全文获取类型
收费全文 | 2187篇 |
免费 | 164篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 140篇 |
妇产科学 | 25篇 |
基础医学 | 227篇 |
口腔科学 | 93篇 |
临床医学 | 188篇 |
内科学 | 444篇 |
皮肤病学 | 37篇 |
神经病学 | 104篇 |
特种医学 | 235篇 |
外科学 | 277篇 |
综合类 | 48篇 |
预防医学 | 266篇 |
眼科学 | 41篇 |
药学 | 127篇 |
中国医学 | 2篇 |
肿瘤学 | 92篇 |
出版年
2021年 | 32篇 |
2020年 | 17篇 |
2019年 | 21篇 |
2018年 | 24篇 |
2017年 | 23篇 |
2016年 | 18篇 |
2015年 | 37篇 |
2014年 | 42篇 |
2013年 | 60篇 |
2012年 | 72篇 |
2011年 | 91篇 |
2010年 | 84篇 |
2009年 | 75篇 |
2008年 | 89篇 |
2007年 | 78篇 |
2006年 | 75篇 |
2005年 | 78篇 |
2004年 | 64篇 |
2003年 | 61篇 |
2002年 | 68篇 |
2001年 | 60篇 |
2000年 | 50篇 |
1999年 | 63篇 |
1998年 | 43篇 |
1997年 | 57篇 |
1996年 | 63篇 |
1995年 | 48篇 |
1994年 | 39篇 |
1993年 | 49篇 |
1992年 | 45篇 |
1991年 | 41篇 |
1990年 | 63篇 |
1989年 | 44篇 |
1988年 | 39篇 |
1987年 | 69篇 |
1986年 | 70篇 |
1985年 | 59篇 |
1984年 | 26篇 |
1983年 | 27篇 |
1982年 | 38篇 |
1981年 | 24篇 |
1980年 | 14篇 |
1979年 | 23篇 |
1978年 | 20篇 |
1977年 | 22篇 |
1976年 | 25篇 |
1975年 | 24篇 |
1974年 | 13篇 |
1973年 | 10篇 |
1971年 | 11篇 |
排序方式: 共有2358条查询结果,搜索用时 15 毫秒
11.
12.
J B Croft J L Cresanta L S Webber S R Srinivasan D S Freedman G L Burke G S Berenson 《Southern medical journal》1988,81(3):341-9, 353
Fasting serum lipids, lipoprotein cholesterol, and other cardiovascular disease risk factors were examined in 321 natural parents of children with low and/or high levels of beta- and pre-beta-lipoprotein cholesterol. Parents of children from low pre-beta-lipoprotein groups had elevated alpha- and lower pre-beta-lipoprotein cholesterol levels. Parents whose children had high beta-lipoprotein cholesterol levels also had high serum total and beta-lipoprotein cholesterol levels. Parents of children with high levels of both beta- and pre-beta-lipoprotein cholesterol had a high prevalence of both abnormal risk factor levels, as well as clinical evidence of early coronary artery disease (before age 50 years). These observations show that parents of children with high beta- and/or pre-beta-lipoprotein cholesterol levels have greatly enhanced risk for cardiovascular disease, and children mirror their parents' lipoprotein cholesterol levels. These observations emphasize the need for cardiovascular risk evaluation early in life, especially in high-risk families. 相似文献
13.
J J Malcorra-Azpiazu M I Balda-Aguirre J C Diaz-Chico H Hu J B Wilson B B Webber F Kutlar A Kutlar T H Huisman 《Hemoglobin》1988,12(2):163-170
A new hemoglobin variant with a Ser----Phe substitution at position beta 49(CD8) was discovered in two members of a family living in the Canary Islands, Spain. Detection was by polyacrylamide gel electrophoresis and by reversed phase high performance liquid chromatography. The variant, which constituted 43% and 45%, respectively, in the two heterozygotes, was slightly unstable. Its presence did not affect hematological values though there was a mild reticulocytosis. 相似文献
14.
Background. The Bogalusa Heart Study, a long-term epidemiologic investigation of the early natural history of atherosclerosis, was conducted for the first time in 1973-1974 on children from birth through the age of 14 in a biracial (black-white) population. Methods. The emergence of clinically recognizable abnormalities (obesity, hypertension, and hyperlipidemia) was studied in 1,928 young adults, ages 19-32 years, examined in the 1988-1991 survey. Results. The occurrence of morbid levels of cardiovascular disease risk factors varied by race and gender. The prevalence of severe overweight, body mass index ≥ 31.1 kg/m2 for males and ≥ 32.3 kg/m2 for females, was much higher for black women (20.1%) than for white women (8.7%), black men (14.0%), or white men (11.7%). The frequency of hypertension [systolic blood pressure (BP) ≥ 140 mm Hg, diastolic BP ≥ 90 mm Hg, or treatment for high BP] was greatest for black women (13.9%) versus black men (10.1%), white men (6.2%), or white women (5.0%). Approximately 9.5% of the men and 6% of the women had elevated LDL cholesterol (≥160 mg/dl), while elevated triglycerides (≥250 mg/dl) ranged from 0% in black females to 7.4% in white males. Dyslipoproteinemia related to HDL cholesterol (≤35 mg/dl) was more marked among white men (16%) compared with the other groups (approximately 4%). Correlations for risk factors in a subgroup of 1,587 individuals initially surveyed as children in 1973-1974 were examined as an indication of tracking over a 15-year period. Highly significant correlations were seen for obesity, blood pressure, and LDL cholesterol. Conclusion. Early identification of adverse levels of cardiovascular disease risk factors defined by clinical experience should help to predict and prevent future cardiovascular disease morbidity and mortality. 相似文献
15.
Prophylactic laparoscopic-assisted total gastrectomy for hereditary diffuse gastric cancer. 总被引:2,自引:0,他引:2
Wesley P Francis Daniald M Rodrigues Nolan E Perez Fulvio Lonardo Donald Weaver John D Webber 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(1):142-147
BACKGROUND: Ten percent of gastric cancer (GC) cases are familial, with one third resulting from a mutation in the tumor suppressor gene CDH1. Loss of this important structure can result in hereditary diffuse gastric cancer (HDGC), which carries a high mortality if early diagnosis is not made. Despite its clear genetic origin, optimal management of HDGC family members is controversial, as the utility and efficacy of current cancer screening programs for mutation carriers are unproven. METHODS: A 53-year-old Caucasian woman was initially seen for genetic screening because multiple family members had mutations of the CDH1 gene. Her pedigree analysis demonstrated 4 generations of gastric cancer, and 2 of the generations carried the CDH1 germline mutation, consistent with HDGC. At endoscopy, the patient's gastric mucosa was normal and random biopsies were also normal. The patient underwent a laparoscopic total gastrectomy. RESULTS: The gross examination of her stomach appeared normal. On histologic examination, however, the stomach was found to have diffuse (signet ring cell) adenocarcinoma in-situ with 11 microscopic foci of invasive adenocarcinoma limited to the lamina propria. CONCLUSION: Our case is the first reported prophylactic total gastrectomy utilizing a laparoscopic approach, and it highlights the importance of taking a thorough family history and obtaining a pedigree analysis. Endoscopic screening in HDGC cannot rule out diffuse GC, because the stomach and biopsies can be normal despite the presence of adenocarcinoma. Therefore, our case supports the recommendation for prophylactic gastrectomy in HDGC. 相似文献
16.
17.
Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease. 总被引:1,自引:0,他引:1
Collins CE Benson MJ Burnham WR Rampton DS 《Alimentary pharmacology & therapeutics》1996,10(3):315-320
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease. 相似文献
18.
Contralateral intrastriatal injection of 0.1 pmol or 1 pmol of endothelin-1 produced ipsilateral turning behaviour in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the nigrostriatal pathway. This effect could be abolished by pretreatment with either the endothelinETA/B receptor antagonist bosentan (1 nmol, intrastriatally) or the dopamine D2 receptor antagonist raclopride (0.1 mg/kg, s.c.) suggesting that endothelin is acting at endothelin receptors to evoke ipsilateral turning behaviour and that this response is mediated by dopamine. Similar ipsilateral turning behaviour was observed upon intrastriatal injection of 1 pmol of endothelin-3 or the specific ETB receptor agonist, [Ala1,3,11,15]endothelin-1 when compared to endothelin-1. Pretreatment with the specific ETB receptor antagonist BQ788 blocked the ipsilateral turning response to intrastriatal injection of endothelin-1 while pretreatment with the specific ETA receptor antagonist BQ123 did not significantly change the response to injection of endothelin-1. This indicates that endothelin-1, which has affinity for both ETA and ETB receptors, is most likely acting at the ETB receptor to elicit its effect. These results suggest that low doses of endothelin may act at ETB receptors to evoke the release of dopamine from the striatum in vivo. 相似文献
19.
20.