全文获取类型
收费全文 | 10213篇 |
免费 | 708篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 167篇 |
妇产科学 | 162篇 |
基础医学 | 1446篇 |
口腔科学 | 444篇 |
临床医学 | 1015篇 |
内科学 | 2197篇 |
皮肤病学 | 214篇 |
神经病学 | 966篇 |
特种医学 | 413篇 |
外科学 | 1806篇 |
综合类 | 60篇 |
一般理论 | 4篇 |
预防医学 | 477篇 |
眼科学 | 190篇 |
药学 | 767篇 |
中国医学 | 23篇 |
肿瘤学 | 550篇 |
出版年
2023年 | 92篇 |
2022年 | 76篇 |
2021年 | 297篇 |
2020年 | 182篇 |
2019年 | 273篇 |
2018年 | 275篇 |
2017年 | 255篇 |
2016年 | 287篇 |
2015年 | 325篇 |
2014年 | 407篇 |
2013年 | 413篇 |
2012年 | 723篇 |
2011年 | 732篇 |
2010年 | 367篇 |
2009年 | 372篇 |
2008年 | 587篇 |
2007年 | 583篇 |
2006年 | 585篇 |
2005年 | 578篇 |
2004年 | 457篇 |
2003年 | 485篇 |
2002年 | 429篇 |
2001年 | 144篇 |
2000年 | 111篇 |
1999年 | 121篇 |
1998年 | 112篇 |
1997年 | 93篇 |
1996年 | 87篇 |
1995年 | 71篇 |
1994年 | 60篇 |
1993年 | 53篇 |
1992年 | 77篇 |
1991年 | 85篇 |
1990年 | 67篇 |
1989年 | 73篇 |
1988年 | 51篇 |
1987年 | 50篇 |
1986年 | 42篇 |
1985年 | 42篇 |
1984年 | 38篇 |
1983年 | 47篇 |
1982年 | 37篇 |
1981年 | 32篇 |
1979年 | 33篇 |
1978年 | 20篇 |
1972年 | 20篇 |
1934年 | 20篇 |
1933年 | 20篇 |
1932年 | 24篇 |
1931年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
1.
2.
Timo Rath Lukas Pfeifer Clemens Neufert reas Kremer Moritz Leppkes Arthur Hoffman Markus F Neurath Steffen Zopf 《World journal of gastroenterology : WJG》2020,26(16):1962-1970
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode. 相似文献
3.
Nicholas E. Anton Tomoko Mizota Lava R. Timsina Jake A. Whiteside Erinn M. Myers Dimitrios Stefanidis 《American journal of surgery》2019,217(2):266-271
Introduction
Several studies demonstrated that simulator-acquired skill transfer to the operating room is incomplete. Our objective was to identify trainee characteristics that predict the transfer of simulator-acquired skill to the operating room.Methods
Trainees completed baseline assessments including intracorporeal suturing (IS) performance, attentional selectivity, self-reported use of mental skills, and self-reported prior clinical and simulated laparoscopic experience and confidence. Residents then followed proficiency-based laparoscopic skills training, and their skill transfer was assessed on a live-anesthetized porcine model. Predictive characteristics for transfer test performance were assessed using multiple linear regression.Results
Thirty-eight residents completed the study. Automaticity, attentional selectivity, resident perceived ability with laparoscopy and simulators, and post-training IS performance were predictive of IS performance during the transfer test.Conclusions
Promoting automaticity, self-efficacy, and attention selectivity may help improve the transfer of simulator-acquired skill. Mental skills training and training to automaticity may therefore be valuable interventions to achieve this goal. 相似文献4.
5.
6.
7.
The association between family affluence and smoking among 15‐year‐old adolescents in 33 European countries,Israel and Canada: the role of national wealth 下载免费PDF全文
8.
Anton A. Semenistyy Elena A. Litvina EA Anna G. Fedotova Chukwuweike Gwam Andrey N. Mironov 《Injury》2019,50(2):515-520
Background
Intramedullary nailing is considered a “gold standard” for treatment of tibial shaft fractures. However, some types of fractures are typically considered as “difficult for nailing”. This group includes the periarticular fractures, fractures of both bones at the same level, comminuted and segmental fractures of the tibia. Fixator-assisted nailing (FAN) is an effective method treatment of these types of fractures. The main requirements for the ideal reduction device are an ease of its installation and an ability of multiplanar fracture reduction. Fixator-assisted nailing (FAN) with the use of two perpendicular to each other monolateral tubular frames perfectly meets these requirements. In this study we present this new surgical technique and the analysis of first 30 cases.Methods
A prospective analysis was conducted for 30 patients with “difficult for nailing” tibial fractures treated with fixator-assisted nailing in our institution between September 1st, 2017, and March 1st, 2018. The duration of surgery and its different stages, the time of fluoroscopy, difficulties encountered during surgery, were analyzed. Clinical and radiological methods were used to evaluated reduction quality.Results
In all 30 cases the acceptable reduction was achieved. The mean duration of the surgical procedure was 73.7?±?3?min. The mean duration of fluoroscopy 85.9?±?4.8?s. In 7 cases we faced with technical difficulties, which were successfully addressed.Conclusion
The described technique of FAN is an effective method for the treatment of “difficult for nailing” tibial fractures. Future multi-centered studies with a larger number of patients are needed to validate our results. 相似文献9.
10.
Theresa M. Thole Joern Toedling Annika Sprüssel Sebastian Pfeil Larissa Savelyeva David Capper Clemens Messerschmidt Dieter Beule Stefanie Groeneveld-Krentz Cornelia Eckert Guido Gambara Anton G. Henssen Sabine Finkler Johannes H. Schulte Anja Sieber Nils Bluethgen Christian R. A. Regenbrecht Annette Künkele Marco Lodrini Angelika Eggert Hedwig E. Deubzer 《International journal of cancer. Journal international du cancer》2020,146(4):1031-1041
Accurate modeling of intratumor heterogeneity presents a bottleneck against drug testing. Flexibility in a preclinical platform is also desirable to support assessment of different endpoints. We established the model system, OHC-NB1, from a bone marrow metastasis from a patient diagnosed with MYCN-amplified neuroblastoma and performed whole-exome sequencing on the source metastasis and the different models and passages during model development (monolayer cell line, 3D spheroid culture and subcutaneous xenograft tumors propagated in mice). OHC-NB1 harbors a MYCN amplification in double minutes, 1p deletion, 17q gain and diploid karyotype, which persisted in all models. A total of 80–540 single-nucleotide variants (SNVs) was detected in each sample, and comparisons between the source metastasis and models identified 34 of 80 somatic SNVs to be propagated in the models. Clonal reconstruction using the combined copy number and SNV data revealed marked clonal heterogeneity in the originating metastasis, with four clones being reflected in the model systems. The set of OHC-NB1 models represents 43% of somatic SNVs and 23% of the cellularity in the originating metastasis with varying clonal compositions, indicating that heterogeneity is partially preserved in our model system. 相似文献