Homogeneous Age-hardening of Large-sized Al-Sc Foams via Micro-alloying with Zr and Ti.

Al-based foams have drawn increasing attention from industry due to their integration of structure and functional properties. However, large-sized Al-based foams still cannot be homogeneously strengthened by long-time aging due to their low thermal conductivity. In this study, we proposed an age-hardening approach that was applied in large-sized Al-0.16Sc-0.17Zr (wt.%) foams via micro-alloying with Zr and Ti compared with Al-0.21Sc foams; it not only achieved homogeneous strength by long-term aging but also reduced the cost of the alloy by substituting Zr and Ti for the more expensive Sc content. The results show that the Al3(Sc, Zr, Ti) phase with a core-shell structure as a crucial precipitation strengthening phase by micro-alloying with Zr and Ti was less prone to coarsening after a prolonged aging heat treatment. Therefore, the yielding strength of Al-Sc foam micro-alloying with Zr and Ti remained almost unchanged after a maximum aging time of 1440 h due to less coarsening precipitate, which is consistent with the results of mechanical experiments. These findings provide a new way for the heat treatment strengthening of large-sized Al-based foams, thus promoting their industrial applications.

[Rapid propagation of Bletilla striata by synthetic seeds technology].

OBJECTIVE: To establish a new manufacturing method for Bletilla striata synthetic seeds, and provided a new way for rapid propagation of B. striata, the correlated influential factors were studied. METHOD: The synthetic seeds were manufactured by taking seeds of B. striata as materials which were beforehand germinated in 1/2 MS medium for 10 days, and the influential factors such as artificial endosperm components, episperm substances, storage conditions and germination groundmass impact on the germination rate and seedling rate of the synthetic seeds were evaluated. RESULT: Compound 4.0% sodium alginate + 0.2 mol x L(-1) CaCl2 + 0.4 mg x L(-1) penicillin + 0.3% carbendazim powder + 0.2% sodium benzoate served as the best episperm substances while MS + 1.0 mg x L(-1) NAA + 2.0 mg x L(-1) KT as the best endosperm components, in which, high germination rate and seedling rate were obtained. The synthetic seeds storing in the 4 degrees C for a long time was able to have still high vitality. CONCLUSION: The B. striata synthetic seeds manufacturing system was established successfully, while efforts should be taken to improve the sowing technique of the synthetic seeds in non-sterile conditions.

[Transurethral resection of the prostate for advanced hormone-refractory prostate cancer: a feasibility study].

OBJECTIVE: To investigate the effect of transurethral resection of the prostate (TURP) in the treatment of advanced prostate cancer with bladder outlet obstruction (BOO). METHODS: We included in this study 43 cases of advanced prostate cancer with BOO treated by TURP, and analyzed their IPSS, maximum urinary flow rate and relevant risk factors pre-operatively and at 3 and 12 months after TURP. RESULTS: Compared with the baseline, IPSS and the maximum urinary flow rate of the patients showed significant differences 3 months after surgery ([19.60 +/- 0.41] score vs. [9.58 +/- 0.33] score, [4.93 +/- 0.68] ml/s vs. [8.96 +/- 0.47] ml/s, P < 0.05), but not at 12 months ([15.73 +/- 0.66] score, [5.67 +/- 0.44] ml/s). In multiple regression analysis, a good outcome was associated with pre-operative acute urinary retention, while poor prognosis with hormone-refractory prostate cancer. CONCLUSION: In the treatment of advanced hormone-refractory prostate cancer with BOO, TURP can reduce IPSS and increase the maximum urinary flow rate in the early period after surgery, but its long-term effect is not so desirable. Meanwhile the operation itself may bring about relevant complications and reduce the patient's quality of life.