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排序方式: 共有165条查询结果,搜索用时 15 毫秒
101.
目的:研究体表胃肠起搏联合多潘立酮治疗餐后不适综合征的疗效。方法:80例餐后不适综合征的患者,随机分为对照组及观察组。对照组40例予以多潘立酮10毫克,三餐前半小时口服;观察组予以多潘立酮10毫克,三餐前半小时口服,同时予以体表胃肠起搏,2次/日,每次45分钟,共2周,采用8导联胃肠电图仪记录患者空腹及进食后的胃电活动,及应用钡条行胃排空试验。分别于治疗前后对其症状、胃肠电图、胃排空情况进行评估。结果:治疗2周后,经胃肠起搏联合多潘立酮治疗的餐后不适综合征患者症状明显改善,较对照组改善更为明显(P<0.05),胃肠起搏治疗后正常胃电节律百分比较对照组显著改善,实验组胃排空率较对照组改善。结论:体表胃肠起搏联合多潘立酮可显著改善餐后不适综合征患者症状、胃电图参数、胃排空情况.  相似文献   
102.
We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained and restrained whole larvae. For direct control of the environment around the heart another approach utilizes the dissected larvae and removal of the internal organs in order to bathe the heart in desired compounds. The exposed heart also allows membrane potentials to be monitored which can give insight of the ionic currents generated by the myocytes and for electrical conduction along the heart tube. These approaches have various advantages and disadvantages for future experiments that are discussed. The larval heart preparation provides an additional model besides the Drosophila skeletal NMJ to investigate the role of intracellular calcium regulation on cellular function. Learning more about the underlying ionic currents that shape the action potentials in myocytes in various species, one can hope to get a handle on the known ionic dysfunctions associated to specific genes responsible for various diseases in mammals.  相似文献   
103.
Although chronic alcohol intake is associated with widespread disruptions of sleep-wake cycles and other daily biological rhythms in both human alcoholics and experimental animals, the extent to which the chronobiological effects of alcohol are mediated by effects on the underlying circadian pacemaker remains unknown. Nevertheless, recent studies indicate that both adult and perinatal ethanol treatments may alter the free-running period and photic responsiveness of the circadian pacemaker. The present experiment was designed to further characterize the effects of chronic ethanol intake on the response of the rat circadian pacemaker to brief light pulses. Ethanol-treated and control animals were exposed to 15-min light pulses during either early or late subjective night on the first day of constant darkness following entrainment to a 12:12 light-dark cycle. Relative to pulses delivered during early subjective night and to “no-pulse” conditions, light pulses delivered during late subjective night resulted in period-shortening after-effects under constant darkness, but only in control animals, not in ethanol-treated animals. These results indicate that chronic ethanol intake reduces the responsiveness of the circadian pacemaker to acute photic stimulation, and suggest that the chronobiological disruptions seen in human alcoholics are due in part to alterations in circadian pacemaker function.  相似文献   
104.
Magnetically induced electric fields and currents in the circulatory system   总被引:7,自引:0,他引:7  
Blood flow in an applied magnetic field gives rise to induced voltages in the aorta and other major arteries of the central circulatory system that can be observed as superimposed electrical signals in the electrocardiogram (ECG). The largest magnetically induced voltage occurs during pulsatile blood flow into the aorta, and results in an increased signal at the location of the T-wave in the ECG. Studies involving the measurement of blood pressure, blood flow rate, heart sounds, and cardiac valve displacements have been conducted with monkeys and dogs exposed to static fields up to 1.5 tesla (T) under conditions producing maximum induced voltages in the aorta. Results of these studies gave no indication of alterations in cardiac functions or hemodynamic parameters. Cardiac activity monitored by ECG biotelemetry during continuous exposure of rats to a 1.5-T field for 10 days gave no evidence for any significant changes relative to the 10 days prior to and following exposure. Theoretical modeling of magnetic field interactions with blood flow has included a complete solution of the equation describing the flow of an electrically conductive fluid in the presence of a magnetic field (the Navier–Stokes equation) using the finite element technique. Magnetically induced voltages and current densities as a function of the applied magnetic field strength have been calculated for the aorta and surrounding tissues structures, including the sinoatrial node. Induced current densities in the region of the sinoatrial node are predicted to be >100 mA/m2 at field levels >5 T in an adult human under conditions of maximum electrodynamic coupling with aortic blood flow. Magnetohydrodynamic interactions are predicted to reduce the volume flow rate of blood in the human aorta by a maximum of 1.3%, 4.9%, and 10.4% at field levels of 5, 10, and 15 T, respectively.  相似文献   
105.
本文采用同步双标测法,研究了窦房结(SN)优势起搏点兴奋向心房传导的规律。在14只麻醉狗心脏界沟部缝上一装有32个电极的电极板,标测优势起搏点(P点),最早起始负电位点(N点),心房激动过程图及最早激动点(O点)。在用异丙肾上腺索、心得安或刺激迷走神经使P点移位后,我们研究了P点位置与P—O、P—N的关系。在计60次实验中:(1)P—O、P—N多数并不重叠(分别为46次和40次);(2)随着P点从SN头部向尾部移位,O(N)点在P点头侧的出现率下降,在P点尾侧的出现率上升;(3)出现两个O点者23次,出现两个N点者11次,但P点始终只有一个。 本文提出了SN兴奋在SN内优先向头、尾两端扩布,再传向心房肌的窦房传导模式。并对心房激动多中心起源、界沟部兴奋超速传导等现象及Boiaeau的“心房综合起搏”假说进行了讨论。  相似文献   
106.
摘要 目的:探讨术前降钙素原(PCT)、血红蛋白(Hb)、中性粒细胞与淋巴细胞比值(NLR)与永久性心脏起搏器植入(PPI)患者术后囊袋感染的关系。方法:回顾性选取2019年7月~2021年7月安徽医科大学第二附属医院收治的400例PPI患者,根据术后1年是否发生囊袋感染分为感染组和非感染组。收集患者临床资料和术前PCT、Hb、NLR水平。采用单因素和多因素Logistic回归分析PPI患者术后囊袋感染的影响因素,采用受试者工作特征(ROC)曲线分析术前PCT、Hb、NLR对PPI患者术后囊袋感染的预测价值。结果:随访1年,400例PPI患者术后囊袋感染发生率为8.00%(32/400)。多因素Logistic回归分析显示,年龄增加、糖尿病、起搏器更换/升级、术后囊袋血肿和PCT、NLR升高、Hb降低为PPI患者术后囊袋感染的独立危险因素(P<0.05)。ROC曲线分析显示,术前PCT、Hb、NLR联合预测PPI患者术后囊袋感染的曲线下面积大于PCT、Hb、NLR单独预测。结论:术前PCT、NLR升高和Hb降低与PPI患者术后囊袋感染有关,术前PCT、Hb、NLR联合预测术后囊袋感染的价值较高。  相似文献   
107.
108.

Background

Cardiac resynchronization therapy (CRT) is indicated in symptomatic heart failure (HF) patients after achieving optimal medical therapy. However, there are still a large percentage of patients who do not respond to CRT. Malnutrition is a frequent comorbidity in patients with HF, and it is associated with a poorer prognosis. Here, we evaluate the nutritional status of patients assessed by Controlling Nutritional Status (CONUT) score and its association with structural remodeling and cardiovascular events.

Methods

We investigated the effect of CONUT on HF/death in 302 consecutive patients with a CRT device implanted between 2005 and 2015 in a single tertiary center. We categorized the patients into three groups: normal nutritional status (CONUT 0–1), mild malnutrition (CONUT 2–4) and moderate-severe malnutrition (CONUT?≥?5). Changes in nutritional status were assessed in patients with mild-to-severe malnutrition prior to CRT.

Results

One hundred and forty-eight patients exhibited normal nutritional status (49.0%), 99 patients exhibited mild malnutrition (32.8%) and 55 patients exhibited moderate-severe malnutrition (18.2%). CONUT scores of at least 2 were associated with higher risk of HF/death compared with CONUT 0–1. Significant left ventricular (LV) reverse remodeling was noted in patients with better nutritional status. In addition, those malnutrition patients at baseline that improved nutritional state exhibited fewer HF/death events at follow-up.

Conclusion

CONUT score prior to CRT was an independent risk factor of death/HF and was correlated with LV reverse remodeling. Improvements in CONUT score during long-term follow-up were associated with a reduction in the rate of HF/death.  相似文献   
109.
Some physiological parameters of the antennal heart, an accessory circulatory organ in the head of Periplaneta americana and the effect of the neuropeptide proctolin on it were investigated. The beat frequency of the antennal heart in vivo or semiisolated is about 2–3 times slower than that of the dorsal vessel and not coordinated with the latter. The extracellular ECG of the antennal heart has a simple biphasic shape with a total duration of 588.7 ± 38.2 ms. Intracellularly recorded parameters showed characteristics typical of myogenic rhythmicity: a slow depolarization with a rate of rise of 7.5 ± 0.7 mV/s, followed by an action potential of 54.9 ± 1.2 mV with a relatively long duration of 201.6 ± 10.8 ms, absence of overshoots and resistance to TTX. Proctolin produced a marked enhancement of the frequency of beat of the antennal heart up to about 400% with a high sensitivity (threshold concentrations: 5·10?9M). The dose-response curve shows a linear relationship between the logarithm of the concentration and the percentage increase in beat frequency. The electrical event most influenced by proctolin was the slow pacemaker depolarization, whose rate of rise was enhanced up to 240%. The action potential remained unchanged; the depolarization of the resting potential was very small and the input resistance did not change. The antennal heart responds to neurohormone D, another neuropeptide in insects, in a similar way as it does to proctolin. The mode of action of proctolin on the antennal heart is discussed in comparison to that found in other systems.  相似文献   
110.
Xiao YF  Sigg DC 《生理学报》2007,59(5):562-570
正常人的心脏节律源于右心房的天然起搏点(pacemaker)——窦房结。窦房结的功能异常或者房室传导阻滞会导致心率异常(如心律缓慢)。治疗严重的心动过缓需要植入在技术上已经相当成熟的电子起搏器,但这种治疗存在一些缺陷和不足。近年来,在动物实验模型中应用基因或细胞来重建心脏的生物起搏点已经取得了进展。超极化活化环核苷酸门控(hyperpolarization-activated cyclic-nucleotide-modulated,HCN)通道(起搏通道)通过超极化活化的阳离子电流(hyperpolarization-activated cation current,It)调制心脏的自律性。利用病毒载体或转染HCN基因的细胞将HCN基因导入动物心脏内可重建生物起搏点。也有导入其它基因或植入自律细胞来探索心脏起搏点的重建。本文总结了重建心脏生物起搏点的一些研究进展。一旦稳定性和寿命等关键问题得到相应解决,遗传工程改造的生物起搏点可用于治疗严重的心动过缓。  相似文献   
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