全文获取类型
收费全文 | 95657篇 |
免费 | 30029篇 |
国内免费 | 1063篇 |
专业分类
耳鼻咽喉 | 2373篇 |
儿科学 | 2655篇 |
妇产科学 | 2283篇 |
基础医学 | 2293篇 |
口腔科学 | 5018篇 |
临床医学 | 25771篇 |
内科学 | 24163篇 |
皮肤病学 | 3226篇 |
神经病学 | 12016篇 |
特种医学 | 3579篇 |
外科学 | 17728篇 |
综合类 | 210篇 |
现状与发展 | 40篇 |
一般理论 | 1篇 |
预防医学 | 13440篇 |
眼科学 | 2117篇 |
药学 | 1108篇 |
中国医学 | 8篇 |
肿瘤学 | 8720篇 |
出版年
2024年 | 740篇 |
2023年 | 5016篇 |
2022年 | 1072篇 |
2021年 | 2657篇 |
2020年 | 5279篇 |
2019年 | 1940篇 |
2018年 | 6794篇 |
2017年 | 7282篇 |
2016年 | 7836篇 |
2015年 | 7914篇 |
2014年 | 10312篇 |
2013年 | 11962篇 |
2012年 | 3521篇 |
2011年 | 3272篇 |
2010年 | 6676篇 |
2009年 | 8975篇 |
2008年 | 3285篇 |
2007年 | 2198篇 |
2006年 | 3425篇 |
2005年 | 1955篇 |
2004年 | 1360篇 |
2003年 | 1060篇 |
2002年 | 970篇 |
2001年 | 1894篇 |
2000年 | 1187篇 |
1999年 | 1710篇 |
1998年 | 2065篇 |
1997年 | 1893篇 |
1996年 | 1949篇 |
1995年 | 1690篇 |
1994年 | 1086篇 |
1993年 | 908篇 |
1992年 | 779篇 |
1991年 | 676篇 |
1990年 | 554篇 |
1989年 | 559篇 |
1988年 | 553篇 |
1987年 | 436篇 |
1986年 | 403篇 |
1985年 | 352篇 |
1984年 | 302篇 |
1983年 | 325篇 |
1982年 | 249篇 |
1981年 | 211篇 |
1980年 | 133篇 |
1979年 | 113篇 |
1978年 | 158篇 |
1977年 | 142篇 |
1974年 | 114篇 |
1972年 | 120篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
211.
212.
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
213.
Qualitative Data Analysis: An Introduction 总被引:1,自引:1,他引:0
214.
PROBLEM: Recent developments in providing care to children with emotional and behavioral disorders, especially those with serious emotional disturbance, have included the establishment of systems of care. Guided by a set of principles and values, these systems of care have organized and delivered services to children and families with complex needs. To date, nurses have not had a salient role in systems of care. RESULTS: It is estimated that 20% of American children and adolescents have an emotional or mental disorder. As many as two thirds of these children are not receiving services. Systems of care have been funded to provide services for these children, particularly for the most severely affected. To date, nursing has not had a prominent role in these systems of care. CONCLUSIONS: Based on their knowledge, skills, and holistic approach to care, nurses could better integrate nursing care into systems of care. Possible roles as case managers, primary therapists, in-home interventionists, and in educational programs are suggested. 相似文献
215.
216.
Susan W. Volk VMD PhD ; Antoneta Radu BS ; Liping Zhang MS ; Kenneth W. Liechty MD 《Wound repair and regeneration》2007,15(5):736-747
Chronic wounds create a formidable clinical problem resulting in considerable morbidity and healthcare expenditure. The etiology for wound healing impairment appears to be multifactorial; however, ischemia is a common factor in most types of chronic wounds. Ideal therapy for such wounds would be to correct deficiencies in growth factors and matrix components and provide cellular precursors required for timely wound closure. We hypothesized that stromal progenitor cell (SPC) therapy could correct the ischemic wound-healing defect through both direct and indirect mechanisms. To test this hypothesis, we used the ischemic rabbit ear model of chronic wound healing. We found that treatment of the wounds with SPCs was able to reverse the ischemic wound-healing impairment, with improved granulation tissue formation and reepithelialization compared with vehicle or bone marrow mononuclear cell controls. In vitro, SPCs were found to produce factors involved in angiogenesis and reepithelialization, and extracellular matrix components, providing evidence for both direct and indirect mechanisms for the observed correction of the healing impairment in these wounds. Treatment of ischemic wounds with SPCs can dramatically improve wound healing and provides a rationale for further studies focused on SPCs as a potential cellular therapy in impaired wound healing. 相似文献
217.
OBJECTIVE: Based on recent safety and efficacy data, combined with the known pharmacokinetic parameters of aminoglycosides in the newborn, once-daily gentamicin should be preferable to the many other dosing regimens currently in use. Although there are growing data to support its use in term newborns, experience with preterm infants is more limited. In our Neonatal Intensive Care Unit, we experienced difficulties regarding complicated dosing regimens, actual dosing errors, and the tendency to check trough and peak levels around the third dose for infants receiving only a 48 hour course. Therefore, we conducted a quality improvement initiative in which we developed and tested a clinical practice guideline for the use of once-daily gentamicin for preterm and term infants that we hoped would yield trough and peak levels in our target range. METHODS: We combined a review of the published English language literature with pharmacokinetic analysis of our own data prior to initiation of this new regimen to design the following dosing regimen: <35 weeks gestation: 3 mg/kg q 24 hours, > or =35 weeks gestation: 4 mg/kg q 24 hours. Our goal serum levels were a trough < or =2 microg/ml and a peak between 6 and 12 microg/ml. We collected and analyzed trough and peak levels from all infants receiving this dosing regimen in the first week of life for at least 72 hours between 3/1/99 and 12/31/00. RESULTS: In total, 214 babies met our inclusion criteria, 75 of whom were <35 weeks gestation. 100% of babies of all gestational ages had a nontoxic trough level. For infants <35 weeks gestation, 79% had a therapeutic peak level, with a mean value of 6.8 microg/ml. For infants of at least 35 weeks gestation, 93% had a therapeutic peak level, with a mean value of 8.4 microg/ml. 92% of nontherapeutic peaks were too low. CONCLUSION: This study of once-daily gentamicin represents the largest sample size of pre-term infants published to date. The proposed regimen is simple and yields a high proportion of desirable levels. We recommend it for use in preterm and term newborns. 相似文献
218.
A. Bogaards PhD H.J.C.M. Sterenborg B.C. Wilson 《Photodiagnosis and Photodynamic Therapy》2007,4(3):170-178
With the advent of molecular-targeted fluorescent markers, there is a renewed interest in fluorescence quantification methods that are based on continuous wave excitation and multi-spectral image acquisition. However, little is known about their in vivo quantification performance. We reviewed the performance of five selected methods by analytically describing these and varying input parameters of irradiance, excitation geometry, collection efficiency, autofluorescence, melanin content, blood volume, blood oxygenation and tissue scattering using optical properties representing those for human skin. We identified one method that corrects for variations in all parameters. This requires image acquisition before and after marker administration, under identical geometry. Hence, it is suited for applications where the site of interest can be relocated (e.g. anaesthetized animals and dermatology). For applications where relocation is not possible, we identified a second method where the uncertainty in the fluorescence signal was ±20%. Hence, use of these methods can substantially aid in vivo fluorescence quantification compared to use of the raw fluorescence signal, as this changed by more than 3 orders of magnitude. Since these methods can be computed in real-time, they are of particular interest for applications where direct feedback is critical, as diagnostic screening or image-guided surgery. 相似文献
219.
220.