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Dysplasia in perforated intestinal pneumatosis complicating a previous jejuno-ileal bypass:A cautionary note
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作者 Nazario Portolani Gian Luca Baiocchi +2 位作者 Stefano Gadaldi Simona Fisogni Vincenzo Villanacci 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第33期4189-4192,共4页
We present the case of an elderly woman who developed a bowel perforation related to pneumatosis intestinalis, 33 years after a jejuno-ileal bypass for severe obesity. Final histological examination revealed the prese... We present the case of an elderly woman who developed a bowel perforation related to pneumatosis intestinalis, 33 years after a jejuno-ileal bypass for severe obesity. Final histological examination revealed the presence of dysplasia in the resected specimen. On the basis of our case and a review of the literature, we discuss the etiopathogenesis, the clinical aspects and the treatment of this rare condition. 展开更多
关键词 Acute abdomen Pneumatosis intestinalis PERITONITIS Obesity DYSPLASIA
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非负矩阵数值域的圆盘性质
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作者 范益政 杨尚骏 《应用数学学报》 CSCD 北大核心 2001年第1期44-48,共5页
本文利用图论方法并结合非负矩阵的有关经典结果,成功地给出了任意阶的非负方阵有以原点为中心的圆盘数值域的充要条件.
关键词 数值域 不可约非负矩阵 有向图 回路积 圆盘性质 谱半径
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Uniform single-layer graphene growth on recyclable tungsten foils
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作者 Zhiyu Zou Xiuju Song +3 位作者 Ke Chen Qingqing Ji Yanfeng Zhang Zhongfan Liu 《Nano Research》 SCIE EI CAS CSCD 2015年第2期592-599,共8页
To meet the rising demand of graphene in electronics and optoelectronics, developing an efficient synthesis strategy for effective control of the layer thickness is highly necessary. Herein, we report the synthesis of... To meet the rising demand of graphene in electronics and optoelectronics, developing an efficient synthesis strategy for effective control of the layer thickness is highly necessary. Herein, we report the synthesis of strictly single- layer graphene on the foil of an early transition metal, tungsten (W), via a simple chemical vapor deposition route. The cracking of hydrocarbons is facilitated by the catalytically active metal surface of W, while the subsequent two-dimensional growth is mediated by the carbide-forming ability within the underlying bulk, leading to the formation of uniform monolayer graphene. The as-grown graphene layers can be transferred onto target substrates rapidly through the recently developed electrochemical method, which also allows for reuse of the substrates at least five times without introducing quality deteriora- tion. Moreover, considering the refractory nature of W foils, a complementary component of nickel is added, by means of which the growth temperature of graphene can be significantly reduced. In brief, a highly-efficient and low-cost synthesis route has been developed for the growth of graphene towards large-area uniformity, single-layer thickness and high crystalline quality. 展开更多
关键词 GRAPHENE chemical vapor deposition single layer TUNGSTEN CARBIDE recyclable substrate
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