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某型飞机调节管子的机上磁粉探伤
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作者 郭海鸥 王宏罡 李科卫 《无损检测》 2009年第5期410-411,共2页
由于某型飞机调节管子在飞机飞行期间受力,因此修理技术文件规定飞机大修时需对其分解后进行磁粉探伤。然而,由于机上位置的限制,拆卸和安装很不方便,且反复拆装会对安装结构产生损害作用。经研究,对其采取不拆卸机上原位磁粉探伤。介... 由于某型飞机调节管子在飞机飞行期间受力,因此修理技术文件规定飞机大修时需对其分解后进行磁粉探伤。然而,由于机上位置的限制,拆卸和安装很不方便,且反复拆装会对安装结构产生损害作用。经研究,对其采取不拆卸机上原位磁粉探伤。介绍了原位磁粉探伤技术的实施参数计算及磁化器的设计。 展开更多
关键词 飞机 调节管子 磁粉探伤 原位检测
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Upregulation of hypoxia inducible factor 1α mRNA is associated with elevated vascular endothelial growth factor expression and excessive angiogenesis and predicts a poor prognosis in gastric carcinoma 被引量:29
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作者 Jie Ma Li Zhang +2 位作者 Guo-Qing Ru Zhong-Sheng Zhao Wen-Juan Xu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第11期1680-1686,共7页
AIM: To investigate the implication of the hypoxia inducible factor HIF-1α mRNA in gastric carcinoma and its relation to the expression of vascular endothelial growth factor (VEGF) protein, tumor angiogenesis inva... AIM: To investigate the implication of the hypoxia inducible factor HIF-1α mRNA in gastric carcinoma and its relation to the expression of vascular endothelial growth factor (VEGF) protein, tumor angiogenesis invasion/metastasis and the patient's survival. METHODS: In situ hybridization was used to examine expression of HIF-1α mRNA, and immunohistochemical staining was used to examine expression of VEGF protein and CD34 in 118 specimens from patients with gastric carcinoma. RESULTS: The positive rates of HIF-1α mRNA and VEGF protein were 49.15% and 55.92%, respectively. Positive expressions of HIF-1α and VEGF in stage T3-T4 tumors and those with vessel invasion, lymph node metastasis and distant metastasis were dramatically stronger than stage T1-T2 cases and those without vessel invasion, lymph node metastasis and distant metastasis. The mean microvascular density (MVD) in stage T3-T4 tumors and those with vessel invasion, lymph node metastasis and distant metastasis was significantly higher than stage T1-T2 tumors and those without vessel invasion, lymph node metastasis and distant metastasis. The mean MVD in tumors with positive HIF-1α and VEGF expression was significantly higher than that in tumors with negative HIF-1α and VEGF expression. The expression of HIF- 1α was positively correlated with VEGF protein. There were positive correlations between MVD and expression of HIF-1α and VEGF. The mean survival time and the S-year survival rate in cases with positive expression HIF-1α and VEGF and MVD value ≥ 41.5/0.72 mm^2 were significantly lower than those with negative expression of HIF-1α and VEGF and MVD value 〈 41.5/0.72 mm^2. CONCLUSION: Overexpression of HIF-1α is found in gastric carcinoma. HIF-1α may induce the angiogenesis in gastric carcinoma by upregulating the transcription of VEGF gene, and take part in tumor invasion and metastasis. They can be used as prognostic markers of gastric cancer in clinical practice. 展开更多
关键词 Gastric carcinoma HIF-1α Vascularendothelial growth factor Microvascular density Prognosis
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Role of nuclear receptor NR4A2 in gastrointestinal inflammation and cancers 被引量:7
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作者 Yi-Fang Han Guang-Wen Cao 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第47期6865-6873,共9页
NR4A2 is a transcription factor belonging to the steroid orphan nuclear receptor superfamily.It was originally considered to be essential in the generation and maintenance of dopaminergic neurons,and associated with n... NR4A2 is a transcription factor belonging to the steroid orphan nuclear receptor superfamily.It was originally considered to be essential in the generation and maintenance of dopaminergic neurons,and associated with neurological disorders such as Parkinson's disease.Recently,NR4A2 has been found to play a critical role in some inflammatory diseases and cancer.NR4A2 can be efficiently trans-activated by some proinflammatory cytokines,such as tumor necrosis factor-α,interleukin-1β,and vascular endothelial growth factor(VEGF).The nuclear factor-κB signaling pathway serves as a principal regulator of inducible NR4A expression in immune cells.NR4A2 can trans-activate Foxp3,a hallmark specifically expressed in regulatory T(Treg) cells,and plays a critical role in the differentiation,maintenance,and function of Treg cells.NR4A2 in T lymphocytes is pivotal for Treg cell induction and suppression of aberrant induction of Th1 under physiological and pathological conditions.High density of Foxp3 + Treg cells is significantly associated with gastrointestinal inflammation,tumor immune escape,and disease progression.NR4A2 is produced at high levels in CD133 + colorectal carcinoma(CRC) cells and significantly upregulated by cyclooxygenase-2-derived prostaglandin E 2 in a cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)-dependent manner in CRC cells.The cAMP/PKA signaling pathway is the common pathway of NR4A2-related inflammation and cancer.NR4A2 trans-activates osteopontin,a direct target of the Wnt/β-catenin pathway associated with CRC invasion,metastasis,and poor prognosis.Knockdown of endogenous NR4A2 expression attenuates VEGF-induced endothelial cell proliferation,migration and in vivo angiogenesis.Taken together,NR4A2 emerges as an important nuclear factor linking gastrointestinal inflammation and cancer,especially CRC,and should serve as a candidate therapeutic target for inflammation-related gastrointestinal cancer. 展开更多
关键词 NR4A2 INFLAMMATION Immune cells Signaling pathway Gastrointestinal carcinoma
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