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   244篇
  免费   6篇
  国内免费   3篇
儿科学   7篇
妇产科学   4篇
基础医学   24篇
口腔科学   3篇
临床医学   12篇
内科学   60篇
皮肤病学   5篇
神经病学   23篇
特种医学   6篇
外科学   46篇
预防医学   5篇
眼科学   28篇
药学   19篇
肿瘤学   11篇
  2022年   3篇
  2021年   2篇
  2020年   2篇
  2019年   2篇
  2018年   8篇
  2017年   4篇
  2016年   2篇
  2015年   5篇
  2014年   8篇
  2013年   2篇
  2012年   11篇
  2011年   15篇
  2010年   3篇
  2009年   7篇
  2008年   14篇
  2007年   13篇
  2006年   5篇
  2005年   6篇
  2004年   16篇
  2003年   7篇
  2002年   6篇
  2001年   4篇
  2000年   12篇
  1999年   5篇
  1998年   1篇
  1997年   3篇
  1995年   3篇
  1993年   1篇
  1992年   9篇
  1991年   5篇
  1990年   7篇
  1989年   4篇
  1988年   6篇
  1987年   7篇
  1986年   3篇
  1985年   11篇
  1984年   5篇
  1983年   5篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1975年   1篇
  1974年   3篇
  1973年   3篇
  1972年   2篇
  1970年   1篇
  1969年   1篇
排序方式: 共有253条查询结果,搜索用时 250 毫秒
1.
From 1976 to 1985, 277 cases of carcinoma of the esophagus were resected in the Second Department of Surgery, Tohoku University School of Medicine. Postoperative cardiocirculatory disturbances occurred in 114 cases (41.2%), arrhythmia being the disturbance most frequently observed (86.8%). Low cardiac output syndrome occurred in 8 cases and myocardial infarction occurred in 3 cases. The majority of the cases were treated successfully, but 5 patients died within one month after operation. Causes of death were as follows: myocardial infarction, constrictive pericarditis, cardiac tamponade, non-occlusive mesenteric ischemia and acute cardiac failure. Postoperative arrhythmia occurred mainly up to the third postoperative day. Low cardiac output syndrome occurred just after operation or on the first postoperative day. All cases of myocardial infarction occurred on the first postoperative day. The rate of occurrence of cardiocirculatory disturbances in aged patients (greater than or equal to 70) was significantly higher than other group (less than or equal to 69), (56.7%:38.1%, p less than 0.05). The rate of occurrence of cardiocirculatory disturbances in patients who had a history of hypertension or in patients with abnormal preoperative electrocardiographic findings were relatively higher than those in patients who had no history of hypertension or in patients with no abnormal preoperative electrocardiographic findings. The rate of occurrence of cardiocirculatory disturbances in patients who had undergone total resection of the thoracic esophagus was significantly higher than that in patients who had undergone partial resection of the thoracic esophagus (42.8%:23.8%, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
2.
3.
Antidromic action potentials were recorded in and around the ventromedial nucleus of the hypothalamus (VMN) of the ovariectomized female rat following stimulation of the central gray matter of the mesencephalon (CG). The animals had either the lateral or caudal trajectory of the VMN efferent disrupted by a small knife cut. Changes in the polarity, peak-to-peak amplitude, and the duration of the initial positive deflection of the antidromic action potentials were recorded for each response as the recording electrode was advanced at 10-micron intervals from the point of detection of the potential until its deterioration. Seventy-four recordings in which potentials exceeded 2 mV at the maxima were subjected to further analysis. The mean spatial spread of the extracellular antidromic action potentials, which was measured by moving the recording electrode at 10-micron intervals, was significantly larger in responses in 17 animals bearing the posterior knife cut (n = 41) than those in 15 animals with the lateral knife cut (n = 33). Mean peak-to-peak amplitude was also significantly greater in responses from the posterior-cut animals than in those from the lateral-cut ones. In the former, action potentials were completed with a shorter time lapse than the latter. In the posterior-cut animals, estrogen treatment of the ovariectomized rats significantly lowered antidromic activation thresholds and shortened absolute refractory periods for CG stimulation. Estrogen had no detectable effect on the excitability of cells that survived the lateral cut. Histological analyses located antidromically driven cells in the posterior-cut animals in the rostral extremity of the VMN and the adjacent retrochiasmatic area; those in the lateral-cut animals were scattered in and around the VMN, caudad to the former. These results suggest that rostral VMN neurons with large soma and laterally projecting axons are responsible for estrogen-dependent autonomic, neuroendocrine, and behavioral functions, such as reproduction and feeding.  相似文献   
4.
5.
6.
BACKGROUND: Abnormalities in the beta-adrenergic control of cardiac function play a role in the pathogenesis of several disease states. Because circulatory failure in patients with septic shock is known to be less responsive to catecholamines, we investigated whether the beta-adrenoceptor-linked signal transduction mechanisms are altered in the heart of a septic animal model METHODS: Rabbits were rendered endotoxemic by an intravenous injection of 100 microg/kg Escherichia coli lipopolysaccharide. Three and 6 h later, the myocardial tissues were used for the experiments. RESULTS: The positive inotropic response to isoproterenol was significantly impaired in papillary muscles isolated from septic rabbits compared with those from controls. The impaired inotropic responsiveness to isoproterenol was not prevented by the nitric oxide synthase inhibitor N(G)-nitro-L-arginine, indicating no involvement of nitric oxide overproduction. Adenylate cyclase activity stimulated with isoproterenol and 5'-guanylyl imidodiphosphate was markedly reduced in septic myocardium. The contractile and adenylate cyclase responses to colforsin daropate, a direct adenylate cyclase activator, were unaffected by sepsis. Radioligand binding experiments with (-)[125I]iodocyanopindolol revealed no significant alteration in myocardial beta-adrenoceptor density or affinity in sepsis. Determination of cardiac G(s alpha) level by Western blotting showed a reduction of approximately 50% in sepsis. The relative content of G(s alpha) messenger RNA in septic myocardium also was reduced from the control level by about 50%, as determined by Northern blot analysis. Little change was found in protein and messenger RNA levels of G(s alpha) in septic myocardium. CONCLUSIONS: Impairment of myocardial functional responsiveness to beta-adrenoceptor stimulation appears in the early stage of sepsis. The impaired response to beta-adrenoceptor stimulation in the heart in this pathologic state may result in part from a decreased level of G(s alpha) protein which occurs at the level of gene expression.  相似文献   
7.
Background: To evaluate the success rates of endoscopic-assisted probing compared to conventional probing in children 48 months or older. Methods: This retrospective study included children 48 months and older with CNLDO who underwent endoscopic-assisted probing or conventional probing between January 2011 to August 2015 at a tertiary eye care hospital in central Saudi Arabia. Probing was considered successful when signals of tearing or discharge disappeared and fluorescein dye disappearance test (FDDT) was normal. Demographic data, clinical features, intraoperative and postoperative variables were correlated to the success rate. Results: One hundred and twelve children with CNLDO undergoing endoscopic-assisted (37 patients) or conventional (75 patients) probing were included. The success rates of endoscopic-assisted and conventional probing were 94.6% [95% confidence interval (CI): 89.5–99.7] and 58.7% [95% (CI): 47.6–69.8], respectively. The success rate was higher with endoscopic probing, especially in older children. Conclusions: Endoscopic-assisted probing can achieve better outcomes to treat CNLDO, even in older children. The significantly higher success rates with endoscopic probing are likely due to the ability to observe and treat associated problems.  相似文献   
8.
9.
Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventional models, we can simulate the propagating pattern of action potential along the axonal membrane based on Ohm's law and Kirchhoff's law. However, we could not fully explain the different conductive patterns in unmyelinated and myelinated nerves with these theories. Also, whether we can really suppose closed electrical circuits in the actual site of the nerves or not has not been fully discussed yet. In this report, a recently introduced new theoretical model of nerve conduction based on electrostatic molecular interactions within the axoplasm will be reviewed. With this new approach, we can explain the different conductive patterns in unmyelinated and myelinated nerves. This new mathematical conductive model based on electrostatic compressional wave in the intracellular fluid may also be able to explain the signal integration in the neuronal cell body and the back-propagation mechanism from the axons to the dendrites. With this new mathematical nerve conduction model based on electrostatic molecular interactions within the intracellular fluid, we may be able to achieve an integrated explanation for the physiological phenomena taking place in the nervous system.  相似文献   
10.
Abstract: Diffuse cutaneous mastocytosis is a rare variant of mast cell disease with widespread erythroderma, which is normally clinically apparent in early infancy. We report the case of a neonate who presented with diffuse erythrodermic rash and bullous lesions. Biopsy specimens showed a dense dermal infiltrate of mast cells. Serum histamine and tryptase levels were elevated. No somatic mutation of the c‐kit gene was found. Blistering ceased at 5 months of age, but atopic dermatitis appeared at 6 months and allergic workup revealed a high level of food‐specific IgE. Herein, we describe the case and provide the first review of the literature on neonatal onset diffuse cutaneous mastocytosis to clarify the prognosis of this condition.  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