全文获取类型
收费全文 | 11849篇 |
免费 | 683篇 |
国内免费 | 183篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 260篇 |
妇产科学 | 176篇 |
基础医学 | 2142篇 |
口腔科学 | 499篇 |
临床医学 | 728篇 |
内科学 | 2119篇 |
皮肤病学 | 132篇 |
神经病学 | 1091篇 |
特种医学 | 120篇 |
外国民族医学 | 4篇 |
外科学 | 1069篇 |
综合类 | 521篇 |
预防医学 | 394篇 |
眼科学 | 104篇 |
药学 | 2020篇 |
中国医学 | 279篇 |
肿瘤学 | 1011篇 |
出版年
2023年 | 117篇 |
2022年 | 146篇 |
2021年 | 277篇 |
2020年 | 284篇 |
2019年 | 359篇 |
2018年 | 343篇 |
2017年 | 302篇 |
2016年 | 269篇 |
2015年 | 329篇 |
2014年 | 628篇 |
2013年 | 972篇 |
2012年 | 476篇 |
2011年 | 577篇 |
2010年 | 434篇 |
2009年 | 468篇 |
2008年 | 540篇 |
2007年 | 503篇 |
2006年 | 509篇 |
2005年 | 425篇 |
2004年 | 388篇 |
2003年 | 379篇 |
2002年 | 317篇 |
2001年 | 299篇 |
2000年 | 281篇 |
1999年 | 284篇 |
1998年 | 248篇 |
1997年 | 200篇 |
1996年 | 225篇 |
1995年 | 225篇 |
1994年 | 223篇 |
1993年 | 172篇 |
1992年 | 164篇 |
1991年 | 129篇 |
1990年 | 118篇 |
1989年 | 106篇 |
1988年 | 108篇 |
1987年 | 72篇 |
1986年 | 97篇 |
1985年 | 111篇 |
1984年 | 113篇 |
1983年 | 82篇 |
1982年 | 69篇 |
1981年 | 71篇 |
1980年 | 59篇 |
1979年 | 36篇 |
1978年 | 33篇 |
1977年 | 28篇 |
1976年 | 24篇 |
1974年 | 27篇 |
1973年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Amorphous silica that was extracted from rice husk was used to synthesize the magMCM-41 mesoporous silica. This was then functionalized by the APTMS group in order to produce NH2-magMCM-41 as a novel and low–cost adsorbent. The XRD, VSM, N2 adsorption–desorption, FT–IR, TGA, SEM and TEM analyses were utilized to characterize the produced materials. In order to optimize the adsorption of the Pb(II) ions, the RSM (response surface methodology) was applied by using the synthesized adsorbent in aqueous solutions. A rotatable CCD (central composite design) was adopted to carry out the experiments and RSM was used to analyze them. Three independent factors namely, initial solution pH (3–7), adsorbent dosage (0.1–2 g L?1), and initial Pb(II) concentration (15–150 mg L?1) were used to investigate the removal procedure. According to the obtained results, the initial solution pH of 5.22, adsorbent dosage of 0.1 g L?1, and initial Pb(II) concentration of 150 mg L?1 were considered as the optimum conditions with 64.32% removal of Pb(II) and an adsorption capacity of 540.64 mg g?1. The maximum removal efficiency of Pb(II) ions was found to be 96.76%. The Sips isotherm model represents a better correlation with equilibrium data. It was reported by the kinetic study that data taken from the experiments fitted better to the pseudo–second–order model compared to the pseudo–first–order and intraparticle diffusion models. Finally, according to the thermodynamic study, the removal process strongly depends on temperature, which indicates an exothermic behavior and spontaneous nature of the adsorption. 相似文献
5.
《Vaccine》2019,37(22):2952-2959
CD8+ T cells are known to control infections, but their role in preventing latent infection from establishing has not been thoroughly investigated.We hypothesized that a potent CD8+ T cell response patrolling the mucosal viral entry points could kill the first infected cells and thereby abrogate the infection before latency is established.To investigate this, replication deficient adenovirus serotype 5 vectors encoding murine γ-herpesvirus-68 CD8+ T cell epitopes linked to the T cell adjuvant Invariant chain, were developed. We show that intranasal vaccination of mice reduces the risk of establishment of latent infection from multiple intranasal ID50 challenges with murine γ-herpesvirus-68 by 81% per exposure at 14 days post vaccination. Protection waned over time, but immune responses were extended by heterologous prime-boost vaccination applied simultaneously intramuscularly and intranasally, and animals vaccinated 66 days prior to challenge showed a strong trend of long-term protection.Our data provides evidence that CD8+ T cells are able to protect against establishment of latent infection. Although the protective efficacy is difficult to maintain over time, this proof-of-concept study suggests a role for a CD8+ T cell arm in future vaccine strategies against latent human viral infections caused by pathogens such as HIV and multiple herpes virus. 相似文献
6.
7.
8.
Yasutoshi Komatsubara Yorihisa Orita Takuma Makino Kazunori Kuroda Yuto Naoi 《Acta oto-laryngologica》2020,140(9):773-778
AbstractBackground: Subglottic cancer (SGC) is extremely rare, as most laryngeal cancers are localized to the glottic region. Accordingly, the clinical characteristics of SGC have not been well characterized.Objectives: In the current study, SGCs were clinically evaluated, and the outcomes of radiotherapy (RT) in patients with stage II SGC were assessed.Materials and Methods: Medical data derived from 11 patients with SGC, who were treated at our hospital between 1995 and 2019, were retrospectively reviewed.Results: In our department SGC accounted for 3.9% of the 280 laryngeal cancer patients treated during the study period. At the time of SGC diagnosis, 9 (81.8%) had stage II cancer, 1 had stage III cancer, and 1 had stage IV cancer. Stage II SGC patients treated with concurrent chemoradiotherapy (CCRT) showed a significantly higher local control rate (p?=?.026) and laryngeal dysfunction free rate (p?=?.026) than those treated with RT alone. Salvage surgery, performed in 4 patients whose disease was not locally controlled with CCRT/RT, was successful in 3 patients.Conclusion: As a treatment strategy for stage II SGC, CCRT is an acceptable initial treatment for laryngeal function and preservation while salvage surgery is effective for recurrence after CCRT/RT treatment. 相似文献
9.
目的探讨益气化瘀解毒方干预后对Sorafenib获得性耐药人肝癌QGY7702细胞(QGY7702/Sora)增殖及MRP、GST-π和Topo Ⅱ基因表达的影响。方法培养QGY7702/Sora细胞和QGY7702细胞,利用Cell Counting Kit-8(CCK-8)法检测Sorafenib对细胞的半数抑制率浓度(IC50值),计算耐药指数RI;观察益气化瘀解毒方对耐药细胞的增殖影响;采用荧光定量PCR检测药物干预前后2种细胞中MRP、GST-π和Topo Ⅱ基因表达水平。结果亲本细胞和耐药细胞Sorafenib的IC50值分别为(7.993±0.522)μmol/L和(19.651±1.216)μmol/L,RI约为2.5。益气化瘀解毒方可抑制耐药细胞的增殖活性。2种细胞的MRP、GST-π、Topo Ⅱ表达量无明显差异(P>0.05)。Sorafenib组可促进耐药细胞MRP 、GST-π基因的过表达(P<0.05),益气化瘀解毒方组可抑制GST-π基因的过表达(P<0.01),且联合Sorafenib可显著提高Topo Ⅱ基因的表达量(P<0.01)。结论 QGY7702/Sora细胞MRP、GST-π和Topo Ⅱ的表达水平与亲本细胞无显著差异。耐药细胞对Sorafenib敏感性降低与MRP、GST-π过表达相关,而益气化瘀解毒方拮抗Sorafenib耐药与抑制GST-π过表达相关。 相似文献
10.
Daniela S. Camilo Fernando Pradella Maria Fernanda Paulino Emilio C. E. Baracat Sofia H. Marini Gil Guerra Elizabeth J. Pavin Candida Parisi Ana Leda F. Longhini Silvia B. Marques Edilaine G. Guariento Sofia R. Lieber Carlos Fernando Macedo Letícia Gama e Silva Alessandro S. Farias Leonilda M. B. Santos Walkyria M. G. Volpini 《Pediatric diabetes》2020,21(4):606-614