全文获取类型
收费全文 | 13206篇 |
免费 | 1318篇 |
国内免费 | 469篇 |
专业分类
耳鼻咽喉 | 52篇 |
儿科学 | 116篇 |
妇产科学 | 113篇 |
基础医学 | 1684篇 |
口腔科学 | 451篇 |
临床医学 | 2592篇 |
内科学 | 3060篇 |
皮肤病学 | 126篇 |
神经病学 | 746篇 |
特种医学 | 721篇 |
外国民族医学 | 5篇 |
外科学 | 978篇 |
综合类 | 2027篇 |
现状与发展 | 1篇 |
预防医学 | 735篇 |
眼科学 | 95篇 |
药学 | 753篇 |
5篇 | |
中国医学 | 408篇 |
肿瘤学 | 325篇 |
出版年
2024年 | 22篇 |
2023年 | 209篇 |
2022年 | 308篇 |
2021年 | 683篇 |
2020年 | 657篇 |
2019年 | 625篇 |
2018年 | 575篇 |
2017年 | 554篇 |
2016年 | 554篇 |
2015年 | 594篇 |
2014年 | 1070篇 |
2013年 | 934篇 |
2012年 | 872篇 |
2011年 | 941篇 |
2010年 | 751篇 |
2009年 | 709篇 |
2008年 | 626篇 |
2007年 | 668篇 |
2006年 | 574篇 |
2005年 | 465篇 |
2004年 | 391篇 |
2003年 | 311篇 |
2002年 | 273篇 |
2001年 | 243篇 |
2000年 | 169篇 |
1999年 | 146篇 |
1998年 | 138篇 |
1997年 | 102篇 |
1996年 | 104篇 |
1995年 | 76篇 |
1994年 | 82篇 |
1993年 | 54篇 |
1992年 | 60篇 |
1991年 | 51篇 |
1990年 | 64篇 |
1989年 | 39篇 |
1988年 | 38篇 |
1987年 | 31篇 |
1986年 | 25篇 |
1985年 | 40篇 |
1984年 | 33篇 |
1983年 | 28篇 |
1982年 | 18篇 |
1981年 | 12篇 |
1980年 | 20篇 |
1979年 | 8篇 |
1978年 | 11篇 |
1977年 | 5篇 |
1976年 | 14篇 |
1973年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 建立一种能够快速鉴定人参和西洋参的双重实时荧光PCR方法。方法 通过对人参属及其近似种基因序列的分析比对,设计特异性的引物探针,建立双重实时荧光PCR检测方法。PCR反应体系为Premix Ex Taq (Probe qPCR) 10 μL,人参上下游引物各0.5 μL,西洋参上下游引物各0.3 μL,人参与西洋参特异性探针各0.4 μL,DNA模板2 μL,灭菌去离子水补至20 μL。反应条件为95℃预变性30 s;然后以95℃变性5 s,60℃退火延伸30 s进行40个循环。应用该方法测试了27份DNA样品,包括7份人参、6份西洋参、4份人参与西洋参混合样、10份其他人参属样品及其他常见中药材样品的DNA,以确定该方法的特异性。将人参与西洋参样品DNA混合后10倍稀释成不同浓度后进行检测,用以确定该方法的灵敏度。结果 人参及西洋参样品均在特定的荧光通道下出现典型的阳性扩增曲线,人参与西洋参混合样品均同时出现两条阳性扩增曲线,其它对照样品及空白对照均没有出现阳性扩增曲线。灵敏度检测结果显示该方法检测人参及西洋参的最低检测限均为2 pg DNA/反应。结论 本实验建立的双重实时荧光PCR方法能够同时快速、准确、灵敏地鉴别出人参和西洋参。 相似文献
2.
Background: Breast cancer (BC) is the most common malignant tumor in women, and its morbidity and mortality are
increasing each year, due to the lack of specific clinical symptoms in the early stage of BC, and the lack of diagnostic
methods for early breast cancer. Therefore, identifying an effective diagnostic method for early BC has become urgent.
Materials and Methods: Breast lesions with a histological diagnosis that were examined by ultrasonic elastography
(UE) in our department from June 2020 to December 2021 were reviewed. qRT-PCR was performed to measure
the expression levels of miR-144-5p and miR-26b-5p in the plasma of patients with BC. The receiver operating characteristics (ROC) curve and area under the curve (AUC) were used to investigate the potential diagnostic value of miR-
144-5p, miR-26b-5p and the elastographic score in BC. Results: The ultrasonic elastography score(UES) was found to
be significantly upregulated in BC compared with that in benign breast lesions, and the AUC, sensitivity and specificity
were 0.809, 0.717 and 0.806 for distinguishing BC from benign breast lesions, respectively. miR-144-5p and miR-26b-
5p were found to be upregulated in the plasma of BC patients, and miR-144-5p+miR-26b-5p had 0.781 sensitivity and
0.780 specificity for the diagnosis of BC. Furthermore, we found that the diagnostic performance of miR-144-5p and
miR-26b-5p combined with UES for BC had 0.913 sensitivity and 0.890 specificity. Conclusions: The combination of
plasma miR-144-5p, miR-26b-5p and UES has a very high clinical application value for the early detection of BC. 相似文献
3.
《Journal of vascular and interventional radiology : JVIR》2022,33(6):631-638
PurposeTo test the following hypotheses: (a) balloon or stent assistance increases coil packing density (CPD) in the endovascular treatment of intracranial aneurysms, and (b) CPD correlates to ostium area (OA) and aneurysm volume (AV).Materials and MethodsThis retrospective study included 60 aneurysms (54 ruptured and 6 unruptured) treated with simple coiling (SC) (n = 18), balloon-assisted coiling (BAC) (n = 7), or stent-assisted coiling (SAC) (n = 35) at the authors’ institution between August 2017 and December 2019. AV and OA measurements were obtained from 3-dimensional digital subtraction angiography images using commercial software. Coil sizes were retrieved from patient files, and coil volume (CV) measurements were obtained from https://www.angiocalc.com/. Analysis of covariance, multivariate covariance analysis, and Pearson correlation analyses were performed.ResultsThe median value for AV, CV, CPD, and OA was 63.4 mm3 (range, 5.5–1,771.4 mm3), 23.13 mm3 (range, 2.03–296.95 mm3), 33.29% (range, 13.41%–81.02%), and 10.7 mm2 (range, 2.7–49.9 mm2), respectively. Multivariate analysis showed that the CPD values were not significantly different among the treatment groups, although OA significantly differed between the SC and SAC groups (P < .05). Pearson correlations showed that similar to AV, OA was negatively correlated with CPD (r = ?0.321, P < .05).ConclusionsThe CPD value in cerebral aneurysms treated with BAC or SAC did not differ from that in aneurysms treated with SC. 相似文献
4.
5.
吕建裕 《中国医疗器械信息》2022,(4)
输尿管上段结石为临床中常见泌尿系结石类型之一,如不能及时诊治,可引起重度积水、泌尿系感染,甚至脓毒血症,对患者肾功能、健康造成严重影响。随着微创治疗技术在泌尿系结石中应用,微创治疗方法能降低对患者造成治疗性创伤,降低相关并发症发生率,促进患者康复,了解临床中微创治疗输尿管上段结石方法,对临床中合理治疗输尿管上段结石有重要价值。 相似文献
6.
This meta-analysis was designed to assess the effectiveness and safety of extracorporeal shock wave therapy (ESWT) for patients with low back pain (LBP). Pubmed, Embase, Cochrane's library, PEDro (Physiotherapy Evidence Database), China National Knowledge Infrastructure (CNKI), and Wanfang Data were searched until December 2019 to identify studies assessing the effectiveness and safety of EPSW for LBP. The prime outcome is pain intensity measured by Visual Analog Scale (VAS) or numeric rating scale (NRS). Other outcomes included functional status, quality of life, psychological outcomes measured by Oswestry Disability Index (ODI), as well as the adverse events. Mean differences (MD) were calculated for continuous outcomes, while odd ratios (OR) were calculated for binary outcomes. Revman 5.3 software was used for statistical analysis. Five randomized controlled trials (RCTs) were finally included in this meta-analysis. The pooled mean difference in post-treatment pain scores was −2.37 (P <0.0001), indicating that post-treatment pain scores was significantly higher by 2.37 in control group than in ESWT group. At a mean follow-up time of 4–6 weeks, the pooled mean difference in ODI scores was −14.10 (P <0.00001), indicating that the pooled mean difference of post-treatment ODI scores was 14.10 higher in control group than in ESWT group. The use of ESWT is effective in alleviating pain and improving the general functional state for patients with LBP. However, more evidence was needed to verify its safety. 相似文献
7.
《Vaccine》2021,39(14):1933-1942
The genetic and antigenic drift associated with the high pathogenicity avian influenza (HPAI) viruses of Goose/Guangdong (Gs/GD) lineage and the emergence of vaccine-resistant field viruses underscores the need for a broadly protective H5 influenza A vaccine. Here, we tested experimental vector herpesvirus of turkey (vHVT)-H5 vaccines containing either wild-type clade 2.3.4.4A-derived H5 inserts or computationally optimized broadly reactive antigen (COBRA) inserts with challenge by homologous and genetically divergent H5 HPAI Gs/GD lineage viruses in chickens. Direct assessment of protection was confirmed for all the tested constructs, which provided clinical protection against the homologous and heterologous H5 HPAI Gs/GD challenge viruses and significantly decreased oropharyngeal shedding titers compared to the sham vaccine. The cross reactivity was assessed by hemagglutinin inhibition (HI) and focus reduction assay against a panel of phylogenetically and antigenically diverse H5 strains. The COBRA-derived H5 inserts elicited antibody responses against antigenically diverse strains, while the wild-type-derived H5 vaccines elicited protection mostly against close antigenically related clades 2.3.4.4A and 2.3.4.4D viruses. In conclusion, the HVT vector, a widely used replicating vaccine platform in poultry, with H5 insert provides clinical protection and significant reduction of viral shedding against homologous and heterologous challenge. In addition, the COBRA-derived inserts have the potential to be used against antigenically distinct co-circulating viruses and future drift variants. 相似文献
8.
9.
Marion Tardieu Najat Salameh Line Souris David Rousseau Laurène Jourdain Hanadi Skeif François Prévot Ludovic de Rochefort Denis Ducreux Bruno Louis Philippe Garteiser Ralph Sinkus Luc Darrasse Marie Poirier-Quinot Xavier Maître 《NMR in biomedicine》2022,35(7):e4701
Magnetic resonance elastography aims to non-invasively and remotely characterize the mechanical properties of living tissues. To quantitatively and regionally map the shear viscoelastic moduli in vivo, the technique must achieve proper mechanical excitation throughout the targeted tissues. Although it is straightforward, ante manibus, in close organs such as the liver or the breast, which practitioners clinically palpate already, it is somewhat fortunately highly challenging to trick the natural protective barriers of remote organs such as the brain. So far, mechanical waves have been induced in the latter by shaking the surrounding cranial bones. Here, the skull was circumvented by guiding pressure waves inside the subject's buccal cavity so mechanical waves could propagate from within through the brainstem up to the brain. Repeatable, reproducible and robust displacement fields were recorded in phantoms and in vivo by magnetic resonance elastography with guided pressure waves such that quantitative mechanical outcomes were extracted in the human brain. 相似文献
10.