全文获取类型
收费全文 | 50565篇 |
免费 | 4020篇 |
国内免费 | 108篇 |
专业分类
耳鼻咽喉 | 547篇 |
儿科学 | 1867篇 |
妇产科学 | 1327篇 |
基础医学 | 6334篇 |
口腔科学 | 488篇 |
临床医学 | 6507篇 |
内科学 | 9107篇 |
皮肤病学 | 1012篇 |
神经病学 | 5218篇 |
特种医学 | 1031篇 |
外科学 | 5306篇 |
综合类 | 415篇 |
现状与发展 | 1篇 |
一般理论 | 88篇 |
预防医学 | 7094篇 |
眼科学 | 851篇 |
药学 | 3535篇 |
中国医学 | 60篇 |
肿瘤学 | 3905篇 |
出版年
2024年 | 48篇 |
2023年 | 478篇 |
2022年 | 702篇 |
2021年 | 1832篇 |
2020年 | 1121篇 |
2019年 | 1825篇 |
2018年 | 1929篇 |
2017年 | 1491篇 |
2016年 | 1568篇 |
2015年 | 1664篇 |
2014年 | 2328篇 |
2013年 | 3056篇 |
2012年 | 4566篇 |
2011年 | 4493篇 |
2010年 | 2452篇 |
2009年 | 2036篇 |
2008年 | 3527篇 |
2007年 | 3506篇 |
2006年 | 3255篇 |
2005年 | 3054篇 |
2004年 | 2638篇 |
2003年 | 2218篇 |
2002年 | 1928篇 |
2001年 | 286篇 |
2000年 | 189篇 |
1999年 | 267篇 |
1998年 | 321篇 |
1997年 | 233篇 |
1996年 | 196篇 |
1995年 | 175篇 |
1994年 | 131篇 |
1993年 | 106篇 |
1992年 | 93篇 |
1991年 | 83篇 |
1990年 | 89篇 |
1989年 | 76篇 |
1988年 | 56篇 |
1987年 | 51篇 |
1986年 | 54篇 |
1985年 | 55篇 |
1984年 | 63篇 |
1983年 | 48篇 |
1982年 | 37篇 |
1981年 | 27篇 |
1980年 | 25篇 |
1979年 | 32篇 |
1978年 | 34篇 |
1976年 | 27篇 |
1975年 | 27篇 |
1972年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
This article describes the proceedings of the 2006 Annual Meeting of the Fetal Alcohol Spectrum Disorders Study Group (FASDSG), which was held in Baltimore, Maryland on June 24, 2006. The meeting was held in conjunction with the annual meeting of the Research Society on Alcoholism and was supported by a grant from the National Institute on Alcohol Abuse and Alcoholism. The 2005-2006 FASDSG officers, Daniel J. Bonthius (President), Heather Carmichael Olson (Vice-President), and Jennifer Thomas (Secretary-Treasurer), organized the meeting. Nationally prominent speakers delivered plenary lectures on topics of newborn screening, ethics, and neuroscience. Selected members of the FASDSG provided brief scientific data (FASt) reports, describing new research findings. Representatives from national agencies involved in fetal alcohol syndrome (FAS) research, treatment, and prevention provided updates regarding priorities, funding, and agency activities. Presentations were also made by the 2006 Student Merit Award recipient and by the 2006 Rosett Award recipient. The meeting served as a forum for clinicians, neuroscientists, psychologists, social scientists, and other professionals to discuss recent advances in FAS research and to identify the most important gaps in the understanding of alcohol-induced teratology. 相似文献
52.
53.
54.
Jennifer Tuboku-Metzger Blakely Ronda L Sinkowitz-Cochran William R Jarvis 《Infection control and hospital epidemiology》2006,27(8):873-875
A 19-item survey instrument was designed and mailed by the Infectious Diseases Society of America to its membership to determine the media preferred by infectious diseases physicians for continuing medical education on general topics and on antimicrobial resistance. The objective of the survey was to offer the developers of educational programs knowledge on which to base more-effective ways to deliver educational materials to physicians in this specialty. 相似文献
55.
Diarrhetic shellfish poisoning (DSP) is a serious and globally widespread phytoplankton-related seafood illness. Although DSP is rarely life-threatening, it causes incapacitating diarrhea and vomiting with no known medical treatments. In addition, phytoplankton producing DSP toxins have been identified in temperate coastal waters worldwide, and their numbers may be increasing as a result of coastal eutrophication. The toxic effects of the major DSP toxins, okadaic acid and dinophysistoxin-1 (35-methylokadaic acid), appear to originate from their inhibitory activity against a family of structurally related serine/threonine protein phosphatases (PSPases). In particular, the inhibition of essential PSPases (e.g. PP1 and PP2A) has catastrophic consequences in most eukaryotic cells. Exploiting the potent inhibitory property of the DSP toxins, we have developed an enzyme-based assay (PP2A assay) capable of detecting both okadaic acid and dinophysis- toxin-1 in nanogram amounts. The assay employs purified PP2A, which has an extremely high affinity for both DSP toxins. This provides the PP2A assay with a level of sensitivity comparable to, or surpassing, that of most monoclonal antibody probes. To evaluate the PP2A assay as a means of detecting contaminated shellfish, a series of spike recovery experiments was conducted. The findings from these studies suggest that the PP2A assay has the potential for development into a rapid and relatively simple method for detecting PSPase inhibitors in crude extracts produced from shellfish. 相似文献
56.
Intratemporal vascular tumors: detection with CT and MR imaging 总被引:1,自引:0,他引:1
Lo WW; Shelton C; Waluch V; Solti-Bohman LG; Carberry JN; Brackmann DE; Wade CT 《Radiology》1989,171(2):445-448
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion. 相似文献
57.
58.
59.
M. Laurin Council Jennifer M. Gardner Cynthia Helms Ying Liu Lynn A. Cornelius Anne M. Bowcock 《Experimental dermatology》2009,18(5):485-487
Abstract: The risks of developing malignant melanoma (MM) include ultraviolet irradiation and genetic factors. To examine the contribution of rare and common variation within known MM genes in sporadic US MM patients, coding regions of known MM susceptibility genes [cyclin-dependent kinase inhibitor 2A ( CDKN2A ), cyclin-dependent kinase 4, melanocortin 1 receptor ( MC1R ) and tyrosinase ( TYR )] were resequenced in 109–135 MM cases. The significance of variants was examined by comparing their frequencies in 390 cancer-free controls. Potential deleterious mutations in CDKN2A were found in two patients and two others had variants of unknown significance. Cases were more likely than controls to harbour the MC1R 'R' variants known or predicted to alter its function ( P = 0.002), particularly the R160W variant ( P = 0.0035). The associated TYR R402Q variant (rs1126809*A) was found in 29% of cases, similar to what has been described previously. One MM patient with a family history of MM, who had developed other skin cancers, was homozygous for a novel TYR variant (P406L) of unknown significance. Hence, rare variants in TYR may be important risk factors for skin cancer. 相似文献
60.
Betsy D. Kennard Susan G. Silva Simon Tonev Paul Rohde Jennifer L. Hughes Benedetto Vitiello Christopher J. Kratochvil John F. Curry Graham J. Emslie Mark Reinecke John March 《Journal of the American Academy of Child and Adolescent Psychiatry》2009,48(2):186-195
ObjectiveWe examine remission rate probabilities, recovery rates, and residual symptoms across 36 weeks in the Treatment for Adolescents with Depression Study (TADS).MethodThe TADS, a multisite clinical trial, randomized 439 adolescents with major depressive disorder to 12 weeks of treatment with fluoxetine, cognitive–behavioral therapy, their combination, or pill placebo. The pill placebo group, treated openly after week 12, was not included in the subsequent analyses. Treatment differences in remission rates and probabilities of remission over time are compared. Recovery rates in remitters at weeks 12 (acute phase remitters) and 18 (continuation phase remitters) are summarized. We also examined whether residual symptoms at the end of 12 weeks of acute treatment predicted later remission.ResultsAt week 36, the estimated remission rates for intention-to-treat cases were as follows: combination, 60%; fluoxetine, 55%; cognitive–behavioral therapy, 64%; and overall, 60%. Paired comparisons reveal that, at week 24, all active treatments converge on remission outcomes. The recovery rate at week 36 was 65% for acute phase remitters and 71% for continuation phase remitters, with no significant between-treatment differences in recovery rates. Residual symptoms at the end of acute treatment predicted failure to achieve remission at weeks 18 and 36.ConclusionsMost depressed adolescents in all three treatment modalities achieved remission at the end of 9 months of treatment. 相似文献