共查询到20条相似文献，搜索用时 359 毫秒
1.
目的：研究1,6二磷酸果糖（fructose-1,6-diphosphate,FDP）对离体蛙心心肌收缩力影响以及其机制。方法：用斯氏法制备离体蛙心标本,用BL-410生物机能实验系统记录心脏的收缩力。结果：FDP在低剂量（1-5ug/ml）心肌收缩力呈下降趋势,但不具备统计学意义（P〉0.05）,随着剂量增大,心肌收缩力降低（P〈0.05）。FDP可阻断氯化钙加强心肌收缩的作用,β受体阻断剂对FDP的作用无影响（P〉0.05）。结论：FDP降低离体蛙心收缩力,其作用机制与降低钙离子内流有关,与β受体作用无关。 相似文献
2.
目的:阐明下丘脑室旁核(the paraventricular nucleus of hypothalamus,PVN)兴奋后对心交感神经放电及心肌收缩力的影响.方法:不同条件下(神经完整、切断双侧颈迷走神经干、静脉注射心得安),电刺激猫的下丘脑室旁核.同时记录刺激前、后下心交感神经放电及心肌收缩力.结果:不同条件下,电刺激猫的下丘脑室旁核,刺激前与刺激后相比,下心交感神经放电均增加;左心室收缩压也均升高,经t检验有统计学意义.结论:电刺激PVN可引起心肌收缩力增加,其中间途径和机制是心交感神经兴奋变力效应改变的结果. 相似文献
3.
目的:探讨黄芪熬液对离体蟾蜍心脏收缩力和心率的影响.方法:采用斯氏蛙心插管法,在保持总量为1.0ml的情况下,分别以不同浓度的黄芪熬剂对离体的蟾蜍心脏进行灌流,经BL-420F生物机能实验系统记录心肌的收缩活动.结果:本实验观察用低浓度(0.002g.ml-1-0.010g.ml-1)黄芪熬液灌流离体蟾蜍心脏时,可使其心肌收缩力、心率明显增加,t检验表明心肌收缩力、心率均变化显著(p<0.05)或极显著(p<0.01);用高浓度(0.02g.ml-1-0.06g.ml-1)黄芪熬液灌流离体蟾蜍心脏时,则抑制心肌收缩力和心率,t检验表明心肌收缩力和心率变化极显著(p<0.01).结论:黄芪熬液对离体蟾蜍心脏起双重调节作用. 相似文献
4.
利用Na^ 、k^ 、Ca^2 等离子作用于离体蟾蜍心脏形成实验性心肌失常，观察在此情况下木通马兜铃煎剂对心肌收缩的影响。结果发现本品芭叶煎剂对离体硅心具有增强收缩力的作用。 相似文献
5.
1 药理作用研究进展[1]1.1 对心血管的作用⑴强化作用 :华蟾毒精剂量为 4ｍｇ/ｋｇ时 ,不影响离体豚鼠的心率 ,而使心肌收缩力增强 ,ＲＢＧ亦有对抗戊巴比妥钠 (ＰＳ)所致心衰作用 ,亦有实验证明家兔在体心脏的动作电位稳定后 ,由兔缘静脉注射ＲＢＧ0 .3ｍｇ/ｋｇ ,给药后立即发挥作用 ,明显减慢兔心率 ,3ｍｉｎ时降至最低 ,其后逐渐恢复 ,约 2 5 0ｍｉｎ后 ,基本恢复至正常水平 ,在 15ｍｉｎ内 ,ＲＢＧ对兔的心肌收缩力 (ＦＣ)具有明显增强作用 ,在给药后 2 0ｍｉｎ心缩力逐渐 ,30ｍｉｎ时基本恢复至正常水平 ,亦有人认为蟾毒配基加强心… 相似文献
6.
《南阳师范学院学报》2015,(3):35-38
为了研究当归对蟾蜍在体心脏活动功能的影响,以蟾蜍为实验动物,利用BL-410生物机能实验系统,以蟾蜍心率、心搏最大收缩力、心搏平均收缩力和心肌电为指标,该药分设四个实验组进行实验.结果表明:当归片对蟾蜍心率没有显著影响,对蟾蜍心搏最大收缩力、心搏平均收缩力和心肌电产生显著影响,随当归片灌胃量的增加,先增大后减小.心搏收缩力与心肌电表现出显著的正相关性.由此获得基本结论:当归对心率基本无显著影响,但对心脏的收缩力和心肌电有影响,适当的用量有利于改善心肌功能,在心肌缺血损伤、心力衰竭情况下,有利于保护心脏. 相似文献
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8.
本实验以家兔离体心脏为对象,以心脏活动时左心室内压力的变化为指标,通过离体灌流法探讨夏至草对心肌收缩功能的影响。实验结果表明,一定浓度的夏至草制剂确能增加心肌收缩力,而且心肌收缩力的增加与药物浓度在一定范围内呈正相关。 相似文献
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10.
以1mg/ml的柑橘和瓯柑橘皮类黄酮溶液、1%的柑橘皮和瓯柑橘皮水、乙醇提取液各0.1mL加入离体蛙心灌流液,结果使蛙心收缩力分别提高101.3±49.6（%）,94.0±25.2（%）,81.4±38.5（%）,93.9±34.0（%）,150.3±117.8（%）,165.1±113.5（%）;心率分别降低19.8±31.9（%）,22.1±22.3（%）,28.0±16.2（%）,28.5±20.8（%）,19.3±14.2（%）,23.0±24.3（%）（均P〈0.05）。说明柑橘和瓯柑橘类黄酮、柑橘皮和瓯柑橘皮的水、醇提取液对离体蛙心均有增强心肌收缩力和减慢心率作用,各药物的持续时间在2～12min之间。 相似文献
11.
静注γ—氨基丁酸100mg/kg,可对抗乌头碱致麻醉大鼠心律失常;明显降低CaCl_2引起麻醉大室颤发生率及死亡率;可明显延长肾上腺素致麻醉大鼠出现室早时间及缩短心律失常持续时间。 相似文献
12.
In this study of the relationship between hypertensive left ventricular hypertrophy (LVH) and neurohumor factors and ventricular
arrhythmias, 180 cases were divided at random into 3 groups: 60 cases with primary hypertension and LVH (PH+LVH); 60 cases
with simple hypertension (PH), and with other diseases and LVH(NPH+LVH). The results showed that 1. The excitability of the
sympathetic nerve was not elevated while the activity of the vagus nerve was not significantly decreased in the patients with
PH+LVH. The increased sympathetic nervous tension was correlated with the ventricular premature beat which was statistically
correlated with the myocardial ischemia. 2. The patients’ condition in group PH+LVH was not correlated with the levels of
aldosterone and insulin and was not even positively correlated with the levels of renin and angiotensin-II. 3. The patients
in group PH+LVH had high incidence of ventricular premature beat and myocardial ischemia. 4. The patients’ condition in group
NPH+LVH was not even positively correlated with the neurohumor factors but their heart failure was positively correlated,
with the levels of aldosterone, sympathetic nervous tension, myocardial ischemia and ventricular premature beat. 相似文献
13.
针对现有电动车电瓶早衰严重的问题,结合电瓶的工作原理,深入分析了电瓶早衰的原因,并提出了具体的预防措施。试验表明,这些措施能够较好地保证电瓶的使用寿命,预防早衰,具有很好的应用参考价值。 相似文献
14.
防止遗传算法成熟前收敛的有效方法(英) 总被引：3，自引：0，他引：3
从群体多样性角度对成熟前收敛的成因进行了分析,并提出了两个有关定理．根据分析结果,提出了基于群体多样性和自适应交叉、变异率的改进遗传算法．通过四个典型函数的实例验证,证明了本文提出的改进遗传算法是一种有效算法． 相似文献
15.
Ingrid Vilà-Giménez Natalie Dowling Ö. Ece Demir-Lira Pilar Prieto Susan Goldin-Meadow 《Child development》2021,92(6):2335-2355
A longitudinal study with 45 children (Hispanic, 13%; non-Hispanic, 87%) investigated whether the early production of non-referential beat and flip gestures, as opposed to referential iconic gestures, in parent–child naturalistic interactions from 14 to 58 months old predicts narrative abilities at age 5. Results revealed that only non-referential beats significantly (p < .01) predicted later narrative productions. The pragmatic functions of the children’s speech that accompany these gestures were also analyzed in a representative sample of 18 parent-child dyads, revealing that beats were typically associated with biased assertions or questions. These findings show that the early use of beats predicts narrative abilities later in development, and suggest that this relation is likely due to the pragmatic–structuring function that beats reflect in early discourse. 相似文献
16.
The shortage of school leaders, mainly caused by the growing complexity of the job is steadily growing in recent years. This study reports on the results of a comparative empirical study into the causes of premature departure for male and female principals in primary and secondary education. Principals who have experienced premature departure themselves served as respondents. The risk factors for premature departure were researched in four areas: the school organization, the working environment including the school culture, the selection procedure and the principal him or herself. The results showed that the causes of premature departure are a combination of factors that are embedded in the context in which the leadership is performed and personal characteristics of the principal. 相似文献
17.
大鼠重度失血性休克30min后,左心室内压的最大上升速率( dp/dt max)和左心室收缩压(LVSP)都显著下降(P<0.01),而左心室舒张末压(LVEDP)却有所增高(P<0.05)。说明心肌的收缩功能和舒张功能均出现障碍,给少量淋巴液后(用量为0.5ml/100g体重)使休克时下降的左心室内压的最大上升速率和左心室收缩压显著回升(P<0.05),而增高的左心室舒张末压回落不明显,提示淋巴液可改善休克心肌的收缩功能障碍,但对低血容量情况下的心肌舒张功能无明显改善。 相似文献
18.
XIA Qin-gui *L Oliver Chung Heidi Spitznagel Thomas Unger 《Journal of Zhejiang University. Science. B》2001,(4)
ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＮａ /Ｈ ｅｘｃｈａｎｇｅｒ (ＮＨＥ)ｉｓａｐＨ ｒｅｇｕｌａｔｏｒｙｐｒｏｔｅｉｎｐｒｅｓｅｎｔｉｎｔｈｅｐｌａｓｍａｍｅｍ ｂｒａｎｃｅｏｆｃａｒｄｉｏｍｙｏｃｙｔｅｓａｎｄｏｔｈｅｒｃｅｌｌｔｙｐｅｓ.ＡｌｔｈｏｕｇｈｓｅｖｅｒａｌｉｓｏｆｏｒｍｓｏｆＮＨＥｈａｖｅｂｅｅｎｄｅ ｃｒｉｂｅｄ,ｔｈｅｐｒｅｄｏｍｉｎａｎｔｉｓｏｆｏｒｍｉｎｔｈｅｈｅａｒｔｉｓｔｈｅｕｂｉｑｕｉｔｏｕｓＮＨＥ 1 ,ｗｈｉｃｈｕｎｄｅｒｃｅｎｔａｉｎｐｈｙｓｉｏｌｏｇｉｃａｌｃｏｎｄｉｔｉ… 相似文献
19.
陈立红 《集美大学学报(教育科学版》2011,12(1):100-104
汉语普通话作为我们民族的共同语,是世界上使用人数最多的语言之一,学好、唱好、用好我们本民族的语言,是每-个学习歌唱的人必须掌握的基本技能.但是方言音调或者说是"方音普通话"直接影响了我们学习歌唱的进程.研究认为闽南方音普通话对声乐教学的具有一定的影响,通过音乐学中的节奏、节拍、音程关系等元素,可以解决那些带"方音普通话... 相似文献
20.
Heart rate variability (HRV) analysis is affected by ectopic beats. An efficient method was proposed to deal with the ectopic
beats. The method was based on trend correlation of the heart timing signal. Predictor of R-R interval (RRI) value at ectopic
beat time was constructed by the weight calculation and the slope estimation of preceding normal RRI. The type of ectopic
beat was detected and replaced by the predictor of RRI. The performance of the simulated signal after ectopic correction was
tested by the standard value using power spectrum density (PSD) estimation, whereas the results of clinical data with ectopic
beats were compared with the adjacent ectopic-free data. The result showed the frequency indexes after ectopy corrected had
less error than other methods with the test of simulated signal and clinical data. It indicated our method could improve the
PSD estimation in HRV analysis. The method had advantages of high accuracy and real time properties to recover the sinus node
modulation. 相似文献