全文获取类型
收费全文 | 1534篇 |
免费 | 84篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 58篇 |
妇产科学 | 35篇 |
基础医学 | 171篇 |
口腔科学 | 47篇 |
临床医学 | 119篇 |
内科学 | 340篇 |
皮肤病学 | 19篇 |
神经病学 | 98篇 |
特种医学 | 200篇 |
外科学 | 136篇 |
综合类 | 79篇 |
预防医学 | 104篇 |
眼科学 | 37篇 |
药学 | 129篇 |
中国医学 | 10篇 |
肿瘤学 | 48篇 |
出版年
2023年 | 22篇 |
2022年 | 44篇 |
2021年 | 55篇 |
2020年 | 32篇 |
2019年 | 49篇 |
2018年 | 59篇 |
2017年 | 28篇 |
2016年 | 50篇 |
2015年 | 77篇 |
2014年 | 67篇 |
2013年 | 58篇 |
2012年 | 93篇 |
2011年 | 94篇 |
2010年 | 74篇 |
2009年 | 57篇 |
2008年 | 60篇 |
2007年 | 61篇 |
2006年 | 47篇 |
2005年 | 45篇 |
2004年 | 40篇 |
2003年 | 33篇 |
2002年 | 41篇 |
2001年 | 24篇 |
2000年 | 17篇 |
1999年 | 18篇 |
1998年 | 24篇 |
1997年 | 46篇 |
1996年 | 37篇 |
1995年 | 30篇 |
1994年 | 23篇 |
1993年 | 20篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 20篇 |
1989年 | 30篇 |
1988年 | 29篇 |
1987年 | 17篇 |
1986年 | 18篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1972年 | 3篇 |
1948年 | 1篇 |
排序方式: 共有1638条查询结果,搜索用时 15 毫秒
1.
Sarah Averbach Othman Kakaire Rachel McDiehl Christine Dehlendorf Felicia Lester Jody Steinauer 《Contraception》2019,99(2):87-93
Objective
This study assessed whether immediate postpartum insertion of levonorgestrel contraceptive implants is associated with a difference in infant growth from birth to 6 months, onset of lactogenesis, or breastfeeding continuation at 3 and 6 months postpartum compared to delayed insertion at 6 to 8 weeks postpartum.Study design
We conducted a randomized trial of women in Uganda who desired contraceptive implants postpartum. We randomly assigned participants to receive either immediate (within 5 days of delivery) or delayed (6 to 8 weeks postpartum) insertion of a two-rod levonorgestrel contraceptive implant system. This is a prespecified secondary analysis evaluating breastfeeding outcomes. The primary outcome of this secondary analysis was change in infant weight; infants were weighed and measured at birth and 6 months. We used a validated questionnaire to assess onset of lactogenesis daily in person while participants were in the hospital, and then daily by phone after they left the hospital, until lactogenesis was documented. We used interviewer-administered questionnaires to assess breastfeeding continuation and concerns at 3 months and 6 months postpartum.Results
Among the 96 women randomized to the immediate group and the 87 women to the delayed group, the mean change in infant weight from birth to 6 months was similar between groups: 4632?g in the immediate group and 4407?g in the delayed group (p=.26). Among the 97 women who had not experienced lactogenesis prior to randomization, the median time to onset of lactogenesis did not differ significantly between the immediate and delayed groups (65?h versus 63?h; p=.84). Similar proportions of women in the immediate and delayed groups reported exclusive breastfeeding at 3 months (74% versus 71%; p=.74) and 6 months (48% versus 52%; p=.58).Conclusion
We found no association between the timing of postpartum initiation of levonorgestrel contraceptive implants and change in infant growth from birth to 6 months, onset of lactogenesis, or breastfeeding continuation at 3 or 6 months postpartum.Implications
This study provides evidence that immediate postpartum initiation of contraception implants does not have a deleterious effect on infant growth or initiation or continuation of breastfeeding. 相似文献2.
3.
4.
5.
Hausegger KA; Cragg AH; Lammer J; Lafer M; Fluckiger F; Klein GE; Sternthal MH; Pilger E 《Radiology》1994,190(1):199
6.
The sonographic appearances in postpartum thyroiditis. 总被引:2,自引:0,他引:2
H Adams M C Jones S Othman J H Lazarus A B Parkes R Hall D I Phillips C J Richards 《Clinical radiology》1992,45(5):311-315
During the postpartum period about 50% of women with circulating thyroid autoantibodies develop a transient autoimmune thyroiditis. To determine the sonographic appearances in postpartum thyroiditis (PPT), serial ultrasound (US) scans of the thyroid were performed in 135 postpartum women who were divided into three clinical groups: Group 1, 37 antibody positive subjects who developed PPT; Group 2, 28 antibody positive subjects in whom thyroid function remained normal; Group 3, 70 antibody negative controls. Thyroid hypoechogenicity was observed in 14/31 patients (45%) who were scanned between 4 and 8 weeks postpartum and who subsequently developed PPT (Group 1) compared with 4/24 patients (17%) in Group 2 (P less than 0.05) and 1/65 patients (1.5%) in Group 3 (P less than 0.001). In antibody positive patients, the positive predictive value of an abnormal scan during this period was 78%. Between 15 and 25 weeks postpartum thyroid hypoechogenicity was present in 32/37 patients (86%) in Group 1 compared with 11/28 patients (39%) in Group 2 (P less than 0.001) and 2/70 patients (3%) in Group 3 (P less than 0.001). Sonographic abnormality persisted beyond 32 weeks postpartum in 36/41 antibody positive patients (87%) who had exhibited thyroid hypoechogenicity earlier during the study and who had late scans. The characteristic US appearance in PPT is thyroid hypoechogenicity. The role of sonography in the prediction, diagnosis and follow up of patients with PPT is discussed. 相似文献
7.
8.
9.
Othman Shibly Robert E. Schifferle Sebastian G. Ciancio Majd Tarakji Maryanne L. Mather 《Journal of clinical periodontology》1997,24(4):260-263
Abstract A single blind 30 day study compared the reduction of plaque and gingivitis for the Hapika® Powerbrush to the Interplak® ultra 10 tuft. A longitudinal parallel group design was utilized and screening evaluation was performed to determine patient eligibility prior to study enrollment. 66 subjects were entered into the study and assigned to 1 of 2 groups, each using one of the toothbrushes. At baseline, subjects received an oral soft tissue exam, a dental hard tissue exam, and were scored by the Lobene modification of the Löe and Silness gingival index (GI). Plaque was then disclosed and scored both pre and post brushing using the modified Turesky plaque/debris examination and an interproximal bleeding examination was performed post-brushing. On days 15 and 30, after an oral soft tissue and GI examination, plaque was graded by the Modified Turesky plaque/debris exam. Subjects then brushed and were graded by the Modified Turesky plaque/debris examination and an interproximal bleeding index examination. The results showed that both brushes provided a similar change in clinical indices. All produced a statistically significant reduction from baseline to day 30 for the gingival index (26.5-29.1%), the bleeding index (13.8-24.1%), and the plaque index (16.9-19.4%), A comparison of pre and post brushing scores for the plaque index at 30 showed that both brushes reduced plaque similarly with a statistically significant reduction (P<0.05) from their pre-brushing plaque index scores at all time periods. 相似文献
10.