全文获取类型
收费全文 | 5749篇 |
免费 | 491篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 121篇 |
妇产科学 | 223篇 |
基础医学 | 859篇 |
口腔科学 | 99篇 |
临床医学 | 547篇 |
内科学 | 1281篇 |
皮肤病学 | 160篇 |
神经病学 | 418篇 |
特种医学 | 325篇 |
外国民族医学 | 5篇 |
外科学 | 784篇 |
综合类 | 64篇 |
一般理论 | 5篇 |
预防医学 | 495篇 |
眼科学 | 51篇 |
药学 | 321篇 |
中国医学 | 6篇 |
肿瘤学 | 439篇 |
出版年
2021年 | 73篇 |
2019年 | 72篇 |
2018年 | 79篇 |
2017年 | 66篇 |
2016年 | 71篇 |
2015年 | 72篇 |
2014年 | 116篇 |
2013年 | 168篇 |
2012年 | 250篇 |
2011年 | 271篇 |
2010年 | 152篇 |
2009年 | 147篇 |
2008年 | 259篇 |
2007年 | 262篇 |
2006年 | 229篇 |
2005年 | 241篇 |
2004年 | 243篇 |
2003年 | 241篇 |
2002年 | 208篇 |
2001年 | 212篇 |
2000年 | 221篇 |
1999年 | 165篇 |
1998年 | 117篇 |
1997年 | 96篇 |
1996年 | 78篇 |
1995年 | 61篇 |
1994年 | 69篇 |
1993年 | 56篇 |
1992年 | 142篇 |
1991年 | 110篇 |
1990年 | 123篇 |
1989年 | 118篇 |
1988年 | 121篇 |
1987年 | 125篇 |
1986年 | 91篇 |
1985年 | 102篇 |
1984年 | 79篇 |
1983年 | 66篇 |
1981年 | 44篇 |
1980年 | 37篇 |
1979年 | 59篇 |
1978年 | 47篇 |
1977年 | 40篇 |
1975年 | 37篇 |
1974年 | 50篇 |
1973年 | 50篇 |
1972年 | 42篇 |
1971年 | 47篇 |
1969年 | 38篇 |
1967年 | 45篇 |
排序方式: 共有6249条查询结果,搜索用时 15 毫秒
21.
J D Tempé J J Muller J Schieber M Hasselmann P Lutun P Kieffer F Schneider 《Revue de pneumologie clinique》1987,43(6):300-305
From a series of 50 patients with acute decompensation of chronic obstructive lung disease (38 of whom were treated by mechanical ventilation), the authors demonstrate the prognostic value of an easily obtained parameter of respiratory function: the vital capacity restitution curve (VCRC). From daily measurements of vital capacity, beginning on the day of admission, a graph is constructed which shows an initial period of increase in the degree of restitution, followed by stabilization of the values. An analysis of the various parameters embodied in this graph provides information about the prognosis. Such graphs can be divided into 3 zones of prognostic value: a favourable zone, an intermediate zone (mediocre survival with or without mechanical ventilation) and an unfavourable zone (death during the acute phase). Although a favourable prognosis can be made after 4 days of observation and almost always by the 10th day, an unfavourable prognosis cannot be made before the 21st day. 相似文献
22.
D Campion M Leboyer D Hillaire L Halle P Gorwood B Cavelier M F Soufflet T d'Amato B Muller C Kaplan 《Psychiatry research》1992,41(2):99-105
The role of the human histocompatibility complex (HLA) in the pathogenesis of schizophrenia has been suggested in previous reports. We conducted a genetic study in 33 new families. Our linkage analysis, which used the affected sib-pair method, did not provide evidence for nonrandom assortment. Moreover, the results of an association study using the "haplotype relative risk" method failed to confirm the positive association between HLA A9 and schizophrenia. Taken together, our data did not support any relationship of HLA type to schizophrenia. 相似文献
23.
Taillandier A Zurutuza L Muller F Simon-Bouy B Serre JL Bird L Brenner R Boute O Cousin J Gaillard D Heidemann PH Steinmann B Wallot M Mornet E 《Human mutation》1999,13(2):171-172
Hypophosphatasia is a rare inherited disorder characterized by defective bone mineralization and deficiency of serum and tissue liver/ bone/kidney tissue alkaline phosphatase (L/B/K ALP) activity. We report the characterization of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 9 families affected by severe hypophosphatasia. Fourteen distinct mutations were found, 3 of which were previously reported in the North American or Japanese populations. Seven of the 11 new mutations were missense mutations (M45L, R119H, G145V, C184Y and H154Y, D289V, E459K), the four others were 2 single nucleotide deletions (544delG and 1172delC), a mutation affecting donor splice site (862 + 5A) and a nonsense mutation (R411X). 相似文献
24.
25.
26.
Leukotriene B4 omega-oxidation by human polymorphonuclear leukocytes is inhibited by pyocyanin, a phenazine derivative produced by Pseudomonas aeruginosa. 下载免费PDF全文
Human polymorphonuclear leukocytes (PMNL) metabolize the potent chemotaxin leukotriene B4 (LTB4) by omega-oxidation to 20-hydroxyl-LTB4 and 20-carboxy-LTB4. The ability of unstimulated human PMNL to metabolize exogenous LTB4 was found to be inhibited by pyocyanin, a phenazine derivative produced by Pseudomonas aeruginosa, in a dose-dependent manner. 1-Hydroxyphenazine (1-OHP), a metabolite of pyocyanin, was not inhibitory under identical conditions. The initial enzymic step in the conversion of LTB4 is catalyzed by an NADPH-dependent cytochrome, P-450. Reduction of the phenazine derivatives by NADPH was measured spectrophotometrically. Pyocyanin was reduced by NADPH in vitro in a pH-dependent manner, while 1-OHP was poorly or negligibly reduced under similar conditions. Formation of NADP+ was 20.3 +/- 1.8 nmol min-1 for pyocyanin (10 microM) at pH 5.5, compared with 0.6 +/- 0.2 nmol min-1 for 1-OHP (10 microM), while at pH 7.5 a value of 2.2 +/- 1.3 nmol min-1 was obtained for pyocyanin, with no detectable activity for 1-OHP. This indicates that inhibition of LTB4 omega-hydroxylase activity by pyocyanin might be achieved by competition for NADPH. Incorporation of exogenous 5-hydroxyeicosatetraenoic acid by PMNL into lipid pools was not affected by either phenazine derivative. The ability of bacterial pyocyanin to limit the omega-oxidation of LTB4 may have important implications for PMNL LTB4 receptor status and chemotaxis in vivo. 相似文献
27.
The rate at which the acute phase protein response occurred after both major and minor surgery was explored. Increases in the plasma concentration of C-reactive protein (CRP), alpha-1-acid glycoprotein (alpha 1 AG) and fibrinogen were not detected until 6-8 h after the initial incision. The peak concentration of CRP occurred at 48 h and that of fibrinogen at 96 h; alpha 1 AG concentrations rose rapidly until 48 h followed by little change until about 120 h. Although there was widespread variation in the concentrations of individual proteins in patients, severity of injury did not seem to have a significant effect on the time course of the change. Plasma cortisol concentration and the total white blood cell count (WBC) reached their peaks before the acute phase proteins, cortisol at 6 h and WBC at 12 h. 相似文献
28.
A MicroRNA signature associated with prognosis and progression in chronic lymphocytic leukemia 总被引:2,自引:0,他引:2
29.
30.
F. J. van der Woude A. F. Michael E. Muller G. K. van der Hem R. L. Vernier Y. Kim 《International journal of experimental pathology》1989,70(1):73-82
Glomerular visceral epithelial cells (GVEC) from normal human glomeruli were grown in tissue culture. Cell surface markers were studied by immunofluorescence microscopy using antibodies against lymphohaemopoietic differentiation antigens which are known to be present early (BA-1, OKB2, BA-2) and late (J5, anti CR1) in renal ontogenesis. Like foetal human glomerular epithelium, the cultured cells reacted with BA-1 and OKB2 (identifying an antigen expressed on B cells and polymorphonuclear leucocytes), and BA-2 (leukaemia-associated antigen), but were consistently negative for CR1 (C3b receptor); J5 which identifies the common acute lymphoblastic leukaemia antigen (CALLA) stained variably. Reactivity with antimyosin or anti factor VIII were absent. The cells produced an extracellular matrix containing laminin, type IV collagen, and fibronectin. This study supports the notion that GVEC undergo dedifferentiation as shown by the acquisition of lymphohaemopoietic differentiation antigens present early in renal ontogeny. In addition, the production of extracellular matrix constituents in vitro may be useful for the investigation of human glomerular basement membranes. 相似文献