全文获取类型
收费全文 | 80798篇 |
免费 | 5760篇 |
国内免费 | 1948篇 |
专业分类
耳鼻咽喉 | 772篇 |
儿科学 | 1111篇 |
妇产科学 | 818篇 |
基础医学 | 8367篇 |
口腔科学 | 1418篇 |
临床医学 | 8954篇 |
内科学 | 7938篇 |
皮肤病学 | 476篇 |
神经病学 | 9175篇 |
特种医学 | 2343篇 |
外国民族医学 | 2篇 |
外科学 | 5405篇 |
综合类 | 12839篇 |
现状与发展 | 7篇 |
一般理论 | 13篇 |
预防医学 | 14773篇 |
眼科学 | 781篇 |
药学 | 8441篇 |
146篇 | |
中国医学 | 2479篇 |
肿瘤学 | 2248篇 |
出版年
2024年 | 205篇 |
2023年 | 1344篇 |
2022年 | 2175篇 |
2021年 | 3353篇 |
2020年 | 3151篇 |
2019年 | 2548篇 |
2018年 | 2449篇 |
2017年 | 2468篇 |
2016年 | 2652篇 |
2015年 | 2580篇 |
2014年 | 5155篇 |
2013年 | 5887篇 |
2012年 | 4974篇 |
2011年 | 5449篇 |
2010年 | 4343篇 |
2009年 | 4165篇 |
2008年 | 4238篇 |
2007年 | 4101篇 |
2006年 | 3634篇 |
2005年 | 3008篇 |
2004年 | 2424篇 |
2003年 | 2139篇 |
2002年 | 1685篇 |
2001年 | 1445篇 |
2000年 | 1245篇 |
1999年 | 1072篇 |
1998年 | 1010篇 |
1997年 | 982篇 |
1996年 | 804篇 |
1995年 | 734篇 |
1994年 | 720篇 |
1993年 | 612篇 |
1992年 | 583篇 |
1991年 | 562篇 |
1990年 | 466篇 |
1989年 | 405篇 |
1988年 | 416篇 |
1987年 | 388篇 |
1986年 | 356篇 |
1985年 | 480篇 |
1984年 | 403篇 |
1983年 | 252篇 |
1982年 | 272篇 |
1981年 | 251篇 |
1980年 | 229篇 |
1979年 | 149篇 |
1978年 | 138篇 |
1977年 | 125篇 |
1976年 | 90篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Background and aimPatient decision aids for oncological treatment options, provide information on the effect on recurrence rates and/or survival benefit, and on side-effects and/or burden of different treatment options. However, often uncertainty exists around the probability estimates for recurrence/survival and side-effects which is too relevant to be ignored. Evidence is lacking on the best way to communicate these uncertainties. The aim of this study is to develop a method to incorporate uncertainties in a patient decision aid for breast cancer patients to support their decision on radiotherapy.MethodsFirstly, qualitative interviews were held with patients and health care professionals. Secondly, in the development phase, thinking aloud sessions were organized with four patients and 12 health care professionals, individual and group-wise.ResultsConsensus was reached on a pictograph illustrating the whole range of uncertainty for local recurrence risks, in combination with textual explanation that a more exact personalized risk would be given by their own physician. The pictograph consisted of 100 female icons in a 10 x 10 array. Icons with a stepwise gradient color indicated the uncertainty margin. The prevalence and severity of possible side-effects were explained using verbal labels.ConclusionsWe developed a novel way of visualizing uncertainties in recurrence rates in a patient decision aid. The effect of this way of communicating risk uncertainty is currently being tested in the BRASA study (NCT03375801). 相似文献
73.
74.
《Collegian (Royal College of Nursing, Australia)》2020,27(4):381-387
BackgroundOur university commenced clinical placements for third-year nursing students in Prison Health Services (PHS) in 2014. Registered nurse preceptors employed in these services facilitated students’ experiential workplace learning, assessed their competence and assisted them to meet course objectives in this challenging environment. To date, no studies have examined preceptors’ experiences of supporting students in the prison health setting.AimThe study aim was to investigate preceptors’ perceptions of supporting nursing students undertaking clinical placements in PHS, in order to inform development of resources and processes.MethodsQualitative data were collected via a focus group and interviews with preceptors (n = 6) working in metropolitan PHS. Data underwent thematic analysis.FindingsParticipants valued the opportunity to support student learning, finding students contributed to the workplace by bringing in new ideas, and conducting beneficial projects. However, preceptors requested better rostering and workload management by their employer. They also wished for more detailed information from the university regarding student orientation and preparation to support student learning. They felt that the employer-provided preceptorship training did not fulfil their needs.DiscussionPreceptors in PHS settings shared many of the support needs of those in other settings, although some challenges were more specific to the setting.ConclusionThis paper makes recommendations on how preceptors in PHS can be better supported to fulfil the role. 相似文献
75.
76.
Shinji Naganawa Rintaro Ito Hisashi Kawai Toshiaki Taoka Tadao Yoshida Michihiko Sone 《Magnetic resonance in medical sciences》2020,19(4):375
Purpose:It has been reported previously that intravenously administered gadolinium-based contrast agent (GBCA) leaks into the subarachnoid space around the cortical veins at 4 h after injection in all old people over 37 years, but not in younger people up to 37 years of age in 3D-real IR images. The purpose of this study was to investigate whether there was a strict threshold of 37 years of age for the leakage of the GBCA into the subarachnoid space.Methods:The subjects included 190 patients, that were scanned for 3D-real IR images at 4 hours after intravenous injection of GBCA as a diagnostic test for endolymphatic hydrops. The patient’s age ranged from 14 to 81 years. Two experienced neuroradiologists evaluated the images to determine whether the GBCA leakage around the cortical veins was positive or negative. Any discrepancies between the two observers were discussed and a consensus was obtained.A Mann–Whitney U test and receiver operating characteristic (ROC) curve analysis were used to compare the positive and the negative group and to set the age cut-off value for the prediction of GBCA leakage.Results:The GBCA leakage around the cortical veins was negative in 35 patients and positive in 155 patients. The average age was 33 ± 11 years in the negative group, and 55 ± 12 years in the positive group (P < 0.01). In the ROC analysis for the age and leakage of the GBCA, an area under the curve was 0.905 and the cut-off age was 37.317 years (sensitivity of 0.942 and specificity of 0.771).Conclusion:Intravenously administered GBCA leaks into the subarachnoid space around the cortical veins in most patients over 37 years of age. However, it should be noted that it can be found occasionally in patients under 37 years of age. 相似文献
77.
ABSTRACT Tryptophan (Trp) is not only a nutrient enhancer but also has systemic effects. Trp metabolites signaling through the well-known aryl hydrocarbon receptor (AhR) constitute the interface of microbiome-gut-brain axis. However, the pathway through which Trp metabolites affect central nervous system (CNS) function have not been fully elucidated. AhR participates in a broad variety of physiological and pathological processes that also highly relevant to intestinal homeostasis and CNS diseases. Via the AhR-dependent mechanism, Trp metabolites connect bidirectional signaling between the gut microbiome and the brain, mediated via immune, metabolic, and neural (vagal) signaling mechanisms, with downstream effects on behavior and CNS function. These findings shed light on the complex Trp regulation of microbiome-gut-brain axis and add another facet to our understanding that dietary Trp is expected to be a promising noninvasive approach for alleviating systemic diseases. 相似文献
78.
《Brain stimulation》2020,13(6):1668-1677
BackgroundEndovascular delivery of current using ‘stentrodes’ – electrode bearing stents – constitutes a potential alternative to conventional deep brain stimulation (DBS). The precise neuroanatomical relationships between DBS targets and the vascular system, however, are poorly characterized to date.ObjectiveTo establish the relationships between cerebrovascular system and DBS targets and investigate the feasibility of endovascular stimulation as an alternative to DBS.MethodsNeuroanatomical targets as employed during deep brain stimulation (anterior limb of the internal capsule, dentatorubrothalamic tract, fornix, globus pallidus pars interna, medial forebrain bundle, nucleus accumbens, pedunculopontine nucleus, subcallosal cingulate cortex, subthalamic nucleus, and ventral intermediate nucleus) were superimposed onto probabilistic vascular atlases obtained from 42 healthy individuals. Euclidian distances between targets and associated vessels were measured. To determine the electrical currents necessary to encapsulate the predefined neurosurgical targets and identify potentially side-effect inducing substrates, a preliminary volume of tissue activated (VTA) analysis was performed.ResultsSix out of ten DBS targets were deemed suitable for endovascular stimulation: medial forebrain bundle (vascular site: P1 segment of posterior cerebral artery), nucleus accumbens (vascular site: A1 segment of anterior cerebral artery), dentatorubrothalamic tract (vascular site: s2 segment of superior cerebellar artery), fornix (vascular site: internal cerebral vein), pedunculopontine nucleus (vascular site: lateral mesencephalic vein), and subcallosal cingulate cortex (vascular site: A2 segment of anterior cerebral artery). While VTAs effectively encapsulated mfb and NA at current thresholds of 3.5 V and 4.5 V respectively, incremental amplitude increases were required to effectively cover fornix, PPN and SCC target (mean voltage: 8.2 ± 4.8 V, range: 3.0–17.0 V). The side-effect profile associated with endovascular stimulation seems to be comparable to conventional lead implantation. Tailoring of targets towards vascular sites, however, may allow to reduce adverse effects, while maintaining the efficacy of neural entrainment within the target tissue.ConclusionsWhile several challenges remain at present, endovascular stimulation of select DBS targets seems feasible offering novel and exciting opportunities in the neuromodulation armamentarium. 相似文献
79.
研究生科学道德和学风建设是学位与研究生教育的重要组成部分。针对近年来科学研究和学术活动中各种违背科学道德和学术规范的行为时有发生,国家教育部对研究生科学道德和学风建设日益重视,因此构建研究生的科学道德和学风教育质量管理体系具有十分重要的意义。实现研究生科学道德和学风教育质量体系的方针和目标需具备三个要素,即教育实践的模式(集主题教育、方法学习、学术实践三位一体)、有效性评价机制和绩效考核机制。此外,尚需建立体系优化机制,以适应各种内外部因素的变化,保持体系的更新和优化。 相似文献
80.