全文获取类型
收费全文 | 27434篇 |
免费 | 2146篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 288篇 |
儿科学 | 872篇 |
妇产科学 | 663篇 |
基础医学 | 4079篇 |
口腔科学 | 467篇 |
临床医学 | 3333篇 |
内科学 | 5197篇 |
皮肤病学 | 672篇 |
神经病学 | 2732篇 |
特种医学 | 825篇 |
外科学 | 2821篇 |
综合类 | 276篇 |
现状与发展 | 1篇 |
一般理论 | 27篇 |
预防医学 | 3068篇 |
眼科学 | 460篇 |
药学 | 1766篇 |
中国医学 | 71篇 |
肿瘤学 | 2051篇 |
出版年
2023年 | 304篇 |
2022年 | 554篇 |
2021年 | 1080篇 |
2020年 | 670篇 |
2019年 | 899篇 |
2018年 | 950篇 |
2017年 | 733篇 |
2016年 | 819篇 |
2015年 | 894篇 |
2014年 | 1096篇 |
2013年 | 1476篇 |
2012年 | 2114篇 |
2011年 | 2177篇 |
2010年 | 1122篇 |
2009年 | 1024篇 |
2008年 | 1595篇 |
2007年 | 1660篇 |
2006年 | 1489篇 |
2005年 | 1488篇 |
2004年 | 1438篇 |
2003年 | 1305篇 |
2002年 | 1105篇 |
2001年 | 224篇 |
2000年 | 181篇 |
1999年 | 215篇 |
1998年 | 234篇 |
1997年 | 205篇 |
1996年 | 152篇 |
1995年 | 168篇 |
1994年 | 145篇 |
1993年 | 113篇 |
1992年 | 124篇 |
1991年 | 128篇 |
1990年 | 124篇 |
1989年 | 103篇 |
1988年 | 99篇 |
1987年 | 98篇 |
1986年 | 87篇 |
1985年 | 99篇 |
1984年 | 99篇 |
1983年 | 85篇 |
1982年 | 80篇 |
1981年 | 94篇 |
1980年 | 79篇 |
1979年 | 51篇 |
1978年 | 61篇 |
1977年 | 49篇 |
1976年 | 66篇 |
1974年 | 49篇 |
1973年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Telma L F Gouveia Julia F O Paim Rita C Pavanello Mayana Zatz Mariz Vainzof 《Diagnostic molecular pathology》2006,15(2):95-100
Sarcoglycanopathies (SGpathies) are highly frequent among severely affected limb-girdle muscular dystrophy patients. On the basis of the findings of 5 common mutations in the 4 sarcoglycan (SG) genes in the Brazilian population, we standardized a multiplex polymerase chain reaction-single-strand conformation polymorphism methodology for their concomitant analysis in DNA samples. The test was able to confirm the diagnosis in about 63% of new patients with a suspected SGpathy and was particularly important in patients in advanced stages of the disease, when obtaining a muscle biopsy for analysis may be very difficult. As common mutations have been described in several countries, this multiplex analysis could be useful for the diagnosis of SGpathies if established according to the most prevalent mutations in each population. Besides, even though the disorder studied is rare, the technique could be broadly applicable to other genes and disorders. 相似文献
42.
43.
Actin-free Gc globulin: a rapidly assessed biomarker of organ dysfunction in acute liver failure and cirrhosis. 总被引:2,自引:0,他引:2
Charalambos G Antoniades Philip A Berry Matthew Bruce Timothy J S Cross Andrew J Portal Munther J Hussain William Bernal Julia A Wendon Diego Vergani 《Liver transplantation》2007,13(9):1254-1261
Reductions in serum levels of Gc globulin, a hepatically synthesized component of the extracellular actin scavenger system responsible for complexing circulating actin and attenuating intravascular microthrombus formation, are associated with poor outcome in acute liver failure. Clinically applicable assays of the important actin-free fraction (Af-Gc) have not been available until now. We measured actin-free Gc globulin levels with a novel, rapid assay in 61 cases of acute liver failure (ALF) and in 91 patients with cirrhosis (40 of whom were clinically unstable with extrahepatic organ dysfunction), and studied associations with liver dysfunction, extrahepatic organ dysfunction, indices of disseminated coagulation, and outcome. Reductions in Af-Gc levels mirrored hepatic dysfunction and organ dysfunction in both groups, and discriminated patients with poor prognosis from those with good prognosis in the ALF cohort. Levels were lowest in patients with ALF (10% of control values), but levels were also markedly reduced in both unstable (28%) and stable (44%) patients with cirrhosis. Associations with markers of disseminated intravascular coagulation were seen in both groups, most notably in the cirrhosis cohort, supporting a pathophysiological role for reduced Af-Gc in the evolution of organ dysfunction. In acetaminophen-induced ALF, Af-Gc identified patients with poor prognosis as well as did the Acute Physiology and Chronic Health Evaluation (APACHE II) score (area under the receiver operating characteristic curve, 0.7), and in cirrhosis, Af-Gc was an independent predictor of mortality by multifactorial analysis. In conclusion, the importance of Af-Gc reductions in the development of multiple organ dysfunction in ALF and cirrhosis is highlighted, probably resulting from reduced hepatic production and peripheral exhaustion of this arm of the extracellular actin scavenger system. 相似文献
44.
45.
46.
47.
Ramón Rodrigo Hernán Prat Walter Passalacqua Julia Araya Cristián Guichard Jean P B?chler 《Hypertension research》2007,30(12):1159-1167
This study investigated the association of blood pressure with blood oxidative stress-related parameters in normotensive and hypertensive subjects. A cross-sectional design was applied to 31 hypertensive patients and 35 healthy normotensive subjects. All subjects were men between the ages of 35 and 60 years. Exclusion criteria were obesity, dyslipidemia, diabetes mellitus, smoking and current use of any medication. All patients underwent 24-h ambulatory blood pressure monitoring and sampling of blood and urine. Antioxidant enzymes activity, reduced/oxidized glutathione ratio (GSH/GSSG), and lipid peroxidation (malondialdehyde) were determined in erythrocytes. Parameters measured in the plasma of test subjects were plasma antioxidant status, lipid peroxidation (8-isoprostane), plasma vitamin C and E, and the blood pressure modulators renin, aldosterone, endothelin-1 and homocysteine. Daytime systolic and diastolic blood pressures of hypertensives were negatively correlated with plasma antioxidant capacity (r=-0.46, p<0.009 and r=-0.48, p<0.007), plasma vitamin C levels (r=-0.53, p<0.003 and r=-0.44, p<0.02), erythrocyte activity of antioxidant enzymes, and erythrocyte GSH/GSSG ratio, with hypertensives showing higher levels of oxidative stress. Blood pressures showed a positive correlation with both plasma and urine 8-isoprostane. Neither plasma vitamin E nor the assessed blood pressure modulator levels showed significant differences between the groups or correlation with blood pressures. These findings demonstrate a strong association between blood pressure and some oxidative stress-related parameters and suggest a possible role of oxidative stress in the pathophysiology of essential hypertension. 相似文献
48.
49.
Caroline Bolton-Smith Marion E T McMurdo Colin R Paterson Patricia A Mole Julia M Harvey Steven T Fenton Celia J Prynne Gita D Mishra Martin J Shearer 《Journal of bone and mineral research》2007,22(4):509-519
Dietary supplementation with vitamin K(1), with vitamin D(3) and calcium or their combination, was examined in healthy older women during a 2-year, double-blind, placebo-controlled trial. Combined vitamin K with vitamin D plus calcium was associated with a modest but significant increase in BMC at the ultradistal radius but not at other sites in the hip or radius. INTRODUCTION: The putative beneficial role of high dietary vitamin K(1) (phylloquinone) on BMD and the possibility of interactive benefits with vitamin D were studied in a 2-year double-blind, placebo-controlled trial in healthy Scottish women > or =60 years of age. MATERIALS AND METHODS: Healthy, nonosteoporotic women (n = 244) were randomized to receive either (1) placebo, (2) 200 microg/day vitamin K(1), (3) 10 microg (400 IU) vitamin D(3) plus 1000 mg calcium/day, or (4) combined vitamins K(1) and D(3) plus calcium. Baseline and 6-month measurements included DXA bone mineral scans of the hip and wrist, markers of bone turnover, and vitamin status. Supplementation effects were tested using multivariate general linear modeling, with full adjustment for baseline and potential confounding variables. RESULTS: Significant bone mineral loss was seen only at the mid-distal radius but with no significant difference between groups. However, women who took combined vitamin K and vitamin D plus calcium showed a significant and sustained increase in both BMD and BMC at the site of the ultradistal radius. Serum status indicators responded significantly to respective supplementation with vitamins K and D. Over 2 years, serum vitamin K(1) increased by 157% (p < 0.001), the percentage of undercarboxylated osteocalcin (%GluOC) decreased by 51% (p < 0.001), serum 25-hydroxyvitamin D [25(OH)D] increased by 17% (p < 0.001), and PTH decreased by 11% (p = 0.049). CONCLUSIONS: These results provide evidence of a modest synergy in healthy older women from nutritionally relevant intakes of vitamin K(1) together with supplements of calcium plus moderate vitamin D(3) to enhance BMC at the ultradistal radius, a site consisting of principally trabecular bone. The substantial increase in gamma-carboxylation of osteocalcin by vitamin K may have long-term benefits and is potentially achievable by increased dietary intakes of vitamin K rather than by supplementation. 相似文献
50.