全文获取类型
收费全文 | 11053篇 |
免费 | 998篇 |
国内免费 | 221篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 131篇 |
妇产科学 | 54篇 |
基础医学 | 1594篇 |
口腔科学 | 430篇 |
临床医学 | 1290篇 |
内科学 | 1300篇 |
皮肤病学 | 713篇 |
神经病学 | 874篇 |
特种医学 | 565篇 |
外国民族医学 | 2篇 |
外科学 | 1045篇 |
综合类 | 1062篇 |
现状与发展 | 1篇 |
预防医学 | 561篇 |
眼科学 | 659篇 |
药学 | 791篇 |
10篇 | |
中国医学 | 311篇 |
肿瘤学 | 783篇 |
出版年
2024年 | 20篇 |
2023年 | 240篇 |
2022年 | 216篇 |
2021年 | 484篇 |
2020年 | 460篇 |
2019年 | 421篇 |
2018年 | 450篇 |
2017年 | 475篇 |
2016年 | 410篇 |
2015年 | 448篇 |
2014年 | 747篇 |
2013年 | 853篇 |
2012年 | 634篇 |
2011年 | 666篇 |
2010年 | 553篇 |
2009年 | 489篇 |
2008年 | 484篇 |
2007年 | 534篇 |
2006年 | 419篇 |
2005年 | 336篇 |
2004年 | 305篇 |
2003年 | 292篇 |
2002年 | 229篇 |
2001年 | 209篇 |
2000年 | 155篇 |
1999年 | 144篇 |
1998年 | 121篇 |
1997年 | 123篇 |
1996年 | 84篇 |
1995年 | 103篇 |
1994年 | 84篇 |
1993年 | 75篇 |
1992年 | 75篇 |
1991年 | 84篇 |
1990年 | 70篇 |
1989年 | 53篇 |
1988年 | 77篇 |
1987年 | 64篇 |
1986年 | 54篇 |
1985年 | 84篇 |
1984年 | 76篇 |
1983年 | 57篇 |
1982年 | 76篇 |
1981年 | 52篇 |
1980年 | 48篇 |
1979年 | 35篇 |
1978年 | 26篇 |
1977年 | 20篇 |
1976年 | 23篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 640 毫秒
71.
MIA SON JEONG‐OK KONG SANG‐BAEK KOH JAEYOUNG KIM MIKKO HÄRMÄ 《Journal of sleep research》2008,17(4):385-394
We investigated the effects of 12‐hour shift work for five to seven consecutive days and overtime on the prevalence of severe sleepiness in the automobile industry in Korea. [Correction added after online publication 28 Nov: Opening sentence of the summary has been rephrased for better clarity.] A total of 288 randomly selected male workers from two automobile factories were selected and investigated using questionnaires and sleep‐wake diaries in South Korea. The prevalence of severe sleepiness at work [i.e. Karolinska Sleepiness Scale (KSS) score of 7 or higher] was modeled using marginal logistic regression and included theoretical risk factors related to working hours and potential confounding factors related to socio‐economic status, work demands, and health behaviors. Factors related to working hours increased the risk for severe sleepiness at the end of the shift in the following order: the night shift [odds ratio (OR): 4.7; 95% confidence interval (CI): 3.6–6.0)], daily overtime (OR: 2.2; 95% CI: 1.7–2.9), weekly overtime (OR: 1.6; 95% CI: 1.0–2.6), and night overtime (OR: 1.6; 95% CI: 0.8–3.0). Long working hours and shift work had a significant interactive effect for severe sleepiness at work. Night shift workers who worked for 12 h or more a day were exposed to a risk of severe sleepiness that was 7.5 times greater than day shift workers who worked less than 11 h. Night shifts and long working hours were the main risk factors for severe sleepiness among automobile factory workers in Korea. Night shifts and long working hours have a high degree of interactive effects resulting in severe sleepiness at work, which highlight the need for immediate measures to address these characteristics among South Korean labor force patterns. 相似文献
72.
73.
I. V. Stupin A. I. Novokshonov A. M. Domborvskii G. G. Belous M. Yu. Ivanov 《Bulletin of experimental biology and medicine》1990,110(4):1407-1409
Department of Experimental Surgery, Interfaculty Laboratory Complex, and Department of Clinical Laboratory Diagnosis, Postgraduate Medical Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 10, pp. 413–145, October, 1990. 相似文献
74.
75.
76.
OBJECTIVE: We examined sleep, daytime sleepiness and the ability to stay awake during the day in patients affected with retinitis pigmentosa (RP), to further delineate the role of photoreceptors in the circadian cycle. METHODS: Twelve individuals diagnosed with RP (40 +/- 8 years) And 12 normally sighted healthy individuals (39 +/- 7 years) matched for age, body mass index (BMI) and sex were selected for the study. Participants had their sleep recorded on two consecutive nights and were monitored on the two following days. On the first day, their ability to stay awake and on the second, their sleep propensity were assessed using the Maintenance of Wakefulness Test (MWT) and the Multiple Sleep Latency Test (MSLT), respectively. Self-report measures were obtained using the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), and the Toronto Hospital Alertness Test (THAT). RESULTS: Subjective daytime sleepiness (ESS: 9 +/- 5 vs. 6 +/- 4, P=0.053) and objectively measured sleep propensity (MSLT: 10 +/- 5 vs. 17 +/- 3 min, P < 0.000) were significantly higher in RP patients than controls, whilst their alertness (THAT: 29 +/- 9 vs. 38 +/- 7, P=0.016) and ability to stay awake (MWT: 21 +/- 9 vs. 29 +/- 2 min, P=0.006) were significantly reduced. Retinitis pigmentosa participants had more disturbed nighttime sleep, with significantly more awakenings (arousal index: 14 +/- 8 vs. 8 +/- 6 h, P=0.039), and tended to have less rapid eye movement (REM) sleep (19 +/- 5 vs. 22 +/- 3%, P=0.094). CONCLUSION: Patients with RP have increased daytime sleepiness, reduced alertness and more disturbed nighttime sleep of poorer quality than their normally sighted counterparts, suggesting an influence of photoreceptor degeneration on the circadian cycle. 相似文献
77.
Y. Epstein J. Rosenblum R. Burstein M. N. Sawka 《European journal of applied physiology》1988,57(2):243-247
Summary The present study was undertaken to examine the energy cost of prolonged walking while carrying a backpack load. Six trained subjects were tested while walking for 120 min on a treadmill at a speed of 1.25 m · s–1 and 5% elevation with a well fitted backpack load of 25 and 40 kg alternately. Carrying 40 kg elicited a significantly higher (p<0.01) enery cost than 25 kg. Furthermore, whereas carrying 25 kg resulted in a constant energy cost, 40 kg yielded a highly significant (p<0.05) increase in energy cost over time. The study implies that increase in load causes physical fatigue, once work intensity is higher than 50% maximal work capacity. This is probably due to altered locomotion biomechanics which in turn lead to the increase in energy cost. Finally, the prediction model which estimates energy cost while carrying loads should be used with some caution when applied to heavy loads and long duration of exercise, since it might underestimate the acutal enery cost. 相似文献
78.
目的比较研究He-Ne激光、微波、红外线和TDP灯照射对高血粘的影响,探索能否利用He-Ne激光、微波、红外线和TDP灯照射降低血液粘度,改善血循环.方法每份血样等分5份,1份作对照,对另外4份分别作He-Ne激光、微波、红外线和TDP灯照射处理.结果高血粘血样经He-Ne激光、微波、红外线和TDP灯照射作用后,全血表观粘度η降低(P<0.01)、红细胞电泳率EPM加快(P<0.01),血沉速度ESR提高(P<0.01),一氧化氮、全血黏度、全血还原黏度降低(P<0.01).红细胞变形指数降低(P<0.01),红细胞聚集时间增加(P<0.01),红细胞压积降低(P<0.01),纤维蛋白降低(P<0.01).结论He-Ne激光、微波、红外线和TDP灯照射能改善高血粘血样的流变特性.而且激光效果最好,依次是TDP灯、微波和红外线.进一步了解物理与临床治疗的密切关系. 相似文献
79.
黑光灯对银屑病血液流变性的影响与疗效 总被引:1,自引:1,他引:1
黑光灯对银屑病血液流变性的影响与疗效刘夕茹1李海生2于霖2银屑病是一种常见、易复发的慢性炎症性皮肤病,人们曾对其发病机制以及治疗有过大量探索。本文通过使用黑光灯对其治疗前后的血液流变学指标的检测和综合分析,对该病作进一步探讨。1资料与方法1.1病例选... 相似文献