ABSTRACT
The magnetic Illite ( MILT) was firstly prepared by an effective polyol-medium solvothermal method. Based on these 3-( methacryloyloxy) propyl trimethoxysilane ( MILT-MPS), magnetic molecularly imprinted polymers (MMIPs) were further synthesized via atom transfer radical polymerization in a mixture solution of methanol and deionized water. The as-prepared MMIIPs were characterized by FT-IR, TEM), XRD, TGA and vibrating sample magnetometer (VSM), and the results indicated that the MMIIPs exhibited magnetic sensitivity ( Ms =3. 866 emu / g ), thermal stability and a larger specific surface area (109. 58 m2 / g). The batch mode adsorption studies were carried out to investigate the recognition specificity and selective capacity. The Langmuir isotherm model was fitted to the equilibrium data, and the monolayer adsorption capacity of MMIPs at 25℃ was 86. 58 mg / g. The selective recognition experiments demonstrated high affinity and selectivity of MMIPs towards ciprofloxacin ( CIP) over competitive compounds. Combined with high performance liquid chromatographic analysis technology, the prepared MMIIPs were successfully applied to extract and enrich trace CIP in environmental samples with the CIP recoveries from 93. 4% to 98. 3% and the limit of detection of 0. 01 mg / L.
ABSTRACT
Objective To study the role of the outer membrane protein Rmp of Neisseria gonor-rhoeae strain in immunosuppression and the strategy of eliminating it .Methods The rmp gene of Neisseria gonorrhoeae strain was amplified by PCR and inserted into pMD 19-T vector .The recombinant vector pMD 19△rmp∷Kan containing Kan and the 5′-and 3′-flanking regions of rmp (△rmp∷Kan) was constructed by replacing 200 nucleotide residues of pMD 19-rmp with kanamycin resistance gene Kan and transformed into Neisseria gonorrhoeae WHO-A strain.PCR and Western blot assay were used to screen and identify the re-combinant mutant strains that could not express Rmp .Mice were immunized with mutant strains and bacteri-cidal activities of the immune sera were detected by antibody-mediated complement-dependent cytotoxicity assay.Results The mutant strains that could not encode Rmp were successfully constructed .Antibodies in-duced by mutant strains showed stronger bactericidal activity against Neisseria gonorrhoeae in comparison with those induced by wild strains .Conclusion The recombinant Neisseria gonorrhoeae strain with rmp gene de-letion might eliminate the immunosuppressive effects of Rmp expressed in wild gonococcal strains , which provides a reference for further development of novel live attenuated whole-cell vaccines of Neisseria gonor-rhoeae.