全文获取类型
收费全文 | 7726篇 |
免费 | 834篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 280篇 |
妇产科学 | 360篇 |
基础医学 | 1076篇 |
口腔科学 | 99篇 |
临床医学 | 883篇 |
内科学 | 1769篇 |
皮肤病学 | 56篇 |
神经病学 | 439篇 |
特种医学 | 261篇 |
外科学 | 1160篇 |
综合类 | 270篇 |
一般理论 | 9篇 |
预防医学 | 907篇 |
眼科学 | 169篇 |
药学 | 475篇 |
中国医学 | 1篇 |
肿瘤学 | 340篇 |
出版年
2021年 | 104篇 |
2020年 | 84篇 |
2019年 | 120篇 |
2018年 | 160篇 |
2017年 | 84篇 |
2016年 | 116篇 |
2015年 | 115篇 |
2014年 | 186篇 |
2013年 | 224篇 |
2012年 | 365篇 |
2011年 | 391篇 |
2010年 | 258篇 |
2009年 | 187篇 |
2008年 | 360篇 |
2007年 | 405篇 |
2006年 | 366篇 |
2005年 | 380篇 |
2004年 | 334篇 |
2003年 | 295篇 |
2002年 | 269篇 |
2001年 | 232篇 |
2000年 | 237篇 |
1999年 | 203篇 |
1998年 | 107篇 |
1997年 | 97篇 |
1996年 | 87篇 |
1995年 | 80篇 |
1994年 | 89篇 |
1993年 | 60篇 |
1992年 | 135篇 |
1991年 | 118篇 |
1990年 | 132篇 |
1989年 | 162篇 |
1988年 | 118篇 |
1987年 | 147篇 |
1986年 | 91篇 |
1985年 | 111篇 |
1984年 | 84篇 |
1983年 | 92篇 |
1982年 | 62篇 |
1981年 | 68篇 |
1980年 | 64篇 |
1979年 | 94篇 |
1978年 | 83篇 |
1977年 | 65篇 |
1975年 | 61篇 |
1974年 | 65篇 |
1973年 | 67篇 |
1972年 | 77篇 |
1971年 | 69篇 |
排序方式: 共有8594条查询结果,搜索用时 109 毫秒
1.
Andy KH Lim 《World journal of gastroenterology : WJG》2020,26(10):1020-1028
Rhabdomyolysis is a syndrome of skeletal muscle injury with release of cellular constituents such as potassium,phosphate,urate and intracellular proteins such as myoglobin into the circulation,which may cause complications including acute kidney injury,electrolyte disturbance and cardiac instability.Abnormal liver function tests are frequently observed in cases of severe rhabdomyolysis.Typically,there is an increase in serum aminotransferases,namely aspartate aminotransferase and alanine aminotransferase.This raises the question of liver injury and often triggers a pathway of investigation which may lead to a liver biopsy.However,muscle can also be a source of the increased aminotransferase activity.This review discusses the dilemma of finding abnormal liver function tests in the setting of muscle injury and the potential implications of such an association.It delves into some of the clinical and experimental evidence for correlating muscle injury to raised aminotransferases,and discusses pathophysiological mechanisms such as oxidative stress which may cause actual liver injury.Serum aminotransferases lack tissue specificity to allow clinicians to distinguish primary liver injury from muscle injury.This review also explores potential approaches to improve the accuracy of our diagnostic tools,so that excessive or unnecessary liver investigations can be avoided. 相似文献
2.
Conall T. Morgan Brigitte Mueller Varsha Thakur Vitor Guerra Callaghan Jull Luc Mertens Mark Friedberg Fraser Golding Mike Seed Steven E.S. Miner Edgar T. Jaeggi Cedric Manlhiot Lynne E. Nield 《The Canadian journal of cardiology》2019,35(4):453-461
Background
The purpose of the study was to evaluate the association between fetal echocardiographic measurements and the need for intervention (primary coarctation repair, staged coarctation repair, or catheter intervention) in prenatally diagnosed coarctation of the aorta.Methods
A single-centre retrospective cohort study (2005-2015) of 107 fetuses diagnosed with suspected coarctation of the aorta in the setting of an apex-forming left ventricle and antegrade flow across the mitral and aortic valves.Results
Median gestational age at diagnosis was 32 weeks (interquartile range, 23-35 weeks). Fifty-six (52%) did not require any neonatal intervention, 51 patients (48%) underwent a biventricular repair. In univariable analysis, an increase in ascending aorta (AAo) peak Doppler flow velocity (odds ratio [OR], 1.40 [95% confidence interval [CI], 1.05-1.91] per 20 cm/s; P = 0.03) was associated with intervention. No intervention was associated with larger isthmus size (OR, 0.23; P < 0.001), transverse arch diameter (OR, 0.23; P < 0.001), and aortic (OR, 0.72; P = 0.02), mitral (OR, 0.58; P = 0.001), and AAo (OR, 0.53; P < 0.001) z-scores. In multivariable analysis, higher peak AAo Doppler (OR, 2.51 [95% CI, 1.54-4.58] per 20 cm/s; P = 0.001) and younger gestational age at diagnosis (OR, 0.81 [95% CI, 0.70-0.93] per week; P = 0.005) were associated with intervention, whereas a higher AAo z-score (OR, 0.65 [95% CI, 0.43-0.94] per z; P = 0.029) and transverse arch dimension (OR, 0.44 [95% CI, 0.18-0.97]; P = 0.05) decreased the risk of intervention.Conclusions
In prenatally suspected coarctation, the variables associated with intervention comprised smaller AAo and transverse arch size, earlier gestational age at diagnosis, and the additional finding of a higher peak AAo Doppler. 相似文献3.
4.
Mithun Sattur Clayton Korson Fraser Henderson Stephen Kalhorn 《The American journal of emergency medicine》2019,37(5):1005.e1-1005.e2
Occipital spur is an abnormal bony outgrowth of the external occipital protuberance (EOP). We describe an interesting and previously unreported case of fracture of an occipital spur following trauma. Our 20-year-old male patient was treated in the emergency department (ED) and discharged home without complication. Neurosurgical consultation was obtained but is not requisite for these injuries. Greater awareness of this unique presentation may help to expedite future emergency department treatment. 相似文献
5.
6.
Rosendo A. Rodriguez MD PhD Fraser Rubens MD MSc Carlos D. Rodriguez Howard J. Nathan MD 《Journal of neuroimaging》2006,16(2):126-132
OBJECTIVE: The application of intensity thresholds for embolus detection with transcranial Doppler (TCD) can exclude from analysis an unrecognized proportion of high-intensity transient signals (HITS))whose intensities are below the threshold. The lack of consistent threshold criteria between clinical trials may explain part of the discrepancy in the reported HITS counts. We investigated the effect of choosing different thresholds on the sensitivity and specificity of detecting HITS during cardiopulmonary bypass (CPB). METHODS: Two observers independently analyzed TCD recordings from 8 patients under CPB. Doppler signals were classified as true HITS, equivocal HITS, artifacts, and Doppler speckles according to preestablished criteria. The relative intensity of Doppler signals was measured by two different methods (TCD software vs manual). Receiver Operating Characteristic curves determined the optimal threshold for each of the two intensity methods. RESULTS: Reviewers achieved agreement in 96% of 2190 Doppler signals (kappa = 0.90). Relative intensities calculated with the TCD-software method were 3 dB (95% CI: 3.0-3.4) higher than the manual method. The optimal threshold was found at 10 dB (sensitivity: 99%; specificity: 90.8%) with the software method and at 7 dB with the manual method (sensitivity: 96%; specificity: 83%). The use of an intensity threshold 2 dB higher than the optimal increased the rejection of true HITS by 8% and 14%, respectively. CONCLUSIONS: Using intensity thresholds higher than the optimal for embolus detection decreases HITS counts. Choosing a threshold depends on the type of method used for measuring the signal intensity. Uniform threshold criteria and comparative studies between different Doppler devices are necessary for making clinical trials more comparable. 相似文献
7.
Background
Hospital episode statistics (HES) is a UK national database for the National Health Service (NHS), now available online. The purpose of this study was to observe trends in ophthalmic operations performed during the period from 1998 to 2004, using this data. 相似文献8.
9.
王伏虎 《南京医科大学学报(英文版)》2002,16(2):49-64
Stroke is a debilitating disease that affects millions each year.While in many cases cerebral ischemic in jury can be limited by effectivw resuscitation or thrombolytic treatment,the injured neurons wither in a process known as delayed neuronal death(DND).Mounting evidence indicates that DND is not simply necrosis played out in slow motion but apoptosis is triggered.Of particular interest are two groups of signal proteins that participate in apoptosis-cyclin dependent kinases(CDKs) and p53-among a myriad of signaling events after an ischemic insult.Recent investigations have shown that CDKs,a family of enzymes initially known for their role in cell cycle regulation,are activated in injured neurons in DND.As for p53,new reports suggest that its up-regulation may represent a failed attempt to rescue in jured neurons,although its up-regulation was previously considered an indication of apoptosis.These observations thus rekindle an old quest to identify new neuroprotective targets to minimize the stroke damage.In this review,the author will examine the evidence that indicates the participation of CDKs and p53 in DND and then introduce pre-clinical data to explore CDK inhibition as a potential neuroprotective target.Finally,using CDK inhibition as an example,this paper will discuss the pertinent criteria for a viable neuroprotective strategy for ischemic in jury. 相似文献
10.