全文获取类型
收费全文 | 2227篇 |
免费 | 155篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 243篇 |
妇产科学 | 44篇 |
基础医学 | 235篇 |
口腔科学 | 40篇 |
临床医学 | 162篇 |
内科学 | 394篇 |
皮肤病学 | 36篇 |
神经病学 | 232篇 |
特种医学 | 162篇 |
外科学 | 247篇 |
综合类 | 99篇 |
预防医学 | 126篇 |
眼科学 | 46篇 |
药学 | 160篇 |
中国医学 | 25篇 |
肿瘤学 | 122篇 |
出版年
2022年 | 19篇 |
2021年 | 44篇 |
2020年 | 18篇 |
2019年 | 21篇 |
2018年 | 34篇 |
2017年 | 22篇 |
2016年 | 40篇 |
2015年 | 38篇 |
2014年 | 45篇 |
2013年 | 89篇 |
2012年 | 94篇 |
2011年 | 66篇 |
2010年 | 66篇 |
2009年 | 56篇 |
2008年 | 79篇 |
2007年 | 84篇 |
2006年 | 90篇 |
2005年 | 77篇 |
2004年 | 75篇 |
2003年 | 57篇 |
2002年 | 69篇 |
2001年 | 62篇 |
2000年 | 58篇 |
1999年 | 62篇 |
1998年 | 46篇 |
1997年 | 39篇 |
1996年 | 34篇 |
1995年 | 25篇 |
1994年 | 31篇 |
1993年 | 30篇 |
1992年 | 48篇 |
1991年 | 42篇 |
1990年 | 39篇 |
1989年 | 36篇 |
1988年 | 47篇 |
1987年 | 24篇 |
1986年 | 42篇 |
1985年 | 21篇 |
1984年 | 23篇 |
1983年 | 21篇 |
1982年 | 18篇 |
1981年 | 24篇 |
1980年 | 18篇 |
1976年 | 21篇 |
1975年 | 20篇 |
1974年 | 21篇 |
1973年 | 27篇 |
1972年 | 16篇 |
1970年 | 18篇 |
1947年 | 15篇 |
排序方式: 共有2389条查询结果,搜索用时 0 毫秒
51.
52.
53.
Temporal artery biopsy is considered the gold standard investigation of giant cell arteritis and is recommended in suspected cases despite a sensitivity of 81–91%. This review highlights the potential risk of facial nerve injury during temporal artery biopsy and introduces recent advances in the emerging role of imaging modalities. When these non-invasive techniques are used in conjunction with American College of Rheumatology scoring, which includes clinical features and biochemical test results, temporal artery biopsy may be avoided in selected cases. 相似文献
54.
DK Bilku AR Dennison TC Hall MS Metcalfe G Garcea 《Annals of the Royal College of Surgeons of England》2014,96(1):15-22
INTRODUCTION
Surgical stress in the presence of fasting worsens the catabolic state, causes insulin resistance and may delay recovery. Carbohydrate rich drinks given preoperatively may ameliorate these deleterious effects. A systematic review was undertaken to analyse the effect of preoperative carbohydrate loading on insulin resistance, gastric emptying, gastric acidity, patient wellbeing, immunity and nutrition following surgery.METHODS
All studies identified through PubMed until September 2011 were included. References were cross-checked to ensure capture of cited pertinent articles.RESULTS
Overall, 17 randomised controlled trials with a total of 1,445 patients who met the inclusion criteria were identified. Preoperative carbohydrate drinks significantly improved insulin resistance and indices of patient comfort following surgery, especially hunger, thirst, malaise, anxiety and nausea. No definite conclusions could be made regarding preservation of muscle mass. Following ingestion of carbohydrate drinks, no adverse events such as apparent or proven aspiration during or after surgery were reported.CONCLUSIONS
Administration of oral carbohydrate drinks before surgery is probably safe and may have a positive influence on a wide range of perioperative markers of clinical outcome. Further studies are required to determine its cost effectiveness. 相似文献55.
J Isherwood G Garcea R Williams M Metcalfe AR Dennison 《Annals of the Royal College of Surgeons of England》2014,96(3):224-228
Introduction
Magnetic resonance cholangiopancreatography (MRCP) is not a routine investigation to exclude choledocholithiasis unless there is clinical or biochemical suspicion of common bile duct (CBD) stones. This study attempted to determine which radiological or serological parameters best predicted CBD stones.Methods
All patients undergoing MRCP from 2005 to 2011 were selected. Patients with pancreatitis were excluded. Liver function tests (LFTs) at admission and prior to MRCP were recorded, as was abdominal ultrasonography and MRCP results. Parameters measured routinely on LFTs included alkaline phosphatase (ALP), alanine transaminase (ALT) and bilirubin. Receiver operating characteristic curve area analysis (area under the curve [AUC]) and chi-squared analysis were undertaken.Results
Overall, 195 patients were identified, 71 of whom had CBD stones on MRCP. Raised ALP levels on admission demonstrated a correlation with CBD stones (AUC: 0.619, odds ratio [OR]: 3.16, p=0.06). At ultrasonography, a dilated CBD (OR: 3.76, p<0.001) and intrahepatic duct dilation (OR: 5.56, p<0.001) were highly significant predictors. However, only 37% of patients had a dilated CBD on ultrasonography. Ongoing elevation of LFT parameters, particularly ALP (AUC: 0.707, OR: 4.64, p<0.001) and ALT (AUC: 0.646, OR: 5.40, p<0.001), displayed a significant correlation with CBD stones.Conclusions
Ongoing (even if minor) elevations of liver function test parameters should prompt the need to exclude CBD stones even in the presence of a normal CBD diameter on ultrasonography. 相似文献56.
57.
58.
We have developed a general quenched-flow approach to study platelet function as early as 0.3 seconds after stimulation. Phosphorylation of 20- and 40-kd proteins has been analyzed during the first five seconds of platelet response to thrombin from 0.1 to 5.0 U/mL and compared with the progress of aggregation and serotonin secretion. The onset time for aggregation and phosphorylation of both proteins was less than one second, although with lowest (less than 0.5 U/mL) thrombin levels, a lag of up to 0.6 seconds occurred before 40K phosphorylation increased. The thrombin sensitivity of aggregation and 20K phosphorylation was approximately twice that of 40K phosphorylation, with Ka values of 0.51 and 0.53 v 1.10 U/mL, respectively. External calcium was necessary for maximal 20K phosphorylation, since EDTA inhibited this by 30%. The 40K phosphorylation was not affected by EDTA. Platelet activation by thrombin thus induced biochemical changes well before one second. The quenched-flow approach may help to reveal relationships between phospholipase activation, calcium fluxes, and protein phosphorylation during these early periods of platelet function. 相似文献
59.
Diagnostic role of an immunoassay-detected polymorphism of factor IX for potential carriers of hemophilia B 总被引:3,自引:1,他引:3
In hemophilia B, assays based on a monoclonal antifactor IX specific for the Thr-148 variant of an exonic polymorphism have diagnosed carriers in selected families by either establishing linkage or by indicating the presence or absence of a given normal factor IX. The sensitivity of the immunoassays for detecting heterozygous women was explored by comparing results from immunoassays with solid-phase polyclonal v the monoclonal antifactor IXs. Factor IX with the normal Ala-148 variant gave a flat dilution curve, qualitatively distinct from factor IX with the Thr-148 variant in the monoclonal assay. The two were indistinguishable in the polyclonal assay. Mixtures of equal amounts of the two types gave an intermediate result, about half as reactive in the monoclonal as compared with the polyclonal assay system. Whereas mixtures with 10% Ala-148 and 90% Thr-148 factor IXs could not readily be distinguished from Thr-148 factor IX plasma, as little as 1% of the Thr-148 protein was detected in Ala-148 factor IX plasma. The frequency of the Ala-148 variant varied in individuals with different ethnic backgrounds; it was found in 29% of white, 12% of black, and none of Asian blood donors' factor IX genes in Seattle. Only 4% of samples from South African black men were nonreactive (ie, Ala- 148). The Thr/Ala-148 dimorphism is in strong linkage disequilibrium with Taql restriction fragment length polymorphisms (RFLPs). Three recombinations were noted in normal white genes and one in a normal black factor IX gene (less than 2% of those examined). In 34 white families with at least one woman being a possible carrier, genetically, the immunoassay results were informative in 18. RFLP analyses were informative in eight of the 15 families tested. In five families each, assignment of carrier status was made to a woman by only DNA or only immunoassay results, whereas the other approach was noninformative. The immunoassays provide a rapid, inexpensive screening test and complement DNA analysis in white women who are potential carriers of hemophilia B. 相似文献
60.
Simon Eggington Francesc Valldeoriola K. Ray Chaudhuri Keyoumars Ashkan Elena Annoni Günther Deuschl 《Journal of neurology》2014,261(1):106-116
Parkinson’s disease (PD) is a complex progressive movement disorder leading to motor and non-motor symptoms that become increasingly debilitating as the disease advances, considerably reducing quality of life. Advanced treatment options include deep brain stimulation (DBS). While clinical effectiveness of DBS has been demonstrated in a number of randomised controlled trials (RCT), evidence on cost-effectiveness is limited. The cost-effectiveness of DBS combined with BMT, versus BMT alone, was evaluated from a UK payer perspective. Individual patient-level data on the effect of DBS on PD symptom progression from a large 6-month RCT were used to develop a Markov model representing clinical progression and capture treatment effect and costs. A 5-year time horizon was used, and an incremental cost-effectiveness ratio (ICER) was calculated in terms of cost per quality-adjusted life-years (QALY) and uncertainty assessed in deterministic sensitivity analyses. Total discounted costs in the DBS and BMT groups over 5 years were £68,970 and £48,243, respectively, with QALYs of 2.21 and 1.21, giving an incremental cost-effectiveness ratio of £20,678 per QALY gained. Utility weights in each health state and costs of on-going medication appear to be the key drivers of uncertainty in the model. The results suggest that DBS is a cost-effective intervention in patients with advanced PD who are eligible for surgery, providing good value for money to health care payers. 相似文献