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目的研究足月妊娠分娩发动前后外周血和胎盘局部人类白细胞抗原G1(HLA-G1)变化并探讨其在分娩发动中的作用。方法应用ELLISA方法检测孕晚期未临产组(剖宫产组)和临产组外周血中人类白细胞抗原G1(sHLA-G1)浓度,并通过RT-PCR法比较两组胎盘组织中HLA-G1mRNA水平。结果与未临产组相比,临产组血浆中sHLA-G1表达强度明显下降,差异有统计学意义(P<0.01),临产组胎盘局部中HLA-G1 mRNA数量也明显低于孕晚期未临产组(P<0.01)。结论分娩发动时胎盘合成和分泌HLA-G1减少导致局部和外周血中sHLA-G1下降,可能激活多种免疫细胞并调节免疫细胞分泌细胞因子,导致循环及胎盘局部各种炎性细胞因子释放增加,使母胎界面细胞因子分泌增加,从而参加了分娩。 相似文献
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S. Giosuè G. Spada V. Rossi G. Carli I. Ponti 《European journal of plant pathology / European Foundation for Plant Pathology》2000,106(6):563-571
An Israeli model forecasting leaf curl disease on peaches caused by Taphrina deformans was validated in the Emilia-Romagna region of northern Italy, during a three-year period (1996–1998), in 13 cases (year × location × cultivar). When the peach trees are susceptible to infection, the model uses mathematical functions to calculate the risk of infection on the basis of weather conditions (daily rainfall greater than 10mm, and maximum air temperature greater than 5°C), and it forecasts periods of possible symptom appearance based on the length of incubation. Peach trees became susceptible to infection between the end of January and mid March, when the first leaf buds attained phenological stage C, i.e. appearance of leaf apex. The trees remained susceptible for at least 9 weeks: the last infection occurred in mid-May.Since most of the leaf curl onsets observed in the orchards fell within the range of model forecasts, the model proved to be accurate in signalling both the first seasonal infection and repeated infections during the primary inoculum season. Few errors occurred, caused either by conditions of rainfall and temperature lower than the thresholds fixed in the model, or by discrepancies between forecast and actual length of incubation. Infection occurred also at 3.1–3.5°C, and with 9.6mm rainfall. Thus, thresholds should not be accepted too rigorously, and perhaps temperature should not be considered as a limiting factor for infection under the conditions of the present work. The length of incubation showed high variability: it was 23 days long on average, with a 95% confidence interval ranging from 20 to 27 days, and extreme values of 9 and 33 days. 相似文献
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本实验室前期构建了腺病毒/甲病毒复制子嵌合载体猪瘟疫苗rAdV-SFV-E2,其免疫效力与商品化猪瘟C株疫苗相同,并具有鉴别检测特性.为进一步确定该嵌合载体猪瘟疫苗最早提供完全攻毒保护的时间,本研究将rAdV-SFV-E2免疫健康仔猪(n=5),免疫后于不同时间点采用猪瘟病毒(CSFV)强毒石门株进行攻毒,并检测其抗体应答、临床症状、病毒血症、病理学及组织病理学变化等.结果显示,rAdV-SFV-E2免疫后1周和2周,分别能对致死性CSFV强毒的攻击提供部分保护(3/5存活)和不完全保护(全部存活,但出现了短暂的发热和低水平的病毒血症);免疫后3周和4周,能够完全抵抗致死性CSFV强毒的攻击,表现为无病毒血症,无临床症状,无病理变化和组织病理学变化.该研究进一步证实rAdV-SFV-E2能够作为一种新型猪瘟标记疫苗,在猪瘟的紧急防控中能够起到一定的作用. 相似文献
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动物性成熟启动是一个复杂的生物学过程,其决定性事件是下丘脑GnRH脉冲式释放增加。GnRH脉冲式释放增加是由跨突触改变和神经胶质输入两个方面共同引起的,其中,跨突触改变由谷氨酸能神经元、Kisspeptin神经元、γ 氨基丁酸能神经元、阿片能神经元及RFRP神经元提供,而神经胶质输入主要由生长因子家族提供。诸多功能基因参与了性成熟启动过程,组成了复杂的基因调控网络,这些基因并不是按照严格的等级顺序排列,而是在功能上有所重叠。转录调节因子的抑制性作用使得性成熟启动不会提早发生。论文还介绍了表观机制在性成熟启动调控中的重要作用。 相似文献
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L. Yang C. Mo A. A. Adetula A. A. Elokil A. Akbar Bhuiyan T. Huang 《British poultry science》2020,61(2):195-199
ABSTRACT1. Measures of the bilateral apex pubis (BAP) in White Leghorn (WLH) hens aged from 16 to 64 weeks (from the time ovaries were completely undeveloped to senility) were ranked into various groups so the relationship between external traits (BAP distance, comb length, comb height, wattle length, wattle height, body weight) and internal traits (largest ovarian follicle diameter (LFD) and oviduct weight and length) could be determined.2. Using correlation and regression analysis with data from 16 weeks of age to the onset of lay, measurements of the apex pubis showed a strong correlation with LFD (r = 0.80, P < 0.01) and oviduct weight (r = 0.80, P < 0.01).3. Multiple comparisons among WLH hens from 16 to 43 weeks of age showed that the BAP distance increased in all groups ranked by LFD or by laying period.4. In the late laying period (>60 weeks of age), BAP distance showed a significant decrease (P < 0.01) in long-term non-laying hens compared to laying hens.5. These findings suggest BAP distance can serve as an index for evaluating the onset and probable stages of follicular development during sexual maturation and/or aid in the identification and selection of non-laying hens during reproduction. 相似文献
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目的 观察利用负重状态下离心收缩的方式是否诱导人体肱二头肌延迟性肌肉酸痛症（DOMS）模型。方法 实验对象从在校大学生中招募志愿者60名,随机分为造模组和对照组,两组各30例;造模组做负重状态下离心收缩运动两组,每组25个,每个动作操作时间20秒,对照组不做任何处理,通过观察志愿者的血清磷酸肌酸激酶（CK）、主观酸痛阈、主观体力等级评定量表（RPE）、DOMS临床评价（CEC）等级来评价模型是否成功。结果 造模组与对照组比较,试验后24 h和48 h主观酸痛阈低于对照组,试验后72 h CK高于对照组,试验后即刻、24 h、48 h、72 h RPE明显高于对照组,试验后即刻、24 h、48 h、72 h、120 h CEC高于对照组,差异均有统计学意义（P<0.05）。造模组试验后与试验前比较,试验后24 h、48 h和72 h主观酸痛阈明显低于试验前,试验后48 h、72 h和120 h CK高于试验前,试验后即刻、24 h、48 h、72 h RPE明显高于试验前,试验后即刻、24 h、48 h、72 h、120 h CEC高于试验前,差异均有统计学意义（P<0.05）。结论 负重状态下离心收缩可以诱导肱二头肌DOMS模型,各项指标变化符合文献记载。 相似文献
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母猪情期启动营养调控分子机制的探讨 总被引：1，自引：0，他引：1
养猪生产中后备母猪年更新率高达40％～50％,哺乳母猪断奶后情期启动失败被淘汰比例占30％～40％,50％的母猪终身仅提供30～40头断奶仔猪就被淘汰,给养猪生产带来巨大经济损失.大量研究表明,下丘脑Kisspeptin信号系统在调控雌性动物情期启动和卵泡发育方面发挥重要作用.本课题组前期研究证实,猪的情期启动只有在营养充足、机体处于合成代谢时才能发生和维持.营养是推动后备母猪由生长向繁殖转换,或断奶母猪由泌乳向繁殖转换的物质基础.本文提出了营养调控母猪情期启动的几种理论假设,综述了能量、蛋白质(氨基酸)、维生素D3和部分矿物元素对机体代谢和下丘脑Kisspeptin信号的影响及其在调控母猪情期启动方面的分子机制. 相似文献
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