Fabrication of Humidity-Resistant Optical Fiber Sensor for Ammonia Sensing Using Diazo Resin-Photocrosslinked Films with a Porphyrin-Polystyrene Binary Mixture.

Ammonia gas sensors were fabricated via layer-by-layer (LbL) deposition of diazo resin (DAR) and a binary mixture of tetrakis(4-sulfophenyl)porphine (TSPP) and poly(styrene sulfonate) (PSS) onto the core of a multimode U-bent optical fiber. The penetration of light transferred into the evanescent field was enhanced by stripping the polymer cladding and coating the fiber core. The electrostatic interaction between the diazonium ion in DAR and the sulfonate residues in TSPP and PSS was converted into covalent bonds using UV irradiation. The photoreaction between the layers was confirmed by UV-vis and Fourier transform infrared spectroscopy. The sensitivity of the optical fiber sensors to ammonia was linear when exposed to ammonia gases generated from aqueous ammonia solutions at a concentration of approximately 17 parts per million (ppm). This linearity extended up to 50 ppm when the exposure time (30 s) was shortened. The response and recovery times were reduced to 30 s with a 5-cycle DAR/TSPP+PSS (as a mixture of 1 mM TSPP and 0.025 wt% PSS in water) film sensor. The limit of detection (LOD) of the optimized sensor was estimated to be 0.31 ppm for ammonia in solution, corresponding to approximately 0.03 ppm of ammonia gas. It is hypothesized that the presence of the hydrophobic moiety of PSS in the matrix suppressed the effects of humidity on the sensor response. The sensor response was stable and reproducible over seven days. The PSS-containing U-bent fiber sensor also showed superior sensitivity to ammonia when examined alongside amine and non-amine analytes.

Equivalent cross-relaxation rate imaging positively correlates with pathological grade and cell density of adipocytic tumors.

OBJECTIVE: Equivalent cross-relaxation rate imaging (ECRI) is an MRI technique used to evaluate qualitative changes in protein-water interactions. We aimed to prospectively evaluate the utility of ECRI for classification of adipocytic tumors. MATERIALS AND METHODS: Institutional Review Board approval was obtained and all patients provided informed consent. Study participants included 40 patients with adipocytic tumors who were diagnosed with lipomas (n=22), atypical lipomatous tissue/well-differentiated liposarcoma (ALT/WDL; n=9), myxoid/round cell liposarcoma (MyL; n=6), and dedifferentiated liposarcoma (DDL; n=3), and 20 control patients for whom subcutaneous fat in the buttock or thigh was analyzed. RESULTS: Mean ECR values of lipomas, ALT/WDL, and subcutaneous fat were low, and those of MyL and DDL were high. Mean ECR values of MyL and DDL were significantly higher than those of ALT/WDL. The cut-off value was 5.1%. There was a positive correlation between ECR value, pathological grade, and cell density in adipocytic tumors. CONCLUSION: The ECR value positively correlates with pathological grade and cell density of adipocytic tumors. Our findings suggest that ECRI is a useful method for preoperative evaluation of adipocytic tumors.

[Effect of radiotherapy and bisphosphonate on bone metastases from renal cell carcinoma].

BACKGROUND: Bone metastases from renal cell carcinoma(RCC)are almost osteolytic and often cause pathological fractures. The objective of this study was to assess the efficacy of radiotherapy and zoledronic acid in patients with bone metastases from RCC. METHODS: We retrospectively analyzed 12 patients with bone metastases from RCC. Of these patients, 5 were treated with radiotherapy(RT group)and 7 were treated with a combination of radiotherapy and zoledronic acid(RT+Z group). We analyzed the radiological changes in the bone metastases and evaluated the response rate, survival rate, and skeletal-related event(SRE)rate. RESULTS: Radiologically, 2 patients showed progressive disease(PD), 3 showed stable disease( SD), 1 showed partial response(PR), and 1 showed complete response(CR)in the RT group(response rate: 28.6%). In the RT+Z group, 1 patient showed PD, 3 showed PR, and 1 showed CR(response rate: 80.0%). CONCLUSIONS: With regard to radiological changes, the response rate was higher in the RT group than in the RT+Z group, but the survival rate did not differ significantly between the 2 groups. SREs were less frequent in the RT+Z group than in the RT group.