全文获取类型
收费全文 | 12133篇 |
免费 | 1272篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 188篇 |
儿科学 | 372篇 |
妇产科学 | 228篇 |
基础医学 | 1679篇 |
口腔科学 | 118篇 |
临床医学 | 1510篇 |
内科学 | 2754篇 |
皮肤病学 | 115篇 |
神经病学 | 1188篇 |
特种医学 | 392篇 |
外科学 | 2101篇 |
综合类 | 139篇 |
一般理论 | 4篇 |
预防医学 | 961篇 |
眼科学 | 398篇 |
药学 | 625篇 |
中国医学 | 7篇 |
肿瘤学 | 664篇 |
出版年
2023年 | 126篇 |
2022年 | 218篇 |
2021年 | 449篇 |
2020年 | 231篇 |
2019年 | 371篇 |
2018年 | 448篇 |
2017年 | 324篇 |
2016年 | 361篇 |
2015年 | 379篇 |
2014年 | 487篇 |
2013年 | 659篇 |
2012年 | 957篇 |
2011年 | 936篇 |
2010年 | 486篇 |
2009年 | 427篇 |
2008年 | 706篇 |
2007年 | 633篇 |
2006年 | 602篇 |
2005年 | 580篇 |
2004年 | 525篇 |
2003年 | 433篇 |
2002年 | 394篇 |
2001年 | 142篇 |
2000年 | 110篇 |
1999年 | 106篇 |
1998年 | 80篇 |
1997年 | 64篇 |
1995年 | 49篇 |
1994年 | 51篇 |
1993年 | 46篇 |
1992年 | 111篇 |
1991年 | 86篇 |
1990年 | 101篇 |
1989年 | 80篇 |
1988年 | 97篇 |
1987年 | 103篇 |
1986年 | 99篇 |
1985年 | 82篇 |
1984年 | 80篇 |
1983年 | 77篇 |
1982年 | 76篇 |
1981年 | 61篇 |
1979年 | 70篇 |
1978年 | 55篇 |
1976年 | 52篇 |
1975年 | 48篇 |
1974年 | 61篇 |
1973年 | 51篇 |
1972年 | 58篇 |
1970年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Well‐being,health and fitness of children who use wheelchairs: Feasibility study protocol to develop child‐centred ‘keep‐fit’ exercise interventions 下载免费PDF全文
2.
3.
ABSTRACTScreening rates for trauma are low in health care settings. We examined the association between health care providers’ (HCPs) experience of physical or sexual trauma and their screening of female patients for trauma. HCPs at an urban academic medical institution were surveyed from September through November 2016. The Brief Trauma (BTQ) and Sexual and Physical Abuse History Questionnaires (SPAHQ) assessed their own experiences of trauma. The Screening Practices Questionnaire (SPQ) assessed HCPs trauma screening. Multiple regression analyses were performed. Among 212 respondents aged 22–67 years, most were female (78.3%) and white (76.1%). Nurses (41.0%) were the largest occupational group. Overall, 85.8% reported having experienced trauma. No significant difference was observed in median SPQ scores between HCPs who had experienced trauma (3.88 [Interquartile Range (IQR) 3.44–4.31]) and those who had not (4.00 [IQR 3.47–4.33], p = .645). In an adjusted model, screening policy awareness and having an obstetrics & gynecology or psychiatry specialty were associated with higher SPQ scores (p < .001). The prevalence of trauma experience in this sample was high, but not associated with screening. Screening policy awareness and practice specialty were associated with screening. HCP factors associated with greater trauma screening should be explored. 相似文献
4.
Nathan Scudder James Robertson Sally F. Kelty Simon J. Walsh Dennis McNevin 《The Australian journal of forensic sciences》2020,52(2):235-241
ABSTRACTForensic DNA analysis is dependent on comparing the known and the unknown. Expand the number of known profiles, and the likelihood of a successful match increases. Forensic use of DNA is moving towards comparing samples of unknown origin with publicly available genetic data, such as the records held by genetic genealogy providers. Use of forensic genetic genealogy has yielded a number of recent high-profile successes but has raised ethical and privacy concerns. Navigating family trees is complex, even more so when combined with a comparison of genetic relationships. This intelligence-gathering process has led to occasional false leads, and its use also risks a public backlash, similar to concerns over Cambridge Analytica. A cautious approach to use of this technique is therefore warranted. 相似文献
5.
6.
Rosendo A. Rodriguez MD PhD Fraser Rubens MD MSc Carlos D. Rodriguez Howard J. Nathan MD 《Journal of neuroimaging》2006,16(2):126-132
OBJECTIVE: The application of intensity thresholds for embolus detection with transcranial Doppler (TCD) can exclude from analysis an unrecognized proportion of high-intensity transient signals (HITS))whose intensities are below the threshold. The lack of consistent threshold criteria between clinical trials may explain part of the discrepancy in the reported HITS counts. We investigated the effect of choosing different thresholds on the sensitivity and specificity of detecting HITS during cardiopulmonary bypass (CPB). METHODS: Two observers independently analyzed TCD recordings from 8 patients under CPB. Doppler signals were classified as true HITS, equivocal HITS, artifacts, and Doppler speckles according to preestablished criteria. The relative intensity of Doppler signals was measured by two different methods (TCD software vs manual). Receiver Operating Characteristic curves determined the optimal threshold for each of the two intensity methods. RESULTS: Reviewers achieved agreement in 96% of 2190 Doppler signals (kappa = 0.90). Relative intensities calculated with the TCD-software method were 3 dB (95% CI: 3.0-3.4) higher than the manual method. The optimal threshold was found at 10 dB (sensitivity: 99%; specificity: 90.8%) with the software method and at 7 dB with the manual method (sensitivity: 96%; specificity: 83%). The use of an intensity threshold 2 dB higher than the optimal increased the rejection of true HITS by 8% and 14%, respectively. CONCLUSIONS: Using intensity thresholds higher than the optimal for embolus detection decreases HITS counts. Choosing a threshold depends on the type of method used for measuring the signal intensity. Uniform threshold criteria and comparative studies between different Doppler devices are necessary for making clinical trials more comparable. 相似文献
7.
J.L. Bernat A.M. D'Alessandro F.K. Port T.P. Bleck S.O. Heard J. Medina S.H. Rosenbaum M.A. DeVita R.S. Gaston R.M. Merion M.L. Barr W.H. Marks H. Nathan K. O'Connor D.L. Rudow A.B. Leichtman P. Schwab N.L. Ascher R.A. Metzger V. Mc Bride W. Graham D. Wagner J. Warren F.L. Delmonico 《American journal of transplantation》2006,6(2):281-291
A national conference on organ donation after cardiac death (DCD) was convened to expand the practice of DCD in the continuum of quality end-of-life care. This national conference affirmed the ethical propriety of DCD as not violating the dead donor rule. Further, by new developments not previously reported, the conference resolved controversy regarding the period of circulatory cessation that determines death and allows administration of pre-recovery pharmacologic agents, it established conditions of DCD eligibility, it presented current data regarding the successful transplantation of organs from DCD, it proposed a new framework of data reporting regarding ischemic events, it made specific recommendations to agencies and organizations to remove barriers to DCD, it brought guidance regarding organ allocation and the process of informed consent and it set an action plan to address media issues. When a consensual decision is made to withdraw life support by the attending physician and patient or by the attending physician and a family member or surrogate (particularly in an intensive care unit), a routine opportunity for DCD should be available to honor the deceased donor's wishes in every donor service area (DSA) of the United States. 相似文献
8.
Matthew J Matasar Ellen K Ritchie Nathan Consedine Carol Magai Alfred I Neugut 《European journal of cancer prevention》2006,15(4):367-370
Despite significant improvements in the prognosis of acute promyelocytic leukemia brought about by therapeutic advances, understanding of the epidemiology of acute promyelocytic leukemia remains limited. Earlier reports have suggested that Hispanics may have an increased incidence of acute promyelocytic leukemia, but no systematic analysis of national data has yet been reported. We performed a retrospective cohort study, using data from the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute from 1992-2001 in order to compare leukemia incidence rates as a function of race and ethnicity. We identified 709 cases of acute promyelocytic leukemia and analyzed incidence rates by race and sex. Hispanics were not found to have greater lifetime incidence rates than whites, with an incidence relative rate (IRR) of 0.86 that of whites (P=0.17). The age distribution among Hispanics was significantly different from non-Hispanic whites, with greater incidence rates for children ages 1-19 years (IRR=1.9, P=0.02) and adult ages 20-44 years (IRR=1.6, P=0.004). Blacks had lower lifetime incidence rates than non-Hispanic whites (IRR=0.75, P=0.04), Hispanics (IRR=0.64, P=0.007), and Asians (IRR=0.67, P=0.03). Asians did not differ from non-Hispanic whites in lifetime or age-specific incidence rates. These results indicate that while US Hispanics do not have greater lifetime incidence rates of acute promyelocytic leukemia, blacks have lower incidence rates of acute promyelocytic leukemia than Hispanics, non-Hispanic whites, and Asians. 相似文献
9.
Edward R. Westrick MS Allan P. Shapiro PhD Peter E. Nathan PhD John Brick PhD 《Alcoholism, clinical and experimental research》1988,12(4):531-533
The present study demonstrates that alcohol-induced memory impairment can be attenuated by pretreatment with an oral tryptophan supplementation. These results provide support for the role of a brain serotonin deficit in this impairment and highlight the impact a dietary manipulation can have on a complex behavioral process. 相似文献
10.