全文获取类型
收费全文 | 827篇 |
免费 | 41篇 |
专业分类
868篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 15篇 |
2021年 | 27篇 |
2020年 | 12篇 |
2019年 | 19篇 |
2018年 | 24篇 |
2017年 | 15篇 |
2016年 | 51篇 |
2015年 | 52篇 |
2014年 | 55篇 |
2013年 | 71篇 |
2012年 | 82篇 |
2011年 | 80篇 |
2010年 | 39篇 |
2009年 | 36篇 |
2008年 | 60篇 |
2007年 | 47篇 |
2006年 | 52篇 |
2005年 | 32篇 |
2004年 | 29篇 |
2003年 | 16篇 |
2002年 | 24篇 |
2001年 | 1篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1991年 | 3篇 |
排序方式: 共有868条查询结果,搜索用时 0 毫秒
861.
Gabriele Cerutti Yicheng Guo Tongqing Zhou Jason Gorman Myungjin Lee Micah Rapp Eswar R. Reddem Jian Yu Fabiana Bahna Jude Bimela Yaoxing Huang Phinikoula S. Katsamba Lihong Liu Manoj S. Nair Reda Rawi Adam S. Olia Pengfei Wang Baoshan Zhang Lawrence Shapiro 《Cell host & microbe》2021,29(5):819-833.e7
862.
863.
Stefania Pagliari Vladimir Vinarsky Fabiana Martino Ana Rubina Perestrelo Jorge Oliver De La Cruz Guido Caluori Jan Vrbsky Pamela Mozetic Antonio Pompeiano Andrea Zancla Sri Ganji Ranjani Petr Skladal Dan Kytyr Zbynk Zdrhal Gabriele Grassi Maurilio Sampaolesi Alberto Rainer Giancarlo Forte 《Cell death and differentiation》2021,28(4):1193
864.
865.
Xu Feng Matthew C. Fox Jason S. Reichenberg Fabiana C.P.S. Lopes Katherine R. Sebastian Andrew K. Dunn Mia K. Markey James W. Tunnell 《Journal of biophotonics》2020,13(2)
Spontaneous Raman micro‐spectroscopy has been demonstrated great potential in delineating tumor margins; however, it is limited by slow acquisition speed. We describe a superpixel acquisition approach that can expedite acquisition between ~×100 and ×10 000, as compared to point‐by‐point scanning by trading off spatial resolution. We present the first demonstration of superpixel acquisition on rapid discrimination of basal cell carcinoma tumor from eight patients undergoing Mohs micrographic surgery. Results have been demonstrated high discriminant power for tumor vs normal skin based on the biochemical differences between nucleus, collagen, keratin and ceramide. We further perform raster‐scanned superpixel Raman imaging on positive and negative margin samples. Our results indicate superpixel acquisition can facilitate the use of Raman microspectroscopy as a rapid and specific tool for tumor margin assessment. 相似文献
866.
Raffaele Saladino Claudia Crestini Fabiana Ciciriello Giovanna Costanzo Ernesto Di Mauro 《Origins of life and evolution of the biosphere》2006,36(5-6):523-531
Formamide NH2CHO chemistry provides a unitary frame into which several pieces of the origin-of-life puzzle may be adjusted. Synthetic processes
were uncovered which, starting from formamide and prebiotically easily available common catalysts, yield all the necessary
nucleic bases precursors, including acyclonucleosides. Formamide allows phosphorylations and trans-phosphorylations, favours
the micellar aggregation of surfactants and, most importantly, determines conditions in which the formation of nucleic polymers
is thermodynamically favoured. In the detected conditions, the phosphoester bonds are more stable in the polymeric than in
the monomeric form, thus allowing formation and survival of informational nucleic polymers.
Presented at: National Workshop on Astrobiology: Search for Life in the Solar System, Capri, Italy, 26 to 28 October, 2005. 相似文献
867.
Anapaula Sommer Vinagre Ana Paula Nunes do Amaral Fabiana Pinto Ribarcki Eliane Fraga da Silveira Eduardo Prico 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(4):514
The aim of this study was to analyze the seasonal variations of carbohydrate and lipid metabolism of the ghost crab Ocypode quadrata (Fabricius, 1787) on a sandy beach in the southern region of Brazil. Crabs and hemolymph samples were collected monthly in the field. Hepatopancreas, gills, gonads and claw muscles were used for glycogen determination. In males, blood glucose levels increased in the summer and in the winter. The glycogen values increased significantly in the hepatopancreas in the winter, but remained constant in the muscle, gonads and gills. In females, hemolymph glucose levels, glycogen values in the hepatopancreas and in the gills remained constant throughout the year; however, muscular glycogen increased in the spring and gonad glycogen decreased in the summer. Hemolymph triglyceride levels of males and females and total cholesterol of males decreased significantly in the spring. In females, a significant increase of total cholesterol levels was found in the winter. The findings suggest that in O. quadrata lipids seem to be an important reserve of energy used during reproduction, both in males and females, while glycogen may be used during periods of intense activity or fasting. 相似文献
868.
Fabiana Latorre 《Aerobiologia》1997,13(1):49-59
An atmospheric pollen survey and a periodical quantitative check of the flowering phases of trees were performed during 1993.
Most of specific flowering seasons lasted from 4 to 8 weeks. October is the month with the highest number of species in bloom.
Anemophylous species flower mainly in coincidence with the relatively low temperatures of late winter and early spring, while
the enthomophylous ones correlate with the high temperatures of late spring and summer. The anemophylous ‘community’ follow
a sigmoid pattern with respect to both the flowering development and the cumulative pollen concentration. Agreement between
floral phenophases and pollen counts were evaluated for 14 genera (27 species). Pollen data of anemophylous species coincide
fairly well with the phenological behaviour. Particular features must be taken into account to interpret this relationship. 相似文献