Analysis of urban dust (PM<Subscript>2</Subscript>/PM<Subscript>10-2</Subscript>) in Daejeon city by instrumental neutron activation analysis

Summary As part of an air pollution monitoring study, airborne particulate matter (PM₂/PM_10-2) samples were collected from 2000 to 2003 at two sampling sites in an urban region, Daejeon, the middle of Korea. Mass concentrations of both fine and coarse fractions and that of the black carbon in the fine particles were measured using the Gent stacked filter unit sampler and the smoke stain reflectometer, respectively. In the collected samples the concentrations of 24 elements were analyzed using instrumental neutron activation analysis. Monitored data were investigated for their temporal trends under different environmental conditions and their seasonal correlation patterns. Crustal enrichment factors were also estimated to establish the contribution between anthropogenic and crustal origin. Patterns for airborne particle matter (APM) and elemental concentrations, seasonal variation of some marker elements were investigated. The results can be applied for the investigation of further air pollution sources and for the evaluation of air quality.     

Airborne particulates (PM2.5/PM10) monitoring in Korea by instrumental neutron activation analysis

Instrumental neutron activation analysis was used for the analysis of 25 trace elements in airborne particulate matter (PM) for air pollution monitoring. For the collection of air samples, the Gent stacked filter unit low volume sampler and two types of Nuclepore polycarbonate filters were employed. Samples were collected at selected sampling dates in suburban and industrial regions of Daejon city in the Republic of Korea. Mass concentrations and black carbon of PM were measured, and enrichment factors were calculated. The results were used to describe the emission sources and their correlation patterns.     

Determination of the elemental contents in stream sediments collected from Cheongju city by instrumental neutron activation analysis

Sediment samples were collected from seven locations of the MeeHo stream in Cheongju city, strained out by a sieve, dried by an oven and pulverized by an agate mortar. Instrumental neutron activation analysis (INAA) was applied for the determination of the elemental contents in the sediment samples by using the NAA #1 and #2 irradiation holes of the HANARO research reactor and HPGe gamma-ray spectrometers. Twenty-five elements were determined by a relative method with NIST SRM 2711-Montan Soil and the ranges of the elemental contents for the seven locations were identified. The contamination levels for elements such as As, Ba, Cr, Mn, Fe and Zn were compared with the guidelines of USEPA. The detection limits and combined uncertainties for the hazardous elements such as As, Ba, Cr, Mn, Sb, V and Zn were estimated under the given analytical conditions.     

Soluble and easily crystallized anthracene derivatives: precursors of solution-processable semiconducting molecules

New soluble anthracene derivatives containing thiophene and phenylenevinylene derivatives were synthesized via well-known synthetic routes. TIPS derivatives were added at the 9,10-positions of anthracene for the solubility and crystallinity. Both of the molecules were found to be promising for high charge mobility and stable organic semiconductors. The soluble anthracene core (TIPSAnt) is a potential precursor for the synthesis of novel semiconducting materials.     

Source identification and long-term monitoring of airborne particulate matter (PM<Subscript>2.5</Subscript>/PM<Subscript>10</Subscript>) in an urban region of Korea

Summary For the identification of air pollution sources, about 500 airborne particulate matter (PM_2.5and PM₁₀) samples were collected by using a Gent air sampler and a polycarbonate filter in an urban region in the middle of Korea from 2000 to 2003. The concentrations of 25 elements in the samples were measured by using instrumental neutron activation analysis (INAA). Receptor modeling was performed on the air monitoring data by using the positive matrix factorization (PMF2) method. According to this analysis, the existence of 6 to 10PMF factors, such as metal-alloy, oil combustion, diesel exhaust, coal combustion, gasoline exhaust, incinerator, Cu-smelter, biomass burning, sea-salt, and soil dust were identified.     

Gut microbiota restoration through fecal microbiota transplantation: a new atopic dermatitis therapy

The pathogenesis of atopic dermatitis (AD) involves complex factors, including gut microbiota and immune modulation, which remain poorly understood. The aim of this study was to restore gut microbiota via fecal microbiota transplantation (FMT) to ameliorate AD in mice. FMT was performed using stool from donor mice. The gut microbiota was characterized via 16S rRNA sequencing and analyzed using Quantitative Insights into Microbial Ecology 2 with the DADA2 plugin. Gut metabolite levels were determined by measuring fecal short-chain fatty acid (SCFA) contents. AD-induced allergic responses were evaluated by analyzing blood parameters (IgE levels and eosinophil percentage, eosinophil count, basophil percentage, and monocyte percentage), the levels of Th1 and Th2 cytokines, dermatitis score, and the number of mast cells in the ileum and skin tissues. Calprotectin level was measured to assess gut inflammation after FMT. FMT resulted in the restoration of gut microbiota to the donor state and increases in the levels of SCFAs as gut metabolites. In addition, FMT restored the Th1/Th2 balance, modulated Tregs through gut microbiota, and reduced IgE levels and the numbers of mast cells, eosinophils, and basophils. FMT is associated with restoration of gut microbiota and immunologic balance (Th1/Th2) along with suppression of AD-induced allergic responses and is thus a potential new therapy for AD.Subject terms: Experimental models of disease, Biological therapy     

Simultaneous Quantification of 3′- and 6′-Sialyllactose in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry and Its Application to a Pharmacokinetic Study

Sialyllactose (SL), an acidic oligosaccharide, has immune-protective effects against pathogens and helps with the development of the immune system and intestinal microorganisms. To elucidate the pharmacokinetic characterization after oral administration to rats, the simultaneous quantification method for 3′-SL and 6′-SL in rat plasma was validated, using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in an electrospray ionization (ESI) mode. Several types of columns [C18, amide, and hydrophilic interaction liquid chromatography (HILIC) phase] were used to separate the peaks of 3′-SL and 6′-SL, which improved chromatographic selectivity. Ultimately, the HILIC phase column had a good peak shape and quick resolution, with a mobile phase comprising ammonium acetate buffer and acetonitrile obtained by gradient elution. In addition, the simultaneous quantification of 3′-SL and 6′-SL in rat plasma samples were adequately applied to pharmacokinetic study.     

Development and Validation of a Bioanalytical Method for 3′- and 6′-Sialyllactose in Minipig Liver and Kidney Using Liquid Chromatography-Tandem Mass Spectrometry and Its Application to Analysis of Tissue Distribution

Breast milk contains human milk oligosaccharides (HMOs), including sialyllactose (SL). SL is composed of sialic acid and lactose, and is divided into 3′-SL and 6′-SL according to the binding position. SL has immunoprotective effects against bacteria and viruses, and acts as a probiotic in the gastrointestinal tract. In this study, we developed a bioanalytical method for simultaneous analysis of 3′-SL and 6′-SL in liver and kidney tissues of Yucatan minipigs using liquid chromatography–tandem mass spectrometry (LC-MS/MS) under conditions optimized in our previous study. LC-MS/MS was performed using a hydrophilic interaction liquid chromatography (HILIC) column (50 mm × 2.1 mm, 3 μm) with a mobile phase consisting of 10 mM ammonium acetate in water (pH 4.5) and acetonitrile with gradient elution at a flow rate of 0.3 mL/min. A surrogate matrix method using water was applied for analysis of endogenous SL. The developed method was validated with regard to selectivity, linearity, precision, accuracy, the matrix effect, recovery, parallelism, dilution integrity, carryover, and stability according to the US Food and Drug Administration guidelines. We performed a tissue distribution study of minipigs, and analyzed liver and kidney tissues using the developed method to determine the tissue distribution of 3′-SL and 6′-SL. The tissue concentrations of 3′-SL and 6′-SL were readily measurable, suggesting that the method would be useful for evaluating the tissue distributions of these compounds in minipigs.     

Effect of extracts from safflower seeds on osteoblast differentiation and intracellular calcium ion concentration in MC3T3-E1 cells

Although safflower seeds have long been used in Korea as herbal medicines, very little research has been published on the effects of safflower seed on bone formation or bone density. The study reported here therefore examined bone nodule formation, calcium uptake, alkaline phosphatase activity, and intracellular concentration of calcium ion [Ca(2+)](i) in murine osteoblastic cells of the MC3T3-E1 line that were cultured on modified Eagle's minimal essential medium alone (controls) or with addition of 0.1% crude extract of safflower seed (experimental group I) or 0.1% aqueous fraction of safflower seed (experimental group II). Fluorescence spectrometry measurement of ([Ca(2+)](i)) showed significantly accelerated rates of osteoblast differentiation in experimental group I (3 microL of crude extract in 8 x 10(4) cells) and experimental group II (2 microL of aqueous fraction in 8 x 10(4) cells) compared to the control group.     

Comparison and determination of elemental composition in Korean space foods using instrumental neutron activation analysis

A quantitative analysis of mineral contents in several kinds of foods is needed to obtain information on a comprehensive elemental composition as well as an investigation on the effects of human health and nutrition based on the dietary intake of mineral elements. In 2012, six kinds of new Korean space foods (KSF) such as sweet pumpkin porridge, dakgalbi (spicy grilled chicken), Manila clam porridge, ox leg bone-cabbage soup, ginseng-chicken porridge, and chicken curry rice were developed by KAERI, and the contents of more than 15 elements in the samples were determined using an instrumental neutron activation analysis. A certified reference material associated with a biological food sample was used for analytical quality control. The analytical results were evaluated according to the elemental concentrations with KSF samples and compared with the reported values. These results will be applied toward the identification of gamma-irradiated foods.