ESSÊNCIAS BRASILEIRAS E SUA CONSERVAÇÃO GENÉTICA NO INSTITUTO FLORESTAL DE SÃO PAULO

exploração intensa e desordenada de espécies nativas do Brasil, para atender àdemandade madeirada população do país, particularmente do estado de São Paulo, vem ocasionando a extinção de espécies florestais não só de valor comercial, como social e científico. Em decorrência disto, as mesmas começam a apresentar um sério comprometimento de seu potencial genético. [...

Waste-derived activated carbons for removal of ibuprofen from solution: Role of surface chemistry and pore structure

7 pages, 4 figures, 3 tables. -- PMID: 19006666 [PubMed]. -- Available online 8 November 2008.The removal of a widespread used drug (i.e., ibuprofen) from water was investigated using high valuable carbon adsorbents obtained from chemical and physical activation of a bioresource (cork) and a municipal waste (plastic). The waste-derived carbons outperformed the adsorption capacity of commercial carbonaceous adsorbents due to their adequate features for the removal of the targeted compound. Regarding the adsorption mechanism, the results obtained point out that ibuprofen retention is favored in activated carbons with basic surface properties. On the other hand, the textural features also play an important role; the presence of a transport pores network (i.e., mesopores) is crucial to ensure the accessibility to the inner porosity, and the microporosity must be large enough to accommodate the ibuprofen molecule. Specifically, adsorbents with a large fraction of ultramicropores (pore widths <0.7 nm) are not adequate to effectively remove ibuprofen.This work was supported by FCT (Portugal) through the pluriannual programme of CQB. Ana S. Mestre thanks FCT for a PhD Grant (SFRH/BD/17942/2004). Conchi O. Ania thanks the Spanish MEC for a Ramon y Cajal research contract and the financial support of MICINN (Project CTM2008-01956/TECNO). The authors thank N.R. Neng and F.C.M. Portugal for technical assistance in HPLC measurements and Generis Farmacêutica SA (Portugal) for the ibuprofen supply. S.A. Bayer and S.L. Nanoquimia are kindly acknowledged for providing LS and Q carbons, respectively.Peer reviewe

Surface heterogeneity effects of activated carbons on the kinetics of paracetamol removal from aqueous solution

The removal of a compound with therapeutic activity (paracetamol) from aqueous solutions using chemically modified activated carbons has been investigated. The chemical nature of the activated carbon material was modified by wet oxidation, so as to study the effect of the carbon surface chemistry and composition on the removal of paracetamol. The surface heterogeneity of the carbon created upon oxidation was found to be a determinant in the adsorption capability of the modified adsorbents, as well as in the rate of paracetamol removal. The experimental kinetic data were fitted to the pseudo-second order and intraparticle diffusion models. The parameters obtained were linked to the textural and chemical features of the activated carbons. After oxidation the wettability of the carbon is enhanced, which favors the transfer of paracetamol molecules to the carbon pores (smaller boundary layer thickness). At the same time the overall adsorption rate and removal efficiency are reduced in the oxidized carbon due to the competitive effect of water molecules.ASM thanks FCT for a PhD grant (SFRH/BD/17942/2004). COA thanks the Spanish MICINN (CTM2008/01956) for financial support.Peer reviewe

Waste-derived activated carbons for removal of ibuprofen from solution: Role of surface chemistry and pore structure

International audienc

Carcinoma gástrico: análise sistemática de 289 gastrectomias consecutivas em Belo Horizonte (MG)

Introdução e objetivos: O carcinoma gástrico (CG), altamente prevalente em nosso meio, é a primeira causa de morte por câncer no país. Neste trabalho relatamos os dados de nossa casuística de um período de dez anos. Material e método: Examinaram-se 289 peças de gastrectomia para CG, seguindo-se protocolo padronizado. Resultados: A maior parte dos CG (n = 170, 59%) tinha localização distal, 230 casos (79%) eram CG avançados (predominantemente Borrmanm III) e 36 casos (12,4%), precoces (predominantemente tipo II); 40% dos casos eram expansivos e 42%, infiltrativos; 178 casos (62%) eram do tipo intestinal (CGI), 61 (21%), do tipo difuso (CGD) e 50 (17%), mistos ou não-classificáveis. Dos 178 casos de CGI, 116 pacientes eram homens e 61, mulheres (1,9:1), com média de idade de 67 ± 12 anos; nos 61 casos de CGD, 36 pacientes eram homens e 25, mulheres (1,4:1), sendo significativamente mais novos que no CGI (59 ± 14 anos) (p = 0,001). O CGI era predominantemente do tipo Borrmann I ou II, enquanto que o CGD era mais comumente do tipo III ou IV de Borrmann (p = 0,004). Os CGD estavam em estádios mais avançados do que os CGI (p = 0,02) e a invasão de nervos foi mais frequentemente (p < 10-7). Gastrite crônica atrófica e metaplasia intestinal foram freqüentes, tanto no CGI (81% e 67%) como no CGD (77% e 59%). Conclusões: Os dados são semelhantes aos da literatura para populações de médio e alto riscos para CG, predominando tumores distais de tipo intestinal. A maioria dos casos é de CG avançado sem possibilidade de cura no momento do diagnóstico