全文获取类型
收费全文 | 5587篇 |
免费 | 393篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 176篇 |
妇产科学 | 154篇 |
基础医学 | 786篇 |
口腔科学 | 99篇 |
临床医学 | 477篇 |
内科学 | 1364篇 |
皮肤病学 | 157篇 |
神经病学 | 489篇 |
特种医学 | 92篇 |
外科学 | 600篇 |
综合类 | 37篇 |
一般理论 | 3篇 |
预防医学 | 674篇 |
眼科学 | 94篇 |
药学 | 354篇 |
中国医学 | 14篇 |
肿瘤学 | 412篇 |
出版年
2023年 | 35篇 |
2022年 | 73篇 |
2021年 | 171篇 |
2020年 | 99篇 |
2019年 | 172篇 |
2018年 | 188篇 |
2017年 | 110篇 |
2016年 | 105篇 |
2015年 | 129篇 |
2014年 | 188篇 |
2013年 | 304篇 |
2012年 | 417篇 |
2011年 | 419篇 |
2010年 | 289篇 |
2009年 | 208篇 |
2008年 | 385篇 |
2007年 | 372篇 |
2006年 | 333篇 |
2005年 | 321篇 |
2004年 | 300篇 |
2003年 | 279篇 |
2002年 | 263篇 |
2001年 | 78篇 |
2000年 | 69篇 |
1999年 | 83篇 |
1998年 | 55篇 |
1997年 | 41篇 |
1996年 | 30篇 |
1995年 | 31篇 |
1994年 | 28篇 |
1993年 | 30篇 |
1992年 | 40篇 |
1991年 | 46篇 |
1990年 | 31篇 |
1989年 | 21篇 |
1988年 | 23篇 |
1987年 | 11篇 |
1986年 | 19篇 |
1985年 | 16篇 |
1984年 | 17篇 |
1983年 | 13篇 |
1982年 | 15篇 |
1981年 | 18篇 |
1980年 | 17篇 |
1978年 | 16篇 |
1976年 | 8篇 |
1975年 | 9篇 |
1973年 | 13篇 |
1971年 | 9篇 |
1967年 | 8篇 |
排序方式: 共有6007条查询结果,搜索用时 31 毫秒
41.
VCAM-1, but not ICAM-1 or MAdCAM-1, immunoblockade ameliorates DSS-induced colitis in mice 总被引:7,自引:0,他引:7
Soriano A Salas A Salas A Sans M Gironella M Elena M Anderson DC Piqué JM Panés J 《Laboratory investigation; a journal of technical methods and pathology》2000,80(10):1541-1551
Adhesion molecule immunoneutralization is envisioned as a promising therapy for inflammatory bowel disease, but the relative value of selective blockade of different adhesion molecules has not been established. The aims of this study were to measure expression and functional relevance of endothelial intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and mucosal addressin cell adhesion molecule 1 (MAdCAM-1) in leukocyte recruitment in experimental colitis and to compare the therapeutic effectiveness of their selective blockade. For this purpose, cell adhesion molecule expression was measured by the dual radiolabeled antibody technique in mice with dextran sulfate sodium-induced colitis and controls. Leukocyte-endothelial cell interactions were determined in colonic venules by fluorescence intravital microscopy. Therapeutic effects of chronic treatment with anti-ICAM-1, anti-VCAM-1, or anti-MAdCAM-1 antibodies were also assessed. Whereas colonic endothelial ICAM-1 was constitutively expressed and had a mild up-regulation in colitic animals, constitutive expression of VCAM-1 and MAdCAM-1 was low, but markedly increased after induction of colitis. Leukocyte adhesion was abrogated by immunoneutralization of VCAM-1 or MAdCAM-1 but not by treatment with an anti-ICAM-1 antibody. Chronic administration of anti-VCAM-1 antibody, but not anti-ICAM-1 or anti-MAdCAM-1, resulted in significant attenuation of colitis in terms of disease activity index, colon length, ratio of colon weight to length, and myeloperoxidase activity. In conclusion, VCAM-1 plays a central role in leukocyte recruitment in colitis and blockade of this adhesion molecule has higher therapeutic effect than immunoneutralization of ICAM-1 or MAdCAM-1 in this experimental model. 相似文献
42.
43.
Fishery products are the main source of dietary n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). Following the European Commission’s request to address the risks and benefits of seafood consumption, and taking into account the great variability of nutrient and contaminant levels in fishery products, the present work aims to estimate the n-3 LC-PUFA provided per serving of selected fishes, shrimps and mollusks that are commonly consumed in Spain. This would enable the establishment of a risk–benefit analysis of fish consumption and provide recommendations for fish intake to comply with nutritional guidelines of n-3 LC-PUFA intake. We confirmed high variation in the pattern and contents of fatty acids for different species. n-6 PUFA were minor fatty acids, whereas palmitic (C16:0), oleic (C18:1 n-9), and mainly eicosapentaenoic (C20:5 n-3) and docosahexaenoic (C22:6 n-3) acids were the major fatty acids in the sample. Therefore, consumption of 2–3 servings per week of a variety of fishery products may contribute to compliance with the recommended daily n-3 LC-PUFA intake while maintaining an adequate balance to avoid contaminant-derived potential risks (metals and others). Taking the fatty acid content of fishery products described in this study into consideration, it is advisable to include one serving of fatty fish per week in order to meet recommended n-3 LC-PUFA levels. 相似文献
44.
M. Dolores del Toro López Javier Arias Díaz José M. Balibrea Natividad Benito Andrés Canut Blasco Erika Esteve Juan Pablo Horcajada Juan Diego Ruiz Mesa Alba Manuel Vázquez Cristóbal Muñoz Casares Jose Luis del Pozo Miquel Pujol Melchor Riera Jaime Jimeno Inés Rubio Pérez Jaime Ruiz-Tovar Polo Alejandro Serrablo Alex Soriano Josep M. Badia 《Cirugía espa?ola》2021,99(1):11-26
Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and antimicrobial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised.The Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis in surgery to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery. 相似文献
45.
46.
Salcedo M Taja L Utrera D Chávez P Hidalgo A Pérez C Benítez L Castañeda C Delgado R Gariglio P 《International journal of experimental pathology》2002,83(6):275-286
The role of tumour suppressor genes in the development of human cancers has been studied extensively. In viral carcinogenesis, the inactivation of suppressor proteins such as retinoblastoma (pRb) and p53, and cellular oncogenes overexpression, such as c-myc, has been the subject of a number of investigations. In uterine-cervix carcinomas, where high-risk human papillomavirus (HPV) plays an important role, pRb and p53 are inactivated by E7 and E6 viral oncoproteins, respectively. However, little is known about the in situ expression of some of these proteins in pre-malignant and malignant cervical tissues. On the other hand, it has also been demonstrated that c-myc is involved in cervical carcinogenesis, and that pRb participates in the control of c-myc gene expression. By using immunostaining techniques, we investigated pRb immunodetection pattern in normal tissues, squamous intraepithelial lesions (SILs) and invasive carcinomas from the uterine cervix. Our data show low pRb detection in both normal cervical tissue and invasive lesions, but a higher expression in SILs. C-Myc protein was observed in most of the cellular nuclei of the invasive lesions, while in SILs was low. These findings indicate a heterogeneous pRb immunostaining during the different stages of cervical carcinogenesis, and suggest that this staining pattern could be a common feature implicated in the pathogenesis of uterine-cervix carcinoma. 相似文献
47.
Joanna Luczkowiak Gonzalo Rivas Nuria Labiod Fátima Lasala Marta Rolo Jaime Lora-Tamayo Mikel Mancheno-Losa David Rial-Crestelo Alfredo Pérez-Rivilla María Dolores Folgueira Rafael Delgado 《Journal of medical virology》2023,95(1):e28268
We have measured the humoral response to messenger RNA (mRNA) vaccines in COVID-19 naïve and convalescent individuals. Third doses of mRNA COVID-19 vaccines induced a significant increase in potency and breadth of neutralization against SARS-CoV-2 variants of concern (VoC) including Omicron subvariants BA.1, BA.2, and BA.2.12.1, that were cross-neutralized at comparable levels and less for BA.4/5. This booster effect was especially important in naïve individuals that only after the third dose achieved a level that was comparable with that of vaccinated COVID-19 convalescents except for BA.4/5. Avidity of RBD-binding antibodies was also significantly increased in naïve individuals after the third dose, indicating an association between affinity maturation and cross neutralization of VoC. These results suggest that at least three antigenic stimuli by infection or vaccination with ancestral SARS-CoV-2 sequences are required to induce high avidity cross-neutralizing antibodies. Nevertheless, the circulation of new subvariants such as BA.4/5 with partial resistance to neutralization will have to be closely monitored and eventually consider for future vaccine developments. 相似文献
48.
Tyl Rochelle W.; Gerhart James M.; Myers Christina B.; Marr Melissa C.; Brine Dolores R.; Seely John C.; Henrich Richard T. 《Toxicological sciences》1997,40(1):90-100
Tributyl phosphate (TBP) was tested for reproductive toxicityin rats. Thirty weanlings/sex (F0) were exposed to TBP in thediet ad libitum at 0, 200, 700, or 3000 ppm for 10 weeks andthen randomly mated within groups for 3 weeks with continuedexposure. F0 parents and 10 F1 weanlings/sex/dose were necropsied,and adult reproductive organs, urinary bladders (both sexes),kidneys (males), and livers (females) were evaluated histologically.Thirty F1 weanlings/sex/dose continued exposure for 11 weeksand were bred as described above. F1 parents and P2 weanlings,10/sex/dose, were then necropsied as described above. Adulttoxicity was observed in both sexes and generations at 700 and3000 ppm; observations included reduced body weights, weightgain and feed consumption, urinary bladder epithelial hyperplasia(both sexes), renal pelvis epithelial hyperplasia only at 3000ppm (male kidneys), and centrilobular hypertrophy (female livers).At 200 ppm, transient reductions in body weight were observedin F0 and F1 females, with urinary bladder epithelial hyperplasiain F0 males and females and in F1 males. There was no evidenceof reproductive toxicity, of reproductive organ pathology, orof effects on gestation or lactation at any dose tested. Postnataltoxicity was evidenced by consistent reductions in F1 and F2pup body weights at 3000 ppm and by occasional weight reductionsin F2 litters at 700 ppm, and was associated with maternal toxicityobserved at these doses and times. Under the conditions of thisstudy, a NOAEL was not determined for adult toxicity; the NOAELfor reproductive toxicity was at least 3000 ppm and the NOAELfor postnatal toxicity was approximately 200 ppm. 相似文献
49.
50.
Differential regulation of platelet aggregation by matrix metalloproteinases-9 and -2 总被引:10,自引:0,他引:10
Fernandez-Patron C Martinez-Cuesta MA Salas E Sawicki G Wozniak M Radomski MW Davidge ST 《Thrombosis and haemostasis》1999,82(6):1730-1735
We have recently found matrix metalloproteinase-2 (MMP-2) in human platelets and reported that the release of this enzyme during platelet activation stimulates aggregation. We have now identified matrix metalloproteinase-9 (MMP-9) in human platelets and resistance-sized (approximately 200 microm) arteries. Resting platelets released small quantities of pro-MMP-9. Maximal release of MMP-9 was detected during partial (appr. 30% maximum) aggregation with thrombin. However, maximal release of MMP-2 was associated with maximal aggregation. MMP-9 antibodies induced aggregation of resting platelets and potentiated aggregation of platelets induced by thrombin and collagen. Moreover, MMP-9 microisolated from arteries as well as recombinant human MMP-9 (0.1-30 ng/ml) inhibited thrombin and collagen-induced aggregation. We conclude that MMP-9 is an inhibitor of aggregation and in this action opposes the effects of MMP-2. The MMP-2/MMP-9 system may play an important role in the regulation of platelet-platelet and platelet-vessel wall interactions. 相似文献