全文获取类型
收费全文 | 8035篇 |
免费 | 436篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 113篇 |
儿科学 | 159篇 |
妇产科学 | 189篇 |
基础医学 | 1331篇 |
口腔科学 | 168篇 |
临床医学 | 492篇 |
内科学 | 1760篇 |
皮肤病学 | 229篇 |
神经病学 | 472篇 |
特种医学 | 301篇 |
外科学 | 1342篇 |
综合类 | 24篇 |
预防医学 | 301篇 |
眼科学 | 129篇 |
药学 | 519篇 |
中国医学 | 8篇 |
肿瘤学 | 981篇 |
出版年
2023年 | 48篇 |
2022年 | 77篇 |
2021年 | 128篇 |
2020年 | 75篇 |
2019年 | 106篇 |
2018年 | 119篇 |
2017年 | 105篇 |
2016年 | 149篇 |
2015年 | 140篇 |
2014年 | 168篇 |
2013年 | 213篇 |
2012年 | 347篇 |
2011年 | 366篇 |
2010年 | 201篇 |
2009年 | 197篇 |
2008年 | 348篇 |
2007年 | 378篇 |
2006年 | 386篇 |
2005年 | 337篇 |
2004年 | 350篇 |
2003年 | 340篇 |
2002年 | 338篇 |
2001年 | 335篇 |
2000年 | 342篇 |
1999年 | 301篇 |
1998年 | 118篇 |
1997年 | 94篇 |
1996年 | 60篇 |
1995年 | 53篇 |
1994年 | 37篇 |
1993年 | 46篇 |
1992年 | 192篇 |
1991年 | 156篇 |
1990年 | 184篇 |
1989年 | 195篇 |
1988年 | 199篇 |
1987年 | 161篇 |
1986年 | 146篇 |
1985年 | 132篇 |
1984年 | 106篇 |
1983年 | 83篇 |
1979年 | 56篇 |
1978年 | 38篇 |
1977年 | 43篇 |
1975年 | 34篇 |
1974年 | 42篇 |
1973年 | 50篇 |
1972年 | 45篇 |
1970年 | 47篇 |
1968年 | 36篇 |
排序方式: 共有8518条查询结果,搜索用时 15 毫秒
41.
Masafumi Ito Atsuko Nakagawa Atsuo Nakayama Yutaka Uno Izumi Takahashi Junpei Asai 《Pathology international》1990,40(2):149-152
Malignant salivary gland tumors in children are very rare. This report describes the autopsy of a child with parotid gland cancer. The patient, a 10 month old girl, was admitted to the Nagoya First Red Cross Hospital with facial nerve palsy. lncisional biopsy of a post-auricular tumor was performed, and undifferentiated carcinoma was diagnosed. The patient died 6 months later of respiratory failure due to pulmonary lymphangitis carcinomatosis. Light and electron microscopic and immunohistochemical examinations of the tumor tissue were performed. The tumor cells were arranged in a medullary, sheet-like manner. Keratinization or mucus lakes were not observed. PAS-alcian blue staining demonstrated intracytoplasmic mucus as granules, and also small intercellular droplets of mucus that might otherwise have been unnoticed. Ultrastructurally, some of the tumor cells had tonofilament-like keratin filaments, and also small hollow spaces bounded by microvilli and containing secretory particles. These were stained by antisera against CEA and keratin. These findings are suggestive of differentiation to mucoepider-moid carcinoma. We also review and discuss malignant salivary tumors of epithelial origin in children. Acta Pathol Jpn 40: 149–152, 1990. 相似文献
42.
Murata K Inami M Hasegawa A Kubo S Kimura M Yamashita M Hosokawa H Nagao T Suzuki K Hashimoto K Shinkai H Koseki H Taniguchi M Ziegler SF Nakayama T 《International immunology》2003,15(8):987-992
CD69, known as an early activation marker antigen on T and B cells, is also expressed on platelets and activated neutrophils, suggesting certain roles in inflammatory diseases. In order to address the role of CD69 in the pathogenesis of arthritis, we established CD69-null mice. CD69-null mice displayed a markedly attenuated arthritic inflammatory response when injected with anti-type II collagen antibodies. Cell transfer experiments with neutrophils, but not T cells or spleen cells, from wild-type mice into CD69-null mice restored the induction of arthritis. These results indicate a critical role for CD69 in neutrophil function in arthritis induction during the effector phase. Thus, CD69 would be a possible therapeutic target for arthritis in human patients. 相似文献
43.
Nagahama H Hatakeyama S Nakayama K Nagata M Tomita K Nakayama K 《Anatomy and embryology》2001,203(2):77-87
The cyclin-dependent kinase (CDK) inhibitors p27Kip1 and p57Kip2 are thought to regulate progression of the cell cycle. We have previously shown that the phenotypes of p27-/- mice are substantially different from those of p57-/- mice, suggesting that spatial and temporal expression patterns of p27Kip1 and p57Kip2 might be distinct. In this study, the roles of p27Kip1 and p57Kip2 in development were examined by characterizing their expression patterns during mouse embryogenesis by immunohistochemical analysis. Whereas certain organs and tissues (brain, lens, ganglion, lung, heart, liver, skin and kidney) expressed both proteins, others expressed only p27Kip1 (thymus, spleen, retina, testis and ovary) or only p57Kip2 (gut, palate, pancreas, cartilage and skeletal muscle). In addition, some organs expressed both p27Kip1 and p57Kip2 but showed mutually exclusive patterns of distribution among tissues. Thus, in the adrenal gland, p57Kip2 was expressed in the cortex but not in the medulla, whereas p27Kip1 was expressed in the medulla but not in the cortex. Whereas the expression of p57Kip2 in most tissues was restricted to embryogenesis, expression of p27Kip1 in many tissues was maintained in adult animals. Double-label immunofluorescence staining with either anti-p27Kip1 or anti-p57Kip2 and anti-BrdU revealed that the expression of p27Kip1 and p57Kip2 was inversely correlated with cell proliferation, suggesting that p27Kip1 and p57Kip2 are expressed exclusively in postmitotic cells. These complex spatial and temporal patterns of expression are consistent with the phenotypes of mice deficient in p27Kip1 or p57Kip2, and they suggest that these proteins might play important roles in tissue development. 相似文献
44.
Masayuki Nakayama Masashi Bando Tatsuya Hosono Hideaki Yamasawa Shoji Ohno Yukihiko Sugiyama 《Arerugī》2007,56(11):1384-1389
BACKGROUND: Our aim is to evaluate the significance of DLST by Shosaikoto. METHODS: We clinically evaluated 3 cases of drug-induced pneumonia assumed to be caused by Shosaikoto, and we performed DLST of Shosaikoto for healthy controls, and compared the data with drug-induced pneumonia cases of Shosaikoto. RESULTS: As clinical characteristics of 3 cases, 2 cases were positive for hepatitis C virus antibody, and 1 case was positive for DLST of Shosaikoto. The observed chest high-resolution CT (HRCT) findings showed hypersensitivity pneumonia (HP) pattern in all 3 cases. Prognosis was good in all 3 cases. DLST of Shosaikoto was positive in 27.5% of healthy controls. Stimulation index (S.I.) of DLST in drug-induced pneumonia cases increased depending on drug dilution density, compared to that of healthy controls. CONCLUSION: DLST of Shosaikoto showed high false-positive rate. However, we may be able to distinguish the true-positive cases with the false-positive cases by comparing the S.I. of DLST according to drug dilution density. 相似文献
45.
S Kageyama O Yamada S S Mohammad S Hama N Hattori M Asanaka E Nakayama T Matsumoto F Higuchi T Kawatani 《Journal of virological methods》1988,22(2-3):125-131
The measurement of HIV antigen levels in sera or plasma of HIV-infected individuals is critical for determining the existence of antigen or infectious virus before seroconversion and for prognosis. Pretreatment of sera or plasma of HIV carriers by heating at 70 degrees C for 10 min at an acidic pH enabled us to estimate antigens efficiently in immune complexes. This procedure will also be useful in determining antigen levels in HIV carriers more precisely. 相似文献
46.
47.
Rat strain differences in the early stage of porcine-serum-induced hepatic fibrosis. 总被引:1,自引:0,他引:1
Yasuko Baba Koji Uetsuka Hiroyuki Nakayama Kunio Dot 《Experimental and toxicologic pathology》2004,55(5):325-330
Rat strain differences in the early development of porcine serum (PS)-induced hepatic fibrosis were histologically and immunohistochemically examined using Brown Norway (BN), Sprague Dawley (SD) and Wistar rats. They were injected i.p. with 0.5 ml sterile PS twice a week for 4 and 8 weeks. In addition, rats treated with physiological saline in the same way served as controls. At 4 weeks, hepatic fibrosis accompanying fibrous septa mainly composed of type III collagens developed in BN and SD rats but not in Wistar rats. In addition, the numbers of eosinophils, CD3-positive cells and ED-1-positive cells significantly increased in BN and SD rats, that of CD45RA-positive cells in BN rats, and that of alpha-smooth muscle actin (SMA)-positive cells in SD rats, respectively. Such differences in the number of inflammatory cells may be related with the absence of hepatic fibrosis in Wistar rats at 4 weeks. At 8 weeks, hepatic fibrosis with formation of many small-sized pseudolobules was observed in all strains at almost similar degree, and the numbers of infiltrating cells increased in all strains of rats with some exception. In addition, the main location of inflammatory cells was different, suggesting a different role of each inflammatory cell in the process of hepatic fibrosis. 相似文献
48.
Yamamoto A Nakayama M Kurosawa Y Sugo K Karasawa H Ogawa T Takasaki T Tashiro M Kurane I 《Journal of virological methods》2002,104(2):195-201
Japanese encephalitis virus-specific IgM is a reliable indicator for serodiagnosis of Japanese encephalitis. A particle agglutination (PA) assay system was developed to detect anti-Japanese encephalitis virus IgM in human serum samples. The newly developed PA assay consisted of hydroxyapatite-coated nylon beads and V-bottom 96-well microplates. Hydroxyapatite-coated nylon beads were coated with Japanese encephalitis virus antigens. Japanese encephalitis virus antigen-coated, hydroxyapatite-coated nylon beads agglutinated in the IgM-captured wells when anti-Japanese encephalitis virus IgM-positive serum samples were used. A button pattern was formed at the bottom of the wells when anti-Japanese encephalitis virus IgM-negative serum samples were used. Thirty anti-Japanese encephalitis virus IgM-positive serum samples from Japanese encephalitis-confirmed cases were tested by the PA assay. All these serum samples were determined to be Japanese encephalitis virus IgM-positive. IgM titers determined by the PA assay corresponded to those determined by enzyme-linked immunosorbent assay. The titers were consistent in two independent PA assays. These results indicate that the newly developed PA assay is a reliable method for detecting anti-Japanese encephalitis virus IgM in human serum samples and that this assay will be a suitable diagnostic system especially in rural areas of Asia. 相似文献
49.
Nobuhiko Okamoto Mashiro Nakayama Chie Narahara Han-suk Kim Masashi Fujioka Isao Imada Tatsuya Arai Soichiro Toda 《Journal of human genetics》1997,42(3):441-444
Summary Mevalonic acidemia is a rare metabolic disorder due to mevalonate kinase deficiency which affects the biosynthesis of cholesterol
and nonsterol isoprenes. We report the first case of Japan. The clinical course is characterized by intrauterine growth retardation,
postnatal growth failure, intractable diarrhea, liver dysfunctions and death at three months of age. Dysmorphic features including
triangular face, protrusion of forehead, hypertelorism, low set ears and micrognathism were noted. High mevalonic acid level
was found by GC/MS. 相似文献
50.
Cytokines and lipopolysaccharide induce nitric oxide synthase in cultured rat pulmonary artery smooth muscle. 总被引:12,自引:0,他引:12
D K Nakayama D A Geller C J Lowenstein H D Chern P Davies B R Pitt R L Simmons T R Billiar 《American journal of respiratory cell and molecular biology》1992,7(5):471-476
In the current study, we describe cytokine and Escherichia coli lipopolysaccharide (LPS) induction of nitric oxide (NO) synthase mRNA levels in cultured smooth muscle from rat pulmonary artery (RPASM). Exposure of RPASM to interleukin-1 beta, interferon-gamma, or LPS alone did not significantly affect NO synthesis, as determined by nitrite concentrations in media. Exposure to tumor necrosis factor-alpha caused a modest (2x) increase in nitrite production. In contrast, exposure to a combination of the above three cytokines and LPS caused a large increase in NO synthesis. Exposure of RPASM to this combination caused an increase in mRNA levels of NO synthase (as described by Northern blot analysis with 32P-cDNA probe to an inducible form of NO synthase present in murine macrophages) that was apparent as early as 4 h. Expression of the induced gene product after exposure to the cytokine and LPS mixture was evident by significant increases in nitrite production at 12 h. Production of nitrite was completely abolished in the presence of NG-monomethyl-L-arginine (NMA), and this inhibition was reversible by the addition of excess L-arginine. NO synthase mRNA levels were not affected by NMA. The nitrite production induced by the combination of cytokines and LPS was abolished by pretreating cells with cycloheximide. These data indicate that a combination of cytokines and LPS affect expression of the gene for the inducible form of NO synthase in cultured RPASM. 相似文献