全文获取类型
收费全文 | 534816篇 |
免费 | 297960篇 |
国内免费 | 51134篇 |
专业分类
耳鼻咽喉 | 4828篇 |
儿科学 | 8453篇 |
妇产科学 | 6440篇 |
基础医学 | 113190篇 |
口腔科学 | 8292篇 |
临床医学 | 91653篇 |
内科学 | 126988篇 |
皮肤病学 | 8190篇 |
神经病学 | 31290篇 |
特种医学 | 20384篇 |
外国民族医学 | 42篇 |
外科学 | 68967篇 |
综合类 | 117911篇 |
现状与发展 | 56篇 |
一般理论 | 27篇 |
预防医学 | 70168篇 |
眼科学 | 23099篇 |
药学 | 87526篇 |
302篇 | |
中国医学 | 63814篇 |
肿瘤学 | 32290篇 |
出版年
2023年 | 5537篇 |
2022年 | 11395篇 |
2021年 | 13957篇 |
2020年 | 14434篇 |
2019年 | 18178篇 |
2018年 | 19216篇 |
2017年 | 20501篇 |
2016年 | 18272篇 |
2015年 | 22470篇 |
2014年 | 25394篇 |
2013年 | 26995篇 |
2012年 | 34438篇 |
2011年 | 38613篇 |
2010年 | 36305篇 |
2009年 | 41231篇 |
2008年 | 31059篇 |
2007年 | 27346篇 |
2006年 | 25044篇 |
2005年 | 22662篇 |
2004年 | 23335篇 |
2003年 | 22124篇 |
2002年 | 20182篇 |
2001年 | 20630篇 |
2000年 | 13828篇 |
1999年 | 17659篇 |
1998年 | 16924篇 |
1997年 | 16769篇 |
1996年 | 16885篇 |
1995年 | 16901篇 |
1994年 | 16555篇 |
1993年 | 15387篇 |
1992年 | 14432篇 |
1991年 | 13619篇 |
1990年 | 12375篇 |
1989年 | 12007篇 |
1988年 | 11314篇 |
1987年 | 10571篇 |
1986年 | 10006篇 |
1985年 | 8882篇 |
1984年 | 6767篇 |
1983年 | 6724篇 |
1982年 | 7727篇 |
1981年 | 7249篇 |
1980年 | 6896篇 |
1979年 | 6752篇 |
1978年 | 5885篇 |
1977年 | 6184篇 |
1976年 | 5793篇 |
1975年 | 5543篇 |
1974年 | 5093篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
L. Dvorakova J. Sikora M. Hrebicek H. Hulkova M. Bouckova L. Stolnaja M. Elleder 《Journal of inherited metabolic disease》2006,29(4):591
Summary We present the third case of Niemann–Pick disease type C without neurological symptoms. The patient was a 53-year-old woman
without significant prior health problems who died of acute pulmonary embolism. Autopsy findings of hepatosplenomegaly, lymphadenopathy
and ceroid-rich foam cells raised the suspicion of the visceral form of acid sphingomyelinase deficiency (Niemann–Pick disease
type B; NPB) or a much rarer disorder, variant adult visceral form of Niemann–Pick disease type C (NPC). To verify the histopathological
findings, SMPD1, NPC1 and NPC2 genes were analysed. Two novel sequence variants, c.1997G>A (S666N) and c.2882A>G (N961S) were detected in the NPC1 gene. No pathogenic sequence variants were found either in the SMPD1 gene mutated in NPB or in NPC2 gene. The pathogenicity of both NPC1 variants was supported by their location in regions important for the protein function. Both variations were not found in
more than 300 control alleles. Identified sequence variations confirm the diagnosis of the extremely rare adult visceral form
of Niemann–Pick disease type C, which is otherwise dominated by neurovisceral symptoms. Although only three patients have
been reported, this (most probably underdiagnosed) form of NPC should be considered in differential diagnosis of isolated
hepatosplenomegaly with foam cells in adulthood.
Electronic supplementary material Supplementary material is available for this article at 相似文献
22.
Background
In meningitis, the cerebrospinal fluid contains high levels of innate immune molecules (e.g. complement) which are essential to ward off the infectious challenge and to promote the infiltration of phagocytes (neutrophils, monocytes). However, epithelial cells of either the ependymal layer, one of the established niche for adult neural stem cells, or of the choroid plexus may be extremely vulnerable to bystander attack by cytotoxic and cytolytic complement components. 相似文献23.
24.
25.
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
26.
27.
TE-AN LEE HUANG-KUANG CHANG STONE YANG SHAOU-MING FANG KUO-MING CHANG 《International journal of urology》2006,13(6):824-826
Most ureteral tumors are transitional cell neoplasms. Neuroendocrine tumors of the genitourinary tract are extremely rare. To our knowledge, only one ureteral carcinoid tumor has been reported before. We report a second case of ureteral carcinoid tumor found in a 70-year-old female. 相似文献
28.
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
29.
加强医疗仪器设备管理提高医疗仪器设备使用效益 总被引:1,自引:0,他引:1
加强医疗设备管理,提高设备使用效益,制定合理的计划,正确选购设备,为医院提供品种、性能、精度适当的技术装备。 相似文献
30.
[目的]探讨降钙素对已行人工假体植入骨质疏松模型免的假体无菌性松动防治作用的实验研究。[方法]将30只假体植入模型的骨质疏松症兔随机分成实验组和对照组,各15只。实验组给予鲑鱼降钙素治疗(6U/kg,肌注,隔日1次),而对照组给予等量的生理盐水肌注,持续治疗半年。两组均分别于术前、术后4、8、12和24周检测假体周围感应区(ROI)骨密度(BMD);于术前及术后4、12、24周行血清骨代谢指标检测:骨特异性碱性磷酸酶(BALP)、骨钙素(BGP)、抗酒石酸酸性磷酸酶-5b(TRAP-5b);所有动物于术后24周处死,分别行假体拔出实验与扭转实验测定和假体周围骨组织形态计量学分析。[结果]术后24周,实验组假体周围局部感兴趣区BMD增加近5%,而对照组假体周围局部感兴趣区BMD下降了6%,两组比较有显著性差异(P〈0.01);骨代谢指标中,术后24周实验组的BALP、BGP稍有下降,但组内无显著性差异(P〉0.05),而TRAP-5b有明显下降(P〈0.05),这些指标与对照组比较差异显著(P〈0.05或P〈0.01);生物力学检测显示,实验组的假体拔出实验较对照组提高了约50%,扭转实验提高近1倍,且两组比较差异显著(P〈0.01);骨组织形态计量学显示,实验组中反映骨吸收的Oc.No/Tb.Pm、ES/BS明显减少;反映骨量和微结构的%Tb.Ar、Tb.N明显增多,而Tb.Sp明显变窄:反映骨形成与骨矿化的OS/BS、MAR、BFR/TV及%L.Pm也均明显增多;这些指标与对照组比较差异显著(P〈0.01或P〈0.05)。[结论]鲑鱼降钙素能明显减少人工假体周围骨量的丢失和抑制骨溶解;并加快假体周围的骨形成,提高骨密度,促进生理性骨矿化;还能改善骨质量,促进骨微结构改变,提高骨的生物力学特性并增加假体四周的支撑力。其对骨质疏松症兔的假体松动有明显的预防和治疗作用。这对临床预防和治疗人工关节的无菌性松动有很好的指导意义。 相似文献