A novel slow-release selenium approach for cadmium reduction and selenium enrichment in rice (Oryza sativa L.).

In this study, a novel slightly-soluble selenium (Se) fertilizer (SSF) was successfully applied to address the problems of Cd pollution in paddy soil and rice, and Se deficiency in human beings. The pot and field experiments showed that Cd content in the rice grains was reduced by 48.4%-82.89% and Se content was increased nearly by 30-fold comparing the control group. The application of SSF increased the soil pH and significantly reduced the DGT-extracted Cd in the soil. Moreover, DCB-extractable Fe content on the surface of roots was prompt by SSF, which formed a physical barrier, namely iron plaque (IP), to inhibit Cd translocation to the above-ground tissues of the rice plants. The Cd content in the IP was also decreased before the filling period, possibly contributing to the reduction in major Cd accumulation in the rice grains. In addition, the continuous Se increase and Cd reduction in the IP by the SSF gradually exceeded that of water-soluble Se during the three periods of rice plant growth. This suggests that SSF has high potential to be an effective Se fertilizer for inhibiting Cd uptake and enriching Se in rice.

Selenium-sulfur functionalized biochar as amendment for mercury-contaminated soil: High effective immobilization and inhibition of mercury re-activation.

The contamination of soils by mercury (Hg) seriously threatens the local ecological environment and public health. S-functionalized amendments are common remediation technology, yet, Hg re-activation often occurs in the commonly used immobilization remediation by S-functionalized amendments, resulting in an unsatisfactory remediation effect. In this study, a novel FeS-Se functionalized biochar composite (FeS-Se-BC) amendment was prepared and applied for the efficient remediation of Hg-polluted soil. An immobilization efficiency of 99.62% and 99.22% for H2O-extractable Hg and TCLP solution-extractable Hg was achieved with the application of FeS-Se-BC(0.05) after 180 d. The analyses of XPS, Hg-TPD, SEM-EDS demonstrated that excellent remediation performance by FeS-Se-BC resulted from the synergistic effect of FeS and Se to form HgS and HgSe concurrently. In comparison to the treatments of biochar and FeS-functionalized biochar (FeS-BC), FeS-Se-BC promoted the transformation of exchangeable, carbonate-bound, and Fe-Mn oxides-bound Hg fractions into organic material-bound, and residual fractions, effectively reducing the risk of Hg-contaminated soil from a highly dangerous level to a low risk. Furthermore, the introduction of Se clearly inhibited the re-activation of Hg and reduced the release of Hg by 81.12% compared to FeS-BC when the ratio of S2- to Hg was 5: 1 due to the formation of extremely stable HgSe. These results suggest that FeS-Se-BC has good potential for remediation of Hg-polluted soils which provides a new inhibitory idea for Hg re-activation after immobilization.

Defluorination by ion exchange of SO42- on alumina surface: Adsorption mechanism and kinetics.

Electrostatic and complexation effects have been considered as the primary adsorption mechanisms for defluorination using aluminum based materials, while the effect of ion exchange between anions and fluorine ion has been mostly ignored, although synthesized alumina materials usually contain a large amount of anions, such as SO42-, NO3-, and Cl-. In this study, the effect of anions exchanges and its key role on defluorination were systematically investigated for adsorption by aluminas loaded with various typical anions (SO42-, NO3- and Cl-). Experimental results showed that SO42-- loading alumina had the best defluorination performance (94.5 mg/g), much higher than NO3- (45.0 mg/g) and Cl- (19.1 mg/g). The contribution ratio of ion exchange between SO42- and F- was as high as 20-60% in all potential defluorination mechanisms. By using Density Functional Theory calculation, the detailed mechanism revealed that the ion exchange process was mainly driven by the tridentate chelation of SO42- which reduced the exchange energy ( [Formula: see text] 4.8 eV). Our study clearly demonstrated that ion exchange between SO42- and F- is a critical mechanism in defluorination using aluminum-based materials and provides a potential alternative method to enhance the adsorption performance of modified alumina.

Mechanisms of multiple neurotransmitters in the effects of Lycopene on brain injury induced by Hyperlipidemia.

BACKGROUND: Lycopene is a kind of carotenoid, with a strong capacity of antioxidation and regulating the bloodlipid. There has been some evidence that lycopene has protective effects on the central nervous system, but few studies have rigorously explored the role of neurotransmitters in it. Therefore, the present study was designed to investigate the effects of several neurotransmitters as lycopene exerts anti-injury effects induced by hyperlipidemia. METHODS: Eighty adult SD rats, half male and half female, were randomly divided into eight groups on the basis of serum total cholesterol (TC) levels and body weight. There was a control group containing rats fed a standard laboratory rodent chow diet (CD); a hypercholesterolemic diet (rat chow supplemented with 4% cholesterol, 1% cholic acid and 0.5% thiouracil - this is also called a CCT diet) group; a positive group (CCT + F) fed CCT, supplemented with 10 mg·kg·bw- 1·d- 1 fluvastatin sodium by gastric perfusion; and lycopene groups at five dose levels (CCT + LYCO) fed with CCT and supplied lycopene at doses of 5, 25, 45, 65, and 85 mg·kg·bw- 1·d- 1. The levels of TC, triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), interleukin-1 (IL-1), tumor necrosis factor alpha (TNF-α), oxidized low density lipoprotein (ox-LDL), low-density lipoprotein receptor (LDLR), nerve growth factor (NGF), glutamic acid (Glu), Gamma aminobutyric acid (GABA), dopamine (DA), 5-hydroxytryptamine (5-HT), N-methyl-D-aspartate (NMDA1R), GABAA, 5-HT1, D1, and apoptosis-related proteins Caspase3, bax, and bcl-2 were measured after the experiment. Nissl staining was adopted to observe the morphological changes in neurons. RESULTS: At the end of the experiment, the levels of TC, TG, LDL-C, IL-1, TNF-α, and ox-LDL in the serum and brain as well as the content of Glu, DA, NMDA, and D1 in the brain of rats in the CCT group were higher than those in the control group (P<0.05); the levels of LDLR, NGF, GABA, 5-HT, GABAA, 5-HT1, and neuron quantities in the hippocampal CA1 and CA3 areas were lower than those in the control group (P<0.05). Compared to the CCT group, levels of TC, TG, LDL-C, IL-1, TNF-α, and ox-LDL in the serum and brain, as well as the content of Glu, DA and the expression of pro-apoptotic Caspase3 in the brain decreased in the rats with lycopene (25 mg to 85 mg) added to the diet (P<0.05); the levels of LDLR, NGF, GABA, 5-HT, GABAA, and 5-HT1 as well as the expression of anti-apoptotic bcl-2 and the neuron quantity in hippocampal CA1 and CA3 areas increased (P<0.05); further, the hippocampal cells were closely arranged. Lycopene dose was negatively correlated with the levels of TC, TG, and LDL-C in the serum and brain as well as levels of IL-1, TNF-α, ox-LDL, Glu/GABA, NMDA1R, and Caspase3 (P<0.05); it was positively correlated with the levels of LDLR, NGF, 5-HT, 5-HT1, GABAA, bcl-2, and the neuron quantity in hippocampal CA1 and CA3 areas (P<0.05). CONCLUSIONS: Lycopene exerts anti-injury effects in the brain as-induced by hyperlipidemia. It can inhibit the elevation of serum TC, TG, and LDL-C in rats with hyperlipidemia while indirectly affecting the levels of TC, TG, and LDL-C in the brain, leading to a reduction in ox-LDL, IL-1, and TNF-α in the brain. This inhibits the release of Glu, which weakens nerve toxicity and downregulates pro-apoptotic Caspase3. Lycopene also plays an anti-injury role by promoting the release of the inhibitory neurotransmitter GABA and 5-HT, which enhances the protective effect, and by upregulating the anti-apoptotic bcl-2.

Fungus hyphae-supported alumina: An efficient and reclaimable adsorbent for fluoride removal from water.

A reclaimable adsorbent of fungus hyphae-supported alumina (FHSA) bio-nanocomposites was developed, characterized and applied in fluoride removal from water. This adsorbent can be fast assembled and disassemble reversibly, promising efficient reclamation and high accessible surface area for fluoride adsorption. Adsorption experiments demonstrate that the FHSA performed well over a considerable wide pH range of 3-10 with high fluoride removal efficiencies (>66.3%). The adsorption capacity was 105.60mgg-1 for FHSA, much higher than that for the alumina nanoparticles (50.55mgg-1) and pure fungus hyphae (22.47mgg-1). The adsorption capacity calculated by the pure content of alumina in the FHSA is 340.27mgg-1 of alumina. Kinetics data reveal that the fluoride adsorption process on the FHSA was fast, nearly 90% fluoride adsorption can be achieved within 40min. The fluoride adsorption on the FHSA is mainly due to the surface complexes formation of fluoride with AlOH and the attraction between protonated NH2 and fluoride through hydrogen bonding. Findings demonstrate that the FHSA has potential applicability in fluoride removal due to its strong fluoride adsorbility and the easy reclamation by its fast reversible assembly and disassembly feature.

Identification of native catechin fatty acid esters in green tea (Camellia sinensis).

Catechins are potent antioxidants and make up the primary class of polyphenols present in tea (Camellia sinensis). They are especially abundant in the less-fermented green teas that have been employed in various foods to enhance shelf life stability (Senanayake, N. J. Funct. Foods 2013, in press. Gramza, A.; Korczak, J. Trends Food Sci. 2005, 16, 351-358). The antioxidative activity of native (polar) catechins has proven to be useful in foods of relatively high polarity, while mixed results have been achieved in high-fat foods. However, the polarity of catechins can be attenuated by esterification with fatty acids, producing adducts that effectively partition into lipids and protect against rancidity even in high-fat foods (Cutler, S.; Fuller, E.; Rotberg, I.; Wray, C.; Troung, M.; Poss, M. International Patent WO 2013/036934 A1, March 14, 2013. Zhong, Y.; Shahidi, F. J. Agric. Food Chem. 2011, 59, 6526-6533). In this work, a search for the presence of naturally occurring lipid-conjugated catechins was undertaken in various green tea varieties. Rather than the traditional aqueous infusion, dried tea leaves were extracted with organic solvents followed by analysis for catechin adducts with both lower polarities and increased molecular weights as monitored by liquid chromatography and tandem mass spectrometry. Native catechin palmitates were identified and indirectly confirmed by synthesis and nuclear magnetic resonance as natural components of several Chinese green teas. Evidence of other fatty catechin esters was also observed.

Sulfate-doped Fe3O4/Al2O3 nanoparticles as a novel adsorbent for fluoride removal from drinking water.

A novel adsorbent of sulfate-doped Fe3O4/Al2O3 nanoparticles with magnetic separability was developed for fluoride removal from drinking water. The nanosized adsorbent was characterized and its performance in fluoride removal was evaluated. Kinetic data reveal that the fluoride adsorption was rapid in the beginning followed by a slower adsorption process, nearly 90% adsorption can be achieved within 20 min and only 10-15% additional removal occurred in the following 8 h. The fluoride adsorption isotherm was well described by Elovich model. The calculated adsorption capacity of this nanoadsorbent for fluoride by two-site Langmuir model was 70.4 mg/g at pH 7.0. Moreover, this nanoadsorbent performed well over a considerable wide pH range of 4-10, and the fluoride removal efficiencies reached up to 90% and 70% throughout the pH range of 4-10 with initial fluoride concentrations of 10 mg/L and 50 mg/L, respectively. The observed sulfate-fluoride displacement and decreased sulfur content on the adsorbent surface reveal that anion exchange process was an important mechanism for fluoride adsorption by the sulfate-doped Fe3O4/Al2O3 nanoparticles. Moreover, a shift of the pH of zero point charge (pHPZC) of the nanoparticles and surface analysis based on X-ray photoelectron spectroscopy (XPS) suggest the formation of inner-sphere fluoride complex at the aluminum center as another adsorption mechanism. With the exception of PO4(3-), other co-existing anions (NO3(-), Cl(-) and SO4(2-)) did not evidently inhibit fluoride removal by the nanoparticles. Findings of this study demonstrate the potential utility of the nanoparticles as an effective adsorbent for fluoride removal from drinking water.