Summary of background data . According to prospective etiologic studies , a causal association exists between certain lifestyle factors and low back pain .
背景数据摘要:根据前瞻性病因学研究,某种生活方式因素和腰背痛存在因果联系。
Objective to investigate the effect of ultrasonography on etiologic diagnosis of digestive tract bleeding .
目的探讨超声检查在急性消化道出血时病因诊断中的作用。
If clinically suspicious , culture specimens and gram stains can be used to identify the specific etiologic agent .
若临床怀疑,可通过标本培养和革兰染色来鉴别特定的病原体。
Objective to investigate the morbidity and related etiologic factors of dry eye .
目的了解干眼症的患病情况及与发病相关因素。
This paper presents a review of the etiologic characteristics of avian influenza virus and the epidemiological characteristics , clinical manifestation , diagnosis and treatment of avian influenza and human-avian influenza .