全文获取类型
收费全文 | 6661篇 |
免费 | 474篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 392篇 |
妇产科学 | 170篇 |
基础医学 | 1027篇 |
口腔科学 | 48篇 |
临床医学 | 489篇 |
内科学 | 1453篇 |
皮肤病学 | 195篇 |
神经病学 | 283篇 |
特种医学 | 88篇 |
外科学 | 639篇 |
综合类 | 323篇 |
一般理论 | 1篇 |
预防医学 | 465篇 |
眼科学 | 178篇 |
药学 | 615篇 |
中国医学 | 38篇 |
肿瘤学 | 628篇 |
出版年
2023年 | 50篇 |
2022年 | 99篇 |
2021年 | 180篇 |
2020年 | 103篇 |
2019年 | 118篇 |
2018年 | 139篇 |
2017年 | 116篇 |
2016年 | 157篇 |
2015年 | 183篇 |
2014年 | 237篇 |
2013年 | 287篇 |
2012年 | 435篇 |
2011年 | 425篇 |
2010年 | 261篇 |
2009年 | 233篇 |
2008年 | 349篇 |
2007年 | 313篇 |
2006年 | 279篇 |
2005年 | 266篇 |
2004年 | 237篇 |
2003年 | 227篇 |
2002年 | 198篇 |
2001年 | 193篇 |
2000年 | 177篇 |
1999年 | 130篇 |
1998年 | 58篇 |
1997年 | 49篇 |
1996年 | 48篇 |
1995年 | 48篇 |
1994年 | 50篇 |
1993年 | 47篇 |
1992年 | 103篇 |
1991年 | 93篇 |
1990年 | 91篇 |
1989年 | 70篇 |
1988年 | 78篇 |
1987年 | 75篇 |
1986年 | 65篇 |
1985年 | 68篇 |
1984年 | 40篇 |
1983年 | 43篇 |
1979年 | 54篇 |
1978年 | 42篇 |
1976年 | 40篇 |
1975年 | 38篇 |
1974年 | 45篇 |
1973年 | 37篇 |
1972年 | 52篇 |
1971年 | 37篇 |
1970年 | 37篇 |
排序方式: 共有7153条查询结果,搜索用时 15 毫秒
101.
Although fiberoptic colonoscopy has gained wide popularity
as a diagnostic and therapeutic tool, there remains an
inherent complication rate following colonoscopic evaluation.
Endoscopically induced bowel perforation and uncontrolled
bleeding often necessitate immediate surgical intervention.
Another often-unrecognized complication is the
introduction of air into the vertebral venous system. A case
of vertebral venous air embolism after routine diagnostic
colonoscopy is reported with a review of current literature. 相似文献
102.
103.
104.
Chronic synovitis affects about 10% of patients with severe haemophilia in India. This disease has some features in common with ankylosing spondylitis, which has been linked to HLA B27. We therefore aimed to test whether there is an association between HLA B27 and chronic synovitis. We studied 473 patients with severe haemophilia (33 of whom had chronic synovitis), and 1175 healthy controls using a standard serological technique and the reverse line strip assay. 64% (21 of 33) of patients with haemophilia and chronic synovitis were positive for HLA B27, compared with 5% (23 of 440) of those with severe haemophilia, but not chronic synovitis (odds ratio 31.6 [95% CI 9.28-39.38], p<0.0001), and 9% (100 of 1175) of healthy controls (18.81 [9.6-27.7], p<0.0001). We conclude that there is a strong association between HLA B27 and chronic synovitis in Indian patients with severe haemophilia and screening in this population could allow treatment and prevention of the complication. 相似文献
105.
Over the last 7 years we have seen more than 200 severe aplastic anemia patients at this centre. Three of them developed an unusual complication in the form of thymic hemorrhage. Following this complication, all 3 patients recovered partially from their aplastic anemia, without any need for further immunosuppression. These cases show possible ways to manipulate the thymus gland as a management strategy for this disease. 相似文献
106.
Kedar PS Nadkarni AH Phanasgoankar S Madkaikar M Ghosh K Gorakshakar AC Colah RB Mohanty D 《American journal of hematology》2005,79(2):168-170
Hb-M is a very rare hemoglobinopathy in the Indian subcontinent. We report a family with Hb-M with lifelong cyanosis from the Ratnagiri district in western India. The propositus was a 11-year-old female child with a history of increasing cyanosis exacerbated by fever and weakness. Similar complaints were also noted in her mother and five maternal family members. There was no history of cardiac illness or exposure to drugs and chemicals. The methemoglobin level was 39.3% in the propositus and 21.1% in her mother with normal NADH-methemoglobin reductase activity. Abnormal absorption peaks by spectroscopic analysis, presence of hemoglobin instability, and a slow-moving band on starch gel electrophoresis supported the presence of Hb-M. Automated DNA sequence analysis of the beta globin gene showed a C-->T substitution at codon 63. This leads to a substitution of histidine (CAT) by tyrosine (TAT) at the beta 63 (E7) position, similar to Hb-M Saskatoon. We have named this variant as Hb-M(Ratnagiri). 相似文献
107.
Abnormalities in nitric oxide and its derivatives in lung cancer 总被引:1,自引:0,他引:1
Masri FA Comhair SA Koeck T Xu W Janocha A Ghosh S Dweik RA Golish J Kinter M Stuehr DJ Erzurum SC Aulak KS 《American journal of respiratory and critical care medicine》2005,172(5):597-605
RATIONALE: A cellular prooxidant state promotes cells to neoplastic growth, in part because of modification of proteins and their functions. Reactive nitrogen species formed from nitric oxide (NO) or its metabolites, can lead to protein tyrosine nitration, which is elevated in lung cancer. OBJECTIVE: To determine the alteration in these NO derivatives and the role they may play in contributing to lung carcinogenesis. METHODS: We analyzed levels of NO, nitrite (NO2-), nitrate (NO3-), and the location of the protein nitration and identified the proteins that are modified. MEASUREMENTS AND MAIN RESULTS: Although exhaled NO and NO2- were increased, endothelial NO synthase or inducible NO synthase expression was similar in the tumor and tumor-free regions. However, immunohistochemistry showed that nitrotyrosine was increased in the tumor relative to non-tumor-bearing sections. We used proteomics to identify the modified proteins (two-dimensional polyacrylamide gel electrophoresis; mass spectrometry). Both the degree of nitration and the protein nitration profile were altered. We identified more than 25 nitrated proteins, including metabolic enzymes, structural proteins, and proteins involved in prevention of oxidative damage. Alterations of the biology of NO metabolites and nitration of proteins may contribute to the mutagenic processes and promote carcinogenesis. CONCLUSIONS: This study provides evidence in favor of a role for reactive nitrogen and oxygen species in lung cancer. 相似文献
108.
109.
Amgalan Anar Maher Alexander S. Ghosh Satyaki Chui Helena C. Bogdan Paul Irimia Andrei 《Age (Dordrecht, Netherlands)》2022,44(5):2509-2525
GeroScience - Adults aged 60 and over are most vulnerable to mild traumatic brain injury (mTBI). Nevertheless, the extent to which chronological age (CA) at injury affects TBI-related brain aging... 相似文献
110.
Signal transduction on platelet activation involves phosphoinositide- specific phospholipase C (PLC)-mediated hydrolysis of phosphatidylinositides and formation of inositol-1,4,5-triphosphate [I(1,4,5)P3], which mediates Ca2+ mobilization, and diacylglycerol (DG), which activates protein kinase C (PKC) to phosphorylate a 47-kD protein (Pleckstrin). We studied these events in two related patients previously reported (Blood 74:664, 1989) to have abnormal aggregation and 14C-serotonin secretion, and impaired intracellular Ca2+ mobilization in response to several agonists. Thrombin-induced I(1,4,5)P3 and phosphatidic acid formation were diminished. Pleckstrin phosphorylation was impaired on activation with thrombin, platelet- activating factor, and ionophore A23187, but was normal with PKC activator 1,2-dioctonyl-sn-glycerol (DiC8). Ca2+ mobilization induced by guanosine triphosphate (GTP) analog guanosine 5'-0-(3 thiotriphosphate) (GTP gamma S) was diminished. Pretreatment with either A23187 or DiC8 did not correct the impaired adenine diphosphate- induced secretion; however, upon stimulation with A23187 plus DiC8, pleckstrin phosphorylation and secretion were normal, indicating that both PKC activation and Ca2+ mobilization are essential for normal secretion. We conclude that these patients have a unique inherited platelet defect in formation of two key intracellular mediators [I(1,4,5)P3 and DG] and in the responses mediated by them due to a defect in postreceptor mechanisms of PLC activation. 相似文献