全文获取类型
收费全文 | 1884篇 |
免费 | 177篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 117篇 |
妇产科学 | 17篇 |
基础医学 | 247篇 |
口腔科学 | 49篇 |
临床医学 | 154篇 |
内科学 | 321篇 |
皮肤病学 | 42篇 |
神经病学 | 63篇 |
特种医学 | 182篇 |
外科学 | 313篇 |
综合类 | 140篇 |
预防医学 | 131篇 |
眼科学 | 12篇 |
药学 | 85篇 |
中国医学 | 41篇 |
肿瘤学 | 155篇 |
出版年
2022年 | 22篇 |
2021年 | 33篇 |
2020年 | 22篇 |
2019年 | 24篇 |
2018年 | 36篇 |
2017年 | 27篇 |
2016年 | 24篇 |
2015年 | 39篇 |
2014年 | 54篇 |
2013年 | 56篇 |
2012年 | 86篇 |
2011年 | 82篇 |
2010年 | 84篇 |
2009年 | 78篇 |
2008年 | 50篇 |
2007年 | 55篇 |
2006年 | 70篇 |
2005年 | 64篇 |
2004年 | 45篇 |
2003年 | 44篇 |
2002年 | 33篇 |
2001年 | 42篇 |
2000年 | 27篇 |
1999年 | 43篇 |
1998年 | 55篇 |
1997年 | 71篇 |
1996年 | 61篇 |
1995年 | 43篇 |
1994年 | 35篇 |
1993年 | 40篇 |
1992年 | 26篇 |
1991年 | 23篇 |
1990年 | 34篇 |
1989年 | 49篇 |
1988年 | 39篇 |
1987年 | 31篇 |
1986年 | 30篇 |
1985年 | 29篇 |
1984年 | 24篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 18篇 |
1979年 | 34篇 |
1978年 | 25篇 |
1977年 | 34篇 |
1976年 | 18篇 |
1975年 | 21篇 |
1974年 | 23篇 |
1973年 | 18篇 |
1972年 | 22篇 |
排序方式: 共有2080条查询结果,搜索用时 31 毫秒
1.
Hommes Franziska Mohsenpour Amir Kropff Dana Pilgram Lisa Matusall Svenja von Philipsborn Peter Sell Kerstin 《Bundesgesundheitsblatt, Gesundheitsforschung, Gesundheitsschutz》2022,65(1):96-106
Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Akteure der öffentlichen Gesundheit (Public Health) tragen wesentlich zu Gesundheitsschutz, -förderung und... 相似文献
2.
3.
We present a case of dural cerebral venous thrombosis with coexisting left frontal hemorrhage that was successfully treated with 13.79 million units of urokinase over a period of 165 hours. 相似文献
4.
Suppurative corneal ulceration in Bangladesh 总被引:8,自引:0,他引:8
AAS Dunlop MB BS ED Wright MRCPath † SA Howlader‡ I Nazrul‡ R Husain‡ K McClellan FRACO § FA Billson FRACO § 《Clinical & experimental ophthalmology》1994,22(2):105-110
Suppurative keratitis is an important preventable cause of blindness, particularly in the developing world. This study analyses 142 cases of suppurative keratitis referred to Chittagong Eye Infirmary, Bangladesh. Some 53.5% of cases were bacterial and 35.9% were fungal. The five most common pathogens were: Pseudomonas sp. 24%, Streptococcus pneumoniae 17%, Aspergillus sp. 13%, Fusarium sp. 7% and Curvularia sp. 6%. Gram stain and culture results were consistent in 62.6% of cases. Previous antibiotic treatment was a significant factor for failure of culture isolation and less so for Gram stain failure. On Gram stain, 55.9% of pseudomonal cases were missed, but only 2% of fungal cases were missed. Over all, Gram stain had a sensitivity of 62% and positive predictive value of 84% for bacterial cases, and 98% and 94% for fungal cases, respectively. Fungal ulcers were typically filamentous, but an antecedent history of trauma was not common. The most frequent injury was due to rice grains, but the inoculum appeared to be introduced during eye washing with contaminated water. Pseudomonal ulcers occurred most frequently in the monsoon season, and Fusarium cases were seen only in the hot, dry season. 相似文献
5.
6.
7.
8.
Nonheme iron in sickle erythrocyte membranes: association with phospholipids and potential role in lipid peroxidation 总被引:5,自引:0,他引:5
Previous studies documented the abnormal association of heme and heme proteins with the sickle RBC membrane. We have now examined RBC ghosts and inside-out membranes (IOM) for the presence of nonheme iron as detected by its formation of a colored complex with ferrozine. Sickle ghosts have 33.8 +/- 18.2 nmol nonheme iron/mg membrane protein, and sickle IOM have 4.3 +/- 3.0 nmol/mg. In contrast, normal RBC ghosts and IOM have no detectable nonheme iron. The combination of heme and nonheme iron in sickle IOM averages nine times the amount of membrane- associated iron in normal IOM. Kinetics of the ferrozine reaction show that some of this nonheme iron on IOM reacts slowly and is probably in the form of ferritin, but most (72% +/- 18%) reacts rapidly and is in the form of some other biologic chelate. The latter iron compartment is removed by deferoxamine and by treatment of IOM with phospholipase D, which suggests that it represents an abnormal association of iron with polar head groups of aminophospholipids. The biologic feasibility of such a chelate was demonstrated by using an admixture of iron with model liposomes. Even in the presence of tenfold excess adenosine diphosphate, iron partitions readily into phosphatidylserine liposomes; there is no detectable association with phosphatidylcholine liposomes. To examine the bioavailability of membrane iron, we admixed membranes and t-butylhydroperoxide and found that sickle membranes show a tenfold greater peroxidation response than do normal membranes. This is not due simply to a deficiency of vitamin E, and this is profoundly inhibited by deferoxamine. Thus, while thiol oxidation in sickle membranes previously was shown to correlate with heme iron, the present data suggest that lipid peroxidation is related to nonheme iron. In control studies, we did not find this pathologic association of nonferritin, nonheme iron with IOM prepared from sickle trait, high-reticulocyte, postsplenectomy, or iron-overloaded individuals. These data provide additional support for the concept that iron decompartmentalization is a characteristic of sickle RBCs. 相似文献
9.
10.
BACKGROUND. The distribution and correlates of serum levels of total cholesterol were studied in cross-sectional analyses of 7,439 1 to 4 year olds examined through the Arizona Department of Health Services. RESULTS. Mean cholesterol levels increased with age, and levels among 2 year olds approached those seen in adolescents. Racial and ethnic differences in cholesterol levels were observed: mean (age-adjusted) levels were 147 mg/dl among American Indians (n = 622), 153 mg/dl among Hispanics (n = 3165), 154 mg/dl among non-Hispanic whites (n = 3448), and 163 mg/dl among blacks (n = 204). Cholesterol levels were not associated either with obesity, as assessed by relative weight or the Quetelet index, or with breast-feeding during infancy. Very overweight (greater than or equal to 20 kg/m2) 3 and 4 year olds, however, tended to have higher mean levels of cholesterol than did other children. The proportion of children with borderline (170 to 199 mg/dl) or high (greater than or equal to 200 mg/dl) levels of cholesterol varied by race/ethnicity: borderline (high) levels were seen among 14% (3%) of American Indians and 29% (11%) of blacks. The proportions of white and Hispanic children having cholesterol levels between 170 and 199 mg/dl or greater than or equal to 200 mg/dl were midway between those seen among American Indians and blacks. CONCLUSION. Additional information on the interrelationships of lipids and lipoproteins may aid in the identification of children who will be at increased risk for cardiovascular disease in adulthood. 相似文献