全文获取类型
收费全文 | 16641篇 |
免费 | 1507篇 |
国内免费 | 964篇 |
专业分类
耳鼻咽喉 | 149篇 |
儿科学 | 163篇 |
妇产科学 | 287篇 |
基础医学 | 2030篇 |
口腔科学 | 265篇 |
临床医学 | 2202篇 |
内科学 | 2642篇 |
皮肤病学 | 186篇 |
神经病学 | 855篇 |
特种医学 | 572篇 |
外国民族医学 | 5篇 |
外科学 | 1963篇 |
综合类 | 2311篇 |
现状与发展 | 1篇 |
一般理论 | 6篇 |
预防医学 | 1123篇 |
眼科学 | 484篇 |
药学 | 1704篇 |
15篇 | |
中国医学 | 806篇 |
肿瘤学 | 1343篇 |
出版年
2024年 | 45篇 |
2023年 | 247篇 |
2022年 | 584篇 |
2021年 | 809篇 |
2020年 | 559篇 |
2019年 | 551篇 |
2018年 | 565篇 |
2017年 | 511篇 |
2016年 | 502篇 |
2015年 | 720篇 |
2014年 | 884篇 |
2013年 | 841篇 |
2012年 | 1207篇 |
2011年 | 1236篇 |
2010年 | 905篇 |
2009年 | 711篇 |
2008年 | 822篇 |
2007年 | 821篇 |
2006年 | 859篇 |
2005年 | 799篇 |
2004年 | 659篇 |
2003年 | 621篇 |
2002年 | 572篇 |
2001年 | 454篇 |
2000年 | 395篇 |
1999年 | 393篇 |
1998年 | 272篇 |
1997年 | 240篇 |
1996年 | 179篇 |
1995年 | 183篇 |
1994年 | 115篇 |
1993年 | 98篇 |
1992年 | 110篇 |
1991年 | 93篇 |
1990年 | 72篇 |
1989年 | 69篇 |
1988年 | 65篇 |
1987年 | 62篇 |
1986年 | 42篇 |
1985年 | 42篇 |
1984年 | 22篇 |
1983年 | 14篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 21篇 |
1976年 | 10篇 |
1974年 | 15篇 |
1973年 | 13篇 |
1972年 | 10篇 |
1969年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
健康和病变人声带振动特性声门图 总被引:1,自引:0,他引:1
本文用多功能声门图仪测定了健康受试者(男46名,女34名)和不同喉病患者(男134名,女87名)声门图的波形及其特征参数。根据测出的正常声门图及其参数分布研究了恶性喉病变、声带麻痹、喉内关节病变、功能性声门发声障碍、声带息肉、声带小结、喉炎和早期喉病的临床声门图表现及其与声带振动模式变异之间的关系,并探讨了上述病变声门图的鉴别诊断指标和用声门图对喉病手术治疗、药物治疗和功能治疗的疗效进行定性和定量评价。研究结果证实:声门图方法能准确、定量、灵敏地反映声带振动模式及其变异;在喉病诊治中具有重要的应用价值。 相似文献
13.
Purpose: The aim of the study was to provide information about the characteristics of three main types of orthokeratology (ortho‐k) lenses used in Hong Kong and to report on their performance based on the clinical impressions of a group of ortho‐k practitioners. Method: Twelve ortho‐k practitioners were interviewed between 1 March and 30 June 2001. Results: Most ortho‐k lenses were ordered from three manufacturers: DreimLens, Fargo and Contex. The median maximum myopia reduction reported for DreimLens, Contex and Fargo lenses were 6.25 D, 6.00 D and 4.50 D respectively. The time to reduce myopia by up to 4.00 D could be up to three weeks for Contex and DreimLens and up to four weeks for Fargo. For reduction of myopia by up to 4.00 D, the treatment usually required only one or two lenses per eye for all three types of lenses. The incidence of lens binding and lens tightening after achieving the optimal reduction was reported to be higher with the DreimLens design. Good centration, less lens binding, relatively lower incidence of complications and lens tightening after achieving the optimal reduction were reported with the Fargo lenses. Conclusions: DreimLens tended to be more effective for myopia reduction. However, some practitioners were concerned with the aggressiveness of myopia reduction using this lens design and the higher potential for ocular complications. Selection of the lens design is dependent on various factors, in particular, practitioners need to be comfortable with the design they choose and to consider the needs of their patients and the final goal of the treatment. 相似文献
14.
15.
A 12-year-old girl with a history of fast myopia progression underwent advanced orthokeratology (ortho-k) treatment and suffered from recurrent lens binding and central corneal staining. The problem could not be fixed by lens fenestration and refitting with a less aggressive lens (three-zone ortho-k) design. After refitting with a lower target advanced ortho-k lens, these complications were no longer occurring, and the amount of power reduction was greater than expected considering the target designed for the refitted lenses. During the following 15 months of ortho-k lens wear, there was no clinically significant change to her refractive error. The patient and her parents were happy with the outcome, although the refractive error was not totally eliminated and she still needed to wear spectacles for clear vision. Possible etiologies of the complications are discussed. 相似文献
16.
W. Y. Zhang Research Fellow A. Li Wan Po Professor 《BJOG : an international journal of obstetrics and gynaecology》1998,105(7):780-789
Objective To quantify the efficacy and safety of naproxen, ibuprofen, mefenamic acid, aspirin and acetaminophen (paracetamol) in the treatment of primary dysmenorrhoea through a systemic overview of randomised controlled trials.
Methods MEDLINE, EMBASE and the Science Citation Index were searched for randomised controlled trials. Efficacy was assessed by measurement of pain relief, requirement for rescue analgesics, restriction of daily life and absence from work or school. The rate ratios of side effects were used to assess safety.
Results Fifty-six trials describing 55 comparisons of analgesics with placebo and 12 direct comparisons with other analgesics met our inclusion criteria. Women taking naproxen were over three times more likely to have at least moderate pain relief than those taking placebo. Ibuprofen, mefenamic acid and aspirin were also superior to placebo but acetaminophen was not. The requirement for rescue analgesics, restriction of daily life and absence from work or school were less frequent with naproxen and ibuprofen than placebo but not with aspirin or acetaminophen. Direct comparisons did not show any difference between naproxen and ibuprofen. Side effects occurred more frequently only with naproxen when compared with placebo.
Conclusion Naproxen, ibuprofen, mefenamic acid and aspirin are all effective in primary dysmenorrhoea. Ibuprofen appears to have the most favourable risk-benefit ratio. Acetaminophen appears to be less effective than nonsteroidal anti-inflammatory drugs, but there was only one trial meeting our inclusion criteria and further studies are required. 相似文献
Methods MEDLINE, EMBASE and the Science Citation Index were searched for randomised controlled trials. Efficacy was assessed by measurement of pain relief, requirement for rescue analgesics, restriction of daily life and absence from work or school. The rate ratios of side effects were used to assess safety.
Results Fifty-six trials describing 55 comparisons of analgesics with placebo and 12 direct comparisons with other analgesics met our inclusion criteria. Women taking naproxen were over three times more likely to have at least moderate pain relief than those taking placebo. Ibuprofen, mefenamic acid and aspirin were also superior to placebo but acetaminophen was not. The requirement for rescue analgesics, restriction of daily life and absence from work or school were less frequent with naproxen and ibuprofen than placebo but not with aspirin or acetaminophen. Direct comparisons did not show any difference between naproxen and ibuprofen. Side effects occurred more frequently only with naproxen when compared with placebo.
Conclusion Naproxen, ibuprofen, mefenamic acid and aspirin are all effective in primary dysmenorrhoea. Ibuprofen appears to have the most favourable risk-benefit ratio. Acetaminophen appears to be less effective than nonsteroidal anti-inflammatory drugs, but there was only one trial meeting our inclusion criteria and further studies are required. 相似文献
17.
视盘血管炎——关于混合型的研讨 总被引:2,自引:0,他引:2
对60例(63眼)视盘血管炎的临床分型进行了探讨,结果表明,除分为Ⅰ、Ⅱ两型外,尚存在混合型,当视盘睫状血管炎性病变波及中央静脉,或两个血管系统同时受炎症侵犯时,即可再现混合型的临床表现,视盘明显水肿,视网膜静脉迂张,散在渗出,出血,动脉狭细。眼底荧光血管造影可见视盘荧光早期充盈明显迟缓,后期渗漏面积〉2.0PD,视网膜循环时间延长,混合型兼有Ⅰ,Ⅱ两型的临床特征,应作为一个独立类型存在,同时观察 相似文献
18.
二氧化硅活化巨噬细胞中早期生长反应因子-1及其信号转导通路的研究 总被引:3,自引:0,他引:3
目的 探讨早期生长反应因子(Egr-1)及其信号转导在矽肺发生发展中的作用。方法用细胞免疫荧光、原位杂交方法检测二氧化硅(SiO2)刺激后Egr-1的表达定位,用报道质粒及EMSA检测其活性改变;用激酶活性分析法检测si0:刺激巨噬细胞后ERK1/2活性改变,进一步用激酶抑制剂初步探讨SiO2活化Egr-1的信号转导通路。结果SiO2刺激RAW264.7细胞短时间Egr-1核蛋白表达及转录因子明显增加;且在处理后30~60min,Egr-1核蛋白结合活性明显升高(为未处理组的20倍);在刺激后15min ERK1/2活性开始升高,30min达高峰(活性为对照组的29倍)而后渐降至基础水平;进一步用激酶阻断发现,Egr-1 mRNA及蛋白表达均减少。结论SiO2能激活巨噬细胞中Egr-1,且此过程可能由ERK1/2、p38介导,提示SiO2-ERK1/2、p38-Egr-1通路可能在矽肺发生发展过程中起重要作用。 相似文献
19.
目的:探讨内皮细胞清除补体攻膜复合物(MAC)的途径及其清除动力学,方法:原代培养的人脐静脉内皮细胞以RH414荧光标记质膜双层,0℃组装亚溶剂量的MAC,37℃复苏后,LSCM实时监MAC沉积诱导的质膜囊泡化形成和胞吞,胞吐情况,流式细胞仪定量检测内皮细胞表面MAC抗原的清除情况,结果:MAC沉积后,内皮细胞有的质膜囊泡化形成,囊泡以胞吞和胞吐2种方式离开细胞,并以前者占优,37度条件下,内皮细胞清除表面MAC的半衰期约为5min。结论:内皮细胞可通过胞吞和胞吐2种机制清除细胞表面沉积的MAC,并以胞吞方式为主。 相似文献
20.