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111.
A new 4alpha-aryltetralin-type lignan called burseranin (1) and a known analogous lignan picropolygamain (2) were isolated along with known triterpenes, lupeol and epi-lupeol from the methanol extract of stems of Bursera graveolens, which showed a remarkable inhibitory activity against human HT1080 fibrosarcoma cells. The whole structure of 1 was established based on combined spectral studies and the absolute structure for 2 was first confirmed by CD spectral evidence. In addition, cytotoxic activities of the stem (methanol) extract and its components are evaluated in this paper.  相似文献   
112.
We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed, and an upper limit of is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.  相似文献   
113.
Two new antineoplastic diterpenes from Taxus mairei   总被引:2,自引:0,他引:2  
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114.
The purpose of this study is to evaluate the clinical efficacy of the liver SPECT about detectability of SOLs (space occupying lesion). The images were interpreted with the planar scintigram (PS) only and combination of PS and SPECT (single photon emission computed tomography) by 11 physicians. Changes of false positive and false negative rate were calculated to evaluate the influence of the diffuse parenchymal liver disease and the localization of the SOLs. Addition of SPECT to PS in the cases who are suspected SOLs is effective in right hepatic lobe (right anterior and posterior segment) to detect the SOLs, but not effective in left lateral segment. Addition of SPECT to PS in the cases with diffuse parenchymal liver disease and SOLs increases the false positive rate.  相似文献   
115.
Two new stilbenoids, vateriaphenols A (1) and B (2), were isolated from the stem bark of Vateria indica along with known 10 stilbenoids (3-12) and bergenin (13). The structures of isolates were established based on spectroscopic analysis. The structures of vateriaphenols A and B were characterized as an octamer and a tetramer of resveratrol, respectively. The spectral properties of the highly condensed vateriaphenol A were also discussed.  相似文献   
116.
Prospective study of bone scintigraphy was performed on 414 patients with breast carcinoma and 88 patients with prostate carcinoma. In 468 of them, confirmative diagnoses of bone, whether metastasis was existent or not, were made after the observations over a year. Finally, the incidences of bone metastasis were 11 percent for breast carcinoma and 54 percent for prostate carcinoma respectively. The efficacy of preoperative bone scintigraphy in breast carcinoma was comparable to that in prostate carcinoma with regard to improvement of predictive probability of bone metastasis: raising up the probability in the positive cases and bringing down in the negative cases.  相似文献   
117.
Protons in naphthalene and p-terphenyl doped with pentacene have been polarized up to 32% and 18%, respectively, at liquid nitrogen temperature in a magnetic field of 0.3 T by means of microwave-induced optical nuclear polarization. The polarization was measured by nuclear magnetic resonance as well as by the neutron transmission method. The relaxation time of the proton polarization at 0.0007 T and 77 K was found to be almost 3 h and the polarization enhancement reached a record value of 8x10(4). The usefulness of the method in many areas of physics and chemistry is discussed.  相似文献   
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