scholarly journals A microfluidic 3D hepatocyte chip for hepatotoxicity testing of nanoparticles

Nanomedicine ◽  
2019 ◽  
Vol 14 (16) ◽  
pp. 2209-2226 ◽  
Author(s):  
Lei Li ◽  
Kurtulus Gokduman ◽  
Aslihan Gokaltun ◽  
Martin L Yarmush ◽  
Osman Berk Usta
Keyword(s):  
Physiological Responses ◽  
Superparamagnetic Iron Oxide ◽  
Rat Hepatocytes ◽  
Oxide Nanoparticles ◽  
Proof Of Concept ◽  
Short Term ◽  
Highly Sensitive ◽  
First Results ◽  
Potential Hepatotoxicity

Aim: To develop a practical microfluidic 3D hepatocyte chip for hepatotoxicity testing of nanoparticles using proof of concept studies providing first results of the potential hepatotoxicity of superparamagnetic iron oxide nanoparticles (SPION) under microfluidic conditions. Methods: A microfluidic 3D hepatocyte chip with three material layers, which contains primary rat hepatocytes, has been fabricated and tested using different concentrations (50, 100 and 200 μg/ml) of SPION in 3-day (short-term) and 1-week (long-term) cultures. Results: Compared with standard well plates, the hepatocyte chip with flow provided comparable viability and significantly higher liver-specific functions, up to 1 week. In addition, the chip recapitulates the key physiological responses in the hepatotoxicity of SPION. Conclusion: Thus, the developed 3D hepatocyte chip is a robust and highly sensitive platform for investigating hepatotoxicity profiles of nanoparticles.

scholarly journals Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age

2014 ◽  
Vol 8 (1) ◽  
pp. 1257-1278
Author(s):  
S. A. Khan ◽  
K. K. Kjeldsen ◽  
K. H. Kjær ◽  
S. Bevan ◽  
A. Luckman ◽  
...  
Keyword(s):  
Mass Balance ◽  
Little Ice Age ◽  
Initial Conditions ◽  
Ice Age ◽  
Short Term ◽  
Episodic Events ◽  
Highly Sensitive ◽  
Decadal Scale ◽  
Speed Up

Abstract. Observations over the past decade show significant ice loss associated with the speed-up of glaciers in southeast Greenland from 2003, followed by a deceleration from 2006. These short-term, episodic, dynamic perturbations have a major impact on the mass balance at the decadal scale. To improve the projection of future sea level rise, a long-term data record that reveals the mass balance beyond such episodic events is required. Here, we extend the observational record of marginal thinning of Helheim glacier (HG) and Kangerdlugssuaq glacier (KG) from 10 to more than 150 yr. We show that although the frontal portion of HG thinned by more than 100 m between 2003 and 2006, it thickened by more than 50 m during the previous two decades. In contrast, KG was stable from 1981 to 1998 and experienced major thinning only after 2003. Extending the record back to the end of the Little Ice Age (ca. 1850) shows no significant thinning of HG from 1850 to 1981, while KG underwent substantial thinning of ~265 m. Analyses of their sensitivity to sub-surface water temperature anomalies and variations in air temperature suggest that both HG and KG are highly sensitive to short-term atmospheric and ocean forcing, and respond very quickly to small fluctuations. At century time-scales, however, multiple external parameters (e.g. outlet shape) dominate the mass change. These findings undermine attempts to use measurements over the last decade as initial conditions to project future dynamic ice loss.

Behavioral, plastic, and evolutionary responses to a changing world

2018 ◽  
Author(s):  
Wolf U. Blanckenhorn
Keyword(s):  
Climate Change ◽  
Life History ◽  
Environmental Change ◽  
Physiological Responses ◽  
Short Term ◽  
Temporal Scales ◽  
Evolutionary Response ◽  
Physiological Adjustments ◽  
Changing World

Organisms can respond to environmental change by modifying their behavior to obtain an instant response, through short-term phenotypically plastic, often physiological, adjustments, and/or by adapting their life history through a more long-term evolutionary response. Behavioural and physiological responses, in fact, can occur at all these three temporal scales. Examples of behaviors so affected include congregation, dispersal, foraging, migration, or mating. Such responses have consequences at the population and community levels, and ultimately for the evolution of species. This chapter discusses insect examples of these kinds, with an emphasis on human-induced factors, such as (primarily) climate change, pollution, fragmentation, and urbanization.

scholarly journals Using A Dynamic Taylor-Type Rule To Examine The Behavior Of Bond Yields: Some International Evidence

2011 ◽  
Vol 8 (3) ◽  
Author(s):  
William L. Seyfried
Keyword(s):  
Output Gap ◽  
Bond Yields ◽  
Short Term ◽  
Government Bonds ◽  
International Evidence ◽  
Highly Sensitive ◽  
Similarities And Differences ◽  
Dynamic Version ◽  
Insight Into

A dynamic version of Taylors rule is applied to the analysis of the behavior of short-term and long-term government bonds in different nations. Results indicate that long-term yields are highly sensitive to inflationary expectations, but support was mixed for short-term maturities. Evidence suggests that short-term rates are more responsive to the output gap than long-term rates for all the countries considered. Taylors rule appears to provide insight into understanding similarities and differences in the behavior of interest rate on government bonds of different maturities in the countries studied.

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