全文获取类型
收费全文 | 2467篇 |
免费 | 121篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 48篇 |
妇产科学 | 22篇 |
基础医学 | 280篇 |
口腔科学 | 57篇 |
临床医学 | 206篇 |
内科学 | 556篇 |
皮肤病学 | 47篇 |
神经病学 | 205篇 |
特种医学 | 185篇 |
外科学 | 405篇 |
综合类 | 15篇 |
一般理论 | 1篇 |
预防医学 | 106篇 |
眼科学 | 23篇 |
药学 | 145篇 |
中国医学 | 1篇 |
肿瘤学 | 262篇 |
出版年
2023年 | 4篇 |
2022年 | 24篇 |
2021年 | 35篇 |
2020年 | 25篇 |
2019年 | 34篇 |
2018年 | 36篇 |
2017年 | 32篇 |
2016年 | 53篇 |
2015年 | 57篇 |
2014年 | 76篇 |
2013年 | 92篇 |
2012年 | 189篇 |
2011年 | 195篇 |
2010年 | 132篇 |
2009年 | 120篇 |
2008年 | 201篇 |
2007年 | 242篇 |
2006年 | 238篇 |
2005年 | 182篇 |
2004年 | 183篇 |
2003年 | 153篇 |
2002年 | 140篇 |
2001年 | 15篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 18篇 |
1997年 | 19篇 |
1996年 | 8篇 |
1995年 | 11篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有2614条查询结果,搜索用时 15 毫秒
71.
Fabian Falkenstein Marco Gessi Daniela Kandels Ho-Keung Ng René Schmidt Monika Warmuth-Metz Brigitte Bison Juergen Krauss Rolf-Dieter Kortmann Beate Timmermann Ulrich-Wilhelm Thomale Michael H. Albert Arnulf Pekrun Eberhard Maaß Astrid K. Gnekow Torsten Pietsch 《International journal of cancer. Journal international du cancer》2020,147(8):2159-2175
Reports on pediatric low-grade diffuse glioma WHO-grade II (DG2) suggest an impaired survival rate, but lack conclusive results for genetically defined DG2-entities. We analyzed the natural history, treatment and prognosis of DG2 and investigated which genetically defined sub-entities proved unfavorable for survival. Within the prospectively registered, population-based German/Swiss SIOP-LGG 2004 cohort 100 patients (age 0.8-17.8 years, 4% neurofibromatosis [NF1]) were diagnosed with a DG2. Following biopsy (41%) or variable extent of resection (59%), 65 patients received no adjuvant treatment. Radiologic progression or severe neurologic symptoms prompted chemotherapy (n = 18) or radiotherapy (n = 17). Multiple lines of salvage treatment were necessary for 19/35 patients. Five years event-free survival dropped to 0.44, while 5 years overall survival was 0.90 (median observation time 8.3 years). Extensive genetic profiling of 65/100 DG2 identified Histone3-K27M-mutation in 4, IDH1-mutation in 11, BRAF-V600-mutation in 12, KIAA1549-BRAF-fusions in 6 patients, while the remaining 32 tumor tissues did not show alterations of these genes. Progression to malignant glioma occurred in 12 cases of all genetically defined subgroups within a range of 0.5 to 10.8 years, except for tumors carrying KIAA1549-BRAF-fusions. Histone3-K27M-mutant tumors proved uniformly fatal within 0.6 to 2.4 years. The current LGG treatment strategy seems appropriate for all DG2-entities, with the exemption of Histone3-K27M-mutant tumors that require a HGG-related treatment strategy. Our data confirm the importance to genetically define pediatric low-grade diffuse gliomas for proper treatment decisions and risk assessment. 相似文献
72.
Daniele Roberto Giacobbe Juergen Prattes Joost Wauters Silvia Dettori Alessio Signori Jon Salmanton-García Johan Maertens Marc Bourgeois Marijke Reynders Lynn Rutsaert Niels Van Regenmortel Piet Lormans Simon Feys Nikolay Klimko Olga Shadrivova Oliver A. Cornely Riina Rautemaa-Richardson Philipp Koehler Katrien Lagrou Matteo Bassetti Martin Hoenigl 《Journal of clinical microbiology》2022,60(4)
73.
Bone marrow aspirations in oncological patients: experience from an in-house standard in paediatrics
Sauer Harald Graeber Stefan Lieser Ulla Foell Juergen 《Wiener Medizinische Wochenschrift》2019,169(3-4):82-86
Wiener Medizinische Wochenschrift - Nearly all paediatric patients require deep sedation when undergoing bone marrow aspiration (BMA). We analyzed the data from our protocols documented in... 相似文献
74.
75.
Automated extraction of genomic DNA from medically important yeast species and filamentous fungi by using the MagNA Pure LC system 总被引:5,自引:0,他引:5 下载免费PDF全文
Loeffler J Schmidt K Hebart H Schumacher U Einsele H 《Journal of clinical microbiology》2002,40(6):2240-2243
A fully automated assay was established for the extraction of DNA from clinically important fungi by using the MagNA Pure LC instrument. The test was evaluated by DNA isolation from 23 species of yeast and filamentous fungi and by extractions (n = 28) of serially diluted Aspergillus fumigatus conidia (10(5) to 0 CFU/ml). Additionally, DNA from 67 clinical specimens was extracted and compared to the manual protocol. The detection limit of the MagNA Pure LC assay of 10 CFU corresponded to the sensitivity when DNA was extracted manually; in 9 of 28 runs, we could achieve a higher sensitivity of 1 CFU/ml blood, which was found to be significant (p 相似文献
76.
Somatoform pain disorder in the general population 总被引:6,自引:0,他引:6
Grabe HJ Meyer C Hapke U Rumpf HJ Freyberger HJ Dilling H John U 《Psychotherapy and psychosomatics》2003,72(2):88-94
BACKGROUND: Chronic pain disorder is assumed to represent a frequent and disabling condition. However, data on the prevalence of somatoform pain symptoms and somatoform pain disorder in the community are limited to date. METHODS: German versions of the Composite International Diagnostic Interview were administered to a representative national sample of 4,075 people. Somatoform pain disorder was diagnosed by standardized diagnostic algorithm based on the DSM-III-R criteria (absence of adequate physical findings). One subgroup was identified as also meeting the DSM-IV criterion B for 'significant distress or psychosocial impairment due to the somatoform pain'. RESULTS: A lifetime prevalence rate of somatoform pain disorder according to DSM-III-R of 33.7% and a 6-month rate of 17.3% was found. When applying the DSM-IV B criterion, the prevalence rate dropped to 12.3 and 5.4%, respectively. In both groups more than 95% of the probands had contacted their doctor because of the pain. In 25% of the probands the pain was positively assigned to psychological factors. A female:male ratio of 2:1 was found. CONCLUSIONS: Somatoform pain disorder (DSM-III-R) is a frequent condition. However, only about one third of these subjects is severely distressed or impaired by the pain. A clear operationalized concept of the DSM-IV criterion C 'psychological factors are judged to have an important role in the onset, severity, exacerbation or maintenance of the pain' should be provided in the further development of the diagnosis 'pain disorder' in order to make this diagnosis suitable for general population surveys. 相似文献
77.
Induction of tolerogenic DCs: 'you are what you eat' 总被引:5,自引:0,他引:5
Dendritic cells (DCs) take up antigens using antigen receptors that can be divided into three major classes: C-type lectins, integrins and Fc receptors. These receptors facilitate effective presentation of MHC-peptide complexes to T cells, resulting in the induction of immune responses. However, we discuss recent evidence that some receptors also cause induction of tolerance. Signaling motifs within the receptors either block maturation of DCs or induce signals that render DCs tolerogenic. These DCs then either induce regulatory T cells or cause deletion of effector T cells, resulting in the induction of tolerance. Antigen receptors expressed by DCs might therefore have an important role in the induction and maintenance of peripheral tolerance. 相似文献
78.
Lucia Musumeci Jonathan W. Arthur Florence S. G. Cheung Ashraful Hoque Scott Lippman Juergen K. V. Reichardt 《Human mutation》2010,31(1):67-73
The creation of single nucleotide polymorphism (SNP) databases (such as NCBI dbSNP) has facilitated scientific research in many fields. SNP discovery and detection has improved to the extent that there are over 17 million human reference (rs) SNPs reported to date (Build 129 of dbSNP). SNP databases are unfortunately not always complete and/or accurate. In fact, half of the reported SNPs are still only candidate SNPs and are not validated in a population. We describe the identification of SNDs (single nucleotide differences) in humans, that may contaminate the dbSNP database. These SNDs, reported as real SNPs in the database, do not exist as such, but are merely artifacts due to the presence of a paralogue (highly similar duplicated) sequence in the genome. Using sequencing we showed how SNDs could originate in two paralogous genes and evaluated samples from a population of 100 individuals for the presence/absence of SNPs. Moreover, using bioinformatics, we predicted as many as 8.32% of the biallelic, coding SNPs in the dbSNP database to be SNDs. Our identification of SNDs in the database will allow researchers to not only select truly informative SNPs for association studies, but also aid in determining accurate SNP genotypes and haplotypes. Hum Mutat 31:67–73, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
79.
Coan P Wagner A Bravin A Diemoz PC Keyriläinen J Mollenhauer J 《Physics in medicine and biology》2010,55(24):7649-7662
Over the last two decades phase contrast x-ray imaging techniques have been extensively studied for applications in the biomedical field. Published results demonstrate the high capability of these imaging modalities of improving the image contrast of biological samples with respect to standard absorption-based radiography and routinely used clinical imaging techniques. A clear depiction of the anatomic structures and a more accurate disease diagnosis may be provided by using radiation doses comparable to or lower than those used in current clinical methods. In the literature many works show images of phantoms and excised biological samples proving the high sensitivity of the phase contrast imaging methods for in vitro investigations. In this scenario, the applications of the so-called analyzer-based x-ray imaging (ABI) phase contrast technique are particularly noteworthy. The objective of this work is to demonstrate the feasibility of in vivo x-ray ABI phase contrast imaging for biomedical applications and in particular with respect to joint anatomic depiction and osteoarthritis detection. ABI in planar and tomographic modes was performed in vivo on articular joints of guinea pigs in order to investigate the animals with respect to osteoarthritis by using highly monochromatic x-rays of 52 keV and a low noise detector with a pixel size of 47 × 47 μm(2). Images give strong evidence of the ability of ABI in depicting both anatomic structures in complex systems as living organisms and all known signs of osteoarthritis with high contrast, high spatial resolution and with an acceptable radiation dose. This paper presents the first proof of principle study of in vivo application of ABI. The technical challenges encountered when imaging an animal in vivo are discussed. This experimental study is an important step toward the study of clinical applications of phase contrast x-ray imaging techniques. 相似文献
80.
Weigmann HJ Schanzer S Antoniou C Sterry W Lademann J 《Journal of biomedical optics》2010,15(5):055008
The absorption of filter substances in sunscreens, reducing the incident ultraviolet (UV) radiation, is the basis for the protecting ability of such formulations. The erythema-correlated sun protection factor (SPF), depending mainly on the intensity of the UVB radiation, is the common value to quantify the efficacy of the formulations avoiding sunburn. An ex vivo method combining tape stripping and optical spectroscopy is applied to measure the absorption of sunscreens in the entire UV spectral range. The obtained relations between the short-wavelength UV (UVB) absorption and the SPF confirm a clear influence of the long-wavelength UV (UVA) absorption on the SPF values. The data reflect the historical development of the relation of the concentration of UVB and UVA filters in sunscreens and points to the influence of additional ingredients, e.g., antioxidants and cell-protecting agents on the efficacy of the products. 相似文献