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- Gårdestedt, Caroline, et al.
(författare)
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Zinc in Soils, Crops, and Meals in the Niger Inland Delta, Mali
- 2009
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 38:6, s. 334-338
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Tidskriftsartikel (refereegranskat)abstract
- Zinc deficiency is a problem in developing countries and not least so in Africa. This concerns both agriculture and human food provision. Zinc deficiency in soils may severely decrease yields, whereas insufficient zinc in food intake primarily affects the immune defense, notably in children. The present investigation concerned zinc availability in soils, crops, and food in the Niger inland delta in Mali. Agricultural soils are largely deficient in plant-available zinc, however, soils in close vicinity to habitation show elevated zinc concentrations. The zinc concentrations in crops are low; in rice, they are about half of reference ranges. Zinc intake assessed from a number of sampled meals was about half the recommended requirement. When zinc concentration is higher phytate was also high, which made the zinc less available. In spite of a recorded sufficient intake of iron, anemia is common and is most likely because of the high phytate concentration in the cereal-dominated diet. Increasing zinc and iron availability would be possible through the use of malting, fermentation, and soaking in food preparation. Finally, in the long run, any trace element deficiency, especially that of zinc in agricultural soils needs to be amended by addition of appropriate amounts in commercial fertilizers.
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| 3. |
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| 4. |
- Limaye, Mukta, V, et al.
(författare)
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Functionalization and patterning of nanocellulose films by surface-bound nanoparticles of hydrolyzable tannins and multivalent metal ions
- 2019
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Ingår i: Nanoscale. - : Royal Society of Chemistry. - 2040-3364 .- 2040-3372. ; 11:41, s. 19278-19284
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Tidskriftsartikel (refereegranskat)abstract
- Inspired by the Bogolanfini dyeing technique, we report how flexible nanofibrillated cellulose (CNF) films can be functionalized and patterned by surface-bound nanoparticles of hydrolyzable tannins and multivalent metal ions with tunable colors. Molecular dynamics simulations show that gallic acid (GA) and ellagic acid (EA) rapidly adsorb and assemble on the CNF surface, and atomic force microscopy confirms that nanosized GA assemblies cover the surface of the CNF. CNF films were patterned with tannin-metal ion nanoparticles by an in-fibre reaction between the pre-impregnated tannin and the metal ions in the printing ink. Spectroscopic studies show that the Fe-III/II ions interact with GA and form surface-bound, stable GA-Fe-III/II nanoparticles. The functionalization and patterning of CNF films with metal ion-hydrolyzable tannin nanoparticles is a versatile route to functionalize films based on renewable materials and of interest for biomedical and environmental applications.
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| 5. |
- Limaye, Mukta V., et al.
(författare)
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On the role of tannins and iron in the Bogolan or mud cloth dyeing process
- 2012
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Ingår i: Textile research journal. - : SAGE Publications. - 0040-5175 .- 1746-7748. ; 82:18, s. 1888-1896
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the chemistry of the Bogolan or mud cloth dyeing process, a traditional technique of coloring cotton cloths deeply rooted in Mali. Textiles produced by the traditional Bogolan process, using tannin-rich plant extract and iron-rich clay-based mud, were compared using infrared (IR) spectroscopy, scanning electron microscopy (SEM) and X-ray absorption near-edge spectroscopy (XANES) with cotton fibers that were impregnated with tannin and iron salt solutions. IR spectroscopy in both reflective mode on the cloth and cotton and in transmission mode on single fibers, together with SEM, showed that gallic and tannic acid adsorb and precipitate onto the cotton fiber surface. IR spectroscopy and comparison with tannin and iron solution-impregnated cotton showed that the black color of the traditional Bogolan cloth is dominated by the formation of iron-tannin complexes. The presence of iron in the Bogolan cloth was confirmed using XANES data, supporting the notion that iron has been transferred from the iron-rich clay-based mud to the cloth. The chemistry of Bogolan cloth is not only historically and culturally significant and of importance in textile conservation, but may also inspire future research on sustainable dyeing and processing techniques based on natural products.
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