A participação dos metais pesados nas reações químicas do metabolismo dos peixes tornou esses elementos um dos principais focos nos estudos de contaminação. O objetivo deste estudo foi determinar as concentrações dos metais Cd, Cr, Cu, Pb, Zn e Hg no tecido muscular de peixes da bacia do rio Cassiporé (Estado do Amapá) e ambiente, visando avaliar os riscos de contaminação. As concentrações de Cd em Plagioscion squamosissimus (1,061 µg g ), Hoplias malabaricus (0.570 µg g -1 e Serrasalmus rhombeus (0.548 µg g -1 ) were above the legal limit. The water column showed high concentrations of heavy metals in all analyzed points, showing a contamination of this river basin. Therefore, the high concentrations of heavy metals in the environment and muscle tissue of fish indicate a high degree of contamination in the Cassiporé river basin and risk to human health.

ObjectivesThe aqueous extracts of currently utilized Amazonian medicinal plants were assayed in vitro searching for antimicrobial activity against human and animal pathogenic microorganisms.MethodsMedium resuspended lyophilized aqueous extracts of different organs of Amazonian medicinal plants were assayed by in vitro screening for antimicrobial activity. ATCC and standardized microorganisms obtained from Oswaldo Cruz Foundation/Brazil were individually and homogeneously grown in agar plate, and holes previously perforated in the gel were filled with diluted plant aqueous extracts. Inhibition halos were evaluated and controlled by the use of the fluoroquinolone ciprofloxacin.ResultsThe Amazonian medicinal plants, Hymenelobium petraeum showed inhibitory activity over Staphylococcus aureus, Enterococcus faecalis, Salmonella enterica serovar Typhi, Acinetobacter baumannii and Candida albicans, while Vatairea guianensis and Symphonia globulifera presented inhibitory activity exclusively for Staphylococcus aureus. Also, Ptychopetalum olacoides and Pentaclethra macroloba inhibited the growth of Klebsiella ozaenae and Acinetobacter baumannii.ConclusionThe aqueous botanic extracts that showed activity against microroganisms of ATTC and Osvaldo Cruz strains had at least 40% of antimicrobial activity when compared to halo inhibition produced by the commercial antibiotic ciprofloxacin utilized as a control. Of all plants extracts assayed, the Hymenelobium petraeum had the best performance, sometimes exhibiting higher activity than ciprofloxacin. It is not well-defined by the physicians the exact indication of the majority of medicinal plants in the Amazon area in Brazil. Natives utilize the plants according to their symptoms, based on the traditional knowledge transmitted orally from generation to generation, among Amerindians, Afrodescendents and ethnic mixed populations. A significant number of Amazonian medicinal plants are totally unknown related to their medicinal properties including mechanism of action and therapeutic effects, as very few information is reported in the scientific literature. A tiny amount of data is presented, as the preliminary antimicrobial properties of the medicinal plants here accessed, under the urgent necessity of new antibiotics in the market and in face of the increased resistance of infectious microorganisms to antimicrobials.

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Foram realizados estudos para avaliar a microestrutura, a dureza e a resistência à corrosão do titânio comercialmente puro-Ti c.p. soldado por laser e utilizado na confecção de prótese sobre implantes. Verificou-se que na soldagem a laser a microestrutura apresentou três regiões distintas: o cordão de solda, a zona afetada pelo calor - ZAC e o metal base. O Ti c.p. possui microestrutura granular, a microestrutura do cordão de solda é mais refinada e de maior dureza do que o metal base. A ZAC obtida por este processo de soldagem foi relativamente pequena quando comparada com o processo de soldagem por brasagem. Os ensaios eletroquímicos mostraram que a região da solda apresentou menor resistência à corrosão em meio de NaCl 0,15 molL-1 à temperatura ambiente.