全文获取类型
收费全文 | 2069篇 |
免费 | 82篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 89篇 |
妇产科学 | 30篇 |
基础医学 | 273篇 |
口腔科学 | 22篇 |
临床医学 | 190篇 |
内科学 | 408篇 |
皮肤病学 | 7篇 |
神经病学 | 210篇 |
特种医学 | 219篇 |
外科学 | 264篇 |
综合类 | 9篇 |
预防医学 | 124篇 |
眼科学 | 18篇 |
药学 | 190篇 |
中国医学 | 1篇 |
肿瘤学 | 99篇 |
出版年
2022年 | 15篇 |
2021年 | 33篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 25篇 |
2017年 | 19篇 |
2016年 | 36篇 |
2015年 | 52篇 |
2014年 | 52篇 |
2013年 | 59篇 |
2012年 | 106篇 |
2011年 | 143篇 |
2010年 | 77篇 |
2009年 | 85篇 |
2008年 | 157篇 |
2007年 | 126篇 |
2006年 | 118篇 |
2005年 | 135篇 |
2004年 | 142篇 |
2003年 | 112篇 |
2002年 | 90篇 |
2001年 | 31篇 |
2000年 | 29篇 |
1999年 | 33篇 |
1998年 | 22篇 |
1997年 | 22篇 |
1996年 | 17篇 |
1995年 | 14篇 |
1994年 | 20篇 |
1993年 | 10篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 23篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 14篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1979年 | 15篇 |
1975年 | 10篇 |
1974年 | 14篇 |
1973年 | 16篇 |
1972年 | 7篇 |
1971年 | 11篇 |
1970年 | 9篇 |
1969年 | 8篇 |
排序方式: 共有2159条查询结果,搜索用时 359 毫秒
1.
D.L. Morgan J.R. Bucher M.R. Elwell H.S. Lilja A.S. Krishna Murthy 《Food and chemical toxicology》1990,28(12):839-845
Studies were conducted to compare the toxicity of ethylene dichloride (EDC) in F344/N rats, Sprague-Dawley rats, and Osborne-Mendel rats. Ten rats/sex/group were exposed to EDC in drinking-water at 0, 500, 1000, 2000, 4000 and 8000 ppm for 13 wk. The highest concentration was limited by the maximum solubility of EDC in water (about 9000 ppm). In addition, F344/N rats (10/sex/group) were administered EDC in corn oil by gavage to compare toxicity resulting from bolus administration with that of continuous exposure in drinking-water. Gavage doses of EDC were within the range of total daily doses (in mg/kg body weight/day) resulting from exposure in drinking-water. EDC administered by gavage resulted in greater toxicity to F344/N rats than did administration of similar doses in drinking-water. All males receiving 240 and 480 mg/kg body weight and 9/10 females receiving 300 mg/kg body weight by gavage died before the end of the study. Necrosis of the cerebellum was observed in the brains of 3 males receiving 240 mg/kg body weight and 3 females receiving 300 mg/kg body weight. Hyperplasia and inflammation of the forestomach mucosa were observed in 8 male and 3 female rats that died or were killed in moribund condition. EDC caused minimal toxicity to F344/N, Sprague-Dawley and Osborne-Mendel rats at the drinking-water concentrations used in these studies; only female F344/N rats had EDC-related renal lesions. Based on mortality and EDC-related lesions, the no-effect levels for EDC administered by gavage to F344/N rats were 120 mg/kg body weight for males and 150 mg/kg body weight for females. 相似文献
2.
Hans-Ulrich Bucher 《Sozial- und Pr?ventivmedizin》1994,39(1):30-31
Conclusion In Switzerland, infants weighing 500–999 g at birth seem to have a relatively high mortality and a relatively low risk for handicap. This impression has to be confirmed by assessing outcome at school age. 相似文献
3.
Neurotoxicity and carcinogenicity of N-methylolacrylamide in F344 rats and B6C3F1 mice 总被引:1,自引:0,他引:1
J R Bucher J Huff J K Haseman S L Eustis A Peters J D Toft 《Journal of toxicology and environmental health》1990,31(3):161-177
Toxicology and carcinogenicity studies of N-methylolacrylamide were conducted by administering the chemical by gavage in water to both sexes of F344/N rats and B6C3F1 mice 5 times per week for 16 d, 13 wk, or 2 yr. In 16-d studies, rats receiving doses of 200 mg/kg or higher and mice receiving 400 mg/kg died. In 13-wk studies, all rats given 100 mg/kg or higher doses died. Rats receiving 50 mg/kg or higher doses developed hindlimb ataxia progressing to paralysis. In neurobehavioral assessments, decreased forelimb and hindlimb grip strength occurred in rats at doses as low as 12.5 mg/kg. Landing footspread was also increased in dosed rats compared to controls. Axon filament and myelin sheath degeneration in the spinal cord and/or peripheral nerves occurred in rats receiving doses of 25 mg/kg or higher. Necrosis in the granular cell layer of the cerebellum was seen in rats given 200 mg/kg. Mice receiving 200 mg/kg in 13-wk studies died. Decreased grip strength was noted in mice at doses as low as 25 mg/kg, and rotarod performance was also affected by N-methylolacrylamide administration, but no neuropathology was seen microscopically. Testicular weights were decreased at doses as low as 12.5 mg/kg, and hepatocellular necrosis, thymic lymphocyte necrosis, and hemorrhage, necrosis, and mineralization of the zona reticularis of the adrenal gland were seen in mice that died (200 mg/kg). In 2-yr studies, survival and weight gains in male and female rats receiving doses of 6 or 12 mg/kg/d were minimally affected. No biologically important clinical signs or neoplastic or nonneoplastic lesions were attributed to N-methylolacrylamide administration to rats, suggesting that higher doses could have been tolerated. In mice, survival was not different between dosed and control groups (0, 25, or 50 mg/kg/d). Body weights were higher by as much as 25% in dosed compared to control groups. No compound-related clinical signs were observed, but increases in neoplasms of the harderian gland, liver, and lung were clearly related to chemical administration in both sexes of mice. Benign granulosa-cell neoplasms of the ovary were also increased in dosed female mice. 相似文献
4.
5.
Socioeconomic indicators and mortality from coronary heart disease and cancer: a 22-year follow-up of middle-aged men. 总被引:13,自引:3,他引:10
下载免费PDF全文
![点击此处可从《American journal of public health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVES: Data from the Western Collaborative Group Study were used to determine the extent to which the inverse association between socioeconomic status (SES) and mortality can be explained by risk factors for major causes of mortality. METHODS: The relation of education and income to subsequent mortality was studied in 3154 employed, middle-aged men over 22 years of follow-up. RESULTS: Over the follow-up period, 584 (18.5%) men died, 214 (6.8%) from coronary heart disease and 70 (2.2%) from lung cancer. A significant inverse association with systolic blood pressure, serum cholesterol, and smoking was found only for education. For education, adjustment for risk factors reduced the relative risk for coronary heart disease mortality from 1.80 (95% confidence interval = 1.33, 2.44) to 1.54 (1.13, 2.09), for lung cancer mortality from 1.60 (0.95, 2.70) to 1.38 (0.81, 2.34), and for all-cause mortality from 1.49 (1.09, 1.13) to 1.33 (1.12, 1.60). For income, adjustment for risk factors did not change relative risk for mortality from coronary heart disease (1.27 [0.97, 1.66]) and all causes (1.21 [1.03, 1.43]), but it did increase the relative risk for lung cancer mortality from 1.68 (1.05, 2.68) to 1.83 (1.13, 2.96). CONCLUSIONS: In middle-aged, employed men, the association between SES and mortality is partially but not completely accounted for by major risk factors for mortality. 相似文献
6.
Heme inhibits human immunodeficiency virus 1 replication in cell cultures and enhances the antiviral effect of zidovudine. 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
Inhibition of intracellular growth of Histoplasma capsulatum yeast cells by cytokine-activated human monocytes and macrophages. 总被引:7,自引:4,他引:3
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Human monocytes/macrophages (M psi) were infected with Histoplasma capsulatum yeast cells, and intracellular growth was quantified after 24 h of incubation in medium alone or in medium containing cytokines. Yeast cells multiplied within freshly isolated monocytes, cultured M psi, and alveolar M psi with intracellular generation times of 14.2 +/- 1.4, 18.5 +/- 2.1, and 19.9 +/- 1.9 h (mean +/- standard error of the mean), respectively. Monocytes and M psi inhibited the intracellular growth of yeast cells in response to cytokine supernatant; maximum inhibition was obtained when cytokines were added to cell monolayers immediately after infection. Opsonization of yeast cells in normal serum or in H. capsulatum-immune serum did not affect the intracellular generation time of yeast cells in either control M psi or cytokine-activated M psi. 相似文献
8.
Hans-Ulrich Wittchen Cecilia Ahmoi Essau Detlev von Zerssen Jürgen-Christian Krieg Michael Zaudig 《European archives of psychiatry and clinical neuroscience》1992,241(4):247-258
Summary The Lifetime and 6 month DSM-III prevalence rates of mental disorders from an adult general population sample of former West Germany are reported. The most frequent mental disorders (lifetime) from the Munich Follow-up Study were anxiety disorders (13.87%), followed by substance (13.51%) and affective (12.90%) disorders. Within anxiety disorders, simple and social phobia (8.01%) were the most common, followed by agoraphobia (5.47%) and panic disorder (2.39%). Females had about twice the rates of males for affective (18.68% versus 6.42%), anxiety (18.13% versus 9.07%), and somatization disorders (1.60% versus 0.00%); males had about three times the rates of substance disorders (21.23% versus 6.11%) of females. Being widowed and separated/divorced was associated with high rates of major depression. Most disordered subjects had at least two diagnoses (69%). The most frequent comorbidity pattern was anxietyand affective disorders. Simple and social phobia began mostly in childhood or early adolescence, whereas agoraphobia and panic disorder had a later average age of onset. The majority of the cases with both anxiety and depression had depression clearly after the occurrence of anxiety. The DIS-DSM-III findings of our study have been compared with both ICD-9 diagnoses assigned by clinicians independently as well as other epidemiological studies conducted with a comparable methodology. 相似文献
9.
K. Vogt G. Keusch U. Baumann H. U. Bucher U. Binswanger 《Pediatric nephrology (Berlin, Germany)》1989,3(2):189-190
We describe a successful pregnancy in a 22-year-old patient with advanced renal failure, who gave birth to a living boy in the 35th week of pregnancy. At the time of spontaneous delivery the mother had a serum creatinine of 851 mol/l. No dialysis treatment had been instituted during this successful pregnancy. 相似文献
10.
P J Bucher B Schimmelpfennig R Faggioni 《Journal of cataract and refractive surgery》1989,15(6):635-639
Fifty-one soft hydrogel posterior chamber intraocular lenses (IOLs) were implanted in the ciliary sulcus after planned extracapsular cataract extractions. In nine cases the IOLs were positioned with one haptic in the capsular bag and the other in the ciliary sulcus. During a one-year follow-up, Nd:YAG capsulotomy was performed on five eyes and cystoid macular edema was present in two cases. No other serious complications were encountered. At one year, visual acuity was 20/30 or better in all eyes that did not have preexisting secondary eye problems. To prevent postoperative rotation, decentration, and deformation of the IOL, unnecessary intraocular manipulation and "in-out" positioning of the IOL should be avoided. 相似文献