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1株产绿原酸菌株的诱变选育及发酵条件优化
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作者 司海燕 朱平川 +2 位作者 唐洁 朱文虎 樊宪伟 《饲料研究》 CAS 北大核心 2023年第14期67-73,共7页
试验旨在利用随机诱变技术选育出高产绿原酸(CGA)菌株,并通过优化发酵条件进一步提高CGA的产量。以烟草肠杆菌(Enterobacter tabaci)N22为试验菌株,利用常压室温等离子体(ARTP)和紫外复合诱变获得高产CGA的菌株,通过单因素与响应面结合... 试验旨在利用随机诱变技术选育出高产绿原酸(CGA)菌株,并通过优化发酵条件进一步提高CGA的产量。以烟草肠杆菌(Enterobacter tabaci)N22为试验菌株,利用常压室温等离子体(ARTP)和紫外复合诱变获得高产CGA的菌株,通过单因素与响应面结合的方法对发酵条件进行优化。结果显示,经ARTP和紫外复合诱变处理获得了一株遗传稳定、CGA产量高的菌株AU-34,产量为4.7mg/L,为野生型菌株的2.8倍。最优培养基成分为玉米浆124g/L、果糖31.06 g/L、MnSO_(4)0.1g/L、L-Tyr1g/L、VB_(1)3mg/L、CaCO_(3)3g/L、Tween-800.05%,此条件下CGA产量达102.55mg/L,约为未优化前的22倍。研究表明,试验结果为工业化发酵生产CGA提供了潜在的菌种资源。 展开更多
关键词 烟草肠杆菌 绿原酸 诱变 响应面优化
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县域医疗卫生资源:评估、功能定位及优化路径 被引量:9
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作者 王哲 范宪伟 +1 位作者 关博 顾严 《中国卫生政策研究》 CSCD 北大核心 2021年第9期62-68,共7页
目的:基于对当前县域医疗卫生资源现状评估,研究当前和未来时期我国县域医疗卫生资源优化路径和对策。方法:采用统计年鉴和研究报告数据进行描述性统计和文献梳理。结果:近年来我国县域医疗卫生资源日益丰富,但资源布局不均衡、服务能... 目的:基于对当前县域医疗卫生资源现状评估,研究当前和未来时期我国县域医疗卫生资源优化路径和对策。方法:采用统计年鉴和研究报告数据进行描述性统计和文献梳理。结果:近年来我国县域医疗卫生资源日益丰富,但资源布局不均衡、服务能力不高和体制机制不灵活等问题仍广泛存在。结论:当前和未来一段时期,应逐步摒弃"追大求全"惯性思维,根据县域人口规模、行政区划、地理区位、交通通达性等特点,差异化确定县域、县本级和县以下卫生功能定位和不同类型县域卫生资源发展重点,更好服务县域群众卫生健康需求。 展开更多
关键词 卫生资源 县域 资源评估 功能定位
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完全性右束支传导阻滞与右心房增大的相关性研究 被引量:2
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作者 张付涛 赵丹清 +9 位作者 刘晓洁 吴金涛 张雷明 胡娟 范宪伟 杨海涛 严丽洁 刘静静 张智文 王山岭 《中国心血管病研究》 CAS 2022年第8期711-714,共4页
目的探讨完全性右束支传导阻滞(complete right bundle branch block,CRBBB)与右心房增大的相关性。方法回顾分析2018年3月1日至3月31日我院住院诊疗的2394例患者的心电图记录,CRBBB定义为心电图QRS波持续时间≥120 ms,I、V_(6)导联S波... 目的探讨完全性右束支传导阻滞(complete right bundle branch block,CRBBB)与右心房增大的相关性。方法回顾分析2018年3月1日至3月31日我院住院诊疗的2394例患者的心电图记录,CRBBB定义为心电图QRS波持续时间≥120 ms,I、V_(6)导联S波时限>R波时限,V_(1)和(或)V_(2)导联QRS波群呈RsR’,R’>R。比较CRBBB与非CRBBB患者的临床资料,并采用单因素及多因素logistic回归分析,评估CRBBB的相关危险因素。结果CRBBB患病率为1.5%(37/2394)。与无CRBBB患者相比,CRBBB患者的年龄及左、右心房直径更大,心房颤动及瓣膜病的发病率更高。多因素logistic回归分析显示,右心房增大(OR=10.537,95%CI 5.332~20.821,P<0.001),年龄(OR=1.031,95%CI 1.005~1.058;P=0.019)、心房颤动(OR=3.251;95%CI 1.402~7.541;P=0.006)是CRBBB存在的独立相关因素。结论在本研究人群中,CRBBB与右心房增大存在相关性。 展开更多
关键词 完全性右束支传导阻滞 右心房增大 QRS波持续时间
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Foci of Future Studies on Abiotic Stress Tolerance of Maize in the Era of Post-Genomics 被引量:1
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作者 LI You-zhi fan xian-wei LIAO Jiang-xiong 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第8期1236-1244,共9页
Genetic and metabolic engineering approaches are powerful tools for improving the tolerance of maize to abiotic stresses because they are faster and can afford greater control over agronomically useful traits. However... Genetic and metabolic engineering approaches are powerful tools for improving the tolerance of maize to abiotic stresses because they are faster and can afford greater control over agronomically useful traits. However, in-depth understanding of the molecular mechanisms controlling response to abiotic stresses is the prerequisite for successful implementation of these strategies. A great flaw to dissect the biological mechanisms by genome sequencing is that genome sequencing approach could not reflect real-time molecular actions of plants especially under the stresses because the living organisms rarely live in unchanging environments. Post-genomics such as transcriptomics, metabolomics, and proteomics can generate knowledge that is closer to the biological processes. With the development of post-genomics, it can be expected that voluminous data will be generated. This paper proposes that future research on maize stress tolerance in the era of post-genomics should focus on metabolomics and proteomics; stress tolerance of whole plant rather than individual tissues or organs; coordination of expression of genes among tissues; characterization of promoters of stress-responsive genes; interrelation between mechanisms for tolerance to, and growth recovery from the stress; hexose metabolism as well as the glycolysis pathway; and foundation genotypes. 展开更多
关键词 MAIZE abiotic stresses research foci era of post-genomics
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Characterization of the Promoter of a Homolog of Maize MADS-Box Gene m18
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作者 QIN Hui-juan PAN Hong +2 位作者 fan xian-wei WU Qiao LI You-zhi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第11期2330-2345,共16页
Maize (Zea mays L.) is one of the world’s major food crops, and often suffers from tremendous yield loss caused by abiotic stresses. The MADS-box genes are known to play versatile roles in plants, controlling plant... Maize (Zea mays L.) is one of the world’s major food crops, and often suffers from tremendous yield loss caused by abiotic stresses. The MADS-box genes are known to play versatile roles in plants, controlling plant responses to multiple abiotic stresses. However, understanding of regulation of their expressions by the conventional loss-of-function approach is very dififcult. So far, regulation of MADS-box gene expression is little known. The best approach to retrieve expression regulation of this category of genes is to characterize expression of their promoters. In this study, the promoter of a homolog (GenBank accession no. EC864166) of maize MADS-box gene m18 was cloned by way of genome-walking PCR, named Pro66. Predicative analysis indicated that Pro66 contains more than one TATA box and multiple cis-acting environmental conditions-responsive elements (ECREs). Pro66 could drive expression of theβ-glucuronidase (GUS)-encoding gene in maize, and heterologous expression of GUS in red pepper stressed by water deifcit, salt, copper, iron deifciency, heat, cold, and grown under short and long photoperiods, echoing predicative ECREs. Conclusively, maize MADS-box gene m18 likely plays versatile functions in maize response to multiple abiotic stresses due to the promoter with multiple cis-acting elements. The complex arrangement of multiple cis-acting elements in the promoter features meticulously regulated expression of m18. The results give informative clues for heterologous utilisation of the promoters in monocot and dicot species. The copy of the ECREs and heterologous expression of the promoter in dicot species are also discussed. 展开更多
关键词 MAIZE MADS-box gene PROMOTER STRESS TRANSCRIPTION
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预激综合征合并阵发性心房颤动患者旁路射频消融术后心房颤动再发的危险因素分析 被引量:9
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作者 吴金涛 赵丹清 +9 位作者 张付涛 张雷明 胡娟 吴蕊 范宪伟 胡光玲 杨海涛 严丽洁 刘静静 王山岭 《中华实用诊断与治疗杂志》 2021年第7期696-699,共4页
目的观察预激综合征合并阵发性心房颤动(atrial fibrillation, AF)患者旁路射频消融术后再发AF情况,探讨AF再发的危险因素。方法 67例预激综合征合并阵发性AF患者,均行旁路射频消融术治疗。随访3-36(31.6±10.0)个月,11例再发AF者... 目的观察预激综合征合并阵发性心房颤动(atrial fibrillation, AF)患者旁路射频消融术后再发AF情况,探讨AF再发的危险因素。方法 67例预激综合征合并阵发性AF患者,均行旁路射频消融术治疗。随访3-36(31.6±10.0)个月,11例再发AF者为再发AF组,56例未再发AF者为未再发AF组,比较2组年龄、性别、CHA_(2)DS_(2)-VASc评分及房间传导阻滞(interatrial block, IAB)比率等临床资料。将67例患者根据术后是否存在IAB分为IAB组及无IAB组,根据年龄分为>50岁组及≤50岁组,采用Kaplan-Meier法分析有无IAB及不同年龄组旁路射频消融术后AF再发率。多因素Cox回归分析预激综合征合并阵发性AF患者旁路射频消融术后AF再发的危险因素。结果再发AF组年龄>50岁(90.9%)、IAB(81.8%)、合并冠心病(27.3%)比率及CHA_(2)DS_(2)-VASc评分[2.0(1.0,3.0)分]均高于未再发AF组[39.3%、7.1%、1.8%、0.0(0.0±1.0)分](P<0.05),男性及合并糖尿病、高血压比率,左心房直径,左室射血分数,旁路前传有效不应期,旁路存在逆向传导、单旁路及多旁路预激综合征比率与未再发AF组比较差异均无统计学意义(P>0.05)。IAB组旁路消融术后AF再发率(69.2%)高于无IAB组(3.7%)(P<0.05),年龄>50岁组旁路消融术后AF再发率(31.3%)高于年龄≤50岁组(2.9%)(P<0.05)。多因素Cox回归分析结果显示,IAB(HR=29.03,95%CI:5.26-160.23,P<0.001)、年龄>50岁(HR=16.68,95%CI:1.61-172.82,P=0.018)是预激综合征合并阵发性AF患者旁路射频消融术后AF再发的危险因素。结论 IAB及年龄>50岁是预激综合征合并阵发性AF患者行旁路射频消融术后AF再发的危险因素。 展开更多
关键词 预激综合征 心房颤动 旁路射频消融术 心房间传导阻滞 年龄 危险因素
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