全文获取类型
收费全文 | 8164篇 |
免费 | 573篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 310篇 |
妇产科学 | 187篇 |
基础医学 | 1114篇 |
口腔科学 | 127篇 |
临床医学 | 733篇 |
内科学 | 1474篇 |
皮肤病学 | 97篇 |
神经病学 | 943篇 |
特种医学 | 224篇 |
外科学 | 1172篇 |
综合类 | 107篇 |
一般理论 | 15篇 |
预防医学 | 583篇 |
眼科学 | 209篇 |
药学 | 585篇 |
中国医学 | 10篇 |
肿瘤学 | 742篇 |
出版年
2023年 | 88篇 |
2022年 | 182篇 |
2021年 | 264篇 |
2020年 | 189篇 |
2019年 | 213篇 |
2018年 | 265篇 |
2017年 | 223篇 |
2016年 | 243篇 |
2015年 | 256篇 |
2014年 | 330篇 |
2013年 | 424篇 |
2012年 | 637篇 |
2011年 | 546篇 |
2010年 | 356篇 |
2009年 | 269篇 |
2008年 | 407篇 |
2007年 | 447篇 |
2006年 | 386篇 |
2005年 | 354篇 |
2004年 | 345篇 |
2003年 | 324篇 |
2002年 | 335篇 |
2001年 | 137篇 |
2000年 | 122篇 |
1999年 | 134篇 |
1998年 | 63篇 |
1997年 | 60篇 |
1996年 | 44篇 |
1995年 | 40篇 |
1994年 | 32篇 |
1993年 | 29篇 |
1992年 | 71篇 |
1991年 | 67篇 |
1990年 | 59篇 |
1989年 | 72篇 |
1988年 | 54篇 |
1987年 | 55篇 |
1986年 | 57篇 |
1985年 | 59篇 |
1984年 | 47篇 |
1983年 | 38篇 |
1982年 | 37篇 |
1981年 | 31篇 |
1979年 | 49篇 |
1978年 | 27篇 |
1977年 | 26篇 |
1976年 | 27篇 |
1975年 | 25篇 |
1973年 | 26篇 |
1972年 | 26篇 |
排序方式: 共有8770条查询结果,搜索用时 11 毫秒
31.
The expression of B7-H1 on keratinocytes in chronic inflammatory mucocutaneous disease and its regulatory role 总被引:8,自引:0,他引:8
Youngnak-Piboonratanakit P Tsushima F Otsuki N Igarashi H Machida U Iwai H Takahashi Y Omura K Yokozeki H Azuma M 《Immunology letters》2004,94(3):215-222
PD-1 and its ligands, B7-H1/PD-L1 and B7-DC/PD-L2, have been identified recently as CD28-B7 family molecules that are implicated in immune regulation. Lichen planus (LP) is a T cell-mediated chronic inflammatory mucocutaneous disease. We investigated the expression and function of PD-1 and its two ligands in LP. Immunohistochemical examination revealed the abundant expression of PD-1 and B7-H1 in infiltrating T cells and macrophages, and lower-level expression of B7-DC on macrophages in the subepithelium. Interestingly, substantial expression of B7-H1 on keratinocytes (KCs) was found close to the numerous T cell infiltrates in the subepithelium. Unstimulated cultured KCs expressed both B7-H1 and B7-DC, and their expression was upregulated by proinflammatory cytokines, particularly IFN-gamma. The T-cell proliferative responses and IFN-gamma production that were induced by IFN-gamma-treated KCs were augmented preferentially by anti-B7-H1 mAb, but not by anti-B7-DC mAb. These results indicate the regulatory role of B7-H1 on KCs in the interactions with T cells. Our results suggest that the induction of B7-H1 on KCs may play an important role in tolerance induction in the inflamed oral mucosa and skin. 相似文献
32.
Running-related injury prevention through barefoot adaptations 总被引:3,自引:0,他引:3
A number of reports indicate an extremely low running-related injury frequency in barefoot populations in contrast to reports about shod populations. It is hypothesized that the adaptations which produce shock absorption, an inherent consequence of barefoot activity and a mechanism responsible for the low injury frequency in unshod populations, are related to deflection of the medial longitudinal arch of the foot on loading. It is also hypothesized that the known inability of this arch of the shod foot to deflect without failure (foot rigidity) is responsible for the high injury frequency in shod populations. To evaluate these hypotheses, 17 recreational runners were analyzed to study the adaptive pattern of the medial longitudinal arch of the foot due to increased barefoot weight-bearing activity. Changes occurred in the medial longitudinal arch which allowed deflection of this arch on loading which substantiated the hypotheses. Other evidence suggests that sensory feedback largely from the glabrous epithelium of the foot is the element of barefoot activity which induced these adaptations. The sensory insulation inherent in the modern running shoe appears responsible for the high injury frequency associated with running. The injuries are considered "pseudo-neuropathic" in nature. 相似文献
33.
Thairu Lucy Gehling Hanna Kafwanda Sarah Yeboah-Antwi Kojo Hamer Davidson H. Lunze Karsten 《Maternal and child health journal》2022,26(6):1375-1383
Maternal and Child Health Journal - Mothers in resource-limited areas face barriers in initiating care for ill newborns, leading to delays that may contribute to newborn mortality. This qualitative... 相似文献
34.
35.
A food allergy is a potentially life-threatening disease with a genetic and environmental background. As its prevalence has increased significantly in recent years, the need for its effective prevention has been emphasized. The role of diet modifications and nutrients in food allergy reduction has been extensively studied. Much less is known about the role of other environmental factors, which can influence the incidence of this disease. Changes in neonates gut microbiome by delivery mode, animal contact, inhalant allergens, oral and then cutaneous allergen exposure, air pollution, smoking, infections and vaccinations can be the potential modifiers of food allergy development. There is some data about their role as the risk or preventive factors, but yet the results are not entirely consistent. In this paper we present the current knowledge about their possible role in primary prevention of food allergies. We discuss the mechanisms of action, difficulties in designing accurate studies about food allergy and the potential biases in interpreting the connection between environmental factors and food allergy prevention. A better understanding of the role of environmental factors in food allergies development may help in implementing practical solutions for food allergy primary prevention in the future. 相似文献
36.
37.
Leo Andrew Benedict Joseph A. Sujka Justin A. Sobrino Hanna Alemayehu Pablo Aguayo Richard Hendrickson Shawn D. St. Peter Tolulope A. Oyetunji 《Journal of pediatric surgery》2021,56(4):663-667
PurposePrevious reports in the literature demonstrate racial and ethnic disparities for children diagnosed with acute appendicitis, with minorities experiencing worse outcomes. At our institution, we have developed an evidence based patient driven protocol for children following laparoscopic appendectomy. However, the influence of such protocol on mitigating racial and ethnic disparities in outcomes remains unknown. The purpose of our study is to assess the impact of our protocol by evaluating the influence of race and ethnicity on surgical outcomes among children treated for acute appendicitis.Material and methodsA retrospective review of prospectively collected data was conducted. Children undergoing a laparoscopic appendectomy at our freestanding children's hospital between December 2015 and July 2017 were included. Demographic data, post-operative length of stay, same day discharge rates and hospital readmission rates were abstracted from patient medical records. Patients were classified by their race and ethnic background. Comparative analysis was performed in STATA with a p value < .05 determined as significant.ResultsA total of 786 children were included, with the majority being either White (70%, n = 547), Black (8%, n = 62) or Hispanic (17%, n = 133); 569 patients (72%) were found to have non-perforated appendicitis. There was no statistically significant difference in the rates of same day discharge among White, Black or Hispanic children respectively (88% vs. 77% vs. 86%, p = .126). Of the 217 children with perforated appendicitis, Hispanic children had increased rates of perforation (41%, n = 55) compared to White and Black children respectively (23%, n = 128 and 29%, n = 18, p = .001). However, average post-operative length of stay were similar among White, Black and Hispanic children (96 h vs. 95 h vs. 98 h, p = .015). On multivariate analysis, the only significant risk factor for an elevated post-operative length of stay was the presence of a perforation.ConclusionOur evidence based patient driven protocol effectively mitigates racial and ethnic disparities found in children with acute appendicitis. Further prospective investigation into the role of such patient-driven protocols to mitigate healthcare disparities is warranted.Levels of EvidenceTherapeutic study; Level 3. 相似文献
38.
39.
40.
This paper presents findings from a study investigating differences in the importance of nineteen criteria in the choice of professionals from three professional groups--physicians, dentists, and lawyers. Knowledge is the most important for all three groups but is less so for doctors. Discussions about the problem and its treatment are both less important for dentists. Six characteristics of professional service providers are used to explain differences. 相似文献