-
Bang Holmes posted an update 1 week ago
Fine particulate matter (PM2.5) poses a significant risk to human health worldwide, by promoting oxidative stress and inflammation; however, the components responsible for these effects have not been fully evaluated. In this study, we investigated the cellular response of a macrophage cell line exposed to PM2.5 extracts in vitro. We obtained a dataset of chemical components of PM2.5 and determined those associated with the generation of reactive oxygen species (ROS) and secretion of inflammatory cytokines through an orthogonal partial least-squares (OPLS) regression. The results indicated that after water extracts exposure, both ROS and interleukin (IL)-1β levels were positively correlated with transition metals. In cells exposed to dichloromethane extracts, IL-1β secretion was significantly correlated with polycyclic aromatic hydrocarbons (PAHs); meanwhile, tumor necrosis factor (TNF)-α secretion was negatively associated with secondary nitrated PAHs, suggesting that atmospheric nitration process might modify the biological effects of PM2.5 components. We also performed source apportionment using a positive matrix factorization (PMF) model to explore the relative influence of different sources of components on cells. BKM120 It was found that components from vehicle emissions promoted both ROS and TNF-α, while IL-1β secretion was induced mainly by those from coal combustion. This study provides information regarding PM2.5 components having biological effects, and the sources thereof, which could inform effective measures for controlling this type of air pollution. In this study the complexation of U(VI) with orthosilicic acid (H4SiO4) was investigated between pH 3.5 and 5 by combining electrospray ionization mass spectrometry (ESI-MS) and laser-induced luminescence spectroscopy. The ESI-MS experiments performed at a total silicon concentration of 5 · 10-3M (exceeding the solubility of amorphous silica at both pH-values) revealed the formation of oligomeric sodium-silicates in addition to the UO2OSi(OH)3+ species. For the luminescence spectroscopic experiments (25 °C), the U(VI) concentration was fixed at 5 · 10-6M, the silicon concentration was varied between 1.3 · 10-4-1.3 · 10-3M (reducing the formation of silicon oligomers) and the ionic strength was kept constant at 0.2 M NaClO4. The results confirmed the formation of the aqueous UO2OSi(OH)3+ complex. The conditional complexation constant at 25 °C, log *β = -(0.31 ± 0.24), was extrapolated to infinite dilution using the Davies equation, which led to log *β0 = -(0.06 ± 0.24). Further experiments at different temperatures (1-25 °C) allowed the calculation of the molal enthalpy of reaction ΔrHm0 = 45.8 ± 22.5 kJ·mol-1 and molal entropy of reaction ΔrSm0 = 152.5 ± 78.8 J·K-1·mol-1 using the integrated van’t Hoff equation, corroborating an endothermic and entropy driven complexation process. BACKGROUND The neurodevelopmental effects of high doses of ionizing radiation (IR) in children are well established. To what extent such effects exist at low-to-moderate doses is unclear. Considering the increasing exposure of the general population to low-to-moderate levels of IR, predominantly from diagnostic procedures, the study of these effects has become a priority for radiation protection. OBJECTIVES We conducted a systematic review of the current evidence for possible effects of low-to-moderate IR doses received during gestation, childhood and adolescence on different domains of neurodevelopment. DATA SOURCES Searches were performed in PubMed, Scopus, EMBASE and Psychinfo on the 6th of June 2017 and repeated in December 2018. STUDY ELIGIBILITY CRITERIA We included studies evaluating the association between low-to-moderate IR doses received during gestation, childhood and adolescence, and neurodevelopmental functions. STUDY APPRAISAL AND SYNTHESIS METHODS Studies were evaluated using the Cochrane Collas found. LIMITATIONS, CONCLUSIONS, AND IMPLICATIONS OF KEY FINDINGS Overall, depending on the domain, there was limited to inadequate evidence for an effect of low-to-moderate IR doses on neurodevelopment. Heterogeneity across studies in terms of outcome and exposure assessment hampered any quantitative synthesis and any stronger conclusion. Future research with adequate dosimetry and covering a range of specific neurodevelopmental outcomes would likely contribute to improve the body of evidence. SYSTEMATIC REVIEW REGISTRATION NUMBER The systematic review protocol was registered in PROSPERO (registration number CRD42018091902). OBJECTIVE To localize the seizure onset zone (SOZ) and irritative zone (IZ) using electric source imaging (ESI) on intracranial EEG (iEEG) and assess their clinical value in predicting epilepsy surgery outcome in children with focal cortical dysplasia (FCD). METHODS We analyzed iEEG data from 25 children with FCD-associated medically refractory epilepsy (MRE) who underwent surgery. We performed ESI on ictal onset to localize SOZ (ESI-SOZ) and on interictal discharges to localize IZ (ESI-IZ). We tested whether resection of ESI-SOZ and ESI-IZ predicted good surgical outcome (Engel 1). We further compared the prediction performance of ESI-SOZ and ESI-IZ to those of SOZ and IZ defined using conventional methods, i.e. by identifying iEEG-contacts showing ictal onsets (conventional-SOZ) or being the most interictally active (conventional-IZ). RESULTS The proximity of ESI-SOZ (p = 0.043, odds-ratio = 3.9) and ESI-IZ (p = 0.011, odds-ratio = 7.04) to resection has higher effect on patients’ outcome than proximity of conventional-SOZ (p = 0.17, odds-ratio = 1.7) and conventional-IZ (p = 0.038, odds-ratio = 2.6). Resection of ESI-SOZ and ESI-IZ presented higher discriminative power in predicting outcome (68% and 60%) than conventional-SOZ and conventional-IZ (48% and 53%). CONCLUSIONS Localizing SOZ and IZ via ESI on iEEG offers higher predictive value compared to conventional-iEEG interpretation. SIGNIFICANCE iEEG-ESI may help surgical planning and facilitate prognostic assessment of children with FCD-associated MRE.