全文获取类型
收费全文 | 8816篇 |
免费 | 485篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 173篇 |
妇产科学 | 189篇 |
基础医学 | 1068篇 |
口腔科学 | 135篇 |
临床医学 | 629篇 |
内科学 | 2216篇 |
皮肤病学 | 242篇 |
神经病学 | 523篇 |
特种医学 | 368篇 |
外科学 | 1374篇 |
综合类 | 18篇 |
预防医学 | 281篇 |
眼科学 | 175篇 |
药学 | 586篇 |
中国医学 | 26篇 |
肿瘤学 | 1294篇 |
出版年
2023年 | 51篇 |
2022年 | 119篇 |
2021年 | 207篇 |
2020年 | 116篇 |
2019年 | 140篇 |
2018年 | 183篇 |
2017年 | 173篇 |
2016年 | 199篇 |
2015年 | 225篇 |
2014年 | 239篇 |
2013年 | 308篇 |
2012年 | 499篇 |
2011年 | 487篇 |
2010年 | 252篇 |
2009年 | 194篇 |
2008年 | 382篇 |
2007年 | 387篇 |
2006年 | 369篇 |
2005年 | 377篇 |
2004年 | 330篇 |
2003年 | 362篇 |
2002年 | 347篇 |
2001年 | 280篇 |
2000年 | 273篇 |
1999年 | 219篇 |
1998年 | 116篇 |
1997年 | 104篇 |
1996年 | 89篇 |
1995年 | 69篇 |
1994年 | 63篇 |
1993年 | 53篇 |
1992年 | 182篇 |
1991年 | 161篇 |
1990年 | 157篇 |
1989年 | 198篇 |
1988年 | 198篇 |
1987年 | 166篇 |
1986年 | 151篇 |
1985年 | 141篇 |
1984年 | 85篇 |
1983年 | 70篇 |
1982年 | 44篇 |
1981年 | 43篇 |
1979年 | 76篇 |
1978年 | 59篇 |
1977年 | 38篇 |
1976年 | 38篇 |
1974年 | 45篇 |
1973年 | 35篇 |
1972年 | 37篇 |
排序方式: 共有9358条查询结果,搜索用时 15 毫秒
61.
Uchimura K Itoh M Yamamoto K Imamura S Makino M Kato T Fujiwara K Sawai Y 《Clinical and experimental immunology》2002,128(2):308-312
The possible roles of CD8+ cells in the abnormal T cell-dependent B-cell activation in Graves' disease were investigated by analysing lymphocyte subsets in peripheral blood mononuclear cells (PBMC) and their production of soluble factors and cytokines such as IL-10 in patients with Graves' disease, Hashimoto's thyroiditis and normal controls. The PBMC were separated into CD8+ and CD8-depleted cells by magnetic separation columns, and cultured for 7 days with or without anti-CD40 monoclonal antibodies and IL-4. The culture supernatant was assayed for sCD23 and IL-10 using EIA, and the remaining cells were analysed by flow cytometry. Stimulation with anti-CD40 antibody together with IL-4 increased sCD23 levels and the number of CD23+ cells. The latter was further augmented by depletion of CD8+ cells. This combination of B cell stimulants increased production of IL-10 by PBMC from patients with Graves' disease. The CD40- and IL-4-activated production of IL-10 was decreased by CD8+ cell depletion. In contrast, constitutive production of IL-10 was increased after CD8+ cell depletion in a group of patients with low basal secretion levels (<35 ng/ml). It was, however, decreased in a group with higher basal production levels, but such a relationship was not found in the normal control group. Thus, T cell-dependent B-cell activation via a CD40 pathway activates CD23+ cells, leading to over-production of IL-10 and a shift of the Th1/Th2 balance to Th2 dominance, while CD8+ cells may suppress this activation to counteract the Th2 deviation in Graves' disease. 相似文献
62.
Yoshioka S Fujiwara H Higuchi T Yamada S Maeda M Fujii S 《Molecular human reproduction》2003,9(6):311-319
Melanoma cell adhesion molecule (MCAM) was originally reported to be involved in the invasion and progression of melanoma. It was also shown to be responsible for the attachment of cells to endothelial cells. In this study, we demonstrated by immunohistochemistry that immunoreactive MCAM was not expressed on granulosa cells in the pre-ovulatory follicle, but it was clearly detected in large luteal cells in corpora lutea from the mid-luteal phase of the menstrual cycle. Northern blotting analysis confirmed the expression of MCAM mRNA in corpus luteum. MCAM was weakly detected by immunocytochemical staining in human luteinizing granulosa cells isolated from patients undergoing IVF treatment. Its expression was found to be increased during time in culture of these cells. Flow cytometry and Northern blot analysis revealed that MCAM expression on luteinizing granulosa cells was enhanced when the cells were cultured for 5 days in the presence of hCG (1 IU/ml) or cytokines such as interleukin-1alpha (10 ng/ml) and tumour necrosis factor-alpha (10 ng/ml). No significant difference of MCAM expression was observed between the cultures under normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. These results indicate that luteinizing granulosa cells express MCAM and that MCAM expression is regulated by LH/hCG and cytokines during luteinization. Since MCAM has been reported to mediate cellular interaction with endothelial cells, this molecule may play a role in neovascularization during corpus luteum formation in the human ovary. 相似文献
63.
64.
Lamont RE Loredo-Osti J Roslin NM Mauthe J Coghlan G Nylen E Frappier D Innes AM Lemire EG Lowry RB Greenberg CR Triggs-Raine BL Morgan K Wrogemann K Fujiwara TM Zelinski T 《American journal of medical genetics. Part A》2005,(2):136-143
Bowen-Conradi syndrome (BCS) is a lethal autosomal recessive disorder with an estimated incidence of 1 in 355 live births in the Hutterite population. A few cases have been reported in other populations. Here, we report the results of a genome-wide scan and fine mapping of the BCS locus in Hutterite families. By linkage and haplotype analysis the BCS locus was mapped to a 3.5 cM segment (1.9 Mbp) in chromosome region 12p13.3 bounded by F8VWF and D12S397. When genealogical relationships among the families were taken into account in the linkage analysis, the evidence for linkage was stronger and the number of potentially linked regions was reduced to one. Under the assumption that all the Hutterite patients were identical by descent for a disease-causing mutation, haplotype analysis was used to infer likely historical recombinants and thereby narrow the candidate region to a chromosomal segment shared in common by all the affected children. This study also demonstrates that BCS and cerebro-oculo-facial-skeletal syndrome (COFS) are genetically distinct. 相似文献
65.
The critical role of ocular-infiltrating macrophages in the development of choroidal neovascularization 总被引:9,自引:0,他引:9
Tsutsumi C Sonoda KH Egashira K Qiao H Hisatomi T Nakao S Ishibashi M Charo IF Sakamoto T Murata T Ishibashi T 《Journal of leukocyte biology》2003,74(1):25-32
Choroidal neovascularization (CNV) is directly related to visual loss in some eye diseases, such as age-related macular degeneration. Although several human histological studies have suggested the participation of macrophages in CNV formation, the precise mechanisms are still not fully understood. In this study, we elucidated the role of ocular-infiltrating macrophages in experimental CNV using CCR2 knockout (KO) mice, wild-type mice, and C57BL/6 (B6) mice. CCR2 is the receptor of monocyte chemoattractant protein-1, and the number of infiltrating macrophage and the area of CNV were significantly reduced in CCR2 KO mice. Enriched ocular-infiltrating macrophages from B6 mice actually showed angiogenic ability in a dorsal air sac assay. Moreover, their expression of class II, CD40, B7-1 and B7-2 molecules, and the mRNA for potential angiogenic factors, such as vascular endothelial growth factor, basic fibroblast growth factor, and tumor necrosis factor alpha, was also observed. Collectively, we conclude that ocular-infiltrating macrophages play an important role in CNV generation. 相似文献
66.
Kitada S Maekura R Toyoshima N Naka T Fujiwara N Kobayashi M Yano I Ito M Kobayashi K 《Clinical and diagnostic laboratory immunology》2005,12(1):44-51
We report the development of a serodiagnostic method for Mycobacterium avium complex (MAC) disease with an enzyme immunoassay (EIA) with the MAC-specific glycopeptidolipid (GPL) core as the antigen. In this study, we confirmed by EIA that the GPL core antibody was in the sera of immunocompetent patients with MAC disease. The EIA for quantifying the GPL core antibody was evaluated as a clinical tool for serodiagnosis of pulmonary MAC disease. A significant increase in GPL core antibodies (immunoglobulins G, A, and M) was detected in sera of patients with MAC pulmonary diseases when they were compared to patients who were colonized with MAC, patients with Mycobacterium kansasii disease or tuberculosis, and healthy subjects. The sensitivities and specificities of the GPL core-based EIA for diagnosis of MAC pulmonary disease were 72.6% and 92.2%, respectively, for IgG, 92.5% and 95.1%, respectively, for IgA, and 78.3% and 91.0%, respectively, for IgM. The best sensitivity and specificity were obtained by measuring immunoglobulin A antibodies against GPL core antigen. The level of GPL core antibodies reflected disease activity, since it decreased in cured MAC patients who had responded to chemotherapy. Measurement of serum antibodies against GPL core is useful for both diagnosis and assessment of disease activity in MAC disease of the lung. 相似文献
67.
Summary After intranasal inoculation of suckling rats mouse hepatitis virus multiplied mostly in the nasal epithelium; though there were no symptoms, antibodies were produced. Antibodies were also demonstrated in adult rats. These findings suggest that the rat may be a natural host for the virus.With 2 Figures 相似文献
68.
Immunohistochemical characteristics of duodenal adenomas in familial adenomatous polyposis with special reference to cell kinetics 总被引:4,自引:0,他引:4
The duodenum is the second most frequent site of cancer in patients with familial adenomatous polyposis (FAP). The main objective of this study was to evaluate the cell kinetics in duodenal and ampullary adenomas in FAP. The endoscopic and biopsy findings of duodenal adenomas in 22 FAP subjects and 18 non-FAP subjects were compared. Adenomas in FAP included 15 ampullary adenomas and 17 nonampullary adenomas. The cell kinetics was evaluated by immunohistochemistry for Ki-67, p53, bcl-2, and cyclooxygenase 2 (COX2), and the apoptotic index (AI) as determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) method. Any correlations between the indices for cell kinetics and the endoscopic findings were identified. All 50 adenomas were histologically verified to be tubular adenoma with low-grade dysplasia. Neither the expression of Ki-67, p53, bcl-2, and COX2 nor the AI differed substantially between FAP and non-FAP subjects. In patients with FAP, duodenal adenoma tended to have a higher Ki-67-labeling index than the ampullary adenoma (54.3 +/- 11.3 versus 46.8 +/- 12.7; .05 < P < .1). In addition, the Ki-67-labeling index in endoscopically normal or slightly enlarged ampullary adenoma was significantly higher than that in markedly enlarged ampullary adenoma (51.8 +/- 11.4 versus 39.4 +/- 11.3; P < .05). Duodenal adenoma in FAP subjects was not found to have a higher proliferative activity or a smaller degree of apoptosis compared with those in non-FAP subjects. The smaller proliferative activity in larger ampullary adenoma may thus be related to the static nature of ampullary adenoma in FAP. 相似文献
69.
Zou Jian-Ping; Yamamoto Norihiko; Fujii Tetsuya; Takenaka Hiroshi; Kobayashi Michiko; Herrmann Steven H.; Wolf Stanley F.; Fujiwara Hiromi; Hamaoka Toshiyuki 《International immunology》1995,7(7):1135-1145
Unfractionated spleen cells taken from tumor-bearing mice 2weeks after tumor implantation contained tumor-primed T cellswhich produced cytokines including IL-2 and IFN- when culturedin vitro. With progressive tumor growth this initial lymphokine-producingcapacity decreased. Here, we investigated the ability of IL-12to (I) restore suppressed IFN- production, (II) cause tumorregression and (II) induce anti-tumor protective immunity. Additionof rIL-12 to spleen cell cultures from 4- to 10-week-old tumor-bearingmice resulted in a striking enhancement in the production ofIFN- compared with cultures of these cells in the absence ofrIL-12 or of normal spleen cells in the presence of rIL-12.Five I.p. injections of rIL-12 into mice bearing s.c. tumorsinduced complete tumor regression. This was found when rIL-12was given at early (1–2 weeks), intermediate (4–5weeks) or even late (7 weeks) stages of tumor growth. Furthermore,IL-12-treated mice which rejected the primary tumor exhibitedcomplete resistance to a rechallenge with the same tumor butdid not reject a second syngenetic tumor. Immunohistochemicalanalyses following IL-12 treatment revealed that CD4+ and CD8+T cells infiltrate the tumor. More importantly, IFN- mRNA expressionwas observed in fresh tumor masses from tumor-bearing mice receivingIL-12 treatment The importance of IFN- was further demonstratedby the observation that the systemic administration of anti-IFN-mAb prior to IL-12 treatment completely abrogated the anti-tumoreffect of IL-12. Thus, these results indicate that administrationof modest levels of rIL-12 to tumor-bearing mice results intumor regression through mechanisms involving reversal of suppressedIFN- production by anti-tumor T cells and the establishmentof a tumor-specific protective immune response. 相似文献
70.
Y. Shimada K. Nakashima Y. Fujiwara T. Komatsu M. Kawanishi J. Takezawa S. Takatani 《Medical & biological engineering & computing》1991,29(5):557-561
The design of a noninvasive reflectance pulse oximeter that uses the same principle of transmittance pulse oximeter and analyses the oxygen saturation of arterial blood was described. Four sets of red and infra-red LEDs were used as light sources. The respective reflectance photoelectric outputs were used to make an internal calibration curve of the instrument relative to the arterial oxygen saturation values measured with a Co-Oximeter (OSM-3) in five healthy nonsmoking subjects during steady-state hypoxaemia. The accuracy of the present instrument was studied in six patients with respiratory failure. From 22 samples, a good correlation coefficient (0.98) with a standard deviation of 1.42 was obtained in the range between 73 and 100 per cent between the arterial oxygen saturation measured with the present instrument and that with the Co-Oximeter. The result strongly suggests the usefulness of this oximeter in monitoring patients with hypoxaemia. 相似文献