全文获取类型
收费全文 | 2651篇 |
免费 | 356篇 |
国内免费 | 155篇 |
专业分类
耳鼻咽喉 | 22篇 |
儿科学 | 31篇 |
妇产科学 | 49篇 |
基础医学 | 316篇 |
口腔科学 | 62篇 |
临床医学 | 303篇 |
内科学 | 456篇 |
皮肤病学 | 42篇 |
神经病学 | 137篇 |
特种医学 | 47篇 |
外科学 | 405篇 |
综合类 | 329篇 |
预防医学 | 151篇 |
眼科学 | 43篇 |
药学 | 341篇 |
8篇 | |
中国医学 | 221篇 |
肿瘤学 | 199篇 |
出版年
2024年 | 34篇 |
2023年 | 66篇 |
2022年 | 160篇 |
2021年 | 182篇 |
2020年 | 132篇 |
2019年 | 118篇 |
2018年 | 119篇 |
2017年 | 121篇 |
2016年 | 105篇 |
2015年 | 126篇 |
2014年 | 155篇 |
2013年 | 119篇 |
2012年 | 181篇 |
2011年 | 198篇 |
2010年 | 105篇 |
2009年 | 97篇 |
2008年 | 127篇 |
2007年 | 113篇 |
2006年 | 100篇 |
2005年 | 105篇 |
2004年 | 79篇 |
2003年 | 78篇 |
2002年 | 76篇 |
2001年 | 39篇 |
2000年 | 59篇 |
1999年 | 33篇 |
1998年 | 27篇 |
1997年 | 33篇 |
1996年 | 26篇 |
1995年 | 22篇 |
1994年 | 16篇 |
1993年 | 17篇 |
1992年 | 31篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 24篇 |
1988年 | 23篇 |
1987年 | 13篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 5篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 4篇 |
1933年 | 1篇 |
排序方式: 共有3162条查询结果,搜索用时 15 毫秒
951.
Phylogenetic analysis of porcine epidemic diarrhea virus field strains prevailing recently in China 总被引:3,自引:0,他引:3
Yueyi Gao Qiuwen Kou Xinna Ge Lei Zhou Xin Guo Hanchun Yang 《Archives of virology》2013,158(3):711-715
Porcine epidemic diarrhea virus (PEDV) is the causative agent of porcine epidemic diarrhea (PED), which is characterized by severe diarrhea, dehydration and high mortality in the affected pigs. Recently, clinical outbreaks of diarrhea in suckling piglets emerged in pig-producing areas of China. In this study, molecular detection of PEDV was conducted using RT-PCR (targeting the M gene) on samples collected from piglets with watery diarrhea from 15 pig farms, and phylogenetic analysis of PEDV field strains was carried out based on their M and S genes. In addition, the complete genome sequence of a PEDV field strain was determined. PEDV was detected in 92.7 % of the samples (267/288). The 15 M genes that were amplified shared 99.6-100 % nucleotide identity and 99.1-100 % amino acid similarity with each other. The 15 S genes exhibited 98.6-99.9 % homology, both at the nucleotide level and at the deduced amino acid level. Phylogenetic analysis showed that all of the amplified M genes grouped in cluster 3, together with some Chinese, Korean and Thai strains, while all of the amplified S genes were in cluster 3 and were closely related to Korean strains. Compared with previous PEDV strains, all of the S genes have common characteristics, namely, a 4-aa (GENQ) insertion between positions 55 and 56, a 1-aa (N) insertion between positions 135 and 136, and a 2-aa (DG) deletion between positions 155 and 156, similar or identical to Korean KNU-serial strains reported in recent years. The genome of the sequenced PEDV field strain is 28,038 nucleotides in length, excluding the poly (A) tail. Our findings suggest that a novel PEDV with a characteristic variant S gene is responsible for recent outbreaks of clinical diarrhea in piglets in China. 相似文献
952.
BackgroundAcute encephalopathy with acute brain swelling (ABS) is a recently proposed disease of unknown etiology, characterized by rapid progression to whole-brain swelling. To our knowledge, we reported the first case of a patient with acute encephalopathy with ABS wherein brain magnetic resonance imaging (MRI) abnormalities were noted prior to the diffuse brain swelling onset.Case presentationAn 11-year-old boy was admitted to our unit owing to prolonged disturbance of consciousness following febrile status epilepticus. At the initial visit, the vital signs were within the normal range, except for the body temperature and consciousness level (Glasgow Coma Scale 6; E1V1M4). The initial laboratory results showed elevated inflammatory marker levels and mild hyponatremia. Cerebrospinal fluid analysis revealed albuminocytologic dissociation, whereas the myelin basic protein level was not elevated. Electroencephalography showed diffuse, high-amplitude slow waves.No abnormalities were detected on the initial brain computed tomography (CT) scan. However, at 11 h after the seizure onset, diffuse hyperintense lesions were observed throughout the cerebrum on T2-weighted brain MRI. The patient was diagnosed with acute encephalopathy and received methylprednisolone-pulse therapy (1 g) with high-dose gamma globulin (1 g/kg) administration. At 14 h after the seizure onset, the patient was declared brain-dead; the brain CT findings revealed whole-brain swelling and herniation.ConclusionOur findings were suggestive of a perivascular pathophysiology and may be used for subtyping acute encephalopathy. In cases where such findings are observed, subsequent development of severe diffuse brain swelling should be considered. 相似文献
953.
Lina Jin Wensheng Zhu Yaqin Yu Changgui Kou Xiangfei Meng Yuchun Tao Jianhua Guo 《Annals of human genetics》2014,78(2):141-153
In case‐control studies, association analysis was designed to test whether genetic variants were associated with human diseases. To evaluate the association, analysing one genetic marker at a time suffered from weak power, because of the correction for multiple testing and possibly small genetic effects. An alternative strategy was to test simultaneous effects of multiple markers, which was believed to be more powerful. However, when the number of markers under investigation was large, they would be subjected to weak power as well, because of the greater degrees of freedom. To conquer these limitations in case‐control studies, we proposed a novel method that could test joint association of several loci (i.e. haplotype), with only a single degree of freedom. In this research, we developed a nonparametric approach, which was based on U‐statistics. We also introduced a new kernel for U‐statistic, which could combine the haplotype structure information, and was expected to enhance the power. Simulations indicated that our proposed approach offered merits in identifying the associations between diseases and haplotypes. Application of our method to a study of candidate genes for internalising disorder illustrated its virtue in utility and interpretation, and provided an excellent result in detecting the associations. 相似文献
954.
Shiwei Duan Yunliang Wang Hongwei Wang Shufei Wang Lindan Ji Dongjun Dai Danjie Jiang Xiaoxi Zhang Qiang Wang 《International journal of medical sciences》2014,11(12):1270-1274
MiRNAs are potent regulators of gene expression, and most miRNAs have from several to several thousands of gene targets. Validating the numerous gene targets of a given miRNA remains challenging despite the existence of various tools and databases that predict candidate gene-miRNA pairs. In the present study, we present a high-throughput but flexible method that applies a PCR-based application to simulate the binding of miRNAs to their gene targets. Using hsa-miR-377 as an illustrative example, our method was able to identify 13 potential targets of hsa-miR-377. Moreover, our results include 2 genes (SOD2 and PPM1A) that have already been verified as targets of hsa-miR-377. Our method may provide an alternative way of identifying the gene targets of miRNAs for future research. 相似文献
955.
Wei Kou Rong Sun Ping Wei Hong-Bing Yao Cheng Zhang Xin-Ye Tang Su-Ling Hong 《Inflammation》2014,37(5):1738-1743
The mechanisms underlying the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) remain largely unknown. CRSwNP has garnered considerable public health concern owing to its high incidence and unsatisfactory treatment outcomes. Herbal remedies are promising candidates for the treatment of CRSwNP. We examined the utility of andrographolide, a diterpenoid lactone extracted from the Chinese herb Andrographis paniculata, an anti-inflammatory agent for CRSwNP treatment by evaluating interleukin (IL)-6 and IL-17 production and monitoring T helper 17 (Th17) differentiation of peripheral blood mononuclear cells (PBMCs) isolated from 20 Chinese CRSwNP patients and 11 control subjects. All CRSwNP patients exhibited clinical features of CRSwNP. Andrographolide significantly inhibited IL-6 and IL-17 production, suppressed p-Stat3 expression, and inhibited Th17 differentiation of PBMCs in vitro. These findings suggested that andrographolide has useful anti-inflammatory properties and could be used for the treatment of CRSwNP. 相似文献
956.
Rheumatoid arthritis (RA) is a chronic autoimmune disease with high morbidity and mortality. Fibroblast-like synoviocytes (FLS) in the synovial tissues play critical roles in joint destruction. Recent studies implicate the sumoylation in the regulation of the inflammation and arthritis. Thus, we explored whether SUMO-conjugating enzyme UBC9 is involved in the progression of RA using a mouse collagen-induced arthritis (CIA) model. The effects of UBC9 siRNA on cell invasion and migration in human RA-FLS were also assessed in vitro. Treatment with siRNA against UBC9 for 3 weeks reduced the arthritis score and joint destruction. The expression of SUMO-1 and UBC9 protein in CIA joints was inhibited by UBC9 knockdown. Serum levels of anti-collagen (CII) antibodies, vascular endothelial growth factor A (VEGF-A), matrix metalloproteinases (MMP)-3, and MMP-9 were also decreased in CIA mice. In vitro, UBC9 silencing inhibited the secretion of VEGF-A, MMP-3, and MMP-9 from TNF-α-stimulated human RA-FLS. TNF-α-induced RA-FLS proliferation and migration were significantly attenuated by UBC9 knockdown. These findings indicate that SUMO-conjugating enzyme UBC9 promotes proliferation and migration of fibroblast-like synoviocytes in rheumatoid arthritis. Inhibition of UBC9 activity may be a viable therapeutic target in amelioration of disease progression in RA by attenuating FLS proliferation, migration, and invasion. 相似文献
957.
Xingfu Bao Xiaoxi Wei Yuzhuo Wang Huan Jiang Dongsheng Yu Min Hu 《Annals of biomedical engineering》2014,42(8):1781-1789
The applications of silica-based nanomaterials in dental fields as multifunctional scaffolds and carriers have been widely documented in recent years. However, toxicity of this type of nanoparticles in dental cells has not been elucidated in detail. The aim of present study was to investigate the effects of naked and PEGylated silica nanoparticles on cementoblasts. Methods including MTT assay, apoptosis, LDH, as well as ROS analysis were introduced in our study. Moreover, ALP analysis and alizarin red staining were additionally performed to indicate the influence of SiO2 and PEG-SiO2 on cementoblast differentiation. Results obtained from our designs and experiments demonstrated that naked silica nanoparticles could induce more cell toxicity than PEG-SiO2 nanoparticles, indicating PEGylation could efficiently reduce in vitro toxicity from several sections including ROS, LDH, and other important routes. Based on above results, we concluded that it was so necessary to process PEGylation while silica-based materials were applied in biomedicine and related fields including dental area. 相似文献
958.
目的比较不同术式对重型颅脑损伤患者血小板活化指标及脑血管痉挛状态的影响。方法选取2011-02—2012-07于本院进行小骨窗开颅手术治疗的34例重型颅脑损伤患者为A组,另将同时期采用标准大骨瓣开颅手术进行治疗的34例患者为B组,然后将2组患者手术后不同时间的GOS评分及手术前后的血小板活化指标及脑血管痉挛状态指标进行比较。结果 B组手术后3个月、6个月的GOS评分均明显优于A组,术后1d、3d、7d的血管痉挛总发生率均低于A组,血小板活化指标也均低于A组,P值均<0.05,差异有统计学意义。结论标准大骨瓣开颅手术救治中,更有助于改善患者的血小板活化指标及脑血管痉挛状态的效果较好。 相似文献
959.
The temporomandibular joint (TMJ) undergoes degenerative changes among patients who suffer from arthritis, and yet the pathogenesis of TMJ osteoarthritis and rheumatoid arthritis is poorly understood. We hypothesized that sustained inflammation in the TMJ induces structural abnormalities, and accordingly characterized the disc and synovium in a novel model with double injections of complete Freund's adjuvant (CFA), using behavioral, morphological, cellular, and molecular assessments. Thirty-five days following double CFA injections in seven-week-old female Sprague-Dawley rats, the disc in the CFA-induced inflammation group demonstrated multiple degenerative changes, including marked thickening, opacity, and deformation. The discs in the CFA group further showed significantly greater wet and net weights, and elevated collagen, aggrecan, and total glycosaminoglycan contents. The synovium in the CFA-induced inflammation group showed marked infiltration of mononucleated cells and accumulated sub-synovial adipose tissue. Both the disc and synovium had significantly higher iNOS and IL-1β mRNA expression than controls (saline injections). These findings are consistent with our hypothesis that sustained TMJ inflammation, even within the presently observed 35 days, may be a predisposing factor for structural abnormalities. Insight into TMJ inflammation and degeneration is anticipated to improve our understanding of the pathogenesis of TMJ arthritis and help design clinically relevant strategies for tissue engineering. 相似文献
960.