花岗岩对硒的吸附研究

本文研究了在模拟地下水介质中花岗岩对硒的吸附、解吸规律。实验结果表明,在本实验条件下花岗岩对硒的吸附和解吸均服从 Freundlich 吸附等温方程;在还原剂(Fe 粉和腐植酸)存在下,花岗岩对硒的吸附量有所增大;在 pH 为4左右硒吸附量最大;硒吸附量还随花岗岩粒径减小即比表面积增大而增大,说明吸附主要发生在固相表面。     

胃癌组织中c—myc基因表达

以＾３２Ｐ－ｃ－ｍｙｃ－ｃＤＮＡ和＾３２Ｐ－ｃ－ｍｙｃ－ＤＮＡ为探针，采用核酸杂交方法研究２４例胃癌、６例胃溃疡正常胃组织ｃ－ｍｙｃ的表达。ＲＮＡ－ＤＮＡ ｄｏｔ证实，７例胃髓样癌、３例粘液癌和１４例腺癌分别有３、１和１例ｃ－ｍｙｃ高表达。Ｎｏｒｔｈｅｒｎ ｂｌｏｔ表明，胃癌组织ｃ－ｍｙｃ ｍＲＮＡ分子量同对照组无差异；Ｓｏｕｔｈｅｒｎ ｂｌｏｔ未发现ｃ－ｍｙｃ扩增与重排。指明胃癌组织ｃ－ｍｙｃ高     

我国高汞低硒地区母子体头发中汞和硒的相关性研究

用仪器中子活化法研究了我国高汞低硒地区第二松花江流域２９对母子体头发中汞、硒水平及其相关性，结果指出，子体中的汞含量与母体相当，而子体中的硒大多比母体的高，硒与汞的摩尔比值亦是子体比母体的高４０％左右，这表明子体能从母体中摄取较多的硒，以抵御汞的毒性，这种“自保护”机制对母体中的胎儿发育起着极为重要的作用。     

流体硒的同步辐射结构研究

液体硒是典型的半导体，在高温高压下临界点邻近发生半导体金属—绝缘体（SC—M—I）转变。为了研究高温高压下流体硒在SC—M—I转变过程中结构的变化，利用SPring—8的同步辐射光对高温高压下流体硒进行了能量色散X射线衍射测量和小角X射线散射测量。测量范围包括液态区、超临界区和稠密气态区域。在衍射实验中，我们获得了精确的结构因子S(k)和偶分布函数g(r)。结果证实了在金属液体区域中流体硒仍保持两配位的链结构和共价键轻微地收缩，还发现随着流体硒的金属特性的增强g(r)的第一极小值发生了显著的增加，即Se链的链问相互作用增强。小角散射结果表明在临界密度邻近，密度的涨落显著，相干长度存在极大值。这些结果表明Se链的共价键的特性和Se链问的相互作用是理解流体硒中的SC—M—I转变的机制的关键。     

海生鱼机体中硒毒性水平的PIXE研究

使用质子激发X荧光(PIXE)分析海生鱼机体表皮、肝、肌肉、鳃等组织中硒元素含量,同时测定肝中谷胱甘肽过氧化物酶和细胞色素水平。结果表明,硒对鱼体的半致死剂量为0.29μg·g~(-1),在致死剂量作用下,死亡鱼体中谷胱甘肽过氧化物酶水平与注入剂量无关,而幸存鱼的酶水平和硒浓度逐步恢复到正常水平。肌肉组织中存在着较低的硒吸收,肝和鳃中硒浓度的生物半衰期几乎一致,而皮肤中硒浓度的半衰期是肝和鳃中的2.5倍。     

硒对辐射诱发HPRT基因突变的保护作用

本研究应用细胞质分裂阻滞法,检测了＾６０Ｃｏγ射线对人胚肺细胞ＨＰＲＴ基因突变的损伤效应,分析了硒对γ射一照射所致细胞ＨＰＲＴ基因突变损伤效应的保护作用,人胚肺细胞经不同剂量＾６０Ｃｏγ射线照射后,ＨＰＲＴ基因突变变异子数,在各剂量组与对照组射组相比均明显增加。细胞ＨＰＲＴ基因突变变异子数随着剂量增加而逐渐增加,两者呈良好的线性关系。人胚肺细胞与１＊１０＾－ｍｏｌ／Ｌ硒作用２４ｈ后接受照射,细胞Ｈ     

79Se-AMS示踪研究亚毒性剂量亚硒酸钠摄入的硒代谢

长寿命放射性核素79Se的半衰期长达2．8×10^5a，其放射性比活度（单个原子的活度）约1×10^-14Bq。79Se衰变时仅放射出能量为150．7keY纯β射线，对生物组织甚至细胞的辐射损伤远小于75Se，而79Se的加速器质谱测量方法（795e—AMS）具有灵敏度高、相对测量准确性高以及测量精度高等特点，因而适合于长周期、无损伤的生物示踪研究。     

188Re-labeled McAb 3H11 used as preventive for the peritoneal micrometasis of gastric cancer

In advancing gastric cancer,especial1y when the serous is invaded,the p1antation of cancer cells in peritoneal is common and it affectspatients' survival time severe1y. Based on successfully labeledMcAb (monoclonal antibody) 3H11 with ¹⁸⁸Re,we investigated the effect of RIT (Radioimmuno-Therapy) with¹⁸⁸Re-3Hll on preventing the peritoneal micrometastasis ofgastric cancer cells in nude mice to     

Effects of selenium and vitamin E deficiencies on level of leukotriene C4

A reduction in the glutatihion peroxidase(GSH-Px) activity of the blood and myocardium accompanied with an increase in the leukotriene C4(LTC4),free radicals and lipid peroxides(LPO) concentrations of the plasma and myocardium are found in Wistar rats fed with the low selenium(Se) and vitamin E(VE) grains from a Keshan disease(KD) endemic area for 11 weeks.The concentrations of LTC4,free radical and LPO were decreased in these rats and the GSH-Px activity is strengthened except the group supplemented with VE alone.Theses results suggest that the dietary deficiencies of Se and VE might take part in the occurrence and devepopment process of myocardial damage in KD and other ischemic and anoxic cardiomyopathy by affecting the activity of lipoxygenase in arachidonic acid metabolism and by cardiomyopathy by affecting the activity of lipoxygenased in arachidonic acid metabolism and by accelerating the synthesis of LTC4 owing to excessive free radicals and LPO.     

^188Re—labeled McAb 3H11 used as preventive for the peritoneal micrometasis of gastric cancer

In advancing gastric cancer, especially when the serous is invaded, the plantation of cancer cells in peritoneal is common and it affects patients' survival time severely. Based on successfully labeled McAb (monoclonal antibody) 3H11 with ~(188)Re, we investigated the effect of RIT (Radioimmuno-Therapy) with ~(188)Re-3H11 on preventing the peritoneal micrometastasis of gastric cancer cells in nude micc to increase the survival time. After 1×10~6 BGC-823 gastric cancer cells were injected into the peritoneal cavity of each mouse, 45BABL/C nude mice were divided into 9 groups. Each group received different doses of ~(188)Re-3H11 or ~(188)Re-IgG, or saline I.P.16 hours postoperation. The injected volume of each mouse was 1.0mL. The results showed that the survival time depended on the injected doses during 0 to 37 MBq. The survival time was 170±25.3d after 37MBq ~(188)Re-3H11 were treated. It was over 5 times more than that for the saline group and about 3 times more than that for 37 MBq ~(188)-Re IgG gro     

The relationship between irradiation induced dimensional change and the coefficient of thermal expansion: a modified Simmons relationship

In the 1960s, a theoretical relationship between the dimensional changes and the coefficient of thermal expansion of irradiated graphite was derived by J.H.W. Simmons. The theory was shown to be comparable with experimental observations at low irradiation doses, but shown to diverge at higher irradiation doses. However, various modified versions of this theory have been used as the foundation of design and life prediction calculations for graphite-moderated reactors.This paper re-examines the Simmons relationship, summarising its derivation and assumptions. The relationship was then modified to incorporate the high dose, high strain changes that were assumed to be represented in the changes in Young’s modulus with irradiation dose. By scrutinising the behaviour of finite element analyses, it was possible to use a modified Simmons relationship to predict the dimensional changes of an isotropic and anisotropic graphite to high irradiation doses.These issues are important to present high-temperature reactors (HTRs) as the life of HTR graphite components is dependent upon their dimensional change behaviour. A greater understanding of this behaviour will help in the selection and development of graphite materials.     

用PIXE技术分析山东省胃癌高,低发区饮水中的微量元素

介绍了用ＰＩＸＥ技术分析饮水中微量元素的方法，给出了山东省胃癌高发区栖霞县与低发区苍山县饮水中的微量元素谱。两地饮水中微量元素含量的检验显示，Ｔｉ，Ｖ，Ｃｕ，Ｆｅ和Ｆｒ等５种元素栖霞均显著高于苍山县。     

Clinical significance of combined determination of serum PG I ,PGⅡ and GAS for diagnosis of gastric cancer

To evaluate the clinical value of combined determination of serum PG I, PG Ⅱ and GAS for early diagnosis of gastric cancer, the serum levels of PG I, PG Ⅱ and GAS in 190 healthy controls and 129 patients with gastric disorders were measured by RIA. The 129 patients include 68 cases of gastric cancer. The results showed that the serum levels of PG I and PG I/PG Ⅱ ratio in gastric cancer patients were obviously lower than those in healthy controls, while comparing with controls, the serum GAS levels were significantly higher. The diagnostic accuracy of the determinations for gastric cancer was evaluated by receiver operating characteristic （ROC） curve analysis. The area under the curve （AUC） levels of serum PG I, PG I/PG Ⅱ ratio and GAS were 0.833, 0.842 and 0.851, respectively. As serum PG I or PG I/PG II ratio or GAS were combined, the sensitivity and specificity of determination for gastric cancer diagnosis were 94.2% and 73.4%, respectively. All these results indicated that the combined determination of serum PG I, PG Ⅱ and GAS levels may be used as a tool for primary screening of gastric cancer.     

Clinical significance of combined determination of serum PGⅠ, PGⅡ and GAS for diagnosis of gastric cancer

To evaluate the clinical value of combined determination of serum PG Ⅰ, PG Ⅱ and GAS for early diagnosis of gastric cancer, the serum levels of PG Ⅰ, PG Ⅱ and GAS in 190 healthy controls and 129 patients with gastric disorders were measured by RIA. The 129 patients include 68 cases of gastric cancer. The results showed that the serum levels of PG Ⅰ and PG Ⅰ/PG Ⅱ ratio in gastric cancer patients were obviously lower than those in healthy controls, while comparing with controls, the serum GAS levels were significantly higher. The diagnostic accuracy of the determinations for gastric cancer was evaluated by receiver operating characteristic (ROC) curve analysis. The area under the curve (AUC) levels of serum PG Ⅰ, PG Ⅰ/PG Ⅱ ratio and GAS were 0.833, 0.842 and 0.851, respectively. As serum PG Ⅰ or PG Ⅰ/PG Ⅱ ratio or GAS were combined, the sensitivity and specificity of determination for gastric cancer diagnosis were 94.2% and 73.4%, respectively. All these results indicated that the combined determination of serum PG Ⅰ, PG Ⅱ and GAS levels may be used as a tool for primary screening of gastric cancer.     

Clinical significance of combined determination of serum PGⅠ , PGⅡ and GAS for diagnosis of gastric cancer

1 Introduction In our country, gastric cancer is one of the most serious diseases threatening people health. Early di-agnosis is considered to be an effective method to de-crease the death ratio caused by gastric cancer. Today, however, effective early diagnosis method is still lacking. Our previous studies demonstrated that it was a helpful method for the early diagnosis of gastric cancer to determine the serum levels of pepsinogenⅠ(PGⅠ) and pepsinogenⅡ(PGⅡ).[1] Stemmermann and his coll…     

60Coγ射线对胃癌细胞STAT3表达的影响研究

为了探讨电离辐射对胃腺癌细胞中STAT3活性及定位的影响,首先利用Western Blot方法检测60Coγ射线照射后胃癌BGC-823细胞内STAT3蛋白含量及活性变化,随后提取60Coγ辐射前后BGC-823细胞核蛋白,检测细胞核内STAT3水平,最后利用免疫荧光染色进一步验证辐射前后STAT3在BGC-823细胞...