全文获取类型
收费全文 | 14365篇 |
免费 | 1274篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 441篇 |
妇产科学 | 381篇 |
基础医学 | 1614篇 |
口腔科学 | 471篇 |
临床医学 | 1359篇 |
内科学 | 3176篇 |
皮肤病学 | 404篇 |
神经病学 | 1269篇 |
特种医学 | 705篇 |
外国民族医学 | 19篇 |
外科学 | 1874篇 |
综合类 | 237篇 |
一般理论 | 11篇 |
预防医学 | 1266篇 |
眼科学 | 587篇 |
药学 | 896篇 |
中国医学 | 7篇 |
肿瘤学 | 832篇 |
出版年
2021年 | 154篇 |
2019年 | 156篇 |
2018年 | 221篇 |
2017年 | 137篇 |
2016年 | 147篇 |
2015年 | 156篇 |
2014年 | 240篇 |
2013年 | 373篇 |
2012年 | 539篇 |
2011年 | 582篇 |
2010年 | 274篇 |
2009年 | 286篇 |
2008年 | 516篇 |
2007年 | 612篇 |
2006年 | 585篇 |
2005年 | 681篇 |
2004年 | 621篇 |
2003年 | 566篇 |
2002年 | 583篇 |
2001年 | 458篇 |
2000年 | 494篇 |
1999年 | 394篇 |
1998年 | 186篇 |
1997年 | 128篇 |
1996年 | 125篇 |
1995年 | 140篇 |
1993年 | 130篇 |
1992年 | 327篇 |
1991年 | 325篇 |
1990年 | 334篇 |
1989年 | 322篇 |
1988年 | 308篇 |
1987年 | 363篇 |
1986年 | 321篇 |
1985年 | 296篇 |
1984年 | 277篇 |
1983年 | 259篇 |
1982年 | 184篇 |
1981年 | 145篇 |
1980年 | 138篇 |
1979年 | 232篇 |
1978年 | 171篇 |
1977年 | 131篇 |
1976年 | 162篇 |
1975年 | 136篇 |
1974年 | 180篇 |
1973年 | 180篇 |
1972年 | 143篇 |
1970年 | 126篇 |
1969年 | 124篇 |
排序方式: 共有10000条查询结果,搜索用时 310 毫秒
1.
Interaction effects between the 5‐hydroxy tryptamine transporter‐linked polymorphic region (5‐HTTLPR) genotype and family conflict on adolescent alcohol use and misuse
下载免费PDF全文
![点击此处可从《Addiction (Abingdon, England)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
2.
3.
4.
Elhaji Youssef A.; Stoica Ileana; Dennis Sheldon; Purisima Enrico O.; Lumbroso Rose; Beitel Lenore K.; Trifiro Mark A. 《Human molecular genetics》2006,15(9):1561
Human Molecular Genetics (2006) 15, 921931; 相似文献
5.
We compared the effects of alpha 2- and beta-adrenoreceptor blockade on the central actions of catecholamines and metabolites of alpha-methyldihydroxyphenylalanine, epinephrine, alpha-methylnorepinephrine, and alpha-methylepinephrine were studied. I.c.v. and nucleus tractus solitarii (NTS) injections were carried out under anesthesia. Following i.c.v. injection, both epinephrine and methylepinephrine rapidly reduced blood pressure and heart rate, but the effects of methylnorepinephrine occurred somewhat later. Following microinjection into the nucleus of the solitary tract, epinephrine, methylepinephrine, and methylnorepinephrine all caused hypotension and bradycardia. The hypotensive effects of all 3 amines in the NTS were attenuated in additive fashion by yohimbine, an alpha 2 adrenoreceptor antagonist, and timolol, a beta-adrenoreceptor antagonist, whereas only yohimbine attenuated the bradycardia. The combination of yohimbine and timolol abolished the effects of the amines. These data suggest that in the NTS both alpha 2 and beta adrenoreceptor stimulation contribute to the hypotensive effects of these amines, but that only alpha 2 adrenoreceptors are principally involved in the heart rate response. 相似文献
6.
Martha A. Warpehoski Paul J. Buscemi David C. Osborn Birdwell Finlayson Eugene P. Goldberg 《Calcified tissue international》1981,33(1):211-222
Summary The quantity of protein and carbohydrate comprising the matrix of calcium oxalate monohydrate (COM) renal stones was found
to decrease with distance from the surface of the stone. The average organic concentration of stones 3 to 30 mm in diameter
ranged from 5.7% at the surface to 2.7% at the core. This concentration gradient suggests matrix involvement in a “growth
front” on stone surfaces with migration of organic material from the “older” interior. The matrix distribution was not readily
correlated with density variations or with the presence of hydroxyapatite or calcium oxalate dihydrate. Surface matrix concentrations
were greater than amounts predicted by physical adsorption. Electron microscopy confirmed the presence of the organic-rich
surface layer and also suggested that increase in stone size occurs predominantly by crystal growth with microcrystal aggregates
as growth centers. 相似文献
7.
Thomas J Birk Rodger D MacArthur Lynn M Lipton Sheldon D Levine 《The Journal of the Association of Nurses in AIDS Care》2002,13(6):20-24
The purpose of this study was to determine whether blood lipid and lipoprotein concentrations varied in 5 men with advanced HIV-1 infection after 12 months of aerobic exercise training. Prior to exercise, the mean baseline cholesterol and high-density lipoprotein cholesterol (HDL-C) serum concentration were each lower, and mean baseline triglyceride concentration was higher compared to a healthy population norm. Consistent exercise training for 12 months failed to significantly (p > .05) alter cholesterol or HDL-C. Triglyceride concentration was significantly (p < .05) elevated above baseline (63 mg/dL) regardless of exercise compliance. The results suggest that long-term exercise training cannot correct lipid profile abnormality, particularly hypertriglyceridemia, common to individuals with advanced HIV-1 infection. 相似文献
8.
Patients at Boston's Children's Hospital diagnosed as having cerebral palsy were filmed walking. These films were digitized and translated into measurements associated with leg motion. In this paper we use the gait measurements of 128 such patients to illustrate that the kth nearest neighbour clustering procedure results in a gait typology for patients with cerebral palsy. The procedure identifies four subpopulations from the sample data; the membership of a patient within this typology is mostly determined by the patient's motor control. The developed typology differs from the present diagnostic system which classifies a cerebral palsy patient as either quadriplegic, diaplegic or hemiplegic. 相似文献
9.
Following administration of phenothiazines for schizophrenia, a 25-year-old patient developed a malignant neuroleptic syndrome followed by bilateral periarticular ossification of the knees, with severely limited motion. Two years later, the patient regained useful motion after bilateral excision of the ossified tissue and intensive physiotherapy. No recurrence of ossification was observed 3 years after operation, and the patient has maintained almost normal motion. 相似文献
10.
Y. Graif A. Goldberg R. Tamir D. Vigiser S. Melamed 《Clinical and experimental allergy》2006,36(12):1532-1537
BACKGROUND: In allergic conditions, the degree of skin test reactivity does not always correlate with the severity of clinical symptoms. Additional factors may contribute to the reported symptom severity. OBJECTIVES: To investigate the association between the magnitude of the skin prick test (SPT) response and the reported symptom severity in patients with allergic rhinitis and the possible modifying role of psychological factors. METHODS: One hundred four patients with allergic rhinitis and 23 with non-allergic rhinitis, classified according to their SPT response to 19 aeroallergens, were asked to rate the severity of five symptoms and to indicate whether their symptoms intensified on exposure to five common aeroallergens. They also completed a psychological questionnaire. Results Reported symptom severity of allergic rhinitis did not correlate with weal size for any of the aeroallergens tested or with the number of positive responses on SPT. It was not related to patient age, sex, or education. The reported symptoms severity correlated positively (0.29, P < 0.01) with reported symptom intensification on exposure to allergens. Moreover, both outcomes were positively associated with the psychological factors of hypochondriasis (0.20, P < 0.05 and 0.18, P < 0.05, respectively), and somatic awareness (0.24, P < 0.05 and 0.33, P < 0.01, respectively), but not with neuroticism. CONCLUSIONS: The severity of symptoms experienced by patients with allergic rhinitis is apparently not related to the magnitude of SPT response, but rather to psychological factors of hypochondriasis and somatic awareness. Physicians should be aware of the contribution of psychological factors to patient perceptions of the intensity of symptoms and of the intensification of symptoms on their exposure to allergens. 相似文献