全文获取类型
收费全文 | 1414719篇 |
免费 | 104347篇 |
国内免费 | 2202篇 |
专业分类
耳鼻咽喉 | 18514篇 |
儿科学 | 45113篇 |
妇产科学 | 37854篇 |
基础医学 | 208797篇 |
口腔科学 | 37771篇 |
临床医学 | 132783篇 |
内科学 | 279740篇 |
皮肤病学 | 29790篇 |
神经病学 | 116783篇 |
特种医学 | 52058篇 |
外国民族医学 | 278篇 |
外科学 | 200996篇 |
综合类 | 27753篇 |
现状与发展 | 6篇 |
一般理论 | 762篇 |
预防医学 | 115940篇 |
眼科学 | 32266篇 |
药学 | 102314篇 |
7篇 | |
中国医学 | 2202篇 |
肿瘤学 | 79541篇 |
出版年
2021年 | 11839篇 |
2019年 | 12428篇 |
2018年 | 16342篇 |
2017年 | 12467篇 |
2016年 | 13749篇 |
2015年 | 15973篇 |
2014年 | 22219篇 |
2013年 | 34067篇 |
2012年 | 47038篇 |
2011年 | 50080篇 |
2010年 | 28828篇 |
2009年 | 27602篇 |
2008年 | 47458篇 |
2007年 | 50644篇 |
2006年 | 49828篇 |
2005年 | 49249篇 |
2004年 | 47299篇 |
2003年 | 45236篇 |
2002年 | 43790篇 |
2001年 | 57316篇 |
2000年 | 58051篇 |
1999年 | 49485篇 |
1998年 | 15375篇 |
1997年 | 13943篇 |
1996年 | 14103篇 |
1995年 | 13261篇 |
1994年 | 12333篇 |
1992年 | 39123篇 |
1991年 | 38535篇 |
1990年 | 37211篇 |
1989年 | 35964篇 |
1988年 | 33412篇 |
1987年 | 32668篇 |
1986年 | 31265篇 |
1985年 | 29596篇 |
1984年 | 22995篇 |
1983年 | 20192篇 |
1982年 | 12753篇 |
1981年 | 11583篇 |
1979年 | 21624篇 |
1978年 | 16187篇 |
1977年 | 13456篇 |
1976年 | 12438篇 |
1975年 | 13307篇 |
1974年 | 16107篇 |
1973年 | 15793篇 |
1972年 | 14855篇 |
1971年 | 13796篇 |
1970年 | 12980篇 |
1969年 | 12255篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
G Salviati R Betto D Danieli-Betto E Biasia M Serena M Mini G Scarlato 《Neurology》1986,36(5):693-697
We evaluated the isoform composition of heavy and light chains of myosin in single muscle fibers from patients with Duchenne dystrophy, myotonic dystrophy, or polymyositis. In all myopathic muscles, there was an increase in the proportion of intermediate fibers which, by analysis of myosin isoforms, fell into two subpopulations, one that contained both fast and slow myosin and another that contained myosin molecular hybrids. The increased proportion of intermediate (or transitional) fibers suggests changes in the equilibrium between fast and slow motor units. These changes could result from regeneration and subsequent maturation of fibers or from direct transformation of mature fibers of one type into the opposite. 相似文献
992.
993.
Renal vascular reactivity in jaundice 总被引:1,自引:0,他引:1
Obstructive jaundice is associated with a predisposition to hypotension and acute renal failure that may be related to changes in renovascular responsiveness, particularly to norepinephrine (NE). This study was undertaken to investigate changes in vascular response to NE and to determine how these changes are related to prostaglandins. Kidneys from bile duct-ligated (BDL) rabbits (n = 5) were perfused with Krebs' solution at 7.65 ml/min, and the response to varying boluses of NE (0.78 to 6.24 micrograms) was measured as changes in perfusion pressure. When compared with sham-operated control kidneys (n = 8), a significantly blunted response was seen at all doses tested. The NE response was further assessed by measuring force development in mounted segments of main renal arteries (MRAs) (n = 8) and interlobar arteries (ILAs) (n = 6) from BDL rabbits and sham-operated controls (MRA, n = 8; ILA, n = 6). The dose-response curves were significantly depressed in both MRAs and ILAs from BDL animals. In addition, MRAs from sham-operated control animals exhibited decreased response to NE after incubation for 1 hour in jaundiced serum. This attenuated response of MRAs to NE was prevented when indomethacin (5 mg/kg) was given to BDL rabbits before death (n = 9) or when 10(-6)mol/L of indomethacin was added to jaundiced serum during incubation (n = 6). These results indicate that obstructive jaundice induces a decreased vascular contractile response in rabbits to NE and that this effect is mediated by prostaglandins. 相似文献
994.
995.
996.
Studies of former prisoners of war (POWs) provide valuable insights into posttraumatic adaptation because they gather information from a large population who survived the traumatic experiences of military captivity. Previous studies of POWs have shown elevated rates of psychiatric symptoms and disorders. This report presents evidence from a longitudinal study of three large, representative, national samples of former POWs. The study finds that depressive symptomatology, as measured by the Center for Epidemiologic Studies Depression Scale, is elevated in World War II POWs from the Pacific and European theaters and in Korean conflict POWs. Decades later, depressive symptomatology is found to be strongly associated with prior treatment in captivity. Differences in depressive symptomatology among the three POW groups can be attributed to captivity-related factors and to buffering factors, such as age at capture and education. 相似文献
997.
The study was undertaken to examine the effect of nimodipine, calcium channels blocker, on the morphological alterations induced by quinolinic acid (QUIN). The experiment was performed on 21-day-old organotypic rat hippocampal cultures. Nimodipine was applied to the nutrient medium simultaneously with QUIN (both at 100 microM). Ultrastructural changes were evaluated 24 h, 5 and 7 days after the exposure to tested agent. It was shown that nimodipine induced distinct cytoprotective effect, especially considering the development of late neurotoxic injury produced by QUIN. However, the protection was not complete, indicating the participation of the other factors in the pathomechanism underlying structural damage produced by QUIN. 相似文献
998.
A I Diadyk O V Siniachenko M V Khomenko A E Bagri? E V Shchukina I N Tsyba 《Klinicheskaia meditsina》1991,69(12):21-24
The study of urinary sediment is essential in laboratory diagnosis. Conventional clinical methods are now used in line with computer-aided techniques and additional microscopy of the sediment elements. The paper provides a brief analysis of clinical situations characterized by appearance in the urine of abnormal numbers of leukocytes, erythrocytes, casts; provides clinical assessment of additional microscopic methods able to accentuate qualitative characteristics of the urinary syndrome; considers possibilities of application of the urinary sediment data in follow-up to improve diagnosis and control on-going treatment. 相似文献
999.
1000.
The clinical, biochemical and pathological features of 31 patients with thyroid carcinoma managed at Hospital Universiti Sains Málaysia, Kubang Kerian from 1985 to 1989 were analyzed. There were 25 females and 6 males. The types of carcinoma were: papillary-17 cases; follicular-10 cases; medullary-2 cases and anaplastic-2 cases. For papillary carcinoma the mean age of the patients was 52.9 years. For follicular carcinoma the mean age was 48.3 years, for medullary carcinoma, 48.5 years and for anaplastic, 74.5 years. All patients had pre-existing goitre except for 2 and most presented with advanced disease. The mean duration of symptoms for papillary carcinoma was 3.7 years, follicular carcinoma 1.6 years, medullary carcinoma 13.5 years and anaplastic carcinoma 6 months. 12 patients presented with goitre of increasing size; 9 had compression symptoms; 4 presented with cervical lymph node enlargement and 6 presented with bony pains of whom 2 had paraplegia. None of the patients were ever thyrotoxic or hypothyroid. Treatment in general was unsatisfactory because of patients' non-acceptance of surgery and/or radioactive iodine. 相似文献