Preparation and luminescence properties of Tb3+ -doped garnet Y2 Mg2 Al2 Si2 O12 luminescent materials.

We prepared Y2 Mg2 Al2 Si2 O12 :xTb3+ (x = 0.02, 0.04, 0.06, 0.08, 0.10, 0.12, 0.14 and 0.16) luminescent materials using a nodulizing procedure. The phase and luminescence properties of these materials were investigated. X-ray diffraction results demonstrated that Tb3+ ions doped into Y2 Mg2 Al2 Si2 O12 hosts successfully and the Y2 Mg2 Al2 Si2 O12 :xTb3+ materials showed a pure cubic phase. Y2 Mg2 Al2 Si2 O12 :xTb3+ materials had the characteristic Tb3+ emission bands derived from 5 D4 →7 F6 , 7 F5 , 7 F4 , and 7 F3 transitions when excited at 365 nm. The green emission band that derived from the 5 D4 →7 F5 transition was highest due to the high possibility of both electric-dipole and magnetic-dipole transitions. Emission spectra indicated that the critical concentration of Tb3+ in the Y2 Mg2 Al2 Si2 O12 host was 0.14. The concentration quenching of Y2 Mg2 Al2 Si2 O12 :Tb3+ was derived from a dipole-dipole interaction.

Zirconium arsenate-modified magnetic nanoparticles: preparation, characterization and application to the enrichment of phosphopeptides.

Phosphorylation, one of the most important post-translational modifications of protein, plays a crucial role in a large number of biological processes. Large-scale identification of protein phosphorylation by mass spectrometry is still a challenging task because of the low abundance of phosphopeptides and sub-stoichiometry of phosphorylation. In this work, a novel strategy based on the specific affinity of zirconium arsenate to the phosphate group has been developed for the effective enrichment of phosphopeptides. Zirconium arsenate-modified magnetic nanoparticles (ZrAs-Fe(3)O(4)@SiO(2)) were prepared by covalent immobilization of zirconium arsenate on Fe(3)O(4)@SiO(2) magnetic nanoparticles under mild conditions, and characterized by transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometer (VSM). The prepared ZrAs-Fe(3)O(4)@SiO(2) was applied for the selective enrichment of phosphopeptides from the digestion mixture of phosphoproteins and bovine serum albumin (BSA). Our results demonstrated that the ZrAs-Fe(3)O(4)@SiO(2) magnetic nanoparticles possess higher selectivity for phosphopeptides and better capture capability towards multiply-phosphorylated peptides than commercial zirconium dioxide (ZrO(2)), which has been widely employed for the enrichment of phosphopeptides. In addition, endogenous phosphopeptides from human serum can be effectively captured by ZrAs-Fe(3)O(4)@SiO(2) magnetic nanoparticles. It is the first report, to the best of our knowledge, in which the zirconium arsenate-modified magnetic nanoparticles were successfully applied to the enrichment of phosphopeptides, which offers the potential application of this new material in phosphoproteomics study.

Genome-Wide Screening for Novel Candidate Virulence Related Response Regulator Genes in Xanthomonas oryzae pv. oryzicola.

Two-component regulatory system (TCS), a major type of cellular signal transduction system, is widely used by bacteria to adapt to different conditions and to colonize certain ecological niches in response to environmental stimuli. TCSs are of distinct functional diversity, genetic diversity, and species specificity (pathovar specificity, even strain specificity) across bacterial groups. Although TCSs have been demonstrated to be crucial to the virulence of Xanthomonas, only a few researches have been reported about the studies of TCSs in Xanthomonas oryzae pathovar oryzicola (hereafter Xoc), the pathogen of rice bacterial streak disease. In the genome of Xoc strain GX01, it has been annotated 110 TCSs genes encoding 54 response regulators (RRs), 36 orthodox histidine kinase (HKs) and 20 hybrid histidine kinase (HyHKs). To evaluate the involvement of TCSs in the stress adaptation and virulence of Xoc, we mutated 50 annotated RR genes in Xoc GX01 by homologous vector integration mutagenesis and assessed their phenotypes in given conditions and tested their virulence on host rice. 17 RR genes were identified to be likely involved in virulence of Xoc, of which 10 RR genes are novel virulence genes in Xanthomonas, including three novel virulence genes for bacteria. Of the novel candidate virulence genes, some of which may be involved in the general stress adaptation, exopolysaccharide production, extracellular protease secretion and swarming motility of Xoc. Our results will facilitate further studies on revealing the biological functions of TCS genes in this phytopathogenic bacterium.

The association of polymorphisms of the vitamin D receptor gene with psoriasis in the Han population of northeastern China.

BACKGROUND: The vitamin D receptor (VDR) is a master regulator of epidermal barrier function, inflammation, stem-cell proliferation, and microbial defense. OBJECTIVE: To evaluate the association between the VDR and psoriasis in the northeastern Chinese Han population. METHODS: In this case-control study, 342 patients with psoriasis and 341 controls were genotyped for five common VDR gene polymorphisms (ApaI, TaqI, BsmI, FokI, and Cdx2) by the Multiplex SNapSHOT method. RESULTS: The frequency of ApaI (rs7975232) allele A was significantly increased in psoriasis relative to the control group (27.8% vs. 22.1%, p=0.018); the allele A of the ApaI polymorphism showed a 1.35-fold increased risk of developing psoriasis. Haplotype analyses showed the BsmI/ApaI/TaqI/Cdx2/FokI GATGC to be significantly over-represented in psoriasis patients compared with controls (p=0.012). The BsmI/ApaI/TaqI haplotype GCT was presented to a lesser extent in psoriasis patients in comparison with control patients (72.2% vs. 77.9%, p=0.012). CONCLUSIONS: These data suggest that VDR polymorphisms are associated with psoriasis in Northeastern Han Chinese population.

Preparation of magnetic poly(diethyl vinylphosphonate-co-ethylene glycol dimethacrylate) for the determination of chlorophenols in water samples.

In this work, a novel type of magnetic polymer particle, magnetic poly(diethyl vinylphosphonate-co-ethylene glycol dimethacrylate) [Fe(3)O(4)@p(DEVP-co-EDMA)], was successfully synthesized and applied for the extraction and determination of chlorophenols in water samples by coupling with high-performance liquid chromatography (HPLC). Fe(3)O(4)@p(DEVP-co-EDMA) was synthesized by a simple seeded radical polymerization method and exhibited well-defined core-shell structure and good magnetic response ability. In addition, the magnetic polymer had the advantages of abundant adsorption sites and high enrichment efficiency. Due to the presence of PO group in the skeleton of polymer, the magnetic polymer material displayed excellent extraction performance for chlorophenols, such as 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). Hydrophobic skeleton of the magnetic polymer also provided strong interaction with the target analytes, especially pentachlorophenol (PCP) which is a kind of non-polar chlorophenol. Desorption solution, pH of water sample, extraction time and desorption time, the amount of adsorbent, and the volume of desorption solution were optimized. Under the optimized conditions, the linear ranges of four chlorophenols were 2-500 ng/mL with the limits of detection (S/N=3) ranging from 0.20 to 0.34 ng/mL. The repeatability was investigated by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) lower than 15.0%. The recoveries for real water samples were in the range of 92.7-108.0%. Collectively, the results indicated that the novel Fe(3)O(4)@p(DEVP-co-EDMA) was successfully applied in the extraction and detection of chlorophenols from water samples, and the magnetic polymer particle showed potential applications in the analysis of polar compounds.

A magnetite/oxidized carbon nanotube composite used as an adsorbent and a matrix of MALDI-TOF-MS for the determination of benzo[a]pyrene.

A magnetite/oxidized carbon nanotube composite, Fe(3)O(4)@SiO(2)/OCNT, was fabricated in a simple way, and it was successfully used as a magnetic solid-phase extraction sorbent and a significant matrix of the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the detection of benzo[a]pyrene (BaP).

The lactase gene -13910T allele can not predict the lactase-persistence phenotype in north China.

The frequency of lactase persistence varies widely in human populations. Study showed that the T allele of a C/T transition 13910bp upstream from exon 1 of lactase gene (LCT) was completely associated with lactase persistence in a Finnish population. To evaluate if the frequency of -13910T allele was in concordance with the lactase persistence in northern Chinese populations, in this study, we used Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) to detect the lactase -13910T allelic frequency in 5 northern Chinese populations for the first time. Results showed that the T allele frequency was low in these populations and that it did not match the lactase persistence phenotype in these populations. Therefore the -13910T allelic frequency can not serve as a predictor of the lactase persistence in these populations and this suggests the existence of other possible mechanisms of lactose tolerance in Chinese populations.