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In this study, we have developed a novel method for ilmenite activation. Sodium hypochlorite was used as an oxidant and surface modifier to promote ilmenite flotation. And it has successfully been performed valence transitions of iron atoms on the ilmenite surface, thereby enhancing the action activity between the surface sites of ilmenite and sodium oleate. Eventually the surface Fe3+ content increased from 42.15 to 63.79%. Oxidation by sodium hypochlorite increased the amount of Fe3+ on the ilmenite surface by 21.64% and improved the ilmenite recovery to 95%, while the maximum recovery of ilmenite without sodium hypochlorite addition was only 85%. The activation mechanism of ilmenite by sodium hypochlorite was studied by batch flotation, Zeta potential measurement, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and reaction thermodynamic analysis. The results of potential measurement show that sodium hypochlorite made the Zeta potentials of ilmenite–sodium oleate system more negative mainly due to the enhanced adsorption effect between them. FTIR results indicate that more prominent absorption peak of iron oleate appeared in the FTIR spectrum of ilmenite treated with sodium oleate after sodium hypochlorite oxidation. XPS analyses suggest that more Fe2+ on ilmenite surface supplied electrons to the oxidant and formed more Fe3+. Reaction thermodynamic analyses also show that compared with Fe2+, Fe3+ was more likely to interact with oleate ions and formed more stable species. In summary, sodium hypochlorite can activate ilmenite and improve its flotation.

The selective action mechanism of sodium butyl xanthate (BX), ammonium salt (NH

A hydroxylated xanthate salt (HXS) was synthesized from ethanol, carbon disulfide, and NaOH. The flotation responses of chalcopyrite and molybdenite when HXS was used as a novel depressant were investigated using bench-scale flotation tests. The bench-scale flotation results indicate that HXS strongly influenced the flotation of chalcopyrite and had little effect on the flotation of molybdenite. These results can be attributed to a significant improvement in the molybdenite/chalcopyrite selectivity surface index after the addition of HXS. The synthesized HXS contained both solid-philic and hydrophilic groups. The molybdenum recovery achieved using HXS was 9.91% higher than that obtained using sodium hydrosulfide, and better separation was achieved. Compared with sodium hydrosulfite, the chemical oxygen demand, sulfates and five-day BOD decreased significantly using the alternative depressant. This HXS is therefore a potential depressant for use in copper-molybdenum separation.

INTRODUCTION Neurotrophin receptors, such as p75(NTR) , direct neuronal response to injury. Insulin-like growth factor-1 receptor (IGF-1R) mediates the increase in p75(NTR) during aging. The aim of this study was to examine the effect of aging and insulin-like growth factor-1 (IGF-1) treatment on recovery after peripheral nerve injury. METHODS Young and aged rats underwent tibial nerve transection with either local saline or IGF-1 treatment. Neurotrophin receptor mRNA and protein expression were quantified. RESULTS Aged rats expressed elevated baseline IGF-1R (34% higher, P = 0.01) and p75(NTR) (68% higher, P

This study proposed a novel activation method for ilmenite by using potassium permanganate as an oxidant and a surface modifier. The valence state of iron atoms on the ilmenite surface was transformed under weak-acid conditions; therefore, the interaction between Fe sites on the ilmenite surface and sodium oleate was enhanced. The flotation of ilmenite was improved with a high recovery close to 90 %. The activation mechanism was studied via batch flotation, zeta-potential measurements, X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The results showed that under weak-acid conditions, potassium permanganate promoted the interaction between sodium oleate and ilmenite. The addition of potassium permanganate resulted in new characteristic absorption peaks in the infrared spectra of the ilmenite, and the chemical shifts at 1559.78 cm−1 and 1444.94 cm−1 were greater than those of the unactivated ilmenite. The positive shift of the binding energy of Fe 2p promoted the electron supply of Fe(II) to the permanganate ions. The Fe(III) content on the ilmenite surface greatly increased, making the interaction with sodium oleate easier. Thus, potassium permanganate promoted the valence transition of Fe(II) to Fe(III) and enhanced the adsorption between minerals and collectors, which ultimately improved the flotation recovery of ilmenite.

Copper-bearing ore containing talc is generally considered as the most refractory type in various chalcopyrite ores, which is predominantly due to the fact that it includes talc and good natural floatability of talc adversely affects the recovery of chalcopyrite. Flotation is the most economical and effective method to separate copper sulfide minerals and talc. For flotation process, there are selective flotation of talc before flotation of copper-bearing minerals, the flotation of copper-bearing minerals with depression of talc, and the bulk flotation of talc and copper-bearing minerals. At present, the researches focus on the depression of talc. The present work reviewed the molecular structure, properties and mechanism of organic and inorganic depressors for talc. The mechanism of action of depressors for talc includes electrostatic interaction, hydrogen bonding and chemical bonding. At the same time, factors such as pH and ionic strength have an important influence on depression effect for talc. The synergism of combined depressors has various novel depression effects on talc surface, which is more efficient than single agent. In the future, separation technology for talc and chalcopyrite develops toward the application of new depressors and the modification of agents. Meanwhile, the development of new depressors for talc needs to consider the properties of associated minerals with talc and copper-bearing minerals. The combined depressors should be developed to maximize the recovery of valuable metals.

A common treatment of advanced prostate cancer involves the deprivation of androgens. Despite the initial response to hormonal therapy, eventually all the patients relapse. In the present study, we sought to determine whether dietary polyunsaturated fatty acid (PUFA) affects the development of castration-resistant prostate cancer. Cell culture, patient tissue microarray, allograft, xenograft, prostate-specific Pten knockout and omega-3 desaturase transgenic mouse models in conjunction with dietary manipulation, gene knockdown and knockout approaches were used to determine the effect of dietary PUFA on castration-resistant Pten-null prostate cancer. We found that deletion of Pten increased androgen receptor (AR) expression and Pten-null prostate cells were castration resistant. Omega-3 PUFA slowed down the growth of castration-resistant tumors as compared with omega-6 PUFA. Omega-3 PUFA decreased AR protein to a similar extent in tumor cell cytosolic and nuclear fractions but had no effect on AR messenger RNA level. Omega-3 PUFA treatment appeared to accelerate AR protein degradation, which could be blocked by proteasome inhibitor MG132. Knockdown of AR significantly slowed down prostate cancer cell proliferation in the absence of androgens. Our data suggest that omega-3 PUFA inhibits castration-resistant prostate cancer in part by accelerating proteasome-dependent degradation of the AR protein. Dietary omega-3 PUFA supplementation in conjunction with androgen ablation may significantly delay the development of castration-resistant prostate cancer in patients compared with androgen ablation alone.

Purpose: Hypoxia is a cause for resistance to cancer therapies. Molecularly targeted recombinant cytotoxins have shown clinical efficacy in the treatment of patients with primary brain tumors, glioblastoma multiforme, but it is not known whether hypoxia influences their antitumor effect. Experimental Design: We have exposed glioblastoma multiforme cells, such as U-251 MG, U-373 MG, SNB-19, and A-172 MG, to either anoxia or hypoxia and then reoxygenated them while treating with an interleukin (IL)-13-based diphtheria toxin (DT)-containing cytotoxin, DT-IL13QM. We measured the levels of immunoreactive IL-13Rα2, a receptor that mediates IL-13-cytotoxin cell killing, and the levels of active form of furin, a protease that activates the bacterial toxin portion in a cytotoxin. Results: We found that anoxia/hypoxia significantly alters the responsiveness of glioblastoma multiforme cells to DT-IL13QM. Interestingly, bringing these cells back to normoxia caused them to become even more susceptible to the cytotoxin than the cells maintained under normoxia. Anoxia/hypoxia caused a highly prominent decrease in the immunoreactive levels of both IL-13R and active forms of furin, and reoxygenation not only restored their levels but also became higher than that in normoxic glioblastoma multiforme cells. Conclusions: Our results show that a recombinant cytotoxin directed against glioblastoma multiforme cells kills these cells much less efficiently under anoxic/hypoxic conditions. The reoxygenation brings unexpected additional benefit of making glioblastoma multiforme cells even more responsive to the killing effect of a cytotoxin.

INTRODUCTION: Neurotrophin receptors, such as p75(NTR), direct neuronal response to injury. Insulin-like growth factor-1 receptor (IGF-1R) mediates the increase in p75(NTR) during aging. The aim of this study was to examine the effect of aging and insulin-like growth factor-1 (IGF-1) treatment on recovery after peripheral nerve injury. METHODS: Young and aged rats underwent tibial nerve transection with either local saline or IGF-1 treatment. Neurotrophin receptor mRNA and protein expression were quantified. RESULTS: Aged rats expressed elevated baseline IGF-1R (34% higher, P =0.01) and p75(NTR) (68% higher, P

Purpose: The novel fusion protein, DAB389EGF, composed of the catalytic and translocation domains of diphtheria toxin (DAB389) fused with a His-Ala linker to human epidermal growth factor (EGF) was tested for antiglioma efficacy in an in vivo model of human glioma. Experimental Design: Female athymic nude mice (ages 4-6 weeks) were inoculated s.c. with 10 million U87MG human glioma cells in the right flank. When tumor volumes reached ∼100 mm3 (∼6-8 days), i.t. injections of saline, DAB389IL2, or DAB389EGF 1, 3, 5 or 10 μg in 50 μL were given every other day for three to six doses. Animals were monitored twice daily and tumor measurements were made by calipers. Results: The maximal tolerated dose (MTD) of DAB389EGF was 3 μg every other day. Above the MTD, animals experienced loss of activity, reduced oral intake, and dehydration. Blood chemistries confirmed elevated blood urea nitrogen, creatinine, aspartate transaminase, and alanine transaminase. Histopathology revealed renal tubular necrosis. At the MTD, tumor regression was seen in all animals. Relapses occurred in 4 of 16 (25%) of animals after 1 month. These tumors contained EGF receptor, were sensitive in vitro to DAB389EGF, and responded to a second course of i.t. DAB389EGF. Conclusions: DAB389EGF fusion protein shows in vivo antiglioma efficacy in a s.c. tumor model and warrants further preclinical testing in an i.c. tumor model for eventual treatment of patients with recurrent or refractory EGF receptor–positive glioblastoma multiforme.