ABSTRACT
Objective To investigate the prevalence and resistance mechanisms of Proteus mirabilis in the ward of neurology de‐partment of our hospital .Methods For a total of 20 clinic isolates of Proteus mirabilis ,PCR were used for the detection of AmpC , ESBLs ,KPC and MBLs and then DNA sequencing was performed .The integrons were also detected by using PCR and then sequen‐cing was carried out .The genetic relationship between isolates were detected and analysed by pulsed‐field gel electrophoresis(PF‐GE) .The results of drug sensitivity tests were analysed .Results TEM‐1 and CTX‐M‐14 gene were found in all the 20 isolates ,the 10 isolates of Proteus mirabilis were also found carrying CMY‐2 gene .Class Ⅰ integrons were amplified from 19 strains carrying gene cassettes aacA4+cmlA1,dfrA12+orfF+aadA2and dfrA32+ereA+aadA2 respectively .PFGE analysis revealed that the 20 isolates were grouped into 11 PFGE types P1-P11 ,the 12 isolates of P1-P3 were same clones .The sensitive rates of the i‐solates to Meropenem ,Amikacin ,Aztreonam ,Ceftazidime and Tazocin were high .Conclusion Nosocomial transmission of the same clone of Proteus mirabilis was appeared in the ward of neurology department of our hospital .The predominance drug‐resistance genes were CTX‐M‐14 andCMY‐2 .The incidence of carrying class Ⅰ integrons was high ,and the major gene cassettes wereaacA4+cmlA1and dfrA12+orfF+aadA2.The 20 isolates were all sensitive to Meropenem ,Amikacin and Aztreonam .Other Clinical departments should also pay attention to the nosocomial infection caused by Proteus mirabilis and strengthen the infection control measures .
ABSTRACT
In this study we synthesized a micro- and mesoporous material, SBA-16. And later on we functionalized it with octyltrimethoxysilane and octadecyltrimethoxysilane, respectively. The materials of SBA-16 and its functionalized form were characterized by nitrogen adsorption isotherms at 77K, small angle X-ray scattering (SAXS), Fourier-transform infrared (FT-IR), thermal gravimetric analysis (TGA), and adsorption isotherms of single component n-heptane, toluene and water vapour. The data of FT-IR and TGA demonstrated the successful chemical modification of surface and porous wall of SBA-16 with different hydrocarbon chains. The results of SAXS, nitrogen adsorption at 77K, and adsorption isotherms of probe molecules revealed that the functionalized SBA-16 materials possessed relatively less regularity, smaller BET surface area and pore volumes, and lower adsorption capacities for the probe molecules compared to the original SBA-16. However, the functionalized SBA-16 materials showed much less affinity to polar molecules such as water. This work provides useful fundamental information for future study of novel mesoporous silica materials as potential drug delivery carriers.
Subject(s)
Adsorption , Drug Carriers , Chemistry , Porosity , Silicon Dioxide , Chemistry , Surface PropertiesABSTRACT
BACKGROUND: Along with the emergence of porcelain-fused-to-metal (PFM) technique, Ni-Cr alloy has been shown to be the most available non-novel metal alloy used for preparation of PFM materials. The metal margin of Ni-Cr based PFM crown possibly produces some effects on periodontal tissue for it is primarily contacted with gingiva. OBJECTIVE: To investigate the influences of Ni-Cr alloy PFM crown on periodontal tissue. DESIGN, TIME AND SETTING: A retrospective case analysis was performed. All cases were from Department of Stomatology, the 476 Hospital of Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA between January 2006 and January 2007.PARTICIPANTS: Totally 23 maxillary incisors were included from 19 patients who averaged (32.5±10.8)years old and received tooth restoration using Ni-Cr based PFM crowns. Healthy contralateral corresponding teeth were used as controls. METHODS: All clinical operations were conducted by one dentist. Dental restoration principles should be strictly followed during preparation of dental prosthesis. A routine tooth preparation was performed. Specifically, gingival retraction cords were used for gingival recession, with a shoulder prepared 0.5 mm below the labial gingiva and concave shoulder thickness 0.5 mm. A temporary crown was made using silicon rubber. The normal physiological anatomical profile of complete crown should be recovered as possible while preparation. Dental axial crown overcontour should be increased within 0.2 mm. Finally, a permanent sticking was followed.MAIN OUTCOME MEASURES: At 6-9 months after wearing Ni-Cr alloy PFM crown, the gingival crevicular fluid was collected from affected and control teeth for quantitation and laboratory examinations (C reactive protein and tumor necrosis factor- a included),PARTICIPANTS: Alter placement of Ni-Cr alloy PFM crown which was clinically accepted, plaque index of affected tooth did not alter significantly, but gingival crevicular fluid volume, probing depth, sulcus bleeding index, and levels of C reactive protein and tumor necrosis factor-α were significantly greater in affected teeth than in control teeth (P < 0.05).CONCLUSION: Ni-Cr alloy PFM crown produces some harmful effects on periodontal tissue.