Resistance to adriamycin was developed in an orignally adriamycin- sensitive strain of Ehrlich ascites carcinoma (EAC) in vivo by treament with the adriamycin during 50 weekly passages of the tumor. The results showed that the growth of the resistant line was slower than that of the EAC, total ascites cell volume,total cell number and mean single-cell volume were significantly smaller of the resistant line than those of original sensitive line. Also, itwas found the homogerously staining region and double minute chromosome in the cells of resistant line. The adriamycin-resistant tumor produced cross resistance to vincristine.mitomycin C,and actinomycin D,while section resistance to VP-16. There was no change in the sensitivity of tumor to oridonin.

AIM: To investigate the antitumor and immunological activities of the polysaccharides obtained from rabdosia rubescens (RRP). METHODS: In vitro and in vivo tumor inhibitory experiments as well as MTT method were used. RESULTS: With increasing concentration, the RRP exerted direct cytotoxicity effect in vitro on the cell growth of EAC mice,and its inhibitory rate in vivo against sarcoma 180 reached 35% ( P

Objective:To explore the relationship between work connectivity behavior after-hours, self-regulatory fatigue and work engagement of nurses, so as to provide reference for developing strategies to improve nurses′work engagement.Methods:This was a cross-sectional survey study. A total of 661 nurses from 10 hospitals in Shandong Province were selected as subjects by convenience sampling method from June to August 2022. The Work Connectivity Behavior After-hours Scale, Self-Regulatory Fatigue Scale and Work Engagement Scale were used to measure the work connectivity behavior after-hours, self-regulatory fatigue level and work engagement level. A structural equation model was constructed to evaluate the mediating effect of self-regulatory fatigue on work connectivity behavior after-hours and work engagement.Results:The scores of work connectivity behavior after-hours, self-regulatory fatigue and work engagement of nurses were (37.66 ± 7.05), (42.98 ± 10.55) and (34.29 ± 6.58) points, respectively. The total effect of work connectivity behavior after hours on work engagement was -0.336 6. The work connectivity behavior after-hours was positively correlated with self-regulatory fatigue ( r = 0.423, P<0.01) and work engagement was negatively correlated with work connectivity behavior after-hours and self-regulatory fatigue ( r = -0.361, -0.479, both P<0.01). Self-regulatory fatigue had a partial mediating effect on work connectivity behavior after-hours and work engagement, accounting for 46.61% of the total effect. Conclusions:Self-regulatory fatigue has a mediating effect on the relationship between nurses′ work connectivity behavior after-hours and work engagement. Nursing managers should reduce the degree of self-regulatory fatigue of nurses by preventing their work connectivity behavior after-hours, so as to improve the work involvement level of nurses.