摘要：Circulating tumor DNA(ctDNA),carrying tumor-specific sequence mutations,is a promising biomarker for classification,diagnosis and prognosis of ***,there is still a great challenge in discriminating single-base difference between ctDNA and its coexisting analogue(normal circulating DNA,ncDNA)at a serum sample.A locked nucleic acid(LNA)probe combined with a-HL nanopore sensor was designed,which achieved a high signal-to-background ratio(SBR)of^8.34 × 10^3,as well as a significant discrimination capability(~12.3 times)of single-base diffe *** accurate discrimination strategy is label-free,convenient,selective and sensitive,which has great potential in the early diagnosis of diseases and biomedical research fields.

摘要：目的 :了解社区老年人跌倒认知与行为现状,并分析其影响因素,为社区医务人员实施跌倒干预措施提供科学依据。方法 :采用自行设计的跌倒认知和预防行为问卷,对本社区200例老年人进行调查。结果 :老年人对药物因素所引起跌倒的认知率低于因疾病因素所引起的跌倒;老年人在个人、环境方面预防跌倒措施较少;文化程度影响老年人对跌倒的认知,但不同文化程度的老人在采取预防跌倒行为方面差异无统计学意义(P>0.05)。结论 :老年人对预防跌倒的认知和行为水平较低,社区医务人员应根据个体情况制定综合性干预措施,降低跌倒的发生率。