全文获取类型
收费全文 | 7294篇 |
免费 | 455篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 189篇 |
妇产科学 | 122篇 |
基础医学 | 917篇 |
口腔科学 | 190篇 |
临床医学 | 479篇 |
内科学 | 1876篇 |
皮肤病学 | 92篇 |
神经病学 | 406篇 |
特种医学 | 319篇 |
外科学 | 1443篇 |
综合类 | 37篇 |
现状与发展 | 1篇 |
预防医学 | 170篇 |
眼科学 | 110篇 |
药学 | 437篇 |
中国医学 | 15篇 |
肿瘤学 | 911篇 |
出版年
2023年 | 71篇 |
2022年 | 154篇 |
2021年 | 265篇 |
2020年 | 128篇 |
2019年 | 184篇 |
2018年 | 240篇 |
2017年 | 184篇 |
2016年 | 172篇 |
2015年 | 170篇 |
2014年 | 210篇 |
2013年 | 253篇 |
2012年 | 394篇 |
2011年 | 484篇 |
2010年 | 250篇 |
2009年 | 203篇 |
2008年 | 327篇 |
2007年 | 339篇 |
2006年 | 310篇 |
2005年 | 316篇 |
2004年 | 294篇 |
2003年 | 289篇 |
2002年 | 287篇 |
2001年 | 176篇 |
2000年 | 223篇 |
1999年 | 177篇 |
1998年 | 72篇 |
1997年 | 79篇 |
1996年 | 66篇 |
1995年 | 56篇 |
1994年 | 51篇 |
1993年 | 39篇 |
1992年 | 118篇 |
1991年 | 90篇 |
1990年 | 125篇 |
1989年 | 103篇 |
1988年 | 101篇 |
1987年 | 97篇 |
1986年 | 79篇 |
1985年 | 106篇 |
1984年 | 65篇 |
1983年 | 49篇 |
1982年 | 27篇 |
1981年 | 21篇 |
1979年 | 39篇 |
1978年 | 35篇 |
1977年 | 22篇 |
1973年 | 26篇 |
1971年 | 25篇 |
1969年 | 28篇 |
1968年 | 29篇 |
排序方式: 共有7789条查询结果,搜索用时 15 毫秒
31.
N Ida S Sakurai T Hosaka K Hosoi T Kunitomo Y Matsuura M Kohase 《Journal of immunological methods》1990,133(2):279-284
An enzyme-linked immunosorbent assay has been developed to measure human interleukin-6. The assay, based on the avidin-biotin amplified two-step sandwich method, is quick (requiring 4.5 h), sensitive (detecting 9.5 pg/ml) and satisfactory in reproducibility and specificity. It shows good correspondence with the results of bioassays, and it is not affected by serum and plasma components. These results indicate that this ELISA is suitable for application to clinical samples, which is a major advantage over the widely used bioassays. 相似文献
32.
Depression of delayed-type hypersensitivity in mice with hypothalamic lesion induced by monosodium glutamate: involvement of neuroendocrine system in immunomodulation. 下载免费PDF全文
K Kato N Hamada N Mizukoshi K Yamamoto T Kimura C Ishihara Y Fujioka T Kato K Fujieda N Matsuura 《Immunology》1986,58(3):389-395
Delayed-type hypersensitivity (DTH) was depressed in mice that had been treated with monosodium glutamate (MSG) in their suckling period. Analysis of the DTH depression by use of the macrophage migration inhibition assay showed dysfunction of DTH effector T cells. The neuronal loss of nuclei in the hypothalamus, which elaborates the corticotropin-releasing factor and the hypersecretion of adrenocorticotrophic hormone, was observed in the MSG-treated mice. Therefore, DTH response may be modulated by the neuroendocrine system. 相似文献
33.
A cDNA of the glycoprotein (G protein) gene of rabies virus Nishigahara strain was cloned and inserted into a baculovirus genome under the control of the polyhedrin promoter. Infection of Spodoptera frugiperda cells with this recombinant virus produced a large quantity of new protein instead of the parental polyhedrin protein. By immunofluorescent and immunoblotting analyses, the recombinant protein was antigenically similar to the authentic G protein. Its molecular mass estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, however, was slightly smaller than that of the authentic one, and this observation was suggested to be due to the difference in glycosylation level between the two G proteins. The recombinant G protein expressed on the cell surface of the insect cells showed a fusion activity at low pH. The fusion activity was inhibited by antiserum against either whole virions or G protein of rabies virus. 相似文献
34.
Kiyohisa Sekizawa MDa Hideki Nakazawa MDa Masatoshi Morikawa MDa Kohei Yamauchi MDb Kazutaka Maeyama MDc Takehiko Watanabe MDc Hidetada Sasaki MDa 《The Journal of allergy and clinical immunology》1995,96(6)
Background: Histamine N-methyltransferase (HMT) modulates histamine- and antigen-induced bronchoconstriction. However, it is unclear whether vascular permeability evoked by an allergic reaction can be exaggerated by inhibition of HMT activity. Methods: We studied the effects of intravenously injected SKF 91488, a specific HMT inhibitor, on increases in plasma extravasation induced by intravenously injected histamine in unsensitized guinea pigs and by intravenously injected ovalbumin antigen in guinea pigs sensitized to ovalbumin in vivo with Evans blue dye as a marker. Results: Pretreatment with SKF 91488 shifted, in a dose-dependent fashion, the dose-response curves of the leakage of dye to histamine to lower concentrations in the trachea, main bronchi, and nasal mucosa. Likewise, pretreatment with SKF 91488 (20 mg/kg intravenously) significantly increased the leakage of dye induced by ovalbumin antigen (200 μg/kg intravenously) in three parts of the airway (p < 0.05). In contrast to SKF 91488, intravenously injected aminoguanidine, a specific inhibitor of diamine oxidase (16 mg/kg intravenously), did not alter the leakage of dye induced by histamine (from 0.001 μg/kg to 10 μg/kg intravenously) (p > 0.20). HMT activities were observed in the nasal mucosa, as well as in the trachea and main bronchi, as shown in a previous study. Conclusion: These findings suggest that HMT modulates the effects of exogenous histamine and endogenously released histamine induced by antigen challenge on plasma extravasation in the airway in guinea pigs in vivo. (J ALLERGY CLIN IMMUNOL 1995;96:910-6.) 相似文献
35.
Statistical detection of HLA and disease association 总被引:1,自引:0,他引:1
Katsuhirci Fukuda Kazuaki Sugawa Akemi Wakisaka Junko Mokiuchi Nobuo Matsuura Yoshiharu Sato 《Tissue antigens》1985,26(2):81-86
36.
Takayasu H Motoi T Kanamori Y Kitano Y Nakanishi H Tange T Nakagawara A Hashizume K 《Human pathology》2002,33(8):852-855
The benign epithelial neoplasm liver cell adenoma is rare, especially in childhood. We report 2 such cases, 1 of which was associated with Prader-Willi syndrome. Differential diagnosis of the liver cell adenomas on the basis of histopathologic findings proved difficult and was based on the absence of cellular and nuclear atypia, mitotic activity, and invasive growth. In both cases, immunohistochemical staining demonstrated the nuclear accumulation of beta-catenin, and in 1 case, the tumor cells carried a mutation of the beta-catenin gene. Recently, disregulation of the Wnt/beta-catenin pathway, attributable to abnormalities of the beta-catenin gene, has been reported to be a major event in the development of hepatocellular carcinomas and hepatoblastomas. Our report may be the first to describe the beta-catenin abnormalities in childhood liver cell adenoma. These findings imply that abnormalities of beta-catenin can be an early initiating event in human liver tumorigenesis. 相似文献
37.
Atsuo Murata Hitoshi Toda Ken -Ichi Uda Hirohito Hayashida Takeshi Kato Hidewaki Nakagawa Shigekazu Yokoyama Hideaki Morishita Toru Yamakawa Jiro Hirose Takesada Mori Nariaki Matsuura 《Inflammation》1994,18(4):337-347
Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and punctureinduced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction. 相似文献
38.
Lateral association of sphingolipids and cholesterol is considered to form membrane microdomains such as “lipid rafts” obtainable as a detergent-resistant membrane microdomain (DRM) fraction after solubilization with a non-ionic detergent and density gradient centrifugation. Since not only sphinogolipids and cholesterol, but also functional lipids such as phosphatidylinositol 4,5-bisphosphate (PIP2) are reported to be localized in DRM prepared from several cultured cells, this domain is considered to be a platform mediating lipid-signaling. Although PIP2 is considered to have pivotal roles in the nervous system, little information is available on the localization of PIP2 in the DRM within the synaptic plasma membrane (SPM) obtained from matured rat brains. In this study, in order to know the localization of PIP2 in SPM-derived DRM, we measured the amount of PIP2 in SPM and SPM-derived DRM, by the thin-layer chromatography blotting method, using a GST-fusion protein of the pleckstrin-homology domain of phospholipase Cδ1 as a PIP2 binding probe. About 10% of the PIP2 in SPM was recovered in DRM. In contrast, over 40% recovery was observed for the membrane cholesterol and sphingomyelin, and about 30% recovery was observed for phosphatidylcholine, phosphatidylethanolamine, and phosphatidylserine in the DRM were detected using the thin-layer chromatography method. Since the recovery of proteins in DRM was about 10%, the result indicates that there occurs no enrichment of PIP2 in DRM prepared from SPM. 相似文献
39.
Sumi S Matsuura T Kidouchi K Togari H Kubota M Kitou O Mikami H Ohura T Matsuda I Wada Y 《International journal of molecular medicine》2000,6(2):177-180
The importance of detecting heterozygosity for X-linked ornithine transcarbamylase deficiency is well known. Although the DNA analysis and the allopurinol loading tests are commonly used for this purpose, both methods require complicated procedures. In order to establish a simple test for detecting female heterozygotes, we examined the uracil and orotic acid in single-voided urine samples from 70 healthy women, and from 12 asymptomatic females with ornithine transcarbamylase deficiency. Based on the results of healthy women, we were able to determine a screening cut-off line of 11.9 micromol/mmol creatinine (mean +/- 1SD in logarithmic form) for uracil. Using this cut-off line, the sensitivity of OCT heterozygotes was 100%. We were also able to establish a second cut-off line of 28.9 micromol/mmol creatinine (mean +/- 3SD in logarithmic form) for diagnosis. Using this second cut-off line, the specificity of OCT heterozygotes was 100%. Our study has shown that the measurement of urinary uracil is a relatively simple and effective method for detecting female heterozygotes. 相似文献
40.
Masami Sakurai Nozomu Mori Ougi Horiuchi Nariaki Matsuura Yasushi Kobayashi 《Pathology international》1988,38(11):1453-1460
A primary tumor of the middle ear was examined histologically, histochemi-cally, immunohistochemically and ultrastructurally. Neuroendocrine cell differentiation, a carcinoid feature, was demonstrated by the presence of numerous argyrophil granules, as well as positive serotonin, glicentin, glucagon, and human pancreatic polypeptide (hPP) granules in some of the Grimelium-positive cells. Chromogranin A was also detected in the cells, but much less frequently than Grimelius-positive staining. Neither neuron-specific enolase (NSE) nor epithelial membrane antigen (EMA) was demonstrated in the tumor. Mucin was demonstrated only intraluminally. Electron microscopy revealed many typical neurosecretory granules in tumor cells, but no apical mucin granules. The tumor appeared to be benign, and there has been no sign of recurrence during a postoperative period of one year. ACTA PATHOL JPN38: 1453–1460, 1988. 相似文献