全文获取类型
收费全文 | 3287篇 |
免费 | 234篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 106篇 |
妇产科学 | 69篇 |
基础医学 | 386篇 |
口腔科学 | 24篇 |
临床医学 | 287篇 |
内科学 | 709篇 |
皮肤病学 | 33篇 |
神经病学 | 310篇 |
特种医学 | 463篇 |
外科学 | 442篇 |
综合类 | 35篇 |
预防医学 | 161篇 |
眼科学 | 48篇 |
药学 | 144篇 |
肿瘤学 | 295篇 |
出版年
2022年 | 17篇 |
2021年 | 49篇 |
2020年 | 21篇 |
2019年 | 36篇 |
2018年 | 49篇 |
2017年 | 35篇 |
2016年 | 47篇 |
2015年 | 54篇 |
2014年 | 67篇 |
2013年 | 100篇 |
2012年 | 142篇 |
2011年 | 141篇 |
2010年 | 101篇 |
2009年 | 110篇 |
2008年 | 164篇 |
2007年 | 148篇 |
2006年 | 166篇 |
2005年 | 138篇 |
2004年 | 125篇 |
2003年 | 116篇 |
2002年 | 104篇 |
2001年 | 120篇 |
2000年 | 118篇 |
1999年 | 108篇 |
1998年 | 103篇 |
1997年 | 83篇 |
1996年 | 82篇 |
1995年 | 79篇 |
1994年 | 73篇 |
1993年 | 46篇 |
1992年 | 60篇 |
1991年 | 60篇 |
1990年 | 58篇 |
1989年 | 80篇 |
1988年 | 60篇 |
1987年 | 49篇 |
1986年 | 51篇 |
1985年 | 35篇 |
1984年 | 36篇 |
1983年 | 34篇 |
1982年 | 31篇 |
1981年 | 23篇 |
1980年 | 21篇 |
1979年 | 32篇 |
1978年 | 21篇 |
1977年 | 19篇 |
1976年 | 17篇 |
1975年 | 15篇 |
1973年 | 12篇 |
1970年 | 12篇 |
排序方式: 共有3567条查询结果,搜索用时 15 毫秒
81.
82.
Background
Although bacterial cholangitis is frequently mentioned as a cause of secondary sclerosing cholangitis, it appears to be extremely rare, with only one documented case ever reported. 相似文献83.
Human interleukin-5 (IL-5) regulates the production of eosinophils in human bone marrow cultures: comparison and interaction with IL-1, IL-3, IL-6, and GMCSF 总被引:33,自引:1,他引:33
Recombinant human interleukin-5 (rhIL-5), in either liquid or semi- solid cultures, selectively induced eosinophil production from normal human bone marrow, with no activity on other cell lineages. The time course of eosinophil production induced by murine IL-5, rhIL-3, and rh granulocyte-macrophage colony stimulating factor (GMCSF) was similar to rhIL-5. The rate of eosinophil maturation in vitro was independent of the stimulating cytokine, mature eosinophils being produced after 4 to 5 weeks in liquid culture with each of these cytokines. The eosinophils produced in response to each cytokine were morphologically indistinguishable, and had the ultrastructural features of maturity except that the electron-dense material in the granules had not formed into crystalline cores. Neither rhIL-1 nor rhIL-6 alone, or in combination with rhIL-5 or rhIL-3, induced eosinophil differentiation or proliferation under the conditions used. rhIL-3 and rhGMCSF induced more eosinophil colonies than rhIL-5, rhIL-5 had an additive, not synergistic, effect on eosinophil colony production when combined with either rhIL-3 or rhGMCSF, suggesting that rhIL-5 stimulates a smaller and possibly different population of eosinophil progenitors. However, rhIL-5 induced the greatest eosinophil production in liquid cultures, suggesting that although it may act on a smaller population of precursors, it is able to stimulate more proliferative steps than either rhIL-3 or rhGMCSF. 相似文献
84.
Disturbed noradrenergic blood pressure control in normotensive members of hypertensive families. 下载免费PDF全文
M G Bianchetti P Weidmann C Beretta-Piccoli U Rupp K Boehringer L Link C Ferrier 《Heart (British Cardiac Society)》1984,51(3):306-311
The possible influence of a family history of hypertension on some variables of adrenergic blood pressure regulation was assessed. Blood pressure, heart rate, plasma renin activity, adrenaline and noradrenaline concentrations, and plasma or urinary electrolyte estimations did not differ significantly between two groups of normotensive subjects matched for age and sex with and without a family history of hypertension. Compared with subjects without a family history, however, an appreciably decreased pressor dose of infused noradrenaline, a distinct shift to the left in the relation between noradrenaline induced changes in mean arterial pressure and concomitant plasma noradrenaline concentrations, and an enhanced pressor response to given increases in plasma noradrenaline concentrations occurred in the group with a family history. These findings suggest that an imbalance between cardiovascular noradrenaline responsiveness and circulating noradrenaline is a common familial disturbance which could possibly predispose to the development of essential hypertension. 相似文献
85.
Zielinsky A; Hirsh J; Straumanis G; Carter CJ; Gent M; Sackett DL; Hull R; Kelton JG; Powers P; Turpie AG 《Blood》1982,59(2):346-350
We have evaluated the fibrinogen/fibrin fragment E antigen assay as a diagnostic test in patients with clinically suspected venous thrombosis by comparing the results of this assay with venography in 272 patients. The result of the fragment E antigen assay was elevated in 79 of 80 patients with positive venograms for recent venous thrombosis (sensitivity 99%) and within the normal range in 161 of 192 patients with normal venograms (specificity 84%). The fragment E assay was also evaluated in 130 medical and surgical controls without evidence of venous thrombosis by leg scanning and the test was found to be relatively nonspecific. However, in the patient group under study, a correct clinical diagnosis of no thrombosis, based on a normal fragment E result, was made in 161 of 162 cases (negative predictive value of 99%). Therefore, a normal test result effectively excludes a diagnosis of venous thrombosis in clinically symptomatic patients. The assay, as currently performed, is technically demanding and takes 24 hr to complete. Therefore, it will have to be simplified before it can be applied to clinical practice. 相似文献
86.
Subcutaneous panniculitis‐like T‐cell lymphoma: Pediatric case series demonstrating heterogeneous presentation and option for watchful waiting 下载免费PDF全文
87.
Isochromosomes in childhood acute lymphoblastic leukemia: a collaborative study of 83 cases. 总被引:2,自引:0,他引:2
C H Pui A J Carroll S C Raimondi M J Schell D R Head J J Shuster W M Crist M J Borowitz M P Link F G Behm 《Blood》1992,79(9):2384-2391
Cytogenetic analysis of leukemic cells from 2,805 children with newly diagnosed acute lymphoblastic leukemia (ALL) identified 83 cases (3%) that had a stemline with at least one isochromosome. The i(9q) was present in 28 (1%), the i(17q) in 23 (0.8%), and the i(7q) in 23 (0.8%). Other isochromosomes--i(21q), i(6p), i(1q), i(8q), or i(Xq)--were found in only 12 cases (0.4%). The isochromosome cases were more likely than were other ALL cases to have a pre-B immunophenotype (38% v 25%, P = .02) and leukemic cell hyperdiploidy greater than 50 (37% v 24%, P = .02); five cases had both features. The i(9q) was associated with age greater than 10 years (P less than .05) and the pre-B immunophenotype (P = .05); both the i(17q) and i(7q) had high frequencies of hyperdiploidy greater than 50 (P less than .0001 and P = .05, respectively). The t(1;19)(q23;p13) was a common feature (23%) in cases with the i(9q), i(7q), i(6p), or i(1q). These findings establish the i(9q), i(17q), and i(7q) as nonrandom chromosomal abnormalities in ALL. The prognostic significance of the presence of isochromosome(s) remains to be determined. 相似文献
88.
89.
90.
Desmond A. Brown Benjamin T. Himes Brittny T. Major Benjamin F. Mundell Ravi Kumar Bruce Kall Fredric B. Meyer Michael J. Link Bruce E. Pollock John D. Atkinson Jamie J. Van Gompel W. Richard Marsh Giuseppe Lanzino Mohamad Bydon Ian F. Parney 《Mayo Clinic proceedings. Mayo Clinic》2018,93(1):16-24