全文获取类型
收费全文 | 2211篇 |
免费 | 128篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 99篇 |
妇产科学 | 37篇 |
基础医学 | 244篇 |
口腔科学 | 65篇 |
临床医学 | 252篇 |
内科学 | 444篇 |
皮肤病学 | 37篇 |
神经病学 | 88篇 |
特种医学 | 333篇 |
外科学 | 251篇 |
综合类 | 43篇 |
一般理论 | 1篇 |
预防医学 | 215篇 |
眼科学 | 36篇 |
药学 | 101篇 |
肿瘤学 | 133篇 |
出版年
2021年 | 21篇 |
2019年 | 16篇 |
2018年 | 18篇 |
2016年 | 15篇 |
2015年 | 24篇 |
2014年 | 34篇 |
2013年 | 51篇 |
2012年 | 71篇 |
2011年 | 64篇 |
2010年 | 52篇 |
2009年 | 55篇 |
2008年 | 49篇 |
2007年 | 119篇 |
2006年 | 62篇 |
2005年 | 68篇 |
2004年 | 65篇 |
2003年 | 52篇 |
2002年 | 57篇 |
2001年 | 48篇 |
2000年 | 52篇 |
1999年 | 52篇 |
1998年 | 80篇 |
1997年 | 78篇 |
1996年 | 81篇 |
1995年 | 62篇 |
1994年 | 49篇 |
1993年 | 57篇 |
1992年 | 43篇 |
1991年 | 45篇 |
1990年 | 58篇 |
1989年 | 67篇 |
1988年 | 50篇 |
1987年 | 68篇 |
1986年 | 43篇 |
1985年 | 57篇 |
1984年 | 32篇 |
1983年 | 44篇 |
1982年 | 31篇 |
1981年 | 27篇 |
1980年 | 27篇 |
1979年 | 25篇 |
1978年 | 18篇 |
1977年 | 21篇 |
1975年 | 14篇 |
1972年 | 18篇 |
1971年 | 20篇 |
1970年 | 14篇 |
1969年 | 14篇 |
1968年 | 15篇 |
1947年 | 15篇 |
排序方式: 共有2406条查询结果,搜索用时 15 毫秒
991.
992.
Migraine is known to have a major genetic component and has been associated with a wide variety of comorbid disorders including arthritis and heart disease. Since migraine and some of its comorbid disorders involve inflammation, complement C3, a protein involved in acute inflammation, was selected for analysis as a candidate gene in an ongoing study of the genetic basis of migraine. Polymorphism frequencies for complement C3F (0.19) and C3S (0.81) in a sample of 137 unrelated migraineurs were found to be consistent with a control group as well as previous population studies, indicating that this common polymorphism has no association with migraine susceptibility. However, C3F positive individuals with migraine were found to have an increased incidence of osteoarthritis (Chi square = 10.06; p < 0.0008) and hypertension (Chi square = 5.18; p < 0.01). Therefore, the data in the present study indicate that certain migraine comorbidities that have been reported in the literature may result from Berkson's bias as opposed to a shared pathophysiological variation in the C3 gene. 相似文献
993.
994.
The T-cell subsets of 129 patients with cancer were counted before and after radiation therapy. The cells were labeled with monoclonal antibodies that were specific for each type of T cell. Significant changes after therapy were decreases in the proportion of T-helper/inducer cells, pan-T cells, and in the ratio of T-helper/inducer to T-suppressor/cytotoxic cells. There was an increase in the percentage of T-suppressor/cytotoxic cells. When the site of the primary cancer was considered, genitourinary cancer and cancer of the head and neck both showed a decreased percentage of T-helper/inducer cells and a reduced ratio of T-helper/inducer to T-suppressor/cytotoxic cells. The percentage of pan-T cells in head and neck cancer and the ratio of T-helper/inducer to T-suppressor/cytotoxic cells in breast cancer were decreased. The percentage of T-helper cells was particularly decreased by radiation therapy in advanced stages of cancer, in higher grade tumors, and in larger tumors. The absolute numbers of various T-cell subsets were decreased in all groups. 相似文献
995.
Acute leukemia occurring after radiotherapy and chemotherapy with a nitrosourea,PCNU 总被引:1,自引:0,他引:1
Kirk V. Shepard Richard Larson Michelle M. Le Beau Lawrence Leichman Bernard Levin 《Investigational new drugs》1988,6(2):121-124
Summary Secondary acute leukemias can occur in patients who have been treated with chemotherapy. Several reports have shown that treatment with nitrosoureas can result in secondary leukemia, but this is the first report implicating the investigational drug PCNU as a cause. This case is unique because of the cytogenetic findings, the short latency period between the chemotherapy and the diagnosis of leukemia, and the successful treatment of the leukemia with high-dose cytarabine (ara-C). 相似文献
996.
997.
The presence of a persistent left-sided superior vena cava (LSVC) in the absence of a right-sided superior vena cava (RSVC) may be suspected on a posteroanterior (PA) chest radiograph because of a prominent-appearing ascending aorta, which results from the absence of the RSVC. In the absence of an RSVC, the right upper lobe abuts and outlines the course of the ascending aorta, allowing better demonstration of its profile. This report describes a patient with this finding on a PA chest radiograph. Computed tomographic correlation is presented. 相似文献
998.
Acute diarrhea on an Apache Indian reservation 总被引:1,自引:0,他引:1
999.
1000.
Secondary neoplasms of the small bowel 总被引:1,自引:0,他引:1