全文获取类型
收费全文 | 1291篇 |
免费 | 96篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 68篇 |
妇产科学 | 33篇 |
基础医学 | 144篇 |
口腔科学 | 25篇 |
临床医学 | 132篇 |
内科学 | 293篇 |
皮肤病学 | 33篇 |
神经病学 | 46篇 |
特种医学 | 272篇 |
外科学 | 82篇 |
综合类 | 58篇 |
预防医学 | 50篇 |
眼科学 | 9篇 |
药学 | 120篇 |
肿瘤学 | 74篇 |
出版年
2023年 | 5篇 |
2022年 | 12篇 |
2021年 | 28篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 16篇 |
2017年 | 18篇 |
2016年 | 24篇 |
2015年 | 26篇 |
2014年 | 29篇 |
2013年 | 41篇 |
2012年 | 36篇 |
2011年 | 33篇 |
2010年 | 36篇 |
2009年 | 45篇 |
2008年 | 26篇 |
2007年 | 51篇 |
2006年 | 32篇 |
2005年 | 41篇 |
2004年 | 34篇 |
2003年 | 24篇 |
2002年 | 24篇 |
2001年 | 35篇 |
2000年 | 26篇 |
1999年 | 34篇 |
1998年 | 63篇 |
1997年 | 65篇 |
1996年 | 57篇 |
1995年 | 59篇 |
1994年 | 38篇 |
1993年 | 47篇 |
1992年 | 18篇 |
1991年 | 23篇 |
1990年 | 27篇 |
1989年 | 54篇 |
1988年 | 38篇 |
1987年 | 42篇 |
1986年 | 23篇 |
1985年 | 25篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 18篇 |
1978年 | 5篇 |
1977年 | 20篇 |
1976年 | 14篇 |
1975年 | 9篇 |
1973年 | 4篇 |
排序方式: 共有1450条查询结果,搜索用时 15 毫秒
11.
12.
Rupture of the distal biceps tendon: evaluation with MR imaging 总被引:2,自引:0,他引:2
13.
锌酞菁脂质体光动力作用引起小鼠肿瘤的细胞程序性死亡 总被引:3,自引:1,他引:3
电镜观察了锌酞菁脂质体光动力作用引起小鼠MS-2纤维肉瘤的形态学变化。发现其作用很强,并对肿瘤细胞有明显的直接影响。肿瘤细胞的结构表现出明显的程序性细胞死亡(apoptosis,programmedceldeath)的特点:胞核染色质凝聚边集、核固缩、核破裂、染色质凝块流失、胞质内吞噬现象、胞膜表面肿胀粗钝的胞突形成、细胞碎裂等。加深了对锌酞菁脂质体光敏作用机理的认识,但其详细的发生机制和调节途径有待阐明。 相似文献
14.
15.
16.
Ortiz-Alvarez O; Cabral D; Prendiville JS; Stringer D; Petty RE; Malleson PN 《Rheumatology (Oxford, England)》1997,36(2):280-284
Two children are reported in whom intestinal pseudo-obstruction was the
initial manifestation of systemic sclerosis. Gastrointestinal symptoms and
skin changes resolved or improved in both children following treatment with
prednisone and penicillamine (case 1) or methotrexate (case 2), although
radiological changes of the gastrointestinal tract persisted at 3 and 2 yr
of follow-up, respectively.
相似文献
17.
Ian M. Graham Emanuele Di Angelantonio Frank Visseren Dirk De Bacquer Brian A. Ference Adam Timmis Martin Halle Panos Vardas Radu Huculeci Marie-Therese Cooney 《Journal of the American College of Cardiology》2021,77(24):3046-3057
Clinical estimation of the combined effect of several risk factors is unreliable and this resulted in the development of a number of risk estimation systems to guide clinical practice. Here, after defining general principles of risk estimation, the authors describe the evolution of the European Society of Cardiology’s (ESC) Systematic COronary Risk Evaluation (SCORE) risk estimation system and some learnings from the data. They move on to describe the establishment of the ESC’s Cardiovascular Risk Collaboration and outline its proposed research directions. First among these is the evolution of SCORE 2, which provides updated, calibrated risk estimates for total cardiovascular events for low, moderate, high, and very high-risk regions of Europe. The authors conclude by considering that the future of risk estimation may be to express risk as years of exposure to a cardiovascular risk factor profile rather than risk over a fixed time period, such as 10 years, and how advances in genetics may permit individualized lifetime risk estimation from childhood on. 相似文献
18.
Coakley G; Mok CC; Hajeer AH; Ollier WE; Turner D; Sinnott PJ; Hutchinson IV; Panayi GS; Lanchbury JS 《Rheumatology (Oxford, England)》1998,37(9):988-991
OBJECTIVE: To examine whether promoter polymorphisms associated with
variation in interleukin-10 (IL-10) production are relevant to the
development of rheumatoid arthritis (RA) or Felty's syndrome (FS). METHODS:
DNA was obtained from 44 FS patients, 117 RA patients and 295 controls. The
promoter region between -533 and - 1120 was amplified by polymerase chain
reaction, and polymorphisms detected by restriction enzyme digest or
sequence-specific oligonucleotide probing. RESULTS: We found no significant
difference in allele or haplotype frequencies between the groups.
CONCLUSION: There is no association between FS or RA and these recently
identified IL-10 promoter polymorphisms. Other genetic or environmental
factors could explain the alterations in IL-10 levels seen in these
conditions.
相似文献
19.
Marco Gerlinger Sergio A Quezada Karl S Peggs Andrew JS Furness Rosalie Fisher Teresa Marafioti Vishvesh H Shende Nicholas McGranahan Andrew J Rowan Steven Hazell David Hamm Harlan S Robins Lisa Pickering Martin Gore David L Nicol James Larkin Charles Swanton 《The Journal of pathology》2013,231(4):424-432
The recognition of cancer cells by T cells can impact upon prognosis and be exploited for immunotherapeutic approaches. This recognition depends on the specific interaction between antigens displayed on the surface of cancer cells and the T cell receptor (TCR), which is generated by somatic rearrangements of TCR α‐ and β‐chains (TCRb). Our aim was to assess whether ultra‐deep sequencing of the rearranged TCRb in DNA extracted from unfractionated clear cell renal cell carcinoma (ccRCC) samples can provide insights into the clonality and heterogeneity of intratumoural T cells in ccRCCs, a tumour type that can display extensive genetic intratumour heterogeneity (ITH). For this purpose, DNA was extracted from two to four tumour regions from each of four primary ccRCCs and was analysed by ultra‐deep TCR sequencing. In parallel, tumour infiltration by CD4, CD8 and Foxp3 regulatory T cells was evaluated by immunohistochemistry and correlated with TCR‐sequencing data. A polyclonal T cell repertoire with 367–16 289 (median 2394) unique TCRb sequences was identified per tumour region. The frequencies of the 100 most abundant T cell clones/tumour were poorly correlated between most regions (Pearson correlation coefficient, –0.218 to 0.465). 3–93% of these T cell clones were not detectable across all regions. Thus, the clonal composition of T cell populations can be heterogeneous across different regions of the same ccRCC. T cell ITH was higher in tumours pretreated with an mTOR inhibitor, which could suggest that therapy can influence adaptive tumour immunity. These data show that ultra‐deep TCR‐sequencing technology can be applied directly to DNA extracted from unfractionated tumour samples, allowing novel insights into the clonality of T cell populations in cancers. These were polyclonal and displayed ITH in ccRCC. TCRb sequencing may shed light on mechanisms of cancer immunity and the efficacy of immunotherapy approaches. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
20.
Johannes Scherr Bernd Wolfarth Jeffrey W. Christle Axel Pressler Stefan Wagenpfeil Martin Halle 《European journal of applied physiology》2013,113(1):147-155
Borg’s rating of perceived exertion (RPE) is a widely used psycho-physical tool to assess subjective perception of effort during exercise. We evaluated the association between Borg’s RPE and physiological exercise parameters in a very large population. In this cohort study, 2,560 Caucasian men and women [median age 28 (IQR 17–44) years] completed incremental exercise tests on treadmills or cycle ergometers. Heart rate, blood lactate concentration, and RPE (Borg scale 6–20) were simultaneously measured at the end of each work load. Rating of perceived exertion was strongly correlated with heart rate (r = 0.74, p < 0.001) and blood lactate (r = 0.83, p < 0.001). The mean values for lactate threshold (LT) and individual anaerobic threshold corresponded to an RPE of 10.8 ± 1.8 and 13.6 ± 1.8, respectively. Fixed lactate thresholds of 3 and 4 mmol/L corresponded to RPEs of 12.8 ± 2.1 and 14.1 ± 2.0. Gender, age, coronary artery disease (CAD), physical activity status and exercise testing modality did not influence this association significantly (all p > 0.05). Borg’s RPE seems to be an affordable, practical and valid tool for monitoring and prescribing exercise intensity, independent of gender, age, exercise modality, physical activity level and CAD status. Exercising at an RPE of 11–13 (“low”) is recommended for less trained individuals, and an RPE of 13–15 may be recommended when more intense but still aerobic training is desired. 相似文献