全文获取类型
收费全文 | 59677篇 |
免费 | 3591篇 |
国内免费 | 115篇 |
专业分类
耳鼻咽喉 | 799篇 |
儿科学 | 2286篇 |
妇产科学 | 1376篇 |
基础医学 | 7408篇 |
口腔科学 | 2619篇 |
临床医学 | 4969篇 |
内科学 | 13376篇 |
皮肤病学 | 1587篇 |
神经病学 | 4933篇 |
特种医学 | 1757篇 |
外科学 | 9045篇 |
综合类 | 250篇 |
一般理论 | 25篇 |
预防医学 | 3954篇 |
眼科学 | 1748篇 |
药学 | 3558篇 |
中国医学 | 257篇 |
肿瘤学 | 3436篇 |
出版年
2024年 | 42篇 |
2023年 | 483篇 |
2022年 | 576篇 |
2021年 | 1440篇 |
2020年 | 856篇 |
2019年 | 1326篇 |
2018年 | 1976篇 |
2017年 | 1354篇 |
2016年 | 1471篇 |
2015年 | 1536篇 |
2014年 | 1814篇 |
2013年 | 2742篇 |
2012年 | 4396篇 |
2011年 | 4989篇 |
2010年 | 2373篇 |
2009年 | 1746篇 |
2008年 | 4248篇 |
2007年 | 4489篇 |
2006年 | 4350篇 |
2005年 | 4192篇 |
2004年 | 3864篇 |
2003年 | 3651篇 |
2002年 | 3415篇 |
2001年 | 976篇 |
2000年 | 1069篇 |
1999年 | 701篇 |
1998年 | 363篇 |
1997年 | 306篇 |
1996年 | 272篇 |
1995年 | 236篇 |
1994年 | 223篇 |
1993年 | 184篇 |
1992年 | 142篇 |
1991年 | 124篇 |
1990年 | 127篇 |
1989年 | 105篇 |
1988年 | 93篇 |
1987年 | 81篇 |
1986年 | 70篇 |
1985年 | 72篇 |
1984年 | 89篇 |
1983年 | 72篇 |
1982年 | 84篇 |
1981年 | 89篇 |
1980年 | 60篇 |
1979年 | 58篇 |
1978年 | 57篇 |
1977年 | 57篇 |
1976年 | 46篇 |
1973年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Umadevi Sajjan PhD Jorge Moreira MD Mingyao Liu PhD Atul Humar MD Cecilia Chaparro MD Janet Forstner MD PhD Shaf Keshavjee MD 《The Journal of heart and lung transplantation》2004,23(12):235-1391
BACKGROUND: Lung infection with Burkholderia cepacia complex before lung transplantation in patients with cystic fibrosis is a major risk factor for decreased post-operative survival rates compared with those of patients colonized with the more common opportunistic pathogen Pseudomonas aeruginosa. Because adherence to mucosal surfaces is an important initial step in infection, we investigated the use of non-toxic neutral polysaccharides and a sugar alcohol to prevent adherence of B cepacia complex to allograft airway epithelium. METHODS: We used human airway explants prepared from donor tracheobronchial tissue to test the effect of dextrans and xylitol in inhibiting the binding of Burkholderia cepacia complex. We used immunofluorescence and electron microscopy to determine the distribution of bacteria in the explants. RESULTS: Burkholderia cepacia complex bound to the explants and was found only in the surface mucus layer. Dextran 40 kd applied before adding the bacteria decreased the number of bound organisms by 80% to 99%. Smaller molecular mass dextrans (4 and 20 kd) were ineffective. Xylitol inhibited bacterial binding by 67% to 85%. Both agents seemed to decrease the thickness of the surface mucus, suggesting that they may indirectly inhibit bacterial binding by removing adherent surface mucus. CONCLUSIONS: Treating donor lungs with dextran 40 kd or xylitol before (and possibly after) surgery may inhibit the adherence of Burkholderia cepacia complex to airways and may prevent or decrease subsequent infection of the allografts. 相似文献
62.
63.
Introduction Hypothalamic hamartomas are congenital malformations. Clinically, they can be asymptomatic, but they cause seizures, mental
retardation and precocious puberty in many cases.
Case report A 20-day-old boy with hypothalamic hamartoma and bilateral anophthalmia was presented. Except those, no other congenital anomaly
was detected.
Conclusion This is a rare case of hypothalamic hamartoma with bilateral anophthalmia. The mutations at SOX2 has an important role in
the developing brain and eyes. 相似文献
64.
Luiz H Castro Luiz K Ferreira Leandro R Teles Carmen L Jorge Paula R Arantes Carla R Ono Carla C Adda Rosa F Valerio 《Seizure》2007,16(1):50-58
PURPOSE: Hypothalamic hamartoma (HH) related epilepsy presents with gelastic seizures (GS), other seizure types and cognitive deterioration. Although seizure origin in GS has been well established, non-GS are poorly characterized. Their relationship with the HH and cognitive deterioration remains poorly understood. We analyzed seizure type, spread pattern in non-GS and their relationship with the epileptic syndrome in HH. METHODS: We documented all current seizure types in six adult patients with HH-epilepsy with video-EEG monitoring, characterized clinical-electrographic features of gelastic and non-gelastic seizures and correlated these findings with cognitive profile, as well as MRI and ictal SPECT data. RESULTS: Only four seizure types were seen: GS, complex partial (CPS), tonic seizures (TS) and secondarily generalized tonic-clonic seizures (sGTC). An individual patient presented either CPS or TS, but not both. GS progressed to CPS or TS, but not both. Ictal patterns in GS/TS and in GS/CPS overlapped, suggesting ictal spread from the HH to other cortical regions. Ictal SPECT patterns also showed GS/TS overlap. Patients with GS-CPS presented a more benign profile with preserved cognition and clinical-EEG features of temporal lobe epilepsy. Patients with GS-TS had clinical-EEG features of symptomatic generalized epilepsy, including mental deterioration. CONCLUSIONS: Video-EEG and ictal SPECT findings suggest that all seizures in HH-related epilepsy originate in the HH, with two clinical epilepsy syndromes: one resembling temporal lobe epilepsy and a more catastrophic syndrome, with features of a symptomatic generalized epilepsy. The epilepsy syndrome may be determined by HH size or by seizure spread pattern. 相似文献
65.
66.
67.
François Béïque Mohamed Ali Scott MacKenzie Mark Hynes 《Journal canadien d'anesthésie》2007,54(2):158-159
68.
69.
Luís Mariano Isabel Vila?a Jorge Almeida Mota Garcia Maria Júlia Maciel 《Revista portuguesa de cardiologia》2007,26(3):265-270
Apical ballooning is a novel clinical entity reported in different contexts of physical and psychological stress, which is more common in middle-aged women. Of unknown etiology, the syndrome is characterized by a sudden and transient dilatation of the left ventricular apex in the absence of obstructive atherosclerotic coronary disease or evidence of myocardial necrosis, with total late recovery of ventricular function. The authors report the case of a 53-year-old woman who was admitted to the emergency room with left arm ischemia and low cardiac output, requiring ventilatory support. Left catheterization showed typical medial and apical myocardial dysfunction, with normal coronary arteries. Transesophageal echocardiography revealed a thrombus attached to the lower face of the aortic arch, which probably explained the thromboembolism of the arm but was unlikely to be the cause of the left ventricular dysfunction since there were no enzymatic or electrocardiographic signs of myocardial necrosis and normal wall motion was fully recovered. 相似文献
70.
George Lourenço PhD Sabine Meunier MD PhD Marie Vidailhet MD PhD Marion Simonetta‐Moreau MD PhD 《Movement disorders》2007,22(4):523-527
A decrease of heteronymous median nerve-evoked inhibition of corticospinal projections to forearm extensor muscles was reported in a group of 10 dystonic patients by Bertolasi and colleagues in 2003. Here we tested the excitability of corticomotoneuronal connections to both wrist extensor (ECR) and flexor (FCR) muscles after conditioning stimulation of median and also radial nerve at rest in a group of 25 patients with focal hand dystonia compared to 20 healthy subjects. We also investigated the effect of the wrist dystonic posture, either in flexion or in extension, on the afferent modulation of ECR and FCR motor evolved potentials (MEPs). The heteronymous (median-induced) but also homonymous (radial-induced) inhibitions (interstimuli intervals 13-21 ms) of ECR MEP size observed in healthy subjects were decreased in patients. In addition, homonymous (median-induced) facilitation of FCR MEP size was also decreased in patients while heteronymous inhibition (radial-induced) was not. Neither the involvement of the target muscle in the dystonic posture nor the origin of the afferent volley (from a dystonic muscle) influenced the degree of impairment of afferent modulation of the MEP. These findings support the view that a global abnormal somatosensory coupling in focal hand dystonia may contribute to an inadequate motor command to wrist muscles. 相似文献