全文获取类型
收费全文 | 5029篇 |
免费 | 359篇 |
国内免费 | 132篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 54篇 |
妇产科学 | 42篇 |
基础医学 | 236篇 |
口腔科学 | 53篇 |
临床医学 | 523篇 |
内科学 | 454篇 |
皮肤病学 | 44篇 |
神经病学 | 445篇 |
特种医学 | 167篇 |
外国民族医学 | 1篇 |
外科学 | 1871篇 |
综合类 | 631篇 |
预防医学 | 377篇 |
眼科学 | 39篇 |
药学 | 209篇 |
2篇 | |
中国医学 | 66篇 |
肿瘤学 | 246篇 |
出版年
2024年 | 11篇 |
2023年 | 72篇 |
2022年 | 112篇 |
2021年 | 171篇 |
2020年 | 149篇 |
2019年 | 202篇 |
2018年 | 158篇 |
2017年 | 131篇 |
2016年 | 132篇 |
2015年 | 109篇 |
2014年 | 252篇 |
2013年 | 298篇 |
2012年 | 220篇 |
2011年 | 227篇 |
2010年 | 177篇 |
2009年 | 223篇 |
2008年 | 189篇 |
2007年 | 146篇 |
2006年 | 200篇 |
2005年 | 157篇 |
2004年 | 146篇 |
2003年 | 156篇 |
2002年 | 137篇 |
2001年 | 160篇 |
2000年 | 107篇 |
1999年 | 94篇 |
1998年 | 112篇 |
1997年 | 116篇 |
1996年 | 102篇 |
1995年 | 88篇 |
1994年 | 106篇 |
1993年 | 93篇 |
1992年 | 79篇 |
1991年 | 93篇 |
1990年 | 73篇 |
1989年 | 67篇 |
1988年 | 74篇 |
1987年 | 62篇 |
1986年 | 49篇 |
1985年 | 58篇 |
1984年 | 46篇 |
1983年 | 25篇 |
1982年 | 20篇 |
1981年 | 38篇 |
1980年 | 30篇 |
1979年 | 21篇 |
1978年 | 8篇 |
1977年 | 13篇 |
1975年 | 4篇 |
1974年 | 3篇 |
排序方式: 共有5520条查询结果,搜索用时 12 毫秒
1.
2.
K. Bhatia Group of Obstetric Anaesthetists of Lancashire Greater Manchester Mersey Study Collaborators 《Anaesthesia》2022,77(4):389-397
Since the start of the COVID-19 pandemic, few studies have reported anaesthetic outcomes in parturients with SARS-CoV-2 infection. We reviewed the labour analgesic and anaesthetic interventions utilised in symptomatic and asymptomatic parturients who had a confirmed positive test for SARS-CoV-2 across 10 hospitals in the north-west of England between 1 April 2020 and 31 May 2021. Primary outcomes analysed included the analgesic/anaesthetic technique utilised for labour and caesarean birth. Secondary outcomes included a comparison of maternal characteristics, caesarean birth rate, maternal critical care admission rate along with adverse composite neonatal outcomes. A positive SARS-CoV-2 test was recorded in 836 parturients with 263 (31.4%) reported to have symptoms of COVID-19. Neuraxial labour analgesia was utilised in 104 (20.4%) of the 509 parturients who went on to have a vaginal birth. No differences in epidural analgesia rates were observed between symptomatic and asymptomatic parturients (OR 1.03, 95%CI 0.64–1.67; p = 0.90). The neuraxial anaesthesia rate in 310 parturients who underwent caesarean delivery was 94.2% (95%CI 90.6–96.0%). The rates of general anaesthesia were similar in symptomatic and asymptomatic parturients (6% vs. 5.7%; p = 0.52). Symptomatic parturients were more likely to be multiparous (OR 1.64, 95%CI 1.19–2.22; p = 0.002); of Asian ethnicity (OR 1.54, 1.04–2.28; p = 0.03); to deliver prematurely (OR 2.16, 95%CI 1.47–3.19; p = 0.001); have a higher caesarean birth rate (44.5% vs. 33.7%; OR 1.57, 95%CI 1.16–2.12; p = 0.008); and a higher critical care utilisation rate both pre- (8% vs. 0%, p = 0.001) and post-delivery (11% vs. 3.5%; OR 3.43, 95%CI 1.83–6.52; p = 0.001). Eight neonates tested positive for SARS-CoV-2 while no differences in adverse composite neonatal outcomes were observed between those born to symptomatic and asymptomatic mothers (25.8% vs. 23.8%; OR 1.11, 95%CI 0.78–1.57; p = 0.55). In women with COVID-19, non-neuraxial analgesic regimens were commonly utilised for labour while neuraxial anaesthesia was employed for the majority of caesarean births. Symptomatic women with COVID-19 are at increased risk of significant maternal morbidity including preterm birth, caesarean birth and peripartum critical care admission. 相似文献
3.
4.
Health care expenditure in Germany shows clear regional differences. Such geographic variations are often seen as an indicator for inefficiency. With its homogeneous health care system, low co‐payments and uniform prices, Germany is a particularly suited example to analyse regional variations. We use data for the year 2011 on expenditure, utilization of health services and state of health in Germany's statutory health insurance system. This data, which originate from a variety of administrative sources and cover about 90% of the population, are enriched with a wealth of socio‐economic variables, data on pollutants, prices and individual preferences. State of health and demography explains 55% of the differences as measured by the standard deviation while all control variables account for a total of 72% of the differences at county level. With other measures of variation, we can account for an even greater proportion. A higher proportion of variation than usually supposed can thus be explained. Whilst this study cannot quantify inefficiencies, our results contradict the thesis that regional variations reflect inefficiency. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
5.
Hand surgery involves the surgical treatment of hand conditions and encompasses small bone fixation, arthroscopy, joint replacement and reconstruction of tendon and nerves. Complications following surgery to the hand may be due to patient factors, surgical decisions and the complex anatomy of the hand. Here we describe the complications associated with common surgical interventions for both elective and traumatic injuries to the hand. Following hand surgery, a balance between immobilisation and early range of motion is offset by the risk of wound complications, non-union of fractures and tendon re-rupture with stiffness and reduced range of motion of the digits. Superficial infection is relatively common following procedures to the hand, however long-term sequelae are rare. Implant failure, subsidence, instability and reduced range of motion are seen following arthroplasty procedures. Complex regional pain syndrome offers a significant challenge following injury to the hand and specifically after surgical procedures. Surgeons should consider the risk of particular surgical techniques, other perioperative factors and patient factors that may contribute to the development of complications following hand surgery. Patients should be adequately counselled in order to make an informed decision regarding the management of their condition. 相似文献
6.
Peter Marhofer Malachy Columb Phil M. Hopkins Manfred Greher Daniela Marhofer Max R. Levi Bienzle Markus Zeitlinger 《British journal of anaesthesia》2019,122(4):525-531
Background
The efficacy of dexamethasone in extending the duration of local anaesthetic block is uncertain. In a randomised controlled triple blind crossover study in volunteers, we tested the hypothesis that neither i.v. nor perineurally administered dexamethasone prolongs the sensory block achieved with ropivacaine.Methods
Ultrasound-guided ulnar nerve blocks (ropivacaine 0.75% wt/vol, 3 ml, with saline 1 ml with or without dexamethasone 4 mg) were performed on three occasions in 24 male volunteers along with an i.v. injection of saline 1 ml with or without dexamethasone 4 mg. The combinations of saline and dexamethasone were as follows: control group, perineural and i.v. saline; perineural group, perineural dexamethasone and i.v. saline; i.v. group, perineural saline and i.v. dexamethasone. Sensory block was measured using a VAS in response to pinprick testing. The duration of sensory block was the primary outcome and time to onset of sensory block the secondary outcome.Results
All 24 subjects completed the trial. The median [inter-quartile range (IQR)] duration of sensory block was 6.87 (5.85–7.62) h in the control group, 7.37 (5.78–7.93) h in the perineural group and 7.37 (6.10–7.97) h in the i.v. group (P=0.61). There was also no significant difference in block onset time between the three groups.Conclusion
Dexamethasone 4 mg has no clinically relevant effect on the duration of sensory block provided by ropivacaine applied to the ulnar nerve.Clinical trial registration
DRKS, 00014604; EudraCT, 2018-001221-98. 相似文献7.
8.
9.
Gordon J. Harris Ph.D. Instructor Jonathan M. Links Ph.D. Associate Professor Godfrey D. Pearlson M.B. B.S. Director Edwaldo E. Camargo M.D. Associate Professor 《Psychiatry research》1991,40(3):167-180
We developed a semiautomatic method termed “cortical circumferential profiling” for objective analysis of cerebral cortex function in emission tomographic neuroimaging studies. This method treats cortex as a continuous ring near the outer brain edge. A computer algorithm samples the cortex at 60 contiguous, equiangular locations, using 1-cm2 samples. These values are plotted as a function of cortical angle to produce the cortical circumferential profile. This method was used in a study of regional cerebral perfusion in 15 patients with Alzheimer's disease and 8 elderly control subjects using N-isopropyl [I-123]-iodoamphetamine. Cortical circumferential profiling decreases variability, examines the entire cortex within slices at preselected levels above the orbital-meatal line, and facilitates intrasubject and intersubject comparisons. 相似文献
10.
Coagulation screening before epidural analgesia in pre-eclampsia 总被引:1,自引:0,他引:1
A questionnaire survey of current practice at a small cross-section of obstetric units, covering 22% of all United Kingdom deliveries, revealed a marked lack of standard practice regarding requests for coagulation screens on pre-eclamptic patients who require epidural procedures. A retrospective audit was therefore carried out on 434 coagulation screens requested for pre-eclamptic patients in whom epidural analgesia might have been considered. Borderline abnormalities of coagulation were found in only 10 patients (2%). Platelet counts of less than 150 x 10(9)/litre were present in 28% of cases. 'Significant' thrombocytopenia (less than 100 x 10(9)/litre) and all coagulation abnormalities were only encountered in severe pre-eclampsia (diastolic blood pressure of greater than 110 mmHg and proteinuria of + + or greater). Furthermore, coagulation abnormality was always associated with a reduced platelet count (mean, 97 x 10(9)/litre). This study would therefore support anaesthetic practice which restricted any requests for coagulation testing to severe pre-eclamptic patients only. For these patients first line testing could be limited to a platelet count. 相似文献