Biexponential parameterization of diffusion and T2 relaxation decay curves in a rat muscle edema model: Decay curve components and water compartments

Dentin and bone are formed when odontoblasts and osteoblasts synthesize and secrete collagen type I-rich extracellular matrix that mineralizes in a highly controlled manner. A wide spectrum of mouse and human disorders affecting tooth and bone biomineralization shows that dentin and bone formation are under strict genetic control. Although the controlling mechanisms of dentinogenesis and osteogenesis require further study, a large body of evidence points to the importance of the matrix metalloproteinases (MMPs) participate in a wide variety of extracellular matrix degradation. Detailed knowledge of MMPs may be important for understanding the pathogenesis of tooth development. Some researchers have pointed MMP-9 is an extracelluar proteinase that is highly expressed in osteoclasts and has been postulated to play an important role in their resorptive activity. Although MMP-9 has been reported to play a role in bone resorption, the association of this enzyme during deciduous tooth resorption has not yet been clarified. Based on accumulating evidence, we hypothesized that MMP-9 should play a role in teeth attrition. In this study, we have applied NMR relaxation technique to assess age-related MMP-9 KO tooth quality in vitro by quantifying changes in dentin and pulp simultaneously. The major hypothesis in this paper was that whether noninvasive NMR relaxation time measurements could be used to characterize MMP-9 KO changes in dentin and pulp, and to predict tooth quality. Specifically, we tested that age-related MMP-9 KO tooth changes result in an alteration of the NMR spin-spin (T2) relaxation time signal due to the structural changes in the tooth matrix. This signal can be further processed to produce a T2 relaxation distribution spectrum related to dentin and pulp, and their derived parameters can be used as descriptors of age-related MMP-9 KO tooth changes. In this study, the proton liquid-like NMR spin-spin (T2) relaxation decay signal was obtained from the Carr-Purcell-Meiboom-Gill (CPMG) NMR spin echo train method [1,2], then the relaxation decay signal was converted to T2 relaxation distribution spectra describing the size domain of dentin and pulp. Therefore, we can calibrate the intensities in NMR inversion T2 relaxation distribution spectra corresponding to the amount of dentin and pulp related to the structural changes. Here, we propose an NMR calibration method “NMR standard estimation” — the ratio of the amount of pulp to the amount of dentin obtained from NMR T2 distribution spectra that can be used to measure the age-related MMP-9 KO structural changes in teeth [3]. We are cognizant of the biological and physiological variability manifest in teeth size variations, but feel that this kind of NMR standard estimation — the ratio of amount of dentin to amount of pulp from the NMR T2 inversion spectrum can be used to determine age-related MMP-9 KO structural changes in teeth and eliminate any variations in size of teeth.

Molecular Mobility of Unfilled and Carbon-Black-Filled Isoprene Rubber: Proton NMR Transverse Relaxation and Diffusion

Rubber Chemistry and Technology ◽

10.5254/1.3539421 ◽

2007 ◽

Vol 80 (5) ◽

pp. 854-872 ◽

Cited By ~ 6

Author(s):

Ximei Sun ◽

Avraam I. Isayev ◽

Tirtha R. Joshi ◽

Ernst von Meerwall

Keyword(s):

Molecular Mobility ◽

Solid State Nmr ◽

T2 Relaxation ◽

Transverse Relaxation ◽

Network Chain ◽

Short T2 ◽

Gradient Diffusion ◽

And Diffusion ◽

Relaxation Decay ◽

Isoprene Rubber

Abstract In an effort to understand the effect of ultrasound on the devulcanization of gum and filled isoprene rubber vulcanizates, solid state NMR 1H transverse relaxation (T2) was employed to analyze rubber molecular mobility. The T2 relaxation decay of the unfilled and the black filled IR was successfully described by a two-component model. The short T2 component arose from the chemically crosslinked (gel) and physically entangled (heavy sol) network. The long T2 decay came from the unentangled sol and dangling network chain ends. Vulcanization decreased the molecular mobility; however, ultrasound devulcanization partially reversed this effect. Addition of processing oil in the filled IR significantly altered the dependence of T2 on the sol fraction. T2 and pulsed-gradient diffusion experiments were carried out on IR melt specimens after sonication with or without subsequent vulcanization. The lowered and broadened M-distribution produced results quantitatively related to earlier work in natural rubber.

EFFECT OF EXCITON DIFFUSION AND REABSORPTION ON DECAY CURVE OF EXCITON LUMINESCENCE

Le Journal de Physique Colloques ◽

10.1051/jphyscol:1985711 ◽

1985 ◽

Vol 46 (C7) ◽

pp. C7-55-C7-59 ◽

Cited By ~ 1

Author(s):

H. Nishimura

Keyword(s):

Decay Curve ◽

Exciton Luminescence ◽

Exciton Diffusion

Amino acid-induced impairment of glucose oxidation by isolated rat muscle: mechanism of action

Experimental and Clinical Endocrinology & Diabetes ◽

10.1055/s-2007-972234 ◽

2007 ◽

Vol 115 (S 1) ◽

Author(s):

K Stadlbauer ◽

B Brunmair ◽

Z Szöcs ◽

M Krebs ◽

A Luger ◽

...

Keyword(s):

Amino Acid ◽

Mechanism Of Action ◽

Glucose Oxidation ◽

Rat Muscle ◽

Isolated Rat

T2 Relaxation and Diffusion of Collagen Gel Oriented.

Journal of the Magnetics Society of Japan ◽

10.3379/jmsjmag.29.347 ◽

2005 ◽

Vol 29 (3) ◽

pp. 347-350

Author(s):

M. Takeuchi ◽

M. Sekino ◽

N. Iriguchi ◽

S. Ueno

Keyword(s):

Collagen Gel ◽

T2 Relaxation ◽

And Diffusion

Effects of exercise training and dietary manipulation on insulin-regulatable glucose-transporter mRNA in rat muscle

Diabetes ◽

10.2337/diabetes.40.2.275 ◽

1991 ◽

Vol 40 (2) ◽

pp. 275-279 ◽

Cited By ~ 10

Author(s):

S. A. Wake ◽

J. A. Sowden ◽

L. H. Storlien ◽

D. E. James ◽

P. W. Clark ◽

...

Keyword(s):

Exercise Training ◽

Glucose Transporter ◽

Dietary Manipulation ◽

Rat Muscle ◽

Glucose Transporter Mrna

A novel approach in numerical simulation of contaminant removal by air sparging

Water Science & Technology Water Supply ◽

10.2166/ws.2007.079 ◽

2007 ◽

Vol 7 (3) ◽

pp. 163-170

Author(s):

N. Jacimovic ◽

T. Hosoda ◽

M. Ivetic ◽

K. Kishida

Keyword(s):

Mass Transfer ◽

Deterministic Model ◽

Water Phase ◽

Air Sparging ◽

Order Kinetic ◽

Contaminant Removal ◽

Water Compartments ◽

Novel Approach ◽

Adopted Model ◽

Air Channels

The paper presents a mechanistic/deterministic model for simulation of mass removal during air sparging. From the point of numerical modeling, there are two issues considering air sparging: modeling of air flow and distribution and modeling of mass transport and transfer. Several processes, which are commonly neglected, such as air channeling and pollutant advection by the water phase, are taken into account. The numerical model presented in this paper considers all relevant for mass transfer during the air sparging. Model includes hydrodynamics of air and water phase; calculated air volume content is divided into a number of air channels surrounded by the water phase, which is divided into two compartments. First compartment is immobile and it is in contact with air phase, while the second compartment is mobile. This “mobile-immobile” formulation is a common approach for description of solute transport by groundwater. Mass transfer between two water compartments is modeled as a first order kinetic, where the mass transfer coefficient, representing diffusion and advection in the water phase towards the air channels, is parameter needed to be calibrated. Sorption for both water compartments is considered. The adopted model of contaminant evaporation at the air-water interface is verified by comparison with experimental results available from published sources. Model is used for simulation of two-dimensional air sparging laboratory experiment. Good overall agreement is observed. It is showed that the efficiency of air sparging can be influenced by natural groundwater flow.

1H NMR characterisation of the diffusional properties of methanogenic granular sludge

Water Science & Technology ◽

10.2166/wst.1999.0358 ◽

1999 ◽

Vol 39 (7) ◽

pp. 187-194 ◽

Cited By ~ 9

Author(s):

P. Lens ◽

F. Vergeldt ◽

G. Lettinga ◽

H. Van As

Keyword(s):

Diffusion Coefficient ◽

Relaxation Time ◽

Bacterial Cell ◽

Granular Sludge ◽

T2 Relaxation ◽

Self Diffusion ◽

Diffusion Analysis ◽

S Matrix ◽

Granular Matrix ◽

Pfg Nmr

The diffusive properties of mesophilic methanogenic granular sludge have been studied using diffusion analysis by relaxation time separated pulsed field gradient nuclear magnetic resonance (DARTS PFG NMR) spectroscopy. NMR measurements were performed at 22°C with 10 ml granular sludge at a magnetic field strength of 0.5 T (20 MHz resonance frequency for protons). Spin-spin relaxation (T2) time measurements indicate that three 1H populations can be distinguished in methanogenic granular sludge beds, corresponding to water in three different environments. The T2 relaxation time measurements clearly differentiate the extragranular water (T2 ≈ 1000 ms) from the water present in the granular matrix (T2 = 40-100 ms) and bacterial cell associated water (T2 = 10-15 ms). Self-diffusion coefficient measurements at 22°C of the different 1H-water populations as the tracer show that methanogenic granular sludge does not contain one unique diffusion coefficient. The observed distribution of self-diffusion coefficients varies between 1.1 × 10−9 m2/s (bacterial cell associated water) and 2.1 × 10−9 m2/s (matrix associated water).

Myocardial BOLD Imaging with T2 Relaxation

The Open Medical Imaging Journal ◽

10.2174/1874347101206010018 ◽

2012 ◽

Vol 6 (1) ◽

pp. 18-30 ◽

Cited By ~ 1

Author(s):

Nilesh R. Ghugre

Keyword(s):

T2 Relaxation ◽

Bold Imaging