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SINGULAR PERTURBATION FOR A CLASS OF NONLINEAR REACTION DIFFUSION SYSTEMS 被引量:213
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作者 莫嘉琪 《Science China Mathematics》 SCIE 1989年第11期1306-1315,共10页
This paper deals with the initial-bounndary value problem for the wider nonlinear reaction diffusion system: where Leading into the variables of multiple scales, we obtained a uniformly valid asymptotic solution to an... This paper deals with the initial-bounndary value problem for the wider nonlinear reaction diffusion system: where Leading into the variables of multiple scales, we obtained a uniformly valid asymptotic solution to any degree of precision by using comparison theorem. 展开更多
关键词 SINGULAR PERTURBATION DIFFERENTIAL INEQUALITY reaction DIFFUSION system.
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ASYMPTOTIC SOLUTION OF ACTIVATOR INHIBITOR SYSTEMS FOR NONLINEAR REACTION DIFFUSION EQUATIONS 被引量:96
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作者 Jiaqi MO Wantao LIN 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2008年第1期119-128,共10页
A nonlinear reaction diffusion equations for activator inhibitor systems is considered. Under suitable conditions, firstly, the outer solution of the original problem is obtained, secondly, using the variables of mult... A nonlinear reaction diffusion equations for activator inhibitor systems is considered. Under suitable conditions, firstly, the outer solution of the original problem is obtained, secondly, using the variables of multiple scales and the expanding theory of power series the formal asymptotic expansions of the solution are constructed, and finally, using the theory of differential inequalities the uniform validity and asymptotic behavior of the solution are studied. 展开更多
关键词 Activator system NONLINEAR reaction diffusion singular perturbation.
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离子液体在有机反应中的应用 被引量:65
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作者 张所波 丁孟贤 高连勋 《有机化学》 SCIE CAS CSCD 北大核心 2002年第3期159-163,共5页
室温离子液体 ,由含氮的有机阳离子和无机阴离子组成 ,可溶解各种有机、无机、金属有机化合物 .它们没有蒸气压、不易燃、容易循环使用 .近年已发现 ,离子液体可广泛地用于许多过渡金属化合物和酶催化的反应 .
关键词 有机反应 离子液体 溶剂 过渡金属催化 合成 应用 有机合成 酶催化
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A mini review of NiFe-based materials as highly active oxygen evolution reaction electrocatalysts 被引量:83
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作者 Ming Gong Hongjie Dai 《Nano Research》 SCIE EI CAS CSCD 2015年第1期23-39,共17页
Oxygen evolution reaction (OER) electrolysis, as an important reaction involved in water splitting and rechargeable metal-air batteries, has attracted increasing attention for clean energy generation and efficient e... Oxygen evolution reaction (OER) electrolysis, as an important reaction involved in water splitting and rechargeable metal-air batteries, has attracted increasing attention for clean energy generation and efficient energy storage. Nickel/iron (NiFe)-based compounds have been known as active OER catalysts since the last century, and renewed interest has been witnessed in recent years on developing advanced NiFe-based materials for better activity and stability. In this review, we present the early discovery and recent progress on NiFe-based OER electrocatalysts in terms of chemical properties, synthetic methodologies and catalytic performances. The advantages and disadvantages of each class of NiFe-based compounds are summarized, including NiFe alloys, electrodeposited films and layered double hydroxide nanoplates. Some mechanistic studies of the active phase of NiFe-based compounds are introduced and discussed to give insight into the nature of active catalytic sites, which could facilitate further improving NiFe based OER electrocatalysts. Finally, some applications of NiFe- based compounds for OER are described, including the development of an electrolyzer operating with a single AAA battery with voltage below 1.5 V and high performance rechargeable Zn-air batteries. 展开更多
关键词 oxygen evolution reaction ELECTROCATALYSIS nickel-iron water splitting
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超重力工程技术应用的新进展 被引量:54
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作者 郭锴 柳松年 +1 位作者 陈建峰 郑冲 《化工进展》 EI CAS CSCD 1997年第1期1-4,15,共5页
超重力技术是一种突破性的过程强化新技术,在化工、能源、环保、材料、生物化工等工业领域中有广阔的商业化应用前景。本文概要介绍了该新技术的特点、国内外应用研究和基础研究的最新进展情况。
关键词 超重力工程 分离 离心分离
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THE SINGULARLY PERTURBED PROBLEM FOR COMBUSTION REACTION DIFFUSION 被引量:68
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作者 莫嘉琪 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2001年第2期255-259,共5页
A singularly perturbed combustion reaction diffusion Robin boundary value problem is considered. Using the theory of differential ineaqality, the existence of solution to the problem is proved and the asymptotic esti... A singularly perturbed combustion reaction diffusion Robin boundary value problem is considered. Using the theory of differential ineaqality, the existence of solution to the problem is proved and the asymptotic estimation of the solution is obtained. 展开更多
关键词 Singular perturbation defferential inequality reaction diffusion
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学科服务互动合作的理念探析与实践进展 被引量:66
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作者 范爱红 邵敏 《图书馆杂志》 CSSCI 北大核心 2010年第4期40-42,共3页
学科馆员制度引入中国图书馆界多年,现迫切需要寻找工作的突破点。清华大学图书馆提出"互动式、合作化"的学科服务理念,强调学科服务的双向互动性,把读者的参与和组织机构之间的合作纳入到学科服务范畴之中。图书馆与学科馆... 学科馆员制度引入中国图书馆界多年,现迫切需要寻找工作的突破点。清华大学图书馆提出"互动式、合作化"的学科服务理念,强调学科服务的双向互动性,把读者的参与和组织机构之间的合作纳入到学科服务范畴之中。图书馆与学科馆员的单边力量有限,"互动式、合作化"将是学科服务深化的必然要求,也是学科服务理论的重要发展。 展开更多
关键词 学科馆员 学科服务 院系联络 互动 合作
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中药炮制过程化学机理研究 被引量:64
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作者 蔡宝昌 秦昆明 +3 位作者 吴皓 蔡皓 陆兔林 张兴德 《化学进展》 SCIE CAS CSCD 北大核心 2012年第4期637-649,共13页
中药炮制是中国的一项传统制药技术,也是中药区别于天然药物的显著特点。中药材经过加工炮制以后发生了复杂的化学变化,随着这些化学变化而改变的物质基础是中药炮制前后性味、功能改变的重要原因。阐明中药炮制过程中发生的这些化学变... 中药炮制是中国的一项传统制药技术,也是中药区别于天然药物的显著特点。中药材经过加工炮制以后发生了复杂的化学变化,随着这些化学变化而改变的物质基础是中药炮制前后性味、功能改变的重要原因。阐明中药炮制过程中发生的这些化学变化是中药炮制机理研究的主要内容。近年来,国内外很多研究机构对中药炮制过程的化学机理进行了深入研究,初步阐明了多味中药炮制过程中发生的化学反应及化学成分变化,主要的化学反应包括水解反应、氧化反应、置换反应、异构化反应和分解反应等。本文对近年来中药炮制过程中化学反应机理领域取得的研究成果进行了综述,并对中药炮制过程化学机理研究的方向及前景进行了探讨。 展开更多
关键词 中药炮制 反应 化学成分 化学机理
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煤中碱金属及其在燃烧中的行为 被引量:55
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作者 张军 汉春利 +1 位作者 刘坤磊 徐益谦 《热能动力工程》 CAS CSCD 北大核心 1999年第2期83-85,共3页
综述了对煤中碱金属存在形式及其在燃烧中释放和反应上的研究,指出了目前研究中存在的问题,提出必须加强这方面的研究。
关键词 碱金属 释放 反应 燃烧行为 煤燃烧
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Relationship between HBV viremia level of pregnant women and intrauterine infection:neated PCR for detection of HBV DNA 被引量:58
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作者 ZHANG Shu-Lin HAN Xiao-Bing YUE Ya-Fei 《World Journal of Gastroenterology》 SCIE CAS CSCD 1998年第1期66-68,共3页
IM To determine the incidence of hepatitis B virus (HBV) intrauterine infection and to explore the relationship between HBV viremia level of pregnant women and HBV intrauterine infection.METHODS Sixtynine pregnant w... IM To determine the incidence of hepatitis B virus (HBV) intrauterine infection and to explore the relationship between HBV viremia level of pregnant women and HBV intrauterine infection.METHODS Sixtynine pregnant women were divided into three groups. Group A, 41 HBsAg positive patients, 14 of them were HBeAg positive (group A1), and 27 HBeAg negative (group A2); Group B, 12 HBsAg negative patients, but positive for antiHBs and/or antiHBe and/or antiHBc; and Group C, 16 patients negative for all HBV markers. Blood samples of mothers were taken at delivery, samples of their infants were collected within 24 hours after birth (before injection of HBIG and HBV vaccine). All the serum samples were stored at -20℃. HBV serum markers were tested by radioimmunoassay and HBV NDA were detected by nested polymerase chain reaction.RESULTS In group C, all of 16 newborns were negative for HBsAg and HBV DNA. In group A, 7 infants were HBsAg positive (171%), and 17 (415%) were HBV DNA positive (P<005). The incidence of intrauterine HBV infection was much higher in group A1 than that in group A2 (HBsAg 429% vs 37%, HBV DNA 929% vs 148%, P<005). The incidence of HBV intrauterine infection was significantly different between high and low HBV viremia of mothers (933% vs 429%, P<005).CONCLUSION The incidence of HBV intrauterine infection is high when HBV DNA in newborns detected with nested PCR is used as a marker of HBV infection. It is related to HBV viremia level of mothers. 展开更多
关键词 hepatitis B DNA viral/analysis RADIOIMMUNOASSAY polymerase chain reaction intrauterine infection
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Effects of different resuscitation fluid on severe acute pancreatitis 被引量:57
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作者 Gang Zhao Jun-Gang Zhang +10 位作者 He-Shui Wu Jin Tao Qi Qin Shi-Chang Deng Yang Liu Lin Liu Bo Wang Kui Tian Xiang Li Shuai Zhu Chun-You Wang 《World Journal of Gastroenterology》 SCIE CAS 2013年第13期2044-2052,共9页
AIM: To compare effects of different resuscitation fluid on microcirculation, inflammation, intestinal barrier and clinical results in severe acute pancreatitis (SAP). METHODS: One hundred and twenty patients with SAP... AIM: To compare effects of different resuscitation fluid on microcirculation, inflammation, intestinal barrier and clinical results in severe acute pancreatitis (SAP). METHODS: One hundred and twenty patients with SAP were enrolled at the Pancreatic Disease Institute between January 2007 and March 2010. The patients were randomly treated with normal saline (NS group), combination of normal saline and hydroxyethyl starch (HES) (SH group), combination of normal saline, hydroxyethyl starch and glutamine (SHG group) in resuscitation. The ratio of normal saline to HES in the SH and SHG groups was 3:1. The glutamine (20% glutamine dipeptide, 100 mL/d) was supplemented into the resuscitation liquid in the SHG group. Complications and outcomes including respiratory and abdominal infection, sepsis, abdominal hemorrhage, intra-abdominal hypertension, abdominal compartment syndrome (ACS), renal failure, acute respiratory distress syndrome (ARDS), multiple organ dysfunction syndrome (MODS), operation intervention, length of intensive care unit stay, length of hospital stay, and mortality at 60 d were compared. Moreover, blood oxygen saturation (SpO 2 ), gastric intramucosal pH value (pHi), intra-abdominal pressure (IAP), inflammation cytokines, urine lactulose/mannitol (L/M) ratio, and serum endotoxin were investigated to evaluate the inflammatory reaction and gut barrier. RESULTS: Compared to the NS group, patients in the SH and SHG groups accessed the endpoint more quickly (3.9 ± 0.23 d and 4.1 ± 0.21 d vs 5.8 ± 0.25 d, P < 0.05) with less fluid volume (67.26 ± 28.53 mL/kg/d, 61.79 ± 27.61 mL/kg per day vs 85.23 ± 21.27 mL/kg per day, P < 0.05). Compared to the NS group, incidence of renal dysfunction, ARDS, MODS and ACS in the SH and SHG groups was obviously lower. Furthermore, incidence of respiratory and abdominal infection was significantly decreased in the SH and SHG groups, while no significant difference in sepsis was seen. Moreover, less operation time was needed in the SH and SHG group than the NS group, but 展开更多
关键词 MICROCIRCULATION INTESTINAL barrier INFLAMMATORY reaction INTRA-ABDOMINAL hypertension CAPILLARY leakage syndrome
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超重力技术进展——从实验室到工业化 被引量:52
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作者 邹海魁 邵磊 陈建峰 《化工学报》 EI CAS CSCD 北大核心 2006年第8期1810-1816,共7页
超重力(旋转床)技术是一种能够极大强化传递和分子混合过程的突破性过程强化新技术,本文对超重力技术的基础研究,在反应与分离过程强化、纳米材料制备方面的应用研究以及工业化应用的最新进展情况进行了综述,重点介绍了本中心的研究成果.
关键词 超重力旋转床技术 过程强化 反应 分离
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A Nonlinear Singularly Perturbed Problem for Reaction Diffusion Equations with Boundary Perturbation 被引量:50
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作者 Jia-qiMo Wan-taoLin 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2005年第1期101-104,共4页
A nonlinear singularly perturbed problems for reaction diffusion equationwith boundary perturbation is considered. Under suitable conditions, the asymptotic behavior ofsolution for the initial boundary value problems ... A nonlinear singularly perturbed problems for reaction diffusion equationwith boundary perturbation is considered. Under suitable conditions, the asymptotic behavior ofsolution for the initial boundary value problems of reaction diffusion equations is studied usingthe theory of differential inequalities. 展开更多
关键词 NONLINEAR differential inequality reaction diffusion SINGULARPERTURBATION boundary perturbation
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Expression of matrix metalloproteinases 2 and 9 in human gastric cancer and superficial gastritis 被引量:46
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作者 Clara Luz Sampieri Sol de la Pea +2 位作者 Mariana Ochoa-Lara Roberto Zenteno-Cuevas Kenneth León-Córdoba 《World Journal of Gastroenterology》 SCIE CAS CSCD 2010年第12期1500-1505,共6页
AIM:To assess expression of matrix metalloproteinases 2(MMP2)and MMP9 in gastric cancer,superficial gastritis and normal mucosa,and to measure metalloproteinase activity.METHODS:MMP2 and MMP9 mRNA expression was deter... AIM:To assess expression of matrix metalloproteinases 2(MMP2)and MMP9 in gastric cancer,superficial gastritis and normal mucosa,and to measure metalloproteinase activity.METHODS:MMP2 and MMP9 mRNA expression was determined by quantitative real-time polymerase chain reaction.Normalization was carried out using three different factors.Proteins were analyzed by quantitative gelatin zymography(qGZ).RESULTS:18S ribosomal RNA(18SRNA)was very highly expressed,while hypoxanthine ribosyltransferase-1(HPRT-1)was moderately expressed.MMP2 was highly expressed,while MMP9 was not detected or lowly expressed in normal tissues,moderately or highly expressed in gastritis and highly expressed in cancer.Relative expression of 18SRNA and HPRT-1 showed no significant differences.Significant differences in MMP2 and MMP9 were found between cancer and normal tissue,but not between gastritis and normal tissue.Absolute quantification of MMP9 echoed this pattern,but differential expression of MMP2 proved conflictive.Analysis by qGZ indicated significant differences between cancer and normal tissue in MMP-2,total MMP-9,250 and 110 kDa bands.CONCLUSION:MMP9 expression is enhanced in gastric cancer compared to normal mucosa;interpretation of differential expression of MMP2 is difficult to establish. 展开更多
关键词 Gastric cancer Superficial gastritis Matrix metalloproteinases Quantitative real-time polymerase chain reaction Quantitative zymography
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超临界水的特性及应用 被引量:33
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作者 张丽莉 陈丽 +2 位作者 赵雪峰 于璟琳 田宜灵 《化学工业与工程》 CAS 2003年第1期33-38,54,共7页
介绍了水在高温高压下的热力学性质、氢键、离子积、扩散系数和粘度等在超临界区域的特殊性 ,以及超临界水溶液在介电常数、偏摩尔体积、溶解性和极性等方面的特殊性质 。
关键词 超临界水 特性 应用 临界曲线 化学反应
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INTERFACE REACTION IN MAGNETIC MULTILAYERS 被引量:47
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作者 G.H. Yu, M.H Li, F. W Zhu, X.F. Cui and J.L. Jin ( Department of Materials Physics, University of Science and Technology Beijing, Beijing 100083, China) ( State key laboratory for Advanced Metals and Materials, University of Science and Technology Beijing 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2001年第6期479-484,共6页
Ta/NiO/NiFe/Ta multilayers were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field (Hex) between NiO and NiFe reached 120O e. The composition and chemical states at the interface region o... Ta/NiO/NiFe/Ta multilayers were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field (Hex) between NiO and NiFe reached 120O e. The composition and chemical states at the interface region of NiO/NiFe were studied using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that there are two thermodynamically favorable reactions at NiO/NiFe interface: NiO+Fe=Ni+FeO and 3NiO+2Fe=3Ni+Fe2O3. The thickness of the chemical reaction as estimated by angle-resolved XPS was about 1-1.5 nm. These interface reaction products are magnetic defects, and we believe that the Hex and the coercivity (Hc) of NiO/NiFe are affected by these defects. Moreover, the results also show that there is an intermixing layer at the Ta/NiO (and NiO/Ta) interface due to a thermodynamically favorable reaction: 2Ta+5NiO+Ta2O5. This interface reaction has an effect on the exchange coupling as well. The thickness of the intermixing layer as estimated by XPS depth-profiles was about 8-10 nm. 展开更多
关键词 FABRICATION Interfaces (materials) Magnetic materials MAGNETRONS reaction kinetics SPUTTERING
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超临界水的性质及其在化学反应中的应用 被引量:28
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作者 田宜灵 冯季军 +2 位作者 秦颖 陈丽 房金刚 《化学通报》 CAS CSCD 北大核心 2002年第6期396-402,共7页
介绍了水的热物理性质、结构性质、离子积、扩散系数和粘度等在超临界区域的特殊性 ,以及超临界水溶液在介电常数、偏摩尔体积、溶解性和极性等方面的特殊性质 。
关键词 应用 超临界水 性质 临界曲线 化学反应 反应媒体
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超重力技术及其工业化应用 被引量:46
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作者 陈建峰 邹海魁 +2 位作者 初广文 赵宏 邵磊 《硫磷设计与粉体工程》 2012年第1期6-10,5,共5页
介绍了超重力技术的基本原理、特点和发展历程,并举例说明了超重力技术在分离和反应等方面的工业化应用情况3,0年的开发和应用成果证明:超重力技术是一项极富前景和有活力的过程强化技术,可望成为21世纪化学工程的支柱技术之一。
关键词 超重力 分离 反应 工业化应用
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水资源与矿井水处理利用 被引量:36
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作者 袁存忠 陈锦如 《合肥工业大学学报(自然科学版)》 CAS CSCD 2000年第z1期927-929,933,共4页
煤矿建设 ,一方面需要大量的生产、生活用水 ,另一方面为保证煤矿安全进行人为排水又大大地破坏了地下水资源。我国淡水资源严重缺乏 ,全国许多矿区更是严重缺水。文章简要介绍了根据矿井水的水质类型 ,将矿井水净化处理为生产、生活用... 煤矿建设 ,一方面需要大量的生产、生活用水 ,另一方面为保证煤矿安全进行人为排水又大大地破坏了地下水资源。我国淡水资源严重缺乏 ,全国许多矿区更是严重缺水。文章简要介绍了根据矿井水的水质类型 ,将矿井水净化处理为生产、生活用水的各种工艺流程 ,分析了矿井水资源化的社会效益。 展开更多
关键词 矿井排水 矿井水资源化 悬浮物 矿化度 反应 混凝 过滤 经济效益
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The relation between HLA-DQA1 genes and genetic susceptibility to duodenal ulcer in Wuhan Hans 被引量:38
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作者 Du YP Deng CS +3 位作者 Lu DY Huang MF Guo SF Hou W 《World Journal of Gastroenterology》 SCIE CAS CSCD 2000年第1期107-110,共4页
AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wa... AIM To study the genetic susceptibility of HLA-DQA1 alleles to duodenal ulcer in Wuhan Hans.METHODS Seventy patients with duodenalulcer and fifty healthy controls were examinedfor HLA-DQA1 genotypes.HLA-DQA1 typing wascarried out by digesting the locus specificpolymerase chain reaction amplified productswith alleles specific restriction enzymes(PCR-RFLP),i.e.,Apal Ⅰ,Bsaj Ⅰ,Hph Ⅰ,Fok Ⅰ,Mbo Ⅱ and Mnl Ⅰ.RESULTS The allele frequencies of DQA1 * 0301and DQA1 * 0102 in patients with duodenal ulcerwere significantly higher and lower respectivelythan those in healthy controls(0.40 vs 0.20,P = 0.003,mcorret = 0.024)and(0.05 vs 0.14,P = 0.012,but Pcorret】0.05),respectively.CONCLUSION DQA1 * 0301 is a susceptiblegene for duodenal ulcer in Wuhan Hans,andthere are immunogenetic differences in HLA-DQA1 locus between duodenal ulcer patients andhealthy controls. 展开更多
关键词 Subject headings DUODENAL ULCER HLA-DQA1 gene POLYMERASE chain reaction restricted FRAGMENT length polymorphism genetic susceptibility
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