全文获取类型
收费全文 | 2661篇 |
免费 | 109篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 50篇 |
妇产科学 | 26篇 |
基础医学 | 196篇 |
口腔科学 | 47篇 |
临床医学 | 307篇 |
内科学 | 334篇 |
皮肤病学 | 13篇 |
神经病学 | 65篇 |
特种医学 | 201篇 |
外科学 | 361篇 |
综合类 | 379篇 |
预防医学 | 249篇 |
眼科学 | 22篇 |
药学 | 236篇 |
中国医学 | 249篇 |
肿瘤学 | 60篇 |
出版年
2024年 | 6篇 |
2023年 | 29篇 |
2022年 | 77篇 |
2021年 | 121篇 |
2020年 | 103篇 |
2019年 | 64篇 |
2018年 | 82篇 |
2017年 | 72篇 |
2016年 | 97篇 |
2015年 | 99篇 |
2014年 | 171篇 |
2013年 | 144篇 |
2012年 | 142篇 |
2011年 | 219篇 |
2010年 | 178篇 |
2009年 | 108篇 |
2008年 | 142篇 |
2007年 | 126篇 |
2006年 | 96篇 |
2005年 | 108篇 |
2004年 | 79篇 |
2003年 | 70篇 |
2002年 | 49篇 |
2001年 | 47篇 |
2000年 | 32篇 |
1999年 | 25篇 |
1998年 | 25篇 |
1997年 | 21篇 |
1996年 | 12篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 17篇 |
1992年 | 16篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 16篇 |
1984年 | 7篇 |
1982年 | 6篇 |
1980年 | 11篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1974年 | 8篇 |
1973年 | 9篇 |
1972年 | 9篇 |
1971年 | 6篇 |
1969年 | 8篇 |
排序方式: 共有2827条查询结果,搜索用时 15 毫秒
1.
2.
Arthroscopic acromioclavicular joint excision is a commonly performed but technically demanding procedure. Incomplete excision can leave residual symptoms. We present a simple, reproducible technique ensuring satisfactory excision of the joint. 相似文献
3.
4.
《Vaccine》2021,39(45):6601-6613
AKS-452 is a biologically-engineered vaccine comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain antigen (Ag) and human IgG1 Fc (SP/RBD-Fc) in clinical development for the induction and augmentation of neutralizing IgG titers against SARS-CoV-2 viral infection to address the COVID-19 pandemic. The Fc moiety is designed to enhance immunogenicity by increasing uptake via Fc-receptors (FcγR) on Ag-presenting cells (APCs) and prolonging exposure due to neonatal Fc receptor (FcRn) recycling. AKS-452 induced approximately 20-fold greater neutralizing IgG titers in mice relative to those induced by SP/RBD without the Fc moiety and induced comparable long-term neutralizing titers with a single dose vs. two doses. To further enhance immunogenicity, AKS-452 was evaluated in formulations containing a panel of adjuvants in which the water-in-oil adjuvant, Montanide™ ISA 720, enhanced neutralizing IgG titers by approximately 7-fold after one and two doses in mice, including the neutralization of live SARS-CoV-2 virus infection of VERO-E6 cells. Furthermore, ISA 720-adjuvanted AKS-452 was immunogenic in rabbits and non-human primates (NHPs) and protected from infection and clinical symptoms with live SARS-CoV-2 virus in NHPs (USA-WA1/2020 viral strain) and the K18 human ACE2-trangenic (K18-huACE2-Tg) mouse (South African B.1.351 viral variant). These preclinical studies support the initiation of Phase I clinical studies with adjuvanted AKS-452 with the expectation that this room-temperature stable, Fc-fusion subunit vaccine can be rapidly and inexpensively manufactured to provide billions of doses per year especially in regions where the cold-chain is difficult to maintain. 相似文献
5.
目的探讨自血穴位注射疗法联合马来酸茚达特罗治疗老年稳定期慢性阻塞性肺疾病(COPD)的临床疗效及其对患者炎性因子、免疫功能及肺功能的影响。 方法将2015年5月至2016年5月我院收治的86例老年缓解期COPD患者分为观察组与对照组。对照组给予马来酸茚达特罗治疗,观察组在对照组治疗基础上另给予自血穴位注射疗法。治疗12周后,评价2组临床疗效。治疗前及治疗12周后,分别检测2组患者肺功能指标(FEV1、FVC与PEF),炎性因子(IL-8、α1-AT、IL-6及TNF-α),免疫功能指标(IgG、IgA、CD3+及CD4+)水平。治疗期间,对2组患者的不良反应进行密切观察。 结果治疗后二组患者各项检测指标均优于治疗前。治疗12周后,观察组总有效率为90.7%,明显高于对照组的72.1%(P<0.05)。治疗12周后,观察组FEV1、FVC与PEF等肺功能指标,IgG、IgA、CD3+及CD4+等免疫功能指标水平均明显高于对照组(P<0.05),而IL-8、α1-AT、IL-6及TNF-α含量分别为(23.23±3.87)ng/L、(3.43±0.41)g/L、(52.25±5.38)ng/L及(43.12±3.98)ng/L,改善程度均明显优于对照组(P<0.05)。治疗期间,2组患者均未出现严重不良反应。 结论自血穴位注射疗法联合马来酸茚达特罗治疗老年稳定期COPD疗效确切,可有效改善患者炎症水平,值得进行深入研究。 相似文献
6.
7.
A Stable Q Compensated Reverse Time Migration Method Based on Excitation Amplitude Imaging Condition
下载免费PDF全文
![点击此处可从《Communications In Computational Physics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Qingqing Li Li-Yun Fu Weijia Sun Wei Wei & Wanting Hou 《Communications In Computational Physics》2020,28(1):141-166
The stability and efficiency, especially the stability, are generally concerned
issues in Q compensated reverse time migration (Q-RTM). The instability occurs because of the exponentially boosted high frequency ambient noise during the forward
or backward seismic wavefield propagation. The regularization and low-pass filtering
methods are two effective strategies to control the instability of the wave propagation in Q-RTM. However, the regularization parameters are determined experimentally, and the wavefield cannot be recovered accurately. The low-pass filtering method
cannot balance the selection of cutoff frequency for varying Q values, and may damage
the effective signals, especially when the signal-to-noise ratio (SNR) of the seismic data
is low, the Q-RTM will be a highly unstable process. In order to achieve the purpose
of stability, the selection of cutoff frequency will be small enough, which can cause
great damage to the effective high frequency signals. In this paper, we present a stable Q-RTM algorithm based on the excitation amplitude imaging condition, which can
compensate both the amplitude attenuation and phase dispersion. Unlike the existing Q-RTM algorithms enlarging the amplitude, the exponentially attenuated seismic
wavefield will be used during both the forward and backward wavefield propagation
of Q-RTM. Therefore, the new Q-RTM algorithm is relative stable, even for the low
SNR seismic data. In order to show the accuracy and stability of our stable Q-RTM
algorithm clearly, an example based on Graben model will be illustrated. Then, a realistic BP gas chimney model further demonstrates that the proposed method enjoys
good stability and anti-noise performance compared with the traditional Q-RTM with
amplitude amplification. Compare the Q-RTM images of these two models to the reference images obtained by the acoustic RTM with acoustic seismic data, the new Q-RTM
results match the reference images quite well. The proposed method is also tested
using a field seismic data, the result shows the effectiveness of our proposed method. 相似文献
8.
稳定性核素测定大鼠小肠蛋白质合成 总被引:2,自引:1,他引:1
目的:建立稳定性核素([L-^15N]亮氨酸)测定大鼠小肠蛋白质合成率的方法。方法:分别测定静脉注射相同剂量[L-^15N]亮氨酸不同时相的大鼠小肠^15N丰度及不同剂量[L-^15N]亮氨酸同一时相的大鼠小肠^15N丰度。结果:大鼠小肠游离氨基酸池中^15N核素丰度在注射后0.5h内呈线性上升并达高峰,维持4h后缓慢下降,小肠蛋白质中的^15N丰度0.5h至12h基本维持不变;随着注射剂量的增加,大鼠小肠蛋白质分数合成率(FSR)亦增加,当[L-^15N]亮氨酸剂量在1.0mmol/kg以上,FSR并不随施加[L15N]亮氨酸剂量的加大而增加。结论:在进行大鼠小肠蛋白质合成率测定时,一次性静脉注射的测量最佳时限为0.5h,剂量为1.0mmol/kg。 相似文献
9.
Sérgio Carreir?o Leandro Pereira Marcelo Wilson Rocha Almeida 《Aesthetic plastic surgery》2009,33(3):445-451
Surgical procedures for the mammary region currently are assuming an important role in body-contouring surgery. Enhancement
of results is a constant challenge to the plastic surgeon. A simple and efficient maneuver for resection of the breast’s lateral
pole based on the mammoplasty technique of Professor Ivo Pitanguy is described.
This study realized at the Private Clinic Sérgio Carreir?o, Rio de Janeiro, RJ, Brazil. 相似文献
10.
目的运用siRNA技术在肝癌细胞株中建立稳定低表达人胰岛素样生长因子1类受体(IGF1R)基因的细胞株。方法构建包含封闭IGF1R基因的真核表达载体pSUPER-IGF1R-siRNA,转染SMMC7721和Hep3B细胞,G418筛选表达稳定的细胞株。通过RT-PCR、Western-blot分析与鉴定IGF1R mRNA和蛋白及cyclin D1、cyclinB1蛋白的表达,并绘制细胞生长曲线。结果在SMMC7721和Hep3B细胞中成功建立低表达IGF1R基因的细胞株,其生长明显减慢(P<0.05),且其cyclinD1表达亦明显下降(P<0.05)。结论pSUPER-IGF1R-siRNA能抑制SMMC7721和Hep3B细胞的生长。 相似文献