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   36559篇
  免费   2943篇
  国内免费   2239篇
耳鼻咽喉   596篇
儿科学   601篇
妇产科学   712篇
基础医学   3868篇
口腔科学   657篇
临床医学   4331篇
内科学   5773篇
皮肤病学   674篇
神经病学   1853篇
特种医学   1613篇
外国民族医学   16篇
外科学   4657篇
综合类   5045篇
现状与发展   7篇
一般理论   6篇
预防医学   2395篇
眼科学   1131篇
药学   3281篇
  19篇
中国医学   1775篇
肿瘤学   2731篇
  2024年   97篇
  2023年   472篇
  2022年   1204篇
  2021年   1554篇
  2020年   1208篇
  2019年   1068篇
  2018年   1114篇
  2017年   1111篇
  2016年   1025篇
  2015年   1873篇
  2014年   2348篇
  2013年   2199篇
  2012年   2917篇
  2011年   3010篇
  2010年   2126篇
  2009年   1785篇
  2008年   2200篇
  2007年   2081篇
  2006年   1935篇
  2005年   1855篇
  2004年   1287篇
  2003年   1025篇
  2002年   840篇
  2001年   681篇
  2000年   604篇
  1999年   626篇
  1998年   427篇
  1997年   408篇
  1996年   309篇
  1995年   310篇
  1994年   272篇
  1993年   205篇
  1992年   217篇
  1991年   210篇
  1990年   152篇
  1989年   157篇
  1988年   149篇
  1987年   114篇
  1986年   94篇
  1985年   69篇
  1984年   40篇
  1983年   70篇
  1982年   33篇
  1981年   44篇
  1980年   35篇
  1979年   36篇
  1977年   18篇
  1976年   18篇
  1974年   13篇
  1973年   16篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
目的 观察急性脑梗死 (ACI)后血浆一氧化氮 (NO)、一氧化氮合成酶 (NOS)、内皮素 (ET)含量的动态变化 ,以及尼莫地平治疗后对其影响。方法 ACI患者 110例 ,随机分成尼莫地平组 (5 0例 ) (在常规治疗基础上用尼莫地平 )和常规治疗组 (6 0例 )。在发病后不同时点动态观察血浆NO、NOS、ET含量 ,并设 5 0例脑动脉硬化患者为对照组。结果 脑梗死后血浆ET含量显著升高 ,直至恢复期 ;NO、NOS先增高后下降 ;尼莫地平组和常规组比较ET有显著差异 (P <0 .0 1) ,NO、NOS差别不显著 (P >0 .0 5 )。结论 NO、NOS、ET参与并影响了ACI后复杂的病理生理过程 ;尼莫地平部分通过对ET含量的影响发挥其对脑梗死的治疗作用  相似文献   
22.
Wegener’s granulomatosis (WG) is a necrotising granulomatous small vessel vasculitis with a clinical predilection for the involvement of the upper airways, lungs and kidneys. It occurs at all ages. The pathogenesis of WG is determined by the pathological activation of phagocytes during transmigration through the vessel. Whereas most aspects of WG are similar at all ages, some features appear to be significantly different. WG in childhood is more frequently complicated by subglottic stenosis and nasal deformity, while treatment related morbidity is less common compared to adults. The introduction of combined treatment with cyclophosphamide and glucocorticoids has resulted in a dramatic improvement in patient outcome; however, commonly occurring disease relapses and the risk of chronic organ damage at all ages make long-term follow-up of all patients necessary.  相似文献   
23.
The standard surgical protocol presented, with resection of the bone that has not healed. stable osteosynthesis with locking plates, and autologous bone graft augmentation, is an established and successful method of treating atrophic nonunion of the distal humerus. Bone healing was observed in all patients, and a single surgical operation was sufficient. In addition, elbow joint arthrolysis was performed to resect joint fibrosis and ossification and release tissue contractures. With this combined approach bony healing and improvement in range of motion and function of the elbow joint were achieved.  相似文献   
24.
尹力平  马丽 《吉林中医药》2005,25(12):33-33
小儿支原体肺炎是由支原体感染引起的呼吸道疾病。近年来支原体肺炎有逐渐增加的趋势,西医采用大环内酯类抗生素治疗,其疗程较长,且近期有一定的复发率。单纯中药治疗是难以控制的,笔者采用中西医结合治疗取得满意疗效,现总结如下。  相似文献   
25.
A factory survey was conducted in three provinces in China from 1985 to 1989. The time-weighted average toluene concentrations in breathing zone air were monitored by diffusive sampling, whereas hippuric acid (HA) concentrations in shift-end urine samples were measured by high performance liquid chromatography (HPLC). Exposed workers (456 men and women) were those for whom toluene (up to 548 ppm toluene) accounted for greater than or equal to 90% of total exposure (by vapor concentration in ppm), whereas 517 nonexposed controls were recruited from the same factories or from factories of the same region. There was a linear correlation between the intensity of toluene exposure and HA concentration in the shift-end urine. Comparison of the results with findings in the literature shows that the toluene-induced increase in urinary HA concentration among workers in China is significantly smaller than the published values, whereas HA concentrations in urine samples from nonexposed controls are comparable to the levels previously reported.  相似文献   
26.
Adrenal incidentalomas are clinically inapparent masses detected incidentally with imaging studies conducted for other reasons. They are relatively common and require structured diagnostic workup. In many cases surveillance is warranted. The diagnostic workflow has to reveal whether the mass is hormonally functioning and/or if there is evidence of malignancy. If the tumor is functionally silent and not larger than 4 cm, surveillance is warranted. Functioning tumors and masses larger than 6 cm have to be resected. Fine-needle aspiration biopsy is indicated in very rare cases, but pheochromocytoma has to be ruled out first.  相似文献   
27.
28.
29.
At birth the human newborn is immature and has not yet acquired fully competent organ functions. During lactation especially the digestive tract and the immune system gain competence. Lactation is regulated by a complex interaction of numerous hormonal factors. Most important are probably prolactin and oxytocin—two hormones produced and secreted in the pituitary. The production and secretion of these two hormones is again regulated by several factors in the central nervous system and these mechanisms can be disturbed by a variety of exogenous factors such as drugs and any other substances interacting with dopamine metabolism in the brain. It is important to know these physiological interactions to be able to understand the regulation of lactation and to be able to assess which factors could interfere with this process.  相似文献   
30.
目的:探讨Syndecan—1和E—candherin两种黏附分子在声门上型喉鳞状细胞癌中的表达情况及与喉癌生物学行为之间的关系。方法:应用SP免疫组织化学法检测了38例声门上型喉鳞状细胞癌和7例喉黏膜慢性炎症组织中的Syndecan-1和E—candherin的表达并根据阳性瘤细胞占肿瘤细胞总数的比率进行半定量分析和统计检验。结果:Syndecan-1和E—candherin的阳性染色部位主要集中于细胞膜,E—candherin也可表达于细胞间质。Syndecan-1和E-candherin在恶性程度高的癌细胞上膜表达明显缺失,并与组织学分化、肿瘤大小密切相关。Syndecan-1和E-candherin在喉鳞状细胞癌细胞上的表达结果有相关性,但无敏感性差异。结论:Syndecan-1和E-candherin的表达可能在声门上型喉鳞状细胞癌的发生发展等生物学行为中起着重要的作用。  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