全文获取类型
收费全文 | 2591篇 |
免费 | 96篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 25篇 |
妇产科学 | 19篇 |
基础医学 | 331篇 |
口腔科学 | 47篇 |
临床医学 | 136篇 |
内科学 | 537篇 |
皮肤病学 | 18篇 |
神经病学 | 362篇 |
特种医学 | 120篇 |
外科学 | 457篇 |
综合类 | 4篇 |
预防医学 | 25篇 |
眼科学 | 15篇 |
药学 | 232篇 |
中国医学 | 6篇 |
肿瘤学 | 351篇 |
出版年
2024年 | 3篇 |
2023年 | 14篇 |
2022年 | 43篇 |
2021年 | 43篇 |
2020年 | 33篇 |
2019年 | 37篇 |
2018年 | 45篇 |
2017年 | 37篇 |
2016年 | 46篇 |
2015年 | 50篇 |
2014年 | 63篇 |
2013年 | 80篇 |
2012年 | 167篇 |
2011年 | 173篇 |
2010年 | 97篇 |
2009年 | 67篇 |
2008年 | 138篇 |
2007年 | 183篇 |
2006年 | 160篇 |
2005年 | 155篇 |
2004年 | 133篇 |
2003年 | 181篇 |
2002年 | 171篇 |
2001年 | 46篇 |
2000年 | 40篇 |
1999年 | 52篇 |
1998年 | 54篇 |
1997年 | 33篇 |
1996年 | 29篇 |
1995年 | 26篇 |
1994年 | 30篇 |
1993年 | 24篇 |
1992年 | 22篇 |
1991年 | 35篇 |
1990年 | 21篇 |
1989年 | 21篇 |
1988年 | 20篇 |
1987年 | 21篇 |
1986年 | 19篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 7篇 |
1982年 | 13篇 |
1981年 | 6篇 |
1980年 | 10篇 |
1979年 | 8篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1971年 | 5篇 |
排序方式: 共有2706条查询结果,搜索用时 31 毫秒
21.
22.
Otagiri Masaki Yamamichi Ryuji Marayama Toru Imai Teruko Suenaga Ayaka Imamura Yorishige Kimachi Kazuhiko 《Pharmaceutical research》1989,6(2):156-159
The interactions of acidic and basic drugs with 1-acid glycoprotein (1-AGP) were investigated using circular dichroism (CD) measurements. Extrinsic Cotton effects were generated by the binding of drugs to 1-AGP. The CD data suggested the presence of a single binding site on the 1-AGP molecule. The induced ellipticities of the acidic drug–1-AGP system decreased with increasing pH, while the ellipticities for the basic drugs increased with pH. The ellipticities for all drugs were reduced by the addition of fatty acids. Furthermore, the induced ellipticities decreased in the presence of cesium chloride for basic drugs bound to 1-AGP. The extrinsic Cotton effects therefore appear to result from hydrophobic interaction with 1-AGP for the acidic drugs and from hydrophobic and electrostatic interactions for the basic drugs. 相似文献
23.
Uenishi H Hiraiwa H Yamamoto R Yasue H Takagaki Y Shiina T Kikkawa E Inoko H Awata T 《Immunology》2003,109(4):515-526
A complete genomic region of 131.2 kb including the swine T-cell receptor alpha/delta constant region (TRAC/TRDC) and joining segments (TRAJ/TRDJ) was sequenced. The structure of this region was strikingly conserved in comparison to that of human or mouse. All of the 61 TRAJ segments detected in the human genomic sequence were detected in the swine sequence and the sequence of the protein binding site of T early alpha, the sequence of the alpha enhancer element and the conserved sequence block between TRAJ3 and TRAJ4 are highly conserved. Insertion of the repetitive sequences that interspersed after the differentiation of the species in mammals such as short interspersed nucleotide elements is markedly suppressed in comparison to other genomic regions, while the composition of the mammalian-wide interspersed sequences is relatively conserved in human and swine. This observation indicates the existence of a highly selective pressure to conserve this genomic region around TRAJ throughout the evolution of mammals. 相似文献
24.
Yamamoto R Isobe T Eguchi T Tang WR Kiyokawa N Amemiya H Fujimoto J Sato E Takagaki Y Yasue H 《Molecular immunology》2005,42(12):1485-1493
Complete porcine CD3ζ-chain cDNA sequence was obtained for the first time, and its genomic nucleotide sequence was investigated from exon 2 down to CD3η-chain exon 8. The sequence of porcine CD3ζ-chain showed homologous amino acid sequence with human and murine counterparts, in contrast to CD3η-chain exon 8 with diversity among animals previously investigated. CD3η-chain peptide is an alternative splice form of CD3ζ-chain exon 7 splicing to CD3η-chain exon 8 instead of CD3ζ-chain exon 8. The genomic sequences revealed that the splice acceptor sequences of CD3η-chain exon 8 of all animals investigated to be completely uniform. Further, CD3η-chain exon 8 amino acid sequences retained the unique characters of having high proline (Pro) and positively charged amino acid content except for rats and mice. Although the biological role of CD3η-chain remains to be enigmatic, these evidences suggests the evolutional pressure to maintain its sequence. 相似文献
25.
K Hayashi Y Ohtsuki H Sonobe J Iwata M Furihata T Hikita T Kishino T Akagi 《Acta medica Okayama》1991,45(1):49-53
We present a case of pre-elastofibroma-like lesion, a kind of elastic-producing fibrous tumor. The small colonic polyp, which was found in a 49-year-old asymptomatic man in association with a large colonic adenoma, showed submucosal nodular deposits of fine granular or fibrillar eosinophilic materials with interspersed fibroblastic cells. Elastic stain revealed these deposits to consist mainly of dark gray granular or partially fibrillar dense elastinophilic materials, most of which were digested with elastase. This stromal lesion somewhat resembled a pre-elastofibroma. Therefore, pre-elastofibroma-like lesions should be kept in mind as a possible origin of colonic polyp. 相似文献
26.
A new algorithmic-based digital filter processing system for real-time continuous blood pressure (BP) measurement and analysis in freely-moving conscious rats has been developed. Real-time recognition of BP waveforms, real-time noise rejection and determination of representative waveform indexes (WIs) at indicated time points using digital filters and Smirnov's rejection test were realized with this system. Digital filters were applied for two different purposes: waveform segmentation and smoothing the calculations of representative WIs. Smirnov's rejection test was used for real-time noise rejection and yielded an accurate rejection rate of 99.99%. The result was that the digital filter processing and Smirnov's rejection test realized accurate real-time BP measurement and analysis in freely-moving conscious rats using a personal computer. 相似文献
27.
28.
29.
Mutsuo Furihata Tamotsu Takeuchi Jun Iwata Hiroshi Sonobe Yuji Ohtsuki Akihiko Wakatsuki Nobuyuki Morioka Yusuke Sagara 《Pathology international》1998,48(12):967-973
Primary ovarian angiosarcoma is extremely rare. Only 16 cases have histologicaliy been reported to date In the Ilterature. A case of angiosarcoma arising In the right ovary of a 46-year-old female is presented. Grossly, the resected right ovary was completely replaced by a solid tumor mass, which revealed multiple necrotic and/or hemorrhagic foci. This case revealed the typical histological features of angiosarcoma with sinusoldal and solid patterns of anaplastic tumor cells. Immunohlstochemically, tumor cells were strongly and diffusely positive for CD31 and CD34, in particular, along the cytoplasmic membrane of the tumor cells. Ultrastructurally, tumor cells possessed the intermediate junctions between tumor cells, discontinuous basal laminae attached to the irregularly shaped blood vessels and occasional cytoplasmic pinocytotlc vesicles. These findings confirmed the case as being one of angiosarcoma of the ovary. The patient died 9 months after surgery as a result of developed multlfocal brain metastases. A total of 17 cases reported as primary ovarian anglosarcoma, including this presented case, are clinicopathologically reviewed. 相似文献
30.
Influence of polymorphisms in the genes for cytokines and glutathione S-transferase omega on sporadic Alzheimer's disease 总被引:2,自引:0,他引:2
We studied promoter region polymorphisms in the interleukin (IL)-1alpha, IL-1beta, IL-6, IL-10, tumor necrosis factor, and transforming growth factor (TGF)-beta1 genes in Japanese patients with Alzheimer's disease (AD) (n = 172) and normal controls (n = 163). We also examined an association of a polymorphism located in the glutathione S-transferase omega 1 (GSTO-1) gene region with AD patients. None of these genotypes or allele frequencies showed a significant difference between AD patients and controls. We also failed to detect any difference in the disease onset between each genotype of the seven polymorphisms. Although AD patients carrying high producer alleles of TGF-beta1 and IL-1beta or TGF-beta1 and IL-6 showed a tendency for an early onset of the disease, neither of these combined effects reached a significant level after multiple comparisons. Our findings suggest that genetic polymorphisms in the cytokines and GSTO do not play a major role in Japanese AD patients. 相似文献