AIM:To summarize clinical,endoscopic,radiologic and pathologic features of special diaphragm-like strictures found in small bowel,with no patient use of nonsteroidal anti-inflammatory drugs(NSAIDs).METHODS:From Januar...AIM:To summarize clinical,endoscopic,radiologic and pathologic features of special diaphragm-like strictures found in small bowel,with no patient use of nonsteroidal anti-inflammatory drugs(NSAIDs).METHODS:From January 2000 to fecember 2009,5 cases(2 men and 3 women,with a mean age of 41.6 years) were diagnosed as having diaphragm-like strictures of small bowel on imaging,,operation and pathology.All the patients denied the use of NSAIDs.The clinical,endoscopic,radiologic and pathologic findings in these 5 patients were retrospectively reviewedfrom the hospital database.Images of capsule endoscopy(CE) and small bowel follow-through(SBFT) obtained in 3 and 3 patients,respectively,and images of double-balloon enteroscopy and computed tomography enterography(CTE) obtained in all 5 patients were available for review.RESULTS:All patients presented with long-term(2-16 years) symptoms of gastrointestinal bleeding and varying degrees of anemia.There was only one stricture in ?our cases and three lesions in one case,and all the lesions were located in the middle or distal segment of ileum.Circumferential stricture was shown in the small bowel in three cases in the CE image,but the capsule was retained in the small bowel of 2 patients.Routine abdomen computed tomography scan showed no other abnormal results except gallstones in one patient.The lesions were shown as circumferential strictures accompanied by dilated small bowel loops in the small bowel on the images of CTE(in all 5 cases),SBFT(in 2 cases) and double-balloon enteroscopy(in all cases).On microscopy,a chronic inflammatory infiltrate and circumferential diaphragm were found in all lesions.CONCLUSION:fiaphragm-like strictures of small bowel might be a special consequence of unclear damaging insults to the intestine,having similar clinical,endoscopic,radiologic and pathologic features.展开更多
Low-energy electron microscopy （LEEM） has been used to study the structure, initial growth orientation, growth progression, and the number of layers of atomically thin hexagonal boron nitride （h-BN） films. The h-B...Low-energy electron microscopy （LEEM） has been used to study the structure, initial growth orientation, growth progression, and the number of layers of atomically thin hexagonal boron nitride （h-BN） films. The h-BN films are grown on heteroepitaxial Co using chemical vapor deposition （CVD） at low pressure. Our findings from LEEM studies include the growth of monolayer film having two, oppositely oriented, triangular BN domains commensurate with the Co lattice. The growth of h-BN appears to be self-limiting at a monolayer, with thicker domains only appearing in patches, presumably initiated between domain boundaries. Reflectivity measurements of the thicker h-BN films show oscillations resulting from the resonant electron transmission through quantized electronic states of the h-BN films, with the number of minima scaling up with the number of h-BN layers. First principles density functional theory （DFT） calculations show that the positions of oscillations are related to the electronic band structure of h-BN.展开更多
基金Supported by Shanghai Leading Academic Discipline Project,No. S30203Key project in biological medicine of Shang-hai Science and Technology Commission,No. 10411953200
文摘AIM:To summarize clinical,endoscopic,radiologic and pathologic features of special diaphragm-like strictures found in small bowel,with no patient use of nonsteroidal anti-inflammatory drugs(NSAIDs).METHODS:From January 2000 to fecember 2009,5 cases(2 men and 3 women,with a mean age of 41.6 years) were diagnosed as having diaphragm-like strictures of small bowel on imaging,,operation and pathology.All the patients denied the use of NSAIDs.The clinical,endoscopic,radiologic and pathologic findings in these 5 patients were retrospectively reviewedfrom the hospital database.Images of capsule endoscopy(CE) and small bowel follow-through(SBFT) obtained in 3 and 3 patients,respectively,and images of double-balloon enteroscopy and computed tomography enterography(CTE) obtained in all 5 patients were available for review.RESULTS:All patients presented with long-term(2-16 years) symptoms of gastrointestinal bleeding and varying degrees of anemia.There was only one stricture in ?our cases and three lesions in one case,and all the lesions were located in the middle or distal segment of ileum.Circumferential stricture was shown in the small bowel in three cases in the CE image,but the capsule was retained in the small bowel of 2 patients.Routine abdomen computed tomography scan showed no other abnormal results except gallstones in one patient.The lesions were shown as circumferential strictures accompanied by dilated small bowel loops in the small bowel on the images of CTE(in all 5 cases),SBFT(in 2 cases) and double-balloon enteroscopy(in all cases).On microscopy,a chronic inflammatory infiltrate and circumferential diaphragm were found in all lesions.CONCLUSION:fiaphragm-like strictures of small bowel might be a special consequence of unclear damaging insults to the intestine,having similar clinical,endoscopic,radiologic and pathologic features.
文摘Low-energy electron microscopy （LEEM） has been used to study the structure, initial growth orientation, growth progression, and the number of layers of atomically thin hexagonal boron nitride （h-BN） films. The h-BN films are grown on heteroepitaxial Co using chemical vapor deposition （CVD） at low pressure. Our findings from LEEM studies include the growth of monolayer film having two, oppositely oriented, triangular BN domains commensurate with the Co lattice. The growth of h-BN appears to be self-limiting at a monolayer, with thicker domains only appearing in patches, presumably initiated between domain boundaries. Reflectivity measurements of the thicker h-BN films show oscillations resulting from the resonant electron transmission through quantized electronic states of the h-BN films, with the number of minima scaling up with the number of h-BN layers. First principles density functional theory （DFT） calculations show that the positions of oscillations are related to the electronic band structure of h-BN.
