全文获取类型
收费全文 | 3773篇 |
免费 | 241篇 |
国内免费 | 144篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 57篇 |
妇产科学 | 32篇 |
基础医学 | 557篇 |
口腔科学 | 184篇 |
临床医学 | 374篇 |
内科学 | 640篇 |
皮肤病学 | 115篇 |
神经病学 | 140篇 |
特种医学 | 290篇 |
外科学 | 529篇 |
综合类 | 56篇 |
预防医学 | 155篇 |
眼科学 | 113篇 |
药学 | 467篇 |
中国医学 | 71篇 |
肿瘤学 | 304篇 |
出版年
2023年 | 36篇 |
2022年 | 90篇 |
2021年 | 139篇 |
2020年 | 77篇 |
2019年 | 83篇 |
2018年 | 125篇 |
2017年 | 96篇 |
2016年 | 134篇 |
2015年 | 206篇 |
2014年 | 236篇 |
2013年 | 293篇 |
2012年 | 362篇 |
2011年 | 316篇 |
2010年 | 191篇 |
2009年 | 159篇 |
2008年 | 184篇 |
2007年 | 210篇 |
2006年 | 171篇 |
2005年 | 142篇 |
2004年 | 114篇 |
2003年 | 76篇 |
2002年 | 75篇 |
2001年 | 77篇 |
2000年 | 58篇 |
1999年 | 48篇 |
1998年 | 56篇 |
1997年 | 44篇 |
1996年 | 38篇 |
1995年 | 32篇 |
1994年 | 34篇 |
1993年 | 25篇 |
1992年 | 21篇 |
1991年 | 18篇 |
1990年 | 17篇 |
1989年 | 21篇 |
1988年 | 29篇 |
1987年 | 14篇 |
1986年 | 6篇 |
1985年 | 12篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1973年 | 4篇 |
1958年 | 14篇 |
1955年 | 4篇 |
排序方式: 共有4158条查询结果,搜索用时 23 毫秒
91.
Objective:To compare the effect of canting correction in anterior maxillary transverse occlusal planes (AMTOP) and posterior maxillary transverse occlusal planes (PMTOP) on the change of lip canting (LC) in two-jaw surgery (TJS) cases.Materials and Methods:The samples consisted of eight young adult patients (three males and five females, mean age = 24.1 ± 4.5 years) who had skeletal Class III malocclusion (CIII), facial asymmetry (FA), and LC and who underwent TJS. Two-dimensional lateral and posteroanterior cephalograms and three-dimensional facial scanning taken 1 week before (T1) and 6 months after TJS (T2) were combined using the Morpheus 3D program. Six linear and angular variables were measured and statistically analyzed.Results:When comparing the values of the linear and angular variables at the T1 and T2 stages there was significant canting correction of AMTOP (1.7 mm vs −0.3 mm; 3.0° vs 0.1°), PMTOP (3.5 mm vs 0.1 mm, 3.3° vs −0.1°), and LC (3.0 mm vs 0.7 mm, 4.7° vs 2.1°) (all P < .05). Although the angular change ratios (ΔLC/ΔAMTOP and ΔLC/ΔPMTOP) did not exhibit a significant difference (0.99 vs 0.83), the linear change ratio of ΔLC/ΔAMTOP was significantly higher than that of ΔLC/ΔPMTOP (1.67 vs 0.74, P < .05). The angular change of ΔLC showed a significant correlation with ΔAMTOP (r2 = 0.64; P < .05). However, the linear change of ΔLC was significantly correlated with both the angular and linear changes of ΔAMTOP (r2 = 0.62 and 0.66; both P < .05). Therefore, the amount of LC change was more related to the canting correction of AMTOP than to that of PMTOP.Conclusion:In TJS cases with CIII, FA, and LC, the amount of canting correction of the AMTOP should be considered to predict the actual LC change. 相似文献
92.
93.
94.
95.
96.
C. E. Metzger K. Baek S. N. Swift M. J. De Souza S. A. Bloomfield 《Osteoporosis international》2016,27(9):2755-2764
Summary
Energy restriction causes bone loss, increasing stress fracture risk. The impact of exercise during energy restriction on bone and endocrine factors is examined. Exercise with energy restriction did not influence endocrine factors, but did mitigate some bone loss seen with energy restriction in sedentary rats.Introduction
Chronic dietary energy restriction (ER) leads to bone loss and increased fracture risk. Strictly controlled trials of long-term ER with and without vigorous exercise are required to determine whether exercise loading can counterbalance ER-induced bone loss. The aim of this current project is to elucidate the impact of exercise and ER on bone mass, estrogen status, and metabolic hormones.Methods
Twenty-four virgin female Sprague-Dawley rats (n?=?8/group) were divided into three groups—ad libitum fed?+?exercise (Adlib?+?EX), 40 % energy restricted?+?exercise (ER?+?EX), and 40 % energy restricted?+?sedentary (ER?+?SED). Energy availability between ER groups was equal. Treadmill running was performed 4 days/week at 70 % VO2max for 12 weeks.Results
Fat and lean mass and areal bone mineral density (aBMD) were lower after 12 weeks (p?<?0.05) for ER?+?EX vs Adlib?+?EX, but ER?+?EX aBMD was higher than ER?+?SED (p?<?0.0001). Serum leptin and a urinary estrogen metabolite, estrone-1-glucuronide (E1G), were lower at week 12 (p?=?0.0002) with ER, with no impact of exercise. Serum insulin-like growth factor I (IGF-I) declined (p?=?0.02) from baseline to week 12 in both ER groups. ER?+?EX exhibited higher cortical volumetric bone mineral density (vBMD) at the midshaft tibia (p?=?0.006) vs ER?+?SED.Conclusion
Exercise during ER mitigated some, but not all, of the bone loss observed in sedentary ER rats, but had little impact on changes in urinary E1G and serum IGF-I and leptin. These data highlight the importance of both adequate energy intake and the mechanical loading of exercise in maintaining bone mass.97.
98.
99.
Prevalence of type 5 familial hemophagocytic lymphohistiocytosis in Korea and novel mutations in STXBP2 下载免费PDF全文
100.
Ho Young Kim Ju Young Kim Hwa Yeon Park Ji Hye Jun Hye Yeon Koo In Young Cho Jinah Han Yuliya Pak Hyun Jung Baek Ju Yeon Lee Sung Hee Chang Jung Hun Lee Ji Soo Choe Sun-kyung Yang Kyung Chul Kim Jeong Ha Park Seul Ki Paik 《Globalization and health》2018,14(1):120