Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculatu...Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculature,it also helps the assessment of therapeutic response of anti-angiogenic drugs as it may reflect tumor angiogenesis.Perfusion CT has been applied in clinical practice to delineate inflammatory or neoplastic lymph nodes irrespective of their size,identify micro-metastases and to predict metastases in advance of their development.It is of increasing significance for preoperative adjuvant therapies and avoidance of unnecessary interventions.Despite controversies regarding the techniques employed,its validity and reproducibility,it can be advantageous in the management of CRCs in which the prognosis is dependent on preoperative staging.With recent advances in the perfusion CT techniques,and incorporation to other modalities like positron emission tomography,perfusion CT will be a novel tool in the overall management of CRCs.This article aims at reviewing the existing clinical applications and recent advances of perfusion CT with a reference to future development in the management of CRCs.展开更多
Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon ...Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon transform and optimal algorithms, which extracts automatically roads on images of rural areas, images that were acquired by digital cameras and airborne laser scanners. The proposed method detects linear segments iteratively and starting from this it generates the centerlines of the roads. The method is based on an objective function which depends on three parameters related to the correlation between the cross-sections, spectral similarity and directions of the segments. Different tests were performed using aerial photos, Ikonos images and laser scanner data of an area located in the state of Parana （Brazil） and their results are presented and discussed. The quality of the detection of the roads centerlines was computed using several indexes - completeness, correctness and RMS. The values obtained reveal the good performance of the proposed methodology.展开更多
Photocatalytic activity of doped polyaniline nanopowders with different molar ratio of An/O （aniline^oxidizer） has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue....Photocatalytic activity of doped polyaniline nanopowders with different molar ratio of An/O （aniline^oxidizer） has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue. By means of scanning electron microscopy and low-temperature N2 adsorption method, it was found that doped PANI （polyaniline） nanopowders have the particles size of 30-50 nm with the specific surface area of 20-35 m2.g＂~. It was found that PANI photocatalytic activity essentially depends on molar ratio of An/O and adsorption interactions between the dye molecules and catalytic active centers on PANI surface and these interactions are greatly affected by pH of the solution 9.2. An optimum of the synergetic effect is found for an initial molar ratio of aniline to oxidizer equal to 0.8.展开更多
Objective： To evaluate the sensitivity and specificity of CT scan findings in patients with blunt abdominal trauma admitted to the university hospital. Methods： All the patients with blunt abdominal trauma admitted ...Objective： To evaluate the sensitivity and specificity of CT scan findings in patients with blunt abdominal trauma admitted to the university hospital. Methods： All the patients with blunt abdominal trauma admitted at a tertiary teaching trauma center in Iran between 2005 and 2007 were enrolled in this study. In the absence of any clinical manifestations, the patients underwent a diagnostic CT scan. Laparatomy was performed in those with positive CT results. Others were observed for 48 hours and discharged in case no problem was reported; otherwise they underwent laparatomy. Information on patients＇ demographic data, mechanism of trauma, indication for CT scan, CT scan findings, results of laparotomy were gathered. The sensitivity, specificity and accuracy of the CT-scan images in regard with the organ injured were calculated. The sensitivity, specificity and accuracy of the CT scan were calculated in each case. Results： CT scan had the highest sensitivity for detecting the injuries to liver （100%） and spleen （86.6%）. The specificity of the method for detecting retroperitoneal hematoma （100%） and injuries to kidney （93.5%） was higher than other organs. The accuracy of CT images to detect the injuries to spleen, liver, kidney and retroperitoneal hematoma was reported to be 96.1%, 94.4%, 91.6% and 91.6% respectively. Conclusion： The findings of the present study reveal that CT scan could be considered as a good choice, especially for patients with blunt abdominal trauma in teaching hospitals where the radiologic academic staff is not present in the hospital in the night shifts.展开更多
A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC)....A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC).Thirty-seven primary open-angle glaucoma patients were divided into two groups depending on the patients having been treated or not.The statistical results showed that there were significant differences between the treated and untreated groups’SC areas(treated,7935.6875±680.003μm2;untreated,3890.71875±871.49844μm2;P<0.001),the circumferences(treated,580.37891±44.96529μm;untreated,381.9026±41.22123μm;P<0.001),and the long diameters(treated,272.87806±25.7254μm;untreated,185.24047±19.72786μm;P<0.001).We hypothesize that,after drug treatment,the SC will expand and the morphometric values especially the areas will become larger,thus helping to reduce intraocular pressure.展开更多
文摘Perfusion computed tomography (CT) has emerged as a novel functional imaging technique with gradually increasing importance in the management of colorectal cancer (CRC).By providing the functional tumor microvasculature,it also helps the assessment of therapeutic response of anti-angiogenic drugs as it may reflect tumor angiogenesis.Perfusion CT has been applied in clinical practice to delineate inflammatory or neoplastic lymph nodes irrespective of their size,identify micro-metastases and to predict metastases in advance of their development.It is of increasing significance for preoperative adjuvant therapies and avoidance of unnecessary interventions.Despite controversies regarding the techniques employed,its validity and reproducibility,it can be advantageous in the management of CRCs in which the prognosis is dependent on preoperative staging.With recent advances in the perfusion CT techniques,and incorporation to other modalities like positron emission tomography,perfusion CT will be a novel tool in the overall management of CRCs.This article aims at reviewing the existing clinical applications and recent advances of perfusion CT with a reference to future development in the management of CRCs.
文摘Digitizing road maps manually is an expensive and time-consuming task. Several methods that intend to develop fully or semi-automated systems have been proposed. In this work we introduce a method, based on the Radon transform and optimal algorithms, which extracts automatically roads on images of rural areas, images that were acquired by digital cameras and airborne laser scanners. The proposed method detects linear segments iteratively and starting from this it generates the centerlines of the roads. The method is based on an objective function which depends on three parameters related to the correlation between the cross-sections, spectral similarity and directions of the segments. Different tests were performed using aerial photos, Ikonos images and laser scanner data of an area located in the state of Parana （Brazil） and their results are presented and discussed. The quality of the detection of the roads centerlines was computed using several indexes - completeness, correctness and RMS. The values obtained reveal the good performance of the proposed methodology.
文摘Photocatalytic activity of doped polyaniline nanopowders with different molar ratio of An/O （aniline^oxidizer） has been studied in the process of photocatalytic decolorization of aqueous solutions of methylene blue. By means of scanning electron microscopy and low-temperature N2 adsorption method, it was found that doped PANI （polyaniline） nanopowders have the particles size of 30-50 nm with the specific surface area of 20-35 m2.g＂~. It was found that PANI photocatalytic activity essentially depends on molar ratio of An/O and adsorption interactions between the dye molecules and catalytic active centers on PANI surface and these interactions are greatly affected by pH of the solution 9.2. An optimum of the synergetic effect is found for an initial molar ratio of aniline to oxidizer equal to 0.8.
文摘Objective： To evaluate the sensitivity and specificity of CT scan findings in patients with blunt abdominal trauma admitted to the university hospital. Methods： All the patients with blunt abdominal trauma admitted at a tertiary teaching trauma center in Iran between 2005 and 2007 were enrolled in this study. In the absence of any clinical manifestations, the patients underwent a diagnostic CT scan. Laparatomy was performed in those with positive CT results. Others were observed for 48 hours and discharged in case no problem was reported; otherwise they underwent laparatomy. Information on patients＇ demographic data, mechanism of trauma, indication for CT scan, CT scan findings, results of laparotomy were gathered. The sensitivity, specificity and accuracy of the CT-scan images in regard with the organ injured were calculated. The sensitivity, specificity and accuracy of the CT scan were calculated in each case. Results： CT scan had the highest sensitivity for detecting the injuries to liver （100%） and spleen （86.6%）. The specificity of the method for detecting retroperitoneal hematoma （100%） and injuries to kidney （93.5%） was higher than other organs. The accuracy of CT images to detect the injuries to spleen, liver, kidney and retroperitoneal hematoma was reported to be 96.1%, 94.4%, 91.6% and 91.6% respectively. Conclusion： The findings of the present study reveal that CT scan could be considered as a good choice, especially for patients with blunt abdominal trauma in teaching hospitals where the radiologic academic staff is not present in the hospital in the night shifts.
基金supported by the Sichuan Youth Science&Technology Foundation(2013JQ0028)the National Natural Science Foundation of China(61108082)+1 种基金the West Light Foundation of the Chinese Academy of Sciencesthe National Major Scientific Equipment Program(2012YQ120080)
文摘A custom built 1310 nm center wavelength swept source optical coherence tomography instrument was used to measure morphological changes in treated and newly diagnosed untreated glaucomatous human Schlemm’s canal(SC).Thirty-seven primary open-angle glaucoma patients were divided into two groups depending on the patients having been treated or not.The statistical results showed that there were significant differences between the treated and untreated groups’SC areas(treated,7935.6875±680.003μm2;untreated,3890.71875±871.49844μm2;P<0.001),the circumferences(treated,580.37891±44.96529μm;untreated,381.9026±41.22123μm;P<0.001),and the long diameters(treated,272.87806±25.7254μm;untreated,185.24047±19.72786μm;P<0.001).We hypothesize that,after drug treatment,the SC will expand and the morphometric values especially the areas will become larger,thus helping to reduce intraocular pressure.
