全文获取类型
收费全文 | 16006篇 |
免费 | 1538篇 |
国内免费 | 1015篇 |
专业分类
耳鼻咽喉 | 149篇 |
儿科学 | 165篇 |
妇产科学 | 139篇 |
基础医学 | 1999篇 |
口腔科学 | 295篇 |
临床医学 | 2101篇 |
内科学 | 2319篇 |
皮肤病学 | 129篇 |
神经病学 | 915篇 |
特种医学 | 557篇 |
外国民族医学 | 9篇 |
外科学 | 1589篇 |
综合类 | 2641篇 |
现状与发展 | 3篇 |
一般理论 | 3篇 |
预防医学 | 1100篇 |
眼科学 | 488篇 |
药学 | 1592篇 |
31篇 | |
中国医学 | 891篇 |
肿瘤学 | 1444篇 |
出版年
2025年 | 3篇 |
2024年 | 323篇 |
2023年 | 427篇 |
2022年 | 807篇 |
2021年 | 1037篇 |
2020年 | 751篇 |
2019年 | 576篇 |
2018年 | 601篇 |
2017年 | 572篇 |
2016年 | 465篇 |
2015年 | 770篇 |
2014年 | 869篇 |
2013年 | 737篇 |
2012年 | 1065篇 |
2011年 | 1182篇 |
2010年 | 689篇 |
2009年 | 574篇 |
2008年 | 812篇 |
2007年 | 795篇 |
2006年 | 735篇 |
2005年 | 848篇 |
2004年 | 470篇 |
2003年 | 430篇 |
2002年 | 403篇 |
2001年 | 317篇 |
2000年 | 372篇 |
1999年 | 360篇 |
1998年 | 229篇 |
1997年 | 218篇 |
1996年 | 153篇 |
1995年 | 150篇 |
1994年 | 131篇 |
1993年 | 115篇 |
1992年 | 106篇 |
1991年 | 97篇 |
1990年 | 72篇 |
1989年 | 64篇 |
1988年 | 56篇 |
1987年 | 46篇 |
1986年 | 39篇 |
1985年 | 35篇 |
1984年 | 12篇 |
1983年 | 11篇 |
1982年 | 7篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 6篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1965年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
目的: 观察FGF2在低氧及低氧预适应条件下小鼠海马神经元细胞中的表达变化,探究FGF2是否参与低氧耐受神经保护作用。方法: 使用生物信息学方法进行搜索和鉴定FGF2基因家族成员。在细胞层面建立低氧和低氧预适应模型,通过Western-blot、qRT-PCR检测细胞中FGF2表达情况。结果: FGFs家族分为7个亚家族,其中FGF2含有一个由17个氨基酸组成的FGF受体结合域,能够与特定的FGF受体结合进行信号的转导。在细胞层面,相比于空白对照组(C),低氧组(H)和低氧预适应组(HPC)FGF2在mRNA水平和蛋白水平的表达均有所下降(P<0.05),而与H组相比,HPC组FGF2 mRNA水平和蛋白水平的表达有所升高(P<0.05)。结论: FGF参与低氧预适应的神经保护作用。 相似文献
42.
Yi Li Yuanyuan Ge Jianfeng Gong Weiming Zhu Lei Cao Zhen Guo Lili Gu Jieshou Li 《Journal of gastrointestinal surgery》2018,22(12):2125-2132
Purpose
The aims of the present study were to examine the density of lymphatic vessels in the mesentery and to assess the predictive value of the mesenteric lymphatic vessel density for postoperative clinical recurrence.Methods
Ileocolonic resection specimens were obtained from 53 patients with Crohn’s disease and 10 non-inflammatory bowel disease control subjects. Mesentery adipose tissues adjacent to the bowel wall were used for the histological quantification of lymphatic vessels using immunohistochemistry with the D2-40 antibody. The relationships between lymphatic vessel density and disease behavior, the presence of granulomas, the presence of creeping fat, and postoperative clinical recurrence were assessed.Results
Median lymphatic vessel density in the mesentery adjacent to inflamed or non-inflamed intestine was lower in control subjects than in Crohn’s disease patients (2.13‰; interquartile range [IQR], 1.83–2.61; 8.34‰; IQR, 6.39–10.22; 4.43‰; IQR, 3.32–5.78; P ? 0.001). Increased mesenteric lymphatic vessel density was significantly associated with stricturing behavior, the presence of intestinal granulomas, the presence of creeping fat, and bowel thickness. Interestingly, patients with disease recurrence had an increased mesenteric lymphatic vessel density of the proximal mesenteric margin at the time of resection compared with those who did not have disease recurrence (6.23‰; IQR, 5.43–6.75 vs. 3.28‰; IQR, 2.93–4.29; P ? 0.001).Conclusions
In addition to its correlation with disease behavior, bowel thickness, and the presence of intestinal granulomas and creeping fat, increased mesenteric lymphatic vessel density in the proximal margin is predictive of early clinical recurrence after surgery in patients with Crohn’s disease.43.
Xiaoyu Yang Tessa Janssen Mark P. Arts Wilco C. Peul Carmen L.A. Vleggeert-Lankamp 《The spine journal》2018,18(9):1678-1693
Objective
The objective of this study was to review current literature on the comparison of the radiological outcome of cervical arthroplasty with fusion after anterior discectomy for radiculopathy.Materials and Methods
A literature search was performed in PubMed, Embase, Web of Science, Cochrane, CENTRAL, and CINAHL using a sensitive search string combination. Studies were selected by predefined selection criteria (patients exclusively suffering from cervical radiculopathy), and risk of bias was assessed using a validated Cochrane checklist adjusted for this purpose. Additionally, an overview of results of articles published in 21 meta-analyses was added, considering a group of patients with myelopathy with or without radiculopathy.Results
Seven articles that compared intervertebral devices in patients with radiculopathy (excluding patients with myelopathy) were included in the study. Another 31 articles were studied as a mixed group, including patients with myelopathy and radiculopathy. Apart from three studies with low risk of bias, all other articles showed intermediate or high risk of bias. Heterotopic ossification was reported to be present in circa 10% of patients, seemingly predominant in patients with radiculopathy, with a very low level of evidence. Radiological signs of adjacent segment disease were present at baseline in 50% of patients, and there is a low level of evidence that this increased more (10%–20%) in the fusion group at long-term follow-up. However, this was only studied in the mixed study population, which is degenerative by diagnosis.Conclusion
Although the cervical disc prosthesis was introduced to decrease adjacent level disease, convincing radiological evidence for this benefit is lacking. Heterotopic ossification as a complicating factor in the preservation of motion of the device is insufficiently studied. Regarding purely radiological outcomes, currently, no firm conclusion can be drawn for implanting cervical prosthesis versus performing fusion. 相似文献44.
Dongchao Zhang Yuqing Long Meng Li Jianfang Gong Xiaohui Li Jing Lin 《Avian pathology》2018,47(2):213-222
Avian infectious bronchitis caused by the infectious bronchitis virus (IBV), and mycoplasmosis caused by Mycoplasma gallisepticum (MG) are two major respiratory diseases in chickens that have resulted in severe economic losses in the poultry industry. We constructed a recombinant adenovirus that simultaneously expresses the S1 spike glycoprotein of IBV and the TM-1 protein of MG (pBH-S1-TM-1-EGFP). For comparison, we constructed two recombinant adenoviruses (pBH-S1-EGFP and pBH-TM-1-EGFP) that express either the S1 spike glycoprotein or the TM-1 protein alone. The protective efficacy of these three vaccine constructs against challenge with IBV and/or MG was evaluated in specific pathogen free chickens. Groups of seven-day-old specific pathogen free chicks were immunized twice, two weeks apart, via the oculonasal route with the pBH-S1-TM-1-EGFP, pBH-S1-EGFP, or pBH-TM-1-EGFP vaccine candidates or the commercial attenuated infectious bronchitis vaccine strain H52 and MG vaccine strain F-36 (positive controls), and challenged with virulent IBV or MG two weeks later. Interestingly, by days 7 and 14 after the booster immunization, pBH-S1-TM-1-EGFP-induced antibody titre was significantly higher (P?0.01) compared to attenuated commercial IBV vaccine; however, there was no significant difference between the pBH-S1-TM-1-EGFP and attenuated commercial MG vaccine groups (P?>?0.05). The clinical signs, the gross, and histopathological lesions scores of the adenovirus vaccine constructs were not significantly different from that of the attenuated commercial IBV or MG vaccines (positive controls) (P?>?0.05). These results demonstrate the potential of the bivalent pBH-S1-TM-1-EGFP adenovirus construct as a combination vaccine against IB and mycoplasmosis. 相似文献
45.
Rui Hua Xiaoyu Jiang Lingxia Qi Shanshan Guan Ziyu Kuai Yongbo Qiao Yan Xu Xin Gong Yuhua Shi Wei Kong Junqi Niu Hao Zhang Yaming Shan 《Immunologic research》2018,66(1):67-73
The high mutation rate of the hepatitis C virus (HCV) genome increases the genotype diversity and renders the detection of the virus more difficult. Therefore, prediction and assessment of highly conserved and strongly antigenic epitope polypeptide sequences have become a focus of current research. The E2 region is the target binding region of neutralizing antibodies. HCV genomics, especially the high mutation rate of E2 region sequence, makes its genotyping more and more diverse, and the detection of HCV and genotype is becoming more and more strict. In this study, four HCV B cell epitope polypeptides were constructed based on assessment of conserved sequences in the HCV E2 region and prediction of B cell epitopes, including sequences specific to genotype 1A (DC-13: 434-DTGWLAGLFYYHK-446), genotype 1B (HC-13: 434-HTGFLAALFYAKS-446), genotype 4D (NC-13: 434-NTGFLASLFYTHK-446), and a consensus sequence (FC-9: 447-FNSSGCPER-455). Epitope polypeptides combined with serum from 29 HCV-infected or 25 non-HCV-infected individuals were assayed by enzyme-linked immunosorbent assay (ELISA), and differences were analyzed by T/T’ test methods in SPSS v20.0 software. Binding levels of genotype 1A, 4D, and consensus epitope polypeptides with sera of HCV-infected patients were higher than those of non-infected individuals. Moreover, binding of genotype 1B epitope polypeptides with serum of HCV 1B-infected patients was higher than that of HCV 2A-infected patients. While the screening results of HCV genotype-specific epitope polypeptides were preliminary, these findings indicated that we successfully established an HCV and genotype serological ELISA detection method. Such an approach would facilitate the discovery of epitope polypeptides which may become new antigen candidates in peptide vaccine development for the prevention of HCV infection. 相似文献
46.
Chen Gong Zhang Zhilin Shang Ruisha Qi Jingru Zhang Yiling Tang Shunming Shen Zhongyuan 《Parasitology research》2018,117(11):3473-3479
Parasitology Research - Nosema bombycis contains functional aquaporins (NbAQPs), which are key targets for exploring the mechanism of N. bombycis infection; however, the regulation of these NbAQPs... 相似文献
47.
Qian Chen Chong Qi Gong Peng Yang Liu Xinyuan Zhang 《Food and Agricultural Immunology》2018,29(1):833-844
Polysaccharides are one of many bioactive compounds found in edible mushrooms. Edible mushrooms have become attractive as “health foods” and as source materials for immunomodulators. The aim of this project was to study the immunoregulatory effects of a purified polysaccharide derived from wild Russula griseocarnosa (PRG1-1) on macrophages. Our data showed that in RAW264.7 macrophage cells, PRG1-1 increased expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Furthermore, PRG1-1 increased the production of nitric oxide (NO) and cytokines, including interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α). Western blotting demonstrated that the regulation of NO and cytokines was mediated through the nuclear factor kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signalling pathways. Therefore, PRG1-1 has the capacity to activate macrophages via the NF-κB and MAPK pathways. These findings helped to elucidate the immune-modulatory properties of the polysaccharide from R. griseocarnosa. 相似文献
48.
Lulu Yang Chenhui Zhang Wei Wang Junqi Wang Yuan Xiao Wenli Lu Xiaoyu Ma Lifen Chen Jihong Ni Defen Wang Jinxiu Shi Zhiya Dong 《BMC medical genetics》2018,19(1):212
Background
Dwarfism is a common severe growth disorder, but the etiology is unclear in the majority of cases. Recombinant human growth hormone may be a treatment option, but it has limited efficacy. The currently known laboratory assays do not meet the precision requirements for clinical diagnosis. Here, we have constructed a targeted next-generation sequencing (NGS) panel of selected genes that are suspected to be associated with dwarfism for genetic screening.Methods
Genetic screening of 91 children with short stature of unknown etiology was performed with the help of the NGS panel. All the coding regions and exon-intron boundaries of 166 genes were included in the panel. To clarify the pathogenicity of these mutations, their clinical data were reviewed and analyzed.Results
The assay identified p.A72G, p.I282V, and p.P491S variants of the PTPN11 gene and a p.I437T variant of the SOS1 gene in 4 cases with Noonan syndrome. A frameshift mutation (p.D2407fs) of the ACAN gene was identified in a case of idiopathic short stature with moderately advanced bone age. A p.R904C variant of the COL2A1 gene was found in a patient, who was accordingly diagnosed with Stickler syndrome. Severe short stature without limb deformity was associated with a p.G11A variant of HOXD13. In addition, we evaluated evidence that a p.D401N variant of the COMP gene may cause multiple epiphyseal dysplasia.Conclusions
Our findings suggest that syndromes, particularly Noonan syndrome, may be overlooked due to atypical clinical features. This gene panel has been verified to be effective for the rapid screening of genetic etiologies associated with short stature and for guiding precision medicine-based clinical management.49.
50.
目的了解社区老年人积极老龄化现状,并分析其影响因素,为社区护理工作者开展健康促进工作,提高社区老年人的健康水平提供参考。方法采用一般问卷调查表、休闲态度量表和积极老龄化量表对衡阳市某国家级示范社区卫生服务中心275名老年人进行问卷调查。结果老年人休闲态度总分为(3.16±0.55)分,积极老龄化总分为(3.24±0.61)分。不同年龄、文化程度、居住情况、休闲类型和身体机能的社区老年人积极老龄化得分比较,差异有统计学意义(均P0.01);社区老年人休闲态度与积极老龄化呈正相关(均P0.01)。回归分析结果表明,身心健康和自我发展是影响积极老龄化的重要因素。结论社区老年人积极老龄化水平和休闲态度水平均待提高,社区护理工作者应采取措施提高社区老年人的休闲态度水平,促进其达到积极老龄化。 相似文献