全文获取类型
收费全文 | 4639篇 |
免费 | 306篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 42篇 |
儿科学 | 156篇 |
妇产科学 | 133篇 |
基础医学 | 513篇 |
口腔科学 | 113篇 |
临床医学 | 559篇 |
内科学 | 821篇 |
皮肤病学 | 61篇 |
神经病学 | 325篇 |
特种医学 | 88篇 |
外科学 | 549篇 |
综合类 | 37篇 |
一般理论 | 5篇 |
预防医学 | 524篇 |
眼科学 | 72篇 |
药学 | 321篇 |
中国医学 | 7篇 |
肿瘤学 | 635篇 |
出版年
2023年 | 26篇 |
2022年 | 41篇 |
2021年 | 101篇 |
2020年 | 88篇 |
2019年 | 100篇 |
2018年 | 126篇 |
2017年 | 108篇 |
2016年 | 97篇 |
2015年 | 130篇 |
2014年 | 178篇 |
2013年 | 261篇 |
2012年 | 311篇 |
2011年 | 340篇 |
2010年 | 218篇 |
2009年 | 162篇 |
2008年 | 319篇 |
2007年 | 309篇 |
2006年 | 321篇 |
2005年 | 270篇 |
2004年 | 261篇 |
2003年 | 248篇 |
2002年 | 236篇 |
2001年 | 55篇 |
2000年 | 29篇 |
1999年 | 45篇 |
1998年 | 59篇 |
1997年 | 56篇 |
1996年 | 46篇 |
1995年 | 45篇 |
1994年 | 31篇 |
1993年 | 34篇 |
1992年 | 31篇 |
1991年 | 36篇 |
1990年 | 27篇 |
1989年 | 17篇 |
1988年 | 14篇 |
1987年 | 18篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1984年 | 24篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1981年 | 12篇 |
1980年 | 17篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1968年 | 5篇 |
排序方式: 共有4961条查询结果,搜索用时 31 毫秒
71.
Yasmeen Niazi Hauke Thomsen Bozena Smolkova Ludmila Vodickova Sona Vodenkova Michal Kroupa Veronika Vymetalkova Alena Kazimirova Magdalena Barancokova Katarina Volkovova Marta Staruchova Per Hoffmann Markus M. Nöthen Maria Dušinská Ludovit Musak Pavel Vodicka Kari Hemminki Asta Försti 《Environmental and molecular mutagenesis》2019,60(1):17-28
Chromosomal aberrations (CAs) in human peripheral blood lymphocytes (PBL) measured with the conventional cytogenetic assay have been used for human biomonitoring of genotoxic exposure for decades. CA frequency in peripheral blood is a marker of cancer susceptibility. Previous studies have shown associations between genetic variants in metabolic pathway, DNA repair and major mitotic checkpoint genes and CAs. We conducted a genome-wide association study on 576 individuals from the Czech Republic and Slovakia followed by a replication in two different sample sets of 482 (replication 1) and 1288 (replication 2) samples. To have a broad look at the genetic susceptibility associated with CA frequency, the sample sets composed of individuals either differentially exposed to smoking, occupational/environmental hazards, or they were untreated cancer patients. Phenotypes were divided into chromosome- and chromatid-type aberrations (CSAs and CTAs, respectively) and total chromosomal aberrations (CAtot). The arbitrary cutoff point between individuals with high and low CA frequency was 2% for CAtot and 1% for CSA and CTA. The data were analyzed using age, sex, occupation/cancer and smoking history as covariates. Altogether 11 loci reached the P-value of 10−5 in the GWAS. Replication 1 supported the association of rs1383997 (8q13.3) and rs2824215 (21q21.1) in CAtot and rs983889 (5p15.1) in CTA analysis. These loci were found to be associated with genes involved in mitosis, response to environmental and chemical factors and genes involved in syndromes linked to chromosomal abnormalities. Identification of new genetic variants for the frequency of CAs offers prediction tools for cancer risk in future. Environ. Mol. Mutagen. 60:17–28, 2019. © 2018 Wiley Periodicals, Inc. 相似文献
72.
73.
Dr. T. Noack A.L. Poetini F.A. Kari F. Emrich M. Lühr S. Schwill E. Kuhn O. Heyn 《Zeitschrift für Herz-, Thorax- und Gef??chirurgie》2013,27(4):265-270
The Young Forum of the German Society for Thoracic and Cardiovascular Surgery (GSTCVS) was founded during the 41st annual meeting of the German Society for Thoracic and Cardiovascular Surgery in Freiburg in 2012. The idea was to establish a stronger representation of the needs and problems of young colleagues within the GSTCVS and to improve the communication between residents, students and representatives of the GSTCVS. The aims are to improve residency programs in Germany in general and in particular, to improve the clinical and scientific exchange of residents in Germany, Europe and foreign countries. Attempts will also be made to find solutions that could lead to a better work-life balance in cardiothoracic surgery and therefore make this field more attractive for young physicians. 相似文献
74.
Christina F. Pacchia Geoff P. Kline Mohamed H. Hamdan Kari G. Clark Michael G. Clark Michael L. Smith 《Clinical autonomic research》2011,21(5):325-332
Background
Atrial fibrillation (AF) is the most common sustained dysrhythmia and appears to be an independent predictor of sudden cardiac death. The irregular ventricular rhythm contains both linear and non-linear patterns; however, it remains unclear whether vagally mediated effects are present within these patterns. 相似文献75.
Iñigo Zabalgogeazcoa Pedro E. Gundel Marjo Helander Kari Saikkonen 《Fungal Diversity》2013,60(1):25-32
Epichloë festucae is an endophytic fungus that infects systemically the aerial tissues of the host grass Festuca rubra. This fungus is transmitted vertically from the mother plant to seeds. Hypothetically, the presence of E. festucae could affect the infection of a plant by other fungal species. This could occur if E. festucae metabolites produced in planta interfere negatively with other fungal infections; or alternatively, if the modulation of plant defenses by the endophyte favour further fungal infections. We have analyzed the presence of culturable non-systemic endophytes in plants of F. rubra infected (E+) and not infected (E?) by E. festucae in two subarctic habitats, meadows and riverbanks in Northern Finland. The observed non-systemic endophyte infection frequencies were similar among E+ and E? plants from riverbanks, and E+ plants from meadows. In contrast to these, the infection frequency was significantly lower in E? plants from meadows. This result suggests that the presence of E. festucae is not a main factor determining the presence of non-systemic endophytes in plants. Instead, plant genetic characteristics related to compatibility with E. festucae and other endophytes in the more stable meadow populations might play a role in these fungus–fungus–plant interactions. As a result of the survey, 18 different taxa of non-systemic endophytes were identified in plants of F. rubra. All were ascomycetes except for one basidiomycete. Three endophytic taxa could not be ascribed to a genus, but sequence data indicated that they were conspecific with other unidentified endophytes that have been isolated in cold biomes at different locations. 相似文献
76.
77.
78.
Johansen K Hedlund KO Zweygberg-Wirgart B Bennet R 《Scandinavian journal of infectious diseases》2008,40(11-12):958-964
The aim of this retrospective observational study was to evaluate age, length of hospital stay and development of complications in children hospitalized with community- or nosocomially- acquired rotavirus gastroenteritis (RV GE). In total, medical records of 984 children with RV GE were analysed retrospectively. The median age was 13.8 months (3 weeks to 99 months) in children with community acquired RV GE (n=723) and 9.0 months (range 3 weeks to 82 months) in children with nosocomially acquired RV GE (n=261). During this 11-y surveillance, only 2 children were admitted twice for a RV GE, suggesting development of subsequent protective immunity against severe rotavirus gastroenteritis after the first episode. Complications occurred in 16.5% of the children with community acquired RV GE and only in 1.9% of the nosocomially acquired RV GE. Identified complications in children with community acquired RV GE were: severe dehydration resulting in intensive care (1.7%), death (0.1%), hypertonic dehydration (9.1%), seizures (4.0%) and encephalitis with abnormal EEG (1.7%). The median age of children in need of intensive care was 9.1 months and in those developing hypertonic dehydration 10.8 months, both significantly lower than in children with no complications (p<0.05). Interestingly, the age of children developing seizures and signs of encephalitis was significantly higher than in children with no complications (p<0.01). 相似文献
79.
80.
Amdam GV Norberg K Hagen A Omholt SW 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(4):1799-1802
Vitellogenin is a female-specific glucolipoprotein yolk precursor produced by all oviparous animals. Vitellogenin expression is under hormonal control, and the protein is generally synthesized directly before yolk deposition. In the honeybee (Apis mellifera), vitellogenin is not only synthesized by the reproductive queen, but also by the functionally sterile workers. In summer, the worker population consists of a hive bee group performing a multitude of tasks including nursing inside the nest, and a forager group specialized in collecting nectar, pollen, water, and propolis. Vitellogenin is synthesized in large quantities by hive bees. When hive bees develop into foragers, their juvenile hormone titers increase, and this causes cessation of their vitellogenin production. This inverse relationship between vitellogenin synthesis and juvenile hormone is opposite to the norm in insects, and the underlying proximate processes and life-history reasons are still not understood. Here we document an alternative use of vitellogenin by showing that it is a source for the proteinaceous royal jelly that is produced by the hive bees. Hive bees use the jelly to feed larvae, queen, workers, and drones. This finding suggests that the evolution of a brood-rearing worker class and a specialized forager class in an advanced eusocial insect society has been directed by an alternative utilization of yolk protein. 相似文献