全文获取类型
收费全文 | 12807篇 |
免费 | 819篇 |
国内免费 | 428篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 227篇 |
妇产科学 | 160篇 |
基础医学 | 2033篇 |
口腔科学 | 202篇 |
临床医学 | 903篇 |
内科学 | 1882篇 |
皮肤病学 | 151篇 |
神经病学 | 1502篇 |
特种医学 | 358篇 |
外国民族医学 | 1篇 |
外科学 | 978篇 |
综合类 | 1079篇 |
一般理论 | 1篇 |
预防医学 | 620篇 |
眼科学 | 196篇 |
药学 | 2368篇 |
5篇 | |
中国医学 | 988篇 |
肿瘤学 | 294篇 |
出版年
2023年 | 156篇 |
2022年 | 184篇 |
2021年 | 428篇 |
2020年 | 324篇 |
2019年 | 354篇 |
2018年 | 324篇 |
2017年 | 315篇 |
2016年 | 352篇 |
2015年 | 417篇 |
2014年 | 572篇 |
2013年 | 878篇 |
2012年 | 649篇 |
2011年 | 672篇 |
2010年 | 505篇 |
2009年 | 571篇 |
2008年 | 559篇 |
2007年 | 489篇 |
2006年 | 522篇 |
2005年 | 452篇 |
2004年 | 348篇 |
2003年 | 348篇 |
2002年 | 283篇 |
2001年 | 252篇 |
2000年 | 193篇 |
1999年 | 220篇 |
1998年 | 213篇 |
1997年 | 186篇 |
1996年 | 172篇 |
1995年 | 247篇 |
1994年 | 195篇 |
1993年 | 180篇 |
1992年 | 161篇 |
1991年 | 170篇 |
1990年 | 161篇 |
1989年 | 152篇 |
1988年 | 137篇 |
1987年 | 169篇 |
1986年 | 170篇 |
1985年 | 204篇 |
1984年 | 190篇 |
1983年 | 133篇 |
1982年 | 164篇 |
1981年 | 151篇 |
1980年 | 152篇 |
1979年 | 92篇 |
1978年 | 82篇 |
1977年 | 67篇 |
1976年 | 53篇 |
1975年 | 18篇 |
1974年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
This commentary focuses on the emerging intersection between BMP/TGF-β signaling roles in nervous system function and the amyotrophic lateral sclerosis (ALS) disease state. Future research is critical to elucidate the molecular underpinnings of this intersection of the cellular processes disrupted in ALS and those influenced by BMP/TGF-β signaling, including synapse structure, neurotransmission, plasticity, and neuroinflammation. Such knowledge promises to inform us of ideal entry points for the targeted modulation of dysfunctional cellular processes in an effort to abrogate ALS pathologies. It is likely that different interventions are required, either at discrete points in disease progression, or across multiple dysfunctional processes which together lead to motor neuron degeneration and death. We discuss the challenging, but intriguing idea that modulation of the pleiotropic nature of BMP/TGF-β signaling could be advantageous, as a way to simultaneously treat defects in more than one cell process across different forms of ALS. 相似文献
5.
《Clinical neurophysiology》2021,132(2):315-322
ObjectivePrevious studies have demonstrated voluntary movement alterations as well as motor cortex excitability and plasticity changes in patients with mild cognitive impairment (MCI). To investigate the pathophysiology of movement abnormalities in MCI, we tested possible relationships between movement abnormalities and primary motor cortex alterations in patients.MethodsFourteen amnestic MCI (aMCI) patients and 16 healthy controls were studied. Cognitive assessment was performed using clinical scales. Finger tapping was recorded by a motion analysis system. Transcranial magnetic stimulation was used to test the input/output curve of motor evoked potentials, intracortical inhibition, and short-latency afferent inhibition. Primary motor cortex plasticity was probed by theta burst stimulation. We investigated correlations between movement abnormalities, clinical scores, and cortical neurophysiological parameters.ResultsMCI patients showed less rhythmic movement but no other movement abnormalities. Cortical excitability measures were normal in patients, whereas plasticity was reduced. Movement rhythm abnormalities correlated with frontal dysfunction scores.ConclusionOur study in MCI patients demonstrated abnormal voluntary movement and plasticity changes, with no correlation between the two. Altered rhythm correlated with frontal dysfunction.SignificanceOur results contribute to the understanding of pathophysiological mechanisms of motor impairment in MCI. 相似文献
6.
7.
Peter H. Egbers Anna-Liisa Sutt Jenny E. Petersson Liza Bergström Eva Sundman 《Acta anaesthesiologica Scandinavica》2023,67(10):1403-1413
Background
Weaning from mechanical ventilation and tracheostomy after prolonged intensive care consume enormous resources with optimal management not currently well described. Restoration of respiratory flow via the upper airway is essential and early cuff-deflation using a one-way valve (OWV) is recommended. However, extended OWV use may cause dry airways and thickened secretions which challenge the weaning process. High-flow therapy via the tracheostomy tube (HFT-T) humidifies inspired air and may be connected via an in-line OWV (HFT-T-OWV) alleviating these problems. We aim to provide clinical and experimental data on the safety of HFT-T-OWV along with a practical guide to facilitate clinical use during weaning from mechanical ventilation and tracheostomy.Methods
Data on adverse events of HFT-T-OWV were retrieved from a quality register for patients treated at an intensive care rehabilitation center between 2019 and 2022. Benchtop experiments were performed to measure maximum pressures and pressure support generated by HFT-T-OWV at 25–60 L/min flow using two different HFT-T adapters (interfaces). In simulated airway obstruction using a standard OWV (not in-line) maximum pressures were measured with oxygen delivered via the side port at 1–3 L/min.Results
Of 128 tracheostomized patients who underwent weaning attempts, 124 were treated with HFT-T-OWV. The therapy was well tolerated, and no adverse events related to the practice were detected. The main reason for not using HFT-T-OWV was partial upper airway obstruction using a OWV. Benchtop experiments demonstrated HFT-T-OWV maximum pressures <4 cmH2O and pressure support 0–0.6 cmH2O. In contrast, 1–3 L/min supplemental oxygen via a standard OWV caused pressures between 84 and 148 cmH2O during simulated airway obstruction.Conclusions
Current study clinical data and benchtop experiments indicate that HFT-T-OWV was well tolerated and appeared safe. Pressure support was low, but humidification may enable extended use of a OWV without dry airway mucosa and thickened secretions. Results suggest the treatment could offer advantages to standard OWV use, with or without supplementary oxygen, as well as to HFT-T without a OWV, for weaning from mechanical ventilation and tracheostomy. However, for definitive treatment recommendations, randomized clinical trials are needed. 相似文献8.
目的对医院制剂通鼻消涕颗粒对慢性鼻窦炎鼻黏膜功能是否有调控作用进行临床研究。方法 收集慢性鼻窦炎不伴鼻息肉患者,采用单盲方法随机将患者分为治疗组(通鼻消涕颗粒组)和对照组(克拉霉素片组)。分别给予口服通鼻消涕颗粒和克拉霉素片治疗4周,并对治疗前、治疗2周后、治疗4周后的患者进行糖精试验、鼻部症状VAS评分与鼻内镜Lund Kennedy评分。并采用t检验统计分析。比较服药前、服药后的评分变化。结果 VAS评分提示:治疗组中,治疗2周后、治疗4周后与治疗前相比差异均有统计学意义(P<0.05),对照组在治疗后的各个阶段与治疗前相比均无明显差异(P>0.05)。Lund Kennedy评分提示:治疗组在治疗2周后与治疗前无明显差异,但在治疗4周后有明显改善(P<0.05),对照组则在治疗后各个阶段无明显变化(P>0.05)。糖精试验提示2组在治疗后2周患者糖精清除时间差异无统计学意义(P>0.05),但治疗组在治疗4周后患者糖精清除时间低于对照组(P<0.05)。结论 通鼻消涕颗粒对慢性鼻窦炎的鼻黏膜形态与传输功能有明显改善作用,可以促进鼻黏膜纤毛功能的恢复,并优于克拉霉素片组,且无毒副作用,值得临床上推广应用。 相似文献
9.
Mayuko Kinoshita Haruka Kaneko Lizu Liu Masashi Nagao Ryo Sadatsuki 《Modern rheumatology / the Japan Rheumatism Association》2019,29(1):157-164
Objectives: To examine the factors associated with increase in lumbar spine bone mineral density (LS-BMD) by bisphosphonates (BPs) with active vitamin D analog (aVD).Methods: Two independent postmenopausal osteoporotic patients treated by BPs with aVD for 24 months (Study 1: n?=?93, Study 2: n?=?99) were retrospectively analyzed.Results: In Study 1, LS-BMD of the patients significantly increased for 24 m (5.4%, p?.001). A multiple regression analysis among baseline characteristics revealed that serum calcium (sCa: 8.5–10.5?mg/dL) was associated with an increased LS-BMD by treatment (r2: 0.088, p?=?.02). While average sCa of the patients was 9.2?mg/dL before treatment, it increased time-dependently to 9.6?mg/dL for 24 m by treatment. As each patient had their LS-BMD five times during the study, there were four instances of %LS-BMD in each patient, resulting in 372 instances of %LS-BMD in Study 1. The smallest Akaike’s information criterion value for the most appropriate cut-off levels of sCa for %LS-BMD by treatment every 6 m was 9.3?mg/dL. The %LS-BMD by treatment for 6 m during 24 m period in patients with sCa ≥9.3?mg/dL (1.5%) was significantly higher than that in patients with sCa <9.3?mg/dL (0.8%, p?=?.038). The results of Study 2 were similar to those of Study 1, confirming the phenomena observed.Conclusion: sCa was associated with an increased LS-BMD by BPs with aVD. 相似文献
10.