Effect of internal diffusion on the apparent stability of nonuniformly distributed biocatalysts

1986 ◽  
Vol 3 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Bong Hyun Chung ◽  
Ho Nam Chang
Keyword(s):  
Internal Diffusion ◽  
Apparent Stability

Modeling Trienzyme Biosensor at Internal Diffusion Limitation

2004 ◽  
Vol 9 (2) ◽  
pp. 139-144 ◽  
Author(s):  
J. Kulys
Keyword(s):  
Immobilized Enzymes ◽  
Internal Diffusion ◽  
Significant Response ◽  
Diffusion Limitation ◽  
Enzyme Reactions ◽  
Substrate Conversion ◽  
Apparent Stability ◽  
Biosensor Response

A model of biosensor containing three immobilized enzymes utilizing consecutive substrate conversion in the chain was developed. The modeling was performed at an internal diffusion limitation and a steadystate condition. The calculations showed that significant response of biosensors was produced if diffusion modules were larger than 1 for all enzyme reactions. Due to diffusion limitation the apparent stability of biosensor response increased many times in comparison to stability of the most labile enzyme of the chain.

Visualization of Invasion into the Body and Internal Diffusion of Nanoparticles

2008 ◽  
Vol 396-398 ◽  
pp. 569-572
Author(s):  
Fumio Watari ◽  
Shigeaki Abe ◽  
I.D. Rosca ◽  
Atsuro Yokoyama ◽  
Motohiro Uo ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Fluorescent Microscopy ◽  
The Body ◽  
Internal Diffusion ◽  
Whole Body ◽  
X Ray ◽  
Body Level ◽  
Organ Level ◽  
Level 2 ◽  
Internal Body

Nanoparticles may invade directly into the internal body through the respiratory or digestive system and diffuse inside body. The behavior of nanoparticles in the internal body is also essential to comprehend for the realization of DDS. Thus it is necessary to reveal the internal dynamics for the proper treatments and biomedical applications of nanoparticles. In the present study the plural methods with different principles such as X-ray scanning analytical microscope (XSAM), MRI and Fluorescent microscopy were applied to enable the observation of the internal diffusion of micro/nanoparticles in the (1) whole body level, (2) inner organ level and (3) tissue and intracellular level. Chemical analysis was also done by ICP-AES for organs and compared with the results of XSAM mapping.

scholarly journals Biological scaling in green algae: the role of cell size and geometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helena Bestová ◽  
Jules Segrestin ◽  
Klaus von Schwartzenberg ◽  
Pavel Škaloud ◽  
Thomas Lenormand ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Population Growth Rate ◽  
Internal Diffusion ◽  
Scaling Exponent ◽  
Power Scaling ◽  
Nutrient Distribution ◽  
Metabolic Scaling ◽  
Key Factor ◽  
Size And Morphology

AbstractThe Metabolic Scaling Theory (MST), hypothesizes limitations of resource-transport networks in organisms and predicts their optimization into fractal-like structures. As a result, the relationship between population growth rate and body size should follow a cross-species universal quarter-power scaling. However, the universality of metabolic scaling has been challenged, particularly across transitions from bacteria to protists to multicellulars. The population growth rate of unicellulars should be constrained by external diffusion, ruling nutrient uptake, and internal diffusion, operating nutrient distribution. Both constraints intensify with increasing size possibly leading to shifting in the scaling exponent. We focused on unicellular algae Micrasterias. Large size and fractal-like morphology make this species a transitional group between unicellular and multicellular organisms in the evolution of allometry. We tested MST predictions using measurements of growth rate, size, and morphology-related traits. We showed that growth scaling of Micrasterias follows MST predictions, reflecting constraints by internal diffusion transport. Cell fractality and density decrease led to a proportional increase in surface area with body mass relaxing external constraints. Complex allometric optimization enables to maintain quarter-power scaling of population growth rate even with a large unicellular plan. Overall, our findings support fractality as a key factor in the evolution of biological scaling.

Studies on the Coordination Reaction of VO2+ and Tannic Acid in the Tannin Extract Desulfurization

2012 ◽  
Vol 239-240 ◽  
pp. 1573-1576
Author(s):  
Zhu Qing Gao ◽  
Xiao Dong Cai ◽  
Kai Cheng Ling
Keyword(s):  
Stability Constants ◽  
Tannic Acid ◽  
Ph Value ◽  
Protonation Constants ◽  
Conditional Stability ◽  
Tannin Extract ◽  
Acid Effect ◽  
Different Temperatures ◽  
The Stability ◽  
Apparent Stability

At different temperatures, the protonation constants of tannic acid and the complex apparent stability constants between tannic acid and VO2+ were determined by using pH potentimetric method. The results showed that the protonation constants and the complex apparent stability constants slightly decreased with the raising temperature. In accordance with the pH value in the tannin extract technology, the conditional stability constants of the complex were calculated on the basis of the acid effect of tannic acid and the hydrolysis effect of VO2+. It was found that pH greatly affected the stability constants of the complex , so pH must be strictly controlled in the tannin extract technology.

The Politics of Instability in Ecuador: The Overthrow of the President, 1961

1975 ◽  
Vol 7 (1) ◽  
pp. 109-133 ◽  
Author(s):  
Peter Pyne
Keyword(s):  
Military Intervention ◽  
Political History ◽  
Political Life ◽  
The Republic ◽  
The Military ◽  
Coups D'etat ◽  
Apparent Stability ◽  
Jose Maria Velasco Ibarra

On 7 November 1961, a crucial date in modern Ecuadorian political history, Dr José María Velasco Ibarra, constitutional President of the Republic of Ecuador, was deposed from his high office and sought refuge in the Mexican Embassy. The apparent stability that had characterized the country's political life since 1948 was shattered. The pattern of politics since November 1961 is similar in many respects to that which occurred in the decades between the two World Wars. Coups d'état, dictatorships and military juntas are political phenomena common to both periods. The military intervention which to Velasco's dewnfall in 1961 re-established a convention which had been dormant since 1947.

scholarly journals Apparent Stability and Subtle Change in Surface and Subsurface Soil Carbon and Nitrogen under a Long-Term Fertilizer Gradient

2017 ◽  
Vol 81 (2) ◽  
pp. 310-321 ◽  
Author(s):  
Sarah M. Collier ◽  
Matthew D. Ruark ◽  
Mack R. Naber ◽  
Todd W. Andraski ◽  
Michael D. Casler
Keyword(s):  
Soil Carbon ◽  
Subtle Change ◽  
Carbon And Nitrogen ◽  
Soil Carbon And Nitrogen ◽  
Subsurface Soil ◽  
Apparent Stability
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