全文获取类型
收费全文 | 56176篇 |
免费 | 4525篇 |
国内免费 | 1710篇 |
专业分类
耳鼻咽喉 | 527篇 |
儿科学 | 1174篇 |
妇产科学 | 1155篇 |
基础医学 | 6148篇 |
口腔科学 | 1140篇 |
临床医学 | 6296篇 |
内科学 | 11132篇 |
皮肤病学 | 1085篇 |
神经病学 | 3330篇 |
特种医学 | 1227篇 |
外国民族医学 | 6篇 |
外科学 | 6259篇 |
综合类 | 6174篇 |
现状与发展 | 2篇 |
一般理论 | 9篇 |
预防医学 | 4872篇 |
眼科学 | 1290篇 |
药学 | 5027篇 |
53篇 | |
中国医学 | 2316篇 |
肿瘤学 | 3189篇 |
出版年
2024年 | 168篇 |
2023年 | 715篇 |
2022年 | 1708篇 |
2021年 | 2706篇 |
2020年 | 1925篇 |
2019年 | 1843篇 |
2018年 | 2003篇 |
2017年 | 1776篇 |
2016年 | 1516篇 |
2015年 | 2214篇 |
2014年 | 2929篇 |
2013年 | 3425篇 |
2012年 | 5067篇 |
2011年 | 5115篇 |
2010年 | 3452篇 |
2009年 | 2985篇 |
2008年 | 3657篇 |
2007年 | 3579篇 |
2006年 | 3136篇 |
2005年 | 2843篇 |
2004年 | 2209篇 |
2003年 | 2089篇 |
2002年 | 1701篇 |
2001年 | 487篇 |
2000年 | 398篇 |
1999年 | 352篇 |
1998年 | 291篇 |
1997年 | 260篇 |
1996年 | 232篇 |
1995年 | 188篇 |
1994年 | 152篇 |
1993年 | 118篇 |
1992年 | 115篇 |
1991年 | 84篇 |
1990年 | 84篇 |
1989年 | 76篇 |
1988年 | 70篇 |
1987年 | 56篇 |
1986年 | 56篇 |
1985年 | 53篇 |
1984年 | 47篇 |
1983年 | 46篇 |
1982年 | 60篇 |
1981年 | 66篇 |
1980年 | 37篇 |
1979年 | 43篇 |
1978年 | 24篇 |
1977年 | 35篇 |
1976年 | 32篇 |
1975年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Hyperoxaluria is frequently seen in patients with inflammatory bowel disease, or after resection of the ileum. It is assumed to be responsible for the development of nephrolithiasis, nephrocalcinosis (oxalate nephrosis) and progressive renal impairment in these patients. Steatorrhea may aggravate the severity of hyperoxaluria. A 60-year-old male underwent massive resection of the jejunum and ileum 10 years prior to admission, due to strangulation of the small bowel, with occlusion of the superior mesenteric artery. He remained well except for steatorrhea which developed two-and-a-half years prior to admission, when microhematuria, proteinuria and oxaluria developed progressively. Since that time, the nephrolithiasis, nephrocalcinosis and renal failure have continued to worsen despite therapy with oxalate restriction and oxalate-binding agents. A renal biopsy, performed late in the clinical course, showed severe changes in the renal parenchyma. The decline in renal function proved irreversible. The unusual metabolic consequences of massive resection of the small intestine and their mechanisms are discussed. 相似文献
22.
Juan A. Rey M. Josefa Bello Ana M. Jimenez-lara Jesus Vaquero M. Elena Kusak Jos M. de Campos Jos L. Sarasa Angel Pestana 《International journal of cancer. Journal international du cancer》1992,51(5):703-706
Loss of constitutional heterozygosity as determined through the analysis of restriction-fragment-length polymorphism (RFLP) on tumoral and constitutional DNA has proven to be helpful to delimit the location of tumor-suppressor genes in the human genome. In malignant gliomas this approach indicates that chromosomes 9p, 10, 17p, and 22 may contain genes of this category involved in its origin and/or progression. Regarding chromosome 22, the data so far provided by molecular studies confirmed those previously reported by cytogenetic studies, suggesting the existence of a sub-group of malignant gliomas characterized by monosomy of this chromosome. However, the precise location of the putative glioma suppressor gene on chromosome 22 remains ambiguous. We have performed a combined cytogenetic and RFLP study on a series of 31 gliomas, looking for structural abnormalities of this chromosome. In 3 instances, terminal deletions of the long arm of chromosome 22 were observed by both methodologies, suggesting that the band q13 region distal to the D22S80 marker might be the critical domain non-randomly involved in tumor suppression of gliomas. 相似文献
23.
大学生生涯规划及其对护理教育的意义 总被引:1,自引:0,他引:1
对大学生生涯规划及国内外研究状况进行综述,指出生涯规划对护理教育的意义,提出在高等护理教育中加强大学生的生涯规划将是我国护理教育的主要发展方向之一。 相似文献
24.
25.
Javier R Caso María A Moro Pedro Lorenzo Ignacio Lizasoain Juan C Leza 《European neuropsychopharmacology》2007,17(9):600-607
Stress is known to be one of the risk factors of stroke. Most of the knowledge on the effects of stress on cerebrovascular disease in humans is restricted to catecholamines and glucocorticoids effects on blood pressure and/or development of atherosclerosis. However, few experimental studies have examined the possible mechanisms by which stress may affect stroke outcome. We have used an acute stress protocol consisting of the exposure of male Fischer rats to an acute, single exposure immobilisation protocol (6 h) prior to permanent middle cerebral artery occlusion (MCAO), and we have found that stress worsens behavioural and neurological outcomes and increased infarct size after MCAO. The possible regulatory role of the TNFalpha and IL-1beta was studied by looking at the release of these cytokines in brain. The results of the present study showed an increase in IL-1beta release in cerebral cortex after exposure to acute stress. Brain levels of IL-1beta are also higher in previously stressed MCAO rats than in MCAO animals without stress. Pharmacological blockade of IL-1beta with an antibody anti-IL-1beta led to a decrease in the infarct size as well as in neurological and behavioural deficits after MCAO. In summary, our results indicate that IL-1beta, but not TNFalpha, accounts at least partly for the worsening of MCAO consequences in brain of rats exposed to acute stress. 相似文献
26.
27.
Juan M. Verdeguer M.D. Dolores Ramon M.D. Manuel Moragon M.D. Isabel Betlloch M.D. Esperanza Jorda M.D. M.D Victoria Planelles M.D. † 《Pediatric dermatology》1988,5(1):56-57
Abstract: Hydantoin is an anticonvulsant drug with several side effects. A teralogenic potential has been suggested. The fetal hydantoin syndrome is an entity that consists of a broad range of morphologic and developmental disorders in children born of epileptic mothers exposed to hydantoin during pregnancy. We treated a girl in whom onychopathy was a monosymptomatic or mild form of this syndrome. 相似文献
28.
自身练习护理操作就是以护生作为练习对象,相互间在各自身上完成注射、输液等操作练习项目,以达到教学要求[1]。在基础护理的教学中,自身练习对于调动护生的参与感,增加真实感,满足成就感方面起着十分重要的作用。但是,也必须看到在积极效果背后的种种矛盾以及由这些矛盾可能导 相似文献
29.
Stephen H Berns Ethan A Halm Hugh A Sampson Scott H Sicherer Paula J Busse Juan P Wisnivesky 《The Journal of asthma》2007,44(5):377-381
BACKGROUND: The objective of this study was to evaluate the relationship between food allergy and asthma morbidity in adults. METHODS: We interviewed a cohort of persistent asthmatics from an inner-city clinic. Allergies to food were assessed by patient report of convincing symptoms of acute allergic reactions. Outcome variables included health resource utilization and medication use. RESULTS: The prevalence of allergy to fish, peanut, tree-nut, shellfish, and seed allergies were 3%, 3%, 3%, 13%, and 1%. Patients with allergies to > 1 food had increased asthma hospitalizations, ED visits, and use of oral steroids (p < 0.05 for all comparisons). Specifically, allergy to fish was associated with a greater risk of health resource utilization and increased frequency of oral steroid use (p < or = 0.03 for all comparisons). CONCLUSIONS: Self-reported allergy to foods was associated with worse outcomes, suggesting that food allergy may be a risk factor for increased asthma morbidity in adults. 相似文献
30.
Familial hypercholesterolaemia is a frequent, inherited, monogenic disorder, associated with accelerated development of atherosclerotic disease leading to coronary artery disease. Life expectancy of patients with familial hypercholesterolaemia is reduced by 15-30 years unless they are adequately treated with lipid-lowering therapy. Given the chronic nature of this disease, the selection of a therapeutic approach should be strongly based on its long-term safety and tolerability. The introduction of HMG-CoA reductase inhibitors has revolutionised the treatment of familial hypercholesterolaemia.Simvastatin 40-80 mg/day effectively reduces serum low density lipoprotein (LDL)-cholesterol levels. Furthermore, simvastatin reduces triglycerides and mildly raises high density lipoprotein-cholesterol levels. In addition to the hypolipidaemic effect, other potentially important effects, such as improvement of endothelial function and reduction of LDL oxidation and vascular inflammation, have been associated with HMG-CoA reductase inhibitor therapy. Simvastatin has also been shown to abolish the progression, and even facilitate the regression, of existing human atherosclerotic lesions.The good safety and tolerability profile of simvastatin is clearly highlighted by the low rate of therapy discontinuation observed in several population-based clinical trials. The most common adverse events leading to the discontinuation of therapy are gastrointestinal upset and headache. Asymptomatic elevations in liver transaminase levels and myopathy are uncommon.The overwhelming clinical evidence regarding the long-term use of HMG-CoA reductase inhibitor therapy in patients with familial hypercholesterolaemia together with the long-term safety data (particularly relating to simvastatin) provide support for the use of this drug as a first-line agent when pharmacological treatment is indicated. Early intervention with simvastatin treatment can be successfully implemented with favourable economic benefits. 相似文献