全文获取类型
收费全文 | 770篇 |
免费 | 37篇 |
出版年
2022年 | 11篇 |
2021年 | 26篇 |
2020年 | 16篇 |
2019年 | 22篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 25篇 |
2015年 | 38篇 |
2014年 | 41篇 |
2013年 | 48篇 |
2012年 | 56篇 |
2011年 | 60篇 |
2010年 | 45篇 |
2009年 | 38篇 |
2008年 | 35篇 |
2007年 | 40篇 |
2006年 | 40篇 |
2005年 | 21篇 |
2004年 | 20篇 |
2003年 | 17篇 |
2002年 | 15篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 11篇 |
1990年 | 10篇 |
1988年 | 5篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1978年 | 2篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1967年 | 3篇 |
1966年 | 3篇 |
1962年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有807条查询结果,搜索用时 15 毫秒
751.
752.
Elimination of laboratory ozone leads to a dramatic improvement in the reproducibility of microarray gene expression measurements 总被引:1,自引:0,他引:1
William S Branham Cathy D Melvin Tao Han Varsha G Desai Carrie L Moland Adam T Scully James C Fuscoe 《BMC biotechnology》2007,7(1):8
Background
Environmental ozone can rapidly degrade cyanine 5 (Cy5), a fluorescent dye commonly used in microarray gene expression studies. Cyanine 3 (Cy3) is much less affected by atmospheric ozone. Degradation of the Cy5 signal relative to the Cy3 signal in 2-color microarrays will adversely reduce the Cy5/Cy3 ratio resulting in unreliable microarray data. 相似文献753.
The aim of the study is to conduct an ecological risk assessment of accidental release of flowback water into freshwater body. Flowback water produced from the hydraulic fracturing process has a complex combination of high concentration of salts, organic compounds and metals. The toxicity of flowback water is assessed and an exposure assessment method for the inorganic constituents of the flowback water is developed. An equation for risk is derived to characterize the risk of the flowback water to the aquatic ecology. A case study is conducted for accidental release of hydraulic fracturing flowback water in Montney unconventional play trend in northern British Columbia. The flowback water quality data for 212 wells, including the concentrations of various salt ions, metal ions, and hydrogen sulfide, is collected for the assessment. The risk quotient is found to be 0.16 (<1), proving no significant risk to the aquatic ecosystem with 90% confidence. However, the overall results of the uncertainty and scenario analysis concludes that the risk to the ecology cannot be completely overlooked. Scenario analysis was done for monthly creek discharge and a relationship between risk quotient and the ratio of spill volume to the creek discharge was derived. 相似文献
754.
755.
756.
B. K. Binukumar Varsha Shukla Niranjana D. Amin Preethi Reddy Suzanne Skuntz Philip Grant Harish C. Pant 《Histochemistry and cell biology》2013,140(1):23-32
The neuronal cytoskeleton is tightly regulated by phosphorylation and dephosphorylation reactions mediated by numerous associated kinases, phosphatases and their regulators. Defects in the relative kinase and phosphatase activities and/or deregulation of compartment-specific phosphorylation result in neurodegenerative disorders. The largest family of cytoskeletal proteins in mammalian cells is the superfamily of intermediate filaments (IFs). The neurofilament (NF) proteins are the major IFs. Aggregated forms of hyperphosphorylated tau and phosphorylated NFs are found in pathological cell body accumulations in the central nervous system of patients suffering from Alzheimer’s disease, Parkinson’s disease, and Amyotrophic Lateral Sclerosis. The precise mechanisms for this compartment-specific phosphorylation of cytoskeletal proteins are not completely understood. In this review, we focus on the mechanisms of neurofilament phosphorylation in normal physiology and neurodegenerative diseases. We also address the recent breakthroughs in our understanding the role of different kinases and phosphatases involved in regulating the phosphorylation status of the NFs. In addition, special emphasis has been given to describe the role of phosphatases and Pin1 in phosphorylation of NFs. 相似文献
757.
Inhibition of influenza viral glycoprotein synthesis by sugars 总被引:14,自引:0,他引:14
758.
Pankaj Pandotra Mohd Kashif Husain Gandhi Ram Suphla Gupta Ajai Prakash Gupta 《Journal of plant biochemistry and biotechnology.》2014,23(2):211-216
Inter-retrotransposon amplified polymorphism (IRAP) and retrotransposon-microsatellite amplified polymorphism (REMAP) techniques were successfully applied, for the first time, to analyze genetic diversity among 92 ginger landraces collected from north-western Himalayan region of India. Six IRAP primer/combinations generated 75 loci with an average of 12 loci/primer displaying an overall polymorphism of 95.95 %. On the other hand, twenty five REMAP primer combinations produced 414 loci with 96.5 % polymorphism. IRAP showed maximum Rp (5.39) and PIC (0.28) values, while the same in REMAP was observed to be 10.92 and 0.34. Cluster analysis using Jaccard’s similarity coefficient for IRAP and REMAP data ranged between 0.21 to 1.0 and 0.21 to 0.85, respectively distinguishing all the genotypes with diverse genetic makup. The results also confirmed the presence of sukkula retrotransposon (RT6) in the ginger genome which effectively acted as genetic marker revealing high regional genetic diversity in the ginger gene pool. The study will help in giving insight to the genetic constitution of vegetatively grown ginger crop and for its further utilization in improvement, conservation and management programmes. 相似文献
759.
Varsha Jha Hitesh Tikariha Nishant A. Dafale Hemant J. Purohit 《World journal of microbiology & biotechnology》2018,34(11):172
Pho regulon is a highly evolved and conserved mechanism across the microbes to fulfil their phosphate need. In this study, 52 proteobacteria genomes were analyzed for the presence of phosphorus acquisition genes, their pattern of arrangement and copy numbers. The diverse genetic architecture of the Pho regulon genes indicates the evolutionary challenge of nutrient limitation, particularly phosphorus, faced by bacteria in their environment. The incongruence between the Pho regulon proteins phylogeny and species phylogeny along with the presence of additional copies of pstS and pstB genes, having cross similarity with other genera, suggest the possibility of horizontal gene transfer event. The substitution rate analysis and multiple sequence alignment of the Pho regulon proteins were analyzed to gain additional insight into the evolution of the Pho regulon system. This comprehensive study confirms that genes perform the regulatory function (phoBR) were vertically inherited, whereas interestingly, genes whose product involved in direct interaction with the environment (pstS) acquired by horizontal gene transfer. The substantial amino acid substitutions in PstS most likely contribute to the successful adaptation of bacteria in different ecological condition dealing with different phosphorus availability. The findings decipher the intelligence of the bacteria which enable them to carry out the targeted alteration of genes to cope up with the environmental condition. 相似文献
760.
Jayanta K. Ray Izhar Sami Gandhi K. Kar Bidhan C. Roy Nitosh K. Brahma 《Bioorganic & medicinal chemistry》1994,2(12):1417-1421
Some novel furogamma lactams have been synthesised by one step condensation of arylaminomalonates with substituted furyl acryloyl chlorides. The annulation of substituted monocyclic gammalactams followed by cyclization produced novel tricyclic furogamma lactams. Some of these furogammalactams are found to exhibit Gram-positive and Gram-negative antibacterial activity at very high concentrations. 相似文献