全文获取类型
收费全文 | 16175篇 |
免费 | 1529篇 |
国内免费 | 951篇 |
专业分类
耳鼻咽喉 | 146篇 |
儿科学 | 177篇 |
妇产科学 | 285篇 |
基础医学 | 2026篇 |
口腔科学 | 270篇 |
临床医学 | 2157篇 |
内科学 | 2619篇 |
皮肤病学 | 183篇 |
神经病学 | 848篇 |
特种医学 | 571篇 |
外国民族医学 | 5篇 |
外科学 | 1913篇 |
综合类 | 2133篇 |
现状与发展 | 1篇 |
一般理论 | 6篇 |
预防医学 | 1077篇 |
眼科学 | 483篇 |
药学 | 1650篇 |
15篇 | |
中国医学 | 741篇 |
肿瘤学 | 1349篇 |
出版年
2024年 | 46篇 |
2023年 | 241篇 |
2022年 | 576篇 |
2021年 | 790篇 |
2020年 | 554篇 |
2019年 | 548篇 |
2018年 | 556篇 |
2017年 | 502篇 |
2016年 | 493篇 |
2015年 | 715篇 |
2014年 | 872篇 |
2013年 | 820篇 |
2012年 | 1165篇 |
2011年 | 1168篇 |
2010年 | 850篇 |
2009年 | 662篇 |
2008年 | 774篇 |
2007年 | 796篇 |
2006年 | 824篇 |
2005年 | 764篇 |
2004年 | 637篇 |
2003年 | 611篇 |
2002年 | 567篇 |
2001年 | 447篇 |
2000年 | 386篇 |
1999年 | 393篇 |
1998年 | 284篇 |
1997年 | 246篇 |
1996年 | 184篇 |
1995年 | 185篇 |
1994年 | 120篇 |
1993年 | 101篇 |
1992年 | 111篇 |
1991年 | 96篇 |
1990年 | 74篇 |
1989年 | 70篇 |
1988年 | 69篇 |
1987年 | 64篇 |
1986年 | 42篇 |
1985年 | 43篇 |
1984年 | 23篇 |
1983年 | 15篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 21篇 |
1976年 | 11篇 |
1974年 | 15篇 |
1973年 | 13篇 |
1972年 | 11篇 |
1969年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
正常国人肺静脉血流多普勒频谱分析 总被引:23,自引:2,他引:21
运用彩色多普勒超声观察了107例正常国人的肺静脉血流(PVF)。结果:正负四相型(SIS2DA),占37%;正负三相型(SDA)占45%,正向两相型(SD)占18%。呼吸,性别不显著影响其表现,但心率、心律及取样容积位置均影响之。94%(101/107)正常者的SF>50%,表明正常国人前向性PVF主要是收缩期占主型,增龄使这一特征更明显。98%(105/107)正常者PVF的Ap<40cm/s,且其不受年龄影响。结论:正常国人PVF超声表现的多形性间有本质上的同一性,正确认识之有助于指导辨别病理性PVF频谱 相似文献
82.
云南省卫生资源配置标准的弹性系数研究 总被引:2,自引:1,他引:1
目的 在进行云南省区域分类基础上制定云南省区域卫生资源配置标准标志值后 ,根据云南省各个地区的特点增加不同弹性系数。方法 采用流行病学研究方法 ,收集和分析云南省不同地州市 1990~ 1999年有关人口、社会经济状况及卫生经费的投入、居民健康状况、居民文化、生活水平、少数民族状况、旅游地区、边境线长短及贫困状况等资料。结果 研究结果表明曲靖地区、玉溪市、保山地区增加弹性系数最少 ,分别为 0 67%、 1 5 8%和1 68% ,怒江州、迪庆州和西双版纳州增加弹性系数最多 ,分别为 11 15 %、 10 2 5 %和 9 84 %。其它地区的弹性系数分别为昆明市 5 88% ,昭通地区 2 3 1% ,楚雄州 2 3 0 % ,红河州 7 0 3 % ,文山州 5 5 3 % ,思茅地区 7 4 3 % ,大理州4 94 % ,德宏州 6 78% ,丽江地区 4 3 5 % ,临沧地区 6 13 %。结论 云南省区域卫生配置标准的弹性系数研究为云南省卫生资源区域分类配置标准提供了科学依据 ,不同弹性系数体现了云南省不同地区的卫生资源区域分类配置标准的公平性、合理性及实用性 相似文献
83.
本文对精神分裂症患者用氯丙嗪治疗前后PAg(T)功能进行观察及BPRS评定,发现精分症患者PAg(T)功能明显高于对照组,用氯丙嗪治疗1个月后,BPRS评定分值下降,患者临床症状消除,而PAg(T)第一时相无变化,第二时相明显升高,说明氯丙嗪聚药物可促发血小板释放内源性致聚物质,同时也说明患者PAg(T)异常不仅仅是情绪应激所致,更重要的是血小板生理功能异常。 相似文献
84.
Jian-Min Qin Xing-Wang Wan Jin-Zhang Zeng Meng-Chao Wu Department of Hepatobiliary Pancreatic Surgery Beijing Chaoyang Hospital Capital University of Medical Sciences Beijing China and Eastern Hepatobiliary Surgery Hospital Second Military Medical University Shanghai China 《Hepatobiliary & Pancreatic Diseases International》2007,(3)
BACKGROUND:Signal regulatory protein alpha1(Sirpα1) is a member of Sirps families containing four immunoreceptor tyrosine-based inhibitory motifs(ITIMs) domains in the cytoplasm of and an activated substrate of receptor tyrosine kinase(RTK),that negatively regulates the RTK-dependent cell proliferating signal transduction pathway.Previously we found that Sirpα1 was closely associated with the occurrence and development of hepatocellular carcinoma(HCC)as well as liver regeneration.Since it is unclear about the regulatory mechanisms,we established the cell line transfected Sirpα1 gene and preliminarily clarified the mechanisms by which Sirpα1 negatively regulates the carcinogenesis and development of HCC. METHODS:Liver cancer Sk-Hep1 cell was respectively transfected with plasmids of pLXSN,pLXSN-Sirpα1 and pLXSN-Sirpα1Δ4Y 2 ,screened with the drug of G418(1200 μg/ml),and various transfected Sk-Hep1 cell lines were obtained.The protein expressions of P65,P50,IκBα,cyclin D1 and Fas in various Sk-Hep1 cell lines were determined by Western blotting,and P65 and P50 were localized by the immunofluorescence technique. RESULTS:Sirpα1 could significantly upregulate the protein expression of IκBα(vs.other cell lines,P<0.05) in the Sk-Hep1 cell,and downregulate the protein expressions of P65,P50 and cyclin D1(vs.other cell lines, P<0.05)in the Sk-Hep1 cell.P65 protein expression was mainly localized in the cytoplasm in the pLXSN Sk-Hep1 cell,and in the nucleus of the Sk-Hep1 cell with mutantSirpα1Δ4Y 2 ,but in nucleus of the Sk-Hep1 cell with wild Sirpα1.P50 protein expression was localized in the cytoplasm and nucleus of the pLXSN Sk-Hep1 cell,but in the nucleus of the Sk-Hep1 cell with wild Sirpα1 and mutant Sirpα1Δ4Y 2 plasmid. CONCLUSIONS:Sirpα1 might negatively regulate and control the abnormal proliferation of liver cancer cells by influencing the protein content and localization of nuclear factor-kappa B,then influence the expression of cyclins such as cyclin D1 in the signal transduction pathway.It may be one of the important mechanisms by which Sirpα1 negatively regulates the carcinogenesis and development of HCC. 相似文献
85.
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
86.
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
87.
吗啡对机械通气病人的应用 总被引:1,自引:0,他引:1
为获得病人在接受呼吸机期间充分的镇静、良好的耐管并与呼吸机合拍达到满意的治疗效果,对60例不同年龄的患者在进行呼吸机支持治疗期间,采用平均045mg/(kgd)的吗啡量持续微量泵静脉注入,间断辅助安定的方法.用药后连续2h观察血压、心率、呼吸、意识等变化.结果:在用药期间病人血压、心率、呼吸平稳,保持清醒,安静耐管,解决了病人与呼吸机拮抗的矛盾.结果表明:该法在临床上有广泛使用价值 相似文献
88.
计算机在医学领域中的应用及展望 总被引:2,自引:0,他引:2
对计算机在医学文献检索、医学统计软件包的编制、疾病诊断、医院管理等医学领域中的应用作了简要的综述,并对未来的发展进行了预测。 相似文献
89.
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
90.