全文获取类型
收费全文 | 3379篇 |
免费 | 192篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 132篇 |
妇产科学 | 28篇 |
基础医学 | 413篇 |
口腔科学 | 162篇 |
临床医学 | 203篇 |
内科学 | 885篇 |
皮肤病学 | 57篇 |
神经病学 | 161篇 |
特种医学 | 153篇 |
外科学 | 584篇 |
综合类 | 19篇 |
预防医学 | 134篇 |
眼科学 | 30篇 |
药学 | 188篇 |
中国医学 | 10篇 |
肿瘤学 | 351篇 |
出版年
2023年 | 15篇 |
2022年 | 30篇 |
2021年 | 44篇 |
2020年 | 40篇 |
2019年 | 46篇 |
2018年 | 51篇 |
2017年 | 49篇 |
2016年 | 57篇 |
2015年 | 66篇 |
2014年 | 94篇 |
2013年 | 101篇 |
2012年 | 144篇 |
2011年 | 173篇 |
2010年 | 110篇 |
2009年 | 87篇 |
2008年 | 175篇 |
2007年 | 208篇 |
2006年 | 158篇 |
2005年 | 199篇 |
2004年 | 197篇 |
2003年 | 195篇 |
2002年 | 206篇 |
2001年 | 77篇 |
2000年 | 71篇 |
1999年 | 77篇 |
1998年 | 67篇 |
1997年 | 51篇 |
1996年 | 37篇 |
1995年 | 40篇 |
1994年 | 26篇 |
1993年 | 34篇 |
1992年 | 66篇 |
1991年 | 57篇 |
1990年 | 65篇 |
1989年 | 75篇 |
1988年 | 60篇 |
1987年 | 50篇 |
1986年 | 54篇 |
1985年 | 39篇 |
1984年 | 27篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1979年 | 36篇 |
1977年 | 11篇 |
1975年 | 9篇 |
1972年 | 9篇 |
1971年 | 8篇 |
1969年 | 8篇 |
1968年 | 9篇 |
1966年 | 9篇 |
排序方式: 共有3606条查询结果,搜索用时 0 毫秒
21.
In the present study, the authors analysed the serial angiographical findings progressing to brain death and their relation to the intracranial pressure (ICP) and the cerebral perfusion pressure (CPP). Seventy two patients, from four to eighty four years old (fourty six males and twenty six females) admitted in the Department of Emergency Medicine, University of Tokyo Hospital during the period from January, 1981 to April, 1986, were studied. Their underlying diseases were supratentorial primary brain lesions except two cases with asphyxias which progressed to brain death. ICP was continuously measured and CPP was calculated as the pressure gradient between the mean arterial blood pressure (MAP) and ICP. The direct carotid angiography was performed to follow the cerebral circulation. Fourty five patients were subjected to barbiturate (pentobarbital sodium) therapy. The degree of the intracranial filling staged as "Non-filling", "Siphon-filling", "Partial-filling", "Delayed-filling", "All-filling" correlated significantly with ICP and CPP. These relationships, however, disappeared once ICP exceeded MAP. When "Non-filling" angiogram was obtained, clinical signs had already showed brain death. On the other hand, minimal flow ("Siphon-filling", "Partial-filling", "Delayed-filling") were still demonstrated in six brain death cases while ICP was approaching its "peak" value. This study showed that clinical diagnosis of brain death preceded the Non-filling phenomenon, suggesting that, for the demonstration of the cerebral circulatory arrest, the angiograms should be performed after the clinical diagnosis of brain death was established and CPP became zero. The evaluation of the extremely slow and minimal filling is still a matter of discussion.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
22.
H. Kanno T. Kuwabara M. Shinonaga C. C. Chang Y. Tanaka Y. Sugio H. Morita H. Yasumitsu M. Umeda Y. Nagashima 《Acta neuropathologica》1989,79(1):30-36
Summary A human glioma cell line (YKG1), which was positively identified for glial fibrillary acidic (GFA) and S-100 proteins, was established from a surgical specimen of a patient with glioblastoma. Chromosome analysis of the cells revealed a homogeneously staining region (HSR) on a marker chromosome. The assay for transforming growth factors (TGFs) in the conditioned medium of the cell line revealed that it contained high levels of - and -type TGFs, which might regulate the growth of glioblastoma and influence on the peritumoral tissues. 相似文献
23.
Terashima Y Onai N Murai M Enomoto M Poonpiriya V Hamada T Motomura K Suwa M Ezaki T Haga T Kanegasaki S Matsushima K 《Nature immunology》2005,6(8):827-835
Ligation of the chemokine receptor CCR2 on monocytes and macrophages with its ligand CCL2 results in activation of the cascade consisting of phosphatidylinositol-3-OH kinase (PI(3)K), the small G protein Rac and lamellipodium protrusion. We show here that a unique clathrin heavy-chain repeat homology protein, FROUNT, directly bound activated CCR2 and formed clusters at the cell front during chemotaxis. Overexpression of FROUNT amplified the chemokine-elicited PI(3)K-Rac-lamellipodium protrusion cascade and subsequent chemotaxis. Blocking FROUNT function by using a truncated mutant or antisense strategy substantially diminished signaling via CCR2. In a mouse peritonitis model, suppression of endogenous FROUNT markedly prevented macrophage infiltration. Thus, FROUNT links activated CCR2 to the PI(3)K-Rac-lamellipodium protrusion cascade and could be a therapeutic target in chronic inflammatory immune diseases associated with macrophage infiltration. 相似文献
24.
Nakamura M Yamanaka G Kawashima H Watanabe Y Ioi H Kashiwagi Y Takekuma K Hoshika A Hayakawa M Suzuki S 《Disease markers》2005,21(4):199-202
The characteristics of influenza-associated encephalopathy is the high mortality and nimble progress with coma which appears in general cases within 48 hours. Most of patients show no abnormalities in the standard blood checks on admission or in early stage. In this study we investigated if a rapid assay of interleukin (IL)-6 is useful in influenza-associated encephalopathy in early stages. The levels of IL-6 in patients with influenza-associated encephalopathy did not show any significant difference compared with those in patients with febrile convulsion and rotavirus-associated convulsion. However the levels of IL-6 in severe cases were significantly higher than those of mild cases with influenza-associated encephalopathy. Consequently the rapid assay of serum IL-6 is useful to evaluate and decide the therapies. 相似文献
25.
Physical Deletion of the p53 Gene in Bladder Cancer: Detection by Fluorescence in Situ Hybridization 总被引:1,自引:6,他引:1 下载免费PDF全文
Guido Sauter Guoren Deng Holger Moch Russell Kerschmann Kouji Matsumura Sandy De Vries Tracy George Jose Fuentes Peter Carroll Michael J. Mihatsch Frederic M. Waldman 《The American journal of pathology》1994,144(4):756-766
To understand better the role of physical p53 deletion in bladder cancer, 106 formalin-fixed and 45 unfixed bladder tumors were examined using fluorescence in situ hybridization. Probes for centromere 17 and the p53 locus were hybridized simultaneously to interphase tumor cells to analyze p53 and chromosome 17 copy number on a cell by cell basis. 17p deletion was found in four of 43 pTa tumors, 18 of 43 pT1 tumors and 29 of 58 pT2-4 tumors (P = 0.0001). 17p deletion was also highly correlated with grade (P = 0.0001) and with p53 immunostaining (P = 0.0005). Chromosome 17 polysomy was associated with stage, grade, 17p deletions, and p53 immunostaining (P = 0.0001). The strong difference in centromere 17 copy number and 17p deletions between pTa and pT1 tumors supports a relevant biological distinction between pTa and pT1 tumors. 相似文献
26.
Analysis of mRNA with microsomal fractionation using a SAGE-based DNA microarray system facilitates identification of the genes encoding secretory proteins 总被引:1,自引:0,他引:1 下载免费PDF全文
Toyoda N Nagai S Terashima Y Motomura K Haino M Hashimoto S Takizawa H Matsushima K 《Genome research》2003,13(7):1728-1736
In the regulation of host defense responses such as inflammation and immunity, the secretory proteins, including membrane proteins, play central roles. Although many secretory proteins have been identified by using methods such as differential display, random screening, or the signal sequence trap method, each method suffers from poor reproducibility, low sensitivity, or time-consuming or laborious work. Therefore, the strategy for facilitating the selection of the genes encoding the secretory proteins is desired. In this paper, we describe a system for isolating the genes encoding secretory proteins by analyzing mRNAs with microsomal fractionation on serial analysis of gene expression (SAGE)-based DNA microarray system. This system succeeded in discriminating the genes encoding secretory proteins from ones encoding nonsecretory proteins with 80% accuracy. We applied this system to human T lymphocytes. As a result, we were able to identify the genes that are not only encoding secretory proteins but also expressing selectively in a specific subset of T lymphocytes. The SAGE-based DNA microarray system is a promising system to identify the genes encoding specific secretory proteins. 相似文献
27.
Satoshi Sato Hisashi Kawashima Yasuyo Kashiwagi Nobuhisa Ushio Makoto Nagai Kouji Takekuma Akinori Hoshika 《Arerugī》2007,56(11):1378-1383
BACKGROUND: Chlamydia pneumoniae is a frequent causative agent of acute respiratory disease and has been recently reported as a possible cause of asthma. We investigated the prevalence of C. pneumoniae infections in childhood patients with acute exacerbations of asthma. METHOD: One hundred twenty-six childhood patients with acute exacerbations of asthma, 77 with acute bronchitis and 22 Respiratory syncytial virus infections were studied. Serum samples were obtained and tested for C. pneumoniae-specific IgM antibody by Enzyme-Linked ImmunoSorbent Assay (ELISA). RESULTS: C. pneumoniae IgM-positive results were observed in 48.4% (Index value>or=1.60) and 23% (Index value>or=1.10) of patients with acute exacerbations of asthma. The prevalence of C. pneumoniae-specific IgM was significantly higher in asthma cases than in other subjects (p<0.05). CONCLUSION: Our data suggest that C. pneumoniae infection may trigger acute exacerbations of childhood asthma. 相似文献
28.
29.
Yoshimoto M Chang H Shiota M Kobayashi H Umeda K Kawakami A Heike T Nakahata T 《Stem cells (Dayton, Ohio)》2005,23(5):610-618
Recent studies have indicated that bone marrow cells can regenerate damaged muscles and that they can adopt phenotypes of other cells by cell fusion. Our direct visualization system gave evidence of massive muscle regeneration by green fluorescent protein (GFP)-labeled CD45+c-Kit+Sca-1+Lin- cells (KSL cells), and we investigated the role of KSL cells in muscle regeneration after transplantation with or without lethal irradiation. In the early phase, GFP signals were clearly observed in all the muscles of only irradiated mice. Transverse cryostat sections showed GFP+myosin+ muscle fibers, along with numerous GFP+ hematopoietic cells in damaged muscle. These phenomena were temporary, and GFP signals had dramatically reduced 30 days after transplantation. After 6 months, GFP+ fibers could hardly be detected, but GFP+c-Met+ mononuclear cells were located beneath the basal lamina where satellite cells usually exist in both conditioned mice. Immunostaining of isolated single fibers revealed GFP+PAX7+, GFP+MyoD+, and GFP+Myf5+ satellite-like cells on the fibers. Single-fiber cultures from these mice showed proliferation of GFP+ fibers. These results indicate two different roles of KSL cells: one leading to regeneration of damaged muscles in the early phase and the other to conversion into satellite cells in the late phase. 相似文献
30.
Kazuko Sukegawa Shunji Tomatsu Toshiyuki Fukao Hideki Iwata Xiang-Qian Song Yukiji Yamada Seiji Fukuda Kouji Isogai Tadao Orii 《Human mutation》1995,6(2):136-143
Mucopolysaccharidosis type II (Hunter disease) is a lysosomal storage disorder caused by a deficiency of the enzyme iduronate-2-sulfatase. Varied clinical phenotypes of this disease have been described. To identify mutations in individual patients and to examine possible correlations between mutations and clinical phenotypes, we analyzed the iduronate-2-sulfatase gene in Japanese patients with different clinical phenotypes. Five missense mutations, S333L (severe), R468Q (severe), R468L (severe), W337R (intermediate), R48P (mild), and three nonsense mutations, W345X (severe), R443X (intermediate), Q531X (mild), were identified by the RT-PCR method. Transient expression in the enzyme-deficient fibroblasts revealed that all five missense mutant enzymes were synthesized as the normal-size precursor (73 kD), and the nonsense mutant enzymes were synthesized as truncated ones (W345X:54 kD, R443X:59 kD, and Q531X:69 kD), although stable mature enzymes (45–56 kD) were not detected by Western blot analysis. Further more, expression of the eight mutant cDNAs resulted in severe reductions of iduronate-2-sulfatase enzyme activity in comparison with a normal cDNA. © 1995 Wiley-Liss, Inc. 相似文献