全文获取类型
收费全文 | 23216篇 |
免费 | 1243篇 |
国内免费 | 205篇 |
专业分类
耳鼻咽喉 | 329篇 |
儿科学 | 513篇 |
妇产科学 | 246篇 |
基础医学 | 3024篇 |
口腔科学 | 347篇 |
临床医学 | 1398篇 |
内科学 | 6620篇 |
皮肤病学 | 558篇 |
神经病学 | 1669篇 |
特种医学 | 976篇 |
外科学 | 3811篇 |
综合类 | 81篇 |
预防医学 | 540篇 |
眼科学 | 452篇 |
药学 | 1273篇 |
中国医学 | 42篇 |
肿瘤学 | 2785篇 |
出版年
2023年 | 148篇 |
2022年 | 292篇 |
2021年 | 636篇 |
2020年 | 315篇 |
2019年 | 413篇 |
2018年 | 625篇 |
2017年 | 483篇 |
2016年 | 540篇 |
2015年 | 587篇 |
2014年 | 716篇 |
2013年 | 892篇 |
2012年 | 1394篇 |
2011年 | 1617篇 |
2010年 | 972篇 |
2009年 | 845篇 |
2008年 | 1428篇 |
2007年 | 1502篇 |
2006年 | 1516篇 |
2005年 | 1519篇 |
2004年 | 1530篇 |
2003年 | 1381篇 |
2002年 | 1370篇 |
2001年 | 298篇 |
2000年 | 235篇 |
1999年 | 300篇 |
1998年 | 301篇 |
1997年 | 247篇 |
1996年 | 186篇 |
1995年 | 197篇 |
1994年 | 170篇 |
1993年 | 151篇 |
1992年 | 159篇 |
1991年 | 166篇 |
1990年 | 119篇 |
1989年 | 130篇 |
1988年 | 101篇 |
1987年 | 97篇 |
1986年 | 91篇 |
1985年 | 101篇 |
1984年 | 89篇 |
1983年 | 71篇 |
1982年 | 57篇 |
1981年 | 66篇 |
1980年 | 56篇 |
1979年 | 54篇 |
1978年 | 48篇 |
1977年 | 43篇 |
1972年 | 39篇 |
1970年 | 46篇 |
1969年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
941.
942.
943.
Ryuji Ochiai Yoko Sugiura Yasushi Shioya Kazuhiro Otsuka Yoshihisa Katsuragi Teruto Hashiguchi 《Nutrition Research》2014
Brewed coffee is a widely consumed beverage, and many studies have examined its effects on human health. We investigated the vascular effects of coffee polyphenols (CPPs), hypothesizing that a single ingestion of CPP during glucose loading would improve endothelial function. To test this hypothesis, we conducted a randomized acute clinical intervention study with crossover design and measured reactive hyperemia index (RHI) to assess the acute effects of a 75-g glucose load with CPP in healthy, nondiabetic adult men. Blood glucose and insulin levels were elevated after glucose loading with and without CPP, with no significant differences between treatments. The RHI did not significantly decrease after glucose loading without CPP. With CPP, however, RHI significantly (P < .05) increased over baseline after glucose loading. The difference between treatments was statistically significant (P < .05). No significant changes were observed in an oxidative stress marker after glucose loading with or without CPP. These findings suggest that a single ingestion of CPP improves peripheral endothelial function after glucose loading in healthy subjects. 相似文献
944.
Rika Watarai Koji Suzuki Naohiro Ichino Keisuke Osakabe Keiko Sugimoto Hiroya Yamada Takeshi Hamajima Nobuyuki Hamajima Takashi Inoue 《Journal of epidemiology / Japan Epidemiological Association》2014,24(3):250-257
Background
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelium nitric oxide synthase (NOS). ADMA binds to a substrate-binding site of NOS and then inhibits nitric oxide production from vascular endothelial cells. Elevated ADMA levels are a risk factor for cardiovascular disease. Recently, it was reported that plasma ADMA levels were negatively correlated with vegetable and fruit consumption. The purpose of this study was to examine the association between serum levels of carotenoids and serum ADMA levels in Japanese subjects.Methods
We conducted a cross-sectional study of 470 subjects (203 men and 267 women) who attended a health examination in August 2011. Serum levels of several carotenoids were separately measured by high-performance liquid chromatography. Serum ADMA levels were determined by using an enzyme-linked immunosorbent assay kit.Results
In women, the multivariate-adjusted odds ratios (ORs) of elevated serum ADMA levels were significantly decreased in the highest tertile for β-cryptoxanthin (OR 0.47, 95% CI 0.23–0.95), α-carotene (OR 0.39, 95% CI 0.18–0.79), and β-carotene (OR 0.36, 95% CI 0.17–0.73) compared to the lowest tertile. In men, significantly decreased ORs were observed in the highest tertiles of serum zeaxanthin/lutein (OR 0.23, 95% CI 0.06–0.69) and α-carotene (OR 0.26, 95% CI 0.07–0.82), and in the middle and the highest tertiles of serum β-carotene (OR 0.27, 95% CI 0.09–0.74 and OR 0.20, 95% CI 0.03–0.88, respectively) when the tertile cutoff points of women were extrapolated to men.Conclusions
Higher serum levels of carotenoids, such as α-carotene and β-carotene, may help to prevent elevated serum ADMA levels in Japanese subjects.Key words: asymmetric dimethylarginine, carotenoids, cross-sectional study 相似文献945.
Yamashita-Kawanishi Nanako Tsuzuki Masano Kasuya Fumi Chang Hui-Wen Haga Takeshi 《Virus genes》2020,56(5):594-599
Virus Genes - Infection of bovine papillomavirus (BPV) has been associated with mucosal and/or cutaneous tumor development in bovids. To date, up to 27 genotypes of BPVs have been identified and... 相似文献
946.
Masamoto Murakami Ryosuke Kawakami Yosuke Niko Teruko Tsuda Hideki Mori Kazuki Yatsuzuka Takeshi Imamura Koji Sayama 《ACTA HISTOCHEMICA ET CYTOCHEMICA》2020,53(6):131
Two-photon, excitation fluorescent microscopy featuring autofluorescence or immunofluorescence, combined with optical clearance using a transparency-enhancing technique, allows deep imaging of three-dimensional (3D) skin structures. However, it remains difficult to obtain high-quality images of individual cells or 3D structures. We combined a new dye with a transparency-enhancing technology and performed high-quality structural analysis of human epidermal structures, especially the acrosyringium. Human fingertip skin samples were collected, formalin-fixed, embedded in both frozen and paraffin blocks, sliced, stained with propidium iodide, optically cleared using a transparency-enhancing technique, and stained with a new fluorescent, solvatochromic pyrene probe. Microscopy revealed fine skin features and detailed epidermal structures including the stratum corneum (horny layer), keratinocytes, eccrine sweat glands, and peripheral nerves. Three-dimensional reconstruction of an entire acrosyringium was possible in one sample. This new fluorescence microscopy technique yields high-quality epidermal images and will aid in histopathological analyses of skin disorders. 相似文献
947.
Tomoko Miki Osamu Yokota Takashi Haraguchi Hideki Ishizu Masato Hasegawa Takeshi Ishihara Shu‐ichi Ueno Shintaro Takenoshita Seishi Terada Norihito Yamada 《Brain pathology (Zurich, Switzerland)》2020,30(4):811-830
Granular/fuzzy astrocytes (GFAs), a subtype of “aging‐related tau astrogliopathy,” are noted in cases bearing various neurodegenerative diseases. However, the pathogenic significance of GFAs remains unclear. We immunohistochemically examined the frontal cortex, caudate nucleus, putamen and amygdala in 105 cases composed of argyrophilic grain disease cases (AGD, N = 26), and progressive supranuclear palsy (PSP, N = 10), Alzheimer’s disease (AD, N = 20) and primary age‐related tauopathy cases (PART, N = 18) lacking AGD, as well as 31 cases bearing other various neurodegenerative diseases to clarify (i) the distribution patterns of GFAs in AGD, and PSP, AD and PART lacking AGD, (ii) the impacts of major pathological factors and age on GFA formation and (iii) immunohistochemical features useful to understand the formation process of GFAs. In AGD cases, GFAs consistently occurred in the amygdala (100%), followed by the putamen (69.2%) and caudate nucleus and frontal cortex (57.7%, respectively). In PSP cases without AGD, GFAs were almost consistently noted in all regions examined (90–100%). In AD cases without AGD, GFAs were less frequent, developing preferably in the putamen (35.0%) and caudate nucleus (30.0%). PART cases without AGD had GFAs most frequently in the amygdala (35.3%), being more similar to AGD than to AD cases. Ordered logistic regression analyses using all cases demonstrated that the strongest independent factor of GFA formation in the frontal cortex and striatum was the diagnosis of PSP, while that in the amygdala was AGD. The age was not significantly associated with GFA formation in any region. In GFAs in AGD cases, phosphorylation and conformational change of tau, Gallyas‐positive glial threads indistinguishable from those in tufted astrocytes, and the activation of autophagy occurred sequentially. Given these findings, AGD, PSP, AD and PART cases may show distinct distributions of GFAs, which may provide clues to predict the underlying processes of primary tauopathies. 相似文献
948.
949.
Clinical evaluation of a bioluminescent enzyme immunoassay for detecting norovirus in fecal specimens from patients with acute gastroenteritis
下载免费PDF全文
![点击此处可从《Journal of medical virology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
950.