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   18812篇
  免费   1837篇
  国内免费   756篇
耳鼻咽喉   222篇
儿科学   467篇
妇产科学   180篇
基础医学   1394篇
口腔科学   563篇
临床医学   2103篇
内科学   2702篇
皮肤病学   271篇
神经病学   662篇
特种医学   973篇
外科学   2163篇
综合类   3587篇
现状与发展   5篇
一般理论   3篇
预防医学   1794篇
眼科学   312篇
药学   1870篇
  23篇
中国医学   1166篇
肿瘤学   945篇
  2023年   192篇
  2022年   456篇
  2021年   626篇
  2020年   503篇
  2019年   314篇
  2018年   319篇
  2017年   405篇
  2016年   303篇
  2015年   601篇
  2014年   746篇
  2013年   947篇
  2012年   1339篇
  2011年   1443篇
  2010年   1267篇
  2009年   1165篇
  2008年   1299篇
  2007年   1253篇
  2006年   1135篇
  2005年   937篇
  2004年   713篇
  2003年   678篇
  2002年   482篇
  2001年   439篇
  2000年   421篇
  1999年   236篇
  1998年   100篇
  1997年   91篇
  1996年   81篇
  1995年   81篇
  1994年   67篇
  1993年   56篇
  1992年   161篇
  1991年   144篇
  1990年   137篇
  1989年   157篇
  1988年   165篇
  1987年   159篇
  1986年   159篇
  1985年   171篇
  1984年   104篇
  1983年   110篇
  1982年   54篇
  1980年   51篇
  1979年   104篇
  1978年   68篇
  1977年   66篇
  1975年   58篇
  1974年   56篇
  1973年   72篇
  1972年   60篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
The wrap around the toe flap from the great toe is considered to be a good reconstructive proce-dure for degloved injuries of the thumb. 1 In this study, we used prefabricated flaps of the medial plan-tar skin to cover a degloved injury of the thumb of a patient unsuitable for application of this method and obtained satisfactory clinical results.  相似文献   
52.
Laparoscopic trans-cystic-duct common-bile-duct exploration   总被引:1,自引:0,他引:1  
One thousand seventy-one consecutive laparoscopic cholecystectomies were performed. Routine cholangiography was employed with a 99% success rate. One hundred thirty patients were found to have common duct stones (CBDS). In 48 (37%) patients they were unsuspected. One hundred eleven patients underwent attempted trans-cystic-duct extraction techniques (TCD-CBDE). One hundred three (93%) were successful. The following techniques were employed: 101—biliary endoscopy, 23—ampullary balloon dilation, 2—fluoroscopic basket retrieval.The average operative time was 136 min. The average postsurgical stay was 3.7 days. There were 19 (17%) complications—6 (5%) major. There were 4 retained stones (2 intentional) and 1 death. Patients over 65 years of age had more complications and patients with unsuspected CBDS under 65 years of age had the fewest.TCD-CBDE is a safe, effective way to extract common duct calculi. Endoscopy and basket stone retrieval was the primary technique employed.Presented at the annual meeting of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES), Nashville, Tennessee, USA, 18–19 April 1994  相似文献   
53.
特发性甲状旁腺机能减退症颅脑CT及MRI表现   总被引:2,自引:0,他引:2  
目的探讨颅脑CT及MRI检查对特发性甲状旁腺机能减退症(IHP)的诊断价值。方法回顾性分析16例经临床确诊的IHP患者头颅CT(16/16)和MRI(3/16)表现,观察病变的范围和密度/信号等特点。结果IHP颅内主要表现为多发钙化性病变,在CT上表现为高密度,CT值114~373HU,在MRT1WI呈稍高信号或高信号,T2WI呈等信号。双侧尾状核、苍白球、壳核及丘脑的对称性、条形或团块状钙化16例;双侧额、颞、顶、枕叶皮层下钙化10例;小脑齿状核钙化6例(双侧4例,单侧2例);侧脑室旁钙化2例。结论CT和MR对IHP的诊断非常重要,其中CT对病变的显示优于MR,与临床结果结合,对IHP具有定性诊断意义。  相似文献   
54.
Objective: To study the differences of gene expression between earlier gestational skin and later gestational skin of rats with the aids of single primer amplification (SPA) and high-density oligonucleotide DNA array to understand the molecular mechanism of scarless healing. Methods: Total RNAs were isolated from fetal rat skin of the scarless (E15) and scar-forming (E18) periods of gestation (term =21.5 days). The RNAs from earlier gestational skin (EGS) and later gestational skin (LGS) were both reversely transcribed to cDNAs, then labeled with the incorporation of fluorescent dCTP for preparing the hybridization probes by SPA method. The mixed probes were then hybridized to the oligonucleotide DNA arrays which contained 5 705 probes representing 5 705 rat genes. After highly stringent washing, these DNA arrays were scanned for fluorescent signals to display the differentially expressed genes between the 2 groups of skin. Results: Among 5 705 rat genes, there were 53 genes (0.93%) with differentially expressed levels between EGS and LGS groups, 27 genes, including fibroblast growth factor 2 ( FGF2 ) and follistatin were up-regulated (0.47%) and 26 genes were down-regulated (0.46%) in fetal skin during scarless period versus scar-forming period. Higher expressions of FGF2 and follistatin in EGS than those in LGS were also revealed by RT-PCR method. Conclusions: High-density oligonucleotide DNA array provided a powerful tool for investigating differential gene expression in earlier and later gestational fetal skins. This technology validates that the mechanism of fetal scarless healing is very complicate and the change of many gene expressions is associated with fetal scarless healing.  相似文献   
55.
目的评价术中输注氨基酸对硬膜外阻滞复合全麻食管癌和贲门癌手术患者围术期深部体温和代谢的影响。方法择期食管癌和贲门癌手术患者21例,ASAⅠ或Ⅱ级,随机分为3组(n =7):从麻醉诱导开始至手术结束,分别静脉输注氨基酸混合液240kJ·h-1(AA组)、等容量乳酸钠林格氏液(LR组)、葡萄糖溶液240kJ·h-1(GLU组)。麻醉诱导前至术后2h每5分钟测定鼓膜温度,于麻醉诱导前即刻、手术开始后1h和术后1h检测指尖血糖,采用4分表法评价术后2h内寒战的发生情况,采用间接测热仪测定术前与术后氧耗。结果与麻醉诱导前即刻比较,术后30min LR组和GLU组氧耗降低,AA组氧耗升高(P<0.01),术后2h LR组、GLU组鼓膜温度降低(P<0.05),AA组差异无统计学意义(P>0.05);与LR组和GLU组比较,AA组术后2h内寒战发生例数减少(P< 0.05),术后30min氧耗增多(P<0.05),LR组与GLU组比较差异无统计学意义(P>0.05)。结论硬膜外阻滞复合全麻开胸手术患者术中静脉输注氨基酸可通过提高基础代谢率,缓解围术期深部体温降低,减少术后寒战发生,而输注葡萄糖不产生此效应。  相似文献   
56.
强骨胶囊治疗骨质疏松早期骨量减少的临床观察   总被引:11,自引:0,他引:11  
强骨胶囊是中国中医研究院西苑医院与岐黄药业科技投资有限责任公司共同开发研制的治疗原发性骨质疏松症(肾阳虚证)的中药二类新药.根据国家药品监督管理局1998XL-131批文,由福建省中医药研究院主持进行强骨胶囊治疗骨质疏松早期骨量减少(肾阳虚证)临床试验,评价强骨胶囊的临床疗效和安全性.……  相似文献   
57.
目的 探讨侧脑室内脑膜瘤诊断特点及显微手术方法.方法 MRI和/或CT确诊并行显微手术切除侧脑室脑膜瘤24例,其中2例内窥镜辅助切除.肿瘤位于左侧三角区13例,右侧三角区7例,右侧体部1例,横跨双侧三角区1例,左侧颞角2例.顶枕入路15例,颞中回入路7例,经胼胝体后部入路2例.结果 24例影像学诊断与术后病理相符合,均给予全切.完整切除5例,分块切除19例.18例获得随访,完全正常10例,3例复发再次手术全切,癫痫2例,同向性偏盲3例.结论 CT和MRI是诊断侧脑室脑膜瘤的最可靠的手段,显微手术是目前侧脑室脑膜瘤的首选治疗方法.  相似文献   
58.
葛勇胜  许戈良 《医学综述》2007,13(19):1443-1445
肝移植已成为原发性肝癌治疗的一种重要选择。选择合适的肝癌病例作为移植对象是决定疗效及预后的关键,另外手术禁忌证及术后复发等问题也要慎重考虑。本文就肝癌肝移植治疗方面相关问题近年来的研究情况进行综述。  相似文献   
59.
A double-blind random-ordered comparison of the effects of placebo and 5-hydroxytryptophan (200 mg, orally) in ten depressed patients with seasonal affective disorder (SAD) and ten controls disclosed slightly but significantly higher basal levels of serum prolactin and a trend toward higher basal levels of serum cortisol in the patients with SAD compared with controls. After administration of 5-HTP, the cortisol level significantly increased and the prolactin level significantly decreased in both patients and controls. No differences in the melatonin level, growth hormone level, blood pressure, or pulse rate and no side effects were noted between patients and controls in the two study conditions; the timing of basal and 5-hydroxytryptophan-stimulated hormonal secretions was similar for both groups. These results are discussed with reference to current hypotheses of the cause of SAD.  相似文献   
60.
In the neonatal period ultrasound and hepatobiliary functional scintigraphy are used to diagnose choledochal cysts. Initial sonography demonstrates hepatobiliary anatomy, hepatobiliary function is assessed by subsequent scintigraphy. The diagnosis can be confirmed by additional computed tomography as shown in this case report.  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