全文获取类型
收费全文 | 24641篇 |
免费 | 1578篇 |
国内免费 | 1175篇 |
专业分类
耳鼻咽喉 | 335篇 |
儿科学 | 495篇 |
妇产科学 | 445篇 |
基础医学 | 4408篇 |
口腔科学 | 357篇 |
临床医学 | 1954篇 |
内科学 | 4240篇 |
皮肤病学 | 258篇 |
神经病学 | 1330篇 |
特种医学 | 498篇 |
外科学 | 2776篇 |
综合类 | 3953篇 |
预防医学 | 1435篇 |
眼科学 | 302篇 |
药学 | 1716篇 |
2篇 | |
中国医学 | 297篇 |
肿瘤学 | 2593篇 |
出版年
2024年 | 18篇 |
2023年 | 144篇 |
2022年 | 406篇 |
2021年 | 445篇 |
2020年 | 401篇 |
2019年 | 299篇 |
2018年 | 406篇 |
2017年 | 466篇 |
2016年 | 537篇 |
2015年 | 588篇 |
2014年 | 1087篇 |
2013年 | 1245篇 |
2012年 | 1358篇 |
2011年 | 1650篇 |
2010年 | 1423篇 |
2009年 | 1480篇 |
2008年 | 1719篇 |
2007年 | 1862篇 |
2006年 | 1860篇 |
2005年 | 1821篇 |
2004年 | 1437篇 |
2003年 | 1356篇 |
2002年 | 1069篇 |
2001年 | 930篇 |
2000年 | 798篇 |
1999年 | 653篇 |
1998年 | 462篇 |
1997年 | 418篇 |
1996年 | 226篇 |
1995年 | 236篇 |
1994年 | 155篇 |
1993年 | 109篇 |
1992年 | 63篇 |
1991年 | 48篇 |
1990年 | 41篇 |
1989年 | 39篇 |
1988年 | 39篇 |
1987年 | 17篇 |
1986年 | 21篇 |
1985年 | 15篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1971年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Survey of ophthalmology》2023,68(5):940-956
Congenital aniridia is a panocular disorder that is typically characterized by iris hypoplasia and aniridia-associated keratopathy (AAK). AAK results in the progressive loss of corneal transparency and thereby loss of vision. Currently, there is no approved therapy to delay or prevent its progression, and clinical management is challenging because of phenotypic variability and high risk of complications after interventions; however, new insights into the molecular pathogenesis of AAK may help improve its management. Here, we review the current understanding about the pathogenesis and management of AAK. We highlight the biological mechanisms involved in AAK development with the aim to develop future treatment options, including surgical, pharmacological, cell therapies, and gene therapies. 相似文献
2.
Lipid nanoparticles (LNPs) are becoming popular as a means of delivering therapeutics, including those based on nucleic acids and mRNA. The mRNA-based coronavirus disease 2019 vaccines are perfect examples to highlight the role played by drug delivery systems in advancing human health. The fundamentals of LNPs for the delivery of nucleic acid- and mRNA-based therapeutics, are well established. Thus, future research on LNPs will focus on addressing the following: expanding the scope of drug delivery to different constituents of the human body, expanding the number of diseases that can be targeted, and studying the change in the pharmacokinetics of LNPs under physiological and pathological conditions. This review article provides an overview of recent advances aimed at expanding the application of LNPs, focusing on the pharmacokinetics and advantages of LNPs. In addition, analytical techniques, library construction and screening, rational design, active targeting, and applicability to gene editing therapy have also been discussed. 相似文献
3.
4.
目的探讨体外转染细胞周期素A2(Cyclin A2)基因对原代大鼠心肌细胞增殖的影响,为心脏再生提供细胞学依据。方法 SD乳鼠12只,分离、培养、鉴定原代乳鼠心肌细胞并分为3组,实验组:转染带有强化绿色荧光蛋白(GFP)和Cyclin A2基因的重组腺病毒(Ad-Cyclin A2-GFP);空病毒组:转染不含目的基因带有GFP的重组腺病毒(Ad-Null-GFP);阴性对照组:未做转染处理,仅加入等量的培养基。利用GFP示踪技术,评估原代心肌细胞转染效率;转染后的细胞继续体外培养3~5d,利用免疫荧光技术分别检测Cyclin A2、磷酸化组蛋白H3(H3P)、心肌肌钙蛋白-T(c Tn T)。结果 1.荧光GFP示踪表明原代心肌细胞的转染效率高达(97±0.74)%;2.免疫荧光标记显示,空病毒组和对照组结果相似;心肌细胞特异性标记蛋白c Tn T分布于细胞质,原代心肌细胞纯度高达(95±0.62)%;心肌细胞Cyclin A2主要在胞核内聚集,少数分布于细胞质。H3P为核蛋白在细胞核内分布。3.转染Cyclin A2后,实验组H3P阳性率明显高于空病毒组和对照组,差异具有统计学意义(P0.05);实验组可见大量多核细胞,以双核为主,伴少量3核细胞。结论腺病毒作为转染载体对原代心肌细胞有很好的侵染效率;Cyclin A2超表达促进原代心肌细胞形成双核。 相似文献
5.
6.
Autoimmune thyroid diseases (AITD) and Type 1 diabetes (T1D) frequently occur in the same individual pointing to a strong shared genetic susceptibility. Indeed, the co-occurrence of T1D and AITD in the same individual is classified as a variant of the autoimmune polyglandular syndrome type 3 (designated APS3v). Our aim was to identify new genes and mechanisms causing the co-occurrence of T1D + AITD (APS3v) in the same individual using a genome-wide approach. For our discovery set we analyzed 346 Caucasian APS3v patients and 727 gender and ethnicity matched healthy controls. Genotyping was performed using the Illumina Human660W-Quad.v1. The replication set included 185 APS3v patients and 340 controls. Association analyses were performed using the PLINK program, and pathway analyses were performed using the MAGENTA software. We identified multiple signals within the HLA region and conditioning studies suggested that a few of them contributed independently to the strong association of the HLA locus with APS3v. Outside the HLA region, variants in GPR103, a gene not suggested by previous studies of APS3v, T1D, or AITD, showed genome-wide significance (p < 5 × 10−8). In addition, a locus on 1p13 containing the PTPN22 gene showed genome-wide significant associations. Pathway analysis demonstrated that cell cycle, B-cell development, CD40, and CTLA-4 signaling were the major pathways contributing to the pathogenesis of APS3v. These findings suggest that complex mechanisms involving T-cell and B-cell pathways are involved in the strong genetic association between AITD and T1D. 相似文献
7.
Haonan Guo Rui Zhang Justice Afrifa Yuanyuan Wang Jingcui Yu 《Pathology, research and practice》2019,215(6):152403
PurposeWe previously demonstrated that the functional inactivation of DAL-1 and TOB1 promotes an aggressive phenotype in gastric cancer cells, but the links between both genes and the survival of patients with gastric cancer are unknown. Here, we investigated the correlations of the expression levels of DAL-1 and TOB1 with the progression of gastric cancer.MethodsA total of 270 patients who underwent resectable gastrectomy were included. The expression of DAL-1 and TOB1 was detected by immunohistochemistry.ResultsLow expression of DAL-1 in cancer tissue was significantly associated with tumor site (p < 0.05), histological grade (p < 0.01), depth of invasion (p < 0.05), lymph node metastasis status (p < 0.05), Lauren classification (p < 0.001), and clinical stage (p < 0.01). A lower level of TOB1 was observed in gastric cancer patients with diffuse type disease compared to patients with either intestinal or mixed type disease (p < 0.001). Additionally, Spearman’s correlation analysis revealed that decreased expression of DAL-1 was positively correlated with low TOB1 expression (r=0.304, p < 0.001). The survival analysis showed that low levels of DAL-1 and TOB1 were significantly associated with poor survival of gastric cancer patients (p <0.001 and p < 0.05, respectively).ConclusionThe downregulation of DAL-1 and TOB1 expression is associated with shorter survival of gastric cancer patients. Hence, DAL-1 and TOB1 may be considered potential novel markers for predicting the outcomes of patients with gastric cancer. 相似文献
8.
9.
目的 探讨γ干扰素诱导蛋白30(IFI 30)、程序性死亡因子配体1(PD-L1)在人脑胶质瘤中的表达及与病人预后的关系。方法 选择2015年5月~2019年5月手术切除的103例人脑胶质瘤组织和瘤旁组织,采用免疫组织化学染色检测IFI 30、PD-L1表达情况。随访24个月,记录无进展生存期和总生存期。结果 胶质瘤组织IFI 30、PD-L1高表达率[分别为70.87%(73/103)、68.93%(71/103)]明显高于瘤旁组织[分别为19.42%(20/103)、21.36%(22/103);P<0.001]。胶质瘤组织IFI 30表达水平与PD-L1表达水平呈明显正相关(r=0.583,P<0.05)。随访24个月,生存75例,死亡28例;多因素logistic回归分析显示,IFI 30高表达、PD-L1高表达是增加病人死亡风险的独立危险因素(P<0.05)。生存曲线分析显示,IFI 30高表达组2年累积生存率(64.52%)和2年累积无进展生存率(65.56%)均明显低于低表达组(分别为82.25%、89.45%;P<0.05)。PD-L1高表达组2年累积生存率(61.78%)和2年累积无进展生存率(60.14%)均明显低于低表达组(分别为88.52%、79.86%;P<0.05)。结论 人脑胶质瘤组织IFI 30、PD-L1呈高表达,与病人不良预后密切相关。 相似文献
10.
The main of this study was to evaluate the mutagenic and carcinogenic potential of (+) – usnic acid (UA), using Somatic Mutation and Recombination Test (SMART) and the test for detecting epithelial tumor clones (wts) in Drosophila melanogaster. Larvae from 72 ± 4 h from Drosophila were fed with UA (5.0, 10.0 or 20.0 mM); urethane (10.0 mM) (positive control); and solvent (Milli-Q water, 1% Tween-80 and 3% ethanol) (negative control). ST cross produced increase in total mutant spots in the individuals treated with 5.0, 10.0 or 20.0 mM of UA. HB cross produced spot frequencies in the concentration of 5.0 mM that were higher than the frequency for the same concentration in the ST cross. In the highest concentrations the result was negative, which means that the difference observed can be attributed, in part, to the high levels of P450, suggesting that increasing the metabolic capacity maximized the toxic effect of these doses. In the evaluation of carcinogenesis using the wts test, the results obtained for the same concentrations of UA show a positive result for the presence of tumors when compared to the negative control. We conclude that UA has recombinogenic, mutagenic and carcinogenic effects on somatic cells in D. melanogaster. 相似文献