全文获取类型
收费全文 | 1234篇 |
免费 | 109篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 59篇 |
妇产科学 | 17篇 |
基础医学 | 98篇 |
口腔科学 | 44篇 |
临床医学 | 109篇 |
内科学 | 247篇 |
皮肤病学 | 18篇 |
神经病学 | 77篇 |
特种医学 | 244篇 |
外科学 | 150篇 |
综合类 | 46篇 |
预防医学 | 123篇 |
眼科学 | 12篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 4篇 |
2021年 | 23篇 |
2020年 | 11篇 |
2019年 | 12篇 |
2018年 | 14篇 |
2017年 | 12篇 |
2016年 | 16篇 |
2015年 | 21篇 |
2014年 | 19篇 |
2013年 | 32篇 |
2012年 | 30篇 |
2011年 | 30篇 |
2010年 | 33篇 |
2009年 | 40篇 |
2008年 | 51篇 |
2007年 | 44篇 |
2006年 | 33篇 |
2005年 | 30篇 |
2004年 | 30篇 |
2003年 | 38篇 |
2002年 | 28篇 |
2001年 | 22篇 |
2000年 | 23篇 |
1999年 | 27篇 |
1998年 | 59篇 |
1997年 | 54篇 |
1996年 | 43篇 |
1995年 | 28篇 |
1994年 | 43篇 |
1993年 | 44篇 |
1992年 | 20篇 |
1991年 | 23篇 |
1990年 | 24篇 |
1989年 | 34篇 |
1988年 | 37篇 |
1987年 | 32篇 |
1986年 | 43篇 |
1985年 | 28篇 |
1984年 | 30篇 |
1983年 | 30篇 |
1982年 | 21篇 |
1981年 | 28篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 15篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1975年 | 13篇 |
1966年 | 7篇 |
1964年 | 3篇 |
排序方式: 共有1363条查询结果,搜索用时 15 毫秒
1.
M. D. Wiles A. El-Nayal G. Elton M. Malaj J. Winterbottom C. Gillies I. K. Moppett K. Bauchmuller 《Anaesthesia》2022,77(2):143-152
Pulse oximetry is used widely to titrate oxygen therapy and for triage in patients who are critically ill. However, there are concerns regarding the accuracy of pulse oximetry in patients with COVID-19 pneumonitis and in patients who have a greater degree of skin pigmentation. We aimed to determine the impact of patient ethnicity on the accuracy of peripheral pulse oximetry in patients who were critically ill with COVID-19 pneumonitis by conducting a retrospective observational study comparing paired measurements of arterial oxygen saturation measured by co-oximetry on arterial blood gas analysis (SaO2) and the corresponding peripheral oxygenation saturation measured by pulse oximetry (SpO2). Bias was calculated as the mean difference between SaO2 and SpO2 measurements and limits of agreement were calculated as bias ±1.96 SD. Data from 194 patients (135 White ethnic origin, 34 Asian ethnic origin, 19 Black ethnic origin and 6 other ethnic origin) were analysed consisting of 6216 paired SaO2 and SpO2 measurements. Bias (limits of agreement) between SaO2 and SpO2 measurements was 0.05% (−2.21–2.30). Patient ethnicity did not alter this to a clinically significant degree: 0.28% (1.79–2.35), −0.33% (−2.47–2.35) and −0.75% (−3.47–1.97) for patients of White, Asian and Black ethnic origin, respectively. In patients with COVID-19 pneumonitis, SpO2 measurements showed a level of agreement with SaO2 values that was in line with previous work, and this was not affected by patient ethnicity. 相似文献
2.
3.
Relationships of plasma viscosity, coagulation and fibrinolysis to coronary risk factors and angina 总被引:1,自引:0,他引:1
G D Lowe D A Wood J T Douglas R A Riemersma C C Macintyre T Takase E G Tuddenham C D Forbes R A Elton M F Oliver 《Thrombosis and haemostasis》1991,65(4):339-343
Plasma viscosity, molecular markers of activated coagulation and fibrinolysis (fibrinopeptides A and B beta 15-42), coagulation factors (fibrinogen and factor VII) and antiplasmins were measured in 529 men aged 35-54 years and related to new angina pectoris (n = 117) and to coronary risk factors in controls without angina (n = 412). Five major risk factors (cigarette-smoking, blood pressure, cholesterol, triglyceride and body mass index) were each associated with increases in plasma viscosity, coagulation factors, and imbalance of coagulation over fibrinolysis (increased ratio of fibrinopeptide A/fibrinopeptide B beta 15-42). Increased viscosity and fibrinogen in smokers were partly reversed in ex-smokers, but the imbalance of coagulation and fibrinolysis persisted. Cholesterol and triglyceride were also associated with increased antiplasmin activity. In men with angina, only fibrinogen was elevated compared to controls. We suggest that increased plasma viscosity and an imbalance of coagulation over fibrinolysis may be mechanisms by which known risk factors promote arterial thrombosis, but are not present in stable angina. 相似文献
4.
Superficial bladder cancer: intravesical chemotherapy and tumour progression to muscle invasion or metastases 总被引:2,自引:0,他引:2
G Smith R A Elton G D Chisholm J E Newsam T B Hargreave 《British journal of urology》1986,58(6):659-663
Of 299 patients who presented with superficial bladder cancer (Ta, T1), 60 were treated by intravesical chemotherapy (Epodyl, methotrexate or mitomycin C). The rate of tumour progression to muscle invasion or metastases was identical for each intravesical regime. There was no evidence that mitomycin C promoted tumour progression. Carcinoma in situ in non-tumour-bearing urothelium was the most significant predictive factor for progression to muscle invasion or metastases. 相似文献
5.
S Prescott M A Hadi R A Elton A W Ritchie G C Foubister J C Gould T B Hargreave 《British journal of urology》1990,66(5):509-514
Two different regimens of cephalosporin antibiotic prophylaxis were compared with antiseptic lubricating jelly to try to prevent infection and complications in 196 men after prostatic surgery. Pre-operative urine was cultured and prostatic chips (170 cases) were also cultured to define the source of any infection. The use of antibiotics was associated with a reduced risk of postoperative bacteriuria. No serious complications occurred, although 1 patient in the antiseptic treated group developed rigors; 79 of 170 patients (46%) had positive prostatic chip cultures, of whom 74 had sterile pre-operative urine. There was no association between the result of chip culture and the presence of a pre-operative catheter. Culture positive patients had an increased risk of post-operative urine infection, although the same organism was found in the prostate and urine in only 36% of cases of post-operative bacteriuria and in 43 (54%) the organism cultured from the prostate was Staphylococcus albus. This study provides further evidence of the benefit of true prophylactic antibiotic therapy for transurethral prostatic surgery and the prostatic chip data suggest that some of the risk is due to pre-operative contamination of the prostate in the absence of per-operative urinary infection or catheterisation. 相似文献
6.
7.
8.
9.
10.