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1.
目的:通过比较出现胎儿窘迫的孕妇胎盘与正常孕妇胎盘的缺氧诱导因子表达及胎盘的绒毛血管变化情况,探讨胎儿窘迫中胎盘变化及其对胎儿的影响.方法:选取产科门诊定期产检并在产科住院分娩的单胎足月孕妇,临床诊断为胎儿窘迫的孕妇所分娩后的胎盘组织60例作为实验组,再按临床情况分为胎心异常组、羊水污染组、窒息组.选取正常单胎足月妊娠孕妇55例作为对照组.对比两组胎盘中HIF-1α表达水平,胎盘绒毛血管情况及新生儿预后.结果:HIF-1α在实验组与对照组两者的光密度对照有统计学差别,新生儿窒息组的光密度值较高;显微镜下实验组中绒毛血管数目及绒毛体积密度皆较对照组明显增加,实验组中各分组的值较对照组均升高.结论:胎儿窘迫孕妇的胎盘组织HIF-1α因子表达、胎盘绒毛微血管体积密度及绒毛体积密度皆高于未出现胎儿窘迫的孕妇.在排除妊娠合并症及并发症等病理情况下,产时胎儿窘迫的发生与胎盘自身HIF-1α因子表达及胎盘绒毛血管改变有关.  相似文献   

2.
妊娠40周后伴胎儿过熟综合征胎盘超微结构电镜观察   总被引:3,自引:0,他引:3  
目的:从形态学角度研究足月妊娠后出现胎儿过熟综合征的病因,为提高对过期妊娠临床管理质量提供依据。方法:应用透射电镜对12例足月妊娠后伴胎儿过熟综合征胎盘进行观察。结果:过熟综合征胎盘线粒体等细胞器出现缺氧、老化等形态学改变,观察到细胞基底部细胞突起的形态退变过程及合胞体细胞微绒毛形成的特殊结构。结论:胎儿过熟综合征的直接病因是由于胎盘老化、缺氧,使细胞失去正常形态结构和功能,甚至胎盘功能失代偿。提示临床应在妊娠足月后严密监测胎盘功能并及时发现,及时终止妊娠以预防胎儿过熟综合征的发生。  相似文献   

3.
米非司酮对人中期妊娠胎盘超微结构的影响   总被引:5,自引:0,他引:5  
目的:研究米非司酮对人中期妊娠胎盘超微结构的影响。方法:运用电子显微镜对8例17-19孕水囊引产的孕妇引产前6h空腹服用米非司酮150mg,胎盘出后进行超微结构的研究,并与同期17-19孕周水囊引产胎盘标本8例对照。结果:与对照组相比,米非司酮组功能活跃的合体滋养细胞表现没程度的退行性变,细胞滋养细胞变化不明显,绒毛间质毛细管部分内皮细胞变性,结论:米非司酮对中期妊娠胎盘组织具有损伤作用,提示米非  相似文献   

4.
用AOT/异辛烷反胶团系统萃取了添加不同浓度镁离子的猪心提取液中的细胞包素C.其结果为:添加0.025mol/LMg2+的萃取率E.R,(ExtractRatio)为96.5%(氧化型和还原型平均值).添加0.3mol/LMg2+的萃取率为28.3%。萃取后水相的吸收光谱中,还原型细胞色素C在520nm、550nm的吸收峰值消失。120nm的吸收峰值显著降低。萃取有机相的吸收光谱中,还原型细胞包素C在420nm、520nm和550nm处的特征吸收峰值显著。经反萃取后水相的吸收光谱与提取液以及萃取有机相的吸收光谱相同。说明添WMg2+后,经AOT/异辛烷萃取和反萃取过程能将细胞包素C从猪心提取液中萃取分离出来。  相似文献   

5.
绒毛白蜡营养器官中Na^+、K^+、Cl^-的分布   总被引:2,自引:0,他引:2  
为研究白蜡的抗盐生理机制,对盐渍生境下1—3年生绒毛白蜡(F.velutina)不同营养器官中盐离子的分布进行了分析。研究结果显示,不同器官中Na^+、K^+和Cl^-含量存在显著差异。根系,Na^+、K^+含量最高,Na^+平均达0.72%,K^+平均达13.95%;叶片,Cl^-含量最高,平均达1.04%;Na^+、Cl^-含量均随树龄的增大而减少,K^+含量随树龄的增大而增加。结果表明绒毛白蜡的高耐盐特性受营养器官中盐离子分布规律支持,并且绒毛白蜡能够随着树龄增长,逐步适应盐渍生境,耐盐能力逐步提高。  相似文献   

6.
文章用坐标平移与旋转方法,获得了曲线方程(a1x+b1y+c1)(a2x+b2y+c2)=1(a1^2+b1^2)(a2^2+b2^2)≠0 (1)在xoy平面上的完全定量几何特征.由其特征,我们可以方便地给出它们的具体方程表示的曲线的重要参数.  相似文献   

7.
人类白细胞抗原-G(HLA-G)主要表达于胎盘组织中,在维持母胎界面的免疫耐受过程中发挥着关键作用。为研究HLA-G在正常胎盘形成过程中的表达模式,实验检测了妊娠不同阶段的胎盘绒毛组织中HLA-G蛋白的表达水平。实验结果显示HLA-G蛋白在孕6周与7周的绒毛中表达量最高,从孕8周开始,表达量逐渐下降,至足月时,表达量达到最低水平。由此推测HLA-G在妊娠早、中期与胎盘形成有关,在妊娠晚期可能参与妊娠维持。  相似文献   

8.
在玉米一叶一心期,分别用自来水、2%NaCl、2%NaCl+20mg·L(-1)的S—3307、2%NaCl+30mg·L(-1)的S—3307进行处理,定期观察其形态变化并测定生理指标,结果表明,在盐胁迫条件下用S-3307处理后,其耐盐性有所提高.具体表现为:含水量提高,脯氨酸、丙二醛积累减少,膜透性变小,叶绿素含量增加,渗透压、呼吸强度及形态上均呈规律性变化.  相似文献   

9.
大豆根系分泌物对根际土壤铝形态的影响   总被引:2,自引:0,他引:2  
对19个大豆(Glycine max)品种进行了筛选试验,选择耐铝性不同的2个大豆品种(铝耐性品种:浙春2号和敏感品种:浙春3号)作为实验材料,设置5个铝处理水平和3个平行组(根际、非根际和外源根系分泌物组),测定了大豆根系分泌物中柠檬酸的含量;在处理30d后用浸提法提取3种类型土样中的各种形态的铝并测定其含量,同时检测了相应土样的pH值变化.实验结果显示,铝胁迫下,耐铝品种浙春2号根系分泌大量的柠檬酸,比铝敏感品种浙春3号显著;随着铝处理量的增加,浙春2号根际土壤相对于非根际土壤而言,Al^3+、(AIOH)^2+、Al(OH)^2+等形态铝的含量均有所降低,单聚体羟基铝((Al0H)^2+、Al(OH)^2+)含量的降低尤为显著,而腐殖酸铝(HA-Al)的含量有所升高;外源根系分泌物组的实验结果和根际土壤组相似,显示出耐铝性大豆根系分泌物具有一定的铝毒缓解效应.实验结果还表明,根系分泌物对根系土壤具有一定的酸化作用,而铝的形态与pH值有直接的关系,所以根系分泌物对铝形态存在一定的间接影响.  相似文献   

10.
本文通过对348例过期妊娠的孕产妇进行分析,结合B超测量羊水量、查验孕妇尿的E/C比值等手段.以监测胎儿宫内安危并观察胎儿预后.分析表明:过期妊娠与围产儿的死亡率有密切关系、过期妊娠合并羊水减少对围产儿预后有非常显著的影响.本文还对羊水量与胎盘功能、羊水减少与分娩方式及围产儿死亡的关系进行了分析、并在此基础上得出厂羊水量是观察胎儿预后的重要指标;且羊水量多少与胎盘功能之间关系甚为密切的结沦.同时也提出了过期妊娠及羊水减小的临床处理措施.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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