Behaviour of flotation tailings from a rare earth element deposit at high salinity.

Various rare earth element (REE) deposits hosted by carbonatite complexes have been identified in southern (Montviel, Niobec) and northern Quebec (Eldor deposit). During the winter in Quebec, the use of road salts to facilitate transportation on the mine site and/or avoid water freezing during mine operation may be necessary. The sources of salinity can be diverse on a mine site: process water, precipitation, alteration of minerals in the soil. Thus, tailings may come in contact with these salts and react. The purpose of the present study was to evaluate the impact of salinity on the behaviour of flotation tailings (Eldor deposit), i.e. the mobility of the elements contained in the tailings under these conditions and the environmental risks involved. For this purpose, leaching column tests were developed. The solutions were deionized water (CW column), NaCl (25 g/L; CS1 column) and CaCl2 (25 g/L; CS2 column). The leachate analysis revealed that the divalent cations (Ba, Cd, Mg, Mn, Sr, and Zn) are more mobile in the presence of CaCl2 (CaCl2 > NaCl > deionized water). The mobility of these elements appears to be governed by the competition with Ca2+ for tailings sorption sites. U and Sc are most mobile in the presence of salts regardless of the applied salt solution, i.e. CaCl2 = NaCl > deionized water. The formation of soluble chloride complexes with these elements could therefore be the cause of this phenomenon. For S, the leaching solution has no impact on its mobility. In conclusion, the presence of salts would tend to increase the mobility of divalent cations present in these residues and enhance their contamination potential. Modeling using PHREEQC software allowed comparison of these results with post-dismantling mineralogical characterization. Both methods showed: (i) total dissolution of fluorite [CaF2], galena [PbS], richterite [Na(CaNa(Mg,Fe2+)5[Si8O22](OH)] and Ba silicate; (ii) precipitation of iron oxides/hydroxides and silicate minerals. However, the modeling was unable to predict the behaviour of carbonate minerals. Further modeling tests involving kinetics should be considered in a future study.

Optimized indium solubilization from LCD panels using H2SO4 leaching.

Spent liquid crystal displays (LCDs) are a secondary source of precious/strategic metals, including indium (In). The present study involved optimizing the solubilization of this strategic element from samples of indium tin oxide (ITO) glass prepared from LCD screens of computer monitors and laptop screens. The influence of operating conditions on In solubilization, as well as optimum conditions for sulfuric acid leaching were defined by a Box-Behnken-type experimental design methodology. Optimum operating conditions include a leaching step for 30 min at a temperature of 70 °C in the presence of 0.4 N H2SO4 and a pulp density of 50% (w/v). Under these conditions, the quadratic model established to predict the solubilization of In from ITO glass samples provided an In solubilization efficiency of 89.7%, which was validated experimentally (99.5%). The analysis of direct operating costs and capital costs for the implementation of such a leaching process revealed that the process is conceivable for a high-capacity plant processing ~100 t/day of ITO glass.

Assessment of the leaching potential of flotation tailings from rare earth mineral extraction in cold climates.

Increasing use of rare earth elements (REEs) in modern technologies and existing or expected imbalances between demand and supply have led many countries, including Canada, to consider the exploitation of their own REEs primary sources. The objective of this study is a thorough characterization of the flotation tailings generated during the pre-concentration of REEs from a carbonatite type deposit with the aim of predicting their geochemical behaviour over time. These tailings were characterized based on physicochemical and mineralogical properties. Weathering cells were also used to assess the impact of temperature (3 and 19 °C) on the geochemical behaviour of the tailings exposed to a sub-arctic climate. Because the tailings consisted mainly of carbonates (97.4%) and had very high neutralization potential (859 kg CaCO3/t) relative to their acidity potential (3.94 kg CaCO3/t), no acid mine drainage (AMD) is anticipated. Compared to regional environmental standards and guidelines, the concentrations of Cd (0.20 µg/l), Zn (17 µg/l), and Pb (close to 4 µg/l) in leachates obtained during kinetic testing may be considered as potentially problematic. Finally, the results of the weathering cells at 3 °C indicate that the exposure to low temperatures may increase the concentrations of elements leached from the tailings. This study confirms that low temperatures and freeze-thaw events, which occur readily in a sub-arctic climate, may impact the geochemical behaviour of tailings produced from the extraction of REEs from carbonatite type deposit.

Effects of pulmonary artery banding in doxorubicin-induced left ventricular cardiomyopathy.

OBJECTIVE: Central pulmonary banding has been proposed as a novel alternative for the treatment of left ventricular dilated cardiomyopathy in children. We sought to investigate the effects of central pulmonary banding in an experimental model of doxorubicin-induced left ventricular dilated cardiomyopathy. METHODS: Four-month-old sheep (n = 28) were treated with intermittent intracoronary injections of doxorubicin (0.75 mg/kg/dose) into the left main coronary artery. A total dose of up to 2.15 mg/kg of doxorubicin was administered until signs of left ventricular dilation with functional impairment occurred by transthoracic echocardiography evaluation. Animals that survived were treated with surgical central pulmonary banding through a left anterior thoracotomy or sham surgery. Transthoracic echocardiography and pressure-volume loop measurements were used to compare left ventricular function preoperatively and 3 months later. Macroscopic and microscopic histologic examinations followed after hearts were harvested. RESULTS: Nine animals from the central pulmonary banding group and 8 animals from the sham group survived and were included in the final analysis. Both groups showed similar inflammation and fibrosis upon histologic examination consistent with the toxic myocardial effects of doxorubicin. There were no differences in the echocardiographic measurements before central pulmonary banding or sham operation. Baseline measurements before the central pulmonary banding/sham operation were considered as 100%. The central pulmonary banding group had better left ventricular ejection fraction (102.5% ± 21.6% vs 76.7% ± 11.7%, P = .01), with a tendency for smaller left ventricular end-diastolic (101.2% ± 7.4% vs 120.4% ± 10.8%, P = .18) and significantly smaller end-systolic (100.3% ± 12.9% vs 116.5 ± 9.6%, P = .02) diameter of the left ventricle in comparison with the sham animals at 3 months. The end-systolic volume (101.4% ± 31.6% vs 143.4% ± 28.6%, P = .02) was significantly lower in the central pulmonary banding group 3 months postoperatively. Fractional shortening in the long axis (118.5% ± 21.5% vs 85.2% ± 22.8%, P = .016) and short axis (122.5% ± 18% vs 80.9% ± 13.6%, P = .0005) revealed significantly higher values in the central pulmonary banding group. In the conductance catheter measurements, no significant differences were seen between the groups for the parameters of systolic and diastolic function. CONCLUSIONS: Central pulmonary artery banding in the setting of experimental toxic left ventricular dilated cardiomyopathy improved left ventricular echocardiographic function and dimensions.

Histological effect on the adipocutaneous flap in rats after preconditioning with 2-chloro-N(6) -cyclopentyladenosine.

BACKGROUND: 2-chloro-N(6) -cyclopentyladenosine (CCPA) was proven to be a protective factor in ischemic reperfusion injury. The purpose of this study was to determine how CCPA would affect the single tissue layers of the adipocutaneous flap. METHODS: Seventy male Wistar rats were divided into 5 experimental groups. Samples were taken of the area of flap necrosis and the wound margin after classical or pharmacological preconditioning on the fifth postoperative day. All samples were fixed in formaldehyde, embedded in paraplast, and analyzed in 3- to 4-µm sections (hemalaun-eosin stain and light microscopy). RESULTS: In general, wound healing was alike and remained unaffected by the experimental design. The most sensitive part of the flap during preconditioning is the subcutis. The number of neutrophils and of plasma cells is reduced significantly (p < .05). CONCLUSION: CCPA has an effect on each tissue layer of the flap. Subcutis became apparent as the most sensitive layer. CCPA influences complement pathway and neutrophils directly and indirectly.

Examination of the Anti-Inflammatory, Antioxidant, and Xenobiotic-Inducing Potential of Broccoli Extract and Various Essential Oils during a Mild DSS-Induced Colitis in Rats.

Phytogenic compounds with antioxidant and anti-inflammatory properties are currently discussed as promising complementary agents in prevention and treatment of inflammatory bowel disease (IBD). Our study aimed to evaluate possible protective and curative effects of broccoli extract (BE) and of the essential oils of turmeric (Cuo), thyme (To), and rosemary (Ro) in a rat model with a mild dextran sulphate sodium- (DSS-) induced colitis. Therefore Wistar rats were fed a diet without an additive (Con) or diets with the addition of BE, Cuo, To, and Ro during the whole experiment. Pretreatment with Ro, Cuo, and To increased the expression of the tight junction protein Cldn3. All additives reduced mRNA of VCAM-1 which plays a crucial role in the first state of inflammatory response. Only Ro pretreatment affected the expression of the antioxidant enzymes HO1, GPx2, and of glutathione-S-transferases. All additives counteracted the DSS-induced rise in COX2 and VCAM-1 expression. Colonic IL-10 was increased by Cuo, To, and Ro. During the recovery phase DSS pretreatment increased NF κ B, VCAM-1, and MCP-1: This response was counter-regulated by all additives. We conclude that the phytogenic additives tested have a promising anti-inflammatory potential in vivo and a particular role in the prevention of IBD.

Advocating for environmental changes to increase access to parks: engaging promotoras and youth leaders.

Access to physical activity opportunities are limited in underserved communities. Community-based programs can increase promotoras and youth leaders' capacity to advocate for built environmental changes. Promotoras and youth leaders were trained on walkability assessment, park audits, and advocacy. The youth and promotoras from one church located adjacent to a park implemented a community survey, conducted walk audits, and engaged in consciousness-raising activities about environmental factors that affect communities. They also mobilized community members to advocate for a nearby park. Advocacy tactics included attending and making presentations at the City Council, planning meetings, organizing health fairs, and speaking to community members. The following changes were made at the park: removed overgrown plants, relocated storage container, increased park security (i.e., lighting, fencing), improved safety (i.e., covered sewer drain, sand lot removed), enhanced amenities (i.e., drinking fountain, bathroom, benches, tables), improved pedestrian safety in park (i.e., leveled the old and added new walking paths), and improved children's play area (i.e., new play equipment, fencing). The current program highlights factors that contributed to park changes and challenges in increasing access to parks. Furthermore, the current study notes steps that other programs can take to make environmental changes.

Feeding of selenium alone or in combination with glucoraphanin differentially affects intestinal and hepatic antioxidant and phase II enzymes in growing rats.

The anti-carcinogenic effects of sulforaphane (SFN) are based on the up-regulation of antioxidant enzymes (AE) and phase II enzymes (PIIE) through the transcription factor Nrf2. Current knowledge on the roles of the SFN precursor glucoraphanin (GRA) on these processes is limited. Anti-carcinogenic effects of Se depending on glutathione peroxidase (GPx) activity have also been reported. We studied effects and possible synergisms of Se and GRA on the expression and activity of a broad spectrum of AE and PIIE in jejunum, colon and the liver of rats fed diets differing in Se and GRA concentration. In all organs, GPx1 mRNA expression was 70 % to 90 % lower in Se deficiency than in Se sufficiency. GPx2 expression increased in jejunum and liver under Se deficiency and decreased in the colon. Se deficiency increased most colonic AE and PIIE compared to Se adequacy. Adequate and in particular supranutritive Se combined with GRA increased colonic AE and PIIE expression up to 3.72-fold. In the liver Se deficiency raised the expression of AE and PIIE up to 4.49-fold. GRA attenuated liver AE and PIIE response in Se deficiency. Expression- and correlation analyses revealed that Keap1 mRNA better reflects AE and PIIE gene expression than Nrf2 mRNA. We conclude that: (1) GPx1 sensitively indicates Se deficiency; (2) the influence of Se and Nrf2/Keap1 on GPx2 expression depends on the organ; (3) GRA combined with supranutritive Se may effectively protect against inflammation and colon cancer; (4) future investigations on AE and PIIE expression should consider the role of Keap1 to a higher extent.

Influence of broccoli extract and various essential oils on performance and expression of xenobiotic- and antioxidant enzymes in broiler chickens.

The aim of our present study was to examine the regulation of xenobiotic- and antioxidant enzymes by phytogenic feed additives in the intestine and the liver of broilers. A total of 240 male Ross-308 broiler chickens (1 d old) were fed a commercial starter diet for 2 weeks. On day 15, the birds were assigned to six treatment groups of forty birds each. The control (Con) group was fed a diet without any additive for 3 weeks. The diet of group sulforaphane (SFN) contained broccoli extract providing 0.075 g/kg SFN, whereas the diets of the other four groups contained 0.15 g/kg essential oils from turmeric (Cuo), oregano (Oo), thyme and rosemary (Ro). Weight gain and feed conversion were slightly impaired by Cuo and Oo. In the jejunum SFN, Cuo and Ro increased the expression of xenobiotic enzymes (epoxide hydrolases 1 and 2 and aflatoxin B1 aldehyde reductase) and of the antioxidant enzyme haeme oxygenase regulated by an 'antioxidant response element' (ARE) compared to group Con. In contrast to our expectations in the liver, the expression of these enzymes was decreased by all the additives. Nevertheless, all the additives increased the Trolox equivalent antioxidant capacity of the jejunum and the liver and reduced Fe-induced lipid peroxidation in the liver. We conclude that the up-regulation of ARE genes in the small intestine reduces oxidative stress in the organism and represents a novel mechanism by which phytogenic feed additives improve the health of farm animals.

Glucoraphanin does not reduce plasma homocysteine in rats with sufficient Se supply via the induction of liver ARE-regulated glutathione biosynthesis enzymes.

Data from human and animal trials have revealed contradictory results regarding the influence of selenium (Se) status on homocysteine (HCys) metabolism. It was hypothesised that sufficient Se reduces the flux of HCys through the transsulphuration pathway by decreasing the expression of glutathione (GSH) synthesising enzymes. Glucoraphanin (GRA) is a potent inducer of genes regulated via an antioxidant response element (ARE), including those of GSH biosynthesis. We tested the hypothesis that GRA supplementation to rat diets lowers plasma HCys levels by increasing GSH synthesis. Therefore 96 weaned albino rats were assigned to 8 groups of 12 and fed diets containing four different Se levels (15, 50, 150 and 450 µg kg(diet)(-1)), either without GRA (groups: C15, C50, C150 and C450) or in combination with 700 µmol GRA kg(diet)(-1) (groups G15, G50, G150 and G450). Rats fed the low Se diets C15 and G15 showed an impressive decrease of plasma HCys. Se supplementation increased plasma HCys and lowered GSH significantly by reducing the expression of GSH biosynthesis enzymes. As new molecular targets explaining these results, we found a significant down-regulation of the hepatic GSH exporter MRP4 and an up-regulation of the HCys exporter Slco1a4. In contrast to our hypothesis, GRA feeding did not reduce plasma HCys levels in Se supplemented rats (G50, G150 and 450) through inducing GSH biosynthesis enzymes and MRP4, but reduced their mRNA in some cases to a higher extent than Se alone. We conclude: 1. That the long-term supplementation of moderate GRA doses reduces ARE-driven gene expression in the liver by increasing the intestinal barrier against oxidative stress. 2. That the up-regulation of ARE-regulated genes in the liver largely depends on GRA cleavage to free sulforaphane and glucose by plant-derived myrosinase or bacterial ß-glucosidases. As a consequence, higher dietary GRA concentrations should be used in future experiments to test if GRA or sulforaphane can be established as HCys lowering compounds.

Study of molecular targets influencing homocysteine and cholesterol metabolism in growing rats by manipulation of dietary selenium and methionine concentrations.

Inconsistent results exist from human and animal studies for Se and methionine (Met) regarding their influence on homocysteine (HCys) and cholesterol (Chol) metabolism. To elucidate these contradictions, sixty-four weanling albino rats were divided into eight groups of 8, and were fed diets containing four different Se levels (15, 50, 150 and 450 microg/kg) either in combination with the recommended Met level of 3 g/kg (C15, C50, C150 and C450) or with an increased Met concentration of 15 g/kg (M15, M50, M150 and M450) for 8 weeks. Plasma HCys was twofold higher in the Se-supplemented C groups than in group C15. Met addition also doubled plasma HCys compared with the respective C groups. In contrast, the expression of the key enzymes of glutathione biosynthesis in the liver was significantly lowered by Se and in particular by Met. Liver Chol concentration was significantly higher in all the Se-supplemented C and M groups than in groups C15 and M15. Plasma Chol was, however, lowered. The uninfluenced expression of sterol-regulatory element-binding protein 2 and of hydroxymethyl-glutaryl-CoA reductase, the increased LDL receptor expression and the reduced expression of the hepatobiliary Chol exporter ATP-binding-cassette-transporter 8 (ABCG8) by Se and/or Met explain these findings. We conclude that the elevation of plasma HCys in rats by Se and Met results from a higher export into plasma. The fact that Se in particular combined with Met increases liver Chol but reduces plasma Chol should be addressed in future investigations focussing on the regulation of ABCG8, which is also selectively involved in the reverse transport of phytosterols in the small intestine.

Selenium and diabetes: an enigma?

In recent years diabetes has become one of the most common metabolic diseases in developed countries and it is closely related to supernutrition and obesity. Since untreated diabetes produces oxidative stress responsible for secondary complications of the disease, antioxidant supplements were considered as being favourable for the therapy of diabetes. However, the situation has changed recently, since large cross-sectional and interventional trials revealed a positive correlation between a high Se status and diabetes incidence in humans. Thus, currently available data on the role of Se in diabetes are inconsistent and an enigma appears to exist for the relation between selenium and diabetes. This review summarizes selected human and animal studies, pointing to beneficial and critical virtues of Se in diabetes. Moreover, the review discusses possible underlying mechanisms how Se may influence diabetes in both directions. From the current literature, the following information can be extracted: (1) In populations with a high Se status, with the single exception of pregnant women, Se supplements cannot be recommended for the prevention of diabetes; (2) Anti-diabetic effects of Se seem to be restricted to high and nearly toxic doses which cannot be used in humans; and (3) Future investigations should consider the stage of the disease.

[Diagnostic value of nasometry--representative study of patients with cleft palate and normal subjects]. / Die diagnostische Wertigkeit der Nasometrie--eine reprasentative Studie fur Patienten mit Lippen-Kiefer-Gaumensegel-Spalten und Gesunde.

In the rehabilitation of cleft palate patients the quality of spoken language represents one of the most important aspects of successful social integration. It is therefore necessary to direct special attention to phoniatric care and speech therapy following operative reconstruction. One of the main problems is the comparison of subjective and objective measures of the degree and type of nasal disorder. In an interdisciplinary project at the University of Jena nasometry was assessed. Due to a lack of norm values for German a representative sample for the calibration of cleft palate patients and normal subjects was collected. Speech was elicited using standardized and phonetically validated reading materials. Nasalance measurements were compared with judgements made by a group of trained listeners who were asked to assess voice quality (RBH) and nasality. A database containing nasalance values and acoustic signals from 120 subjects was built up. The results generally exhibited highly significant correlations between instrumental measurements and auditory judgements. Profiles of norm values for a phonetically and statistically reliable standard for German were obtained, which in turn can be used as a comparative basis for further studies.

Restaurant and food shopping selections among Latino women in Southern California.

OBJECTIVE: This study describes and examines determinants of restaurant and food store selections in a sample of Latino women. DESIGN: Data were collected at the baseline home-based interview from women involved in a randomized community trial to improve dietary behaviors. The interview consisted of both a structured interview and the measurements of height, weight, and waist-to-hip ratio. SUBJECTS/SETTING: Participants included 357 Latino women recruited via random-digit dial in the Southern and Central areas of San Diego County, California. Women were included if they were between 18 and 67 years of age, not currently pregnant, and Spanish-language dominant; women were excluded if a family member was on a special diet or was planning to leave the area during the study. STATISTICAL ANALYSES PERFORMED: Means and frequencies were used to describe preference for various types of restaurants and food stores based on the North American Industry Classification System (NAICS). Independent samples t tests examined differences in levels of importance for preferring fast-food vs other restaurants and supermarkets/produce markets vs other grocery stores. Logistic regression models examined correlates of preferring fast-food restaurants vs all other restaurants and preferring supermarkets/produce markets vs all other grocery stores. RESULTS: More women reported eating at fast-food restaurants, followed by full-service restaurants and cafeterias. Younger women, employed women, women living in higher income households, and women living in the United States for a greater number of years preferred fast food. Supermarkets; grocery stores; and discount, bulk-purchase stores were equally represented as the primary food store. Women who lived in smaller households, had a smaller measured body mass, were married, and were more acculturated to the Anglo culture were more likely to shop at supermarkets compared with women who shopped at other grocery stores. CONCLUSIONS: Our findings suggest specific recommendations for targeting dietary interventions for the growing Latino population that take into account differences in levels of acculturation. For example, young Latino women who more closely identify with the Anglo culture and/or who report living in the United States for a longer period of time may benefit from targeted information on healthy restaurant behavior. On the other hand, traditional Latino women may benefit from instrumental support interventions such as tours to large supermarkets.