全文获取类型
收费全文 | 6399篇 |
免费 | 609篇 |
国内免费 | 3篇 |
出版年
2023年 | 25篇 |
2022年 | 55篇 |
2021年 | 123篇 |
2020年 | 65篇 |
2019年 | 85篇 |
2018年 | 109篇 |
2017年 | 99篇 |
2016年 | 165篇 |
2015年 | 279篇 |
2014年 | 318篇 |
2013年 | 403篇 |
2012年 | 432篇 |
2011年 | 479篇 |
2010年 | 284篇 |
2009年 | 267篇 |
2008年 | 388篇 |
2007年 | 380篇 |
2006年 | 316篇 |
2005年 | 336篇 |
2004年 | 315篇 |
2003年 | 325篇 |
2002年 | 314篇 |
2001年 | 56篇 |
2000年 | 34篇 |
1999年 | 58篇 |
1998年 | 82篇 |
1997年 | 53篇 |
1996年 | 54篇 |
1995年 | 39篇 |
1994年 | 46篇 |
1993年 | 49篇 |
1992年 | 45篇 |
1991年 | 37篇 |
1990年 | 30篇 |
1989年 | 36篇 |
1988年 | 29篇 |
1987年 | 36篇 |
1984年 | 23篇 |
1983年 | 29篇 |
1982年 | 39篇 |
1981年 | 27篇 |
1980年 | 27篇 |
1979年 | 32篇 |
1978年 | 35篇 |
1977年 | 26篇 |
1974年 | 30篇 |
1973年 | 26篇 |
1972年 | 33篇 |
1967年 | 28篇 |
1966年 | 21篇 |
排序方式: 共有7011条查询结果,搜索用时 296 毫秒
981.
Eric S. Goetzman John F. Alcorn Sivakama S. Bharathi Radha Uppala Kevin J. McHugh Beata Kosmider Rimei Chen Yi Y. Zuo Megan E. Beck Richard W. McKinney Helen Skilling Kristen R. Suhrie Anuradha Karunanidhi Renita Yeasted Chikara Otsubo Bryon Ellis Yulia Y. Tyurina Valerian E. Kagan Rama K. Mallampalli Jerry Vockley 《The Journal of biological chemistry》2014,289(15):10668-10679
Long-chain acyl-CoA dehydrogenase (LCAD) is a mitochondrial fatty acid oxidation enzyme whose expression in humans is low or absent in organs known to utilize fatty acids for energy such as heart, muscle, and liver. This study demonstrates localization of LCAD to human alveolar type II pneumocytes, which synthesize and secrete pulmonary surfactant. The physiological role of LCAD and the fatty acid oxidation pathway in lung was subsequently studied using LCAD knock-out mice. Lung fatty acid oxidation was reduced in LCAD−/− mice. LCAD−/− mice demonstrated reduced pulmonary compliance, but histological examination of lung tissue revealed no obvious signs of inflammation or pathology. The changes in lung mechanics were found to be due to pulmonary surfactant dysfunction. Large aggregate surfactant isolated from LCAD−/− mouse lavage fluid had significantly reduced phospholipid content as well as alterations in the acyl chain composition of phosphatidylcholine and phosphatidylglycerol. LCAD−/− surfactant demonstrated functional abnormalities when subjected to dynamic compression-expansion cycling on a constrained drop surfactometer. Serum albumin, which has been shown to degrade and inactivate pulmonary surfactant, was significantly increased in LCAD−/− lavage fluid, suggesting increased epithelial permeability. Finally, we identified two cases of sudden unexplained infant death where no lung LCAD antigen was detectable. Both infants were homozygous for an amino acid changing polymorphism (K333Q). These findings for the first time identify the fatty acid oxidation pathway and LCAD in particular as factors contributing to the pathophysiology of pulmonary disease. 相似文献
982.
Helen P Laburn Alida Faurie Kathleen Goelst Duncan Mitchell 《Journal of applied physiology》2002,92(2):802-808
We exposed Dorper-cross ewes at approximately 120-135 days of gestation to a hot (40 degrees C, 60% relative humidity) and a cold (4 degrees C, 90% relative humidity) environment and to treadmill exercise (2.1 km/h, 5 degrees gradient) and measured fetal lamb and ewe body temperatures using previously implanted abdominal radiotelemeters. When ewes were exposed to 2 h of heat or 30 min of exercise, body temperature rose less in the fetus than in the mother, such that the difference between fetal and maternal body temperature, on average 0.6 degrees C before the thermal stress, fell significantly by 0.54 +/- 0.06 degrees C (SE, n = 8) during heat exposure and by 0.21 +/- 0.08 degrees C (n = 7) during exercise. During 6 h of maternal exposure to cold, temperature fell significantly less in the fetus than in the ewe, and the difference between fetal and maternal body temperature rose to 1.16 +/- 0.26 degrees C (n = 9). Thermoregulatory strategies used by the pregnant ewe for thermoregulation during heat or cold exposure appear to protect the fetus from changes in its thermal environment. 相似文献
983.
984.
985.
986.
987.
Albert Jan van Hoek Nick Andrews Helen Campbell Gayatri Amirthalingam W. John Edmunds Elizabeth Miller 《PloS one》2013,8(10)
Insight into how humans interact helps further understanding of the transmission of infectious diseases. For diseases such as pertussis, infants are at particular risk for severe outcomes. To understand the contact pattern of infants, especially those too young to be vaccinated, we sent contact diaries to a representative sample of 1000 mothers in the United Kingdom. We received 115 responses with a total of 758 recorded contacts. The average number of daily contacts for an infant was 6.68 overall and 5.7 for those aged ≤10 weeks. Of the latter, 2.1 (37%) contacts were with non-household members and were >15 minutes duration, suggesting that a cocooning programme may miss a substantial proportion of exposures leading to disease transmission. The least contact was between adolescents and infants. Thus the impact of adolescent (pertussis) vaccination on infants would likely be limited, unless it reduces transmission to other age groups whose contact with infants is greater. 相似文献
988.
989.
Helen M. Cockerton Robert J. Vickerstaff Amanda Karlström Fiona Wilson Maria Sobczyk Joe Q. He Daniel J. Sargent Andy J. Passey Kirsty J. McLeary Katalin Pakozdi Nicola Harrison Maria Lumbreras-Martinez Laima Antanaviciute David W. Simpson Richard J. Harrison 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2018,131(9):1995-2007
990.