Quinoline Group Modified Carbon Nanotubes for the Detection of Zinc Ions

Carbon nanotubes (CNTs) were covalently modified by fluorescence ligand (glycine-N-8-quinolylamide) and formed a hybrid material which could be used as a selective probe for metal ions detection. The anchoring to the surface of the CNTs was carried out by the reaction between the precursor and the carboxyl groups available on the surface of the support. Fourier transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA) unambiguously proved the existence of covalent bonds between CNTs and functional ligands. Fluorescence characterization shows that the obtained organic–inorganic hybrid composite is highly selective and sensitive (0.2 μM) to Zn(II) detection

Identification of Genome-Wide Variations among Three Elite Restorer Lines for Hybrid-Rice

Rice restorer lines play an important role in three-line hybrid rice production. Previous research based on molecular tagging has suggested that the restorer lines used widely today have narrow genetic backgrounds. However, patterns of genetic variation at a genome-wide scale in these restorer lines remain largely unknown. The present study performed re-sequencing and genome-wide variation analysis of three important representative restorer lines, namely, IR24, MH63, and SH527, using the Solexa sequencing technology. With the genomic sequence of the Indica cultivar 9311 as the reference, the following genetic features were identified: 267,383 single-nucleotide polymorphisms (SNPs), 52,847 insertion/deletion polymorphisms (InDels), and 3,286 structural variations (SVs) in the genome of IR24; 288,764 SNPs, 59,658 InDels, and 3,226 SVs in MH63; and 259,862 SNPs, 55,500 InDels, and 3,127 SVs in SH527. Variations between samples were also determined by comparative analysis of authentic collections of SNPs, InDels, and SVs, and were functionally annotated. Furthermore, variations in several important genes were also surveyed by alignment analysis in these lines. Our results suggest that genetic variations among these lines, although far lower than those reported in the landrace population, are greater than expected, indicating a complicated genetic basis for the phenotypic diversity of the restorer lines. Identification of genome-wide variation and pattern analysis among the restorer lines will facilitate future genetic studies and the molecular improvement of hybrid rice

Strontium concentrations and isotope ratios in enamel of healthy and carious teeth in southern Shaanxi, China

RATIONALE: As the trace element strontium (Sr) plays a significant role in dental health, it is important to determine the Sr concentration and isotope composition (Sr-87/Sr-86) of teeth and whether these values are related to caries formation, age and sex. METHODS: A total of 160 permanent teeth were collected from 7- to 79-year-old people from the southern Shaanxi area of China, including 100 healthy teeth and 60 carious teeth (men and women each accounted for half of the samples). The concentration and isotope composition of Sr elements in the dental enamel of the teeth were measured using inductively coupled plasma mass spectrometry (ICP-MS) and thermal ionization mass spectrometry (TIMS). RESULTS: A significantly lower Sr concentration was found in the enamel of the carious teeth than in that of the healthy teeth for individuals of varying ages and sex. The Sr concentration in human carious teeth ranged between 79.70 mu g/g and 85.80 mu g/g; while the Sr concentration in healthy teeth ranged between 128 mu g/g and 156.77 mu g/g. Our results also demonstrated that the Sr-87/Sr-86 ratio did not appear to be affected by the caries formation, age or sex. The Sr-87/Sr-86 ratio in the enamel of the healthy and carious teeth of individuals of varying ages and genders ranged between 0.710935 and 0.711037, which falls into the range of Sr-87/Sr-86 ratios found in the local, naturally occurring water, soils and rocks. CONCLUSIONS: Sr plays a significant role in dental health, and there is a negative correlation between Sr and the occurrence of dental caries. The Sr-87/Sr-86 ratio of teeth reflects the Sr-87/Sr-86 ratio of the associated environment, and there is no significant relationship with the frequency of dental caries, age or sex.</p