全文获取类型
收费全文 | 105317篇 |
免费 | 8754篇 |
国内免费 | 6183篇 |
专业分类
耳鼻咽喉 | 1114篇 |
儿科学 | 1569篇 |
妇产科学 | 2317篇 |
基础医学 | 12479篇 |
口腔科学 | 1950篇 |
临床医学 | 14074篇 |
内科学 | 16663篇 |
皮肤病学 | 909篇 |
神经病学 | 5831篇 |
特种医学 | 3541篇 |
外国民族医学 | 42篇 |
外科学 | 11269篇 |
综合类 | 14845篇 |
现状与发展 | 23篇 |
一般理论 | 20篇 |
预防医学 | 6147篇 |
眼科学 | 2944篇 |
药学 | 10773篇 |
56篇 | |
中国医学 | 4852篇 |
肿瘤学 | 8836篇 |
出版年
2024年 | 280篇 |
2023年 | 1508篇 |
2022年 | 3818篇 |
2021年 | 5000篇 |
2020年 | 3536篇 |
2019年 | 3254篇 |
2018年 | 3562篇 |
2017年 | 2943篇 |
2016年 | 2856篇 |
2015年 | 4429篇 |
2014年 | 5636篇 |
2013年 | 5045篇 |
2012年 | 7576篇 |
2011年 | 8315篇 |
2010年 | 5034篇 |
2009年 | 3859篇 |
2008年 | 5332篇 |
2007年 | 5583篇 |
2006年 | 5453篇 |
2005年 | 5738篇 |
2004年 | 3857篇 |
2003年 | 3424篇 |
2002年 | 3020篇 |
2001年 | 2448篇 |
2000年 | 2660篇 |
1999年 | 2712篇 |
1998年 | 1585篇 |
1997年 | 1482篇 |
1996年 | 1315篇 |
1995年 | 1166篇 |
1994年 | 990篇 |
1993年 | 637篇 |
1992年 | 1002篇 |
1991年 | 806篇 |
1990年 | 685篇 |
1989年 | 600篇 |
1988年 | 594篇 |
1987年 | 531篇 |
1986年 | 421篇 |
1985年 | 330篇 |
1984年 | 208篇 |
1983年 | 159篇 |
1982年 | 85篇 |
1981年 | 98篇 |
1980年 | 83篇 |
1979年 | 115篇 |
1978年 | 54篇 |
1977年 | 56篇 |
1975年 | 44篇 |
1974年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
61.
Zhi-gang Wang Yi-dong Huang Ke-luo Cheng Xiao-bi Cai Zheng Wu Jian-dong Zhan 《第一军医大学学报》2004,24(3):345-6, 351
OBJECTIVE: To study how blood supply of the esophageal and gastric stumps influences the anastomotic healing after esophagogastrostomy in rabbits. METHODS: Twenty-seven New Zealand rabbits were randomly divided into 3 groups to receive esophagogastrostomy, followed by different procedures. Except for those in group I, all the rabbits were subjected to procedures of reducing the blood supply either of the esophageal or the gastric stump (group II and group III, respectively), followed by single-layer esophagogastric anastomoses using interrupted 5-0 polypropylene sutures. Ten days after operation, all the rats were killed and the anastomotic sites excised for measurement of the inner diameter, tensile strength, and hydroxyproline concentration. RESULTS: Healing of the esophagograstric anastomosis was obtained in all the rabbits but one with anastomotic leakage in group I and one with perforation of the gastric fundus in group III. The anastomotic inner diameters were similar in all the three groups, whereas the tensile strength and hydroxyproline concentration at the anastomoses decreased in group III in comparison with the other two groups (P<0.05) that had similar measurements (P>0.05). CONCLUSIONS: Extended length of the free esophageal stump does not significantly affect anastomotic healing as decrease of blood supply in the gastric stump. 相似文献
62.
1.5T超导磁共振制冷系统的工作原理及日常维护 总被引:1,自引:0,他引:1
介绍GE 1.5T超导磁共振制冷系统的组成和工作原理,讨论日常维护的要点及其必要性。 相似文献
63.
用放射免疫法测定产后40天和60天乳母血清泌乳素基础水平和吸吮后泌乳素最大反应性增值,发现其与乳母泌乳量、婴儿吸吮频率、吸吮时间之间均不存在正相关关系,推测引起泌乳素分泌除吸吮外,还存在其他机理。 相似文献
64.
65.
在1000人中统计白鼻毛发生率为36.4%,白发为26.1%,白须为7.5%,白眉为3.3%,白睫为1.6%。我们认为白鼻毛比白发等作为衰老的一项指标更有其代表性。白鼻毛发生率:男性(53.4%)高于女性(13.4%),知识分子(60.8%)高于工人(26.3%)及农民(26.4%),日本人高于中国人,差异显著。 相似文献
66.
持续压力超负荷对兔左心室细胞凋亡的影响 总被引:3,自引:1,他引:2
OBJECTIVE: To study the effect of chronic pressure overload on the apoptosis of the left ventricle myocytes in rabbits. METHODS: Rabbit models of chronic pressure overload-induced heart failure were prepared in which dynamic changes of apoptotic myocytes in the left ventricle were observed by way of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay. RESULTS: Only a few apoptotic cells was observed in the sham-operated group, while in the experimental group, the apoptotic left ventricle myocytes significantly increased after operation, presenting a peak level between day 3 and day 7. Seven days after the operation, the apoptotic myocytes began to decrease and till day 14, the apoptotic cell number had been smaller than that measured on day 1. When signs of heart failure set in, the apoptotic myocytes were again increased (P<0.001). CONCLUSION: During chronic pressure overload, myocyte apoptosis in the left ventricle is elevated at the early stages and undulates subsequently, with the peak occurring before hypertrophy is obvious. 相似文献
67.
68.
The biomechanical effects of disc injury on flexion-extension were investigated in nine fresh porcine functional spinal units. Under 12 N-m in extension and 6 N-m in flexion, the range of motion among intact specimens were 23.11 degrees -33.29 degrees (mean = 26.07 degrees , SD = 3.25 degrees ), which shifted to 28.04 degrees -38.46 degrees (mean = 31.69 degrees , SD = 3.50 degrees ) when discs were injured. Similarly, the neutral zones among intact and disc injured specimens were 4.88 degrees -12.75 degrees (mean = 9.32 degrees , SD = 2.60 degrees ) and 9.50 degrees -24.43 degrees (mean = 16.80 degrees , SD = 4.69 degrees ) respectively. To obviate the differences between tested specimens, the changes of neutral zone and the range of motion after disc injury were normalized and expressed as ratios as compared to the same items before disc injury. The neutral zone ratio ranged from 1.29 to 3.18 (mean = 1.87, SD = 0.55, p < 0.01). For range of motion, it ranged from 1.13 to 1.42 (mean = 1.22, SD = 0.09, p < 0.01). The change of flexibility coefficient, however, was statistically insignificant in either flexion or extension. The model presented defines the range of motion, the neutral zone as well as the flexibility coefficient under a specific load. It suggests that major spinal instability can be elicited by a minimum flexion-extension moment, as reflected by a profound change of the neutral zone, after disc injury. 相似文献
69.
There is little information concerning the effects of passive exercise training in healthy humans. This prompted an investigation to evaluate muscle activity and the associated changes in strength and lean body mass resulting from a passive exercise program. Twenty-eight healthy volunteers, aged 26 to 44 years, participated in this six-week study. Lean body mass changes were evaluated by tetrapolar bioelectric impedance measurements, strength changes by isokinetic strength evaluation, and muscle activity by surface EMG techniques. Reproducible muscle activity was recorded in all three muscles studied during two of three preselected exercises. This involuntary muscle activity was attributed to fusimotor and postural reflexes. No significant change (p greater than .05), however, occurred in muscle strength or lean body mass at the end of the six weeks. Lack of these physiologic changes in light of the documented muscle activity is attributed to insufficient training effect. 相似文献
70.
X M Huang 《Health services management research》1994,7(1):2-8
Patient waiting time in outpatient clinics is often the major reason for patients' complaints about their experiences of visiting outpatient clinics. Therefore, patient satisfaction with waiting time plays a crucial role in the process of health quality assurance or quality management. This paper reports the results of a survey on patient attitude towards waiting in an outpatient surgery clinic. Generally patients appear reasonably satisfied if they wait no more than 37 minutes when arriving on time, and no more than 63 minutes when late for appointments. Patients coming up to 15 minutes early are prepared to take full responsibility for the extra waiting caused, but the patients coming even earlier intend to be seen earlier and are only prepared to wait 15 minutes longer than otherwise. The potential applications of patient attitude towards waiting in the quality assurance process, ie setting up waiting time limits and designing patient dispatching rules, are also discussed. 相似文献