在基于Mesh-under的IPv6低功耗无线个域网(IPv6over low-power wireless personal area networks,6LoWPAN)中,针对传输路径上中间节点重传缓存溢出导致重传数据分片丢失,造成网络性能下降等问题,提出一种基于Mesh-under的备用缓存机制...在基于Mesh-under的IPv6低功耗无线个域网(IPv6over low-power wireless personal area networks,6LoWPAN)中,针对传输路径上中间节点重传缓存溢出导致重传数据分片丢失,造成网络性能下降等问题,提出一种基于Mesh-under的备用缓存机制。本文所提机制根据传输路径上各节点重传缓存使用情况及数据分片剩余跳数等信息,设置动态重传缓存门限,并为超过该门限的节点从其邻居节点中挑选合适的备用缓存节点,从而完成数据分片的缓存与重传过程,达到均衡使用各节点重传缓存的目的。结果表明,所提机制能够有效避免重传缓存溢出,减小网络能耗,同时进一步提高目的端重组成功率。展开更多
利用初等方法研究了类似广义Dedekind和S2(h,m,n,k)的算术性质.借助Bernoulli多项式及三角恒等式,探究了S2(qh,m,n,qk)与S2(h,m,n,k)的关系,以及当p为奇素数时sum from b=0 to (p-1) S2(h+bk,m,n,pk)与S2(h,m,n,k)和S2(ph,m,n,k)的关系...利用初等方法研究了类似广义Dedekind和S2(h,m,n,k)的算术性质.借助Bernoulli多项式及三角恒等式,探究了S2(qh,m,n,qk)与S2(h,m,n,k)的关系,以及当p为奇素数时sum from b=0 to (p-1) S2(h+bk,m,n,pk)与S2(h,m,n,k)和S2(ph,m,n,k)的关系,提出并证明了两个恒等式,推广了有关文献的结论.展开更多
现有研究集中于企业国际化节奏的作用及其影响因素,缺乏对CM N Es海外资源获取过程中国际化节奏不规律的后果及其应对机制的关注。本文采用事件路径分析方法,抽取两家典型CM N Es的海外技术与市场资源获取相关事件,基于悖论视角,分析国...现有研究集中于企业国际化节奏的作用及其影响因素,缺乏对CM N Es海外资源获取过程中国际化节奏不规律的后果及其应对机制的关注。本文采用事件路径分析方法,抽取两家典型CM N Es的海外技术与市场资源获取相关事件,基于悖论视角,分析国际化节奏不规律下技术与市场资源获取对立关系的演化趋势。根据资源获取对象和获取方式,本文提出一个海外资源获取矩阵结构,揭示了资源获取跨领域互动过程中的缓冲机制。研究结果表明,CM N Es能够分别通过桥接和支撑协调冲突,形成惯例与能动双缓冲机制,二者共同促进技术和市场领域从二元对立向相互依赖对立演化,以应对连续的国际化节奏不规律。展开更多
BACKGROUND Adult-onset Ménétrier’s disease is strongly associated with Helicobacter pylori(H.pylori)infection and an elevated risk of carcinogenesis.Cases of early-stage gastric cancer developed in H.pylori...BACKGROUND Adult-onset Ménétrier’s disease is strongly associated with Helicobacter pylori(H.pylori)infection and an elevated risk of carcinogenesis.Cases of early-stage gastric cancer developed in H.pylori-negative Ménétrier’s disease are extremely rare.We report a case of early gastric cancer in H.pylori-negative Ménétrier’s disease that was curatively resected with endoscopic submucosal dissection(ESD).CASE SUMMARY A 60-year-old woman was referred to our hospital after her medical examination detected anemia.Contrast-enhanced upper gastrointestinal(UGI)radiography revealed translucency of the nodule-aggregating surface with giant rugae.Blood tests showed hypoproteinemia and were negative for serum H.pylori immunoglobulin G antibodies.The 99mTc-DTPA-human serum albumin scintigraphy showed protein loss from the stomach.UGI endoscopy showed a 40-mm protruding erythematous lesion on giant rugae of the greater curvature of lower gastric body,suggesting early-stage gastric cancer due to Ménétrier’s disease.En bloc resection with ESD was performed for diagnosis and treatment.Histology of ESD showed well-differentiated tubular adenocarcinoma.The cancer was confined to the mucosa,and complete curative resection was achieved.Foveolar hyperplasia and atrophy of the gastric glands were observed in non-tumor areas,histologically corresponding to Ménétrier’s disease.Three years after ESD,gastric cancer had not recurred,and Ménétrier’s disease remained in remission with spontaneous regression of giant gastric rugae.CONCLUSION Complete curative resection was achieved through ESD in a patient with earlystage gastric cancer and H.pylori-negative Ménétrier’s disease.展开更多
BACKGROUND Ménétrier’s disease is a rare condition characterized by enlarged gastric folds,usually located in the whole body and fundus of the stomach.This report presents an unusual case of localized M...BACKGROUND Ménétrier’s disease is a rare condition characterized by enlarged gastric folds,usually located in the whole body and fundus of the stomach.This report presents an unusual case of localized Ménétrier’s disease elevated by a submucosal lipoma and thus looking like a polypoid mass and causing an episode of upper gastrointestinal bleeding.The mass was successfully removed with endoscopic submucosal dissection.CASE SUMMARY Esophagogastroduodenoscopy was performed on a 76-year-old male patient after an episode of upper gastrointestinal bleeding,manifesting as fatigue and melena.A large polypoid mass(4 cm×1 cm)with enlarged mucosal folds was found in the body of the stomach,between the lesser curvature and posterior wall.A small ulcer at the distal end of the mass was identified as the source of the bleeding.Biopsy was negative for neoplasia.Computed tomography showed a submucosal lesion beneath the affected mucosa,most likely a lipoma.The mass was removed en bloc with tunneling endoscopic submucosal dissection.Final pathology determined that the mass included Ménétrier’s disease and a submucosal lipoma.The patient was scheduled for follow-up esophagogastroduodenoscopy.CONCLUSION Localized Ménétrier’s disease can coexist with a submucosal lipoma creating a polypoid mass with risk of bleeding.展开更多
文摘在基于Mesh-under的IPv6低功耗无线个域网(IPv6over low-power wireless personal area networks,6LoWPAN)中,针对传输路径上中间节点重传缓存溢出导致重传数据分片丢失,造成网络性能下降等问题,提出一种基于Mesh-under的备用缓存机制。本文所提机制根据传输路径上各节点重传缓存使用情况及数据分片剩余跳数等信息,设置动态重传缓存门限,并为超过该门限的节点从其邻居节点中挑选合适的备用缓存节点,从而完成数据分片的缓存与重传过程,达到均衡使用各节点重传缓存的目的。结果表明,所提机制能够有效避免重传缓存溢出,减小网络能耗,同时进一步提高目的端重组成功率。
文摘利用初等方法研究了类似广义Dedekind和S2(h,m,n,k)的算术性质.借助Bernoulli多项式及三角恒等式,探究了S2(qh,m,n,qk)与S2(h,m,n,k)的关系,以及当p为奇素数时sum from b=0 to (p-1) S2(h+bk,m,n,pk)与S2(h,m,n,k)和S2(ph,m,n,k)的关系,提出并证明了两个恒等式,推广了有关文献的结论.
文摘现有研究集中于企业国际化节奏的作用及其影响因素,缺乏对CM N Es海外资源获取过程中国际化节奏不规律的后果及其应对机制的关注。本文采用事件路径分析方法,抽取两家典型CM N Es的海外技术与市场资源获取相关事件,基于悖论视角,分析国际化节奏不规律下技术与市场资源获取对立关系的演化趋势。根据资源获取对象和获取方式,本文提出一个海外资源获取矩阵结构,揭示了资源获取跨领域互动过程中的缓冲机制。研究结果表明,CM N Es能够分别通过桥接和支撑协调冲突,形成惯例与能动双缓冲机制,二者共同促进技术和市场领域从二元对立向相互依赖对立演化,以应对连续的国际化节奏不规律。
文摘BACKGROUND Adult-onset Ménétrier’s disease is strongly associated with Helicobacter pylori(H.pylori)infection and an elevated risk of carcinogenesis.Cases of early-stage gastric cancer developed in H.pylori-negative Ménétrier’s disease are extremely rare.We report a case of early gastric cancer in H.pylori-negative Ménétrier’s disease that was curatively resected with endoscopic submucosal dissection(ESD).CASE SUMMARY A 60-year-old woman was referred to our hospital after her medical examination detected anemia.Contrast-enhanced upper gastrointestinal(UGI)radiography revealed translucency of the nodule-aggregating surface with giant rugae.Blood tests showed hypoproteinemia and were negative for serum H.pylori immunoglobulin G antibodies.The 99mTc-DTPA-human serum albumin scintigraphy showed protein loss from the stomach.UGI endoscopy showed a 40-mm protruding erythematous lesion on giant rugae of the greater curvature of lower gastric body,suggesting early-stage gastric cancer due to Ménétrier’s disease.En bloc resection with ESD was performed for diagnosis and treatment.Histology of ESD showed well-differentiated tubular adenocarcinoma.The cancer was confined to the mucosa,and complete curative resection was achieved.Foveolar hyperplasia and atrophy of the gastric glands were observed in non-tumor areas,histologically corresponding to Ménétrier’s disease.Three years after ESD,gastric cancer had not recurred,and Ménétrier’s disease remained in remission with spontaneous regression of giant gastric rugae.CONCLUSION Complete curative resection was achieved through ESD in a patient with earlystage gastric cancer and H.pylori-negative Ménétrier’s disease.
文摘BACKGROUND Ménétrier’s disease is a rare condition characterized by enlarged gastric folds,usually located in the whole body and fundus of the stomach.This report presents an unusual case of localized Ménétrier’s disease elevated by a submucosal lipoma and thus looking like a polypoid mass and causing an episode of upper gastrointestinal bleeding.The mass was successfully removed with endoscopic submucosal dissection.CASE SUMMARY Esophagogastroduodenoscopy was performed on a 76-year-old male patient after an episode of upper gastrointestinal bleeding,manifesting as fatigue and melena.A large polypoid mass(4 cm×1 cm)with enlarged mucosal folds was found in the body of the stomach,between the lesser curvature and posterior wall.A small ulcer at the distal end of the mass was identified as the source of the bleeding.Biopsy was negative for neoplasia.Computed tomography showed a submucosal lesion beneath the affected mucosa,most likely a lipoma.The mass was removed en bloc with tunneling endoscopic submucosal dissection.Final pathology determined that the mass included Ménétrier’s disease and a submucosal lipoma.The patient was scheduled for follow-up esophagogastroduodenoscopy.CONCLUSION Localized Ménétrier’s disease can coexist with a submucosal lipoma creating a polypoid mass with risk of bleeding.
