全文获取类型
收费全文 | 9104篇 |
免费 | 443篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 191篇 |
儿科学 | 233篇 |
妇产科学 | 290篇 |
基础医学 | 1010篇 |
口腔科学 | 51篇 |
临床医学 | 617篇 |
内科学 | 2468篇 |
皮肤病学 | 140篇 |
神经病学 | 658篇 |
特种医学 | 280篇 |
外科学 | 1553篇 |
综合类 | 85篇 |
一般理论 | 1篇 |
预防医学 | 455篇 |
眼科学 | 148篇 |
药学 | 658篇 |
中国医学 | 16篇 |
肿瘤学 | 744篇 |
出版年
2023年 | 37篇 |
2022年 | 156篇 |
2021年 | 334篇 |
2020年 | 129篇 |
2019年 | 191篇 |
2018年 | 250篇 |
2017年 | 194篇 |
2016年 | 219篇 |
2015年 | 255篇 |
2014年 | 327篇 |
2013年 | 413篇 |
2012年 | 653篇 |
2011年 | 725篇 |
2010年 | 362篇 |
2009年 | 258篇 |
2008年 | 517篇 |
2007年 | 581篇 |
2006年 | 550篇 |
2005年 | 527篇 |
2004年 | 528篇 |
2003年 | 511篇 |
2002年 | 390篇 |
2001年 | 145篇 |
2000年 | 123篇 |
1999年 | 109篇 |
1998年 | 54篇 |
1997年 | 56篇 |
1996年 | 40篇 |
1995年 | 45篇 |
1994年 | 27篇 |
1993年 | 36篇 |
1992年 | 65篇 |
1991年 | 49篇 |
1990年 | 56篇 |
1989年 | 47篇 |
1988年 | 56篇 |
1987年 | 52篇 |
1986年 | 37篇 |
1985年 | 51篇 |
1984年 | 37篇 |
1983年 | 37篇 |
1982年 | 24篇 |
1981年 | 24篇 |
1979年 | 52篇 |
1978年 | 32篇 |
1977年 | 24篇 |
1976年 | 24篇 |
1974年 | 31篇 |
1973年 | 33篇 |
1972年 | 25篇 |
排序方式: 共有9598条查询结果,搜索用时 31 毫秒
1.
2.
A case of gasless laparoscopic esophagogastric myotomy for achalasia is presented. The technical aspects of the technique as well as the benefits of this approach are reviewed. 相似文献
3.
Release of cholecystokinin from rat cerebral cortex in vivo: role of GABA and glutamate receptor systems 总被引:1,自引:0,他引:1
Using cortical cups in chloralose-urethanized rats, the in vivo release of cholecystokinin-like immunoreactivity (CCK-LI) from cerebral cortex was examined. Resting levels of cholecystokinin-like immunoreactivity ranged from 20 to 30 pg/20 min sample. The addition of potassium (40 mM) in excess, resulted in a highly significant elevation in the levels of CCK-LI in the cortical superfusate. Deletion of calcium and the substitution of cobalt (10 mM), resulted in a significant reduction in both resting release and the release otherwise evoked by the addition of potassium. Focal electrical stimulation of the cortex (20 Hz), resulted in a significant (1.9 +/- 0.2-fold, n = 8) increase in the levels of CCK-LI. The addition of glutamate (10(-6)-10(-4) M) of kainic acid (10(-8)-10(-6) M), also resulted in significant elevations in the levels of CCK-LI. The co-administration of a putative glutamate receptor antagonist, kynurenic acid (10(-4) M) resulted in a significant reduction in the levels of release otherwise evoked by the addition of glutamate, but not by electrical stimulation. The addition of GABA (10(-5)-10(-3) M) resulted in a dose-dependent decrease in the resting release of CCK-LI, and the release evoked by glutamate. Picrotoxin (10(-6)-10(-4) M), resulted in a highly significant increase in the levels of CCK-LI in the cortical effluent. These results are consistent with a tonic GABAergic inhibition of CCK-releasing neurons. The treatment of the animal with diazepam (30 mg/kg, i.p.) also resulted in a significant reduction in resting release and the release otherwise evoked by focal cortical stimulation. 相似文献
4.
The relationship between the immunoglobulin kappa light chain allotypes and autoantibodies was studied in a series of seven human monoclonal kappa-bearing IgM antibodies with Rheumatoid Factor (RF) activity, two IgM anti-low density lipoprotein (LDL) antibodies, and one IgM anti-intermediate filament (IF) antibody. Residues at amino acid positions 153 and 191 related to the Km allotypes in human kappa chains were determined by an HPLC tryptic fingerprint and corroborated by amino acid sequence analysis. All the autoantibodies shared similar variable regions derived from the V kappa IIIb gene(s). The seven RF and the anti-IF were associated with the Km(3) constant region allotype whereas the two anti-LDL were associated with the Km(1,2) allotype. Thus, monoclonal autoantibodies showed the same Km allotypic distribution as the normal population. However, although the number of samples is small, it seems likely that a preferential association may exist between particular V kappa genes and Km alleles in the generation of autoantibodies with different specificities. 相似文献
5.
Atrial natriuretic peptide (ANP) is a hormone release into the circulation by atrial cardiocytes (Gutkowska et al. 1984). Extracellular fluid volume expansion acts as a powerful stimulus for ANP secretion and results in the augmentation of its plasma concentration (Lang et al. 1985). Patients with active acromegaly demonstrate the increased extracellular fluid volume (Falkheden et al. 1964), while a successful treatment of the disease results in the disappearance of hypervolemia (Strauch et al. 1977). We have recently demonstrated that in patients with active acromegaly the increased total body plasma volumes are accompanied by the elevated plasma ANP concentrations, whereas, in the successfully treated patients, both: total plasma volumes and plasma ANP levels do not differ significantly from these in healthy subjects (Czekalski et al. 1988b). 相似文献
6.
7.
Proprioception is a term covering together joint position sense, kinesthesia and integration of these stimuli in the central nervous system which is needed to keep homeosthasis of joints during motion. The aim of this study is to present authors originally created measuring device working according to the principles of Barrett, aiming at evaluation of proprioception of the knee. The construction of this device is based on the Summer chair, model UPR-01B, working in connection with Bosh goniometer DWM-40L measuring angles with a precision of 0,1 degree. The device presented in this study fulfills all criteria required for this kind of apparatus and may be an alternative to other constructs produced commercially and available on the market. 相似文献
8.
9.
Antioxidative and anti-inflammatory effects of repaglinide in plasma of diabetic animals. 总被引:5,自引:0,他引:5
Anna Gumieniczek Hanna Hopka?a Jacek Roliński Agnieszka Bojarska-Junak 《Pharmacological research》2005,52(2):162-166
Oxidative stress, defined as an imbalance between the production of reactive oxygen species (ROS) and antioxidant defense, is considered to be an important pathogenic factor in diabetes mellitus and its complications. In diabetic state, ROS might also be implicated in promoting a state of systemic inflammation. Recently, it was demonstrated that antioxidant therapy could be used to stop the initiation and propagation of this inflammatory response. Repaglinide is a new oral antidiabetic agent with a possible antioxidant activity. Therefore, in the present study, a possible therapeutic value of repaglinide in ameliorating the oxidative and inflammatory processes was tested in diabetic animals. In the study, the levels of total antioxidant status (TAS), ascorbic acid (AA), protein carbonyl groups (PCG) and interleukin-6 (IL-6) were determined in plasma of diabetic rabbits after 4 and 8 weeks of repaglinide treatment (1mg daily). Ex vivo analysis revealed that there were significant differences in these markers between hyperglycemic and control animals (P<0.05). Some of these parameters were ameliorated by repaglinide treatment. In diabetic rabbits treated with repaglinide, protein oxidation was diminished by 17.8% after 8 weeks of experiment. The level of AA in plasma of diabetic treated animals was higher than in non-treated diabetic groups (by 9.4 and 22.6% after 4 and 8 weeks, respectively). In diabetic treated animals, the TAS level was also significantly increased (by 23.6 and 16.7%). However, in diabetic rabbits, repaglinide did not affect the concentration of IL-6. 相似文献
10.