Water Fraction Research Articles

Pt(II) Complexes Showing Multicolor Emissions from Nanoparticles in Solution and Reversible Grinding- and Heating-Induced Luminescence Switching in Solid State.

To well understand luminescence modulation of Pt(II) complexes by inter-molecular interactions, three platinum complexes [Pt(moppy)Cl(L)] have been synthesized (Scheme 1) through incorporating the same C^N ligand moppyH = 2-(4-methoxyphenyl)pyridine, while different auxillary ligands L: SEt2 in 1, iccy = isocyanocyclohexane in 2, and icna = isocyanonaphthalene in 3. Crystal structures indicate that neighbouring molecules are connected through π⋅⋅⋅π interactions, forming supramolecular dimer structures in both 1 and 2, while supramolecular chain structure in 3. In a CH3CN-H2O mixed solvent, complexes 1-3 reveal enhanced luminescence due to nanoparticle formation. Upon increasing water fraction from 0% to 90%, complex 1 exhibits increasing green luminescence with two broad emissions at 450 and 516 nm. In contrast, both 2 and 3 show multicolour emissions, transiting from blue to yellow-green for 2, and from blue green to orange red for 3. Moreover, complex 3 exhibits reversible luminescence switching between on state with orange-red emission and off state upon alternately grinding and heating. In this paper, we discuss the influences of molecular structures and inter-molecular π⋅⋅⋅π and Pt-Pt interactions on luminescence behaviours of complexes 1-3.

Inland Water Body Fraction Map for Canada and Adjacent Regions at 250-m Spatial Resolution

We present a novel raster dataset of surface inland water body fraction over Canada and neighbouring regions, including the northern parts of the United States, as well as Greenland, Iceland, and the northeastern sector of Russia, at 250-m spatial resolution. It was derived from the Global Surface Water (GSW) dataset (version 5) using a two-step resampling to ensure an accurate replication of the original data and spatial consistency in terms of extent and resolution with the Long-Term Satellite Data Records derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Imaging Radiometer Suite (VIIRS) sensors. Additional input data and several coastline vector shape databases were utilized to refine the delineation of waterbodies and land-ocean interface. The resulting dataset is an 8-bit signed integer map, where each pixel represents either the water fraction or a land/ocean mask. Positive values indicate water bodies within Canada, while negative values represent areas outside of Canada. This dataset provides a more precise and up-to-date tool for medium-resolution studies of surface inland water in Canada, aligning closely with satellite imagery of similar spatial resolution. The dataset is freely available through the Government of Canada’s Open Government Portal.

Multi-decadal stability of water ages and tracer transport in a temperate-humid river basin

Abstract The temporal dynamics of water ages provide crucial insights into hydrological processes and transport mechanisms, yet there remains a significant gap in quantifying water age variability across different temporal scales. This study utilizes a comprehensive dataset spanning 70 years of hydrological observations and tritium records (1953–2022) with a semi-distributed hydrological model with integrated tracer routing routine based on StorageAge Selection functions SAS, to explore the temporal evolution of water ages in the 4000 km2 Upper Neckar River basin, Germany. Our findings indicate a systematic convergence of the variability of young water fractions and other metrics of water age in riverflow and evaporation towards stable values when averaging over increasing time scales. While at daily scales exhibiting considerable variability with young water fractions in riverflow F wy,Q ∼ 0.01–0.91 and in evaporation F wy,E ∼ 0.02–0.75, the variability of F wy,Q and F wy,E gradually reduces with increasing averaging time scales and converge to 0.45–0.47 and 0.96–0.97, respectively, between individual decades. Liquid water input (P L), comprising rainfall and snow melt, emerges as the dominant driver of F wy,Q across all time scales. In contrast, F wy,E shows varying controls with time scale: soil moisture content governs daily fluctuations, whereas P L dominates at the decadal scale. Overall, water ages demonstrate remarkable stability with only minor deviations in response to climatic variability: a 20% fluctuation in average decadal P L results in only ∼4% variation in F wy,Q and ∼1% in F wy,E over the study period. These findings suggest a lack of major long-term dynamics in water ages. Consequently, the results suggest that the physical transport dynamics in the Upper Neckar River basin, and potentially in comparable river basins with similar water age characteristics, can be considered near-stationary over multiple decades.

Dynamics of water status during fruiting body development of Agaricus bisporus and its relationship to mushroom quality

BackgroundThe analysis of changes in subcellular water distribution during mushroom fruiting is essential for elucidating the movement of water molecules within subcellular compartments. However, prior research on mushrooms has predominantly concentrated on alterations in water status during drying and postharvest processes in the food processing sector. Knowledge regarding subcellular water compartments throughout mushroom growth and fruiting remains limited. In the present study, the dynamics of subcellular water status across various growth stages of Agaricus bisporus were investigated using LF-NMR relaxometry.ResultsThree components were resolved from transverse relaxation curves, assigned to cell wall, cytoplasmic and vacuolar water, in both whole mushroom and mushroom tissues (stalk and Pileus). As fruiting body developed, the proton degree of freedom of three water fractions determined by T2 measurement all increased. The T2 values of three water fractions in stalk were higher than those in pileus during the first three stages, whereas they became lower compared to those in pileus from somewhere between the two stages of 2–3 and 3–4. Apparently different patterns of change in three water contents were observed, indicating the variations in water distribution at subcellular level. Furthermore, relative humidities caused obvious changes in water status. In addition, highly significant correlations were observed between T2 and textural parameters, indicating that the dynamics of water status exert a substantial influence on the formation of mushroom quality.ConclusionsA consistent increase in the transverse proton degree of freedom of three distinct water fractions, accompanied by markedly divergent patterns in the variations of the three water contents, was observed across different growth stages of fruiting bodies. Subsequently, highly significant correlations between T2 and textural parameters were established. This study would contribute to reveal macroscopic water transport within mushroom tissues and provide theoretical insights for optimizing high-quality mushroom cultivation.Graphical

Effect of Hydration States on the Anti-Icing/Frosting Performance of Zwitterionic Hydrogel-Coated Surfaces.

Zwitterionic polymers have gained considerable research attention because of their unique properties and have been widely used in many biomedical and electrochemical applications. Recently, zwitterionic polymers have been investigated for use as anti-icing/frosting surfaces; however, key factors influencing their anti-icing/frosting performance and effectiveness under real operational conditions remain underexplored. Therefore, in this study, we quantitatively analyze the hydration states of zwitterionic hydrogels synthesized from polymerizable zwitterions, such as carboxybetaine methacrylate (CBMA), 2-methacryloyloxyethyl phosphorylcholine (MPC), and sulfobetaine methacrylate (SBMA). We focused on the effect of these hydration states on anti-icing/frosting performance in practical environments through a thermodynamic approach. The fractions of freezable water were 14% in pCBMA, 16% in pMPC, and 34% in pSBMA. The activation energy for ice formation within the hydrogel was observed as pCBMA (101.71 kJ mol-1) > pMPC (74.32 kJ mol-1) > pSBMA (59.82 kJ mol-1), suggesting that the zwitterionic hydrogel-coated surface makes ice formation more challenging compared to the uncoated bare substrate (45.79 kJ mol-1). We confirm that a reduction in the freezable water fraction within the hydration state can enhance the anti-icing/frosting performance. Our results demonstrate that zwitterionic hydrogels with strong interaction energies offer significant potential as anti-icing/frosting coatings. This work also reveals the in-depth mechanism of ice propagation and frost growth on hydrogel coatings and proposes insights that can be used to efficiently design future anti-icing/frosting coatings.

Antiproliferative Effect of Methanolic Extract of Vernonia greggii (Asteraceae) on Human Tumoral HeLa Cells Nanoencapsulated into PLGA-Nanoparticles

Vernonia greggii belongs to the Asteraceae family, and some members of this family have been reported to possess anticancer properties. This study evaluated the antiproliferative effect of V. greggii methanol extract (ME), both in its free form and encapsulated into poly(lactic-co-glycolide) (PLGA) nanoparticles (NPs), on human cervical cancer cells (HeLa) and human epidermal keratinocytes (HaCaT). The extract was subsequently sub-fractionated into n-hexane (F-He), methanol (F-Me), and distilled water (F-Ac) fractions, and their antiproliferative effects were assessed. Time-dependent toxicity on HeLa cells was observed for the free-form fractions, with the F-Me fraction showing the highest efficacy compared to the others. Additionally, an NP formulation based on PLGA and F-Me (NPs F-Me) was developed, achieving 64.21% encapsulation efficiency and 11.38% drug loading. The NPs had an average size of 146.9 nm, a polydispersity index (PDI) of 0.103, and a ζ-potential of 23.3 mV. NPs F-Me were tested on HeLa and HaCaT cells, with toxicity observed at concentrations of 300 and 500 μg/mL, affecting tumor cell morphology. Furthermore, the hemolytic activity of F-Me and NPs F-Me was evaluated. The major bioactive compounds in the F-Me fraction were identified using Liquid Chromatography–Mass Spectrometry (LC-MS). These findings suggest that the F-Me fraction of V. greggii exerts an antineoplastic effect both in its free form and when encapsulated in nanoparticles.

Aggregation Behavior of α-Substituted Dibenzoylmethanatoboron Difluoride Complex with Various Alkyl Groups in Water/Acetone Mixtures

Abstract Dibenzoylmethanatoboron difluoride complexes (BF2DBM) exhibit aggregation-induced emission (AIE) properties by introducing a methyl group at the α-position of the dioxaboroline ring. In this study, we synthesized α-substituted BF2DBM derivatives with alkyl groups and evaluated their photophysical and AIE properties as a function of water fraction (fw) in water/acetone mixtures. The aggregation behavior of the BF2DBMs differed depending on fw, although they exhibited AIE independently of the alkyl groups. The fw dependence suggested that the alkyl groups exhibit hierarchical aggregation behavior, indicating that alkyl groups affect the intermolecular stacking pattern based on the X-ray crystallography, leading to the difference in the fluorescence properties of the crystals.

Correlations between postmortem quantitative MRI parameters and demyelination, axonal loss and gliosis in multiple sclerosis: A systematic review and meta-analysis.

Magnetic resonance imaging (MRI) is frequently used to monitor disease progression in multiple sclerosis (MS). This study aims to systematically evaluate the correlation between MRI measures and histopathological changes, including demyelination, axonal loss, and gliosis, in the central nervous system of MS patients. We systematically reviewed post-mortem histological studies evaluating myelin density, axonal loss, and gliosis using quantitative imaging in MS. Relevant studies were identified through searches in PubMed, EMBASE, and Web of Science. A total of 38 studies involving 1782 regions of interest from 229 subjects were included. Pooled random-effects models were used to calculate the correlation between demyelination, axonal loss, gliosis, and various MRI parameters, including magnetization transfer ratio (MTR), T1 and T2 relaxation times, myelin water fraction (MWF), proton density (PD), and diffusivities. Pair-wise analyses compared results between lesioned and non-lesioned tissues. Our results demonstrated moderate to strong correlations between MRI parameters and myelin density in MS, with correlation coefficients: T1 (0.72), T2 (0.72), MTR (-0.73), FA (-0.73), RD (0.70), MD (0.70), MWF (-0.82), and PD (0.73). Interestingly, stronger correlations were found in lesioned tissues compared to non-lesioned tissues (P < 0.001). Moderate correlations were found between MRI parameters and axonal loss and gliosis. Our study reveals significant correlations between MRI techniques and histological assessments of myelin, axonal damage, and gliosis in MS. MRI metrics exhibited a more robust association with demyelination in lesioned areas than in non-lesioned brain tissue, highlighting the pronounced degree of myelin degradation in MS lesions. Further investigation is warranted to corroborate these results and refine MRI-based monitoring of MS pathology.

Investigating the association between human brainstem microstructural integrity and hypertension using magnetic resonance relaxometry.

The brainstem plays a vital role in regulating blood pressure, and disruptions to its neural pathways have been linked to hypertension. However, it remains unclear whether subtle microstructural changes in the brainstem are associated with an individual's blood pressure status. This exploratory, cross-sectional study investigated the relationship between brainstem microstructure, myelination, and hypertensive status in 116 cognitively unimpaired adults (aged 22-94 years). Advanced MRI techniques, including relaxometry (R1, R2) and myelin water fraction (MWF) analysis, were employed to assess microstructural integrity and myelin content in ten brainstem subregions. Our results revealed significant associations between higher microstructural damage or lower myelin content (indicated by lower R1, R2, or MWF values) and hypertensive status, particularly in the midbrain tegmentum. Notably, combining these MRI metrics yielded high classification accuracy (AUC > 0.85). Our findings suggest a potential link between disrupted brainstem tissue integrity, myelin content, and elevated blood pressure, warranting further longitudinal investigations to explore this relationship.

Coupling machine learning and group contribution method to predict density and viscosity of ionic liquid-inorganic solvent-water ternary mixtures

Accurate prediction of the physical properties of mixed systems is essential for efficient industrial design and process optimization. This study explores the use of a hybrid approach that combines the group contribution (GC) method with advanced machine learning (ML) algorithms to predict the density and viscosity of ternary mixtures comprising ionic liquids (ILs), inorganic solvents (ICs), and water. The machine learning algorithms employed include artificial neural networks (ANN), XGBoost, and LightGBM. A comprehensive dataset was compiled, encompassing 5738 density data points for 25 classes of ILs and 34 classes of ICs, and 1551 viscosity data points for 12 classes of ILs and 16 classes of ICs. The results indicate that all three ML-GC models significantly outperformed traditional GC models without ML algorithms. Notably, the XGBoost-GC model exhibited the highest prediction accuracy for density, with an R2 of 0.9983, while the ANN-GC model with 7 neurons in the hidden layer delivered the best predictions for viscosity, with an R2 of 0.9967. Additionally, the Shapley Additive Interpretation (SHAP) analysis reveals that the molar fractions of water and IC primarily influence density, whereas the presence of the IC anion NO3 and temperature significantly impact viscosity. Moreover, a practical example is provided to illustrate the real-world applicability of the ML-GC models developed in this work, highlighting their potential to enhance industrial processes through precise property predictions.

Heterogeneous dynamics in aging phosphate-based geopolymer.

The time-evolution of dynamics as well as microstructure and mechanical response of phosphate-based geopolymers was probed using x-ray photon correlation spectroscopy and rheological tests. The analyzed relaxation processes in the freshly prepared geopolymer mixes evidenced a q-independent mode of the autocorrelation function, ascribed to density fluctuations of the already established molecular network, undergoing reconfiguration without significant mass transport. Upon curing, the detected motions are localized and depict a system evolving toward structural arrest dominated by slower hyperdiffusive dynamics, characterized by a compressed exponential regime, pointing to a structural relaxation process subjected to internal stresses, in a context of marked dynamical and structural heterogeneity. The system ages through a "densification" process producing declining small angle scattered intensity, as two finely intermixed gel-like reaction products, namely, one hydrated aluminophosphate and one hydrated silica, form a percolated network possessing surface fractal scaling of progressively shorter average correlation length. In this scenario, the nominal Al/P molar ratio of the mix, being an index of network-forming ability, is positively correlated with the dynamic viscosity and the overall kinetics, whereas the contrary occurs for the fraction of water.

Comparative Sensitivity of MRI Indices for Myelin Assessment in Spinal Cord Regions.

Background/Objectives: Although multiple magnetic resonance imaging (MRI) indices are known to be sensitive to the noninvasive assessment of myelin integrity, their relative sensitivities have not been directly compared. This study aimed to identify the most sensitive MRI index for characterizing myelin composition in the spinal cord's gray matter (GM) and white matter (WM). Methods: MRI was performed on a deer's ex vivo cervical spinal cord. Quantitative indices known to be sensitive to myelin, including the myelin water fraction (MWF), magnetization transfer ratio (MTR), the signal ratio between T1- and T2-weighted images (T1W/T2W), fractional anisotropy (FA), mean diffusivity (MD), electrical conductivity (σ), and T1, T2, and T1ρ relaxation times were calculated. Their mean values were compared using repeated measures analysis of variance (ANOVA) and post hoc Bonferroni tests or Friedman and post hoc Wilcoxon tests to identify differences across GM and WM columns possessing distinct myelin distributions, as revealed by histological analysis. Relationships among the indices were examined using Spearman's rank-order correlation analysis. Corrected p < 0.05 was considered statistically significant. Results: All indices except σ differed significantly between GM and all WM columns. Two of the three WM columns had significantly different MWF, FA, MD, and T2, whereas one WM column had significantly different MTR, σ, T1, and T1ρ from the others. A significant moderate to very strong correlation was observed among most indices. Conclusions: The sensitivity of MRI indices in distinguishing spinal cord regions varied. A strategic combination of two or more indices may allow the accurate differentiation of spinal cord regions.

Electric Conductivity Transitions of Water-Absorbable Polybenzimidazole Films.

Transitions seen in the electric properties of water-absorbable poly(2,5-benzimidazole) (ABPBI) films were confirmed by electric conductivity, dielectric constant, and time-domain nuclear magnetic resonance (NMR) measurements. The electric resistance of the films was measured at room temperature using a high-resistance meter, and the dielectric constant at room temperature was measured using an LCR meter in the frequency range of 90 Hz to 8 MHz. The water absorption ratio at equilibrium absorption for the films was 37%, which corresponded to a volume fraction of water of 0.33. The electric conductivity of the films without water absorption was ~1014 S·cm-1, and it increased to ~1010 S·cm-1 with increasing volume fraction, showing a percolation threshold at a volume fraction of 0.025, and remarkable transitions at volume fractions of 0.075 and 0.135. The dielectric constant of the films without water absorption was 3.4, and it increased to 8.1 with increasing volume fraction, showing a transition only at a volume fraction of 0.135. Above a volume fraction of 0.075, where a transition in conductivity was observed, there were two relaxation times at 18-31 μs and 20-93 μs, as determined from the time-domain NMR, and these relaxation times increased with increasing volume fraction. The longer relaxation time increased significantly at a volume fraction of 0.072, which was close to the volume fraction of the transition seen in conductivity. The relationship between the chain mobility of ABPBI and the deterioration in electric insulating properties is discussed.

Shaping the structural dynamics of motor learning through cueing during sleep.

Enhancing the retention of recent memory traces through sleep reactivation is possible via Targeted Memory Reactivation (TMR), involving cueing learned material during post-training sleep. Evidence indicates detectable short-term microstructural changes in the brain within an hour after motor sequence learning, and post-training sleep is believed to contribute to the consolidation of these motor memories, potentially leading to enduring microstructural changes. In this study, we explored how TMR during post-training sleep affects performance gains and delayed microstructural remodeling, using both standard Diffusion Tensor Imaging (DTI) and advanced Neurite Orientation Dispersion & Density Imaging (NODDI). Sixty healthy young adults participated in a five-day protocol, undergoing five Diffusion-Weighted Imaging (DWI) sessions, pre- and post-two motor sequence training sessions, and after a post-training night of either regular sleep (RS) or TMR. Results demonstrated rapid skill acquisition on Day 1, followed by performance stabilization on Day 2, and improvement on Day 5, in both RS and TMR groups. (Re)training induced widespread microstructural changes in motor-related areas, initially involving the hippocampus, followed by a delayed engagement of the caudate nucleus. Mean Diffusivity (MD) changes were accompanied by increased Neurite Density Index (NDI) in the putamen, suggesting increased neurite density, while Free Water Fraction (FWF) reduction indicated glial reorganization. TMR-related structural differences emerged in the dorsolateral prefrontal cortex (DLPFC) on Day 2 and the right cuneus on Day 5, suggesting unique sleep TMR-related neural reorganization patterns. Persistence of practice-related structural changes, although moderated over time, suggest a lasting neural network reorganization, partially mediated by sleep TMR.

Structural and functional changes of Post-Stroke Depression: A multimodal magnetic resonance imaging study.

This study investigated changes in gray matter volume (GMV), white matter microstructure, and spontaneous brain activity in post-stroke depression (PSD) using multiple MRI techniques, including neurite orientation dispersion and density imaging (NODDI). Changes in GMV, neurite density index (NDI), orientation dispersion index (ODI), fraction of isotropic water (ISO), diffusion tensor imaging (DTI) parameters, and the amplitude of frequency fluctuations (ALFF) were assessed between PSD (n=20), post-stroke without depression (n=20), and normal control (n=20) groups. Receiver operating characteristic (ROC) curve analysis was performed to test the classification performance of the variant parameters of each MRI modality, each single MRI modality and multiple MRI modality. Compared to patients with post-stroke without depression (non-PSD), those with PSD showed increased ODI and ISO in the widespread white matter, as well as increased ALFF in the left pallidum. No significant differences in the GMV or DTI parameters were observed between the two groups. Furthermore, the ODI of the right superior longitudinal fasciculus and NODDI showed the best classification performance for PSD at their respective comparison level (the areas under the ROC curves (AUC)=0.917(0.000), 0.933(0.000)). The model of NODDI-derived parameters combined with non-diffusion MRI modality parameters (i.e., GMV and ALFF) showed better diagnostic performance than that of DTI-derived parameters. These findings suggest that PSD is associated with structural and functional abnormalities that may contribute to depressive symptoms. Additionally, NODDI showed its advantages in the description of structural alterations in emotion-related white matter pathways and classification performance in PSD.

Characterizing Dyeing Constituents from Walnut Green Husks: Utilization of a Harmful Agricultural By-product as Natural Dye to Alleviate Its Environmental Pollution

Walnut green husks (WGHs), a by-product of walnut cultivation, poses significant environmental concerns due to their indiscriminate disposal practices. To alleviate this problem, this study explored the possibility of utilizing WGHs as a resource of natural dyes focusing on the characterization of responsible bioactive compounds. The crude aqueous extract of WGHs displayed excellent dyeing activity on fabrics, resulting in a brownish color; further chromatographic fractionation revealed that the distilled water (dH2O) fraction of the extract yielded from macroporous resin column chromatography exhibited the best dyeing effect compared with other ethanol-based fractions (20%, 60%, and 90%). Based on the subsequent LC-MS/MS, FTIR, and UV-Vis analysis, six most dominant, colored compounds that are commercially available were chosen for evaluating their dyeing capacity, including β-carotene, 2,4-dinitrophenol, phylloquinone, astaxanthin, quercetin 3-sambubioside and avicularin, and indeed their mixture displayed similar dyeing effect as the dH2O fraction and the crude extract of WGHs on fabrics. The isolated compounds and their mixture exhibited comparable dyeing performance to the crude extract, with notable K/S color strength values. Colorimetric analysis revealed distinct CIEL*a*b* values for each compound; furthermore, the dyed fabrics demonstrated moderate-excellent colorfastness. Our study implied that WGHs extract and ingredients have the potential to be utilized as natural dyeing agents, which provides a new insight for eliminating environmental pollution triggered by hazardous agricultural wastes.

Use of multi-modal non-contrast MRI to predict functional outcomes after stroke: A study using DP-pCASL, DTI, NODDI, and MAP MRI.

This study aims to assess whether water exchange rate (kw), a surrogate for blood-brain barrier (BBB) permeability, is associated with functional outcomes in patients with acute ischemic stroke (AIS). We studied 22 AIS patients enrolled from 1/2022 to 4/2024 who underwent multi-modal non-contrast imaging on a 3.0-Tesla scanner, including DP-pCASL, DTI, NODDI and MAP imaging. For each parametric map, the intensity and standard deviation (SD) were calculated for the infarcted region. The diffusion maps included were b0, Fractional Anisotropy (FA), Mean Diffusivity (MD), Intra-cellular Volume Fraction (ICVF), Free Water Fraction (FWF), and Orientation Dispersion Index (ODI), q-Space Mean Square Displacement (QMSD), Return-to-Axis Probability (RTAP), Return-to-Plane Probability (RTPP), Return-to-Origin Probability (RTOP), Propagator Anisotropy (PA), and non-Gaussianity (NG). The perfusion-based maps were cerebral blood flow (CBF), arterial transit time (ATT), and kw. The outcome variable was modified Rankin Scale (mRS). Twenty-two patients were included. The average age was 69.5±13.5, the mean NIHSS of 12.4±7.7, and the median infarct of 25.7 (8.4-98.8) ml. Multivariable linear regression identified lower kw (β=-0.029, p=0.041), longer time to MRI (β=0.012, p=0.013) and larger stroke volume (β=0.014, p=0.006) as predictive of higher mRS. Higher CBF (β=0.660, p=0.003) and RTAP (β=1.528, p=0.010), and lower SD RTAP (β=-0.709, p=0.016), RTPP (β=-2.132, p=0.006), and NG (β=-1.036, p=0.011) were identified as most predictive of kw through multivariable linear regression analysis. Lower kw is predictive of higher mRS in patients with AIS. Increasing CBF and RTAP and lower SD RTAP, RTPP, and NG were correlated with higher kw.

Quantifying the young water fraction and residence time of five inflow rivers for Lake Poyang using stable hydrogen and oxygen isotopes

Quantifying the young water fraction and residence time of five inflow rivers for Lake Poyang using stable hydrogen and oxygen isotopes

Histological Validation of Multi-Echo Gradient Echo (MGRE)-Derived Myelin Water Fraction (MWF) at 9.4 T and the Influence of Orientation on Quantification.

Myelin is essential in the nervous system of mammals. As the location and degree of myelin loss can reflect varied pathophysiological status, noninvasive measurement of myelin is of high importance. The magnetic resonance imaging (MRI) technique of myelin water fraction (MWF) derived from multi-echo gradient echo (MGRE) sequence is a promising tool for the quantification of myelin content due to the low specific absorption rate (SAR) compared with the spin-echo sequence, time efficiency, and wide availability. Yet to our knowledge, MGRE-derived MWF has never been quantitatively validated with histology. The main objective of this study was to quantitatively validate the MRI findings by referencing the myelin histology using a rat model. As a second objective, we investigated how the orientation of white matter fibers with respect to the static B0 field impacted both the apparent transverse relaxation rate (R2* = 1/T2*) and the derived MWF. Moreover, MWF is known to change with age; thus, we compared rat brains of different ages. The orientation effect of MWF in a clinical setting was studied using 3 T human data. Twenty exvivo rat brains with different ages and three healthy volunteers were scanned on a 9.4 T Bruker and 3.0 T Siemens systems, respectively. The 3D MGRE and diffusion tensor imaging (DTI) data were acquired. Our results showed a highly significant correlation between MGRE-derived MWF and histological stain of myelin, and susceptibility and diffusivity also demonstrated a significant association with myelin. Both MWF and R2* (R2* = 1/T2*) values changed as a function of orientation, and the function varied with age. Furthermore, MWF and R2* were more sensitive to age than DTI. Invivo 3 T human MWF also changed substantially with the orientation as well. Our results support that MGRE-derived MWF can be used to assess the myelin content quantitatively.

Water fraction of Schizochytrium sp. protein: A functional ingredient with superior gelation properties for sustainable food applications

In order to assess the potential of fractionated Schizochytrium sp. protein as functional proteins, the proteins were fractionally extracted. The structure, thermal characteristic and cross-linking interaction of proteins, along with the gel properties of heat-induced gels were analyzed and compared to those of albumin from chicken egg white (ACEW). Water fraction of Schizochytrium sp. protein (WFSP) was identified as the dominant fractionated protein. Classified as globular proteins, WFSP exhibited a molecular weight range of 30–250 kDa. Compared to ACEW, WFSP displayed a significantly lower denaturation temperature, indicating reduced energy consumption during food processing. Moreover, at a concentration of 50 g/L, WFSP gels displayed superior strength and stability by higher G' (114.7 kPa) and fracture strain (2.38 %) compared to ACEW gels (92.2 kPa and 1.33 %). Besides, WFSP gels had lower hardness, chewiness and water holding capacity, but higher springiness and cohesiveness than ACEW gels. WFSP formed porous particulate stranded three-dimensional gel network structures with uniform pore size, flat surface and complete sheet. The temperature sweeps and protein-protein interactions results suggested that hydrogen bonds played a dominant role in the formation of WFSP gel network. Overall, WFSP exhibits excellent gelation properties and holds promise as a functional protein for food production.