全文获取类型
| 收费全文 | 1088906篇 |
| 免费 | 80869篇 |
| 国内免费 | 2962篇 |
专业分类
| 耳鼻咽喉 | 14014篇 |
| 儿科学 | 36781篇 |
| 妇产科学 | 30087篇 |
| 基础医学 | 156620篇 |
| 口腔科学 | 29388篇 |
| 临床医学 | 100128篇 |
| 内科学 | 211808篇 |
| 皮肤病学 | 24084篇 |
| 神经病学 | 88404篇 |
| 特种医学 | 41885篇 |
| 外国民族医学 | 308篇 |
| 外科学 | 163993篇 |
| 综合类 | 24740篇 |
| 一般理论 | 512篇 |
| 预防医学 | 85467篇 |
| 眼科学 | 24555篇 |
| 药学 | 77780篇 |
| 27篇 | |
| 中国医学 | 2130篇 |
| 肿瘤学 | 60026篇 |
出版年
| 2021年 | 8890篇 |
| 2019年 | 9192篇 |
| 2018年 | 12832篇 |
| 2017年 | 9851篇 |
| 2016年 | 11156篇 |
| 2015年 | 12614篇 |
| 2014年 | 17471篇 |
| 2013年 | 26283篇 |
| 2012年 | 35750篇 |
| 2011年 | 37971篇 |
| 2010年 | 22616篇 |
| 2009年 | 21169篇 |
| 2008年 | 35162篇 |
| 2007年 | 37127篇 |
| 2006年 | 37454篇 |
| 2005年 | 35848篇 |
| 2004年 | 34955篇 |
| 2003年 | 33264篇 |
| 2002年 | 31969篇 |
| 2001年 | 47677篇 |
| 2000年 | 48523篇 |
| 1999年 | 41056篇 |
| 1998年 | 12277篇 |
| 1997年 | 10917篇 |
| 1996年 | 10834篇 |
| 1995年 | 10400篇 |
| 1994年 | 9631篇 |
| 1993年 | 8994篇 |
| 1992年 | 32629篇 |
| 1991年 | 31818篇 |
| 1990年 | 31297篇 |
| 1989年 | 30128篇 |
| 1988年 | 27407篇 |
| 1987年 | 27561篇 |
| 1986年 | 25650篇 |
| 1985年 | 24845篇 |
| 1984年 | 18667篇 |
| 1983年 | 15753篇 |
| 1982年 | 9595篇 |
| 1979年 | 16947篇 |
| 1978年 | 12335篇 |
| 1977年 | 10407篇 |
| 1976年 | 9823篇 |
| 1975年 | 10239篇 |
| 1974年 | 12374篇 |
| 1973年 | 11910篇 |
| 1972年 | 10927篇 |
| 1971年 | 10146篇 |
| 1970年 | 9400篇 |
| 1969年 | 8757篇 |
排序方式： 共有10000条查询结果，搜索用时 31 毫秒
41.
Partha Sardar Deepak L. Bhatt Ajay J. Kirtane Kevin F. Kennedy Saurav Chatterjee Jay Giri Peter A. Soukas William B. White Sahil A. Parikh Herbert D. Aronow 《Journal of the American College of Cardiology》2019,73(13):1633-1642
Background
There are conflicting data regarding the relative effectiveness of renal sympathetic denervation (RSD) in patients with hypertension.Objectives
The purpose of this study was to evaluate the blood pressure (BP) response after RSD in sham-controlled randomized trials.Methods
Databases were searched through June 30, 2018. Randomized trials (RCTs) with ≥50 patients comparing catheter-based RSD with a sham control were included. The authors calculated summary treatment estimates as weighted mean differences (WMD) with 95% confidence intervals (CIs) using random-effects meta-analysis.Results
The analysis included 977 patients from 6 trials. The reduction in 24-h ambulatory systolic blood pressure (ASBP) was significantly greater for patients treated with RSD than sham procedure (WMD ?3.65 mm Hg, 95% CI: ?5.33 to ?1.98; p < 0.001). Compared with sham, RSD was also associated with a significant decrease in daytime ASBP (WMD ?4.07 mm Hg, 95% CI: ?6.46 to ?1.68; p < 0.001), office systolic BP (WMD ?5.53 mm Hg, 95% CI: ?8.18 to ?2.87; p < 0.001), 24-h ambulatory diastolic BP (WMD ?1.71 mm Hg, 95% CI: ?3.06 to ?0.35; p = 0.01), daytime ambulatory diastolic BP (WMD ?1.57 mm Hg, 95% CI: ?2.73 to ?0.42; p = 0.008), and office diastolic BP (WMD ?3.37 mm Hg, 95% CI: ?4.86 to ?1.88; p < 0.001). Compared with first-generation trials, a significantly greater reduction in daytime ASBP was observed with RSD in second-generation trials (6.12 mm Hg vs. 2.14 mm Hg; p interaction = 0.04); however, this interaction was not significant for 24-h ASBP (4.85 mm Hg vs. 2.23 mm Hg; p interaction = 0.13).Conclusions
RSD significantly reduced blood pressure compared with sham control. Results of this meta-analysis should inform the design of larger, pivotal trials to evaluate the long-term efficacy and safety of RSD in patients with hypertension. 相似文献42.
M. Tobias Heinrichs George L. Drusano David L. Brown Michael S. Maynard Sherwin K.B. Sy Kenneth H. Rand Charles A. Peloquin Arnold Louie Hartmut Derendorf 《International journal of antimicrobial agents》2019,53(3):275-283
Introduction
There is an urgent need for new anti-tuberculosis (TB) drugs and optimization of current TB treatment. Moxifloxacin and linezolid are valuable options for the treatment of drug-resistant TB; however, it is crucial to find a dose at which these drugs not only show high efficacy but also suppress the development of further drug resistance.Methods
Activity of moxifloxacin and linezolid against Mycobacterium tuberculosis was studied in the hollow-fiber infection model system in log-phase growth under neutral pH and slow growth in an acidic environment. Doses that achieved maximum bacterial kill while suppressing the emergence of drug resistance were determined. Through Monte Carlo simulations the quantitative output of this in vitro study was bridged to the human patient population to inform optimal dosage regimens while accounting for clinical minimum inhibitory concentration (MIC) distributions.Results and Discussion
Moxifloxacin activity was significantly decreased in an acidified environment. The loss of activity was compensated by accumulation of the drug in TB lung lesions; therefore, moderate efficacy can be expected. Moxifloxacin 800 mg/day is the dose that most likely leads to resistance suppression while exerting maximum bacterial kill. Linezolid demonstrated very good activity even at a reduced pH. Linezolid 900 mg once-daily (QD) is likely to achieve a maximum killing effect and prevent the emergence of drug resistance; 600 mg QD in a robust drug regimen may have similar potential. 相似文献43.
P. Herent B. Schmauch P. Jehanno O. Dehaene C. Saillard C. Balleyguier J. Arfi-Rouche S. Jégou 《Diagnostic and interventional imaging》2019,100(4):219-225
Purpose
The purpose of this study was to assess the potential of a deep learning model to discriminate between benign and malignant breast lesions using magnetic resonance imaging (MRI) and characterize different histological subtypes of breast lesions.Materials and methods
We developed a deep learning model that simultaneously learns to detect lesions and characterize them. We created a lesion-characterization model based on a single two-dimensional T1-weighted fat suppressed MR image obtained after intravenous administration of a gadolinium chelate selected by radiologists. The data included 335 MR images from 335 patients, representing 17 different histological subtypes of breast lesions grouped into four categories (mammary gland, benign lesions, invasive ductal carcinoma and other malignant lesions). Algorithm performance was evaluated on an independent test set of 168 MR images using weighted sums of the area under the curve (AUC) scores.Results
We obtained a cross-validation score of 0.817 weighted average receiver operating characteristic (ROC)-AUC on the training set computed as the mean of three-shuffle three-fold cross-validation. Our model reached a weighted mean AUC of 0.816 on the independent challenge test set.Conclusion
This study shows good performance of a supervised-attention model with deep learning for breast MRI. This method should be validated on a larger and independent cohort. 相似文献44.
45.
Sarah J. Schrauben Haochang Shou Xiaoming Zhang Amanda Hyre Anderson Joseph V. Bonventre Jing Chen Steven Coca Susan L. Furth Jason H. Greenberg Orlando M. Gutierrez Joachim H. Ix James P. Lash Chirag R. Parikh Casey M. Rebholz Venkata Sabbisetti Mark J. Sarnak Michael G. Shlipak Sushrut S. Waikar Paul L. Kimmel Ramachandran S. Vasan Harold I. Feldman Jeffrey R. Schelling 《Journal of the American Society of Nephrology : JASN》2021,32(1):115
46.
The present study enumerates the attenuating effects of curcumin and α-tocopherol against propoxur induced oxidative DNA damage in human peripheral blood mononuclear cells (PBMC). Cultured cells were isolated from peripheral blood of healthy volunteers, and were exposed to varying concentrations of propoxur (0–21?μg/ml) for 6, 12, and 24?h, and in combination with curcumin (9.2?μg/ml) or α-tocopherol (4.3?μg/ml) or both. Cytotoxic effect of propoxur was examined by MTT assay. The role of oxidative stress beneath the cytotoxicity of propoxur was evaluated by the measurement of reduced glutathione (GSH), malondialdehyde (MDA) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) levels in cell lysate. A concentration-dependent cell death, depletion of GSH, an increase in the level of both MDA and 8-OH-dG were observed. Co-treatment with curcumin or α-tocopherol significantly attenuates depleted GSH, decrease in MDA and 8-OH-dG levels in propoxur exposed cells (p?相似文献
47.
48.
49.
50.