全文获取类型
收费全文 | 13600篇 |
免费 | 1119篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 187篇 |
儿科学 | 534篇 |
妇产科学 | 375篇 |
基础医学 | 1656篇 |
口腔科学 | 115篇 |
临床医学 | 1523篇 |
内科学 | 2430篇 |
皮肤病学 | 258篇 |
神经病学 | 1548篇 |
特种医学 | 329篇 |
外科学 | 1483篇 |
综合类 | 91篇 |
一般理论 | 20篇 |
预防医学 | 2115篇 |
眼科学 | 324篇 |
药学 | 808篇 |
1篇 | |
中国医学 | 15篇 |
肿瘤学 | 932篇 |
出版年
2024年 | 47篇 |
2023年 | 315篇 |
2022年 | 475篇 |
2021年 | 928篇 |
2020年 | 536篇 |
2019年 | 788篇 |
2018年 | 853篇 |
2017年 | 571篇 |
2016年 | 590篇 |
2015年 | 572篇 |
2014年 | 714篇 |
2013年 | 869篇 |
2012年 | 1258篇 |
2011年 | 1224篇 |
2010年 | 591篇 |
2009年 | 479篇 |
2008年 | 775篇 |
2007年 | 712篇 |
2006年 | 546篇 |
2005年 | 496篇 |
2004年 | 405篇 |
2003年 | 331篇 |
2002年 | 252篇 |
2001年 | 35篇 |
2000年 | 24篇 |
1999年 | 24篇 |
1998年 | 41篇 |
1997年 | 31篇 |
1996年 | 19篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 20篇 |
1992年 | 13篇 |
1991年 | 19篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1976年 | 5篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Until the 1960s, the sexuality of people with mental retardation was handled by denial and suppression. The eugenics movement of 1880–1940 led to forced mass sterilization and the segregation of these members of our society. The civil rights movement and the sexual revolution were among the catalysts for change as was the move toward normalization and deinstitutionalization of people with mental retardation. In the last 25 years, parents and professionals have begun to work together to find ways to help mentally handicapped individuals to understand their sexuality and to engage in appropriate self-affirming sexual behaviors. We have established goals, guidelines, and curricula for sexuality education. We have trained parents and staff and developed policies for handling sensitive issues, such as sterilization and problematic sexual expression. The AIDS epidemic has provided new impetus for improving education and training in this emerging field.A.C.S.W.Private practice (as a consultant, lecturer, and trainer in sexuality and mental retardation). 相似文献
72.
Duration discrimination in listeners with cochlear hearing loss: effects of stimulus type and frequency. 总被引:3,自引:0,他引:3
This study examined the effects of cochlear hearing loss on the ability to discriminate increments in the duration of a stimulus under conditions where the frequency and/or amplitude of the stimulus change dynamically. Three stimulus types were used: pure tones, frequency-modulated tones, and narrow bands of noise. The carrier/center frequency of each 250-ms stimulus either remained constant at 1035 Hz or varied randomly from presentation to presentation across the frequency range 432-2804 Hz. Two groups of listeners participated: 9 with bilateral cochlear hearing loss and 7 with normal hearing sensitivity. The results showed no differences in performance between the 2 groups. However, both groups showed poorer duration discrimination for the conditions where the carrier/center frequency changed randomly than for the conditions where the carrier/center frequency remained constant. In addition, performance was poorer for the narrowband noise stimuli than for the tonal stimuli. This pattern of results suggests that across-frequency temporal judgments are more difficult than isofrequency temporal judgments, but that cochlear hearing loss does not exacerbate this difficulty per se. 相似文献
73.
74.
Emily S Patterson Emilie M Roth David D Woods Renée Chow José Orlando Gomes 《International journal for quality in health care》2004,16(2):125-132
OBJECTIVE: To describe strategies employed during handoffs in four settings with high consequences for failure. DESIGN: ANALYSIS: of observational data for evidence of use of 21 handoff strategies. SETTING: NASA Johnson Space Center in Texas, nuclear power generation plants in Canada, a railroad dispatch center in the United States, and an ambulance dispatch center in Toronto. MAIN MEASURE: Evidence of 21 handoff strategies from observations and interviews. RESULTS: Nineteen of 21 strategies were used in at least one domain, on at least an 'as needed' basis. CONCLUSIONS: An understanding of how handoffs are conducted in settings with high consequences for failure can jumpstart endeavors to modify handoffs to improve patient safety. 相似文献
75.
Heidi M B Lesscher Emily Hoogveld J Peter H Burbach Jan M van Ree Mirjam A F M Gerrits 《European neuropsychopharmacology》2005,15(1):31-37
The endogenous cannabinoid system is a relatively novel discovered system consisting of cannabinoid CB1 receptors, which are expressed both in the periphery and in the central nervous system, peripheral cannabinoid CB2 receptors and endogenous cannabinoids, which are anandamide and 2-arachidonyl glycerol. The cannabinoid CB1 receptors have recently been implicated in rewarding aspects of not only the cannabinoid drug Delta9-tetrahydrocannabinol (Delta9-THC), but also of other drugs of abuse, including cocaine. The present study was designed to further investigate the role of CB1 receptors in reward-related effects of cocaine. Using the CB1 receptor selective antagonist SR141716A, the involvement of CB1 receptors in cocaine reinforcement was determined by intravenous cocaine self-administration. In addition, the effects of the CB1 receptor selective antagonist SR141716A upon the development of cocaine-induced behavioural sensitization were investigated. SR141716A did not affect cocaine reinforcement nor did it affect the development of behavioural sensitization to the locomotor stimulant effects of cocaine. These findings suggest that CB1 receptors are not involved in acute cocaine reinforcement nor in cocaine-induced behavioural sensitization. 相似文献
76.
Daan P Livestro Alona Muzikansky Emily M Kaine Thomas J Flotte Arthur J Sober Martin C Mihm James S Michaelson A Benedict Cosimi Kenneth K Tanabe 《Journal of clinical oncology》2005,23(27):6739-6746
PURPOSE: Previous studies have established that patients with desmoplastic melanoma (DM) have thicker primary tumors. Consequently, comparisons with other forms of melanoma have been strongly biased by differences in Breslow stage. This is the first case-matched control study comparing DM with other forms of melanoma. PATIENTS AND METHODS: From a database of 3,202 melanoma patients treated at one institution, 89 patients with DM and 178 case-matched control patients (2:1) were identified by matching for tumor thickness, age, sex, and year of diagnosis. Clinical, pathologic, and outcome information was obtained from chart review. RESULTS: Controls were matched successfully to patients for tumor thickness, age, sex, and year of diagnosis. Presentation with American Joint Committee on Cancer stage III or IV disease is less common in patients with DM compared to case-matched control patients (5% v 21%; P < .001). Re-excisions to obtain clear surgical margins are required more often in patients with DM compared to case-matched control patients (21% v 6%; P < .001). Risk of positive sentinel nodes is lower in patients with DM compared to case-matched control patients (8% v 34%; P = .013). Despite these differences, survival rates of patients with DM are the same as case-matched control patients. CONCLUSION: Use of case-matched control patients matched for tumor thickness avoids biases introduced by the advanced Breslow stage of DMs. DMs are more locally aggressive than thickness-matched controls, and positive sentinel nodes are limited to patients with thick primary tumors. Importantly, patients with DM have survival rates similar to patients with other melanomas of similar thickness. 相似文献
77.
Morgan C. Willson Emily C. Bell Sanjay Dave Sheila J. Asghar Brent M. McGrath Peter H. Silverstone 《European neuropsychopharmacology》2005,15(6):633-639
Dextroamphetamine administration in healthy controls produces a range of subjective and physiological effects, which have been likened to those occurring during mania. However, it is uncertain if these can be attenuated by lithium since conflicting results have been reported. To date there have been no previous studies examining the effects of valproate on dextroamphetamine-induced mood and physiological changes. The current study was a double-blind, placebo-controlled, study in which volunteers received either 1000 mg sodium valproate (n = 12), 900 mg lithium (n = 9), or placebo (n = 12) pre-treatment for 14 days. Subjective and physiological measures were then obtained prior to administration of a 25 mg dose of dextroamphetamine, and at two time points after administration. Differences in the response to dextroamphetamine were assessed between the three treatment groups. The results of this study show that pre-treatment with lithium only significantly attenuated dextroamphetamine-induced change in happiness, while valproate pre-treatment significantly attenuated the effects of dextroamphetamine on happiness, energy, alertness and on the diastolic blood pressure. These results suggest that lithium and valproate do not have the same mechanism of action on dextroamphetamine-induced changes, and this finding may relate to differences in their mechanism of action in mood disorders. 相似文献
78.
Emily Banks Gillian Reeves Valerie Beral Diana Bull Barbara Crossley Moya Simmonds Elizabeth Hilton Stephen Bailey Nigel Barrett Peter Briers Ruth English Alan Jackson Elizabeth Kutt Janet Lavelle Linda Rockall Matthew G Wallis Mary Wilson Julietta Patnick 《British medical journal》2004,328(7451):1291-1292
79.
80.
Caroline Egloff Doug Crump Emily Porter Kim L. Williams Robert J. Letcher Lewis T. Gauthier Sean W. Kennedy 《Toxicology and applied pharmacology》2014
The organophosphate flame retardants tris(2-butoxyethyl) phosphate (TBOEP) and triethyl phosphate (TEP) are used in a wide range of applications to suppress or delay the ignition and spread of fire. Both compounds have been detected in the environment and TBOEP was recently measured in free-living avian species. In this study, TBOEP and TEP were injected into the air cell of chicken embryos at concentrations ranging from 0 to 45,400 ng/g and 0 to 241,500 ng/g egg, respectively. Pipping success, development, hepatic mRNA expression of 9 target genes, thyroid hormone levels, and circulating bile acid concentrations were determined. Exposure to the highest doses of TBOEP and TEP resulted in negligible detection of the parent compounds in embryonic contents at pipping indicating their complete metabolic degradation. TBOEP exposure had limited effects on chicken embryos, with the exception of hepatic CYP3A37 mRNA induction. TEP exposure decreased pipping success to 68%, altered growth, increased liver somatic index (LSI) and plasma bile acids, and modulated genes associated with xenobiotic and lipid metabolism and the thyroid hormone pathway. Plasma thyroxine levels were decreased at all TEP doses, including an environmentally-relevant concentration (8 ng/g), and gallbladder hypotrophy was evident at ≥ 43,200 ng/g. Tarsus length and circulating thyroxine concentration emerged as potential phenotypic anchors for the modulation of transthyretin mRNA. The increase in plasma bile acids and LSI, gallbladder hypotrophy, and discoloration of liver tissue represented potential phenotypic outcomes associated with modulation of hepatic genes involved with xenobiotic and lipid metabolism. 相似文献