全文获取类型
收费全文 | 658篇 |
免费 | 50篇 |
国内免费 | 4篇 |
专业分类
儿科学 | 8篇 |
妇产科学 | 1篇 |
基础医学 | 71篇 |
口腔科学 | 3篇 |
临床医学 | 75篇 |
内科学 | 213篇 |
皮肤病学 | 5篇 |
神经病学 | 65篇 |
特种医学 | 10篇 |
外科学 | 87篇 |
综合类 | 13篇 |
预防医学 | 90篇 |
眼科学 | 10篇 |
药学 | 42篇 |
肿瘤学 | 19篇 |
出版年
2022年 | 4篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 11篇 |
2014年 | 19篇 |
2013年 | 22篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 23篇 |
2009年 | 21篇 |
2008年 | 36篇 |
2007年 | 30篇 |
2006年 | 35篇 |
2005年 | 35篇 |
2004年 | 39篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 27篇 |
2000年 | 20篇 |
1999年 | 24篇 |
1998年 | 5篇 |
1997年 | 6篇 |
1996年 | 10篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 23篇 |
1991年 | 14篇 |
1990年 | 17篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1979年 | 5篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1970年 | 4篇 |
1966年 | 4篇 |
1965年 | 4篇 |
排序方式: 共有712条查询结果,搜索用时 15 毫秒
41.
L A Mandell L E Nicolle A R Ronald S J Landis R Duperval G K Harding H G Robson R Feld J Vincelette I Fong 《The Journal of antimicrobial chemotherapy》1987,20(1):95-107
Ceftazidime and cefazolin/tobramycin were compared in the treatment of hospitalized patients with pneumonia. Iv doses 8-hourly were: ceftazidime--2 g, cefazolin--1.5 g, tobramycin--1.7 mg/kg. For patients with pseudomonas infection randomized to cefazolin/tobramycin, ticarcillin (3 g iv 4-hourly) was used instead of cefazolin. One hundred and ten of 129 patients were evaluable (ceftazidime = 52, cefazolin/tobramycin = 58). Seventy five cases (68%) had documented pathogens of which 81% were aerobic Gram-negative bacilli. Analysis of clinical response showed no difference in overall results (P = 0.77), or separate outcomes: cured (P = 0.85), improved (P = 0.62), failed (P = 0.53), or relapsed (P = 0.50). No differences in bacteriological response were noted either: eradication (P greater than 0.10), elimination with recurrence (P greater than 0.10), persistence (P greater than 0.10). The incidence of enterococcal and fungal colonization and superinfection was the same for both regimens. There was a greater incidence of Coombs' test positivity with ceftazidime (P less than 0.01) but greater nephrotoxicity with cefazolin/tobramycin (P less than 0.02). Ceftazidime appears to be as efficacious as cefazolin/tobramycin in the treatment of hospitalized patients with pneumonia, and is less nephrotoxic. 相似文献
42.
There is evidence that hyperglycemia results in the generation of reactive oxygen species, leading to oxidative stress in various tissues, including vascular system. An important link between oxidative stress, inflammatory response and insulin activity is now well established. The ability of antioxidants to protect against the deleterious effects of hyperglycemia and also to improve glucose metabolism and intake must be considered as leads of choice in diabetes treatment. In addition to their antioxidative activity, many flavonoids were demonstrated to act on biological targets involved in type 2 diabetes mellitus such as: α-glycosidase, glucose cotransporter or aldose reductase. In this context, flavonoids behaving as antioxidants were studied as potential drugs by acting as biological targets involved in diabetes development. In this review, we propose to shed light on antioxidants flavonoids investigated as antidiabetics. A special focus was made to address the structure-activity relationship related to the effect of these naturally occurring molecules on different targets involved in diabetes development. 相似文献
43.
Cardiovascular atherosclerotic and ischemic diseases constitute the leading cause of morbidity and mortality throughout middle- and high-income countries. More efficient preventive and regenerative therapeutic strategies are therefore urgently needed. The repeated finding that putative "endothelial progenitor cells" (EPCs) can efficiently promote angiogenesis and restore perfusion of ischemic tissues has provoked a wealth of studies evaluating and developing their therapeutic potential. In the present review, we discuss the growing knowledge about various distinct cell populations which have been collectively termed "EPCs", including myeloid cells and progenitor cells of different origin. We also present clinical studies aiming to examine their therapeutic potential for cardiovascular disease. In addition, we will discuss recent insights into mechanisms leading to dysfunction of "EPCs" in cardiovascular disease. Those findings may help to optimize autologous cell-based treatment approaches, as well as to establish cellular dysfunction itself as an interesting novel therapeutic target. 相似文献
44.
The objective of our study was to investigate the cellular communication between the axon and its postsynaptic targets in the synapse. We used the neuromuscular junction (NMJ) model, which is a highly specialized structure between the nerve, the muscle, and the Schwann cell terminal where the motor neuron orders the muscle to contract. We used experimental models of motor nerve reimplantation in a denervated muscle to determine whether 1) the formation of new NMJ could participate in reinnervation of the muscle necessary to contraction or 2) the blockage of neurotransmitter release using botulinum toxin could be compensated by the formation of new NMJ. We also studied human genetic diseases that affect neuromuscular transmission – congenital myasthenic syndromes – to identify the mutations in the genes coding for synaptic molecules and to analyze the compensatory processes involved in NMJ dysfunction so that muscle contraction can occur in these conditions. 相似文献
45.
Nicolle LE 《The Urologic clinics of North America》2008,35(1):1-12, v
Acute uncomplicated urinary tract infection and acute pyelonephritis are very common infections affecting many women throughout their lives. The determinants of infection have been well described and current strategies to prevent recurrent infections are highly effective. While antimicrobial management is straightforward for most episodes, the evolution of antimicrobial susceptibility of E. coli in community-acquired infection requires continuing re-evaluation of appropriate empiric therapy. 相似文献
46.
Title. Determinants of early retirement intentions among Belgian nurses Aim. This paper is a report of a study to gain insight into older nurses’ retirement intentions and to establish factors determining early retirement intention in these individuals. Background. In many developed countries, the working population is ageing. This will lead to a structural labour shortage in the near future. In nursing, this is already taking place. To retain nurses in employment, information on the determinants of their early retirement intentions are imperative. Method. A cross-sectional study was carried out in 2005 in one Belgian hospital. Data were collected by questionnaire with 100 nurses aged 45 or older. The response rate was 69·9%. Findings. No fewer than 77% of the nurses wanted to stop working before the age of 65 years. The following individual, work-related, and organizational factors contributed to older nurses’ intention to retire early: perceived health, marital status, gender, opportunities for change and development, workload, and negative stereotyping of older employees. Conclusion. Our findings offer insight regarding the influencing factors of early retirement intentions in nurses. This information may be useful to human resource managers and may enable them to successfully prevent early retirement in nurses. More research on this topic is needed as this will enable the development, implementation and evaluation of well-founded measures for retaining older nurses in the workplace. 相似文献
47.
Neis Vivian B. Werle Isabel Moretti Morgana Rosa Priscila B. Camargo Anderson de O. Dalsenter Yasmim Platt Nicolle Rosado Axel F. Engel William D. de Almeida Gudrian Ricardo L. Selhorst Ingrid Dafre Alcir Luiz Rodrigues Ana Lúcia S. 《Metabolic brain disease》2022,37(5):1597-1608
Metabolic Brain Disease - Cholecalciferol deficiency has been associated with stress-related psychiatric disorders, particularly depression. Therefore, the present study investigated the... 相似文献
48.
Hippocampal receptor-mediated phosphoinositide (PI) turnover is severely blunted in aged rats that demonstrate cognitive deficits in the Morris water maze. To further examine the anatomical localization of this deficit, we examined the topography of muscarinic receptor-mediated PI turnover in young and aged-learning impaired rats by taking advantage of an autoradiographic method that visualizes PI turnover by measuring the diacylglycerol (DAG) branch of the PI turnover signal transduction system. Using this method, muscarinic cholinergic receptors were stimulated in hippocampal slices with agonist, and the receptor-mediated incorporation of [3H] cytidine into [3H]CDP-DAG was subsequently quantified in subregions of the hippocampus using film autoradiography. Our results show a significant decrease in basal incorporation of [ 3H]CDP-DAG in the subiculum and in the dentate gyrus in the aged rats. The muscarinic receptor-mediated [3H]CDP-DAG response was significantly blunted in the aged rats in subiculum, CA3, and CA1. In contrast, the receptor-mediated response was maintained in the dentate gyrus and hilus. These results indicate that the age-associated impairment in receptor-mediated PI turnover differs regionally, with a reduction in the subiculum and hippocampus proper that is pronounced relative to the hilus and dentate gyrus. 相似文献
49.
Repetitive phrenic nerve stimulation in myasthenia gravis. 总被引:2,自引:0,他引:2
OBJECTIVE: In patients with MG it may be difficult to determine whether respiratory insufficiency is due to a defect in neuromuscular transmission. We therefore studied the clinical value of repetitive electrical stimulation of the phrenic nerve. METHODS: Repetitive phrenic nerve stimulation at 3 Hz was performed in 25 patients with MG. We recorded from the ipsilateral hemidiaphragm with surface electrodes before and after exercising the diaphragm for 10 and 90 seconds. The percent decrement of the negative peak (NP) area between the first and the fifth or sixth diaphragmatic compound muscle action potential (DCMAP) was analyzed and results compared with those from 10 healthy individuals. RESULTS: The mean +/- standard deviation percent change of the NP area in healthy individuals was -2.1 +/- 4.2%, with a normal cutoff of > or = 11%. Twelve patients (48%) had an abnormal decrement of DCMAP--9 had a decrement when the diaphragm was rested, 3 only after fatiguing of the diaphragm. The mean percent change in the 12 patients was 20% at rest, -18% after 10 seconds of exercise, and -23% after 90 seconds of exercise-a pattern consistent with MG. Repetitive stimulation of the accessory nerve with recording of the trapezius CMAP (TCMAP) was abnormal in nine patients (36%). The three patients with abnormal decrement of the DCMAP despite normal TCMAP had symptoms of dyspnea. CONCLUSIONS: Repetitive phrenic nerve stimulation studies are a promising tool in the diagnosis of respiratory muscle weakness in MG and should be part of electrophysiologic studies in patients with undiagnosed respiratory failure. 相似文献
50.