BACKGROUND Regional lymph node metastasis in patients with hepatocellular carcinoma(HCC)is not uncommon, and is often under-or misdiagnosed. Regional lymph node metastasis is associated with a negative prognosis in pa...BACKGROUND Regional lymph node metastasis in patients with hepatocellular carcinoma(HCC)is not uncommon, and is often under-or misdiagnosed. Regional lymph node metastasis is associated with a negative prognosis in patients with HCC, and surgical resection of lymph node metastasis is considered feasible and efficacious in improving the survival and prognosis. It is critical to characterize lymph node preoperatively. There is currently no consensus regarding the optimal method for the assessment of regional lymph nodes in patients with HCC.AIM To evaluate the diagnostic value of single source dual energy computed tomography(CT) in regional lymph node assessment for HCC patients.METHODS Forty-three patients with pathologically confirmed HCC who underwent partial hepatectomy with lymphadenectomy were retrospectively enrolled. All patients underwent dual-energy CT preoperatively. Regional lymph nodes(n = 156) were divided into either a metastatic(group P, n = 52) or a non-metastasis group(group N, n = 104), and further, according to pathology, divided into an active hepatitis(group P1, n = 34; group N1, n = 73) and a non-active hepatitis group(group P2, n = 18; group N2, n = 31). The maximal short axis diameter(MSAD),iodine concentration(IC), normalized IC(NIC), and the slope of the spectralcurve(λ_(HU)) of each group in the arterial phase(AP), portal phase(PP), and delayed phase(DP) were analyzed.RESULTS Analysis of the MSAD, IC, NIC, and λ_(HU) showed statistical differences between groups P and N(P < 0.05) during all three phases. To distinguish benign from metastatic lymph nodes, the diagnostic efficacy of IC, NIC, and λ_(HU) in the PP was the best among the three phases(AP, PP, and DP), with a sensitivity up to 81.9%,83.9%, and 81.8%, and a specificity up to 82.4%, 84.1% and 84.1%, respectively.The diagnostic value of combined analyses of MSAD with IC, NIC, or λ_(HU) in the PP was superior to the dual energy CT parameters alone, with a sensitivity up to84.5%, 86.9%, and 86.2%, and a specificity up to 83.0%, 93.6% and 89.8%,respectively. Between groups P1 and P2 and groups N1 and N2, only IC, NIC,and λ_(HU) between groups N1 and N2 in the PP had a statistically significant difference(P < 0.05).CONCLUSION Dual-energy CT contributes beneficially to regional lymph node assessment in HCC patients. Combination of MSAD with IC, NIC, or λ_(HU) values in the PP is superior to using any single parameter alone. Active hepatitis does not deteriorate the capabilities for characterization of metastatic lymph nodes.展开更多
Combining Dual Reciprocity Method （DRM） with Hybrid Boundary Node Method （HBNM）, the Dual Reciprocity Hybrid Boundary Node Method （DRHBNM） is developed for three-dimensional linear elasticity problems with body ...Combining Dual Reciprocity Method （DRM） with Hybrid Boundary Node Method （HBNM）, the Dual Reciprocity Hybrid Boundary Node Method （DRHBNM） is developed for three-dimensional linear elasticity problems with body force. This method can be used to solve the elasticity problems with body force without domain integral, which is inevitable by HBNM. To demonstrate the versatility and the fast convergence of this method, some numerical examples of 3-D elasticity problems with body forces are examined. The computational results show that the present method is effective and can be widely applied in solving practical engineering problems.展开更多
Closed form expressions for the PDF and MGF of the harmonic mean of two independent exponential variates are cited and derived, and then applied to study the performance of cellular multi-node and dual-hop cooperative...Closed form expressions for the PDF and MGF of the harmonic mean of two independent exponential variates are cited and derived, and then applied to study the performance of cellular multi-node and dual-hop cooperative communication systems with non-regenerative relays over flat Rayleigh fading channels. We derive the probability density function (PDF) and asymptotic symbol error rate (SER) expression with MRC scheme. Then we use Matlab to simulate the performance.展开更多
目的 分析双源CT能谱成像多参数对宫颈癌区域淋巴结的定性诊断价值。方法 选择2021年5月至2022年5月新疆维吾尔自治区人民医院收治的102例经病理活检诊断为宫颈癌且存在区域淋巴结肿大患者,年龄27~68岁,平均年龄51.23岁;身体质量指数21~...目的 分析双源CT能谱成像多参数对宫颈癌区域淋巴结的定性诊断价值。方法 选择2021年5月至2022年5月新疆维吾尔自治区人民医院收治的102例经病理活检诊断为宫颈癌且存在区域淋巴结肿大患者,年龄27~68岁,平均年龄51.23岁;身体质量指数21~29 kg/m^(2),平均身体质量指数22.86 kg/m^(2);根据国际妇产科联盟(FIGO)分期标准,Ⅰ期15例,Ⅱ期39例,Ⅲ期42例,Ⅳ期6例;组织病理学类型,鳞癌86例,腺癌12例,腺鳞癌3例,透明细胞癌1例。所有患者均进行双源CT能谱成像检查,行动脉期及静脉期增强扫描,检测标准化碘浓度(NIC)和能谱曲线斜率(λHU);根据术后淋巴结的病理结果,分为淋巴结转移组和淋巴结未转移组,比较两组动脉期及静脉期的NIC、λHU,使用受试者工作特性(ROC)曲线分析其诊断效能。结果 在102例经病理活检诊断为宫颈癌且存在区域淋巴结肿大患者中,CT检出淋巴结共531个。根据术后淋巴结的病理诊断,分为淋巴结转移组345个和淋巴结未转移组186个。淋巴结转移组动脉期及静脉期的NIC、λHU均大于淋巴结未转移组,差异均有统计学意义(动脉期:0.41±0.19 vs 0.20±0.12,6.78±1.43 vs 2.41±0.55。静脉期:0.68±0.56 vs 0.39±0.27,5.85±1.37 vs 3.72±0.61。P <0.05);经ROC曲线分析,动脉期NIC、λHU及静脉期NIC、λHU定性诊断宫颈癌区域淋巴结的ROC曲线下面积(AUC)分别为0.925、0.905和0.935、0.930,最佳截断值分别为0.44、7.53和0.76、5.95,灵敏度分别为76.65%、68.91%和72.53%、75.76%,特异度分别为81.92%、93.47%和74.58%、82.43%。结论 运用双源CT能谱成像多参数进行定量分析,在宫颈癌区域淋巴结定性诊断中具有较大意义,可作为术前判断区域淋巴结转移的重要依据之一。展开更多
针对水下传感器网络中节点能耗不均衡和能量有限的问题,提出一种能耗均衡与节能的自适应水下路由协议ECBES(energy consumption balanced and energy saving adaptive underwater routing protocol)。构建双区非均匀分层拓扑。基于能耗...针对水下传感器网络中节点能耗不均衡和能量有限的问题,提出一种能耗均衡与节能的自适应水下路由协议ECBES(energy consumption balanced and energy saving adaptive underwater routing protocol)。构建双区非均匀分层拓扑。基于能耗均衡因子,利用拓扑和节点剩余能量计算节点转发优先级,实现自适应转发节点选择,均衡网络能耗。与此同时,通过候选转发区域各分区域中节点参与转发数据包的比例确定次优候选转发区域,将次优候选转发区域作为初始策略,利用策略迭代思想确定最优候选转发区域,保证投递率的同时减少不同网络规模中重复数据包的转发,降低网络的整体能耗。仿真结果表明,ECBES相比VBF、ES-VBF和ALRP,在不同节点数量下,节点死亡率均最低,在保证数据包投递率的同时,能耗最少。展开更多
文摘BACKGROUND Regional lymph node metastasis in patients with hepatocellular carcinoma(HCC)is not uncommon, and is often under-or misdiagnosed. Regional lymph node metastasis is associated with a negative prognosis in patients with HCC, and surgical resection of lymph node metastasis is considered feasible and efficacious in improving the survival and prognosis. It is critical to characterize lymph node preoperatively. There is currently no consensus regarding the optimal method for the assessment of regional lymph nodes in patients with HCC.AIM To evaluate the diagnostic value of single source dual energy computed tomography(CT) in regional lymph node assessment for HCC patients.METHODS Forty-three patients with pathologically confirmed HCC who underwent partial hepatectomy with lymphadenectomy were retrospectively enrolled. All patients underwent dual-energy CT preoperatively. Regional lymph nodes(n = 156) were divided into either a metastatic(group P, n = 52) or a non-metastasis group(group N, n = 104), and further, according to pathology, divided into an active hepatitis(group P1, n = 34; group N1, n = 73) and a non-active hepatitis group(group P2, n = 18; group N2, n = 31). The maximal short axis diameter(MSAD),iodine concentration(IC), normalized IC(NIC), and the slope of the spectralcurve(λ_(HU)) of each group in the arterial phase(AP), portal phase(PP), and delayed phase(DP) were analyzed.RESULTS Analysis of the MSAD, IC, NIC, and λ_(HU) showed statistical differences between groups P and N(P < 0.05) during all three phases. To distinguish benign from metastatic lymph nodes, the diagnostic efficacy of IC, NIC, and λ_(HU) in the PP was the best among the three phases(AP, PP, and DP), with a sensitivity up to 81.9%,83.9%, and 81.8%, and a specificity up to 82.4%, 84.1% and 84.1%, respectively.The diagnostic value of combined analyses of MSAD with IC, NIC, or λ_(HU) in the PP was superior to the dual energy CT parameters alone, with a sensitivity up to84.5%, 86.9%, and 86.2%, and a specificity up to 83.0%, 93.6% and 89.8%,respectively. Between groups P1 and P2 and groups N1 and N2, only IC, NIC,and λ_(HU) between groups N1 and N2 in the PP had a statistically significant difference(P < 0.05).CONCLUSION Dual-energy CT contributes beneficially to regional lymph node assessment in HCC patients. Combination of MSAD with IC, NIC, or λ_(HU) values in the PP is superior to using any single parameter alone. Active hepatitis does not deteriorate the capabilities for characterization of metastatic lymph nodes.
文摘Combining Dual Reciprocity Method （DRM） with Hybrid Boundary Node Method （HBNM）, the Dual Reciprocity Hybrid Boundary Node Method （DRHBNM） is developed for three-dimensional linear elasticity problems with body force. This method can be used to solve the elasticity problems with body force without domain integral, which is inevitable by HBNM. To demonstrate the versatility and the fast convergence of this method, some numerical examples of 3-D elasticity problems with body forces are examined. The computational results show that the present method is effective and can be widely applied in solving practical engineering problems.
文摘Closed form expressions for the PDF and MGF of the harmonic mean of two independent exponential variates are cited and derived, and then applied to study the performance of cellular multi-node and dual-hop cooperative communication systems with non-regenerative relays over flat Rayleigh fading channels. We derive the probability density function (PDF) and asymptotic symbol error rate (SER) expression with MRC scheme. Then we use Matlab to simulate the performance.
文摘目的 分析双源CT能谱成像多参数对宫颈癌区域淋巴结的定性诊断价值。方法 选择2021年5月至2022年5月新疆维吾尔自治区人民医院收治的102例经病理活检诊断为宫颈癌且存在区域淋巴结肿大患者,年龄27~68岁,平均年龄51.23岁;身体质量指数21~29 kg/m^(2),平均身体质量指数22.86 kg/m^(2);根据国际妇产科联盟(FIGO)分期标准,Ⅰ期15例,Ⅱ期39例,Ⅲ期42例,Ⅳ期6例;组织病理学类型,鳞癌86例,腺癌12例,腺鳞癌3例,透明细胞癌1例。所有患者均进行双源CT能谱成像检查,行动脉期及静脉期增强扫描,检测标准化碘浓度(NIC)和能谱曲线斜率(λHU);根据术后淋巴结的病理结果,分为淋巴结转移组和淋巴结未转移组,比较两组动脉期及静脉期的NIC、λHU,使用受试者工作特性(ROC)曲线分析其诊断效能。结果 在102例经病理活检诊断为宫颈癌且存在区域淋巴结肿大患者中,CT检出淋巴结共531个。根据术后淋巴结的病理诊断,分为淋巴结转移组345个和淋巴结未转移组186个。淋巴结转移组动脉期及静脉期的NIC、λHU均大于淋巴结未转移组,差异均有统计学意义(动脉期:0.41±0.19 vs 0.20±0.12,6.78±1.43 vs 2.41±0.55。静脉期:0.68±0.56 vs 0.39±0.27,5.85±1.37 vs 3.72±0.61。P <0.05);经ROC曲线分析,动脉期NIC、λHU及静脉期NIC、λHU定性诊断宫颈癌区域淋巴结的ROC曲线下面积(AUC)分别为0.925、0.905和0.935、0.930,最佳截断值分别为0.44、7.53和0.76、5.95,灵敏度分别为76.65%、68.91%和72.53%、75.76%,特异度分别为81.92%、93.47%和74.58%、82.43%。结论 运用双源CT能谱成像多参数进行定量分析,在宫颈癌区域淋巴结定性诊断中具有较大意义,可作为术前判断区域淋巴结转移的重要依据之一。
文摘针对水下传感器网络中节点能耗不均衡和能量有限的问题,提出一种能耗均衡与节能的自适应水下路由协议ECBES(energy consumption balanced and energy saving adaptive underwater routing protocol)。构建双区非均匀分层拓扑。基于能耗均衡因子,利用拓扑和节点剩余能量计算节点转发优先级,实现自适应转发节点选择,均衡网络能耗。与此同时,通过候选转发区域各分区域中节点参与转发数据包的比例确定次优候选转发区域,将次优候选转发区域作为初始策略,利用策略迭代思想确定最优候选转发区域,保证投递率的同时减少不同网络规模中重复数据包的转发,降低网络的整体能耗。仿真结果表明,ECBES相比VBF、ES-VBF和ALRP,在不同节点数量下,节点死亡率均最低,在保证数据包投递率的同时,能耗最少。
