Quantum and variational monte-carlo interaction potentials for li2 (x1-sigma-g+)

Optimized trial functions are used in quantum Monte Carlo and variational Monte Carlo calculations of the Li₂(X ¹Σ⁺_g) potential curve. The trial functions used are a product of a Slater determinant of molecular orbitals multiplied by correlation functions of electron—nuclear and electron—electron separation. The parameters of the determinant and correlation functions are optimized simultaneously by reducing the deviations of the local energy E_L (E_L  Ψ⁻¹_THΨ_T, where Ψ_T denotes a trial function) over a fixed sample. At the equilibrium separation, the variational Monte Carlo and quantum Monte Carlo methods recover 68% and 98% of the correlation energy, respectively. At other points on the curves, these methods yield similar accuracies.

Trichosanthin suppresses the elevation of p38 MAPK, and Bcl-2 induced by HSV-1 infection in Vero cells

Trichosanthin (TCS) is a type I ribosome-inactivating protein (RIP) effective against HIV-1 and HSV-1 replication. The mechanism of its antiviral activity is not clear. Many believe that it is related to ribosome inactivation. Some RIPs and viral infectio

重离子诱导人舌鳞癌细胞凋亡和Bax/Bcl-2蛋白表达的变化

In order to investigate the effect of carbon ion irradiation on apoptosis and Bax/Bcl-2 expression inhuman tongue carcinoma cells, exponentially growing human tongue carcinoma cells (Tb) cultured in vitro were irradiated with 0, 0.5, 1.0, 2.0 or 4.0 Gy of 12C6+ ions respectively. Survival rate of irradiated cells at various doses were measured by MTT assay. The nucleus changes of apoptosis and necrosis of cells stained by Hochest/PI were observed through fluorescence microscope. The cell cycle changes were detected by flow cytometry (FCM). The expressions of Bax and Bcl-2 were detected by Western blot analysis. The results show that the viability of Tb cells decreases gradually with increment of irradiation doses of carbon ions. The proportions of apoptosis cells in the irradiated groups are significantly higher than those in the control group. There is a positive correlation between irradiation doses and retardation strength in G2 /M phase at 24 h after irradiation (P<0.05). And the expressions of Bax and bcl-2 are significantly up-regulated and down-regulated respectively by 12C6+ ion irradiation. It can be concluded from above that cell apoptosis induced by heavy ion with high-LET may be mediated through the Bax/Bcl-2 expression pathway. 探讨重离子辐照对人舌鳞癌Tb细胞的凋亡及Bax/Bcl-2蛋白表达的影响。采用0、0.5、1.0、2.0、4.0 Gy重离子束辐照人舌鳞癌 Tb 细胞，应用 MTT 法检测细胞存活，流式细胞技术检测细胞周期变化，Hoechst33258/PI 复染法观察 Tb 细胞凋亡形态，并采用 Western-blot 法检测 Bax/Bcl-2 蛋白表达情况。结果发现，Tb细胞经12C6+离子束辐照后存活率显著下降，呈剂量依赖性的生长抑制；Tb细胞呈现蓝色荧光浓集成团的凋亡形态，且凋亡比例随辐照剂量增加；G2/M 期细胞百分数随照射剂量增加而增加（P＜0.05） 。Western-blot结果显示 Bax 蛋白表达水平随辐照剂量逐渐上升，但在 4 Gy 组其表达不再增高，Bcl-2 蛋白在 1.0、2.0、4.0 Gy组随剂量增大呈下降趋势。以上结果提示重离子束辐照对 Tb 细胞有抑制作用，Bax/Bcl-2 蛋白表达是重离子治癌的机制之一。

重离子诱导人舌鳞癌细胞凋亡和Bax/Bcl-2蛋白表达的变化

探讨重离子辐照对人舌鳞癌Tb细胞的凋亡及Bax/Bcl-2蛋白表达的影响。采用0、0.5、1.0、2.0、4.0Gy重离子束辐照人舌鳞癌Tb细胞,应用MTT法检测细胞存活,流式细胞技术检测细胞周期变化,Hoechst 33258/PI复染法观察Tb细胞凋亡形态,并采用Western-blot法检测Bax/Bcl-2蛋白表达情况。结果发现,Tb细胞经12C6+离子束辐照后存活率显著下降,呈剂量依赖性的生长抑制;Tb细胞呈现蓝色荧光浓集成团的凋亡形态,且凋亡比例随辐照剂量增加;G2/M期细胞百分数随照射剂量增加而增加(P<0.05)。Western-blot结果显示Bax蛋白表达水平随辐照剂量逐渐上升,但在4Gy组其表达不再增高,Bcl-2蛋白在1.0、2.0、4.0Gy组随剂量增大呈下降趋势。以上结果提示重离子束辐照对Tb细胞有抑制作用,Bax/Bcl-2蛋白表达是重离子治癌的机制之一。

Study on the apoptosis and Bcl-2/Bax expression of human hepatoma SMMC-7721 cells after exposure to heavy-ion and X-ray irradiations

This study is aimed at observing the apoptosis and Bcl-2/Bax gene expression of mammalian cells following heavy-ion and X-ray irradiations. Exponentially growing human hepatoma SMMC-7721 cells cultured in vitro were irradiated with a C-12 ion beam of 50 MeV/u (corresponding to a LET value of 44.56 keV/mu m) from Heavy Ion Research Facility in Lanzhou (HIRFL) at doses varying from 0 to 3 Gy. The X-ray irradiation (8 MV) was performed in the therapy unit of the General Hospital of the Lanzhou Military Area. Survival fractions of irradiated cells at various doses were measured by means of MTT assay. Apoptotic cells after irradiation were analyzed with fluorescence microscope and flow cytometer (FCM). Immuno-histological assay were applied to detect the expression of Bcl-2/Bax genes in the irradiated cells. The survival fraction of SMMC-7721 cells decreased gradually (vs. control p<0.05) with increasing the dose of the carbon ion beam more obviously than X-ray irradiation, and the carbon ion irradiation efficiently induced cell apoptosis and significantly promoted the expression of Bax gene while Bcl-2 gene expression was restrained. High-LET heavy ion beam would induce cell apoptosis effectively than low-LET X-ray, and the apoptosis rate is correlated with the transcription of Bcl-2/Bax and the ratio of Bcl-2/Bax in human hepatoma SMMC-7721 cells after irradiation to heavy ion beam.