全文获取类型
收费全文 | 119850篇 |
免费 | 12024篇 |
国内免费 | 6754篇 |
专业分类
耳鼻咽喉 | 990篇 |
儿科学 | 1970篇 |
妇产科学 | 1487篇 |
基础医学 | 31218篇 |
口腔科学 | 3569篇 |
临床医学 | 9122篇 |
内科学 | 17178篇 |
皮肤病学 | 2186篇 |
神经病学 | 9144篇 |
特种医学 | 2376篇 |
外国民族医学 | 27篇 |
外科学 | 10359篇 |
综合类 | 17591篇 |
现状与发展 | 32篇 |
一般理论 | 2篇 |
预防医学 | 3092篇 |
眼科学 | 3258篇 |
药学 | 11035篇 |
20篇 | |
中国医学 | 3518篇 |
肿瘤学 | 10454篇 |
出版年
2024年 | 192篇 |
2023年 | 1456篇 |
2022年 | 2550篇 |
2021年 | 3662篇 |
2020年 | 3626篇 |
2019年 | 3279篇 |
2018年 | 3444篇 |
2017年 | 3923篇 |
2016年 | 4532篇 |
2015年 | 5191篇 |
2014年 | 7798篇 |
2013年 | 9537篇 |
2012年 | 7326篇 |
2011年 | 8582篇 |
2010年 | 7021篇 |
2009年 | 6718篇 |
2008年 | 6926篇 |
2007年 | 6973篇 |
2006年 | 6362篇 |
2005年 | 5481篇 |
2004年 | 4584篇 |
2003年 | 3753篇 |
2002年 | 2835篇 |
2001年 | 2374篇 |
2000年 | 2015篇 |
1999年 | 1685篇 |
1998年 | 1568篇 |
1997年 | 1456篇 |
1996年 | 1308篇 |
1995年 | 1343篇 |
1994年 | 1209篇 |
1993年 | 1049篇 |
1992年 | 855篇 |
1991年 | 809篇 |
1990年 | 701篇 |
1989年 | 685篇 |
1988年 | 588篇 |
1987年 | 533篇 |
1986年 | 463篇 |
1985年 | 709篇 |
1984年 | 626篇 |
1983年 | 435篇 |
1982年 | 561篇 |
1981年 | 430篇 |
1980年 | 382篇 |
1979年 | 316篇 |
1978年 | 215篇 |
1977年 | 165篇 |
1976年 | 158篇 |
1975年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 对比研究朝鲜淫羊藿酸性多糖酯化还原前后的理化特性,并探讨其改善油酸诱导的肝癌HepG2细胞脂质堆积活性的差异。方法 采用高效凝胶渗透色谱法测定朝鲜淫羊藿酸性多糖(EFPA)的均一性和分子量,高效液相色谱法测定EFPA和酯化还原后朝鲜淫羊藿酸性多糖(EFPA-R)的单糖组成;采用油酸(OA)处理HepG2细胞诱导建立脂质蓄积模型,不同浓度EFPA与EFPA-R(10、30、100、300 μg·mL-1)分别和OA共同作用于细胞24 h,采用CCK-8试剂盒测定细胞存活率,油红O染色观察细胞内脂滴蓄积情况,并采用试剂盒测定细胞内总胆固醇(TC)、甘油三酯(TG)含量。结果 EFPA为成分均一的多糖组分,分子量为125.8 kDa,由甘露糖、葡萄糖、半乳糖、葡萄糖醛酸和阿拉伯糖组成,摩尔比为1.7∶7.4∶1.4∶1.8∶1.0,葡萄糖占比最大,EFPA-R由甘露糖、葡萄糖、半乳糖和阿拉伯糖组成,摩尔比为0.8∶10.6∶2.1∶1.0;在10-300 μg·mL-1范围内,EFPA和EFPA-R对HepG2细胞的抑制作用较弱,作为给药浓度;与空白组相比,模型组细胞中TC、TG含量显著升高(P < 0.01),细胞内红色脂滴显著增多,与模型组相比,EFPA可显著降低细胞中TC、TG含量(P < 0.01),明显减少细胞内红色脂滴(P < 0.05或P < 0.01),EFPA-R干预后细胞则无明显变化。结论 EFPA可明显改善HepG2细胞脂质堆积情况,且呈现剂量依赖性,而半乳糖醛酸(GalA)的存在可能是其抑制HepG2细胞脂质蓄积的关键因素。 相似文献
2.
《Cancer cell》2022,40(2):153-167.e11
- Download : Download high-res image (229KB)
- Download : Download full-size image
3.
4.
5.
Bortezomib is a novel proteasome inhibitor, which has been successfully used to treat mantle cell lymphoma and multiple myeloma. However, the direct effects of bortezomib on acute promyelocytic leukaemia (APL) have not been fully investigated. In the present study, the WST-8 assay, western blotting, flow cytometry, monodansylcadaverine staining and transmission electron microscopy were performed. It was demonstrated that bortezomib treatment induced a time- and dose-dependent decrease in the viability of NB4 cells. Bortezomib treatment induced cell apoptosis in NB4 cells, as assessed by Annexin V/propidium iodide analysis, and the detection of cleaved caspase-3, cleaved poly(ADP-ribose) polymerase, Bax and Bcl-2 expression. Furthermore, bortezomib treatment induced autophagy in NB4 cells, as indicated by autophagosome formation, p62 degradation, LC3-I to LC3-II conversion and formation of acidic autophagic vacuoles. Notably, autophagy induced by bortezomib was initiated prior to apoptosis. Inhibition of autophagy by knocking down Beclin-1 expression increased bortezomib-induced apoptosis in NB4 cells. Therefore, the present study revealed that the combination of bortezomib and autophagy inhibition may be a potential treatment strategy for APL. 相似文献
6.
7.
Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment. 相似文献
8.
目的:观察非霍奇金淋巴瘤(non-Hodgkin's lymphoma,NHL)患者自体造血干细胞移植(autologous hematopoietic stem cell transplantation,ASCT)术后应用重组人α-2b干扰素(α-2b IFN)进行早期干预治疗的临床疗效。方法:选取18例行ASCT的NHL患者为研究对象,移植前疾病评估均未达到完全缓解(complete remission,CR),试验组血象恢复后给予IFN 3 000 000 U次/隔日干预治疗,3个月后停用;对照组未行干扰素干预治疗,分析总体疗效及两组对比的生存情况。结果:随访中位时间为34(10~50)个月,患者中位生存时间为37(31~45)个月,3年总体无进展生存(progressive free survival,PFS)、总生存(overall survivial,OS)分别为54.7%、66.8%。ASCT后试验组1年内无疾病复发,2年内复发率为12.5%;对照组1年内复发率为20%,2年内复发率为30%。结论:NHL患者在ASCT后给予重组人α-2b IFN早期干预治疗,患者耐受性好,可能降低移植后早期复发率。 相似文献
9.
10.
《Biomedical and environmental sciences : BES》2020,33(5):295-305
Objective Interferon-induced transmembrane protein 3(IFITM3) is an important member of the IFITM family. However, the molecular mechanisms underlying its antiviral action have not been completely elucidated. Recent studies on IFITM3, particularly those focused on innate antiviral defense mechanisms, have shown that IFITM3 affects the body's adaptive immune response. The aim of this study was to determine the contribution of IFITM3 proteins to immune control of influenza infection in vivo.Methods We performed proteomics, flow cytometry, and immunohistochemistry analysis and used bioinformatics tools to systematically compare and analyze the differences in natural killer(NK) cell numbers, their activation, and their immune function in the lungs of Ifitm3-/-and wild-type mice.Results Ifitm3-/-mice developed more severe inflammation and apoptotic responses compared to wild-type mice. Moreover, the NK cell activation was higher in the lungs of Ifitm3-/-mice during acute influenza infection.Conclusions Based on our results, we speculate that the NK cells are more readily activated in the absence of IFITM3, increasing mortality in Ifitm3-/-mice. 相似文献