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   52185篇
  免费   5997篇
  国内免费   3474篇
耳鼻咽喉   391篇
儿科学   598篇
妇产科学   515篇
基础医学   5675篇
口腔科学   901篇
临床医学   7363篇
内科学   7153篇
皮肤病学   582篇
神经病学   2609篇
特种医学   1611篇
外国民族医学   24篇
外科学   4682篇
综合类   9607篇
现状与发展   14篇
一般理论   7篇
预防医学   3757篇
眼科学   1760篇
药学   6239篇
  55篇
中国医学   3787篇
肿瘤学   4326篇
  2024年   250篇
  2023年   1078篇
  2022年   2716篇
  2021年   3317篇
  2020年   2669篇
  2019年   2190篇
  2018年   2093篇
  2017年   2176篇
  2016年   1806篇
  2015年   2773篇
  2014年   3169篇
  2013年   2904篇
  2012年   4119篇
  2011年   4286篇
  2010年   2890篇
  2009年   2260篇
  2008年   2741篇
  2007年   2527篇
  2006年   2427篇
  2005年   2477篇
  2004年   1445篇
  2003年   1250篇
  2002年   1142篇
  2001年   975篇
  2000年   863篇
  1999年   904篇
  1998年   581篇
  1997年   538篇
  1996年   426篇
  1995年   401篇
  1994年   321篇
  1993年   234篇
  1992年   285篇
  1991年   240篇
  1990年   224篇
  1989年   171篇
  1988年   167篇
  1987年   119篇
  1986年   119篇
  1985年   87篇
  1984年   53篇
  1983年   44篇
  1982年   22篇
  1981年   26篇
  1980年   17篇
  1979年   19篇
  1977年   12篇
  1975年   12篇
  1974年   12篇
  1972年   14篇
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
81.
Objective To investigate the value of endovascular surgery for the treatment of thromboangitis obliterans (TAO). Methods Sixteen patients (18 limbs) with thromboangitis obliterans were treated by percutaneous transluminal plasty (PTA). Results Angiographic success on the limb basis was achieved in 15 of 18 treated limbs and the initial technical success rate was 83.34%. Doppler anklebrachial index (ABI) increased from 0.33±0.16 to 0.79±0.23 one week after PTA. The follow-up time was 2~24 months, the average time was 10.84 months. The 3-month, 12-month accumulated primary patency rate were 81.33% and 60. 23% respectively. Conclusion PTA is effective primary invasive treatment for thromboangitis obliterans yielding acceptable primary clinical success with a low complication rate and resulting in moderate long-term clinical patency and a high limb salvage rate.  相似文献   
82.
83.
84.
富含血管的听神经瘤   总被引:1,自引:0,他引:1  
目的探讨富含血管的听神经瘤的手术治疗。方法复习20年(1975—1995)手术治疗单侧听神经瘤90例,其中4例为富含血管的听神经瘤(HAT),与86例非富含血管的听神经瘤(NHAT),做回顾性分析,据临床表现、放射学检查、手术所见做比较。结果HAT较NHAT年轻(28±10与54±17岁)(P〈0.01),MRI显示HAT为实质性,无肿瘤囊变,多数较NHAT为大(P〈0.05);MRI示HAT有多个代表较大引流静脉的流空效应;经皮股动脉、椎动脉造影显示HAT有广泛的肿瘤着色及早期引流静脉的充盈,并证实由椎基动脉供血。过去文献报道认为以分期手术为宜。作者在控制性低血压麻醉下,成功地完成了4例HAT的切除术,未输血,术后无明显伤残。结论HAT是一种实质性大型肿瘤,出现于青年期,血管造影能够提供特征性发现。MRI能显示肿瘤表面的流空效应而确诊。采用控制性低血压麻醉有望能一期全切除肿瘤。  相似文献   
85.
Objective: The main aim of the present study was to examine the effectiveness and complication rate of the 1 cm right‐sided unilateral sublabial trans‐sphenoidal surgery for patients with pituitary adenoma equal to or greater than 5 mm in diameter. Method: A total of 350 patients were surgically treated for pituitary adenomas between December 1999 and December 2003 in an academic neurosurgical unit in China. Three hundred patients (86%) were treated with the 1‐cm right‐sided unilateral sublabial trans‐sphenoidal approach. The mean age of patients was 43 years (range 10–78 years) and female patients accounted for 59% of the total. One hundred and ninety‐six (64%) patients had functioning endocrine tumours and 104 (36%) patients had non‐functioning tumours or macroadenomas. Tumours which were outside this simple and basic classification were excluded from the study. Results: There were no operative mortalities. One patient developed hypopituitarism and 16 (5%) developed transient diabetes insipidus that required pituitrin treatment. The remission rate for macroadenoma was 85% and that for microadenoma was 98.5% during a medium term follow‐up of 1–5 years. One hundred and fifteen patients had prolactin secreting tumours and 90.4% achieved endocrine remission. Fifty‐six patients had growth hormone secreting tumours and 75.4% achieved endocrine remission. Preoperatively, one hundred and fifty‐one patients presented with visual impairment and 148 (98%) achieved a documented improvement in visual acuity. The mean duration of hospital stay was 4 days (range 3–7 days). Conclusion: This minimally invasive trans‐sphenoidal surgery for pituitary adenomas could be used as the primary treatment for small pituitary tumours. The effectiveness of the tumour removal and low morbidity rate compare favourably with the conventional sublabial approach as well as the more recently developed endoscopic endonasal approaches.  相似文献   
86.
Aim: To examine the survival benefit of liver and lung resection for colorectal metastasis and the potential prognostic factors that affect patient survival. Methods: All patients who had resection of lung or liver metastasis for colorectal metastasis in Queen Elizabeth Hospital, Hong Kong from 1995 to 2004 were retrospectively reviewed. The overall and disease‐free survival was analysed, in particularly between liver and lung metastasis. All factors that may have affected the survival were entered into Cox's proportional hazards regression model to identify significant variables associated with survival. Results: At 5 years, the overall survival of patients who had resection of lung and liver metastasis was 44% and 38%, respectively; the disease‐free survival was 26% and 24%, respectively. Overall and disease‐free survival of patients with resection of lung metastasis was comparable to those with resection of liver metastasis. The differentiations of primary tumour and time to metastasis were shown to be significant prognostic factors influencing overall survival. Those patients with systemic chemotherapy after resection of colorectal metastasis demonstrated a significantly higher probability of overall survival. Conclusion: Resection of lung and liver metastases from colorectal origin was safe and both procedures improved survival. The use of chemotherapy after resection of metastasis significantly improved the overall survival.  相似文献   
87.
电视胸腔镜辅助胸腺切除术   总被引:4,自引:2,他引:2  
目的探讨电视胸腔镜辅助胸腺切除的临床应用价值. 方法 2002年9月~2004年6月,18例胸腺疾病和重症肌无力(myasthenia gravis,MG)行胸腔镜辅助下胸腺切除手术,其中胸腺全切7例,11例MG行胸腺扩大切除. 结果 17例在胸腔镜辅助下完成, 1例中转小切口(7 cm)开胸手术.3例MG术后须短暂呼吸机辅助通气(<12 h),二次气管插管1例,余无严重并发症,无手术死亡.手术时间47~115 min,平均95 min;胸腔引流时间1.2~2.6 d,平均2 d;术后住院时间4~9 d,平均5.5 d.9例良性胸腺瘤或胸腺囊肿随访3~20个月,平均13个月,无复发.11例MG随访3~19个月,平均10个月,4例症状完全缓解,7例都分缓解. 结论胸腔镜辅助下胸腺切除手术,具有创伤小、恢复快等优点,胸腔镜下胸腺扩大切除治疗重症肌无力在技术上是可行的.  相似文献   
88.
应用鸡卵清蛋白致敏和刺激小鼠复制过敏性气道炎症反应模型研究血小板激活因子选择性拮抗剂YM-264对抗原引起气道嗜酸性粒细胞(EOS)浸润的影响。结果发现,正常小鼠支气管肺泡灌洗液(BALF)中未见到EOS;致敏小鼠给予抗原多次反复吸入刺激后,BALF中EOS急剧增多。在YM-264治疗各组中,YM-264的不同剂量分别导致EOS数下降27.0%、48.2%及67.9%。还发现YM-264抑制EOS对气道的浸润伴随着白细胞介素(IL)-5水平的明显下降。提示YM-264通过抑制IL-5的产生从而抑制了EOS在气道的聚集。  相似文献   
89.
用液体闪烁计数法测定离体再灌注兔心肌线粒体内45Ca2+的放射性强度.观察三磷酸腺苷-氯化镁冷稀释血停搏液和冷稀释血停搏液对缺血再灌注兔心肌线粒体内45Ca2+的影响.结果表明,在30min以内使用冷稀释血停搏液组兔心肌线粒体内45Ca2+放射性强度高于三磷酸腺苷-氯化镁冷稀释血停搏液组(P<0.05),而60min时冷稀释血停搏液组的放射性强度稍高或接近于三磷酸腺苷-氯化镁冷稀释血停搏液组,差异无显著性(P>0.05).在27例心内直视手术中使用三磷酸腺苷-氯化镁冷稀释血停搏液均获良好效果.  相似文献   
90.
根据形态学观察对一氧化氮(NO)在癫痫发作中的意义、NO与抑制性神经递质γ-氨基丁酸(GABA)的关系进行探讨.方法:选用红藻氨酸(KA)诱导的复杂部分性痫病模型.SD大鼠20只,随机分为KA30,60,90,200min组及对照组.脑组织进行还原性辅酶见依赖性黄递酶(Nd)染色,在Nd染色的基础上进行GABA免疫组织化学染色.结果:在海马CA1区、CA3区、齿状回(DG),KA建模组各时点一氧化氮合酶(NOS)与GABA双标阳性细胞数较对照组为低,具有显著性统计学差异.结论:Nd与GABA在脑内共存;GABA释放的减少导致GABA能系统解抑制;NO的释放减少,使其负反馈性抑制减弱,因而使神经元同步的阵发性放电增加.说明GABA与NO通过各自的途径起抗癫痫,也许在抗癌的发生、发展中起协同作用.  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