全文获取类型
收费全文 | 88453篇 |
免费 | 7039篇 |
国内免费 | 477篇 |
专业分类
耳鼻咽喉 | 1104篇 |
儿科学 | 2697篇 |
妇产科学 | 2134篇 |
基础医学 | 13154篇 |
口腔科学 | 1171篇 |
临床医学 | 9321篇 |
内科学 | 17085篇 |
皮肤病学 | 2343篇 |
神经病学 | 8878篇 |
特种医学 | 3504篇 |
外科学 | 9587篇 |
综合类 | 858篇 |
现状与发展 | 2篇 |
一般理论 | 90篇 |
预防医学 | 8427篇 |
眼科学 | 1928篇 |
药学 | 6760篇 |
中国医学 | 458篇 |
肿瘤学 | 6468篇 |
出版年
2023年 | 911篇 |
2022年 | 1792篇 |
2021年 | 3261篇 |
2020年 | 1871篇 |
2019年 | 2794篇 |
2018年 | 3152篇 |
2017年 | 2261篇 |
2016年 | 2910篇 |
2015年 | 3403篇 |
2014年 | 4213篇 |
2013年 | 5119篇 |
2012年 | 7331篇 |
2011年 | 7118篇 |
2010年 | 3968篇 |
2009年 | 3347篇 |
2008年 | 4907篇 |
2007年 | 4983篇 |
2006年 | 4354篇 |
2005年 | 4066篇 |
2004年 | 3472篇 |
2003年 | 2986篇 |
2002年 | 2716篇 |
2001年 | 1116篇 |
2000年 | 1045篇 |
1999年 | 982篇 |
1998年 | 596篇 |
1997年 | 472篇 |
1996年 | 402篇 |
1995年 | 395篇 |
1994年 | 341篇 |
1993年 | 352篇 |
1992年 | 642篇 |
1991年 | 661篇 |
1990年 | 566篇 |
1989年 | 610篇 |
1988年 | 603篇 |
1987年 | 592篇 |
1986年 | 518篇 |
1985年 | 523篇 |
1984年 | 419篇 |
1983年 | 348篇 |
1982年 | 265篇 |
1981年 | 245篇 |
1980年 | 227篇 |
1979年 | 312篇 |
1978年 | 269篇 |
1977年 | 191篇 |
1974年 | 209篇 |
1973年 | 224篇 |
1972年 | 186篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
Diana H. Yu BA ; Kimberly A. Mace PhD ; Scott L. Hansen MD ; Nancy Boudreau PhD ; David M. Young MD 《Wound repair and regeneration》2007,15(5):628-635
Insulin-like growth factor-1 (Igf-1), a critical mediator of tissue repair, is significantly decreased in diabetic wounds. Furthermore, decreased levels of hypoxia-inducible factor 1-alpha (Hif-1alpha) and its target genes are also associated with impaired wound healing in diabetic mice. The aim of our study was to examine whether the reduced levels of Igf-1 are responsible for the reduction in Hif-1alpha protein synthesis and activity in diabetic wounds. We provide evidence that Igf-1 regulates Hif-1alpha protein synthesis and activity during wound repair. In addition, Igf-1 stimulated phosphytidylinositol 3-kinase activity in diabetic fibroblasts, which, in turn, increased activation of the translational regulatory protein, p70 S6 kinase. Moreover, improved healing of diabetic wounds by addition of recombinant IGF-1 protein was associated with an increase in Hif-1alpha protein synthesis and function in vivo. 相似文献
63.
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
64.
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
65.
66.
Monica Conciatori Christopher J Stodgell Susan L Hyman Melanie O'Bara Roberto Militerni Carmela Bravaccio Simona Trillo Francesco Montecchi Cindy Schneider Raun Melmed Maurizio Elia Lori Crawford Sarah J Spence Lucianna Muscarella Vito Guarnieri Leonardo D'Agruma Alessandro Quattrone Leopoldo Zelante Daniel Rabinowitz Tiziana Pascucci Stefano Puglisi-Allegra Karl-Ludvig Reichelt Patricia M Rodier Antonio M Persico 《Neuropsychopharmacology》2004,55(4):413-419
BACKGROUND: The HOXA1 gene plays a major role in brainstem and cranial morphogenesis. The G allele of the HOXA1 A218G polymorphism has been previously found associated with autism. METHODS: We performed case-control and family-based association analyses, contrasting 127 autistic patients with 174 ethnically matched controls, and assessing for allelic transmission disequilibrium in 189 complete trios. RESULTS: A, and not G, alleles were associated with autism using both case-control (chi(2) = 8.96 and 5.71, 1 df, p <.005 and <.025 for genotypes and alleles, respectively), and family-based (transmission/disequilibrium test chi(2) = 8.80, 1 df, p <.005) association analyses. The head circumference of 31 patients carrying one or two copies of the G allele displayed significantly larger median values (95.0th vs. 82.5th percentile, p <.05) and dramatically reduced interindividual variability (p <.0001), compared with 166 patients carrying the A/A genotype. CONCLUSIONS: The HOXA1 A218G polymorphism explains approximately 5% of the variance in the head circumference of autistic patients and represents to our knowledge the first known gene variant providing sizable contributions to cranial morphology. The disease specificity of this finding is currently being investigated. Nonreplications in genetic linkage/association studies could partly stem from the dyshomogeneous distribution of an endophenotype morphologically defined by cranial circumference. 相似文献
67.
68.
69.
70.