全文获取类型
收费全文 | 2404篇 |
免费 | 187篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 46篇 |
妇产科学 | 7篇 |
基础医学 | 309篇 |
口腔科学 | 57篇 |
临床医学 | 172篇 |
内科学 | 677篇 |
皮肤病学 | 84篇 |
神经病学 | 276篇 |
特种医学 | 108篇 |
外科学 | 430篇 |
综合类 | 13篇 |
预防医学 | 43篇 |
眼科学 | 31篇 |
药学 | 115篇 |
中国医学 | 1篇 |
肿瘤学 | 217篇 |
出版年
2023年 | 50篇 |
2022年 | 64篇 |
2021年 | 146篇 |
2020年 | 63篇 |
2019年 | 107篇 |
2018年 | 93篇 |
2017年 | 86篇 |
2016年 | 91篇 |
2015年 | 118篇 |
2014年 | 131篇 |
2013年 | 125篇 |
2012年 | 189篇 |
2011年 | 181篇 |
2010年 | 106篇 |
2009年 | 92篇 |
2008年 | 133篇 |
2007年 | 128篇 |
2006年 | 107篇 |
2005年 | 101篇 |
2004年 | 87篇 |
2003年 | 101篇 |
2002年 | 76篇 |
2001年 | 28篇 |
2000年 | 27篇 |
1999年 | 21篇 |
1998年 | 19篇 |
1997年 | 9篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 13篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1967年 | 2篇 |
1965年 | 2篇 |
排序方式: 共有2616条查询结果,搜索用时 15 毫秒
31.
Tomoyuki Nakamura Ryosuke Yamaguchi Akifusa Wada Kazuyuki Takamura Haruhisa Yanagida Toru Yamaguchi 《Journal of orthopaedic science》2021,26(4):644-649
BackgroundAlthough acetabular dysplasia is a common etiology of osteoarthritis of the hip regardless of the history of developmental dysplasia of the hip (DDH), whether or not corrective surgeries are beneficial for the childhood asymptomatic acetabular dysplasia remains controversial due to a lack of evidence. We conducted a longitudinal study to compare the cartilaginous morphology on childhood magnetic resonance imaging (MRI) and the mature hip morphology of the same patient and to assess the predictive indicators for future acetabular dysplasia.MethodsA total of 92 unaffected hips (47 unilateral DDH and 45 unilateral Legg-Calvé-Perthes disease) were reviewed for X-ray and MRI findings on childhood (mean age: 6.0 years) and X-ray findings from a skeletally mature age with a mean follow-up period of 15.1 years. The following parameters were measured and compared: the immature-acetabular index (AI) and center edge angle (CE) on immature X-ray; the cartilage- and bone- AI, CE, Sharp and acetabular head index (AHI) on childhood MRI; and the mature-acetabular roof obliquity (ARO), CE, Sharp and AHI on skeletally mature X-ray. The prognostic factors on childhood MRI for acetabular dysplasia, defined by a CE of <20° on skeletally mature X-ray were also assessed.ResultsPositive correlations were shown between the cartilage-AI and mature-ARO (7.6°/6.3°; r = 0.44), the cartilage-CE and mature-CE (27.8°/28.0°; r = 0.62), the cartilage-Sharp and mature-Sharp (44.4°/41.8°; r = 0.52) and the cartilage-AHI and mature-AHI (78.7%/80.3%; r = 0.46). A multivariate analysis indicated cartilage-CE to be an independent predictor for acetabular dysplasia with a cut-off value of 22°. Children with a cartilage-CE <22° developed more frequently acetabular dysplasia compared to the others (52.4% vs. 1.4%).ConclusionsChildhood MRI findings are useful for the prediction of acetabular dysplasia without a DDH history. Children with a cartilage-CE ≥23° are likely to achieve a non-dysplastic hip without the need for surgical intervention. 相似文献
32.
33.
Ultrasonic measurement of the effects of light irradiation and presence of water on the polymerization of self‐adhesive resin cement 下载免费PDF全文
Hirotaka Takenaka Hajime Ouchi Keiichi Sai Ryo Kawamoto Ryosuke Murayama Hiroyasu Kurokawa Masashi Miyazaki 《European journal of oral sciences》2015,123(5):369-374
Self‐adhesive resin cements are useful in restorations because they reduce the number of clinical steps involved in the restoration process. This study evaluated, using ultrasonic measurements, the influence of light irradiation and the presence of water on the polymerization behavior and elastic modulus of a self‐adhesive resin cement. A self‐adhesive resin cement (RelyX Unicem 2 Automix) or a resin cement (RelyX ARC) was inserted into a transparent mold on a sample stage, and the presence of water and effect of light‐irradiation were evaluated. The transit time of a sonic wave through the cement disk was divided by the specimen thickness to obtain the sonic velocity, and longitudinal and shear waves were used to determine the elastic modulus. When the resin cements were light‐irradiated, the sonic velocity rapidly increased and plateaued at 2,500–2,700 m s?1. When the cements were not irradiated, the rates of increase in the sonic velocity were reduced. When water was applied to the sample stage, the sonic velocity was reduced. The elastic modulus values of the specimens ranged from 9.9 to 15.9 GPa after 24 h. The polymerization behavior of self‐adhesive resin cements is affected by the polymerization mode and the presence of water. 相似文献
34.
35.
36.
Yumani Kuba Sonoko Ishino Takeshi Yamagami Masahiro Tokuhara Tamotsu Kanai Ryosuke Fujikane Hiromi Daiyasu Haruyuki Atomi Yoshizumi Ishino 《Genes to cells : devoted to molecular & cellular mechanisms》2012,17(11):923-937
The DNA sliding clamp is a multifunctional protein involved in cellular DNA transactions. In Archaea and Eukaryota, proliferating cell nuclear antigen (PCNA) is the sliding clamp. The ring‐shaped PCNA encircles double‐stranded DNA within its central hole and tethers other proteins on DNA. The majority of Crenarchaeota, a subdomain of Archaea, have multiple PCNA homologues, and they are capable of forming heterotrimeric rings for their functions. In contrast, most organisms in Euryarchaeota, the other major subdomain, have a single PCNA forming a homotrimeric ring structure. Among the Euryarchaeota whose genome is sequenced, Thermococcus kodakarensis is the only species with two genes encoding PCNA homologues on its genome. We cloned the two genes from the T. kodakarensis genome, and the gene products, PCNA1 and PCNA2, were characterized. PCNA1 stimulated the DNA synthesis reactions of the two DNA polymerases, PolB and PolD, from T. kodakarensis in vitro. PCNA2, however, only had an effect on PolB. We were able to disrupt the gene for PCNA2, whereas gene disruption for PCNA1 was not possible, suggesting that PCNA1 is essential for DNA replication. The sensitivities of the Δpcna2 mutant strain to ultraviolet irradiation (UV), methyl methanesulfonate (MMS) and mitomycin C (MMC) were indistinguishable from those of the wild‐type strain. 相似文献
37.
38.
Possible pro‐inflammatory role of heparin‐binding epidermal growth factor‐like growth factor in the active phase of systemic sclerosis 下载免费PDF全文
Megumi Hirabayashi Yoshihide Asano Takashi Yamashita Shunsuke Miura Kouki Nakamura Takashi Taniguchi Ryosuke Saigusa Takehiro Takahashi Yohei Ichimura Takuya Miyagawa Ayumi Yoshizaki Tomomitsu Miyagaki Makoto Sugaya Shinichi Sato 《The Journal of dermatology》2018,45(2):182-188
Heparin‐binding epidermal growth factor (EGF)‐like growth factor (HB‐EGF) is a member of the EGF family growth factors, which affects multiple aspects of the wound healing process such as epithelialization, wound contraction and angiogenesis. In our study, we measured the serum HB‐EGF levels of 51 systemic sclerosis (SSc) patients, which showed a significant increase compared with those of 20 normal subjects. Further analysis revealed a positive correlation between the HB‐EGF level and pulmonary ground‐glass score but no correlation between the former and pulmonary fibrosis score. Other findings include: a significant increase of serum sialylated carbohydrate antigen KL‐6 levels and significant shortness of disease duration in the diffuse cutaneous SSc patients with elevated HB‐EGF levels; and significantly higher HB‐EGF levels in the presence of Raynaud's phenomenon, in that of telangiectasia, and in the absence of contracture of phalanges in all SSc patients. We then evaluated HB‐EGF mRNA levels of fibroblasts harvested from skin samples of the SSc patients and those of foreskin‐derived fibroblasts treated with transforming growth factor‐β, both of which were significantly higher than each control. In conclusion, we speculate that HB‐EGF plays a pro‐inflammatory role in the active skin and lung lesions of SSc. 相似文献
39.
40.