全文获取类型
收费全文 | 15711篇 |
免费 | 1285篇 |
国内免费 | 286篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 1491篇 |
妇产科学 | 951篇 |
基础医学 | 1251篇 |
口腔科学 | 170篇 |
临床医学 | 1428篇 |
内科学 | 2085篇 |
皮肤病学 | 51篇 |
神经病学 | 830篇 |
特种医学 | 261篇 |
外科学 | 1114篇 |
综合类 | 1656篇 |
一般理论 | 1篇 |
预防医学 | 3291篇 |
眼科学 | 118篇 |
药学 | 1746篇 |
5篇 | |
中国医学 | 447篇 |
肿瘤学 | 359篇 |
出版年
2024年 | 53篇 |
2023年 | 277篇 |
2022年 | 593篇 |
2021年 | 703篇 |
2020年 | 539篇 |
2019年 | 627篇 |
2018年 | 552篇 |
2017年 | 597篇 |
2016年 | 559篇 |
2015年 | 556篇 |
2014年 | 995篇 |
2013年 | 1325篇 |
2012年 | 851篇 |
2011年 | 964篇 |
2010年 | 763篇 |
2009年 | 710篇 |
2008年 | 797篇 |
2007年 | 727篇 |
2006年 | 595篇 |
2005年 | 557篇 |
2004年 | 454篇 |
2003年 | 429篇 |
2002年 | 332篇 |
2001年 | 290篇 |
2000年 | 235篇 |
1999年 | 191篇 |
1998年 | 171篇 |
1997年 | 140篇 |
1996年 | 121篇 |
1995年 | 113篇 |
1994年 | 118篇 |
1993年 | 98篇 |
1992年 | 93篇 |
1991年 | 83篇 |
1990年 | 81篇 |
1989年 | 55篇 |
1988年 | 65篇 |
1987年 | 54篇 |
1986年 | 62篇 |
1985年 | 115篇 |
1984年 | 105篇 |
1983年 | 83篇 |
1982年 | 69篇 |
1981年 | 65篇 |
1980年 | 63篇 |
1979年 | 58篇 |
1978年 | 48篇 |
1977年 | 27篇 |
1976年 | 33篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
极低出生体重儿两种喂养效果观察 总被引:4,自引:0,他引:4
目的:探讨极低出生体重儿(VLBW)的早期微量持续鼻饲喂养(CNG)与间断鼻饲喂养(ING)的喂养耐受性及喂养效果.方法:将60例VLBW进行随机分组,CNG组起始奶量1-2ml/h,以后泵速增加1-2ml/h.ING组奶量以1-2ml/kg开始, 以后每天增加1-2ml/kg/次.所有VLBW均同时进行部分静脉营养,直至达到完全胃肠道喂养时间(FEF).对比两组喂养不耐受性、达到FEF、停止静脉补液时间及黄疸持续时间.结果:CNG组较ING组患儿发生腹胀、呕吐者明显减少(P<0.05),黄疸持续时间、吸吮动作出现时间及住院时间较对照组明显缩短(P<0.05),但两组体重增长情况统计学无差异(P>0.05).结论:CNG更适合VLBW的早期微量喂养. 相似文献
62.
目的探讨低分子肝素联合辛伐他汀治疗不稳定型心绞痛的疗效。方法将100例不稳定型心绞痛患者随机分为对照组50例和观察组50例。对照组仅采取常规治疗(硝酸酯类、β-受体阻滞剂、钙拮抗剂、阿司匹林等),观察组在常规治疗的基础上加用低分子肝素和辛伐他汀,观察比较各组的疗效。结果观察组总有效率为90.0%,对照组总有效率为60.0%,两组疗效比较差异有显著性意义(P〈0.05)。结论低分子肝素联合辛伐他汀治疗不稳定型心绞痛取得满意的疗效。 相似文献
63.
低分子肝素对急性脑梗塞的影响 总被引:2,自引:0,他引:2
为了探讨低分子肝素(LMWH)在脑梗塞应用中的安全性及实用性,采用随机单盲对照方法,对39例急性脑梗塞病人,予LMWH治疗,并与低分子右旋糖酐治疗进行比较。结果显示:LMWH组对不同程度患者的神经功能恢复程度明显优于低右组(P<001),LMWH组头颅CT扫描脑梗塞体积缩小的范围比对照组明显(P<005),LMWH不减少血小板数量及纤维蛋白量,不引起出血,可改善血液流变学,降低微循环总积分值。总有效率8718%。 相似文献
64.
A. A. Paul A. E. Black J. Evans T. J. Cole R. G. Whitehead 《Journal of human nutrition and dietetics》1988,1(6):437-450
Longitudinal measurements of breastmilk intake in 48 Cambridge infants showed that intake reached a peak of 824 g/24 h in boys and 741 g/24 h in girls in the third and fourth months, respectively. Regression analysis demonstrated that, in the early months, the infants' weight accounted for a major part of the variance in breastmilk intake. Infants in non-manual social classes received more breastmilk and started solids later than those in manual groups. In the early months weight gain showed a relative increase compared to growth standards, but later infancy was characterized by a progressive deceleration in weight and length gain. Adiposity, as measured by triceps skinfold thickness differed most markedly from growth charts and was only equivalent to the tenth standard centile at all ages. The lower skinfold thickness measurements are considered to be more appropriate to breastfed infants in general. 相似文献
65.
综述了低分子量肝素的化学和生物活性的不均一性,以及药理作用,药物动力学、临床应用等方面的差异。 相似文献
66.
NAOTO TAKAHASHI HIROSHI NISHIDA TOSHIHIKO ARAI YOSHIO KANEDA 《Pediatrics international》1995,37(3):341-346
Four infants with severe intrauterine growth retardation (IUGR) weighing less than 1000 g at birth developed heart failure and died in our unit, where heart failure of IUGR infants is the main reason of death in extremely low birth-weight infants. The causes of their heart failure are one of the main themes in current neonatal medicine. The subjects of this study were four small for gestational age infants; all died due to heart failure 5 to 10 days after birth. Microscopic specimens of hearts from autopsies were evaluated with respect to the following characteristics: thickness of myocardial fibers, maturation of nuclei, presence of dysgenesis or necrosis in myocardium, and amount of glycogen in the heart. Neither dysgenesis nor infarction of the heart was found but hypoplasia in myocardial fibers and decreased glycogen levels were observed. Maturation delay in myocytes' nuclei did not appear to be severe. We conclude that these infants' hearts failed to adapt to postnatal hemodynamic changes because of inadequate myocardial function and inadequate glycogen reserves. 相似文献
67.
68.
目的:建立测定生长激素(GH)在体生物活性的方法.方法:以去垂体大鼠体重增长(BWG)和胫骨骺软骨板宽度(TEW)为指标,观察动物性别、给药途径、次数和周期不同对效应的影响;同时进行4dBWG,6dBWG和6dTEW法,测定GH的效价(平行线3×3设计).结果:♀和♂sc和im给药以及每日给药1次和2次的BWG和TEW差异无显著意义.给药6d比给药4d引起较大的BWG和TEW(P<005).4dBWG法和6dBWG法在0020-0500IU·d-1有较好的λ值(00660和01747)和r值(09000和09237);4dBWG,6dBWG和6dTEW法测得rhGH的效价为46132,39829和48023IU/amp.6dBWG法有较小的λ值和较低的ARFL值.结论:可在同一组去垂体大鼠体内同时用4dBWG,6dBWG和6dTEW法测GH活性,以6dBWG法较好. 相似文献
69.
In recent decades, there has been a dramatic increase in unhealthy weight for both children and adults. The Canadian standard of living has changed in favour of more easily prepared, calorie-dense foods and sedentary practices. Many family characteristics have also changed over the past 50 years. More Canadian families are living in disadvantaged situations, forecasting a host of unhealthy behaviours and attitudes in adults. The poor are not only getting poorer, they are also becoming heavier. Children from disadvantaged families seem to be leading the trend in increasing prevalence of unhealthy weight. Because they live in neighbourhoods that are perceived as unsafe, these children are likely spending more time indoors. This is associated with watching more television, which not only displaces other forms of educational and active entertainment but also places them at risk of learning inaccurate information about proper eating. Social science research helps identify factors contributing most to the rise in excess weight within this population, thus providing essential clues for effective approaches to its eradication. 相似文献
70.
D. L. Smith J. M. Clarke D. E. Stableforth 《Journal of human nutrition and dietetics》1994,7(4):257-262
Fourteen adult patients (mean age 22.5 years, range 18–35) with cystic fibrosis undertook nocturnal nasogastric feeding for a mean period of 14.7 (range 6–18) months consuming an average of 1042 ml of a high energy feed on five nights of each week. Following this protocol all patients gained weight (mean weight gain 5.4 kg, range 2–17). For the group as a whole, lung function remained stable during the period of feeding; however a significant correlation between improvement in lung function and weight gain was demonstrated. Hyperglycaemia during feeding in this adult population was common (9/14, 64%) but was easily controlled with insulin therapy. 相似文献