全文获取类型
收费全文 | 11514篇 |
免费 | 1253篇 |
国内免费 | 125篇 |
专业分类
耳鼻咽喉 | 98篇 |
儿科学 | 399篇 |
妇产科学 | 217篇 |
基础医学 | 1515篇 |
口腔科学 | 225篇 |
临床医学 | 1517篇 |
内科学 | 2258篇 |
皮肤病学 | 116篇 |
神经病学 | 1118篇 |
特种医学 | 390篇 |
外科学 | 1360篇 |
综合类 | 757篇 |
一般理论 | 13篇 |
预防医学 | 1151篇 |
眼科学 | 341篇 |
药学 | 758篇 |
中国医学 | 4篇 |
肿瘤学 | 655篇 |
出版年
2022年 | 102篇 |
2021年 | 216篇 |
2020年 | 134篇 |
2019年 | 183篇 |
2018年 | 288篇 |
2017年 | 175篇 |
2016年 | 180篇 |
2015年 | 170篇 |
2014年 | 259篇 |
2013年 | 464篇 |
2012年 | 505篇 |
2011年 | 509篇 |
2010年 | 336篇 |
2009年 | 285篇 |
2008年 | 460篇 |
2007年 | 578篇 |
2006年 | 546篇 |
2005年 | 543篇 |
2004年 | 481篇 |
2003年 | 447篇 |
2002年 | 449篇 |
2001年 | 420篇 |
2000年 | 415篇 |
1999年 | 376篇 |
1998年 | 183篇 |
1997年 | 147篇 |
1996年 | 180篇 |
1995年 | 144篇 |
1994年 | 113篇 |
1993年 | 131篇 |
1992年 | 288篇 |
1991年 | 271篇 |
1990年 | 290篇 |
1989年 | 243篇 |
1988年 | 219篇 |
1987年 | 241篇 |
1986年 | 193篇 |
1985年 | 152篇 |
1984年 | 152篇 |
1983年 | 130篇 |
1982年 | 99篇 |
1981年 | 65篇 |
1980年 | 68篇 |
1979年 | 109篇 |
1978年 | 98篇 |
1977年 | 83篇 |
1976年 | 71篇 |
1975年 | 73篇 |
1973年 | 56篇 |
1970年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
Karen A. Sullivan Katherine M. White Ross McD. Young Clinton Scott 《International journal of behavioral medicine》2010,17(1):67-73
Background
Worldwide stroke is serious problem and one that necessitates continued efforts towards prevention. The health belief model suggests that improvements in prevention will follow from incorporating strategies that change beliefs, but this approach relies on the availability of tools for measuring such change. The Cerebrovascular Attitudes and Beliefs Scale (CABS-R) was developed to meet this need. 相似文献962.
963.
964.
Evidence for self-renewing lung cancer stem cells and their implications in tumor initiation,progression, and targeted therapy 总被引:1,自引:0,他引:1
The discovery of rare tumor cells with stem cell features first in leukemia and later in solid tumors has emerged as an important
area in cancer research. It has been determined that these stem-like tumor cells, termed cancer stem cells, are the primary
cellular component within a tumor that drives disease progression and metastasis. In addition to their stem-like ability to
self-renew and differentiate, cancer stem cells are also enriched in cells resistant to conventional radiation therapy and
to chemotherapy. The immediate implications of this new tumor growth paradigm not only require a re-evaluation of how tumors
are initiated, but also on how tumors should be monitored and treated. However, despite the relatively rapid pace of cancer
stem cell research in solid tumors such as breast, brain, and colon cancers, similar progress in lung cancer remains hampered
in part due to an incomplete understanding of lung epithelial stem cell hierarchy and the complex heterogeneity of the disease.
In this review, we provide a critical summary of what is known about the role of normal and malignant lung stem cells in tumor
development, the progress in characterizing lung cancer stem cells and the potential for therapeutically targeting pathways
of lung cancer stem cell self-renewal. 相似文献
965.
Use of a new simplified assay for phospholipase A2 to measure bacterial enzyme levels 总被引:2,自引:0,他引:2
M R Lumb C K Roseblade R Helmig N Uldbjerg M H Sullivan M G Elder 《Clinica chimica acta; international journal of clinical chemistry》1990,189(1):39-46
During investigation of possible phospholipase A2 (PLA2) production by pathogenic bacteria associated with preterm labour, a rapid and simple assay method was developed which involved few steps and which could be applied easily to large numbers of samples. The principle difference from previously described methods lies in separation of the reaction products by partitioning them between organic and aqueous solvents, rather than by using thin layer chromatography. This enabled us to determine that none of the bacteria studied released PLA2 into the culture medium spontaneously, and that only Escherichia coli contained high levels of PLA2. 相似文献
966.
967.
968.
OBJECTIVE: The association of C4A deficiency with systemic lupus erythematosus (SLE) is well documented. In Caucasian populations, the most common cause of C4A deficiency is a large gene deletion in linkage disequilibrium with a conserved MHC haplotype. Because of this linkage disequilibrium, it has been difficult to determine which of the genes constitutes the disease susceptibility allele. Evidence from non-caucasoid populations has supported a role for C4A deficiency in SLE. We investigated whether a specific genetic cause of C4A deficiency, not associated with A1, B8, DR3, is found with increased frequency in SLE compared to controls. METHODS: Polymerase chain reaction was used to identify carriers of a 2 base pair (bp) insertion in exon 29. In total, 188 patients with SLE from the Johns Hopkins lupus cohort and 222 controls were genotyped. RESULTS: The 2 bp insertion was found more frequently in patients with SLE compared to controls and was more common in Caucasian than in African American SLE patients. There were no clinical differences between patients that carried the mutation and those that did not. CONCLUSION: The association of this C4A null allele with SLE supports a role for C4A deficiency independent of other MHC associations in the etiopathogenesis of SLE. 相似文献
969.
970.
R N Jones R Pifarré H J Sullivan A Montoya M Bakhos J G Grieco B K Foy J Wyatt 《The Annals of thoracic surgery》1987,44(2):159-163
In 1983 and 1984, coronary artery bypass grafting (CABG) was performed on 107 consecutive patients for postinfarction angina. In each instance, CABG was done within 30 days of infarction. Sixty-three patients (59%) required intravenous administration of nitroglycerin and/or the intraaortic balloon pump (IABP) for relief of angina. Oral medications relieved angina in the remaining 44 patients. Thirty-eight patients underwent CABG 7 days or less after the infarction (Group 1), 25 received it between 8 and 15 days later (Group 2), and 44 had CABG between 16 and 30 days later (Group 3). There were 9 in-hospital deaths: 4 in Group 1, 2 in Group 2, and 3 in Group 3. Thirteen patients needed the IABP for hemodynamic stability as well as relief of angina. Even when the patient was stable hemodynamically, death was more likely to occur among these 13 patients if CABG was conducted within 7 days of infarction. Follow-up was 94% complete at 29.4 months. Eighty-six percent of patients were asymptomatic or in New York Heart Association Functional Class I, and 6% were in Class II. There were 2 late deaths. CABG for angina can be accomplished within 30 days of an acute infarction with good results. The exception to this rule is the patient in whom shock develops after a myocardial infarction and who, despite stabilization, receives CABG within 7 days of the infarction. 相似文献