全文获取类型
收费全文 | 41631篇 |
免费 | 2811篇 |
国内免费 | 1177篇 |
专业分类
耳鼻咽喉 | 756篇 |
儿科学 | 493篇 |
妇产科学 | 147篇 |
基础医学 | 1942篇 |
口腔科学 | 2214篇 |
临床医学 | 5183篇 |
内科学 | 5773篇 |
皮肤病学 | 190篇 |
神经病学 | 2824篇 |
特种医学 | 9645篇 |
外国民族医学 | 26篇 |
外科学 | 4114篇 |
综合类 | 4888篇 |
现状与发展 | 4篇 |
预防医学 | 673篇 |
眼科学 | 3066篇 |
药学 | 990篇 |
8篇 | |
中国医学 | 143篇 |
肿瘤学 | 2540篇 |
出版年
2024年 | 113篇 |
2023年 | 1039篇 |
2022年 | 1469篇 |
2021年 | 2480篇 |
2020年 | 1882篇 |
2019年 | 1766篇 |
2018年 | 1633篇 |
2017年 | 1571篇 |
2016年 | 1496篇 |
2015年 | 1558篇 |
2014年 | 2865篇 |
2013年 | 2230篇 |
2012年 | 2049篇 |
2011年 | 2235篇 |
2010年 | 1894篇 |
2009年 | 1937篇 |
2008年 | 1981篇 |
2007年 | 2092篇 |
2006年 | 1828篇 |
2005年 | 1547篇 |
2004年 | 1310篇 |
2003年 | 1039篇 |
2002年 | 894篇 |
2001年 | 770篇 |
2000年 | 679篇 |
1999年 | 556篇 |
1998年 | 458篇 |
1997年 | 509篇 |
1996年 | 471篇 |
1995年 | 400篇 |
1994年 | 374篇 |
1993年 | 286篇 |
1992年 | 240篇 |
1991年 | 210篇 |
1990年 | 194篇 |
1989年 | 188篇 |
1988年 | 164篇 |
1987年 | 175篇 |
1986年 | 121篇 |
1985年 | 159篇 |
1984年 | 157篇 |
1983年 | 96篇 |
1982年 | 141篇 |
1981年 | 116篇 |
1980年 | 80篇 |
1979年 | 63篇 |
1978年 | 37篇 |
1977年 | 40篇 |
1976年 | 24篇 |
1968年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Michelle Linda Ferderbar Thomas E. Doyle Reza Samavi David Koff 《Journal l'Association canadienne des radiologistes》2019,70(2):119-124
Several regulatory bodies have agreed that low-dose radiation used in medical imaging is a weak carcinogen that follows a linear, non-threshold model of cancer risk. While avoiding radiation is the best course of action to mitigate risk, computed tomography (CT) scans are often critical for diagnosis. In addition to the as low as reasonably achievable principle, a more concrete method of dose reduction for common CT imaging exams is the use of a diagnostic reference level (DRL). This paper examines Canada's national DRL values from the recent CT survey and compares it to published provincial DRLs as well as the DRLs in the United Kingdom and the United States of America for the 3 most common CT exams: head, chest, and abdomen/pelvis. Canada compares well on the international scale, but it should consider using more electronic dose monitoring solutions to create a culture of dose optimization. 相似文献
52.
《Radiologic clinics of North America》2019,57(6):1083-1091
53.
《Journal of Medical Imaging and Radiation Sciences》2020,51(1):173-181
IntroductionThis study aims to construct learning curves related to the realization of standardized postprocessing by radiographer students and to discuss their exploitation and interest.Materials and MethodsThis study was carried out in 21 French students in their 3rd year of training. Two postprocessing protocols in CT (#1 traumatic shoulder; #2 petrous bone) were repeated 15 times by each student. Each achievement was timed to obtain overall learning curves. The realization accuracy was also assessed for each student at each repetition.ResultsThe learning rates for the two protocols are 63% and 56%, respectively. The number of repetitions to reach the reference time for each protocol is 11 and 12, respectively. In both protocols, the standard deviations are significantly reduced and stabilized during repetitions. The mean accuracy progresses more quickly in protocol #1.DiscussionThe measured learning rates reflect a rapid learning process for each protocol. The analysis of the standard deviations shows that students have reached a homogeneous level. The average times and accuracies measured during the last repetitions show that the group has reached a high level of performance. Building learning curves helps students measure their progress and motivates them.ConclusionObtaining learning curves allows trainers/supervisors to qualify the learning difficulty of a task while motivating students/radiographers. The use of learning curves is inline with the competency-based training paradigm. 相似文献
54.
Matthew D. Li Katrina F. Chu Allegra DePietro Vincent Wu Eric Wehrenberg-Klee Omar Zurkiya Raymond W. Liu Suvranu Ganguli 《Journal of vascular and interventional radiology : JVIR》2019,30(3):314-319
Purpose
To evaluate the feasibility of a same-day yttrium-90 (90Y) radioembolization protocol with resin microspheres (including pretreatment angiography, lung shunt fraction [LSF] determination, and radioembolization) for the treatment of hepatocellular carcinoma (HCC) and liver metastases.Materials and Methods
All same-day radioembolization procedures performed over 1 y (February 2017 to January 2018) were included in this single-institutional retrospective analysis, in which 34 procedures were performed in 26 patients (median age, 63 y; 13 women), 19 with liver metastases and 7 with HCC. Yttrium-90 treatment activities were calculated by body surface area method. Tumor imaging response was assessed by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 for liver metastases and modified RECIST for HCC. Clinical side effects and adverse events were graded per Common Terminology Criteria for Adverse Events version 4.0.Results
All planned cases were technically successful, and no cases were canceled for elevated LSF or vascular anatomic reasons. Pretreatment angiography modified the planned 90Y treatment activity in 1 case in which vascular anatomy required a lobar-dose split into 2 for segmental infusions. In 18% of cases, patients were briefly admitted after the procedure for observation or symptom management. Imaging evaluation of initial efficacy at 1 month demonstrated partial response in 25% and stable disease in 67% of patients with liver metastases and partial/complete response in 43% and stable disease in 14% of patients with HCC. Grade ≥ 3 adverse events occurred in 6% of cases, with no systemic therapy–limiting toxicities. The mean total procedure time was 4.2 hours.Conclusions
A same-day 90Y radioembolization protocol with resin microspheres is feasible in select patients, which can expedite cancer therapy. 相似文献55.
56.
Xiaoxuan Liu Ameenat L. Solebo Livia Faes Sophie Beese Tasanee Braithwaite Matthew E. Round 《Ocular immunology and inflammation》2020,28(6):898-907
ABSTRACT
Purpose
New instrument-based techniques for anterior chamber (AC) cell counting can offer automation and objectivity above clinician assessment. This review aims to identify such instruments and its correlation with clinician estimates. 相似文献57.
58.
59.
60.