Southwest University

About: Southwest University is a education organization based out in Chongqing, China. It is known for research contribution in the topics: Gene & Population. The organization has 29772 authors who have published 27755 publications receiving 409441 citations. The organization is also known as: Southwest University in Chongqing & SWU.

Polyethyleneimine modified eggshell membrane as a novel biosorbent for adsorption and detoxification of Cr(VI) from water

Abstract: The polyethyleneimine (PEI) functionalized biosorbent which uses an eggshell membrane (ESM) as a model was synthesized based on the cross linking reaction between aldehydes in glutaraldehyde and functional groups such as amines and amides in ESM. The as-prepared biosorbent (PEI–ESM) strongly interacted with chromium(VI). After modification, the dynamic uptake capacity of the PEI–ESM increased by 105% compared with the control, and the maximum equilibrium adsorption capacity for Cr(VI) can reach about 160 mg g−1 with an initial pH of 3.0. The Langmuir adsorption isotherm was applicable to fit the removal process. Kinetics of the Cr(VI) removal were found to follow a pseudo-second-order rate equation. The results obtained by Raman spectroscopy and X-ray photoelectron spectroscopic analysis (XPS), performed on the as-prepared biosorbent before and after Cr(VI) adsorption, suggested that some of adsorbed Cr(VI) anions were reduced to Cr(III) in Cr2O3 or Cr(OH)3 during the sorption process, demonstrating that the PEI–ESM could detoxify Cr(VI). The developed biosorbent promises advantages such as low cost, high adsorption capacity, Cr(VI) detoxification, and environmental friendliness.

‘GM‐gene‐deletor’: fused loxP‐FRT recognition sequences dramatically improve the efficiency of FLP or CRE recombinase on transgene excision from pollen and seed of tobacco plants

Abstract: Pollen- and seed-mediated transgene flow is a concern in plant biotechnology. We report here a highly efficient 'genetically modified (GM)-gene-deletor' system to remove all functional transgenes from pollen, seed or both. With the three pollen- and/or seed-specific gene promoters tested, the phage CRE/loxP or yeast FLP/FRT system alone was inefficient in excising transgenes from tobacco pollen and/or seed, with no transgenic event having 100% efficiency. When loxP-FRT fusion sequences were used as recognition sites, simultaneous expression of both FLP and CRE reduced the average excision efficiency, but the expression of FLP or CRE alone increased the average excision efficiency, with many transgenic events being 100% efficient based on more than 25,000 T(1) progeny examined per event. The 'GM-gene-deletor' reported here may be used to produce 'non-transgenic' pollen and/or seed from transgenic plants and to provide a bioconfinement tool for transgenic crops and perennials, with special applicability towards vegetatively propagated plants and trees.