Flow Injection Photochemical Vapor Generation Coupled with Miniaturized Solution-Cathode Glow Discharge Atomic Emission Spectrometry for Determination and Speciation Analysis of Mercury

A novel, compact, and green method was developed for the determination and speciation analysis of mercury, based on flow injection photochemical vapor generation (PVG) coupled with miniaturized solution cathode glow discharge-atomic emission spectroscopy (SCGD-AES). The SCGD was generated between a miniature hollow titanium tube and a solution emerging from a glass capillary. Cold mercury vapor (Hg(0)) was generated by PVG and subsequently delivered to the SCGD for excitation, and finally the emission signals were recorded by a miniaturized spectrograph. The detection limits (DLs) of Hg­(II) and methylmercury (MeHg) were both determined to be 0.2 μg L^–1. Moreover, mercury speciation analysis could also be performed by using different wavelengths and powers from the UV lamp and irradiation times. Both Hg­(II) and MeHg can be converted to Hg(0) for the determination of total mercury (T-Hg) with 8 W/254 nm UV lamp and 60 s irradiation time; while only Hg­(II) can be reduced to Hg(0) and determined selectively with 4 W/365 nm UV lamp and 20 s irradiation time. Then, the concentration of MeHg can be calculated by subtracting the Hg­(II) from the T-Hg. Because of its similar sensitivity and DL at 8 W/254 nm, the simpler and less toxic Hg­(II) was used successfully as a primary standard for the quantification of T-Hg. The novel PVG-SCGD-AES system provides not only a 365-fold improvement in the DL for Hg­(II) but also a nonchromatographic method for the speciation analysis of mercury. After validating its accuracy, this method was successfully used for mercury speciation analysis of water and biological samples

Data_Sheet_1_Roseicella aerolata GB24T from bioaerosol attenuates Streptococcus pneumoniae-introduced inflammation through regulation of gut microbiota and acetic acid.docx

Streptococcus pneumoniae (Spn) is the most common respiratory pathogen causing community-acquired pneumonia. Probiotics represent a new intervention target for Spn infection. Hence, the discovery and development of new potential probiotic strains are urgently needed. This study was designed to investigate the beneficial effect and mechanism of a new bacterium named Roseicella aerolata GB24T that antagonizes Spn at cellular and animal levels. The results revealed that GB24T strain inhibited the growth of Spn on sheep blood agar plates, forming inhibition circles with a diameter of 20 mm. In cultured bronchial epithelium transformed with Ad 12-SV40 2B (BEAS-2B) cells, Spn infection induced an elevation in the expression levels of interleukin-1β, interleukin-6, and tumor necrosis factor-α to 4.289 ± 0.709, 5.587 ± 2.670, and 5.212 ± 0.772 folds compared to healthy controls, respectively. Moreover, pre-infection with GB24T for 1.5 h almost eliminated the cellular inflammation caused by Spn infection. Additionally, male Sprague–Dawley rats infected with Spn were randomly allocated into two groups: GB24T pre-infection and Spn infection groups, with healthy rats as control. GB24T significantly alleviated inflammatory lung injury caused by Spn infection, which was associated with obvious changes in the abundance of gut microbiota and a trend toward enhanced secretion of short-chain fatty acids, especially acetic acid. Acetic acid was validated to be effective in alleviating inflammation due to Spn infection in cellular assays. Together, these findings highlight that GB24T strain is an important protective feature in the respiratory tract.</p

Relationship between the mutagenic ratio on TA98 without S9 activation and IR by SOS/<i>umu</i> test without S9 activation.

<p>Relationship between the mutagenic ratio on TA98 without S9 activation and IR by SOS/<i>umu</i> test without S9 activation.</p

Evaluation of Genotoxic and Mutagenic Activity of Organic Extracts from Drinking Water Sources - Fig 2

<p><b>Mutagenicity of TA98 (a) and TA100 (b) detected by Ames test without S9 mix in organic extracts from source water at dose 0.25L (c), 0.5L (d), 1.0L (e) and 2.0L (f) collected during the dry season at six sampling locations in Guangzhou drinking water source</b>. Lower-case letters and upper-case letters indicated pairwise comparison in the TA98 and TA100 in the different sampling regions at the same water level, respectively. *indicated the significant difference compared with the strain TA100 at the same water level in the same sampling regions.</p

Genotoxic activity of organic extracts in water samples detected by SOS/<i>umu</i> test from six sampling locations in Guangzhou drinking water source.

<p>Lower-case letters indicated pair-wise comparison in the dry season in different sampling regions at the same water level and upper-case letters indicated pair-wise comparison in the wet season in different sampling regions at the same water level. *indicated the significant difference from the wet season.</p