全文获取类型
收费全文 | 27294篇 |
免费 | 1621篇 |
国内免费 | 256篇 |
专业分类
耳鼻咽喉 | 235篇 |
儿科学 | 539篇 |
妇产科学 | 578篇 |
基础医学 | 2783篇 |
口腔科学 | 665篇 |
临床医学 | 1933篇 |
内科学 | 7871篇 |
皮肤病学 | 352篇 |
神经病学 | 2382篇 |
特种医学 | 1041篇 |
外科学 | 5144篇 |
综合类 | 54篇 |
一般理论 | 5篇 |
预防医学 | 999篇 |
眼科学 | 518篇 |
药学 | 1626篇 |
中国医学 | 55篇 |
肿瘤学 | 2391篇 |
出版年
2023年 | 271篇 |
2022年 | 233篇 |
2021年 | 908篇 |
2020年 | 585篇 |
2019年 | 838篇 |
2018年 | 1000篇 |
2017年 | 727篇 |
2016年 | 880篇 |
2015年 | 899篇 |
2014年 | 1218篇 |
2013年 | 1497篇 |
2012年 | 2284篇 |
2011年 | 2170篇 |
2010年 | 1250篇 |
2009年 | 1202篇 |
2008年 | 1874篇 |
2007年 | 1816篇 |
2006年 | 1704篇 |
2005年 | 1692篇 |
2004年 | 1591篇 |
2003年 | 1359篇 |
2002年 | 1223篇 |
2001年 | 120篇 |
2000年 | 118篇 |
1999年 | 150篇 |
1998年 | 164篇 |
1997年 | 137篇 |
1996年 | 129篇 |
1995年 | 149篇 |
1994年 | 123篇 |
1993年 | 119篇 |
1992年 | 88篇 |
1991年 | 55篇 |
1990年 | 66篇 |
1989年 | 50篇 |
1988年 | 40篇 |
1987年 | 36篇 |
1986年 | 42篇 |
1985年 | 38篇 |
1984年 | 34篇 |
1983年 | 33篇 |
1982年 | 50篇 |
1981年 | 28篇 |
1980年 | 27篇 |
1979年 | 18篇 |
1978年 | 12篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 12篇 |
1933年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 33 毫秒
51.
Paolo Fontana Francesco Fioravanti Passaretti Marianna Maioli Giuseppina Cantalupo Francesca Scarano Fortunato Lonardo 《World Journal of Medical Genetics》2020,9(1):1-11
Wiedemann-Steiner syndrome (OMIM #605130) is a rare congenital malformation syndrome characterized by hypertrichosis cubiti associated with short stature; consistent facial features, including long eyelashes, thick or arched eyebrows with a lateral flare, wide nasal bridge, and downslanting and vertically narrow palpebral fissures; mild to moderate intellectual disability; behavioral difficulties; and hypertrichosis on the back. It is caused by heterozygous pathogenic variants in KMT2A. This gene has an established role in histone methylation, which explains the overlap of Wiedemann-Steiner syndrome with other chromatinopathies, a heterogeneous group of syndromic conditions that share a common trigger: The disruption of one of the genes involved in chromatin modification, leading to dysfunction of the epigenetic machinery. 相似文献
52.
Javier Jarazo PhD Kyriaki Barmpa MSc Jennifer Modamio PhD Cláudia Saraiva PhD Sònia Sabaté-Soler MSc Isabel Rosety MSc Anne Griesbeck PhD Florian Skwirblies BSc Gaia Zaffaroni PhD Lisa M. Smits PhD Jihui Su BSc Jonathan Arias-Fuenzalida PhD Jonas Walter PhD Gemma Gomez-Giro PhD Anna S. Monzel PhD Xiaobing Qing PhD Armelle Vitali MSc Gerald Cruciani MSc Ibrahim Boussaad PhD Francesco Brunelli PhD Christian Jäger PhD Aleksandar Rakovic PhD Wen Li PhD Lin Yuan PhD Emanuel Berger PhD Giuseppe Arena PhD Silvia Bolognin PhD Ronny Schmidt PhD Christoph Schröder PhD Paul M.A. Antony PhD Christine Klein MD Rejko Krüger MD Philip Seibler PhD Jens C. Schwamborn PhD 《Movement disorders》2022,37(1):80-94
53.
Francois Rheault Alessandro De Benedictis Alessandro Daducci Chiara Maffei Chantal M. W. Tax David Romascano Eduardo Caverzasi Felix C. Morency Francesco Corrivetti Franco Pestilli Gabriel Girard Guillaume Theaud Ilyess Zemmoura Janice Hau Kelly Glavin Kesshi M. Jordan Kristofer Pomiecko Maxime Chamberland Muhamed Barakovic Nil Goyette Philippe Poulin Quentin Chenot Sandip S. Panesar Silvio Sarubbo Laurent Petit Maxime Descoteaux 《Human brain mapping》2020,41(7):1859-1874
Investigative studies of white matter (WM) brain structures using diffusion MRI (dMRI) tractography frequently require manual WM bundle segmentation, often called “virtual dissection.” Human errors and personal decisions make these manual segmentations hard to reproduce, which have not yet been quantified by the dMRI community. It is our opinion that if the field of dMRI tractography wants to be taken seriously as a widespread clinical tool, it is imperative to harmonize WM bundle segmentations and develop protocols aimed to be used in clinical settings. The EADC‐ADNI Harmonized Hippocampal Protocol achieved such standardization through a series of steps that must be reproduced for every WM bundle. This article is an observation of the problematic. A specific bundle segmentation protocol was used in order to provide a real‐life example, but the contribution of this article is to discuss the need for reproducibility and standardized protocol, as for any measurement tool. This study required the participation of 11 experts and 13 nonexperts in neuroanatomy and “virtual dissection” across various laboratories and hospitals. Intra‐rater agreement (Dice score) was approximately 0.77, while inter‐rater was approximately 0.65. The protocol provided to participants was not necessarily optimal, but its design mimics, in essence, what will be required in future protocols. Reporting tractometry results such as average fractional anisotropy, volume or streamline count of a particular bundle without a sufficient reproducibility score could make the analysis and interpretations more difficult. Coordinated efforts by the diffusion MRI tractography community are needed to quantify and account for reproducibility of WM bundle extraction protocols in this era of open and collaborative science. 相似文献
54.
55.
Laura Tapella Teresa Soda Lisa Mapelli Valeria Bortolotto Heather Bondi Federico A. Ruffinatti Giulia Dematteis Alessio Stevano Marianna Dionisi Simone Ummarino Annalisa Di Ruscio Carla Distasi Mariagrazia Grilli Armando A. Genazzani Egidio D'Angelo Francesco Moccia Dmitry Lim 《Glia》2020,68(3):543-560
Astrocytes perform important housekeeping functions in the nervous system including maintenance of adequate neuronal excitability, although the regulatory mechanisms are currently poorly understood. The astrocytic Ca2+/calmodulin-activated phosphatase calcineurin (CaN) is implicated in the development of reactive gliosis and neuroinflammation, but its roles, including the control of neuronal excitability, in healthy brain is unknown. We have generated a mouse line with conditional knockout (KO) of CaN B1 (CaNB1) in glial fibrillary acidic protein-expressing astrocytes (a stroglial c alcin eurin KO [ACN-KO]). Here, we report that postnatal and astrocyte-specific ablation of CaNB1 did not alter normal growth and development as well as adult neurogenesis. Yet, we found that specific deletion of astrocytic CaN selectively impairs intrinsic neuronal excitability in hippocampal CA1 pyramidal neurons and cerebellar granule cells (CGCs). This impairment was associated with a decrease in after hyperpolarization in CGC, while passive properties were unchanged, suggesting impairment of K+ homeostasis. Indeed, blockade of Na+/K+-ATPase (NKA) with ouabain phenocopied the electrophysiological alterations observed in ACN-KO CGCs. In addition, NKA activity was significantly lower in cerebellar and hippocampal lysates and in pure astrocytic cultures from ACN-KO mice. While no changes were found in protein levels, NKA activity was inhibited by the specific CaN inhibitor FK506 in both cerebellar lysates and primary astroglia from control mice, suggesting that CaN directly modulates NKA activity and in this manner controls neuronal excitability. In summary, our data provide formal evidence for the notion that astroglia is fundamental for controlling basic neuronal functions and place CaN center-stage as an astrocytic Ca2+-sensitive switch. 相似文献
56.
Mood disorders are often characterised by alterations in circadian rhythms, sleep disturbances and seasonal exacerbation. Conversely, chronobiological treatments utilise zeitgebers for circadian rhythms such as light to improve mood and stabilise sleep, and manipulations of sleep timing and duration as rapid antidepressant modalities. Although sleep deprivation (“wake therapy”) can act within hours, and its mood‐elevating effects be maintained by regular morning light administration/medication/earlier sleep, it has not entered the regular guidelines for treating affective disorders as a first‐line treatment. The hindrances to using chronotherapeutics may lie in their lack of patentability, few sponsors to carry out large multi‐centre trials, non‐reimbursement by medical insurance and their perceived difficulty or exotic “alternative” nature. Future use can be promoted by new technology (single‐sample phase measurements, phone apps, movement and sleep trackers) that provides ambulatory documentation over long periods and feedback to therapist and patient. Light combinations with cognitive behavioural therapy and sleep hygiene practice may speed up and also maintain response. The urgent need for new antidepressants should hopefully lead to reconsideration and implementation of these non‐pharmacological methods, as well as further clinical trials. We review the putative neurochemical mechanisms underlying the antidepressant effect of sleep deprivation and light therapy, and current knowledge linking clocks and sleep with affective disorders: neurotransmitter switching, stress and cortico‐limbic reactivity, clock genes, cortical neuroplasticity, connectomics and neuroinflammation. Despite the complexity of multi‐system mechanisms, more insight will lead to fine tuning and better application of circadian and sleep‐related treatments of depression. 相似文献
57.
Ilaria Franzese MD Alessandra Francica MD Gabriele Pesarini MD Leonardo Gottin MD Flavio L. Ribichini MD Francesco Onorati MD PhD Giuseppe Faggian MD 《Journal of cardiac surgery》2020,35(8):2093-2096
Balloon rupture is an uncommon complication during balloon-expandable transcatheter aortic valve replacement (TAVR). We describe a balloon rupture and tearing with intraventricular entrapment complicating transapical-TAVR, as well as our bailout retrieval of the failed device. 相似文献
58.
59.
Claudia Enrichi Cristiano Zanetti Rosaria Stabile Carla Carollo Luca Ghezzo Francesco Piccione 《The journal of spinal cord medicine》2020,43(5):710-713
Context: Magnetic Resonance Imaging (MRI) is an essential diagnostic tool for neuroimaging tissues such as the spinal cord. Unfortunately, the use of MRI may be limited in ventilated patients, who cannot maintain the supine position in spontaneous breathing for the whole duration of the exam (i.e. neuro-muscular patients with diaphragm involvement). The use of MRI-compatible ventilator during MRI could be a solution but they are not universally available. Furthermore, their performances are not up to those of the conventional ones and they are not always compatible with Non Invasive Ventilation (NIV). Findings: This case report describes an easy and low-cost solution to ventilate a patient non-invasively during the MRI procedure. The patient in this case was a 45-yr-old man, wheelchair-dependent and chronically ventilated in NIV with a forced vital capacity in supine position of 370?ml (10% of predicted normal), affected by Arnold-Chiari Syndrome, and in need of a MRI diagnostic control. Conclusion: The technique proposed, that does not affect the MRI images quality, consists in ventilating the patient using a simple nonmetallic Ventilation Bag, operated by a Respiratory Therapist. This has been proven a useful and economical solution for ventilatory support during MRI for a respiratory-dependent patient with Arnold-Chiari Syndrome. 相似文献
60.