Indicators of soil quality associated with N‐cycling were assessed under different land‐use systems (native forest – NAT, reforestation with Araucaria angustifolia or Pinus taeda and agricultural use – AGR) to appraise the effects on the soil potential for N supply. The soil total N ranged from 2 to 4 g/kg (AGR and NAT, respectively), and the microbial biomass N ranged from 80 to 250 mg/kg, being higher in NAT and A. angustifolia, and lower in P. taeda and AGR sites. Activities of asparaginase (ca. 50–200 mg NH4+‐N/kg per h), glutaminase (ca. 200–800 mg NH4+‐N/kg per h) and urease (ca. 80–200 mg NH4+‐N/kg/h) were also more intense in the NAT and A. angustifolia‐reforested soils, indicating greater capacity for N mineralization. The NAT and AGR soils showed the highest and the lowest ammonification rate, respectively (ca. 1 and 0.4 mg NH4+‐N/kg per day), but the inverse for nitrification rate (ca. 12 and 26%), indicating a low capacity for N supply, in addition to higher risks of N losses in the AGR soil. A multivariate analysis indicated more similarity between NAT and A. angustifolia‐reforested sites, whilst the AGR soil was different and associated with a higher nitrification rate. In general, reforestation with the native species A. angustifolia had less impact than reforestation with the exogenous species P. taeda, considering the soil capacity for N supply. However, AGR use caused more changes, generally decrease in indicators of N‐cycling, showing a negative soil management effect on the sustainability of this agroecosystem.
Background: Cholelithiasis is one of the diseases with greater surgical indication. Currently, laparoscopic cholecystectomy is the gold standard in the treatment of cholelithiasis. Aim: To analyze the culture of bile from patients with cholelithiasis, mainly in the occurrence of brown and mixed stones. Methods: Was carried out a prospective study with 246 cases with biliary lithiasis who underwent elective laparoscopic cholecystectomy. Bile culture was performed in all. During anesthetic induction the patients received a single dose of intravenous cefazolin 1 g. At the end of the surgery, the gallbladder was punctured, its contents extracted and immediately placed in a sterile 20 ml propylene flask and promptly sent to bacterioscopy with Maconkey and blood agars. Incubation at 37° C for 24 h was carried out. A protocol was elaborated to include the main factors potentially related to cholelithiasis and the possible presence of associated bacterial infection. Results: Of the 246 patients, 201 had negative bile culture and 45 positive. Of the 45 patients with bacteriobilia, 34 had growth of a single type of bacterium in bile culture and 11 more than one. Conclusions: It was observed a relationship between bacteriobilia and age, suggesting that age is a risk factor for bacteriobilia. The use of antibiotic prophylaxis in the elderly is therefore recommended.
The involvement of neurotoxicants in the etiology of emotional pathologies is becoming an issue in neurotoxicology. Lead (Pb) exposure during childhood has been associated with increased impulsivity, aggressivity, and delinquency. Considering the paucity of experimental studies investigating the involvement of developmental Pb exposure in emotional disorders, our objective was to investigate whether Pb exposure during pregnancy and/or lactation could be related to depressive symptoms in adult male and female rats. Wistar dams received 10 mg of Pb, as Pb acetate, or 13.4 mg of Na acetate, by gavage, daily, during pregnancy and lactation. By cross-fostering at the time of birth, pups were either exposed to Pb or Na acetate during pregnancy only, lactation only, or during both pregnancy and lactation. At 70 days of age, animals were submitted to the open-field test followed by the forced swimming test. Pb levels were measured in the blood of dams (weaning) and pups (after behavioral evaluation). The results demonstrated that exposure to Pb during both pregnancy and lactation induced, in males, an increased emotionality state detected in the open-field test, and in females, depressive-like behavior detected in the forced swimming test. These alterations were observed at residual blood Pb levels (i.e., around 5 microg/dL).
Neste trabalho são destacadas as técnicas de separação e de purificação de terras raras por precipitação fracionada e troca iônica, além das técnicas usualmente utilizadas no controle analítico destes materiais. A aplicação destas técnicas é mostrada neste trabalho para a obtenção de óxido ou nitrato de cério com pureza > 99%. O principal objetivo é a obtenção de precursores à base de cério para o processamento de cerâmicas de zircônia-céria ou céria contendo terras raras. A disponibilidade de cloretos mistos, matéria-prima para a preparação de terras raras individuais, e o conhecimento das técnicas de separação, purificação e controle analítico de terras raras no IPEN, permite sua obtenção local para uso em pesquisa e desenvolvimento.
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