In order to extend the detection range of super ̄sensitive DNA damage responded yeast HUG1 ̄yEGFP biosensor which was constructed by our laboratory, and to accumulate more relevant data for practical application, 26 kinds of chemicals which were widely distributed in the environment and human lives were detected and 8 kinds of genotoxic compounds were screened out. Compared with three existed microbiological whole ̄cell sensing sys ̄ tems, the detection results in this study matched over 50% of the data from Ames test and SOS colorimetric test 第 1 期 汤花梅等:应用超敏感酵母 HUG1 ̄yEGFP 生物传感器筛选基因毒性化合物 195 based on bacterial cell, and over 85% of the data from the GSA test based on yeast cell. The differences of the re ̄ sults between the test systems based on eukaryotic yeast cell and prokaryotic bacteria cells reflected the different mechanisms of stress resistance. In this study, three kinds of genotoxicity ̄positive compounds, mancozeb, malachite green and acrylamide which were reported as potential carcinogens, were specifically detected by super ̄sensitive yeast HUG1 ̄yEGFP biosensor. The results of the study indicated that super ̄sensitive yeast HUG1 ̄yEGFP biosen ̄ sor can be used to effectively detect genotoxic compounds which were related to environmental pollution. There ̄ fore, they are valuable in environmental health risk assessment for chemical pollutant as a complementary method for other existed detection systems.

To investigate the sample preparation conditions of Cryo?scanning electron microscopy ( Cryo?SEM ) for Haematococcus pluvialis, we compared two sample fixing methods and four sublimation times. The agar cultures were directly pasted on the sample stub by conductive glue, while the liquid cultures were dropped on the filter papers which had been pasted on the stub in advance. Then the samples were sublimated at -90℃ for 2 min, 10 min, 20 min and 30 min respectively. It was found that both of the two sample fixing methods could receive good Cryo?SEM images. The method using filter paper was better. For Haematococcus pluvialis cells, being sublimated at -90 ℃ for 2 min was enough. However, the prolonged sublimation time ( up to 30 min) would not cause damages to the cell surface structures.

相对于动物和微生物而言,流式细胞术在植物科学上的应用会因植物组织与细胞(如细胞壁、中央液泡、特殊细胞器等)的特殊结构以及次生代谢产物等特殊成分,造成样品在前期处理、染色及测试等方面的困难,甚至导致检测失败或结果不准确.笔者在长期运用流式细胞仪测试工作中,积累了大量的植物样本检测经验,并参考国内外相关文献,总结出从植物取材、样品制备到植物细胞核DNA流式检测的方法和技巧,可为植物科学研究者及从事流式细胞检测的技术人员提供实验参考.

To preserve important biological structures and obtain satisfying images,it is important to select an appropriate method for the drying of biological samples.The drying method can be selected according to the characteristics of biological samples,the requirements of scanning electron microscopic observation and the equipment condition.To acquire the general principles for the selection of drying methods,the related Chinese literature in the VIP Chinese journal database,the China Knowledge Network and other well-known Chinese core periodical databases were search.A total of 122 related papers since 2001 were classified according to the types of biological samples and the drying methods.Five of the most commonly used drying methods are the natural drying method,the bake-drying method,the critical point drying method,the tert-butyl alcohol vacuum-drying method and the freeze-drying method.The applications,effects,advantages and disadvantages of these drying methods in biological sample preparation process for scanning electron microscopic observation were analyzed and the appropriate drying methods for samples of different microorganisms,plants and animals were summarized.

In order to examine the prevalence of posttraumatic stress disorder(PTSD) and the developments of the symptoms among orphans aged 9 to 15 after Wenchuan earthquake,188 orphans and normal children completed the Children's impact of event scale in half-year and one year.The results indicate that the prevalence rate of probable PTSD among orphans was higher than that among normal children at the two time points.Moreover,orphans' scores on the intrusion symptom were significantly higher than that of the normal children at the two time points.The present study indicates that the orphans were more susceptible to PTSD than normal children,especially with a higher level of intrusive symptoms and a longer latency.

Objective: To test the situation of PTSD and self-concept of the orphans after earthquake and explore the relationship between PTSD and self-concept. Methods: Children's Revised Impact of Event Scale and Piers-Harris Children's Self-concept Scale were adopted to test 111 orphans after earthquake. The Correlation and Regression analysis were used to investigate the relationship between PTSD and self-concept. Results: 39.6% orphans were screened to have PTSD. 38 orphans of all had low self-concept(34.2%). Except Intellectual and School Status and Physical Appearance and Attributes, other factors of self-concept were negative related to PTSD. Moreover, Freedom from Anxiety (FRE) was a significant predictor of PTSD. Conclusion: Low score of FRE can predict PTSD and screen the level of self-concept in time after earthquake can to some extent guide the psychological aid for orphans.

Objective To investigate the relationship between executive function and earthquake-related posttraumatic stress symptoms of children.Methods Children's revised impact of event scale(CRIES)is used to evalulate children's posttraumatic stress symptoms in the study.Thirty children with high level of posttraumatic stress symptoms(CRIES total score≥30)and thirty children with low level of posttraumatic stress symptoms(CRIES total score<30)were chosen from 409 Wenchuan earthquake survived children.Thirty gender-,age-,and intelligence quotient(IQ)-matched children who did not experience the earthquake were chosen as controls.The executive function was tested for all children.Results The three groups did not statistically differ on digit updating reaction time,figure updating reaction time,digit shifting reaction time,figure shifting reaction time,digit rate of commission error,and figure rate of commission error(All P>0.05).Conclusions There was no relationship between executive function and post traumatic stress symptoms of children one year after Wenchuan Earthquake.

Objective: Introducing resilience into this study to investigate the mediating role of self-esteem in the peer relationships and mental health of the orphans in Sichuan Earthquake. Methods: 401 children including the orphans in Sichuan Earthquake and three control groups were surveyed with questionnaires including Self-esteem Scale and Peer Nomination Questionnaire and Chinese Mental Health Inventory. Results: There was significant group difference in Self-esteem, and the Rizhao control group had higher score than the other groups. The orphans in earthquake had more peer acceptance than the other groups. There was no difference between children in Sichuan and Rizhao. The mental health and peer relationships were mediated by self-esteem of the orphans in earthquake, who paid more attention to peer acceptance to influence self-denial that had a negative connection with mental health. Conclusion: The important effect of self-esteem in peer relationships and mental health was supported by SEM in this study.