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   41946篇
  免费   3583篇
  国内免费   1295篇
耳鼻咽喉   54篇
儿科学   1259篇
妇产科学   183篇
基础医学   2805篇
口腔科学   85篇
临床医学   5723篇
内科学   13523篇
皮肤病学   113篇
神经病学   417篇
特种医学   1887篇
外国民族医学   7篇
外科学   3035篇
综合类   8576篇
现状与发展   2篇
预防医学   2110篇
眼科学   78篇
药学   4041篇
  44篇
中国医学   2018篇
肿瘤学   864篇
  2024年   164篇
  2023年   723篇
  2022年   1343篇
  2021年   1904篇
  2020年   1931篇
  2019年   1646篇
  2018年   1615篇
  2017年   1715篇
  2016年   1775篇
  2015年   1713篇
  2014年   3045篇
  2013年   3259篇
  2012年   2636篇
  2011年   2675篇
  2010年   2178篇
  2009年   1955篇
  2008年   1820篇
  2007年   1816篇
  2006年   1679篇
  2005年   1450篇
  2004年   1186篇
  2003年   1059篇
  2002年   878篇
  2001年   779篇
  2000年   687篇
  1999年   595篇
  1998年   495篇
  1997年   484篇
  1996年   489篇
  1995年   422篇
  1994年   374篇
  1993年   282篇
  1992年   289篇
  1991年   232篇
  1990年   225篇
  1989年   165篇
  1988年   155篇
  1987年   137篇
  1986年   127篇
  1985年   155篇
  1984年   123篇
  1983年   60篇
  1982年   78篇
  1981年   60篇
  1980年   59篇
  1979年   43篇
  1978年   34篇
  1977年   29篇
  1976年   35篇
  1975年   16篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Objective Postoperative pericardial effusion commonly occurs after open heart surgery. However, after general thoracotomy such as pulmonary resection, there have been few reports of pericardial effusion. The purpose of this study is to investigate patients with pericardial effusion following pulmonary resection.Methods: Among 2,385 patients with pulmonary resection for lung neoplasm in our institute, eight patients, whose pericardium had never been opened during the operation, developed pericardial effusion. The clinical characteristics of the eight patients were analyzed.Results: Pericardial effusion after pulmonary resection was divided into two subtypes: pericardial effusion in three patients with left thoracotomy occurring within 30 days postoperatively, and pericardial effusion in the remaining five patients with right thoracotomy occurring more than 30 days postoperatively. Pericardiotomy or pericardiocentesis was performed in three symptomatic patients, and the remaining five asymptomatic patients were treated with diuretics. Pericardial effusion disappeared in three of the five patients about 1–3 months after the conservative treatment, while, in the remaining patients, because pericardial effusion had increased gradually, pericardiocentesis was performed.Conclusion: From our experience, the treatment strategy of drainage for early pericardial effusion and diuretics for late pericardial effusion seems to be appropriate. (Jpn J Thorac Cardiovasc Surg 2006; 54:193-198)  相似文献   
42.
将动、静脉阻断法用于恒速灌流的在体山羊左肺,使其总压力降区分为动脉端、静脉端及中间段三部分。大肠杆菌内毒素主要升高肺静脉端压力降及肺毛细血管压;山莨菪碱可显著缓解内毒素所致的改变,但对正常肺血管各段压力降无明显影响。5-羟色胺主要升高肺动脉端压力降,对肺静脉端及毛细血管压无明显影响。去甲肾上腺素及组胺主要升高肺静脉端压力降及肺毛细血管压,但对肺动脉端无明显影响。去甲肾上腺素和组胺可能介导内毒素性肺动脉高压。  相似文献   
43.
本文报道应用高分子右旋糖酐制成软脑膜微循环障碍的动物实验模型。软脑膜微循环障碍模型的标志;软脑膜微血管血流速度减慢,血液流态呈粒状流或絮状流,血细胞聚集。 将98只家兔分成甲、乙二组。甲组38只,静脉注射平均分子量为25万的高分子右旋糖酐,乙组60只,静脉注射平均分子量为49万的高分子右旋糖酐。实验结果发现,甲组38只家兔仅28只可复制成软脑膜微循环障碍的实验模型,模型复制成功率为73.6%;乙组60只家兔,59只可形成软脑膜微循环障碍实验模型,成功率为98.3%。本实验证明复制动物模型以49万分子量的高分子有旋糖酐为宜。 本实验模型可用于脑微循环障碍和改善脑微循环药物的研究工作。  相似文献   
44.
Brain-dead donors are the major source of lungs for transplantation. Brain death is characterized by two hemodynamic phases. Initially, massive sympathetic discharge results in a hypertensive crisis. This is followed by neurogenic hypotension. Up-regulation of pro-inflammatory mediators occurs in all organs and lung injury develops; this can adversely affect graft function post-transplantation. The mechanisms of the systemic and lung inflammation are unknown. We hypothesized that the hemodynamic changes are responsible for these inflammatory phenomena. Brain death was induced by intra-cranial balloon inflation in rats. This resulted in hypertensive crisis, followed by hypotension. There was a significant increase in blood neutrophil CD11b/CD18 expression and pro-inflammatory cytokine levels in serum and bronchoalveolar lavage, compared with control animals. Rupture of the capillary-alveolar membrane was demonstrated by electron microscopy. Elimination of the hypertensive response by α-adrenergic antagonist pre-treatment prevented inflammatory lung injury, reduced the systemic inflammatory markers and preserved capillary-alveolar membrane integrity. Correction of the neurogenic hypotension with noradrenaline ameliorated the systemic inflammatory response and improved oxygenation. We conclude that the sympathetic discharge triggers systemic and lung inflammation, which can be further enhanced by neurogenic hypotension. Management of the brain-dead donor with early anti-inflammatory treatment and vasoconstrictors is warranted.  相似文献   
45.
15例肺心病血液高粘滞患者自体血250ml用XZY-Ⅰ型量子血液治疗机进行紫外线照射和充以纯氧后再输入,每周一次,最多连续做三次(平均1.86±0.71次)后,作者发现血液全血高切、低切粘度,全血高切、低切还原粘度,血浆比粘度,血浆纤维否白原含量,红细胞聚集指数,红细胞电泳率等有显著性改变,单纯常规治疗组15例患者血液流变无此变化,分析认为,这些变化可能与红细胞聚集性降低、纤维蛋白源溶解度提高及血氧饱和度增加有关。  相似文献   
46.
作者报道28例经手术及病理证实的肺部囊性病变,其中21例为先天性,7例为后天性.x线表现可分为:①单发气囊腔.②多发性气囊腔.③单发液囊腔.④单或多发液气囊腔,内有液平面.⑤肺隔离症.讨论了形成机理以及与肺结核,肺脓肿,肺癌,转移性肺肿瘤,肺包虫囊肿等的x线鉴别诊断  相似文献   
47.
A case is reported of Wilms' tumor associated with multiple pulmonary metastases histologically showing maturation of the tumor cells at 9 years after the resection of the primary tumor and intensive therapy. A huge tumor of a 22-month-old patient's right kidney was resected. The tumor was diagnosed as Wilms' tumor of mesenchymal type (stage 1), which consisted of predominantly immature mesenchymal tissue including rhabdomyoblasts, smooth muscle and fibrous tissue, and few blastemal and epithelial components. Intensive preoperative and postoperative chemotherapy with actinomycin D and vincristine and postoperative irradiation therapy totaling 16 Gy were carried out. The patient was regularly followed up uneventfully until 9 years after the surgery. On routine chest x ray at the age of 10 years 11 months, multiple pulmonary nodules were found. The excised nodules from the bilateral lungs disclosed similar histology, exclusively composed of dense collagen bundles and fibrocytes intermingled with mature striated muscle bundles. No immature tumor components were detected. The possible effect of intensive therapy in this maturation was stressed, although spontaneous benign differentiation of tumor cells cannot be excluded.  相似文献   
48.
本文报导了用40只白色短毛家兔所做的动物模拟失重实验,得出各脏器微血管通透性的动态反应曲线。并用微循环研究方法,分析了模拟失重时各脏器微血管功能状态与微血管通透性之间的关系;阐述了各脏器微循环功能变化特点;并对变化机理作了初步探讨。  相似文献   
49.
目的 探讨慢性阻塞性肺疾病(慢阻肺)患者的家庭支持与自我概念的关系。方法 用方便抽样法选取108位慢阻肺患者,应用修订的个人资源问卷、自我概念量表和一般资料问卷分别测定其家庭支持、自我概念水平和一般资料。结果 该组患者家庭支持程度为中到高度,自我概念中度积极;家庭支持与总的自我概念呈中度正相关,与自我概念中的体感、自我一致性、理想自我及道德一伦理一精神自我有显著相关.与体象无关。结论 慢阻肺患者的家庭支持水平越高,其自我概念越积极。  相似文献   
50.
Summary Partial anomalous pulmonary venous connections (PAPVCs) are rare in association with an intact atrial septum. However, the diagnosis should be considered in patients with otherwise unexplained findings of left-to-right shunt and right heart enlargement. An unusual variant is presented, which we considered unsuitable for operative repair, based on findings at catheterization. Developmental, hemodynamic, and surgical considerations 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