The logistics nodes and logistics enterprises are the core carriers and organiza- tional subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to opti...The logistics nodes and logistics enterprises are the core carriers and organiza- tional subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to optimizing urban logistics spatial patterns and ensuring reasonable resource allocation. Based on Tencent Online Maps Platform from December 2014, 4396 logistics points of interest （POI） were collected in Beijing, China. By the methods of industrial concentration evaluation and kernel density analysis, the spatial distribution pattern of logistics in Beijing are explored, the interaction mechanism among the type differ- ence, supply-demand side factors and location choice behavior are clarified, and the internal mechanism of spatial differentiation under the combined influence of transportation, land rent and assets are revealed. The following conclusions are drawn in the paper. （1） Logistics en- terprises and logistics nodes exhibit the characteristic of both co-agglomeration and spatial separation in location, and logistics activities display the spatial pattern of ＂marginal area of downtown area, suburbs and exurban area＂, which have a weak coupling degree with logis- tics employment space. （2） The public logistics space, namely, logistics parks and logistics centers, is produced under the guidance of the government, and the terminal logistics space consisting of logistics distribution centers serving for the specific industries and terminal users is dominated by enterprises. The Iocational differentiation between the two modes of logistics space is significant. （3） In the formation of the logistics spatial location, the government can change the traffic condition by re-planning the transport routes and freight station locations, and control the land rent and availability of different areas by increasing or decreasing the land use of logistics, to impact the enterprise behavior and form different types of logistics space and function differentiation. In comparison, logistics enterprises meet the diverse de- mands of service objects through differentiation of asset allocation to promote the specializa- tion of division and form the object differentiation of logistics space.展开更多
目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根...目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根据有无淋巴结转移,将患者分为阳性组与阴性组。收集患者的临床及影像学资料,采用单因素和多因素logistic回归分析可切除肺腺癌淋巴结转移的独立危险因素,并建立淋巴结转移的空间位置-临床-影像特征联合预测模型,将其与不包含空间位置特征的传统淋巴结转移预测模型进行对比。结果共纳入611例患者,阳性组333例,其中男172例、女161例,平均年龄(58.9±9.7)岁;阴性组278例,其中男127例、女151例,平均年龄(60.1±11.4)岁。单因素及多因素logistic回归分析显示,病灶距离肺门的空间位置关系、结节类型、胸膜改变、血清癌胚抗原(carcinoembryonic antigen,CEA)水平是淋巴结转移的独立危险因素,以此为基础构建的空间位置-临床-影像特征联合预测模型敏感性为91.67%,特异性为74.05%,准确性为87.88%,曲线下面积(area under the curve,AUC)为0.885。不包含空间位置特征的传统淋巴结转移预测模型敏感性为76.40%,特异性为72.10%,准确性为53.86%,AUC为0.827。两种预测方法的AUC差异有统计学意义(P=0.026)。与传统预测模型相比,空间位置-临床-影像特征联合预测模型的预测效能有显著提升。结论在可切除肺腺癌患者中,空间位置、实性密度、胸膜改变为宽基底凹陷以及血清CEA水平升高者发生淋巴结转移的风险更高。展开更多
基金Foundation： National Natural Science Foundation of China, No.41501123, No.71703219
文摘The logistics nodes and logistics enterprises are the core carriers and organiza- tional subjects of the logistics space, and their location characteristics and differentiation strategies are of key importance to optimizing urban logistics spatial patterns and ensuring reasonable resource allocation. Based on Tencent Online Maps Platform from December 2014, 4396 logistics points of interest （POI） were collected in Beijing, China. By the methods of industrial concentration evaluation and kernel density analysis, the spatial distribution pattern of logistics in Beijing are explored, the interaction mechanism among the type differ- ence, supply-demand side factors and location choice behavior are clarified, and the internal mechanism of spatial differentiation under the combined influence of transportation, land rent and assets are revealed. The following conclusions are drawn in the paper. （1） Logistics en- terprises and logistics nodes exhibit the characteristic of both co-agglomeration and spatial separation in location, and logistics activities display the spatial pattern of ＂marginal area of downtown area, suburbs and exurban area＂, which have a weak coupling degree with logis- tics employment space. （2） The public logistics space, namely, logistics parks and logistics centers, is produced under the guidance of the government, and the terminal logistics space consisting of logistics distribution centers serving for the specific industries and terminal users is dominated by enterprises. The Iocational differentiation between the two modes of logistics space is significant. （3） In the formation of the logistics spatial location, the government can change the traffic condition by re-planning the transport routes and freight station locations, and control the land rent and availability of different areas by increasing or decreasing the land use of logistics, to impact the enterprise behavior and form different types of logistics space and function differentiation. In comparison, logistics enterprises meet the diverse de- mands of service objects through differentiation of asset allocation to promote the specializa- tion of division and form the object differentiation of logistics space.
文摘目的联合空间位置-临床-影像特征探讨可切除肺腺癌淋巴结转移的危险因素,并构建淋巴结转移预测模型。方法回顾性纳入2016年6月—2020年6月于南京医科大学第一附属医院接受胸部CT,并经手术确诊为有或无淋巴结转移的浸润性肺腺癌患者。根据有无淋巴结转移,将患者分为阳性组与阴性组。收集患者的临床及影像学资料,采用单因素和多因素logistic回归分析可切除肺腺癌淋巴结转移的独立危险因素,并建立淋巴结转移的空间位置-临床-影像特征联合预测模型,将其与不包含空间位置特征的传统淋巴结转移预测模型进行对比。结果共纳入611例患者,阳性组333例,其中男172例、女161例,平均年龄(58.9±9.7)岁;阴性组278例,其中男127例、女151例,平均年龄(60.1±11.4)岁。单因素及多因素logistic回归分析显示,病灶距离肺门的空间位置关系、结节类型、胸膜改变、血清癌胚抗原(carcinoembryonic antigen,CEA)水平是淋巴结转移的独立危险因素,以此为基础构建的空间位置-临床-影像特征联合预测模型敏感性为91.67%,特异性为74.05%,准确性为87.88%,曲线下面积(area under the curve,AUC)为0.885。不包含空间位置特征的传统淋巴结转移预测模型敏感性为76.40%,特异性为72.10%,准确性为53.86%,AUC为0.827。两种预测方法的AUC差异有统计学意义(P=0.026)。与传统预测模型相比,空间位置-临床-影像特征联合预测模型的预测效能有显著提升。结论在可切除肺腺癌患者中,空间位置、实性密度、胸膜改变为宽基底凹陷以及血清CEA水平升高者发生淋巴结转移的风险更高。
