全文获取类型
收费全文 | 10591篇 |
免费 | 587篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 151篇 |
妇产科学 | 117篇 |
基础医学 | 1330篇 |
口腔科学 | 260篇 |
临床医学 | 711篇 |
内科学 | 2641篇 |
皮肤病学 | 270篇 |
神经病学 | 720篇 |
特种医学 | 778篇 |
外科学 | 1647篇 |
综合类 | 69篇 |
预防医学 | 337篇 |
眼科学 | 328篇 |
药学 | 680篇 |
中国医学 | 31篇 |
肿瘤学 | 1056篇 |
出版年
2023年 | 77篇 |
2022年 | 161篇 |
2021年 | 234篇 |
2020年 | 120篇 |
2019年 | 188篇 |
2018年 | 216篇 |
2017年 | 178篇 |
2016年 | 245篇 |
2015年 | 262篇 |
2014年 | 304篇 |
2013年 | 330篇 |
2012年 | 500篇 |
2011年 | 536篇 |
2010年 | 347篇 |
2009年 | 269篇 |
2008年 | 450篇 |
2007年 | 505篇 |
2006年 | 502篇 |
2005年 | 552篇 |
2004年 | 514篇 |
2003年 | 526篇 |
2002年 | 550篇 |
2001年 | 358篇 |
2000年 | 336篇 |
1999年 | 294篇 |
1998年 | 134篇 |
1997年 | 117篇 |
1996年 | 93篇 |
1995年 | 76篇 |
1994年 | 88篇 |
1993年 | 79篇 |
1992年 | 214篇 |
1991年 | 178篇 |
1990年 | 158篇 |
1989年 | 159篇 |
1988年 | 137篇 |
1987年 | 156篇 |
1986年 | 147篇 |
1985年 | 149篇 |
1984年 | 104篇 |
1983年 | 76篇 |
1982年 | 45篇 |
1979年 | 67篇 |
1978年 | 39篇 |
1977年 | 37篇 |
1976年 | 34篇 |
1975年 | 44篇 |
1971年 | 38篇 |
1970年 | 37篇 |
1969年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
A Hoshino I Honda A Ishimori K Itoh M Mizugaki M Nose 《Rinsho byori. The Japanese journal of clinical pathology》1990,38(7):756-764
Modified nucleosides are components of ribosomal RNA (rRNA), transfer RNA (tRNA) and messenger RNA (mRNA). 1-methyladenosine and pseudouridine are members of those modified nucleosides. The urinary concentration of 1-methyladenosine and pseudouridine of cancer patients are higher than that of healthy controls, and those compounds were reduced after effective chemotherapy. Thus those compounds might be expected to use as tumor markers. In this study cellular origin of 1-methyladenosine and pseudouridine were analysed about two tumor cell lines (HUT-102, THP-1), peripheral blood lymphocytes (PBL) from healthy adult and PBL under the phytohemagglutinin stimulation, by flow cytometric analysis and immunofluorescent staining of cellular RNA using monoclonal antibodies specific for 1-methyladenosine (AMA) and pseudouridine (APU). Both 1-methyladenosine and pseudouridine were detected in more than 90% of tumor cells above the thresholds of flow cytometric detection (Spectrum III, Ortho). The PBL under the PHA stimulation also tended to take the same way of the tumor cell lines, whereas few of the PBL contained 1-methyladenosine above the thresholds. According to the DNA analysis of those cell lines, high contents of the modified nucleosides in the cell might follow DNA synthesis, this leads to one reason for high levels of the urinary excretion of the modified nucleosides in cancer patient. 相似文献
52.
Yasunari Nakamoto Shuichi Kaneko Masao Honda Masashi Unoura Jaehun Cheong Akihisa Harada Kouji Matsushima Kenichi Kobayashi Seishi Murakami 《Journal of medical virology》1994,42(4):374-379
The question was asked whether a predicted envelope protein, considered to be processed from the polyprotein precursor encoded by the putative E2/NS1 region of the hepatitis C virus (HCV) genome, may be observed in HCV-infected humans. Two polyclonal antibodies against recombinant E2/NS1 proteins were prepared and their reactivity tested against liver extracts from HCV-infected patients by immunoblotting analysis. A band corresponding to a size of 44 kDa was detected in liver extracts from patients who were positive for the HCV-specific antibody anti-C100-3 but not in liver extracts from patients who did not have anti-C100-3 antibody. Additionally, no band was detected using preimmune sera or antisera which had been preabsorbed with recombinant E2/NS1 proteins. Deglycosylation studies demonstrated that the 44 kDa protein was a glycosylated form of a 38 kDa protein which corresponds to the predicted molecular weight of the putative E2/NS1 protein. These results suggest that the 44 kDa protein is a product of the E2/NS1 region. Frequent observation of the 44 kDa band in cases of chronic active hepatitis C suggests a correlation between the expression of this protein and the progression of hepatitis. © 1994 Wiley-Liss, Inc. 相似文献
53.
We compared the influences of the parameters of several pulse sequences using two major commercially available gadolinium (Gd) contrast media for MR imaging. The phantom of Gd solutions of various concentration (0.1 - 10mmol/L) was prepared, and was scanned with a 1.5T clinical MR unit, using a spin-echo T1-weighted sequence, 2DFLASH, 3DFLASH, and 3DVIBE. The signal intensity was measured and the contrast enhancement ratio (CER) was calculated and plotted as a function of Gd concentration. The results were compared between the pulse sequences, and between the contrast media as well. Both 3DFLASH and 3DVIBE showed higher CER than other two sequences, showing similar CER curve configuration. There was no significant difference both in CER value and CER curve configuration between the two contrast media for each pulse sequence. 相似文献
54.
Development of enzyme-labeled oligonucleotide probe for detection of mecA gene in methicillin-resistant Staphylococcus aureus. 总被引:2,自引:0,他引:2 下载免费PDF全文
M Shimaoka M Yoh A Segawa Y Takarada K Yamamoto T Honda 《Journal of clinical microbiology》1994,32(8):1866-1869
A DNA hybridization method with an enzyme-labeled oligonucleotide probe (mecA-ELONP) was developed to detect the methicillin-resistant gene (mecA) in methicillin-resistant Staphylococcus aureus. For rapid identification, bacterial colonies were transferred from agar plates directly onto nylon membranes. Lysis of cells, denaturation of DNA, and hybridization were performed on the membranes. These procedures required only 3 h for completion. The results obtained by this test closely corresponded with those obtained by determining the MICs of oxacillin against S. aureus. The results of the mecA-ELONP also correlated well with those of a commercially available PCR test. Thus, mecA-ELONP proved to be a reliable and convenient method for the rapid identification of methicillin-resistant S. aureus, which could be useful in clinical microbiology laboratories. 相似文献
55.
Masahito Katoh Yasushi Itoh Kazumasa Ogasawara Kiichi Kajino Hiroki Nishihori Akio Takahashi Naoto Matsuki Kazuya Iwabuchi Takato O. Yoshida Robert A. Good Kazunori Ono 《European journal of immunology》1996,26(5):976-980
In a previous study, we identified T cell receptor and major histocompatibility complex (MHC) contact sites on the pigeon cytochrome c p43-58 peptide. Positions 46 and 54 of p43-58 were shown to be the MHC-binding sites. Specific amino acids were identified on the MHC-binding sites which bound to the relevant I-A molecule. In the present study, using NOD (I-Ag7) mice, we established a T cell hybridoma, NOE33-1-2, specific for a p43-58 analog 46R50E54A with arginine (R) and alanine (A) at positions 46 and 54, respectively. Interestingly, NOE 33-1-2 recognized 46R50E54A in the presence of not only I-Ag7, but also I-Ad, s, u and v. In contrast to previous reports that promiscuous T cells were able to recognize peptide antigens with various HLA-DR or I-E molecules consist of monomorphic α and polymorphic β chains, the promiscuous T cell clone NOE33-1-2 recognized peptides with various I-A molecules lacking the monomorphic chain. 相似文献
56.
57.
58.
Azelastine, a newly synthesized anti-allergic agent, was tested for its effects on guinea pig macrophage chemotaxis and phagocytosis. As specific macrophage chemo-attractants, we used macrophage chemotactic factors a and c; separated and highly purified from inflamed skin sites. Macrophage chemotaxis induced by skin extract or chemotactic factors was significantly suppressed by a low concentration of the agent (1 microgram/ml); the effect was dose-dependent. The inhibition of chemotaxis was reversible, because chemotactic activity was restored when the agents was removed by washing cells before chemotactic assay. Inactivation of chemotactic factors was not detected by mixing azelastine and factors a and c. Azelastine may directly interact with macrophages to decrease their chemotactic responsiveness. beta-Glucuronidase activity in the medium and macrophages after phagocytosis of polystyrene latex particles was not affected by this agent at concentrations ranging from 1 to 10 micrograms/ml. The phagocytosis of latex particles or sheep red blood cells opsonized with IgG antibodies (EA) and anchoring of macrophages to substrate were not inhibited and azelastine did not damage the macrophages as determined by lactate dehydrogenase (LDH) release assay. 相似文献
59.
H Yoshimura H Uchida H Ohishi N Honda S Ohue Y Kinoshita M Katsuragi N Matuso Y Hosogi M Hatakeyama 《European journal of radiology》1986,6(3):195-198
The hepatic arteries of 122 patients were analysed on angiography to identify the left medial segment of the liver. Left medial arterial branches were classified into three types: type I arising from the left hepatic artery on the umbilical portion of the portal vein; type II arising from proximal portion of left hepatic artery before reaching the umbilical portion of the portal vein; type III arising from right hepatic artery. Incidence of each type is 37.2%, 35.8% and 27.0%, respectively. The artery frequently kinks at the right side of the umbilical portion of the portal vein and a total of incidence is 68% and that of each type is 23.5%, 89.8% and 100%, respectively. We call this characteristic kinking point of the left medial arterial branches, the "M-point". 相似文献