全文获取类型
收费全文 | 3483026篇 |
免费 | 297545篇 |
国内免费 | 13927篇 |
专业分类
耳鼻咽喉 | 47683篇 |
儿科学 | 110421篇 |
妇产科学 | 88682篇 |
基础医学 | 553434篇 |
口腔科学 | 93384篇 |
临床医学 | 318025篇 |
内科学 | 616705篇 |
皮肤病学 | 89828篇 |
神经病学 | 300340篇 |
特种医学 | 138523篇 |
外国民族医学 | 299篇 |
外科学 | 536372篇 |
综合类 | 106413篇 |
现状与发展 | 24篇 |
一般理论 | 2333篇 |
预防医学 | 298428篇 |
眼科学 | 79243篇 |
药学 | 239876篇 |
24篇 | |
中国医学 | 9595篇 |
肿瘤学 | 164866篇 |
出版年
2021年 | 55314篇 |
2020年 | 35237篇 |
2019年 | 58307篇 |
2018年 | 71707篇 |
2017年 | 54640篇 |
2016年 | 60286篇 |
2015年 | 74355篇 |
2014年 | 108753篇 |
2013年 | 174023篇 |
2012年 | 94933篇 |
2011年 | 95283篇 |
2010年 | 117504篇 |
2009年 | 121717篇 |
2008年 | 82060篇 |
2007年 | 85622篇 |
2006年 | 96090篇 |
2005年 | 91717篇 |
2004年 | 93571篇 |
2003年 | 84293篇 |
2002年 | 73199篇 |
2001年 | 111255篇 |
2000年 | 104769篇 |
1999年 | 102337篇 |
1998年 | 66323篇 |
1997年 | 63898篇 |
1996年 | 62087篇 |
1995年 | 57816篇 |
1994年 | 51823篇 |
1993年 | 48422篇 |
1992年 | 73569篇 |
1991年 | 70291篇 |
1990年 | 66621篇 |
1989年 | 65178篇 |
1988年 | 60456篇 |
1987年 | 59105篇 |
1986年 | 55932篇 |
1985年 | 56023篇 |
1984年 | 50472篇 |
1983年 | 45803篇 |
1982年 | 42582篇 |
1981年 | 39996篇 |
1980年 | 37702篇 |
1979年 | 41806篇 |
1978年 | 36595篇 |
1977年 | 33134篇 |
1976年 | 30475篇 |
1975年 | 29065篇 |
1974年 | 30300篇 |
1973年 | 29052篇 |
1972年 | 27053篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Juvenile hypocalcemia provokes persistent electroencephalographic change in renally compromised rats
J J Lipman D L White P L Lawrence P E Teschan 《Journal of the American College of Nutrition》1988,7(6):453-460
In view of the putative involvement of calcium in uremic encephalopathy and the critical importance of this element in juvenile development, we examined the effect of temporary restriction of dietary calcium intake on serum chemistry and the quantitative electroencephalogram (Q.EEG) in unilaterally 3/4 nephrectomized juvenile male Sprague-Dawley rats. Animals were renally infarcted at 22-26 days of age (50-74 g) and placed on one of two isocaloric dietary regimens: powdered normal rat diet (ND, n = 25) or low calcium diet (LCD, n = 8) for 30 days. At this time, ND animals showed normal serum chemistries, whereas LCD rats were hypocalcemic and azotemic with significantly elevated blood urea nitrogen (BUN) and serum creatinine concentrations and reduced renal creatinine clearance values. All animals thereafter received ND for 25-34 further days, during which time chronic Q.EEG electrodes were implanted. At the end of the common ND feeding period, serum chemistry values were equal and normal in both groups. The average theta/alpha ratio (TAR) of the overnight Q.EEG was assessed for 3 days. We found that the TAR of previously LCD animals was significantly elevated compared with ND rats. This indicates an encephalopathic slowing of the background rhythm of these animals. We conclude that, following restoration of a transient uremic and hypocalcemic episode induced by LCD feeding, the Q.EEG background frequency of juvenile renally impaired rats was abnormally slow after 30 days of ND feeding. 相似文献
992.
993.
A 77-year-old man with a history of Buerger's disease developed an anterior ischemic optic neuropathy. This disease, while rare in the United States at the present time, is common in other parts of the world. None the less, this appears to be the first reported case of this type of optic neuropathy in a patient with documented Buerger's disease. A possible mechanism is suggested. 相似文献
994.
The clinical, radiologic, and histopathologic findings of a case of bilateral dacryops is reported in a 49-year-old man. The patient presented with cystic masses located in superior lateral orbits and underwent bilateral excisions of these without any postoperative complications. 相似文献
995.
996.
997.
998.
J. E. BLUNDELL 《Nutrition Bulletin》1988,13(1):29-38
Do brain systems exist which control not only increases or decreases in food intake, but also bring about specific changes in the size and distribution of meals consumed, alter the selection of particular macronutrients and adjust feeding responses to the perceived pleasantness (hedonic value) of the food? A cautious yes can be given to each of these questions. Moreover, since most experimental work has been carried out on the brains of animals, we can also ask how well these animal data relate to the human condition; given the methodological issues involved in making such inferences, the answer is remarkably well. 相似文献
999.
1000.
【目的】探讨地塞米松的用药方式对孕妇糖代谢的影响。【方法】对 1999年 9月至 2 0 0 1年 1月在本院住院的15 0名不同用药方式使用地塞米松促胎儿肺成熟的孕妇进行研究 ,在用药前及用药后 18~ 2 4h抽取肘前静脉血查空腹血糖、血浆C肽 ,糖负荷后 2h血糖、血浆C肽。【结果】使用地塞米松后 ,空腹血糖值、糖负荷后 2h血糖值、空腹C肽及糖负荷后 2hC肽值较用药前高 ;用药方式对母体空腹血糖值和空腹C肽值的影响差异无统计学意义 (P >0 0 5 ) ,对母体糖负荷后 2h血糖值和糖负荷后 2hC肽值的影响差异有统计学意义 (P <0 0 5 ) ;不同糖代谢状态的受试者使用地塞米松后 ,空腹C肽值、糖负荷后 2hC肽值的改变差异有统计学意义 (P <0 0 5 )。【结论】孕妇使用地塞米松促胎儿肺成熟对母体的糖代谢均有一定程度的影响 ,用药过程中和用药后需严密监测母体血糖和胎儿宫内状况 相似文献