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Both transverse relaxation time (T2*) and intravoxel incoherent motion (IVIM) on magnetic resonance imaging (MRI) are promising for discriminating fetal growth restriction (FGR). We aimed to compare the utility of these two parameters and their combination in the same cohort.Twenty-seven FGR and 24 control pregnancies after 28 weeks of gestation in which both T2* and IVIM scans were performed on a 3.0 T MRI were recruited. We compared the T2* Z-score, perfusion fraction (f), diffusion coefficient (D) and pseudodiffusion coefficient (D*) between groups. Binary logistic regression analysis and areas under the curve (AUCs) with receiver operating characteristic (ROC) curve were used to evaluate the diagnostic efficacy of these parameters and their combination.Compared with normal pregnancies, T2* Z-score (0.036 ± 0.95 vs. -2.479 ± 1.56, p 0.001), f (0.2753 ± 0.035 vs. 0.3304 ± 0.035, p 0.001), D* (48279.82 ± 7497.36 μm2/s vs. 56167.92 ± 8549.87 μm2/s, p = 0.001) and D (1664.32 ± 288.53 μm2/s vs. 1887.15 ± 204.08 μm2/s, p = 0.002) were significantly decreased in FGR pregnancies. However, only AUC(T2* Z-score) (0.903) and AUC(f) (0.873) were good predictors of FGR. The AUC(T2* Z-score-IVIM) (0.937), calculated with the combination of T2* Z-score and f, was similar to AUC(T2* Z-score) and ACU(f).Both T2* and f were effective in discriminating FGR. However, the combination of the two parameters did not further improve diagnostic efficacy. We suggest that T2* might be more suitable for evaluating placental dysfunction, as it is fast to obtain and easy to measure.

The associations of four proteins – AK4, ITPK1, HSPB2, and IGFBP5 – with cognitive function in older adults were largely unexplained by known brain pathologies. We examined the extent to which individual protein associations with cognitive decline were attributable to microstructural changes in the brain. This study included 521 participants (mean age 90.3, 65.9–108.3) with the postmortem reciprocal of transverse relaxation time (R(2)) magnetic resonance image. All participants came from one of two ongoing longitudinal cohorts of aging and dementia, the Religious Orders Study and Rush Memory and Aging Project. Higher abundance of AK4, HSPB2, and IGFBP5 was associated with faster cognitive decline, and mediated through lower postmortem R(2) in the frontal and temporal white matter regions. In contrast, higher abundance of ITPK1 was associated with slower cognitive decline, and mediated through higher postmortem R(2) in the frontal and temporal white matter regions. The association of four proteins - AK4, ITPK1, IGFBP5, and HSPB2 - with cognition in late life were explained via microstructural changes in the brain.

Summary Objective To develop a model of early osteoarthritis, by examining whether radiographically normal knees with contralateral joint space narrowing (JSN), but without contralateral trauma history, display greater longitudinal cartilage composition change (transverse relaxation time; T2) than subjects with bilaterally normal knees. Methods 120 radiographically normal knees (Kellgren Lawrence grade [KLG] 0) from the Osteoarthritis Initiative were studied. 60 case knees displayed definite contralateral radiographic knee osteoarthritis (KLG ≥ 2) whereas 60 reference subjects were bilaterally KLG0, and were matched 1:1 to cases based on age, sex, and BMI. All had multi-echo spin-echo MRI acquired at year (Y) 1 and 4 follow-up, with cartilage T2 being determined in superficial and deep cartilage layers across 16 femorotibial subregions. T2 across all regions was considered the primary analytic focus. Results Of 60 KLG0 case knees (30 female, age: 65.0 ± 8.8 y, BMI: 27.6 ± 4.4 kg/m2), 21/22/13/4 displayed contralateral JSN 0/1/2/3, respectively. The longitudinal increase in the deep layer cartilage T2 between Y1 and Y4 was significantly greater (P = 0.03; Cohen's D 0.50) in the 39 KLG0 case knees with contralateral JSN (1.2 ms; 95% confidence interval [CI] [0.4, 2.0]) than in matched KLG0 reference knees (0.1 ms; 95% CI [−0.5, 0.7]). No significant differences were identified in superficial T2 change. T2 at Y1 was significantly greater in case than in reference knees, particularly in the superficial layer of the medial compartment. Conclusions Radiographically normal knees with contralateral, non-traumatic JSN represent an applicable model of early osteoarthritis, with deep layer cartilage composition (T2) changing more rapidly than in bilaterally normal knees. Clinicaltrials.gov identification NCT00080171 .

Purpose To evaluate whether baseline MRI-defined structural abnormalities are associated with subsequent change in laminar femorotibial cartilage transverse relaxation time (T2) of participants without radiographic signs, symptoms or risk factors for knee osteoarthritis (OA). Method We studied all right knees with longitudinal MRI data of the refined Osteoarthritis Initiative Healthy Reference cohort. Baseline osteophytes, effusion-synovitis, Hoffa-synovitis, bone marrow lesions, cartilage lesions, and meniscus morphology and - extrusion were scored semiquantitatively from MR images by an expert reader. Deep and superficial layer cartilage T2 was computed in the medial and lateral femorotibial compartment (MFTC/LFTC) at baseline and at 1- and 4-year follow-up from multi-echo spin-echo MR images. Statistical analyses were performed using UNIANOVA. Results 82 participants (age 54.1 ± 7.2y, BMI 24.2 ± 3.0 kg/m²; 61% women, bilateral Kellgren-Lawrence 0) were studied. Number of baseline MRI pathologies was not significantly associated with longitudinal change in MFTC or LFTC cartilage T2 over 1 or 4 years. Feature-specific analyses suggested that presence of baseline MFTC osteophytes may be associated with prolongation in superficial MFTC cartilage T2 over one (0.8 vs. 0.0 ms, p = 0.02) and four years (2.3 vs. 0.9 ms, p = 0.01), and that MFTC meniscal damage or extrusion may be associated with prolongation in deep layer T2 times over the first year (0.7 vs. 2.1 ms, p = 0.02). Conclusions Our study does not provide evidence that, in knees without radiographic OA, baseline structural MRI abnormalities are strongly related to compositional progression during normal aging and/or the potentially earliest phases of the disease as measured by cartilage T2.

Nuclear magnetic resonance (NMR) transverse relaxation time (T2) measurements of fully water-saturated rock samples can provide a reference for pore size distribution (PSD). Commonly, surface relaxivity of the rock must be known before obtaining an absolute PSD sample using NMR data. There are many reports concerning the surface relaxivity of sandstones, shales, and carbonate rocks, however, little research has been performed on the surface relaxivity of coals, which limit the application of the NMR in PSD evaluation of coals. To obtain a standard surface relaxivity for PSD measurements of coals, we performed NMR, low-temperature N2 adsorption (LTNA), and mercury intrusion porosimetry (MIP) measurements for 15 bituminous and anthracite coals, whose Ro range from 0.52% to 3.07%. The results show that the values of surface relaxivity from LTNA (ρ2-SVR) are inconsistent with those from MIP (ρ2-MIP) for all samples. Moreover, the applications of ρ2-SVR and ρ2-MIP for PSD conversions are valid only for the smaller pores and larger pores, respectively. Evidently, both these two surface relaxivities cannot be used individually to calculate full-scale PSD. To obtain the actual surface relaxivity (ρ2) for full-scale PSD, we rebuilt a full-scale PSD by combining the pores smaller than 25 nm from LTNA and the pores larger than 25 nm from MIP. The results indicate that the calculated ρ2 provides excellent function for PSD transformation for all coal samples. Finally, the references of ρ2 for different coals are provided, i.e., values of 2.1 μm/s for sub-bituminous coal (low-rank coal), 3.0 μm/s for bituminous coal (medium-rank coal) and 1.6 μm/s for anthracite coal (high-rank coal). Using these referential surface relaxivities, a T2 distribution from NMR measurement can be converted to a PSD, which is applicable not only in the laboratory but also in field applications such as well logging.

Numerous quality characteristics of food products are dependent on the microstructure and water status. In this study, LF-NMR and MRI techniques were applied for the evaluation of quality and water dynamics in apple jellies of Yinduqing cultivar during the course of 45 days storage. The present study investigated the impact of processing potentiality and formulation of hydrocolloid on water migration in jellies through non-destructive technique. The ingredients utilized in preparing the jelly were 500 mL juice, 400 g/kg sugar with 0, 2.0, 2.5 and 3.0% gelatin, respectively. Transverse relaxation time T2 exhibited three distinct water fractions (T21, T22, and T23) in the jelly samples during processing. Significant correlations were established between LF-NMR and physicochemical parameters. The macromolecular substance and gelatin influenced the water dynamics and caused a considerable variation in the T1 and T2 weighted MR images. Thus, the study revealed the feasibility of using non-destructive techniques in determining the dynamics of water within jelly products.

A visualization experimental method of foam flooding was developed by combining nuclear magnetic resonance (NMR) and traditional core flooding method. On this basis, a new method to evaluate the dynamic stability of foam in the core during displacement process was established. Using this method, the displacement characteristics and dynamic stability of foam of S-2 (the main component is sodium lauryl sulfate) and S-NP-2 (the main components are sodium lauryl sulfate and silica nanoparticles) in two different displacement modes, i.e. direct foam flooding and foam flooding after water flooding, were studied. The results show that the NMR images and the T2 (transverse relaxation time) spectrum reflected the displacement characteristics. The flooding efficiency of S-2 and S-NP-2 after water flooding was increased by 18.05% and 25.68% and reached 63.72% and 67.50% respectively at last, higher than direct foam flooding. The same foam system had better stability in foam flooding after water flooding than in direct foam flooding, and foam S-NP-2 is more stable than foam S-2 under the same displacement mode. Key words: foam flooding, flooding experiment, flooding efficiency, nuclear magnetic resonance (NMR), foam stability, evaluation method

Low fat Cheddar cheese (LFC) with up to 91% fat reduction were prepared using four levels of sodium alginate (alginate): 0.12 (LFCA1), 0.17 (LFCA2), 0.18 (LFCA3) and 0.23% (w/w) (LFCA4). Control full fat cheese (CFFC) and control low fat cheese (CLFC) were used for comparison. Physical characteristics, namely texture profile, microstructure, transverse relaxation time (T2) distribution (measured by low-field NMR) and color were analysed periodically during ripening until 180 days. Texture profile analysis illustrated a significant improvement in texture of alginate added LFC (P < 0.05) as compared to CLFC. The textural attributes of LFCA1 ripened for 30 days were comparable to CFFC ripened for 60 days and beyond. A close resemblance in textural attributes between alginate added LFC and CFFC, not previously reported when using other fat replacers, was observed. Scanning electron micrograph (SEM) images revealed that alginate added LFCs had smoother surfaces as compared to CFFC and CLFC, and the dense and compact protein matrix characteristic of CLFC was not observed. Confocal laser scanning microscopy (CLSM) suggested that the fat particle size, area and volume were affected in all LFCs due to their lower fat level and these parameters increased during ripening in CFFC. NMR results revealed increase in higher mobility water fraction in alginate added cheese compared to CFFC and CLFC. Hunter L, a and b values for alginate added LFCs indicated that they were whiter than CLFC and less yellowish than CFFC at the beginning of ripening; the color of some of the alginate added LFCs was comparable to CFFC after 120 days of ripening. Overall, addition of alginate significantly improved the textural, microstructural properties and color of LFCs, affirming its potential as a promising texture modifier. (C) 2018 Elsevier Ltd. All rights reserved.

The high consumption of gasoline in the Brazilian highway sector (around 32.1%) makes the fuel adulteration a target, especially due to the content of anhydrous ethanol. The excess of ethanol in gasoline beyond the 27% limit (v/v) that is the maximum content allowed by the Brazilian National Agency of Petroleum, Gas and Biofuels (ANP) can cause premature corrosion in the fuel tank, and problems with ignition and engine performance problems. This work proposes the application of a new methodology, time domain nuclear magnetic resonance (TD-NMR) to detect the adulteration of gasoline with ethanol. The results showed that the commercial gasoline has transverse relaxation time (T2) changing between 2.02 and 2.05 s, while the ethanol has T2 equal to 1.6 s. Samples adulterated with percentage of ethanol between 5% and 50% (v/v) showed T2 ranges between 1.70 s and 2.05 s. The methodology proposed here showed excellent agreement with infrared in the middle region (MIR) and can used to diverse commercial gasoline. Besides, TD-NMR is simple, the measure are rapid, non-destructiveness and data are easy to be interpreted.

Instant sea cucumber has become one popular product due to its convenience to eat, favourable taste and minimal loss of nutrients and bioactive components. However, there was rare information about the water dynamic of instant sea cucumber subjected to multiple freeze-thaw cycles. In this study, low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance image (MRI) were employed to investigate the effect of freeze-thaw cycles on water status of instant sea cucumber. Four water populations corresponding to strongly bound water, weakly bound water, immobile water and free water were observed in instant sea cucumber. With the increase of freeze-thaw cycles, the transverse relaxation time of immobile and free water increased, while the peak area of free water decreased significantly. MRI enabled the visualization of water migration of instant sea cucumber during multiple freeze-thaw cycles. Multiple freeze-thaw cycles also led to significant changes of other quality properties including thawing loss, WHC, color parameters, texture and protein content, and enlarge the interspace between fiber network in microstructure. Good correlations between T22, A22, A23 and thaw loss, WHC, L*, hardness and collagen content (0.873 ≤ r ≤ 0.958) revealed LF-NMR may be an effective real-time monitoring method of these physicochemical parameters as a non-destructive technique.

The development of new therapeutic agents for the treatment of Duchenne muscular dystrophy has put a focus on defining outcome measures most sensitive to capture treatment effects. This cross-sectional analysis investigates the relation between validated clinical assessments such as the 6-minute walk test, motor function measure and quantitative muscle MRI of thigh muscles in ambulant Duchenne muscular dystrophy patients, aged 6.5 to 10.8 years (mean 8.2, SD 1.1). Quantitative muscle MRI included the mean fat fraction using a 2-point Dixon technique, and transverse relaxation time (T2) measurements. All clinical assessments were highly significantly inter-correlated with p

This paper discusses the relationship among capillary pressure ( P C ), nuclear magnetic transverse relaxation time ( T 2 ) and resistivity index ( I ). The three parameters are related to the geometry of pore structure. We use the fractal concept to describe the relationship between T 2 and I .In addition, a new T 2 -I model is established. 8 Cores from tight sandstone reservoir in China are selected to do experiments. The results reveal that the cores have continuous fractal dimension characteristics. Additionally, the fractal dimensions appear great differences in the different pore radius scales. Therefore, a piece-wise fitting method is adopted. We divided the pores into macropore, mesopore and micropore. Through the verification, our T 2 -I model and piece-wise fitting method are feasible. An application example is also provided in this paper. Based on our researches, we adopt NMR logging data to obtain dynamic parameters of Archie’s formula b and n for calculating water saturation in Tight Sandstone Reservoir. The comparison between our method and normal method demonstrated that our model is much better at matching the core water saturation.

The mercury injection capillary pressure (MICP) curves have been widely used for the evaluation of the pore structure. In practical application, the MICP curves are usually obtained by the mercury injection experiment, but the experimental measurement can not obtain the MICP curves of the reservoir continuously. Since the pore size distribution obtained from the nuclear magnetic resonance (NMR) transverse relaxation time (T2) distribution is related to the pore-throat size distribution obtained from the MICP curve, so in previous studies, the MICP curves were predicted based on the NMR T2 distribution. However, the NMR T2 distribution obtained by the inversion of the NMR echo data has uncertainty, which affects the prediction accuracy of the MICP curves. In this paper, a new method for predicting the MICP curves of sandstone based on NMR echo data is proposed for the first time. Multiple characteristic parameters of the NMR echo data are calculated. The relationship between the parameters and the mercury saturation (Shg) is established at each capillary pressure point to predict the MICP curves. And the parameters of the MICP curves and the physical parameters are selected to create a reservoir classification index. The results show that the method for predicting the MICP curves of sandstone based on NMR echo data has high prediction accuracy and strong stability, and the reservoir classification index provides an accurate classification of sandstone reservoirs.

Ultrasound was applied to facilitate starch-protein separation during ultrasound-assisted laboratory-scale corn wet-milling. The effects of ultrasound on the properties of mill starch and protein were investigated to explore the possible mechanisms in this study. A higher starch yield was obtained with sonication treatment in starch-protein separation (15 min, 200 W) and the results showed that ultrasound did not induce damage to the product starch. The differences in the distribution of water proton transverse relaxation time for mill starch suggested that the interaction between starch granules and protein in mill starch was destroyed. The free sulfhydryl content increased by 37.21% and the disulfide bond content decreased by 43.66% of the separated proteins indicated that ultrasound destroyed the disulfide bonds effectively (p

Purpose To compare the acute effect of running and bicycling of an equivalent cumulative load on knee cartilage composition and morphometry in healthy young men. A secondary analysis investigated the relationship between activity history and the change in cartilage composition after activity. Methods In fifteen men (25.8±4.2 years), the vertical ground reaction force was measured to determine the cumulative load exposure of a 15-min run. The vertical pedal reaction force was recorded during bicycling to define the bicycling duration of an equivalent cumulative load. On separate visits that were spaced on average 17 days apart, participants completed these running and bicycling bouts. Mean cartilage transverse relaxation times (T2) were determined for cartilage on the tibia and weight-bearing femur before and after each exercise. T2 was measured using a multi-echo spin-echo sequence and 3T MRI. Cartilage of the weight bearing femur and tibia was segmented using a highly-automated segmentation algorithm. Activity history was captured using the International Physical Activity Questionnaire. Results The response of T2 to bicycling and running was different (p=0.019; mean T2: pre-running=34.27 ms, pre-bicycling=32.93 ms, post-running=31.82 ms, post-bicycling=32.36 ms). While bicycling produced no change (−1.7%, p=0.300), running shortened T2 (−7.1%, p

In order to ensure the safety of food, particularly ready-to-eat (RTE) food, a sensitive and rapid method for the detection of foodborne pathogenic bacteria is always in high demand. An accurate and reliable detection method for Listeria monocytogenes has been developed based on the aggregation of biofunctionalized magnetic nanoparticles induced by specific binding between L. monocytogenes and antibody-modified nanoparticles, which results in the change of the transverse relaxation time (T2) of surrounding water protons of nanoparticles detected by nuclear magnetic resonance. The detection limit of this method is 3 MPN (using the most-probable-number (MPN) assay) and the functionalized Fe/Fe 3 O 4 nanoparticles exhibit a high specificity with the existence of other interfering bacteria. Furthermore, this detection method is successfully applied to detect L. monocytogenes in milk powder and lettuce. This method could be a useful tool for sensitive and rapid detection of foodborne pathogenic bacteria.

Knowledge of the process and kinetics of solid food disintegration in the human stomach is essential for assessing bioaccessibility of nutrients and understanding gastric emptying. It is desirable to develop advanced techniques for non-invasively and non-destructively studying the kinetics of gastric disintegration and nutrient release during digestion. The main objective of this study was to verify the feasibility of monitoring gastric disintegration of carrot sample during digestion in vitro by a Low-Field Nuclear Magnetic Resonance (LF-NMR) device. Static soaking in different liquid medium was also carried out using as comparison with the LF-NMR data to validate the feasibility. The wet and dry weight retention ratio, water content, hardness and effective diffusivity of the carrot were measured during the soaking tests following a course of time. The transverse relaxation time (T2) and magnetic resonance imaging (MRI) from the LF-NMR was employed to illustrate the transient water status throughout each sample. The T23 relaxation time at peak maximum migrated from ~1300 ms to 500 ms after static soaking in the simulated gastric juice with pH of 1.8 for 240 min, with the total peak area decreasing by 9.10% throughout the measurement of T2 quantitatively supporting the similar reduction of 8.89% in the wet mass retention ratio. Moreover, the time evolutions of the carrot sample size as shown from the MRI imaging results were also in line with the decrease of the solid loss during the static soaking. These consistent results indicate that the LF-NMR provides a non-invasive and non-destructive technique for potentially characterizing the disintegration of solid food samples during gastric digestion.

Based on the analytical 1H low-field nuclear magnetic resonance (NMR) technique, we developed a novel method and corresponding model to analyze the hydration degree (αt) of cement in cement paste under different curing conditions. The hydration degree can be calculated quantitatively based on the transverse relaxation time (T2) distributions using NMR measurements. The T2 distributions of the cement paste samples with the water/cement (W/C) ratios of 0.25, 0.35 and 0.45 under standard curing, steam curing at 40 °C and steam curing at 60 °C were obtained. The αt of cement was studied by the hydration heat method and portlandite (CH) quantitative measurements. The results show that the intensity-weighted T2 value of non-surface water peaks ( T 2 ¯ ) has a significant correlation with αt that can be expressed by an exponential equation. In this paper, the derivation of this exponential equation is given, and the effects of W/C ratio and curing condition on its parameters are analyzed.

The changes in water distribution and structural properties of myofibrillar protein (MP) in marinated pork belly induced by the addition of different concentrations (0.00, 0.25, 0.50, 1.00, and 2.00 g/kg) of tannic acid (TA) were examined. Transverse relaxation time and population measurements revealed that the 0.50 g/kg TA treatment improved water retention in the marinated pork belly samples. There was an initial increase and a subsequent decrease in the free amino group, α-helix, and β-sheet content, as well as fluorescence intensity, as TA concentration increased. Meanwhile, the opposite trend was observed in the dityrosine content and surface hydrophobicity of the marinated pork belly samples. The free amino group, α-helix content and fluorescence intensity of 0.50 g/kg TA samples were increased by 23.1%, 10.3% and 28.6%, and dityrosine content and surface hydrophobicity were decreased by 2.6% and 2.9% compared with the samples without TA. Therefore, the effect of TA on water distribution and protein structural properties in marinated pork belly is related to its concentration. Addition of 0.50 g/kg TA can significantly delay the loss of water and improve protein structure stability of MP in pork belly during marinating.

The objective of this study is to investigate the effects of l-arginine (Arg) on the physicochemical and gel properties of chicken actomyosin. The results showed that Arg increased the content of surface hydrophobicity and reactive sulfhydryl group of chicken actomyosin, but decreased storage modulus (G0). Also, Arg enhanced the first thermal transition temperature (TM1) but decreased the second thermal transition temperature (TM2). The addition of Arg favored to form a dense and uniform gel with the increased water holding capacity (WHC), strength and transverse relaxation time (T2). These results suggested that Arg may result in the formation of a uniform and continuous gel by changing the structural and thermal behavior of actomyosin in turn, ultimately contributing to the elevated WHC and strength. The results may provide new insight into the effects of Arg on the WHC and texture of meat products in the previous literatures.

A magnetic sensor for detection of Pb 2+ has been developed based on Fe/Fe 3 O 4 nanoparticles modified by 3-(3,4-dihydroxyphenyl)propionic acid (DHCA). The carboxyl groups of DHCA have a strong affinity to coordination behavior of Pb 2+ thus inducing the transformation of Fe/Fe 3 O 4 nanoparticles from a dispersed to an aggregated state with a corresponding decrease, then increase in transverse relaxation time ( T 2 ) of the surrounding water protons. Upon addition of the different concentrations of Pb 2+ to an aq. solution of DHCA functionalized Fe/Fe 3 O 4 nanoparticles (DHCA-Fe/Fe 3 O 4 NPs) ([Fe] = 90 μmol/L), the change of T 2 values display a good linear relationship with the concentration of Pb 2+ from 40 μmol/L to 100 μmol/L and from 130 μmol/L to 200 μmol/L, respectively. Owing to the especially strong interaction between DHCA and Pb 2+ , DHCA-Fe/Fe 3 O 4 NPs exhibited a high selectivity over other metal ions.

Many of the world's oil reservoirs are sandstones and some equations have been widely explored to estimate their permeability from NMR measurements, especially those based on the Schlumberger Doll Research (SDR) and Timur–Coates models. In both cases, the permeability is assumed to be related to pore sizes. Brownstein and Tarr showed that, under fast diffusion regime, the NMR transverse relaxation time is proportional to the pore size and the proportionality constant is defined by the interaction fluid/surface and represented by the surface relaxivity ρ. However, although there are several methods in the literature to estimate ρ, no standard methods have been established so far, to our knowledge. In this work, we estimated surface relaxivity by combining experimental and simulated NMR data using a recently developed computational method to emulate the NMR signal of fluids within Digital Rocks. In addition, we analyzed the correlation between the pore radii and the experimentally measured gas permeability. Comparing Schlumberger and Timur-Coates models for permeability prediction, we propose that the macro and microporosity intensities identified in the T2 distribution are correlated with characteristics of the sandstone surface. Thus, sandstone surface relaxivity can be estimated using the ratio of macro and microporosity intensities from NMR and, consequently, the pore size distribution can be obtained using only T2 distribution data.

Understanding and characterizing the distribution and occurrence state of microcosmic residual oil is helpful to optimize judicious strategy for enhancing oil recovery (EOR). In this paper, frozen phase technology was developed to realize accurately characterize the oil and water saturation and their occurrence state. First, the core was placed in liquid nitrogen to frozen the oil and water inside it, and the solidified oil and water guarantees no destroying of their original distribution of oil and water, and 0.05 mm slice could be obtained. Second, taking advantage of different freezing point of oil and water, the low-field NMR is employed to achieve high-resolution single oil signal under freezing point of water and both oil and water signal at room temperature, thus, the oil and water saturation could be accessed, and their distribution in different-sized pore could be achieved based on conversion calculation of transverse relaxation time of NMR. Third, the displacing performance of water flooding and CO2 flooding was investigated. The results characterized by laser confocal indicates that the water flooding has strong scouring capability for free-state oil and CO2 flooding has strong stripping capability for bound-state oil, suggesting CO2 water-alternating-gas injection has unique advantage for EOR. Our work develops a frozen phase technique to realize accurate characterization the residual oil and water saturation and give their original distribution, which could provide basic foundation for EOR design.

Golden pompano (Trachinotus blochii) fillets were dehydrated by four drying methods including vacuum freeze (VFD), vacuum microwave (VMD), hot air (HAD), and microwave (MD) drying in this study. The quality, water distribution and states, protein degradation of dried fillets were determined. VFD fillets had looser microstructure and higher contents of protein (62.72 g/100g) than VMD, HAD and MD, while the VMD fillets had the highest lipid content (15.13%). The transverse relaxation time of immobilized water significantly decreased during the drying process, and the water content was uniform during VFD and VMD compared with MD and HAD processes. In addition, regarding protein degradation, VFD maintained a higher ratio of α-helical structure and higher protein denaturation temperature compared to the heating process (VMD, HAD and MD). Thus, VFD was considered as the appropriate non-thermal drying method of golden pompano fillets with the advantages of high product quality and protein stability. And in the thermal drying processing, the VMD fillets had better quality and higher efficiency.

At the conclusion of waterflooding phase, significant volume of oil still remains in reservoir formations. In this paper, waterflooding was performed at a designed sequential rate mode with an aim to further reduce the remaining oil saturation (Sor). Waterflooding process was monitored continuously by a low-field Nuclear Magnetic Resonance (NMR) spectrometer attempting to map pore-scale displacing behaviors and also quantify the reduction in Sor in-situ. The results showed that the main pore size of the cores ranged from 1.6 μm to 63.0 μm inferred by T2 (transverse relaxation time) distributions. The value of Sor in the cores increased towards the outlet face during waterflooding because of capillary end effect, which became more significant for heavy oil. At the termination of this waterflooding process, Sor was found to be further reduced by approximately 5.0% in the presence of thief water pathways as a result of the improved viscous forces. Water fingering and capillary imbibition effects were clearly visualized in the NMR images. These observations are expected to be useful for heavy oil waterflooding operations especially in post-breakthrough phase.

Vitreous liquefactive processes play an integral role in ocular health. Knowledge of the degree of liquefaction would allow better monitoring of ocular disease progression and enable more informed therapeutic dosing for an individual patient. Presently this process cannot be monitored in a non-invasive manner. Here, we evaluated whether magnetic resonance imaging (MRI) could predict the viscoelasticity and in turn liquefactive state of artificial and biological vitreous humour. Gels comprising identical concentrations of hyaluronic acid and agar ranging from 0.125 to 2.25 mg/ml of each polymer were prepared and their T2 was measured using a turbo-spin echo sequence via 3T clinical MRI. The gels were subsequently subjected to rheological frequency and flow sweeps and trends between T2 and rheological parameters were assessed. The relationship between T2 and vitreous humour rheology was further assessed using ex vivo porcine eyes. An optimised imaging technique improved homogeneity of obtained artificial vitreous humour T2 maps. Strong correlations were observed between T2 and various rheological parameters of the gels. Translation to porcine vitreous humour demonstrated that the T2 of biological tissue was related to its viscoelastic properties. This study shows that T2 can be correlated with various rheological parameters within gels. Future investigations will assess the translatability of these findings to live models.

This study investigated the bleeding properties of fresh cement paste mixed with various polycarboxylate superplasticizers (PCEs) using low-field nuclear magnetic resonance (NMR). The PCE superplasticizers were synthesized with various acid to ether ratio, molecule weight of methyl allyl alcohol polyoxyethylene ether (HPEG) and functional groups. The bleeding process of fresh cement paste mixed with the PCE superplasticizers was monitored by low-field NMR and the bleeding rate was obtained with the calculation of transverse relaxation time (T2) peaks. Results showed that the proposed NMR method can not only evaluate the bleeding extent, probe the microstructure of fresh cement paste but also provide information about the PCEs concentration of bleeding water. It was found that PCE superplasticizers synthesized with high acid to ether ratio would reduce the bleeding, and PCE superplasticizers synthesized with the HPEG of molecule weight 4400 and functional group of methyl methacrylate (MMA) would lead to less bleeding when the fresh cement paste reached the same fluidity. The T2 relaxation time of bleeding water increased with bleeding rate, which implies the PCEs molecules in bleeding water was diluted during the bleeding process. Furthermore, the results suggest more bleeding water coming out from the pore water results in larger microstructure changes due to sedimentation.

Knowledge of the onset of the asphaltene precipitation point is important in preventing pipe clogging and the reduction of productivity. In this study, we propose a new and simple strategy to determine the onset point of asphaltene precipitation by a low-field nuclear magnetic resonance (NMR) technique based on transverse relaxation time (T2) measurements. Six Brazilian crude oil (light, medium, and heavy) samples, with asphaltene contents ranging from 0.10 to 7.10 wt%, were assessed using n-heptane as the precipitant, according to the ASTM D6560 method. The good correlation between T2 and the n-heptane/oil ratio indicated the onset precipitation values between 0.931 and 2.759 mL g−1. NMR results shows agreement with optical microscopy and literature results. We also propose a correlation between asphaltene content and onset of the asphaltene precipitation. This new idea expand the applicability of low-field NMR in crude oil studies, providing an alternative method for asphaltene precipitation under laboratory conditions and opens the possibility to quantifying the asphaltene content in crude oil without the laborious standard ASTM method.

International audience; The transverse relaxation time (T2), measured with Carr-Purcell-Meiboom-Gill (CPMG) sequence, has been widely used to obtain the direct dimension data in two-dimension time domain NMR (2D TD-NMR). In this paper we are demonstrating that Continuous Wave Free Precession sequence, with low flip angle (CWFP-T1), can be an alternative to CPMG as direct detection dimension. CWFP-T1 is a fast single shot sequence, like CPMG, and yields an exponential signal governed predominantly by the longitudinal (T1) relaxation time. To obtain the correlations between T1 and T2 (T1-T2 maps) we are proposing the use of CPMG-CWFP-T1 pulse sequence. In this sequence CPMG encodes T2 information (indirect dimension) that modulates the CWFP-T1 (direct dimension) signal amplitudes. CPMG-CWFP-T1 experiments were compared with classical 2D sequences such as Saturation-Recovery-CPMG (SR-CPMG) and Inversion-Recovery-CPMG (IR-CPMG) sequence and yields similar results in phantom sample. The experimental time for the 2D sequences, using single scan, shows that SR-CPMG ' CPMG-CWFP-T1 < IR-CPMG. Experimental and simulated results demonstrated that 2D-CPMG-CWFP-T1 maps have higher resolution in T1 dimension than the techniques that uses CPMG as direct dimension. CPMG-CWFP-T1 sequence was also applied to study beef samples, and 2D maps showed higher resolution in the two fat signals than the classical IR-CPMG method. © 2019 Elsevier Inc.

This research compared the distribution and mobility of water in the longissimus thoracis muscle of 51 Apulo-Calabrese and 52 crossbred pigs differing in growth performances. The Apulo-Calabrese and crossbreed pigs were fed the same diet and slaughtered at 135 and 155 kg live weight, respectively. Besides meat quality measurement, water status was assessed from transverse relaxation time (T2) weighted signals registered by Time Domain Nuclear Magnetic Resonance (TD-NMR). A mixed model indicated that Apulo-Calabrese pigs had higher a* (P-value

The present work explored the possibility of using wheat malt flour (WMF) to improve the physicochemical properties of wheat dough and cookie-making performance. The effect of WMF substitution on rheology, pasting properties, water mobility and microstructure of wheat dough and the texture, physiognomy of cookies was investigated. The results illustrated that incorporation of WMF significantly (p 0.05), while the transverse relaxation time of free water (T23) decreased gradually with increasing WMF level. Microstructure results showed that starch granules were connected and enmeshed in weak protein matrix for samples with WMF addition. Lightness (L*) and hardness of cookies decreased with increasing WMF level while redness (a*) and spread ratio augmented. Overall, WMF can be used as baking improver for cookies-making by selecting appropriate substitution level for conventional WF.

A bifunctional sensor based on Au-Fe 3 O 4 nanoparticles (NPs) modified by ethyl 1-(2-(3′,4′-dihydroxyphenyl)-2-oxoethyl)-1H-1,2,3-triazole-4-carboxylate (ETC) was developed. Due to the coordination interaction between cadmium (Cd 2+ ) and ETC, Cd 2+ induced the aggregation of Au-Fe 3 O 4 NPs from dispersion, concomitant with a change in UV–vis spectra and transverse relaxation time ( T 2 ). The combined signals provided high selectively for Cd 2+ ions.

A magnetic sensor for Cd2+ has been developed based on (Zn, Mn)-doped iron oxide nanoparticles [(Zn, Mn)Fe3O4 NPs], which was modified by ethyl 1-(2-(3′,4′-dihydroxyphenyl)-2-oxoethyl)-1H-1,2,3-triazole-4-carboxylate (ETC). ETC provided the binding sites to Cd2+ to induce the transformation of (Zn, Mn)Fe3O4 NPs from a dispersed to an aggregated state with a corresponding increase in the transverse relaxation time (T2) of surrounding water protons. Owing to the special strong interaction between ETC and Cd2+, ETC coordinated (Zn, Mn)Fe3O4 [(ETC-(Zn, Mn)Fe3O4)] NPs exhibited a low limit of detection of Cd2+ of 3.5 nM and a high selectivity over other metal ions. Furthermore, ETC-(Zn, Mn)Fe3O4 NPs can be used to detect Cd2+ in living cells by magnetic resonance (MR) imaging.

A new study using magnetic resonance imaging (MRI) evaluated successfully the transverse relaxation time T2 as a non-invasive imaging biomarker for monitoring hepatic fibrogenesis in schistosomiasis. However, there are some drawbacks that need special attention. This preliminary data opens new opportunities to understand and monitor liver fibrosis in schistosomiasis and other fibrogenic diseases.

The objective is to characterize the changes in water mobility in drying process of chicken breast using 1 H low-field nuclear magnetic resonance (LF-NMR). Chicken breast was dried at different temperatures, i.e. 50 °C, 55 °C, 60 °C, 65 °C, 70 °C and 75 °C, respectively. Indicators related to water mobility were gained by LF-NMR and the shear force, the main relevant quality indicator, was also measured. The total water content measured by the conventional determination method-oven drying method were recorded and analyzed. The results showed that the total water content, the transverse relaxation time of immobilized water ( T 21 ) and the signal per mass of the immobilized water ( A 2 ) and the total water content ( A ) decreased significantly but the shear force value (SFV) increased with the drying time increasing at each drying temperature. A 2 and A had extremely significant correlations with the total moisture content, whose correlation coefficients were 0.983 and 0.992 for 50 °C, 0.928 and 0.901 for 55 °C, 0.975 and 0.970 for 60 °C, 0.920 and 0.938 for 65 °C, 0.821 and 0.798 for 70 °C, 0.911 and 0.906 for 75 °C. So, the immobilized water of the dried chicken breast determined the changes of the total moisture content at the same drying time. A 2 and A can be on behalf of the total moisture content in this respect of change rule. A 2 and A also had extremely significant correlations with the shear force. Therefore, the LF-NMR was able to evaluate the drying degree and the quality of chicken jerky.

The rapid prediction of fluid viscosity, especially the fluid in heavy-oil petroleum reservoirs, is of great importance for oil exploration and transportation. We suggest a new method for rapid prediction of fluid viscosity using two-dimensional (2D) NMR relaxation time distributions. DEFIR, Driven-Equilibrium Fast-Inversion Recovery, a new pulse sequence for rapid measurement of 2D relaxation times, is proposed. The 2D relation between the ratio of transverse relaxation time to longitudinal relaxation time (T1/T2) and T1 distribution of fluid are obtained by means of DEFIR with only two one-dimensional measurements. The measurement speed of DEFIR pulse sequence over 2 times as fast as that of the traditional 2D method. Using Bloembergen theory, the relation between the distributions and fluid viscosity is found. Precise method for viscosity prediction is then established. Finally, we apply this method to a down-hole NMR fluid analysis system and realized on-site and on-line prediction of viscosity for formation fluids. The results demonstrated that the new method for viscosity prediction is efficient and accurate.

The purpose of this study was to evaluate skeletal muscle composition of lower extremity muscles in a manifesting female carrier of Duchenne muscular dystrophy (MFC DMD ) using magnetic resonance imaging (MRI) and spectroscopy (MRS). MRI/MRS was performed on the lower extremities and heart of a MFC DMD (47years, 51kg) on four occasions within 21months and in a control subject. Heterogeneity and asymmetry among muscles in the MFC DMD was observed in lipid fraction and mean transverse relaxation time (T 2 ) of lower extremity muscles with some muscles presenting as unaffected (e.g., rectus femoris) and others showing substantial deterioration and lipid infiltration (e.g., vasti muscles). There was an association of abnormal MRI findings and strength and motor function. Over the 21months a small decrease in CSA max and increase in lipid fraction and T 2 was observed in the MFC DMD in some muscles. In summary, this MFC DMD revealed significant imaging evidence of pathologic heterogeneity among muscles. Furthermore, this study shows the feasibility of combining various quantitative MRI and MRS approaches to monitor skeletal muscle involvement.

In this paper we present a method to determine the pore and grain size heterogeneity using a correlation between the transverse relaxation time and the susceptibility induced inhomogeneous magnetic field. By using a CPMG echo train, we are able to correlate T 2 with the inhomogeneous internal magnetic field, B z i . We first introduce a simple simulation to study the correlation between the internal magnetic field gradient, ∣ g ∣, and B z i , where this correlation is analogous to the T 2 – B z i correlation with horizontal inversion. We then acquire experimental data from two samples, one a simple bead pack, and the other a more complicated sandstone rock core. We find that indeed this method can indicate the presence of pore and grain size heterogeneities in the sample.

Low field Nuclear Magnetic Resonance (LF-NMR) relaxation time measurements were used to evaluate the effect of different pre-salting methods (brine injection of salt and/or phosphates followed by brining, solely brining, pickling and kench salting) on the protein denaturation and change in muscle properties during the production steps of dry salted cod fillets followed by rehydration. The NMR relaxation curves were affected by the salting method and represented well the structural differences between the salting methods at each processing step. Significant correlations were observed between the NMR relaxation parameters and all physicochemical quality properties measured, except the cooking yield, when samples from all processing stages were analyzed together. The longitudinal relaxation time T 1 , and the faster relaxing transverse relaxation time T 21 were shown to be especially sensitive to protein denaturation in the fillets. The water distribution indicated that the salting and rehydration processes changed the cells irreversibly. The study indicated that pre-brining by brine injection followed by brining, with low salt concentrations, led to the least protein denaturation during the dry salting and rehydration process.

Substantial resolution and sensitivity enhancements of solid-state (1)H detected (14)N HMQC NMR spectra at very fast MAS rates up to 80 kHz, in a 1mm MAS rotor, are presented. Very fast MAS enhances the (1)H transverse relaxation time and efficiently decouples the (1)H-(14)N interactions, both effects leading to resolution enhancement. The micro-coil contributes to the sensitivity increase via strong (14)N rf fields and high sensitivity per unit volume. (1)H-(14)N HMQC 2D spectra of glycine and glycyl-L-alanine at 70 kHz MAS at 11.7 T are observed in a few minutes with a sample volume of 0.8 μL.

The influence of crosslinking on the hydration structure of collagen has been investigated. Nuclear magnetic resonance, dielectric relaxation and thermoporometry were used to investigate water structure in native and crosslinked collagen fibers on both wet and dried specimen. Measurements reveal the influence of different chemical treatments on the transverse relaxation time and polarization of the collagen fibers. The frequency dependence of dielectric constant of collagen fibers displays an induction behavior on low frequencies. Bound water constrained in collagen fibers seems to provide signatures for changes induced by crosslinking agents on the pore diameter and distribution in collagen fibers. A correlation of transverse relaxation time of water in dry and wet states presented in this study presents an experimental tool for examining the differences in efficacy of crosslinking agents. Changes in the dielectric relaxation, dynamics of water structure and hydroporometric structure of collagen are dependent on the nature of crosslinking material.

The purpose of the present study is to determine whether muscle functional MRI (mfMRI) can be used to obtain three-dimensional (3-D) images useful for evaluating muscle activity, and if so, to measure the distribution of muscle activity within a medial gastrocnemius (MG) muscle. Seven men performed 5 sets of 10 repetitions of a calf-raise exercise with additional 15% of body-weight load. Magnetic resonance images were obtained before and immediately after the exercise. To threshold images, only those pixels showing transverse relaxation time (T2) greater than the mean+1 S.D. of the entire regions of interest (ROIs) in the preexercise image and T2 lower than the mean+1 S.D. of the entire ROIs in the postexercise image were identified. The survived pixels showing T2 are defined as active muscle. Those thresholded images were 3-D reconstructed, and this was used to determine area of active muscle along transverse, longitudinal and vertical axes. At the exercise level used in the present study, the percentage volume of activated muscle in the MG was 62.8+/-4.5%. There was a significant correlation between percentage volume of activated muscle and integrated electromyography (r=.78, P.05). Percentage areas of activated muscle were significantly larger in the medial than in the lateral region, in the anterior than in the posterior region and in the distal than in the proximal region (P.05). These results suggest that mfMRI can be used to evaluate the muscle activity and to determine intramuscular variations of activity within skeletal muscle.

The origin of the transverse relaxation time in optically excited semiconductor quantum wells is investigated based on the vector property of the interband transition matrix elements. The dephasing rate due to carrier-carrier (CC) scattering is found to be equal to half of the common momentum relaxation rate. The analytical expression of the polarization dephasing due to CC scattering in two-dimension is established and the dependence of the dephasing rate Gamma(cc) on the carrier density N is determined to be Gamma(cc) = constant (.) N-1/2, which is used to explain the experimental results and provides a promising physical picture. (C) 2004 Elsevier B.V. All rights reserved.

Transverse relaxation time (T(2*))-weighted (1)H-MRI of mouse lungs has been performed using partial liquid ventilation (PLV) with a perfluorocarbon (PFC)-in-water emulsion as a contrast modality for lung MRI. Significant sensitivity enhancement in MRI of mouse lungs has been demonstrated with the protocol. The results show that the T(2*) value in lung is approximately proportional to the infusion dose up to a dose of 5 ml/kg body weight (BW) (4.5 g PFC/kg BW) and becomes essentially constant beyond this dosage. T(2*) maps of lungs have been calculated and T(2*) in lungs is in the range of 10-35 ms with this technique, which is an order of magnitude greater than the T(2*) value of mouse lungs without using a PFC-in-water emulsion. T(2*)-weighted (1)H-MR images of mouse lungs have been obtained with good quality under our experimental conditions. We have applied this technique to detect tumors in mouse lungs. Our technique can detect small lung tumors of B16 melanoma, about 1 mm in diameter, in mice. With its significant MR sensitivity enhancement and technical simplicity, T(2*)-weighted (1)H-MRI using PLV with PFC-in-water emulsion offers a promising approach to investigate lung cancers using rodent models.

Transverse relaxation time (T2)-weighted images and T2 maps of white salted noodles (WSN) were investigated by magnetic resonance imaging technique. T2-weighted images and T2 maps clearly showed the differences in water status between noodles. The migration of moisture from surface regions to central regions of boiled WSN at different migration rates were investigated during storage. The distribution of T2 values changed differently depending on the cooking and storage times. The small differences in T2 values between surface region and central region of noodles cooked for 5 and 15 min were attributed to the limited water absorption during short cooking time, which resulted in high firmness. The changes in starch granules morphology observed under scanning electron microscope and the increase of noodle firmness measured by texture analyzer were significantly affected by the water status in noodles. The water status can be controlled by the cooking time.

Quantitative mapping of the effective transverse relaxation time, T2* and proton density was performed in a motor activation functional MRI (fMRI) study using multi-echo, echo planar imaging (EPI) and NumART2* (Numerical Algorithm for Real time T2*). Comparisons between NumART2* and conventional single echo EPI with an echo time of 64 ms were performed for five healthy participants examined twice. Simulations were also performed to address specific issues associated with the two techniques, such as echo time-dependent signal variation. While the single echo contrast varied with the baseline T2* value, relative changes in T2* remained unaffected. Statistical analysis of the T2* maps yielded fMRI activation patterns with an improved statistical detection relative to conventional EPI but with less activated voxels, suggesting that NumART2* has superior spatial specificity. Two effects, inflow and dephasing, that may explain this finding were investigated. Particularly, a statistically significant increase in proton density was found in a brain area that was detected as activated by conventional EPI but not by NumART2* while no such changes were observed in brain areas that showed stimulus correlated signal changes on T2* maps.

Low-field 1H nuclear magnetic resonance (NMR) transverse relaxation was used to measure water mobility and distribution of water in fresh cod fillets. The NMR relaxations were analysed with the so-called SLICING method giving uni-exponential profiles from which the transverse relaxation time (T2-values) and the relative sizes of the water populations were calculated. Two water populations with the T2-values of 50 and 94 ms were obtained. The shortest relaxation time was primarily found near the head, and water with the longest relaxation time was primarily found near the tail. This variation can be explained by the smaller muscle cells and muscle fibers in the tail, which may influence the distributions of water into the different pools. The amount of one of the water populations was correlated to the overall water content with a correlation coefficient of −0.94.