全文获取类型
收费全文 | 50464篇 |
免费 | 5535篇 |
国内免费 | 80篇 |
专业分类
耳鼻咽喉 | 389篇 |
儿科学 | 1418篇 |
妇产科学 | 964篇 |
基础医学 | 7017篇 |
口腔科学 | 1317篇 |
临床医学 | 6284篇 |
内科学 | 9883篇 |
皮肤病学 | 770篇 |
神经病学 | 4258篇 |
特种医学 | 1999篇 |
外国民族医学 | 1篇 |
外科学 | 7098篇 |
综合类 | 1223篇 |
一般理论 | 29篇 |
预防医学 | 5668篇 |
眼科学 | 1001篇 |
药学 | 4078篇 |
中国医学 | 84篇 |
肿瘤学 | 2598篇 |
出版年
2022年 | 381篇 |
2021年 | 765篇 |
2020年 | 454篇 |
2019年 | 856篇 |
2018年 | 975篇 |
2017年 | 695篇 |
2016年 | 751篇 |
2015年 | 853篇 |
2014年 | 1210篇 |
2013年 | 1689篇 |
2012年 | 2485篇 |
2011年 | 2488篇 |
2010年 | 1374篇 |
2009年 | 1296篇 |
2008年 | 2273篇 |
2007年 | 2367篇 |
2006年 | 2292篇 |
2005年 | 2215篇 |
2004年 | 2006篇 |
2003年 | 1863篇 |
2002年 | 1852篇 |
2001年 | 1582篇 |
2000年 | 1505篇 |
1999年 | 1509篇 |
1998年 | 630篇 |
1997年 | 487篇 |
1996年 | 505篇 |
1995年 | 510篇 |
1994年 | 449篇 |
1993年 | 492篇 |
1992年 | 1243篇 |
1991年 | 1142篇 |
1990年 | 1087篇 |
1989年 | 1062篇 |
1988年 | 992篇 |
1987年 | 981篇 |
1986年 | 994篇 |
1985年 | 913篇 |
1984年 | 780篇 |
1983年 | 647篇 |
1982年 | 431篇 |
1981年 | 361篇 |
1979年 | 592篇 |
1978年 | 489篇 |
1977年 | 373篇 |
1976年 | 383篇 |
1974年 | 435篇 |
1973年 | 404篇 |
1972年 | 391篇 |
1969年 | 363篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Ramya Deepthi Vinnakota Allan S. Brett 《The American journal of the medical sciences》2019,357(2):160-163
Iron deficiency anemia is often listed among potential adverse effects of gastric acid-suppressive medications, given that gastric acidity promotes intestinal absorption of nonheme iron. Additionally, the antacid calcium carbonate can inhibit iron absorption. However, there is little direct clinical evidence that proton-pump inhibitors, histamine-2 receptor antagonists, or calcium carbonate cause iron deficiency anemia. Most case reports have had substantial limitations (e.g., minimal follow-up and presence of other causes of iron deficiency), and retrospective cohort studies have lacked sufficient patient-specific detail to make strong causal inferences. We present 2 cases—both with detailed, prospective 10-year follow-up—in which combinations of proton-pump inhibitors, histamine-2 receptor antagonists and calcium carbonate were clearly associated with development of iron deficiency anemia. Overt iron-deficiency anemia is probably uncommon in patients who use acid-modifying medications and who have no other conditions that predispose to iron deficiency. Nevertheless, clinicians should be aware of this potential complication, given widespread use of these agents. 相似文献
4.
Kelly H. M. Cooijmans Roseriet Beijers Bonnie E. Brett Carolina de Weerth 《Maternal & child nutrition》2022,18(1):e13241
This randomized controlled trial evaluated the effect of a 5-week daily skin-to-skin contact (SSC) intervention between mothers and their full-term infants, compared with care-as-usual, on exclusive and continued breastfeeding duration during the first post-natal year. Healthy pregnant women (n = 116) from a community sample were enrolled and randomly allocated to the SSC or care-as-usual condition. SSC mothers were requested to provide one daily hour of SSC for the first five post-natal weeks. Twelve months post-partum, mothers indicated the number of exclusive and continued breastfeeding months. Multiple regression analyses were conducted using intention-to-treat, per-protocol and exploratory dose–response frameworks. In intention-to-treat analyses, exclusive and continued breastfeeding duration was not different between groups (exclusive: 3.61 ± 1.99 vs. 3.16 ± 1.77 months; adjusted mean difference 0.28, 95% confidence interval [CI] ?0.33 to 0.89; p = 0.36; continued: 7.98 ± 4.20 vs. 6.75 ± 4.06 months; adjusted mean difference 0.81, 95% CI ?0.46 to 2.08; p = 0.21). In per-protocol analyses, exclusive and continued breastfeeding duration was longer for SSC than care-as-usual dyads (exclusive: 4.89 ± 1.26 vs. 3.25 ± 1.80 months; adjusted mean difference 1.28, 95% CI 0.31–2.24; p = 0.01; continued: 10.81 ± 1.97 vs. 6.98 ± 4.08 months; adjusted mean difference 2.33, 95% CI 0.13–4.54; p = 0.04). Exploratory dose–response effects indicated that more SSC hours predicted longer exclusive and continued breastfeeding duration. This study demonstrates that for the total group, the 5-week daily SSC intervention did not extend exclusive and continued breastfeeding duration. However, for mothers performing a regular daily hour of SSC, this simple and accessible intervention may extend exclusive and continued breastfeeding duration by months. Future studies are required to confirm these promising findings. Trial registration: Netherlands Trial Register (NTR5697). 相似文献
5.
Victoria A. Chang Dawn M. Meyer Brett C. Meyer 《Journal of stroke and cerebrovascular diseases》2019,28(1):163-166
Background
Acute stroke codes may be activated for anisocoria, but how often these codes lead to a final stroke diagnosis or alteplase treatment is unknown. The purpose of this study was to assess the frequency of anisocoria in stroke codes that ultimately resulted in alteplase administration.Methods
We retrospectively assessed consecutive alteplase-treated patients from a prospectively-collected stroke registry between February 2015 and July 2018. Based on the stroke code exam, patients were categorized as having isolated anisocoria [A+(only)], anisocoria with other findings [A+(other)], or no anisocoria [A?]. Baseline demographics, stroke severity, alteplase time metrics, and outcomes were also collected.Results
Ninety-six patients received alteplase during the study period. Of the 94 who met inclusion criteria, there were 0 cases of A+(only). There were 9 cases of A+(other) (9.6%). A+(other) exhibited higher baseline National Institutes of Health (NIH) Stroke Scale scores compared to A? (17 versus 7; P?=?.0003), and no additional differences in demographics or alteplase time metrics. Final stroke diagnosis and other outcome measures were no different between A+(other) and A?. Of the A+ patients without pre-existing anisocoria, 5 of 6 (83%) had posterior circulation events or diffuse subarachnoid hemorrhage.Conclusions
In this exploratory analysis, zero patients with isolated anisocoria received alteplase treatment. Anisocoria as a part of the neurologic presentation occurred in 10% of alteplase patients, and was strongly associated with a posterior circulation event. Therefore, we conclude that anisocoria has a higher likelihood of leading to alteplase treatment when identified in the presence of other neurologic deficits. 相似文献6.
7.
8.
9.
10.