Biological sulphate removal from industrial effluent in an upflow packed bed reactor

A biological process for the removal of sulphate, using molasses as organic carbon source, is described. Sulphate is converted to sulphur via sulphide, and molasses to bicarbonate. Sulphate reducing bacteria are responsible for the reduction of sulphate to sulphide, while photosynthetic sulphur bacteria oxidize sulphide to elemental sulphur. It has been shown that these bacteria can live symbiotically in an upflow anaerobic packed bed reactor. The process is accompanied by the precipitation of calcium carbonate and heavy metal sulphides. Sulphate reduction follows zero order kinetics with respect to both reactants and products. The reduction of 1 g sulphate consumes 1.2 ml molasses and requires 6 h for completion. The optimum temperature for sulphate reduction was found to be 31°C.     

Isoflavonoid feeding deterrents forCostelytra zealandica Structure — Activity relationships

A number of naturally occurring isoflavonoids of differing substitution patterns and oxidation states have been tested for feeding deterrent activity in a bioassay with larvae ofCostelytra zealandica White. The most active deterrents, which reduced feeding significantly at 0.2-1.0 g/g, are those compounds containing a ring B-fused cycloprenoid moiety. The least active compounds were highly oxidized coumestans and isoflavones. The ring B-fused cyclic isoprenoid moiety and the presence of a 2'-oxy function appear to be structural features important for high activity. It is suggested that the feeding deterrent activity of isoflavonoids relates to their stereochemistry and that the most active compounds have or can adopt a similar nonplanar molecular shape with a similar arrangement of polar and lipophilic groups.     

Modification of cardiovascular risk in hemodialysis patients: an evidence-based review

Cardiovascular disease accounts for 40% to 50% of deaths in dialysis populations. Overall, the risk of cardiac mortality is 10-fold to 20-fold greater in dialysis patients than in age and sex-matched controls without chronic kidney disease. The aim of this paper is to review critically the evidence that cardiac outcomes in dialysis patients are modified by cardiovascular risk factor interventions. There is limited, but as yet inconclusive controlled trial evidence that cardiovascular outcomes in dialysis populations may be improved by antioxidants (vitamin E or acetylcysteine), ensuring that hemoglobin levels do not exceed 120 g/L (especially in the setting of known cardiovascular disease), prescribing carvedilol in the setting of dilated cardiomyopathy, and by using cinacalcet in uncontrolled secondary hyperparathyroidism. Similarly, there are a number of negative controlled trials, which have demonstrated that statins, high-dose folic acid, angiotensin-converting enzyme inhibitors, multiple risk factor intervention via multidisciplinary clinics, and high-dose or high-flux dialysis are ineffective in preventing cardiovascular disease. Although none of these studies could be considered conclusive, the negative trials to date should raise significant concerns about the heavy reliance of current clinical practice guidelines on extrapolation of findings from cardiovascular intervention trials in the general population. It may be that cardiovascular disease in dialysis populations is less amenable to intervention, either because of the advanced stage of chronic kidney disease or because the pathogenesis of cardiovascular disease in dialysis patients is different from that in the general population. Large, well-conducted, multicenter randomized-controlled trials in this area are urgently required.     

(±)3,4-Methylenedioxymethamphetamine, d-Amphetamine, and Cocaine Impair Delayed Matching-to-Sample Performance by an Increase in Susceptibility to Proactive Interference.

This study compared the effects of (±)3,4-methylenedioxymethamphetamine, d-amphetamine, and cocaine on performance of rats in a delayed matching-to-sample procedure using a variety of indices of performance to determine the mechanism by which working memory task impairments arise. All 3 drugs produced an overall delay-independent decrease in accuracy rather than a delay-dependent increase in the rate of forgetting. This impairment arose as a result of current-trial choice responses being progressively more affected by responses made in the immediately preceding trial as drug dose increased. Therefore, all 3 drugs produced qualitatively similar disruptions in memory task performance best characterized as an impairment arising from proactive sources of interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The gypsum reduction process and its validation using the Mintek Pyrosim model

Waste gypsum is produced as a by-product from the fertilizer, mining industries, and acid mine water neutralization using calcium carbonate and/or lime and desalination processes using reverse osmosis and ion-exchange processes, resulting in environmental and storage problems. The purpose of the study was to establish optimum operating conditions for the recovery of valuable products, e.g., sulfur and precipitated calcium carbonate, from waste gypsum, hence, offer an attractive solution to the gypsum waste problem. The paper presents results on thermal studies of waste gypsum in a tube furnace and its validation using the Mintek Pyrosim model. Gypsum was homogeneously mixed with coal and the reduction experiments conducted. The following findings were made: (i) reduction of waste gypsum is an endothermic reaction since, ΔH values were greater than 0 (ΔH?>?0) when the reduction temperature was increased from 25 to 1200°C, (ii) energy requirement is dependent on temperature and gypsum to coal ratio. Gypsum to calcium sulfide conversion of 83.5 and 83.8% was obtained at the optimum temperature range of 1100–1200°C and gypsum to calcium sulfide conversion of 85.4% was obtained at the optimum coal to gypsum mole ratio of 2.1:1, (iii) excess coal gave a lower conversion, and (iv) the predicted data using Mintek Pyrosim were found to be similar to the experimental data.     

Distribution of Fucosylated Xyloglucans among the Walls of Different Cell Types in Monocotyledons Determined by Immunofluorescence Microscopy

Xyloglucans in the non-lignified primary cell walls of different species of monocotyledons have diverse structures,with widely varying proportions of oligosaccharide units that contain fucosylated side chains(F side chains).To determine whether fucosylated xyloglucans occur in all non-lignified walls in a range of monocotyledon species,we used immunofluorescence microscopy with the monoclonal antibody CCRC-M1.The epitope of this antibody,α-L-Fucp-(1→2)-β-D-Galp.occurs in F side chains.In most non-commelinid monocotyledons,the epitope was found in all non-lignified walls.A similar distribution was found in the palm Phoenix canariensis,which is a member of the basal commelinid order Arecales.However,in the other commelinid orders Zingiberales,Commelinales,and Poales,the occurrence of the epitope was restricted,sometimes occurring in only the phloem walls,but often also in walls of other cell types including stomatal guard and subsidiary cells and raphide idioblasts.No epitope was found in the walls of the commelinids Tradescantia virginiana(Commelinaceae,Commelinales)and Zea mays(Poaceae,Poales),but it occurred in the phloem walls of two other Poaceae species,Lolium multiflorum and L.perenne.The distribution of the epitope is discussed in relation to xyloglucan structures in the different taxa.However,the functional significance of the restricted distributions is unknown.     

Barium Carbonate Process for Sulphate and Metal Removal from Mine Water

Abstract.  The removal of sulphate and metals from mine water was assessed using the integrated barium carbonate process and the co-precipitation of barium sulphate with calcium carbonate. The rate of sulphate removal was influenced by the BaCO₃ concentration and the cation associated with sulphate, and increased with increasing BaCO₃-concentration. BaCO₃ can only be used for removal of sulphate that is associated with calcium, as calcium is needed to remove the added carbonate associated with the barium cation. Sulphate removal was only marginally influenced by alkalinity. Sulphide can be stripped with CO₂ from a BaS-solution. The (CO₂ dosed/sulphide removed) molar ratio was close to unity for the first 50% of sulphide in solution. The stripped H₂S-gas can be absorbed into zinc acetate. BaSO₄ and CaCO₃ can be converted simultaneously to BaS and CaO, respectively at an optimum temperature of 1050°C. The CaCO₃/BaSO₄ molar ratio has little influence on the yield of BaS. The running cost of the barium carbonate process for the removal of 2 g/L of sulphate totalled ZAR1.28/m³ (US$1.00 = ZAR7.0, Feb 2007), the capital redemption cost was R1.08/m³, and the value of the products (water and sulphur) totalled R2.76/m³.     

Herbal medicines and chemotherapy induced peripheral neuropathy (CIPN): A critical literature review

Background: Chemotherapy induced peripheral neuropathy [CIPN] is a common significant and debilitating side-effect resulting from the administration of neurotoxic chemotherapeutic agents. These pharmaco–chemotherapeutics can include taxanes, vinca alkaloids, platinum analogues, and others. Moderate to severe CIPN significantly decreases the quality of life and physical abilities of cancer patients and current pharmacotherapy for CIPN e.g. Amifostine, and antidepressants have had limited efficacy and may themselves induce adverse side-effects. Methods: To determine the potential use of herbal medicines as adjuvants in cancer treatments, a critical literature review was conducted by electronic and manual search on nine databases. These include PubMed, the Cochrane Library, Science Direct, Scopus, EMBASE, MEDLINE, Google Scholar, and two Chinese databases CNKI and CINAHL. Thirty-four studies were selected from 5614 studies assessed and comprising animal studies, case reports, retrospective studies, and minimal randomized clinical trials investigating the anti-CIPN effect of herbal medicines as the adjuvant intervention in patients administered chemotherapy. The thirty-four studies were assessed on methodological quality and limitations identified. Results: Studies were mixed in their recommendations for herbal medicines as an adjuvant treatment for CIPN. Conclusion: Currently no agent has shown solid beneficial evidence to be recommended for the treatment or prophylaxis of CIPN. Given that the number of cancer survivors is increasing, the long-term side effects of cancer treatment, is of major importance.