全文获取类型
收费全文 | 8336篇 |
免费 | 220篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 198篇 |
儿科学 | 736篇 |
妇产科学 | 370篇 |
基础医学 | 764篇 |
口腔科学 | 223篇 |
临床医学 | 686篇 |
内科学 | 1652篇 |
皮肤病学 | 398篇 |
神经病学 | 322篇 |
特种医学 | 178篇 |
外科学 | 1264篇 |
综合类 | 313篇 |
一般理论 | 3篇 |
预防医学 | 727篇 |
眼科学 | 169篇 |
药学 | 424篇 |
1篇 | |
中国医学 | 13篇 |
肿瘤学 | 155篇 |
出版年
2017年 | 46篇 |
2016年 | 35篇 |
2015年 | 62篇 |
2014年 | 63篇 |
2013年 | 99篇 |
2012年 | 115篇 |
2011年 | 131篇 |
2010年 | 124篇 |
2009年 | 154篇 |
2008年 | 82篇 |
2007年 | 84篇 |
2006年 | 109篇 |
2005年 | 68篇 |
2002年 | 31篇 |
2001年 | 46篇 |
1999年 | 65篇 |
1998年 | 150篇 |
1997年 | 185篇 |
1996年 | 205篇 |
1995年 | 159篇 |
1994年 | 160篇 |
1993年 | 157篇 |
1992年 | 93篇 |
1991年 | 100篇 |
1990年 | 98篇 |
1989年 | 108篇 |
1988年 | 90篇 |
1987年 | 100篇 |
1986年 | 80篇 |
1985年 | 60篇 |
1984年 | 62篇 |
1983年 | 52篇 |
1982年 | 52篇 |
1981年 | 58篇 |
1980年 | 44篇 |
1979年 | 38篇 |
1978年 | 29篇 |
1977年 | 42篇 |
1976年 | 38篇 |
1975年 | 33篇 |
1959年 | 343篇 |
1958年 | 759篇 |
1957年 | 868篇 |
1956年 | 771篇 |
1955年 | 803篇 |
1954年 | 780篇 |
1953年 | 40篇 |
1952年 | 35篇 |
1949年 | 182篇 |
1948年 | 125篇 |
排序方式: 共有8596条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
HEIM DE BALSAC R 《Hospital》1949,35(2):169-182
25.
The efficacy of MC903, a vitamin D3 analogue, in reducing hyperproliferation as determined by levels of ornithine decarboxylase (ODC) was investigated in a double-blind study of 15 patients with chronic plaque psoriasis. The lesions of psoriasis were treated for 8 weeks with MC903 in one of two different cream bases or with a placebo cream. Biopsies were taken before and after treatment. In addition an uninvolved area of skin was treated during the last 3 weeks and this as well as control areas were then sellotape stripped and biopsied after 8 h. Clinical improvement was seen in eight out of 11 patients treated with MC903 but there was no reduction in the level of ODC in psoriatic lesions after 8 weeks of treatment. The levels of ODC in the tape-stripped uninvolved skin after 3 weeks of treatment with MC903 averaged 22.5 +/- 4.2 pmol/min/mg protein as compared to 58.6 +/- 12.6 pmol/min/mg protein (P = 0.004). The trauma-induced induction of ODC activity was markedly inhibited by the application of MC903. 相似文献
26.
27.
Expression of CD35 (CR1) and CD11b (CR3) on circulating neutrophils and eosinophils from allergic asthmatic children 总被引:3,自引:0,他引:3
C. BERENDS M. O. HOEKSTRA B. DIJKHUIZEN J. G. R. DE MONCHY J. GERRITSEN H. F. KAUFFMAN 《Clinical and experimental allergy》1993,23(11):926-933
Complement receptors on neutrophils and eosinophils play a role in activation and adhesion. During asthmatic reactions these receptors have been found elevated on circulating granulocytes. In the present study we compared the expression of CD35 (complement receptor type 1) and CD11b (complement receptor type 3) on neutrophils and eosinophils from asthmatic and non-asthmatic children. This was done in whole blood samples using depolarized light scattering for the discrimination of neutrophils and eosinophils. The non-stimulated expression as well as the upregulated expression of receptors by the chemotactic peptide N-formylmethionyl-leucyl-phenyl-alanine (fMLP) were studied. The results showed that without prior stimulation only the expression of CD35 on neutrophils was significantly elevated in children with asthma (P<0.05). After up-regulation with fMLP, the CD11b expression on neutrophils (P<0.005, fMLP: 0.002 microM) and eosinophils (P<0.05, fMLP: 0.02 microM) was significantly higher in asthmatic children than in the controls. These results indicate that the inducible expression of CD11b on neutrophils and eosinophils from allergic asthmatic children is primed in vivo. 相似文献
28.
J. A. HASRAT T. DE BRUYNE J.-P. DE BACKER G. VAUQUELIN A. J. VLIETINCK 《The Journal of pharmacy and pharmacology》1997,49(11):1145-1149
The fruit and the leaves of Annona muricata (Annonaceae) are used in traditional medicine for their tranquillizing and sedative properties. Extracts of the plant have been shown to inhibit binding of [3H]rauwolscine to 5-HTergic 5-HT1A receptors in calf hippocampus, and three alkaloids, annonaine ( 1 ), nornuciferine ( 2 ) and asimilobine ( 3 ), isolated from the fruit have been shown to have IC50 values of 3 μm , 9 μm and 5 μm , respectively, although in ligand-binding studies it was not possible to determine whether interaction of these ligands with the receptor was agonistic or antagonistic. This paper presents the results of functional assays of the alkaloids. The inhibition of cAMP accumulation was tested in NIH-3T3 cells stably transfected with the 5-HT1A receptor from man. None of the alkaloids showed antagonistic properties towards the 5-HT1A receptors because in the antagonistic tests no influence on the forskolin-stimulated increase of cAMP level was detected. Full agonistic properties were measured for all three compounds; the inhibition constants (Ki) for 1, 2 and 3 were < 10 μm . Inhibition of the binding of the radioligand to the 5-HT1A receptor was observed in every ligand-binding assay performed with the alkaloids; the Ki values for 1, 2 and 3 were in the μm range. These results imply that the fruit of Annona muricata possesses anti-depressive effects, possibly induced by compounds 1, 2 and 3 , and that in the past potent leads for the development of anti-depressive therapeutics have not been used. 相似文献
29.
Granular cell tumours rarely involve the lower respiratory tract. We report eight cases surgically resected at our institution. There were four females and four males, aged between 18 to 56 years (mean 40). One tumour associated with a peripheral lung adenocarcinoma was asymptomatic. The other lesions presented with obstructive pneumonitis (3 cases), haemoptysis (2), dyspnea (1) or cough (1). These tumours were tracheal (1) or bronchial (6) and one case was located in the lung parenchyma. Four cases were multicentric with associated lesions located in a bronchus (2), the oesophagus (1) or a mediastinal lymph node (1). All tumours, with the largest diameter ranging from 0.5–4.5 cm, were histologically invasive. The tumours were positive for S-100 protein, neuron specific enolase, KP1 (CD68) and vimentin. No tumour expressed desmin, keratin or p53 oncoprotein. Our study demonstrates that, in spite of marked anatomical and clinical polymorphism, the rare granular cell tumours of the lower respiratory tract have a constant histological appearance. Our observations confirm that large tumours (> 8–10 mm) usually extend beyond the tracheo-bronchial cartilages and, therefore, only surgical treatment may avoid recurrence. 相似文献
30.