全文获取类型
收费全文 | 14915篇 |
免费 | 815篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 291篇 |
儿科学 | 400篇 |
妇产科学 | 473篇 |
基础医学 | 2069篇 |
口腔科学 | 1110篇 |
临床医学 | 909篇 |
内科学 | 3313篇 |
皮肤病学 | 521篇 |
神经病学 | 1324篇 |
特种医学 | 415篇 |
外科学 | 2283篇 |
综合类 | 55篇 |
一般理论 | 3篇 |
预防医学 | 930篇 |
眼科学 | 202篇 |
药学 | 774篇 |
中国医学 | 76篇 |
肿瘤学 | 646篇 |
出版年
2023年 | 101篇 |
2022年 | 211篇 |
2021年 | 523篇 |
2020年 | 358篇 |
2019年 | 430篇 |
2018年 | 514篇 |
2017年 | 364篇 |
2016年 | 374篇 |
2015年 | 482篇 |
2014年 | 659篇 |
2013年 | 755篇 |
2012年 | 1171篇 |
2011年 | 1250篇 |
2010年 | 760篇 |
2009年 | 634篇 |
2008年 | 1060篇 |
2007年 | 1033篇 |
2006年 | 994篇 |
2005年 | 964篇 |
2004年 | 743篇 |
2003年 | 658篇 |
2002年 | 590篇 |
2001年 | 80篇 |
2000年 | 59篇 |
1999年 | 89篇 |
1998年 | 103篇 |
1997年 | 112篇 |
1996年 | 82篇 |
1995年 | 83篇 |
1994年 | 58篇 |
1993年 | 61篇 |
1992年 | 40篇 |
1991年 | 43篇 |
1990年 | 33篇 |
1989年 | 23篇 |
1988年 | 31篇 |
1987年 | 23篇 |
1986年 | 21篇 |
1985年 | 12篇 |
1984年 | 22篇 |
1983年 | 20篇 |
1982年 | 20篇 |
1981年 | 20篇 |
1980年 | 14篇 |
1979年 | 10篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1975年 | 15篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Neuromuscular transmission as a function of motor unit size in patients with prior poliomyelitis. 总被引:2,自引:0,他引:2
We studied neuromuscular transmission in 16 patients with prior poliomyelitis by measuring single fiber electromyographic (SFEMG) jitter. This was compared with 3 indirect methods of assessing reinnervation: SFEMG fiber density, macro EMG, and the presence of fiber type grouping on muscle biopsy. In patients with acute poliomyelitis before the age of 10, there was a positive correlation between the extent of neuromuscular transmission impairment, demonstrated by increased SFEMG jitter, and the enlargement of the motor unit, as indicated by increased fiber density, increased macro EMG signals, and fiber type grouping on muscle biopsy. However, there was no correlation between any of these parameters and the presence or absence of new symptoms of weakness. These findings suggest that impaired neuromuscular transmission is most common in patients with prior poliomyelitis whose motor units have been maximally enlarged by axonal sprouting, but is independent of the presence or absence of new symptoms of weakness. 相似文献
44.
Ictal chronology and interictal spikes predict perfusion patterns in temporal lobe epilepsy: a multivariate study. 总被引:2,自引:0,他引:2
Lauro Wichert-Ana Tonicarlo Rodrigues Velasco Vera Cristina Terra-Bustamante Veriano Alexandre Ricardo Guarnieri Roger Walz Mery Kato Whemberton Martins Araújo Carlos Gilberto Carlotti David Araújo Antonio Carlos Dos Santos Américo Ceiki Sakamoto 《Seizure》2004,13(5):346-357
Typical (TPP) and atypical (APP) perfusion patterns (PP) may be seen in ictal SPECT of patients with temporal lobe epilepsy (TLE). APP may pose problem in the lateralization of the epileptogenic zone (EZ). We aimed to investigate predictive variables for the occurrence of TPP and APP. Fifty-one TLE patients were submitted to successful anterior-mesial temporal lobectomy. Univariate (UVA) and multivariate (MVA) analysis were performed upon clinical data, distribution of interictal spikes, and ictal chronology of seizures. From MVA, a final predictive model (FPM) was determined to better predict TPP and APP. Forty patients showed TPP (78.5%) and 11 patients APP (21.5%). Accuracy of ictal SPECT was higher in the unilateral (UIS) than in the bilateral (BIS) interictal spikes group (P = 0.05). FPM showed that patients exhibiting BIS, with shorter proportion of the electrographic seizure occurring after completion of tracer injection, and longer clinical than EEG seizure duration had more APP (P = 0.003). Generalized tonic-clonic seizures did not result in more APP. We concluded that analysis of ictal SPECT in TLE requires the knowledge of TPP and APP, the distribution of interictal spikes on temporal lobes and the ictal chronology of seizures. BIS showed that beyond a more complex epileptogenicity and seizure propagation, they may also lead to APP. 相似文献
45.
46.
Sinotubular junction reconstruction in reimplantation type of valve-sparing aortic procedure can present some problem when a Valsalva graft is used. Since in the Valsalva graft the sinotubular junction height is predetermined, correct matching with native commissures height can be difficult. We propose a method by which it is possible to create a new sinotubular junction in Valsalva graft without altering its original configuration. 相似文献
47.
Ricardo GONZALEZ Odelsa ANCHETA Marlien MARQUEZ Sandra RODRIGUEZ 《Acta pharmacologica Sinica》1994,(6)
This research was carried out to determine a potential role of leukotrienes in the acute hepatotoxicity induced by CC14 in rats. An inhibitor of leukotrienes biosynthesis, diethylcarbamazine (DEC, 25 and 50 mg ·kg-1 ip) exerted hepatoprotective effects, decreasing the activity of alanine aminotransfer-ase in serum and the concentration of liver triglycerides. DEC reduced histological damage of liver evidenced by electron microscopy. The hepatoprotective effects of DEC were dose-dependent. The results favor the role of leukotrienes in CC14 hepatotoxicity. 相似文献
48.
49.
Carlos Villas Rodrigo Martinez-Peric Ricardo Preite Raul H. Barrios 《Acta orthopaedica》1994,65(6):620-622
With a mean follow-up of 3 (1-6) years, we report on 21 patients who underwent multiple level cervical fusion, using autologous iliac crest grafts. Dis-cectomies were performed in 14 patients and cor-pectomies in another 7. Instrumentation was used in all patients with colectomies and in 2 patients who underwent 2-level and 3-level discectomies. Non-union occurred in 1 patient at 1 level. Graft displacement requiring reoperation was observed in 2 patients with massive corpectomies, in 1 of them as a consequence of trauma. In both patients complete bony fusion was obtained after reoperation and no other complications were observed. We conclude that the success rate with multiple-level fusion is comparable to that of single-level fusion when adequate fixation is achieved. 相似文献
50.
BACKGROUND/AIMS: Hepatocytes (HEP) have been the major target for structural quantification in the liver, but an estimation of their total number (N), their percentage in relation to the global number of liver cells and the evaluation of the percentage of binucleated hepatocytes (BnHEPs) have never been performed with modern design-based stereological techniques. The establishment of sound technical guidelines and baseline quantitative data in non-pathological conditions are relevant to properly evaluate HEP hyperplasia and BnHEP responses. METHODS: In this study, we combined immunocytochemistry with sound design-based stereology for estimating the N of HEP and the N of non-hepatocytic cells (NHCs). For obtaining systematic uniform random sections (30 microm thick), a smooth fractionator sampling scheme was applied to the liver of five male Wistar rats (3 month old). Those sections were immunostained with polyclonal antibodies against carcinoembryonic antigen. Because biliary canaliculi were then marked, an unequivocal counting of mononucleated hepatocytes (MnHEP) and BnHEP was allowed. RESULTS: The N of HEP was estimated to be 1.93 x 10(9), with a coefficient of error (CE) of 0.02, corresponding to 129 x 10(6) HEP/g of liver. BnHEP represented 26% of total HEP number. The N of NHC was estimated as 1.31 x 10(9) (CE=0.02). CONCLUSION: The strategy here presented provides a reliable method for accessing the N of HEP (distinguishing MnHEP from BnHEP) in situations in which these parameters are relevant, namely for evaluating the magnitude of an hyperplastic liver response from its very early onset. 相似文献