期刊文献+
共找到148篇文章
< 1 2 8 >
每页显示 20 50 100
“起源”号采样太阳粒子 满载而归
1
《国外科技动态》 2004年第4期48-48,共1页
关键词 “起源”号探测器 太阳风粒子 采样工作 美国宇航局
下载PDF
语言的制度意义——卢梭语言起源问题新论
2
作者 吕康宁 《湖北师范大学学报(哲学社会科学版)》 2024年第1期59-67,共9页
通过思考语言起源,卢梭发现了“真正的社会”的形成及其特质,由此构成他反思现代社会的理论基础,进而提炼出建构更加合理的社会需要的最珍贵的东西——一种人与人之间心理上的、作为整体的凝聚物——政治德性。这是一种在理性基础上缔... 通过思考语言起源,卢梭发现了“真正的社会”的形成及其特质,由此构成他反思现代社会的理论基础,进而提炼出建构更加合理的社会需要的最珍贵的东西——一种人与人之间心理上的、作为整体的凝聚物——政治德性。这是一种在理性基础上缔结社会契约的最初约定,即个人的意志服从普遍的意志的政治美德。普遍的意志具有超越个体、统一社会的强大力量,在于其普遍性,是人人都会认同的判断和信条。学界以往对卢梭语言著述的研究着重从语言学角度展开,遮蔽了语言与政治制度的隐秘关联,阐明卢梭语言著述的理论内涵,有助于把握卢梭社会理论的整全逻辑。 展开更多
关键词 语言起源 风格差异 制度反思 精神连结
下载PDF
藜麦开花期干旱胁迫对其形态特征及生理特性的影响
3
作者 罗小燕 华劲松 +2 位作者 朱春蓉 戴红燕 刘永嘉 《耕作与栽培》 2024年第2期18-21,共4页
为探究干旱胁迫对开花期藜麦形态特征的影响,以陇藜1号、青藜1号两个藜麦品种为试验材料,以正常灌溉为对照,设置3个干旱胁迫强度处理,在藜麦开花期进行干旱胁迫15 d后,测定各处理植株叶片相对含水量、叶比重、过氧化氢酶(CAT)活性、丙二... 为探究干旱胁迫对开花期藜麦形态特征的影响,以陇藜1号、青藜1号两个藜麦品种为试验材料,以正常灌溉为对照,设置3个干旱胁迫强度处理,在藜麦开花期进行干旱胁迫15 d后,测定各处理植株叶片相对含水量、叶比重、过氧化氢酶(CAT)活性、丙二醛(MDA)含量等生理指标,干旱胁迫15 d后恢复正常灌水,成熟时测定植株高度、主穗长和有效分枝数。结果表明,植株叶片相对含水量和叶比重随土壤水分的降低而下降,不同程度干旱胁迫处理对叶片相对含水量影响差异不显著,但对叶比重影响显著;MDA含量、CAT活性也与干旱胁迫程度呈正相关,即随干旱胁迫强度的加重而上升。干旱胁迫处理后,植株高度、主穗长和有效分枝数下降,但轻度和中度干旱胁迫对株高、主穗长度影响差异不显著,重度干旱胁迫显著影响株高和主穗长,中度和重度干旱胁迫显著影响有效分枝数。说明开花期适度干旱胁迫对藜麦形态特征影响不大。 展开更多
关键词 藜麦 开花期 干旱胁迫 形态特征 生理特性
下载PDF
施特劳斯和“两城之争” 被引量:1
4
作者 梁慧 黄天海 《浙江大学学报(人文社会科学版)》 CSSCI 2005年第4期138-144,共7页
“耶路撒冷和雅典”的关系问题是一个古老的命题,但西方政治哲学家利奥·施特劳斯涉入该命题却源于对现代学术传统的批判,他认为现代可遵循的“传统”只是启蒙以来的传统,它试图变更耶路撒冷和雅典之间深刻的对立。施特劳斯对此所... “耶路撒冷和雅典”的关系问题是一个古老的命题,但西方政治哲学家利奥·施特劳斯涉入该命题却源于对现代学术传统的批判,他认为现代可遵循的“传统”只是启蒙以来的传统,它试图变更耶路撒冷和雅典之间深刻的对立。施特劳斯对此所做的独创性贡献就在于倡导回到“两城之争”的原始反差,他将哲学与启示之间的冲突定义为两种生活方式的对抗,前者是自由探寻之路,而后者要求的是敬畏与谦卑,正是这两种不同生活观念的对立构成了西方文明活力的源泉。 展开更多
关键词 现代“综合” 启示(律法) 哲学(理性) “起源”
下载PDF
超越文化是大众文化的一个主要特征 被引量:1
5
作者 蔡宝玺 《南京社会科学》 CSSCI 北大核心 2008年第10期87-92,共6页
大众文化超越文化这个重要的文化现象在文化批评领域被忽视或被粗暴地排斥在批评的视野之外。论文从文化的延伸迁移、大众文化对高雅文化的整合和大众文化转化经典艺术范型等三个方面探讨大众文化的超越文化特征;同时,对大众文化超越文... 大众文化超越文化这个重要的文化现象在文化批评领域被忽视或被粗暴地排斥在批评的视野之外。论文从文化的延伸迁移、大众文化对高雅文化的整合和大众文化转化经典艺术范型等三个方面探讨大众文化的超越文化特征;同时,对大众文化超越文化在批评中被排斥的现象作必要的分析。 展开更多
关键词 超越文化 文化迁移 “起源”文化 艺术深层效果
下载PDF
Genetic Variation of Mitochondrial D-loop Region and Evolution Analysis in Some Chinese Cattle Breeds 被引量:13
6
作者 贾善刚 陈宏 +4 位作者 张桂香 王志刚 雷初朝 姚茹 韩旭 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第6期510-518,共9页
The complete mitochondrial D-loop region from 123 individuals in 12 Chinese cattle breeds and two individuals in Germany Yellow cattle breed was sequenced and analyzed. The results were shown as follows: 93 variation... The complete mitochondrial D-loop region from 123 individuals in 12 Chinese cattle breeds and two individuals in Germany Yellow cattle breed was sequenced and analyzed. The results were shown as follows: 93 variations and 57 haplotypes were detected, and the average number of nucleotide difference was 22.708, nucleotide diversity (π) was 0.0251 ± 0.00479, and haplotype diversity (Hd) was 0.888 ± 0.026, indicating very high genetic diversity in Chinese cattle breeds. In the Neighbor-Joining tree, 13 cattle breeds were divided into two main clades, Bos taurus and Bos indicus; new Clade Ill had only one sequence from Apeijiaza cattle breed in Tibet, which was similar to that of yak at a higher level than other cattle breeds, proving the introgression of genes from the yak. The proportions of Bos taurus and Bos indicus were 64.3 % and 35.7 % respectively in Xigaze Humped cattle breed, and 50.0% and 50.0% respectively in Apeijiaza cattle breed, which revealed that Tibet cattle included Bos indicus haplotypes. The importance of Yunnan cattle in the origin of Chinese cattle was also confirmed based on their abundant haplotypes. Then, a very special haplotype il discovered in 27 Chinese cattle breeds, including 11 breeds in this study and 16 breeds in the GenBank, played the role of a nucleus in Chinese zebu and was further discussed. At the same time, the construction of Chinese zebu core group based on haplotype il validated the distinct origin of Bos indicus in Tibet, which was different from that of the other cattle breeds with zebu haplotypes in China. 展开更多
关键词 ORIGIN evolution CATTLE mitochondrial D-loop genetic diversity
下载PDF
Comparison of stand structure and growth between artificial and natural forests of Pinus sylvestiris var. mongolica on sandy land 被引量:21
7
作者 朱教君 范志平 +2 位作者 曾德慧 姜凤岐 MATSUZAKI Takeshi 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第2期103-111,共9页
Mongolian pine (Pinus sylvestiris Linnaeus var. mongolica Litvinov) as a valuable conifer tree species has been broadly introduced to the sandy land areas in 揟hree North?regions (North, northwest and northeast of Chi... Mongolian pine (Pinus sylvestiris Linnaeus var. mongolica Litvinov) as a valuable conifer tree species has been broadly introduced to the sandy land areas in 揟hree North?regions (North, northwest and northeast of China), but many problems occurred in the earliest Mongolian pine plantations in Zhanggutai, Zhangwu County, Liaoning Province (ZZL). In order to clarify the reason, comprehensive investigations were carried out on differences in structure characteristics, growth processes and ecological factors between artificial stands (the first plantation established in ZZL in 1950s) and natural stands (the origin forests of the tree species in Honghuaerji, Inner Mongolia) on sandy land. The results showed that variation of diameter-class distributions in artificial stands and natural stands could be described by Weibull and Normal distribution models, respectively. Chapman-Richards growth model was employed to reconstruct the growth process of Mongolian pine based on the data from field investigation and stem analysis. The ages of maximum of relative growth rate and average growth rate of DBH, height, and volume of planted trees were 11, 22 years, 8, 15 years and 35, 59 years earlier than those of natural stand trees, respectively. In respect of the incremental acceleration of volume, the artificial and natural stands reached their maximum values at 14 years and 33 years respectively. The quantitative maturity ages of artificial stands and natural stands were 43 years and 102 years respectively. It was concluded that the life span of the Mongolian pine trees in natural stands was about 60 years longer than those in artificial stands. The differences mentioned above between artificial and natural Mongolian pine forests on sandy land were partially attributed to the drastic variations of ecological conditions such as latitude, temperature, precipitation, evaporation and height above sea level. Human beings' disturbances and higher density in plantation forest may be ascribed as additional reasons. Those results may be potentially useful for the management and afforestation of Mongolian pine plantations on sandy land in arid and semi-arid areas. 展开更多
关键词 Pinus sylvestiris var. mongolica Mongolian pine Sandy land COMPARISON Growth model
下载PDF
A Unique Aegilops tauschii Genotype Needless to Immature Embryo Culture in Cross with Wheat 被引量:8
8
作者 刘登才 兰秀锦 +3 位作者 杨足君 郑有良 魏育明 周永红 《Acta Botanica Sinica》 CSCD 2002年第6期708-713,共6页
Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD... Common or bread wheat ( Triticum aestivum L., AABBDD, 2n=42) originated ca. 8 000 years ago from hybridization of tetraploid wheat ( Triticum turgidum L., AABB, 2n=28) and diploid Aegilops tauschii Coss. (DD, 2n=14). An essential prerequisite for this evolutionary step is that the natural hybrids between tetraploid wheat and diploid Aegilops tauschii can produce relatively many filled seeds which germinated well. In this study, without special techniques, e.g. immature embryo culture, out of 22 Ae. tauschii accessions, the genotype AS60 produced relatively many filled seeds which germinated well. The seed germination percentages in the crosses of Ae. tauschii ×tetraploid wheat, tetraploid wheat× Ae. tauschii and Ae. tauschii ×common wheat were, respectively, 50.0%, 57.1% and 45.5%. It seems that Ae. tauschii accession AS60 has a unique genotype which facilitate hybrid seed development and viability, and which meets with the prerequisite for wheat evolutionary. Furthermore, the significance of this finding for common wheat improvement and evolution was discussed. 展开更多
关键词 Aegilops tauschii common wheat Triticum turgidum immature embryo culture evolution wheat improvement
下载PDF
Relationship between Rice Cultural Diversity and Ecological Environment in Yunnan Province of China 被引量:3
9
作者 曾亚文 杜娟 +3 位作者 普晓英 罗曦 杨树明 杨涛 《Agricultural Science & Technology》 CAS 2012年第10期2247-2256,共10页
[Objective] This paper aims to confirm that Yunnan is one origin center of rice and human in the world.[Method] The complicated and unique ecological environment in Yunnan makes Yunnan Province the largest center of g... [Objective] This paper aims to confirm that Yunnan is one origin center of rice and human in the world.[Method] The complicated and unique ecological environment in Yunnan makes Yunnan Province the largest center of genetic diversity and cultural diversity of rice and human being as well as the cradle of human childhood.[Result] The genetic diversity and cultural diversity of rice and human being is closely related to the ecosystem diversity.Rice civilization in Yunnan can be divided into four types,including the diversity center region of rice civilization in southwestern Yunnan,diffusion region of rice civilization of Hani-Zhuang in southern Yunnan,rice civilization region of water-drought rotation in central Yunnan and poverty region of rice civilization in northern Yunnan.Southwestern Yunnan is not only the center of genetic ecological diversity and rice cultural diversity,but also the center of origin and diversity of crop genetic diversity.It is not only a transitional region among East Asia continent,South Asian sub-continent and Indo-China Peninsula,but also a core integration area of Chinese culture,Indian culture and Mid-south Peninsula culture which all merge with the local culture.[Conclusion] Yunnan is one common sphere where the origin of human evolution is closely related to the origin of rice evolution. 展开更多
关键词 Rice culture Ecological environment Origin evolution Human being YUNNAN
下载PDF
A New Model on Origin and Evolution of Biology 被引量:1
10
作者 王奕蛟 冯綮一 柴立和 《Agricultural Science & Technology》 CAS 2009年第4期4-7,共4页
Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on th... Modified classical Boltzmann entropy as generalized entropy, then proposed Maximum Generalized Entropy Principle fusing physics and biology, and established a new model for biological origin and evolutions based on this principle, finally took protein evolution for an example to analyze. The model provided some reference for biological complexity research. 展开更多
关键词 Biological origin and evolution COMPLEXITY Generalized entropy
下载PDF
Analysis on the Origin and Phylogenetic Status of Tong Sheep Using 12 Blood Protein and Nonprotein Markers
11
作者 孙伟 常洪 +5 位作者 杨章平 耿荣庆 角田健司 任战军 陈宏宇 Musa H.Hussein 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第12期1097-1105,共9页
This study is based on the Tong sheep obtained by the random sampling method of typical colonies in the central area of Baishui County in Shaanxi Province, China. An investigation was undertaken to clarify the gene co... This study is based on the Tong sheep obtained by the random sampling method of typical colonies in the central area of Baishui County in Shaanxi Province, China. An investigation was undertaken to clarify the gene constitution of blood protein and nonprotein types of Tong sheep. Twelve genetic markers were examined by starch-gel electrophoresis and cellulose acetate electrophoresis. Polymorphism in Tong sheep was found at the following 10 loci, transferrin (Tf), alkaline phosphatase (Alp), leucine aminopeptidase (Lap), arylesterase (Ary-Es), hemoglobin-β (Hb-β), X-protein (X-p), carbonic anhydrase (CA), catalase (Cat), malate dehydrogenase (MDH), and lysine (Ly), whereas, albumin (A1) and postalbumin (Po) loci were monomorphic. Genetic approach degree method and phylogenetic relationship clustering method were used to judge the origin and phylogenetic status of Tong sheep. Results from both methods maintained that Tong sheep belonged to the "Mongolia group", and Mongolia sheep was the origin of Tong sheep. This was also supported by the history of Tong sheep breeding. Compared to the phylogenetic relationship clustering method, the genetic approach degree method was more reliable for the extraction from East and South of Central Asia, and was more effective in reflecting the breeding course of Tong sheep. 展开更多
关键词 Tong sheep ORIGIN phylogenetic status genetic approach degree phylogenetic relationship clustering
下载PDF
Phylogenetic Analysis of Chirality of Twining Plants
12
作者 林恭华 慈海鑫 +1 位作者 刘永安 苏建平 《Agricultural Science & Technology》 CAS 2010年第2期34-38,共5页
Phylogenetic relations of twining chirality of Dioscorea sp.in China were analyzed based on the genes matK,rbcL and trnL;phylogenetic character of higher-level phylogeny of twining plants was analyzed at a high taxon ... Phylogenetic relations of twining chirality of Dioscorea sp.in China were analyzed based on the genes matK,rbcL and trnL;phylogenetic character of higher-level phylogeny of twining plants was analyzed at a high taxon level based on matK gene.A significant phylogenetic framework of chirality was found:(i)based on matK analysis,right-handed Dioscorea species in China congregate completely to form a monophyly;(ii)rbcL and trnL data sets also supported Chinese right-handed Dioscorea a monophyly,although with ex... 展开更多
关键词 Twining plant CHIRALITY Phylogenetic structure ORIGIN
下载PDF
Rock-forming mechanism of Qingshanjiao intrusion in Dongguashan copper(gold) deposit, Tongling area, Anhui province, China
13
作者 刘忠法 邵拥军 +1 位作者 隗含涛 汪程 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第9期2449-2461,共13页
Dongguashan deposit is a large porphyry-skarn copper(gold) deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magm... Dongguashan deposit is a large porphyry-skarn copper(gold) deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magma origin, rock-forming dynamic background and rock-forming process were studied, and the rock-forming mechanism of Qingshanjiao intrusion was discussed, based on geological characteristics, detailed observation of petrography and systematic investigation of petrochemistry, trace elements and REE geochemistry characteristics of Qingshanjiao intrusion. The results show that Qingshanjiao rock body belongs to high-K calc-alkaline series with higher LREE elements, Th, Rb and Sr abundance, but depleted in HREE elements, Ba, Nb and Ta. The primary magma originated from the mantle-crust mixtures which were caused by basaltic magma of mantle mixing with syenite magma of partial melting of the lower crust, and the formation environment of Qingshanjiao intrusion was emplaced in the transitional environment from compression to extension. The Harker diagram and hybrid structures of plagioclase and potassium feldspar indicate that the fractional crystallization occurred in the process of magmatic evolution. The petrochemistry, trace elements and REE geochemistry characteristics indicate that the magma was contaminated by crustal material during the rock-forming. These results suggested that the Qingshanjiao intrusion was formed by fractional crystallization and assimilation and hybridization of mantle-crust magma in the transitional environment from compression to extensional. 展开更多
关键词 Qingshanjiao intrusion geological and geochemical characteristics rock-forming and geodynamic setting magma derivation rock-forming Dongguashan copper(gold) deposit
下载PDF
Biogeography of the leafhopper subfamily Stegelytrinae(Hemiptera:Cicadellidae),based on a cluster analysis of geographical distribution in areas of endemism combined with phylogeny of the subfamily
14
作者 魏琮 程若琳 张雅林 《Entomotaxonomia》 CSCD 北大核心 2012年第4期575-586,共12页
Biogeography of the leaflaopper subfamily Stegelytrinae Baker is studied based on an analysis of geographical distribution of this subfamily worldwide using a cluster analysis of the zoological distribution of areas o... Biogeography of the leaflaopper subfamily Stegelytrinae Baker is studied based on an analysis of geographical distribution of this subfamily worldwide using a cluster analysis of the zoological distribution of areas of endemism as well as the phylogeny of representatives of this subfamily. Results show that the Stegelytrinae mainly occur in the Oriental Region and in the Mediterranean area of the Palaearctic Region, and this extends to the east side of both Wallaee's and Weber's lines. Eleven areas of endemism of this subfamily are recognized. The proportions of endemic taxa in different areas of endemism are generally very high in comparison with other leaflaopper groups, but distinct differences could be found among the different areas of endemism of Stegelytrinae. This subfamily is most intensively diversified in the Indochina Peninsula (INCN). This is the stegelytrine distribution center, having the highest biodiversity at both genetic and species levels. The dendrogram of endemic areas of Stegelytrinae constructed using cluster analysis of the zoological distribution of Stegelytrinae at generic level shows the endemic areas of Stegelytrinae can be divided into 4 large groups. Relationships among different endemic areas of Stegelytrinae correspond largely to the geologic history of related areas, which indicates that the evolution and vicariance of this subfamily have been closely related to the history of continental drift and climate changes. It is deduced that the presumed monophyletic Stegelytrinae originated in the Oriental Region after North America had separated from Eurasia; this is the case in the monophyletic genera group which is supported by the lateral frontal sutures extending dorsally well beyond the corresponding ocellus. In addition, two expanding traces of the Stegelytrinae are presumed, which remain plausible explanations for the dispersal of Stegelytrinae: (1) New Guinea (and probably (+ Australia)) - Kalimantan - Sumatra - Malay Peninsula - Indochina Peninsula - Central and Southern China - (Southwestern China + Nepal + Northeastern India) - (Northwestern India + Eastern Afghanistan); and (2) Indochina Peninsula- Central and Southern China- (Western Asia + Mediterranean Sea coastal area). 展开更多
关键词 distribution biodiversity origin historical biogeography
下载PDF
Effects of different N sources on growth, nutrient uptake and ionic balance of Larlix gmelini seedlings 被引量:1
15
作者 陈永亮 韩士杰 苏宝玲 《Journal of Forestry Research》 SCIE CAS CSCD 2001年第3期153-156,209,共4页
The effect of different sources and levels of N on dry matter production, nutrient uptake and ionic balance ofLarlix gmelini was studied. The results showed that the growth of the plants fertilized with ammonium was n... The effect of different sources and levels of N on dry matter production, nutrient uptake and ionic balance ofLarlix gmelini was studied. The results showed that the growth of the plants fertilized with ammonium was not as good as the control treatment. The growth of the plants fertilized with ammonium nitrate did not differ significantly from that in control or nitrate treatment, but was better than that in the ammonium treatment. Total cation concentrations in shoots varied little with N level in the ammonium and ammonium nitrate treatments, while those in the shoot increased with N level in the nitrate treatment. The treatments had little effect on the anion concentrations in the shoot. In the roots, the concentrations of both cations and anions changed little except for SO4 2? and Ca2+. There existed a higher carboxylate production in the plants fertilized with nitrate. The ratio between the production of carboxylate and the production of organic N Δ(C-A)/ΔNorg was constant with N supply in the plants receiving nitrate, but obviously declined with N supply for ammonium-fed plants. Δ (C-A)/ΔNorg values were intermediate between those of the nitrate and the ammonium-fed plants as for the mixed N source. 展开更多
关键词 N resource GROWTH Nutrient uptake Ionic balance
下载PDF
科技风尚
16
《财经》 2004年第18期20-20,共1页
关键词 美国 “起源”号宇宙飞船 太阳风 硅谷 高新技术行业
下载PDF
美国旅馆业巨头建造首家私人空间站
17
《国外科技动态》 2004年第9期43-43,共1页
关键词 美国 私人空间站 毕基洛夫空间公司 “起源”号太空舱
下载PDF
Role of probiotics,prebiotics and synbiotics in chemoprevention for colorectal cancer 被引量:17
18
作者 Constantine Iosif Fotiadis Christos Nikolaou Stoidis +1 位作者 Basileios Georgiou Spyropoulos Eleftherios Dimitriou Zografos 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第42期6453-6457,共5页
Colorectal cancer is the third most common form of cancer.Current treatments are all associated with a high risk of complications and a low success rate.Recently,synbiotics have been proposed as a new preventive and t... Colorectal cancer is the third most common form of cancer.Current treatments are all associated with a high risk of complications and a low success rate.Recently,synbiotics have been proposed as a new preventive and therapeutic option.There is no direct experimental evidence for cancer suppression in humans as a result of the consumption of pro-,pre-or synbiotics.However,there is a wealth of evidence emerging from laboratory studies.The mechanisms by which pro-,pre-and synbiotics may inhibit colon cancer are now beginning to be understood and will be addressed in the present review. 展开更多
关键词 PROBIOTICS PREBIOTICS SYNBIOTICS COLORECTALCANCER Treatment Prevention
下载PDF
Endoscopic therapy for gastric stromal tumors originating from the muscularis propria 被引量:20
19
作者 Liu-Ye Huang Jun Cui +2 位作者 Yun-Xiang Liu Cheng-Rong Wu De-Liang Yi 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第26期3465-3471,共7页
AIM:To explore endoscopic therapy methods for gastric stromal tumors originating from the muscularis propria.METHODS:For 69 cases diagnosed as gastric stromal tumors originating from the muscularis propria,three types... AIM:To explore endoscopic therapy methods for gastric stromal tumors originating from the muscularis propria.METHODS:For 69 cases diagnosed as gastric stromal tumors originating from the muscularis propria,three types of endoscopic therapy were selected,based on the size of the tumor.These methods included endoscopic ligation and resection(ELR),endoscopic submucosal excavation(ESE) and endoscopic full-thickness resection(EFR).The wound surface and the perforation of the gastric wall were closed with metal clips.Immunohistostaining for CD34,CD117,Dog-1,S-100 and smooth muscle actin(SMA) was performed on the resected tumors.RESULTS:A total of 38 cases in which the tumor size was less than 1.2 cm were treated with ELR;three cases were complicated by perforation,and the perforations were closed with metal clips.Additionally,18 cases in which the tumor size was more than 1.5 cm were treated with ESE,and no perforation occurred.Finally,13 cases in which the tumor size was more than 2.0 cm were treated with EFR;all of the cases were complicated by artificial perforation,and all of the perforations were closed with metal clips.All of the 69 cases recovered with medical treatment,and none required surgical operation.Immunohistostaining demonstrated that among all of the 69 gastric stromal tumors diagnosed by gastroscopy,12 cases were gastric leiomyomas(SMA-positive),and the other 57 cases were gastric stromal tumors.CONCLUSION:Gastric stromal tumors originating from the muscularis propria can be treated successfully with endoscopic techniques,which could replace certain surgical operations and should be considered for further application. 展开更多
关键词 Gastrointestinal stromal tumors THERAPY ENDOSCOPY Muscularis propria RESECTION
下载PDF
Initiation and evolution of the South China Sea: an overview 被引量:27
20
作者 Weidong Sun 《Acta Geochimica》 EI CAS CSCD 2016年第3期215-225,共11页
Different models have been proposed for the formation and tectonic evolution of the South China Sea (SCS), including extrusion of the Indochina Peninsula, backarc extension, two-stage opening, proto-SCS dragging, ex... Different models have been proposed for the formation and tectonic evolution of the South China Sea (SCS), including extrusion of the Indochina Peninsula, backarc extension, two-stage opening, proto-SCS dragging, extension induced by a mantle plume, and integrated models that combine diverse factors. Among these, the extrusion model has gained the most attention. Based on simplified physical experiments, this model proposes that collision between the Indian and Eurasian Plates resulted in extrusion of the Indochina Peninsula, which in turn led to opening of the SCS. The extrusion of the Indochina Peninsula, however, should have led to preferential open- ing in the west side of the SCS, which is contrary to observations. Extensional models propose that the SCS was a backarc basin, rifted off the South China Block. Most of the backarc extension models, however, are not compatible with observations in terms of either age or subduction direction. The two-stage extension model is based on extensional basins surrounding the SCS. Recent dating results indeed show two-stage opening in the SCS, but the Southwest Subbasin of the SCS is much younger, which contradicts the two-stage extension model. Here we pro- pose a refined backarc extension model. There was a wide Neotethys Ocean between the Australian and Eurasian Plates before the Indian-Eurasian collision. The ocean floorstarted to subduct northward at ~ 125 Ma, causing backarc extension along the southem margin of the Eurasian Plate and the formation of the proto-SCS. The Neotethys sub- duction regime changed due to ridge subduction in the Late Cretaceous, resulting in fold-belts, uplifting, erosion, and widespread unconformities. It may also have led to the subduction of the proto-SCS. Flat subduction of the ridge may have reached further north and resulted in another backarc extension that formed the SCS. The rollback of the fiat subducting slab might have occurred ~ 90 Ma ago; the second backarc extension may have initiated between 50 and 45 Ma. The opening of the Southwest Subbasin is roughly simultaneous with a ridge jump in the East Sub- basin, which implies major tectonic changes in the sur- rounding regions, likely related to major changes in the extrusion of the Indochina Peninsula. 展开更多
关键词 South China Sea NEOTETHYS Platesubduction Ridge subduction Indochina Peninsulaextrusion Backarc extension Multiple plate interactionsProto South China Sea
下载PDF
上一页 1 2 8 下一页 到第
使用帮助 返回顶部