This paper brings forward the concept of stability of the spatial structure of urban agglomeration(UA)based on Central Place Theory by introducing centrality index and fractal theory.Before assessment,K=4 is selected ...This paper brings forward the concept of stability of the spatial structure of urban agglomeration(UA)based on Central Place Theory by introducing centrality index and fractal theory.Before assessment,K=4 is selected as parameter to calculate centrality index and fractal dimension(K represents the quantitive relationship between city and the counties in Central Place Theory),and then found the number of nodes,the type of spatial structure,the spatial allocation of nodes with different hierarchy affecting the stability of spatial structure.According to spatial contact direction and the level of stability,UAs in China are classified into five types.Finally,it is posed as a further question that how to use hierarchical relation K=6 and K=7 in central place system to coordinate with the assessment of stability of soatial structure is brought forward.展开更多
Urban agglomeration (UA) compactness means spatial concentration degree of physical entities, such as cities (towns), industries, resources, funds, traffic and technologies, whose concentration is formed according to ...Urban agglomeration (UA) compactness means spatial concentration degree of physical entities, such as cities (towns), industries, resources, funds, traffic and technologies, whose concentration is formed according to specified economic and technologic association in the process of UA formation and development. The UA industrial compactness means the concentration degree of industry and industry clusters with reference to the industrial, technologi- cal and economic relations among the cities in the UA in the process of rational industrial division and with the exten- sion of industrial chain. After analyzing the researches on compactness, this paper finds that the relevant measurement coefficient and methods reflecting industrial geographical concentration fail to link industries spatial concentration with urban spatial concentration. Taking 23 UAs as samples and classifying them by development degree, this paper probes into UA compactness and spatial distribution characteristics from the perspective of industry by adopting UA index systems of industry and measurement models. The research finds out: 1) there is obvious positive correlation between UA industrial compactness and UA development degree; 2) the spatial distribution difference of UA industrial compactness is relatively great; and 3) UA industrial compactness shows a gradually decreasing tendency from the eastern part, the middle part to the western part of China. From the research thoughts and approaches, this article suggests that studies on the UA integrated compactness measurement should be enhanced from a multidimensional perspective involving space, traffic, population density and so on.展开更多
目的全面了解我国门静脉高压食管胃静脉曲张内镜治疗的现状,为我国内镜治疗的发展提供数据支持和参考。方法本研究由中国肝脏健康联盟(Liver Health Consortium in China,CHESS)发起,通过网络分发调查问卷了解2022年国内开展门静脉高压...目的全面了解我国门静脉高压食管胃静脉曲张内镜治疗的现状,为我国内镜治疗的发展提供数据支持和参考。方法本研究由中国肝脏健康联盟(Liver Health Consortium in China,CHESS)发起,通过网络分发调查问卷了解2022年国内开展门静脉高压食管胃静脉曲张内镜治疗的基本情况。问卷问题主要包括各类内镜治疗例数和适应证,依照指南预防食管胃静脉曲张出血(esophagogastric variceal bleeding,EGVB)的依从性,急性EGVB的处理、治疗时机,胃底及特殊类型静脉曲张的处理、内镜治疗的改善等方面。统计各项治疗数据的医院数量占参与调查问卷医院数量的比例,各级医院的指南依从性比较使用卡方检验进行分析。结果31个省(自治区、直辖市)共836家医院参与本调研,调查显示内镜治疗的主要适应证是控制急性出血(49.3%,412/836)和预防再出血(38.3%,320/836)。参与调研医院对于我国指南中EGVB一级预防的推荐意见(非选择性β受体阻滞剂或内镜治疗)的依从性为72.5%(606/836),对于EGVB二级预防推荐意见(非选择性β受体阻滞剂联合内镜治疗)的依从性为39.2%(328/836),三级医院和二级医院对于一级预防[71.0%(495/697)比79.9%(111/139),χ^(2)=4.11,P=0.033]和二级预防的依从性[41.6%(290/697)比27.3%(38/139),χ^(2)=9.31,P=0.002]差异有统计学意义。78.2%(654/836)的医院首选内镜治疗处理急性EGVB,三级医院首选内镜治疗的比例明显高于二级医院[82.6%(576/697)比56.1%(78/139),χ^(2)=46.33,P<0.001]。治疗时机通常为出血后12h内(48.5%,317/654)和12~24h(36.9%,241/654)。对于近贲门大弯侧的胃底静脉曲张和孤立性胃静脉曲张,分别有48.2%(403/836)和29.9%(250/836)的医院首选组织胶联合硬化剂注射进行处理,而12.4%(104/836)和26.4%(221/836)的医院首选以止血夹为基础的内镜治疗术式。参与调研医院认为提高内镜医师水平(84.2%,704/836)和对患者进行准确的术前评估并提高多学科诊疗水平(78.9%,660/836)是当前内镜治疗急需改进的方面。结论多种门静脉高压食管胃静脉曲张内镜治疗技术已在全国范围广泛开展,各级医院在开展急诊内镜进行EGVB止血方面较为积极,但对于预防EGVB首次出血和再出血方面的指南依从性欠佳。参与调研医院在胃静脉曲张的内镜治疗选择方面差异较大。展开更多
目的探讨甲状腺乳头状癌(PTC)患者行甲状腺系膜切除术的中央区淋巴结清扫的临床价值。方法回顾性分析2017年10月至2019年4月173例PTC患者临床资料。根据术式不同分为两组,常规组98例,术中行常规中央区淋巴结清扫;系膜组75例,术中行甲状...目的探讨甲状腺乳头状癌(PTC)患者行甲状腺系膜切除术的中央区淋巴结清扫的临床价值。方法回顾性分析2017年10月至2019年4月173例PTC患者临床资料。根据术式不同分为两组,常规组98例,术中行常规中央区淋巴结清扫;系膜组75例,术中行甲状腺系膜切除术清扫中央区淋巴结。使用统计软件SPSS 24.0分析,围术期指标、甲状旁腺素(PTH)、血钙等计量资料采用(±s)表示,独立样本t检验;术后并发症、复发转移率等计数资料采用χ^(2)检验。以P<0.05差异有统计学意义。结果两组患者在手术时间、术中出血量、术后住院时间及中央区淋巴结清扫数目中差异均无统计学意义(P>0.05);两组患者术后3 d PTH及血钙水平均较术前明显下降,且常规组较系膜组均更低(P<0.05);常规组术后并发症发生率为20.4%明显高于系膜组9.3%(P<0.05);术后平均随访12.7个月,术后3个月内,所有患者PTH均恢复正常,无永久性喉返神经损伤及永久性甲状旁腺功能低下发生。随访期内常规组复发转移率为5.1%,系膜组为2.7%,差异无统计学意义(P>0.05)。结论在PTC手术中,通过甲状腺系膜切除术清扫中央区淋巴结,具有手术并发症发生率低,更好地保护甲状旁腺功能,避免血钙水平过度下降的优势。展开更多
基金Under the auspices of the National Natural Science Foundation of China(No.40335049,40471059)
文摘This paper brings forward the concept of stability of the spatial structure of urban agglomeration(UA)based on Central Place Theory by introducing centrality index and fractal theory.Before assessment,K=4 is selected as parameter to calculate centrality index and fractal dimension(K represents the quantitive relationship between city and the counties in Central Place Theory),and then found the number of nodes,the type of spatial structure,the spatial allocation of nodes with different hierarchy affecting the stability of spatial structure.According to spatial contact direction and the level of stability,UAs in China are classified into five types.Finally,it is posed as a further question that how to use hierarchical relation K=6 and K=7 in central place system to coordinate with the assessment of stability of soatial structure is brought forward.
基金Under the auspices of National Major Programs of Scientific and Technological Support Plan of the 11th Five-Year Plan Period of China(No.2006BAJ14B03)Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-YW-307-02)
文摘Urban agglomeration (UA) compactness means spatial concentration degree of physical entities, such as cities (towns), industries, resources, funds, traffic and technologies, whose concentration is formed according to specified economic and technologic association in the process of UA formation and development. The UA industrial compactness means the concentration degree of industry and industry clusters with reference to the industrial, technologi- cal and economic relations among the cities in the UA in the process of rational industrial division and with the exten- sion of industrial chain. After analyzing the researches on compactness, this paper finds that the relevant measurement coefficient and methods reflecting industrial geographical concentration fail to link industries spatial concentration with urban spatial concentration. Taking 23 UAs as samples and classifying them by development degree, this paper probes into UA compactness and spatial distribution characteristics from the perspective of industry by adopting UA index systems of industry and measurement models. The research finds out: 1) there is obvious positive correlation between UA industrial compactness and UA development degree; 2) the spatial distribution difference of UA industrial compactness is relatively great; and 3) UA industrial compactness shows a gradually decreasing tendency from the eastern part, the middle part to the western part of China. From the research thoughts and approaches, this article suggests that studies on the UA integrated compactness measurement should be enhanced from a multidimensional perspective involving space, traffic, population density and so on.
文摘目的全面了解我国门静脉高压食管胃静脉曲张内镜治疗的现状,为我国内镜治疗的发展提供数据支持和参考。方法本研究由中国肝脏健康联盟(Liver Health Consortium in China,CHESS)发起,通过网络分发调查问卷了解2022年国内开展门静脉高压食管胃静脉曲张内镜治疗的基本情况。问卷问题主要包括各类内镜治疗例数和适应证,依照指南预防食管胃静脉曲张出血(esophagogastric variceal bleeding,EGVB)的依从性,急性EGVB的处理、治疗时机,胃底及特殊类型静脉曲张的处理、内镜治疗的改善等方面。统计各项治疗数据的医院数量占参与调查问卷医院数量的比例,各级医院的指南依从性比较使用卡方检验进行分析。结果31个省(自治区、直辖市)共836家医院参与本调研,调查显示内镜治疗的主要适应证是控制急性出血(49.3%,412/836)和预防再出血(38.3%,320/836)。参与调研医院对于我国指南中EGVB一级预防的推荐意见(非选择性β受体阻滞剂或内镜治疗)的依从性为72.5%(606/836),对于EGVB二级预防推荐意见(非选择性β受体阻滞剂联合内镜治疗)的依从性为39.2%(328/836),三级医院和二级医院对于一级预防[71.0%(495/697)比79.9%(111/139),χ^(2)=4.11,P=0.033]和二级预防的依从性[41.6%(290/697)比27.3%(38/139),χ^(2)=9.31,P=0.002]差异有统计学意义。78.2%(654/836)的医院首选内镜治疗处理急性EGVB,三级医院首选内镜治疗的比例明显高于二级医院[82.6%(576/697)比56.1%(78/139),χ^(2)=46.33,P<0.001]。治疗时机通常为出血后12h内(48.5%,317/654)和12~24h(36.9%,241/654)。对于近贲门大弯侧的胃底静脉曲张和孤立性胃静脉曲张,分别有48.2%(403/836)和29.9%(250/836)的医院首选组织胶联合硬化剂注射进行处理,而12.4%(104/836)和26.4%(221/836)的医院首选以止血夹为基础的内镜治疗术式。参与调研医院认为提高内镜医师水平(84.2%,704/836)和对患者进行准确的术前评估并提高多学科诊疗水平(78.9%,660/836)是当前内镜治疗急需改进的方面。结论多种门静脉高压食管胃静脉曲张内镜治疗技术已在全国范围广泛开展,各级医院在开展急诊内镜进行EGVB止血方面较为积极,但对于预防EGVB首次出血和再出血方面的指南依从性欠佳。参与调研医院在胃静脉曲张的内镜治疗选择方面差异较大。
文摘目的探讨甲状腺乳头状癌(PTC)患者行甲状腺系膜切除术的中央区淋巴结清扫的临床价值。方法回顾性分析2017年10月至2019年4月173例PTC患者临床资料。根据术式不同分为两组,常规组98例,术中行常规中央区淋巴结清扫;系膜组75例,术中行甲状腺系膜切除术清扫中央区淋巴结。使用统计软件SPSS 24.0分析,围术期指标、甲状旁腺素(PTH)、血钙等计量资料采用(±s)表示,独立样本t检验;术后并发症、复发转移率等计数资料采用χ^(2)检验。以P<0.05差异有统计学意义。结果两组患者在手术时间、术中出血量、术后住院时间及中央区淋巴结清扫数目中差异均无统计学意义(P>0.05);两组患者术后3 d PTH及血钙水平均较术前明显下降,且常规组较系膜组均更低(P<0.05);常规组术后并发症发生率为20.4%明显高于系膜组9.3%(P<0.05);术后平均随访12.7个月,术后3个月内,所有患者PTH均恢复正常,无永久性喉返神经损伤及永久性甲状旁腺功能低下发生。随访期内常规组复发转移率为5.1%,系膜组为2.7%,差异无统计学意义(P>0.05)。结论在PTC手术中,通过甲状腺系膜切除术清扫中央区淋巴结,具有手术并发症发生率低,更好地保护甲状旁腺功能,避免血钙水平过度下降的优势。
