全文获取类型
收费全文 | 18263篇 |
免费 | 913篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 221篇 |
儿科学 | 365篇 |
妇产科学 | 385篇 |
基础医学 | 2272篇 |
口腔科学 | 1278篇 |
临床医学 | 1422篇 |
内科学 | 4322篇 |
皮肤病学 | 394篇 |
神经病学 | 1638篇 |
特种医学 | 375篇 |
外科学 | 2657篇 |
综合类 | 122篇 |
一般理论 | 7篇 |
预防医学 | 1421篇 |
眼科学 | 301篇 |
药学 | 999篇 |
中国医学 | 85篇 |
肿瘤学 | 1007篇 |
出版年
2023年 | 169篇 |
2022年 | 351篇 |
2021年 | 643篇 |
2020年 | 388篇 |
2019年 | 561篇 |
2018年 | 634篇 |
2017年 | 475篇 |
2016年 | 467篇 |
2015年 | 549篇 |
2014年 | 777篇 |
2013年 | 971篇 |
2012年 | 1578篇 |
2011年 | 1567篇 |
2010年 | 852篇 |
2009年 | 739篇 |
2008年 | 1254篇 |
2007年 | 1232篇 |
2006年 | 1065篇 |
2005年 | 1006篇 |
2004年 | 806篇 |
2003年 | 715篇 |
2002年 | 680篇 |
2001年 | 182篇 |
2000年 | 166篇 |
1999年 | 139篇 |
1998年 | 129篇 |
1997年 | 87篇 |
1996年 | 73篇 |
1995年 | 68篇 |
1994年 | 66篇 |
1993年 | 53篇 |
1992年 | 64篇 |
1991年 | 58篇 |
1990年 | 41篇 |
1989年 | 48篇 |
1988年 | 50篇 |
1987年 | 46篇 |
1986年 | 54篇 |
1985年 | 50篇 |
1984年 | 36篇 |
1983年 | 21篇 |
1982年 | 21篇 |
1981年 | 27篇 |
1980年 | 21篇 |
1979年 | 31篇 |
1978年 | 24篇 |
1977年 | 22篇 |
1975年 | 23篇 |
1974年 | 20篇 |
1969年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Rafael T Mikolajczyk Maren Bredehorst Nadia Khelaifat Claudia Maier Annette E Maxwell 《BMC public health》2007,7(1):21
Background
The prevalence of depression is increasing not only among adults, but also among adolescents. Several risk factors for depression in youth have been identified, including female gender, increasing age, lower socio-economic status, and Latino ethnic background. The literature is divided regarding the role of acculturation as risk factor among Latino youth. We analyzed the correlates of depressive symptoms among Latino and Non-Latino White adolescents residing in California with a special focus on acculturation. 相似文献32.
A clinical, microbiologic, and radiographic study of deep caries lesions after incomplete caries removal. 总被引:3,自引:0,他引:3
Marisa Maltz Elenara F de Oliveira Vania Fontanella Rafael Bianchi 《Quintessence international, dental digest》2002,33(2):151-159
OBJECTIVE: Clinical, radiographic, and microbiologic changes in deep caries lesions were assessed after incomplete carious dentin removal and tooth sealing. METHOD AND MATERIALS: Thirty-two teeth with deep caries lesions were studied. Treatment consisted of incomplete excavation of the demineralized dentin, application of calcium hydroxide, and sealing for a 6- to 7-month period. The color and consistency of the dentin were clinically assessed. Differences in radiographic density were assessed by digital image subtraction. Microbiologic samples were obtained from the demineralized dentin before the temporary sealing and after the experimental period. The samples were cultivated on blood agar under aerobic and anaerobic conditions, in Mitis Salivarius agar, and Rogosa selective Lactobacillus agar. RESULTS: Two cases were lost during the study; one presented pulpal necrosis. In the other case, there was pulpal exposure during removal of provisional sealing. In all teeth, the initial demineralized dentin was soft and wet; one lesion was yellow, 21 were light brown, and eight were dark brown. After treatment, the dentin was dry, and 80.00% of specimens were hard, 16.67% were leathery, and 3.33% remained soft. The dentin was light brown in five teeth and dark brown in 25. There was a statistically significant mean difference in radiographic density (pixel intensity), 88.77 +/- 7.02 in the control areas and 94.66 +/- 6.75 in the test areas. The counts of anaerobic and aerobic bacteria, lactobacilli, and Streptococci mutans had decreased significantly by the end of treatment. CONCLUSION: Incomplete removal of carious dentin and subsequent tooth sealing resulted in the arrest of the lesions, suggesting that complete dentinal caries lesion removal is not essential to the control of caries lesions. 相似文献
33.
Rafael E. Cuellar MD Walter H. Kaye MD L. K. George Hsu MD Dr. David H. Van Thiel MD 《Digestive diseases and sciences》1988,33(12):1549-1553
Bulimia nervosa is a health problem of increasing magnitude that is estimated to affect 2–5% of the American adolescent and young adult female population. Because of the magnitude of this clinical problem and because of the importance of the upper gastrointestinal tract in its expression, a intradepartmental program of health care for patients affected with the disease was initiated. Eleven consecutive symptomatic bulimic individuals have been evaluated jointly by the gastroenterology and the psychiatry departments of the University of Pittsburgh. Five of these 11 individuals were found to have clinically important upper gastrointestinal pathology including ulcerative esophagitis, erosive gastritis, duodenal ulcer, and delayed gastric emptying. These gastrointestinal conditions could have been either a result of or have contributed to the symptomatology of these five patients. These data suggest that bulimic subjects have clinically important gastroenterological disease processes that require specific diagnosis and treatment independent of the psychiatric treatment provided for the bulimic condition.This work was supported in part by grants from NIDDK AM 32556. 相似文献
34.
The authors describe a case of ventricular fibrillation occasionally induced by high rate transesophageal pacing, performed to treat an atrial flutter. They conclude that, although this technique is generally safe and well tolerated, it must be performed exclusively where an intensive care can be provided. 相似文献
35.
36.
Julia Valderrama Fernando Zacarías Rafael Mazin 《Pan American journal of public health》2004,16(3):211-217
From the data submitted to the Pan American Health Organization (PAHO) by nationwide programs against sexually transmitted diseases (STD), HIV infection, and AIDS (2002), one can estimate the overall prevalence of syphilis among pregnant women to be 3.1% and to range from 1.00% in Peru to 6.21% in Paraguay. According to these data, the incidence of congenital syphilis ranges from 1.4 per 1000 live births in El Salvador to 12.0 per 1000 live births in Honduras. Among men who engage in sex with other men, who often classify themselves as heterosexual, as well as in female sex workers, the prevalence of syphilis ranged from 5% to 15%. Factors that determine the persistence of congenital syphilis as public health problem include a lack of awareness of the seriousness of the problem among politicians, health officials, and health care providers, difficult access to prenatal care, and screening services, a low demand for the test among users, and the stigma and discrimination that surround sexually transmitted diseases (STD). This paper seeks to focus the attention of health professionals on maternal and congenital syphilis so they will undertake actions, using an interprogrammatic approach, to eliminate congenital syphilis from Latin America and the Caribbean. Eliminating congenital syphilis will only become possible if interventions targeting vulnerable groups are also implemented. PAHO's role in eliminating congenital syphilis includes determining the baseline situation in the Region as a whole and in each country, developing communication and procurement strategies, supporting nationwide programs, promoting operational research, and facilitating interprogrammatic coordination. 相似文献
37.
Samuel E. Lynch DMD DMSc ; Stephen B. Trippel MD ; Richard D. Finkelman DDS PhD ; Rafael A. Hernandez DMD ; Christopher P. Kiritsy BA ; Harry N. Antoniades PhD 《Wound repair and regeneration》1994,2(3):182-190
The combination of insulin-like growth factor-I and platelet-derived growth factor-BB has previously been shown to stimulate healing of soft tissue wounds and the formation of bone and ligament around teeth. The purpose of the present study was to evaluate the effects of platelet-derived growth factor-BB and insulin-like growth factor-I individually and in combination on the healing of osseous wounds. Four standardized cortical wounds were created in each tibia of 11 adult Yucatan miniature pigs. The wounds in one tibia per animal were treated with either purified recombinant human insulin-like growth factor-I, platelet-derived growth factor-BB, or both in a methylcellulose gel. The wounds in each contralateral tibia received placebo gel alone. Coded serial sections of each wound were evaluated by computer-aided histomorphometry 21 days after surgery. The area and perimeter of the newly formed mineralized callus, the thickness of the total callus, and the percentage of mineralized tissue within the callus were significantly increased compared with the values of matched controls only in wounds treated with a combination of insulin-like growth factor-I and platelet-derived growth factor-BB. No significant differences in the measured parameters of callus formation were found in wounds treated with either insulin-like growth factor-I or platelet-derived growth factor-BB alone. Cartilage was present only in sites treated with insulin-like growth factor-I alone. These results suggest that the combination of platelet-derived growth factor-BB and insulin-like growth factor-I stimulates bone formation in wounds in long bones of adult animals and that these growth factors act via different pathways during the repair process. 相似文献
38.
Carlos Calderón Rafael Rotaeche Arritxu Etxebarria Mercé Marzo Rosa Rico Marta Barandiaran 《BMC health services research》2006,6(1):138-11
Background
The GRADE method represents a new approach to grading the quality of evidence and strength of recommendations in the preparation of Clinical Practice Guidelines (CPG). In the context of a pilot study to assess the implementability of the system in Spain, we considered it relevant to gain an insight into the significance of the perceptions and attitudes expressed by the actual experts participating in the system try-out. 相似文献39.
Antonio Z Gimeno‐García Adolfo Parra‐Blanco David Nicols‐Prez Cipriano Manzano‐Sanz Rafael Mndez‐Medina Enrique Quintero 《Digestive endoscopy》2006,18(2):144-146
Gastric mucormycosis involvement is a rare condition that usually occurs in inmunocompromised patients and frequently has a fatal outcome. We report the case of a 73‐year‐old woman admitted to the intensive care unit with severe bleeding after an acute pulmonary disease. Upper endoscopy disclosed wide and deep necrotic ulcers in the body and fundus of the stomach and greenish exudates with the antrum and the duodenum undamaged. Autopsy revealed an invasive mucormycosis and a severe atheromatosis. Several predisposing factors for mucormycosis infection have been reported until now. We postulate that ischemic gastritis could be a predisposing factor for colonization of zygomycete. 相似文献
40.