lobular hepatic fibrosis and the presence of myofibroblasts were studied in heroin abusers, by quantitative automatic image analysis. Nineteen addicts (DA) and thirteen patients having stopped consumption (exDA) were compared to a non-addict group (CONTROL). Addicts, all anti-HIV and HBsAg negative, showed increased transaminase levels. Hepatitis C markers were ot available, at the time of biopsy. The surface of the centrolobular fibrosis, measured on picrosirius stained slides, was respectively 1.9 and 3.5 times larger in DA and exDA than in CONTROL (p < 0.0001). Immunolabelling with an alpha-smooth muscle actin antibody (alpha-SMA) revealed stellate cells in a perisinusoidal location, mainly in areas of matrix thickening in the space of Disse. Morphometric analysis of alpha-SMA expression showed significant differences between the three groups of patients, p < 0.0001 (CONTROL: 198.06 +/- 5.59 microns2; DA: 2227.91 +/- 88.02 microns2; exDA: 3469.10 +/- 154.98 microns2). The surface density of collagen and of alpha-SMA reactivity was also significantly different between these groups (p < 0.0001). These data strongly suggest that heroin is responsible for an early and progressive centrolobular liver fibrosis, occurring simultaneously with a myofibroblastic response. It might represent a reparative phenomenon arising from a direct vascular injury, leading to an impairment of blood-hepatocyte exchange.


Assuntos
Actinas/efeitos dos fármacos , Colágeno/metabolismo , Dependência de Heroína/metabolismo , Cirrose Hepática/metabolismo , Fígado/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Actinas/metabolismo , Adulto , Feminino , Dependência de Heroína/patologia , Humanos , Fígado/patologia , Cirrose Hepática/patologia , Masculino , Músculo Liso/patologia , Estudos Retrospectivos , Transtornos Relacionados ao Uso de Substâncias/patologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-8465514

RESUMO

The aim of the present work was to analyse, at the ultrastructural level, the action of heroin of 150 centrilobular sinusoids from liver biopsies of five intravenous drug abusers, who presented clinical and biological manifestations of hepatic impairment. A comparative study of 90 sinusoids from liver biopsies of three control patients was performed. Electron microscopic observations showed a thickening of the sinusoidal wall related to endothelial cell hypertrophy and to fibrosis of the space of Disse. This was generally associated with basement-membrane-like material and hepatocyte microvilli flattening. In addicts, hepatic vascular pole changes were a constant finding, accompanied by interhepatocyte space disjunction and perisinusoidal collagenization. Morphometric assessment confirmed a significant increase of sinusoidal wall surface, endothelial cell body and processes and Ito cell process surface was significantly different between the patient groups. This cellular hypertrophy may represent hyperactivation of the sinusoidal cell functional capacity, triggering the fibrogenesis in the space of Disse. While this mechanical barrier might hinder the free exchange through the space of Disse, it may equally well protect the liver against heroin toxicity.


Assuntos
Matriz Extracelular/ultraestrutura , Heroína , Fígado/patologia , Transtornos Relacionados ao Uso de Substâncias , Adulto , Endotélio Vascular/patologia , Endotélio Vascular/ultraestrutura , Humanos , Hipertrofia , Fígado/ultraestrutura , Cirrose Hepática/patologia , Masculino , Microscopia Eletrônica
5.
Artigo em Inglês | MEDLINE | ID: mdl-1549903

RESUMO

A histological and morphometric study demonstrated a relationship between vascular changes in the hepatic lobule and heroin consumption. To establish the role of hepatocytes in the genesis of sinusoidal dilatation, morphometric analysis was performed on ten drug abusers and eight controls. A total of 1800 hepatocytes, in 67 centrilobular areas, were analysed from biopsies from the total patient number. Computerized results of hepatocyte surface area, perimeter, maximum linear dimension and minimum linear dimension demonstrated no statistically significant difference for these variables, particularly for hepatocyte surface area (Controls: 268.66 +/- 95.25; drug abusers: 252.00 +/- 78.94, p = 0.24), when the two groups of patients were compared. Hepatocyte morphology at the time of the biopsy was unaltered, although transaminase values were elevated for all drug abusers. It is, therefore, possible that the hepatocytes were not implicated in the pathogenesis of sinusoidal dilatation. This suggestion supports our previous results, which suggested that heroin was capable of inducing direct vascular hepatotoxicity.


Assuntos
Dependência de Heroína/patologia , Fígado/patologia , Transtornos Relacionados ao Uso de Substâncias/patologia , Adulto , Circulação Êntero-Hepática/efeitos dos fármacos , Heroína , Humanos , Fígado/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos
6.
Artigo em Inglês | MEDLINE | ID: mdl-2125388

RESUMO

The hepatotoxic effect of heroin has been demonstrated in liver biopsies by morphometric analysis of four groups of patients: twenty-one drug abusers (DA) at the time of the biopsy, eighteen patients who had stopped drug consumption for at least six months (ex-DA), twelve patients with post-transfusional chronic active hepatitis (PTCAH), and eleven controls (CONTROL). Semiquantitative assessment showed the extent of sinusoidal dilatation and the inflammatory and fibrotic reaction in the terminal hepatic vein (THV). Thickening and cellularity of the venular wall and the volume density of sinusoidal lumen (Vsl) in the Zone I and III of the hepatic acinus, were also evaluated. The morphometric analysis used computerized measurements. In DA, the sinusoidal dilatation (100% of cases), the sinusoidal and THV inflammation (81% and 67.7%, respectively), localized mainly in the centrilobular zone, were more pronounced than in ex-DA, in patients with PTCAH and in CONTROL (significantly different P less than 0.0001). Conversely, the fibrotic reaction (perisinusoidal fibrosis--44.4% and perivenular fibrosis--61.1%) was more frequent in ex-DA. The THV inflammation in DA was replaced by a fibrotic matrix deposit in the THV wall (wall surface/internal surface = 2.72 +/- 0.37 in ex-DA; 1.38 +/- 0.32 in DA; 0.87 +/- 0.14 in PTCAH and 0.45 +/- 0.03 in CONTROL--significantly different P less than 0.001), associated with a perisinusoidal fibrosis, after drug withdrawal. Moreover, there was significantly decreased venular wall cellularity in ex-DA (wall surface/mesenchymal cells = 949 +/- 158 in ex-DA; 622 +/- 40 in DA; 619 +/- 61 in PTCAH; 547 +/- 23 in CONTROL--P less than 0.001). Semiquantitative and morphometric data suggest that these vascular lesions and their reversibility may be due to the direct hepatotoxic effects of heroin.


Assuntos
Veias Hepáticas/patologia , Heroína , Transtornos Relacionados ao Uso de Substâncias/patologia , Adulto , Fibrose , Veias Hepáticas/efeitos dos fármacos , Heroína/efeitos adversos , Humanos , Vasculite/induzido quimicamente , Vasodilatação
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