全文获取类型
收费全文 | 39143篇 |
免费 | 4416篇 |
国内免费 | 3026篇 |
专业分类
耳鼻咽喉 | 470篇 |
儿科学 | 352篇 |
妇产科学 | 310篇 |
基础医学 | 3842篇 |
口腔科学 | 633篇 |
临床医学 | 4937篇 |
内科学 | 5046篇 |
皮肤病学 | 466篇 |
神经病学 | 1739篇 |
特种医学 | 1676篇 |
外国民族医学 | 13篇 |
外科学 | 4846篇 |
综合类 | 8233篇 |
现状与发展 | 14篇 |
一般理论 | 2篇 |
预防医学 | 3040篇 |
眼科学 | 876篇 |
药学 | 4375篇 |
36篇 | |
中国医学 | 2783篇 |
肿瘤学 | 2896篇 |
出版年
2024年 | 219篇 |
2023年 | 885篇 |
2022年 | 2106篇 |
2021年 | 2547篇 |
2020年 | 2016篇 |
2019年 | 1513篇 |
2018年 | 1520篇 |
2017年 | 1503篇 |
2016年 | 1323篇 |
2015年 | 2040篇 |
2014年 | 2390篇 |
2013年 | 2455篇 |
2012年 | 3259篇 |
2011年 | 3529篇 |
2010年 | 2558篇 |
2009年 | 2066篇 |
2008年 | 2276篇 |
2007年 | 2224篇 |
2006年 | 1947篇 |
2005年 | 1799篇 |
2004年 | 1172篇 |
2003年 | 974篇 |
2002年 | 836篇 |
2001年 | 630篇 |
2000年 | 572篇 |
1999年 | 532篇 |
1998年 | 258篇 |
1997年 | 261篇 |
1996年 | 216篇 |
1995年 | 187篇 |
1994年 | 156篇 |
1993年 | 77篇 |
1992年 | 90篇 |
1991年 | 86篇 |
1990年 | 81篇 |
1989年 | 59篇 |
1988年 | 55篇 |
1987年 | 35篇 |
1986年 | 28篇 |
1985年 | 11篇 |
1984年 | 17篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1979年 | 6篇 |
1978年 | 11篇 |
1977年 | 5篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
991.
Rapid growth of a pseudosarcoma of the esophagus 总被引:2,自引:0,他引:2
K Sasajima Y Taniguchi K Morino K Yamashita M Onda K Hao K Takubo 《Journal of clinical gastroenterology》1988,10(5):533-536
The growth of a pseudosarcoma of the esophagus was observed chronologically by serial esophagography. Esophagograms taken 12 and 6 months prior to diagnosis showed no abnormalities. At diagnosis, the tumor in the lower esophagus had a polypoid and nodular surface with a stalk, and it was approximately 3 cm in diameter. Four months later, the tumor had increased in size to 4 cm in diameter. The tumor was 5 cm in length and incarcerated into the stomach with an elongated stalk at operation. The growth curve was linear on semilogarithmic paper; its doubling time was calculated as 2.2 months. The surgical specimen showed squamous cell carcinoma and spindle cell sarcoma-like elements that comprised the greater part of the tumor. The sarcoma-like elements had metastasized to the abdominal lymph nodes. These findings confirm that this polypoid tumor grows rapidly. 相似文献
992.
小鼠肝癌树突状细胞融合瘤苗抗肿瘤作用的研究 总被引:3,自引:0,他引:3
目的 探讨小鼠肝癌树突状细胞(D C)融合瘤苗抗肿瘤作用及其机制。 方法 用聚乙二醇(P E G)法制备小鼠肝癌D C融合瘤苗;流式细胞仪检测融合细胞表型特征;体内预防试验观察融合瘤苗免疫小鼠抵抗肿瘤攻击能力,乳酸脱氢酶(L D H)法检测其诱导的杀伤性T淋巴细胞活性;体内治疗试验观察荷瘤小鼠生存期及肿瘤组织中肿瘤坏死因子(TNF-α)、γ干扰素(IFN-γ)表达。 结果 小鼠肝癌D C融合瘤苗具备D C及肝癌细胞表型特征,能抵抗H 22小鼠肝癌细胞的攻击及诱导较强的细胞毒性T淋巴细胞(CTL)活性,DC/H22、DC H22、DC、H22各组CTL活性(A值)分别为0.624±0.014、0.330±0.014、0.262±0.019、0.246±0.017,F=65.46,P<0.01,能显著促进肿瘤组织中TNF-α、IFN—γ表达(F值分别为47.84、37.23,P值均<0.01)及延长荷瘤小鼠生存期(x2=18.45,P<0.01)。 结论 小鼠肝癌DC融合瘤苗能有效地诱导抗肿瘤免疫反应,在预防和治疗肝癌的复发及转移中有广阔的应用前景。 相似文献
993.
994.
Jian Li Geng Guo Jin Li Jiehe Hao Jianjun Zhang Yongping Guo Hui Yu 《The Journal of surgical research》2014
Background
The proto-oncogene dishevelled (Dvl) is a critical component of the Wnt/β-catenin signaling pathway, and its elevated expression in various tumor types is associated with malignancy. However, a role for Dvl in glioma has not been explored.Materials and methods
To determine whether Dvl expression is elevated in human glioma, we examined the protein levels in 67 human glioma samples and 3 normal brain specimens by Western blotting and immunohistochemistry. To investigate a possible association of Dvl with the malignant phenotype in glioma, the correlation of the Dvl immunoreactivity score (IRS) with β-catenin IRS, the tumor proliferation index (PI), and tumor invasion index (II) were determined for each sample.Results
The Dvl IRS, β-catenin IRS, PI, and II increased significantly with the pathologic grade of glioma (P <0.001) with average scores of 3.46 ± 3.45, 3.92 ± 3.28, 30.93 ± 17.92, and 20.43 ± 11.79, respectively. Furthermore, the PI and II were significantly higher for the Dvl-positive group than the Dvl-negative group (P <0.001). Correlation analysis demonstrated that β-catenin IRS, PI, and II were positively correlated with Dvl IRS.Conclusions
Dvl overexpression may contribute to the malignant proliferation and invasion of human glioma. 相似文献995.
Daofang Ding Leqin Xu Hao Xu Xiaofeng Li Qianqian Liang Yongjian Zhao Yongjun Wang 《中国神经再生研究》2014,9(1):25-32
To date, it remains poorly understood whether astrocytes can be easily reprogrammed into neurons. Mashl and Brn2 have been previously shown to cooperate to reprogram fibroblasts into neurons. In this study, we examined astrocytes from 2-month-old Sprague-Dawley rats, and found that Brn2 was expressed, but Mashl was not detectable. Thus, we hypothesized that Mashl alone could be used to reprogram astrocytes into neurons. We transfected a recombinant MSCV-MASH1 plasmid into astrocytes for 72 hours, and saw that all cells expressed Mashl. One week later, we observed the changes in morphology of astrocytes, which showed typical neuro- nal characteristics. Moreover, β-tubulin expression levels were significantly higher in astrocytes expressing Mashl than in control cells. These results indicate that Mashl alone can reprogram astrocytes into neurons. 相似文献
996.
Bo Xiang Zhenxing Yang Yin Lin Lijie Guan Xuan Li Wei Deng Zeyu Jiang Guohui Lao Qiang Wang Xiaoyu Hao Xiang Liu Yingcheng Wang Liansheng Zhao Xiaohong Ma Tao Li Liping Cao Xun Hu 《神经科学通报》2014,30(1):33-42
Serotonin plays an important role in mood regulation, but the involvement of serotonin pathway genes in the development of bipolar I disorder (BP-I), a mood disorder, is not clear. We selected 21 singlenucleotide polymorphisms (SNPs) within the HTR2A gene, 8 within the SLC6A4 gene and 23 within the TPH2 gene for genotyping using the GoldenGate genotyping assay. A total of 375 patients with BP-I and 475 normal controls were recruited. Two out of 21 SNPs (rs1475196 and rs9567747) in the HTR2A gene and 1/23 SNPs (rs17110566) in the TPH2 gene were significantly associated with BP-I, both genotype-wise and allele-wise. Furthermore, a specific haplotype in the HTR2A gene showed a significant association with BP-I. Our results indicate that the HTR2A and TPH2 genes in the serotonin pathway play important roles in susceptibility to BP-I. 相似文献
997.
目的:在《江苏省中药饮片炮制规范》修订时,增加MS测定中药材桂丁香中β-谷甾醇的含量。方法:采用气相色谱-串联质谱法(GC-MS/MS),大气压电喷雾离子源,负离子模式,多反应检测(MRM)定性离子对(m/z)329.0/95.2和定量离子对329.0/189.2,精确测定了β-谷甾醇含量。结果:β-谷甾醇在4.97~49.7 ng范围内线性关系良好(r=0.999 5),平均回收率为99.4%,RSD为1.4%(n=6)。结论:本方法操作简便,专属性强,检测灵敏度高,重复性好,可测定桂丁香中β-谷甾醇的含量。 相似文献
998.
Tong Zou Zhigang Zhang Chenggang Zou Keping Chen Yan Dai Jiabin Tong Xue Yu Junpeng Liu Dongke Chen Hongtao Xu Haifeng Shi Zhilei Wang Sujuan Wu Chen Sun Wen Cui Hao Chen Jun Yu Jiefu Yang 《International journal of cardiology》2014
While bacteria exist in CIED patients without clinical signs of infection, the underlying bacterial community structure and diversity in the bloodstream and pocket tissue of asymptomatic CIED patients remain unknown. In this study, we performed high-throughput 454 pyrosequencing of bacterial 16S rDNA of blood and pocket tissue from 54 asymptomatic CIED patients as well as blood from 30 normal individuals (normal controls). Firstly, we observed a significant increase of blood bacterial diversity in patients as compared with blood of normal subjects or patient tissues. We also found significant differences in 13 blood-associated bacterial genera between patients and normal subjects, and 14 bacteria genera between blood and tissues within patients. Secondly, we found that the serum levels of four inflammatory markers (CRP, IL-1β, IL-6, and MCP-1) in CIED patients were significantly higher than those in normal subjects. Thirdly, we found that there were significant correlations between 43 bacterial species and these inflammatory markers. Taken together, our results reveal a high diversity in the microbial community in CIED patients, and suggest the potential roles of multiple bacteria co-occurrence in the CIED subclinical infections. 相似文献
999.
Lili Tan Limin Liu Zhenyu Jiang Xiaojiao Hao 《Journal of pharmacological sciences》2019,139(4):280-288
Atherosclerosis (AS) is a chronic inflammatory disease of the arterial wall. Macrophages are considered to be closely associated with the development and progression of AS. However, the precise mechanism of miR-17-5p in the macrophages under AS remains incompletely clarified. This study investigated the regulatory effect of miR-17-5p on the inflammation and lipid accumulation in mouse macrophages both in vivo and in vitro. It was found that miR-17-5p was highly expressed with lowered ATP-binding cassette transporterA1 (ABCA1) level in the peripheral blood leucocytes (PBLs) of AS patients. Moreover, the level of miR-17-5p was up-regulated in the macrophages of ApoE?/? mice fed with a high-cholesterol diet. Furthermore, we injected miR-17-5p antagomir into AS mice or transfected miR-17-5p inhibitors into mouse macrophage RAW264.7 cells. Results showed that downregulation of miR-17-5p significantly reduced the production of inflammatory cytokines, inhibited the lipid accumulation and up-regulated ABCA1, and activated peroxisome proliferator-activated receptor (PPAR) γ/Liver X receptor (LXR) α signaling pathway. Additionally, ABCA1 was found to be a target of miR-17-5p by directly binding to 3′-untranslated region (3′-UTR) of its mRNA. Our study indicates a novel regulatory mechanism for miR-17-5p by interacting with ABCA1, which could be a therapy-target for the treatment of AS. 相似文献
1000.