全文获取类型
收费全文 | 12666篇 |
免费 | 940篇 |
国内免费 | 94篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 378篇 |
妇产科学 | 307篇 |
基础医学 | 1426篇 |
口腔科学 | 199篇 |
临床医学 | 1177篇 |
内科学 | 2673篇 |
皮肤病学 | 167篇 |
神经病学 | 979篇 |
特种医学 | 414篇 |
外科学 | 1973篇 |
综合类 | 266篇 |
一般理论 | 13篇 |
预防医学 | 870篇 |
眼科学 | 1006篇 |
药学 | 807篇 |
中国医学 | 74篇 |
肿瘤学 | 875篇 |
出版年
2023年 | 110篇 |
2022年 | 167篇 |
2021年 | 367篇 |
2020年 | 219篇 |
2019年 | 308篇 |
2018年 | 343篇 |
2017年 | 237篇 |
2016年 | 230篇 |
2015年 | 285篇 |
2014年 | 382篇 |
2013年 | 466篇 |
2012年 | 713篇 |
2011年 | 796篇 |
2010年 | 466篇 |
2009年 | 421篇 |
2008年 | 697篇 |
2007年 | 784篇 |
2006年 | 772篇 |
2005年 | 742篇 |
2004年 | 660篇 |
2003年 | 621篇 |
2002年 | 552篇 |
2001年 | 447篇 |
2000年 | 401篇 |
1999年 | 330篇 |
1998年 | 117篇 |
1997年 | 99篇 |
1996年 | 94篇 |
1995年 | 71篇 |
1994年 | 72篇 |
1993年 | 72篇 |
1992年 | 182篇 |
1991年 | 177篇 |
1990年 | 150篇 |
1989年 | 119篇 |
1988年 | 125篇 |
1987年 | 144篇 |
1986年 | 101篇 |
1985年 | 95篇 |
1984年 | 60篇 |
1983年 | 74篇 |
1982年 | 49篇 |
1981年 | 45篇 |
1980年 | 42篇 |
1979年 | 67篇 |
1978年 | 49篇 |
1977年 | 20篇 |
1976年 | 13篇 |
1973年 | 18篇 |
1972年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
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4.
5.
6.
Prevalence of Potentially Inappropriate Prescribing Among Hong Kong Older Adults: A Comparison of the Beers 2003, Beers 2012, and Screening Tool of Older Person's Prescriptions and Screening Tool to Alert doctors to Right Treatment Criteria
下载免费PDF全文
![点击此处可从《Journal of the American Geriatrics Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
7.
Esophageal foreign body causing direct aortic injury. 总被引:4,自引:0,他引:4
Foreign bodies in the esophagus are uncommon causes of esophageal perforation. Many nonperforating cases are successfully managed by flexible gastroscopy. However, complicated foreign bodies such as those that result in esophageal perforation and vascular injury are best managed surgically. Gastroscopy remains the primary method of diagnosis. A case of a 59-year-old woman who developed retrosternal and intrascapular pain, odynophagia and hematemesis after eating fish is reported. Flexible gastroscopy showed arterial bleeding from the midthoracic esophagus. Computed tomography scan localized a 3 cm fish bone perforating the esophagus with surrounding hematoma. An aortogram did not reveal an actively bleeding aortoesophageal fistula. The fish bone was surgically removed and the patient recovered with no postoperative complications. This case illustrates the importance of early consideration for surgical intervention when confronted with a brisk arterial bleed from the esophagus with suggestive history of foreign body ingestion. 相似文献
8.
The YAG (yttrium aluminum garnet) laser has been recommended for anterior capsulotomies. One major complication is elevated intraocular pressure. We report a study of the biochemical content of the aqueous humor after a YAG laser anterior capsulotomy. We analyzed 6-keto-prostaglandin F1 alpha, thromboxane B2 and protein concentrations in the aqueous humor of human eyes. The average values of protein, 6-keto-prostaglandin F1 alpha, and thromboxane B2 in the control eyes were 81.3 +/- 14.0 mg/dL, 17 +/- 30 pg/mL, and 10 +/- 10 pg/mL, respectively. These values were elevated to 182.4 +/- 81.3 mg/dL, 401 +/- 55 pg/mL, and 576 +/- 148 pg/mL, respectively, after YAG laser anterior capsulotomy. The samples with a moderate level of 6-keto-prostaglandin F1 alpha (less than 300 pg/mL) had negligible changes of thromboxane. The elevation of thromboxane was obvious only when prostaglandin levels rose above 300 pg/mL. 相似文献
9.
10.