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   6272篇
  免费   397篇
  国内免费   131篇
耳鼻咽喉   86篇
儿科学   121篇
妇产科学   472篇
基础医学   837篇
口腔科学   19篇
临床医学   755篇
内科学   993篇
皮肤病学   96篇
神经病学   400篇
特种医学   121篇
外国民族医学   2篇
外科学   670篇
综合类   965篇
现状与发展   1篇
预防医学   361篇
眼科学   88篇
药学   474篇
  4篇
中国医学   211篇
肿瘤学   124篇
  2024年   16篇
  2023年   89篇
  2022年   184篇
  2021年   255篇
  2020年   235篇
  2019年   211篇
  2018年   218篇
  2017年   224篇
  2016年   236篇
  2015年   196篇
  2014年   352篇
  2013年   441篇
  2012年   315篇
  2011年   373篇
  2010年   333篇
  2009年   282篇
  2008年   257篇
  2007年   284篇
  2006年   228篇
  2005年   212篇
  2004年   197篇
  2003年   171篇
  2002年   161篇
  2001年   121篇
  2000年   109篇
  1999年   98篇
  1998年   90篇
  1997年   67篇
  1996年   89篇
  1995年   86篇
  1994年   74篇
  1993年   59篇
  1992年   61篇
  1991年   50篇
  1990年   39篇
  1989年   40篇
  1988年   26篇
  1987年   33篇
  1986年   30篇
  1985年   49篇
  1984年   52篇
  1983年   31篇
  1982年   26篇
  1981年   23篇
  1980年   21篇
  1979年   14篇
  1978年   12篇
  1977年   7篇
  1976年   9篇
  1970年   3篇
排序方式: 共有6800条查询结果,搜索用时 15 毫秒
1.
目的:为更清晰地显示顽固性气胸的漏气部位和性质,为不能耐受手术者摸索一种新的治疗手段。方法:选择18例患者,先用76%泛影葡胺行胸膜腔造影,而后在局部注入少量粘连剂。结果:造影后发现多发性肺大泡8例,单发性肺大泡6例,肺大泡伴粘连带4例。病变分别位于左上肺,右上肺,中下肺野及叶间裂。注射粘连剂后,15例一次成功,3例第二次成功。随防6~18个月,未见复发。结论:该方法易掌握,无明显副作用。病变显示明显,易被患者接受,具有明显的临床效果和推广价值  相似文献   
2.
目的探讨自发性高血压大鼠颈动脉中抑癌基因P53和原癌基因c-jun、c-fos、c-myc mRNA的表达.方法用逆转录聚合酶链式反应检测两种基因的表达水平.正常雄性大鼠作为对照组.结果 SHR颈动脉中,抑癌基因P53和原癌基因c-jun、c-fos、c-myc均有高表达,较WKY差异有显著性(P<0.05).结论自发性高血压大鼠颈动脉组织中抑癌基因P53和原癌基因c-jun、c-fos、c-myc均有高表达,癌基因的活化可能与自发性高血压大鼠颈动脉血管重构有关.  相似文献   
3.
4.
1. The mechanism of action of drugs might change according to the test used. Several noradrenergic drugs were tested in order to understand their implication in the mobility tests.

2. It was found that clonidine, an Alpha 2 agonist, acted differently according to the tast used. It provoked sedation in spontaneous activity test, and anti-immobility effects in the other tests.

3. Tall suspension test is able to show the double acting of clonidine.

4. Idazoxan might act either as an alpha 2 antagonist or as partial alpha 2 agonist. TST shown the unexpected partial alpha agonist effect of the molecule.

5. Forced swimming test is more specific for predicting antidepressant activity than tail suspension test which is close to a spontaneous activity model.  相似文献   

5.
James H. Diaz  MD  DrPH 《Pain practice》2004,4(4):295-302
Abstract:   Spontaneous intracranial hypotension (SIH) is a postural headache syndrome unrelated to dural puncture. Because of the increasing failure of epidural blood patch (EBP) to relieve headache in SIH, we retrospectively investigated the epidemiological features and treatment outcomes in 55 cases of SIH. The study population was stratified by age and sex; continuous variables were compared for differences by t -tests; categorical variables were compared by Chi-squared analysis or Fisher exact tests. Significant differences were identified by P values of 0.05 or less. The mean age of the study population was 44 ± 12 years with a female to male ratio of 1.3:1.0. Men presented with subdural hematomas ( P  = 0.001) more often than women. Meningeal enhancement on contrast magnetic resonance imaging (MRI) was the most consistent radiographic finding. Radionuclide cisternography (RC) demonstrated thoracolumbar dural leaks in 16 of 22 patients. EBP failures were more common in patients aged 40 and younger than in older patients ( P  = 0.003). Postural headache from SIH was not uniformly responsive to EBP, and had significant comorbidities, especially in men. The management of postural headache in SIH by other techniques to restore brain position and cerebrospinal fluid dynamics should be investigated.  相似文献   
6.
Abstract: Background: The laryngeal mask airway (LMA) can be used in general anaesthesia without neuromuscular block. The laryngeal tube (LT) is a new airway device with similar airway features as LMA. LT is provided with a distal cuff to prevent regurgitation. In this study we compared the LMA and LT concerning patient and user aspects. Methods: Sixty patients with ASA (American Society of Anestesiologists) score 1–2 scheduled for minor surgery were randomized to be ventilated either through LMA or LT. After insertion, the number of insertion attempts, and “positioning” and “airway-assessment” was evaluated. The patients reported on “sore throat” after 30 and 60 minutes and the day after anaesthesia. Results: Gender and mean age were equal in both groups. The first insertion attempt was successful in 25 of 28 patients randomised to LMA and in 23 of 27 patients randomised to LT. LMA was evaluated to be easier in “positioning” whereas no difference in “sore throat” was reported. Conclusion: We found no difference between the LMA and the LT in terms user and patient friendliness and safety.  相似文献   
7.
目的探讨老年人自发性气胸的诊断及治疗,以提高老年人自发性气胸的诊治水平。方法回顾性分析我科1996年2月3日~2006年2月23日我科89例老年人自发性气胸的诊治经过。结果老年人自发性气胸的临床症状易被原发病掩盖,其临床特点有:(1)临床表现多不典型,症状以紫绀、气急多见,无明显胸痛;(2)以继发性气胸为多;(3)老年自发性气胸并发症、伴发病多;(4)肺复张时间长,负压吸引效果差;(5)交通型和张力型在老年自发性气胸当中较为多见;(6)易误诊;(7)由于基础疾病存在,肺功能差,发生气胸后易出现肺部感染、呼吸衰竭等并发症,死亡率高。结论老年人各器官储备功能差,肺功能差,同时多并存基础疾病,老年人自发性气胸后易出现肺部感染、呼吸衰竭等并发症,死亡率高,早期诊断和积极合理的治疗是降低老年人自发性气胸病死率的关键。  相似文献   
8.
Boerhaave’s syndrome is a life-threatening disease with a high mortality. With regard to the heterogeneity of treatment strategies, no comparative studies exist and recommendations remain controversial. Seventeen cases of Boerhaave’s syndrome operated on between 1989 and 2000 at our hospital were reviewed retrospectively to compare the time period between perforation and diagnosis, and the morbidity and mortality among the different treatment options. In addition, we conducted a meta-analysis of the literature including all series containing five or more patients and compared the findings with our own data. Our patients with a perforation history of less than 12 hours showed significantly fewer signs of sepsis compared to patients with a history of more than 12 hours. In a comparison of patients with primary repair vs. patients treated with esophageal resection or an exclusion operation, no differences were found. In the literature, patients with a long period of perforation (more than 24 hours) were treated more often with an esophageal resection than patients with primary repair. In cases of Boerhaave’s syndrome, primary suturing of the esophageal perforation should be reserved only for those patients presenting within 12 hours after perforation. In all other cases, depending on the extent of the tissue damage, a two-stage esophageal resection with cervical esophagostomy and gastrostomy is recommended as the safest treatment.  相似文献   
9.
We experienced a case of familial spontaneous pneumothorax in three generations. Six of 13 family members had episodes of spontaneous pneumothorax. It is well established that there are some diseases associated with human leukocyte antigen (HLA). We performed HLA phenotyping for HLA of A, B and C. In our study, we detected the HLA haplotype A2, B61 in three of 4 who had episodes of spontaneous pneumothorax. The HLA haplotype A2, B70 were also detected in three of 4 who had episodes. This suggests that familial spontaneous pneumothorax might have hereditary factors.  相似文献   
10.
报道7例自发性食管穿孔治疗经验,并对诊断和治疗和治疗新方法进行了讨论,自发性食管穿孔早期诊断的重要依据是迅速获得完整,详细的发病史。可疑时通过食道造影,胸腔穿刺刺液的分析而确诊。一经确诊应急取早期食管修补,对发病时间长,全身情况差的病人,经积极准备后仍应急取食管修补,对不宜手术者给予食管冲洗促进穿孔愈合。同时给予有效的食管腔内外引流。  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