全文获取类型
收费全文 | 262868篇 |
免费 | 24927篇 |
国内免费 | 20506篇 |
专业分类
耳鼻咽喉 | 2011篇 |
儿科学 | 2301篇 |
妇产科学 | 3005篇 |
基础医学 | 32562篇 |
口腔科学 | 4268篇 |
临床医学 | 37852篇 |
内科学 | 38474篇 |
皮肤病学 | 2393篇 |
神经病学 | 14857篇 |
特种医学 | 9534篇 |
外国民族医学 | 198篇 |
外科学 | 25075篇 |
综合类 | 44045篇 |
现状与发展 | 74篇 |
一般理论 | 27篇 |
预防医学 | 15847篇 |
眼科学 | 8168篇 |
药学 | 28167篇 |
299篇 | |
中国医学 | 15567篇 |
肿瘤学 | 23577篇 |
出版年
2024年 | 931篇 |
2023年 | 4356篇 |
2022年 | 11323篇 |
2021年 | 14006篇 |
2020年 | 10642篇 |
2019年 | 9231篇 |
2018年 | 9666篇 |
2017年 | 8510篇 |
2016年 | 8093篇 |
2015年 | 12174篇 |
2014年 | 14955篇 |
2013年 | 12521篇 |
2012年 | 18719篇 |
2011年 | 21530篇 |
2010年 | 13029篇 |
2009年 | 10057篇 |
2008年 | 13332篇 |
2007年 | 13359篇 |
2006年 | 13594篇 |
2005年 | 13848篇 |
2004年 | 8200篇 |
2003年 | 7607篇 |
2002年 | 6375篇 |
2001年 | 5695篇 |
2000年 | 6423篇 |
1999年 | 7179篇 |
1998年 | 4735篇 |
1997年 | 4753篇 |
1996年 | 3677篇 |
1995年 | 3511篇 |
1994年 | 2896篇 |
1993年 | 1964篇 |
1992年 | 2213篇 |
1991年 | 1842篇 |
1990年 | 1565篇 |
1989年 | 1333篇 |
1988年 | 1133篇 |
1987年 | 991篇 |
1986年 | 748篇 |
1985年 | 608篇 |
1984年 | 348篇 |
1983年 | 214篇 |
1982年 | 115篇 |
1981年 | 126篇 |
1980年 | 82篇 |
1979年 | 90篇 |
1965年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Edward J. Holland Walter O. Whitley Kenneth Sall Stephen S. Lane Aparna Raychaudhuri Steven Y. Zhang 《Current medical research and opinion》2016,32(10):1759-1765
Objective: Report efficacy findings from three clinical trials (one phase 2 and two phase 3 [OPUS-1, OPUS-2]) of lifitegrast ophthalmic solution 5.0% for treatment of dry eye disease (DED).Research design and methods: Three 84-day, randomized, double-masked, placebo-controlled trials. Adults (≥18 years) with DED were randomized (1:1) to lifitegrast 5.0% or matching placebo. Changes from baseline to day 84 in signs and symptoms of DED were analyzed.Main outcome measures: Phase 2, pre-specified endpoint: inferior corneal staining score (ICSS; 0–4); OPUS-1, coprimary endpoints: ICSS and visual-related function subscale (0–4 scale); OPUS-2, coprimary endpoints: ICSS and eye dryness score (EDS, VAS; 0–100).Results: Fifty-eight participants were randomized to lifitegrast 5.0% and 58 to placebo in the phase 2 trial; 293 to lifitegrast and 295 to placebo in OPUS-1; 358 to lifitegrast and 360 to placebo in OPUS-2. In participants with mild-to-moderate baseline DED symptomatology, lifitegrast improved ICSS versus placebo in the phase 2 study (treatment effect, 0.35; 95% CI, 0.05–0.65; p?=?0.0209) and OPUS-1 (effect, 0.24; 95% CI, 0.10–0.38; p?=?0.0007). Among more symptomatic participants (baseline EDS ≥40, recent artificial tear use), lifitegrast improved EDS versus placebo in a post hoc analysis of OPUS-1 (effect, 13.34; 95% CI, 2.35–24.33; nominal p?=?0.0178) and in OPUS-2 (effect, 12.61; 95% CI, 8.51–16.70; p?<?0.0001).Limitations: Trials were conducted over 12 weeks; efficacy beyond this period was not assessed.Conclusions: Across three trials, lifitegrast improved ICSS in participants with mild-to-moderate baseline symptomatology in two studies, and EDS in participants with moderate-to-severe baseline symptomatology in two studies. Based on the overall findings from these trials, lifitegrast shows promise as a new treatment option for signs and symptoms of DED. 相似文献
42.
Anatoly E Martynyuk Ling-Sha Ju Timothy E Morey Jia-Qiang Zhang 《World Journal of Psychiatry》2020,10(5):81-94
The progress of modern medicine would be impossible without the use of general anesthetics (GAs). Despite advancements in refining anesthesia approaches, the effects of GAs are not fully reversible upon GA withdrawal. Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly. Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research, but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects. The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents, which are far more extensively studied than any other species. Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated. Specifically, we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities (somatic effects), but also epigenetic reprogramming of germ cells (germ cell effects). The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring, who may be affected even at levels of anesthesia that are not harmful to the exposed parents. The large number of patients who require general anesthesia, the even larger number of their future unexposed offspring whose health may be affected, and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs. In this mini review, we discuss emerging experimental findings on neuroendocrine, epigenetic, and intergenerational effects of GAs. 相似文献
43.
44.
45.
Assessment of Myocardial Infarct Size by Three‐Dimensional and Two‐Dimensional Speckle Tracking Echocardiography: A Comparative Study to Single Photon Emission Computed Tomography
下载免费PDF全文
![点击此处可从《Echocardiography (Mount Kisco, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
46.
47.
Context: Baicalin has many pharmacological activities, including protective function against myocardial ischemia by antioxidant effects and free radical scavenging activity. However, its rapid elimination half-life in plasma and poor water solubility limits its clinical efficacy.Objective: Novel baicalin-loaded PEGylated nanostructured lipid carriers (BN-PEG-NLC) were developed to improve bioavailability of BN, to prolong retention time in vivo and to enhance its protective effect.Methods: In this study, BN-PEG-NLC were prepared by the emulsion-evaporation and low temperature-solidification method using a mixture of glycerol monostearate and polyethylene glycol monostearate as solid lipids, and oleic acid as the liquid lipid. The physicochemical properties of NLC were characterized. The pharmacokinetic and pharmacodynamic behaviors of BN-PEG-NLC or BN-NLC were evaluated in acute MI rats.Results and discussion: The particle size, zeta potential, and entrapment efficiency for BN-PEG-NLC were observed as 83.9?nm, ?32.1?mV, and 83.5%, respectively. The release profiles of BN from both BN-PEG-NLC and BN-NLC were fitted to the Ritger–Peppas modal, which presented burst release initially and prolonged release afterwards. Pharmacokinetics results indicated that BN-PEG-NLC exhibited a 7.2-fold increase in AUC in comparison to BN solution, while a 3-fold increase in comparison to BN-NLC. Biodistribution results revealed that BN-PEG-NLC exhibited higher heart drug concentration compared with BN-NLC as well as BN solution. In the present study, BN-PEG-NLC significantly ameliorated infarct size.Conclusion: The results of the present study imply that PEG-NLC could be the biocompatible carriers for heart-targeted drug delivery to improve myocardial ischemia. 相似文献
48.
Shengxuan Cao Chen Wang Xin Ma Xu Wang Jiazhang Huang Chao Zhang Li Chen Xiang Geng Kan Wang 《Journal of orthopaedic research》2019,37(8):1860-1867
Patients with mechanic ankle instability experience increased tibiotalar and subtalar joint laxity. However, in vivo joint kinematics in functional ankle instability (FAI) patients and lateral ankle sprain (LAS) copers, especially during dynamic activities, are poorly understood. Ten FAI patients, 10 LAS copers, and 10 healthy controls were included in this study. A dual fluoroscopic imaging system was used to analyze the tibiotalar and subtalar joint kinematics during stair descent. Five key poses of stair descent were analyzed. Kinematic data from six degrees of freedom were calculated utilizing a solid modeling software. The range of motion and joint positions in each degree of freedom were compared among the three groups. The tibiotalar joints of FAI patients and LAS copers were significantly more inverted than those of healthy controls during the foot strike (p = 0.016, = 0.264). The subtalar joints of FAI patients were significantly more anteriorly translated (pose 2, p = 0.003, = 0.352; pose 3, p < 0.001, = 0.454; pose 4, p = 0.004, = 0.334), inverted (pose 4, p = 0.027, = 0.234; pose 5,p = 0.034, = 0.221), and externally rotated (pose 4, p = 0.037, = 0.217; pose 5; p = 0.004, = 0.331) than those of healthy controls during the mid‐stance and the heel off. The FAI patients showed excessive tibiotalar inversion and subtalar joint hypermobility during stair descent. Meanwhile, the LAS copers maintained subtalar joint stability, and only showed excessive tibiotalar inversion in foot strike. These data provide insight into the mechanisms behind the development of FAI after initial LAS. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:1860–1867, 2019 相似文献
49.
50.