Hexanoyl chitosan and polystyrene blends are immiscible by the elucidation of the glass transition temperature （Tg） as well as the viscometric and morphological analyses. Selective localization of the lithium salt i...Hexanoyl chitosan and polystyrene blends are immiscible by the elucidation of the glass transition temperature （Tg） as well as the viscometric and morphological analyses. Selective localization of the lithium salt in hexanoyl chitosan phase as the percolation pathway enhanced the conductivity in the blends as compared to the neat hexanoyl chitosan. The ionic conductivity of a polymer electrolyte is described by σ = enp. Thus, estimation of charge carrier density （n） and mobility （μ） is important in order to assess the performance. In this work, these parameters are calculated using impedance spectroscopy and FTIR.展开更多
Using a rabbit model, we examined N epsilon-(hexanoyl) lysine (HEL) levels in bone and urine to detect when peroxidative reaction first occurs after steroid administration. Japanese white rabbits weighing about 3.5 kg...Using a rabbit model, we examined N epsilon-(hexanoyl) lysine (HEL) levels in bone and urine to detect when peroxidative reaction first occurs after steroid administration. Japanese white rabbits weighing about 3.5 kg each were injected with a single intramuscular dose of methylprednisolone 40 mg/kg and divided into groups consisting of 10 rabbits each, which were killed after 1, 3, 5 and 14 days (groups A, B, C and D respectively). As a control, 10 untreated rabbits (group N) were also studied. The proximal femurs were examined histopathologically and immunohistochemically using monoclonal antibody HEL, which is a highly specific antibody against N epsilon-(hexanoyl) lysine, an early peroxidation marker. In addition, urinary levels of HEL were measured by enzyme-linked immunosorbent assay in group N, A, B and C. Osteonecrosis was detected only in group D (90%). Increase of positive reaction of HEL in the bone was observed in group A and D. HEL expression in group D was judged to be a secondary reaction resulting from the development of osteonecrosis. Urinary level of HEL showed a significant increase in only group A (P < 0.001). The present findings suggest that peroxidation in bone occurred within 24 hours after steroid administration in a rabbit model and that it is possible to noninvasively grasp the timing of this peroxidative reaction by measuring the urinary level of HEL.展开更多
This study presents a fast, accurate and sensitive technique using gas chromatography-mass spectrometry (GC-MS) for the identification and quantification of N-acyl homoserine lactones (AHLs) in the extracts of bacteri...This study presents a fast, accurate and sensitive technique using gas chromatography-mass spectrometry (GC-MS) for the identification and quantification of N-acyl homoserine lactones (AHLs) in the extracts of bacterial strain of Pseudomonas aeruginosa and sputum sample of a cystic fibrosis patient. This method involves direct separation and determination of AHLs by using GC-MS as simultaneous separation and characterization of AHLs were possible without any prior derivatiza-tion. Electron ionization resulted in a common fragmentation pattern with the most common fragment ion at m/z 143 and other minor peaks at 73, 57 and 43. The limit of detection for N-butanoyl, N-hexanoyl, N-octanoyl, N-decanoyl, N-dodecanoyl and N-tetradecanoyl homoserine lactones was 2.14, 3.59, 2.71, 2.10, 2.45 and 2.34 μg/L, respectively. The presence of AHLs in the culture of P. aeruginosa strain and spu-tum of a cystic fibrosis patient was achieved in selected ion monitoring (SIM) mode by using the prominent fragment at m/z 143.展开更多
文摘Hexanoyl chitosan and polystyrene blends are immiscible by the elucidation of the glass transition temperature （Tg） as well as the viscometric and morphological analyses. Selective localization of the lithium salt in hexanoyl chitosan phase as the percolation pathway enhanced the conductivity in the blends as compared to the neat hexanoyl chitosan. The ionic conductivity of a polymer electrolyte is described by σ = enp. Thus, estimation of charge carrier density （n） and mobility （μ） is important in order to assess the performance. In this work, these parameters are calculated using impedance spectroscopy and FTIR.
文摘Using a rabbit model, we examined N epsilon-(hexanoyl) lysine (HEL) levels in bone and urine to detect when peroxidative reaction first occurs after steroid administration. Japanese white rabbits weighing about 3.5 kg each were injected with a single intramuscular dose of methylprednisolone 40 mg/kg and divided into groups consisting of 10 rabbits each, which were killed after 1, 3, 5 and 14 days (groups A, B, C and D respectively). As a control, 10 untreated rabbits (group N) were also studied. The proximal femurs were examined histopathologically and immunohistochemically using monoclonal antibody HEL, which is a highly specific antibody against N epsilon-(hexanoyl) lysine, an early peroxidation marker. In addition, urinary levels of HEL were measured by enzyme-linked immunosorbent assay in group N, A, B and C. Osteonecrosis was detected only in group D (90%). Increase of positive reaction of HEL in the bone was observed in group A and D. HEL expression in group D was judged to be a secondary reaction resulting from the development of osteonecrosis. Urinary level of HEL showed a significant increase in only group A (P < 0.001). The present findings suggest that peroxidation in bone occurred within 24 hours after steroid administration in a rabbit model and that it is possible to noninvasively grasp the timing of this peroxidative reaction by measuring the urinary level of HEL.
文摘This study presents a fast, accurate and sensitive technique using gas chromatography-mass spectrometry (GC-MS) for the identification and quantification of N-acyl homoserine lactones (AHLs) in the extracts of bacterial strain of Pseudomonas aeruginosa and sputum sample of a cystic fibrosis patient. This method involves direct separation and determination of AHLs by using GC-MS as simultaneous separation and characterization of AHLs were possible without any prior derivatiza-tion. Electron ionization resulted in a common fragmentation pattern with the most common fragment ion at m/z 143 and other minor peaks at 73, 57 and 43. The limit of detection for N-butanoyl, N-hexanoyl, N-octanoyl, N-decanoyl, N-dodecanoyl and N-tetradecanoyl homoserine lactones was 2.14, 3.59, 2.71, 2.10, 2.45 and 2.34 μg/L, respectively. The presence of AHLs in the culture of P. aeruginosa strain and spu-tum of a cystic fibrosis patient was achieved in selected ion monitoring (SIM) mode by using the prominent fragment at m/z 143.
