A new extraction process of refractory gold arsenosulfide concentrates

A new hydrometallurgical process for the refractory gold arsenosulfideconcentrates under normal temperature and pressure was presented. The experimental results of arefractory gold concentrate show that the total consumption of NaOH in alkaline leaching is only 40%of those theoretically calculated under the conditions of full oxidization at the same oxidation ofarsenic to ar-senate and sulfur to sulfate. After alkaline leaching, cyanidation and adsorptionwere carried out for 24 h. The dissolution of gold by NaCN is increased to 95.3% from 12.8% beforepretreatment, and meanwhile 99.3% of the adsorption of gold by activated charcoal. The consumptionof NaCN for one ton ore is 10 kg, which is 1.2 times less than that before pretreatment. As it iscarried out under normal temperature and pressure, the investment of installations is alsodecreased.

弹性蛋白酶注射部位及结扎动脉对小鼠颅内动脉瘤模型成瘤率的影响

目的探索弹性蛋白酶注射的两种不同部位以及结扎左颈总动脉及右肾动脉对于小鼠颅内动脉瘤成瘤率及破裂率的影响。方法16周龄C57BL/6雄性野生型小鼠行左颈总动脉及右肾动脉结扎,1周后依据脑定位图谱向囟前注射点定位坐标(前囟点前侧1.2mm,右侧0.7 mm,深5 mm)或囟后注射点定位坐标(前囟点后侧2.5 mm,右侧1.0mm,深5 mm)注射35 mU弹性蛋白酶,随即皮下植入血管紧张素Ⅱ微渗透泵。通过体视镜观察小鼠颅内动脉瘤成瘤及破裂,通过H&E染色观察脑血管形态,TUNEL染色评价血管平滑肌细胞凋亡。结果动脉结扎显著增加颅内动脉瘤模型小鼠成瘤率及破裂率,且该动脉结扎手术显著加重了Willis环血管平滑肌细胞凋亡水平。但无论选择前囟门前方位置还是后方位置进行弹性蛋白酶注射,对于颅内动脉瘤模型小鼠成瘤率及破裂率均无显著影响。结论给予动脉结扎手术能显著提高颅内动脉瘤动物模型成瘤率及破裂率,为研究颅内动脉瘤分子机制及药物干预方法提供了新的可靠动物模型。