首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   57篇
  免费   7篇
  国内免费   3篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   1篇
  2016年   3篇
  2015年   2篇
  2014年   4篇
  2013年   1篇
  2012年   5篇
  2011年   1篇
  2010年   4篇
  2009年   4篇
  2008年   5篇
  2007年   2篇
  2006年   1篇
  2005年   2篇
  2004年   1篇
  2003年   2篇
  2002年   2篇
  2001年   3篇
  1999年   1篇
  1997年   1篇
  1996年   3篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1989年   2篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1978年   2篇
排序方式: 共有67条查询结果,搜索用时 15 毫秒
1.
微血管密度异常、血管生长因子(VEGF、PDGF等)及其受体表达异常通过一系列级联反应导致血管异常生长的结果。众多因子均和血管形成有关,在妊娠过程中对胎盘的血管发育有着重要的作用,导致滋养细胞的表型转换障碍、血管结构发育不良、血管生成受阻、血管数目减少,引起胎盘血管重铸障碍,胎儿胎盘单位灌注不足发生流产。研究表明许多自然流产的发生与胎盘组织中血管增生平衡和胎儿血液供应不足有密切关系,从而认为血管生长异常是导致流产的又一重要因素。随着研究的深入进展血管的异常生长与流产的关系是有确定关系的,对于血管生长异常所致的流产,抑制血管各种血管因子的形成、阻止其与受体结合,从而抑制血管的异常生长最终达到克服流产的发展,无异于把幸福带给更多的家庭,不仅是妇产科发展的里程碑,更是人类医学发展史上光辉的一笔。  相似文献   
2.
血立停胶囊对早孕大鼠RU486药流后子宫收缩的实验研究   总被引:1,自引:0,他引:1  
目的:研究血立停胶囊对早孕大鼠Ru486药物流产后对子宫平滑肌收缩频率、收缩幅度及活动力变化的影响,旨在探讨血立停胶囊治疗药物流产后出血的作用机制。方法:选择妊娠Wistar大鼠,随机分为6组,即对照组,米非司酮组,大剂量血立停组,小剂量血立停组,催产素组,止血敏组。于妊娠第7天,开始相应处理,妊娠第14天分别监测以下指标后处死:在体子宫平滑肌收缩力,收缩幅度、收缩频率。结果:大剂量血立停可明显增强大鼠在体子宫平滑肌活动力、提高子宫平滑肌收缩频率、收缩幅度,与对照组比较差异有显著性(p<0.05)。结论:血立停胶囊可增强大鼠子宫平滑肌兴奋性,从而起到对药物流产后阴道出血的治疗作用。  相似文献   
3.
目的:探讨复发性自然流产患者外周血中Th17、Treg细胞以及相关细胞因子的变化。方法:选择复发性自然流产患者25例,正常妊娠妇女25例以及正常非妊娠育龄妇女25例,流式细胞术测定外周血中Th17和Treg细胞数量,ELISA法测定血清IL-10、TGF-β及IL-17的浓度。结果:复发性自然流产患者外周血中Th17细胞百分率显著高于正常妊娠以及正常非孕妇女(P0.05),Treg细胞百分率显著低于正常非孕妇女(P0.05),但与正常妊娠妇女相比无显著性差异(P0.05);复发性自然流产患者外周血IL-10及TGF-β水平显著低于正常妊娠妇女以及正常非孕妇女(P0.05),而IL-17水平显著高于正常妊娠妇女以及正常非孕妇女(P0.05)。结论:外周血Th17细胞数和IL-17水平的升高以及抑制性细胞因子IL-10和TGF-β水平的下降可能是复发性自然流产发生的重要原因。  相似文献   
4.
目的:探讨定坤丹联合益母草冲剂治疗孕妇流产后月经失调的临床效果。方法:选取2016年1月-2016年12月我院接受药物流产终止妊娠的妇女120例为研究对象,根据数字随机表法将其随机分为研究组和对照组,每组60例。研究组在妊娠囊排出宫腔后开始服益母草冲剂,1包/次,3次/日,服用2周后加服定坤丹,1丸/次,2次/日,持续服用到月经恢复正常。对照组在同一时间段期间服用益母草冲剂。对比两组患者腹痛消失时间和月经恢复正常时间、恢复正常月经后月经周期、月经量以及治疗有效率。结果:对照组和研究组腹痛消失时间分别为7.62±1.33 d、3.17±0.76 d,月经恢复正常时间分别为69.62±8.45 d、43.21±6.65 d,研究组均显著短于对照组(P0.05)。患者月经恢复后,对照组中有42例正常,研究组有54例正常,研究组月经周期时间正常率显著高于对照组(P0.05)。对照组中月经量有45例正常,研究组中月经量有54例正常,两组月经量比较,研究组月经量正常率显著高于对照组(P0.05)。对照组中痊愈39例,研究组中痊愈51例,研究组治疗有效率显著高于对照组(P0.05)。结论:定坤丹联合益母草冲剂治疗孕妇流产后月经失调临床疗效明显优于单用益母草冲剂治疗。  相似文献   
5.
In Sri Lanka, termination of pregnancy, other than in extreme circumstances, is strictly illegal. Among the public and large sections of the medical community there is widespread support for some degree of liberalization of the law, particularly where this relates to serious genetic conditions which can be identified prenatally. Tension emerges out of a publicly maintained conservatism on issues of abortion on the one hand and a growing disconnection from unregulated practices of termination in the private sector on the other. Social science approaches have much to contribute when understanding the ‘therapeutic gap’ that opens up and, in particular, the way that local ideas of fate, destiny and how suffering might be ameliorated become blended with the predictive power of genetic testing.  相似文献   
6.
Water buffalo (Bubalus bubalis) are affected by high rates of embryonic mortality and abortion related to infectious diseases and non-infectious factors. A number of viral and bacterial infections have been associated with reproductive failure, but there is limited information on the role of chlamydial infections.

In order to investigate the presence and the role of Chlamydiaceae in water buffalo a retrospective study was performed in a herd with a history of reproductive failure. During an 11-month period, the pregnant heifers suffered an abortion rate of 36.8% between the 3rd and 7th month of pregnancy. Antibodies to Chlamydiaceae were detected in 57% of the aborted cows, and in 0% of the overtly healthy cows used as control. By a nested-PCR assay, three of 14 vaginal swabs from aborted animals tested positive for Chlamydophila agents and, additionally, three out of seven aborted fetuses tested positive for Chlamydophila spp., with two being co-infections by Cp. abortus and Cp. pecorum and one being characterised as Cp. abortus. Sequence analysis of the amplicons confirmed the results of the nested-PCR. The presence of anti-Chlamydiaceae antibodies in more than half of the aborting animals (P < 0.002) and the detection of Chlamydophila agents in several fetal organs and in the vaginal swabs are consistent with the history of abortions observed in the herd and suggest an abortifacient role by Chlamydophila spp. in water buffalo (B. Bubalis) herds.  相似文献   

7.
The proband was a 22-year-old woman who had two spontaneous abortions in the first trimester of pregnancy. She had a consanguineous marriage with no history of malformation or developmental disorders in the family. Her gynecological examination was normal. Chromosome analysis of the family showed two different katyotypes 46,XY,t(1;16)(p22;p13) and 46,XX,t(1;16)(q24;q24) using high-resolution banding (HRB). Proband's family was also examined for chromosome analysis. A t(1;16)(p22;p13) was found in the husband's father and other relatives, and a t(1;16)(q24;q24) translocation in the proband's family. This second tanslocation is not found in her parents.  相似文献   
8.
Changes in unit structures and infanticide observed in Arsi geladas   总被引:1,自引:0,他引:1  
In 1989 a new gelada baboon (Theropithecus gelada) population was found in Arsi, on the opposite side of the Rift Valley to that of the known gelada populations of Semien and Showa. Previous comparisons of units of the band at Gado Goro, Arsi, in the same season in consecutive years, indicated that unit structure is less stable among Arsi geladas as compared to the Semien population. Gelada units of the band at Gado-Goro were studied for 7 months in order to investigate the processes of social changes. Changes in unit structure were observed. Provisioning was carried out for 1.5 months at the beginning of the 7-month study period, in order to capture and obtain blood samples from the geladas. Following this, changes in male leadership of some units were observed, presumably as a consequence of the capture. However, natural changes also occurred. One change in unit structure occurred after a female gave birth, and changes in another unit occurred after the disappearance of the leader male. These changes involved female desertion of a unit, her subsequent transfer to a male unit, and culminated in the formation of a unit consisting of one female and one male. One successful and one attempted case of unification of units, and one case of change of a unit leader male are reported. These changes occurred among eight resident units in a period of 7 months (196 female months). Though the types of social changes were not much different from previous observations in Semien National Park, their frequencies seemed to be much higher. The characteristics of Arsi gelada social changes are proposed to be related to the small size of the units. We also describe a new confirmed case and one suspected case of infanticide, as well as one case of abortion at the time of male leader change.  相似文献   
9.
The parasite Neospora caninum is an important cause of abortion in cattle world-wide. Chronically infected dams transmit the parasite transplacentally and infected foetuses may be aborted or born chronically infected but clinically normal. Chronically infected cows repeatedly transmit the parasite to foetuses in several pregnancies and some may abort more than once suggesting that the immune response in these cattle is compromised during pregnancy. To investigate the nature of the immune response in chronically infected cattle, five naturally, chronically infected cows were challenged with N. caninum tachyzoites at 10 weeks of gestation. No foetopathy occurred and all five delivered live calves at full-term. In four naive pregnant cows challenged at the same time, all four foetuses died within 3-5 weeks of challenge. Of the five live calves born to the chronically infected challenged cows, three were transplacentally infected with N. caninum. The kinetics of the maternal anti-N. caninum antibody responses during gestation suggested that these transplacental infections were not the result of the superimposed challenge, but the result of the recrudescence of the maternal chronic infection-which occurred concurrently in non-challenged, chronically infected pregnant controls. These data provide the first experimental evidence that protective immunity occurs in neosporosis. They also suggest that whilst immunity to a pre-existing infection will protect against an exogenous challenge, this protective immunity will not prevent transplacental infection. This implies that a subtle form of concomitant immunity exists in chronically infected cattle and has important implications for vaccine development.  相似文献   
10.
Plants of white clover ( Trifolium repens L.) cv. Olwen were grown in an open glasshouse maintained at a mean temperature of 20oC and ovule growth and seed production measured. Differences in the rate of growth of ovules within ovaries were observed as early as 2 days after pollination. Ovules reached a maximum size after 8 days with the smallest only half the size of the largest. After 8 days, the smallest ovules became flaccid and shrivelled. Ovule position within the ovary had little effect on the frequency of seed set and although there was an apparently higher probability that central ovules produced a seed than those nearer the peduncle or style this was not statistically significant. Inflorescence position and floret position on the inflorescence had a significant effect on the number of seeds per floret and seed weight; the first formed inflorescences and the first florets to be pollinated on each inflorescence had more seeds per floret and heavier seeds and fewer florets with no seed than later pollinated florets. There were also differences between florets within the same whorl. The role of a number of factors which may influence floret site utilisation are discussed.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号