Role of native defects and the effects of metal additives on the kinetics of magnesium borohydride

2019 ◽  
Vol 21 (21) ◽  
pp. 11226-11233 ◽  
Author(s):  
Zhuonan Huang ◽  
Yuqi Wang ◽  
Di Wang ◽  
Fusheng Yang ◽  
Zhen Wu ◽  
...  
Keyword(s):  
Native Defects ◽  
Metal Additives ◽  
And Migration ◽  
Rate Limiting ◽  
Kinetics Of

The formation and migration of Mgi2+ are the rate-limiting processes for decomposing Mg(BH4)2.

Continuous Time Random Walk and Migration–Proliferation Dichotomy of Brain Cancer

2015 ◽  
Vol 10 (01) ◽  
pp. 37-57 ◽  
Author(s):  
A. Iomin
Keyword(s):  
Random Walk ◽  
Brain Cancer ◽  
Continuous Time ◽  
Continuous Time Random Walk ◽  
Suggested Model ◽  
Cell Dynamics ◽  
Fractional Kinetics ◽  
And Migration ◽  
Kinetics Of

A theory of fractional kinetics of glial cancer cells is presented. A role of the migration-proliferation dichotomy in the fractional cancer cell dynamics in the outer-invasive zone is discussed and explained in the framework of a continuous time random walk. The main suggested model is based on a construction of a 3D comb model, where the migration-proliferation dichotomy becomes naturally apparent and the outer-invasive zone of glioma cancer is considered as a fractal composite with a fractal dimension Dfr< 3.

scholarly journals The substrate specificity of acid α-glucosidase from rabbit muscle

1971 ◽  
Vol 124 (4) ◽  
pp. 701-711 ◽  
Author(s):  
T. N. Palmer
Keyword(s):  
Substrate Inhibition ◽  
Physiological Role ◽  
Liver Glycogen ◽  
Rabbit Muscle ◽  
Ph Optimum ◽  
Enzyme Action ◽  
Rate Limiting ◽  
Kinetics Of ◽  
Hydrolysis Of

1. Acid α-glucosidase was purified 3500-fold from rabbit muscle. 2. The enzyme was activated by cations, the degree of activation varying with the substrate. Enzyme action on glycogen was most strongly activated and activation was apparently of a non-competitive type. With rabbit liver glycogen as substrate, the relative Vmax. increased 15-fold, accompanied by an increase in Km from 8.3 to 68.6mm-chain end over the cation range 2–200mm-Na+ at pH4.5. Action on maltose was only moderately activated (1.3-fold, non-competitively) and action on maltotriose was marginally and competitively inhibited. 3. The pH optimum at 2mm-Na+ was 4.5 (maltose) and 5.1 (glycogen). Cation activation of enzyme action on glycogen was markedly pH-dependent. At 200mm-Na+, the pH optimum was 4.8 and activity was maximally stimulated in the range pH4.5–3.3. 4. Glucosidase action on maltosaccharides was associated with pronounced substrate inhibition at concentrations exceeding 5mm. Of the maltosaccharides tested, the enzyme showed a preference for p-nitrophenyl α-maltoside (Km 1.2mm) and maltotriose (Km 1.8mm). The extrapolated Km for enzyme action on maltose was 3.7mm. 5. The macromolecular polysaccharide substrate glycogen differed from linear maltosaccharide substrates in the kinetics of its interaction with the enzyme. Activity was markedly dependent on pH, cation concentration and polysaccharide structure. There was no substrate inhibition. 6. The enzyme exhibited constitutive α-1,6-glucanohydrolase activity. The Km for panose was 20mm. 7. The enzyme catalysed the total conversion of glycogen into glucose. The hydrolysis of α-1,6-linkages was apparently rate-limiting during the hydrolysis of glycogen. 8. Enzyme action on glycogen and maltose released the α-anomer of d-glucose. 9. The results are discussed in terms of the physiological role of acid α-glucosidase in lysosomal glycogen catabolism.

Role Of Hydrogen And Hydrogen Complexes In Doping Of Gan

1996 ◽  
Vol 423 ◽  
Author(s):  
Jörg Neugebauer ◽  
Chris G. Van de wallei
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
State Of The Art ◽  
Growth Conditions ◽  
Fundamental Difference ◽  
First Principles Calculations ◽  
Native Defects ◽  
In Doping ◽  
And Migration

AbstractWe have calculated electronic structure, energetics and migration for hydrogen and hydrogen complexes in GaN employing state-of-the-art first-principles calculations. Using these results in combination with previous detailed investigations about native defects we have calculated the concentration of hydrogen and dopants for different growth conditions. Our results reveal a fundamental difference in the behavior of hydrogen in p-type and n-type material. In particular, we explain why hydrogen has little effect on donor impurities and why H concentrations are low in n-type GaN. We discuss why hydrogen is beneficial for acceptor incorporation in GaN, and identify the limitations of this process.

scholarly journals Measuring kinetics and metastatic propensity of CTCs by blood exchange between mice

2020 ◽  
Author(s):  
Bashar Hamza ◽  
Alex B. Miller ◽  
Lara Meier ◽  
Max Stockslager ◽  
Emily M. King ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Half Life ◽  
Transfer Rates ◽  
Tumor Bearing ◽  
Blood Exchange ◽  
Clinical Methods ◽  
Lung Cancer Model ◽  
Rate Limiting ◽  
Kinetics Of

AbstractExisting pre-clinical methods for acquiring dissemination kinetics of rare circulating tumor cells (CTCs) en route to forming metastases have not been capable of providing a direct measure of CTC intravasation rate and subsequent half-life in the circulation. Here, we demonstrate an approach for measuring endogenous CTC kinetics by continuously exchanging CTC-containing blood over several hours between un-anesthetized, tumor-bearing mice and healthy, tumor-free counterparts. By tracking CTC transfer rates using an autochthonous small cell lung cancer model, we extrapolated half-life times in the circulation of 50-100 seconds and intravasation rates between 4,000 and 27,000 CTCs/hour – an average daily shedding rate equivalent to ∼0.07% of the total number of primary tumor cells in the lung. Additionally, transfer of 1-2% of daily-shed CTCs from late-stage tumor-bearing mice generated macrometastases in healthy recipient mice. We envision that our technique will help further elucidate the role of CTCs and the rate-limiting steps in metastasis.

scholarly journals The role of P2Y12 in the kinetics of microglial self-renewal and maturation in the adult visual cortex in vivo

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Monique Mendes ◽  
Linh Le ◽  
Jason Atlas ◽  
Zachary Brehm ◽  
Antonio Ladron-de-Guevara ◽  
...  
Keyword(s):  
Immune Cells ◽  
Self Renewal ◽  
Knock Out ◽  
Two Photon ◽  
And Migration ◽  
Knock Out Mice ◽  
Morphological Maturation ◽  
Kinetics Of

Microglia are the brain's resident immune cells with a tremendous capacity to autonomously self-renew. Because microglial self-renewal has largely been studied using static tools, its mechanisms and kinetics are not well understood. Using chronic in vivo two-photon imaging in awake mice, we confirm that cortical microglia show limited turnover and migration under basal conditions. Following depletion, however, microglial repopulation is remarkably rapid and is sustained by the dynamic division of remaining microglia, in a manner that is largely independent of signaling through the P2Y12 receptor. Mathematical modeling of microglial division demonstrates that the observed division rates can account for the rapid repopulation observed in vivo. Additionally, newly-born microglia resemble mature microglia within days of repopulation, although morphological maturation is different in newly born microglia in P2Y12 knock out mice. Our work suggests that microglia rapidly locally and that newly-born microglia do not recapitulate the slow maturation seen in development but instead take on mature roles in the CNS.

Credit constraints and Rural Migration: Evidence from Six Villages in Uttar Pradesh

2018 ◽  
Vol 15 (3) ◽  
pp. 389-398
Author(s):  
Ruchi Singh
Keyword(s):  
Credit Constraints ◽  
Uttar Pradesh ◽  
Binary Logistic Regression ◽  
Binary Logistic Regression Model ◽  
Male Migration ◽  
Rural Economies ◽  
And Migration ◽  
The Relationship ◽  
The Empirical Analysis

Rural economies in developing countries are often characterized by credit constraints. Although few attempts have been made to understand the trends and patterns of male out-migration from Uttar Pradesh (UP), there is dearth of literature on the linkage between credit accessibility and male migration in rural Uttar Pradesh. The present study tries to fill this gap. The objective of this study is to assess the role of credit accessibility in determining rural male migration. A primary survey of 370 households was conducted in six villages of Jaunpur district in Uttar Pradesh. Simple statistical tools and a binary logistic regression model were used for analyzing the data. The result of the empirical analysis shows that various sources of credit and accessibility to them play a very important role in male migration in rural Uttar Pradesh. The study also found that the relationship between credit constraints and migration varies across various social groups in UP.

Role of microenvironment on proliferation and migration of an SDHB silenced murine Pheochromocytoma cell line

2017 ◽  
Author(s):  
Serena Martinelli ◽  
Vanessa D'Antongiovanni ◽  
Susan Richter ◽  
Letizia Canu ◽  
Tonino Ercolino ◽  
...  
Keyword(s):  
Cell Line ◽  
Pheochromocytoma Cell ◽  
And Migration ◽  
Proliferation And Migration
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