Measurement of neutron-removal cross section of neutron-rich nucleus He-8 by using the transmission method

The neutron-rich nucleus He-8 is selected by RIBLL from the breakup of 50MeV/u C-13 on be target at HIRFL. The 2n-removal and 4n-removal cross section of He-8 was measured by using the transmission method. The point that He-4 is He-8 core can be reduced from the experiment data via the Ogawa's theory.

8种花卉植物种子萌发对石油烃污染土壤的响应

石油污染土壤的植物修复技术以其处理成本低、无二次污染、自然美观等特点,正逐步成为石油污染治理研究的一个重要方向.而修复植物的筛选是植物修复技术首要解决的问题.为此以花卉植物种子发芽作为生态指示,探讨其对石油污染土壤的反应,设置了4组不同浓度的石油污染土壤处理,对8种供试花卉植物的种子发芽率进行了盆栽实验观测.结果表明:不同的花卉种子对石油污染表现出不同的耐受性,与清洁对照土壤相比,大多数花卉种子的萌发都明显受到石油烃污染的抑制,其中受石油烃污染影响最严重的是二月兰(Orychophragmus violace).相比之下,4组浓度处理下硫华菊(Cosmos sulphureus)和孔雀草(Tagetes patula)具有较高的耐受性和种子发芽率,因而具有修复石油污染土壤的潜力.

Determination of urinary oxidative DNA damage marker 8-hydroxy-2 '-deoxyguanosine and the association with cigarette smoking

8-hydroxy-2'-deoxyguanosine (8OHdG) has been widely used as a biomarker of oxidative DNA damage in both animal models and human studies. To evaluate the effect of cigarette smoking on oxidative stress, we studied the levels of urinary 8OHdG from smokers and non-smokers and investigated the association with cigarette smoking. The urinary 8OHdG concentrations were determinated by capillary electrophoresis with end-column amprometric detection (CE-AD) after a single-step solid phase extraction (SPE), and then quantitatively expressed as a function of creatinine excretion. To increase the concentration sensitivity, a dynamic pH junction was used and the focusing effect was obvious when using 30 mM phosphate (pH 6.50) as sample matrix. The limit of detection is 4.3 nM (signal-to-noise ratio S/N = 3). The relative standard deviation (R.S.D.) was 1.1% for peak current, and 2.3% for migration time. Based on the selected CE-AD method, it was found that the mean value of urinary 8OHdG levels in the smokers significantly higher than that in non-smokers (31.4 +/- 18.9 nM versus 14.4 +/- 7.6 nM, P = 0.0004; 23.5 +/- 21.3 mug g(-1) creatinine versus 12.6 +/- 13.2 mug g(-1) creatinine, P = 0.028). (C) 2004 Elsevier B.V. All rights reserved.

Study of urinary 8-hydroxydeoxyguanosine as a biomarker of oxidative DNA damage in diabetic nephropathy patients

Increased oxidative stress induced by hyperglycemia may contribute to the pathogenesis of diabetic complications. Urinary 8-hydroxydeoxyguanosine (8-OHdG) has been reported to serve as a sensitive biomarker of oxidative DNA damage and also of oxidative stress. This article studied oxidative DNA damage in patients with diabetic nephropathy and in healthy control subjects by urinary 8-OHdG evaluations. Contents of 8-OHdG in urine were analyzed by capillary electrophoresis with end-column amperometric detection (CE-AD) after a single-step solid-phase extraction (SPE). Levels of urinary 8-OHdG in diabetic nephropathy patients with macroalbuminuria was significant higher than in control subjects (5.72 +/- 6.89 mumol/mol creatinine versus 2.33 +/- 2.83 mumol/mol creatinine, P = 0.018). A significant difference of 24 h urinary 8-OHdG excretions exists between the patients with macroalbuminuria and the patients with nonnoalbuminuria (19.2 +/- 16.8 mug/24 h versus 8.1 +/- 1.7 mug/24 h, P = 0.015). There was a positive correlation between urinary excretion of 8-OHdG and glycosylated hemoglobin (HbA(1)c) (r = 0.287, P = 0.022). A weak correlation exists between the levels of 8-OHdG and triglyceride (r = 0.230, P = 0.074). However, the urinary 8-OHdG contents are not correlated with blood pressure and total cholesterol. The increased excretion of urinary 8-OHdG is seen as indicating an increased systemic level of oxidative DNA damage in diabetic nephropathy patients. (C) 2004 Elsevier B.V. All rights reserved.

Synthesis of monomethylated dioscin derivatives and their antitumor activities

All possible eight monomethylated dioscin derivatives (1-8) were synthesized. Their inhibitory activities against P388 and A-549 cells were determined, and the results indicate that six of the eight hydroxyls of dioscin are the 'key polar groupings' for tumor inhibitory activities. (C) 2002 Elsevier Science Ltd. All rights reserved.