全文获取类型
收费全文 | 8551篇 |
免费 | 531篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 141篇 |
儿科学 | 227篇 |
妇产科学 | 341篇 |
基础医学 | 1338篇 |
口腔科学 | 143篇 |
临床医学 | 761篇 |
内科学 | 1599篇 |
皮肤病学 | 89篇 |
神经病学 | 793篇 |
特种医学 | 353篇 |
外科学 | 885篇 |
综合类 | 57篇 |
一般理论 | 3篇 |
预防医学 | 806篇 |
眼科学 | 87篇 |
药学 | 788篇 |
中国医学 | 14篇 |
肿瘤学 | 685篇 |
出版年
2021年 | 89篇 |
2020年 | 56篇 |
2019年 | 101篇 |
2018年 | 125篇 |
2017年 | 67篇 |
2016年 | 95篇 |
2015年 | 127篇 |
2014年 | 189篇 |
2013年 | 278篇 |
2012年 | 385篇 |
2011年 | 448篇 |
2010年 | 226篇 |
2009年 | 206篇 |
2008年 | 414篇 |
2007年 | 419篇 |
2006年 | 435篇 |
2005年 | 451篇 |
2004年 | 440篇 |
2003年 | 417篇 |
2002年 | 356篇 |
2001年 | 205篇 |
2000年 | 164篇 |
1999年 | 179篇 |
1998年 | 109篇 |
1997年 | 108篇 |
1996年 | 116篇 |
1995年 | 106篇 |
1994年 | 102篇 |
1993年 | 106篇 |
1992年 | 156篇 |
1991年 | 183篇 |
1990年 | 146篇 |
1989年 | 120篇 |
1988年 | 126篇 |
1987年 | 101篇 |
1986年 | 101篇 |
1985年 | 106篇 |
1984年 | 113篇 |
1983年 | 101篇 |
1982年 | 77篇 |
1981年 | 76篇 |
1980年 | 80篇 |
1979年 | 85篇 |
1978年 | 64篇 |
1977年 | 55篇 |
1976年 | 69篇 |
1975年 | 60篇 |
1974年 | 81篇 |
1973年 | 78篇 |
1972年 | 55篇 |
排序方式: 共有9110条查询结果,搜索用时 0 毫秒
11.
Herman Buschke Martin J Sliwinski Gail Kuslansky Mindy Katz Joe Verghese Richard B Lipton 《Journal of the International Neuropsychological Society》2006,12(3):436-440
Impaired recall for early items (primacy) and late items (recency) on word list recall tests are seen in Alzheimer's disease (AD). We compared conventional scoring on the Telephone Instrument for Cognitive Status (TICS) recall list with scorings based on retention-weighted recall (RWR: each item weighted by its serial position) in older adults participating in a community-based aging study. Subjects with mild AD (N=18) did not differ from those without dementia (N=231) with respect to recency (46% vs. 59%, p = 0.2), but had impaired primacy (2% vs. 39%, p < .001) on word recall on the TICS. RWR scoring improved the effect size (1.52 SD) compared to conventional scoring (1.08 SD). With a fixed sensitivity of 85%, specificity was lower using conventional scoring (56%) than RWR (76%) scoring. Our findings suggest that optimized RWR scoring of word list free recall can improve detection of mild AD compared to conventional scoring. 相似文献
12.
13.
D Johnstone M Limacher M Rousseau C S Liang L Ekelund M Herman D Stewart M Guillotte G Bjerken W Gaasch 《The American journal of cardiology》1992,70(9):894-900
The Studies of Left Ventricular Dysfunction (SOLVD) trials were designed to evaluate the effects of enalapril on long-term mortality in patients with severe left ventricular (LV) dysfunction. Patients with LV ejection fractions less than or equal to 0.35 and symptoms of congestive heart failure (CHF) were enrolled in the treatment trial, whereas those with no history of overt CHF and taking no treatment directed for LV dysfunction were enrolled in the prevention trial. The baseline clinical characteristics of SOLVD patients were compared to characterize differences between patients in these 2 separate but concurrent trials. From over 70,000 patients screened with LV dysfunction, 4,228 patients were enrolled in the prevention trial and 2,569 patients in the treatment trial. Ischemic heart disease was the primary cause of LV dysfunction in both prevention (83%) and treatment (71%) trial patients. Prior myocardial infarction was present in 80% of the prevention and 66% of the treatment trial patients (p less than 0.001). In the prevention trial, infarction was recent (less than or equal to 6 months) in 27% patients and remote (greater than 6 months) in 57% patients. Treatment trial patients had proportionately more women (20 vs 13%; p less than 0.001) and non-Caucasians (20 vs 14%; p less than 0.001), as well as the coexisting risk factors of hypertension (42 vs 37%; p less than 0.001) and diabetes (26 vs 15%; p less than 0.001) than did prevention trial patients. Clinical characteristics of patients in both trials were influenced by the gender and race of enrolled patients. Similarly, coronary artery bypass surgery was performed less often in women and non-Caucasians.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
14.
Alysa R. Herman MD Klaus J. Busam MD Robert A. Greenberg MD Kishwer S. Nehal MD 《Dermatologic surgery》2003,29(4):436-439
BACKGROUND: Basal cell carcinoma shows a wide spectrum of clinical and histologic appearances. A distinct tumor variant with follicular infundibulocystic differentiation is recognized, and there are only a few reports on its clinical presentation and management. OBJECTIVE: To report a case of multiple infundibulocystic basal cell carcinomas with a unique unilateral presentation. METHODS: A clinical history was obtained. Photographs were taken, and punch biopsies were performed. RESULTS: An 83-year-old Caucasian female presented with multiple unilateral, asymptomatic, skin-colored, dome-shaped papules around the right mouth for 11 years without apparent change. Punch biopsies revealed findings typical of infundibulocystic basal cell carcinoma. CONCLUSIONS: A patient with clinically indolent multiple unilateral infundibulocystic basal cell carcinomas is described. Given the location of these multiple lesions, standard treatment modalities for basal cell carcinomas would have significant cosmetic and functional implications. A management approach with clinical follow-up and surgical intervention only for changing lesions is discussed. 相似文献
15.
Results of previous studies have shown that when rats consume higher concentrations of ethanol during initiation both the amount consumed and the pattern of consumption change with the return to a lower concentration. In this study, an across-sessions breakpoint procedure in the sipper-tube model was used to examine the effect that experience with drinking higher concentrations (a concentration manipulation) of both ethanol and sucrose had on appetitive and consummatory behaviors. A follow-up study was then conducted in the ethanol-consuming group with across-session breakpoint and intake examined before, during, and after a 3% sucrose/10% ethanol solution was presented in the sipper tube. As ethanol concentration increased, intake was not changed. Exposure to higher ethanol concentrations had no effect on the amount of 10% ethanol consumed when retested. The exposure tended to increase appetitive behavior (breakpoint), but this effect was not unique to ethanol, as rats self-administering 3% sucrose showed a similar increase. When the combined ethanol-sucrose solution was available, a significant increase in both intake and appetitive responding occurred; however, there was no change from prior intake or breakpoint when 10% ethanol was retested. That the addition of sucrose to the ethanol solution significantly increased appetitive and consummatory behaviors supports the suggestion that the composition of the alcoholic beverage can have a strong influence over the control of self-administration. Because most consumption of ethanol by human beings is in solutions that contain mixers that alter the taste of the solution, this taste factor needs to be considered in the regulation of ethanol drinking. 相似文献
16.
17.
18.
19.
20.
Johannes M. A. Van Gerven Johan P. Boot Herman H. P. J. Lemkes Jaap A. Van Best PhD 《Documenta ophthalmologica. Advances in ophthalmology》1992,80(2):183-188
The morphological base for the impaired function of the blood retinal barrier was studied in 50 eyes of 10 insulin dependent and 21 non-insulin dependent patients with various levels of diabetic retinopathy. The permeability of the blood retinal barrier (PBRB) was determined by vitreous fluorophotometry with correction for autofluorescence, lenstransmission and non-protein bound plasma fluorescein concentration. Morphological abnormalities of diabetic retinopathy assessed by fundus photography and fluorescein angiography were individually scored on a decimal scale and related to the PBRB by multiple regression analysis. The Pbrb was not correlated to morphological abnormalities of non-proliferative retinopathy [(1) microaneurysms, (2) hard exudates, (3) soft exudates, (4) intraretinal hemorrhages, (5) fluorescein leakage, and (6) capillary closure, p > 0.3]. The PBRB was correlated to morphological abnormalities of (pre)proliferative retinopathy [(1) intraretinal microvascular abnormalities (Sirma) and (2) new vessels (Sneo): pbrb = A – B.SIRMA – C.Sneo with PBRB in nm/sec, A = 1.5 ± 0.5, B = 0.9 ± 0.2 and C = 1.7 ± 0.4, R2 = 0.65, p < 0.0001]. It can be concluded that the increased blood retinal barrier permeability in diabetic patients is mainly due to (pre)proliferative abnormalities and not to non-proliferative abnormalities. 相似文献