Objective: To explore the characteristics of the primary ureteral carcinoma (PUC) and discuss the value of spiral CT (SCT) in the diagnosis of PUC. Methods: The SCT findings of the primary ureteral carcinoma in 16 cas...Objective: To explore the characteristics of the primary ureteral carcinoma (PUC) and discuss the value of spiral CT (SCT) in the diagnosis of PUC. Methods: The SCT findings of the primary ureteral carcinoma in 16 cases were analyzed and compared with the histopathological diagnosis and staging. Results: The transverse diameters of the lesions were 1.0–2.1 cm, and the longitudinal lengths were 1.5–15.2 cm. There were no statistically significant differences (P>0.1) in diam- eters and lengths among the low staging group (pT0–T2) and the high staging group (pT3–T4). The average CT value of the lesions was 43 HU on plain scanning, and 73 HU on CE scanning. The increment was 30 HU. The lesions were clearer on CE scanning. Curved planar reconstruction (CPR) could show the entire course of the urinary tract. Among 6 cases of pT3 stage, CT gave a correct diagnosis in 1 case. For 2 cases of pT4 stage, CT gave correct diagnoses in both cases. Conclusion: The carcinomatous lesions spread along the ureter. The longitudinal length of each lesion is longer than its transverse diameter. Tumor cannot be staged merely according to its diameter and length. CT is difficult to differentiate stage T0–T3, while for stage T4, CT diagnosis is accurate. Contrast enhancement CT scanning has the confirming and differentiating roles. CPR offers direct and easy observing images for clinical doctors.展开更多
Based on the Fuchs and Sondheimer thin film theory (F-S film theory) and a revised valence band split-off model, considering a mixed scattering by lattice vibrations, ionized impurities and surfaces, a theoretical des...Based on the Fuchs and Sondheimer thin film theory (F-S film theory) and a revised valence band split-off model, considering a mixed scattering by lattice vibrations, ionized impurities and surfaces, a theoretical description of the piezoresistive effect (PR effect) in p-type heteroepitaxial diamond films was presented by solving the Boltzmann transport equation in the relaxation time approximation and using the parallel connection resistance model. A calculating expression of the PR effect was given. The main characteristics that were identical with the experiment were obtained by theoretical calculation. Giving out a model to show that the energy level interval between the split-off band and the heavy-hole band was changed by strain, a reasonable explanation was presented for the error between experimental results and theoretical values of saturated PR effect under big strain.展开更多
文摘Objective: To explore the characteristics of the primary ureteral carcinoma (PUC) and discuss the value of spiral CT (SCT) in the diagnosis of PUC. Methods: The SCT findings of the primary ureteral carcinoma in 16 cases were analyzed and compared with the histopathological diagnosis and staging. Results: The transverse diameters of the lesions were 1.0–2.1 cm, and the longitudinal lengths were 1.5–15.2 cm. There were no statistically significant differences (P>0.1) in diam- eters and lengths among the low staging group (pT0–T2) and the high staging group (pT3–T4). The average CT value of the lesions was 43 HU on plain scanning, and 73 HU on CE scanning. The increment was 30 HU. The lesions were clearer on CE scanning. Curved planar reconstruction (CPR) could show the entire course of the urinary tract. Among 6 cases of pT3 stage, CT gave a correct diagnosis in 1 case. For 2 cases of pT4 stage, CT gave correct diagnoses in both cases. Conclusion: The carcinomatous lesions spread along the ureter. The longitudinal length of each lesion is longer than its transverse diameter. Tumor cannot be staged merely according to its diameter and length. CT is difficult to differentiate stage T0–T3, while for stage T4, CT diagnosis is accurate. Contrast enhancement CT scanning has the confirming and differentiating roles. CPR offers direct and easy observing images for clinical doctors.
基金the water saving project funding of Ministry of Water Resources of P.R.China(code:200970)the research funding of North China University of Water Conservancy and Electric Power of 2006+1 种基金the project of Henan Excellent Teacher Funding of 2006,Henan Science and Technology project(092102310197)Henan natural science research project of Education Department(2009A170004)
基金This work was supported by the National Natural Science Foundation of China (Grant No. 69486001) .
文摘Based on the Fuchs and Sondheimer thin film theory (F-S film theory) and a revised valence band split-off model, considering a mixed scattering by lattice vibrations, ionized impurities and surfaces, a theoretical description of the piezoresistive effect (PR effect) in p-type heteroepitaxial diamond films was presented by solving the Boltzmann transport equation in the relaxation time approximation and using the parallel connection resistance model. A calculating expression of the PR effect was given. The main characteristics that were identical with the experiment were obtained by theoretical calculation. Giving out a model to show that the energy level interval between the split-off band and the heavy-hole band was changed by strain, a reasonable explanation was presented for the error between experimental results and theoretical values of saturated PR effect under big strain.
