全文获取类型
收费全文 | 35528篇 |
免费 | 2561篇 |
国内免费 | 109篇 |
专业分类
耳鼻咽喉 | 318篇 |
儿科学 | 1370篇 |
妇产科学 | 1017篇 |
基础医学 | 4799篇 |
口腔科学 | 453篇 |
临床医学 | 4451篇 |
内科学 | 6771篇 |
皮肤病学 | 654篇 |
神经病学 | 3814篇 |
特种医学 | 833篇 |
外科学 | 3560篇 |
综合类 | 455篇 |
一般理论 | 33篇 |
预防医学 | 4244篇 |
眼科学 | 624篇 |
药学 | 2025篇 |
中国医学 | 57篇 |
肿瘤学 | 2720篇 |
出版年
2024年 | 41篇 |
2023年 | 263篇 |
2022年 | 479篇 |
2021年 | 960篇 |
2020年 | 604篇 |
2019年 | 1008篇 |
2018年 | 1083篇 |
2017年 | 754篇 |
2016年 | 877篇 |
2015年 | 903篇 |
2014年 | 1288篇 |
2013年 | 1910篇 |
2012年 | 2829篇 |
2011年 | 2873篇 |
2010年 | 1606篇 |
2009年 | 1327篇 |
2008年 | 2303篇 |
2007年 | 2491篇 |
2006年 | 2416篇 |
2005年 | 2272篇 |
2004年 | 2049篇 |
2003年 | 1884篇 |
2002年 | 1819篇 |
2001年 | 342篇 |
2000年 | 264篇 |
1999年 | 292篇 |
1998年 | 355篇 |
1997年 | 310篇 |
1996年 | 250篇 |
1995年 | 210篇 |
1994年 | 176篇 |
1993年 | 212篇 |
1992年 | 156篇 |
1991年 | 143篇 |
1990年 | 127篇 |
1989年 | 124篇 |
1988年 | 113篇 |
1987年 | 78篇 |
1986年 | 96篇 |
1985年 | 82篇 |
1984年 | 82篇 |
1983年 | 88篇 |
1982年 | 69篇 |
1981年 | 54篇 |
1980年 | 68篇 |
1979年 | 59篇 |
1978年 | 46篇 |
1977年 | 41篇 |
1974年 | 35篇 |
1973年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Michael Rosenzweig Martha Skinner Tatiana Prokaeva Roger Théberge Catherine Costello Brian M Drachman Lawreen H Connors 《Amyloid》2007,14(1):65-71
We report the identification of a new transthyretin (TTR) gene mutation and variant protein, Glu61Gly, in a 55-year-old man with progressive cardiomyopathy, mild peripheral neuropathy and bilateral carpal tunnel syndrome. A diagnosis of TTR-associated familial amyloidosis (ATTR) was considered after an endomyocardial biopsy revealed amyloid deposits in the heart of a patient who had no family history of amyloidosis and no evidence of a plasma cell dyscrasia. Serum screening for a TTR variant by isoelectric focusing (IEF) was positive and prompted further studies to identify the genetic abnormality and to characterize the amyloidogenic protein. Direct DNA sequence analysis of all four coding regions in the TTR gene demonstrated heterozygosity in exon 3. Near equal amounts of guanine (G) and adenine (A) were observed at the second base position of codon 61. The wild-type (GAG) and mutated (GGG) sequences found in codon 61 correspond to glutamic acid (Glu) and glycine (Gly) residues, amino acids which differ in mass by -72 Da. Mass spectrometric analyses of TTR immunoprecipitated from serum showed the presence of both wild-type and variant proteins. The observed mass results for the wild-type and variant proteins were consistent with the predicted values calculated from the genetic analysis data. 相似文献
22.
Prof. Philip Harber Kaochoy Saechao Catherine Boomus 《Adverse drug reactions and toxicological reviews》2006,25(4):261-272
Diacetyl is a diketone flavouring agent that is commonly employed for buttery taste as well as other purposes. Industrial exposure to flavouring agents, particularly diacetyl, has recently been associated with bronchiolitis obliterans, a severe respiratory illness producing fibrosis and obstruction of the small airways. This has been most commonly reported in the microwave popcorn production industry, but it has occurred elsewhere. In addition to bronchiolitis obliterans, spirometry abnormalities (fixed airflow obstruction) and respiratory symptoms have been associated with exposure. A direct effect on the respiratory epithelium with the disorganised fibrotic repair appears most likely as the underlying mechanism. Current data suggest that diacetyl is the agent responsible, although it is possible that diacetyl is simply a marker for another causative agent. 相似文献
23.
24.
Paul M. Brunet Jennifer J. Heisz Catherine J. Mondloch David I. Shore Louis A. Schmidt 《Journal of anxiety disorders》2009,23(7):909-914
Contrary to popular beliefs, a recent empirical study using eye tracking has shown that a non-clinical sample of socially anxious adults did not avoid the eyes during face scanning. Using eye-tracking measures, we sought to extend these findings by examining the relation between stable shyness and face scanning patterns in a non-clinical sample of 11-year-old children. We found that shyness was associated with longer dwell time to the eye region than the mouth, suggesting that some shy children were not avoiding the eyes. Shyness was also correlated with fewer first fixations to the nose, which is thought to reflect the typical global strategy of face processing. Present results replicate and extend recent work on social anxiety and face scanning in adults to shyness in children. These preliminary findings also provide support for the notion that some shy children may be hypersensitive to detecting social cues and intentions in others conveyed by the eyes. Theoretical and practical implications for understanding the social cognitive correlates and treatment of shyness are discussed. 相似文献
25.
Catherine Guette Christian Legros Guewen Tournois Max Goyffon Marie-Louise Célérier 《Toxicon》2006,47(6):640-649
In order to establish a venom fingerprint and a peptide profile of the Lasiodora parahybana tarantula venom gland, we used conventional methods such as reversed phase liquid chromatography coupled to an electrospray-ionisation hybrid quadrupole time of flight mass spectrometer (LC/ESI-QqTOFMS), matrix-assisted laser desorption/ionization time-of-flight-MS (MALDI-TOFMS) and direct study of L. parahybana venom by nanospray-ionization QqTOFMS (nanoESI-QqTOFMS) and a new technology for the direct analysis of fresh tissues using MALDI-TOFMS. The analysis of the crude venom allowed the characterization of specific juvenile and adult biomarkers. In situ MALDI analysis of L. parahybana venom gland sections revealed different peptide expression levels all along the gland and non-processed peptide precursors, demonstrating the power of the method for the dynamic investigation of peptide evolution in the venom gland of spiders. 相似文献
26.
David H. Wilson Catherine R. Chittleborough Kerry Kirke Janet F. Grant Richard E. Ruffin 《Sozial- und Pr?ventivmedizin》2004,13(5):406-412
Objectives: Heavy smokers are a segment of the smoking population who are at increased risk of smoking-related morbidity and least likely to achieve cessation. This study identifies the impact of heavy smoking on quality of life by gender and describes the subpopulation for improved targeting.Methods: South Australian representative population data (n = 3010) was used to compare the health-related quality of life status of male and female heavy smokers as assessed by the SF-36. 相似文献
27.
Yew Kuang Cheng Paul A Decker Megan M O'Byrne Catherine R Weiler 《Annals of allergy, asthma & immunology》2006,97(3):306-311
BACKGROUND: There are limited studies of large cohorts of patients with specific polysaccharide antibody deficiency (SPAD) syndrome. OBJECTIVE: To study the clinical and laboratory characteristics of patients with specific polysaccharide antibody deficiency syndrome. METHODS: We retrospectively studied 75 patients with total IgG levels of at least 500 mg/dL and fewer than 9 of 12 responses to vaccination with pneumococcal vaccine polyvalent. Exclusion criteria included an IgG level less than 500 mg/dL, established immunodeficiency syndrome, and secondary immunodeficiency. RESULTS: The most common clinical presentation was frequent infections (n = 69; 92%), including sinusitis (n = 53; 77%), pneumonia (n = 29; 42%), ear infections (n = 18; 26%), and bronchitis (n = 19; 28%). Other presentations were systemic infections (n = 5; 7%), autoimmune or rheumatic diseases (n = 6; 8%), and chronic diarrhea (n = 4; 5%). The median IgG2 level of patients with no response to pneumococcal vaccine polyvalent tended to be lower than that of patients with at least 1 response (150 vs 193 mg/dL, respectively; P = .06). There was no association between total IgG level (categorized as 500-600 or > or = 600 mg/dL) and frequency of infection (P = .43). Patients with fewer responses to pneumococcal vaccine polyvalent and a higher frequency of infections were more likely to receive intravenous immunoglobulin (IVIG) therapy (P = .01 and .003, respectively). Treatment with IVIG significantly reduced the number of infections (P < .001). CONCLUSION: Patients with no response to pneumococcal vaccine polyvalent tended to have lower IgG2 levels; those with fewer responses were more likely to receive IVIG therapy. 相似文献
28.
29.
30.