全文获取类型
收费全文 | 668篇 |
免费 | 72篇 |
出版年
2022年 | 9篇 |
2021年 | 15篇 |
2020年 | 10篇 |
2019年 | 10篇 |
2018年 | 4篇 |
2017年 | 16篇 |
2016年 | 19篇 |
2015年 | 34篇 |
2014年 | 33篇 |
2013年 | 35篇 |
2012年 | 48篇 |
2011年 | 52篇 |
2010年 | 30篇 |
2009年 | 14篇 |
2008年 | 39篇 |
2007年 | 32篇 |
2006年 | 30篇 |
2005年 | 23篇 |
2004年 | 25篇 |
2003年 | 29篇 |
2002年 | 30篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 18篇 |
1998年 | 13篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 9篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1984年 | 8篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1969年 | 3篇 |
1968年 | 4篇 |
1966年 | 4篇 |
1965年 | 3篇 |
1963年 | 4篇 |
1961年 | 4篇 |
1956年 | 2篇 |
排序方式: 共有740条查询结果,搜索用时 359 毫秒
731.
732.
733.
Patrick G. Negulescu Derrick Risner Edward S. Spang Daniel Sumner David Block Somen Nandi Karen A. McDonald 《Biotechnology and bioengineering》2023,120(4):1055-1067
Increases in global meat demands cannot be sustainably met with current methods of livestock farming, which has a substantial impact on greenhouse gas emissions, land use, water consumption, and farm animal welfare. Cultivated meat is a rapidly advancing technology that produces meat products by proliferating and differentiating animal stem cells in large bioreactors, avoiding conventional live-animal farming. While many companies are working in this area, there is a lack of existing infrastructure and experience at commercial scale, resulting in many technical bottlenecks such as scale-up of cell culture and media availability and costs. In this study, we evaluate theoretical cultivated beef production facilities with the goal of envisioning an industry with multiple facilities to produce in total 100,000,000 kg of cultured beef per year or ~0.14% of the annual global beef production. Using the computer-aided process design software, SuperPro Designer®, facilities are modeled to create a comprehensive analysis to highlight improvements that can lower the cost of such a production system and allow cultivated meat products to be competitive. Three facility scenarios are presented with different sized production reactors; ~42,000 L stirred tank bioreactor (STR) with a base case cost of goods sold (COGS) of $35/kg, ~211,000 L STR with a COGS of $25/kg, and ~262,000 L airlift reactor (ALR) with a COGS of $17/kg. This study outlines how advances in scaled up bioreactors, alternative bioreactor designs, and decreased media costs are necessary for commercialization of cultured meat products. 相似文献
734.
Xavier Martini Lanette Sobel Derrick Conover Agenor Mafra‐Neto Jason Smith 《Agricultural and Forest Entomology》2020,22(1):83-91
- Laurel wilt is a disease that has caused extensive mortality of redbay Persea borbonia in the southeastern U.S.A. The redbay ambrosia beetle Xyleborus glabratus is the vector of the causal agent of laurel wilt, the fungus Raffaelea lauricola.
- We tested two potential repellents to the redbay ambrosia beetle, verbenone and methyl salicylate (MeSA) in an 8‐month large‐scale experiment conducted in three locations in Florida. In each location, redbay trees were treated with a single or double application of SPLAT (Specialized Pheromone and Lure Application Technology; ISCA Technologies, Riverside, California) verbenone, as well as SPLAT with a 1:2 mix of MeSA and verbenone.
- The MeSA + verbenone mixes did not reduce beetle captures compared with the control treatment, whereas SPLAT verbenone alone significantly reduced the number of beetles captured on sticky traps placed on redbay trees in the three locations. The reduction of beetle capture was similar regardless of one or two treatments of SPLAT verbenone. The reduction of tree death with the SPLAT verbenone treatment was not statistically significant.
- The results of the present study suggest that trunk application of verbenone can reduce landing rates of the redbay ambrosia beetle on live redbay trees and shows promise for use in an integrated pest management strategy against laurel wilt.
735.
Derrick J. Martin 《BMJ (Clinical research ed.)》1944,2(4372):531-532
736.
Impact of Substrate Glycoside Linkage and Elemental Sulfur on Bioenergetics of and Hydrogen Production by the Hyperthermophilic Archaeon Pyrococcus furiosus
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
737.
738.
Physical force has emerged as a key regulator of tissue homeostasis, and plays an important role in embryogenesis, tissue regeneration, and disease progression. Currently, the details of protein interactions under elevated physical stress are largely missing, therefore, preventing the fundamental, molecular understanding of mechano-transduction. This is in part due to the difficulty isolating large quantities of cell lysates exposed to force-bearing conditions for biochemical analysis. We designed a simple, easy-to-fabricate, large-scale cell stretch device for the analysis of force-sensitive cell responses. Using proximal biotinylation (BioID) analysis or phospho-specific antibodies, we detected force-sensitive biochemical changes in cells exposed to prolonged cyclic substrate stretch. For example, using promiscuous biotin ligase BirA* tagged α-catenin, the biotinylation of myosin IIA increased with stretch, suggesting the close proximity of myosin IIA to α-catenin under a force bearing condition. Furthermore, using phospho-specific antibodies, Akt phosphorylation was reduced upon stretch while Src phosphorylation was unchanged. Interestingly, phosphorylation of GSK3β, a downstream effector of Akt pathway, was also reduced with stretch, while the phosphorylation of other Akt effectors was unchanged. These data suggest that the Akt-GSK3β pathway is force-sensitive. This simple cell stretch device enables biochemical analysis of force-sensitive responses and has potential to uncover molecules underlying mechano-transduction. 相似文献
739.
740.
A comparison of the wild-type firefly luciferase reporter gene to a codon-modified gene, available from Promega, demonstrates
that in tobacco cell cultures, an increase in G+C content of 1.8%, as a consequence of 36 A/T→G/C synonymous codon alterations
and removal of the lysosomal targeting sequence, has no significant effect on expression. In maize Black Mexican Sweet cells
and wheat scutellum, increases in activity of 14- to 23-fold and 53- to 59-fold, respectively, are obtained using the codon-modified
luciferase with the UBI1 promoter and its leader intron. The observed increase in luc+ expression is most likely a consequence
of differences in codon usage reflecting tRNA abundance rather than an increase in the efficiency of intron splicing resulting
from the small increase in the G+C content of the coding sequence. This difference in light emission between the wild-type
and codon-modified luciferases can be clearly visualised in a low-light imaging camera, making the latter a much more sensitive
and useful reporter gene for detecting luciferase activity in vivo.
Received: 7 September 1996 / Revision received: 28 November 1996 / Accepted: 6 December 1996 相似文献