Different frequencies of vibration strains affect the early proliferation and differentiation of osteoclasts / 中国组织工程研究

BACKGROUND:Studies have shown that low-intensity and short-time vibration with a certain frequency can reduce the absorption of bone tissue and increase the quantity and quality of bone through promoting the proliferation and differentiation of osteoblasts. OBJECTIVE:To investigate the effects of different frequencies of vibration strains on cycle, proliferation and differentiation potency of RAW264.7 cel s cultured in vitro. METHODS:Passage 6 RAW264.7 cel s in good conditions were randomly divided into six groups, and each group was induced cultured with Dulbecco’s modified Eagle’s medium containing receptor activator of nuclear factor kappa B ligand. The final concentration of receptor activator of nuclear factor kappa B ligand was adjusted to 50μg/L, and then kept without changes. The non-loading group did not loaded with vibration strain, and the other five groups were loaded with 3-10 Hz, 15-35 Hz, 35-45 Hz, 50-70 Hz and 70-90 Hz vibration strains on the RAW264.7 cel s respectively. The other vibration parameters were consistent;the vibration time was 15 min/time with the vibration intensity of 0.3 g, twice per day. The cel cycle and cel proliferation were detected at 3 and 6 days after loading of vibration strains. RESULTS AND CONCLUSION:After composite vibration loading for 6 days, the cel cycle phase in the vibration groups was changed to some extent when compared with the non-loading group. Compared with non-loading group, the cel number in the G 1 phase of the vibration group was significantly increased (P<0.01);the cel number in the S phase and G 2+M phase of the vibration group was significantly decreased (P<0.01);the vibration parameters in the vibration group were significantly decreased (P<0.01). The results indicate that different frequencies of vibration strains can affect the cel cycle and proliferation, and can inhibit the proliferation and differentiation of osteoblasts.

Receptor activator of nuclear factor kappa B ligand-induced mature osteoclasts / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.24.002

The moderate effect of work control on the work stress-job satisfaction relationship and work stress-organizational citizenship behavior relationship / 中华行为医学与脑科学杂志

Objective To explore the moderate effect of work control on the work stress-organizational citizenship behavior relationship and work stress-job satisfaction relationship.Methods 200 employees of five corporations in Shandong province were surveyed by questionnaires using work control scale,work stress scale,organizational citizenship behavior scale and job satisfaction scale.Results Work stress was negatively correlated with job satisfaction(r=-0.28,P＜0.01)and organizational citizenship behavior(r=-0.25,P＜0.01).Job satisfaction was significantly higher for employees who perceived high work control under certain work stress(β=0.16,P＜0.05).The relationship between work stress and organizational citizenship behavior was significantly stronger for employees who perceived high work control under certain work stress(β=0.19,P＜0.05).Conclusion The final results showed that work stress Was negatively correlated with organizational citizenship behavior.Work control had a positively moderate effect on the relationship between work stress and organizational citizenship behavior and the relationship between work stress and job satisfaction.