全文获取类型
收费全文 | 85681篇 |
免费 | 8179篇 |
国内免费 | 5920篇 |
专业分类
耳鼻咽喉 | 791篇 |
儿科学 | 1414篇 |
妇产科学 | 922篇 |
基础医学 | 10015篇 |
口腔科学 | 1436篇 |
临床医学 | 11324篇 |
内科学 | 12639篇 |
皮肤病学 | 817篇 |
神经病学 | 4599篇 |
特种医学 | 3292篇 |
外国民族医学 | 40篇 |
外科学 | 9415篇 |
综合类 | 14203篇 |
现状与发展 | 19篇 |
一般理论 | 4篇 |
预防医学 | 6142篇 |
眼科学 | 2263篇 |
药学 | 8859篇 |
72篇 | |
中国医学 | 4287篇 |
肿瘤学 | 7227篇 |
出版年
2024年 | 281篇 |
2023年 | 1352篇 |
2022年 | 3384篇 |
2021年 | 4361篇 |
2020年 | 3225篇 |
2019年 | 2792篇 |
2018年 | 3037篇 |
2017年 | 2700篇 |
2016年 | 2531篇 |
2015年 | 3953篇 |
2014年 | 4762篇 |
2013年 | 4153篇 |
2012年 | 6379篇 |
2011年 | 6941篇 |
2010年 | 4575篇 |
2009年 | 3404篇 |
2008年 | 4341篇 |
2007年 | 4454篇 |
2006年 | 4366篇 |
2005年 | 4378篇 |
2004年 | 2925篇 |
2003年 | 2754篇 |
2002年 | 2366篇 |
2001年 | 1925篇 |
2000年 | 1978篇 |
1999年 | 1982篇 |
1998年 | 1281篇 |
1997年 | 1216篇 |
1996年 | 903篇 |
1995年 | 820篇 |
1994年 | 806篇 |
1993年 | 493篇 |
1992年 | 668篇 |
1991年 | 596篇 |
1990年 | 510篇 |
1989年 | 449篇 |
1988年 | 387篇 |
1987年 | 340篇 |
1986年 | 298篇 |
1985年 | 234篇 |
1984年 | 169篇 |
1983年 | 126篇 |
1982年 | 100篇 |
1981年 | 97篇 |
1980年 | 61篇 |
1979年 | 120篇 |
1978年 | 60篇 |
1973年 | 81篇 |
1972年 | 58篇 |
1971年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
23.
A novel surgical technique to prevent post-enucleation conjunctival cyst:conjunctival staining with methylthioninium 下载免费PDF全文
Dear Editor,Conjunctival cyst of the orbit acquired from enucleation is an infrequent but serious complication;which can occur in 3%-7%of patients,more commonly after a secondary procedure;.The most common manifestations are the inability to retain the external prosthesis. 相似文献
24.
器官移植术是20世纪出现的针对器官功能衰竭的最有效治疗方法,每年拯救全球超过12万例患者。但供器官短缺的现状,与器官移植技术和辅助药物的发展不匹配,制约了器官移植事业的发展。我国自2015年起已成为全球器官捐献和移植大国之一,2017年公民逝世后器官捐献数量超过5 000例,占全球捐献总量的15%以上。黄洁夫教授总结的器官捐献与移植"中国模式"得到了世界卫生组织、国际移植界的高度重视和充分肯定。本文通过整理全球及各国的器官捐献与移植数据,剖析全球现状与发展趋势,进一步探索我国公民器官捐献的影响因素并提出针对性的应对策略,以期实现我国器官捐献和移植的"自给自足"。 相似文献
25.
Alexander S. Dakos Ellen M. Walker Huai Jiang Barry E. Stein Benjamin A. Rowland 《The European journal of neuroscience》2019,50(11):3702-3712
Unilateral lesions of visual cortex have the secondary consequence of suppressing visual circuits in the midbrain superior colliculus (SC), collectively producing blindness in contralesional space (“hemianopia”). Recent studies have demonstrated that SC visual responses and contralesional vision can be reinstated by a non‐invasive multisensory training procedure in which spatiotemporally concordant visual‐auditory pairs are repeatedly presented within the blind hemifield. Despite this recovery of visual responsiveness, the loss of visual cortex was expected to result in permanent deficits in that hemifield, especially when visual events in both hemifields compete for attention and access to the brain's visuomotor circuitry. This was evaluated in the present study in a visual choice paradigm in which the two visual hemifields of recovered cats were simultaneously stimulated with equally valent visual targets. Surprisingly, the expected disparity was not found, and some animals even preferred stimuli presented in the previously blind hemifield. This preference persisted across multiple stimulus intensity levels and there was no indication that animals were less aware of cues in the previously blind hemifield than in its spared counterpart. Furthermore, when auditory cues were combined with visual cues, the enhanced performance they produced on a visual task was no greater in the normal than in the previously blind hemifield. These observations suggest that the multisensory rehabilitation paradigm revealed greater inherent visual information processing potential in the previously blind hemifield than was believed possible given the loss of visual cortex. 相似文献
26.
27.
Yaobin Ouyang Gongmeizi Liu Wenting Xu Zhen Yang Nianshuang Li Chuan Xie Chun Zhou Jiang Chen Yin Zhu Junbo Hong Nonghua Lu 《Oncology Letters》2021,21(2)
Helicobacter pylori (H. pylori) is a main risk factor for gastric cancer (GC). Epithelial-mesenchymal transition (EMT) is involved in the development and progression of H. pylori-associated GC. However, the exact molecular mechanism of this process remains unclear. The AKT/GSK3β signaling pathway has been demonstrated to promote EMT in several types of cancer. The present study investigated whether H. pylori infection induced EMT, and promoted the development and metastasis of cancer in the normal gastric mucosa, and whether this process was dependent on AKT activation. The expression levels of the EMT-associated proteins, including E-cadherin and N-cadherin, were determined in 165 gastric mucosal samples of different disease stages by immunohistochemical analysis. The expression levels of E-cadherin, N-cadherin, AKT, phosphorylated (p-)AKT (Ser473), GSK3β and p-GSK3β (Ser9) were further determined in H. pylori-infected Mongolian gerbil gastric tissues and cells co-cultured with H. pylori by immunohistochemical analysis and western blotting. The results indicated that the expression levels of the epithelial marker E-cadherin were decreased, whereas the expression levels of the mesenchymal marker N-cadherin were increased during gastric carcinogenesis. Their expression levels were associated with H. pylori infection. Furthermore, H. pylori infection resulted in downregulation of E-cadherin expression and upregulation of N-cadherin expression in Mongolian gerbils and GES-1 cells. In addition, an investigation of the associated mechanism of action revealed that p-AKT (Ser473) and p-GSK3β (Ser9) were activated in GES-1 cells following co-culture with H. pylori. Furthermore, following pretreatment of the cells with the AKT inhibitor VIII, the expression levels of E-cadherin, N-cadherin, p-AKT and p-GSK3β did not show significant differences between GES-1 cells that were co-cultured with or without H. pylori. The levels of p-AKT and p-GSK3β were increased in H. pylori-infected Mongolian gerbils. In conclusion, the present study demonstrated that H. pylori infection activated AKT and resulted in the phosphorylation and inactivation of GSK3β, which in turn promoted early stage EMT. These effects were AKT-dependent. This mechanism may serve as a prerequisite for GC development. 相似文献
28.
目的探讨T3、T4期结直肠癌患者淋巴结转移危险因素,为临床诊疗提供参考。方法回顾性分析2008年1月至2017年12月在空军军医大学西京消化病医院行结直肠癌根治术的1112例T3、T4期结直肠癌患者的临床病理资料,分析淋巴结转移状态与临床病理因素及肿瘤标志物的相关性,应用logistic多因素回归法分析淋巴结转移的相关危险因素。结果单因素分析结果显示,性别、年龄、肿瘤部位分层的结直肠癌患者间淋巴结转移率差异均无统计学意义(均P>0.05),淋巴结转移率在不同肿瘤长径[<5 cm和≥5 cm分别为37.75%(211/559)、52.26%(289/553),χ^2=23.666,P<0.01]、大体类型[浸润、溃疡、蕈伞、隆起分别为37.04%(20/54)、47.52%(432/909)、34.33%(23/67)、69.51%(57/82),χ^2=13.787,P=0.003]、分化程度[高、中、低分化分别为34.11%(102/299)、49.00%(317/647)、48.80%(81/166),χ^2=19.771,P<0.01]、错配修复缺陷(dMMR)[是和否分别为26.34%(64/243)、50.17%(436/869),χ^2=43.996,P<0.01]、神经侵犯[是和否分别为48.17%(421/874)、33.20%(79/238),χ^2=16.954,P<0.01]、脉管侵犯[是和否分别为79.16%(338/427)、23.65%(162/685),χ^2=327.493,P<0.01]以及术前癌胚抗原(CEA)[阳性(≥5 mg/ml)和阴性(<5 mg/ml)分别为52.87%(249/471)、39.16%(251/641),χ^2=20.162,P<0.01]和CA199[阳性(≥35 U/ml)和阴性(<35 U/ml)分别为59.33%(124/209)、41.64%(376/903),χ^2=21.465,P<0.01]分层患者间差异均有统计学意义。logistic多因素回归分析显示,脉管侵犯和术前CA199阳性是T3、T4期结直肠癌患者淋巴结转移独立危险因素(OR=13.006,95%CI 9.329~17.276,P<0.01;OR=2.194,95%CI 1.513~3.181,P<0.01),dMMR阳性是淋巴结转移的保护性因素(OR=0.279,95%CI 0.190~0.411,P<0.01)。结论脉管侵犯是T3、T4期结直肠癌患者淋巴结转移的主要危险因素。术前肿瘤标志物CA199的检测可以作为预测T3、T4期结直肠癌患者淋巴结转移状态的指标,一定程度上可为诊疗方案的制订提供参考。 相似文献
29.
30.