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Molecular Grouping of Grateloupia Tissues Collected Along Chinese Coast and Microsatellite Diversity Analysis of G. asiatica 被引量:1
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作者 PENG Chong DING Haiyan +2 位作者 TANG Zhihong GUO Li YANG Guanpin 《Journal of Ocean University of China》 SCIE CAS CSCD 2018年第4期925-931,共7页
Genus Grateloupia is one of the most speciose genera in family Halymeniales. It is also one of the sources for natural materials, food and medicine. With different environments, Grateloupia change their morphological ... Genus Grateloupia is one of the most speciose genera in family Halymeniales. It is also one of the sources for natural materials, food and medicine. With different environments, Grateloupia change their morphological characteristics, making their morphological identification very difficult. In addition, few of the species diversity in this genus has been described before. In this study, phylogenetic analysis based on rbc L gene sequence was employed to group Grateloupia collected from three locations along Chinese coast. The microsatellites were also used to evaluate their genetic diversity. In total, the tissue parts of 6 putative species were collected from G. asiatica, G. livida, G. lanceolate, G. catenata, G. turuturu and G. filicina. In order to evaluate their genetic diversity and then conserve them better, 40 microsatellites available for Grateloupia were used to evaluate their genetic diversity, and 11 microsatellites were found to be applicable to determine the genetic diversity of G. asiatica. It was found that the genetic diversity of G. asiatica around Qingdao was very rich. We suggested that the species of genus Grateloupia should be identified based on rbc L phylogenetic analysis before the diversity evaluation with microsatellites. The microsatellites should be developed for each species of Grateloupia so that their genetic diversity can be evaluated appropriately. 展开更多
关键词 GRATELOUPIA RBC L molecular groupING MICROSATELLITE genetic diversity
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Single-atom catalysts modified by molecular groups for electrochemical nitrogen reduction 被引量:1
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作者 Zengxi Wei Yuchang Liu +7 位作者 Hongjie Liu Shaopeng Wang Minchen Hou Liwei Wang Dong Zhai Shuangliang Zhao Kefu Yu Shaolong Zhang 《Nano Research》 SCIE EI CSCD 2022年第10期9663-9669,共7页
Electrochemical nitrogen reduction reaction(eNRR)is one of the most important chemical reactions for the production of ammonia under ambient environment.However,the lack of in-depth understanding of the structure-acti... Electrochemical nitrogen reduction reaction(eNRR)is one of the most important chemical reactions for the production of ammonia under ambient environment.However,the lack of in-depth understanding of the structure-activity relationship impedes the development of high-performance catalysts for ammonia production.Herein,the density functional theory(DFT)calculations are performed to reveal the structure–activity relationship for the single-atom catalysts(SACs)supported on g-C_(3)N_(4),which is modified by molecular groups(i.e.,H,O,and OH).The computational results demonstrate that the W-based SACs are beneficial to produce ammonia with a low limiting potential(UL).Particularly,the W-OH@g-C_(3)N_(4) catalyst exhibits an ultralow UL of−0.22 V for eNRR.And the competitive eNRR selectivity can be identified by the dominant*N2 adsorption free energy than that of*H.Our findings provide a theoretical basis for the synthesis of efficient catalysts to produce ammonia. 展开更多
关键词 AMMONIA nitrogen reduction reaction single-atom catalysts(SACs) molecular groups density functional theory(DFT)calculations
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Molecular Epidemiological Analysis of Group A Streptococci Isolated from Children in Chaoyang District of Beijing, 2011:emm Types, Virulence Factor Genes and Erythromycin Resistant Genes 被引量:3
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作者 WANG Hai Bin SONG Yan Yan +4 位作者 YOU Yuan Hai WANG Heng Wei HAN Qin Hua ZHAO Jian Hong ZHANG Xiao Xi 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2013年第9期782-784,共3页
Group A streptococcus (GAS) causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to inv... Group A streptococcus (GAS) causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties. 展开更多
关键词 Virulence Factor Genes and Erythromycin Resistant Genes emm Types molecular Epidemiological Analysis of group A Streptococci Isolated from Children in Chaoyang District of Beijing GAS
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Board-invited review: Sensitivity and responses of functional groups to feed processing methods on a molecular basis 被引量:2
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作者 Peiqiang Yu 《Journal of Animal Science and Biotechnology》 SCIE CAS 2013年第1期1-4,共4页
In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore... In complex feed structures, there exist main chemical functional groups which are associated with nutrient utilization and availability and functionality. Each functional group has unique molecular structure therefore produce unique molecular vibration spectral profile. Feed processing has been used to improve nutrient utilization for many years. However, to date, there was little study on processing-induced changes of feed intrinsic structure and functional groups on a molecular basis within intact tissue. This is because limited research technique is available to study inherent structure on a molecular basis. Recently bioanalytical techniques: such as Synchrotron Infrared Microspectroscopy as well as Diffuse Reflectance Infrared Fourier Transform molecular spectroscopy have been developed. These techniques enable to detect molecular structure change within intact tissues. These techniques can prevent destruction or alteration of the intrinsic protein structures during processing for analysis. However, these techniques have not been used in animal feed and nutrition research. The objective of this review was show that with the advanced technique, sensitivity and responses of functional groups to feed processing on a molecular basis could be detected in my research team. These functional groups are highly associated with nutrient utilization in animals. 展开更多
关键词 Sensitivity and responses of functional groups molecular structures Feed processing Nutrient utilizationand availability
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Comparison of Blood Group Molecular Genotyping to Traditional Serological Phenotyping in Patients with Chronic or Recent Blood Transfusion 被引量:2
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作者 Zhan Ye Daoping Zhang +2 位作者 Leonard Boral Counts Liz John May 《Journal of Biosciences and Medicines》 2016年第3期1-8,共8页
Objectives: Accurately identifying the Antigens (Ags) on recipient red blood cells (RBCs) is critical in prevention of RBC alloimmunization in chronically transfused patients. The goal of this study was to compare RBC... Objectives: Accurately identifying the Antigens (Ags) on recipient red blood cells (RBCs) is critical in prevention of RBC alloimmunization in chronically transfused patients. The goal of this study was to compare RBC molecular genotyping to serological phenotyping in those patients. Methods: Serological phenotyping and molecular genotyping methods were used to study blood samples from 18 healthy blood donors and 16 transfused patients. Reticulocyte harvesting or hypotonic cell separation was added to recheck RBC phenotypes of the patients with discrepancies between phenotyping and genotyping. Results: No discrepancies were found between the two genotyping methods in all the donors and patients. 1 of 9 sickle-cell disease (SCD) patients and all 3 thalassemia patients demonstrated discrepancies in multiple blood groups between phenotyping and genotyping, which were not corrected by reticulocyte harvesting or hypotonic cell separation. Conclusions: These findings suggest that RBC molecular genotyping is superior to serological phenotyping in chronically transfused SCD or thalassemia patients. 展开更多
关键词 Blood group molecular Genotyping Serological Phenotyping Chronic Blood Transfusion
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Molecular group dynamics study on slip flow of thin fluid film based on the Hamaker hypotheses
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作者 ZHOU JianFeng, SHAO ChunLei & GU BoQin College of Mechanical and Power Engineering, Nanjing University of Technology, Nanjing 210009, China 《Science China(Technological Sciences)》 SCIE EI CAS 2010年第7期1833-1838,共6页
The thin fluid film was assumed to consist of a number of spherical fluid molecular groups and the attractive forces of molecular group pairs were calculated by the derived equation according to the three Hamaker homo... The thin fluid film was assumed to consist of a number of spherical fluid molecular groups and the attractive forces of molecular group pairs were calculated by the derived equation according to the three Hamaker homogeneous material hypotheses. Regarding each molecular group as a dynamics individual, the simulation method for the shearing motion of multilayer fluid molecular groups, which was initiated by two moving walls, was proposed based on the Verlet velocity iterative algorithm. The simulations reveal that the velocities of fluid molecular groups change about their respective mean velocities within a narrow range in steady state. It is also found that the velocity slips occur at the wall boundary and in a certain number of fluid film layers close to the wall. Because the dimension of molecular group and the number of group layers are not restricted, the hypothetical thickness of fluid film model can be enlarged from nanometer to micron by using the proposed simulation method. 展开更多
关键词 Hamaker hypotheses molecular group VELOCITY SLIP LENNARD-JONES potential
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THE CONTROL OF POLYMETHACRYLATE MOLECULAR STRUCTURE BY GROUP TRANSFER POLYMERIZATION
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作者 OWEN W. WEBSTER 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第1期1-9,共9页
INTRODUCTION Group transfer polymerization (GTP) is a method for controlling the structure of acrylic polymers in which reactive chain ends are covalentiy bound to a trimethylsilyl group. In the presence of a catalyst... INTRODUCTION Group transfer polymerization (GTP) is a method for controlling the structure of acrylic polymers in which reactive chain ends are covalentiy bound to a trimethylsilyl group. In the presence of a catalyst, monomer inserts into these chain ends between the silyl group and the last monomer unit. The process is illustrated by equation (1) for methyl methacrylate. GTP is a living polymerization, i. e., there is little or no chain termination and no chain transfer. A significant advantage of GTP is that it 展开更多
关键词 PMMA EA GTP rate PBMA THE CONTROL OF POLYMETHACRYLATE molecular STRUCTURE BY group TRANSFER POLYMERIZATION
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A Simple Approach for Synthesis of TAPO-11 Molecular Sieve with Controllable Space Group
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作者 Yue Ming LIU Huan Yan ZHANG Hai Jiao ZHANG Hai Hong WU Peng WU Ming Yuan HE 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第10期1409-1412,共4页
A TAPO-11 molecular sieve with the space group lcm2 was synthesized successfully. The samples with different space group were controlled simply only by adjusting the crystallization temperature (CT) in the hydrother... A TAPO-11 molecular sieve with the space group lcm2 was synthesized successfully. The samples with different space group were controlled simply only by adjusting the crystallization temperature (CT) in the hydrothermal system. In the system of gel with a molar composition of 0.7R- xTiO2: P2O5: Al2O3: 30H2O, where x is 0.01-0.10 and the R is a mixture of di-n-propylamine and diisopropylamine as templates. When CT was between 150-160℃, the calcined sample showed the space group of Icm^2, while it showed Pna21 at CT larger than 190℃. The characterizations of UV-Vis and FT-IR confirmed that Ti was incorporated into the AEL framework successfully. 展开更多
关键词 TAPO-11 molecular sieve space group SYNTHESIS TITANOSILICATE
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Molecular Phylogeny of the “True Citrus Fruit Trees” Group (Aurantioideae, Rutaceae) as Inferred from Chloroplast DNA Sequence
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作者 LU Zhen-hua ZHOU Zhi-qin XIE Rang-jin 《Agricultural Sciences in China》 CAS CSCD 2011年第1期49-57,共9页
The genus Citrus L. has a long controversial taxonomy history, and a well-resolved molecular phylogeny of the "true citrus fruit trees" group in the future will provide new information for advancing breeding techniq... The genus Citrus L. has a long controversial taxonomy history, and a well-resolved molecular phylogeny of the "true citrus fruit trees" group in the future will provide new information for advancing breeding techniques and developing better conservation strategies. In the present study, three cpDNA fragments (TrnL-TrnF, PsbH-PetB, and TrnS-TrnG) of 30 genotypes chosen from the six genera of the "true citrus fruit trees" group were analyzed. A molecular phylogenetic tree of the "true citrus fruit trees" group "~as reconstructed based on plastid DNA sequences. The results confirmed that the "true citrus fruit trees" group was monophyletic, and thereby the group was divided into genera as previously suggested based on morphological characters. The cpDNA data also suggested that Poncirus might be the first genus separated from the other five genera in the group. The genus Fortunella were of hybrid origin and Citrus might be as its putative paternal parent. The genera Microcitrus, Eremocitrus, and Clymenia were possibly monophyletic and their common ancestor might branch out from Citrus. Furthermore, the phylogenetic relationships within the Citrus genus were discussed. 展开更多
关键词 RUTACEAE Aurantioideae true citrus fruit trees group molecular phylogenetics cpDNA sequence
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Current molecular methods for the detection of hepatitis C virus in high risk group population:A systematic review 被引量:4
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作者 Rushna Firdaus Kallol Saha +1 位作者 Aritra Biswas Provash Chandra Sadhukhan 《World Journal of Virology》 2015年第1期25-32,共8页
Hepatitis C virus(HCV) is an emerging infection worldwide and the numbers of persons infected are increasing every year. Poor blood transfusion methods along with unsafe injection practices are potential sources for t... Hepatitis C virus(HCV) is an emerging infection worldwide and the numbers of persons infected are increasing every year. Poor blood transfusion methods along with unsafe injection practices are potential sources for the rapid spread of infection. Early detection of HCV is the need of the hour especially in high riskgroup population as these individuals are severely immunocompromised. Enzyme Immunoassays are the most common detection techniques but they provide no evidence of active viremia or identification of infected individuals in the antibody-negative phase and their efficacy is limited in individuals within high risk group population. Molecular virological techniques have an important role in detecting active infection with utmost specificity and sensitivity. Technologies for assessment of HCV antibody and RNA levels have improved remarkably, as well as our understanding of how to best use these tests in patient management. This review aims to give an overview of the different serological and molecular methods employed in detecting HCV infection used nowadays. Additionally, the review gives an insight in the new molecular techniques that are being developed to improve the detection techniques particularly in High Risk Group population who are severely immunocompromised. 展开更多
关键词 molecular DETECTION Enzyme IMMUNOASSAY High risk group population Nucleic acid amplification assays POLYMERASE chain reaction
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实时定量PCR应用于研讨式分组实验教学实践
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作者 李欣 张伟英 +2 位作者 陈容容 赵玉红 石建党 《实验室科学》 2024年第2期160-165,共6页
实时定量PCR作为一项生命科学及其相关领域的重要技术,已成为高校生物实验教学中不可或缺的知识内容。以分子生物学实验基础教学内容为依托,围绕实时定量PCR技术面向本科生开设了综合性实验。在充分考虑学生的理论和操作水平以及本科实... 实时定量PCR作为一项生命科学及其相关领域的重要技术,已成为高校生物实验教学中不可或缺的知识内容。以分子生物学实验基础教学内容为依托,围绕实时定量PCR技术面向本科生开设了综合性实验。在充分考虑学生的理论和操作水平以及本科实验教学特点的基础上,对实验设计和实验方法进行了优化,并采取研讨式分组教学模式,提高教学效率与教学质量的同时,更突出了学生在实验教学中的主体地位,有助于培养学生的科学思维、科学素养以及综合实践能力。 展开更多
关键词 实时定量PCR 分子生物学 研讨式分组 实验教学
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茂金属聚乙烯薄膜晶点的组成及形成原因
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作者 樊洁 朱珍珍 +3 位作者 张鹏 李朋朋 李艳芹 魏福庆 《塑料工业》 CAS CSCD 北大核心 2024年第2期98-103,158,共7页
采用凝胶渗透色谱仪(GPC)、差示扫描量热仪(DSC)、偏光显微镜以及红外光谱等分析手段,从原料的分子链结构分析了茂金属聚乙烯薄膜晶点的组成及其形成原因。结果表明,茂金属聚乙烯薄膜晶点的结晶形态与无晶点的正常薄膜的不同,构成晶点... 采用凝胶渗透色谱仪(GPC)、差示扫描量热仪(DSC)、偏光显微镜以及红外光谱等分析手段,从原料的分子链结构分析了茂金属聚乙烯薄膜晶点的组成及其形成原因。结果表明,茂金属聚乙烯薄膜晶点的结晶形态与无晶点的正常薄膜的不同,构成晶点的晶体尺寸均匀性远不如无晶点的正常薄膜,这是因为晶点中含有类似于纤维状的晶体,这种晶体先结晶,导致随后形成的晶体在此处生长不均匀。此外,分子链上的端基双键(RCH CH 2)在吹膜过程中引起的分子间交联和分子链中存在的亚甲基序列较长的规整结构,是形成类纤维状晶体的主要因素,而较长亚甲基序列的规整结构是由于共聚单体分布不均匀引起的。 展开更多
关键词 茂金属聚乙烯 晶点 纤维状晶体 分子链结构 端基双键 亚甲基序列 共聚单体
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ABO血型基因外显子1上新变异的鉴定
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作者 薛阳 李抄 +5 位作者 辛文龙 曾星 马涛 陈芳芳 曹晨 高宏军 《中国实验血液学杂志》 CAS CSCD 北大核心 2024年第4期1212-1216,共5页
目的:应用血清学和分子生物学方法鉴定1例ABO正反定型不一致患者的血型,并探讨其遗传学特点。方法:采用试管法鉴定该患者的ABO表型,荧光PCR法测定患者及其父母的ABO血型基因型,并对ABO基因7个外显子进行直接测序分析。结果:本例患者血... 目的:应用血清学和分子生物学方法鉴定1例ABO正反定型不一致患者的血型,并探讨其遗传学特点。方法:采用试管法鉴定该患者的ABO表型,荧光PCR法测定患者及其父母的ABO血型基因型,并对ABO基因7个外显子进行直接测序分析。结果:本例患者血清学初步鉴定为Bel亚型;基因分型检测患者及其父亲的基因型为B/O1,其母亲的基因型为O1/O1;测序发现在患者及其父亲ABO基因外显子1上有新的c.16_17delins TGTTGCA杂合变异。结论:外显子1上新的变异导致该患者ABO血型出现Bel亚型,并具有遗传性。 展开更多
关键词 ABO血型 Bel亚型 分子生物学 基因 外显子
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ABO血型变异的分子基础研究
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作者 雷航 王学锋 +2 位作者 程晓文 张慧 蔡晓红 《中国输血杂志》 CAS 2024年第4期385-391,共7页
目的 对临床ABO血型变异标本进行ABO亚型、类孟买血型与基因型关联性研究,以探讨这2种血型产生的可能分子背景,为ABO血型的准确鉴定与预判提供精确的基因检测靶点和理论依据。方法 对2022年2—12月瑞金医院2.42万名血型鉴定患者,以及期... 目的 对临床ABO血型变异标本进行ABO亚型、类孟买血型与基因型关联性研究,以探讨这2种血型产生的可能分子背景,为ABO血型的准确鉴定与预判提供精确的基因检测靶点和理论依据。方法 对2022年2—12月瑞金医院2.42万名血型鉴定患者,以及期间来自外院送检10例ABO疑难标本(疑似ABO亚型3例,疑似类孟买血型7例)进行血清学分析,对血清学鉴定为ABO亚型、类孟买血型的行DNA直接测序或克隆后测序分析ABO、FUT1、FUT2基因序列。结果 在共计2.42万血型鉴定患者中检出7例ABO亚型;外院送检的10例疑难标本检出2例ABO亚型、1例正常A型、7例类孟买血型。我们共鉴定出:1)9例ABO亚型,表型及其对应基因型分别为:1例A_(el)(AEL.02/O.01.02)、1例A_(el)B(AEL.05/B.01)、3例B_(3)(2例B3.03/O.01.01、1例B3.03/O.01.02)、1例B(A)(BA.02/O.01.01)、1例AB_(weak)(A1.02/BW.07)、1例B_(weak)(BW.31/O.01.02)、1例A_(2)B_(weak)(A2.05/BW.31);2)7例类孟买血型,表型及其对应基因型分别为:1例AB_(m)^(h)(FUT1^(*)01N.13/FUT1^(*)01N.13)、4例A_(m)^(h)(3例FUT1^(*)01N.06/FUT1^(*)01N.13、1例FUT1^(*)01N.13/FUT1^(*)01N.13)、2例B_(m)^(h)(FUT1^(*)01N.06/FUT1^(*)01N.06、FUT1^(*)01N.06/FUT1^(*)01N.13),7例类孟买的FUT2基因型均为FUT2^(*)01/FUT2^(*)01。结论 ABO血型变异标本需联合血清学与分子生物学方法进行鉴定,方能提高对血型变异标本的鉴定准确率,从而为临床安全输血、器官移植、胎母免疫性溶血病的预测与防治提供参考。 展开更多
关键词 ABO亚型 类孟买血型 基因突变 分子机制
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郑州地区RhD变异型献血者分子生物学分析
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作者 杨贺才 曾群娟 +3 位作者 马晓莉 吕永磊 耿明璐 王丽萍 《中国输血杂志》 CAS 2024年第8期866-871,共6页
目的研究郑州地区RhD变异型献血者血清学特征及基因突变机制。方法选择2023年1月—2023年12月送至本实验室的1619名RhD阴性献血者为研究对象,应用试管法和微柱凝胶间接抗球蛋白试验方法进行RhD阴性确认试验及RhCE表型检测。采用RHD基因... 目的研究郑州地区RhD变异型献血者血清学特征及基因突变机制。方法选择2023年1月—2023年12月送至本实验室的1619名RhD阴性献血者为研究对象,应用试管法和微柱凝胶间接抗球蛋白试验方法进行RhD阴性确认试验及RhCE表型检测。采用RHD基因扩增和Sanger测序检测RhD变异型标本基因型。结果RhD阴性确认试验共检出RhD变异型69例,比例为4.26%(69/1619)。RhCE表型分别为ccEe、Ccee、CcEe、CCee。包含17种基因型,15种D变异型表型。RHD^(*)weak partial 15等位基因最多(33例),频率为47.83%(33/69),主要表型为ccEe;其次是RHD^(*)DVI.3等位基因20例,频率为28.99%(20/69),主要表型为Ccee。RHD^(*)weak partial 15/RHD^(*)01EL.01杂合子3例,频率为4.35%(3/69),皆为CcEe表型。其他罕见基因型共13例,频率为18.84%(13/69)。抗筛阳性3例,比例为4.35%(3/69)。女性献血者2名,皆有孕产史,经抗体鉴定为抗-D;男性献血者1名,为抗-M。结论郑州地区RhD变异型献血者中RHD^(*)weak partial 15基因型最常见,其次为RHD^(*)DVI.3基因型。对保障安全供血,指导临床精准输血具有重要作用。 展开更多
关键词 RH血型 RhD变异型 基因型 分子生物学 郑州
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利用三代测序技术鉴定c.586T>C突变导致的Bel亚型
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作者 崔文燕 刘金华 付威义 《临床输血与检验》 CAS 2024年第2期262-266,共5页
目的利用PacBio三代测序技术鉴定c.586T>C突变导致的Bel亚型,并分析Bel亚型家系的血型血清学特点。方法ABO血型表型检测使用血清学方法,对ABO正反定型不符的家系标本进行ABO基因第6、7号外显子Sanger测序。利用PacBio三代技术对先证... 目的利用PacBio三代测序技术鉴定c.586T>C突变导致的Bel亚型,并分析Bel亚型家系的血型血清学特点。方法ABO血型表型检测使用血清学方法,对ABO正反定型不符的家系标本进行ABO基因第6、7号外显子Sanger测序。利用PacBio三代技术对先证者及其子女的3例样本进行ABO基因全长单体型分析。结果先证者血清学表型为Bel亚型,测序技术鉴定ABO基因序列第7外显子存在c.586T>C位点突变,三代测序单体型鉴定先证者ABO基因型为ABO^(*)BEL(c.586T>C)/O01.02,其长子和长女基因型为:ABO^(*)A1.02/BEL(c.586T>C)、ABO^(*)B.01/BEL(c.586T>C)。结论c.586T>C位点突变是导致本例Bel的分子基础,PacBio三代测序技术能够精准鉴定ABO亚型单体型。 展开更多
关键词 Bel亚型 血型血清学 分子机制 单体型鉴定 PacBio三代测序技术
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水蒸气在褐煤孔隙中的吸附行为:试验研究与分子动力学模拟
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作者 王成勇 邢耀文 +3 位作者 王市委 陈鹏 李吉辉 桂夏辉 《洁净煤技术》 CAS CSCD 北大核心 2024年第5期162-171,共10页
深入理解水在褐煤上的吸附是褐煤干燥提质技术的理论基础之一。采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和低温氮吸附/脱附试验分析了褐煤的含氧官能团和孔隙结构,利用水蒸气吸附/脱附试验和分子动力学(MD)模拟探究了水蒸气... 深入理解水在褐煤上的吸附是褐煤干燥提质技术的理论基础之一。采用傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和低温氮吸附/脱附试验分析了褐煤的含氧官能团和孔隙结构,利用水蒸气吸附/脱附试验和分子动力学(MD)模拟探究了水蒸气在褐煤孔隙中的吸附行为。研究结果表明:褐煤样品丰富的含氧官能团和较多的微孔、中孔(孔径约2 nm),为水蒸气提供了吸附位点和吸附场所。水蒸气在煤样上的吸附过程可分为3个阶段。第1阶段,相对蒸气压(P/P_(0))<0.21,水分子直接吸附于含氧官能团上,此时的吸附速度最大;第2阶段(P/P_(0)=0.21~<0.71),水分子与已吸附的水分子相互作用,促使水团簇逐渐生长;第3阶段(P/P_(0)≥0.71),水团簇填充孔隙,并发生毛细凝聚,此时的吸附速度略大于第2阶段。根据Dent模型对水蒸气吸附等温线的拟合结果,吸附类型属于多级吸附,包括初级吸附(第1阶段)和次级吸附(第2、3阶段)。初级吸附能(-48.77 kJ/mol)显著大于水的液化热(E L=-43.99 kJ/mol),而次级吸附能(-42.28 kJ/mol)略小于E L,表明吸附于褐煤的水呈液态。水蒸气脱附过程存在明显的脱附迟滞现象,表明水蒸气吸附稳定,较难去除,其中高压迟滞发生在P/P_(0)≈0.4~0.9,主要由毛细凝聚和“墨水瓶”效应引起;而低压迟滞发生在P/P_(0)<0.4,由水分子与含氧官能团间强相互作用引起。MD模拟结果与水蒸气吸附/脱附等温线分析结果一致,水分子优先吸附在孔隙中,与孔隙壁的含氧官能团形成氢键,且其扩散系数(2.98×10^(-5)cm^(2)/s)与液态水的分子扩散系数相近。 展开更多
关键词 褐煤 孔隙结构 含氧官能团 水蒸气吸附 Dent模型 分子动力学模拟
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油酸和Span80协同煤油对低阶煤的浮选强化及分子模拟计算 被引量:1
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作者 刘凯歌 李钰炳 +2 位作者 李志红 栗褒 高建川 《煤炭转化》 CAS CSCD 北大核心 2024年第2期12-21,共10页
低阶煤表面含有较多含氧基团,可浮性差,采用传统煤油捕收剂不仅药剂消耗大,而且分选效果差。复配捕收剂可以选择性地作用于矿物表面,从而提升浮选效果。以内蒙古色连二矿选煤厂低阶煤为研究对象,考察了传统捕收剂煤油的作用效果,并在此... 低阶煤表面含有较多含氧基团,可浮性差,采用传统煤油捕收剂不仅药剂消耗大,而且分选效果差。复配捕收剂可以选择性地作用于矿物表面,从而提升浮选效果。以内蒙古色连二矿选煤厂低阶煤为研究对象,考察了传统捕收剂煤油的作用效果,并在此基础上引入含氧有机药剂油酸和Span80与其复配,考察复配药剂对低阶煤浮选的强化作用,并对其作用机理进行分析。结果表明:煤油-油酸和煤油-Span80复配药剂对实验煤样浮选均有促进作用。捕收剂用量为4000 g/t,起泡剂用量为800 g/t时,煤油-Span80复配药剂对应的精煤产率为83.17%,精煤灰分为11.78%,尾煤灰分为69.15%,可燃体回收率达到93.48%,浮选完善指标为42.18%。与煤油和煤油-油酸复配药剂相比,煤油-Span80复配药剂可显著提升尾煤灰分和可燃体回收率,达到了较为理想的分选效果。机理研究结果显示,油酸和Span80与煤油复配,可显著降低药剂在矿浆中的分散粒径,提高其与颗粒的接触概率;同时,油酸和Span80与煤作用,掩蔽了煤样表面的亲水基团,改善了煤样疏水性,使其更易在煤粒表面铺展。模拟计算发现油酸和Span80药剂的前线轨道能隙小于正十二烷(煤油)的前线轨道能隙,煤油-油酸和煤油-Span80复配药剂与煤表面的相互作用能大于正十二烷(煤油)与煤表面的相互作用能,表明复配药剂更具活性,更容易与煤表面发生吸附。 展开更多
关键词 低阶煤 复配捕收剂 含氧官能团 浮选 分子模拟
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黏土矿物表面羟基介导的分子氧活化机理
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作者 杜晴 牛慧斌 +6 位作者 徐艳 张静 兰星 黄应平 谈云志 陈晓婷 方艳芬 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2024年第3期103-113,共11页
天然黏土矿物表面羟基(Me-OH,Me=Al,Si,Fe)对分子氧(O2)活化机制目前尚不明晰.本文通过在N2气氛中对红黏土(R-Clay)进行不同温度热处理,调控其表面Me-OH位点数及形态,使其不同程度地活化O_(2),进而降解水中四环素(TC).研究结果表明,随... 天然黏土矿物表面羟基(Me-OH,Me=Al,Si,Fe)对分子氧(O2)活化机制目前尚不明晰.本文通过在N2气氛中对红黏土(R-Clay)进行不同温度热处理,调控其表面Me-OH位点数及形态,使其不同程度地活化O_(2),进而降解水中四环素(TC).研究结果表明,随着温度的升高,R-Clay内高岭土结构逐渐被破坏,Fe_(2)O_(3)结构更加突显.其中,红黏土R-Clay400表面Me-OH以Al-Al-OH和Al-Si-OH形态存在,可高效降解(86.36%)和矿化TC(40%,6 h).在可见光照射下,R-Clay400 Si-O-Al上氧原子和TC分子均可作为电子供体,它们将光生电子(e-)转移给吸附在R-Clay400表面的O_(2)生成超氧自由基(•O_(2)-)及单线态氧(1O_(2)),实现对TC的高效降解.机理研究表明,表面Me-OH可作为Brönsted酸位点,通过氢键吸附O_(2),促进了电子转移,而非传统认为的电子供体. 展开更多
关键词 热处理 红黏土 表面羟基 分子氧活化机理 降解
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基于程序升温试验的煤自燃特性及微观机理研究
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作者 刘垚 王福生 +1 位作者 董轩萌 高东 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第S01期94-106,共13页
针对煤在变氧条件下氧化自燃能力不同这一情况,选取褐煤、气煤、肥煤3种不同变质程度的煤作为试验样品开展了氧气体积分数为3%、5%、10%、14%、18%条件下的程序升温-气相色谱试验和基于ReaxFF力场的分子动力学模拟,根据CO、CO_(2)等的... 针对煤在变氧条件下氧化自燃能力不同这一情况,选取褐煤、气煤、肥煤3种不同变质程度的煤作为试验样品开展了氧气体积分数为3%、5%、10%、14%、18%条件下的程序升温-气相色谱试验和基于ReaxFF力场的分子动力学模拟,根据CO、CO_(2)等的生成规律和路径,探究不同变质程度煤在变氧条件下基团受氧气影响的变化特征。结果表明:煤受温度和氧气影响容易产生CO、CO_(2)等指标气体,且指标气体CO、CO_(2)呈指数上升趋势,煤的变质程度越低,在相同氧气体积分数条件下产生指标气体的温度就越低。模拟结果显示,变氧条件下煤与氧的反应可能是氧与煤受温度影响产生的活性中间体片段反应,而不是直接攻击煤的主体结构。煤在受温度影响后煤结构基团并不是直接发生改变,而是经历结构调整进行键的扭转、断裂和原子上的转变生成适合与氧气反应的活性中间体片段。变质程度越高的煤分子结构越稳定越不易受温度的影响产生活性中间体片段,通入氧气后氧与活性中间体反应的速度低于煤受温度影响产生活性中间体的速度,所以变氧条件下氧一般是与活性中间体反应生成水、CO等指标气体,而不是直接与煤主体结构反应。综合分析试验结果与模拟结果发现:褐煤在氧气体积分数处于3%、气煤在氧气体积分数处于10%~14%、肥煤在氧气体积分数处于14%~18%时,水和含氧气体的数量相较于其他阶段明显增加,说明在氧含量较低的区间内这3种不同变质程度的煤受氧气影响较大,加速了煤氧化反应进程,煤自燃倾向性高。 展开更多
关键词 煤自燃 ReaxFF力场 变氧条件 分子结构 活性基团
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