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- Author or Editor: X. Yang x
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Summary
Rapid high-performance liquid chromatographic methods with evaporative light scattering detection (HPLC-ELSD) and electrospray ionization multistage mass spectrometry (HPLC-ESI-MSn) have been established and validated for simultaneous qualitative and quantitative analysis of eight steroidal saponins in ten batches of Gongxuening capsule (GXN), a widely commercially available traditional Chinese preparation. The optimum chromatographic conditions entailed use of a Kromasil C18 column with acetonitrile-water (30:70 to 62:38, υ/υ) as mobile phase at a flow rate of 1.0 mL min−1. The drift tube temperature of the ELSD was 102°C and the nebulizing gas flow rate was 2.8 L min−1. Separation was successfully achieved within 25 min. LC-ESI-MSn was used for unequivocal identification of the constituents of the samples by comparison with reference compounds. The assay was fully validated for precision, repeatability, accuracy, and stability, then successfully applied to quantification of the eight compounds in samples. The method could be effective for evaluation of the clinical safety and efficacy of GXN.
The hypothesis of niche differentiation with respect to resources is considered to be one of the most influential explanations for the maintenance of species diversity. The hypothesis has been examined extensively by testing its prediction of species-habitat association, which posits that the spatial distribution of species is highly correlated with environmental variables. However, we argue that widespread evidence of the species-habitat association lacks adequate rigor to justify the niche differentiation hypothesis. In this study, we tested whether and to what extent the observed species-habitat association could be caused by ecological processes other than niche differentiation, in a 20-ha subtropical forest plot. The niche differentiation hypothesis was evaluated by testing the species-habitat association and performing a cross-evaluation of the habitat-diversity expectation, which posits that a strong positive correlation exists between species diversity and habitat complexity. Failure to support the habitat-diversity expectation would at a minimum indicate that the niche differentiation hypothesis might not be the main underlying process of species distribution, despite prevalence of the species-habitat association in the same plot. Our analysis revealed that distributions of most species (86.11%) in the plot were significantly associated with at least one of eight topographical and soil nutrient variables. However, there was almost no significant positive correlation between species diversity and habitat complexity at various spatial scales in the same plot. The results indicate that additional caution is warranted when interpreting the species-habitat association from the niche differentiation perspective. A significant species-habitat association indicates only a species’ habitat preference. The association may reveal nothing about interspecific differences in habitat preference, which is a requirement of the niche differentiation hypothesis.
Abstract
57Co was produced with high pure nature iron irradiated by 8.5MeV deuterons. TBP-benzene extraction method and anion-exchange method were used to separate and purify it. The purified57Co was prepared into standard solution of about 30 to 50 
g Co2+/ml carrier concentration and about 0.1 mol/l HCl. The specific activity of the standard solution was measured with 4 
(ppc)-
coincidence counting method. The final result was 476.82(1±0.42%)Bq/mg.
Some wild species of the genus Oryza such as O. rufipogon and O. longistaminata show a high level of resistance to pests and diseases including rice blast (caused by Magnaporthe grisea). To transfer blast resistance from wild species into cultivatedvarieties (O. sativa), interspecific hybrids were produced and anther culture was used toaccelerate the procedure of resistance breeding. Anther culture efficiency depended onboth the medium and the genotype of the cultivated varieties and the wild species. Afterinoculation with a mixture of six strains with wide spectrum virulence, all the F1 hybridswere resistant to blast; the F2 plants segregated, from high resistance to susceptibility, anda similar result was obtained for the H1 and H2 plants. At the H3 stage, blast resistancetended to be stable and almost 100% of inoculated H5 plants were highly resistant to riceblast. For agronomic characteristics, the F2 and H1 showed segregation, but no significantdifferences were seen between the cultivated parents and the H2 to H5 generations. Theresults demonstrate that blast resistance genes can be transferred from wild rice speciesinto cultivated varieties through crossing and anther culture, and the H5 can be used asstable lines in future breeding programmes.
Abstract
Liquid liquid extraction of 46Sc was studied with 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP). It has been found that PMBP extracts almost quantitatively scandium from 10-3 to 10-2M HCl solutions. Tributyl phosphate (TBP) has a pronounced antagonistic effect on the extraction process.
Partial abortion of gametes possessing S-5 j in S-5 i / S-5 j genotype at locus S-5 is responsible for hybrid sterility between indica and japonica subspecies in rice ( Oryza sativa L.), while a single wide compatibility (WC) allele S-5 n can restore normal hybrid fertility between the two groups. In this study, Pei’ai 64S, one of the most popular WC line widely used for subspecific hybrid rice breeding program in South China was studied for location of its S-5 locus. Twenty SSR (Simple Sequence Repeat) markers derived from Cornell SSR linkage map and 9 developed using sequences from GenBank database were employed to perform bulked segregant analysis of the mapping population derived from a three-way cross (Pei’ai 64S/T8//Akihikari) to tag fine location of the hybrid sterility locus, S-5 . This S-5 locus was mapped on chromosome 6 approximately 0.2 cM from GXR6 and RM276 SSR markers. This tight linkage of the markers and the S-5 locus would be very useful for efficient marker-assisted selection for WC varieties and for map-based cloning of the gene.
Starch is a product of photosynthetic activities in leaves. Wheat yields largely depend on photosynthetic carbon fixation and carbohydrate metabolism in flag leaves. The mapping of quantitative trait loci (QTLs) associated with flag leaf starch content (FLSC) in wheat (Triticum aestivum L.) was completed using unconditional and conditional QTL analyses. The FLSC of this population during the early grain-filling stage was measured at six stages in six environments. Combining unconditional and conditional QTL mapping methods, eight unconditional QTLs and nine conditional QTLs were detected, with five QTLs identified as unconditional and conditional QTLs. Four unconditional QTLs (i.e. qFLS-1B, qFLS-1D-1, qFLS-4A, and qFLS-7D-1) and one conditional QTL (i.e. qFLS-3A-1) were identified in two of six environments. Two QTLs (qFLS-1D-2 and qFLS-7D-1), which significantly affected the FLSC, were identified using the unconditional QTL mapping method, while three QTLs (i.e. qFLS-1A, qFLS-3A-1, and qFLS-7D-1) were detected using the conditional QTL mapping method. Our findings provide new insights into the genetic mechanism and regulatory network underlying the diurnal FLSC in wheat.
Summary
The method of high-performance liquid chromatography (HPLC) with diode array detector (DAD) was used and validated for the simultaneous determination of nine flavonoids (rutin, myricetin, quercitrin, quercetin, luteolin, genistein, kaempferol, apigenin, and isorhamnetin) in beagle dog plasma. Plasma sample was pre-treated with acetonitrile (containing 0.05% formic acid). Chromatographic separation was performed on a kromasil C18 column (250 × 4.6 mm, 5 µm) maintained at 35 °C. The mobile phase was a mixture of methanol and 0.2% formic acid with a step linear gradient. At 1.0 mL min−1 flow rate, the eluent of other eight flavonoids was detected simultaneously at 360 nm with good separation except genistein (detected at 254 nm). Under optimum conditions, the correlation coefficient between the peak area and the concentrations for each analyte was all above 0.999. The intra-day and inter-day precisions were less than 10% for all analytes. The limit of detection and the limit of quantification for the selected nine flavonoids were 0.006–0.03 and 0.02–0.12 g mL−1, respectively. The extracted recoveries of selected nine flavonoids were 74.02%–99.37%. The assay has been successfully applied to determine concentrations of nine flavonoids in plasma from beagle dog after being intravenously administrated Ginkgo biloba extract.
Summary
A simple and rapid HPLC method using a photodiode array (PDA) detector for the analysis of 3-hydroxycarboplatin and its related complex has been established for the first time. Separation of 3-hydroxycarboplatin and 3-hydroxy-1,1-cyclobutanedicarboxylic acid (3-HO-cbdca) was carried out on a Phenomenex ODS3 column using an aqueous solution containing 50 mM ammonium acetate and 5 mM sodium 1-octanesulfonate as the mobile phase. The flow rate was 0.8 mL min−1, the column temperature was 40°C, and the detection wavelength was 230 nm for 3-hydroxycarboplatin and 220 nm for 3-HO-cbdca. Different analytical performance parameters such as precision, accuracy, linearity, stability of the solution, specificity, limit of detection (LOD), limit of quantification (LOQ), and system suitability were determined using the Empower 2 software. The calibration curve of standard 3-hydroxycarboplatin showed good linearity (r = 0.9995) within the range 0.5–1.4 mg mL−1. The method was accurate and precise, with an average accuracy of 100.4% (RSD = 1.53%, n = 9), and the results of the system suitability test showed symmetrical peaks, good resolution (R s), and repeatability. It can be applied to the quality control of 3-hydroxycarboplatin.
