全文获取类型
收费全文 | 18194篇 |
免费 | 1654篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 153篇 |
儿科学 | 698篇 |
妇产科学 | 586篇 |
基础医学 | 2440篇 |
口腔科学 | 384篇 |
临床医学 | 1968篇 |
内科学 | 3187篇 |
皮肤病学 | 269篇 |
神经病学 | 1829篇 |
特种医学 | 1174篇 |
外科学 | 2157篇 |
综合类 | 357篇 |
一般理论 | 21篇 |
预防医学 | 1929篇 |
眼科学 | 338篇 |
药学 | 1424篇 |
中国医学 | 21篇 |
肿瘤学 | 987篇 |
出版年
2021年 | 243篇 |
2020年 | 196篇 |
2019年 | 227篇 |
2018年 | 296篇 |
2017年 | 241篇 |
2016年 | 241篇 |
2015年 | 293篇 |
2014年 | 388篇 |
2013年 | 571篇 |
2012年 | 787篇 |
2011年 | 799篇 |
2010年 | 511篇 |
2009年 | 439篇 |
2008年 | 733篇 |
2007年 | 780篇 |
2006年 | 714篇 |
2005年 | 680篇 |
2004年 | 604篇 |
2003年 | 639篇 |
2002年 | 580篇 |
2001年 | 559篇 |
2000年 | 560篇 |
1999年 | 514篇 |
1998年 | 278篇 |
1997年 | 260篇 |
1996年 | 258篇 |
1995年 | 212篇 |
1994年 | 192篇 |
1993年 | 181篇 |
1992年 | 406篇 |
1991年 | 426篇 |
1990年 | 429篇 |
1989年 | 400篇 |
1988年 | 424篇 |
1987年 | 430篇 |
1986年 | 365篇 |
1985年 | 386篇 |
1984年 | 272篇 |
1983年 | 237篇 |
1982年 | 155篇 |
1979年 | 260篇 |
1978年 | 205篇 |
1977年 | 151篇 |
1976年 | 180篇 |
1975年 | 142篇 |
1974年 | 180篇 |
1973年 | 172篇 |
1972年 | 151篇 |
1969年 | 169篇 |
1968年 | 146篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
991.
Dhawan A Trivedi P Cheeseman P Baker AJ Howard ER Mieli-Vergani G 《Journal of pediatric surgery》2001,36(3):443-446
PURPOSE: The aim of this study was to assess whether serum concentrations of hyaluronic acid (HA), measured at diagnosis is an early biochemical marker of prognosis in biliary atresia. METHODS: Serum HA was measured at diagnosis using a radiometric assay in 84 infants with biliary atresia (BA), and related to outcome by 5 years of age. RESULTS: Serum HA was higher in the 29 patients who died or required liver transplant by 5 years of age compared with the 56 who survived to 5 years without transplant (490 +/- 216 microg/L v 262 +/- 163 microg/L; P <.001, 95% confidence intervals of the difference 145 to 311 microg/L). CONCLUSION: High serum concentrations of HA at diagnosis may help to identify at an early stage those patients with BA who have a poor prognosis and will require liver transplant by 5 years of age. 相似文献
992.
Hemangioma of the heart is a rare lesion, representing 5% to 10% of benign cardiac tumors. Hemangioma of the mitral valve has been reported previously in one autopsy case report. We describe the excision and repair of a hemangioma of the mitral valve in a 33-year-old African-American woman. 相似文献
993.
Baker CJ Paoletti LC Rench MA Guttormsen HK Carey VJ Hickman ME Kasper DL 《The Journal of infectious diseases》2000,182(4):1129-1138
An estimated 15% of invasive group B streptococcal (GBS) disease is caused by type II capsular polysaccharide (II CPS). In developing a pentavalent vaccine for the prevention of GBS infections, individual GBS CPSs have been coupled to tetanus toxoid (TT) to prepare vaccines with enhanced immunogenicity. Type II GBS (GBS II) vaccine was created by direct, covalent coupling of II CPS to TT by reductive amination. In 2 clinical trials, 75 healthy nonpregnant women 18-45 years old were randomized to receive II CPS-TT (II-TT) conjugate (dose range, 3.6-57 microg of CPS component) or uncoupled II CPS vaccine. Both vaccines were well tolerated. II CPS-specific IgG serum concentrations (as well as IgM and IgA) peaked 2 weeks after immunization, being significantly higher in recipients of conjugated vaccine than in recipients of uncoupled CPS. Immunological responses to conjugate were dose dependent and correlated with opsonophagocytosis in vitro. These results support inclusion of II-TT conjugate when preparing a multivalent GBS vaccine. 相似文献
994.
995.
996.
997.
Baker BL Heller TL Henker B 《Journal of child psychology and psychiatry, and allied disciplines》2000,41(7):907-915
Expressed Emotion (EE), a measure of the emotional climate of the family, predicts subsequent adjustment of adults with mental disorder (Leff & Vaughn, 1985). Despite the acknowledged importance of the family in childhood disorders, there have been relatively few studies of expressed emotion with adolescents and school-aged children and virtually none focused on preschoolers. The present study utilized the Five Minute Speech Sample (FMSS) to examine how Expressed Emotion relates concurrently and longitudinally to child problem status in a community sample of 112 preschool-aged children. At preschool, the proportion of high EE increased significantly across three child groups: Comparison (8.1%), Borderline Problem (15.8%), and High Problem (41.2%); however, preschool EE was not predictive of subsequent child status at 1st grade. Expanded FMSS codes. tapping positive affect and worry about the child, were also related to child problem group at preschool and were predictive of subsequent child status at 1st grade. Because parents' stress and adjustment were also highly related to child problem group status, we examined whether the FMSS codes were essentially a proxy for these or whether they explained unique variance. In two stepwise regressions on preschool child group status (divided by total problems and by externalizing problems), maternal stress was the only variable to enter. Also, in predicting to 1st grade externalizing child group status, only maternal stress entered. Discussion focused on the extension of the EE construct and other FMSS coding to young children, and the need to recognize that to some extent these variables may reflect maternal stress and adjustment. 相似文献
998.
999.
Daniel Scott Jon Ruckle Marilyn Dar Sherryl Baker Hiroaki Kondoh Stephen Lockhart 《Pediatrics international》2008,50(3):295-299
Background: A 7-valent pneumococcal conjugate vaccine (7vPnC) has markedly reduced invasive pneumococcal disease (IPD) in routine use in the USA and is in clinical development in Japan. But a 13-valent pneumococcal conjugate vaccine (13vPnC) would cover even more serotypes. Because vaccines are administered to children by s.c. injection in Japan but by i.m. injection in the USA, a phase I study of s.c. injected 13vPnC in healthy Japanese adults was appropriate before commencing trials in Japanese children and older adults.
Methods: This was a randomized comparison in healthy Japanese adults of s.c. administered 13-valent pneumococcal conjugate vaccine and s.c. administered 23-valent plain polysaccharide pneumococcal vaccine (23vPn). Local and systemic reactions were recorded in a daily diary for 14 days after injection. IgG antibodies to serotype-specific capsular polysaccharide were measured on enzyme-linked immunosorbent assay on samples taken before and approximately 1 month after immunization.
Results: A total of 15 subjects were evaluable for safety review in each treatment group. There was a trend towards more local reactions in the 13vPnC group, which may be associated with s.c. administration of aluminum-containing vaccines as used routinely in Japan; but the local reactogenicity was mostly mild or moderate. Both 13vPnC and 23vPn were immunogenic for all types, with the exception of 6A, which is not included in 23vPn and for which only 13vPnC was immunogenic.
Conclusions: Overall, immunogenicity and tolerance was adequate to lead to studies of 13vPnC in both infants and older adults in Japan, using the s.c. route if appropriate. 相似文献
Methods: This was a randomized comparison in healthy Japanese adults of s.c. administered 13-valent pneumococcal conjugate vaccine and s.c. administered 23-valent plain polysaccharide pneumococcal vaccine (23vPn). Local and systemic reactions were recorded in a daily diary for 14 days after injection. IgG antibodies to serotype-specific capsular polysaccharide were measured on enzyme-linked immunosorbent assay on samples taken before and approximately 1 month after immunization.
Results: A total of 15 subjects were evaluable for safety review in each treatment group. There was a trend towards more local reactions in the 13vPnC group, which may be associated with s.c. administration of aluminum-containing vaccines as used routinely in Japan; but the local reactogenicity was mostly mild or moderate. Both 13vPnC and 23vPn were immunogenic for all types, with the exception of 6A, which is not included in 23vPn and for which only 13vPnC was immunogenic.
Conclusions: Overall, immunogenicity and tolerance was adequate to lead to studies of 13vPnC in both infants and older adults in Japan, using the s.c. route if appropriate. 相似文献
1000.