全文获取类型
收费全文 | 12167篇 |
免费 | 1082篇 |
国内免费 | 554篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 126篇 |
妇产科学 | 175篇 |
基础医学 | 1561篇 |
口腔科学 | 325篇 |
临床医学 | 1078篇 |
内科学 | 1460篇 |
皮肤病学 | 115篇 |
神经病学 | 1275篇 |
特种医学 | 355篇 |
外科学 | 1032篇 |
综合类 | 1625篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 1800篇 |
眼科学 | 280篇 |
药学 | 1549篇 |
3篇 | |
中国医学 | 270篇 |
肿瘤学 | 651篇 |
出版年
2024年 | 24篇 |
2023年 | 176篇 |
2022年 | 223篇 |
2021年 | 456篇 |
2020年 | 433篇 |
2019年 | 468篇 |
2018年 | 457篇 |
2017年 | 506篇 |
2016年 | 514篇 |
2015年 | 511篇 |
2014年 | 702篇 |
2013年 | 1138篇 |
2012年 | 580篇 |
2011年 | 779篇 |
2010年 | 577篇 |
2009年 | 613篇 |
2008年 | 643篇 |
2007年 | 581篇 |
2006年 | 532篇 |
2005年 | 490篇 |
2004年 | 404篇 |
2003年 | 396篇 |
2002年 | 331篇 |
2001年 | 290篇 |
2000年 | 221篇 |
1999年 | 180篇 |
1998年 | 180篇 |
1997年 | 157篇 |
1996年 | 101篇 |
1995年 | 119篇 |
1994年 | 106篇 |
1993年 | 109篇 |
1992年 | 103篇 |
1991年 | 96篇 |
1990年 | 94篇 |
1989年 | 95篇 |
1988年 | 69篇 |
1987年 | 65篇 |
1986年 | 48篇 |
1985年 | 37篇 |
1984年 | 40篇 |
1983年 | 28篇 |
1982年 | 23篇 |
1981年 | 25篇 |
1980年 | 22篇 |
1979年 | 12篇 |
1978年 | 16篇 |
1977年 | 11篇 |
1976年 | 7篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
以中药验方胃久灵对大白鼠的两种急性溃疡模型、一种慢性溃疡模型及两种胃炎模型用药治疗,证明胃久灵确有抗溃疡抗胃炎作用.其中对慢性溃疡的治疗作用较为突出.经急、慢性毒性实验,未见对重要脏器有任何毒性损害. 相似文献
52.
Acute myeloid leukaemia (AML) is predominantly a disease of the elderly; the median age of incidence is 64 years, and 60% of all cases are over 60. With improved chemotherapy regimens and maximal supportive care, remission rates of up to 60% may be achieved in selected elderly patients. Whilst intensive chemotherapy is the treatment of choice for fit patients, it may be inappropriate for debilitated patients with poor prognosis disease in whom supportive care or palliative chemotherapy may be more suitable. AML in the elderly exhibits biological differences from AML in younger patients, and elderly patients may be unable to withstand the rigors of the intensive treatment regimens given to younger patients. 相似文献
53.
Models of Parkinson's disease. 总被引:2,自引:0,他引:2
Parkinson's disease (PD) is a heterogenous disease likely to be caused by more than one specific aetiological factor. In rare familial cases of PD with similar clinical features to the idiopathic form of the disease, the underlying genetic cause has been identified. These PD-associated genes have been manipulated to create animal and cell culture models of the disease that have helped to further our understanding of the pathogenesis of PD, particularly concerning causes of the selective loss of dopaminergic neurons at the molecular level. In addition, these models will aid the future development of rational therapeutic strategies. This study briefly reviews toxin-induced models and the genetics of PD. It focuses on recently developed animal models of PD, as well as in vitro approaches to model the disease. 相似文献
54.
The ontogeny of seizure genesis within the inferior collicular cortex was characterized in rats ranging in age from 3 days old to adult. Brief electrical stimulation of the right inferior collicular cortex in 30-day-old rats evoked poststimulus wild running behavior that coincided with afterdischarge activity in the inferior collicular cortex but not in the adjacent occipital cortex. Similar electrical stimulation in 16-day-old rats produced poststimulus wild running and jumping behaviors, which also coincided with afterdischarge in the inferior collicular cortex. In 10- and 5-day-old rats, electrical stimulation of the inferior collicular cortex produced poststimulus locomotion and coincident afterdischarge activity, but unlike older rats the locomotor behaviors consisted of forelimb paddling, hindlimb treading, and rolling/curling movements of the torso. Identical behaviors can be electrically elicited in 3-day-old rats. Although many of the seizure characteristics appear to be similar among the different age groups, 5-day-old rats were more sensitive to low frequency stimulation than 16-day-old rats, who in turn were more sensitive than adult rats. Thus, the inferior collicular cortex is capable of generating seizure activity in rats as young as 3 days of age, providing a focal model of neonatal seizure genesis. 相似文献
55.
Jeffrey V. Rosenfeld MS FRACS FRCS 《Journal of clinical neuroscience》1994,1(4):231-242
Great advances in neurobiology have resulted from 100 years of neural transplantation research. In the last 20 years, there has been a focus on using neural transplantation to repair the damaged central nervous system (CNS) utilising experimental animal models of various human neurodegenerative disease and CNS injury. Since 1985, there has been a rapid proliferation of adrenal medullary autograft transplantation to the caudate nucleus of humans with Parkinson's disease. However, this operation proved to be unsuccessful and was associated with unacceptable morbidity. Implantation of human fetal mesencephalon into patients with severe parkinsonism has supplanted the adrenal operation and has produced promising results, with some patients reported to improve markedly and some evidence of graft survival noted on positron emission tomography (PET). Host tissue recovery appears to be an important mechanism for this clinical improvement. The optimal technique is to use three to four fetuses from induced abortions of 6.5 to 8 weeks gestation, with multiple stereotactic implants into the putamen and caudate nucleus. Many biological questions still remain and the community remains troubled by the ethical problems of using fetal tissue obtained from abortions. This procedure is still experimental and should be restricted to a few centres with excellence in cell and molecular biology. A multicentre study is needed to more carefully evaluate CNS transplantation. Cloned neural precursor cells or immortalized embryonic cell lines genetically modified to manufacture selected growth factors or neurotransmitters may offer an alternative to the use of human fetal tissue. Much more experimental animal research is necessary before transplantation can be used to treat other CNS maladies. 相似文献
56.
57.
Mark C. K. Yang Ronald G. Marks William B. Clark Ingvar Magnusson 《Journal of clinical periodontology》1992,19(2):77-83
Abstract Several statistical models that have been suggested in the periodontal literature for describing longitudinal attachment level changes, such as the gradual loss, single-burst, multiple-burst, and random walk models as well as other models introduced in this paper are compared by their power to predict future attachment loss. The data used in this analysis is from 1061 sites of 8 subjects, with moderate to severe periodontal disease, monitored monthly for about a year. This study found that none of the suggested models could significantly outperform the naive mean predictor, which predicts the future attachment level from the past mean. It was also found that no single model, such as the burst, gradual, or random walk, together with measurement error can fully explain the variation in the data. These results indicate that in the course of one year, the attachment level change may not follow the same model. Consequently, a model that fits well to past data cannot be accurately extended to the future. 相似文献
58.
Martin V. Pusic MD George S. Pachev PhD Wendy A. MacDonald MD 《Academic emergency medicine》2007,14(2):138-148
Objectives
To explore medical students' use of computer tutorials embedded in a busy clinical setting; to demonstrate that such tutorials can increase knowledge gain over and above that attributable to the clinical rotation itself.
Methods
Six tutorials were installed on a computer placed in a central area in an emergency department. Each tutorial was made up of between 33 and 85 screens of information that include text, graphics, animations, and questions. They were designed to be brief (10 minutes), focused, interactive, and immediately relevant. The authors evaluated the intervention using quantitative research methods, including usage tracking, surveys of faculty and students, and a randomized pretest-posttest study.
Results
Over 46 weeks, 95 medical students used the tutorials 544 times, for an overall average of 1.7 times a day. The median time spent on completed tutorials was 11 minutes (average [SD], 14 [±12] minutes). Seventy-four students completed the randomized study. They completed 65% of the assigned tutorials, resulting in improved examination scores compared with the control (effect size, 0.39; 95% confidence interval = 0.15 to 0.62). Students were positively disposed to the tutorials, ranking them as "valuable." Fifty-four percent preferred the tutorials to small group teaching sessions with a preceptor. The faculty was also positive about the tutorials, although they did not appear to integrate the tutorials directly into their teaching.
Conclusions
Medical students on rotation in a busy clinical setting can and will use appropriately presented computer tutorials. The tutorials are effective in raising examination scores. 相似文献
To explore medical students' use of computer tutorials embedded in a busy clinical setting; to demonstrate that such tutorials can increase knowledge gain over and above that attributable to the clinical rotation itself.
Methods
Six tutorials were installed on a computer placed in a central area in an emergency department. Each tutorial was made up of between 33 and 85 screens of information that include text, graphics, animations, and questions. They were designed to be brief (10 minutes), focused, interactive, and immediately relevant. The authors evaluated the intervention using quantitative research methods, including usage tracking, surveys of faculty and students, and a randomized pretest-posttest study.
Results
Over 46 weeks, 95 medical students used the tutorials 544 times, for an overall average of 1.7 times a day. The median time spent on completed tutorials was 11 minutes (average [SD], 14 [±12] minutes). Seventy-four students completed the randomized study. They completed 65% of the assigned tutorials, resulting in improved examination scores compared with the control (effect size, 0.39; 95% confidence interval = 0.15 to 0.62). Students were positively disposed to the tutorials, ranking them as "valuable." Fifty-four percent preferred the tutorials to small group teaching sessions with a preceptor. The faculty was also positive about the tutorials, although they did not appear to integrate the tutorials directly into their teaching.
Conclusions
Medical students on rotation in a busy clinical setting can and will use appropriately presented computer tutorials. The tutorials are effective in raising examination scores. 相似文献
59.
60.
一种新型人TNFα对人肝癌裸鼠移植瘤的抗瘤作用 总被引:1,自引:1,他引:0
用人肝癌Bel7402瘤株建立了人肝癌裸鼠移植瘤模型,探讨新型重组人TNFa对这种移植瘤的抗瘤作用,结果表明,rhTFaD11a和原型重组人TNFa的抑瘤率在30%左右时,后者后用的活性产闰数是前者的2倍;两者用量相同时,前者的抑产经比后者提高23个百分 相似文献