Objective: To investigate the effects of plateau environment exposure on the reproductive system of male rats, so as to provide the reference for mechanisms of reproductive damage in plateau environment. Methods: Sixty SPF-grade 12-week-old male Wistar rats were randomly divided into the plain-exposed group, the 1 day-, 3 day-, 7 day-, 14 day- and 28 day- plateau-exposed groups. The rats in the plain-exposed group were raised under normal conditions for 28 days, while the rats in the plateau-exposed groups were raised in a simulated high-altitude plateau chamber. After the completion of the designated feeding periods, the rats were sacrificed under anesthesia, and testicular tissue and abdominal aortic blood were collected to detect the testicular index and evaluate sperm quality. Histological and cellular morphologies of the testicular tissue were analyzed. Additionally, the levels of malondialdehyde (MDA), superoxide dismutase (SOD) and reactive oxygen (ROS) in the testicular tissue were determined, along with serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and testosterone (T). Conclusions Plateau environment may cause a decrease in testicular index and sperm quality, impair mitochondrial function, induce oxidative stress, and thus affect reproductive system of male rats. However, there are signs of self-repair in the reproductive system with the increase of exposure duration.

Objective:To understand the current situation and trend of nursing cost research in China so as to provide a reference for researchers in the field of nursing cost research.Methods:We retrieved literature on nursing cost from January 1, 1990 to December 13, 2019 in China National Knowledge Infrastructure (CNKI) . CiteSpace software was used for visual analysis.Results:A total of 463 related literature were obtained, and the number of publications was on the rise as a whole, and research institutions had little cooperation. Nursing economics, nursing human resources, nursing management, cost analysis were the main research directions at present. Long-term care insurance with the highest emergent word intensity was the research frontier in the field.Conclusions:We should strengthen the cooperation in scientific research institutions, and rely on big data, computers and other means to establish a nursing cost accounting model, and extend the scope of research to communities and homes so as to provide a quantitative basis for Chinese long-term care insurance compensation standards.