全文获取类型
收费全文 | 17111篇 |
免费 | 883篇 |
国内免费 | 170篇 |
专业分类
耳鼻咽喉 | 214篇 |
儿科学 | 327篇 |
妇产科学 | 379篇 |
基础医学 | 1962篇 |
口腔科学 | 633篇 |
临床医学 | 1323篇 |
内科学 | 4399篇 |
皮肤病学 | 214篇 |
神经病学 | 1999篇 |
特种医学 | 629篇 |
外科学 | 2830篇 |
综合类 | 41篇 |
一般理论 | 2篇 |
预防医学 | 657篇 |
眼科学 | 274篇 |
药学 | 899篇 |
中国医学 | 17篇 |
肿瘤学 | 1365篇 |
出版年
2024年 | 14篇 |
2023年 | 193篇 |
2022年 | 453篇 |
2021年 | 702篇 |
2020年 | 416篇 |
2019年 | 575篇 |
2018年 | 617篇 |
2017年 | 469篇 |
2016年 | 520篇 |
2015年 | 572篇 |
2014年 | 751篇 |
2013年 | 1001篇 |
2012年 | 1436篇 |
2011年 | 1500篇 |
2010年 | 785篇 |
2009年 | 754篇 |
2008年 | 1086篇 |
2007年 | 1082篇 |
2006年 | 934篇 |
2005年 | 926篇 |
2004年 | 912篇 |
2003年 | 705篇 |
2002年 | 660篇 |
2001年 | 97篇 |
2000年 | 53篇 |
1999年 | 88篇 |
1998年 | 132篇 |
1997年 | 115篇 |
1996年 | 86篇 |
1995年 | 72篇 |
1994年 | 70篇 |
1993年 | 51篇 |
1992年 | 32篇 |
1991年 | 28篇 |
1990年 | 36篇 |
1989年 | 36篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 22篇 |
1985年 | 9篇 |
1984年 | 18篇 |
1983年 | 20篇 |
1982年 | 24篇 |
1981年 | 15篇 |
1980年 | 18篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1973年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
Malignant granular cell tumor of the lateral femoral cutaneous nerve: report of a case with cytogenetic analysis 总被引:5,自引:0,他引:5
Di Tommaso L Magrini E Consales A Poppi M Pasquinelli G Dorji T Benedetti G Baccarini P 《Human pathology》2002,33(12):1237-1240
Malignant granular cell tumors (MGCTs) are rare neoplasms of uncertain histogenesis. We report a case of MGCT involving a peripheral nerve with peritoneal and omental dissemination in which cytogenetic findings are available. Our results show that MGCTs share some cytogenetic abnormalities with malignant peripheral nerve sheath tumors (MPNSTs), supporting the hypothesis that they may represent histogenetically related lesions. 相似文献
63.
Alessandro Antonelli Mario Rotondi Poupak Fallahi Paola Romagnani Silvia Martina Ferrari Ele Ferrannini Mario Serio 《Journal of interferon & cytokine research》2005,25(9):547-552
Circulating levels of cytokines are deeply influenced by aging, and few data about serum chemokines are available. The aim of this study was to evaluate the influence of aging on circulating CXCL10. One hundred forty healthy subjects (70 males and 70 females), 10-79 years of age, underwent fasting plasma glucose, total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride, and CXCL8 serum assay. Thyroid hormone testing for thyroid-stimulating hormone (TSH), antithyroglobulin (AbTg), and antithyroperoxidase (AbTPO) autoantibodies and thyroid ultrasonography were performed in all subjects to exclude the presence of clinical or subclinical thyroid disease. Serum CXCL10 levels were assayed in all subjects and found to be increased in 14 of 70 females (20%) and in 4 of 70 males (5.7%) (p = 0.01). In a multiple linear regression model including age, body mass index (BMI), systolic and diastolic blood pressure, glycemia, total cholesterol, HDL, LDL, triglycerides, TSH, AbTPO, AbTg, and CXCL8, only age was significantly related to CXCL10 [C.R. 1.30 (0.28-2.33), p = 0.001]. No relationship was present between CXCL8 serum levels and age, suggesting a specificity of CXCL10 elevation as a function of age. Results of this study, performed in healthy subjects on an age gradient, demonstrate an increase in serum CXCL10 with advancing age overall in females, supporting the hypothesis of enhanced Th1 immune responses in aging. 相似文献
64.
Ermanno Ciccone Daniela Pende Massimo Vitale Luca Nanni Carolina Di Donato Cristina Bottino Luigia Morelli Oriane Viale Antonio Amoroso Alessandro Moretta Lorenzo Moretta 《European journal of immunology》1994,24(4):1003-1006
The surface expression of given HLA class I alleles protects target cells from lysis mediated by natural killer (NK) clones specific for these (or related) alleles. We could define two groups of NK clones specifically recognizing either Cw4 and related C alleles (“group 1”) or Cw3 and related C alleles (“group 2”), respectively. Monoclonal antibodies (mAb) to class I molecules should interfere with the interaction between NK receptors and class I molecules, thus resulting in lysis of protected target cells. However, none of the numerous available mAb to class I molecules had this effect. Therefore, we attempted to select new mAb on the basis of their ability to induce lysis of Cw4- or Cw3-protected lymphoblastoid cell lines by “group 1” or “group 2” NK clones, respectively. From mice immunized with phytohemagglutinin (PHA)-activated lymphocytes expressing either Cw3 or Cw4 alleles, two mAb were selected, the 6A4 (IgG1) and the A6-136 (IgM), on the basis of their ability to induce lysis of protected target cell. Both mAb immunoprecipitated molecules which, in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gave two bands of 45 and 12 kDa, typical of the class I heavy chain and β2 microglobulin, respectively. It has been proposed (but not proven), that self major histocompatibility complex class I molecules protect normal cells from autologous NK cell lysis. Thus, we used the 6A4 and A6-136 mAb to assess this possibility directly. Cw4-specific (“group 1”) and Cw3-specific (“group 2”) NK clones were isolated from donors expressing the corresponding (or related) protective C alleles. None of these clones lysed autologous PHA-induced blasts, used as target cells. However, addition of the F(ab′)2 of 6A4 mAb or the A6-136 mAb resulted in lysis of autologous target cells by “group 1” or “group 2” NK clones, respectively. These data provide direct evidence that the expression of class I molecules protects normal cells from lysis by autologous NK cells. 相似文献
65.
Cusin C Serretti A Lattuada E Lilli R Lorenzi C Smeraldi E 《American journal of medical genetics》2002,114(4):380-390
The aim of our study was to investigate a possible influence of monoamine oxydase A (MAO-A), catechol-O-methyltransferase (COMT), serotonin receptor 2A (5-HT2A), dopamine receptor D2 (DRD2), and dopamine receptor D4 (DRD4) gene variants on timing of recurrence in mood disorders. Gene variants were determined using PCR-based techniques in 550 inpatients affected by recurrent mood disorders (major depressives: n = 212; bipolars: n = 338), rapid cycling mood disorder (n = 81), and 663 controls. We investigated possible genetic influences by comparing illness time course of subjects subdivided according to genotype using multivariate analysis of variance (MANOVA). We could not observe a significantly different time course. No demographic and clinical variables such as sex, age or polarity of onset, presence of psychotic features, genetic loading, or education level influenced the observed results. Our results suggest that MAO-A, COMT, 5-HT2A, DRD2, and DRD4 gene variants are not involved in susceptibility toward different time courses in mood disorders. 相似文献
66.
Salvatore Moricca Takao Kasuga Keith Mitchelson Alessandro Ragazzi Stephanos Diamandis 《Current genetics》1996,29(4):388-394
Mixed aeciospore isolates ofCronartium flaccidum andPeridermium pini were obtained from single-tree infections in Britain, Italy and Greece. The 5.8s ribosomal RNA gene and flanking intergenic transcribed spacer regions ITS 1 and ITS2 were found to be highly similar betweenC. flaccidum andP. pini. Within samples heterogeneity was detected at three nucleotide loci in the ITS1 and at four loci in the ITS2 suggesting that several fungal genotypes may occur at a single infection court. The heterogeneity was confirmed by heteroduplex polymorphism analysis of mixed aeciospore products. RFLP of the ribosomal intergenic spacer region 1 (IGSI) amplified from the same templates indicated limited sequence polymorphism in some copies of this repeated locus. Both the sexual and asexual forms ofC. flaccidum show evidence of sequence polymorphism in two independent, non-coding regions of the ribosomal gene array. Variation appears to be greater in the sexual formC. flaccidum, than in the monoaecious formP. pini. 相似文献
67.
Laura Masi Raffaella Recenti Sandra Silvestri Pamela Pinzani Monica Pepi Milena Paglierani Maria Luisa Brandi Alessandro Franchi 《Applied immunohistochemistry & molecular morphology》2007,15(1):70-76
Several studies indicate that cyclooxygenase-2 (COX-2) is overexpressed in human malignancies, where it produces high levels of prostaglandins and contributes to tumor growth. In this study we have analyzed the expression of COX-2 in a series of 48 skeletal osteosarcomas of different subtypes by immunohistochemistry. In addition, we examined the effects of the specific COX-2 inhibitor Celecoxib on the growth of the human osteosarcoma cell line SaOS-2. Immunoreactivity for COX-2 was observed in 39 out of 48 tumors (81.2%), 30 (76.9%) of which showed a moderate or diffuse immunostaining. Considering the group of 42 primary osteosarcomas, COX-2 immunoreactivity was significantly higher in high grade osteosarcomas, where moderate or diffuse expression was detected in 23 out of 32 cases (71.8%), than in low grade osteosarcomas, where moderate or diffuse expression was detected in 2 out of 10 cases (20%) (P = 0.008, Fisher exact test). In addition, low COX-2 expression was always associated with a good response to chemotherapy (5 out of 5 cases), whereas moderate or diffuse COX-2 expression was associated with a good response in 11 out of 20 cases (55%) (P = 0.12, Fisher exact test). In SaOS-2 osteosarcoma cells, which express COX-2, treatment with Celecoxib determined inhibition of cell proliferation and induction of apoptosis. These results indicate that COX-2 is expressed at high levels in high grade osteosarcomas and support the use of COX-2 inhibitors to improve both the tumor response to chemotherapy and the outcome of osteosarcoma patients. 相似文献
68.
Jeff Alexander Marie-France Del Guercio John D Fikes Robert W Chesnut Francis V Chisari Kyong-Mi Chang Ettore Appella Alessandro Sette 《Human immunology》1998,59(12):776-782
Using short term CTL lines derived from HLA A2/Kb transgenic mice and IFN-gamma release assays we demonstrate that the NS4.1769 epitope, is generated from natural processing of the NS4 antigen, and presented in the context of the A2/Kb molecules. Interestingly, T cell recognition of the naturally processed form of the NS4.1769 epitope was associated with significant IFN-gamma release, but no direct cytolytic activity. Epitopes of this phenotype might be of interest, in terms of therapy of chronic HCV infection by associating the benefit of localized lymphokine release with low or absent direct cytopathicity. 相似文献
69.
70.
Mancuso M Conforti FL Rocchi A Tessitore A Muglia M Tedeschi G Panza D Monsurrò M Sola P Mandrioli J Choub A DelCorona A Manca ML Mazzei R Sprovieri T Filosto M Salviati A Valentino P Bono F Caracciolo M Simone IL La Bella V Majorana G Siciliano G Murri L Quattrone A 《Neuroscience letters》2004,371(2-3):158-162
Mitochondrial impairment has been implicated in the pathogenesis of the amyotrophic lateral sclerosis (ALS). Furthermore, mitochondrial-specific polymorphisms were previously related to other neurodegenerative diseases, such as Parkinson, Friedreich and Alzheimer disease. To investigate if specific genetic polymorphisms within the mitochondrial genome (mtDNA) could act as susceptibility factors and contribute to the clinical expression of sporadic ALS (sALS), we have genotyped predefined European mtDNA haplogroups in 222 Italian patients with sALS and 151 matched controls. Individuals classified as haplogroup I demonstrated a significant decrease in risk of ALS versus individuals carrying the most common haplogroup, H (odds ratio 0.08, 95% confidence interval 0.04-0.4, p < 0.01). Further stratification of the dataset by sex, age and site of onset of disease and survival failed to reach significance for association. Our study provides evidence of the contribution of mitochondrial variation to the risk of ALS development in Caucasians. Further it may help elucidate the mechanism of the mitochondrial dysfunction detectable in ALS, and may be of relevance in development of strategies for the treatment of this disease. 相似文献