全文获取类型
收费全文 | 4838篇 |
免费 | 354篇 |
国内免费 | 227篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 18篇 |
妇产科学 | 46篇 |
基础医学 | 410篇 |
口腔科学 | 113篇 |
临床医学 | 261篇 |
内科学 | 566篇 |
皮肤病学 | 97篇 |
神经病学 | 241篇 |
特种医学 | 81篇 |
外科学 | 435篇 |
综合类 | 717篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 589篇 |
眼科学 | 455篇 |
药学 | 637篇 |
2篇 | |
中国医学 | 383篇 |
肿瘤学 | 347篇 |
出版年
2024年 | 4篇 |
2023年 | 85篇 |
2022年 | 185篇 |
2021年 | 224篇 |
2020年 | 166篇 |
2019年 | 156篇 |
2018年 | 151篇 |
2017年 | 169篇 |
2016年 | 159篇 |
2015年 | 158篇 |
2014年 | 263篇 |
2013年 | 343篇 |
2012年 | 258篇 |
2011年 | 314篇 |
2010年 | 267篇 |
2009年 | 276篇 |
2008年 | 274篇 |
2007年 | 296篇 |
2006年 | 241篇 |
2005年 | 235篇 |
2004年 | 204篇 |
2003年 | 169篇 |
2002年 | 118篇 |
2001年 | 106篇 |
2000年 | 104篇 |
1999年 | 75篇 |
1998年 | 79篇 |
1997年 | 66篇 |
1996年 | 41篇 |
1995年 | 34篇 |
1994年 | 22篇 |
1993年 | 35篇 |
1992年 | 24篇 |
1991年 | 17篇 |
1990年 | 14篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 7篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有5419条查询结果,搜索用时 15 毫秒
1.
2.
《Vaccine》2021,39(26):3498-3508
Adenovirus infections are a major cause of epidemic keratoconjunctivitis (EKC), which can lead to corneal subepithelial infiltrates and multifocal corneal opacity. In the current study, we investigated the use of an E1/E3-deleted adenovirus serotype 5 (Ad5) vector as a vaccine administered intramuscularly (IM) or intranasally (IN) against subsequent challenges with a luciferase-expressing Ad5 (Ad5-Luci) vector via eyedrop. We evaluated the adaptive immune response to Ad5 vector vaccination and confirmed a robust polyfunctional CD8 T cell response in splenic cells. Neutralizing Ad5 antibodies were also measured in the sera of vaccinated mice as well as Ad5 antibody in the eye wash solutions. Upon challenge with Ad5-Luci vector 8 weeks post the primary immunization, transduction was significantly reduced by > 70% in the vaccinated mice, which was slightly better in IM- vs. that in IN-vaccinated animals. Resistance to subsequent challenge was observed 10 months post primary IM vaccination, with sustained reduction up to 60% in the Ad5-Luci vector transduction. Passive immunization of naive mice with antisera from IM to vaccinated mice subsequently challenged with the Ad5-Luci vector resulted in approximately 40% loss in transduction efficiency. Furthermore, the mice that received IM immunization with or without CD8 T cell depletion showed > 40% and 70% reductions, respectively, in Ad8 genomic copies after Ad8 topical challenge. We conclude that Ad-vector vaccination successfully induced an adaptive immune response that prevented subsequent Ad transduction in the cornea and conjunctiva-associated tissues in a mouse model of adenovirus keratoconjunctivitis, and that both cellular and humoral immunity play an important role in preventing Ad transduction. 相似文献
3.
4.
5.
《European journal of surgical oncology》2019,45(11):2151-2158
IntroductionLymph node yield (LNY) in neck dissection has been identified as a prognostic factor in oral cavity cancer. The purpose of this study was to investigate the impact of additional use of optical imaging on LNY in therapeutic ND in oral cancer.MethodsConsecutive patients with oral squamous cell carcinoma with clinical neck metastasis planned for primary tumor resection were randomized to conventional neck dissection or near-infrared fluorescence (NIRF)-guided neck dissection, respectively. In the intervention group, patients were injected with ICG-Nanocoll prior to surgery. Intraoperatively, an optical hand-held camera system was used for lymph node identification. Also, NIRF imaging of the neck specimen was performed, and optical signals were pinned with needle markings to guide the pathological examination. The endpoint of the study was LNY per neck side in levels Ib-III.Results31 patients were included with 18 neck sides in the control group and 18 neck sides in the intervention group for evaluation. During NIRF-guided ND, individual lymph nodes could be identified by a bright fluorescent signal and individual tumor-related drainage patterns could be observed in the neck. The LNY in the intervention group was significantly higher compared to the control group (p = 0.032) with a mean of 24 LN (range: 12–33 LN in levels Ib-III compared to 18 LN (range: 10–36 LN) in the control group, respectively.ConclusionsNIRF-guided ND significantly improved the nodal yield compared to the control group. Intraoperative real-time optical imaging enabled direct visualization of tumor-related drainage patterns within the neck lymphatics. 相似文献
6.
7.
Gholamreza Azizi Sanaz Afraei Reza Sedaghat Mir Hadi Seyedzadeh 《Food and Agricultural Immunology》2015,26(6):782-793
Experimental autoimmune encephalomyelitis (EAE) is a mouse model for multiple sclerosis (MS), in which an inflammatory demyelination and axonal damage occurs. Kombucha tea is a fermented beverage made from kombucha mushroom, brewed tea, and sugar. In recent years kombucha tea has attracted interest due to its pharmacological properties like antioxidant effects. The aim of the present research was to test the therapeutic effect of kombucha tea in EAE. We induced EAE model in 18 female C57BL/6 mice by inoculation of myelin oligodendrocyte glycoprotein-35-55 (MOG35-55) in complete Freund’s adjuvant emulsion. Then, in order to ameliorate EAE symptoms, we used kombucha tea. During the course of study clinical evaluation was assessed, and on the day 21 post-immunization, for evaluation of nitric oxide (NO), total antioxidants capacity and tumor necrosis factor-alpha (TNF-α), blood samples were taken from the heart of mice. The mice were sacrificed and brains and cerebellums of mice were removed for histological analysis. Our findings demonstrated that kombucha tea had beneficial effects on EAE by lower incidence, attenuation in the severity, and also a delay in the onset of disease. Histological analysis showed that inflammatory criteria including the number of infiltrated immune cells and plaques as well as demyelination in kombucha tea dosed mice were significantly lower than the control group. Also, in comparison with control mice, the serum levels of NO and TNF-α in kombucha tea-treated mice were significantly decreased. Kombucha tea with its potential therapeutic effects and immunomodulatory properties might be proposed, after additional necessary tests and trials, for treatment of MS. 相似文献
8.
DTF降茶氟剂降茶氟初步研究 总被引:9,自引:1,他引:8
王连方 《中国地方病防治杂志》2003,18(1):17-19
目的探讨DTF制剂降茶氟效果。方法在不同制茶方法程序中加入DTF制剂观察其降氟效果。结果在冲泡或煮沸(1.0g茶叶,200ml水量)沏茶中,0.2gDTF可使茶氟降低约60%,使茶水氟浓度由2.0~4.0mg/L降到1.0mg/L左右,茶液色、味、pH值无改变。结论DTF是1种有效的降茶氟剂。 相似文献
9.
Christos Haritoglou Wolfgang Freyer Siegfried G. Priglinger Anselm Kampik 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2006,244(9):1196-1202
BACKGROUND: To evaluate potential differences in light absorbing properties and stability of indocyanine green (ICG) adsorbed to the retinal surface and of ICG dissolved in water and balanced salt solution. METHODS: The retina of four human donor eyes was prepared by removing the vitreous from the retinal surface. The inner surface of the specimen was covered with two to three drops of a 0.05% or 0.15% ICG solution respectively. After 1 min, the dye was removed by careful irrigation using BSS plus. The retinal specimens were then investigated by diffuse reflection spectroscopy (UV/VIS/NIR Spectrometer Lambda 900/Perkin Elmer equipped with a PELA-1020 integrating sphere accessory) and their absorption evaluated by the Kubelka-Munk function. To control the sensitivity of the setting, diffuse reflectance spectra of ICG adsorbed to a cellulose membrane and Al(2)O(3) were measured. For comparison, absorption spectra of ICG dissolved in water and BSS plus solution were measured in relation to ICG concentration and time using an UV/VIS/NIR Spectrometer Lambda 900/Perkin Elmer. RESULTS: On the retinal surface, absorption spectra exhibited a steep increase of absorption beginning at 620 nm, with a maximum at 736 nm (0.05%) and a shoulder at 745 (0.15%) and a second maximum at approximately 800 nm for both concentrations. Repeated measurement of the retinal surface 13 days after the ICG exposure revealed no changes in the position of the maxima as compared to the initial measurements. Light absorbing properties of ICG on cellulose or Al(2)O(3) are similar to those seen on the retinal surface with respect to the pattern and location of absorption maxima. In contrast, ICG dissolved in water or BSS plus disclosed variations in absorption characteristics depending on dye concentration, solute and time of measurement. CONCLUSIONS: Absorption characteristics and stability of ICG bound to the retinal surface could be of relevance when investigating potential pathomechanisms of ICG related toxicity, which might be related not only to intraoperative but also to postoperative light exposure of patients after intravitreal use of ICG. 相似文献
10.
茶水提取物和茶多酚抑制诱变的类型及其机制 总被引:3,自引:0,他引:3
目的 :研究茶水提取物和茶多酚的去突变特征和机制 ,鉴别茶和茶多酚去突变的量效关系和抑菌关系 ,了解去突变剂与直接诱变剂(1_NP)、间接(Trp_P_1)诱变剂的抗突变作用方式和抑制效果。 方法 :用细胞外抑制诱变试验和改进型两次活化的Ames试验方法。 结果 :茶水提取物和与其相关的儿茶素等都存在非抑菌性的去突变效果 ,其中表没食子儿茶素没食子酸酯(EGCG)和茶黄素(TF)的效果最好。抗突变试验结果表明 ,茶水提取物对Trp_P_1( +S9)有显著的抗突变性 ,与Trp_P_1的混合液在非代谢活性条件时无诱变性 ;茶水提取物对1_NP( -S9)也有抑制活性 ,但比对Trp_P_1的抑制活性低(P<0.01) ,与1_NP混合物经代谢活化后有诱变性 ,且与非代谢活化的抗突变结果呈较高的相关性(r= -0.9694)。 结论 :茶多酚能抑制间接诱变剂的前体形成 ,也有对直接诱变剂构成阻断剂的作用 ,但是在阻断具有强氧化性的诱变剂时可能形成不稳定的结合物或不安全的结构物。 相似文献