全文获取类型
收费全文 | 281797篇 |
免费 | 25819篇 |
国内免费 | 19578篇 |
专业分类
耳鼻咽喉 | 2398篇 |
儿科学 | 2912篇 |
妇产科学 | 3328篇 |
基础医学 | 31461篇 |
口腔科学 | 4832篇 |
临床医学 | 38059篇 |
内科学 | 39968篇 |
皮肤病学 | 2629篇 |
神经病学 | 14566篇 |
特种医学 | 10978篇 |
外国民族医学 | 157篇 |
外科学 | 28601篇 |
综合类 | 50725篇 |
现状与发展 | 70篇 |
一般理论 | 22篇 |
预防医学 | 18933篇 |
眼科学 | 7890篇 |
药学 | 29392篇 |
256篇 | |
中国医学 | 16944篇 |
肿瘤学 | 23073篇 |
出版年
2024年 | 893篇 |
2023年 | 4187篇 |
2022年 | 10802篇 |
2021年 | 13621篇 |
2020年 | 10347篇 |
2019年 | 8901篇 |
2018年 | 9420篇 |
2017年 | 8699篇 |
2016年 | 8067篇 |
2015年 | 12660篇 |
2014年 | 15688篇 |
2013年 | 14296篇 |
2012年 | 21077篇 |
2011年 | 23391篇 |
2010年 | 14997篇 |
2009年 | 12163篇 |
2008年 | 15502篇 |
2007年 | 15396篇 |
2006年 | 15159篇 |
2005年 | 14672篇 |
2004年 | 9957篇 |
2003年 | 9870篇 |
2002年 | 8214篇 |
2001年 | 7028篇 |
2000年 | 6762篇 |
1999年 | 6494篇 |
1998年 | 3937篇 |
1997年 | 3912篇 |
1996年 | 3099篇 |
1995年 | 2847篇 |
1994年 | 2370篇 |
1993年 | 1505篇 |
1992年 | 1994篇 |
1991年 | 1696篇 |
1990年 | 1376篇 |
1989年 | 1154篇 |
1988年 | 1054篇 |
1987年 | 928篇 |
1986年 | 749篇 |
1985年 | 540篇 |
1984年 | 347篇 |
1983年 | 245篇 |
1982年 | 158篇 |
1981年 | 151篇 |
1980年 | 111篇 |
1979年 | 146篇 |
1978年 | 49篇 |
1977年 | 53篇 |
1975年 | 57篇 |
1974年 | 56篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
We report clinical, neuroradiologic features, and neuropathologic findings of a 76‐year‐old man with coexistent Pick’s disease and progressive supranuclear palsy. The patient presented with loss of recent memory, abnormal behavior and change in personality at the age of 60. The symptoms were progressive. Three years later, repetitive or compulsive behavior became prominent. About 9 years after onset, he had difficulty moving and became bed‐ridden because of a fracture of his left leg. His condition gradually deteriorated and he developed mutism and became vegetative. The patient died from pneumonia 16 years after the onset of symptoms. Serial MRI scans showed progressive cortex atrophy, especially in the bilateral frontal and temporal lobes. Macroscopic inspection showed severe atrophy of the whole brain, including cerebrum, brainstem and cerebellum. Microscopic observations showed extensive superficial spongiosis and severe neuronal loss with gliosis in the second and third cortical layers in the frontal, temporal and parietal cortex. There were Pick cells and argyrophilic Pick bodies, which were tau‐ and ubiquitin‐positive in neurons of layers II–III of the above‐mentioned cortex. Numerous argyrophilic Pick bodies were observed in the hippocampus, especially in the dentate fascia. In addition, moderate to severe loss of neurons was found with gliosis and a lot of Gallyas/tau‐positive globus neurofibrillary tangles in the caudate nucleus, globus pallidus, thalamus, substantia nigra, locus coeruleus and dentate nucleus. Numerous thorned‐astrocytes and coiled bodies but no‐tuft shaped astrocytes were noted in the basal ganglion, brainstem and cerebellar white matter. In conclusion, these histopathological features were compatible with classical Pick’s disease and coexistence with progressive supranuclear palsy without tuft‐shaped astrocytes. 相似文献
22.
A Trakic F Liu H Sanchez Lopez H Wang S Crozier 《Magnetic resonance in medicine》2007,57(6):1119-1130
The switching of magnetic field gradient coils in magnetic resonance imaging (MRI) inevitably induces transient eddy currents in conducting system components, such as the cryostat vessel. These secondary currents degrade the spatial and temporal performance of the gradient coils, and compensation methods are commonly employed to correct for these distortions. This theoretical study shows that by incorporating the eddy currents into the coil optimization process, it is possible to modify a gradient coil design so that the fields created by the coil and the eddy currents combine together to generate a spatially homogeneous gradient that follows the input pulse. Shielded and unshielded longitudinal gradient coils are used to exemplify this novel approach. To assist in the evaluation of transient eddy currents induced within a realistic cryostat vessel, a low-frequency finite-difference time-domain (FDTD) method using the total-field scattered-field (TFSF) scheme was performed. The simulations demonstrate the effectiveness of the proposed method for optimizing longitudinal gradient fields while taking into account the spatial and temporal behavior of the eddy currents. 相似文献
23.
在给病人使用化疗药物的过程中,护士不可避免地接触抗肿瘤药物,因而对自身健康产生危害。为了维护护士的健康,提高护理人员的防护意识,我们对肿瘤专科护士做一个防护调查,现将情况介绍如下。1临床资料与方法1.1临床资料选取山西省肿瘤医院临床一线,参加工作2年以上并经常接触化 相似文献
24.
Pulmonary Lophomonas blattarum infection in patients with kidney allograft transplantation 总被引:3,自引:0,他引:3
Yong Wang Zheng Tang Shuming Ji Zhen Zhang Jinsong Chen Zhen Cheng Dongrui Cheng Zhihong Liu Leishi Li 《Transplant international》2006,19(12):1006-1013
The aim of the study was to analyse the clinical manifestation and management of pulmonary Lophomonas blattarum infection in four allograft transplantation recipients retrospectively. Four patients with pulmonary L. blattarum infection were diagnosed by using Fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) examination. Their clinical manifestation and management are summarized. Four cases of pulmonary L. blattarum were found during the period from the second month to the third month after transplantation. Concurring infection by other pathogens was found in three of them. Common initial symptoms included fever (>38 degrees C) without cough and breathlessness. Lower lobe shadowing could be found on chest X-ray. Body temperature decreased to the normal range in three patients and to 37.5 degrees C in the other one, after intravenous injection of metronidazole and tapering immunosuppressant. Radiological examination confirmed improved health condition of the patients afterwards. Two patients received repeated FOB and only dead L. blattarum was found. Pulmonary L. blattarum infection in allograft transplant recipients carry relatively obscure initial symptoms. Possible L. blattarum infection needs to be screened in post-transplantation pulmonary infection patients with similar symptoms, especially in those who respond poorly to anti-infection treatment. Microscopic examination of BAL fluid can help to identify pulmonary L. blattarum infection and metronidazole is an ideal treatment choice. 相似文献
25.
妊娠期糖尿病62例临床分析 总被引:1,自引:0,他引:1
目的 探讨妊娠期糖尿病的合理处理及预后.方法 选择62例妊娠期糖尿病患者进行回顾性分析.结果 妊娠期糖尿病62例,其中单纯饮食控制17例,饮食控制 胰岛素治疗43例,2例未治疗.剖宫产42例,阴道产20例.合并妊高症3例,羊水过多2例,羊水过少4例,羊水栓塞1例,早产5例,高胆红素血症3例,真性红细胞增多症2例,死胎2例,新生儿窒息4例,新生儿畸形1例.结论 对妊娠合并糖尿病的孕妇进行早期的诊断及治疗,选择合适的时间及方式终止妊娠可以减少母儿并发症的发生率. 相似文献
26.
内镜辅助方型脸改型术 总被引:4,自引:0,他引:4
目的探讨内镜在方型脸改型术中的临床应用效果。方法采用口内入路,在内镜辅助下,用高速涡轮气钻截除肥大下颌角、切除部分咬肌和颊脂垫,进行方型脸的面部改型。结果本组共38例,其中男3例,女35例,年龄21~40岁。内镜完全可以清楚显示下颌升支、下颌角、下颌体下缘,视野清晰。使用高速涡轮气钻截除肥大下颌角可以更加精确和容易,且创伤小,出血少,手术时间短,感染风险低。下面部轮廓改善满意。结论内镜辅助方型脸改型术,有助于获得良好的手术效果。 相似文献
27.
Vincent Chung Liang Liu Zhaoxiang Bian Zhongzhen Zhao Wai Leuk Fong Wan Fung Kum Jing Gao Min Li 《Movement disorders》2006,21(10):1709-1715
The objective of this study is to assess the efficacy and safety of herbal medicines (HMs), as a monotherapy or adjunct therapy, compared to placebo or conventional approaches in the treatment of idiopathic Parkinson's disease (PD). We conducted a systematic review of randomized controlled trials from both conventional and alternative medicine sources. Outcome measures were overall improvement, quality of life, reduction of levodopa dose, and adverse events. Nine studies were included, each testing a different HM. Six of the trials had limited internal validity due to major flaws in design, including the lack of proper randomization; insufficient blinding; unclear inclusive criteria in terms of diagnostic criteria, baseline staging, and duration of disease; lack of proper sample size calculation; and insufficient data analysis. Imbalances in gender and ethnicity among the patients in the included trials were observed. No major adverse events emerged, and no specific pattern was detected from the trials describing such data. In addition to major methodological defects, heterogeneity in (1) HM tested, (2) control treatment, and (3) outcome measure hindered in-depth data analysis and synthesis. Current evidence is insufficient to evaluate the efficacy and safety of various HMs. Further studies with improved trial design and reporting, with assessment on cost-effectiveness, quality of life, and qualitative data are warranted. 相似文献
28.
分析近年来国内高校教育形式的变化,肯定扎实学生基础、培养创新型人才的重要性,结合多年来在工科物理教改中的探索经验和初步成果,提出了深化工科物理教学改革、培养创新型人才的思路和实现途径。 相似文献
29.
30.
晶体玻璃体视网膜联合手术治疗复杂性视网膜脱离 总被引:6,自引:2,他引:4
目的探讨玻璃体视网膜手术(vitreretinalsurgery,VR术)联合晶体切除/超声粉碎的效果。方法对81例(81只眼)应用晶体玻璃体视网膜联合手术(lenticular-vitreoretinalsurgery,LVR术)治疗的复杂性视网膜脱离进行回顾性分析。结果解剖性成功者64只眼(79.01%),功能性成功者45只眼(55.56%);手术成功率显著降低的原因是前部增殖性玻璃体视网膜病变(proliferativevitreo-retinopathy,PVR)(成功率42.86%,P<0.01)和术中/术后眼内出血(成功率58.82%,P<0.025)。结论LVR术是治疗复杂性视网膜脱离的主要方法;显著影响手术预后的因素是前部PVR和术中/术后眼内出血。 相似文献