全文获取类型
收费全文 | 3300篇 |
免费 | 380篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 86篇 |
妇产科学 | 70篇 |
基础医学 | 482篇 |
口腔科学 | 92篇 |
临床医学 | 417篇 |
内科学 | 824篇 |
皮肤病学 | 30篇 |
神经病学 | 268篇 |
特种医学 | 86篇 |
外科学 | 422篇 |
综合类 | 45篇 |
一般理论 | 8篇 |
预防医学 | 391篇 |
眼科学 | 31篇 |
药学 | 161篇 |
中国医学 | 3篇 |
肿瘤学 | 266篇 |
出版年
2023年 | 45篇 |
2022年 | 50篇 |
2021年 | 127篇 |
2020年 | 78篇 |
2019年 | 122篇 |
2018年 | 98篇 |
2017年 | 69篇 |
2016年 | 85篇 |
2015年 | 98篇 |
2014年 | 136篇 |
2013年 | 163篇 |
2012年 | 240篇 |
2011年 | 207篇 |
2010年 | 108篇 |
2009年 | 114篇 |
2008年 | 167篇 |
2007年 | 165篇 |
2006年 | 161篇 |
2005年 | 158篇 |
2004年 | 121篇 |
2003年 | 107篇 |
2002年 | 110篇 |
2001年 | 58篇 |
2000年 | 63篇 |
1999年 | 66篇 |
1998年 | 47篇 |
1997年 | 29篇 |
1996年 | 34篇 |
1995年 | 22篇 |
1994年 | 17篇 |
1993年 | 18篇 |
1992年 | 49篇 |
1991年 | 28篇 |
1990年 | 28篇 |
1989年 | 32篇 |
1988年 | 21篇 |
1987年 | 28篇 |
1986年 | 24篇 |
1985年 | 24篇 |
1984年 | 37篇 |
1982年 | 19篇 |
1979年 | 19篇 |
1978年 | 16篇 |
1976年 | 16篇 |
1975年 | 18篇 |
1974年 | 18篇 |
1973年 | 19篇 |
1971年 | 16篇 |
1969年 | 15篇 |
1968年 | 19篇 |
排序方式: 共有3688条查询结果,搜索用时 15 毫秒
1.
Sarah Hallas Andrea Nelson Susan O'Meara Una Adderley Pauline Meskell Jane Nixon Aonghus O'Loughlin Sebastian Probst Wael Tawfick Thomas Wild Georgina Gethin 《Journal of tissue viability》2021,30(3):317-323
BackgroundA venous leg ulcer is a chronic leg wound caused by poor venous blood circulation in the lower limbs. It is a recurring condition causing pain, malodour, reduced mobility, and depression. Randomised controlled trials evaluating treatments for venous leg ulcers provide important evidence to inform clinical decision-making. However, for findings to be useful, outcomes need to be clinically meaningful, consistently reported across trials, and fully reported. Research has identified the large number of outcomes reported in venous leg ulcer trials, impacting both synthesis of results, and clinical decision-making. To address this, a core outcome set will be developed. A core outcome set is an agreed standardised set of outcomes which should be, as a minimum, measured and reported in all trials which evaluate treatment effectiveness for a given indication. A core outcome set has the potential to reduce research waste, improve the utility of RCTs, reduce reporting bias, facilitate treatment comparisons across different sources of evidence and expedite the production of systematic reviews, meta-analyses and evidence-based clinical guidelines.AimThe aim of this project is to develop a core outcome set for research evaluating the effectiveness of interventions for treating venous leg ulceration.MethodsThrough a scoping review of the literature on venous leg ulceration, we will firstly identify a list of candidate outcome domains (broad categories in relation to what is being measured) from randomised controlled trials and qualitative research, and outcomes (specific methods in relation to what is being measured). In two further stages, we will use the resulting lists of outcome domains and outcomes to design two online surveys. A range of stakeholders will be invited to participate in the surveys and they will be asked to indicate which outcome domains and outcomes are most important and should be considered as core in future research reports. 相似文献
2.
Vanaporn Wuthiekanun Varunee Desakorn Gumphol Wongsuvan Premjit Amornchai Allen C. Cheng Bina Maharjan Direk Limmathurotsakul Wirongrong Chierakul Nicholas J. White Nicholas P. J. Day Sharon J. Peacock 《Clinical and Vaccine Immunology : CVI》2005,12(4):555-556
An immunofluorescent (IF) method that detects Burkholderia pseudomallei in clinical specimens within 10 min was devised. The results of this rapid method and those of an existing IF method were prospectively compared with the culture results for 776 specimens from patients with suspected melioidosis. The sensitivities of both IF tests were 66%, and the specificities were 99.5 and 99.4%, respectively. 相似文献
3.
The present study was performed to determine if a host nutritional treatment, insulin, in the absence of antitumor treatment could improve survival of cachectic tumor-bearing (TB) rats. Initially food intake and host weight were correlated with survival of untreated rats with similar size sarcomas (45-50 cm3). TB rat food intake (r = 0.69, p less than 0.0001) and host weight (r = 0.47, p less than 0.004) correlated positively with subsequent survival. Once daily neutral protamine hagedorn (NPH) insulin treatment (2 units/100 g) significantly improved food intake (p less than 0.01) and host weight (p less than 0.01) of cachectic TB rats without increasing tumor growth. Twice daily NPH insulin (2 units/100 g) maintained normal food intake of cachectic TB rats and turned a host weight loss into a host weight gain which was significantly greater than untreated controls (p less than 0.001) and all other methods of insulin administration including once daily (p less than 0.001). Twice daily NPH insulin maintained mild hypoglycemia (glucose = 84 +/- 12 mg/dl) compared to once daily NPH insulin which resulted in hyperglycemia (glucose = 140 +/- 8 mg/dl, p less than 0.001) prior to next dose. In addition, twice daily NPH insulin did not increase tumor growth. Once daily NPH insulin for 5 days during cachectic decline was well tolerated (no treatment deaths), and improved median survival of TB rats randomized to insulin (15 days) compared to controls (13 days, p = 0.06). However, twice daily NPH insulin during cachectic decline failed to improve survival because of treatment deaths.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Differential modulation by dopamine of responses evoked by excitatory amino acids in human cortex. 总被引:9,自引:0,他引:9
C Cepeda Z Radisavljevic W Peacock M S Levine N A Buchwald 《Synapse (New York, N.Y.)》1992,11(4):330-341
The responses of human neocortical neurons to iontophoretic application of excitatory amino acids and their modulation by dopamine (DA) were studied in vitro. Brain slices were obtained from children undergoing surgery for intractable epilepsy. Application of N-methyl-D-aspartate (NMDA) to the slices induced slow depolarizations accompanied by decreased input conductances and sustained action potentials in cortical neurons. Glutamate produced rapid depolarizations and firing with few changes in input conductances. Quisqualate also induced depolarization and firing, but input conductances increased during the rising phase of the membrane depolarization. Iontophoretic application of DA alone produced no change in membrane potential or input conductance. However, when DA was applied in conjunction with the excitatory amino acids, it produced contrasting effects. With either bath application of DA or when iontophoresis of DA preceded application of NMDA, the amplitude of the membrane depolarizations and the number of action potentials were increased, whereas the latency of these responses decreased. In contrast, DA decreased the amplitude of the depolarizations and the number of action potentials evoked by glutamate or quisqualate. The fact that DA affects responses to NMDA and glutamate or quisqualate in opposite directions is of considerable importance to the understanding of cellular mechanisms of neuromodulation and the role of DA in cognitive processing and in epilepsy. 相似文献
5.
Several studies have shown that after fibreoptic bronchoscopy there may be a deterioration in lung function but it is not known whether this is due to the premedication, the topical anaesthetic, or the obstruction produced by the bronchoscope. The effects of each part of the procedure on spirometric measurements were studied in patients with lung disease and in normal non-smokers. Measurements were made after premedication (papaveretum and atropine) in seven patients and after topical anaesthesia of the bronchial tree (340 mg lignocaine) with and without the bronchoscope in the trachea in 21 patients and 10 control subjects. Premedication had no effect. In the normal subjects lignocaine produced significant falls in FEV1, forced vital capacity (FVC), peak expiratory flow (PEF), and peak inspiratory flow (PIF), and insertion of the bronchoscope caused further falls that were also significant. In the patients, however, although anaesthesia produced significant falls in FEV1, FVC, PEF, and PIF of similar magnitude to those found in the normal subjects, there was no further important decrease when the bronchoscope was inserted. It is concluded that the major effect of bronchoscopy on lung function is due to topical lignocaine in the airways, and in patients with lung disease (excluding asthma or a central obstructing carcinoma) the insertion of the bronchoscope causes little additional obstruction. 相似文献
6.
N. Crowcroft H. Maguire M. Fleming J. Peacock J. Thomas 《The Journal of hospital infection》1996,34(4):301-309
A retrospective case-control study of 50 MRSA-positive patients was carried out during an outbreak of methicillin-resistant Staphylococcus aureus (MRSA) at an acute general hospital in London. Controls were randomly selected from MRSA-negative patients admitted during the outbreak period. Risk factors investigated included length of admission prior to screening, number of ward changes, main diagnosis, extent of staff contact, pressure sores, surgical and other invasive procedures and antibiotic treatment. Outcome variables examined were rates of infection (versus colonization) with MRSA and mortality. Patients with MRSA were in hospital longer before microbiological specimens were taken and moved wards more often than controls. In a logistic regression analysis, length of stay in hospital, pressure sores, physiotherapy and surgical procedures were associated with a significantly increased risk of acquiring MRSA. Odds ratios (and 95% confidence intervals) for having acquired MRSA were: 8·3 (1·02−71·43) if a patient had pressure sores; 3·7 (1·10−12·5) if they received physiotherapy; and 3·2 (1·82−10·0) if they underwent surgical procedures. The rate of clinical infection amongst patients with this strain of MRSA was 26% and included life-threatening infections such as septicaemia, underlining the potential virulence of MRSA. Surgery and physiotherapy may have been markers of debility. Physiotherapy was probably a marker of increased rates of contact with all hospital staff, and high standards of hand hygiene should be promoted amongst all staff as the most important factor in controlling an outbreak of MRSA. Good bed management is essential for hospital infection control. 相似文献
7.
8.
9.
Effects on birthweight of alcohol and caffeine consumption in smoking women. 总被引:1,自引:1,他引:0 下载免费PDF全文
STUDY OBJECTIVE--Previous work found no effect on birthweight of alcohol and caffeine consumption in non-smokers but such an effect was found in smokers. This report investigates further the effects on birthweight of alcohol and caffeine at three stages of pregnancy in smoking women. DESIGN--This was a prospective population study. SETTING--District general hospital in inner London. PARTICIPANTS--Out of 1309 women who completed all pregnancy interviews, 895 were excluded because they did not smoke, leaving a sample of 414 smokers. MEASUREMENTS AND MAIN RESULTS--Number and brand of cigarettes smoked, and quantity of alcohol and caffeine consumed were obtained by interview at booking, 28, and 36 weeks gestation. Birthweight was corrected for gestation and adjusted for maternal height, sex of infant and parity. The effect on birthweight of alcohol consumption was not explained by the amount smoked in terms of quantity and yield. Similarly the effect of caffeine was independent of smoking. When alcohol, caffeine, and smoking were analysed together, alcohol and caffeine were both associated with reductions in birthweight. Alcohol was associated with a reduction of up to 8% after adjusting for tobacco and caffeine intake, and caffeine was associated with a reduction of up to 6.5% after adjusting for tobacco and alcohol intake. Women who at booking were heavy smokers (greater than or equal to 13 cigarettes/day or greater than or equal to 15 mg carbon monoxide/cigarette), heavy drinkers (greater than or equal to 100 g/week alcohol), and had high caffeine intake (greater than or equal to 2801 mg/week) had a predicted reduction in mean birthweight of 18% (95% CI 11% to 24%). CONCLUSIONS--It is well known that women who smoke in pregnancy have smaller babies than non-smokers. Our study suggests that if these women also drink alcohol and high quantities of caffeine then the risk of poor fetal growth is increased even further. 相似文献