全文获取类型
收费全文 | 2012篇 |
免费 | 146篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 74篇 |
妇产科学 | 44篇 |
基础医学 | 242篇 |
口腔科学 | 57篇 |
临床医学 | 210篇 |
内科学 | 527篇 |
皮肤病学 | 68篇 |
神经病学 | 144篇 |
特种医学 | 44篇 |
外科学 | 279篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 135篇 |
眼科学 | 21篇 |
药学 | 99篇 |
中国医学 | 2篇 |
肿瘤学 | 170篇 |
出版年
2023年 | 21篇 |
2022年 | 7篇 |
2021年 | 65篇 |
2020年 | 44篇 |
2019年 | 80篇 |
2018年 | 107篇 |
2017年 | 55篇 |
2016年 | 52篇 |
2015年 | 66篇 |
2014年 | 90篇 |
2013年 | 150篇 |
2012年 | 149篇 |
2011年 | 161篇 |
2010年 | 130篇 |
2009年 | 115篇 |
2008年 | 84篇 |
2007年 | 77篇 |
2006年 | 79篇 |
2005年 | 67篇 |
2004年 | 59篇 |
2003年 | 53篇 |
2002年 | 68篇 |
2001年 | 61篇 |
2000年 | 55篇 |
1999年 | 43篇 |
1998年 | 17篇 |
1997年 | 22篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 19篇 |
1991年 | 21篇 |
1990年 | 15篇 |
1989年 | 15篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1981年 | 3篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1937年 | 2篇 |
1918年 | 2篇 |
排序方式: 共有2161条查询结果,搜索用时 62 毫秒
1.
Wenjing Tao Miia Artama My von Euler-Chelpin Mark Hull Rickard Ljung Elsebeth Lynge Guðríður H. Ólafsdóttir Eero Pukkala Pål Romundstad Mats Talbäck Laufey Tryggvadottir Jesper Lagergren 《International journal of cancer. Journal international du cancer》2020,147(3):728-735
Obesity is a risk factor for colorectal cancer. Yet, some research indicates that weight-reducing bariatric surgery also increases colorectal cancer risk. Our study was undertaken because current evidence examining bariatric surgery and risk of colorectal cancer is limited and inconsistent. This population-based cohort study included adults with a documented obesity diagnosis in Denmark, Finland, Iceland, Norway or Sweden in 1980–2015. The incidence of colorectal cancer in participants with obesity who had and had not undergone bariatric surgery was compared to the incidence in the corresponding background population by calculating standardized incidence ratios (SIR) with 95% confidence intervals (CI). Additionally, operated and nonoperated participants with obesity were compared using multivariable Cox regression, providing hazard ratios (HR) with 95% CIs adjusted for confounders. Among 502,772 cohort participants with an obesity diagnosis, 49,931(9.9%) underwent bariatric surgery. The overall SIR of colon cancer was increased after bariatric surgery (SIR 1.56; 95% CI 1.28–1.88), with higher SIRs ≥10 years postsurgery. The overall HR of colon cancer in operated compared to nonoperated participants was 1.13 (95% CI 0.92–1.39) and 1.55 (95% CI 1.04–2.31) 10–14 years after bariatric surgery. Bariatric surgery did not significantly increase the risk of rectal cancer (SIR 1.14, 95% CI 0.83–1.52; HR 1.08, 95% CI 0.79–1.49), but the risk estimates increased with longer follow-up periods. Our study suggests that bariatric surgery is associated with an increased risk of colon cancer, while the support for an increased risk of rectal cancer was weaker. 相似文献
2.
3.
Amalia Moreno Concepción Montón Yolanda Belmonte Miguel Gallego Xavier Pomares Jordi Real 《Archivos de bronconeumologia》2009,45(4):181-185
ObjectiveThe objective of this study was to assess the causes of death and risk factors for mortality in a cohort of patients with severe chronic obstructive pulmonary disease (COPD).Patients and methodsWe studied 203 patients with severe COPD (forced expiratory volume in 1 second [FEV1] <50%), who were attended in our respiratory department day hospital (2001-2006). Clinical variables were recorded on inclusion, and clinical course and causes of death were retrospectively reviewed.ResultsThe mean (SD) age of patients was 69 (8) years and the mean FEV1 was 30.8% (8.2%). One-hundred and nine patients died (53.7%); death was attributed to respiratory causes in 72 (80.9%), with COPD exacerbation being the most frequent specific cause within this category (48.3%). During follow-up, 18.7% required admission to the intensive care unit (ICU). Survival at 1, 3, and 5 years was 80%, 53%, and 26%, respectively. The multivariate analysis showed that mortality was associated with age, stage IV classification according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), cor pulmonale, and hospital admission during the year prior to inclusion. Need for admission to the ICU during follow-up was a factor independently associated with higher mortality.ConclusionsMortality in patients with severe COPD was high and exacerbation of the disease was one of the most frequent causes of death. Age, GOLD stage, cor pulmonale, prior admission to hospital, and need for admission to the ICU during follow-up were independent predictors of mortality. 相似文献
4.
5.
6.
7.
8.
9.
10.
Changes in the human immunodeficiency virus p7-p1-p6 gag gene in drug-naive and pretreated patients 下载免费PDF全文
Resistance to antiretroviral agents often results from mutations within the human immunodeficiency virus (HIV) pol gene. Moreover, insertions within the p6 gag-pol region have recently been found to be involved with resistance to nucleoside analogs. Overall, we found that 21% of 156 specimens collected from HIV-infected individuals (17.6% from 74 drug-naive patients and 24.4% from 82 pretreated patients) harbored these insertions. Insertions around the KQE (Lys-Gln-Glu) motif were found in 12.2% of the pretreated patients but in none of the drug-naive subjects (P = 0.002). In contrast, insertions around the PTAP (Prol-Thre-Ala-Prol) motif were seen at similar rates ( approximately 15%) among drug-naive and pretreated patients, which supports the idea that they may be natural polymorphisms. 相似文献