Clayey silt reservoirs bearing natural gas hydrates(NGH)are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit.They are proved to be exploitabl...Clayey silt reservoirs bearing natural gas hydrates(NGH)are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit.They are proved to be exploitable by the first NGH production test conducted in the South China Sea in 2017.Based on the understanding of the first production test,the China Geological Survey determined the optimal target NGH reservoirs for production test and conducted a detailed assessment,numerical and experimental simulation,and onshore testing of the reservoirs.After that,it conducted the second offshore NGH production test in 1225 m deep Shenhu Area,South China Sea(also referred to as the second production test)from October 2019 to April 2020.During the second production test,a series of technical challenges of drilling horizontal wells in shallow soft strata in deep sea were met,including wellhead stability,directional drilling of a horizontal well,reservoir stimulation and sand control,and accurate depressurization.As a result,30 days of continuous gas production was achieved,with a cumulative gas production of 86.14×104 m3.Thus,the average daily gas production is 2.87×10^4 m^3,which is 5.57 times as much as that obtained in the first production test.Therefore,both the cumulative gas production and the daily gas production were highly improved compared to the first production test.As indicated by the monitoring results of the second production test,there was no anomaly in methane content in the seafloor,seawater,and atmosphere throughout the whole production test.This successful production test further indicates that safe and effective NGH exploitation is feasible in clayey silt NGH reservoirs.The industrialization of hydrates consists of five stages in general,namely theoretical research and simulation experiments,exploratory production test,experimental production test,productive production test,and commercial production.The second production test serves as an important step from the exploratory production test to exper展开更多
胡庚申教授系生态翻译学创始人。原为清华大学二级教授,现为郑州大学生态翻译学研究院院长、外国语与国际关系学院特聘教授,博士生导师。兼任国际生态翻译学研究会(International Association for Eco-translatology Research)创始会长...胡庚申教授系生态翻译学创始人。原为清华大学二级教授,现为郑州大学生态翻译学研究院院长、外国语与国际关系学院特聘教授,博士生导师。兼任国际生态翻译学研究会(International Association for Eco-translatology Research)创始会长,亚太国际交流英语学会(Asia-Pacific Association for English of International Communication)理事长,海峡两岸暨港澳地区翻译与跨文化交流系列会议执委会主席,国际期刊《生态翻译学学刊》(Journal of Eco-translation Studies)主编,外语教学与研究出版社《国际交流英语系列教程》总主编,上海外语教育出版社《翻译与跨文化交流系列文集》总主编等。他分别于2008年和2018年主持生态翻译学方面的国家社科基金项目,在国内外学术期刊发表论文200余篇,出版各类著作38部。其中,2019年在世界著名的施普林格出版社(Springer)出版专著《生态翻译学:翻译研究的生态范式建构》(Eco-Trans-latology:Towards an Eco-Paradigm of Translation Studies),被学界誉为"开发本土学术资源的一面旗帜"。胡庚申教授在2013年出版的专著《生态翻译学:建构与诠释》中提出"三生"的概念。所谓"三生",即翻译生态、译本生命和译者生存,指的是以"生"为线索展开研究和论证阐述,表明"生"是生态翻译学发展之基石(1)。2016年,胡庚申在国际期刊发表文章指出,"生"是指翻译过程中文本的"生命"及其生存条件和生存状态(Life here refers to the life of the texts involved in translation process, the vital status and living conditions of the texts)(2)。在2018年"第六届国际生态翻译学研讨会"的主旨报告中,胡庚申又提出"生生之谓译",成为生态翻译学的新发展和新方向。2019年,胡庚申在研究论文中反复强调生态翻译学的"三生"主题和翻译文本的"生命"形态(3),并在"全国第三届生态翻译与认识翻译研讨会"的主旨报告中,进一步明确了"尚生—摄展开更多
In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a ...In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.展开更多
Background Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awarenes...Background Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awareness and effective treat-ments, to further standardize and strengthen the clinical management and to reduce the mortality of HFMD, the guidelines for diagnosis and treatment have been developed. Methods National Health Commission of China assembled an expert committee for a revision of the guidelines. The com-mittee included 33 members who are specialized in diagnosis and treatment of HFMD. Results Early recognition of severe cases is utmost important in diagnosis and treatment of patients with HFMD. The key to diagnosis and treatment of severe cases lies in the timely and accurate recognition of stages 2 and 3 of HFMD, in order to stop progression to stage 4. Clinicians should particularly pay attention to those EV-A71 cases in children aged less than 3 years, and those with disease duration less than 3 days. The following indicators should alert the clinician of possible deterioration and impending critical disease: (1) persistent hyperthermia;(2) involvement of nervous system;(3) worsening respiratory rate and rhythm;(4) circulatory dysfunction;(5) elevated peripheral WBC count;(6) elevated blood glucose and (7) elevated blood lactic acid. For treatment, most mild cases can be treated as outpatients. Patients should be isolated to avoid cross-infection. Intense treatment modalities should be given for those severe cases. Conclusion The guidelines can provide systematic guidance on the diagnosis and management of HFMD.展开更多
Chang'E-1 lunar Orbiter was launched by Long March 3A rocket from Xichang Satel-lite Launch Center at 18:05BT(Beijing Time) Oct.24,2007.It is the first step of its ambitious three-stage moon program,a new mileston...Chang'E-1 lunar Orbiter was launched by Long March 3A rocket from Xichang Satel-lite Launch Center at 18:05BT(Beijing Time) Oct.24,2007.It is the first step of its ambitious three-stage moon program,a new milestone in the Chinese space exploration history.The primary science objectives of Chang'E-1 lunar orbiter are to obtain three-Dimension(3D) stereo images of the lunar surface,to analyze the distribution and abundance of elements on the surface,to investigate the thickness of lunar soil,evaluate helium-3 resources and other characteristics,and to detect the space environment around the moon.To achieve the above four mission objectives,eight sets of scientific instruments are chosen as the payloads of the lunar orbiter,including a CCD stereo camera(CCD),a Sagnac-based interferometer spectrometer(ⅡM),a Laser Altimeter(LAM),a Microwave Radiometer(MRM),a Gamma-Ray Spectrometer(GRS),an X-ray spectrometer(XRS),a High-Energy Particle Detector(HPD),and two Solar Wind Ion Detectors(SWID).The detected data of the payloads show that all payloads work well.This paper introduces the status of payloads in the first phase and preliminary scientific results.展开更多
目的基于既往冠状病毒的研究,探索利巴韦林用于新型冠状病毒肺炎治疗的有效性和安全性。方法计算机检索PubMed、Web of Science、Embase、EBSCO、中国期刊全文数据库、维普、万方等数据库,检索有关利巴韦林用于SARS、MERS治疗有效性和...目的基于既往冠状病毒的研究,探索利巴韦林用于新型冠状病毒肺炎治疗的有效性和安全性。方法计算机检索PubMed、Web of Science、Embase、EBSCO、中国期刊全文数据库、维普、万方等数据库,检索有关利巴韦林用于SARS、MERS治疗有效性和安全性的队列研究以及案例报道,检索时间范围为2003年1月到2020年1月30日。结果有效性研究结果显示部分SARS和MERS患者使用利巴韦林后,病情得到控制和改善,治愈率和临床治疗结局也较好;安全性研究结果显示利巴韦林不良反应发生率较高,主要为贫血和心律失常,同时也有其他不良反应的报告。结论利巴韦林用于COVID-19治疗可能有效性,但还需进一步的临床实验来证实,同时由于不良反应发生率较高,临床使用前应仔细综合评估各项指标,排除存在用药禁忌证的患者,并在治疗过程中密切监测。展开更多
A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides...A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides （OCPs） were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX （DDD, DDE and DDT） had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p＇-（DDD＋DDE）/DDT in soils under three land usages were： paddy field 〉 tree land 〉 fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p＇-（DDD＋DDE）/DDT 〉1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.展开更多
Background The incidence of autosomal trisomy in livebirths is strongly dependent on maternal age. Special consideration is given to the provision of prenatal screening and cytogenetic testing to women of advanced mat...Background The incidence of autosomal trisomy in livebirths is strongly dependent on maternal age. Special consideration is given to the provision of prenatal screening and cytogenetic testing to women of advanced maternal age （AMA）. The aim of this study was to evaluate the effectiveness of second trimester prenatal screening and amniocentesis for Down syndrome （DS） and compare the trends of choice of screening and amniocentesis among AMA women. Methods A total of 5404 AMA patients with natural singleton pregnancy were recruited for this prospective study from January 2008 to December 2010. The gestational weeks were from 15 weeks to 20~6 weeks. The patients referred were grouped into a screening group （2107 cases） and an amniocentesis group （3297 cases） by their own decision. The prevalence of DS was compared between the two groups by chi-square test. Choice rates for each maternal age with trends were compared by regression analysis. Results There were 18 cases of fetal DS detected in the screening group with a prevalence of 8.54%o （18/2107）. Twenty- five cases of fetal DS were diagnosed in the amniocentesis group with a prevalence of 7,58%0 （25/3297）. No statistical difference was observed in the prevalence of DS between the screening and amniocentesis group （P=0.928）. The invasive testing rate for DS in the amniocentesis group was 5.54 times higher than that of the screening group （1/131.88 vs. 1/23.78）. With the increase of the maternal age, the choice of amniocentesis increased while the choice of the screening showed an opposite trend. The choice of the AMA women between the screening and amniocentesis was significantly age relevant （P=0.012）. Conclusions The second trimester serum screening age alone to screen for DS. We suggest educating screening and amniocentesis options. in combination with maternal age was more effective than maternal the patients by recommending AMA women be informed of both展开更多
基金This study is supported by the offshore NGH production test projects under the Marine Geological Survey Program initiated by the China Geological Survey(DD20190226,DD20190218)the Major Program of National Natural Science Foundation of China(41730528,51991365)。
文摘Clayey silt reservoirs bearing natural gas hydrates(NGH)are considered to be the hydrate-bearing reservoirs that boast the highest reserves but tend to be the most difficult to exploit.They are proved to be exploitable by the first NGH production test conducted in the South China Sea in 2017.Based on the understanding of the first production test,the China Geological Survey determined the optimal target NGH reservoirs for production test and conducted a detailed assessment,numerical and experimental simulation,and onshore testing of the reservoirs.After that,it conducted the second offshore NGH production test in 1225 m deep Shenhu Area,South China Sea(also referred to as the second production test)from October 2019 to April 2020.During the second production test,a series of technical challenges of drilling horizontal wells in shallow soft strata in deep sea were met,including wellhead stability,directional drilling of a horizontal well,reservoir stimulation and sand control,and accurate depressurization.As a result,30 days of continuous gas production was achieved,with a cumulative gas production of 86.14×104 m3.Thus,the average daily gas production is 2.87×10^4 m^3,which is 5.57 times as much as that obtained in the first production test.Therefore,both the cumulative gas production and the daily gas production were highly improved compared to the first production test.As indicated by the monitoring results of the second production test,there was no anomaly in methane content in the seafloor,seawater,and atmosphere throughout the whole production test.This successful production test further indicates that safe and effective NGH exploitation is feasible in clayey silt NGH reservoirs.The industrialization of hydrates consists of five stages in general,namely theoretical research and simulation experiments,exploratory production test,experimental production test,productive production test,and commercial production.The second production test serves as an important step from the exploratory production test to exper
文摘胡庚申教授系生态翻译学创始人。原为清华大学二级教授,现为郑州大学生态翻译学研究院院长、外国语与国际关系学院特聘教授,博士生导师。兼任国际生态翻译学研究会(International Association for Eco-translatology Research)创始会长,亚太国际交流英语学会(Asia-Pacific Association for English of International Communication)理事长,海峡两岸暨港澳地区翻译与跨文化交流系列会议执委会主席,国际期刊《生态翻译学学刊》(Journal of Eco-translation Studies)主编,外语教学与研究出版社《国际交流英语系列教程》总主编,上海外语教育出版社《翻译与跨文化交流系列文集》总主编等。他分别于2008年和2018年主持生态翻译学方面的国家社科基金项目,在国内外学术期刊发表论文200余篇,出版各类著作38部。其中,2019年在世界著名的施普林格出版社(Springer)出版专著《生态翻译学:翻译研究的生态范式建构》(Eco-Trans-latology:Towards an Eco-Paradigm of Translation Studies),被学界誉为"开发本土学术资源的一面旗帜"。胡庚申教授在2013年出版的专著《生态翻译学:建构与诠释》中提出"三生"的概念。所谓"三生",即翻译生态、译本生命和译者生存,指的是以"生"为线索展开研究和论证阐述,表明"生"是生态翻译学发展之基石(1)。2016年,胡庚申在国际期刊发表文章指出,"生"是指翻译过程中文本的"生命"及其生存条件和生存状态(Life here refers to the life of the texts involved in translation process, the vital status and living conditions of the texts)(2)。在2018年"第六届国际生态翻译学研讨会"的主旨报告中,胡庚申又提出"生生之谓译",成为生态翻译学的新发展和新方向。2019年,胡庚申在研究论文中反复强调生态翻译学的"三生"主题和翻译文本的"生命"形态(3),并在"全国第三届生态翻译与认识翻译研讨会"的主旨报告中,进一步明确了"尚生—摄
基金supported by the National Science and Technology Major Project of China(2019ZX09732-001)the Key R&D Plan Projects in Shaanxi Province(2020ZDXM2-SF-01)Young Talent fund of the University Association for Science and Technology in Shaanxi,China(20200304).
文摘In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2,no specific and effective drugs for treating this disease have been reported until today.Angiotensin-converting enzyme 2(ACE2),a receptor of SARS-CoV-2,mediates the virus infection by binding to spike protein.Although ACE2 is expressed in the lung,kidney,and intestine,its expressing levels are rather low,especially in the lung.Considering the great infectivity of COVID-19,we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection.Here,we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein.The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody,Meplazumab,inhibits SARSCoV-2 amplification.Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells,which can be neutralized by CD147 extracellular fragment.Viral loads are detectable in the lungs of human CD147(hCD147)mice infected with SARS-CoV-2,but not in those of virus-infected wild type mice.Interestingly,virions are observed in lymphocytes of lung tissue from a COVID-19 patient.Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dosedependent manner,which is specifically inhibited by Meplazumab.Furthermore,CD147 mediates virus entering host cells by endocytosis.Together,our study reveals a novel virus entry route,CD147-spike protein,which provides an important target for developing specific and effective drug against COVID-19.
文摘Background Hand, foot, and mouth disease (HFMD) is a common infectious disease in childhood caused by an enterovirus (EV), and which is principally seen in children under 5 years of age. To promote diagnostic awareness and effective treat-ments, to further standardize and strengthen the clinical management and to reduce the mortality of HFMD, the guidelines for diagnosis and treatment have been developed. Methods National Health Commission of China assembled an expert committee for a revision of the guidelines. The com-mittee included 33 members who are specialized in diagnosis and treatment of HFMD. Results Early recognition of severe cases is utmost important in diagnosis and treatment of patients with HFMD. The key to diagnosis and treatment of severe cases lies in the timely and accurate recognition of stages 2 and 3 of HFMD, in order to stop progression to stage 4. Clinicians should particularly pay attention to those EV-A71 cases in children aged less than 3 years, and those with disease duration less than 3 days. The following indicators should alert the clinician of possible deterioration and impending critical disease: (1) persistent hyperthermia;(2) involvement of nervous system;(3) worsening respiratory rate and rhythm;(4) circulatory dysfunction;(5) elevated peripheral WBC count;(6) elevated blood glucose and (7) elevated blood lactic acid. For treatment, most mild cases can be treated as outpatients. Patients should be isolated to avoid cross-infection. Intense treatment modalities should be given for those severe cases. Conclusion The guidelines can provide systematic guidance on the diagnosis and management of HFMD.
文摘Chang'E-1 lunar Orbiter was launched by Long March 3A rocket from Xichang Satel-lite Launch Center at 18:05BT(Beijing Time) Oct.24,2007.It is the first step of its ambitious three-stage moon program,a new milestone in the Chinese space exploration history.The primary science objectives of Chang'E-1 lunar orbiter are to obtain three-Dimension(3D) stereo images of the lunar surface,to analyze the distribution and abundance of elements on the surface,to investigate the thickness of lunar soil,evaluate helium-3 resources and other characteristics,and to detect the space environment around the moon.To achieve the above four mission objectives,eight sets of scientific instruments are chosen as the payloads of the lunar orbiter,including a CCD stereo camera(CCD),a Sagnac-based interferometer spectrometer(ⅡM),a Laser Altimeter(LAM),a Microwave Radiometer(MRM),a Gamma-Ray Spectrometer(GRS),an X-ray spectrometer(XRS),a High-Energy Particle Detector(HPD),and two Solar Wind Ion Detectors(SWID).The detected data of the payloads show that all payloads work well.This paper introduces the status of payloads in the first phase and preliminary scientific results.
文摘目的基于既往冠状病毒的研究,探索利巴韦林用于新型冠状病毒肺炎治疗的有效性和安全性。方法计算机检索PubMed、Web of Science、Embase、EBSCO、中国期刊全文数据库、维普、万方等数据库,检索有关利巴韦林用于SARS、MERS治疗有效性和安全性的队列研究以及案例报道,检索时间范围为2003年1月到2020年1月30日。结果有效性研究结果显示部分SARS和MERS患者使用利巴韦林后,病情得到控制和改善,治愈率和临床治疗结局也较好;安全性研究结果显示利巴韦林不良反应发生率较高,主要为贫血和心律失常,同时也有其他不良反应的报告。结论利巴韦林用于COVID-19治疗可能有效性,但还需进一步的临床实验来证实,同时由于不良反应发生率较高,临床使用前应仔细综合评估各项指标,排除存在用药禁忌证的患者,并在治疗过程中密切监测。
基金Project supported by the Outstanding Young Scholar Fund and Innovative Research Group of the National Natural Science Foundation of China (No. 40325001, 40621001)the National Basic Research and Development Program of China (No. 2002CB410805) the Natural Science Foundation of Jiangsu Province (No. BK2005220).
文摘A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides （OCPs） were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX （DDD, DDE and DDT） had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p＇-（DDD＋DDE）/DDT in soils under three land usages were： paddy field 〉 tree land 〉 fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p＇-（DDD＋DDE）/DDT 〉1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.
文摘Background The incidence of autosomal trisomy in livebirths is strongly dependent on maternal age. Special consideration is given to the provision of prenatal screening and cytogenetic testing to women of advanced maternal age （AMA）. The aim of this study was to evaluate the effectiveness of second trimester prenatal screening and amniocentesis for Down syndrome （DS） and compare the trends of choice of screening and amniocentesis among AMA women. Methods A total of 5404 AMA patients with natural singleton pregnancy were recruited for this prospective study from January 2008 to December 2010. The gestational weeks were from 15 weeks to 20~6 weeks. The patients referred were grouped into a screening group （2107 cases） and an amniocentesis group （3297 cases） by their own decision. The prevalence of DS was compared between the two groups by chi-square test. Choice rates for each maternal age with trends were compared by regression analysis. Results There were 18 cases of fetal DS detected in the screening group with a prevalence of 8.54%o （18/2107）. Twenty- five cases of fetal DS were diagnosed in the amniocentesis group with a prevalence of 7,58%0 （25/3297）. No statistical difference was observed in the prevalence of DS between the screening and amniocentesis group （P=0.928）. The invasive testing rate for DS in the amniocentesis group was 5.54 times higher than that of the screening group （1/131.88 vs. 1/23.78）. With the increase of the maternal age, the choice of amniocentesis increased while the choice of the screening showed an opposite trend. The choice of the AMA women between the screening and amniocentesis was significantly age relevant （P=0.012）. Conclusions The second trimester serum screening age alone to screen for DS. We suggest educating screening and amniocentesis options. in combination with maternal age was more effective than maternal the patients by recommending AMA women be informed of both
