全文获取类型
收费全文 | 127088篇 |
免费 | 7154篇 |
国内免费 | 1094篇 |
专业分类
耳鼻咽喉 | 1951篇 |
儿科学 | 1926篇 |
妇产科学 | 1874篇 |
基础医学 | 20243篇 |
口腔科学 | 3081篇 |
临床医学 | 11783篇 |
内科学 | 22723篇 |
皮肤病学 | 3968篇 |
神经病学 | 10306篇 |
特种医学 | 7300篇 |
外科学 | 16624篇 |
综合类 | 538篇 |
现状与发展 | 3篇 |
一般理论 | 27篇 |
预防医学 | 6694篇 |
眼科学 | 3191篇 |
药学 | 11414篇 |
中国医学 | 1455篇 |
肿瘤学 | 10235篇 |
出版年
2023年 | 904篇 |
2022年 | 2715篇 |
2021年 | 4396篇 |
2020年 | 2104篇 |
2019年 | 2945篇 |
2018年 | 3674篇 |
2017年 | 2988篇 |
2016年 | 3902篇 |
2015年 | 5436篇 |
2014年 | 6444篇 |
2013年 | 7502篇 |
2012年 | 11241篇 |
2011年 | 10774篇 |
2010年 | 6169篇 |
2009年 | 5293篇 |
2008年 | 7530篇 |
2007年 | 7155篇 |
2006年 | 6464篇 |
2005年 | 5988篇 |
2004年 | 5216篇 |
2003年 | 4539篇 |
2002年 | 3905篇 |
2001年 | 3033篇 |
2000年 | 2786篇 |
1999年 | 2139篇 |
1998年 | 919篇 |
1997年 | 679篇 |
1996年 | 523篇 |
1995年 | 458篇 |
1994年 | 396篇 |
1993年 | 346篇 |
1992年 | 749篇 |
1991年 | 697篇 |
1990年 | 641篇 |
1989年 | 564篇 |
1988年 | 469篇 |
1987年 | 469篇 |
1986年 | 334篇 |
1985年 | 371篇 |
1984年 | 263篇 |
1983年 | 193篇 |
1982年 | 132篇 |
1981年 | 169篇 |
1980年 | 130篇 |
1979年 | 223篇 |
1978年 | 162篇 |
1976年 | 134篇 |
1975年 | 120篇 |
1974年 | 139篇 |
1973年 | 119篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
Diseases like rotavirus afflict both upper- and lower-income countries, but most serious illnesses and deaths occur among the latter. It is a vital public health issue that vaccines for these types of global diseases can recover research and development (R&D) costs from high-priced markets quickly so that manufacturers can offer affordable prices to lower-income nations. Cost recovery depends on how high R&D costs are, and this study attempts to replace high, unverified estimates with lower, more verifiable estimates for two new vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline or GSK), based on detailed searches of public information and follow-up interviews with senior informants. We also offer a new perspective on “cost of capital” as a claim for recovery from public bodies. Our estimates suggest that companies can recover all fixed costs quickly from affluent markets and thus can offer these vaccines to lower-income countries at prices they can afford. Better vaccines are a shared project between companies and public health agencies; greater transparency and consistency in reporting of R&D costs is needed so that fair prices can be established. 相似文献
85.
86.
87.
88.
89.
Su Jin Lee Young Keun On Eun Jeong Lee Joon Young Choi Byung-Tae Kim Kyung-Han Lee 《Journal of nuclear medicine》2008,49(8):1277-1282
Vascular 18F-FDG uptake marker represents inflammation in atherosclerotic lesions, but whether inflammation can be reversed by risk-modifying interventions has not, to our knowledge, been demonstrated. In this study, we evaluated the change of vascular 18F-FDG uptake in response to lifestyle intervention on serial PET/CT scans and further assessed how the findings relate to atherogenic risk reduction. METHODS: A total of 60 healthy adults underwent 18F-FDG PET/CT scans and atherogenic risk-factor assessment at baseline and again after 17.1 +/- 8.3 mo of practicing lifestyle modification. The PET/CT images were evaluated for the presence of vascular 18F-FDG lesions, and vessel-to-blood-pool 18F-FDG ratios were measured. Indices from summed ratios of positive lesions were compared and correlated to atherogenic risk factors. RESULTS: At follow-up, significant reductions in diastolic blood pressure (P < 0.05), total cholesterol (P < 0.05), and low-density lipoprotein level (P < 0.05) and an increase in high-density lipoprotein (HDL) level (P < 0.0001) were demonstrated. On the initial PET/CT scan, 50 of 60 subjects showed 1 or more 18F-FDG-positive lesions (5.9 +/- 5.0/subject), leading to a total of 352 vascular sites. On follow-up, 18F-FDG-positive lesions were significantly reduced to 2.1 +/- 2.2 sites per subject (P < 0.0001) and a total of 124 sites (64.8% reduction). Follow-up 18F-FDG-positive rates were significantly reduced for the aorta and iliac arteries. In addition, significant reductions in the whole-body 18F-FDG index from 1.39 +/- 1.23 to 0.53 +/- 0.59 (P < 0.0001) and carotid 18F-FDG index from 0.08 +/- 0.16 to 0.03 +/- 0.06 (P = 0.01) were shown. The whole-body 18F-FDG index correlated with total cholesterol (P < 0.05) and HDL level (P < 0.05), and the magnitude of reduction in the 18F-FDG index closely correlated to the amount of increase in plasma HDL level (P = 0.005). CONCLUSION: Our study demonstrated that vascular 18F-FDG uptake is reversed in response to atherogenic risk reduction by lifestyle intervention and that the magnitude of improvement correlates to increases in plasma HDL levels. Thus, serial 18F-FDG PET/CT may be useful for monitoring improvements in the inflammatory component of atherosclerotic lesions in response to risk modification. 相似文献
90.
Eun Young Jung Hyung Joo Suh Wan Soo Hong Dong Geon Kim Yang Hee Hong In Sun Hong Un Jae Chang 《Nutrition Research》2009,29(7):457-461
Cooking processes that gelatinize granules or disrupt structure might increase the glucose and insulin responses because a disruption of the structure of starch by gelatinization increases its availability for digestion and absorption in the small intestine. We hypothesized that the uncooked form of rice, which has a relatively low degree of gelatinization even though in powder form, would result in lower metabolic glucose and insulin responses compared with cooked rice (CR). To assess the effects of the gelatinization of rice on metabolic response of glucose and insulin, we investigated the glucose and insulin responses to 3 rice meals of different gelatinization degree in female college students (n = 12): CR (76.9% gelatinized), uncooked rice powder (UP; 3.5% gelatinized), and uncooked freeze-dried rice powder (UFP; 5.4% gelatinized). Uncooked rice powders (UP and UFP) induced lower glucose and insulin responses compared with CR. The relatively low gelatinization degree of UPs resulted in low metabolic responses in terms of the glycemic index (CR: 72.4% vs UP: 49.7%, UFP: 59.8%) and insulin index (CR: 94.8% vs UP: 74.4%, UFP: 68.0%). In summary, UPs that were less gelatinized than CR induced low postprandial glucose and insulin responses. 相似文献