全文获取类型
收费全文 | 1620篇 |
免费 | 100篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 48篇 |
妇产科学 | 14篇 |
基础医学 | 163篇 |
口腔科学 | 37篇 |
临床医学 | 119篇 |
内科学 | 260篇 |
皮肤病学 | 31篇 |
神经病学 | 93篇 |
特种医学 | 33篇 |
外科学 | 460篇 |
综合类 | 34篇 |
预防医学 | 79篇 |
眼科学 | 47篇 |
药学 | 121篇 |
中国医学 | 5篇 |
肿瘤学 | 115篇 |
出版年
2023年 | 9篇 |
2022年 | 31篇 |
2021年 | 60篇 |
2020年 | 25篇 |
2019年 | 49篇 |
2018年 | 59篇 |
2017年 | 41篇 |
2016年 | 34篇 |
2015年 | 37篇 |
2014年 | 52篇 |
2013年 | 55篇 |
2012年 | 107篇 |
2011年 | 129篇 |
2010年 | 65篇 |
2009年 | 61篇 |
2008年 | 94篇 |
2007年 | 91篇 |
2006年 | 121篇 |
2005年 | 92篇 |
2004年 | 78篇 |
2003年 | 68篇 |
2002年 | 79篇 |
2001年 | 40篇 |
2000年 | 51篇 |
1999年 | 30篇 |
1998年 | 20篇 |
1997年 | 12篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 12篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1973年 | 2篇 |
1966年 | 2篇 |
1957年 | 2篇 |
1933年 | 1篇 |
1929年 | 1篇 |
排序方式: 共有1724条查询结果,搜索用时 15 毫秒
951.
Purpose. To pilot-test and evaluate an innovative program providing information technology (IT) access to people with disabilities transitioning out of nursing homes into the community using a participatory approach.
Methods. Pre- and post-training data was collected on the 61 program participants to reflect three broad areas related to the IT training experience: performance; self-efficacy; importance, satisfaction and control. Additionally, semi-structured interviews were conducted with seven participants and five members of the program staff to explore environmental barriers to IT access for this group and the efficacy of the program in addressing these barriers. Data analyses followed a mixed methods approach incorporating both qualitative and quantitative techniques.
Results. Participants showed substantive changes in different spheres of IT use after completion of training. Post-training changes were significant particularly in areas related to self-efficacy, importance and satisfaction pertaining to use of IT. Qualitative findings substantiated the quantitative results and also revealed the numerous barriers to IT access that persons with disabilities continue to face within their communities.
Conclusion. Results indicate the feasibility, effectiveness and value of IT access to people with disabilities particularly those transitioning from institutional life to community living. Further action research aimed at increasing IT access for this group within local communities and neighborhoods is needed to address this issue at a broader societal level. 相似文献
Methods. Pre- and post-training data was collected on the 61 program participants to reflect three broad areas related to the IT training experience: performance; self-efficacy; importance, satisfaction and control. Additionally, semi-structured interviews were conducted with seven participants and five members of the program staff to explore environmental barriers to IT access for this group and the efficacy of the program in addressing these barriers. Data analyses followed a mixed methods approach incorporating both qualitative and quantitative techniques.
Results. Participants showed substantive changes in different spheres of IT use after completion of training. Post-training changes were significant particularly in areas related to self-efficacy, importance and satisfaction pertaining to use of IT. Qualitative findings substantiated the quantitative results and also revealed the numerous barriers to IT access that persons with disabilities continue to face within their communities.
Conclusion. Results indicate the feasibility, effectiveness and value of IT access to people with disabilities particularly those transitioning from institutional life to community living. Further action research aimed at increasing IT access for this group within local communities and neighborhoods is needed to address this issue at a broader societal level. 相似文献
952.
OBJECTIVES: To compare and document balance performance between patients with multiple sclerosis (MS) and healthy control subjects and balance performance among patients with different MS forms using a set of clinical balance tests. MATERIAL AND METHODS: Twenty eight primary progressive (PPMS), 34 secondary progressive (SPMS), and 62 relapsing remitting (RRMS), totalling 124 MS patients were included in the present study. Results from patients were compared with those of 31 healthy control subjects matching in age, gender, weight and height. Ashworth scale, mini-mental state examination and motricity index were used consecutively to evaluate spasticity, cognitive impairment and lower extremity muscle strength. Vision, sensation, proprioception, cerebellar and vestibular tests were also performed on the patients. The balance performance was evaluated using a set of clinical tests including steady stance tests (eyes in opened and closed positions, feet apart, feet together, stride stance, tandem stance and single stance), self-generated perturbations (functional reach, arm raise and step test), external perturbations, Tinetti-gait and 10 m gait time tests. RESULTS: There were no differences in age, sex, weight, height, sense impairment and lower extremity strength in patients with the three MS forms (p>0.05). No difference was found among patients with the three MS forms and the control subjects in the test of eyes closed with feet apart (p>0.05). The PPMS patients in all the balance tests except tests of eyes closed with feet apart and eyes opened with feet together, SPMS patients in all the balance tests except that of eyes closed with feet apart and RRMS patients in tandem stance, single leg stance, self-generated perturbations, external perturbations, Tinetti-gait and 10 m gait time tests had weaker balance than the control subjects (p<0.001). There were some differences between patients in the PPMS and SPMS groups in the eyes closed and feet apart test, between patients in the PPMS and RRMS groups in all the balance tests except eyes closed and feet apart and eyes opened and feet together tests and between patients in SPMS and RRMS group in all the balance tests except right and left arm raised tests (p<0.001). CONCLUSION: Balance in MS patients is impaired. The results of the present study show that there is more impairment in progressive MS forms than in RRMS. Meanwhile, patients with progressive MS are more likely to fall. 相似文献
953.
Huey ED Mirza N Putnam KT Soares H Csako G Levy JA Copenhaver B Cohen RM Sunderland T 《Dementia and geriatric cognitive disorders》2006,22(1):48-53
BACKGROUND: Cerebrospinal fluid (CSF) measures of beta-amyloid(1-42 )and tau differ between patients with Alzheimer's Disease (AD) and elderly normal controls. The effect of time and APOE genotype on these biomarkers continues to be elucidated. METHODS: We assessed CSF beta-amyloid(1-42) and tau in 20 mild-to-moderate AD patients, 11 APOE epsilon4+ and 9 APOE epsilon4-, over a mean time of 3.8 years (range 1-11.1 years). RESULTS: Over the period measured, CSF beta-amyloid(1-42) levels were lower in APOE epsilon4+ compared to APOE epsilon4- patients, and the levels decreased over time. Tau levels were stable over time and did not show an effect of APOE allele. CONCLUSIONS: While this is a limited clinical sample, the further decrease in CSF beta-amyloid(1-42 )(i.e., more abnormal) combined with the CSF tau stability over a mean period of almost 4 years suggests that beta-amyloid(1-42 )and tau maintain their potential usefulness as diagnostic biomarkers over time. These findings should be taken into account if CSF beta-amyloid(1-42) and tau are used as measures of treatment response. 相似文献
954.
Head and neck squamous cell carcinoma (HNSCC) are a heterogeneous group of tumors, mainly caused by exposure to cigarette smoke and/or alcohol. In recent years, a virally driven subset of cancers driven by human papillomavirus subtype 16 [HPV‐16]) has emerged. Our own data and data from other groups have demonstrated the favorable clinical outcome of HPV‐driven oropharyngeal tumors and in both HPV+ and HPV? cancers the importance of a high density of tumor‐associated lymphocytes for survival. These data underpin manipulation and activation of the patients' immune system by treatment, and as a result immunotherapy is rapidly taking its place in the management of HNSCC. Here we review the role the immune system in relation to HNSCC and consider the implications these have for HNSCC immunotherapy. Studies to quantify survival benefits and treatment‐associated toxicities are ongoing. 相似文献
955.
956.
957.
Da Ma Karteek Popuri Mahadev Bhalla Oshin Sangha Donghuan Lu Jiguo Cao Claudia Jacova Lei Wang Mirza Faisal Beg 《Human brain mapping》2019,40(5):1507-1527
When analyzing large multicenter databases, the effects of multiple confounding covariates increase the variability in the data and may reduce the ability to detect changes due to the actual effect of interest, for example, changes due to disease. Efficient ways to evaluate the effect of covariates toward the data harmonization are therefore important. In this article, we showcase techniques to assess the “goodness of harmonization” of covariates. We analyze 7,656 MR images in the multisite, multiscanner Alzheimer's Disease Neuroimaging Initiative (ADNI) database. We present a comparison of three methods for estimating total intracranial volume to assess their robustness and correct the brain structure volumes using the residual method and the proportional (normalization by division) method. We then evaluated the distribution of brain structure volumes over the entire ADNI database before and after accounting for multiple covariates such as total intracranial volume, scanner field strength, sex, and age using two techniques: (a) Zscapes, a panoramic visualization technique to analyze the entire database and (b) empirical cumulative distributions functions. The results from this study highlight the importance of assessing the goodness of data harmonization as a necessary preprocessing step when pooling large data set with multiple covariates, prior to further statistical data analysis. 相似文献
958.
R. Bourcier D. Abed M. Piotin H. Redjem J.C. Ferré F. Eugène H. Raoult M. Mirza R. Chapot H. Desal H. Nordmeyer 《Journal of neuroradiology. Journal de neuroradiologie》2018,45(4):230-235
Background and purpose
Mechanical thrombectomy predominantly using stent retrievers effectively restores cerebral blood flow and improves functional outcomes in patients with acute ischemic stroke. We sought to determine the safety and efficacy of mechanical thrombectomy using the EmboTrap device.Materials and methods
We identified 80 consecutive patients from 4 centers with acute ischemic stroke treated with EmboTrap from June 2015 to December 2016. All patients had confirmed large vessel occlusions in the anterior circulation using CT or MR angiography with salvageable tissue. We assessed baseline characteristics and treatment related parameters including onset-to-treatment time, recanalization success (mTICI 2b or greater), complications, and good clinical outcome (mRS 0 to 2).Results
Successful recanalization was achieved in 72 patients (90%). When considering the use of a second thrombectomy device as failure, the EmboTrap successfully recanalized 65 patients (81%), with complete (mTICI 3) recanalization in 40 patients (50%) within 1 or 2 passes. Median procedure time (groin to recanalization) was 35 minutes (8–161 minutes). During the procedure, distal emboli in previously unaffected territories were found in 5 (6%) patients. There were 3 vasospasms (4%) and no vessel perforations. Intracranial hemorrhage on CT at day 1 was found in 18 17 (2321%) patients, none with subarachnoid hemorrhages, and 5 were symptomatic (6%). Good clinical outcome occurred in 4749/68 78 patients (6963%).Conclusions
In this multicenter retrospective study, the EmboTrap device achieved high recanalization rates, good clinical outcomes and was safe in treating acute stroke patients with large vessel occlusions. 相似文献959.
Hypoxic exposure produces a consistent decrease of rectal temperature (Tb), which is recognized as a potent protective response. While some of the neural mechanisms underlying this response have recently been described, it remains poorly known how these mechanisms evolve during post-natal development. We recently reported that in rat pups NMDA glutamate receptor limits Tb drop upon hypoxic exposure, an effect that has not been reported by others in adult rats. Accordingly, we tested the hypothesis that the implication of NMDA receptors on temperature control during hypoxic exposure evolves during development. To this aim, we evaluated the hypoxic (30 min - 12% O(2)) responses of Tb, metabolic rate, and ventilation in rats after injection of vehicle, or the NMDA receptor antagonist MK-801, at different ages (post-natal days 4, 10, 20 and 2-3 month-old - P4, P10, P20 and P60). MK-801 amplified the magnitude of the hypoxic-induced Tb drop in P4, P10 and P20 rats, but this effect was not apparent in adults. In P20 rats MK-801 tripled the hypoxic induced Tb drop, which was 0.5 degrees C in control and 1.4 degrees C in treated rats (p<0.0001). This effect was specific to temperature regulation, and was not accompanied by similar changes of other recorded parameters. MK-801 induced a significant decrease of the hypoxic ventilatory response in adults only. We conclude that NMDA glutamate receptor acts as a counter-regulatory factor that limits the hypoxic-induced drop of rectal temperature during post-natal development in rats. 相似文献
960.