High-density genetic map is a valuable tool for fine mapping locus controlling a specific trait especially for perennial woody plants. In this study, we firstly constructed a high-density genetic map of mei (Prunus mume) using SLAF markers, developed by specific locus amplified fragment sequencing (SLAF-seq). The linkage map contains 8,007 markers, with a mean marker distance of 0.195 cM, making it the densest genetic map for the genus Prunus. Though weeping trees are used worldwide as landscape plants, little is known about weeping controlling gene(s) (Pl). To test the utility of the high-density genetic map, we did fine-scale mapping of this important ornamental trait. In total, three statistic methods were performed progressively based on the result of inheritance analysis. Quantitative trait loci (QTL) analysis initially revealed that a locus on linkage group 7 was strongly responsible for weeping trait. Mutmap-like strategy and extreme linkage analysis were then applied to fine map this locus within 1.14 cM. Bioinformatics analysis of the locus identified some candidate genes. The successful localization of weeping trait strongly indicates that the high-density map constructed using SLAF markers is a worthy reference for mapping important traits for woody plants.
The concentration and composition of PAHs emitted from biomass cooking fuel were characterized in a rural non-smoking household in northern China. Twenty-two parent PAHs (pPAHs), 12 nitro-PAHs (nPAHs), and 4 oxy-PAHs (oPAHs) were measured in the kitchen, bedroom, and outdoors during both summer and winter. The most severe contamination occurred in the kitchen in the winter, where the daily mean concentrations of pPAHs, nPAHs, and oPAHs were 7500±4100, 38±29, and 8400±9200 ng/m3, respectively. Our results suggest that the nPAHs were largely from secondary formation in ambient air while oPAHs were either from primary emission of biomass burning or secondary formation from pPAHs in the kitchen. The daily mean benzo(a)pyrene equivalent exposure concentration was as high as 200±160 ng/m3 in the winter for the housewife who did the cooking compared to 59±37 ng/m3 for the control group that did not cook.
Daily dietary and inhalation exposures to 16 parent polycyclic aromatic hydrocarbons (PAHs) and urinary excretion of 13 monohydroxy metabolites (OHPAHs) were monitored for 12 non-smoking university students in Beijing, China, during a controlled feeding experiment. The relationship between the urinary excretion of OHPAHs and the uptake of PAHs was investigated. The results suggest severe exposure of the subjects to PAHs via both dietary and inhalation pathways. Large increase of most urinary OHPAHs occurred after the ingestion of lamb kabob. Higher concentrations of OHPAHs were observed for female subjects, with the intakes of parent PAHs lower than those by males, likely due to the gender differences in metabolism. It appears that besides 1-PYR, metabolites of PHE could also be used as biomarkers to indicate the short-term dietary exposure to PAHs and urinary 3-BaA may serve as the biomarker for inhalation intake of high molecular weight PAHs.
Utilizing porous polyacrylonitrile (PAN) fibers as the precursors, porous carbon fibers were obtained by cross-linking of precursor fibers with hydrazine hydrate and subsequent heat treatment. A nitrogen content of more than 14 wt % was achieved in the carbon fibers. The porous carbon fiber that was prepared at low concentration of hydrazine hydrate (5 wt %) showed an optimal BET surface area of 277.4 m 2 /g with micro-/meso-/macropores. The CO 2 adsorbed amount of this porous carbon fiber was 101 mg/g at 25 °C under atmospheric pressure, which was 2.1 times that of the fiber without cross-linking with hydrazine hydrate. In the simulated flue gas environment (10% CO 2 /90% N 2 ), the adsorption capacity of the above-mentioned porous fiber was 32 mg/g at 25 °C, which was 1.4 times that of the fiber without cross-linking. These CO 2 adsorption results demonstrated that the nitrogen functionalities and porous structure of the porous carbon fiber played an equivalent important role in the adsorption of CO 2 . The porous carbon fiber also owned an excellent CO 2 reusability, and 96% of the adsorption capacity was maintained after 20 cycles of CO 2 adsorption and desorption. The porous carbon fibers enriched with nitrogen could thus be a potential material for CO 2 capture.
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