全文获取类型
收费全文 | 795篇 |
免费 | 52篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 12篇 |
妇产科学 | 62篇 |
基础医学 | 104篇 |
口腔科学 | 11篇 |
临床医学 | 119篇 |
内科学 | 151篇 |
皮肤病学 | 12篇 |
神经病学 | 76篇 |
特种医学 | 27篇 |
外科学 | 62篇 |
综合类 | 8篇 |
预防医学 | 86篇 |
眼科学 | 2篇 |
药学 | 51篇 |
中国医学 | 2篇 |
肿瘤学 | 56篇 |
出版年
2022年 | 6篇 |
2021年 | 18篇 |
2020年 | 12篇 |
2019年 | 11篇 |
2018年 | 16篇 |
2017年 | 8篇 |
2015年 | 9篇 |
2014年 | 13篇 |
2013年 | 23篇 |
2012年 | 38篇 |
2011年 | 33篇 |
2010年 | 24篇 |
2009年 | 14篇 |
2008年 | 45篇 |
2007年 | 37篇 |
2006年 | 30篇 |
2005年 | 41篇 |
2004年 | 35篇 |
2003年 | 31篇 |
2002年 | 32篇 |
2001年 | 24篇 |
2000年 | 25篇 |
1999年 | 24篇 |
1998年 | 12篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 8篇 |
1988年 | 15篇 |
1987年 | 6篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1981年 | 5篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1971年 | 4篇 |
1970年 | 9篇 |
1968年 | 4篇 |
1967年 | 6篇 |
1942年 | 13篇 |
1941年 | 20篇 |
1940年 | 6篇 |
排序方式: 共有848条查询结果,搜索用时 78 毫秒
81.
82.
83.
Ringdahl JE Falcomata TS Christensen TJ Bass-Ringdahl SM Lentz A Dutt A Schuh-Claus J 《Research in developmental disabilities》2009,30(2):330-341
Recent research has suggested that variables related to specific mand topographies targeted during functional communication training (FCT) can affect treatment outcomes. These include effort, novelty of mands, previous relationships with problem behavior, and preference. However, there is little extant research on procedures for identifying which mand topographies to incorporate into FCT. In the current study, a mand topography assessment was conducted following functional analyses to identify the proficiency with which individuals used several different mand topographies. Two mand topographies (high and low proficiency) were then compared during FCT-based treatments. FCT was more effective when the mand topography identified as high proficiency was incorporated into FCT as compared to FCT that included the lower proficiency response. The results are discussed in terms of the need for individualized assessment procedures for selecting mand topographies that are targeted during FCT. 相似文献
84.
85.
Rason MA Andrianantenaina HB Ariey F Raveloson A Domarle O Randrianarivelojosia M 《The American journal of tropical medicine and hygiene》2007,76(6):1079-1083
We assessed the status of point mutations associated with chloroquine resistance in pfcrt codon 76 and in pfmdr1 codon 86 among Plasmodium falciparum isolates from symptomatic patients in 3 sites in Madagascar. The in vitro susceptibility of P. falciparum isolates to quinoline-containing drugs was also determined. All isolates (N = 117) successfully typed were pfcrt wild-type, except one from Tsiroanomandidy (1 of 27). However, 67.5% (95% CI: 58.2-75.9%) of these isolates contained mutant pfmdr1 86Y. The pfmdr1 N86Y mutation is associated with higher mefloquine susceptibility, but it did not affect the sensitivity of parasites to chloroquine or quinine. Our findings demonstrate that pfmdr1 mutant P. falciparum are prevalent in Madagascar and confirm the low prevalence of pfcrt mutant P. falciparum after 60 years of chloroquine use. They provide additional field-based evidence for increased mefloquine susceptibility in pfmdr1 mutant P. falciparum and are suggestive of the intrahost selection of pfmdr1 mutant parasites. 相似文献
86.
Janvier MA Durand LG Cardinal MH Renaud I Chayer B Bigras P de Guise J Soulez G Cloutier G 《Medical image analysis》2008,12(3):275-290
3D-ultrasound (US) imaging systems offer many advantages such as convenience, low operative costs and multiple scanning options. Most 3D-US freehand tracking systems are not optimally adapted for the quantification of lower limb arterial stenoses because their performance depends on the scanning length, on ferro-magnetic interferences or because they require a constant line of sight with the US probe. Robotic systems represent a promising alternative since they can control and standardize the 3D-US acquisition process for large scanning distances without requiring a specific line of sight. The performance of a new prototype medical robot, in terms of positioning and inter-target accuracies (i.e., difference between measurements and ground truth values) was evaluated with a lower-limb mimicking phantom throughout the robot workspace. The teach/replay repeatability (i.e., difference between taught and replayed points) was also assessed. A mean positioning accuracy between 0.46 mm and 0.75 mm was found on all scanning zones. The mean inter-target distance accuracy varied between 0.26 mm and 0.61 mm. Teach/replay repeatability below 0.20mm was also obtained. Additionally, a 3D reconstruction of in-vitro stenoses was performed with the robotic US scanner. The quantification error of a 80% area reduction (AR) stenosis was 3.0%, whereas it was -0.9% for a less severe 75% AR stenosis. Altogether, these results suggest that the robot may be of value for the clinical evaluation of lower limb vessels over long and tortuous segments starting from the iliac artery down to the popliteal artery below the knee. 相似文献
87.
Lentz KA Quitko M Morgan DG Grace JE Gleason C Marathe PH 《Journal of pharmaceutical sciences》2007,96(2):459-472
A preclinical canine model capable of predicting a compound's potential for a human food effect was developed. The beagle dog was chosen as the in vivo model. A validation set of compounds with known propensities for human food effect was studied. Several diets were considered including high-fat dog food and various quantities of the human FDA meal. The effect of pentagastrin pretreatment was also investigated. The high-fat dog food did not predict human food effect and was discontinued from further evaluation. The amount of FDA meal in the dog was important in the overall prediction of the magnitude of human food effect. Fed/fasted Cmax and AUC ratios using a 50-g aliquot of the FDA meal in the dog were in the closest qualitative agreement to human data. Pentagastrin pretreatment did not affect the AUC in the fed state, but increased the fasted AUC for weakly basic compounds. Pentagastrin pretreatment and a 50-g aliquot of the FDA meal in the dog predicted the human food effect for a validation set of compounds. This model, which is intended for compound screening, will be helpful for determining food effect as a liability when compounds progress from discovery to clinical development. 相似文献
88.
L. Daniel Maxim John Allshouse Richard E. Fairfax T. J. Lentz Dean Venturin Thomas E. Walters 《Inhalation toxicology》2013,25(3):289-309
This article presents a 17-year (1990–2006) retrospective summary of ongoing studies of occupational exposure to refractory ceramic fiber (RCF) in the United States. Beginning in 1990, RCF producers integrated and harmonized individual workplace monitoring programs to provide data useful for various longitudinal and cross-sectional analyses, benchmarking, and various technical analyses. For 10 of these 17 years, the program has been conducted in partnership with government agencies, first a 5-year (1993–1998) program with the U.S. Environmental Protection Agency and later another 5-year (2002–2006) program with the Occupational Safety and Health Administration and the National Institute for Occupational Safety and Health. This article updates earlier published studies and provides lessons to be learned in the design of industrial hygiene monitoring and control programs. 相似文献
89.
90.
Limit of detection and threshold for positivity of the Centers for Disease Control and Prevention assay for factor VIII inhibitors
下载免费PDF全文
![点击此处可从《Journal of thrombosis and haemostasis》网站下载免费的PDF全文](/ch/ext_images/free.gif)