Microstructure and Properties of Mg-Zn-Y Alloy Powder Compacted by Equal Channel Angular Pressing.

Mg97Zn1Y2 (at %) alloy with a long period stacking ordered (LPSO) phase has attracted a great deal of attention due to its excellent mechanical properties. It has been reported that this alloy could be fabricated by warm extrusion of rapid solidified alloy powders. In this study, an alternative route combining mechanical milling and equal channel angular pressing (ECAP) was selected to produce the bulk Mg97Zn1Y2 alloy. Microstructural characterization, mechanical properties and corrosion behavior of the ECAP-compacted alloys were studied. The as-cast alloy contained α-Mg and LPSO-Mg12Zn1Y1 phase. In the as-milled powder, the LPSO phase decomposed and formed Mg24Y5 phase. The ECAP-compacted alloy had identical phases to those of the as-milled sample. The compacted alloy exhibited a hardness of 120 HV and a compressive yield strength of 308 MPa, which were higher than those of the as-cast counterpart. The compacted alloy had better corrosion resistance, which was attributed to the reduced volume fraction of the secondary phase resulting in lower microgalvanic corrosion in the compacted alloy. The increase in Y content in the α-Mg matrix also contributed to the improvement of corrosion resistance.

[Controlled study of auricular point taping and pressing therapy for treatment of vascular dementia].

OBJECTIVE: To assess the therapeutic effect of auricular point taping and pressing therapy on vascular dementia (VD). METHODS: One hundred and eighty cases of vascular dementia were randomly divided into an auricular point taping and pressing group and a western medicine group, 90 cases in each group. The auricular point taping and pressing group was treated by auricular point taping and pressing at auricular points Shennen, Nao (brain), Shen (kidney), Zhen (pulvinal), and the western medicine group by oral administration of Nimodipine, thrice each day, 30 mg each time. They were treated for 12 weeks. The scores of mini-mental state examination (MMSE) and activities of daily living (ADL), and adverse reaction were observed. RESULTS: The scores of MMSE before treatment and 12 weeks after treatment were 18.00 +/- 3.88 and 20.83 +/- 3.74 in the auricular point taping and pressing group, and 17.80 +/- 3.82 and 20.70 +/- 3.53 in the western medicine group, respectively, with significant increases in scores of MMSE after treatment in the two groups (both P < 0.01) and with no significant difference between the two groups (P > 0.05). The scores of ADL before treatment and 12 weeks after treatment were 44.90 +/- 14.84 and 39.60 +/- 12.45 in the auricular point taping and pressing group, and 45.70 +/- 14.86 and 39.10 +/- 13.44 in the western medicine group, respectively, with significant decreases after treatment in the two groups (both P < 0.01) and with no significant difference between the two groups (P > 0.05). In the auricular point taping and pressing group, 2 cases withdrew from the test because adhesive plaster allergic reaction induced severe itch of the auricle. In the western medicine group, one case had mild dizziness and another case had diarrhea respectively. CONCLUSION: Auricular point taping and pressing and Nimodipine have similar therapeutic effect on vascular dementia, and have no obvious adverse reaction, except adhesive plaster allergic reaction.