The study examined the contamination levels of the soil and plantain leaves in three communities in Atakunmosa west local government area of Osun State in southwest Nigeria, where gold mining activities have recently ...The study examined the contamination levels of the soil and plantain leaves in three communities in Atakunmosa west local government area of Osun State in southwest Nigeria, where gold mining activities have recently become intensive. Plantain is a major food crop, whose leaves are used to wrap food items for household consumption. The objectives were to examine the heavy metal concentrations in the soil and plantain leaves around the gold mine site and compare them with standard recommended safe limits for the environment. Soil and plantain leaves were sampled at different locations around the sites and at a control site from a neighboring local government area with no history of gold mining activities between March 2015 and February 2016. Both soil and leave samples were processed and analyzed for selected heavy metals (Cd, As, Cu, Zn, Cr, Mn and Fe) using the Particle Induced X-ray Emission (PIXE) in the laboratory. The study showed higher concentrations than the World Health Organization’s recommended safe limits of the heavy metals in the soils and plantain leaves. Dry season concentrations of the variables were also higher than the wet season and the heavy metal concentrations at the control station were significantly (p < 0.05) lower than those of the mining environment. The study concluded that the ecosystems in the artisanal gold mining region are vulnerable to bioaccumulation of heavy metals and the leaves from the sites are sources of heavy metal contamination if consumed or used to wrap food items.展开更多
A system is described in which a graphite furnace electrothermal vaporization device is employed for the introduction of microlitre liquid sample into an inductively coupled argon plasma. The technique provides a pico...A system is described in which a graphite furnace electrothermal vaporization device is employed for the introduction of microlitre liquid sample into an inductively coupled argon plasma. The technique provides a picogram detection limit and an adequate precision with a relative standard deviation of 4%. Mechanism of analyte condensation in transport process is explored. As an application, the technique combined with DDTC/CCl4 extraction is used to enrich and determine non- rare earth impurities in highly pure La2O3.展开更多
AIM： To systematically evaluate the accuracy of 18-fu-orodeoxy-D-glucose-positron emission tomography （18-FDG PET） to assess response to neoadjuvant che-motherapy in bone and soft tissue sarcomas.METHODS： Studies ...AIM： To systematically evaluate the accuracy of 18-fu-orodeoxy-D-glucose-positron emission tomography （18-FDG PET） to assess response to neoadjuvant che-motherapy in bone and soft tissue sarcomas.METHODS： Studies published in English language re-garding the accuracy of F-18 FDG PET for the indication were retrieved from MEDLINE. The QUADAS tool was utilized for methodological quality appraisal. Relevant data were extracted, and quantitative data synthesis included pooled estimation and subgroup analysis. RESULTS： A total of ffteen studies involving 420 pa-tients with pathologically confrmed sarcoma were col-lected. Methodological quality was relatively high. The pooled sensitivity and specifcity of PET to predict histo-pathological response were 87% （95%CI： 81%-91%） and 83% （95%CI： 77%-87%）, respectively. Ten stud-ies employed a lower standardized uptake value （SUV） after chemotherapies （mostly 2.5） and/or a higher SUV reduction rate （mostly around 50%） as PET criteria of good response. Subgroup analysis showed that PET ex-hibited a signifcantly better specifcity in osteosarcoma （OS） and Ewing sarcoma （ES） than in soft-tissue sarco-ma （STS） （91% vs 75%, P 〈 0.05）, and a higher speci-fcity in pediatric patients than in adults （90% vs 74%, P 〈 0.01）. PET yielded a lower specifcity in ifosfamide-contained chemotherapies than in the alternative regi-men （70% vs 97%, P 〈 0.01）.CONCLUSION： F-18 FDG PET is promising to predict neoadjuvant therapy response in sarcoma, especially in pediatric patients with OS or ES. Certain chemothera-peutic agents could potentially cause false positives of PET.展开更多
文摘The study examined the contamination levels of the soil and plantain leaves in three communities in Atakunmosa west local government area of Osun State in southwest Nigeria, where gold mining activities have recently become intensive. Plantain is a major food crop, whose leaves are used to wrap food items for household consumption. The objectives were to examine the heavy metal concentrations in the soil and plantain leaves around the gold mine site and compare them with standard recommended safe limits for the environment. Soil and plantain leaves were sampled at different locations around the sites and at a control site from a neighboring local government area with no history of gold mining activities between March 2015 and February 2016. Both soil and leave samples were processed and analyzed for selected heavy metals (Cd, As, Cu, Zn, Cr, Mn and Fe) using the Particle Induced X-ray Emission (PIXE) in the laboratory. The study showed higher concentrations than the World Health Organization’s recommended safe limits of the heavy metals in the soils and plantain leaves. Dry season concentrations of the variables were also higher than the wet season and the heavy metal concentrations at the control station were significantly (p < 0.05) lower than those of the mining environment. The study concluded that the ecosystems in the artisanal gold mining region are vulnerable to bioaccumulation of heavy metals and the leaves from the sites are sources of heavy metal contamination if consumed or used to wrap food items.
文摘A system is described in which a graphite furnace electrothermal vaporization device is employed for the introduction of microlitre liquid sample into an inductively coupled argon plasma. The technique provides a picogram detection limit and an adequate precision with a relative standard deviation of 4%. Mechanism of analyte condensation in transport process is explored. As an application, the technique combined with DDTC/CCl4 extraction is used to enrich and determine non- rare earth impurities in highly pure La2O3.
基金Supported by Scientific Research Subject of Health Department of Sichuan,China,No.070045
文摘AIM： To systematically evaluate the accuracy of 18-fu-orodeoxy-D-glucose-positron emission tomography （18-FDG PET） to assess response to neoadjuvant che-motherapy in bone and soft tissue sarcomas.METHODS： Studies published in English language re-garding the accuracy of F-18 FDG PET for the indication were retrieved from MEDLINE. The QUADAS tool was utilized for methodological quality appraisal. Relevant data were extracted, and quantitative data synthesis included pooled estimation and subgroup analysis. RESULTS： A total of ffteen studies involving 420 pa-tients with pathologically confrmed sarcoma were col-lected. Methodological quality was relatively high. The pooled sensitivity and specifcity of PET to predict histo-pathological response were 87% （95%CI： 81%-91%） and 83% （95%CI： 77%-87%）, respectively. Ten stud-ies employed a lower standardized uptake value （SUV） after chemotherapies （mostly 2.5） and/or a higher SUV reduction rate （mostly around 50%） as PET criteria of good response. Subgroup analysis showed that PET ex-hibited a signifcantly better specifcity in osteosarcoma （OS） and Ewing sarcoma （ES） than in soft-tissue sarco-ma （STS） （91% vs 75%, P 〈 0.05）, and a higher speci-fcity in pediatric patients than in adults （90% vs 74%, P 〈 0.01）. PET yielded a lower specifcity in ifosfamide-contained chemotherapies than in the alternative regi-men （70% vs 97%, P 〈 0.01）.CONCLUSION： F-18 FDG PET is promising to predict neoadjuvant therapy response in sarcoma, especially in pediatric patients with OS or ES. Certain chemothera-peutic agents could potentially cause false positives of PET.
