[Show abstract][Hide abstract] ABSTRACT: Meiotic non-reduction resulting in unreduced gametes is thought to be the predominant mechanism underlying allopolyploid formation in plants. Until now, however, its genetic base was largely unknown. The allohexaploid crop common wheat (Triticum aestivum L.), which originated from hybrids of T. turgidum L. with Aegilops tauschii Cosson, provides a model to address this issue. Our observations on meiosis in pollen-mother-cells from T. turgidum×Ae. tauschii hybrids indicated that first division restitution, which exhibited prolonged cell division during meiosis I, was responsible for unreduced gamete formation. A major quantitative trait locus (QTL) for this trait, named QTug.sau-3B, was detected on chromosome 3B in two T. turgidum×Ae. tauschii haploid populations. This QTL is situated between markers Xgwm285 and Xcfp1012, covered a genetic distance of 1 cM in one population. QTug.sau-3B is a haploid-dependent QTL since it was not detected in doubled haploid populations. Comparative genome analysis indicated that this QTL was close to Ttam-3B, a collinear homolog of tam in wheat. Although the relationship between QTug.sau-3B and Ttam requires further study, high frequencies of unreduced gametes may be related to reduced expression of Ttam in wheat.
[Show abstract][Hide abstract] ABSTRACT: APOBEC3 proteins are a family of cytidine deaminases that exhibit broad antiretroviral activity. Among APOBEC3 proteins, APOBEC3G (hA3G) and APOBEC3F (hA3F) exhibit the most potent anti-HIV-1 activities. Although the incorporation of hA3F into virions is a prerequisite for exerting its antiviral function, the detail mechanism underlying remains incompletely understood. In this work, we present data showing that the nucleocapsid (NC) domain of HIV-1 Gag and a linker sequence between the two cytidine deaminase domains within hA3F, i.e., 104-156 amino acids, are required for viral packaging of hA3F. A detailed mapping study reveals that the cluster of basic residues surrounding the N-terminal zinc finger (ZF) and the linker region between the ZFs of HIV-1 NC play an important role in A3F incorporation, in addition, at least one of two ZFs is required. A hA3F fragment is able to compete with both hA3G and hA3F for viral incorporation, suggesting a common mechanism underlying virion encapsidation of hA3G and hA3F. Taken together, these results shed a light on the detail mechanism underlying viral incorporation of hA3F.
[Show abstract][Hide abstract] ABSTRACT: Polysaccharides were extracted from Salvia miltiorrhiza Bunge using response surface methodology (RSM) with ultrasonication. A Box-Behnken design was used to optimize the extraction parameters to maximize the polysaccharide extraction yield. The polysaccharide SMP-U1 was isolated and characterized, then the antioxidant and antiproliferation activities were evaluated in vitro. The modified optimal conditions were an ultrasonic power of 180W, an extraction temperature of 54°C, and an extraction time of 32min, achieving an extraction yield of 40.54%±0.25%. The results indicate that SMP-U1 has significant antioxidant activity, scavenging the free radical 2,2-diphenyl-1-picrylhydrazyl. It has also exhibited effect on the proliferation of human breast carcinoma cells Bcap-37 and human esophageal carcinoma cells Eca-109, especially at a concentration of 0.30mg/mL. In conclusion, SMP-U1 has remarkable in vitro antioxidant and antiproliferation activity, and has potential for application as a natural antioxidant or antitumor agent.
International journal of biological macromolecules. 06/2014;
[Show abstract][Hide abstract] ABSTRACT: Polysaccharides from Camellia oleifera leaves were extracted by ultrasonic-assisted extraction and optimized with response surface methodology. The optimal conditions of the extraction of polysaccharides were determined to be the extraction time of 1.6h, extraction temperature of 88°C and ratio of liquid to raw material of 20, which contributed to the highest yield of 3.77%. The crude polysaccharide was purified and three fractions (CLP-1, CLP-2 and CLP-3) were obtained. Their physicochemical properties were investigated with chemical method. The results indicated that the uronic acid content of CLP-2 was significantly higher than those of CLP-1 and CLP-3, and CLPs were mainly composed of glucose and galactose residue. In vitro antioxidant assay indicated that three polysaccharide fractions showed remarkable antioxidant activities in a concentration-dependent manner. Compared with CLP-1 and CLP-2, CLP-3 exhibited higher iron chelating activity. CLP-2 possessed significant higher hydroxyl radial and 2,2-diphenyl-1 -picrydrazy (DPPH) radical scavenging activities than those of CLP-1 and CLP-3. Overall, the polysaccharides derived from C. oleifera leaves might be explored as potential natural antioxidant.
International journal of biological macromolecules 04/2014; · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Salinity has a great influence on plant growth and distribution. A few existing reports on Artemisia annua L. response to salinity are concentrated on plant growth and artemisinin content; the physiological response and salt damage mitigation are yet to be understood. In this study, the physiological response of varying salt stresses (50, 100, 200, 300, or 400 mM NaCl) on A. annua L. and the effect of exogenous salicylic acid (0.05 or 0.1 mM) at 300-mM salt stress were investigated. Plant growth, antioxidant enzyme activity, proline, and mineral element level were determined. In general, increasing salt concentration significantly reduced plant growth. Superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were stimulated by salt treatment to a higher enzyme activity in treated plants than those in untreated plants. Content of proline had a visible range of increment in the salt-treated plants. Distribution of mineral elements was in inconformity: Na(+) and Ca(2+) were mainly accumulated in the roots; K(+) and Mg(2+) were concentrated in leaves and stems, respectively. Alleviation of growth arrest was observed with exogenous applications of salicylic acid (SA) under salt stress conditions. The activity of SOD and POD was notably enhanced by SA, but the CAT action was suppressed. While exogenous SA had no discernible effect on proline content, it effectively inhibited excessive Na(+) absorption and promoted Mg(2+) absorption. Ca(2+) and K(+) contents showed a slight reduction when supplemented with SA. Overall, the positive effect of SA towards resistance to the salinity of A. annua will provide some practical basis for A. annua cultivation.
Physiology and Molecular Biology of Plants 04/2014; 20(2):161-9.
[Show abstract][Hide abstract] ABSTRACT: Leymus is a polyploid genus with a diverse array of morphology, cytology, ecology and distribution in Triticeae. To investigate the phylogenetic relationships and maternal genome donor of polyploid Leymus, chloroplast trnH-psbA region and mitochondria coxII intron sequences of 33 Leymus taxa were analyzed with those of 36 diploid perennial species representing 19 basic genomes in Triticeae. The results demonstrated that reticulate evolution occurred in Leymus species, with cytoplasmic lineage of Leymus being contributed by different progenitors. Interspecific relationships of Leymus were also elucidated on the basis of orthologous comparison. Our data suggested that: (1) due to incomplete lineage sorting and/or difference in the pattern of chloroplast and mitochondrial inheritance, the genealogical conflict between the two genealogical patterns suggest the contribution of Psathyrostachys, Agropyron, Eremopyrum, Pseudoroegneria, Thinopyrum, and Lophopyrum to the cytoplasmic lineage of Leymus; (2) there is a close relationship among Leymus species from the same area or neighboring geographic regions; (3) L. coreanus, L. duthiei, L. duthiei var. longearistatus, and L. komarovii are closely related to other Leymus species, and it is reasonable to transfer these species from the genus Hystrix to Leymus; (4) Leymus species from North America are closely related to L. coreanus from the Russian Far East and L. komarovii from northeast China but are evolutionarily distinct from Leymus species from Central Asia and the Qinghai-Tibetan Plateau. The occurrence of multiple origin and introgression could account for the rich diversity and ecological adaptation of Leymus species.
Journal of Systematics and Evolution 04/2014; · 1.85 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives. Published association studies of killer cell immunoglobulin-like receptors (KIRs) and ankylosing spondylitis (AS) in populations are inconsistent. The aim of this study is to determine whether the KIR polymorphisms confer susceptibility to AS in populations by conducting a meta-analysis. Methods. A computer search was carried out up to August 2013 for literature pertaining to AS and KIR polymorphisms. Publications addressing the association between the KIR polymorphisms and susceptibility to AS in populations were selected from the Pubmed, Elsevier Science Direct, China National Knowledge Infrastructure (CNKI) and Chinese Biomedical Literature Database (CBM) databases. The odds ratio (OR) with 95% confidence interval (95%CI) was calculated. Results. A total of 13 case-control studies in 9 articles were included in this meta-analysis. Meta-analysis results identified two positive associations of 2DS4 and 3DS1 with susceptibility to AS in populations. In subgroup analysis, there was a positive association between 2DS4 and susceptibility to AS in Asians, but not in Caucasians. And there were associations between 3DL1, 3DS1 and susceptibility to AS in Caucasians, but not in Asians. Results of subgroup analysis also showed that there were associations between 2DL5, 2DS4, 2DS5, 3DL1, 3DS1 and susceptibility to AS in HLA-B*27-positive patients and HLA-B*27-positive healthy controls. Conclusions. This meta-analysis confirms that 2DS4 and 3DS1 might be potential risk factors for AS in populations.
[Show abstract][Hide abstract] ABSTRACT: Src-suppressed C kinase substrate (SSeCKS), an in vivo and in vitro protein kinase C substrate, is a major lipopolysaccharide (LPS) response protein which markedly upregulated in several organs, including brain, lung, heart, kidney etc., indicating a possible role of SSeCKS in inflammatory process. However, the expression and biological function of SSeCKS during neuronal inflammation remains to be elucidated, so we established an inflammatory model injected with LPS to investigate the gene expression patterns of SSeCKS in neural tissues by using TaqMan quantitative real-time PCR and immunohistochemistry in rat. Real-time PCR showed that LPS stimulated the expression of SSeCKS mRNA in a dose- and time-dependent manner in sciatic nerves, spinal cords and dorsal root ganglions. Immunohistochemistry showed that SSeCKS colocalized with nerve fibers in sciatic nerve after LPS administration, but there was no colocalization between SSeCKS and Schwann cells. In addition, SSeCKS colocalized with neurons which existed in dorsal root ganglions and spinal cords. These findings indicated that SSeCKS might play some important roles in sciatic nerve fibers and neurons in spinal cords and dorsal root ganglions after LPS injection.
Neurochemical Research 03/2014; · 2.13 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Mesenchymal stem cells (MSCs) have both multi-lineage differentiation potential and immunosuppressive properties, making them ideal candidates for regenerative medicine. However, their immunosuppressive properties potentially increase the risk of cancer progression and opportunistic infections. In this study, MSCs isolated from human umbilical cord blood (UCMSCs) and adult bone marrow (BMMSCs) were infected with human cytomegalovirus (HCMV). Cytopathic changes were observed 10 days post infection. PCR products amplified from genomic DNA and cDNA were used to confirm the HCMV infection of the UCMSCs and BMMSCs. Real-time PCR was conducted to quantify the expression of immunomodulatory molecules, including cytokines, chemokines, growth factors, adhesion molecules and cancer-related genes. Our results indicate high upregulation of the majority of these molecules, including many growth factors, tumor necrosis factor alpha, interleukin-8, interleukin-6 and interferon gamma. Adhesion molecules (VCAM-1, TCAM-1 and selectin-E) were downregulated in the infected UCMSCs and BMMSCs. Antibody chip array evaluation of cell culture media indicated that the growth factor secretion by UCMSCs and BMMSCs was greatly influenced (p < 0.001) by HCMV. The stimulation of MSCs with HCMV led to the activation of downstream signaling pathways, including pSTAT3 and Wnt2. Our results show that HCMV can significantly alter the functions of both UCMSCs and BMMSCs, although not in the same way or to the same extent. In both cases, there was an increase in the expression of proangiogenic factors in the microenvironment following HMCV infection. The discrepancy between the two cell types may be explained by their different developmental origin, although further analysis is necessary. Future studies should decipher the underlying mechanism by which HCMV controls MSCs, which may lead to the development of new therapeutic treatments.
[Show abstract][Hide abstract] ABSTRACT: The karyomorphology of nine taxa of Paris from Sichuan province in China were reported. The primary lesions of P. undulatis were newly observed, the chromosome number and karyotype were reported for the first time. All of the materials were diploids. The chromosome numbers of all taxa studied were 2n = 2x = 10. The karyotypic asymmetry types of all taxa studied were 2A, except for P. polyphylla var. chinensis was 2B. Satellites were observed in four taxa, P. undulatis, P. polyphylla var. polyphylla, P. fargesii var. brevipetalata and P. polyphylla var. polyphylla. All of the investigated taxa were absent B chromosome except for P. polyphylla var. polyphylla and P. axialis. Karyotypic formula of nine Paris taxa were as follows: P. undulatis, 2n = 6m + 4t (2sat); P. polyphylla var. chinensis, 2n = 6m + 4t (2sat); P. polyphylla var. yunnanensis, 2n = 6m + 4t; P. cronquistii, 2n = 6m + 4t; P. polyphylla var. polyphylla, 2n = 6m + 2st (2sat) + 2t (2sat) + 2bs; P. axialis, 2n = 6m + 4t + 2bs; P. fargesii var. brevipetalata, 2n = 6m + 4t (2sat); P. mairei, 2n = 6m + 4t; P. marmorata, 2n = 6m + 1st + 3t. The variability of karyotypes occurred among taxa and phylogenetic positions of some taxa were investigated, and the infrageneric and the intergeneric relation ships of Paris were discussed.
[Show abstract][Hide abstract] ABSTRACT: — Observations were made on chromosome morphology and behavior during meiosis of PMCs (pollen mother cells) for eight taxa in the genus Salvia: S. miltiorrhiza Bunge, S. miltiorrhiza Bunge var. miltiorrhiza f. alba C. Y. Wu et H. W. Li, S. cynica Dunn., S. flava Forrest, S. yunnanensis C. H. Wright, S. cavaleriei Levl. var. simplicifolia Stib., S. przewalskii Maxim. and S. brevilabra Franch. Results show that the basic chromosome number in the genus Salvia is × = 8. The chromosome configurations in S. miltiorrhiza (from Sichuan, Shandong, Zhejiang and Shanxi), S. miltiorrhiza f. alba, S. cynica, S. flava, S. yunnanensis and S. cavaleriei var. simplicifolia are formulated uniformly as 8II. In S. miltiorrhiza from Henan, the typical chromosome configuration observed at metaphase is 0.13 I +7.80 II+0.07 IV, whereas that in S. przewalskii is 0.33 I+15.50 II+0.16 IV and in S. brevilabra is 0.53 I+15.73 II. Configurations of the bivalents in all materials investigated are different. According to the chromosomes pairing in metaphase I, except that S. przewalskii and S. brevilabra are tetraploids, the others are diplonts. Chromosomes bridges or lagging chromosomes are appeared at anaphase II in S. miltiorrhiza from Henan, S. przewalskii and S. brevilabra. The abnormal behaviors of the chromosomes in meiosis observed may have effects on the development of pollen grains in these taxa.
Caryologia: International Journal of Cytology, Cytosystematics and Cytogenetics. 02/2014; 62(4):334-340.
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[Show abstract][Hide abstract] ABSTRACT: To detect the content of polysaccharides in the root of Salvia miltiorrhiza collected from different provenances, and to discover the dynamic change rules of polysaccharides at various growing stages.
[Show abstract][Hide abstract] ABSTRACT: To investigate the phylogenetic relationships among Leymus and related diploid genera, the genome donor of Leymus, and the evolutionary history of polyploid Leymus species, chloroplast trnQ–rps16 sequences were analyzed for 36 accessions of Leymus representing 25 species, together with 11 diploid taxa from six monogenomic genera. The phylogenetic analyses (Neighbor-Joining and MJ network) supported three major clades (Ns, St and Xm). Sequence diversity and genealogical analysis suggested that 1) Leymus species from the same areas or neighboring geographic regions are closely related; 2) most of the Eurasian Leymus species are closely related to Psathyrostachys: P. juncea might serve as the Ns genome donor of polyploid Eurasian Leymus species; 3) the Xm genome may originate from ancestral lineages of Pseudoroegneria (St), Lophopyrum (Ee), Australopyrum (W) and Agropyron (P); 4) the trnQ–rps16 sequences of Leymus are evolutionarily distinct, and may clarify parental lineages and phylogenetic relationships in Leymus.
Nordic Journal of Botany 02/2014; · 0.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Each approach for artificial cornea design is toward the same goal: to develop a material that best mimics the important properties of natural cornea. Accordingly, the selection and optimization of corneal substitute should be based on their physicochemical properties. In this study, three types of polyvinyl alcohol (PVA) hydrogels with different polymerization degree (PVA1799, PVA2499 and PVA2699) were prepared by freeze-thawing techniques. After characterization in terms of transparency, water content, water contact angle, mechanical property, root-mean-square roughness and protein adsorption behavior, the optimized PVA2499 hydrogel with similar properties of natural cornea was selected as a matrix material for artificial cornea. Based on this, a biomimetic artificial cornea was fabricated with core-and-skirt structure: a transparent PVA hydrogel core, surrounding by a ringed PVA-matrix composite skirt that composed of graphite, Fe-doped nano hydroxyapatite (n-Fe-HA) and PVA hydrogel. Different ratio of graphite/n-Fe-HA can tune the skirt color from dark brown to light brown, which well simulates the iris color of Oriental eyes. Moreover, morphologic and mechanical examination showed that an integrated core-and-skirt artificial cornea was formed from an interpenetrating polymer network, no phase separation appeared on the interface between the core and the skirt.
Journal of Materials Science Materials in Medicine 01/2014; · 2.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Ethylene-vinyl acetate copolymer (EVA) was used to toughen the hydroxyapatite/polyamide 66 (HA/PA66) composites, which were analyzed by SEM, DMA, FTIR, XRD and mechanical testing. The results indicated that the change of composition influenced significantly the properties of the composites by different mechanism, and the presence of 10 wt.% EVA could improve the impact strength of HA/PA66 composites more effectively. This was traced to the combined favorable physical characteristics of the flexibility of EVA molecular chains, more homogeneous distribution of HA in PA66 matrix, and the presence of interactions between EVA, HA and PA66.
Polymer-Plastics Technology and Engineering 01/2014; 53(3). · 1.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: High performance magnetic Fe3O4/PAH/PSS@Pd core-shell microspheres are successfully synthesized via layer-by-layer self-assembly method. Fe3O4 cores with a rough surface are synthesized by hydrothermal method. Subsequently, Pd nanoparticle shells and Fe3O4/PAH/PSS@Pd microspheres are in situ simultaneously constructed by alternating immersion of Fe3O4 particles in PSS (poly(sodium 4-styrenesulfonate)) and PAH-Pd(II) (Poly(allylamine hydrochloride)-Pd(II)) solutions, followed by chemical reduction in NaBH4 solution. The structural and magnetic properties of microspheres are characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), X-ray diffraction analysis (XRD), and vibrating sample magnetometer (VSM), respectively. These microspheres demonstrate excellent structural uniformity (190nm) and superior magnetization, leading to easy collection of microspheres using an external field. With highly active and stable Pd nanoparticle shells, these microspheres exhibit more efficient catalytic activity for the oxidation of benzyl alcohol.
Journal of Colloid and Interface Science 01/2014; 421:1–5. · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Artemisinin is a compound extracted from Artemisia annua L. with a remarkable curative effect against malaria. It can be extracted using ultrasound-assisted extraction (UAE) and then detected via HPLC. In this study, response surface methodology (RSM) was used to optimize UAE conditions for obtaining the maximum yield of artemisinin. Three independent variables (ratio of solvent to material, extraction temperature, and ultrasonic power) were evaluated using the Box-Behnken experimental design, with the yield of artemisinin as a response variable. Experimental data were highly fitted to a mathematical-regression model using multiple linear regression (MLR). Based on response surface plots, the three independent variables exhibited interactive effects on the yield of artemisinin. The optimal extraction conditions were as follows: 42.71 mL/g ratio of solvent to material, 41.86°C extraction temperature and 120 W ultrasonic power. The predicted yield of artemisinin by model was 0.7848%, whereas the actual yield in the extracts was 0.7826% ± 0.0790% in adjusted optimal conditions, with a relative error of 0.28%. The results undoubtedly demonstrated that RSM could be used to explore the optimum conditions of artemisinin extraction.
Separation Science and Technology 01/2014; 49(5). · 1.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Multiwall carbon nanotubes (MCNTs) films have been prepared by using single and efficient screen printing method and used as counter electrodes for dye-sensitized solar cells (DSSCs). The asprepared MCNTs counter electrodes exhibit a highly interconnected network structures with high electrical conductivity and good catalytic activity. By the optimization of as-prepared MCNTs film thickness, photovoltaic conversion efficiency of the cell based on MCNTs counter electrode with 1 μm thickness reaches 6.14% at one sun condition (AM 1.5G, 100 mW cm–2), which is comparable to the cell based on conventional Pt counter electrode. These results suggest that the screen- printed MCNTs films provide a potential feasibility for replacing conventional Pt counter electrodes for DSSCs.
Nanoscience and Nanotechnology Letters 01/2014; 6(7). · 1.44 Impact Factor