全文获取类型
收费全文 | 31061篇 |
免费 | 2908篇 |
国内免费 | 125篇 |
专业分类
耳鼻咽喉 | 315篇 |
儿科学 | 708篇 |
妇产科学 | 457篇 |
基础医学 | 3840篇 |
口腔科学 | 1325篇 |
临床医学 | 3890篇 |
内科学 | 6563篇 |
皮肤病学 | 663篇 |
神经病学 | 2396篇 |
特种医学 | 1170篇 |
外科学 | 4524篇 |
综合类 | 550篇 |
一般理论 | 39篇 |
预防医学 | 3195篇 |
眼科学 | 417篇 |
药学 | 2405篇 |
中国医学 | 30篇 |
肿瘤学 | 1607篇 |
出版年
2021年 | 443篇 |
2020年 | 260篇 |
2019年 | 437篇 |
2018年 | 468篇 |
2017年 | 353篇 |
2016年 | 422篇 |
2015年 | 474篇 |
2014年 | 679篇 |
2013年 | 1043篇 |
2012年 | 1409篇 |
2011年 | 1488篇 |
2010年 | 803篇 |
2009年 | 715篇 |
2008年 | 1347篇 |
2007年 | 1428篇 |
2006年 | 1437篇 |
2005年 | 1421篇 |
2004年 | 1309篇 |
2003年 | 1271篇 |
2002年 | 1256篇 |
2001年 | 1092篇 |
2000年 | 1150篇 |
1999年 | 951篇 |
1998年 | 378篇 |
1997年 | 322篇 |
1996年 | 300篇 |
1995年 | 310篇 |
1994年 | 244篇 |
1993年 | 241篇 |
1992年 | 704篇 |
1991年 | 701篇 |
1990年 | 671篇 |
1989年 | 578篇 |
1988年 | 561篇 |
1987年 | 550篇 |
1986年 | 558篇 |
1985年 | 533篇 |
1984年 | 407篇 |
1983年 | 364篇 |
1982年 | 268篇 |
1981年 | 250篇 |
1979年 | 367篇 |
1978年 | 294篇 |
1977年 | 257篇 |
1976年 | 201篇 |
1975年 | 209篇 |
1974年 | 261篇 |
1973年 | 245篇 |
1972年 | 220篇 |
1971年 | 226篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Phoebe Hammer Kevin White Stephanie Mengden Vessy Korcheva Philipp W. Raess 《Journal of cutaneous pathology》2019,46(5):343-346
Cutaneous leiomyomas are rare benign smooth‐muscle tumors. These lesions are distinguished based on their cell of origin and are subclassified as pilar leiomyoma, angioleiomyoma, and genital‐type leiomyoma. Nipple leiomyoma is the least common genital‐type leiomyoma, arising from the dartoic muscle cell of the nipple. Histologic examination of the lesion is necessary for definitive diagnosis, and these uncommon tumors can pose a diagnostic challenge. We describe herein a series of six nipple leiomyomas with a spectrum of histologic appearances. 相似文献
2.
Tonya J.H. White 《Journal of the American Academy of Child and Adolescent Psychiatry》2019,58(11):1042-1050
3.
4.
5.
Jamaal L. Benjamin MD PhD Rebecca Dennis DO Stacy White Jr MD David Munson MD Sudha A. Anupindi MD Maciej Piskunowicz MD Kassa Darge MD PhD Ami Gokli MD Misun Hwang MD 《Journal of ultrasound in medicine》2020,39(5):1031-1036
Bowel diseases of prematurity, including necrotizing enterocolitis, are dreaded ailments of neonates. Early diagnosis is difficult, with clinical and radiographic findings often inconclusive. We present a novel use of contrast-enhanced ultrasound in detection of pediatric bowel disease. Early identification of compromised blood flow or an at-risk bowel can be quantitatively detected and monitored. This ability has implications for guidance of emerging therapies, allowing targeting of inflammation. These findings represent an advancement in detection of bowel disease in neonates. 相似文献
6.
Eric E Rasmussen Autumn Shafer Malinda J. Colwell Shawna White Narissra Punyanunt-Carter Rebecca L. Densley 《Journal of Children and Media》2016,10(4):443-461
This study explored the relationship between active mediation, exposure to Daniel Tiger’s Neighborhood, and key indicators of preschoolers’ social and emotional development. One hundred and twenty-seven children aged 2–6 either watched or did not watch 10 episodes of Daniel Tiger’s Neighborhood over a two-week period. Results revealed that preschoolers who watched the program exhibited higher levels of empathy, self-efficacy, and emotion recognition when their regular TV-watching experiences are frequently accompanied by active mediation. This was especially true for younger preschoolers and preschoolers from low-income families. Implications for policy-makers, parents, producers of prosocial programming, and educators are discussed. 相似文献
7.
8.
9.
Alan. B. Franklin Sarah N. Bevins Jeremy W. Ellis Ryan S. Miller Susan A. Shriner J. Jeffrey Root Daniel P. Walsh Thomas J. Deliberto 《Transboundary and Emerging Diseases》2019,66(2):705-714
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security. 相似文献
10.
Susan C. Fox Jane A. May Natalia Dovlatova Jackie R. Glenn Andrew Johnson Ann E. White 《Platelets》2019,30(3):290-295
Measurement of P-selectin on activated platelets as a means of measuring platelet function utilizing the technology described here has the advantage of not requiring immediate access to specialist equipment and expertise. Blood samples are activated, fixed, stored, and transported to a central laboratory for flow cytometric analysis. Here we have compared P-selectin with other more traditional approaches to measuring platelet function in blood and/or platelet-rich plasma (PRP) from patients with acute coronary syndromes on treatment for at least 1 month with either aspirin and clopidogrel or aspirin with prasugrel. The comparators were light transmission aggregometry (LTA), VerifyNow and Multiplate aggregometry (for determining the effects of aspirin) and LTA, VerifyNow and Multiplate together with the BioCytex VASP phosphorylation assay (for the P2Y12 antagonists). The P-selectin Aspirin Test revealed substantial inhibition of platelet function in all but three of 96 patients receiving aspirin with clopidogrel and in none of 51 patients receiving aspirin and prasugrel. The results were very similar to those obtained using LTA. There was only one patient with high residual platelet aggregation and low P-selectin expression. The same patients identified as “non-responders” to aspirin also presented with the highest residual platelet activity as measured using the VerifyNow system, although not quite as well separated from the other values. With the Multiplate test only one of these patients clearly stood out from the others. The results obtained using the P-selectin P2Y12 Test in 102 patients taking aspirin and clopidogrel were similar to the more traditional approaches in that a wide scatter of results was obtained. Generally, high values seen with the P-selectin P2Y12 Test were also high with the LTA, VerifyNow, Multiplate, and BioCytex VASP P2Y12 Tests. Similarly, low residual platelet function using the P2Y12 test was seen irrespective of the testing procedure used. However, there were differences in some patients. Prasugrel was always more effective than clopidogrel in inhibiting platelet function with none of 56 patients (P-selectin and VerifyNow), only 2 of 56 patients (Multiplate) and only 3 of 56 patients (Biocytex VASP) demonstrating high on-treatment residual platelet reactivity (HRPR) defined using previously published cut-off values. The exception was LTA where there were 11 of 56 patients with HRPR. It remains to be seen which experimental approach provides the most useful information regarding outcomes after adjusting therapies in treated patients. 相似文献