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Low-grade polymetallic chalcopyrite ore has a high lead and iron content and a low softening point, which is difficult to treat using conventional pyrometallurgical and hydrometallurgical processes. In order to investigate the suitable methodology for efficient utilization, it was pelletized with CaO for oxidation roasting in the present work. By controlling the Po2 and Pso2 in the gas phase, the metal sulfide in the ore was converted into easily soluble metal oxide, the thermal analysis of the roasting process was carried out and the acid leaching of the extracted calcine at atmospheric pressure was investigated. The results show that by pelletizing with CaO and then roasting at 800 ℃ for 1 h, chalcopyrite is converted into CuO, which can be easily dissolved, galena and pyrite are converted into PbO2 and Fe2O3, respectively, and sulfur reacts with CaO and turns into CaSO4, which can fix the sulfur in the calcine. The copper leaching rate of calcine can reach 98.60 wt.% under atmospheric pressure in the H2SO4-H2O system. CaO can increase the softening point of raw materials, improve the roasting effect, promote the phase transformation of chalcopyrite in the oxidation process, and convert sulfur into CaSO4 to fix sulfur, effectively avoiding SO2 pollution to the environment.

OBJECTIVE: Dysregulation of miR-592 has been reported in several tumors. However, its role in acute myeloid leukemia (AML) remains unknown. The present study aimed at investigating the expression pattern and biological function of miR-592 in AML and to elucidate the mechanism involved. PATIENTS AND METHODS: qRT-PCR was used to analyze the expression of miR-592 in bone marrow and serum obtained from AML patients and healthy controls. The associations between serum miR-592 expression and clinical features and prognosis of AML patients were statistically analyzed. Then we detected the effect of miR-592 on proliferation, metastasis and apoptosis by CCK-8 assay, Transwell assays and flow cytometry, respectively. Dual-luciferase reporter assays were performed to validate the regulation of a putative target of miR-592. Rescue experiments were performed to confirm whether ROCK1 was a direct and functional target of miR-592 in AML. RESULTS: We found that the expression level of miR-592 was significantly lower in AML patients and AML cell lines. Low expression of serum miR-592 was associated with advanced French-American-British classification, cytogenetics and poor prognosis. Multivariate analysis confirmed that serum miR-592 expression was an independent prognostic factor for AML patients. Functionally, overexpression of miR- 592 suppressed AML cell growth and metastasis, and promoted apoptosis. Further mechanistic investigation showed ROCK1 was a direct target gene of miR-592. Finally, ROCK1 overexpression rescued the effect of miR-592-mediated AML cell proliferation and metastasis. CONCLUSIONS: These findings suggest that miR-592 acted as a tumor suppressor by targeting ROCK1 and may serve as a potential biomarker in AML. [ABSTRACT FROM AUTHOR]

Pseudobinary Pr[sub 1-x]Tb[sub x](Fe[sub 0.6]Co[sub 0.4])[sub 2] (0≤x≤0.4) cubic Laves single phases have been synthesized by melt spinning and subsequent annealing. Their structure, magnetic properties and stability have been investigated. The composition, at which the anisotropy of Pr[sub 1-x]Tb[sub x](Fe[sub 0.6]Co[sub 0.4])[sub 2] is compensated, is close to x=0.1. The spontaneous magnetostrictions λ[sub 111] of Pr[sub 0.9]Tb[sub 0.1](Fe[sub 0.6]Co[sub 0.4])[sub 2] and Pr[sub 0.8]Tb[sub 0.2](Fe[sub 0.6]Co[sub 0.4])[sub 2] are larger than 1500×10[sup -6] and 1900×10[sup -6], respectively. Pr[sub 1-x]Tb[sub x](Fe[sub 0.6]Co[sub 0.4])[sub 2] (0.1≤x≤0.4) ribbon-based materials with 3% epoxy resin combine high magnetostriction with significant magnetic coercivity. Pr[sub 0.9]Tb[sub 0.1](Fe[sub 0.6]Co[sub 0.4])[sub 2] is a promising magnetostrictive material. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]