全文获取类型
收费全文 | 2761篇 |
免费 | 252篇 |
国内免费 | 115篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 9篇 |
妇产科学 | 13篇 |
基础医学 | 328篇 |
口腔科学 | 18篇 |
临床医学 | 196篇 |
内科学 | 224篇 |
皮肤病学 | 13篇 |
神经病学 | 101篇 |
特种医学 | 66篇 |
外国民族医学 | 1篇 |
外科学 | 74篇 |
综合类 | 283篇 |
预防医学 | 33篇 |
眼科学 | 10篇 |
药学 | 1256篇 |
中国医学 | 127篇 |
肿瘤学 | 366篇 |
出版年
2024年 | 5篇 |
2023年 | 39篇 |
2022年 | 64篇 |
2021年 | 88篇 |
2020年 | 66篇 |
2019年 | 79篇 |
2018年 | 115篇 |
2017年 | 99篇 |
2016年 | 109篇 |
2015年 | 145篇 |
2014年 | 162篇 |
2013年 | 520篇 |
2012年 | 146篇 |
2011年 | 148篇 |
2010年 | 115篇 |
2009年 | 121篇 |
2008年 | 158篇 |
2007年 | 128篇 |
2006年 | 119篇 |
2005年 | 85篇 |
2004年 | 82篇 |
2003年 | 80篇 |
2002年 | 84篇 |
2001年 | 53篇 |
2000年 | 36篇 |
1999年 | 55篇 |
1998年 | 38篇 |
1997年 | 24篇 |
1996年 | 32篇 |
1995年 | 33篇 |
1994年 | 23篇 |
1993年 | 21篇 |
1992年 | 10篇 |
1991年 | 18篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 7篇 |
1985年 | 5篇 |
1984年 | 1篇 |
排序方式: 共有3128条查询结果,搜索用时 234 毫秒
1.
地鳖中的纤溶活性蛋白是从地鳖中提取的具有抗栓及抗肿瘤作用的有效成分,其口服易被上消化道酶分解从而限制了应用。采用恒流泵滴制法开发地鳖纤溶活性蛋白时间/pH依赖口服结肠靶向微囊(EnpolypHaga fibrinolytic protein oral colon targeting microcapsules, CTM-EFP)。采用单因素实验和正交实验相结合的方法寻找到包封率为60.17 % ± 2.72 %、载药量为15.50 % ± 0.44 % 的最佳配方。扫描电子显微镜(SEM)显示微囊呈球形、表面光滑,在人工肠液中24 h的累积释放度为99.53 % ± 0.69 %,在人工胃液中24 h累积释放度为7.43 ± 1.04 %,通过时间/pH依赖达到结肠靶向作用。CTM-EFP在人工肠液中的体外释放曲线符合Korsmeyer方程,提示地鳖纤溶活性蛋白(EnpolypHaga fibrinolytic protein, EFP)是通过扩散和侵蚀机制结合释放的。CTM-EFP为EFP的口服给药提供了一种新的剂型,为EFP应用于临床提供参考。 相似文献
2.
3.
Michael J. Rigby 《Child: care, health and development》2022,48(1):170-174
While children in general are usually seen as a societal priority, many children are disadvantaged by marginalization, with adverse effects on health and development. Following feasibility studies, the European Commission has now adopted a formal Child Guarantee of service access. This paper links the Feasibility Studies to other reports on the need to address marginalized and institutionalized children. The problems in identifying and quantifying such children are outlined, as are the challenges of planning for these groups of children and the difficulty of finding universal definitions and data. This European Union initiative is timely, given that around a quarter of European children are marginalized, while the effects of Covid-19 will add to this marginalization. 相似文献
4.
肺癌是目前全球发病率和死亡率均居前列的恶性肿瘤,其中肺鳞癌经手术、放化疗等综合治疗后,其疗效仍不满意。随着分子靶向治疗在肺腺癌中取得了令人瞩目的成果,而肺鳞癌患者中EGFR基因突变及ALK融合基因少见,急需探索新的靶点指导肺鳞癌患者的临床治疗。研究表明,FGFR家族(FGFR1-4)是肺鳞癌中突变频率较高的基因,FGFR基因的激活突变和扩增与肺鳞癌的发生和发展密切相关,同时许多小分子 FGFR 抑制剂在临床应用中已经取得较好的治疗效果。目前,许多FGFR抑制剂治疗肺鳞癌的临床试验也正在进行研究,针对FGFR靶点的基因治疗可为肺鳞癌的治疗提供一种新的策略。本文就FGFR在肺鳞癌的靶向治疗中的最新研究进展进行综述。 相似文献
5.
原发性肝癌(PLC)是临床上常见的消化系统恶性肿瘤之一,90%以上为肝细胞癌(HCC)。大多数原发性肝细胞癌患者存在肝炎基础疾病,肝功能差,局部治疗后易复发,确诊时已到晚期,进展快,预后极差。晚期原发性肝细胞癌系统治疗包括基础肝病治疗、系统化疗、分子靶向治疗、免疫治疗,本文就晚期原发性肝细胞癌的系统化疗、分子靶向治疗、免疫治疗作一综述。 相似文献
6.
《Biomaterials》2015
We have developed methotrexate (MTX)-loaded poly(lactic-co-glycolic acid, PLGA) gold (Au)/iron (Fe)/gold (Au) half-shell nanoparticles conjugated with arginine-glycine-aspartic acid (RGD), which can be applied for magnetic targeted chemo-photothermal treatment, and in vivo multimodal imaging of rheumatoid arthritis (RA). Upon near-infrared (NIR) irradiation, local heat is generated at the inflammation region due to the NIR resonance of Au half-shells and MTX release from PLGA nanoparticles is accelerated. The Fe half-shell layer embedded between the Au half-shell layers enables in vivo T2-magnetic resonance (MR) imaging in addition to NIR absorbance imaging. Furthermore, the delivery of the nanoparticles to the inflammation region in collagen-induced arthritic (CIA) mice, and their retention can be enhanced under external magnetic field. When combined with consecutive NIR irradiation and external magnetic field application, these nanoparticles provide enhanced therapeutic effects with an MTX dosages of only 0.05% dosage compared to free MTX therapy for the treatment of RA. 相似文献
7.
《Brain stimulation》2019,12(5):1261-1270
BackgroundThe motor potentials evoked by transcranial magnetic stimulation (TMS) over the motor hand area (M1-HAND) show substantial inter-trial variability. Pericentral mu-rhythm oscillations, might contribute to inter-trial variability. Recent studies targeting mu-activity based on real-time electroencephalography (EEG) reported an influence of mu-power and mu-phase on the amplitude of motor evoked potentials (MEPs) in a preselected group with strong pericentral mu-activity. Other studies that determined mu-power or mu-phase based on post-hoc trial sorting according in non-preselected individuals were largely negative.ObjectivesTo reassess if cortico-spinal activity is modulated by the mu-rhythm, we applied single-pulse TMS to the M1-HAND conditional on the phase of the intrinsically expressed pericentral mu-rhythm in 14 non-preselected healthy young participants.MethodsTMS was given at 0, 90, 180, and 270° of the mu-phase. Based on the absence of effects of mu-phase or mu-power when analyzing the mean MEP amplitudes, we also computed a linear mixed effects model, which included mu-phase, mu-power, inter-stimulus interval (ISIs) as fixed effects, treating the subject factor as a random effect.ResultsMixed model analysis revealed a significant effect of mu-power and ISI, but no effect of mu-phase and no interactions. MEP amplitude scaled linearly with lower mu-power or longer ISIs, but these modulatory effects were very small relative to inter-trial MEP variability.ConclusionOur largely negative results are in agreement with previous offline TMS-EEG studies and point to a possible influence of ISI. Future research needs to clarify under which circumstances the responsiveness of human the M1-HAND to TMS depends on the synchronicity with mu-power and mu-phase. 相似文献
8.
《Vaccine》2019,37(35):4963-4974
Vaccination is the most efficient strategy to protect from infectious diseases and the induction of a protective immune response not only depends on the nature of the antigen, but is also influenced by the vaccination strategy and the co-administration of adjuvants. Therefore, the precise monitoring of adjuvant candidates and their immune modulatory properties is a crucial step in vaccine development. Here, one central aspect is the induction of appropriate humoral and cellular effector mechanisms.In our study we performed a direct comparison of two promising candidates in adjuvant development, the STING activator bis-(3,5)-cyclic dimeric adenosine monophosphate (c-di-AMP) and the Toll-like receptor ligand formulation poly(I:C)/CpG. These were evaluated in C57BL/6 mice using the model antigen ovalbumin (OVA) in subcutaneous vaccination with soluble protein as well as in a dendritic cell (DC) targeting approach (αDEC-OVA). Strikingly, c-di-AMP as compared to poly(I:C)/CpG resulted in significantly higher antigen-specific IgG antibody levels when used in immunization with soluble OVA as well as in antigen targeting to DC. In vaccination with soluble OVA, c-di-AMP induced a significantly stronger CTL, Th1 and IFNγ-producing CD8+ memory T cell response than poly(I:C)/CpG. The response was CTL and Th1 cell dominated, a profile shared by both adjuvants. In the context of targeting OVA to DC, c-di-AMP induced significantly increased Th1 and Th2 cell responses as compared to poly(I:C)/CpG. Interestingly, the Th1 response dominated the overall T cell response only when c-di-AMP was used, indicating a distinct modulatory property of c-di-AMP when the DC targeting immunization approach was exploited.Taken together, we describe superior properties of c-di-AMP as compared to poly(I:C)/CpG in subcutaneous vaccination with soluble antigen as well as antigen targeting to DC. This indicates exceptionally effective adjuvant properties for c-di-AMP and provides compelling evidence of its potential for further adjuvant development, especially also when using DC targeting approaches. 相似文献
9.
目的 优化线粒体靶向金丝桃苷脂质体(DLD/Hyp-Lip)制备的最佳处方,并研究研究其在胎牛血清中的稳定性及体外释放行为,考察其线粒体靶向性。方法 采用薄膜分散法制备DLD/Hyp-Lip,以包封率和载药量为考察指标进行单因素实验,考察磷脂总量与金丝桃苷(hyperoside,Hyp)用量比、二硬脂酰磷脂酰乙醇胺-聚乙二醇(DSPE-PEG)与DLD用量比等条件对DLD/Hyp-Lip的影响,结合星点设计-效应面法优化DLD/Hyp-Lip处方。使用透射电子显微镜和粒径仪观察测定脂质体粒子外观、平均粒径和Zeta电位,采用血清稳定性实验和体外释药、线粒体靶向性对该载药系统进行评价。结果 DLD/Hyp-Lip最佳处方为磷脂总量和金丝桃苷用量比为12.50:1,磷脂总量与胆固醇用量比为6.00:1,DSPE-PEG与DLD用量比为3:5;测得金丝桃苷包封率为(95.57±0.56)%,载药量为(8.55±0.57)%。所制备的DLD/Hyp-Lip外观良好,平均粒径为(124.9±3.4)nm,Zeta电位为(-6.2±1.9)mV;在胎牛血清中性状稳定,在体外释放介质中24 h累积释放量达到40%。线粒体靶向实验表明DLD/Hyp-Lip可以促进药物聚集在线粒体部位。结论 采用此方法能够精准有效的优化DLD/Hyp-Lip的制备工艺,该方法操作简单方便,可以用于DLD/Hyp-Lip制备与处方的优化,制备的DLD/Hyp-Lip包封率高,粒径小,分布均匀,且具有良好的缓释作用,为DLD/Hyp-Lip的进一步体内研究奠定了基础。载金丝桃苷的DLD/Hyp-Lip具有良好的肝癌细胞线粒体靶向性,是一种潜在高效的肝癌细胞线粒体靶向给药系统。 相似文献
10.
《Drug discovery today》2022,27(8):2043-2050