全文获取类型
收费全文 | 2094篇 |
免费 | 114篇 |
国内免费 | 76篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 173篇 |
妇产科学 | 27篇 |
基础医学 | 236篇 |
口腔科学 | 59篇 |
临床医学 | 257篇 |
内科学 | 506篇 |
皮肤病学 | 75篇 |
神经病学 | 69篇 |
特种医学 | 391篇 |
外科学 | 110篇 |
综合类 | 47篇 |
预防医学 | 91篇 |
眼科学 | 20篇 |
药学 | 96篇 |
2篇 | |
中国医学 | 2篇 |
肿瘤学 | 122篇 |
出版年
2023年 | 5篇 |
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 14篇 |
2019年 | 16篇 |
2018年 | 32篇 |
2017年 | 23篇 |
2016年 | 22篇 |
2015年 | 43篇 |
2014年 | 49篇 |
2013年 | 60篇 |
2012年 | 53篇 |
2011年 | 46篇 |
2010年 | 90篇 |
2009年 | 90篇 |
2008年 | 54篇 |
2007年 | 93篇 |
2006年 | 57篇 |
2005年 | 55篇 |
2004年 | 27篇 |
2003年 | 23篇 |
2002年 | 29篇 |
2001年 | 39篇 |
2000年 | 33篇 |
1999年 | 28篇 |
1998年 | 128篇 |
1997年 | 155篇 |
1996年 | 134篇 |
1995年 | 110篇 |
1994年 | 114篇 |
1993年 | 97篇 |
1992年 | 28篇 |
1991年 | 35篇 |
1990年 | 37篇 |
1989年 | 54篇 |
1988年 | 50篇 |
1987年 | 42篇 |
1986年 | 50篇 |
1985年 | 45篇 |
1984年 | 26篇 |
1983年 | 17篇 |
1982年 | 26篇 |
1981年 | 30篇 |
1980年 | 26篇 |
1979年 | 4篇 |
1978年 | 9篇 |
1977年 | 18篇 |
1976年 | 25篇 |
1975年 | 14篇 |
1970年 | 2篇 |
排序方式: 共有2284条查询结果,搜索用时 15 毫秒
991.
We aimed to explore the real experience of patients after liver transplantation in the intensive care unit (ICU).Objective sampling method was used to select patients transferred to the ICU in 10 hospitals in Zhuhai from May 2018 to August 2020. Patients need liver transplantation due to advanced liver cancer and decompensated cirrhosis. The eligibility criteria of patients mainly included liver transplant patients who were clear-minded and willing to participate in the study and had stayed in ICU. Phenomenological research methods and in-depth interviews were used in this qualitative study.The results showed that the true experience of patients after liver transplantation during ICU stay was summarized into four themes. The strengths of our qualitative research are that we can find the trend from a phenomenon through interviews and other methods to provide a directional foundation for future quantitative research. Its limitations are that it requires a lot of manpower and time, and its objectivity and universality are limited.Hospitalization experience in the ICU may lead to many negative experiences for liver transplant patients. Nurses should fully understand and pay attention to the psychological changes in patients. Nurses should take effective targeted measures to reduce or eliminate patients’ fear of ICU stay and promote rehabilitation. 相似文献
992.
Evi SA de Cock Wilco HM Emons Giesje Nefs Victor JM Pop François Pouwer 《BMC psychiatry》2011,11(1):1-19
Background
Depression is a common complication in type 2 diabetes (DM2), affecting 10-30% of patients. Since depression is underrecognized and undertreated, it is important that reliable and validated depression screening tools are available for use in patients with DM2. The Edinburgh Depression Scale (EDS) is a widely used method for screening depression. However, there is still debate about the dimensionality of the test. Furthermore, the EDS was originally developed to screen for depression in postpartum women. Empirical evidence that the EDS has comparable measurement properties in both males and females suffering from diabetes is lacking however.Methods
In a large sample (N = 1,656) of diabetes patients, we examined: (1) dimensionality; (2) gender-related item bias; and (3) the screening properties of the EDS using factor analysis and item response theory.Results
We found evidence that the ten EDS items constitute a scale that is essentially one dimensional and has adequate measurement properties. Three items showed differential item functioning (DIF), two of them showed substantial DIF. However, at the scale level, DIF had no practical impact. Anhedonia (the inability to be able to laugh or enjoy) and sleeping problems were the most informative indicators for being able to differentiate between the diagnostic groups of mild and severe depression.Conclusions
The EDS constitutes a sound scale for measuring an attribute of general depression. Persons can be reliably measured using the sum score. Screening rules for mild and severe depression are applicable to both males and females. 相似文献993.
同型半胱氨酸(Hcy)是蛋氨酸代谢中间产物,是一种含硫基的氨基酸。1964年Gibson等首先报道高同型半胱氨酸血症与血管性疾病和血栓形成相关,1969年Mcully提出Hcy可能与动脉粥样硬化有关。随着近30年的深入研究,众多资料表明高Hcy血症(hHcy)是心脑血管病变的一个独立危险因素。 相似文献
994.
995.
996.
997.
Objectives
Efavirenz‐based HIV therapy is associated with breast hypertrophy and gynaecomastia. Here, we tested the hypothesis that efavirenz induces gynaecomastia through direct binding and modulation of the oestrogen receptor (ER).Methods
To determine the effect of efavirenz on growth, the oestrogen‐dependent, ER‐positive breast cancer cell lines MCF‐7, T47D and ZR‐75‐1 were treated with efavirenz under oestrogen‐free conditions in the presence or absence of the anti‐oestrogen ICI 182,780. Cells treated with 17β‐oestradiol in the absence or presence of ICI 182,780 served as positive and negative controls, respectively. Cellular growth was assayed using the crystal violet staining method and an in vitro receptor binding assay was used to measure the ER binding affinity of efavirenz.Results
Efavirenz induced growth in MCF‐7 cells with an estimated effective concentration for half‐maximal growth (EC50) of 15.7 μM. This growth was reversed by ICI 182,780. Further, efavirenz binds directly to the ER [inhibitory concentration for half maximal binding (IC50) of ~52 μM] at a roughly 1000‐fold higher concentration than observed with 17β‐oestradiol.Conclusions
Our data suggest that efavirenz‐induced gynaecomastia may be caused, at least in part, by drug‐induced ER activation in breast tissues. 相似文献998.
999.
van der Krogt Hanneke JM Meskers Carel GM de Groot Jurriaan H Klomp Asbjørn Arendzen J Hans 《Journal of neuroengineering and rehabilitation》2012,9(1):1-7
Background
In rehabilitation, training intensity is usually adapted to optimize the trained system to attain better performance (overload principle). However, in balance rehabilitation, the level of intensity required during training exercises to optimize improvement in balance has rarely been studied, probably due to the difficulty in quantifying the stability level during these exercises. The goal of the present study was to test whether the stabilizing/destabilizing forces model could be used to analyze how stability is challenged during several exergames, that are more and more used in balance rehabilitation, and a dynamic functional task, such as gait.Methods
Seven healthy older adults were evaluated with three-dimensional motion analysis during gait at natural and fast speed, and during three balance exergames (50/50 Challenge, Ski Slalom and Soccer). Mean and extreme values for stabilizing force, destabilizing force and the ratio of the two forces (stability index) were computed from kinematic and kinetic data to determine the mean and least level of dynamic, postural and overall balance stability, respectively.Results
Mean postural stability was lower (lower mean destabilizing force) during the 50/50 Challenge game than during all the other tasks, but peak postural instability moments were less challenging during this game than during any of the other tasks, as shown by the minimum destabilizing force values. Dynamic stability was progressively more challenged (higher mean and maximum stabilizing force) from the 50/50 Challenge to the Soccer and Slalom games, to the natural gait speed task and to the fast gait speed task, increasing the overall stability difficulty (mean and minimum stability index) in the same manner.Conclusions
The stabilizing/destabilizing forces model can be used to rate the level of balance requirements during different tasks such as gait or exergames. The results of our study showed that postural stability did not differ much between the evaluated tasks (except for the 50/50 Challenge), compared to dynamic stability, which was significantly less challenged during the games than during the functional tasks. Games with greater centre of mass displacements and changes in the base of support are likely to stimulate balance control enough to see improvements in balance during dynamic functional tasks, and could be tested in pathological populations with the approach used here. 相似文献1000.
Replacing the tissue lost after a stroke potentially provides a new neural substrate to promote recovery. However, significant neurobiological and biotechnological challenges need to be overcome to make this possibility into a reality. Human neural stem cells (hNSCs) can differentiate into mature brain cells, but require a structural support that retains them within the cavity and affords the formation of a de novo tissue. Nevertheless, in our previous work, even after a week, this primitive tissue is void of a vasculature that could sustain its long-term viability. Therefore, tissue engineering strategies are required to develop a vasculature. Vascular endothelial growth factor (VEGF) is known to promote the proliferation and migration of endothelial cells during angio- and arteriogenesis. VEGF by itself here did not affect viability or differentiation of hNSCs, whereas growing cells on poly(d,l-lactic acid-co-glycolic acid) (PLGA) microparticles, with or without VEGF, doubled astrocytic and neuronal differentiation. Secretion of a burst and a sustained delivery of VEGF from the microparticles in?vivo attracted endothelial cells from the host into this primitive tissue and in parts established a neovasculature, whereas in other parts endothelial cells were merely interspersed with hNSCs. There was also evidence of a hypervascularization indicating that further work will be required to establish an adequate level of vascularization. It is therefore possible to develop a putative neovasculature within de novo tissue that is forming inside a tissue cavity caused by a stroke. 相似文献