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   83344篇
  免费   7710篇
  国内免费   5399篇
耳鼻咽喉   580篇
儿科学   1036篇
妇产科学   1271篇
基础医学   9950篇
口腔科学   1634篇
临床医学   10702篇
内科学   12813篇
皮肤病学   869篇
神经病学   4437篇
特种医学   2870篇
外国民族医学   32篇
外科学   7916篇
综合类   13607篇
现状与发展   14篇
一般理论   12篇
预防医学   5911篇
眼科学   2160篇
药学   8984篇
  81篇
中国医学   4617篇
肿瘤学   6957篇
  2024年   335篇
  2023年   1309篇
  2022年   3240篇
  2021年   4145篇
  2020年   3155篇
  2019年   2705篇
  2018年   2862篇
  2017年   2576篇
  2016年   2427篇
  2015年   3685篇
  2014年   4524篇
  2013年   4295篇
  2012年   6473篇
  2011年   6844篇
  2010年   4461篇
  2009年   3514篇
  2008年   4691篇
  2007年   4488篇
  2006年   4093篇
  2005年   3962篇
  2004年   2837篇
  2003年   2549篇
  2002年   2261篇
  2001年   1849篇
  2000年   1916篇
  1999年   1997篇
  1998年   1272篇
  1997年   1256篇
  1996年   981篇
  1995年   952篇
  1994年   777篇
  1993年   485篇
  1992年   560篇
  1991年   511篇
  1990年   435篇
  1989年   387篇
  1988年   302篇
  1987年   306篇
  1986年   235篇
  1985年   186篇
  1984年   123篇
  1983年   84篇
  1982年   62篇
  1981年   47篇
  1980年   33篇
  1979年   44篇
  1978年   18篇
  1974年   17篇
  1973年   17篇
  1966年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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   
62.
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   
63.
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   
64.
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   
65.
BACKGROUND: Concept of the 'super-thin perforator flap' was introduced in 1994 by authors. Since then, various types of 'super-thin perforator flaps' were applied successfully especially for contour sensitive reconstruction such as face and neck. METHODS: Eleven patients requiring large flaps who presented with extensive disfiguring facial scar (male: seven cases, female: four cases). On the consideration of flaps' colour, texture and thickness requirements, the authors selected 'super-thin' anterior intercostal perforator flaps (AICP, range from 4 x 14 cm to 25 cm x 9 cm) for reconstruction purpose. First, tissue expanders (volume range from 800 cc to 1200 cc) were carefully inserted under the AICP. After the flaps were expanded for 2 months, distant scars were removed and the covering super-thinned flaps were transferred into recipient site. Two weeks later, pedicles in the anterior chest were cut down and flaps were transferred to replace all the left scars. RESULTS: Flap were survived without any complications. The colour, texture and thickness of the transferred flap were satisfactory, shrink of flaps were not observed after long term follow-up. The authors present a method of facial reconstruction that has the advantages of creating a large amount of thin tissue of both good colour and texture, without the need of microsurgery and few disadvantages of donor-site morbidity. The disadvantages are three-staged procedures, complications of tissue expansion and uncomfortable compulsory posture for patients. In our opinion, this is an alternative method of choice for reconstructing all large defects in the lower two-thirds of the face.  相似文献   
66.
路志正教授从事中医临床多年,不仅对内科杂病有丰富的临床经验,对妇科疾病的诊疗,亦很有特色。笔者于2003年有幸侍诊左右,耳濡目染,略有所得,不揣浅陋,举述验案二则。健脾祛湿行水治疗闭经、不孕患者某,女,32岁,已婚,2003年10月9日初诊。主诉:月经稀少10余年,闭经2年。患者15岁  相似文献   
67.
68.
预测哪些人可能因急性发病而需要急诊入院,已成为英国国家医疗卫生服务体系(NHS)的一个重要话题。卫生部门将那些患有复杂的慢性疾病,经常不定期地去二级医疗机构就医的人们视为高危人群。确定这些人之后,社区护理员或其他卫生人员将通过“个案管理”的方法照顾他们。“个案管理”此前被定义为“对疾病尚未控制或所需费用昂贵的患者进行加强医疗计划”。社区护理人员可来自任何护理部门,但一般认为社区护士更能胜任这一角色。此方法能够减少可避免的急诊入院患者数量,并有助于实现到2008年3月减少5%急诊住院床位日的公共医疗服务目标。但是,如何才能界定需要急诊入院的高危人群呢?  相似文献   
69.
烧伤创面切削痂植皮对纠正烧伤后肾脏损害的价值   总被引:1,自引:0,他引:1  
目的 探讨烧伤合并肾脏损害的治疗方法。方法 对 47例烧伤合并肾损害进行烧伤创面切削痂植皮 ,以减少烧伤毒素、促进创面修复、促进肾脏功能恢复。结果 术后 1周观察 ,3 6例肾损害治愈、9例好转、2例无效 ;完成手术后 ,最快 3d肾损害即可控制。本组最后治愈41例、死亡 6例。结论 对于烧伤合并肾损害 ,及时采用手术治疗 ,不仅利于肾功能的恢复 ,也是保证患者最终康复的重要手段。一旦烧伤病人出现肾功能损害 ,应尽早进行烧伤创面切削痂植皮术修复深度创面。  相似文献   
70.
The distinction between atypical hyperplasia and carcinoma in situ in breast lesions can be difficult. The identification of myoepithelial cell layers may be helpful in establishing a diagnosis of proliferative breast disease vs. intraepithelial neoplasia. We reviewed pathologic material on 20 cases of atypical hyperplasia and 29 cases of carcinoma in situ. Immunohistochemical stains were employed against muscle-specific actin, S-100 protein, and cytokeratin to identify myoepithelial cells and to recognize different staining patterns. In atypical hyperplasia, muscle-specific actin staining identified myoepithelial cells in fine branching fibrovascular layers or as scattered cells between other proliferating cells. This pattern was absent in carcinoma in situ. S-100 protein showed more positive staining in atypical hyperplasia than in carcinoma in situ with patterns distinct from muscle-specific actin. Immunostaining for cytokeratin demonstrated distinctly different patterns between the two lesions. This study suggests that muscle-specific actin, S-100 protein, and cytokeratin in combination may assist in distinguishing proliferative breast disease with atypia from carcinoma in situ.  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