全文获取类型
收费全文 | 175180篇 |
免费 | 4406篇 |
国内免费 | 1995篇 |
专业分类
耳鼻咽喉 | 1724篇 |
儿科学 | 6183篇 |
妇产科学 | 3123篇 |
基础医学 | 19870篇 |
口腔科学 | 4455篇 |
临床医学 | 13060篇 |
内科学 | 32447篇 |
皮肤病学 | 2949篇 |
神经病学 | 9881篇 |
特种医学 | 4057篇 |
外国民族医学 | 1篇 |
外科学 | 26578篇 |
综合类 | 11841篇 |
现状与发展 | 1篇 |
一般理论 | 9篇 |
预防医学 | 10682篇 |
眼科学 | 3343篇 |
药学 | 18883篇 |
68篇 | |
中国医学 | 7619篇 |
肿瘤学 | 4807篇 |
出版年
2023年 | 839篇 |
2022年 | 1426篇 |
2021年 | 2961篇 |
2020年 | 1827篇 |
2019年 | 13147篇 |
2018年 | 12823篇 |
2017年 | 6060篇 |
2016年 | 1625篇 |
2015年 | 1596篇 |
2014年 | 3550篇 |
2013年 | 5512篇 |
2012年 | 3534篇 |
2011年 | 3522篇 |
2010年 | 2877篇 |
2009年 | 2735篇 |
2008年 | 3218篇 |
2007年 | 4191篇 |
2006年 | 4430篇 |
2005年 | 4230篇 |
2004年 | 3306篇 |
2003年 | 3340篇 |
2002年 | 3194篇 |
2001年 | 3162篇 |
2000年 | 3379篇 |
1999年 | 3028篇 |
1998年 | 3077篇 |
1997年 | 2439篇 |
1996年 | 2294篇 |
1995年 | 2638篇 |
1994年 | 2452篇 |
1993年 | 1901篇 |
1992年 | 1505篇 |
1991年 | 1491篇 |
1990年 | 1246篇 |
1989年 | 983篇 |
1988年 | 1025篇 |
1987年 | 989篇 |
1985年 | 5402篇 |
1984年 | 7274篇 |
1983年 | 5822篇 |
1982年 | 6258篇 |
1981年 | 5705篇 |
1980年 | 4904篇 |
1979年 | 4959篇 |
1978年 | 4062篇 |
1977年 | 3047篇 |
1976年 | 3523篇 |
1975年 | 2732篇 |
1974年 | 2524篇 |
1973年 | 2227篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
目的采用图像融合技术获得T2WI与T2WI-FS的融合图像,评估其在肛瘘及肛周结构显示中的优势。
方法2016年6月至2018年6月,前瞻性选择中山大学附属第一医院29例肛瘘患者进行肛管磁共振(MR)检查,采用图像融合技术获取T2WI与T2WI-FS的融合图像T2WI-Fusion,利用Fisher score算法计算瘘管及肛门括约肌的组织间分辨力Fisher值、脂肪与肛门括约肌间的Fisher值,评估融合图像中瘘管及肛周结构的显示情况。采用改进的双刺激连续质量量表(DSCQS)对T2WI-FS、T2WI、增强3D-VIBE和T2WI-Fusion序列图像进行主观图像质量评价。
结果29例患者均成功获得T2WI与T2WI-FS的融合图像T2WI-Fusion。T2WI-Fusion、T2WI瘘管与括约肌间Fisher均值分别为6.46、3.31,T2WI-Fusion图像对瘘管的显示优于T2WI序列图像(P<0.001)。T2WI-Fusion、T2WI-FS脂肪与括约肌间Fisher均值分别为10.61、2.45,T2WI-Fusion图像对括约肌的显示优于T2WI-FS序列图像(P<0.001)。T2WI-Fusion对瘘管与括约肌的图像质量评价总评分均高于T2WI-FS、T2WI、增强3D-VIBE序列(P<0.001)。
结论MRI图像融合技术同时具备T2WI及T2WI-FS的优势,无需增加扫描序列及扫描时间,且操作简单,花费时间短,显著提高病变及肛周解剖结构的对比度和图像质量。 相似文献
62.
63.
Pavan Brahmamdam Stephen L. Carveth Mary Smyth Brian S. Gendelman M. Jeffrey Maisels 《Journal of pediatric surgery》2019,54(9):1800-1803
PurposeTo examine what proportion of caregivers, if given a choice, would choose medical versus surgical treatment of appendicitis and what factors would be important in their decision.MethodsA survey was devised and given to the caregivers of children presenting to the pediatrician for a routine visit in community and academic pediatric clinics. The survey presented a summary of outcomes after medical (non-operative) and surgical treatment of uncomplicated appendicitis. Participants were then asked to choose medical versus surgical treatment if their child were to develop appendicitis. They were also asked to rate the importance of certain factors in their decision ? 1 being “not important” and 5 being “very important”.ResultsFour hundred surveys were distributed with an 86.2% (345/400) response rate. Six percent (21/342) of respondents reported a history of appendicitis and 49.4% (168/340) reported having known someone who had appendicitis. The majority of respondents, 85.3% (284/333), were mothers. A minority of respondents, 41.7% (95% CI: 36.7, 47.0), chose medical treatment over surgery for appendicitis. There was no statistical difference in the proportion of mothers (41.6%) versus fathers who chose medical treatment (41.3%). Caregivers who chose medical treatment were more likely to rate time in hospital (p = .008) and time out of school (p = 05) as important in decision making when compared with those who chose surgery. Those who chose surgical treatment were more likely to rate risk of recurrent appendicitis (p < .001) as important to decision making. In the multivariate analysis, those who rated time in hospital as very important had more than twice the odds of choosing medical therapy (OR 2.20, p = 0.02) when compared with those who rated it as less important. Not knowing someone who has had appendicitis was significantly associated with choosing medical therapy when compared with those who do know someone who has had appendicitis, OR 2.3, p = .002. Rating pain as very important was also significantly associated with choosing medical therapy, when compared to those rating pain 1–3, OR 3.38, p = .03.ConclusionsIn this survey of caregivers of children presenting for routine care, 41.7% would choose medical, or non-operative, therapy for their children with acute appendicitis. The risk of recurrence, time in hospital, and time out of school, pain, and knowing someone who has had appendicitis were all important factors that families may consider when making a decision. These data may be useful for surgeons counseling patients on which treatment to pursue. 相似文献
64.
Mei-Yi Wu Yu-Wei Chen Lie-Yee Hung Chii-Hong Lee Hsin-An Chen Yung-Ho Hsu Mai-Szu Wu 《Transplantation proceedings》2019,51(5):1472-1474
IntroductionThe immunosuppressant agents in kidney transplantation (KT) may lead to various complications such as opportunistic infections and malignancies. BK virus associated nephropathy is a significant complication following KT, and it can result in graft failure. BK virus causes tubulointerstitial nephritis, ureter stenosis, and even graft failure in KT recipients with impaired immune system. We described a 63-year-old woman, who was a hepatitis C carrier and on dialysis for 22 years before KT, who received cadaveric-donor KT 2 years previously. She reported decreasing urine output and general weakness. The serum creatinine level was slightly increased from 2.94 to 4.38 mg/dL.MethodsImmunosuppressant medications including prednisolone, everolimus, cyclosporin, and mycophenolate sodium were continued as maintenance therapy post KT. Kidney biopsy was performed due to deterioration of graft function.ResultsThe kidney biopsy showed consistent results with early-stage polyomavirus nephropathy, characterized by focal viral cytopathic changes with positive immunohistochemical signals and mesangial proliferative glomerulonephritis, immune-complex-mediated (Fig 1 and Fig 2). Negative C4d staining at peritubular capillary was reported. The dosage of mycophenolate sodium was tapered from 720 to 360 mg daily and that of everolimus increased from 0.5 to 1.0 mg daily due to BK viral infection with BK nephropathy. The serum creatinine level was 2.75 mg/dL after treatment.ConclusionEarly detection of BK nephropathy and decreasing immunosuppressant agents are the mainstay of treatment. Substituting leflunomide for mycophenolate sodium and increasing dosage of everolimus has been proposed to solve BK nephropathy. We presented that the use of leflunomide in such situation is in a timely manner. 相似文献
65.
66.
67.
68.
69.
70.