全文获取类型
收费全文 | 73249篇 |
免费 | 5461篇 |
国内免费 | 1744篇 |
专业分类
耳鼻咽喉 | 538篇 |
儿科学 | 1837篇 |
妇产科学 | 1695篇 |
基础医学 | 5895篇 |
口腔科学 | 1512篇 |
临床医学 | 12379篇 |
内科学 | 7604篇 |
皮肤病学 | 653篇 |
神经病学 | 2415篇 |
特种医学 | 11709篇 |
外国民族医学 | 35篇 |
外科学 | 5256篇 |
综合类 | 14506篇 |
现状与发展 | 11篇 |
一般理论 | 2篇 |
预防医学 | 4126篇 |
眼科学 | 1055篇 |
药学 | 3529篇 |
80篇 | |
中国医学 | 1392篇 |
肿瘤学 | 4225篇 |
出版年
2024年 | 120篇 |
2023年 | 842篇 |
2022年 | 1524篇 |
2021年 | 2588篇 |
2020年 | 2606篇 |
2019年 | 1853篇 |
2018年 | 1847篇 |
2017年 | 1972篇 |
2016年 | 2545篇 |
2015年 | 2281篇 |
2014年 | 4614篇 |
2013年 | 4458篇 |
2012年 | 4605篇 |
2011年 | 5020篇 |
2010年 | 4272篇 |
2009年 | 4142篇 |
2008年 | 4080篇 |
2007年 | 4377篇 |
2006年 | 4128篇 |
2005年 | 3544篇 |
2004年 | 3041篇 |
2003年 | 2345篇 |
2002年 | 1870篇 |
2001年 | 1666篇 |
2000年 | 1336篇 |
1999年 | 1044篇 |
1998年 | 902篇 |
1997年 | 845篇 |
1996年 | 776篇 |
1995年 | 737篇 |
1994年 | 647篇 |
1993年 | 553篇 |
1992年 | 436篇 |
1991年 | 399篇 |
1990年 | 341篇 |
1989年 | 280篇 |
1988年 | 334篇 |
1987年 | 256篇 |
1986年 | 209篇 |
1985年 | 204篇 |
1984年 | 153篇 |
1983年 | 97篇 |
1982年 | 107篇 |
1981年 | 89篇 |
1980年 | 90篇 |
1979年 | 78篇 |
1978年 | 56篇 |
1977年 | 35篇 |
1976年 | 32篇 |
1975年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
31.
32.
《Indian journal of medical microbiology》2019,37(3):433-437
This prospective cohort study was conducted to compare the accuracy of QuantiFERON®-TB (QFT) Gold In-Tube test and tuberculin skin test (TST) in diagnosing tuberculosis (TB) in predominantly bacille Calmette–Guerin-vaccinated children with a high incidence of malnutrition. The sensitivity of the QFT versus the TST was 69.6% versus 52.9% for WHO-defined TB, with specificity of 86% versus 78.3%, respectively. The concordance of the TST and QFT was 79% overall (κ = 0.430), 62.5% in those with WHO-defined TB and 85.7% in those without TB. Majority of the QFT+/TST − discordance was seen in children with TB, whereas majority of the TST+/QFT − discordance was seen in those without TB. The TST was more likely to be negative in children with moderate-to-severe malnutrition (P = 0.003) compared to the QFT, which was more likely to be positive in younger children. The significantly better performance of the QFT in malnourished children and those at younger ages supports its use for TB diagnosis in these subpopulations. 相似文献
33.
34.
《Pancreatology》2022,22(7):864-870
BackgroundMetagenomic next-generation sequencing (mNGS) is increasingly used for the clinical diagnosis of infectious diseases, but there is a paucity of data regarding the application of mNGS in the early diagnosis of infected pancreatic necrosis (IPN).ObjectiveTo investigate the clinical application value of mNGS in the pathogenic diagnosis of IPN.MethodsForty-two patients with suspected IPN were prospectively and consecutively enrolled from August 2019 to August 2021. Blood samples were collected for mNGS and microbial culture simultaneously during fever (T ≥ 38.5 °C). For patients who had indications of surgical interventions, peri-pancreatic specimens were collected for mNGS and microbial culture simultaneously during the first surgical intervention to confirm IPN. The clinical performance of mNGS and microbial culture were compared.ResultsA total of 21 patients (50.0%) were confirmed to have IPN during hospitalization. The sensitivity of blood mNGS was significantly higher than blood culture (95.2% vs. 23.8%, P < 0.001) in diagnosing IPN. The negative predictive value of blood mNGS was 90.0%. The turnaround time of mNGS was significantly shorter than that of microbial culture [(37.70 ± 1.44) vs. (115.23 ± 8.79) h, P < 0.01] and the average costs of mNGS accounted for 1.7% of the average total cost of hospitalization. The survival analysis demonstrates that the positive blood mNGS result was not associated with increased mortality (P = 0.119).ConclusionsWith more valuable diagnostic performance and shorter turnaround time, clinical mNGS represents a potential step forward in the early diagnosis of IPN. 相似文献
35.
《Radiography》2022,28(2):518-523
IntroductionSelection of optimal image acquisition protocols in medical imaging remains a grey area, the superimposed use of the Likert scale in radiological image quality evaluations creates an additional challenge for the statistical analysis of image quality data.Using a simulation study, we have trialled a novel approach to analysing radiological image quality Likert scale data.MethodsA simulation study was undertaken where simulated datasets were generated based on the distribution of Likert scale values according to varying image acquisition protocols from a real dataset. Simulated Likert scale values were pooled in four different ways; the mean, median, mode and the summation of patient Likert scale values of which the total was assigned a categorical Likert scale value. Estimates of bias, MAPE and RMSPE were then calculated for all four pooling approaches to determine which method most accurately represented an expert's opinion.ResultsWhen compared to an expert's opinion, the method of summation and categorisation of Likert scale values was most accurate 49 times out of the 114 (43.0%) tests. The mean 28 times out of 114 (24.6%), the median 23 times out of 114 (20.2%) and the mode 17 times out of 114 (14.9%).ConclusionWe conclude that our method of summation and categorisation of Likert scale values is most often the best representation of the simulated data compared to the expert's opinion.Implications for practiceThere is scope to reproduce this simulation study with multiple observers to reflect clinical reality more accurately with the dynamic nature of multiple observers. This also prompts future investigation into other anatomical areas, to see if the same methods produce similar results. 相似文献
36.
37.
通过回顾分析我院2例确诊为胰岛素自身免疫综合征(IAS)患者的临床资料,并复习相关文献,总结发病机制及治疗方法,探讨IAS患者的临床特点,提高对低血糖症的诊治水平。 相似文献
38.
Yuan Peng Yuman Li Haiyan Cao Liu Hong Yu Wang Mingxing Xie 《Journal of ultrasound in medicine》2019,38(2):539-544
A pulmonary artery (PA) sling is a very rare congenital cardiovascular anomaly, and only a few studies have reported PA slings in fetuses. The relationship of the PA, aorta, ductus arteriosus, and trachea can be evaluated in the 3‐vessel and 3‐vessel and trachea views during fetal echocardiography. A PA sling can be detected by abnormal positioning of the left PA in relation to the trachea when sweeping from the 3‐vessel view cranially to the 3‐vessel and trachea view. Here we report 3 cases of fetal PA slings and their follow‐ups. Two cases were confirmed by postnatal echocardiography, and the other case was confirmed by a cardiovascular cast after pregnancy termination. We emphasize that the 3‐vessel and 3‐vessel and trachea views are of crucial importance in the prenatal diagnosis of a PA sling. 相似文献
39.
Denise Lee Marcella D. Walker Hsin Yi Chen John A. Chabot James A. Lee Jennifer H. Kuo 《Surgery》2019,165(1):107-113
Background
Bone mineral density (BMD) has been found to improve after parathyroidectomy (PTX) in patients with primary hyperparathyroidism. There are few data on the effect of PTX on BMD in normocalcemic and normohormonal primary hyperparathyroidism.Methods
A retrospective analysis of 92 primary hyperparathyroidism patients who underwent PTX between 2004 and 2012 with pre- and post-PTX dual-energy x-ray absorptiometry was performed. Within-person changes in BMD pre- and post-PTX were analyzed using log linear mixed models, stratified by biochemical status.Results
Bone mineral density increased post-PTX in the whole cohort at the lumbar spine (+2.5%), femoral neck (+2.1%), and total hip (+1.9%) and decreased at the one-third radius (–0.9%). On comparison of BMD changes by profile, BMD increased in those with the typical profile at the lumbar spine (3.2%), femoral neck (2.9%), and total hip (2.9%) but declined at the one-third radius (–1.5%). In contrast, BMD improved only at the femoral neck (4.3%) in the normohormonal group and did not change at any site in the normocalcemic group. The typical group had a greater increase in BMD over time at the femoral neck and total hip compared with normocalcemic patients.Conclusion
Our results indicate that the skeletal benefit of PTX was attenuated in normocalcemic and normohormonal patients, suggesting that skeletal changes after PTX may depend on biochemical profile. 相似文献40.