全文获取类型
收费全文 | 2932篇 |
免费 | 199篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 186篇 |
妇产科学 | 73篇 |
基础医学 | 332篇 |
口腔科学 | 55篇 |
临床医学 | 286篇 |
内科学 | 586篇 |
皮肤病学 | 35篇 |
神经病学 | 124篇 |
特种医学 | 527篇 |
外科学 | 329篇 |
综合类 | 42篇 |
一般理论 | 2篇 |
预防医学 | 189篇 |
眼科学 | 26篇 |
药学 | 173篇 |
中国医学 | 3篇 |
肿瘤学 | 183篇 |
出版年
2021年 | 36篇 |
2020年 | 16篇 |
2019年 | 25篇 |
2018年 | 40篇 |
2017年 | 26篇 |
2016年 | 45篇 |
2015年 | 53篇 |
2014年 | 51篇 |
2013年 | 95篇 |
2012年 | 85篇 |
2011年 | 95篇 |
2010年 | 106篇 |
2009年 | 93篇 |
2008年 | 92篇 |
2007年 | 82篇 |
2006年 | 85篇 |
2005年 | 70篇 |
2004年 | 53篇 |
2003年 | 76篇 |
2002年 | 67篇 |
2001年 | 68篇 |
2000年 | 67篇 |
1999年 | 69篇 |
1998年 | 152篇 |
1997年 | 130篇 |
1996年 | 138篇 |
1995年 | 113篇 |
1994年 | 78篇 |
1993年 | 95篇 |
1992年 | 56篇 |
1991年 | 43篇 |
1990年 | 42篇 |
1989年 | 76篇 |
1988年 | 68篇 |
1987年 | 70篇 |
1986年 | 74篇 |
1985年 | 70篇 |
1984年 | 39篇 |
1983年 | 40篇 |
1982年 | 41篇 |
1981年 | 25篇 |
1980年 | 44篇 |
1979年 | 25篇 |
1978年 | 24篇 |
1977年 | 27篇 |
1976年 | 36篇 |
1975年 | 34篇 |
1973年 | 12篇 |
1971年 | 15篇 |
1966年 | 10篇 |
排序方式: 共有3156条查询结果,搜索用时 125 毫秒
1.
Esther M. John Amanda I. Phipps Lisa M. Hines Jocelyn Koo Sue A. Ingles Kathy B. Baumgartner Martha L. Slattery Anna H. Wu 《International journal of cancer. Journal international du cancer》2020,147(7):1808-1822
We pooled multiethnic data from four population-based studies and examined associations of menstrual and reproductive characteristics with breast cancer (BC) risk by tumor hormone receptor (HR) status [defined by estrogen receptor (ER) and progesterone receptor (PR)]. We estimated odds ratios and 95% confidence intervals using multivariable logistic regression, stratified by age (<50, ≥50 years) and ethnicity, for 5,186 HR+ (ER+ or PR+) cases, 1,365 HR− (ER− and PR−) cases and 7,480 controls. For HR+ BC, later menarche and earlier menopause were associated with lower risk in non-Hispanic whites (NHWs) and Hispanics, and higher parity and longer breast-feeding were associated with lower risk in Hispanics and Asian Americans, and suggestively in NHWs. Positive associations with later first full-term pregnancy (FTP), longer interval between menarche and first FTP and shorter time since last FTP were limited to younger Hispanics and Asian Americans. Except for nulliparity, reproductive characteristics were not associated with risk in African Americans. For HR− BC, lower risk was associated with later menarche, except in African Americans and older Asian Americans and with longer breast-feeding in Hispanics and Asian Americans only. In younger African Americans, HR− BC risk associated with higher parity (≥3 vs. 1 FTP) was increased fourfold in women who never breast-fed, but not in those with a breast-feeding history, suggesting that breast-feeding may mitigate the adverse effect of higher parity in younger African American women. Further work needs to evaluate why menstrual and reproductive risk factors vary in importance according to age and ethnicity. 相似文献
2.
Pure motor hemiplegia (PMH) is, in most cases, caused by a lacunar infarction. However, pure motor monoparesis (PMM), i.e., isolated motor involvement with spasticity in one limb, has drawn little attention. We studied prospectively 5 patients with PMM and found that it was always due to a mass lesion in the contralateral superficial cerebral hemisphere. Our observation suggests that PMM should not be regarded as simply a variant of PMH. 相似文献
3.
JA HYEON KU CHEOL KWAK SEUNG-JUNE OH EUNSIK LEE SANG EUN LEE JAE-SEUNG PAICK 《International journal of urology》2004,11(7):489-493
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population. 相似文献
4.
G L Hines Y Mishriki L Williams K Monroe N Metwally 《The Journal of cardiovascular surgery》1991,32(4):485-490
This study attempted to evaluate the efficacy of chronic extra-aortic counterpulsation with a latissimus dorsi neuro vascular flap. Five dogs had a preliminary procedure consisting of the creation of a latissimus dorsi flap and a thoracotomy in which the flap was wrapped around the descending aorta just distal to the left subclavian artery. An epicardial lead was placed on the left ventricle and a nerve stimulating lead placed around the thoraco-dorsal nerve. Three weeks later, both leads were connected to a cardiomyostimulator programmed to function in a counterpulsation mode with a 1:2 assist frequency. Hemodynamic measurements were made at 6 and 8 and 10 and 12 weeks and the dogs were sacrificed. Three dogs had all sets of hemodynamic measurements made. Two of the three dogs demonstrated diastolic augmentation at 6 and 8 and 10 and 12 weeks average 20 to 25 mmHg. The third dog failed to demonstrate any change. All dogs were sacrificed at 12 weeks and specimens were submitted for histologic evaluation. The muscle flap was preserved in all animals. The aorta subjacent to the flap showed, (1) normal intima with no evidence of disruption or thrombus in all animals, (2) in the animals in whom counterpulsation was observed, there appeared to be thinning of the media in the aorta subjacent to the muscle flap, and (3) no evidence of distal emboli. This study demonstrated that chronic counterpulsation can be obtained with a latissimus dorsi flap. The actual hemodynamic benefits are not determined from this study. The medial thinning in the aortic wall may limit the long-term benefit of this procedure. 相似文献
5.
6.
7.
8.
9.
10.
Cerebellar toxicity with high-dose cytosine arabinoside 总被引:1,自引:0,他引:1
R H Herzig J D Hines G P Herzig S N Wolff P A Cassileth H M Lazarus D J Adelstein R A Brown P F Coccia S Strandjord 《Journal of clinical oncology》1987,5(6):927-932
CNS dysfunction, especially impaired cerebellar function, is the dose-limiting toxicity associated with high-dose cytosine arabinoside, which precludes doses of greater than 48 g/m2. Four hundred eighteen patients between the ages of 2 and 74 years with leukemia or lymphoma received 36 to 48 g/m2 cytosine arabinoside either alone or with anthracycline antibiotics, 4'-(9-acridinylamino) methane sulfon-m-anisidine (m-AMSA), or total body irradiation. In only 35 of 418 patients (8%) did severe cerebellar toxicity develop; it was irreversible or fatal in four (1%) patients. The age of the patient was a critical factor in the incidence of severe cerebellar toxicity. Patients greater than 50 years old had a statistically significant greater incidence of cerebellar toxicity compared with younger patients (26/137, 19%, v 9/281, 3%; P less than .0005, chi 2). Neither the diagnosis, disease status, sex, nor the regimen altered the incidence of severe cerebellar toxicity (when corrected for age). A second course of high-dose cytosine arabinoside, administered to 62 patients, did not increase the incidence of severe cerebellar toxicity, which occurred in five (8%) of these patients. Two of the five patients had severe toxicity with the initial course. Of the 60 patients with no antecedent cerebellar dysfunction, three (5%) had severe toxicity with the second course: one of 41 patients were less than 50 years old; two of 19 patients were greater than or equal to 50 years. Since the occurrence of severe cerebellar dysfunction is greatly affected by age, reduced doses of high-dose cytosine arabinoside should be given to patients greater than 50 years old, and methods for reducing the cerebellar toxicity should be investigated in these patients. 相似文献