全文获取类型
收费全文 | 84577篇 |
免费 | 6530篇 |
国内免费 | 4229篇 |
专业分类
耳鼻咽喉 | 1035篇 |
儿科学 | 1042篇 |
妇产科学 | 689篇 |
基础医学 | 9550篇 |
口腔科学 | 1424篇 |
临床医学 | 8563篇 |
内科学 | 11557篇 |
皮肤病学 | 1356篇 |
神经病学 | 4231篇 |
特种医学 | 4063篇 |
外国民族医学 | 8篇 |
外科学 | 11359篇 |
综合类 | 13688篇 |
现状与发展 | 14篇 |
一般理论 | 7篇 |
预防医学 | 5990篇 |
眼科学 | 1795篇 |
药学 | 8481篇 |
57篇 | |
中国医学 | 4350篇 |
肿瘤学 | 6077篇 |
出版年
2024年 | 168篇 |
2023年 | 783篇 |
2022年 | 2129篇 |
2021年 | 3130篇 |
2020年 | 2292篇 |
2019年 | 2099篇 |
2018年 | 2244篇 |
2017年 | 2277篇 |
2016年 | 2446篇 |
2015年 | 3704篇 |
2014年 | 4641篇 |
2013年 | 5147篇 |
2012年 | 7581篇 |
2011年 | 7637篇 |
2010年 | 5803篇 |
2009年 | 4971篇 |
2008年 | 5714篇 |
2007年 | 5532篇 |
2006年 | 5095篇 |
2005年 | 4373篇 |
2004年 | 3400篇 |
2003年 | 3267篇 |
2002年 | 2912篇 |
2001年 | 2056篇 |
2000年 | 1436篇 |
1999年 | 926篇 |
1998年 | 476篇 |
1997年 | 472篇 |
1996年 | 340篇 |
1995年 | 284篇 |
1994年 | 213篇 |
1993年 | 134篇 |
1992年 | 190篇 |
1991年 | 186篇 |
1990年 | 158篇 |
1989年 | 137篇 |
1988年 | 123篇 |
1987年 | 103篇 |
1986年 | 93篇 |
1985年 | 86篇 |
1984年 | 46篇 |
1983年 | 51篇 |
1982年 | 31篇 |
1981年 | 34篇 |
1980年 | 30篇 |
1979年 | 52篇 |
1978年 | 59篇 |
1977年 | 33篇 |
1975年 | 39篇 |
1974年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
Transforminggrowthfactor-β1(TGF-β1)is amultifunctionalpolypeptidethatregulatesanum-berofcellularprocesses,includingcellprolifera-tion,differentiation,apoptosis,migration,matrix synthesis,andtheimmuneresponse[1,2].Inchron-icrenaldiseases,TGF-β1isakeymediatorofex-tracellularmatrix(ECM)accumulation[3].Oneof thetargetrenalcellsforTGF-β1isglomerular mesangialcellsthatarecapableofproducingcom-ponentsofECM,suchascollagens,lamininand fibronectin[4,5].Recentstudiesindicatedthatinhi-bitionofT… 相似文献
33.
双头加压螺纹钉贴股骨距内固定治疗股骨颈骨折 总被引:8,自引:0,他引:8
在X光电视下采用双头加压螺纹钉贴股骨距内固定治疗新鲜股骨颈骨折42例,随访平均2.5年,其中16例随访3年以上,骨折愈合率95.2%,骨折不愈合并股骨头缺血性坏死率4.76%。认为加压螺纹钉贴股骨距内固定可使钉的受力由较大剪应力变为较大轴向力承受,减少骨折处的剪应力,并加压于骨折端能促进骨折愈合。具有操作简单、进钉准确、创伤小、固定牢靠、并发症少等优点。 相似文献
34.
真皮下血管网岛状皮瓣抗菌力的实验研究 总被引:2,自引:0,他引:2
为研究真皮下血管网薄皮瓣用于感染创面的可行性,在家猪臀部两侧分别形成以旋髂深血管主干分支为蒂的传统岛状皮瓣和远侧50%修薄的真皮下血管网岛状皮瓣。用细菌计数、吖啶橙荧光染色测定白细胞吞噬指数和白细胞内杀菌率,应用激光多普勒、墨汁灌注、透明标本等方法,对两种皮瓣的抗菌力作自身对照研究。结果表明,真皮下血管网岛状皮瓣的抗菌力明显降低,可能与皮瓣修薄后血供减少,白细胞功能相应降低有关。 相似文献
35.
本文总结了北京大学口腔医学院3届八年制口腔医学专业学生口腔固定修复学临床前期实习教学的经验,针对实习中出现的典型问题进行了分析,采取了相应的对策和方法,取得了良好的效果. 相似文献
36.
37.
The increasing demands of clinical audit have resulted in the need for accurate data collection. The use of tumour maps allows standardization of the records of patients with head and neck cancer, which facilitates collation of data in multicentre studies and makes interdepartmental comparisons more meaningful. The aim of this study was to develop an improved standard set of tumour maps for recording the stage of head and neck tumours. A review of the existing tumour diagrams was performed to identify those anatomical areas that are not adequately represented or where ambiguity exists. The areas where improvements could be made were identified as: (1) the anterior commissure of the larynx; (2) axial and sagittal views of the larynx; (3) the pyriform fossa and cervical oesophagus; (4) the oropharynx and vallecula; (5) the nasal cavity and paranasal sinuses; and (6) cervical nodal involvement. A new set of tumour maps is presented in an attempt to correct some of the limitations of the existing diagrams. 相似文献
38.
The effects of intramuscular injections of succinylcholine with or without atropine on heart rate and rhythm were studied in 50 unpremedicated children 6-18 months of age. All had anesthesia induced with N2O-O2 and halothane 2% by face mask. Sixty seconds later, one of four study drugs or drug combinations was injected into the deltoid muscle of patients in groups 1-4. Following injection, halothane concentration was reduced to 1%, and ventilation was controlled. Patients given atropine only (0.02 mg/kg), succinylcholine only (4 mg/kg), or a combination of both (4 mg/kg succinylcholine plus 0.02 mg/kg atropine) showed transient increases in heart rate to 106 +/- 7.5%, 113 +/- 11.8%, and 109 +/- 10.1% (mean +/- SD) of control, followed by a decrease to 78 +/- 6.7%, 79 +/- 9.4%, and 80 +/- 10.5%, respectively, in 2-3 min after injection. Patients given a combination of succinylcholine (4 mg/kg) plus a higher dose of atropine (0.03 mg/kg) also had a transient increase in heart rate to 107 +/- 7.5%, followed by a decrease to 82 +/- 11.8% 2 min after injection. However, this group differed from the other three groups in presenting a second, prolonged increase in heart rate to 115 +/- 9.0% of preinjection levels. Patients in group 5 (controls) received no injections. Their heart rate decreased to 76 +/- 10.78% of preinduction level within 90 sec of induction, and remained unchanged thereafter. We conclude that succinylcholine (4 mg/kg) can be used intramuscularly with or without atropine (0.02 mg/kg) in lightly anesthetized young children without producing severe bradycardia.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
39.
Immediate and delayed cord clamping in infants born between 24 and 32 weeks: a pilot randomized controlled trial. 总被引:1,自引:0,他引:1
Judith S Mercer Margaret M McGrath Angelita Hensman Helayne Silver William Oh 《Journal of perinatology》2003,23(6):466-472
OBJECTIVE: This pilot study's aim was to establish feasibility of a protocol for delayed cord clamping (DCC) versus immediate cord clamping (ICC) at preterm birth and to examine its effects on initial blood pressure and other outcomes. STUDY DESIGN: A randomized controlled trial recruited 32 infants between 24 and 32 weeks. Immediately before delivery, mothers were randomized to ICC (cord clamped at 5 to 10 seconds) or DCC (30- to 45-second delay in cord clamping) groups. RESULTS: Intention-to-treat analyses revealed that the DCC group were more likely to have higher initial mean blood pressures (adjusted OR 3.4) and less likely to be discharged on oxygen (adjusted OR 8.6). DCC group infants had higher initial glucose levels (ICC=36 mg/dl, DCC=73.1 mg/dl; p=0.02). CONCLUSION: The research design is feasible. The immediate benefit of improved blood pressure was confirmed and other findings deserve consideration for further study. 相似文献
40.
目的探讨术中实时超声导航在脑动静脉畸形(AVM)外科治疗中的应用价值。方法26例脑AVM显微手术切除术中,使用Aloka SSD 4000型超声检查仪扫描,进行AVM定位、辨别供血动脉和引流静脉;确定血肿与AVM的关系以及血流动力学监测。病变切除后重复超声检查AVM残留与否,并与术后脑血管造影结果对比。结果26例畸形血管团均住实时超声下清晰显示并获得全切除。血肿区为高同声无血流信号;供血动脉与正常血管在血流动力学上有差别;术中超声影像所示的病变全切除为术后血管造影所证实。结论术中实时超声能够对脑AVM进行准确定位,指导皮质切口的设计,并可判定病灶是否全切除.对于术前的MRI、DSA检查起到很有价值的补充作用。 相似文献