Heavy metal tolerance traits of filamentous fungi isolated from gold and gemstone mining sites

ABSTRACT Increased environmental pollution has necessitated the need for eco-friendly clean-up strategies. Filamentous fungal species from gold and gemstone mine site soils were isolated, identified and assessed for their tolerance to varied heavy metal concentrations of cadmium (Cd), copper (Cu), lead (Pb), arsenic (As) and iron (Fe). The identities of the fungal strains were determined based on the internal transcribed spacer 1 and 2 (ITS 1 and ITS 2) regions. Mycelia growth of the fungal strains were subjected to a range of (0-100 Cd), (0-1000 Cu), (0-400 Pb), (0-500 As) and (0-800 Fe) concentrations (mgkg-1) incorporated into malt extract agar (MEA) in triplicates. Fungal radial growths were recorded every three days over a 13-days' incubation period. Fungal strains were identified as Fomitopsis meliae, Trichoderma ghanense and Rhizopus microsporus. All test fungal exhibited tolerance to Cu, Pb, and Fe at all test concentrations (400-1000 mgkg-1), not differing significantly (p > 0.05) from the controls and with tolerance index >1. T. ghanense and R. microsporus demonstrated exceptional capacity for Cd and As concentrations, while showing no significant (p > 0.05) difference compared to the controls and with a tolerance index >1 at 25 mgkg-1 Cd and 125 mgkg-1 As. Remarkably, these fungal strains showed tolerance to metal concentrations exceeding globally permissible limits for contaminated soils. It is envisaged that this metal tolerance trait exhibited by these fungal strains may indicate their potentials as effective agents for bioremediative clean-up of heavy metal polluted environments.

Biosynthesis of gold nanoparticles by two bacterial and fungal strains, Bacillus cereus and Fusarium oxysporum, and assessment and comparison of their nanotoxicity in vitro by direct and indirect assays

Background: Although nanoparticles (NPs) have many advantages, it has been proved that they may be absorbed by and have toxic effects on the human body. Recent research has tried to evaluate and compare the nanotoxicity of gold nanoparticles (AuNPs) produced by two types of microorganisms in vitro by two different methods. AuNPs were produced by Bacillus cereus and Fusarium oxysporum, and their production was confirmed by visible spectral, transmission electron microscope, and X-ray diffraction (XRD) analyses. The human fibroblast cell line CIRC-HLF was treated with AuNPs, and the induced nanotoxicity was measured using direct microscopic and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Results: The results showed that the produced AuNPs had a maximum absorbance peak around 510­530 nanometer (nm), with spherical, hexagonal, and octagonal shapes and average sizes around 20­50 nm. The XRD results confirmed the presence of GNPs in the microbial culture supernatants. An MTT assay showed that GNPs had dose-dependent toxic effects, and microscopic analysis showed that GNPs induced cell abnormalities in doses lower than the determined half-maximal inhibitory concentrations (IC50s). Conclusions: In conclusion, the biologically produced AuNPs had toxic effects in the cell culture, and direct techniques such as microscopic evaluation instead of indirect methods such as MTT assay were more useful for assessing the nanotoxicity of the biologically produced AuNPs. Thus, the use of only MTT assay for nanotoxicity evaluation of AuNPs is not desirable.

Bioleaching of gold, copper and nickel from waste cellular phone PCBs and computer goldfinger motherboards by two Aspergillus nigerstrains

In an effort to develop alternate techniques to recover metals from waste electrical and electronic equipment (WEEE), this research evaluated the bioleaching efficiency of gold (Au), copper (Cu) and nickel (Ni) by two strains of Aspergillus niger in the presence of gold-plated finger integrated circuits found in computer motherboards (GFICMs) and cellular phone printed circuit boards (PCBs). These three metals were analyzed for their commercial value and their diverse applications in the industry. Au-bioleaching ranged from 42 to 1% for Aspergillus niger strain MXPE6; with the combination of Aspergillus niger MXPE6 + Aspergillus niger MX7, the Au-bioleaching was 87 and 28% for PCBs and GFICMs, respectively. In contrast, the bioleaching of Cu by Aspergillus niger MXPE6 was 24 and 5%; using the combination of both strains, the values were 0.2 and 29% for PCBs and GFICMs, respectively. Fungal Ni-leaching was only found for PCBs, but with no significant differences among treatments. Improvement of the metal recovery efficiency by means of fungal metabolism is also discussed.

Undergraduate dental sudents' perspectives about experiences in primary care for their education in the field of health / Perspectivas de graduandos em odontologia acerca das experiências na atenção básica para sua formação em saúde

Supervised training periods in primary care have been used as spaces for teaching and extension in the area of health, making it feasible to include undergraduates in concrete teaching-learning scenarios. The aim of this study was to analyze the perceptions of dental students about the importance of supervised training periods in Family Health Units to their professional education. The sample consisted of 185 students who answered the question: What is your opinion about the importance of this training period in SUS to your professional education? Comment on this experience and its positive and negative aspects The responses were analyzed by the quali-quantitative Collective Subject Discourse (CSD) technique. The students appreciated learning through practice in the service; contact with professionals from other areas; opportunity for technical-operative improvement and demonstrated sensitivity in the face of social reality, although they appeared to be concerned about being absent from the faculty, arguing that they were being prejudiced as regards their intramural clinical productivity, exhaustively demanded of them. It was concluded that students placed value on the extramural experience, however, it was perceived that there was still a predominant influence of focus on intramural clinical training.

Os estágios supervisionados na atenção básica vêm sendo utilizados como espaços de ensino e extensão nas áreas da saúde, viabilizando a inserção dos graduandos em cenários concretos de ensino-aprendizagem. O objetivo deste estudo foi analisar as percepções de acadêmicos de odontologia sobre a importância do estágio supervisionado em Unidades de Saúde da Família, para sua formação profissional. A amostra foi constituída por 184 acadêmicos que responderam à questão: Qual a sua opinião em relação à importância deste estágio no SUS para a sua formação profissional? Comente esta experiência e seus aspectos positivos e negativos. As respostas foram analisadas através da técnica qualiquantitativa do discurso do sujeito coletivo. Os alunos valorizaram o aprendizado através da prática no serviço, do contato com profissionais de outras áreas, da oportunidade de aperfeiçoamento técnico-operatório e demonstraram sensibilização frente à realidade social, embora tenham aparentado incômodo por se ausentarem da faculdade, sob o argumento de serem prejudicados quanto à produtividade da clínica intramuros, exaustivamente cobrada. Concluiu-se que os alunos valorizaram a experiência extramural, entretanto, percebeu-se que ainda há uma hegemonia do foco no treinamento clínico intramuros.

Microbial mediated preparation, characterization and optimization of gold nanoparticles

The need for eco-friendly and cost effective methods for nanoparticles synthesis is developing interest in biological approaches which are free from the use of toxic chemicals as byproducts. This study aimed to biosynthesize and optimize the size of gold nanoparticles which produced by biotechnological method using Penicillium crustosum isolated from soil. Initially, Penicillium crustosum was grown in fluid czapek dox broth on shaker at 28 ºC and 200 rpm for ten days and then the supernatant was separated from the mycelia to convert AuCl4 solution into gold nanoparticles. The synthesized nanoparticles in the optimum conditions were formed with fairly well-defined dimensions and good monodispersity. The characterizations were done by using different methods (UV-Visible Spectroscopy, Fluorescence, FT-IR, AFM (Atomic Force Microscopy) and DLS (Dynamic Light Scattering). The bioconversion was optimized by Box-Behnken experimental design. The results show that the effective factors in this process were concentration of AuCl4, pH of medium and temperature of shaker incubator. The R² value was calculated to be 0.9999 indicating the accuracy and ability of the polynomial model. It can be concluded that the use of multivariate analysis facilitated to find out the optimum conditions for the biosynthesis of gold nanoparticles induced by Penicillium crustosum in a time and cost effective process. The current approach suggested that rapid synthesis of gold nanoparticles would be suitable for developing a biological process for mass scale production of formulations.

O custo de soluções alcalinas em sessões de hemodiálise ambulatorial: uma análise sobre o desperdício a partir do controle dos processos / The cost of alkaline solutions in ambulatory hemodialysis: an analysis about wasteful from the processes control

Introdução: São escassos estudos dos custos dos insumos consumidos em hemodiálise e, dentre estes gastos, os compostos que compõem o dialisato estão entre os valores considerados como representativos nessa terapia. Contudo, não foram encontrados estudos que orientem sobre o comportamento de custos dessas soluções. Objetivo: O objetivo do artigo é avaliar se há desperdício no consumo de soluções alcalinas em hemodiálise ambulatorial e, consequentemente, a possibilidade de redução no custo a partir da simulação de padronização no processo de estabelecimento do fluxo do dialisato nos períodos entre turnos em sessões de hemodiálise ambulatorial. Métodos: Partindo de um estudo observacional analítico, foi realizada uma simulação de 20 cenários, sendo 10 estabelecidos pela padronização dos processos de controle no fluxo do dialisato nos intervalos das sessões. A combinação dos dados foi realizada tomando por base os preços de três fornecedores de soluções alcalinas líquidas ou em pó. Resultados: Observou-se, dentre os cenários com processos padronizados, uma variação entre 7,7% e 33,3% de economia no custo da solução alcalina (em pó ou líquida), pela redução do desperdício. Conclusão: É possível refrear o desperdício no uso de soluções alcalinas, tanto em pó quanto líquidas e, consequentemente, seus custos, a partir da padronização na redução do fluxo de dialisato durante os intervalos verificados entre os turnos na hemodiálise ambulatorial. Todavia, estes resultados estão condicionados ao comprometimento de profissionais de saúde, principalmente no que tange ao exercício da supervisão e controle das atividades ...

Introduction: There are few studies about costs of inputs used in hemodialysis and among these expenditures, the compounds that make up the dialysate are one of the values considered as representative of this therapy. However, there aren’t costs studies that guiding solutions. Objective: The objective of this article is discuss whether there is wasteful of alkaline solutions in ambulatory hemodialysis and hence the possibility of reduction in cost from the standardization process simulation of establishment of dialysate flow in periods between shifts in hemodialysis outpatients. Methods: Starting from an observational analytic, a simulation was performed twenty case scenarios, which ten cases established by standardizing processes control on the dialysate flow in recession. The combination of data was performed using as a basis the prices of three suppliers of alkali liquid or powder. Results: It was observed among the scenarios with standardized processes, ranging between 7.7% and 33.3% savings in the alkaline solution cost (powder or liquid), by reducing waste. Conclusion: It is possible to restrain the wasteful use of alkaline solutions, both powder and liquid. Consequently, its cost from the patterning on reducing the flow of dialysate during the intervals between shifts observed in the outpatient hemodialysis. However, these results are conditional upon the commitment of health professionals, mainly to supervision exercise and control of activities in quality function deployment. .

Depósitos corneanos / Corneal deposits

Os autores relatam achados biomicroscópicos que podem ser notados na clínica diária. Achados estes que podem refletir-se por depósitos corneanos, devido a doença sistêmicas, uso de medicaçäo sistêmica ou mesmo local