Physical property measurement of therapeutic carbon ion beam in the shallow-seated tumor therapy terminal at HIRFL

For the first time the physical properties of therapeutic carbon-ion beam supplied by, the shallow-seated tumor therapy terminal at the Heavy Ion Research Facility in Lanzhou (HIRFL) are measured. For a 80.55MeV/u C-12 ion beam delivered to the therapy terminal, the homogeneity of irradiation fields is 73.48%, when the beam intensity varied in the range of 0.001-0.1nA (i.e. 1 X 10(6) - 1 X 10(8) particles per second). The stability of the beam intensity within a few minutes is estimated to be 80.87%. The depth-dose distribution of the beam at the isocenter of the therapy facility is measured, and the position of the high-dose Bragg peak is found to be located at the water-equivalent depth of 13.866mm. Based on the relationship between beam energy and Bragg peak position, the corresponding beam energy at the isocenter of the therapy terminal is evaluated to be 71.71MeV/u for the original 80.55MeV/u C-12 ion beam, which consisted basically with calculation. The readout of the previously-used air-free ionization chamber regarding absorbed dose is calibrated as well in this experiment. The results indicate that the performance of the therapy facility should be optimized further to meet the requirements of clinical trial.

Schilancidilactones A and B: two novel tetranortriterpenoids with an unprecedented skeleton from Schisandra lancifolia

Schilancidilactones A (1) and B (2). two novel tetranortriterpenoids possessing an unprecedented skeleton, have been isolated from the stems of Schisandra lancifolia. Their structures were elucidated on the basis of extensive spectroscopic analysis. The r

Lignans with Anti-HIV Activity from Schisandra propinqua var. sinensis

Fourteen new lignans, tiegusanins A-N (1-14), together with 13 known compounds were isolated from the aerial parts of Schisandra propinqua var. sinensis. The structures and absolute configurations of 1-13 were established using a combination of spectrosco

Anti-HIV Activities of the Compounds Isolated from Polygonum cuspidatum and Polygonum multiflorum

The 70% EtOH extract of Polygonum cuspidatum showed inhibitory action against HIV-1-induced syncytium formation at non-cytotoxic concentrations in vitro with a 50% effective concentration (EC50) of 13.94 +/- 3.41 mu g/mL. Through bioactivity-guided fractionation, 20 phenolic compounds, including eight stilbenoids, were isolated from the roots of Polygonum cuspidatum, and their anti-HIV-1 activities were evaluated. Results showed that compounds 1, 13, 14, and 16 demonstrated fairly strong antiviral activity against HIV-1-induced cytopathic effects in C8166 lymphocytes at non-cytotoxic concentrations, with EC50 values of 4.37 +/- 1.96 mu g/mL, 19.97 +/- 5.09, 14.4 +/- 1.34 mu g/mL, and 11.29 +/- 6.26 mu g/mL and therapeutic index (TI) values of 8.12, > 10.02, > 13.89, and > 17.71, respectively. Other compounds showed either weak or no effects. Compound 6 also showed weak inhibition (153.42 +/- 19.25 mu g/mL); however, it possesses very good water solubility and showed almost no cytotoxicity (> 2000 mu g/mL), therefore achieving a fairly good TI (13.04). The activities of the two compounds (3 and 18) from Polygonum multiflorum were also assayed. The relationship between molecular structures and their bioactivities was also discussed.

Chemical Constituents from the Leaves and Stems of Schisandra lancifolia

A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3-5) and nine known phenolics (6-14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1-2, 6-7, and 9-11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the range of 3.0-99.0 mu g/ml. Compound 12 was not bioactive in this assay with EC50 more than 200 mu g/ml.

Threatened fishes of the world: Plesiomyzon baotingensis (Zheng & Chen, 1980) (Cypriniformes: Balitoridae)

We are grateful to all the voluntary donors of DNA samples in this study. We thank Hui Zhang and Yan-jiao Li for their technical help. We also thank Dr. Darren Curnoe for his critical reading of the manuscript. This study was supported by grants from the National 973 project of China (2007CB947701,2007CB815705), the Chinese Academy of Sciences (KSCX1YW-R-34, Westlight Doctoral Program), the National Natural Science Foundation of China (30525028, 30700445, 30630013 and 30771181), and the Natural Science Foundation of Yunnan Province of China (2007C100M, 2009CD107).

Chemical Constituents from the Leaves and Stems of Schisandra lancifolia

A new nortriterpenoid, 20-hydroxymicrandilactone D (1) and a novel lignan glycoside, lancilignanside A (2) were isolated from leaves and stems of Schisandra lancifolia, together with three known nortriterpenoids (3—5) and nine known phenolics (6—14). The structures of new compounds 1 and 2 were determined by detailed analysis of their 1D and 2D NMR spectra, and chemical evidences. In addition, compounds 1—2, 6—7, and 9—11 showed anti-human immunodeficiency virus (HIV)-1 activities with 50% effective concentration (EC50) in the range of 3.0—99.0m g/ml. Compound 12 was not bioactive in this assay with EC50 more than 200m g/ml.

Quasi-Elastic Scattering of C-16 from C-12 at 47.5 MeV/Nucleon

Differential cross sections for the quasi-elastic scattering of C-16 at 47.5 MeV/nucleon from C-12 target are measured. Coupled-channels calculations are carried out and the optical potential parameters are obtained by fitting the experimental angular distribution.

A pilot experiment for mass measurement at CSRe

A pilot experiment of mass measurement was performed at CSRe with the method of isochronous mass spectrometry. The secondary fragments produced via RIBLL2 with the primary beam of 400 MeV/u, Ar-36 delivered by CSRm were injected into CSRe. The revolution periods of the stored ions, which depend on the mass-to-charge ratios of the stored ions, were measured with a time-of-flight detector system. The results show that the mass resolution around 8 x 10(-6) for Delta m/m is achieved.

Characteristics of a 4-fold segmented clover detectore

Four high-purity germanium 4-fold segmented Clover detectors have been applied in the experiment of neutron-rich nucleus N-21. The performance of those, four Clovers have been tested with radioactive sources and in-beam experiments and the main results including energy resolution, peak-to-total ratios, the variation of the hit pattern distribution in difficult crystals of one Clover detector with the energy of gamma ray, and absolute full energy peak detection efficiency curve, were presented.

The beta decay of N-21

The beta-delayed neutron and gamma energy spectra taken from the decay of neutron-rich nucleus N-21 were measured by using the beta - gamma and beta - n coincidence detection method. Thirteen new neutron groups ranging from 0.28MeV to 4.98 MeV and with a total branching ratio of 88.7 +/- 4.2% were observed and presented. One gamma transition with an energy of 1222 keV emitted from the excited state of O-21, and four gamma transitions with energies of 1674, 2397, 2780, and 3175 keV emitted from the excited states of O-20 were identified in the 3 decay chain of N-21. The beta decay half-life for N-21 is determined to be 82.9 +/- 1.9 ms. The uncertainty of half-life is much smaller than the previous result.

丰中子奇异核17B的实验研究

在兰州重离子加速器国家实验室(HIRFL)放射性次级束流线(RIBLL)上，用束流透射法测量了丰中子奇异核17B与C靶反应的总截面.假定17B具有15B(核芯)＋2n结构，采用Gauss＋HO形式的密度分布和零力程Glauber模型进行计算的结果可以很好地拟合实验数据，并得出17B的密度分布有一个很大的弥散，表明17B是双中子晕核.