全文获取类型
收费全文 | 37980篇 |
免费 | 1947篇 |
国内免费 | 579篇 |
专业分类
耳鼻咽喉 | 324篇 |
儿科学 | 1331篇 |
妇产科学 | 417篇 |
基础医学 | 3628篇 |
口腔科学 | 302篇 |
临床医学 | 3824篇 |
内科学 | 3392篇 |
皮肤病学 | 224篇 |
神经病学 | 7135篇 |
特种医学 | 3518篇 |
外国民族医学 | 4篇 |
外科学 | 3545篇 |
综合类 | 4053篇 |
现状与发展 | 3篇 |
预防医学 | 1076篇 |
眼科学 | 192篇 |
药学 | 2789篇 |
14篇 | |
中国医学 | 571篇 |
肿瘤学 | 4164篇 |
出版年
2023年 | 368篇 |
2022年 | 814篇 |
2021年 | 1071篇 |
2020年 | 921篇 |
2019年 | 786篇 |
2018年 | 822篇 |
2017年 | 987篇 |
2016年 | 1160篇 |
2015年 | 1059篇 |
2014年 | 2005篇 |
2013年 | 2226篇 |
2012年 | 2010篇 |
2011年 | 2150篇 |
2010年 | 1926篇 |
2009年 | 1892篇 |
2008年 | 1988篇 |
2007年 | 1883篇 |
2006年 | 1811篇 |
2005年 | 1614篇 |
2004年 | 1277篇 |
2003年 | 1086篇 |
2002年 | 843篇 |
2001年 | 856篇 |
2000年 | 749篇 |
1999年 | 665篇 |
1998年 | 655篇 |
1997年 | 620篇 |
1996年 | 556篇 |
1995年 | 537篇 |
1994年 | 514篇 |
1993年 | 372篇 |
1992年 | 386篇 |
1991年 | 354篇 |
1990年 | 326篇 |
1989年 | 248篇 |
1988年 | 249篇 |
1987年 | 254篇 |
1986年 | 224篇 |
1985年 | 263篇 |
1984年 | 247篇 |
1983年 | 156篇 |
1982年 | 202篇 |
1981年 | 191篇 |
1980年 | 180篇 |
1979年 | 171篇 |
1978年 | 132篇 |
1977年 | 137篇 |
1976年 | 121篇 |
1975年 | 84篇 |
1973年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Ali Devrim Karaosmano?lu Mehmet Ruhi Onur Ali Shirkhoda Mustafa Ozmen Peter F. Hahn 《Korean journal of radiology》2015,16(4):853-859
Malignant kidney neoplasms are the most frequently encountered solid kidney masses. Although renal cell carcinoma is the major renal malignancy, other solid malignant renal masses should be considered in the differential diagnosis of solid renal masses that do not contain a macroscopic fatty component. In this pictorial essay, we present the imaging findings of a primitive neuroectodermal tumor, primary liposarcoma of the kidney, primary neuroendocrine tumor, leiomyosarcoma, synovial sarcoma, malignant fibrous histiocytoma, sclerosing fibrosarcoma and renal metastasis of osteosarcoma. 相似文献
994.
Harshad Jawalkar Venkateshwar Reddy Maryada Venkatramana Brahmajoshyula Guruvardhan Kumar V Kotha 《Indian Journal of Orthopaedics》2015,49(4):403-407
Background:Glomus tumors are benign hamartomas arising from the glomus body, mostly occurring in the subungual region of the digits. A triad of excruciating pain, localized tenderness and cold sensitivity is the key to diagnosing these tumors. Two surgical approaches are described in the literature for excision of subungual glomus tumors-transungual and periungual. We reviewed retrospectively the results of subungual glomus tumors of the hand treated by transungual excision.Results:All patients had complete pain relief. There was no new nail deformity and no recurrence till last followup. One patient had deformity of the nail preoperatively due to previous surgery, which persisted after excision of the tumor. All of them returned to their preoperative occupation and regained full function of the hand.Conclusions:The transungual approach provides good access to the entire lesion and facilitates complete excision. Contrary to reported literature, we did not find the development of any new nail deformity with this approach. 相似文献
995.
Salvage combined chemotherapy with paclitaxel,ifosfamide and nedaplatin for patients with advanced germ cell tumors 下载免费PDF全文
996.
Manouchehr Aghajanzadeh Ali Alavi Gilda Aghajanzadeh Hannan Ebrahimi Sina Khajeh Jahromi Sara Massahnia 《The Indian journal of surgery》2015,77(1):39-43
Wide surgical resection is the most effective treatment for the vast majority of chest wall tumors. This study evaluated the clinical success of chest wall reconstruction using a Prolene mesh and bone cement prosthetic sandwich. The records of all patients undergoing chest wall resection and reconstruction were reviewed. Surgical indications, the location and size of the chest wall defect, diaphragm resection, pulmonary performance, postoperative complications, and survival of each patient were recorded. From 1998 to 2008, 43 patients (27 male, 16 female; mean age of 48 years) underwent surgery in our department to treat malignant chest wall tumors: chondrosarcoma (23), osteosarcoma (8), spindle cell sarcoma (6), Ewing''s sarcoma (2), and others (4). Nine sternectomies and 34 antero-lateral and postero-lateral chest wall resections were performed. Postoperatively, nine patients experienced respiratory complications, and one patient died because of respiratory failure. The overall 4-year survival rate was 60 %. Chest wall reconstruction using a Prolene mesh and bone cement prosthetic sandwich is a safe and effective surgical procedure for major chest wall defects. 相似文献
997.
Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder characterized by impairments in communication and social interaction, as well as repetitive behaviors and interests. However, these traits are highly variable across individuals with ASD and are also present in the typically developing population. Brain structural correlates of ASD are also heterogeneous. Recent findings have indicated that ASD traits as measured by the autism quotient (AQ) are reflected in white matter structural differences in a continuous way across both typically-developed and ASD individuals. Here, we tested for the first time, how ASD traits are related to gray matter structural differences (and particularly cortical thickness) in both ASD and typically developing adults. The present results show that ASD traits are primarily correlated with reductions in cortical thickness in a continuous fashion across ASD and typically developing adults in social brain areas and the default mode network including the orbitofrontal cortex, postcentral gyrus, and lingual gyrus. These findings provide new evidence that ASD traits are primarily reflected in neural structure that exists along a continuum extending into the typically developing population. 相似文献
998.
Tine Verreet Roel Quintens Debby Van Dam Mieke Verslegers Mirella Tanori Arianna Casciati Mieke Neefs Liselotte Leysen Arlette Michaux Ann Janssen Emiliano D’Agostino Greetje Vande Velde Sarah Baatout Lieve Moons Simonetta Pazzaglia Anna Saran Uwe Himmelreich Peter Paul De Deyn Mohammed Abderrafi Benotmane 《Journal of Neurodevelopmental Disorders》2015,7(1)
Background
In humans, in utero exposure to ionising radiation results in an increased prevalence of neurological aberrations, such as small head size, mental retardation and decreased IQ levels. Yet, the association between early damaging events and long-term neuronal anomalies remains largely elusive.Methods
Mice were exposed to different X-ray doses, ranging between 0.0 and 1.0 Gy, at embryonic days (E) 10, 11 or 12 and subjected to behavioural tests at 12 weeks of age. Underlying mechanisms of irradiation at E11 were further unravelled using magnetic resonance imaging (MRI) and spectroscopy, diffusion tensor imaging, gene expression profiling, histology and immunohistochemistry.Results
Irradiation at the onset of neurogenesis elicited behavioural changes in young adult mice, dependent on the timing of exposure. As locomotor behaviour and hippocampal-dependent spatial learning and memory were most particularly affected after irradiation at E11 with 1.0 Gy, this condition was used for further mechanistic analyses, focusing on the cerebral cortex and hippocampus. A classical p53-mediated apoptotic response was found shortly after exposure. Strikingly, in the neocortex, the majority of apoptotic and microglial cells were residing in the outer layer at 24 h after irradiation, suggesting cell death occurrence in differentiating neurons rather than proliferating cells. Furthermore, total brain volume, cortical thickness and ventricle size were decreased in the irradiated embryos. At 40 weeks of age, MRI showed that the ventricles were enlarged whereas N-acetyl aspartate concentrations and functional anisotropy were reduced in the cortex of the irradiated animals, indicating a decrease in neuronal cell number and persistent neuroinflammation. Finally, in the hippocampus, we revealed a reduction in general neurogenic proliferation and in the amount of Sox2-positive precursors after radiation exposure, although only at a juvenile age.Conclusions
Our findings provide evidence for a radiation-induced disruption of mouse brain development, resulting in behavioural differences. We propose that alterations in cortical morphology and juvenile hippocampal neurogenesis might both contribute to the observed aberrant behaviour. Furthermore, our results challenge the generally assumed view of a higher radiosensitivity in dividing cells. Overall, this study offers new insights into irradiation-dependent effects in the embryonic brain, of relevance for the neurodevelopmental and radiobiological field.Electronic supplementary material
The online version of this article (doi:10.1186/1866-1955-7-3) contains supplementary material, which is available to authorized users. 相似文献999.
Neuroimaging studies demonstrate considerable changes in white matter volume and microstructure during adolescence. Most studies have focused on age-related effects, whilst puberty-related changes are not well understood. Using diffusion tensor imaging and tract-based spatial statistics, we investigated the effects of pubertal status on white matter mean diffusivity (MD) and fractional anisotropy (FA) in 61 males aged 12.7–16.0 years. Participants were grouped into early-mid puberty (≤Tanner Stage 3 in pubic hair and gonadal development; n = 22) and late-post puberty (≥Tanner Stage 4 in pubic hair or gonadal development; n = 39). Salivary levels of pubertal hormones (testosterone, DHEA and oestradiol) were also measured. Pubertal stage was significantly related to MD in diverse white matter regions. No relationship was observed between pubertal status and FA. Regression modelling of MD in the significant regions demonstrated that an interaction model incorporating puberty, age and puberty × age best explained our findings. In addition, testosterone was correlated with MD in these pubertally significant regions. No relationship was observed between oestradiol or DHEA and MD. In conclusion, pubertal status was significantly related to MD, but not FA, and this relationship cannot be explained by changes in chronological age alone. 相似文献
1000.
Radiological Follow-up of a Cerebral Tuberculoma with a Paradoxical Response Mimicking a Brain Tumor
Jeong-Kwon Kim Tae-Young Jung Kyung-Hwa Lee Seul-Kee Kim 《Journal of Korean Neurosurgical Society》2015,57(4):307-310
We report a case of a paradoxical response of a tuberculoma in the brain mimicking a brain tumor. A 76-year-old woman presented with a 2 week history of headache, dysarthia, and orthopnea. Brain magnetic resonance images (MRI) revealed two rim-enhancing lesions on the pons and occipital lobe, and chest computed tomography showed randomly distributed miliary nodules. The tentative diagnosis was tuberculosis (TB) of the brain and lung. She complained of right hemiparesis and worsening general weakness after taking the anti-TB medication. On the monthly follow-up images, the enhanced lesions were enlarged with increased perfusion and choline/creatinine ratio, suggesting a high grade glioma. A surgical resection was completed to diagnose the occipital lesion, and the tuberculoma was pathologically confirmed by a positive TB-polymerase chain reaction. The anti-TB medication was continued for 13 months. A follow-up MRI showed decreased size of the brain lesions associated with perilesional edema, and the clinical symptoms had improved. Brain tuberculoma could be aggravated mimicking brain malignancy during administration of anti-TB medication. This paradoxical response can be effectively managed by continuing the anti-TB drugs. 相似文献