全文获取类型
收费全文 | 15155篇 |
免费 | 961篇 |
国内免费 | 230篇 |
专业分类
耳鼻咽喉 | 223篇 |
儿科学 | 139篇 |
妇产科学 | 152篇 |
基础医学 | 2482篇 |
口腔科学 | 281篇 |
临床医学 | 1441篇 |
内科学 | 2842篇 |
皮肤病学 | 493篇 |
神经病学 | 1067篇 |
特种医学 | 1341篇 |
外科学 | 1783篇 |
综合类 | 72篇 |
一般理论 | 3篇 |
预防医学 | 494篇 |
眼科学 | 237篇 |
药学 | 1840篇 |
中国医学 | 269篇 |
肿瘤学 | 1187篇 |
出版年
2024年 | 8篇 |
2023年 | 127篇 |
2022年 | 471篇 |
2021年 | 658篇 |
2020年 | 312篇 |
2019年 | 467篇 |
2018年 | 551篇 |
2017年 | 462篇 |
2016年 | 646篇 |
2015年 | 866篇 |
2014年 | 1015篇 |
2013年 | 1098篇 |
2012年 | 1466篇 |
2011年 | 1490篇 |
2010年 | 897篇 |
2009年 | 679篇 |
2008年 | 882篇 |
2007年 | 848篇 |
2006年 | 699篇 |
2005年 | 644篇 |
2004年 | 556篇 |
2003年 | 408篇 |
2002年 | 318篇 |
2001年 | 172篇 |
2000年 | 141篇 |
1999年 | 83篇 |
1998年 | 69篇 |
1997年 | 56篇 |
1996年 | 40篇 |
1995年 | 24篇 |
1994年 | 31篇 |
1993年 | 16篇 |
1992年 | 26篇 |
1991年 | 16篇 |
1990年 | 18篇 |
1989年 | 18篇 |
1988年 | 14篇 |
1987年 | 7篇 |
1986年 | 14篇 |
1985年 | 9篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1981年 | 6篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Piao XL Piao XS Kim SW Park JH Kim HY Cai SQ 《Biological & pharmaceutical bulletin》2006,29(9):1911-1915
The objectives of this study were to investigate the radical-scavenging activity and protective potential of Sophora flavescens from oxidative damage by the radical generator 2,2'-azobis(2-amidinopropane)dihydrochloride (AAPH) in renal epithelial LLC-PK(1) cells and to identify the active components using the bioassay-linked fractionation method. The MeOH extract and fractions of CH(2)Cl(2), BuOH, and H(2)O from S. flavescens showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging effects in a dose-dependent manner (p<0.01),whereas only the BuOH and CH(2)Cl(2) fractions showed protective effects against LLC-PK(1) cellular damage induced by AAPH in a dose-dependent manner (p<0.01). In particular, the BuOH fraction had the most effective (p<0.05) antioxidative capacity. Employing a bioassay-linked HPLC/MS method, the active constituents from the BuOH fraction of S. flavescens were isolated and characterized as sophoraflavanone G and kurarinone with potent antioxidant effects against the DPPH radical, with IC(50) values of 5.26 and 7.73 microg/ml, respectively. Moreover, the compounds dose dependently recovered cell viability decreased by AAPH treatment (p<0.01), suggesting their protective roles against cellular oxidative damage. The results of this study suggest that S. flavescens has excellent antioxidative and kidney-protective potential and that flavonoids from S. flavescens, i.e., sophoraflavanone G and kurarinone, are the active constituents. 相似文献
52.
Hwang YP Kim HG Hien TT Jeong MH Jeong TC Jeong HG 《Toxicology and applied pharmacology》2011,257(1):48-58
The cardioprotective properties of puerarin, a natural product, have been attributed to the endothelial nitric oxide synthase (eNOS)-mediated production of nitric oxide (NO) in EA.hy926 endothelial cells. However, the mechanism by which puerarin activates eNOS remains unclear. In this study, we sought to identify the intracellular pathways underlying eNOS activation by puerarin. Puerarin induced the activating phosphorylation of eNOS on Ser1177 and the production of NO in EA.hy926 cells. Puerarin-induced eNOS phosphorylation required estrogen receptor (ER)-mediated phosphatidylinositol 3-kinase (PI3K)/Akt signaling and was reversed by AMP-activated protein kinase (AMPK) and calcium/calmodulin-dependent kinase II (CaMKII) inhibition. Importantly, puerarin inhibited the adhesion of tumor necrosis factor (TNF)-α-stimulated monocytes to endothelial cells and suppressed the TNF-α induced expression of intercellular cell adhesion molecule-1. Puerarin also inhibited the TNF-α-induced nuclear factor-κB activation, which was attenuated by pretreatment with NG-nitro-l-arginine methyl ester, a NOS inhibitor. These results indicate that puerarin stimulates eNOS phosphorylation and NO production via activation of an estrogen receptor-mediated PI3K/Akt- and CaMKII/AMPK-dependent pathway. Puerarin may be useful for the treatment or prevention of endothelial dysfunction associated with diabetes and cardiovascular disease. 相似文献
53.
Jeong Min Yang Su bin Lee Ye ji Kim Douk young Chon Jong Youn Moon Jae Hyun Kim 《Medicine》2022,101(32)
This empirical study identifies the negative aspects of private health insurance (PHI) by analyzing the association between subjective health conditions, 2 weeks of outpatient care, chronic diseases, and hospitalizations for 1 year. We used frequency analysis, χ2 testing, an analysis of variance, and logistic and multiple logistic regression models to analyze the association between PHI and subjective health conditions, outpatient care, chronic disease status, and hospitalization. The PHI group had good subjective health but had more outpatient care for 2 weeks. There were few chronic diseases in the private insurance group, and there was no significant difference in hospitalizations for 1 year. Hospitalization may occur when essential medical care is required, regardless of health insurance type. This study confirmed that as the PHI lowers the burden of personal medical expenses, the PHI can lead to an increase in the medical resource expenditures on the outpatient medical service and higher public health costs. The government should work to redefine the role of private and national health insurance. Also, the effectiveness of PHI should be reevaluated so that it does not lead to indiscriminate use of medical services by minimizing the burden of private insurance. 相似文献
54.
55.
56.
57.
Ten new sesterterpene compounds (4-13) and seven known metabolites (1-3, 14-17) were isolated from the sponge Smenospongia sp. collected from Korean coastal waters. On the basis of combined spectroscopic analyses, the new compounds exhibited diverse functionalities on a common scalarane sesterterpene structure. The presence of a 23-aldehyde on compound 6 and a 20-carboxylic acid on 11 is unprecedented among sponge-derived scalarane sesterterpenes. Several of the new compounds showed significant cytotoxicity and antimicrobial activity, as well as moderate inhibitory activity against isocitrate lyase. 相似文献
58.
Song JS Jeong HJ Kim SJ Son MS Na HJ Song YS Hong SH Kim HM Um JY 《The American journal of Chinese medicine》2008,36(1):71-80
Interleukin-1 (IL-1), a cytokine produced predominantly by cells from the macrophage lineage, can affect multiple neuroendocrine and metabolic functions. IL-1alpha production by cultured peripheral blood mononuclear cells from an obese group was significantly elevated in comparison to a control group. The aim of this study was to investigate whether the IL-1alpha polymorphism and Sasang constitution, a major branch in Korean traditional medicine, were related to obesity. Genotyping was done in 182 healthy females with a marked variation in body mass index (BMI) by a PCR-restriction fragment length polymorphism assay. The T allele was associated with decreased BMI (p = 0.020). In a subgroup with BMI values ranging from 27 approximately 29 kg/m(2), the frequency of the T allele was significantly decreased (p = 0.004, odds ratio, OR = 0.141 compared to a subgroup with a BMI values less than 25 Kg/m(2)). In addition, in Taeumin female subjects, the frequency of the IL-1alpha T allele was markedly decreased in a subgroup with BMI values in the range of 27 approximately 29 kg/m(2) compared to a lean group with BMI values less than 25 kg/m(2) (p = 0.004, OR = 0.139). In Korean women, an association was found between -889C/T polymorphism in the regulatory region of the IL-1alpha gene and BMI values. In addition, an association was found among IL-1alpha polymorphism, obesity, and the Sasang constitution. 相似文献
59.
60.
OBJECTIVES: The purpose of our study is to provide reference values for the great vessels obtained from images of the three-vessel view of the fetal heart, with an emphasis on the size discrepancy of the great vessels. METHODS: From February 2003 to May 2003, the main pulmonary artery (MPA), ascending aorta (AA), and SVC were measured in well-dated, nonanomalous fetuses scanned at 14-38 weeks of gestation. RESULTS: The size of each great vessel had a significant positive relationship with advance in gestation (P < 0.001); MPA (mm) = -2.76 + 0.34 x GA, ascending aorta (AA) (mm) = -1.73 + 0.26 x GA - 1.18E - 05 x GA(3), and SVC (mm) = 0.33 + 0.01 x GA(2) - 4.12E - 05 x GA(3). The AA/MPA ratio was significantly decreased with advance in gestation, while the SVC/AA ratio was significantly increased; AA/MPA ratio = -1.24 - 0.03 x GA + 3.88E - 04 x GA(2); P < 0.001, SVC/AA ratio = 0.63 - 5.43E - 03 x GA + 1.96E - 04 x GA(2); P < 0.001. CONCLUSION: On the three-vessel view of the fetal heart, the interpretation of the size discrepancy of the great vessels needs to be adjusted according to fetal growth. 相似文献