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   29789篇
  免费   2917篇
  国内免费   1909篇
耳鼻咽喉   198篇
儿科学   402篇
妇产科学   446篇
基础医学   3740篇
口腔科学   505篇
临床医学   3859篇
内科学   4949篇
皮肤病学   278篇
神经病学   1831篇
特种医学   1025篇
外国民族医学   21篇
外科学   3178篇
综合类   4225篇
现状与发展   6篇
一般理论   1篇
预防医学   2148篇
眼科学   767篇
药学   3024篇
  23篇
中国医学   1449篇
肿瘤学   2540篇
  2024年   111篇
  2023年   524篇
  2022年   1200篇
  2021年   1604篇
  2020年   1148篇
  2019年   1025篇
  2018年   1073篇
  2017年   999篇
  2016年   905篇
  2015年   1346篇
  2014年   1604篇
  2013年   1512篇
  2012年   2203篇
  2011年   2427篇
  2010年   1383篇
  2009年   1076篇
  2008年   1519篇
  2007年   1474篇
  2006年   1458篇
  2005年   1436篇
  2004年   1048篇
  2003年   842篇
  2002年   833篇
  2001年   687篇
  2000年   713篇
  1999年   781篇
  1998年   449篇
  1997年   434篇
  1996年   340篇
  1995年   315篇
  1994年   217篇
  1993年   173篇
  1992年   261篇
  1991年   218篇
  1990年   181篇
  1989年   179篇
  1988年   164篇
  1987年   141篇
  1986年   129篇
  1985年   129篇
  1984年   55篇
  1983年   42篇
  1982年   29篇
  1981年   30篇
  1980年   29篇
  1979年   26篇
  1978年   18篇
  1975年   13篇
  1971年   13篇
  1970年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的 了解本社区高血压患者的危险因素现状,探讨干预对策。方法 采用分层整群抽样的方法,随机抽取社区4个里委2级、3级高血压患者402例作为研究对象,收集各项危险因素如性别、年龄、血脂、血糖、吸烟、饮食、体育锻炼、体重等,并进行统计分析。结果402例高血压患者1年内进行所有相关辅助检查者有14例,占3.48%;1年内进行相关辅助检查一项者306例,占76.12%。饮食控制及进行体育锻炼有300例,占74.43%;吸烟62例,占15.42%。结论 高血压患者对饮食控制及体育锻炼、吸烟有害的知晓率明显提高,而对相关辅助检查认识不足。  相似文献   
62.
Objective: To explore the effect of Shenfu Injection, SFI) on the secondary aplastic anemia (AA) of tumor patients after chemotherapy (CT).Methods: The 15 cases of SFI treated group, 10 cases of control group, 25 cases of SFI + granulocyte-macrophage colony stimulating factor (GMCSF) treated group and the group of 23 GM-CSF-treated tumor cases of secondary AA after CT were compared, with their increasing rate and the rebound speed of neutrophil, platelet, bone marrow nucleated RBC, granulocyte, and megakaryocyte all being investigated.Results: The increasing rate and rebound speed of granulocyte, platelet, and the increasing rate of bone marrow nucleated RBC, granulocyte, megakaryocyte were obviously higher than those of the control, and the clinical manifestations were also obviously improved. The increasing rate of platelet, bone marrow nucleated RBC, megakaryocyte of the SFI + GM-CSF group were higher than those of the group which used GM-CSF alone, while the increasing rate of granulocyte in blood and bone marrow in both groups was similar.Conclusion: Significant efficacy was shown in SFI for the treatment of secondary AA of tumor patients after CT.  相似文献   
63.
The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rab-bits were co-cultured for 3-7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as con-trol. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts,trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the sur-face of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good bio-compatibility and ectopic induced osteogentic activty.  相似文献   
64.
Why study transport of peptides and proteins at the neurovascular interface   总被引:2,自引:0,他引:2  
The blood–brain barrier (BBB) is an immense neurovascular interface. In neurodegenerative, ischemic, and traumatic disorders of the central nervous system (CNS), the BBB may hinder the delivery of many therapeutic peptides and proteins to the brain and spinal cord. Fortunately, the mistaken dogma that peptides and proteins do not cross the BBB has been corrected during the past two decades by the accumulating evidence that peptides and proteins in the periphery exert potent effects in the CNS. Not only can peptides and proteins serve as carriers for selective therapeutic agents, but they themselves may directly cross the BBB after delivery into the bloodstream. Their passage may be mediated by simple diffusion or specific transport, both of which can be affected by interactions in the blood compartment (outside the BBB) and within the endothelial cells (at the BBB level). Although the majority of current delivery strategies focuses on modification of the molecule to be delivered, understanding the mechanisms of transport will eventually facilitate regulation of the BBB directly. We review the different aspects of interactions and discuss recent advances in the cell biology of peptide/protein transport across the BBB. Better understanding of the nature and regulation of the transport systems at the BBB will provide a new direction to enhance the interactions of peripheral peptides and proteins with the CNS.  相似文献   
65.
肾上腺皮质腺癌的诊断与治疗   总被引:2,自引:0,他引:2  
目的 探讨肾上腺皮质腺癌的早期诊断、手术及围手术期处理。方法 回顾分析了1990年至2001年间31例肾上腺皮质腺癌临床资料.并与1978年至1989年同种病例作比较。结果 近10年患者病理分期更趋向早期,更易行根治性切除,5年的存活率明显提高。结论 影像学的发展,使患者易早期诊断;围手术期的充分准备是减少手术并发症及死亡率的关键。  相似文献   
66.
Accordingtothedatafromepidemiology,thein-cidenceofcancerrisessteadilywithadvancingage.Age?specificincidenceratesfromtheThirdNationalCancerSurveyoftheUnitedStatesrevealedthattheriskofcancerdevelopmentinthe6thdecadeoflifeisapproximately1%,whichincreasesto2%inthe81styearoflife(1).Theincidencesofmostgyneco-logiccancersincludingcervicalcancer,endometrialcancer,ovariancancerandvulvarcancerpeakaftertheageof60years(2-4).Surgeryisoneofthemaintreatmentoptionsforgynecologiccancerandmaybringaboutsomeeff…  相似文献   
67.
目的探讨声敏剂血卟啉衍生物在肿瘤组织中的富集情况,以便在给药后超声结合血卟啉治疗肿瘤时选择最佳的超声处理时间。方法H-22肝癌荷瘤小鼠尾静脉注射HpD后,不同时间点取材,采用荧光分光光度法测定不同组织提取液中HpD的荧光强度,研究HpD在不同组织中的分布以及代谢变化。结果给药后2 h肿瘤组织以外的其他各组织内(血浆、肝、肾、皮肤、肌肉)血卟啉含量均达到其代谢过程的最高点,后逐渐下降;肿瘤组织中的HpD含量注射后不断上升,6 h时达到顶峰,随后又开始下降,10~24 h代谢比较缓慢,表现为肿瘤组织中对HpD的滞留作用,24 h时肿瘤组织中的HpD含量高于其他各组织,48~72 h趋于稳定在较低水平。结论提出了不同部位的肿瘤应选择各自适当的时间点进行超声处理。  相似文献   
68.
69.
本文应用XD—Ⅰ型微电脑程序刺激器检查26例患者,在窦房结功能检查中测定了窦房结恢复时间、窦房传导时间及固有心率;在房室传导功能的估计中测定了文氏点,2∶1阻滞点及房室结的有效不应期;在室上性心动过速中测定了旁路不应期,房室结双通道,折返区及折返性心动过速区;还进行了心脏负荷试验及右束支不应期等方面的测定。并就其方法,判断标准及临床意义等分别作了讨论。  相似文献   
70.
Two triazaspirodienes, having similar phenoxy propyloxy side chain, were identified as potent mammalian dihydrofolate reductase inhibitors; one having a 6,5‐spiro bicyclic ring system (IC50 = 2.3 nm ) and the other a 6,6‐spiro bicyclic system (IC50 = 6.9 nm ). They also showed more than 50% antiproliferative activity against the MCF‐7 breast cancer cells at 20 μm . This study demonstrated the potential lead of the diamino‐triazaspirodienes in anticancer chemotherapeutical agents’ discovery.  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