The Rh blood group system,especially the D antigen,is crucial in transfusion medicine and obstetrics.Weak D phenotypes,caused by mutations in the Rhesus D antigen(RhD)blood group(RHD)gene,result in reduced antigen exp...The Rh blood group system,especially the D antigen,is crucial in transfusion medicine and obstetrics.Weak D phenotypes,caused by mutations in the Rhesus D antigen(RhD)blood group(RHD)gene,result in reduced antigen expression,posing challenges in serological testing and clinical management.Variability in detection methods leads to inconsistent results,making accurate classification difficult.Molecular techniques like polymerase chain reaction and DNA sequencing have significantly improved the identification of weak D variants,offering more reliable transfusion strategies and reducing the risk of alloimmunization.However,challenges such as lack of standardized protocols,cost constraints,and population-specific variations remain.In obstetrics,proper management of pregnant women with weak D is essential to prevent hemolytic disease of the fetus and newborn.Non-invasive prenatal testing using cell-free fetal DNA shows promise in predicting RhD incompatibility and minimizing unnecessary Rh immune globulin administration.Future advancements in highthroughput genotyping and discovery of novel RHD alleles could enhance RhD testing accuracy and efficiency.Standardizing RHD genotyping and adopting genotype-based management strategies for Rh immune globulin therapy and red blood cell transfusions will improve patient safety and clinical outcomes.This review examines the molecular basis,challenges,and future prospects in weak D phenotype management.展开更多
Background Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles varied in different populations. The purpose of this study is to determine the molecular basis of weak D...Background Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles varied in different populations. The purpose of this study is to determine the molecular basis of weak D and DEL phenotype in Anhui Chinese Han population. Methods The D antigen was determined with IgM monoclonal anti-D conformed to the guidelines for donor testing in China. Weak D samples were identified by an indirect antiglobulin test. DEL phenotype was determined by adsorption and elution test. All the RHD 10 exons were screened by PCR with sequence-specific priming or sequenced for the first-time donors who typed weak D, DEL or D negative by serologic test. Results Of all the 30 799 blood donors, 155 blood samples were found D negative with IgM anti-D; 34 blood samples were found D positive by indirect antiglobulin test or absorption elution test. RHD alleles were identified by nucleotide sequencing. Total 4 RHD alleles were found including two new. One hundred and twenty of 155 （77.4%） of the serologically D negative samples lacked the RHD gene. One D negative was RHD（615de12）. Thirty-two of 155 （20.6%） carried RHD（K409K） among them one carrying 1227G〉A and 845G〉A. Two of 155 （1.3%） was weak D type 15. Conclusions In this study at the molecular level, all DEL phenotype is RHD（K409K）; weak D type 15 is the prevalent weak D allele in Anhui Chinese Han population. Additionally, an improved more efficient method was adopted to amplify all the RHD exons in one PCR program. Our study added to the understanding of molecular mechanisms underlying D antigen expression in Anhui Han population and provided useful information for adopting suitable genotyping strategies in routine use.展开更多
Assume that D is a nuclear space and D'its strong topological dual space.Let{B_t}t∈(0,∞)be a Wiener D'-process.In this paper,the real-valued and D'-valued weak stochastic integral with respect to{B_t}are...Assume that D is a nuclear space and D'its strong topological dual space.Let{B_t}t∈(0,∞)be a Wiener D'-process.In this paper,the real-valued and D'-valued weak stochastic integral with respect to{B_t}are established.AMS Subject Classification.60H05.展开更多
Nitrogen doping in chemical vapor deposition-derived ultrananocrystalline diamond(UNCD)films in-creases the electronic conductivity,yet its microstructural effects on electron transport are insufficiently understood.W...Nitrogen doping in chemical vapor deposition-derived ultrananocrystalline diamond(UNCD)films in-creases the electronic conductivity,yet its microstructural effects on electron transport are insufficiently understood.We investigated the formation of nitrogen-induced diaph-ite structures(hybrid diamond-graphite phases)and their role in changing the conductivity.Nitrogen doping in a hy-drogen-rich plasma environment promotes the emergence of unique sp^(3)-sp^(2)bonding interfaces,where diamond grains are covalently integrated with graphitic domains,facilitating a structure-driven electronic transition.High-resolution transmis-sion electron microscopy and selected area electron diffraction reveal five-fold,six-fold and twelve-fold symmetries,along with an atypical{200}crystallographic reflection,confirming diaphite formation in 5%and 10%N-doped UNCD films,while high-er doping levels(15%and 20%)result in extensive graphitization.Raman spectroscopy tracks the evolution of sp^(2)bonding with increasing nitrogen content,while atomic force microscopy and X-ray diffraction indicate a consistent diamond grain size of~8 nm.Cryogenic electronic transport measurements reveal a conductivity increase from 8.72 to 708 S/cm as the nitrogen dop-ing level increases from 5%to 20%,which is attributed to defect-mediated carrier transport and 3D weak localization.The res-ulting conductivity is three orders of magnitude higher than previously reported.These findings establish a direct correlation between diaphite structural polymorphism and tunable electronic properties in nitrogen-doped UNCD films,offering new ways for defect-engineering diamond-based electronic materials.展开更多
目的了解广州地区人群中弱D72血型的血清学特征及分子遗传背景。方法从广州血液中心献血者人群中收集了62人份D变异型标本,采用多重连接依赖的探针扩增(MLPA)技术做RHD及RHCE基因分型;对于MLPA检测不到的RHD突变型等位基因,对其10个外...目的了解广州地区人群中弱D72血型的血清学特征及分子遗传背景。方法从广州血液中心献血者人群中收集了62人份D变异型标本,采用多重连接依赖的探针扩增(MLPA)技术做RHD及RHCE基因分型;对于MLPA检测不到的RHD突变型等位基因,对其10个外显子做直接测序分析,并采用D抗原表位分析试剂盒(DScreen)及其他7种单克隆抗-D做D抗原表位血清学检测。结果在62例D变异型标本中,共发现26例弱D表型,其中弱D72突变型等位基因5例[占8.1%(5/62)],4例为RHD*weak D type 72/RHD*01N.01(RHD基因缺失)和Ccee,1例为RHD*weak D type 72/RHD*DVI.3和CCeee。取1例RHD*weak D type 72/RHD*01N.01的红细胞标本做D抗原表位血清学检测:其与D-Screen试剂盒的9种单克隆抗-D均呈阳性反应,反应强度为1+~2+,与其余7种单克隆抗-D也均呈阳性反应,反应强度为w+~1+。结论血型血清学分析初步提示弱D72血型D抗原表位完整,但该血型个体在免疫刺激下是否不会产生抗-D仍需进一步临床证据证实。展开更多
文摘The Rh blood group system,especially the D antigen,is crucial in transfusion medicine and obstetrics.Weak D phenotypes,caused by mutations in the Rhesus D antigen(RhD)blood group(RHD)gene,result in reduced antigen expression,posing challenges in serological testing and clinical management.Variability in detection methods leads to inconsistent results,making accurate classification difficult.Molecular techniques like polymerase chain reaction and DNA sequencing have significantly improved the identification of weak D variants,offering more reliable transfusion strategies and reducing the risk of alloimmunization.However,challenges such as lack of standardized protocols,cost constraints,and population-specific variations remain.In obstetrics,proper management of pregnant women with weak D is essential to prevent hemolytic disease of the fetus and newborn.Non-invasive prenatal testing using cell-free fetal DNA shows promise in predicting RhD incompatibility and minimizing unnecessary Rh immune globulin administration.Future advancements in highthroughput genotyping and discovery of novel RHD alleles could enhance RhD testing accuracy and efficiency.Standardizing RHD genotyping and adopting genotype-based management strategies for Rh immune globulin therapy and red blood cell transfusions will improve patient safety and clinical outcomes.This review examines the molecular basis,challenges,and future prospects in weak D phenotype management.
文摘Background Rh blood group system is the most complex and immunogenetic blood group system. Prevalent RHD alleles varied in different populations. The purpose of this study is to determine the molecular basis of weak D and DEL phenotype in Anhui Chinese Han population. Methods The D antigen was determined with IgM monoclonal anti-D conformed to the guidelines for donor testing in China. Weak D samples were identified by an indirect antiglobulin test. DEL phenotype was determined by adsorption and elution test. All the RHD 10 exons were screened by PCR with sequence-specific priming or sequenced for the first-time donors who typed weak D, DEL or D negative by serologic test. Results Of all the 30 799 blood donors, 155 blood samples were found D negative with IgM anti-D; 34 blood samples were found D positive by indirect antiglobulin test or absorption elution test. RHD alleles were identified by nucleotide sequencing. Total 4 RHD alleles were found including two new. One hundred and twenty of 155 （77.4%） of the serologically D negative samples lacked the RHD gene. One D negative was RHD（615de12）. Thirty-two of 155 （20.6%） carried RHD（K409K） among them one carrying 1227G〉A and 845G〉A. Two of 155 （1.3%） was weak D type 15. Conclusions In this study at the molecular level, all DEL phenotype is RHD（K409K）; weak D type 15 is the prevalent weak D allele in Anhui Chinese Han population. Additionally, an improved more efficient method was adopted to amplify all the RHD exons in one PCR program. Our study added to the understanding of molecular mechanisms underlying D antigen expression in Anhui Han population and provided useful information for adopting suitable genotyping strategies in routine use.
文摘Assume that D is a nuclear space and D'its strong topological dual space.Let{B_t}t∈(0,∞)be a Wiener D'-process.In this paper,the real-valued and D'-valued weak stochastic integral with respect to{B_t}are established.AMS Subject Classification.60H05.
文摘Nitrogen doping in chemical vapor deposition-derived ultrananocrystalline diamond(UNCD)films in-creases the electronic conductivity,yet its microstructural effects on electron transport are insufficiently understood.We investigated the formation of nitrogen-induced diaph-ite structures(hybrid diamond-graphite phases)and their role in changing the conductivity.Nitrogen doping in a hy-drogen-rich plasma environment promotes the emergence of unique sp^(3)-sp^(2)bonding interfaces,where diamond grains are covalently integrated with graphitic domains,facilitating a structure-driven electronic transition.High-resolution transmis-sion electron microscopy and selected area electron diffraction reveal five-fold,six-fold and twelve-fold symmetries,along with an atypical{200}crystallographic reflection,confirming diaphite formation in 5%and 10%N-doped UNCD films,while high-er doping levels(15%and 20%)result in extensive graphitization.Raman spectroscopy tracks the evolution of sp^(2)bonding with increasing nitrogen content,while atomic force microscopy and X-ray diffraction indicate a consistent diamond grain size of~8 nm.Cryogenic electronic transport measurements reveal a conductivity increase from 8.72 to 708 S/cm as the nitrogen dop-ing level increases from 5%to 20%,which is attributed to defect-mediated carrier transport and 3D weak localization.The res-ulting conductivity is three orders of magnitude higher than previously reported.These findings establish a direct correlation between diaphite structural polymorphism and tunable electronic properties in nitrogen-doped UNCD films,offering new ways for defect-engineering diamond-based electronic materials.
文摘目的了解广州地区人群中弱D72血型的血清学特征及分子遗传背景。方法从广州血液中心献血者人群中收集了62人份D变异型标本,采用多重连接依赖的探针扩增(MLPA)技术做RHD及RHCE基因分型;对于MLPA检测不到的RHD突变型等位基因,对其10个外显子做直接测序分析,并采用D抗原表位分析试剂盒(DScreen)及其他7种单克隆抗-D做D抗原表位血清学检测。结果在62例D变异型标本中,共发现26例弱D表型,其中弱D72突变型等位基因5例[占8.1%(5/62)],4例为RHD*weak D type 72/RHD*01N.01(RHD基因缺失)和Ccee,1例为RHD*weak D type 72/RHD*DVI.3和CCeee。取1例RHD*weak D type 72/RHD*01N.01的红细胞标本做D抗原表位血清学检测:其与D-Screen试剂盒的9种单克隆抗-D均呈阳性反应,反应强度为1+~2+,与其余7种单克隆抗-D也均呈阳性反应,反应强度为w+~1+。结论血型血清学分析初步提示弱D72血型D抗原表位完整,但该血型个体在免疫刺激下是否不会产生抗-D仍需进一步临床证据证实。
