[Short-term memory characteristics of vibro-tactile perception in human fingertips].

This paper discusses the short-term memory of vibro-tactile perception of human fingertips. By using a self-developed vibro-tactile expression device, a recall experiment was firstly carried out among 20 subjects aged 20-30 (10 males and 10 females) to discover the memory span about the vibro-tactile perception of human fingertips. Within this memory span, a cognitive experiment analyzing the recognition accuracy and the reaction time was carried out. The results showed: (1) The vibro-tactile memory span of human fingertip is 4 ± 1; (2) The vibro-tactile memory span increases as the discrete intensity between vibration stimuli increases; (3) Too long or too short vibration duration will reduce the vibro-tactile memory span, and the optimal vibration duration for men is 400 ms, for women is 300 ms; (4) The more the number of vibration stimuli is perceived by the human fingertip, the lower the recognition accuracy and the longer the reaction time it needs; (5) Compared with the vibration stimuli in disorder, people are more likely to remember the vibration stimuli in increasing/decreasing order; (6) The information extraction mechanism of the short-term memory about fingertip vibro-tactile perception bases a point to point scanning process among these stimuli. These results help to understand the human fingertip tactile characteristics and provide a physiological basis for the study of tactile feedback technologies.

[Synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells and its related mechanism].

OBJECTIVE: To investigate the synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells and the down-regulating effect of curcumin on the Keapl-Nrf2 pathway, a well recognized anti-drug pathway in almost drugged tumor cells. METHODS: T24 cells were cultured and treated with increasing concentrations of curcumin(5 ,10 and 20 µmol/mL) combined with cisplatin(30 µg/mL) for 24 hours. The inhibitory effects on T24 cells were tested with MTI colorimetric assay. Nuclear Nrf2 and Keapl , cytoplasmic Keapl and two typical phase II enzymes (GSTP1 and NQOl) were checked with Western blotting. RESULTS: The proliferation of T24 cells was significantly inhibited by different concentrations of curcumin combined with cisplatin. After the treatment with different concentrations of curcumin, Nuclear Nrf2 was decreased but Keapl was increased, and GSTP1 and NQO1 were decreased. CONCLUSION: Synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells is observed in this research. The Keapl-Nrf2 pathway in T24 cells is down-regulated by curcumin. The expression of typical phase I enzymes (GSTP1 and NQO1) mediated by Nrf2 are decreased by curcumin. The sensitivity of tumor cells to chemotherapeutic drugs is then enhanced. These may be the mechanism of synergism effect of curcumin combined with cisplatin.