全文获取类型
收费全文 | 53416篇 |
免费 | 2764篇 |
国内免费 | 206篇 |
专业分类
耳鼻咽喉 | 799篇 |
儿科学 | 1368篇 |
妇产科学 | 1146篇 |
基础医学 | 7052篇 |
口腔科学 | 3540篇 |
临床医学 | 3447篇 |
内科学 | 12418篇 |
皮肤病学 | 1426篇 |
神经病学 | 5023篇 |
特种医学 | 1255篇 |
外国民族医学 | 1篇 |
外科学 | 6695篇 |
综合类 | 289篇 |
一般理论 | 15篇 |
预防医学 | 4698篇 |
眼科学 | 1180篇 |
药学 | 3694篇 |
中国医学 | 324篇 |
肿瘤学 | 2016篇 |
出版年
2023年 | 453篇 |
2022年 | 973篇 |
2021年 | 1870篇 |
2020年 | 1050篇 |
2019年 | 1573篇 |
2018年 | 2038篇 |
2017年 | 1315篇 |
2016年 | 1390篇 |
2015年 | 1660篇 |
2014年 | 2181篇 |
2013年 | 2684篇 |
2012年 | 4026篇 |
2011年 | 4320篇 |
2010年 | 2311篇 |
2009年 | 1898篇 |
2008年 | 3300篇 |
2007年 | 3125篇 |
2006年 | 2878篇 |
2005年 | 2664篇 |
2004年 | 2468篇 |
2003年 | 2042篇 |
2002年 | 1872篇 |
2001年 | 1126篇 |
2000年 | 1132篇 |
1999年 | 935篇 |
1998年 | 324篇 |
1997年 | 202篇 |
1996年 | 188篇 |
1995年 | 174篇 |
1994年 | 177篇 |
1993年 | 140篇 |
1992年 | 400篇 |
1991年 | 357篇 |
1990年 | 330篇 |
1989年 | 285篇 |
1988年 | 265篇 |
1987年 | 245篇 |
1986年 | 203篇 |
1985年 | 179篇 |
1984年 | 152篇 |
1983年 | 131篇 |
1979年 | 102篇 |
1978年 | 86篇 |
1974年 | 71篇 |
1973年 | 73篇 |
1972年 | 73篇 |
1971年 | 81篇 |
1970年 | 64篇 |
1969年 | 69篇 |
1967年 | 88篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Adilson Cunha Ferreira Edward Araujo Júnior Wellington P. Martins João Francisco Jordão Antônio Hélio Oliani Simon E. Meagher 《The journal of maternal-fetal & neonatal medicine》2015,28(14):1706-1710
Objective: To assess the quality of images and video clips of fetal central nervous (CNS) structures obtained by ultrasound and transmitted via tele-ultrasound from Brazil to Australia.Methods: In this cross-sectional study, 15 normal singleton pregnant women between 20 and 26 weeks were selected. Fetal CNS structures were obtained by images and video clips. The exams were transmitted in real-time using a broadband internet and an inexpensive video streaming device. Four blinded examiners evaluated the quality of the exams using the Likert scale. We calculated the mean, standard deviation, mean difference, and p values were obtained from paired t tests.Results: The quality of the original video clips was slightly better than that observed by the transmitted video clips; mean difference considering all observers = 0.23 points. In 47/60 comparisons (78.3%; 95% CI?=?66.4–86.9%) the quality of the video clips were judged to be the same. In 182/240 still images (75.8%; 95% CI?=?70.0–80.8%) the scores of transmitted image were considered the same as the original.Conclusion: We demonstrated that long distance tele-ultrasound transmission of fetal CNS structures using an inexpensive video streaming device provided images of subjective good quality. 相似文献
2.
3.
4.
Leonardo Jönck Staub Roberta Rodolfo Mazzali Biscaro Erikson Kaszubowski Rosemeri Maurici 《The Journal of emergency medicine》2019,56(1):53-69
Background
Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.Objective
Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.Methods
PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).Results
Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.Conclusion
Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma. 相似文献5.
Jaros?aw Felu? Wojciech Rad?o Bart?omiej Kowalczyk 《Chirurgia narzadów ruchu i ortopedia polska》2006,71(2):107-112
Nine wrists in eight patients were treated surgically between 1988 and 2003 for symptomatic Madelung's deformity. The pain of involved wrist followed by forearm deformation fulfilled criteria for surgery. Closing wedge osteotomy of the distal radius were carried out eight times accompanied by shortening of the ulna (four patients), excision of the distal ulna (one patient), and no ulnar surgery (three patients). Pain relieved after surgery. The follow up period ranged from 1 to 9.5 years. No pour results were stated in subjective patient's estimation during final check up. Wrist appearance were stated to be satisfactory. Limitation of the range of motion concerning supination and pronation of the forearm were stated invariably. X-ray retrospective assessment of the inclination angle, lunate coverage and presence of arthritic changes were conducted. Time and method of surgical treatment for Madelung's deformity should be considered individually. 相似文献
6.
Roberto Manfredi Sergio Sabbatani Leonardo Calza 《The Brazilian journal of infectious diseases》2007,11(6):605-609
A patient with HIV infection developed the first episode of AIDS-defining opportunism (severe Candida albicans esophagitis) with an underlying CD4+ lymphocyte count of 1,025 cells/microL. After treatment with a highly active antiretroviral therapy (HAART), taken with insufficient compliance and leaving a residual viral load, our patient suffered from two relapses of esophageal candidiasis, which occurred three months and seven years later, when his CD4+ lymphocyte count was 930 and 439 cells/microL, respectively, and a viral load slightly above 10(4) copies/mL was still present. Also in the HAART era, Candida esophagitis remains one of the most common AIDS-defining diseases, but a presentation with a concurrent CD4+ count above 1,000 cells/microL remains a rare exception, as well as the two isolated, subsequent relapses, occurred with a CD4+ count ranging from 439 to 930 cells/microL, and a residual HIV viremia due to insufficient adherence to the prescribed HAART regimens. Our case report represents the opportunity to revisit the epidemiology and, especially, the pathogenesis of this opportunistic fungal complication in HIV-infected patients and in other subjects at risk, on the ground of an extensive literature review, and to explore possible alternative supporting factors other than the crude absolute CD4+ lymphocyte count, with emphasis on the possible role of a persisting HIV viremia, and other potential contributing factors. Clinicians engaged with immunocompromised patients and subjects with HIV disease, should be aware that a Candida esophagitis may occur and relapse also when the cell-mediated immunity, as measured by a simple CD4+ cell count, do not show relevant abnormalities. 相似文献
7.
Abnormal spinal interactions from hand afferents to forearm muscles in writer's cramp. 总被引:1,自引:0,他引:1
G Louren?o J-P Bleton C Iglesias M Vidailhet V Marchand-Pauvert 《Clinical neurophysiology》2007,118(10):2215-2226
OBJECTIVE: Spinal reflexes from hand to wrist muscles were investigated in writer's cramp. METHODS: Stimulus-triggered rectified EMG averages after ulnar nerve and cutaneous stimulation, in wrist flexors and extensors during tonic contraction, were compared in 18 controls and 19 patients. RESULTS: On the patient dystonic side, ulnar-induced EMG suppression was decreased in wrist extensors, and facilitation in wrist flexors modified dependent on the dystonic wrist posture during writing. No change was found on the patient non-dystonic side. Cutaneous stimulation increased wrist flexor EMG on both sides of the patients with normal wrist posture during writing, but had no effect in controls and patients with abnormal wrist posture. CONCLUSIONS: Comparison between cutaneous and mixed nerve stimuli suggests that spindle afferents from intrinsic hand muscles may mediate patients' ulnar-induced EMG modulations. Abnormal proprioceptive control was only observed on dystonic side, while bilateral unusual cutaneous control was found in patients. Changes in spinal transmission were partly related to the dystonic wrist posture, suggesting that systems involved in sensory processing can be differentially altered in writer's cramp. SIGNIFICANCE: Changes in spinal transmission, probably related to peripheral and/or cortical inputs, might either take part in primary or adaptive mechanisms underlying writer's cramp. 相似文献
8.
o. goetze a. b. nikodem j. wiezcorek † m. banasch h. przuntek † t. mueller † w. e. schmidt & d. woitalla † 《Neurogastroenterology and motility》2006,18(5):369-375
Predictors of gastric emptying (GE) in patients with idiopathic Parkinson's disease (PD) of a solid and liquid meal are not well defined. For measurement of GE 80 patients with PD were randomly assigned to receive either a solid meal (250 kcal) containing 13C-octanoate (n = 40) or a liquid meal (315 kcal) with 13C-acetate (n = 40). All patient groups were off medication affecting motility and were matched for age, gender, body mass index, disease duration and severity, using Unified Parkinson's Disease Rating Scale (UPDRS). Gastric emptying was compared with a healthy control group (n = 40). Multiple regression analysis was used to determine predictors of gastric emptying. Exactly 88% and 38% of PD patients had delayed GE of solids and liquids respectively. Solid and liquid emptying was similar in women and men. There were no differences in GE in PD patients < 65 years of age when compared with patients > or = 65 years. Multiple regression analysis showed that motor handicaps such as rigour and action tremor are independent predictors of solid GE (r = 0.68, P < 0.001). The severity of motor impairment, but not any other neurological symptom, as assessed by UPDRS is associated with gastroparesis in PD and solid emptying is more likely to be delayed. 相似文献
9.
10.