全文获取类型
收费全文 | 17288篇 |
免费 | 1601篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 152篇 |
儿科学 | 669篇 |
妇产科学 | 545篇 |
基础医学 | 2322篇 |
口腔科学 | 159篇 |
临床医学 | 2667篇 |
内科学 | 2868篇 |
皮肤病学 | 215篇 |
神经病学 | 1921篇 |
特种医学 | 300篇 |
外科学 | 1710篇 |
综合类 | 313篇 |
一般理论 | 27篇 |
预防医学 | 2374篇 |
眼科学 | 195篇 |
药学 | 1136篇 |
中国医学 | 12篇 |
肿瘤学 | 1329篇 |
出版年
2023年 | 125篇 |
2022年 | 153篇 |
2021年 | 507篇 |
2020年 | 314篇 |
2019年 | 536篇 |
2018年 | 594篇 |
2017年 | 435篇 |
2016年 | 470篇 |
2015年 | 484篇 |
2014年 | 675篇 |
2013年 | 931篇 |
2012年 | 1375篇 |
2011年 | 1471篇 |
2010年 | 745篇 |
2009年 | 670篇 |
2008年 | 1134篇 |
2007年 | 1121篇 |
2006年 | 1166篇 |
2005年 | 1170篇 |
2004年 | 886篇 |
2003年 | 777篇 |
2002年 | 696篇 |
2001年 | 196篇 |
2000年 | 209篇 |
1999年 | 168篇 |
1998年 | 144篇 |
1997年 | 92篇 |
1996年 | 87篇 |
1995年 | 68篇 |
1994年 | 75篇 |
1993年 | 53篇 |
1992年 | 84篇 |
1991年 | 73篇 |
1990年 | 83篇 |
1989年 | 92篇 |
1988年 | 66篇 |
1987年 | 68篇 |
1986年 | 63篇 |
1985年 | 78篇 |
1984年 | 63篇 |
1981年 | 38篇 |
1980年 | 40篇 |
1979年 | 52篇 |
1978年 | 53篇 |
1977年 | 36篇 |
1976年 | 48篇 |
1974年 | 39篇 |
1973年 | 34篇 |
1972年 | 37篇 |
1971年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 859 毫秒
991.
992.
Ferguson HM Gouagna LC Obare P Read AF Babiker H Githure J Beier JC 《The American journal of tropical medicine and hygiene》2005,73(2):312-320
We conducted a field study in an area of endemic malaria transmission in western Kenya to determine whether mosquitoes that feed on gametocyte-infected blood but do not become infected have reduced or enhanced fecundity in comparison to mosquitoes fed on uninfected blood. Fifteen paired membrane-feeding experiments were conducted in which two strains of Anopheles gambiae mosquitoes were simultaneously fed on either Plasmodium falciparum-infected blood from children or uninfected control blood from adults. The presence of noninfecting gametocytes in blood increased the probability that An. gambiae would produce eggs after one blood meal by sixfold (odds ratio for control relative to infected blood group 0.16; 95% CI 0.10-0.23). This result could not be explained by variation in blood meal size or hemoglobin content between hosts. When children cleared their infections, the difference in gravidity between mosquitoes fed on their blood and uninfected adults disappeared, suggesting this phenomenon is due to the presence of Plasmodium gametocytes in blood and not to host-specific factors such as age. This result was observed in two mosquito strains that differ in their innate fecundity, suggesting it may apply generally. To our knowledge, this is the first time that Plasmodium has been implicated as enhancing vector gravidity. 相似文献
993.
Dynamics of neurogenesis in the dentate gyrus of adult rats 总被引:6,自引:0,他引:6
Hippocampal neurogenesis declines steadily over the first year of life in the rodent, but the process persists into senescence despite a dramatic drop in the number of neurons it produces. At this point though, the survival and development patterns exhibited by new granule cells in the aging brain remain unclear in relation to patterns observed in the younger brain. The present study was carried out in order to obtain a direct quantitative comparison of hippocampal neurogenesis in juvenile and middle-aged rats with a high degree of temporal resolution, and to compare the survival and differentiation of the new cells over time. Thirty-eight-day-old and 12-month-old, male Sprague--Dawley rats were injected with 5-bromo-2'-deoxyuridine (BrdU) in order to label cells dividing in the dentate gyrus over a 24-h period, and immunohistochemical labeling was performed in order to record cell production and survival at eight different time points over the following two-month period. Using a marker of neuronally committed precursors and immature neurons (doublecortin; DCX), as well as a marker of mature neurons (calbindin d-28K; CaBP), the extent and timeline of neuronal differentiation, maturation, and migration of the new cells were also characterized. Results indicated that 12-month-old rats experienced a nearly 94% reduction in neurogenesis relative to juveniles, due almost entirely to a 92% drop in cell production. A largely preserved course of development and migration in the remaining newborn cells suggests treatments that enhance cell proliferation could be crucial in reversing the age-related decline in neurogenesis. 相似文献
994.
Psychological and behavioral risk factors for obesity onset in adolescent girls: a prospective study
Because little is known about risk factors for obesity, the authors tested whether certain psychological and behavioral variables predicted future onset of obesity. The authors used data from a prospective study of 496 adolescent girls who completed a baseline assessment at age 11-15 years and 4 annual follow-ups. Self-reported dietary restraint, radical weight-control behaviors, depressive symptoms, and perceived parental obesity--but not high-fat food consumption, binge eating, or exercise frequency-predicted obesity onset. Results provide support for certain etiologic theories of obesity, including the affect regulation model. The fact that self-reported, weight-control behaviors identified girls at risk for obesity implies that high-risk youths are not engaging in effective weight-control methods and suggests the need to promote more effective strategies. 相似文献
995.
Van Epps HL 《The Journal of experimental medicine》2005,201(9):1351
In 1934, pathologist Harry Goldblatt established the first animal model of hypertension. This model provided researchers with the tools to delineate the renin-angiotensin system of blood pressure control and, eventually, to design enzyme inhibitors for the treatment of chronic hypertension. 相似文献
996.
997.
Van Epps HL 《The Journal of experimental medicine》2005,202(4):460
In 1990, Charles Mackay and colleagues combined classical physiology with modern molecular biology to provide the first concrete evidence that naive and memory T cells follow distinct migratory routes out of the bloodstream--a discovery that helped invigorate the field of lymphocyte homing. 相似文献
998.
999.
1000.
Phala A. Helm E. Ralph Johnson Ann McIntosh Carlton 《Burns : journal of the International Society for Burn Injuries》1977,3(2):123-125
Electromyographic and nerve conduction data in evaluation of 66 burn patients revealed a 29 per cent incidence of peripheral polyneuropathy. Patchy myopathic findings, probably related to multiple injections, were noted in the proximal muscles of 22 patients. Entrapment mononeuropathies of the ulnar, median and peroneal nerver were found. These neuromuscular abnormalities produce clinical motor and sensory deficits which limit rehabilitation in the burned patient, and further work is immediately needed to determine the pathophysiology of these abnormalities. 相似文献