全文获取类型
收费全文 | 31071篇 |
免费 | 2667篇 |
国内免费 | 556篇 |
专业分类
耳鼻咽喉 | 236篇 |
儿科学 | 1825篇 |
妇产科学 | 321篇 |
基础医学 | 3040篇 |
口腔科学 | 4906篇 |
临床医学 | 1886篇 |
内科学 | 3193篇 |
皮肤病学 | 180篇 |
神经病学 | 1861篇 |
特种医学 | 994篇 |
外科学 | 3637篇 |
综合类 | 4065篇 |
现状与发展 | 2篇 |
预防医学 | 2022篇 |
眼科学 | 837篇 |
药学 | 1193篇 |
17篇 | |
中国医学 | 3800篇 |
肿瘤学 | 279篇 |
出版年
2024年 | 119篇 |
2023年 | 623篇 |
2022年 | 1218篇 |
2021年 | 1597篇 |
2020年 | 1451篇 |
2019年 | 1140篇 |
2018年 | 1094篇 |
2017年 | 1271篇 |
2016年 | 1319篇 |
2015年 | 1124篇 |
2014年 | 2052篇 |
2013年 | 2033篇 |
2012年 | 1650篇 |
2011年 | 1774篇 |
2010年 | 1352篇 |
2009年 | 1307篇 |
2008年 | 1305篇 |
2007年 | 1323篇 |
2006年 | 1129篇 |
2005年 | 922篇 |
2004年 | 850篇 |
2003年 | 785篇 |
2002年 | 608篇 |
2001年 | 572篇 |
2000年 | 500篇 |
1999年 | 437篇 |
1998年 | 450篇 |
1997年 | 383篇 |
1996年 | 328篇 |
1995年 | 345篇 |
1994年 | 285篇 |
1993年 | 254篇 |
1992年 | 243篇 |
1991年 | 233篇 |
1990年 | 220篇 |
1989年 | 199篇 |
1988年 | 207篇 |
1987年 | 166篇 |
1986年 | 181篇 |
1985年 | 195篇 |
1984年 | 156篇 |
1983年 | 97篇 |
1982年 | 137篇 |
1981年 | 118篇 |
1980年 | 88篇 |
1979年 | 99篇 |
1978年 | 66篇 |
1977年 | 60篇 |
1976年 | 73篇 |
1975年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Comprehensive evidence regarding the treatment of non-anaemic iron deficiency in patients undergoing valvular heart surgery is lacking. This study aimed to investigate the association between non-anaemic iron deficiency and postoperative outcomes in these patients. We retrospectively analysed 321 patients of which 180 (56%) had iron deficiency (defined as serum ferritin < 100 ng.ml-1 or < 300 ng.ml-1 with transferrin saturation < 20%). While the iron-deficient group had lower pre-operative haemoglobin levels than the non-iron deficient group (median (IQR [range]) 134 (127–141 [120–172]) g.l-1, 143 (133–150 [120–179]) g.l-1, p = 0.001), there was no between-group difference in allogeneic red blood cell transfusion. Median (IQR [range]) days alive and out of hospital at postoperative day 90 was 1 day shorter in the iron-deficient group (80 (77–82 [9–85]) days vs. 81 (79–83 [0–85]) days, p = 0.026). In multivariable analysis, only cardiopulmonary bypass duration (p = 0.032) and intra-operative allogeneic red blood cell transfusion (p = 0.011) were significantly associated with reduced days alive and out of hospital at postoperative day 90. Iron deficiency did not exert any adverse influence on secondary outcomes except length of hospital stay. Our findings indicate that non-anaemic iron deficiency alone is not associated with adverse effects in patients undergoing valvular heart surgery when it does not translate into an increased risk of allogeneic transfusion. 相似文献
4.
目的 运用核磁共振弥散张量成像技术(DTI),从皮质脊髓束损伤程度评价的角度,探讨肾虚髓亏证与急性缺血性脑卒中运动功能缺损程度相关性,丰富中风病病机及证候诊断,拓宽缺血性脑卒中的中医药防治思路,为急性缺血性脑卒中肾虚髓亏证患者运动功能损伤程度提供临床依据,强调肾虚髓亏证在急性缺血性脑卒中运动功能损伤中的重要意义。方法 纳入符合诊断标准的90例病例,根据证候分别归入肾虚髓亏组和非肾虚髓亏组,每组各45例。每组患者均给予常规西药治疗。对两组患者入院后行弥散张量成像检测,同时分别于治疗前及治疗后14天,记录两组患者NIHSS评分、改良Barthel指数量表及简化Fugl-Meyer运动功能评分量表评分,比较两组病例发病时的轻重程度及治疗前后两组病例组间的恢复差异。结果 研究显示,治疗前肾虚髓亏组在NIHSS评分方面高于非肾虚髓亏组(P<0.05);治疗前肾虚髓亏组在改良Barthel指数量表及简化Fugl-Meyer运动功能评分方面低于非肾虚髓亏组(P<0.05)。治疗前后NIHSS评分、改良Barthel指数评分及简化Fugl-Meyer运动功能评分改善情况,非肾虚髓亏组要优于肾虚髓亏组(P<0.05)。治疗前两组患者在健侧内囊后肢及大脑脚外侧处FA值及ADC值无明显差异;肾虚髓亏组在患侧内囊后肢及大脑脚外侧处FA值及ADC值均低于非肾虚髓亏组(P<0.05)。相关性分析得出,两组患者患侧内囊后肢FA值与患者治疗前NIHSS评分呈负相关;两组患者患侧内囊后肢FA值与患者改良Barthel指数评分及简化Fugl-Meyer运动功能评分呈正相关;肾虚髓亏组患者患侧内囊后肢FA值与肾虚髓亏证中医证候评分呈负相关。结论 肾虚髓亏是急性缺血性脑卒中运动功能障碍的重要病机。研究结果显示,两组皮质脊髓束损伤程度与神经功能及运动功能损伤存在相关性,且肾虚髓亏组在皮质脊髓束的损伤程度方面与其中医证候评分呈负相关。 相似文献
5.
6.
7.
《Gait & posture》2022
BackgroundAnteriorly-loaded walking is common in many occupations and may increase fall risk. Dynamic gait stability, defined by the Feasible Stability Region (FSR) theory, quantifies the kinematic relationship between the body’s center of mass (COM) and base of support (BOS). FSR-based dynamic gait stability has been used to evaluate the fall risk.Research questionHow does front load carriage affect dynamic gait stability, step length, and trunk angle among young adults during treadmill walking?MethodsIn this between-subject design study, 30 healthy young adults were evenly randomized into three load groups (0%, 10%, or 20% of body weight). Participants carried their assigned load while walking on a treadmill at a speed of 1.2 m/s. Body kinematics were collected during treadmill walking. Dynamic gait stability (the primary variable) was calculated for two gait events: touchdown and liftoff. Step length and trunk angle were measured as secondary variables. One-way analysis of variance was conducted to detect any group-related differences for all variables. Post-hoc analysis with Bonferroni correction was performed when main group differences were found.ResultsNo significant differences but medium to large effect sizes were found between groups for dynamic gait stability at touchdown (p = 0.194, η2 = 0.114) and liftoff (p = 0.122, η2 = 0.139). Trunk angle significantly increased (indicating backward lean) with the front load at touchdown (p < 0.001, η2 = 0.648) and liftoff (p < 0.001, η2 = 0.543). No significant between-group difference was found related to the step length (p = 0.344, η2 = 0.076).SignificanceCarrying a front load during walking significantly alters the trunk orientation and may change the COM-BOS kinematic relationship and, therefore, fall risk. The findings could inform the design of future studies focusing on the impact of anterior load carriage on fall risk during different locomotion. 相似文献
8.
9.
10.