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1.
ＩＮＴＲＯＤＵＣＴＩＯＮＲｉｂｏｚｙｍｅｗａｓｆｉｒｓｔｄｅｓｃｒｉｂｅｄｂｙＣｅｃｈａｎｄＡｌｔｍａｎｉｎ 1 981 .ＴｈｉｓｆｏｒｍｏｆＲＮＡｈａｄｈｉｇｈｌｙｓｐｅｃｉｆｉｃｅｎｄｏｎｕｃｌｅａｓｅａｃｔｉｖｉｔｉｅｓｔｏＲＮＡ (Ｋｒｕｇｅｒｅｔａｌ.,1 982 ) .Ｒｉｂｏｚｙｍｅｓｈａｖｅｔｈｒｅｅｓｔｒｕｃｔｕｒｅｓ:ｈａｍｍｅｒｈｅａｄ ,ｈａｉｒｐｉｎａｎｄａｘｅｒｉｂｏｚｙｍｅｓ.Ａｍｏｎｇｔｈｅｍ ,ｔｈｅｈａｍｍｅｒｈｅａｄｒｉｂｏｚｙｍｅｈａｓａｓｉｍｐｌｅｒｓｅｃｏｎｄａｒｙｓｔｒｕｃ…  相似文献   

2.
INTRODUCTION Chronic infection by hepatitis B virus (HBV) isassociated with a high risk of liver cirrhosis and pri-mary hepatocellular carcinoma (HCC). It remains animportant global health problem with over 350 mil-lion chronic HBV carriers worldwide. Among thesechronic carriers, about one million people die ofHBV-associated liver failure or HCC annually (Kaoand Chen, 2002). Although chronically infected pa-tients have been treated with interferons and nucleo-side analogs, th…  相似文献   

3.
Two stable transformed lines containing antisense LeERT1 or LeERT2 sequences and their hybridized line were investigated to determine the effect of LeERT1 and LeERT2 specificity in the ethylene receptor family in tomato （Lycopersicon esculenturn Mill.） on ethylene signaling. The transgenic line alel containing antisense LeER T1 displayed shorter length of seedling grown in the dark and adult plant in the light, severe epinastic petiole, and accelerated abscission of petiole explant and senescence of flower explant, compared with its wild type B 1. The transgenic line ale2 containing antisense LeERT2 also exhibited shorter hypocotyls and slightly accelerated abscission. The phenotypes of cross line dale of LeERT1 and LeERT2 were close to alel in many aspects. These results suggested that LeERT1 probably plays a relatively important role in ethylene signaling of tomato growth and development.  相似文献   

4.
In this experiment we studied the effect of goal setting on the strategies used to perform a block design task called SAMUEL. SAMUEL can measure many indicators, which are then combined to determine the strategies used by participants when solving SAMUEL problems. Two experimental groups were created: one group was given an explicit, difficult goal and the other was not given a goal. The two groups were comparable in their average visual–spatial ability. The results indicated no goal effect on the strategies, defined in terms of the combined indicators. However, the goal did have an effect on some of the indicators taken alone (total problem-solving time, total viewing time, and model-viewing frequency) but this was true only for subjects with a low cognitive ability. These findings demonstrate that setting a goal can have an effect on some strategy indexes used to assess performance on a visual-intelligence design task. This research has implications for defining intelligence-test instructions and educational requirements in school.  相似文献   

5.
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6.
目的:探讨中药组方综合治疗化脓性阑尾炎术后腹腔残余脓肿的临床治疗护理效果.方法:将62例化脓性阑尾炎术后腹腔残余脓肿术后患者随机分成两组,实验组采用西药辅以中药组方综合治疗方案,对照组采用西医保守治疗方案,分别观察两组的治疗护理效果.结果:实验组总有效率为100%,其中治愈率为95.0%,显效率为4.0%,有效率为1.0%.对照组总有效率为90.0%,其中治愈率为52.0%,显效率为10.0%,有效率为28.0%,无效率为10.0%,两组比较差异显著(P0.01).结论:中药组方综合治疗化脓性阑尾炎术后腹腔残余脓肿疗效显著,不良反应与并发症少,治疗效果好于单纯用西药治疗,提示精心的观察及护理是提高治疗效果的重要保证.  相似文献   

7.
Objective: To study the roles of different truncated hepatitis C virus (HCV) core proteins (CORE) in the pathogenesis of HCV persistent infection and hepatocellular carcinoma (HCC) and to assess intracellular localization in transiently transfected cells. Methods: Seven truncated CORE-GFP (green fluorescent protein) fusion protein expression plasmids were constructed,which contained HCV CORE sequences derived from tumor tissues (BT) and non-tumor tissues (BNT) from one patient infected with HCV. Amino acid (aa) lengths were BT: 1-172 aa, 1-126 aa, 1-58 aa, 59-126 aa, 127-172 aa; BNT: 1-172 aa and C191:1-172 aa respectively. Subcellular localization of CORE-GFP was analyzed by con-focal laser scanning microscope. Apoptosis and necrosis were quantified by flow cytometry. Results: Different truncated CORE-GFP localized mainly in the cytoplasm, but nuclear staining was also observed. HCV CORE could induce apoptosis and necrosis, and different truncated COREs could induce cell apoptosis and necrosis at different levels. Among the same length 1-172 aa of BT, BNT and C191, the cell apoptosis and necrosis percentage of BT is highest, and C191 is the lowest (BT＞BNT＞C191). To the different fragment COREs of BT,N-terminal of CORE induced apoptosis and necrosis higher, compared with that of C-terminal (1-172 aa＞1-126 aa＞1-58aa＞ 127-172 aa＞59-126 aa). Conclusion: These results suggest HCV CORE could induce apoptosis and necrosis of cells, which might play an important role in the pathogenesis of HCV persistent infection and HCC and the different CORE domains of different HCV quasi-species might have some difference in their pathogenesis.  相似文献   

8.
INTRODUCTION Entomopathogenic nematodes of the generaSteinernema and Heterorhabditis have been used tocontrol a wide range of agriculturally important insectpests (Kaya and Gaugler, 1993). The mechanism bywhich these nematodes are able to infect and repro-duce in the insect host involves a mutual relationshipbetween the nematode and the symbiotic bacteria,Xenorhabdus spp. and Photorhabdus spp. (Akhurstand Dunphy, 1993; Forst and Nealson, 1996). Poinarand Thomas (1966) established tha…  相似文献   

9.
目的观察高光功率红光照射加药物治疗带状疱疹的疗效。方法162例患者随机分成2组,治疗组采用药物加红光照射,对照组单独药物治疗。结果治疗2周后2组总有效率分别为90%和67%,差异有统计学意义。结论药物联合红光照射治疗带状疱疹起效快,疗效好,可显著缩短病程。  相似文献   

10.
目的:探求适用于低收入人群十二指肠溃疡(DU)患者经济、有效的治疗方案。方法:将156例活动性DU患者随机分成2组,治疗组82例,用呋喃唑酮200mg、乐得胃2片每天三次,法莫替丁20mg早晚各一次治疗2周:对照组74例,用羟氨苄青霉素500mg、胶体果胶铋100mg(以Bi计)每天三次,奥美拉唑40mg每天早晨一次治疗2周,疗程结束时复查胃镜观察溃疡愈合情况,疗程结束后4周取胃粘膜检查幽门螺杆菌(HP),观察HP根除情况。结果:治疗组和对照组对DU有效率分别为93.6％和94.5％,无统计学差异(P>0.05),HP根除率分别为82.3％和95.7％,对照组明显高于治疗组(P<0.01);治疗组2例出现白细胞轻度降低(3.5×10~9/L),对照组1例ALT轻度升高,治疗结束后均恢复,余无严重不良反应。呋喃唑酮、乐得胃、法莫替丁联合治疗DU,虽然HP根除率稍低,但经济、安全、有效,尤其适用于低收入患者。  相似文献   

11.
Abstract

A questionnaire designed to determine accessibility of a car was given to a Senior class of a suburban high school. Two grade-point averages were collected: the first before the students were legally able to drive, and the second after they had been legally able to drive for about one and one-half to two years. An IQ score was also collected. The subjects were divided into boys and girls. Car accessibility was divided into three categories: (1) no driver's license; (2) moderate accessibility; and (3) a group having maximum accessibility. It was concluded that the students' access to cars has no effect on the grade-point average over this period. This Is true even when their Hi is taken into account. It was determined that there is a differential pattern of access to cars by intellectual ability levels. Questions regarding the Interpretations of previous work seem justified.  相似文献   

12.
The big-fish-little-pond effect (BFLPE) model predicts students’ academic self-concept to be negatively predicted by the achievement level of their reference group, controlling for individual achievement. Despite an abundance of empirical evidence supporting the BFLPE, there have been relatively few studies searching for possible moderators. Integrating the BFLPE model with Achievement Goal Theory, the present study aims to determine whether the negative effect of class-average achievement on academic self-concept is moderated by individual and class-average achievement goals. Our sample comprised of 2987 students (50% boys) from Grade 6 in 112 elementary schools in the Flemish region of Belgium (174 classes). Applying multilevel modelling, we found a stronger BFLPE when students’ individual achievement goals were higher, regardless of the specific nature of these goals. The BFLPE was not moderated by class-average levels of achievement goals. Overall, our findings demonstrate that the BFLPE is moderated by individual goal-related factors.  相似文献   

13.
A previous study showed that pairs of students interacting in a second language produced more words when they were assigned a fictitious expert position in a specific competence dimension than when they were assigned a nonexpert position. It has also been shown that the usual level of expertise has an impact on the assigned fictitious expertise effect. The present study was designed to determine whether the processing capacity allotted to the current task could partly determine performance. A given position of expertise may demand a large or small attentional capacity. Two experiments were conducted using a dual-task paradigm. As expected, the different expertise positions led to different reaction times on the secondary task. The second experiment showed that the impact of assigning a position of expertise to students depends on their usual academic standing. This study supports the idea that in interactive situations, performance variations as a function of the expertise position can be partially explained by differences in the processing resources allocated to the task. Implications for teaching are discussed.  相似文献   

14.
Polymerase chain reaction (PCR) and gel electrophoresis have become common techniques used in undergraduate molecular and cell biology labs. Although students enjoy learning these techniques, they often cannot fully comprehend and analyze the outcomes of their experiments because of a disconnect between concepts taught in lecture and experiments done in lab. Here we report the development and implementation of novel exercises that integrate the biological concepts of DNA structure and replication with the techniques of PCR and gel electrophoresis. Learning goals were defined based on concepts taught throughout the cell biology lab course and learning objectives specific to the PCR and gel electrophoresis lab. Exercises developed to promote critical thinking and target the underlying concepts of PCR, primer design, gel analysis, and troubleshooting were incorporated into an existing lab unit based on the detection of genetically modified organisms. Evaluative assessments for each exercise were aligned with the learning goals and used to measure student learning achievements. Our analysis found that the exercises were effective in enhancing student understanding of these concepts as shown by student performance across all learning goals. The new materials were particularly helpful in acquiring relevant knowledge, fostering critical-thinking skills, and uncovering prevalent misconceptions.  相似文献   

15.

Two research questions guided this study of teacher selection: (a) What characteristics do Chinese principals look for when hiring teachers? And (b) what is the effect of participants’ gender, experience, or school location on perceived characteristics of effective teacher candidates in hiring? Both interviews and a questionnaire survey were used to collect data from a southwest city of Shandong Province, China. In this mixed design study, quantitative results were consistent with the qualitative results. Additionally, the study results are intended to help readers better understand school principals’ perceived characteristics of effective teachers in a Chinese context and provides a framework for future comparative research between China and the USA.

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16.
Previous experiments have shown that the intake of a 0.15% saccharin solution is suppressed if saccharin access is followed by access to 32 % sucrose in brief daily pairings. The present experiments found that: (1) the degree of suppression was not altered when no time elapsed between presentation of the two solutions each day (15 sec had been the minimum in previous experiments and was used as the control in this experiment); (2) the degree of suppression was not altered by chlordiazepoxide (6, 12, or 20 mg/kg), although the drug had large appetite-stimulating effects; (3) suppression was not influenced by amphetamine (0.25 or 0.50 mg/kg); and (4) contrast could be established or eliminated, even after extended training, by manipulating the sequences of solutions presented (saccharin-saccharin or saccharin-sucrose). The results were interpreted in terms of a contrast effect based on the learned anticipation of a preferred substance. The chlordiazepoxide data suggest that this contrast is different from successive negative contrast, and the intersolution interval data suggest that the occurrence of contrast rather than a reinforcement effect is not due to a time gap between presentations of the two solutions.  相似文献   

17.
目的:采用Trizol一步法提取人肝癌细胞总RNA电转染人外周血树突状细胞(Dendritic Cell,DC),观察其对混合T淋巴细胞的体外激活效应。方法:通过密度梯度离心法分离人外周血单核细胞,用细胞因子体外培养诱导其成为DC。Trizol一步法提取人肝癌细胞总RNA。通过电转染法将人肝癌细胞总RNA导入DC内;通过混合淋巴细胞实验,获取DC激活的特异性效应T细胞。用MTT法测定效应T细胞的增殖率。结果:电转染方法可将人肝癌细胞总RNA导入DC;电转染前后DC分子表达无显著差异。转染了人肝癌细胞总RNA的DC可特异的激活T细胞且增殖率明显增强(P<0.05)。结论:电转染为人肝癌细胞总RNA导入DC提供技术上的可行性;转染了人肝癌细胞总RNA的DC可特异激活T细胞。  相似文献   

18.
黄连素与优降糖联合治疗糖尿病疗效的观察   总被引：2，自引：0，他引：2  
为观察非降糖药黄连素治疗糖尿病患者的疗效,将30例Ⅱ型糖尿病患者随机分为2组进行对照观察。治疗两个月后,血糖即出现显著下降,近期疗效观察提示黄连素合用小量优降糖治疗糖尿病与单一降糖药比较,具有显著性差异(P<0.05),疗效优于单一用药,总有效率达87％,提示两者有协同作用。  相似文献   

19.
Two studies were conducted to examine the effect of grade inflation on the piling up of grades in fewer grade categories and on the reliability of grade point averages (GPAs). In all comparisons, grades were more bunched after grade inflation, which in turn, was associated with only slight, nonsignificant decreases in GPA reliability. As expected, grades were more bunched when the traditional 5-point letter scale was used than when plus and minus grades were also allowed. In the latter case as well, grade inflation seemed to have had very little effect on the reliability of GPAs. GPA reliability began to suffer, however, for graduate programs in which almost all grades were placed into just two categories, A and B.  相似文献   

20.
This article contextualizes the significance of lived experience in relation to personal narratives and learning largely by examining Zainab Salbi’s autobiography Between Two Worlds: Escape from Tyranny: Growing Up in the Shadow of Saddam. Discussing Salbi’s education and personal life as the daughter of Saddam’s private pilot, the article explores the learner’s reluctance to share what Donald Winnicott calls ‘the secret self’. This resistance on the part of the learner complicates the notion of communication as a therapeutic method that educators usually use as the bases for teaching and learning, as explicated by Alice Pitt. In Salbi’s politicized world, she explains how suppressed memory and reluctance to express oneself are tools of survival that ultimately turn into a lifestyle inside and outside the classroom. By employing Winnicott’s metaphor of hide and seek to demonstrate ambivalence in communication, this study explores how Salbi’s experience as a woman with a suppressed personal history can culturally and psychologically be very similar to teachers and students who are reluctant to share their own memories. In effect, this paper examines the implications of suppressed memory and knowledge among reluctant learners for pedagogical practices worldwide.  相似文献   

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