全文获取类型
收费全文 | 6753篇 |
免费 | 366篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 419篇 |
妇产科学 | 66篇 |
基础医学 | 707篇 |
口腔科学 | 319篇 |
临床医学 | 486篇 |
内科学 | 1331篇 |
皮肤病学 | 182篇 |
神经病学 | 545篇 |
特种医学 | 285篇 |
外科学 | 973篇 |
综合类 | 105篇 |
一般理论 | 2篇 |
预防医学 | 264篇 |
眼科学 | 319篇 |
药学 | 501篇 |
中国医学 | 32篇 |
肿瘤学 | 521篇 |
出版年
2023年 | 42篇 |
2022年 | 92篇 |
2021年 | 252篇 |
2020年 | 120篇 |
2019年 | 192篇 |
2018年 | 196篇 |
2017年 | 173篇 |
2016年 | 202篇 |
2015年 | 229篇 |
2014年 | 330篇 |
2013年 | 383篇 |
2012年 | 592篇 |
2011年 | 605篇 |
2010年 | 324篇 |
2009年 | 268篇 |
2008年 | 400篇 |
2007年 | 407篇 |
2006年 | 340篇 |
2005年 | 359篇 |
2004年 | 309篇 |
2003年 | 232篇 |
2002年 | 231篇 |
2001年 | 60篇 |
2000年 | 71篇 |
1999年 | 68篇 |
1998年 | 42篇 |
1997年 | 30篇 |
1996年 | 29篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 26篇 |
1992年 | 43篇 |
1991年 | 35篇 |
1990年 | 29篇 |
1989年 | 37篇 |
1988年 | 28篇 |
1987年 | 34篇 |
1986年 | 28篇 |
1985年 | 28篇 |
1984年 | 21篇 |
1983年 | 15篇 |
1982年 | 26篇 |
1981年 | 14篇 |
1980年 | 15篇 |
1979年 | 13篇 |
1978年 | 16篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1972年 | 12篇 |
1970年 | 12篇 |
排序方式: 共有7136条查询结果,搜索用时 15 毫秒
1.
2.
3.
Niya Narayanan Dukhabandhu Naik Jayaprakash Sahoo Sadishkumar Kamalanathan 《World Journal of Virology》2022,11(6):399-410
Coronavirus disease 2019 (COVID-19) is associated with a high risk of mortality and complications in patients with diabetes mellitus. Achieving good glycemic control is very important in diabetic patients to reduce complications and mortality due to COVID-19. Recent studies have shown the mortality benefit and anti-inflammatory effects of Dipeptidyl-peptidase-4 inhibitors (DPP-4i) in diabetic patients with COVID-19. DPP-4i may have a beneficial role in halting the severity of infection primarily by three routes, namely viral entry inhibition, anti-inflammatory and anti-fibrotic effects and glycemic control. This has raised the pro-mising hypothesis that DPP-4i might be an optimal strategy for treating COVID-19 in patients with diabetes. This review aims to summarise the possible therapeutic non-glycemic effects of DPP-4i in diabetic patients diagnosed with COVID-19 in the light of available evidence. 相似文献
4.
5.
Pankaj Hari Anand Srivastava Arun Kumar Gupta Rajendra N. Srivastava 《Pediatric nephrology (Berlin, Germany)》1997,11(4):497-498
Acute renal failure (ARF) developed in a 7-week-old infant due to bilateral candidal bezoars (fungal balls) causing obstruction
at the pelviureteric junction. The baby was born at term with an appropriate birthweight, and had been treated with broad-spectrum
antibiotics for respiratory distress and septicemia during the 1st week of life. Recovery from ARF followed renal decompression
with bilateral nephrostomy tube placement and parenteral administration of amphotericin B and 5-flucytosine.
Received August 21, 1996; received in revised form and accepted January 3, 1997 相似文献
6.
Ramshekhar N. Menon Nirav Sanghani Mahendra Javali Neeraj Jain Arun B. Shah 《Annals of Indian Academy of Neurology》2009,12(1):40-44
We report an unusual case of sporadic adult onset cerebellar ataxia with hypogonadism. A 40-year-old unmarried man presented with progressive ataxia and dysarthria along with complaints of non-development of secondary sexual characteristics and erectile dysfunction. There were complaints of intermittent diarrhea. Clinical examination revealed a pan-cerebellar syndrome with features of hypoandrogenism. No eye movement abnormalities were evident. There were signs of malabsorption. Investigations confirmed the presence of auto-antibodies found in celiac disease, and a duodenal biopsy confirmed the same. Hypoandrogenism was postulated to be due to hypergonadotropic hypogonadism which has been mentioned in a few patients of celiac disease. However, the pattern seen in our patient was of a hypogonadotropic hypogonadism. This is probably secondary to an autoimmune hypophysitis seen in some patients in the absence of other clinical manifestations. Autoantibody testing should be a diagnostic necessity in any adult with a sporadic cerebellar ataxia. 相似文献
7.
P. Hendrik Pretorius Michael A. King Howard C. Gifford Seth T. Dahlberg Frederick Spencer Ellen Simon Jason Rashkin Naomi Botkin William Berndt Manoj V. Narayanan Jeffrey A. Leppo 《Journal of nuclear cardiology》2005,12(3):284-293
BACKGROUND: Past receiver operating characteristic (ROC) studies have demonstrated that single photon emission computed tomography (SPECT) perfusion imaging by use of iterative reconstruction with combined compensation for attenuation, scatter, and detector response leads to higher area under the ROC curve (A(z)) values for detection of coronary artery disease (CAD) in comparison to the use of filtered backprojection (FBP) with no compensations. A new ROC study was conducted to investigate whether this improvement still holds for iterative reconstruction when observers have available all of the imaging information normally presented to clinical interpreters when reading FBP SPECT perfusion slices. METHODS AND RESULTS: A total of 87 patient studies including 50 patients referred for angiography and 37 patients with a lower than 5% likelihood for CAD were included in the ROC study. The images from the two methods were read by 4 cardiology fellows and 3 attending nuclear cardiologists. Presented for the FBP readings were the short-axis, horizontal long-axis, and vertical long-axis slices for both the stress and rest images; cine images of both the stress and rest projection data; cine images of selected cardiac-gated slices; the CEQUAL-generated stress and rest polar maps; and an indication of patient gender. This was compared with reading solely the iterative reconstructed stress slices with combined compensation for attenuation, scatter, and resolution. With A(z) as the criterion, a 2-way analysis of variance showed a significant improvement in detection accuracy for CAD for the 7 observers (P = .018) for iterative reconstruction with combined compensation (A(z) of 0.895 +/- 0.016) over FBP even with the additional imaging information provided to the observers when scoring the FBP slices (A(z) of 0.869 +/- 0.030). When the groups of 3 attending physicians or 4 cardiology fellows were compared separately, the iterative technique was not statistically significantly better; however, the A(z) for each of the 7 observers individually was larger for iterative reconstruction than for FBP. Compared with results from our previous studies, the additional imaging information did increase the diagnostic accuracy of FBP for CAD but not enough to undo the statistically significantly higher diagnostic accuracy of iterative reconstruction with combined compensation. CONCLUSIONS: We have determined through an ROC investigation that included two classes of observers (experienced attending physicians and cardiology fellows in training) that iterative reconstruction with combined compensation provides statistically significantly better detection accuracy (larger A(z)) for CAD than FBP reconstructions even when the FBP studies were read with all of the extra clinical nuclear imaging information normally available. 相似文献
8.
9.
Bing Feng P. Hendrik Pretorius Troy H. Farncombe Seth T. Dahlberg Manoj V. Narayanan Miles N. Wernick Anna M. Celler Jeffrey A. Leppo Michael A. King 《Journal of nuclear cardiology》2006,13(3):354-361
BACKGROUND: Dynamic single photon emission computed tomography (SPECT) acquisition and reconstruction of early poststress technetium 99m teboroxime washout images has been shown to be useful in the detection of coronary disease. Assessment of poststress regional wall motion may offer additional use in assessing coronary disease. Our goal was to investigate the feasibility of simultaneously imaging myocardial ischemia and transient poststress akinesis using gated-dynamic SPECT. METHODS AND RESULTS: A gated-dynamic mathematical cardiac torso (MCAT) phantom was developed to model both teboroxime kinetics and cardiac regional wall motion. A lesion was simulated as having delayed poststress teboroxime washout together with a transient poststress wall motion abnormality. Gated projection data were created to represent a 3-headed SPECT system undergoing a total rotation of 480 degrees . The dynamic expectation-maximization reconstruction algorithm with postsmoothing across gating intervals by Wiener filtering, and the ordered-subset expectation maximization reconstruction algorithm with 3-point smoothing across gating intervals were compared. Compared with the ordered-subset expectation maximization with 3-point smoothing, the dynamic expectation-maximization algorithm with Wiener filtering was able to produce visually higher-quality images and more accurate left ventricular ejection fraction estimates. CONCLUSION: From simulations, we conclude that changing cardiac function and tracer localization possibly can be assessed by using a gated-dynamic acquisition protocol combined with a 5-dimensional reconstruction strategy. 相似文献
10.
R Jeyamani N K Shyamkumar Kumar Narayanan H S Subhash Biju George George Kurian 《Indian journal of gastroenterology》2003,22(4):147-148
We report a 40-year-old man with rheumatic heart disease who presented with abdominal pain for three weeks and hematemesis for 24 hours. CT scan showed a large splenic artery aneurysm without evidence of pancreatitis. Mycotic aneurysm due to infective endocarditis was considered and confirmed by echocardiogram, which showed aortic and mitral valve regurgitation and vegetations. He was managed successfully with coil embolization of the aneurysm and antibiotics. 相似文献