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   94182篇
  免费   8456篇
  国内免费   5315篇
耳鼻咽喉   762篇
儿科学   1338篇
妇产科学   1597篇
基础医学   11438篇
口腔科学   1831篇
临床医学   11673篇
内科学   15309篇
皮肤病学   935篇
神经病学   5466篇
特种医学   3284篇
外国民族医学   32篇
外科学   9936篇
综合类   13165篇
现状与发展   14篇
一般理论   25篇
预防医学   6712篇
眼科学   2962篇
药学   9334篇
  80篇
中国医学   4368篇
肿瘤学   7692篇
  2024年   339篇
  2023年   1365篇
  2022年   3345篇
  2021年   4384篇
  2020年   3248篇
  2019年   2877篇
  2018年   3136篇
  2017年   2753篇
  2016年   2599篇
  2015年   3937篇
  2014年   4804篇
  2013年   4724篇
  2012年   7118篇
  2011年   7507篇
  2010年   4737篇
  2009年   3780篇
  2008年   5331篇
  2007年   5155篇
  2006年   4789篇
  2005年   4692篇
  2004年   3592篇
  2003年   3273篇
  2002年   2992篇
  2001年   1960篇
  2000年   2004篇
  1999年   2147篇
  1998年   1421篇
  1997年   1393篇
  1996年   1079篇
  1995年   1061篇
  1994年   881篇
  1993年   567篇
  1992年   647篇
  1991年   578篇
  1990年   508篇
  1989年   453篇
  1988年   365篇
  1987年   378篇
  1986年   292篇
  1985年   263篇
  1984年   214篇
  1983年   156篇
  1982年   150篇
  1981年   151篇
  1980年   117篇
  1979年   95篇
  1978年   66篇
  1977年   46篇
  1976年   48篇
  1974年   43篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
GM1 ganglioside is believed to be important in promoting the recovery of neurons from injury. The present study assesses the ability of GM1 to repair or prevent the damage of dopamine neurons caused by the neurotoxin 1-methyl-4-phenylpyridinium (MPP+). Treatment of mesencephalic cell cultures with 2.5 μM MPP+ resulted in the loss of 30% of tyrosine hydoxylase (TH) immunoreactive neurons. In contrast, cultures administered 100 μM GM1 ganglioside for 3 days after toxin treatment contained nearly control numbers of TH+ neurons (97%). This reparative effect of GM1 was reflected in parallel increases in TH enzyme activity, dopamine and dopac levels. Cultures sustaining greater insult from higher doses of MPP+ (5.0–10.0 μM) did not benefit from ganglioside treatment, suggesting that rescue by GM1 depended on the degree of initial damage to cells. Moreover, the timing of ganglioside treatment was critical; pretreatment with GM1 alone did not prevent or attenuate the damage caused by subsequent incubation in 2.5 μM MPP+.  相似文献   
72.
Z Lu 《中西医结合杂志》1990,10(7):413-5, 389
In this survey, 60 patients with pulmonary infection (mainly nosocimial pneumonia) were divided into two groups randomly. 30 patients treated by injection of Scutelleria compound and 30 patients by intravenous piperacillin sodium as control. Before treatment there was no significant difference of clinical data between two groups. The total efficacy was evaluated after treatment for one week. 40%, 36.7% were marked effective in corresponding. 33.3%, 40% were effective and 26.7%, 23% were ineffective respectively. Total effective rates were 73.3% and 76.7% in corresponding group. Temperature was average decreased for 7.43 +/- 3.02 and 7.63 +/- 5.79 days, symptoms disappeared or relieved for 11.67 +/- 6.75 days and 11.53 +/- 7.30 days, leucocyte decreased to normal on 9.03 +/- 6.53 days and 10.13 +/- 6.23 days, roentgenographical shadows disappeared or became smaller for 16.1 +/- 7.02 days and 16.1 +/- 9.88 days in corresponding group. There were no side-effect of the functions of liver, kidney and medulla ossium in two groups. In piperacillin sodium group, fungal infection were found in 4 of 30 patients, but there was no any case suffered from fungal infection in injection of Scutelleria compound group. It was suggested that injection on Scutelleria compound is a hopeful preparation and should be studied further.  相似文献   
73.
74.
A crescentic osteotomy of the first metatarsal is unstable during the preliminary healing stage. The authors present a modification in the direction of the cut of the osteotomy. This alteration increases stability at the first metatarsal base.  相似文献   
75.
C S Lu  C N Chang 《台湾医志》1992,91(12):1216-1218
We report on a 44-year-old woman with a right frontal meningioma, who presented with resting tremor, rigidity and bradykinesia in the left limbs. There were no other neurologic manifestations. A computed tomography scan demonstrated a huge high-density mass in the right frontal lobe and marked surrounding edema causing compression of the basal ganglia. Cerebral angiography showed a typical sunburst tumor stain and three feeding vessels from the bilateral middle meningeal arteries and the right callosomarginal artery. The pathologic diagnosis was transitional type meningioma. Before surgery, treatment with levodopa and bromocriptine was significantly effective in controlling hemiparkinsonism, which completely disappeared after surgical removal of the tumor. This outcome supports the notion that local compression due to edema may cause a functional disorder in the basal ganglia producing reversible contralateral parkinsonism.  相似文献   
76.
Leukotriene receptor antagonists (LTRAs) were recently added to the method of treating allergic rhinitis (AR). However, in children under 6 yr old, there has been no study about its efficacy in treating AR. We aim to compare the clinical efficacy of montelukast, cetirizine and placebo in the treatment of children from 2 to 6 yr old with perennial allergic rhinitis (PAR), to see if there are any significant differences. Sixty children were selected and treated with montelukast, or cetirizine, or placebo once daily. The efficacy of the three agents was compared with the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and Total Symptom Score (TSS) by diary. In addition, we also examined serum IgE, serum eosinophil cationic protein (ECP), blood eosinophil counts, nasal airway resistance (NAR) and eosinophil percentage in nasal smears. The results revealed that both montelukast and cetirizine were significantly efficacious compared with placebo in NAR, eosinophil percentage in nasal smears, PRQLQ, TSS and all symptom items except nasal itching, throat itching and tearing. For nasal itching, only cetirizine was significantly efficacious. On the other hand, for night sleep quality, montelukast was significantly superior to cetirizine.  相似文献   
77.
We compared the aniseikonia, Seidel aberrations, spot diagrams, and peripheral refractive power errors of a schematic eye with a super-reversed intraocular lens (IOL) and with conventional IOLs. The results did not indicate that the super-reversed IOL performs better optically than the other IOLs, primarily because of its poorer on-axis image performance. However, this disadvantage can be overcome by aspherizing the super-reversed IOL.  相似文献   
78.
过去,为了保证前段的血液供应,外直肌全麻痹的手术治疗要分2~3次完成,考虑到全麻痹的外直肌已无功能,我们提出在这种条件下可以不动含睫状前动脉的外直肌,只退后内直肌和将上,下直肌的外侧1/2移到外直肌的附着处,如此安排,可以一次手术完成治疗,这样可以缩短治疗时间,减少病人的痛苦和负担,我们治疗了7例8眼,结果比较满意。  相似文献   
79.
Summary To characterize and compare the pathologic, hemodynamic and electrocardiographic changes of both transeatheter laser and electrical energy on ventricle, 33 subendocardial myocardium lesions were induced at energy 60, 120 and 240 Joules by either transcatheter laser irradiation or electrical shock in 7 anesthetized dogs. The following results were observed: 1) Both laser and electrical ablation on myocardium created nonhomogeneous myocardium injury, but laser ablation caused mainly focal tissue vaporization and necrosis, while electrical shock induced widespread tissue degenerations; 2) Both laser and electrical induced-lesion dimensions increased parallel to the total dosage of energy; 3) Laser ablation caused mainly (90%) single ventricular premature beats and 86 % of them occurred within the first minute after energy discharged, while ventricular tachycardias were found in any electrical energy groups; ventricular fibrillations occurring during laser and electrical ablation were 5 % and 13 % respectively (P< 0.01): 4) A decrease in aortic blood pressure and an increase in central verous pressure induced by laser ablation were significantly less than that produced by the same amount of electrical energy (P<0.0l). Our preliminary results have shown that transeatheter laser ablation has great potential for becoming a practical method in the management of refractory tachycardias.  相似文献   
80.
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