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- Author or Editor: Dong-Hui Yang x
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Abstract
According to the definition of reliability-based citation impact factor (R-impact factor) proposed by KUO & RUPE and the cumulative citation age distribution model, a mathematical expression of the relationship between R-impact factor and impact factor is established in this paper. By simulation of the change processes of the R-impact factor and impact factor in the manipulation process of the impact factor, it is found that the effect of manipulation can be partly corrected by the R-impact factor in some cases. Based on the Journal Citation Report database, impact factors of 4 normal journals and 4 manipulated journals were collected. The journals’ R-impact factors and self-cited rates in the previous two years were calculated for each year during the period 2000 to 2007, and various characteristics influenced by the manipulation were analyzed. We find that the R-impact factor has greater fairness than the impact factor for journals with relatively short cited half-lives. Finally, some issues about using the R-impact factor as a measure for evaluating scientific journals are discussed.
Abstract
In boron neutron capture therapy (BNCT), the proportion of the fast neutron in the tumor (PFN) must be no more than 3%. If a D–T neutron generator is used as a thermal neutron source in BNCT, the moderator must be optimized to decrease the PFN. Based on the analysis of the theory, water, heavy water, polythene, graphite, lead, and tungsten were used to moderate the fast neutrons. If the three-layer material is composed of a 4 cm thickness layer of tungsten, a 13 cm thickness layer of lead, and a 23 cm thickness layer of heavy water, its thermalization efficiency (TE) is highest, which is increased by 191.5% than the maximum TE moderated by single-layer materials and by 19.3% than the maximum TE moderated by double-layer materials.
Abstract
The aim of this study was to examine the radioiodinating condition of betulinic acid and understand the possibility of 131I–betulinic acid (131I–BA) as a potential tumor radiotherapy agent through in vitro uptake and in vivo biodistribution studies 131I–BA was prepared by the reaction of betulinic acid with Na131I in the presence of hydrogen peroxide, and then purified by HPLC. The labeling yield was about 80%, and the radiochemical purity was greater than 95%. 131I–BA was found to be stable at 4 °C in saline containing 1% ethanol. In vitro studies showed that 131I–betulinic acid accumulated in the cancer cell lines (BEL-7402 and NCI-H446) in comparison with free 131I−. In vivo biodistribution study in KM mice bearing HepA tumor showed that 131I–BA stayed longer time in tumors than free 131I−. A significant differences were seen in tumor/muscle ratio at 4 h postinjection between 131I–BA and free 131I−. In vivo and in vitro studies showed the higher fraction of 131I–BA can be utilized for therapy and a higher dose will be delivered per targeting event. 131I–BA is a promising radiopharmaceutical in nuclear medicine, especially for hepatocellular tumor targeted radionuclide brachytherapy.
Abstract
23-Hydroxybetulinic acid (23-HBA) is the efficient antitumor compound extracted from the roots of a Chinese Medicinal Herb, Pulsatilla chinensis (Bge) Regel. To evaluate the effect of radioiodination on cytotoxicity, 23-HBA was radioiodinated with 125I. 125I-23-HBA could be prepared in high yields and good radiochemical purity and was characterized using reverse phase HPLC. In ICR mice bearing Liver Cancer HepA tumor, 125I-23-HBA showed a tumor uptake of 2.1% ID/g at 2 h p.i. and 0.15% ID/g at 48 h p.i on i.v. injection. When injected intratumorally, greater tumor uptake and retention was observed (20% ID/g at 2 h p.i. and 4.6% ID/g at 48 h p.i. respectively).
