全文获取类型
收费全文 | 31504篇 |
免费 | 2558篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 544篇 |
儿科学 | 1253篇 |
妇产科学 | 1014篇 |
基础医学 | 4311篇 |
口腔科学 | 832篇 |
临床医学 | 2748篇 |
内科学 | 7344篇 |
皮肤病学 | 747篇 |
神经病学 | 3254篇 |
特种医学 | 996篇 |
外国民族医学 | 3篇 |
外科学 | 3899篇 |
综合类 | 534篇 |
一般理论 | 43篇 |
预防医学 | 2301篇 |
眼科学 | 633篇 |
药学 | 1769篇 |
中国医学 | 8篇 |
肿瘤学 | 1901篇 |
出版年
2021年 | 413篇 |
2020年 | 271篇 |
2019年 | 454篇 |
2018年 | 507篇 |
2017年 | 363篇 |
2016年 | 405篇 |
2015年 | 461篇 |
2014年 | 642篇 |
2013年 | 971篇 |
2012年 | 1266篇 |
2011年 | 1338篇 |
2010年 | 789篇 |
2009年 | 682篇 |
2008年 | 1209篇 |
2007年 | 1307篇 |
2006年 | 1303篇 |
2005年 | 1234篇 |
2004年 | 1237篇 |
2003年 | 1123篇 |
2002年 | 1192篇 |
2001年 | 1096篇 |
2000年 | 1167篇 |
1999年 | 982篇 |
1998年 | 365篇 |
1997年 | 306篇 |
1996年 | 320篇 |
1995年 | 295篇 |
1994年 | 289篇 |
1993年 | 303篇 |
1992年 | 863篇 |
1991年 | 805篇 |
1990年 | 685篇 |
1989年 | 728篇 |
1988年 | 676篇 |
1987年 | 708篇 |
1986年 | 650篇 |
1985年 | 676篇 |
1984年 | 536篇 |
1983年 | 465篇 |
1982年 | 300篇 |
1980年 | 259篇 |
1979年 | 457篇 |
1978年 | 307篇 |
1977年 | 258篇 |
1976年 | 280篇 |
1975年 | 268篇 |
1974年 | 297篇 |
1973年 | 294篇 |
1972年 | 267篇 |
1971年 | 261篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Oren S Cohen Eli Vakil David Tanne Zeev Nitsan Roseline Schwartz Sharon Hassin-Baer 《Cognitive and behavioral neurology》2007,20(1):68-72
OBJECTIVES: To test a possible association between the educational level (EL), cognitive performance, and neuropsychiatric features in Parkinson disease (PD). BACKGROUND: An inverse association has been reported between EL and cognitive dysfunction in patients with senile dementia of Alzheimer type but it is yet unsettled whether education has a similar effect on cognition in PD. METHODS: Seventy-two PD patients (45 males, mean age 68.7+/-11.6 y) underwent a detailed neurologic examination, a battery of neuropsychologic tests, and questionnaires for the evaluation of psychosis, sleep disturbances, and depression. According to the number of educational years, patients were divided into 3 groups: low EL (0 to 8 y), (15 patients), intermediate EL (9 to 12 y) (28 patients), and high EL (>/=13 y) (29 patients). RESULTS: Patients with a higher EL had a better cognitive function and an association was found between the patients' EL and their scores in various neuropsychologic tests mainly those sensitive to frontal lobe dysfunction. Low education was associated with an increased risk for hallucinations and a trend for more depression, delusions, and sleep disturbances. CONCLUSIONS: The association between high educational attainment and the lower risk of cognitive dysfunction suggest that education might modulate cognitive performance in PD. 相似文献
23.
24.
Andrea Berger Michelle Sadeh Gabriel Tzur I Avinoam Shuper Liora Kornreich Dov Inbar Ian J Cohen Shalom Michowiz Isaac Yaniv Shlomi Constantini Eli Vakil 《Journal of the International Neuropsychological Society》2005,11(4):482-487
Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1-11 years at surgery and 9-17 years at testing. The children were tested not earlier than 2.5 years after surgery (M = 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients. 相似文献
25.
Mohammed N Islam Indraneel Bhattacharyya Junu Ojha Karen Bober Donald M Cohen James G Green 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):501-509
Hemifacial hypertrophy (HFH) is rare and characterized by unilateral enlargement of the head and teeth. Hemifacial hypertrophy is classified as true HFH (THFH) with unilateral enlargement of the viscerocranium, and partial HFH (PHFH) in which not all structures are enlarged. We present a case of THFH and compare and contrast it with a case of PHFH. Hemifacial hypertrophy may cover a wide spectrum of defects or may involve only muscle or bone. Myohyperplasia, reported previously as a separate syndrome, may actually represent a forme fruste of PHFH or THFH. The PHFH patient lead a healthy, normal life without significant psychosocial problems and was reluctant to accept his deformity. Contrastingly, the THFH patient had significant social stigma and compromised health together with major aesthetic morbidity. Treatment planning in THFH is arduous and involves multiple modalities. Therefore, it is imperative to differentiate THFH and PHFH for better understanding and management of the condition. 相似文献
26.
27.
28.
B M Cohen G Stramentinoli A L Sosa S M Babb V Olgiati 《European journal of pharmacology》1989,170(3):201-207
alpha 1- and beta-adrenoceptors were studied ex vivo in the brains of rats receiving repeated daily treatment with the standard antidepressant imipramine or the atypical antidepressant S-adenosyl-L-methionine (SAM), which has minimal effects on monoamine reuptake or turnover. Consistent with past studies, a decrease in the density of beta receptors at three weeks and an increase in the affinity of alpha 1 receptors for the agonist phenylephrine at one week of treatment was observed with imipramine. By comparison, an increase in the density of beta receptors and a decrease in the affinity of alpha 1 receptors for phenylephrine was observed at one week of treatment with SAM. These changes were no longer apparent at three weeks of treatment. The results suggest that treatment with SAM does lead to changes in adrenergic neurotransmission, but that down regulation of beta receptors or increased agonist affinity of alpha 1 receptors may not be necessary for the production of antidepressant effects. 相似文献
29.
An early accurate diagnosis of subungual melanoma depends upon an alert podiatric physician. Clinically, the lesion is often easily misdiagnosed and mistreated because of its resemblance to benign nail conditions. This paper discusses the incidence, histology, clinical findings, diagnosis, and treatment of this malignant lesion. An illustrative case report is presented. 相似文献
30.