全文获取类型
收费全文 | 1802篇 |
免费 | 78篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 46篇 |
妇产科学 | 40篇 |
基础医学 | 166篇 |
口腔科学 | 47篇 |
临床医学 | 526篇 |
内科学 | 219篇 |
皮肤病学 | 58篇 |
神经病学 | 59篇 |
特种医学 | 235篇 |
外科学 | 185篇 |
综合类 | 41篇 |
预防医学 | 67篇 |
眼科学 | 13篇 |
药学 | 104篇 |
中国医学 | 4篇 |
肿瘤学 | 109篇 |
出版年
2023年 | 6篇 |
2021年 | 13篇 |
2020年 | 14篇 |
2019年 | 17篇 |
2018年 | 22篇 |
2017年 | 10篇 |
2016年 | 14篇 |
2015年 | 33篇 |
2014年 | 44篇 |
2013年 | 64篇 |
2012年 | 63篇 |
2011年 | 65篇 |
2010年 | 58篇 |
2009年 | 72篇 |
2008年 | 72篇 |
2007年 | 79篇 |
2006年 | 64篇 |
2005年 | 59篇 |
2004年 | 71篇 |
2003年 | 53篇 |
2002年 | 58篇 |
2001年 | 66篇 |
2000年 | 57篇 |
1999年 | 54篇 |
1998年 | 98篇 |
1997年 | 95篇 |
1996年 | 85篇 |
1995年 | 68篇 |
1994年 | 54篇 |
1993年 | 58篇 |
1992年 | 29篇 |
1991年 | 32篇 |
1990年 | 35篇 |
1989年 | 27篇 |
1988年 | 37篇 |
1987年 | 14篇 |
1986年 | 16篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1973年 | 5篇 |
1971年 | 7篇 |
1970年 | 7篇 |
1966年 | 9篇 |
排序方式: 共有1923条查询结果,搜索用时 15 毫秒
41.
Joanne M. Pohl PhD RN CS Charles W. Given PhD Clare E. Collins PhD RN FAAN Barbara A. Given PhD RN FAAN 《Health care for women international》2013,34(5):385-395
Variables that have been conceptually linked with social vulnerability—income, educational level, employment, cessation of work to provide care, marital status, social support, and health—were used to predict four categories of reaction to caregiving in 159 daughters and daughters‐in‐law caring for their disabled aging parents. Social support, income, and health best predicted negative reactions to caregiving; social support alone best predicted feelings of family abandonment, impact on health, and impact on schedule. Compared with daughters and daughters‐in‐law who had not quit work to provide care, those who had quit work were significantly older, had lower incomes and fewer social supports, and were more involved in care. The results suggest that quitting work may be a precursor to social isolation that places the caregiver at increased risk for social vulnerability and negative reaction to caregiving. The implications of the findings for health care policy are discussed. 相似文献
42.
43.
Erin S Calipari Mark J Ferris Benjamin A Zimmer David CS Roberts Sara R Jones 《Neuropsychopharmacology》2013,38(12):2385-2392
The dopamine transporter (DAT) is responsible for terminating dopamine (DA) signaling and is the primary site of cocaine''s reinforcing actions. Cocaine self-administration has been shown previously to result in changes in cocaine potency at the DAT. To determine whether the DAT changes associated with self-administration are due to differences in intake levels or temporal patterns of cocaine-induced DAT inhibition, we manipulated cocaine access to produce either continuous or intermittent elevations in cocaine brain levels. Long-access (LgA, 6 h) and short-access (ShA, 2 h) continuous self-administration produced similar temporal profiles of cocaine intake that were sustained throughout the session; however, LgA had greater intake. ShA and intermittent-access (IntA, 6 h) produced the same intake, but different temporal profiles, with ‘spiking'' brain levels in IntA compared with constant levels in ShA. IntA consisted of 5-min access periods alternating with 25-min timeouts, which resulted in bursts of high responding followed by periods of no responding. DA release and uptake, as well as the potency of cocaine for DAT inhibition, were assessed by voltammetry in the nucleus accumbens slices following control, IntA, ShA, and LgA self-administration. Continuous-access protocols (LgA and ShA) did not change DA parameters, but the ‘spiking'' protocol (IntA) increased both release and uptake of DA. In addition, high continuous intake (LgA) produced tolerance to cocaine, while ‘spiking'' (IntA) produced sensitization, relative to ShA and naive controls. Thus, intake and pattern can both influence cocaine potency, and tolerance seems to be produced by high intake, while sensitization is produced by intermittent temporal patterns of intake. 相似文献
44.
45.
Jin Ho Whang Min Keun Kim Kyueng‐Whan Min Jae Young Hong Hitesh N. Modi Seung Woo Suh 《Clinical anatomy (New York, N.Y.)》2012,25(8):1066-1073
In the present study, we investigated whether there is a difference between visual depth (VD) and radiological image depth (RD) of cages (i.e., structural interbody support devices) placed in disc spaces during posterior lumbar interbody fusion and whether soft tissues covering the posterior border of the vertebral body and associated disc space are the cause of any observed differences. Using digital calipers, cages were inserted at a depth of 5 mm from the soft tissues covering the posterior border of the vertebral body and disc space under direct vision; this depth was defined as VD. After insertion, RD was measured in triplicate. The reliability of RD measurements was evaluated using an intraclass coefficient test. To identify the cause of differences between VD and RD, the thicknesses of soft tissues were measured microscopically. A total of 40 lumbar intervertebral disc spaces with cages were evaluated. The mean RD of cages was 3.12 mm, while the mean difference between the VD and RD of cages (DVRD) was 1.91 mm. On histological examination, the mean thickness of the soft tissue was 2.02 mm. Comparative analysis between histological values and DVRD showed no statistical difference (P = 1.14, 1.55, 0.06). There was a significant difference between VD and RD during cage placement, and soft tissue structure appeared to be responsible for the DVRD of inserted cages. Therefore, cages should be inserted deeper to account for differences between visual and radiological image depths. Clin. Anat. 25:1066–1073, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
46.
Failure to mix 24.5 mM of magnesium, added as 50% MgSO4 in 1 liter of intravenous fluid, results in a high concentration of Mg in the initial 10-cc aliquot: 1,145.7 mM/liter. Adequate dispersion can be obtained after three inversions. We conclude that because of the extremely high concentrations of Mg that can result if no mixing is done, it is imperative that hospital personnel ensure that added Mg is adequately dispersed in intravenous fluid prior to administration. A method of signalling the inadequacy of mixing is to color code additives with a harmless dye to alert personnel to the problem of inadequate dispersement. 相似文献
47.
The relationship between sex role identity and depression in nurses was explored. It was posited that nurses tend to be high in feminine traits and have traditional attitudes and that these traits and attitudes will be correlated with depressive symptoms. The sample consisted of 203 nurses employed at a 350‐bed metropolitan hospital. The research questionnaire included: (a) the Maferr Inventory of Feminine Values, (b) the Bem Sex Role Inventory, (c) the Zung Self‐Rating Depression Scale, and (d) demographic data. It was found that a strong and positive association existed between traditional attitudes toward feminine sex roles and depressive symptoms. However, relationships between feminine traits and depressive symptoms were not found. Data analysis also indicated statistically significant relationships between both androgenous traits, masculine traits, and lack of depressive symptoms. Limitations in scope and sampling procedures were discussed. In addition, the significance to nursing was discussed. 相似文献
48.
CL Sanchez CS Biskup S Herpertz TJ Gaber CM Kuhn SH Hood FD Zepf 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2015,18(10)
The neurotransmitters serotonin and dopamine both have a critical role in the underlying neurobiology of different behaviors. With focus on the interplay between dopamine and serotonin, it has been proposed that dopamine biases behavior towards habitual responding, and with serotonin offsetting this phenomenon and directing the balance toward more flexible, goal-directed responding. The present focus paper stands in close relationship to the publication by Worbe et al. (2015), which deals with the effects of acute tryptophan depletion, a neurodietary physiological method to decrease central nervous serotonin synthesis in humans for a short period of time, on the balance between hypothetical goal-directed and habitual systems. In that research, acute tryptophan depletion challenge administration and a following short-term reduction in central nervous serotonin synthesis were associated with a shift of behavioral performance towards habitual responding, providing further evidence that central nervous serotonin function modulates the balance between goal-directed and stimulus-response habitual systems of behavioral control. In the present focus paper, we discuss the findings by Worbe and colleagues in light of animal experiments as well as clinical implications and discuss potential future avenues for related research. 相似文献
49.
50.
Interleukin-1 alpha (IL-1 alpha) is a macrophage-derived, multifunctional cytokine that broadly potentiates myelopoiesis and induces the synthesis of hematopoietic colony-stimulating factors (CSF) in vitro and in vivo. To evaluate the possibility for use of IL-1 alpha in ameliorating in vivo bone marrow suppression induced by drugs or radiation, we examined the in vivo effects of the cytokine on erythropoietic and other hematopoietic progenitor cells. Normal mice were treated with a single intraperitoneal (IP) injection of recombinant human IL-1 alpha at varying doses and were assayed at various times post-treatment. By six hours postinjection, a significant suppression of mature erythroid progenitors (CFU-E) was observed in animals treated with IL-1 alpha (0.5 micrograms/mouse), with maximum suppression of CFU-E and peripheral blood reticulocyte counts occurring at 24 hours. Decreases in peripheral blood hematocrit did not occur after a single IL-1 alpha injection but were observed after multiple injections of the cytokine. The suppressive effects of IL-1 alpha on late-stage erythropoiesis were abrogated by simultaneous administration of erythropoietin (EPO). At 48 hours post-treatment, a marked stimulation was observed in the numbers of spleen and marrow immature erythroid (BFU-E), macrophage (CFU-M), granulocyte (CFU-G), granulocyte- macrophage (CFU-GM), and megakaryocyte (CFU-meg) progenitor cells. These results demonstrate the potential use of IL-1 alpha as a generalized stimulator of hematopoiesis and show that the cytokine- induced suppression of late-stage erythropoiesis can be prevented by EPO. 相似文献