EFFECT OF MECHANICAL ACTIVATION ON THE POTASSIUM AVAILABILITY OF PHONOLITE ROCK
Background: Researchers are carried out to assess rocks containing potassium as an alternative source of fertilizers. These studies are important in reducing the external dependence of Brazil on this commodity. Phonolite is a rock of volcanic origin that has in its mineralogical composition the predominance of feldspar and has been potential to use as an alternative potassium source. The studied rock has 6% total-K but is unavailable to plants in natural rock. Aim: This project evaluated the effect of mechanical activation, wet and dry, on K availability for extractors different and its K leaching curves of phonolite from Poços de Caldas, MG, Brazil. Methods: Phonolite rock was subjected to mechanical activation for 30 and 60 min by wet and dry processes. Particle size distribution, XRD, and FTIR analyses characterized phonolite activated. These results were compared to the behavior of the rock with no activation. K availability (total; water-soluble; exchangeable, non-exchangeable, and structural) was determined in samples activated and no activation. K leaching curves were obtained by successive extractions with 0.01 mol L-1 citric acid and Mehlich-1 solutions to 1812 h and analyzed by FAAS. Results: The samples mechanical activation promoted a reduction in the intensity of the diffraction peaks. In the sample dry mechanical activation for 60 min, K released increased by 15% in relation to the no activation sample. K leaching curves were observed with similar behavior for the extractors and higher K availability after 235 h of total contact time. Discussion: Mechanical activation promoted a decrease in structural K and an increase in non-exchangeable K, released into the soil solution in the medium term. Since the mineralogical composition was not changed, the process action is more efficient in creating the structural defects suggested. K leaching curves corroborate these results, with a continuous and slow K released for a longer contact time. Conclusions: It was concluded that the phonolite activated by dry mechanical activation for 60 min increased K-released content compared with the wet process and ratified the possibility of the activated phonolite rock as a slow-release fertilizer.
Read ArticleSURVEY ON KNOWLEDGE OF SEXUALLY TRANSMITTED INFECTIONS AND GONORRHEA: DO WE KNOW ENOUGH?
Background: Sexually Transmitted Infections (STIs) constitute an important group of infections with serious implications for public health. According to WHO, 1 million new contagions are produced daily, with more than 370 million new cases yearly. STIs can be originated from viruses, bacteria, fungi, or parasites. Regardless of their nature, they can be either cured or treated and controlled, but more importantly, they are preventable. Aims: The best tool to fight against STIs is prevention, which has a strong dependence on knowledge. This work aimed to assess the level of knowledge of society about STIs and gonorrhea. Methods: We conducted an online survey, covering a wide range of ages and levels of education, inquiring about areas such as origin, ways of contagion, prevention, associated diseases, and treatment of STIs and gonorrhea. We performed a statistical analysis of the answers. Results and Discussion: it was found that the general level of knowledge about STIs was independent of the age and level of education of the respondents. The respondent has shown better familiarity with prevention and contagion than with origin, diseases, and treatment. When the question was focused on gonorrhea, we found a lack in the cognizance of several points. Conclusions: Based on our findings, we conclude it is necessary to improve sexual education programs, starting at early ages but directed to all populations, particularly about gonorrhea.
Read ArticleADVANCES IN NATURAL EXTRACTS USED FOR ANTIBIOTIC-RESISTANT BACTERIA TREATMENT: THE GRAM-NEGATIVE CASES
Background: Infectious diseases are a global problem, the second human cause of death. Infectious diseases caused by pathogenic bacteria have been treated with a high degree of efficacy. However, even when the 20th century was considered the “golden age” of antibiotics, bacteria developed a different resistance mechanism to antibiotics. In 2017, the WHO issued an alert about 12 bacteria with an urgent need to develop new antibiotics. Aims: The aim of the present review is to analyze the current knowledge of the antibacterial activity of natural extract-based treatments against the pathogens listed by WHO. Methods: A systematic review of the literature in PubMed was performed to search for publications describing the use of natural extracts as antibiotics over bacteria. We focused on the Gram-Negative group. The exclusion criteria consisted of limiting papers on natural extracts tested over the bacteria culture related to eight selected bacteria, according to an alert issued by WHO in 2017, and seven plant extracts. Results: All the Gram-Negative bacteria listed in 2017 by WHO have been treated, with different degrees of advance, with some of the plant extracts and plant-based compounds reviewed. In general, the first approach is using inhibition disks applied over the bacterial biofilm in solid culture media. Discussion: While Salmonellae and P. aeruginosa have been extensively studied, over N. gonorrhoeae, A. baumannii have been tested with fewer natural extracts. Edible herbs are more often used, as well as artemisa and wine byproducts. In all cases, they are in the early stages of study, not being tested in patients at present. Conclusions: Plant extracts and plant-based compounds are effective as antibacterial, with minimal effects on the host cell. Furthermore, they are sustainable, environmentally friendly, and renewable.
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