[The role of poloxamer 188 for cord blood mononuclear cells into megakaryocytes cultivation and induction in three-dimensional WAVE Bioreactor].

Objective: To observe the effect of poloxamer 188 (P188) on megakaryocyte cultivation and induction from cord blood mononuclear cells in order to obtain more megakaryocyte progenitor cells (MPC). Methods: The cord blood mononuclear cells were isolated and inoculated in cell culture bag or cell culture flask respectively. The WIGGENS shaker and cell culture bags were used to mimick WAVE Bioreactor for three-dimensional (3D) cell culture, and the P188 was added to induction medium, The cells were detected for morphology, surface marker, viability, and number on day 14. Results: In the two-dimensional (2D) culture, CD41(+), CD41(+)/CD61(+), CD61(+) megakaryocytic numbers increased significantly after adding P188 (all P<0.01). And in the 3D culture of adding P188, the cell volume became larger and the nuclear shape was irregular, the cytoplasm appeared magenta granules, and the megakaryocyte cells became more mature. By 3D culture, the expression of CD41/CD61 was (36.30±1.27)% vs (23.95±1.34)%, hence the differentiation for MPC was significantly higher than that in the 2D group (P<0.01). Furthermore, adding P188 in 3D culture resulted in highest differentiation efficiency for MPC [(59.45±1.20)%]. There were no significantly differences in terms of cell viability and cell number among 3D culture containing P188, 2D and 3D culture groups (all P>0.05). Conclusion: 3D culture was beneficial for the differentiation of MPC, but the cell viability was lower than 2D group; However, the satisfied cell growth and better induction efficiency were obtained by adding of P188, which might provide a new method of megakaryocytes production for clinical application.

Expression Patterns of Three Genes Under Short and Long Term Cold Exposure in Thitarodes pui (Lepidoptera: Hepialidae), A Host of Ophiocordyceps sinensis.

　　BACKGROUND: Thitarodes larvae are the host of the caterpillar fungus Ophiocordyceps sinensis. Low temperature is the main environmental limitation for larvae growth. OBJECTIVE: To better understand the cold adaption process in T. pui larvae, the expression patterns of trehalose-6-phosphate synthase (TpTPS), heat shock protein 70 (TpHSP70), and heat shock protein 90 (TpHSP90) were investigated upon short and long-term exposure to 0°C. MATERIALS AND METHODS: The 6th instar T. pui larvae were collected in July 2013. TpTPS was firstly sequenced and expression patterns of TpTPS, TpHSP70 and TpHSP90 were investigated using quantitative PCR. RESULTS: Full-length cDNA of TpTPS was 3,012 bp, with an open reading frame of 2,472 bp and an encoding protein of 823 amino acids. TpTPS up-regulation was induced by cold exposure. TpHSP70 expression is altered by cold exposure, but remained low. TpHSP90 expression was obviously up regulated in long-term cold stimulation. CONCLUSION: All three genes (TpTPS, TpHSP70 and TpHSP90) have likely contributed to cold tolerance in T. pui larvae, TpTPS and TpHSP90 potentially being more important.

Current-pulse-induced enhancement of transient photodetective effect in tilted manganite film.

A current-pulse-induced enhancement effect of transient photovoltage has been discovered in tilted manganite La(2/3)Ca(1/3)MnO(3) film at room temperature. Here, by applying a pulsed current stimulus before pulse laser irradiation, we observed a significant enhancement of more than 50% in photovoltaic sensitivity. The current-pulse-induced photovoltaic enhancement can be tuned not only by the stimulating current value but also by the stimulating time. Such enhancement is time-sensitive and reproducible. This electrically induced effect, observed at room temperature, has both the benefit of a discovery in materials properties and the promise of applications for thin film manganites in photodetectors.