全文获取类型
收费全文 | 2413篇 |
免费 | 192篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 74篇 |
妇产科学 | 18篇 |
基础医学 | 274篇 |
口腔科学 | 62篇 |
临床医学 | 250篇 |
内科学 | 608篇 |
皮肤病学 | 40篇 |
神经病学 | 173篇 |
特种医学 | 124篇 |
外科学 | 307篇 |
综合类 | 48篇 |
一般理论 | 2篇 |
预防医学 | 120篇 |
眼科学 | 68篇 |
药学 | 115篇 |
中国医学 | 8篇 |
肿瘤学 | 307篇 |
出版年
2023年 | 13篇 |
2022年 | 12篇 |
2021年 | 44篇 |
2020年 | 33篇 |
2019年 | 48篇 |
2018年 | 57篇 |
2017年 | 49篇 |
2016年 | 52篇 |
2015年 | 80篇 |
2014年 | 113篇 |
2013年 | 118篇 |
2012年 | 168篇 |
2011年 | 159篇 |
2010年 | 117篇 |
2009年 | 90篇 |
2008年 | 125篇 |
2007年 | 144篇 |
2006年 | 144篇 |
2005年 | 129篇 |
2004年 | 118篇 |
2003年 | 110篇 |
2002年 | 103篇 |
2001年 | 81篇 |
2000年 | 68篇 |
1999年 | 65篇 |
1998年 | 33篇 |
1997年 | 26篇 |
1996年 | 30篇 |
1995年 | 30篇 |
1994年 | 21篇 |
1993年 | 18篇 |
1992年 | 34篇 |
1991年 | 12篇 |
1990年 | 16篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 20篇 |
1986年 | 12篇 |
1985年 | 14篇 |
1984年 | 15篇 |
1983年 | 6篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 4篇 |
1976年 | 4篇 |
1973年 | 5篇 |
1971年 | 8篇 |
1970年 | 5篇 |
1967年 | 5篇 |
排序方式: 共有2622条查询结果,搜索用时 15 毫秒
11.
We report two cases of acute myeloid leukemia with deletion of the long arm of chromosome 9 [del(9q)] and trisomy 21. del(9q) and +21 do not often occur as a sole karyotypic abnormality in acute myeloid leukemia (AML). Their concomitant presence is rare; the significance of the findings in leukemia is discussed. 相似文献
12.
Collision tumour of the oesophagus: a challenge for histological diagnosis. 总被引:2,自引:0,他引:2 下载免费PDF全文
An unusual case of mantle cell lymphoma metastasising to squamous cell carcinoma of the oesophagus, in a 62 year old Chinese man, is reported. A histological diagnosis based on examination of a small endoscopic biopsy specimen, in the absence of detailed clinical information, may be difficult, as the lymphoma component can be mistaken for reactive lymphoid infiltrate which is sometimes present adjacent to squamous cell carcinoma. Correlation with the clinical history, careful assessment of the subtle histological changes, and use of ancillary methods such as immunohistochemistry are most helpful in making the correct diagnosis. This case also illustrates further the possible occurrence of lymphomatous infiltrates surrounding other lesions in patients with a previous or concurrent history of lymphoma. 相似文献
13.
Trisomy 8/8q is a common cytogenetic event in myelocytic malignancies, ranging from myelodysplastic syndrome (MDS) to acute myelocytic leukemia (AML) to blastic transformation of chronic myelocytic leukemia. Isochromosome 8q results in the same gene dosage effect. Duplication of i(8q), resulting in pentasomy 8q, has been reported only in two cases of AML. A patient with fibrosing alveolitis on prolonged cyclophosphamide treatment developed therapy-related MDS. Karyotyping, FISH, and CGH analysis showed a duplicated i(8q) among other complex abnormalities. The clinical features of 11 cases of myelocytic leukemia with pentasomy and hexasomy 8/8q were summarized. Compared with trisomy and tetrasomy 8, significant features included reduced median survival (90 days), treatment refractoriness (even with transplantation), monocytic differentiation, trilineage dysplasia, and radiation or toxin exposure. Increasing copy numbers of chromosome 8/8q may therefore be a marker of advanced leukemic evolution, exposure to toxins, underlying myelodysplasia, and an overall poor prognosis. 相似文献
14.
Acute catatonic syndromes occurring in the context of various medical and neuropsychiatric conditions, including schizophrenia,
have been shown to respond well to benzodiazepines (BZD). However, there have been no studies specifically designed to address
the BZD treatment response of persistent catatonic states. Eighteen patients with clinically stable chronic schizophrenia,
who also displayed enduring catatonic features, underwent a 12-week long, random assignment, double-blind, placebo-controlled
cross-over trial with lorazepam (6 mg/day). A comprehensive assessment, including the subjects’ clinical and motor (catatonic
as well as drug-induced movement disorders) condition, was performed at baseline and four weekly intervals thereafter. Pre-existing
medication was kept constant throughout the study. Lorazepam had no effect on the subjects’catatonic signs and symptoms, suggesting
that acute and chronic catatonic syndromes associated with schizophrenic illness might have a different neurobiological basis.
Received: 25 May 1998/Final version: 22 September 1998 相似文献
15.
16.
17.
Mackenzie A. Hamilton Ying Liu Andrew Calzavara Maria E. Sundaram Mohamed Djebli Dariya Darvin Stefan Baral Rafal Kustra Jeffrey C. Kwong Sharmistha Mishra 《Influenza and other respiratory viruses》2022,16(6):1072
BackgroundShared and divergent predictors of clinical severity across respiratory viruses may support clinical and community responses in the context of a novel respiratory pathogen.MethodsWe conducted a retrospective cohort study to identify predictors of 30‐day all‐cause mortality following hospitalization with influenza (N = 45,749; 2010‐09 to 2019‐05), respiratory syncytial virus (RSV; N = 24 345; 2010‐09 to 2019‐04), or severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2; N = 8988; 2020‐03 to 2020‐12; pre‐vaccine) using population‐based health administrative data from Ontario, Canada. Multivariable modified Poisson regression was used to assess associations between potential predictors and mortality. We compared the direction, magnitude, and confidence intervals of risk ratios to identify shared and divergent predictors of mortality.ResultsA total of 3186 (7.0%), 697 (2.9%), and 1880 (20.9%) patients died within 30 days of hospital admission with influenza, RSV, and SARS‐CoV‐2, respectively. Shared predictors of increased mortality included older age, male sex, residence in a long‐term care home, and chronic kidney disease. Positive associations between age and mortality were largest for patients with SARS‐CoV‐2. Few comorbidities were associated with mortality among patients with SARS‐CoV‐2 as compared with those with influenza or RSV.ConclusionsOur findings may help identify patients at greatest risk of illness secondary to a respiratory virus, anticipate hospital resource needs, and prioritize local prevention and therapeutic strategies to communities with higher prevalence of risk factors. 相似文献
18.
Functional MRI of brain activation by eye blinking. 总被引:5,自引:0,他引:5
Functional magnetic resonance imaging (fMRI) was used to map cortical areas that control eye blinking. T2*-weighted asymmetric spin-echo MRI (or BOLD-blood oxygen level dependent-MRI) was used to detect changes caused by focal variations in blood oxygenation. Six normal volunteers and two cases of dry eye (less than 5-mm Schirmer's test) entered the study. The experimental scheme consisted of three cycles of a two-step sequence: (eyes closed)-(blink or blink inhibition). And to minimize contamination from photic activation, the experiments were carried out in a dark environment and the volunteers reported no light perception during the MR scans.In all eight cases, normal blinking (about one blink every 4 sec) activated areas in the orbitofrontal cortex and in some cases, the visual cortex including the anterior portion of the visual cortex and the primary visual cortex. In severe dry eye, blink-inhibition strongly activated the visual cortex even after irritation due to corneal desiccation was removed by topical anesthesia.The blinking process, especially the rate, appears to be controlled in the orbitofrontal cortex. The significance of visual cortex activation in the dark and in the case of severe dry eye still remains unclear; although it may be associated with attention and arousal. 相似文献
19.
Wayne K.W. Chan Kwong‐Yau Chan Ka‐Hung Pang Kong‐Ling Mak John C.K. Kwok 《Surgical Practice》2011,15(1):21-23
We present a case of histologically confirmed lipomatous meningioma, the first to our knowledge reported in Hong Kong. A 75‐year‐old woman presented to us with on and off dizziness for 1 month. Computed tomography (CT) of the brain showed an extra‐axial mass lesion containing fat and solid enhancing foci at her right frontal region. The definitive diagnosis could be made preoperatively. Postoperative histological examination of the tumour revealed the diagnosis of lipomatous meningioma. We have reviewed the literature and discussed the diagnostic clues, clinical presentation and pathology of this rare tumour. 相似文献
20.