全文获取类型
收费全文 | 224377篇 |
免费 | 7312篇 |
国内免费 | 2677篇 |
专业分类
耳鼻咽喉 | 2901篇 |
儿科学 | 7830篇 |
妇产科学 | 6134篇 |
基础医学 | 28078篇 |
口腔科学 | 6392篇 |
临床医学 | 19496篇 |
内科学 | 38381篇 |
皮肤病学 | 4817篇 |
神经病学 | 12724篇 |
特种医学 | 11571篇 |
外国民族医学 | 109篇 |
外科学 | 31482篇 |
综合类 | 7892篇 |
现状与发展 | 7篇 |
一般理论 | 3篇 |
预防医学 | 19175篇 |
眼科学 | 4856篇 |
药学 | 16933篇 |
39篇 | |
中国医学 | 3103篇 |
肿瘤学 | 12443篇 |
出版年
2022年 | 1579篇 |
2021年 | 1898篇 |
2020年 | 1663篇 |
2019年 | 1130篇 |
2018年 | 4605篇 |
2017年 | 4984篇 |
2016年 | 4089篇 |
2015年 | 6298篇 |
2014年 | 6047篇 |
2013年 | 5008篇 |
2012年 | 12272篇 |
2011年 | 7320篇 |
2010年 | 4100篇 |
2009年 | 5407篇 |
2008年 | 3723篇 |
2007年 | 4412篇 |
2006年 | 4437篇 |
2005年 | 12279篇 |
2004年 | 13533篇 |
2003年 | 9248篇 |
2002年 | 4327篇 |
2001年 | 5132篇 |
2000年 | 2221篇 |
1999年 | 6268篇 |
1992年 | 7020篇 |
1991年 | 7212篇 |
1990年 | 7412篇 |
1989年 | 7010篇 |
1988年 | 6523篇 |
1987年 | 6296篇 |
1986年 | 5991篇 |
1985年 | 5270篇 |
1984年 | 3614篇 |
1983年 | 2922篇 |
1982年 | 1009篇 |
1979年 | 3838篇 |
1978年 | 2361篇 |
1977年 | 1781篇 |
1976年 | 1559篇 |
1975年 | 2473篇 |
1974年 | 3105篇 |
1973年 | 2738篇 |
1972年 | 2756篇 |
1971年 | 2742篇 |
1970年 | 2555篇 |
1969年 | 2464篇 |
1968年 | 2237篇 |
1967年 | 2163篇 |
1966年 | 1898篇 |
1965年 | 1131篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
J?rg Müller Klaus Seppi Nadia Stefanova Werner Poewe Irene Litvan Gregor K Wenning 《Movement disorders》2002,17(5):1041-1045
The frequency and pathophysiology of freezing of gait (FoG) in atypical parkinsonism is unknown. We analysed the frequency of FoG in postmortem-confirmed atypical parkinsonian disorders (APD) comprising corticobasal degeneration (CBD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and progressive supranuclear palsy (PSP). Sixty-six patients with pathologically confirmed APD (CBD, n = 13; DLB, n = 14; MSA, n = 15; PSP, n = 24) formed the basis for a multicenter clinicopathological study. Clinical features at first and last clinical visit were abstracted from patient records on standardized forms following strict instructions. At the first visit (median 36 months after symptom onset), 24% of APD had FoG (CBD, 8%; DLB, 21%; PSP, 25%; MSA, 40%). Logistic regression analysis showed a significant association of FoG and urinary incontinence (P = 0.04) at first visit. At last visit, 47% of APD had FoG (CBD, 25%; PSP, 53%; DLB, 54%; MSA, 54%). Clinicopathological correlation based on routine postmortem examination failed to identify a consistent neuropathological substrate of FoG. This study demonstrates that (1) FoG is common in APD, and (2) urinary incontinence is significantly associated with FoG in these disorders. Whether FoG and urinary incontinence share similar neuropathological substrates remains to be determined by future studies. 相似文献
82.
83.
84.
Adult coeliac disease within a defined geographic area in Sweden. A study of prevalence and associated diseases 总被引:3,自引:0,他引:3
An epidemiologic study of coeliac disease in a geographically defined area of Sweden showed that the prevalence was 95.5/10(5) inhabitants aged 15 years or more. The highest prevalence, 178/10(5) inhabitants, was found in the age group 65-74 years. The lowest prevalence, 39/10(5) inhabitants, was found in patients aged 15-24 years. Among the associated diseases an especially high incidence of associated thyroid disease was observed: thyrotoxicosis occurred in 5.0% and hypothyroidism in 5.8% of the patients. 相似文献
85.
86.
The splenic arteriovenous differences in plasma amino acid concentrations were assessed in situ by peroperative sampling in 11 patients undergoing splenectomy because of benign and malignant hematologic diseases. The total difference was about 250 mumol/l, which suggests that the spleen contributes about 11 mumol/100 g spleen/min of amino acids to the portal vein. This means that the liver extraction of amino acids may be at least 10% greater than previously believed. 相似文献
87.
J R Andersen G Lose M N?rgaard H Stimpel J T Andersen 《British journal of urology》1988,61(4):310-313
In a randomised, double-blind study, 20 women with idiopathic detrusor instability and associated symptoms were treated with terodiline 25 mg bd, placebo, and emepronium bromide 200 mg tds--each drug being given for 3 weeks with placebo as wash-out period before cross-over. The results were evaluated according to drug preference, frequency charts and elimination of detrusor instability on cystometry. Serum levels of both drugs were monitored as control of tablet intake. The preference for terodiline to placebo was statistically significant: 14/3 women (P less than 0.05), and the majority of women (12/4) preferred terodiline to emepronium. Terodiline also gave a small but significant reduction in 24 h micturition frequency and eliminated detrusor instability in almost 50% of the patients (P less than 0.05). Side effects were frequent but mild in all three treatment periods. It was concluded that terodiline offers an alternative in the treatment of female detrusor instability. 相似文献
88.
The influence of the pore size of Nucleopore diffusion-chamber filters on the rate of proliferation and differentiation of periosteal cells in muscle was studied in 44 growing rabbits. Periosteal grafts were placed in chambers (16-19 in each experimental group) sealed with filters with a pore size of 0.4, 0.6, 0.8, 1.0, or 2.0 micron. Each chamber was implanted into the paraspinal muscle of the rabbit, where it remained for 16 weeks. The osteochondrogenic activity of the graft grew linearly when the pore size increased from 0.4 to 1.0 micron. In the chambers with a pore size of 2.0 micron, both bone and cartilage were found in only one chamber. Bone and cartilage were not found outside any of the chambers. The present results showed that the pore size of the filters significantly affected the ability of the periosteal graft to form bone and cartilage. 相似文献
89.
C Schmitt J Brachmann W Saggau T Beyer B Waldecker K Scharowski T Hilbel M Montero B Offner W Sch?ls 《Zeitschrift für Kardiologie》1991,80(11):665-672
In 41 patients with recurrent sustained ventricular tachycardia and/or ventricular fibrillation an integrated pacemaker-defibrillator-system (PCD, Medtronic, model 7216 A or 7217 B) was implanted. In 21 out of 24 (88%) patients a new transvenous implantation technique in combination with a subcutaneous patch electrode was used. The implanted devices comprise antibradycardiac pacemaker functions, two different forms of antitachycardiac pacemaker functions (ramp and burst pacing), and internal cardioversion or defibrillation capabilities. During a mean follow-up of 8 months 147 episodes of ventricular tachycardia were detected, 131 of them were terminated successfully by antitachycardiac pacing; in 13 episodes internal cardioversion was applied to revert ventricular tachycardia. Twenty-seven episodes of ventricular fibrillation or rapid ventricular tachycardia (greater than 200/min) were detected and successfully terminated by internal defibrillation. In six patients with intermittent rapid atrial fibrillation, change of antiarrhythmic therapy was required to avoid activation of the device. The new integrated pacemaker-defibrillator systems improve therapy in patients with life-threatening tachyarrhythmias by reducing the number of internal cardioversions/defibrillations; the non-thoracotomy approach reduces the post operative risk. 相似文献
90.
L Lehtola H Lehv?slaiho P Koskinen K Alitalo 《Acta oncologica (Stockholm, Sweden)》1992,31(2):147-150
As the factor binding to the neu protein has been unknown, it has not been possible to confirm experimentally the proposed growth-factor receptor like functions of the neu protein. To approach this problem we constructed a recombinant receptor which enabled ligand regulation of the neu tyrosine kinase. The hybrid receptor consisted of the extracellular ligand binding, transmembrane and protein kinase C-substrate domains joined to the intracellular tyrosine kinase and carboxyl-terminal domains of the neu protein. Several properties of NIH3T3 cells carrying this construct were tested. We obtained the first experimental evidence that the neu proto-oncogene has mitogenic and transforming activities only in the presence of a ligand stimulating its tyrosine kinase activity. Various cellular and molecular biological parameters indicated that the chimeric receptor behaved very similarly to the EGFR. Also, this chimeric receptor has allowed us to compare the constitutive oncogenic and the ligand-activated non-oncogenic activities of the neu tyrosine kinase. In the future we plan to focus on characterization of possible differences between EGFR and neu signalling in more differentiated cellular backgrounds. 相似文献