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PE100管材料的聚集态结构和性能的固体NMR分析 被引量:11
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作者 严小伟 历伟 +4 位作者 任晓红 王靖岱 阳永荣 Siegfried Stapf Bernhard Blumich 《材料研究学报》 EI CAS CSCD 北大核心 2008年第2期157-163,共7页
PE100管材料基体树脂中界面区的含量比较高(高于10%),而完全无定形区的含量极低.界面区含量表征非晶区中运动部分受阻的链段所占的比重,因而上述结果意味着PE100管材料中非晶区中链段表现出强烈的缠结倾向.界面区的含量(或非晶区的组成... PE100管材料基体树脂中界面区的含量比较高(高于10%),而完全无定形区的含量极低.界面区含量表征非晶区中运动部分受阻的链段所占的比重,因而上述结果意味着PE100管材料中非晶区中链段表现出强烈的缠结倾向.界面区的含量(或非晶区的组成特征)决定了材料的耐慢速裂纹增长性能,而固相区含量则决定了材料的力学强度,两种影响因素的平衡决定了最终管材料的长期使用性能. 展开更多
关键词 有机高分子材料 PE100管材料 固体核磁共振 聚集态结构 力学性能
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农村废弃生物质资源开发获重要突破 被引量:3
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作者 李宗奉 郑延海 +9 位作者 刘雪莉 冯素飞 Mario Lucas 吴光磊 贺新华 李勇 李彩虹 刘慧 蒋高明 李向东 《生态学报》 CAS CSCD 北大核心 2009年第9期5158-5160,共3页
关键词 资源开发 废弃生物质 农村 化石能源 能源与环境 能源危机 光合产物 可再生
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转化生长因子β信号传导途径的失活与胃癌的癌变过程的关系 被引量:4
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作者 唐朝晖 袁明 +4 位作者 胡元龙 邹声泉 郝友华 杨想平 夏穗生 《临床外科杂志》 2002年第6期339-340,共2页
目的 探讨转化生长因子 β(transforminggrowthfactotβ ,TGF β)信号传导途径的失活与胃癌的癌变过程的关系。方法  12 1例标本包括正常胃粘膜 3 3例 ,肠化生 2 3例 ,不典型增生 2 0例 ,早期胃癌 11例 ,进展期胃癌 3 4例 ,通过免疫... 目的 探讨转化生长因子 β(transforminggrowthfactotβ ,TGF β)信号传导途径的失活与胃癌的癌变过程的关系。方法  12 1例标本包括正常胃粘膜 3 3例 ,肠化生 2 3例 ,不典型增生 2 0例 ,早期胃癌 11例 ,进展期胃癌 3 4例 ,通过免疫组化法检测了它们的TGF β受体 (RⅠ、RⅡ、RⅢ )和Smad4蛋白的表达。结果 TGF βRⅠ、RⅡ、RⅢ表达的阳性率随着胃组织恶性程度的增加而降低 ,差异有显著性 (P <0 .0 1)。且伴局部淋巴结转移的胃癌中TGF βRⅡ表达的阳性率较低 ,与不伴局部淋巴结转移的相比差异有显著性 (P <0 .0 5 )。仅仅于 4例 (11% )进展期胃癌患者 (均伴局部淋巴结转移 )中观察到了Smad4的缺失表达。结论 TGF β信号传导途径与胃癌的癌变过程密切相关 ,其失活使癌细胞失去了对TGF β的生长抑制反应。我们推测TGF β信号传递途径的失活在两个不同的方面影响着胃癌 ,一个是通过TGF β受体的失活 ,另一个是通过Smad4蛋白的失活。 展开更多
关键词 转化生长因子Β 信号传导途径 胃癌 免疫组织化学
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Role of mammalian target of rapamycin complex 2 in primary and secondary liver cancer 被引量:1
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作者 Katharina Joechle Jessica Guenzle +4 位作者 Claus Hellerbrand Pavel Strnad Thorsten Cramer Ulf Peter Neumann Sven Arke Lang 《World Journal of Gastrointestinal Oncology》 SCIE 2021年第11期1632-1647,共16页
The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated wit... The mammalian target of rapamycin(mTOR)acts in two structurally and functionally distinct protein complexes,mTOR complex 1(mTORC1)and mTOR complex 2(mTORC2).Upon deregulation,activated mTOR signaling is associated with multiple processes involved in tumor growth and metastasis.Compared with mTORC1,much less is known about mTORC2 in cancer,mainly because of the unavailability of a selective inhibitor.However,existing data suggest that mTORC2 with its two distinct subunits Rictor and mSin1 might play a more important role than assumed so far.It is one of the key effectors of the PI3K/AKT/mTOR pathway and stimulates cell growth,cell survival,metabolism,and cytoskeletal organization.It is not only implicated in tumor progression,metastasis,and the tumor microenvironment but also in resistance to therapy.Rictor,the central subunit of mTORC2,was found to be upregulated in different kinds of cancers and is associated with advanced tumor stages and a bad prognosis.Moreover,AKT,the main downstream regulator of mTORC2/Rictor,is one of the most highly activated proteins in cancer.Primary and secondary liver cancer are major problems for current cancer therapy due to the lack of specific medical treatment,emphasizing the need for further therapeutic options.This review,therefore,summarizes the role of mTORC2/Rictor in cancer,with special focus on primary liver cancer but also on liver metastases. 展开更多
关键词 Mammalian target of rapamycin Mammalian target of rapamycin complex 2 RICTOR Liver cancer Liver metastases Hepatocellular carcinoma Cholangiocellular carcinoma
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EXPRESSION OF DPC4 PROTEIN IN COLORECTAL CARCINOMA IN DIFFERENT STAGES
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作者 唐朝晖 邹声泉 +3 位作者 郝友华 杨想平 陈启奇 裘法祖 《Chinese Medical Sciences Journal》 CAS CSCD 2003年第3期162-166,共5页
Objective.To d etermine whether the non-expression of DPC4protein only occurs late in the dev el-opment of colorectal carcinoma.Methods.In this study,we examined the ex pression of DPC4protein in formalin-fixed archiv... Objective.To d etermine whether the non-expression of DPC4protein only occurs late in the dev el-opment of colorectal carcinoma.Methods.In this study,we examined the ex pression of DPC4protein in formalin-fixed archival specimens from102colorec tal neoplasm with immunohistochemical analysis.Those specimens were classi-fie d into5stages:stageⅠ;stageⅡ(intramucosal carcinoma ,8cases);stageⅢ(primary invasive carcinoma without infiltration of the l ymph nodes,11cases);stageⅣ(primary invasive carcinoma with infiltration of the lymph nodes,25cases);and stageⅤ(carcinoma metastasized to dis-ta nt tissue,22cases).Results.The frequency of non-expression of DPC4prote ins were5.5%in stage I,12.5%in stage II;9% in stage III;36%in stage IV;32%in stag e V.The frequency of negative expression of DPC4protein were analyzed by÷ 2 test for stage II and III versus stage IV and V and there was statistically significant difference.At same time ,there was statistically signifi-cant differencefor adenoma versus carcinoma .Conclusions.The frequency of non-expression of DPC4protein increases as the stage of colorectal carcinoma advances and the non-expressio n of DPC4protein is likely to be a late event in the sequential pathogenesis o f colorectal carcinoma.The non-expression DPC4protein in colorectal neoplasm may sug-gest its malignant characteristic,which will help us to increase the insight on colorectal carcinoma. 展开更多
关键词 DPC4protein colorectal carcinoma IMMUNOHISTOCHEMISTRY
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Student Evaluations of the Courses in Medical Psychology at the Medical Department of the RWTH Aachen: A Three-Year Report
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作者 Anne Scherer Thomas Forkmann +1 位作者 Sandra Sudmann Siegfried Gauggel 《Open Journal of Medical Psychology》 2012年第4期63-67,共5页
Introduction: With the introduction of a new curriculum “Modellstudiengang Medizin” in Aachen, the education in medical psychology was also restructured. This paper presents data from the students’ evaluations of t... Introduction: With the introduction of a new curriculum “Modellstudiengang Medizin” in Aachen, the education in medical psychology was also restructured. This paper presents data from the students’ evaluations of the Basic Course in Medical Psychology and the new teaching format “Systemblock Psyche” over a three-year time span. Method: All students were asked to evaluate the courses anonymously online. Effect sizes [1] were calculated to compare acceptance of the different course types and also changes across time. Results: Both the Basic Course in Medical Psychology and the Systemblock Psyche were rated as “good” to “satisfactory” and were in their overall acceptance comparable to other courses and system blocks. Continuous improvement in acceptance was found for the Basic Course (d = 0.30 - 0.57). The Systemblock Psyche received varying evaluations but achieved higher scores on comprehensibility (d = 0.20) and communication among teachers (d = 0.34) than other system blocks. On the other hand, students rated the education in medical psychology as less relevant than other courses (d = 0.28 and 0.77, respectively). Conclusion: Overall, the acceptance rating was satisfactory and comparable to other evaluation studies conducted in earlier curricula. However, ratings of the relevance of the courses in medical psychology were disappointing and indicate the difficulty of teaching a biopsychosocial model to medical students. 展开更多
关键词 Teaching Evaluation Education in Medical Psychology Modellstudiengang Systemblock
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