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Clinical significance of type V_I pit pattern subclassification in determining the depth of invasion of colorectal neoplasms 被引量:17
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作者 Hiroyuki Kanao Shinji Tanaka +5 位作者 Shiro Oka Iwao Kaneko Shigeto Yoshida Koji Arihiro Masaharu Yoshihara Kazuaki Chayama 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第2期211-217,共7页
AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.METHODS: We retrospe... AIM: To clarify whether subclassification of the type VI pit pattern on the basis of magnifying colonoscopy findings is useful in determining the type and depth of invasion of colorectal neoplasms.METHODS: We retrospectively analyzed 272 colorectal neoplasms (117 dysplasias and 155 submucosal invasive carcinomas; 228 patients) with a type V pit pattern [type VI, n = 202; type VN, n = 70 (Kudo and Tsuruta classification system)]. We divided lesions with a type VI pit pattern into two subclasses, mildly irregular lesions and severely irregular lesions, according to the prominent and detailed magnifying colonoscopy findings. We examined the relation between these two subclasses and histology/invasion depth.RESULTS: One hundred and four lesions (51.5%) were judged to be mildly irregular, and 98 lesions (48.5%) were judged to be severely irregular. Ninety-seven (93.3%) mildly irregular lesions showed dysplasias or submucosal invasion of less than 1000 μm (SM < 1000 μm). Fifty-five (56.1%) severely irregular lesions showed submucosal invasion equal to or deeper than 1000 μm (SM ≥ 1000 μm). Mild irregularity was found significantly more often in dysplasias or lesions with SM < 1000 μm than in lesions with SM ≥ 1000 μm (P < 0.01).CONCLUSION: Subclassification of the type VI pit pattern is useful for identifying dysplasias or lesions with SM < 1000 μm. 展开更多
关键词 Colorectal neoplasm MAGNIFICATION type VI pit pattern Depth of invasion
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Weathering,shock metamorphism and type distribution patterns of 98 ordinary chondrites from the Grove Mountains,Antarctica 被引量:1
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作者 戴德求 王道德 缪秉魁 《Chinese Journal of Polar Science》 2009年第2期215-224,共10页
Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains (GRV), Antarctica, were presented and their. Weathering effect, shock metamorphism and type distribution patterns were discu... Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains (GRV), Antarctica, were presented and their. Weathering effect, shock metamorphism and type distribution patterns were discussed in this study. Among them, six are unequilibrated ordinary chondrites, including 3 H3 and 3 L3 ; and 92 meteorites are equilibrated ordinary chondrites, including 24 H-group ( 13 H4, 10 H5, 1 H6), 64 L-group (2 L4, 44 L5, 18 L6) and 4 LL-group (3 LL4, 1 LL5). Most GRV ehondrites ( 〉 90% ) displayed minor weathering effect ( W1 and W2). About half of the meteorites experienced severe shock metamorphism. They commonly contain shock-induced melt veins and pockets. These heavily shocked meteorites provide us with natural samples for study of high-pressure polymorphs of minerals. In addition, the Grove Mountains collection seems to have more abundant unequilibrated and L group ordinary ehondrites compared to the US Antarctic meteorite collection which were mainly found along the Transantarctic Mountains. 展开更多
关键词 ordinary chondrites WEATHERING shock metamorphism type distribution patterns Antarctica.
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Structural patterns of land types and optimal allocation of land use in Qinling Mountains 被引量:12
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作者 LIU Yan-sui, DENG Xiang-zheng (Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2001年第1期99-109,共11页
The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward ... The case study based on Qinling Mountains in Shaanxi Province of China, in virtue of the information from TM image, classifies the land types and analyzes their spatial and temporal differential law, and puts forward three structural patterns of land types in mountainous areas, namely, spatial, quantitative and qualitative structures of mountainous land types. Furthermore, it has been noticed that the analysis of structural patterns can disclose the heterogeneity and orderliness of combination of land types, which can lay the theoretic foundation for comprehensively recognizing ecological characteristics and succession law of structure and function of land types. After the all-around comparative analysis, an optimal allocation of land use in Qinling Mountains has been put forward according to the principle of sustainable development and landscape ecology, which can lay the scientific foundation in practice for the structural adjustment and distribution optimization from the macro level to micro level. 展开更多
关键词 land types succession of land types structural patterns optimal allocation Qinling Mountains
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The regional types of China's floating population: Identification methods and spatial patterns 被引量:9
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作者 LIU Shenghe HU Zhang +1 位作者 DENG Yu WANG Yingjie 《Journal of Geographical Sciences》 SCIE CSCD 2011年第1期35-48,共14页
With the rapid increase of the number and influence of floating population in China,it is urgently needed to understand the regional types of China's floating population and their spatial characteristics. After revie... With the rapid increase of the number and influence of floating population in China,it is urgently needed to understand the regional types of China's floating population and their spatial characteristics. After reviewing the current methods for identifying regional types of floating population,this paper puts forward a new composite-index identification method and its modification version which is consisted of two indexes of the net migration rate and gross migration rate. Then,the traditional single-index and the new composite-index identification methods are empirically tested to explore their spatial patterns and characteristics by using China's 2000 census data at county level. The results show:(1) The composite-index identification method is much better than traditional single-index method because it can measure the migration direction and scale of floating simultaneously,and in particular it can identify the unique regional types of floating population with large scale of immigration and emigration. (2) The modified composite-index identification method,by using the share of a region's certain type of floating population to the total in China as weights,can effectively correct the over-or under-estimated errors due to the rather large or small total population of a region. (3) The spatial patterns of different regional types of China's floating population are closely related to the regional differentiation of their natural environment,population density and socio-economic development level. The three active regional types of floating population are mainly located in the eastern part of China with lower elevation,more than 800 mm precipitation,rather higher population densities and economic development levels. 展开更多
关键词 China floating population regional types spatial pattern composite-index identification method
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Dietary Patterns and Their Association with Depression among Type 2 Diabetes Patients in Gaza Strip, Palestine 被引量:1
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作者 Abdel Hamid el Bilbeisi Mohammed Srour +2 位作者 Amany el Afifi Halgord Ali M. Farag Kurosh Djafarian 《Food and Nutrition Sciences》 2019年第5期533-550,共18页
Background: Depression is a common mental disorder. Globally, more than 340 million people of all ages suffer from depression. The aim of our study was to determine the association between major dietary patterns and d... Background: Depression is a common mental disorder. Globally, more than 340 million people of all ages suffer from depression. The aim of our study was to determine the association between major dietary patterns and depression among type 2 diabetes patients. Methods: This cross-sectional study was conducted among 480 type 2 diabetes patients attending primary healthcare centers in Gaza Strip, Palestine. The depression, anxiety, stress scales (DASS, 21-items) questionnaire was used to measure the score of depression. The participants’ demographic, socioeconomic and medical history data was collected and the 98-items semi-quantitative food frequency questionnaire was used for evaluating the dietary patterns. Statistical analysis was performed using SPSS version 20. Results: Based on depression scale, 29.0% of type 2 diabetes patients had depression, (58.3% females, and 41.7% males). The prevalence of mild, moderate, severe, and very severe depression was 11.7%, 8.5%, 6.7%, and 2.1%, respectively. Furthermore, two major dietary patterns were identified by factor analysis: The Western, and the grains-vegetables, and fruits patterns. After adjusting for the potential confounders, patients in the lowest tertile (T1) of the grains-vegetables, and fruits dietary pattern had a lower odds for depression (OR 0.763 95% CI (0.667 - 0.871), P value = 0.001);where as a higher odds for healthy (OR 1.443 95% CI (1.131 - 1.839), P value = 0.004), compared to those in the highest tertile (T3). Conclusion: The grains-vegetables, and fruits dietary pattern may be associated with a lower prevalence of depression, and has been shown to be the healthiest dietary pattern among type 2 diabetes patients. 展开更多
关键词 DEPRESSION DIETARY patterns Factor Analysis PREVALENCE type 2 DIABETES MELLITUS
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Identification of SNPs and expression patterns of FZD3 gene and its effect on wool traits in Chinese Merino sheep(Xinjiang Type) 被引量:4
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作者 ZHAO Bing-ru FU Xue-feng +9 位作者 TIAN Ke-chuan HUANG Xi-xia DI Jiang BAI Yan XU Xin-ming TIAN Yue-zhen WU Wei-wei ABLAT Sulayman ZENG Wei-dan HANIKEZI Tulafu 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2019年第10期2351-2360,共10页
As a member of the Frizzled family, Frizzled3 (FZD3) is a receptor of the canonical Wnt signaling pathway and plays a vital role in mammalian hair follicle developmental processes. However, its effects on wool traits ... As a member of the Frizzled family, Frizzled3 (FZD3) is a receptor of the canonical Wnt signaling pathway and plays a vital role in mammalian hair follicle developmental processes. However, its effects on wool traits are not clear. The objectives of this study were to identify the single nucleotide polymorphisms (SNPs) and the expression patterns of FZD3 gene, and then to determine whether it affected wool traits of Chinese Merino sheep (Xinjiang Type) or not. PCR-single stranded conformational polymorphism (PCR-SSCP) and sequencing were used to identify mutation loci, and general linear model (GLM) with SAS 9.1 was used for the association analysis between wool traits and SNPs. Quantitative real-time PCR (qRT-PCR) was used to investigate FZD3 gene expression levels. The results showed that six exons of FZD3 gene were amplified and two mutation loci were identified in exon 1 (NC_019459.2: g.101771685 T>C (SNP1)) and exon 3 (NC_019459.2: g.101810848, A>C (SNP2)), respectively. Association analysis showed that SNP1 was significantly associated with mean fiber diameter (MFD)(P=0.04) and live weight (LW)(P=0.0004), SNP2 was significantly associated with greasy fleece weight (GFW)(P=0.04). The expression level of FZD3 gene in skin tissues of the superfine wool (SF) group was significantly lower (P<0.05) than that of the fine wool (F) group. Moreover, it had a higher expression level (P<0.01) in skin tissues than in other tissues of Chinese Merino ewes. While, its expression level had a fluctuant expression in skin tissues at different developmental stages of embryos and born lambs, with the highest expression levels (P<0.01) at the 65th day of embryos. Our study revealed the genetic relationship between FZD3 variants and wool traits and two identified SNPs might serve as potential and valuable genetic markers for sheep breeding and lay a molecular genetic foundation for sheep marker-assisted selection (MAS). 展开更多
关键词 Chinese MERINO SHEEP (Xinjiang type) FZD3 single NUCLEOTIDE polymorphism (SNP) expression pattern association analysis WOOL TRAITS
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Stand development patterns of forest cover types in the natural forests of northern Baekdudaegan in South Korea
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作者 Ji Hong Kim Guangze Jin Sang Hoon Chung 《Journal of Forestry Research》 SCIE CAS CSCD 2015年第2期381-390,共10页
The purpose of this study was to classify current forest cover types,and to investigate stand development patterns for natural forests in six areas in northern Baekdudaegan,South Korea.Twenty-eight independent forest ... The purpose of this study was to classify current forest cover types,and to investigate stand development patterns for natural forests in six areas in northern Baekdudaegan,South Korea.Twenty-eight independent forest communities were aggregated into eight forest cover types by species composition in the overstory of each forest community.The forest cover types were of mixed mesophytic,‘‘others’ ’ deciduous,Quercus mongolica dominant,Q.mongolica pure,Pinus densiflora–Q.mongolica,P.densiflora,Betula ermanii,and Q.mongolica–P.koraiensis.The ecological information was organized by importance value and species diversity for each forest type.Based on the correlation between species diversity index and the abundance of Q.mongolica plus P.densiflora for corresponding forest cover types,we compared the developmental process and approximate successional pathway between each cover type.The P.densiflora forest cover type changes into the P.densiflora–Q.mongolica cover type,followed by the Q.mongolica dominant cover type through continuous invasion of the oak trees.Furthermore,the Q.mongolica pure cover type would spread toward the Q.mongolica dominant cover type with a mixture of various deciduous tree species.The Q.mongolica dominant cover type progresses through the other deciduous cover types to the mixed mesophytic cover type with diversified composition and structure.On the mid to lower slopes,with loamy soils and good moisture conditions,various deciduous forest types should progress,by ecological succession,toward the mixed mesophytic cover type without any further disturbance. 展开更多
关键词 Baekdudaegan Forest cover type Species composition Species diversity Stand development patternS
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Utilization Pattern of Oral Hypoglycemic Agents for Diabetes Mellitus Type 2 Patients Attending Out-Patient Department at a University Hospital in New Delhi
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作者 Mohammad Shamshir Alam Mohammed Aqil +2 位作者 Syed Akmal Shah Qadry Prem Kapur Krishna K. Pillai 《Pharmacology & Pharmacy》 2014年第7期636-645,共10页
Diabetes mellitus is the chronic disorder emerging as major world health problem which increases the rate of morbidity and mortality. The aim of the present study was to ascertain patterns of prescription of oral hypo... Diabetes mellitus is the chronic disorder emerging as major world health problem which increases the rate of morbidity and mortality. The aim of the present study was to ascertain patterns of prescription of oral hypoglycemic agents to type 2 diabetic patients attending a university hospital, and to assess patient compliance. A prospective, observational and non comparative study was conducted in 200 established diabetes mellitus type 2 patients attending outpatient department at Majeedia Hospital, New Delhi, India. Prescriptions from registered patients were included in the study. Once the consultation by the physician was over, the prescriptions were reviewed and the patients were interviewed. The information was collected in an inhouse designed documentation proforma. In a pool of 200 type 2 diabetics, more than half were female (n=106, 53%). The mean age of the patients were found to be 50.4 ± 11.7 years and mean body mass index, 25.8 ± 4.4 kg/m2. A total of 432 oral hypoglycemic agents were prescribed to the patients. Highly significant number of patients were prescribed combination therapy, (n=143, 71.5%) as compared to monotherapy (n=57, 28.5%), 展开更多
关键词 Diabetes Mellitus type 2 Medicine Usage Evaluation Drug UTILIZATION PRESCRIBING pattern. Oral HYPOGLYCEMIC Agent
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针对XML流数据的复杂Twig Pattern查询处理 被引量:9
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作者 杨卫东 王清明 施伯乐 《软件学报》 EI CSCD 北大核心 2007年第4期893-904,共12页
XML流数据处理在研究领域引起了研究者的广泛兴趣.针对XML流数据的、具有嵌套AND/OR谓词的复杂Twig Pattern查询处理,提出一种新方法.为了提高查询处理性能,将所有Twig Pattern合并为一个共享前缀的查询树,其中,AND/OR谓词被表示为单独... XML流数据处理在研究领域引起了研究者的广泛兴趣.针对XML流数据的、具有嵌套AND/OR谓词的复杂Twig Pattern查询处理,提出一种新方法.为了提高查询处理性能,将所有Twig Pattern合并为一个共享前缀的查询树,其中,AND/OR谓词被表示为单独的抽象语法树,因而能够以文档顺序、单遍地处理复杂Twig Pattern的匹配,并避免了YFilter中对嵌套谓词进行后置处理所产生的中间结果.实验结果表明,该方法能够有效改善Twig Pattern的处理性能,尤其是在处理大文档的情况下.基于已有的研究工作,讨论如何利用DTD(document type definition)的结构和约束信息优化Twig Pattern,即这种优化是在系统运行前进行的预处理. 展开更多
关键词 XML文档流 xPam TWIG pattern 查询树 DTD(document type definition)
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基于景观生态学原理的区域生态格局优化研究——以烟台市为例
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作者 赵高舒 乔楚晶 +2 位作者 宋江寒 王怀昱 高杨晓惠 《城市建筑》 2026年第2期23-26,共4页
构建城市生态安全格局对于维护国家和区域生态安全至关重要,是实现城市可持续发展的核心基础。这一过程既是保障生态安全的基本条件,也是推动城市持续进步的关键路径。本研究基于2000—2020年烟台市土地利用类型数据,运用ArcGIS和Fragst... 构建城市生态安全格局对于维护国家和区域生态安全至关重要,是实现城市可持续发展的核心基础。这一过程既是保障生态安全的基本条件,也是推动城市持续进步的关键路径。本研究基于2000—2020年烟台市土地利用类型数据,运用ArcGIS和Fragstats软件进行数据处理和运算,采用景观格局指数分析方法,通过对研究区各类景观要素面积变化、斑块属性、粒级结构及其动态变化过程进行分析,揭示烟台市多个时期景观格局的演变过程,阐明景观要素斑块规模的动态变化特点及其与景观格局指数的关联性。研究得出区域生态安全格局与土地利用格局间的内在联系,并针对其动态变化过程提出相应的生态格局优化策略,为滨海城市景观格局优化、生境保护与可持续发展提供一定的参考。 展开更多
关键词 景观生态格局 土地利用类型 斑块规模 景观指数
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饮酒对血压影响的研究进展
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作者 潘雪 许丽娜 《安徽医药》 2026年第2期254-258,共5页
随着我国进入小康社会,现代人的消费水平逐步提高,饮用乙醇饮料的人群日益增多,多种疾病的发生与饮用乙醇有关,对人类的身体健康造成严重威胁。高血压为心脑血管疾病的重要危险因素,近几年逐渐年轻化,尤其是在大量饮酒的人群中。饮酒作... 随着我国进入小康社会,现代人的消费水平逐步提高,饮用乙醇饮料的人群日益增多,多种疾病的发生与饮用乙醇有关,对人类的身体健康造成严重威胁。高血压为心脑血管疾病的重要危险因素,近几年逐渐年轻化,尤其是在大量饮酒的人群中。饮酒作为不健康的生活方式,在高血压的发生发展中发挥重要作用。现论述饮酒剂量、饮酒类型、饮酒模式、性别、遗传因素在乙醇对血压变化中的影响,以期为临床减少饮酒及戒酒控制高血压提供理论依据。 展开更多
关键词 饮酒 高血压 饮酒剂量 饮酒类型 饮酒模式
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Distribution patterns of the contents of five biologically activate ingredients in the root of Scutellaria baicalensis 被引量:8
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作者 LIU Rong-Xiu SONG Guo-Hu +7 位作者 WU Pei-Gen ZHANG Xue-Wen HU Hui-Juan LIU Jia MIAO Xiao-Su HOU Zhi-Yan WANG Wen-Quan WEI Sheng-Li 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2017年第2期152-160,共9页
As an important herbaceous plant, Scutellaria baicalensis Georgi(Chinese skullcap) is geographically widespread and commonly used throughout the world. In the Chinese medicine market, S. baicalensis has been divided i... As an important herbaceous plant, Scutellaria baicalensis Georgi(Chinese skullcap) is geographically widespread and commonly used throughout the world. In the Chinese medicine market, S. baicalensis has been divided into two primary types, "Ku Qin"(WXR) and "Tiao Qin"(TST). Moreover, TST is also divided into different grades according to the diameter of roots. To explore the distribution patterns of the contents of five biologically activate ingredients(FBAI), we used six-year-old cultivated S. baicalensis and analyzed its growth characteristics as well as the quality difference among different types and diameters in roots. Throughout the entire root, we discovered that contents of the FBAI all initially increased and subsequently decreased from the top to the bottom of the roots. The baicalin content of WXR was less than that of TST. On the contrary, the contents of baicalein, wogonin, and oroxylin A in WXR were up to about two times higher than that in TST. We also found that the 0 to 40 cm part of the S. baicalensis root possessed about 87% of the root biomass and about 92% of the contents of the active ingredients. 展开更多
关键词 Scutellaria baicalensis Distribution patterns type DIAMETER Biologically active ingredients
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基于《中国百年百名中医临床家丛书》探讨名家治疗不寐病的证型、证素与处方用药规律
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作者 苏啟后 彭俊杰 +1 位作者 李中 张维维 《中西医结合心脑血管病杂志》 2026年第1期27-34,共8页
目的:通过数据挖掘,探寻名家治疗不寐病的证型、证素与处方用药规律。方法:统计《中国百年百名中医临床家丛书》中所有医家治疗不寐病的医案处方,运用数据挖掘软件进行证型、证素及用药规律分析。结果:最终纳入32位现代中医名家治疗不... 目的:通过数据挖掘,探寻名家治疗不寐病的证型、证素与处方用药规律。方法:统计《中国百年百名中医临床家丛书》中所有医家治疗不寐病的医案处方,运用数据挖掘软件进行证型、证素及用药规律分析。结果:最终纳入32位现代中医名家治疗不寐病的处方共114首,药物共计197味药,总使用频次1 381次,提取出证型35种,病位证素8项和病性证素14项,统计其高频药物共有37味(频次≥10次),共计使用887次,占所有药物使用频次的64.23%。将高频次药物由高到低排序,分别统计出了其常用三种剂量及药物剂量的使用范围。证型以心肾不交证型最为常见,病位证素以心为主,病性证素以热/火为主。药物类别主要为安神药;药性以平性为重;药味尤重甘味;归经则以心经占比最高。关联规则分析发现关联强度较高的组合有16个,因子分析提取公因子14个,系统聚类分析得出5个聚类,决策树分析筛选出甘草、蒺藜和石决明3味主要中药,复杂网络分析提示核心药物为龙骨、牡蛎、酸枣仁、甘草、半夏、陈皮、茯苓等,且药物间的配伍关联性较强。结论:数据挖掘全面探讨了治疗不寐病的证型、证素与处方用药规律,对临床具有重要的指导意义。 展开更多
关键词 不寐病 《中国百年百名中医临床家丛书》 证型证素 处方用药规律 数据挖掘
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普通内镜与pit pattern分型在结直肠肿瘤中的病理诊断及浸润深度判断 被引量:2
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作者 朱振华 冯一中 《临床医学研究与实践》 2019年第32期10-11,30,共3页
目的探讨普通内镜与pit pattern分型在结直肠肿瘤中的病理诊断及浸润深度。方法回顾性分析2014年4月至2017年4月因锯齿状腺瘤(SA)于我院消化科进行治疗的30例患者的SA内镜及病理学资料,比较病理诊断及肿瘤浸润深度判断结果。结果本研究... 目的探讨普通内镜与pit pattern分型在结直肠肿瘤中的病理诊断及浸润深度。方法回顾性分析2014年4月至2017年4月因锯齿状腺瘤(SA)于我院消化科进行治疗的30例患者的SA内镜及病理学资料,比较病理诊断及肿瘤浸润深度判断结果。结果本研究中,内镜检出了35枚SA,隆起型和表面型分别21、14枚,两种类型的SA平均直径分别为10.5、16.5 mm。10 mm以下的SA上皮内瘤变多于10 mm以上的SA上皮瘤变。pit pattern分型中,共有Ⅱ型23枚,Ⅲ型11枚,Ⅳ型1枚。按照腺体上皮内瘤变的级别,其中Ⅰ、Ⅱ、Ⅲ级分别为28、6、1枚。SA的pit pattern分型与病理学分型、上皮内瘤变级别有显著相关性(χ^2=20.035、18.320,P=0.000)。结论 SA具有息肉肿瘤学的一般生物学行为,与结直肠癌的发病密切相关,在临床检查中应该给予高度的重视。 展开更多
关键词 普通内镜 PIT pattern 分型 结直肠肿瘤 病理诊断 浸润深度
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Study on the pattern of train arrival headway time in high-speed railway 被引量:1
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作者 Changhai Tian Shoushuai Zhang 《Railway Sciences》 2024年第3期344-366,共23页
Purpose-The design goal for the tracking interval of high-speed railway trains in China is 3 min,but it is difficult to achieve,and it is widely believed that it is mainly limited by the tracking interval of train arr... Purpose-The design goal for the tracking interval of high-speed railway trains in China is 3 min,but it is difficult to achieve,and it is widely believed that it is mainly limited by the tracking interval of train arrivals.If the train arrival tracking interval can be compressed,it will be beneficial for China's high-speed railway to achieve a 3-min train tracking interval.The goal of this article is to study how to compress the train arrival tracking interval.Design/methodologylapproach-By simulating the process of dense train groups arriving at the station and stopping,the headway between train arrivals at the station was calculated,and the pattern of train arrival headway was obtained,changing the traditional understanding that the train arrival headway is considered the main factor limiting the headway of trains.Findings-When the running speed of trains is high,the headway between trains is short,the length of the station approach throat area is considerable and frequent train arrivals at the station,the arrival headway for the first group or several groups of trains will exceed the headway,but the subsequent sets of trains will havea headway equal to the arrival headway.This convergence characteristic is obtained by appropriately increasing the running time.Originality/value-According to this pattern,there is no need to overly emphasize the impact of train arrival headway on the headway.This plays an important role in compressing train headway and improving high-speedrailwaycapacity. 展开更多
关键词 High speed railway Train headway Train arrival headway Regular pattern Paper type Research paper
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Assessment of wetland fragmentation in the middle reaches of the Heihe River by the type change tracker model 被引量:6
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作者 RuiFeng ZHAO ZuoLun XIE +3 位作者 LiHua ZHANG Wen ZHU Jie LI Dan LIANG 《Journal of Arid Land》 SCIE CSCD 2015年第2期177-188,共12页
The quantitative research of wetland landscape fragmentation in the middle reaches of the Heihe River is important for the wetland and oasis sustainable development in the Hexi Corridor. Based on the data of remote se... The quantitative research of wetland landscape fragmentation in the middle reaches of the Heihe River is important for the wetland and oasis sustainable development in the Hexi Corridor. Based on the data of remote sensing and GIS, we constructed the type change tracker model with sliding window technique and spatially mor- phological rule. The suitable scale and optimum scale of the fragmentation model of wetland landscape in the middle reaches of the Heihe River were determined by the area frequency statistics method, Chi-square distribution normal- ized scale variance, fractal dimension and diversity index. By integrating type change tracker model and the optimum scale with GIS spatial analysis, the spatial distribution characteristics of wetland landscape fragmentation in different periods and the related spatial-temporal change process were clarified. The results showed that (1) the type change tracker model, which analyzes the spatial pattern of wetland fragmentation on the pixel level, is better than the tradi- tional wetland fragmentation analysis on the landscape and patch levels; (2) The suitable scale for the wetland frag- mentation ranged from 150 rex150 m to 450 mx450 m and the optimum scale was 250 mx250 m in the middle reaches of the Heihe River; and (3) In the past 35 years, the total wetland area decreased by 23.2% and the frag- mentatJon of wetland markedly increased in the middle reaches of the Heihe River. The areas of core wetlands re- duced by 12.8% and the areas of perforated, edge and patch wetlands increased by 0.8%, 3.1% and 8.9%, respec- tively. The process of wetland fragmentation in the research region showed the order of core wetland, perforated or edge wetland, patch wetland or non-wetland. The results of this study would provide a reference for the protection, utilization and restoration of limited wetland resources and for the sustainable development of the regional eco-environment in the Heihe River Basin. 展开更多
关键词 WETLAND landscape pattern FRAGMENTATION the type change tracker model Heihe River
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基层内镜医师pit pattern分型在线培训效果观察
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作者 游云龙 王誉敏 +5 位作者 刘芳 郑义 蔺蓉 田书信 陈卫刚 郑勇 《农垦医学》 2023年第6期526-530,共5页
目的:观察新疆兵团基层内镜医师pit pattern分型的在线培训效果。方法:选取2021-2022年新疆兵团基层医院的内镜医师81名,将肠镜操作量≥3000例医师分为专家组39名,非专家组42名。对所有医师进行pit pattern分型在线培训和培训前、后测... 目的:观察新疆兵团基层内镜医师pit pattern分型的在线培训效果。方法:选取2021-2022年新疆兵团基层医院的内镜医师81名,将肠镜操作量≥3000例医师分为专家组39名,非专家组42名。对所有医师进行pit pattern分型在线培训和培训前、后测试。比较培训前后医师判断结直肠息肉pit pattern分型的准确率,并分析判断结果与正确结果的一致性。结果:对兵团基层内镜医师的pit pattern分型在线培训取得了满意的效果。培训前、后测试表现:(1)所有医师及专家组、非专家组医师培训后判断总体息肉pit pattern分型的准确率明显高于培训前(P<0.001),所有医师培训后判断肿瘤性、非肿瘤性息肉pit pattern分型的准确率高于培训前(P<0.001),且所有医师培训后判断息肉pit pattern分型的每一分型的准确率也高于培训前(P<0.001)。(2)相较于培训前,培训后所有医师及专家组、非专家组医师息肉pit pattern分型判断结果与正确结果的Kappa值有提高,且培训后所有医师息肉性质判断结果与正确结果的Kappa值也有提高。结论:在线培训的方式能够提升基层内镜医师使用pit pattern分型辨别结直肠息肉性质的能力。 展开更多
关键词 pit pattern分型 在线培训 基层内镜医师
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Evolution and Spatial Patterns of Spheres of Urban Influence in China 被引量:5
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作者 WANG Kaiyong DENG Yu +1 位作者 SUN Daowei SONG Tao 《Chinese Geographical Science》 SCIE CSCD 2014年第1期126-136,共11页
This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimize... This article presents the findings of a study of the spheres of urban influence with regard to all cities in China(not including Hong Kong,Macao and Taiwan Province of China)in the years 1990,2000 and 2009.An optimized gravity model with comprehensive time distance was used to carry out a detailed analysis of the spatial patterns of Chinese spheres of urban influence and the spatial characteristics of urban agglomerations.Such urban agglomerations are characterized by high density population and a developed economy,which are also considered as the national competition unit.This paper initially identifies four spatial patterns of urban agglomerations based on the spatial layout of city groups during their evolution.Some basic characteristics of urban agglomerations are outlined,including the number of cities,the size of cities and the functions of urban centers.These characteristics are examined by using statistical methods and Geographic Information System(GIS).The main findings from this research are that the development stages and structures of urban agglomerations in China vary significantly.It is also clear that the stages and evolution of spatial patterns are strongly affected and dominated by both policy and location factors. 展开更多
关键词 SPHERES of URBAN INFLUENCE types of spatial pattern dynamic EVOLUTION URBAN AGGLOMERATION
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Sustainable land-use patterns for arid lands: A case study in the northern slope areas of the Tianshan Mountains 被引量:6
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作者 LUO Geping FENG Yixing +1 位作者 ZHANG Baiping CHENG Weiming 《Journal of Geographical Sciences》 SCIE CSCD 2010年第4期510-524,共15页
Sustainable land use patterns are ecological and economic prerequisites of regional sustainable development. This is especially true for arid lands, where the environment is wholly fragile thanks to extremely limited ... Sustainable land use patterns are ecological and economic prerequisites of regional sustainable development. This is especially true for arid lands, where the environment is wholly fragile thanks to extremely limited precipitation, and where human activities have greatly transformed natural desert system by clearing natural vegetation, expanding oases and even building dams on inland rivers. However, the current studies on land use patterns are still characterized by field investigations and case studies, with almost no solid scientific basis. This paper holds that land types and their combination patterns are the principal basis for designing sustainable land use patterns, and that GIS and RS-based large-scale land type mapping and the study of their spatial combination structures should be coordinated with the demand of social development. The existing environmental problems induced by irrational land use mostly result from their deviation from the natural properties of land types. Taking the northern slope of the Tianshan Mountains (NSTM) as an example and considering land type patterns as the basis of land use patterns, this paper improves the vertical oa- sis-and-mid-mountain two-belts development model and the sustainable mountain land use model for arid lands put forward in recent years; and in terms of oases patterns, it outlines oasis development models, including intensive land use pattern in alluvial-diluvial fans, moderate agricultural development pattern in alluvial plains, and ecological land use pattern in river-end oases. 展开更多
关键词 northern slope of the Tianshan Mountains land type land-use pattern oases
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Spatial distribution features of sequence types of moderate and strong earthquake in Chinese mainland 被引量:5
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作者 蒋海昆 李永莉 +4 位作者 曲延军 华爱军 郑建常 代磊 侯海峰 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2006年第4期417-427,共11页
Based on 294 earthquake sequences with magnitude greater than or equal to 5.0 occurred in Chinese mainland since 1970, the spatial distribution features of sequence types have been studied. In southwestern China, it t... Based on 294 earthquake sequences with magnitude greater than or equal to 5.0 occurred in Chinese mainland since 1970, the spatial distribution features of sequence types have been studied. In southwestern China, it takes mainshock-aftershock sequence type (MAT) as the major in Chuan-Dian rhombic block and concerned Xianshuihe-Anninghe-Xiaojiang seismic belt, as well as in Jinshajiang-Honghe seismic belt. Multiple mainshock type (MMT) mainly distributes in western Yunnan, and Longlin and Lancang areas in Tengchong-Baoshan block in west of Nujiang-Lancangjiang fault zone. A few isolated earthquake type (IET) mainly occurred in northwestern Sichuan and there is no IET occurred in Yunnan region. In northwestern China, it takes mainshock-aftershock sequence type (MAT) as the major in west segment of South Tianshan in Xinjiang region. Some MMT also occurred in this area in the intersection of Kalpin block and the Puchang fault zone. It takes IET as the major in middle Tianshan in Xinjiang. Along the Qilianshan seismic belt, most of sequences are MAT. In Qinghai region, it takes MAT as the major, but the regional feature of the spatial distribution of sequence types is not very clear. In North China, it takes MAT as the major in Yinshan-Yanshan-Bohai seismic belt, north edge of North China, and in Hebei plain seismic belt, as well as in sub-plate of lower river area of Yangtze River. In intersection of north segment of Shanxi seismic belt and the NW-trending Yinshan-Yanshan-Bohai seismic belt, there are several moderate or strong MMT with magnitude from 5.0 to 6.0 occurred. In south of North China around the latitude line of 35°N, it takes IET as the major. The spatial distribution of sequence types is relevant to the patterns of tectonic movements. MAT is mostly produced by the ruptures of locked units or asperities or the neonatal separating segments inside the fault zones. MMT is generally relevant to the conjugate structures or intersection of many tectonic settings. Further extension of simple fault often produces IET. Spatial distribution of sequence types is also correlative to the regional and deep environment of crustal medium to some extent. MAT mainly distributes in high velocity area in upper crust or in the transition zone between high velocity area and low velocity area, MMT mostly occurred in the low velocity area in upper crust. 展开更多
关键词 spatial distribution of sequence types isolated earthquake malnshock-aftershock sequence multi-ple malnshock type patterns of tectonic movement medium environment in depth of the earth
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