全文获取类型
收费全文 | 45668篇 |
免费 | 2567篇 |
国内免费 | 192篇 |
专业分类
耳鼻咽喉 | 608篇 |
儿科学 | 1245篇 |
妇产科学 | 962篇 |
基础医学 | 6282篇 |
口腔科学 | 2875篇 |
临床医学 | 4258篇 |
内科学 | 9413篇 |
皮肤病学 | 998篇 |
神经病学 | 3769篇 |
特种医学 | 904篇 |
外国民族医学 | 3篇 |
外科学 | 5066篇 |
综合类 | 319篇 |
一般理论 | 15篇 |
预防医学 | 5552篇 |
眼科学 | 781篇 |
药学 | 2919篇 |
中国医学 | 303篇 |
肿瘤学 | 2155篇 |
出版年
2023年 | 404篇 |
2022年 | 921篇 |
2021年 | 1725篇 |
2020年 | 1078篇 |
2019年 | 1512篇 |
2018年 | 1710篇 |
2017年 | 1212篇 |
2016年 | 1222篇 |
2015年 | 1468篇 |
2014年 | 1917篇 |
2013年 | 2371篇 |
2012年 | 3576篇 |
2011年 | 3849篇 |
2010年 | 1943篇 |
2009年 | 1567篇 |
2008年 | 2733篇 |
2007年 | 2762篇 |
2006年 | 2388篇 |
2005年 | 2173篇 |
2004年 | 1903篇 |
2003年 | 1791篇 |
2002年 | 1589篇 |
2001年 | 676篇 |
2000年 | 680篇 |
1999年 | 543篇 |
1998年 | 305篇 |
1997年 | 218篇 |
1996年 | 140篇 |
1995年 | 141篇 |
1994年 | 158篇 |
1993年 | 135篇 |
1992年 | 330篇 |
1991年 | 282篇 |
1990年 | 276篇 |
1989年 | 224篇 |
1988年 | 213篇 |
1987年 | 162篇 |
1986年 | 193篇 |
1985年 | 176篇 |
1984年 | 129篇 |
1983年 | 112篇 |
1982年 | 87篇 |
1981年 | 78篇 |
1979年 | 128篇 |
1978年 | 88篇 |
1974年 | 80篇 |
1973年 | 79篇 |
1970年 | 83篇 |
1969年 | 99篇 |
1967年 | 79篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
Guilherme Janson Karina Santana Cruz Donald G Woodside Angelos Metaxas Marcos Roberto de Freitas José Fernando Castanha Henriques 《American journal of orthodontics and dentofacial orthopedics》2004,126(4):451-463
The objective of this study was to evaluate the dentoskeletal changes consequent to orthodontic treatment in subjects with Class II subdivision malocclusions, treated with asymmetric extractions, compared with a normal-occlusion control group. The sample consisted of 3 groups, with 30 subjects in each: normal-occlusion subjects (group 1), untreated Class II subdivision subjects (group 2), and Class II subdivision patients treated with asymmetric extractions (group 3). All subjects had a full complement of permanent teeth at the beginning of treatment. The average ages of the subjects were 22.42, 15.76, and 18.57 years, respectively, in groups 1, 2, and 3. Measurements of relative differences in the spatial position of dental and skeletal bilateral landmarks were obtained from the submentovertex and posteroanterior cephalometric (PA) radiographs. The t test for independent samples was used to compare group 1 with groups 2 and 3 at different times. Results from the submentovertex radiograph showed that asymmetric extractions in Class II subdivision malocclusions will maintain the differences in the anteroposterior positions of right and left, maxillary and mandibular first molars, as would be expected with the treatment protocols used. There were no significant skeletal changes that could be attributed to the treatment approaches investigated or transverse collateral effects with the asymmetric mechanics used. It was also demonstrated that treatment of Class II subdivision malocclusions with asymmetric extractions produced corrections of maxillary and mandibular dental midline deviations with the midsagittal plane, without canting the occlusal plane or any other investigated horizontal plane, as seen in the PA radiograph. Treatment of Class II subdivision malocclusions with asymmetric extractions constitutes a beneficial approach to this problem. 相似文献
93.
Camila Oliveira Rodini Flávia Sirotheau Corrêa Pontes Hélder Ant?nio Rebelo Pontes Paulo Sérgio da Silva Santos Marina Gallottini Magalh?es Décio Santos Pinto 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):e50-e55
Leiomyosarcoma of the oral cavity is a very rare tumor associated with aggressive clinical behavior and low survival. In this paper, we report 2 cases of leiomyosarcoma, affecting the gingival mucosa of a 54-year-old female and the maxillary bone of a 63-year-old male. Histologically, the tumors were composed of variably oriented fascicles of spindle-shaped cells with cigar-shaped nuclei and eosinophilic cytoplasm. The lesions were treated by surgical resection. Immunoreactivity to anti-vimentin, anti-smooth muscle actin, anti-desmin, anti-laminin, and anti-muscle-specific actin antibodies were found; conversely, the tumor cells were negative for anti-S100 and AE1/AE3 proteins. This report emphasizes the role of immunohistochemical study for correct diagnosis of leiomyosarcoma. 相似文献
94.
Anna Letícia Soares Marinez de Oliveira Sousa Luci Maria Dusse Ana Paula Salles Moura Fernandes Marcelo Carvalho Lasmar Bethania Alves Novelli Geralda de Fátima Guerra Lages Maria das Gra?as Carvalho 《Blood coagulation & fibrinolysis》2007,18(5):395-399
This study aimed to investigate whether endothelial cells are damaged and to evaluate fibrinolytic system function in patients with type 2 diabetes. For this proposal, plasma levels of von Willebrand factor (an endothelial marker of injury), homocysteine (an inductor of endothelial injury), D-dimer (a marker of coagulation cascade activation) and plasminogen activator inhibitor-1 (a fibrinolysis marker) were measured in individuals with both type 2 diabetes and high blood pressure, with type 2 diabetes, with high blood pressure and in healthy control individuals. No significant differences among groups were observed for von Willebrand factor and homocysteine plasma levels. The type 2 diabetes and high blood pressure group presented a significant difference to the other groups for D-dimer and also presented high values for plasminogen activator inhibitor-1. The high blood pressure group and type 2 diabetes group presented separately higher values of plasminogen activator inhibitor-1 compared with the control group. High levels of D-dimer and plasminogen activator inhibitor-1 in patients with type 2 diabetes and high blood pressure with normoalbuminuria therefore indicate a state of hypercoagulability and hypofibrinolysis, despite no evident microvascular injury supported by normal levels of von Willebrand factor and homocysteine. 相似文献
95.
Maria Fernanda Nince Ferreira Verônica Moraes Oliveira Priscila Vieira da Cunha Osmindo Rodrigues Pires Júnior 《Toxicon》2010,55(7):1255-1262
This study evaluated the effects of [D-Leu1]Microcystin-LR variants, by the exposure of Hypophthalmichthys molitrix to Microcystis aeruginosa NPLJ4. Fish was placed in aquariums and exposed to 105 cells mL−1. For 15 days, 05 individuals were removed every 05 days, and tissue samples of liver, skeletal muscle and intestinal tract were collected for histopathologic analyses. Following exposure, those surviving were placed in clean water for 15 days to evaluate their recovery. A control without toxins was maintained in the same conditions and exhibited normal histology and no tissue damage. In exposed fish, samples were characterized by serious damages that similarly affected the different organs, such as dissociation of cells, necrosis and haemorrhage. Samples showed signs of recovery but severe damages were still observed. The results should be valuable to analyze the potency of microcystin toxicity and to help in the diagnosis of fish deaths. 相似文献
96.
Eduardo Kazuo Sannomiya Jun-ichi Asaumi Kanji Kishi Gisele da Silva Dalben 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(2):e41-e44
Dens invaginatus is a developmental variation resulting from an alteration in the normal growth pattern of the dental papilla. Synonyms of this disturbance include dens in dente, invaginated odontome, tooth inclusion, and dentoid in dente. Radiographically, it is observed as infolding of a radiopaque ribbon-like structure, with equal density as enamel, extending from the cingulum into the root canal and sometimes reaching the root apex, assigning the appearance of a small tooth within the coronal pulp cavity. This article presents 2 case reports. The first describes an 8-year-old girl with dens invaginatus in a mesiodens; the second report describes a 16-year-old boy presenting with 2 mesiodens, both associated with dens invaginatus. 相似文献
97.
Pierre E Wallemacq Arnaud Capron Roger Vanbinst Eric Boeckmans Jean Gillard Bertrand Favier 《American journal of health-system pharmacy》2006,63(6):547-556
PURPOSE: The permeability of 13 different gloves to 13 cytotoxic agents under controlled dynamic conditions is described. METHODS: Thirteen cytotoxic agents were prepared at the highest concentrations normally encountered by pharmacy personnel. Four glove types--neoprene, natural rubber latex, nitrile, and vinyl--were exposed to the cytotoxic agents for 15, 30, and 60 minutes. Tests were conducted using the middle finger of each glove. Linearity, reproducibility, and sensitivity were evaluated for each drug tested. Assays were run using liquid chromatographic tandem mass spectrometry (LC/MS/MS) and high-performance liquid chromatography with ultraviolet light (HPLC-UV). Permeability testing was conducted using an original system designed to evaluate dynamic constraints, such as rubbing, stretching, and tension. RESULTS: Linearity by LC/MS/MS and HPLC-UV was confirmed at concentrations up to 1000 ng/mL for all drugs. Most glove materials were permeable at rates below ASTM recommendations over the one-hour testing period. Vinyl was the most permeable material. Carmustine permeated the widest variety of materials. Due to the high sensitivity of the analytic methods, all materials displayed low but significant permeability for at least one drug after one hour. Higher resistance to permeation was recorded for all neoprene, some natural rubber latex, and one nitrile glove. CONCLUSION: Neoprene, natural rubber latex, and nitrile gloves displayed the highest resistance to permeation of the 13 cytotoxic agents studied. Additional factors, such as duration of exposure, glove thickness, and drug liposolubility and molecular weight, also affected permeability. 相似文献
98.
P. A. da Silva M. M. S. Boffo I. G. de Mattos A. B. S. Silva J. C. Palomino A. Martin H. E. Takiff 《Clinical microbiology and infection》2006,12(3):293-296
Rapid, accurate and inexpensive methods are essential to detect drug-resistant Mycobacterium tuberculosis and allow timely application of effective treatment and precautions to prevent transmission. The proportion method, the MTT and Alamar Blue redox methods, and the D29 mycobacteriophage assay, were compared for their ability to detect resistance to isoniazid and rifampicin. When tested against a panel of known M. tuberculosis strains, the redox methods and the D29 assay showed good sensitivity and specificity compared to the proportion method, suggesting that they could be useful alternatives for identifying multidrug resistance in M. tuberculosis. 相似文献
99.
Alfredo Avellaneda Fernández álvaro Pérez Martín Maravillas Izquierdo Martínez Mar Arruti Bustillo Francisco Javier Barbado Hernández Javier de la Cruz Labrado Rafael Díaz-Delgado Pe?as Eduardo Gutiérrez Rivas Cecilia Palacín Delgado José Ramón Ramón Giménez Javier Rivera Redondo 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2009,41(10):e1-e5
100.
Edmo Atique Gabriel Rafael Fagionato Locali Carla Cristina Romano Alberto José da Silva Duarte José Honório Palma Enio Buffolo 《European journal of cardio-thoracic surgery》2007,31(3):406-412
OBJECTIVE: The objective of this study is to evaluate the inflammatory response caused by endovascular stents in the treatment of aortic aneurysms. METHODS: Twenty-five patients underwent endovascular stent treatment from March through December 2005. The evolution of mediators (sedimentation velocity, C reactive protein, interleukin-6, interleukin-8, tumor necrosis factor-alpha, intercellular adhesion molecule-1, l-selectin), inflammatory cells (leukocytes, lymphocytes, platelets), serum creatinine and body temperature within preoperative period and in the following postoperative periods--1, 6, 24 and 48 h, 7 days, 1-3 months, was analyzed. In order to achieve statistic significance, Friedman test and Wilcoxon test were used, with index of significance of 5% (p<0.05). RESULTS: Peak values of sedimentation velocity, C reactive protein and interleukin-6 were observed at 7 days (p<0.0001), 48 h (p<0.0001) and 24h (p<0.0001), respectively. Tumor necrosis factor-alpha and interleukin-8 did not show statistically significant variability during the entire follow-up. In terms of intercellular adhesion molecule-1 and l-selectin, their expressive values were found in late phase of follow-up, although without statistical significance. Elevation of leukocytes count occurred in premature phase of follow-up (p<0.0001), while lymphocyte and platelet count occurred in a late phase of follow-up (p<0.0001). Serum levels of creatinine did not show significant variability during follow-up. The period between 24 and 48 h corresponded to major frequency for fever (p<0.0001). CONCLUSION: Individual mediators analysis and inflammatory cells demonstrated variability of their values during postoperative follow-up. This could help in the analysis of the inflammatory response evolution caused by endovascular stent treatment for aortic aneurysms in premature and late phases after implantation of the vascular prosthesis. 相似文献