全文获取类型
收费全文 | 2527篇 |
免费 | 132篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 82篇 |
妇产科学 | 23篇 |
基础医学 | 242篇 |
口腔科学 | 82篇 |
临床医学 | 237篇 |
内科学 | 586篇 |
皮肤病学 | 56篇 |
神经病学 | 196篇 |
特种医学 | 81篇 |
外科学 | 324篇 |
综合类 | 53篇 |
一般理论 | 2篇 |
预防医学 | 171篇 |
眼科学 | 122篇 |
药学 | 230篇 |
中国医学 | 31篇 |
肿瘤学 | 149篇 |
出版年
2023年 | 33篇 |
2022年 | 72篇 |
2021年 | 90篇 |
2020年 | 88篇 |
2019年 | 112篇 |
2018年 | 133篇 |
2017年 | 89篇 |
2016年 | 95篇 |
2015年 | 101篇 |
2014年 | 154篇 |
2013年 | 161篇 |
2012年 | 256篇 |
2011年 | 251篇 |
2010年 | 112篇 |
2009年 | 95篇 |
2008年 | 153篇 |
2007年 | 160篇 |
2006年 | 95篇 |
2005年 | 93篇 |
2004年 | 55篇 |
2003年 | 48篇 |
2002年 | 31篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 13篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 10篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 8篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1974年 | 6篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1956年 | 2篇 |
排序方式: 共有2681条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
The establishment of drainage and the elimination of the origin of infection are essential procedures for successful management of odontogenic infections. Irrigation and aspiration are considered as the 2 main procedures for the treatment of facial space infections; we invented a new method named simultaneous irrigation and aspiration. The simultaneous irrigation and aspiration method is significantly less painful and less invasive compared with the standard surgical incision and drainage. This method was thought to be useful for managing facial infections if proper patient selection is performed. 相似文献
45.
Kazem Darvish Bastami Nariman Shabani Mohammad Reza Imanpour Majid Afkhami 《Comparative clinical pathology》2013,22(5):965-970
Fatty acid composition of ovules (ovulated oocytes) from kutum (Rutilus frisii kutum) was investigated to assess their relationship to gonad biological characteristics, larval size, fertilization, and hatching success. Forty-eight kutum were captured in the wild during the spawning season. Results revealed an inverse relationship between linoleic acid (18:2n-6) and ovule weight (P?<?0.05). Arachidonic acid (20:4n-6) and eicosapentaenoic acid (20:5n-3) contents showed a direct correlation with the number of ovules per gram (P?<?0.05); the latter had an inverse relationship with the ratio of surface to volume (P?<?0.01). There was a direct and significant correlation between docosahexaenoic acid (22:6n-3) and ovule weight (P?<?0.05). High unsaturated fatty acid levels indicated a direct relationship with egg and yolk diameters and also an inverse correlation with ovule surface to volume ratio (P?<?0.l05). Direct relationships were found between polyunsaturated fatty acids and the diameter of egg and yolk as well as the ratio of surface to volume (P?<?0.05). There was a direct correlation between saturated fatty acid content and the number of eggs (per gram) (P?<?0.01). Total lipid and weight of newly hatched larvae represented a direct relationship (P?<?0.05). Despite living in brackish water and migrating to fresh water during the reproductive season, kutum exhibited greater similarity in ovule fatty acid composition to saltwater fish than species in fresh water. Moreover, with respect to biological characteristics, this species shows more significant relationships with n-3 fatty acids than with n-6 fatty acids. 相似文献
46.
Saeed Rayati Elham Khodaei Parinaz Nafarieh Majid Jafarian Bahareh Elmi Andrzej Wojtczak 《RSC advances》2020,10(29):17026
In this study, a novel Mn(iii)–Schiff base complex was synthesized and characterized. The structure of this complex was determined to be a deformed octahedral coordination sphere by single-crystal X-ray diffraction analysis. The Mn(iii)–Schiff base complex was supported on silica-coated iron magnetic nanoparticles via axial coordination by one-step complex anchoring to produce a heterogenized nanocatalyst. After this, the complex was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and powder X-ray diffraction (XRD). Moreover, atomic absorption spectroscopy was used to determine the amount of the loaded metal. The heterogenized nanocatalyst effectively catalyzed the oxidation of a broad range of sulfides and alkenes with H2O2 in the presence of a glassy carbon electrode, applying voltage to the reaction mixture. The results showed that the application of a potential to the reaction mixture could significantly decrease the reaction time when compared with the case of similar chemical oxidation reactions. In addition, an excellent value of turnover frequency (17 750 h−1) was achieved for the electrochemical oxidation of styrene. Moreover, the nanocatalyst showed good recoverability without significant loss of its activity within six successive runs in the electrochemical oxidation of methyl phenyl sulfide and cyclooctene. The electrochemical properties and stability of Fe3O4@SiO2-[MnL(OAc)] were investigated by cyclic voltammetry measurements and chronoamperometry technique.A Mn–Schiff base complex supported on silica-coated iron magnetic nanoparticles was used for the electrochemical oxidation of sulfides and alkenes. 相似文献
47.
Mahsa Asadniaye Fardjahromi Amir Razmjou Graham Vesey Fatemeh Ejeian Balarka Banerjee Subhas Chandra Mukhopadhyay Majid Ebrahimi Warkiani 《RSC advances》2020,10(34):20118
Metal–organic frameworks (MOFs) have high porosity, large surface area, and tunable functionality and have been widely used for drug loading. The aim of this study was to exploit unique features of zeolitic imidazolate framework-8 (ZIF8) to develop an innovative composite microcarrier (MC) for human mesenchymal stem cells (hMSCs) adhesion and proliferation. ZIF8 MCs were prepared by immobilization of polydopamine/polyethyleneimine (PDA/PEI) and ZIF8 on the surface of polystyrene beads. The chemical properties of MCs such as coating stability and homogeneity were characterized by different techniques such as ATR-FTIR, XRD, EDX, SEM, and contact angle. The prepared MCs were tested using human adipose-derived mesenchymal stem cells (hADSCs) in both static and dynamic conditions, and results were compared to a commercially available MC (Star-Plus), polydopamine coated MCs and amine-functionalized MCs as a control. Results show that PDA/PEI/ZIF8 coated MCs (in short: ZIF8 MCs) provides an excellent biocompatible environment for hADSCs adhesion and growth. In conclusion, ZIF8 MCs represent suitable and low-cost support for hADSCs culture and expansion, which can maximize cell yield and viability while preserving hADSCs multipotency. The present findings have revealed this strategy has the potential for chemical and topographical modification of MCs in tissue engineering applications.Mussel inspired ZIF8 microcarriers with high surface area, biocompatibility, and nanoscale surface roughness are applied to enhance mesenchymal stem cell attachment and proliferation in 3D cell culture. 相似文献
48.
49.
50.