全文获取类型
收费全文 | 23368篇 |
免费 | 1516篇 |
国内免费 | 393篇 |
专业分类
耳鼻咽喉 | 51篇 |
儿科学 | 581篇 |
妇产科学 | 251篇 |
基础医学 | 3864篇 |
口腔科学 | 407篇 |
临床医学 | 2285篇 |
内科学 | 2235篇 |
皮肤病学 | 163篇 |
神经病学 | 4043篇 |
特种医学 | 200篇 |
外国民族医学 | 1篇 |
外科学 | 654篇 |
综合类 | 2059篇 |
一般理论 | 1篇 |
预防医学 | 5149篇 |
眼科学 | 41篇 |
药学 | 2455篇 |
9篇 | |
中国医学 | 346篇 |
肿瘤学 | 482篇 |
出版年
2023年 | 353篇 |
2022年 | 635篇 |
2021年 | 1157篇 |
2020年 | 853篇 |
2019年 | 736篇 |
2018年 | 686篇 |
2017年 | 712篇 |
2016年 | 770篇 |
2015年 | 737篇 |
2014年 | 1437篇 |
2013年 | 1820篇 |
2012年 | 1162篇 |
2011年 | 1367篇 |
2010年 | 960篇 |
2009年 | 1029篇 |
2008年 | 1072篇 |
2007年 | 1034篇 |
2006年 | 936篇 |
2005年 | 758篇 |
2004年 | 614篇 |
2003年 | 558篇 |
2002年 | 492篇 |
2001年 | 391篇 |
2000年 | 304篇 |
1999年 | 284篇 |
1998年 | 234篇 |
1997年 | 225篇 |
1996年 | 193篇 |
1995年 | 184篇 |
1994年 | 163篇 |
1993年 | 141篇 |
1992年 | 165篇 |
1991年 | 146篇 |
1990年 | 136篇 |
1989年 | 132篇 |
1988年 | 135篇 |
1987年 | 113篇 |
1986年 | 153篇 |
1985年 | 263篇 |
1984年 | 257篇 |
1983年 | 180篇 |
1982年 | 222篇 |
1981年 | 207篇 |
1980年 | 201篇 |
1979年 | 189篇 |
1978年 | 133篇 |
1977年 | 148篇 |
1976年 | 135篇 |
1975年 | 96篇 |
1973年 | 78篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Differential mechanisms involved in the anticonflict action of benzodiazepines injected into the central amygdala and mammillary body 总被引:1,自引:0,他引:1
The present study was designed to clarify the mechanism of action of benzodiazepines (BDZ) injected into the central amygdala (ACE) and mammillary body (MB). When gamma-aminobutyric acid (GABA) at doses of 30 and 70 micrograms, muscimol (0.01 and 0.03 microgram), valproate (200 micrograms), atropine (20 micrograms) and cyproheptadine (3 micrograms) were bilaterally injected into ACE, a significant and marked increase in the punished responses of conflict schedule was observed. These drugs injected into MB failed to increase the punished responses. In MB, only noradrenaline (NA, 20 micrograms) showed the anticonflict action. NA 20 micrograms also produced the anticonflict action in ACE. These results suggest that the mechanism of anticonflict action of BDZ is different in brain areas. The GABA-ergic, cholinergic, serotonergic and NA-ergic systems seem to be involved in the mechanism of anticonflict action of BDZ in ACE. While the NA-ergic system appears to be operative in MB. 相似文献
32.
8—2岁市区学龄儿童感觉统合失调与不良行为及家庭因素调查分析 总被引:4,自引:0,他引:4
目的:调查本市区小学儿童感觉统合失调现状与不良行为及家庭因素的关系。方法:用感觉统合诊断量表和自制儿童生长发育调查表对1775名学龄儿童进行心理行为问题调查。结果:感觉统合轻度失调23.4%,重度失调13.5%,男童失调发和率(42.86%)明显高于女童(31.36%)P<0.0),前庭功能失衡发生率最高(21.30%);统合失调组儿童不良行为发生率高达64.38%明显高于统合正常组(31.11%)P<0.01,失调组不良行为各因子的发生率亦明显高于统合正常组P<0.01;学习能力不足儿童与父母文化程度和不同职业有关P<0.01。结论:儿童感觉纺合失调现状易成为成人心理障碍的潜在因素,应引起重视。 相似文献
33.
D. Caroline Blanchard Jon K. Shepherd Antonio De Padua Carobrez Robert J. Blanchard 《Neuroscience and biobehavioral reviews》1991,15(4):461-468
Female rats consistently show a pattern of differences in defensive behaviors compared to males which parallel the effects of exposure to a nonpainful threat stimulus (cat or cat odor) in the same tests and measures. These indications of greater defensiveness for females are particularly common in situations involving potential, as opposed to actual and present, threat, a factor which probably also reflects ceiling or floor effects in situations involving very intense defensiveness. In addition, pharmacological studies indicate sex differences in the effects of selective serotonin (5-HT) receptor agonists and antagonists on defensive responding. These findings indicate that sex effects must be considered in studies of the pharmacological control of defensive behaviors, and suggest that responsivity to sex effects may be an additional criterion for the suitability of animal models of anxiety. 相似文献
34.
铁叶绿酸钠为叶绿素衍生物,研究表明铁叶绿酸钠治疗妊娠期缺铁性贫血,疗效显著。由于妊娠期用药可能对子代产生行为发育毒性,因此本文重点针对铁叶绿酸钠在动物围产期用药后,可能对子代动物的神经行为发育产生的毒性进行了测试,试验结果表明在高、中、低三种剂量下其对子代小鼠无明显行为发育毒性。 相似文献
35.
36.
ngela P. de Mattos Tereza C.M. Ribeiro Patrícia S.A. Mendes Sandra S. Valois Carlos M.C. Mendes Hugo C. Ribeiro Jr 《Nutrition Research》2009,29(7):462-469
Although previous studies have shown successful treatment of persistent diarrhea (PD) with the use of yogurt-based diets, some recent ones speculate the need of special formulas for the nutritional management of PD complicated cases. In the present study, we tested the hypothesis that the consumption of 3 lactose-free diets, with different degrees of complexity, is associated with lower stool output and shorter duration of diarrhea when compared with the use of a yogurt-based one on the nutritional management of PD. A total of 154 male infants, aged between 1 and 30 months, with PD and with or without dehydration, were randomly assigned to 1 of 4 treatment groups. Throughout the study, the patients were placed in a metabolic unit; their body weights and intakes of oral rehydration solution, water, and formula diets, in addition to outputs of stool, urine, and vomit, were measured and recorded at 24-hour intervals. Four different diets were used in this study: diet 1, yogurt-based formula; diet 2, soy-based formula; diet 3, hydrolyzed protein-based formula; and diet 4, amino acid–based formula. Throughout the study, only these formula diets were fed to the children. The data showed that children fed the yogurt-based diet (diet 1) or the amino acid–based diet (diet 4) had a significant reduction in stool output and in the duration of diarrhea. The use of an inexpensive and worldwide-available yogurt-based diet is recommended as the first choice for the nutritional management of mild to moderate PD. For the few complicated PD cases, when available, a more complex amino acid–based diet should be reserved for the nutritional management of these unresponsive and severe presentations. Soy-based or casein-based diets do not offer any specific advantage or benefits and do not seem to have a place in the management of PD. 相似文献
37.
38.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
39.
目的:探讨婴儿轮状病毒肠炎的饮食弓临床疗效关系。方法:将93例轮状病毒肠炎的婴儿按不同的喂养方式随机分为A、B、C3组,在其他治疗方法相同时,A组予去乳糖奶粉喂养,B组继续母乳喂养,C组普通罂儿奶粉喂养,两两比较其临床疗效。结果:A组总有效率明显高于B、C组,止泻天数短于B、C组,而体重降低程度明显低于B、C组(P〈0.01):结论:轮状病毒肠炎的婴儿以去乳精奶粉喂养为宜。 相似文献
40.