This project compares various bibliometric measures and scientists' own judgments. Publication and cittion data are compiled for two cohorts of chemists awarded Sloan Fellowships. Citation patterns differ substantially between most cited papers and those these authors identify as their best. Theoretical, empirical, and methodological papers are contrasted as well. In addition, temporal citation patterns show that recognition spreads beyond the research area of a particular paper to yield cross-disciplinary citation surprisingly rapidly. Results suggest the utility of studying citation patterns among the Institute for Scientific Information Subject Categories, but also caution against equating publication and citation counts with scientific progress.
A separation procedure of trace platinum from large amounts of mercury and other interfering elements is described. After irradiation, the HgO target was dissolved in concentrated HCl solution. The thallium fraction was removed by solvent extraction with ether. In the aqueous phase after extraction the radioisotope of platinum produced by irradiation was precipitated as (NH4)2PtCl6 by adding a saturated solution of NH4Cl in the presence of H2PtCl6·6H2O as stable carrier. The decontamination factor of mercury, gold and thallium and the recovery of platinum in the process of separation are satisfactory.
Radioiodination of tri-n-butylstannyl-3-quinuclidinyl benzilate (TQNB) and N-succinimidyl-3-(tri-n-butylstannyl) benzoate (STB) was studied. STB was radiolabeled efficiently using iodogen to prepare radioactive N-succinimidyl-3- iodobenzoate (S125IB). TQNB was radioiodinated using Chloramine-T to obtain radioactive iodo-3-quinuclidinyl benzilate (125IQNB). Both S125IB and 125IQNB showed good stability at room temperature in the dark.
Authors:J. Wu, H. Xing, D. Tang, Y. Gao, X. Yin, Q. Du, X. Jiang and D. Yang
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.
Authors:Y. Wang, M. Xu, G. Yin, L. Tao, D. Wang and X. Ye
Although significant progress has been made on
-mediated wheat transformation, the current methodologies use immature embryos as recipient tissues, a process which is labor intensive, time consuming and expensive. In this study, we have managed to develop an
-based transformation scheme using explants derived from mature embryos. Based on transient expression of
-glucuronidase (GUS) marker, mature embryo halves prepared from freshly imbibed seeds were generally most susceptible to
-mediated T-DNA transfer. According to the results of callus induction and shoot production, Yumai 66 and Lunxuan 208 showed higher selection and regeneration efficiency than Bobwhite. In line with this finding, fertile T
transgenic plants were most readily obtained for both spring and winter wheat when mature embryo halves were used for co-inoculation by
cells. The presence of the antibiotic selection marker (
, encoding neomycin phosphotransferase II) in the T
plants was revealed by both genomic PCR amplification and the enzyme-linked immunosorbent assay (ELISA). Additional analysis showed that the transgene was stably inherited from the two different generations and segregated normally among the T
progenies. Further development along this line will raise the efficiency of wheat transformation and increase the use of this approach in the molecular breeding of wheat crop.
Authors:Z. Xiao, D. Liu, C. Wang, Z. Cao, X. Zhan, Z. Yin, Q. Chen, H. Liu, F. Xu and L. Sun
The effect of mechanical alloying on Zn-Sb alloy system is investigated with X-ray diffraction (XRD), laser grain size analysis
and differential scanning calorimetry (DSC) respectively. The results of laser particle size analysis shows that the particle
size decreases with increasing of the grinding time between 0 and 24 h. XRD and DSC results indicate that longer the grinding
time of Zn-Sb is, the more content of Zn4Sb3 become in the product in this process.