全文获取类型
收费全文 | 222323篇 |
免费 | 4211篇 |
国内免费 | 192篇 |
专业分类
耳鼻咽喉 | 1667篇 |
儿科学 | 7813篇 |
妇产科学 | 3846篇 |
基础医学 | 22663篇 |
口腔科学 | 2773篇 |
临床医学 | 16902篇 |
内科学 | 40268篇 |
皮肤病学 | 1377篇 |
神经病学 | 20989篇 |
特种医学 | 11412篇 |
外国民族医学 | 6篇 |
外科学 | 35760篇 |
综合类 | 2898篇 |
一般理论 | 40篇 |
预防医学 | 21904篇 |
眼科学 | 3896篇 |
药学 | 12266篇 |
中国医学 | 691篇 |
肿瘤学 | 19555篇 |
出版年
2023年 | 185篇 |
2022年 | 333篇 |
2021年 | 818篇 |
2020年 | 624篇 |
2019年 | 829篇 |
2018年 | 22735篇 |
2017年 | 18015篇 |
2016年 | 20277篇 |
2015年 | 1927篇 |
2014年 | 2240篇 |
2013年 | 2782篇 |
2012年 | 9921篇 |
2011年 | 24034篇 |
2010年 | 20506篇 |
2009年 | 13101篇 |
2008年 | 22321篇 |
2007年 | 24621篇 |
2006年 | 3584篇 |
2005年 | 5139篇 |
2004年 | 6168篇 |
2003年 | 7016篇 |
2002年 | 5064篇 |
2001年 | 897篇 |
2000年 | 984篇 |
1999年 | 818篇 |
1998年 | 798篇 |
1997年 | 669篇 |
1996年 | 506篇 |
1995年 | 497篇 |
1994年 | 415篇 |
1993年 | 352篇 |
1992年 | 416篇 |
1991年 | 437篇 |
1990年 | 443篇 |
1989年 | 406篇 |
1988年 | 348篇 |
1987年 | 354篇 |
1986年 | 306篇 |
1985年 | 334篇 |
1984年 | 327篇 |
1983年 | 314篇 |
1982年 | 343篇 |
1981年 | 298篇 |
1980年 | 303篇 |
1979年 | 234篇 |
1978年 | 245篇 |
1977年 | 207篇 |
1976年 | 184篇 |
1975年 | 184篇 |
1974年 | 209篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Jay Nicholson Peter Mirtschin Frank Madaras Michael Venning Michael Kokkinn 《Toxicon》2006,48(4):422-428
The digestive properties of Australian elapid snake venoms have not been studied to any great extent. To address this, the in vitro digestive properties of Oxyuranus scutellatus (Australian Coastal Taipan) venom were investigated in a simulation of the in vivo conditions using the parameters reported for the stomach of snakes and representative prey for this species. The amount of soluble protein released was measured over time using a bicinchoninic acid (BCA) assay. Dismembered mouse hindlegs were injected intramuscularly with 0.1 ml O. scutellatus venom (concentration 10 mg/ml) and maintained in a micro-anaerobic, acidic environment (pH approximately 1.2-1.7) at 25 degrees C. The bathing liquid was sampled every 24 h for 7 days, and assayed for soluble protein. Statistical analysis revealed that O. scutellatus venom increased the rate at which proteins were released when compared to a negative control suggesting the potential importance of envenomation in the digestion of whole prey. 相似文献
52.
Frank A Middleton Marco G Trauzzi Antony E Shrimpton Karen L Gentile Christopher P Morley Helena Medeiros Michele T Pato Carlos N Pato 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2006,(1):28-32
Uniparental isodisomy (iUPD) is a rare genetic condition caused by non-disjunction during meiosis that ultimately leads to a duplication of either the maternal or paternal chromosome in the affected individual. Two types of disorders can result, those due to imprinted genes and those due to homozygosity of recessive disease-causing mutations. Here, we describe the third known case of complete chromosome 4 iUPD of maternal origin. This condition became apparent during whole genome linkage studies of psychiatric disorders in the Portuguese population. The proband is an adult female with normal fertility and no major medical complaints, but a history of major depressive disorder and multiple suicide attempts. The proband's siblings and parents had normal chromosome 4 genotypes and no history of mood disturbance. A brief review of other studies lends support for the possibility that genes on chromosome 4 might confer risk for mood disorders. We conclude that chromosome 4 maternal uniparental disomy (UPD) is a rare disorder that may present with a major depressive phenotype. The lack of a common disease phenotype between this and two other cases of chromosome 4 iUPD [Lindenbaum et al. [1991] Am J Med Genet 49(Suppl 285):1582; Spena et al. [2004] Eur J Hum Genet 12:891-898) would suggest that there is no vital maternal gene imprinting on chromosome 4. However, since there is no reported case of paternal chromosome 4 UPD, paternal gene imprinting on chromosome 4 cannot be excluded. 相似文献
53.
54.
杨娅 Thomas Bartel Loredana Latina Guido Caspari 王新房 Raimund Erbel 《华中科技大学学报(医学英德文版)》2002,22(2):158-163
Coronary flow reserve (CFR) has been used toassess coronary microcirculation and epicardial coro-nary stenoses[1— 3 ] . CFR is defined as the ratio ofcoronary flow under maximal coronary vasodilatationto coronary flow under resting conditions[4 ] .Whenthe cross- sectional area of epicardial coronary arteriesis constant,coronary flow velocity (CFV) ratios areequal to volume flow ratios.The most common method used clinically formeasuring CFVR is intracoronary Doppler flow(ICD) analysis re… 相似文献
55.
56.
57.
58.
Frank G. Shellock Jerrold H. Mink Andrew L. Deutsch James Fox Todd Molnar Ronald Kvitne Richard Ferkel 《Journal of magnetic resonance imaging : JMRI》1994,4(4):590-594
The effect of a newly developed patellar realignment brace was evaluated in 21 patellofemoral joints (19 patients) with patellar subluxation (13 joints with lateral subluxation and eight with medial subluxation) by using active-movement, loaded kinematic magnetic resonance (MR) imaging. Sixteen patellofemoral joints (76%) demonstrated a qualitative correction of or improvement in patellar subluxation (ie, centralization of the patella or a decrease in the displacement of the patella) after application of the brace. Four of the five “failures” occurred in patellofemoral joints that had patella alta and/or dysplastic bone anatomy. These results indicate that the patellar realignment brace was able to counteract patellar subluxation in the majority of patellofemoral joints studied, as shown by active-movement, loaded kinematic MR imaging. This brace appears to be useful for conservative treatment of patients with patellofemoral joint pain secondary to patellar malalignment and maltracking. 相似文献
59.
Thomas Donohue Morton J. Kern Richard Bach Frank Aguirre Thomas Wolford 《Catheterization and cardiovascular interventions》1993,28(2):155-161
The vasomotor response of native human collateral vessels to pharmacologic or hemodynamic vasodilatory stimuli is not well known. We describe a case where retrograde collateral flow velocity was measured both at baseline and following selected hemodynamic and pharmacologic interventions. This index case represents the first in a series of potential human physiologic studies designed to address questions pertaining to control of collateral blood supply in humans. © 1993 Wiley-Liss, Inc. 相似文献
60.
Irwin L. Flink 《Brain structure & function》2002,205(3):235-244