全文获取类型
收费全文 | 17350篇 |
免费 | 894篇 |
国内免费 | 156篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 347篇 |
妇产科学 | 592篇 |
基础医学 | 1918篇 |
口腔科学 | 448篇 |
临床医学 | 1382篇 |
内科学 | 4411篇 |
皮肤病学 | 309篇 |
神经病学 | 1861篇 |
特种医学 | 729篇 |
外科学 | 2610篇 |
综合类 | 49篇 |
一般理论 | 1篇 |
预防医学 | 591篇 |
眼科学 | 311篇 |
药学 | 1038篇 |
中国医学 | 24篇 |
肿瘤学 | 1641篇 |
出版年
2024年 | 22篇 |
2023年 | 177篇 |
2022年 | 345篇 |
2021年 | 603篇 |
2020年 | 390篇 |
2019年 | 478篇 |
2018年 | 602篇 |
2017年 | 408篇 |
2016年 | 492篇 |
2015年 | 552篇 |
2014年 | 758篇 |
2013年 | 900篇 |
2012年 | 1379篇 |
2011年 | 1386篇 |
2010年 | 761篇 |
2009年 | 701篇 |
2008年 | 1108篇 |
2007年 | 1106篇 |
2006年 | 1063篇 |
2005年 | 962篇 |
2004年 | 927篇 |
2003年 | 796篇 |
2002年 | 684篇 |
2001年 | 157篇 |
2000年 | 166篇 |
1999年 | 174篇 |
1998年 | 154篇 |
1997年 | 113篇 |
1996年 | 116篇 |
1995年 | 104篇 |
1994年 | 72篇 |
1993年 | 63篇 |
1992年 | 95篇 |
1991年 | 91篇 |
1990年 | 54篇 |
1989年 | 54篇 |
1988年 | 42篇 |
1987年 | 42篇 |
1986年 | 42篇 |
1985年 | 33篇 |
1984年 | 41篇 |
1983年 | 33篇 |
1982年 | 27篇 |
1981年 | 22篇 |
1980年 | 12篇 |
1976年 | 9篇 |
1974年 | 8篇 |
1971年 | 8篇 |
1970年 | 9篇 |
1969年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Paolo Ambrosetto Stefano Zucchini Alessandro Cicognani Emanuele Cacciari 《Pediatric radiology》1998,28(5):288-289
A girl with Diamond-Blackfan syndrome and hypopituitarism was suspected of having pituitary haemosiderosis because of the
clinical picture and the long history of blood transfusions. On T1-weighted MR images the pituitary exhibited a markedly hypointense
anterior lobe (mimicking the empty sella), suggesting iron deposition, while on T2W MRI the low signal of the pituitary was
surrounded by the high signal of the CSF. MR may be considered the examination of choice for detecting iron overload in the
pituitary.
Received: 10 November 1997 Accepted: 21 November 1997 相似文献
52.
A Giorgio P Amoroso G Francica G de Stefano P Fico G Lettieri L Tarantino L Finelli F Fiorentino P Pierri 《Gastrointestinal radiology》1988,13(4):336-340
To clarify the therapeutic role of echo-guided percutaneous puncture (EPP) in management of amebic liver abscess, 20 patients (24 abscesses) received metronidazole plus EPP. Fluid was aspirated through Chiba needles under real-time sonographic guidance so as to reduce cavity size to less than 3 cm. Not more than two EPPs were necessary in the majority of cases and no complication followed the procedure. This scheme resulted in a shortening of time of both hospitalization (less than or equal to 20 days) and liver lesion healing as assessed by ultrasound (less than or equal to 4 months). It is concluded that EPP is a valuable and safe therapeutic tool for hepatic amebic abscess. 相似文献
53.
通过人工合成了人类免疫缺陷性病毒(Humanimmunodeficiencyvirus,HIV)糖蛋白肽GP120对人和无脊椎动物(Mytilusedulis)免疫细胞的抑制作用的研究。人单核细胞和Mytilusedulis免疫细胞分别与GP120保温后,均抑制细胞的吞噬细菌(Psudomonasstretzi)作用。应用计算机显微图像术(Computer-assistedmicroscopy)直 相似文献
54.
Peripheral blood dendritic cells increase in kidney-transplant patients without rejection 总被引:2,自引:0,他引:2
Saresella M Marini M Guerini F Ferrante P Della Bella S Chiaramonte S Riva A 《Clinical immunology (Orlando, Fla.)》2004,110(2):191-3; author reply 194
55.
The improvements in the motor ability in patients with Parkinson's disease due to antiparkinsonian medication is well-known and widely documented. Recent results, based both on kinematic parameters and standard electromyographic (EMG) signal analysis, clearly indicated that the medication reduced, as expected, the clinical signs of Parkinson's disease, but did not restore agonist burst duration modulation with distance in elbow flexion movements. The main aim of the present work is to shed more light on this medication effect using a wavelet analysis approach on multiple EMG signals recorded both on shoulder and elbow muscles in ballistic or rapid movements. The wavelet cross-correlation information allows us to evidence some important quantitative features of the EMG signals due to medication. 相似文献
56.
57.
58.
Vitamin E affects cell death in adult rat dentate gyrus 总被引:1,自引:0,他引:1
Ferri P Cecchini T Ciaroni S Ambrogini P Cuppini R Santi S Benedetti S Pagliarani S Del Grande P Papa S 《Journal of neurocytology》2003,32(9):1155-1164
We have previously reported the presence of dying cells in the granule cell layer (GCL) of adult rat dentate gyrus (DG), where neurogenesis occurs. In particular, we found that cell death in the GCL increased in vitamin E deficiency and decreased in vitamin E supplementation. These findings were regarded as related to changes in neurogenesis rate, which in turn was influenced by vitamin E availability; a neuroprotective effect of vitamin E on cell death was also proposed. In order to verify this latter hypothesis, we have studied cell death in all layers of DG in vitamin E-deficient and vitamin E-supplemented rats and in control rats at different ages, using TUNEL and nick translation techniques. The phenotype of TUNEL-positive cells was characterized and the existence of dying BrdU-positive cells was investigated. Dying cells with neuronal phenotype were observed throughout the DG in all experimental groups. The number of TUNEL-positive cells decreased from juvenile to adult age. A higher number of TUNEL-positive cells in vitamin E-deficient rats and a lower number in vitamin E-supplemented rats, with respect to age-matched controls, were found; moreover, in these groups, TUNEL-positive cells had a different percentage distribution in the different layers of the DG. Our results confirm the occurrence of cell death in DG, demonstrate that cell death affects neuronal cells and support the hypothesis that the effect of vitamin E on cell death is not related to neurogenesis. 相似文献
59.
Claudia Ciaccio Chiara Pantaleoni Donatella Milani Enrico Alfei Francesca L. Sciacca Laura Canafoglia Alessandra Erbetta Stefano D'Arrigo 《American journal of medical genetics. Part A》2020,182(10):2317-2324
Potocki–Lupski syndrome is a condition mainly characterized by infantile hypotonia, developmental delay/intellectual disability (DD/ID), and congenital anomalies, caused by duplications of the 17p11.2 region, encompassing RAI1 gene. Its clinical presentation is extremely variable, especially for what concerns the cognitive level and the behavioral phenotype. Such aspects, as well as the dysmorphic/malformative ones, have been covered by previous studies; otherwise neurological features have never been systematically described. In order to delineate the neurological phenotype of Potocki–Lupski Syndrome, we collect an 8‐patients cohort. Developmental milestones are delayed and a mild to moderate cognitive impairment is present in all patients, variably associated with features of autism spectrum disorder, behavioral disturb, and sleep disturb. Hypotonia appears a less frequent finding than what previously reported, while motor clumsiness/coordination impairment is frequent. EGG registration demonstrated a common pattern with excess of diffuse rhythmic activity in sleep phases or while the patient is falling asleep. Brain MRI did not reveal common anomalies, although unspecific white matter changes may be present. We discuss such findings and compare them to literature data, offering an overview on the neurological and cognitive‐behavioral presentation of the syndrome. 相似文献
60.
In the context of a medical surveillance program aimed at preventing cancer risk from exposure to ionizing radiation, we investigated chromosomal damage in peripheral lymphocytes from 37 hospital workers exposed to low levels of ionizing radiation and 37 controls. The micronuleus (MN) assay was used as a biomarker of genetic damage. The influence of confounding factors like smoking status, age and gender was investigated by multiple regression analysis. The results indicated that, overall, MN frequency was higher in exposed workers than in controls, although the difference was not statistically significant. Interestingly, smoking status significantly raised MN frequency among the exposed workers but not among controls. This suggests that smoking can influence chromosomal damage induced in humans by ionizing radiation. Among both exposed workers and controls, MN frequency was found to increase with age. Female gender influenced the increase in MN frequency in the exposed group. Our results suggest that the effect of cigarette smoking should be carefully factored into genetic monitoring studies assessing the risks associated with low level radiation exposure. 相似文献