全文获取类型
收费全文 | 23823篇 |
免费 | 1804篇 |
国内免费 | 777篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 512篇 |
妇产科学 | 191篇 |
基础医学 | 2666篇 |
口腔科学 | 408篇 |
临床医学 | 2863篇 |
内科学 | 3872篇 |
皮肤病学 | 354篇 |
神经病学 | 1359篇 |
特种医学 | 1333篇 |
外国民族医学 | 2篇 |
外科学 | 2079篇 |
综合类 | 3200篇 |
现状与发展 | 5篇 |
预防医学 | 1484篇 |
眼科学 | 318篇 |
药学 | 3732篇 |
6篇 | |
中国医学 | 1156篇 |
肿瘤学 | 728篇 |
出版年
2024年 | 35篇 |
2023年 | 272篇 |
2022年 | 590篇 |
2021年 | 856篇 |
2020年 | 648篇 |
2019年 | 651篇 |
2018年 | 722篇 |
2017年 | 737篇 |
2016年 | 793篇 |
2015年 | 867篇 |
2014年 | 1645篇 |
2013年 | 1790篇 |
2012年 | 1499篇 |
2011年 | 1697篇 |
2010年 | 1350篇 |
2009年 | 1276篇 |
2008年 | 1340篇 |
2007年 | 1203篇 |
2006年 | 1025篇 |
2005年 | 944篇 |
2004年 | 750篇 |
2003年 | 709篇 |
2002年 | 617篇 |
2001年 | 428篇 |
2000年 | 392篇 |
1999年 | 348篇 |
1998年 | 318篇 |
1997年 | 303篇 |
1996年 | 290篇 |
1995年 | 285篇 |
1994年 | 231篇 |
1993年 | 216篇 |
1992年 | 181篇 |
1991年 | 180篇 |
1990年 | 117篇 |
1989年 | 113篇 |
1988年 | 122篇 |
1987年 | 92篇 |
1986年 | 94篇 |
1985年 | 106篇 |
1984年 | 100篇 |
1983年 | 76篇 |
1982年 | 75篇 |
1981年 | 69篇 |
1980年 | 55篇 |
1979年 | 45篇 |
1978年 | 43篇 |
1977年 | 30篇 |
1976年 | 17篇 |
1971年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
目的:探讨脑出血对酵母沉默信息调节因子2(Sirt2)和炎症的影响。方法:将胶原酶Ⅳ注入SD大鼠右侧
纹状体中建立脑出血模型,通过免疫印迹和ELISA 等方法测定大鼠脑出血后48 h 的Sirt2 的表达及炎症变化。利
用Hemin 诱导PC12 细胞损伤模拟体外脑出血模型,并检测Sirt2 及炎症变化;采用短发夹RNA(shRNA)-Sirt2 沉
默Sirt2 在PC12 细胞中的表达及对炎症的影响。结果:手术后48 h 脑出血行为学评分最低。脑出血组Sirt2 的表达
显著高于假手术组。脑出血组IL-6、IL-1β 表达显著升高。结论:脑出血可以促进Sirt2 的表达和炎症反应,降低
Sirt2 的表达可减缓炎症反应。
关键词 脑出血;沉默信息调节 相似文献
2.
3.
4.
5.
6.
《Respiratory investigation》2022,60(1):137-145
BackgroundSome chronic obstructive pulmonary disease (COPD) patients develop hypoxemia with disease progression, with some even requiring long-term oxygen therapy (LTOT). Lung function, especially diffusing capacity, and the annual decline in PaO2, are reported to be predictive factors of chronic respiratory failure. However, the association between lung morphometry evaluated using computed tomography (CT) images and LTOT initiation is unknown.MethodsWe retrospectively evaluated the relationship between clinical indices, including pulmonary function, body mass index (BMI), and CT parameters, at baseline and LTOT initiation in two prospective COPD cohorts. In the Nara Medical University cohort (n = 76), the low attenuation area (LAA) and its fractal dimension (fractal D) were adapted as the indices for parenchymal destruction in CT images. The association between these CT measurements and LTOT initiation was replicated in the Kyoto University cohort (n = 130).ResultsIn the Nara Medical University cohort, lower BMI (hazard ratio [HR]:0.70, p = 0.006), lower % diffusing capacity (%DLCO) (HR: 0.92, p = 0.006), lower %DLCO/VA (HR, 0.90, p = 0.008), higher RV/TLC (HR, 1.26, p = 0.012), higher LAA% (HR: 1.18, p = 0.001), and lower fractal D (HR: 3.27 × 10?8, p < 0.001) were associated with LTOT initiation. Multivariate analysis in the Kyoto University cohort confirmed that lower %DLCO and lower fractal D were independently associated with LTOT initiation, whereas LAA% was not.ConclusionFractal D, which is the index for morphometric complexity of LAA in CT analysis, is predictive of LTOT initiation in COPD patients. 相似文献
7.
Tasuku Ogita Rosaly Vallejo Manaois Manabu Wakagi Tomoyuki Oki Yuko Takano Ishikawa 《International journal of food sciences and nutrition》2016,67(4):431-440
Two cultivars of Japanese parsley were harvested in different seasons; their antioxidant capacities were evaluated by oxygen radical absorbance capacity (ORAC) methods, and the contents of hydrophilic and lipophilic antioxidants were compared. Japanese parsley possessed potent antioxidant capacities both in hydrophilic and lipophilic extracts when evaluated by ORAC methods. LC/MS/MS analyses revealed that chlorogenic acid and four kinds of quercetin glycosides were major antioxidants in the hydrophilic extract. Lutein was the main contributor to the antioxidant capacity of the lipophilic extract. Antioxidant capacities of the hydrophilic extracts of both cultivars tended to be higher in winter because of the increase in the contents of chlorogenic acid and quercetin glycosides. An obvious trend in the lipophilic antioxidant capacities or lutein contents was not observed irrespective of the cultivar. 相似文献
8.
9.
10.
《Drug discovery today》2022,27(6):1733-1742
Compounds that exhibit assay interference or undesirable mechanisms of bioactivity are routinely encountered in assays at various stages of drug discovery. We observed that assays for the investigation of thiol-reactive and redox-active compounds have not been collected in a comprehensive review. Here, we review these assays and subject them to experimental optimization to improve their reliability. We demonstrate the usefulness of our assay cascade by assaying a library of bioactive compounds, chemical probes, and a set of approved drugs. These high-throughput assays should complement the array of wet-lab and in silico assays during the initial stages of hit discovery campaigns to pursue only hit compounds with tractable mechanisms of action. 相似文献