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Four novel 2-(trimethylsilyl)ethyl glycosides have been synthesized by a short and efficient route starting from d-glucose. Their structures were elucidated by applying high-resolution mass spectra, and one-dimensional and two-dimensional NMR techniques. These glycosides were prepared and used as intermediate building blocks in the scheme developed for oligosaccharide construction. [ABSTRACT FROM AUTHOR]

The nanoscale zero-valent iron supported on biochar (B-nZVI) was prepared by liquid-phase reduction method and used for the removal of acid orange 7 (AO). The structure of composited B-nZVI was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction analysis, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller surface area analysis. nZVI was well dispersed on the surface of biochar with a specific surface area 52.21 m/g, and no obvious aggregation was observed. Batch experiments demonstrated that the degradation of AO (20 mg/L) by B-nZVI (2 g/L) at initial pH 2 reached 98.3 % within 10 min. There was a good linearity ( r = 0.99) between k and B-nZVI dosage. The reductive cleavage of the azo group in AO to amino group may be the dominant stage. This study demonstrated that B-nZVI has the potential to be a promising material for the removal of azo dyes. [ABSTRACT FROM AUTHOR]

Four novel 2-(trimethylsilyl)ethyl glycosides have been synthesized by a short and efficient route starting from d-glucose. Their structures were elucidated by applying high-resolution mass spectra, and one-dimensional and two-dimensional NMR techniques. These glycosides were prepared and used as intermediate building blocks in the scheme developed for oligosaccharide construction. [ABSTRACT FROM AUTHOR]

simple liquid chromatography (LC) method has been developed and validated to determine rhaponticin in rat plasma, faeces and urine. Chromatographic separation was achieved through mobile phase consisting of acetonitrile and water at a flow rate of 1.0 mL min. Rhaponticin was quantified using UV detection at 324 nm. The assay was linear over the concentration range of 50-4,000 ng mL for plasma, faeces and urine. The intra- and inter-day RSD were less than 10%. The plasma, faeces and urine rhaponticin levels were monitored in rats after oral administration. This simple LC method appears to be useful in the pharmacokinetic investigation of rhaponticin. [ABSTRACT FROM AUTHOR]

Coupled with evaporative light scattering detection, a high-speed countercurrent chromatography method was successfully applied to the separation and purification of three tauro-conjugated cholic acids from the traditional Chinese medicine Pulvis Fellis Suis. With a two-phase solvent system composed of chloroform-methanol-water-acetic acid (4:4:2:0.3, v/ v), taurochenodeoxycholic acid (10.2 mg), taurohyodeoxycholic acid (11.8 mg) and taurohyocholic acid (5.3 mg), were obtained from 100 mg of the crude extract with purities of 94.6, 96.5 and 95.4%, respectively, in one-step separation. The structures of the three tauro-conjugated cholic acids were identified by ESI-MS, H NMR and C NMR. [ABSTRACT FROM AUTHOR]

A simple, rapid and reproducible micellar electrokinetic chromatography method has been established for the simultaneous determination of four conjugated cholic acids, glycohyodeoxycholic acid, taurohyodeoxycholic acid, glycohyocholic acid and taurochenodeoxycholic acid, in dry bile of Sus scrofa domestica Brisson (Pig Gall Powder). The optimum separation conditions included 15 mM sodium tetraborate buffer solution containing 30 mM SDS, 10 mM β-CD, and 20% ( v/ v) acetonitrile (pH 10.5). Applied voltage was 20 kV and temperature was at 25 °C. Gentiopicroside was used as an internal standard and detection was at 200 nm. The effects on separation of buffer pH, buffer concentration, and organic modifiers were investigated. The extracts of dry bile of Sus scrofa domestica Brisson were well separated within 20 min. [ABSTRACT FROM AUTHOR]

A simple, accurate and reproducible capillary electrophoresis method with UV detection has been developed for the simultaneous determination of four iridoid glycosides, 6- O-methyl-catalpol, aucubin, harpagide, and harpagoside, in Scrophularia ningpoensis (Xuan-shen). The running buffer was 100 mM borate (pH 9.3) containing 20% methanol. Applied voltage was 20 kV and temperature was 25 °C. Diphylloside A was used as an internal standard (IS) and detection was at 200 nm. The effects on separation of buffer pH, buffer concentration, and organic modifiers were investigated. The extracts of S. ningpoensis were well separated within 45 min. [ABSTRACT FROM AUTHOR]

Administration of donor-derived immature dendritic cells (DC) can prolong the survival of MHC-mismatched cardiac allografts. Genetic modification of DC by immunosuppressive molecules can enhance their potential tolerogenicity. In this study bone marrow derived immature DC were genetically modified by transforming growth factor (TGF) β1 by recombinant Ad. TGF-β1 gene modified immature DC (TGF-β-DC) displayed a characteristic phenotype of immature DC, decreased ability to secrete interleukin 12, and reduced allostimulatory ability. TGF-β-DC induced alloantigen-specific T cell hyporesponsiveness in vitro and in vivo, and Th2 cytokine polarization. mRNA expression of donor MHC class II (Iab) and human TGF-β1 was detected in spleen and lymph nodes of the allogeneic recipients for 3 weeks after TGF-β-DC infusion, indicating that microchimerism of TGF-β-DC is exhibited in allogeneic recipients. In this murine cervical heterotopic heart transplantation model, the survival of the allograft in recipients intravenously infused with TGF-β-DC 7 days before transplantation was greatly prolonged, and about 67% of cardiac grafts survived more than 40 days. Histological analysis of the allografts showed that the normal myocardial architecture was well preserved, accompanied by very little necrotic cells, but interstitial fibrosis replaced myocytes, and moderate collagen suffused the whole cardiac allograft in the recipients infused with TGF-β-DC. mRNA expression of type III procollagen was markedly increased in the allografts of the recipients infused with TGF-β-DC. Our results suggest that infusion of TGF-β1 gene modified immature DC prolongs the survival of the allograft through the effective induction of donor-specific T cell hyporesponsiveness. However, TGF-β1 expressed by gene modified immature DC can cause the fibrosis of the allografts, which may limit the application of this approach in the allograft transplantation. [ABSTRACT FROM AUTHOR]

Species with large intraspecific trait variability (ITV) have larger niche breadth than species with low ITV and thus are expected to be more abundant at the local scale. However, whether the positive ITV–abundance relationship holds in heterogeneous local environments remains uncertain. Using an individual-based trait dataset encompassing three leaf traits (leaf area, specific leaf area, and leaf dry mass content) of 20,248 individuals across 80 species in an environmentally heterogeneous subtropical forest in eastern China, ITV for each trait of each species was estimated by rarefaction. Resource-based niche breadth and marginality (the absolute distance between the mean resource states used by a species and the mean plot-wise resource states) were estimated simultaneously by the K–S method and the outlying mean index, respectively. Species with moderate ITV were often locally abundant, while species with large or small ITV were locally rare. This unimodal relationship between ITV and species abundance persisted when traits were analyzed separately and for all tree size classes. There was also a hump-backed relationship between niche breadth and marginality, and ITV was positively associated with niche breadth. The combined results suggest either a trade-off between the benefit from expanding niche breadth to adapt to multiple habitats and the disadvantage of reducing competitive ability, or a scarcity of favorable resources. Our results do not support the traditional thought that ITV positively correlates with species abundance in heterogeneous local environments. Instead, our study suggests that moderate—rather than large—intraspecific trait variability increases species abundance at local scales. [ABSTRACT FROM AUTHOR]

The importance of intraspecific trait variability (ITV) to the spatial distribution of individual species is unclear. We hypothesized that intraspecific trait dispersions underlying niche processes deviate more from null model expectations, by reducing their spread (range and variance), kurtosis, and standard deviation of near-neighbor distance, for species with aggregated than those with random distributions. The link between species’ spatial distributions and ITV patterns was examined using an individual tree-based trait data set, in which specific leaf area, mean leaf area, leaf dry matter content, and diameter at breast height were measured for 18,773 stems of 45 species in a 4.84 ha mapped subtropical forest plot in China. The nearest-neighbor distance analysis showed that, of 45 species, 14 species were distributed in random and 31 species were distributed in aggregation, while no species was distributed in uniform in the plot. The dispersions of all studied traits in species with an aggregated distribution on average deviated more strongly from the null expectation than those in species with a random distribution and that the extent of deviation was negatively associated with the degree of spatial randomness across species. Our results indicate that niche processes are primarily responsible for the spatial structure of species with aggregated distributions, while stochastic processes drive those with random distributions. Our results highlight the fundamental role of ITV in shaping spatial patterns of co-existing species. [ABSTRACT FROM AUTHOR]