An electrochemical method for the simultaneous determinations of Hg" concentration and total As"' and AsV concentration has been developed. The method does not require the additional preliminary step of the chemical reduction of AsV to As"', or oxidation of As"' to AsV before stripping analysis takes place. Also, the method for the simultaneous determination of Hg" concentration and As"' concentration is described. Measurements were performed in 0.1 M HCI using a gold-plated graphite electrode as sensor. Detection limits for both methods are below 0.4ppb. Relative standard deviation did not exceed 15 70. The possible interference by other trace metals was investigated. Analyses of natural water and industrial solutions were made using proposed methods and AAS. The t-test demonstrates that there was no significant difference between the results obtained with these methods. Proposed methods decrease the time of analysis because concentrations of the Hg" and arsenic ions were measured simultaneously. Also, the removal of the additional step of chemical reduction of AsV to AsIn or oxidation of As"' to AsV decreases analysis time, and also reduces the chance of contamination due to the use of additional reagents.

Background: Porphyromonas gingivalis lipid A heterogeneity modulates cytokine expression in human cells. This study investigates the effects of two lipid A isoforms of P. gingivalis, lipopolysaccharide (LPS)1435/1449 and LPS1690, on the secretion of proinflammatory and regulatory cytokines in total blood cultures from patients with and without chronic periodontitis (CP).Methods: A cross‐sectional study was conducted in 38 systemically healthy individuals divided in two groups: 1) the CP group (n = 19), in which patients were diagnosed with CP; and 2) the no periodontitis (NP) group (n = 19), which included control patients without CP. Blood samples were collected from all patients, and whole‐blood cell cultures (WBCCs) were stimulated for 48 hours with P. gingivalis LPS1435/1449 and LPS1690 and Escherichia coli LPS. Unstimulated WBCCs served as negative controls. The secretion of interferon‐γ (IFN‐γ), interleukin‐10 (IL‐10), and transforming growth factor‐β (TGF‐β) was detected in WBCC supernatants by enzyme‐linked immunosorbent assays.Results: E. coli LPS significantly increased the expression of all cytokines in WBCCs from both the NP and CP groups when compared to non‐stimulated cells (control treatment). P. gingivalis LPS preparations increased IFN‐γ levels in the CP group but not in the NP group when compared with controls (P <0.05). P. gingivalis LPS preparations also increased IL‐10 and TGF‐β levels in both CP and NP groups, but P. gingivalis LPS1690 showed a three‐fold increase on IL‐10 production in the NP group (P <0.05) when compared to P. gingivalis LPS1435/144.Conclusions: These data demonstrate that WBCC cell populations obtained from healthy individuals and patients with CP may differ in the cytokine response to P. gingivalis but not E. coli LPS. This is consistent with the notion that CP alters the systemic WBCC response and that this can be detected by the different P. gingivalis LPS structures.

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The purpose of this work was to optimize the synthesis yield of {[Ce(BTC)(H 2 O)]•DMF} n , a metal-organic framework (MOF)-76 family member, by solvothermal method. CeCl 3 .7H 2 O and 1,3,5-benzenetricarboxylic acid, 2:1 molar proportion, were added to N,N-dimethylformamide (DMF). Reaction time and temperature were evaluated to optimize the synthesis through a factorial design followed by a statistical analysis of the response variable (reaction yield). Infrared spectroscopy (IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analyses were performed to characterize the obtained white powders. Reaction yield was estimated based on {[Ce(BTC)(H 2 O)]•DMF} n molecular formula, which was confirmed by analytical techniques. The proposed statistic model of the response variable showed good agreement with the experimental values. Temperature parameter was the only significant variable on the reaction yields, being the highest yield (94.4%) obtained at 115 °C for 36 h, and it was accompanied by an improvement on the particle morphology (uniformity of shape and size), forming particles with strawsheave-like morphology.

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O objetivo deste artigo é analisar as orientações dos Bispos e seus Visitadores delegados à população escrava das Minas Setecentistas. Através dos registros das visitas pastorais, procuraremos demonstrar: as estratégias de resistência de senhores e dos cativos diante da vigilância, bem como a relação entre a orientação episcopal e o universo normativo de Portugal.