Endoscopic detection and diagnostic strategies for minute gastric cancer:A real-world observational study

BACKGROUND Minute gastric cancers(MGCs)have a favorable prognosis,but they are too small to be detected by endoscopy,with a maximum diameter≤5 mm.AIM To explore endoscopic detection and diagnostic strategies for MGCs.METHODS This was a real-world observational study.The endoscopic and clinicopathological parameters of 191 MGCs between January 2015 and December 2022 were retrospectively analyzed.Endoscopic discoverable opportunity and typical neoplastic features were emphatically reviewed.RESULTS All MGCs in our study were of a single pathological type,97.38%(186/191)of which were differentiated-type tumors.White light endoscopy(WLE)detected 84.29%(161/191)of MGCs,and the most common morphology of MGCs found by WLE was protruding.Narrow-band imaging(NBI)secondary observation detected 14.14%(27/191)of MGCs,and the most common morphology of MGCs found by NBI was flat.Another three MGCs were detected by indigo carmine third observation.If a well-demarcated border lesion exhibited a typical neoplastic color,such as yellowish-red or whitish under WLE and brownish under NBI,MGCs should be diagnosed.The proportion with high diagnostic confidence by magnifying endoscopy with NBI(ME-NBI)was significantly higher than the proportion with low diagnostic confidence and the only visible groups(94.19%>56.92%>32.50%,P<0.001).CONCLUSION WLE combined with NBI and indigo carmine are helpful for detection of MGCs.A clear demarcation line combined with a typical neoplastic color using nonmagnifying observation is sufficient for diagnosis of MGCs.MENBI improves the endoscopic diagnostic confidence of MGCs.

具有完全形状记忆效应的Cu−13.5Al−4Ni−6Fe形状记忆马氏体单晶

通过对铸态合金进行简单退火处理,制备具有完全形状记忆效应的厘米级Cu−13.5Al−4Ni−6Fe马氏体单晶。通过光学显微镜、透射电子显微镜、差示扫描量热仪、热机械分析仪以及压缩测试研究单晶的显微组织、逆马氏体转变和形状记忆效应。研究结果表明,Cu−13.5Al−4Ni−6Fe单晶拥有18R和2H 2种马氏体,同时拥有体心立方富Fe纳米析出相。马氏体转变和逆转变的起始温度和结束温度分别为387、397、365和432 K。当对单晶施加6%、7%以及8%的预应变时,单晶分别拥有4.4%、4.7%以及5.2%的完全形状记忆效应。获得的Cu−13.5Al−4Ni−6Fe马氏体单晶具有可与传统形状记忆合金相媲美的形状记忆性能。

α-二亚胺镍钯配合物合成及催化混合癸烯低聚研究

α-二亚胺镍钯催化剂具有独特的链行走的特点,通过对催化剂结构设计可以进一步调控其催化性能和链行走过程来制备性能优异的聚烯烃产品.本文合成和表征了莰基骨架的α-二亚胺镍钯配合物,并研究了其在一氯二乙基铝的助催化作用下催化混合癸烯低聚性能.详细探究了催化剂金属中心、溶剂、温度及铝镍比对混合癸烯低聚结果的影响.钯催化剂催化混合癸烯低聚时几乎无活性;而镍催化剂具有较好的催化活性,结合单体的异构化过程线性的单体几乎能完全低聚转化.所得到的产物是高度支化、低分子量的油状聚烯烃产物,并且具有高的黏度指数(>170),低的倾点(<-30℃),在润滑油基础油领域具有良好应用前景.