全文获取类型
收费全文 | 219篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 19篇 |
妇产科学 | 34篇 |
基础医学 | 20篇 |
口腔科学 | 3篇 |
临床医学 | 19篇 |
内科学 | 55篇 |
皮肤病学 | 8篇 |
神经病学 | 20篇 |
特种医学 | 8篇 |
外科学 | 25篇 |
综合类 | 1篇 |
预防医学 | 7篇 |
眼科学 | 4篇 |
药学 | 2篇 |
肿瘤学 | 4篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2015年 | 7篇 |
2014年 | 9篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 10篇 |
2006年 | 10篇 |
2005年 | 10篇 |
2004年 | 10篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1956年 | 1篇 |
1949年 | 1篇 |
排序方式: 共有236条查询结果,搜索用时 31 毫秒
1.
2.
Progressive de novo DNA methylation at the bcr-abl locus in the course of chronic myelogenous leukemia. 总被引:4,自引:1,他引:3
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
3.
4.
Yoseph Shalev Menashe Epstein Oded Ayzenberg Abraham Caspi Herzl Ben-Hur Zion Hagay Isaac Blickstein Alan Gelven 《Clinical cardiology》1993,16(10):754-756
Acute myocardial infarction during pregnancy is considered to be associated with approximately 50% mortality of both mother and fetus. However, there are not enough data regarding the role of acute myocardial ischemia. We present a 36-year-old, pregnant, white female who was admitted twice at 18 and 20 weeks of gestation with acute myocardial ischemia. Cardiac catheterization revealed 70–80% stenosis of the mid left anterior descending artery (LAD) with normal antegrade flow and very good retrograde filling of the LAD from distal collaterals of the right coronary artery. Therefore, due to angiographic suggestion of protected LAD territory, we recommended medical therapy and scheduled a vaginal delivery that was successfully completed without cardiovascular complications. A stress thallium test performed 6 months later was normal, supporting our clinical judgment. In conclusion, every case of a pregnant woman with coronary insufficiency should be treated according to individual coronary anatomy and blood supply to the territory of the diseased artery, and should not be based on the old data in the literature. The decision for revascularization prior to delivery versus medical therapy, or Caesarean section versus natural delivery, should be made by a team of a cardiologist and an obstetrician. 相似文献
5.
An MR-Conditional High-Torque Pneumatic Stepper Motor for MRI-Guided and Robot-Assisted Intervention
Magnetic resonance imaging allows for visualizing detailed pathological and morphological changes of soft tissue. MR-conditional actuations have been widely investigated for development of image-guided and robot-assisted surgical devices under the Magnetic resonance imaging (MRI). This paper presents a simple design of MR-conditional stepper motor which can provide precise and high-torque actuation without adversely affecting the MR image quality. This stepper motor consists of two MR-conditional pneumatic cylinders and the corresponding supporting structures. Alternating the pressurized air can drive the motor to rotate each step in 3.6° with the motor coupled to a planetary gearbox. Experimental studies were conducted to validate its dynamics performance. Maximum 800 mN m output torque is achieved. The motor accuracy independently varied by two factors: motor operating speed and step size, was also investigated. The motor was tested within a 3T Siemens MRI scanner (MAGNETOM Skyra, Siemens Medical Solutions, Erlangen, Germany) and a 3T GE MRI scanner (GE SignaHDx, GE Healthcare, Milwaukee, WI, USA). The image artifact and the signal-to-noise ratio (SNR) were evaluated for study of its MRI compliancy. The results show that the presented pneumatic stepper motor generated 2.35% SNR reduction in MR images. No observable artifact was presented besides the motor body itself. The proposed motor test also demonstrates a standard to evaluate the pneumatic motor capability for later incorporation with motorized devices used under MRI. 相似文献
6.
7.
Maria Ferris Edward Iglesia Zion Ko Ahinee Amamoo John Mahan Tejas Desai 《Renal failure》2014,36(8):1340-1344
A workforce crisis for many pediatric specialties, particularly nephrology, is due to growing retirement rates, attrition during training, and retention difficulties. To obtain specific information regarding pediatric nephrology trainee shortages, we administered two cross-sectional surveys to non-renal pediatric subspecialty fellows and pediatric nephrology program directors. We characterized the fellows' experiences with nephrology and the program directors' experiences with their fellows as well as their outcomes in the last 10 years. We analyzed responses from 531 non-renal fellows (14.4% response rate). Overall, 317 (60%) fellows rated nephrology as difficult, particularly women (65.4% vs. 49.5%, p?0.001), with American women medical graduates rating nephrology as more difficult compared to all others (p?=?0.001). More men than women (24% vs. 8%, p?0.001) considered the monetary benefit as not adequate. Program directors (25; 64% response rate) represented 57% of all USA fellows in training, and 15 (60%) found it difficult to recruit qualified applicants. Of the 183 graduates in the past 10 years, 35 (19%) were reported as not in the USA pediatric nephrology workforce. These findings support our belief that a strong effort needs to be made by the academic community to teach nephrology in more interesting and understandable formats. While these are national samples, we were unable to contact non-nephrology fellows directly and program directors from larger programs were underrepresented. Difficulties in attracting/retaining trainees (particularly women) to nephrology must be addressed systematically, identifying incentives to practice in this field. Bold concerted efforts are required and we propose seven steps to achieve this goal. 相似文献
8.
9.
Sam Esfandiari Zion Sasson Jack M. Goodman 《European journal of applied physiology》2014,114(2):331-343
Purpose
This study examined the effects of short-term high-intensity interval training (HIT) and continuous moderate-intensity training (CMT) on cardiac function in young, healthy men.Methods
Sixteen previously untrained men (mean age of 25.1 ± 4.1 years) were randomly assigned to HIT and CMT (n = 8 each) and assessed before and after six sessions over a 12-day training period. HIT consisted of 8–12 intervals of cycling for 60 s at 95–100 % of pre-training maximal aerobic power ( $\dot{V}$ O2max), interspersed by 75 s of cycling at 10 % $\dot{V}$ O2max. CMT involved 90–120 min of cycling at 65 % pre-training $\dot{V}$ O2max. Left ventricular (LV) function was determined at rest and during submaximal exercise (heart rate ~105 bpm) using two-dimensional and Doppler echocardiography.Results
Training resulted in increased calculated plasma volume (PV) in both groups, accompanied by improved $\dot{V}$ O2max in HIT (HIT: from 39.5 ± 7.1 to 43.9 ± 5.5 mL kg?1 min?1; CMT: from 39.9 ± 5.9 to 41.7 ± 5.3 mL kg?1 min?1; P < 0.001). Resting LV function was not altered. However, increased exercise stroke volume (P = 0.02) and cardiac output (P = 0.02) were observed, secondary to increases in end-diastolic volume (P < 0.001). Numerous Doppler and speckle tracking indices of diastolic function were similarly enhanced during exercise in both training groups and were related to changes in PV.Conclusion
Short-term HIT and CMT elicit rapid improvements in $\dot{V}$ O2max and LV filling without global changes in cardiac performance at rest. 相似文献10.
Iris Barshack Gila Lithwick-Yanai Arnon Afek Kinneret Rosenblatt Hila Tabibian-Keissar Merav Zepeniuk Lahav Cohen Harel Dan Orit Zion Yulia Strenov Sylvie Polak-Charcon Marina Perelman 《Pathology, research and practice》2010
For surgical pathologists, distinguishing whether a pulmonary neoplasm is primary or metastatic can be challenging, and current biomarkers do not always aid lung tumor classification. The tissue-associated expression of microRNA likely explains the remarkable finding that many tumors can be classified based solely on their microRNA expression signature. Here we show that microRNAs can serve as biomarkers for lung tumor classification. Using microRNA microarray data generated from 76 formalin-fixed, paraffin-embedded (FFPE) samples of either primary lung cancer or metastatic tumors to the lung, we have identified a set of microRNAs expressed differentially between these two groups. This set includes hsa-miR-182, which was most strongly over-expressed in the lung primary tumors, and hsa-miR-126, which was over-expressed in the metastatic tumors. The differential expression of this set of microRNAs was confirmed using qRT-PCR on a set of 54 samples. In light of our data, microRNA expression should be considered as a potential clinical biomarker for surgical pathologists faced with discerning the tumor type of an inscrutable lung neoplasm. 相似文献