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Biomedical subjects

J B da Silva

Publications and source records attributed to J B da Silva.

14 recordsLinked to original sources
PubMed2001

On-line preconcentration with different solid adsorbents for lead determination.

An on-line column preconcentration method based on the combined use of ammonium O,O-diethyldithiophosphate and activated carbon or polyurethane foam as adsorbents has been developed for the determination of Pb in water samples. The complexed Pb was eluted with ethanol and determined by flame atomic absorption spectrometry. The optimum preconcentration conditions are given for each adsorbent. The enrichment factors were 63 and 294, and the detection limits (3sigma) 3 microg L(-1) and 0.8 microg L(-1), respectively, for the carbon and foam systems. When the optimized procedures were applied to the determination of Pb in water samples the recovery efficiency was > 96%.

Adsorption↗
PubMed2000

Mycoflora and occurrence of aflatoxin B(1) and fumonisin B(1) during storage of Brazilian sorghum.

The present study is a 1-year follow up of the mycoflora of 140 samples of Brazilian freshly harvested (10) and stored (130) sorghum, the levels of aflatoxin and fumonisin contamination detected in the grains, and the prevailing abiotic factors (grain moisture content, water activity, temperature, relative humidity, and mean rainfall) at the time of sampling. The results show a predominance of the genera Phoma (57.1%), Aspergillus (42.7%), Fusarium (25.0%), and Rhizopus (21.4%) and the presence of nine other filamentous fungi. Fusarium, Aspergillus, and Penicillium, the three most important genera in terms of toxicity, presented numbers of colony forming units per gram of sorghum (CFU/g) that varied from 1 x 10(3) to 36 x 10(3), from 1 x 10(3) to 295 x 10(3), and from 1 x 10(3) to 20 x 10(3) CFU/g, respectively. The species most frequently found were Aspergillus flavus and Fusarium moniliforme. Of the total samples analyzed, 12.8% were contaminated with aflatoxin B(1) (concentration mean = 7-33 microg/kg) and 74.2% with fumonisin B(1) (concentration mean = 0.11-0.15 microg/g). This paper is the first report of the natural occurrence of aflatoxins and fumonisins in sorghum grain from Brazil.

Aflatoxin B1↗
PubMedDate not supplied

Synthesis and analgesic profile of novel N-containing heterocycle derivatives: arylidene 3-phenyl-1,2,4-oxadiazole-5-carbohydrazide.

This paper describes recent results of a research program aimed at the synthesis and pharmacological evaluation of new heterocyclic N-acylhydrazone (NAH) compounds, belonging to the arylidene (3-phenyl)-1,2,4-oxadiazolyl-5-carboxyhydrazide (8a-p) series. These compounds were structurally planned by applying the molecular hybridization strategy on previously described arylidene 1-phenylpyrazole-4-carbohydrazide (5) derivatives, considered as lead-compounds, which present potent analgesic properties. The analgesic profile of the title compounds 8a-p, evaluated in the model of abdominal constrictions induced by acetic acid, showed that the 4-methoxybenzylidene derivatives 8c and 8k were the most active ones, exhibiting a relative analgesic activity comparable with that of dipyrone 1 used as standard.

Analgesics, Non-Narcotic↗
PubMedDate not supplied

[Mental suffering of nurses who care for cancer patients].

In this qualitative study, four nurses of a teaching hospital in the city of Campinas, São Paulo-Brazil, all of them working with oncological patients were interviewed in order to verify the situation that most caused mental suffering in the day by day with these patients. Data collection were performed as proposed by the ethnographic approach and the non-directive interview and the direct observation was employed. The contain analysis has been utilized to the data analysis. The results have shown that many situations of the relationship nurses-oncological patients cause mental suffering in that professional. Those situations are tied to the work of the nurses, to the kind of patient treated by those professionals and to the kind of sickness presented by the patient. That study has shown that, many times, the nurses utilize defense mechanisms against that mental suffering. This work aims to contribute to the knowledge of the subject and therefore be itself a base in which one could elaborate measures that can make these problems that occur with the nurses that work in the Oncology area lighter. With that study to contribute to the comprehension of the challenge that the cancer, sickness that make professional and population frightened, is.

Adaptation, Psychological↗