Free Water Research Articles

Inflammation in the white matter relates to core Alzheimer's disease pathophysiological processes

AbstractBackgroundIn‐vivo PET imaging studies have demonstrated neuroinflammation (microglia reactivity) in the neocortex of Alzheimer’s disease (AD) patients. However, the extent and implication of microglia reactivity in white matter regions remains unclear. Here, we explored microglia reactivity in white matter using PET imaging of the translocator protein (TSPO) in relation to core AD biomarkers (amyloid, tau, and astrogliosis), microstructural damage, and cognitive decline.MethodNinety‐one participants from the Translational Biomarkers in Aging and Dementia cohort (45% Aβ‐positive, 39% cognitively impaired) underwent diffusion‐weighted MRI, TSPO‐PET (11C‐PBR28), amyloid‐PET (18F‐NAV4694), tau‐PET (18F‐MK6240), and plasma Aβ42/40, ptau181, ptau217, and ptau231. We investigated the associations of TSPO‐PET SUVR in white matter lobes (eroded by 2mm3) with each of the AD biomarkers, diffusion metrics, and cognition, adjusted for demographics and global cortical TSPO‐PET. Longitudinally, we investigated the interaction between time (up to 2y) and baseline white matter TSPO‐PET SUVR on cognitive decline, adjusted for demographics and cortical amyloid.ResultWhite matter TSPO‐PET was increased globally with older age and frontally with male sex (p<0.05). In impaired individuals, TSPO‐PET was elevated in temporo‐occipital white matter regions compared to controls (p=0.01‐0.02). The occipital increases were associated with reactive astrogliosis (p=0.011) and higher‐Braak tau‐PET (p=0.003‐0.034 for Braak3‐4) and plasma ptau181 (p=0.014) (Figure 1A‐B), but not with Aβ, ptau231 or ptau217. In addition, higher occipital TSPO‐PET was associated with lower fibre integrity (fractional anisotropy, p=0.025) but not free water. Finally, in relation to cognition, higher occipital and parietal TSPO‐PET was significantly associated with impaired memory and language, respectively, independent of Aβ (Figure 1C). Longitudinally, within the same patient, higher white matter TSPO‐PET at baseline was significantly associated with favorable clinical outcome over time (Figure 1D).ConclusionIncreased microglia reactivity (TSPO‐PET) in posterior white matter may indicate later‐stage AD associated with astrogliosis, tau, and dysfunction of the memory and language domains. Another novel finding is that individuals with higher white matter TSPO‐PET at baseline displayed better clinical prognosis over time. As such, assessing white matter inflammation could be promising to evaluate target engagement in clinical trials of anti‐inflammatory drugs and to subtype patients for better patient‐centric treatment outcome.

Unraveling contributions to the Z-spectrum signal at 3.5 ppm of human brain tumors.

To evaluate the influence of the confounding factors, direct water saturation (DWS), and magnetization transfer contrast (MTC) effects on measured Z-spectra and amide proton transfer (APT) contrast in brain tumors. High-grade glioma patients were scanned using an RF saturation-encoded 3D MR fingerprinting (MRF) sequence at 3 T. For MRF reconstruction, a recurrent neural network was designed to learn free water and semisolid macromolecule parameter mappings of the underlying multiple tissue properties from saturation-transfer MRF signals. The DWS spectra and MTC spectra were synthesized by solving Bloch-McConnell equations and evaluated in brain tumors. The dominant contribution to the saturation effect at 3.5 ppm was from DWS and MTC effects, but 25%-33% of the saturated signal in the gadolinium-enhancing tumor (13%-20% for normal tissue) was due to the APT effect. The APT# signal of the gadolinium-enhancing tumor was significantly higher than that of the normal-appearing white matter (10.1% vs. 8.3% at 1 μT and 11.2% vs. 7.8% at 1.5 μT). The RF saturation-encoded MRF allowed us to separate contributions to the saturation signal at 3.5 ppm in the Z-spectrum. Although free water and semisolid MTC are the main contributors, significant APT contrast between tumor and normal tissues was observed.

Sex, racial/ethnic, and APOE‐ε4 allele differences in longitudinal white matter microstructure in multiple cohorts of aging

AbstractBackgroundThere is growing recognition that white matter microstructural integrity is affected in Alzheimer’s disease. The goal of this study was to characterize sex, racial/ethnic, and apolipoprotein (APOE)‐ε4 allele differences in white matter integrity.MethodsThis study included participants from ADNI, BLSA, ROS/MAP/MARS, and VMAP, all longitudinal cohorts of aging. This combined dataset included 6,837 imaging sessions from 2,619 participants age 50+ with diffusion MRI (dMRI) and demographic and clinical data (60% female, 31.4% APOE‐ε4 carriers, 78.9% White). dMRI was preprocessed using the PreQual pipeline. Free‐water (FW) correction was used to generate FW and FW‐corrected intracellular metrics including fractional anisotropy (FAFWcorr), mean diffusivity (MDFWcorr), axial diffusivity (AxDFWcorr), and radial diffusivity (RDFWcorr). Conventional and FW‐corrected metrics were harmonized using the Longitudinal ComBat package. Linear mixed‐effects models related sex, race/ethnicity, and APOE‐ε4 allele status to longitudinal diffusion metrics in 48 white matter tracts, adjusting for age at baseline, sex, education, race/ethnicity, APOE‐ε4 carrier status, cognitive status at baseline, and converter status. All models were corrected for multiple comparisons using the FDR approach.ResultSex differences in white matter were most notable in projection tracts (Figure 1A) and were primarily in FW‐corrected metrics. Females had lower FAFWcorr and higher RDFWcorr, indicative of worse microstructure, but lower AxDFWcorr. This sex difference was most pronounced for FAFWcorr in the ventral premotor projection tract (p=1.53x10‐62). There were global differences in white matter integrity by race/ethnicity (Figure 1B). Non‐Hispanic White participants tended to have higher conventional FA, FAFWcorr and AxDFWcorr and lower RDFWcorr. There was no association between APOE‐ε4 status and white matter integrity and no significant sex x race/ethnicity, sex x APOE‐ε4, or race/ethnicity x APOE‐ε4 interactions for conventional or FW‐corrected metrics when corrected for multiple comparisons.ConclusionThere were striking sex and racial/ethnic (but not APOE‐ε4) differences in white matter tract integrity in a large cohort of aging adults. Female participants tended to have measures reflective of worse white matter integrity, and non‐Hispanic White participants tended to have measures reflective of greater integrity. Additional research exploring the etiology of these differences will be important to better understand disparities in Alzheimer’s disease.

Distinct Spatial Patterns for White Matter Microstructure Changes in an Aging and Alzheimer’s Disease Cohort

AbstractBackgroundWhite matter (WM) damage is seen with neurodegenerative and cerebrovascular pathologies and contributes to cognitive dysfunction. We hypothesized that there are multiple disease progression patterns in WM microstructural changes related to aging and dementia, and these can be identified using SuStaIn (data‐driven clustering algorithm for disease subtype and stage discovery) on multishell diffusion MRI (NODDI) data. NODDI provides information on cellular tissue architecture – neurite density index (NDI) measures packing density of axons and dendrites, and free water fraction (FWF) measures unrestricted water, e.g., interstitial and cerebrospinal fluid.MethodWe identified 1136 participants (mean age=70 years, 51% male, 40% Aβ‐positive, 19% MCI/AD dementia) from the Mayo ADRC and Mayo Clinic Study of Aging. We analyzed NDI and FWF in 55 WM regions. We selected a subset of WM features that monotonically changed with clinical disease progression and then applied the Z‐score SuStaIn algorithm.ResultNDI in seven regions and FWF in six regions survived selection criteria (Figure 1). Noteworthy, the NDI regions were predominantly located in the temporal lobe, while FWF regions were primarily distributed in the frontal and subcortical regions. The SuStaIn algorithm discovered two stable clusters: the NDI‐First (Temporal) and FWF‐First (Frontal) groups (Figure 2). For the NDI‐First group, temporal lobe NDI changed early followed by frontal FWF. The FWF‐First group had the reverse order. There was clear phase separation based on which measure changed first. Stages of the NDI‐First group correlated better with meta‐ROI Tau‐PET SUVR and with MMSE than the FWF‐First group (p<0.01), suggesting that NDI‐First may be indicative of a primarily AD pathway.ConclusionGiven NDI changes are likely degenerative and FWF are suggested to be other processes such as neurodegeneration or inflammatory, the observed changes in the temporal and frontal regions may be due to distinct etiologies, i.e., neurodegenerative in the temporal lobes vs. vascular dysfunction often observed in the frontal lobes. The SuStaIn algorithm showed promise in discovering disease subtypes of WM microstructural changes. Further work is needed to understand the mechanistic basis of these observed changes and integrate WM changes for differential etiology identification and disease staging.

Impacts of zein-fucoidan nanoparticles with and without curcumin on gel properties of golden threadfin bream (Nemipterus virgatus) surimi.

Zein-fucoidan nanoparticles (ZFNPs) as an excellent colloidal delivery system for bioactive compounds, such as curcumin (CUR), show a great application potential in the food industry. Herein, various amount of ZFNPs, ZFNPs loaded with CUR (CZFNPs) and free CUR were added into golden threadfin bream (Nemipterus virgatus) surimi to explore their impacts on the gel properties. Dynamic rheological tests showed that storage modulus (G') and loss modulus (G") of surimi gels with the additive amount of ZFNPs and CZFNPs under 0.8% significantly increased and their loss tangent (tan δ) slightly reduced during thermal gelation, indicating stronger networks and better structural configuration. Puncture test and textural profile analysis confirmed the improvements in breaking force, hardness, chewiness and gumminess of surimi gels. Furthermore, 0.8% of ZFNPs and CZFNPs induced conformational changes of surimi proteins from α-helix to β-sheet and random coil, and then facilitating the cross-link between proteins. Low-field nuclear magnetic resonance revealed that ZFNPs and CZFNPs promoted the redistribution of water in surimi gel networks, converting more free water to tightly bounded water, and thus increasing the water holding capacity. However, the addition of equivalent amount of CUR caused detrimental to surimi gel properties. In conclusion, ZFNPs and CZFNPs conferred better gel properties and nutritional characteristics to surimi gels, and this study provided a theoretical basis for the development of high-quality surimi products.

Use of mean apparent propagator (MAP) MRI in patients with acute ischemic stroke: A comparative study with DTI and NODDI

PurposeTo evaluate the Mean Apparent Propagator (MAP) MRI for processing multi-shell diffusion imaging in patients with acute ischemic stroke (AIS) and correlate to diffusion tensor imaging (DTI) and neurite orientation and dispersion density imaging (NODDI). MethodsWe enrolled patients with AIS from 1/2022 to 4/2024 who underwent multi-shell diffusion imaging on a 3.0-Tesla scanner to generate DTI, NODDI and MAP measures. Mean intensity and standard deviation (SD) were calculated for the infarcted regions-of-interest in b0, fractional anisotropy (FA), mean diffusivity (MD), intra-cellular volume fraction (ICVF), free water fraction (FWF), and orientation dispersion index (ODI), return to the origin probability (RTOP), return to the plane probability (RTPP), return to the axis probability (RTAP), propagator anisotropy (PA), q-space Mean Square Displacement (QMSD), and non-Gaussianity (NG). ResultsTwenty-two patients were included with an average age of 69.5 ± 13.5, mean NIHSS of 12.4 ± 7.7, and median infarct of 73.3 ± 10.1 ml. ICVF was correlated with RTPP (ρ = 0.82, p < 0.01), RTAP (ρ = 0.76, p < 0.01) and RTOP (ρ = 0.79, p < 0.01), ODI with PA (ρ = −0.83, p < 0.01), FWF with RTOP (ρ = −0.73, p < 0.01), RTAP (ρ = −0.69, p < 0.01), and RTPP (ρ = −0.73, p < 0.01), MD with RTPP (ρ = −0.80, p < 0.01), RTOP (ρ = −0.79, p < 0.01), and RTAP (ρ = −0.77, p < 0.01), FA with RTAP (ρ = 0.77, p < 0.01), RTOP (ρ = 0.67, p = 0.01), PA (ρ = 0.74, p < 0.01), and SD PA (ρ = 0.85, p < 0.01). Multivariable linear regression identified the SD QMSD (β = 0.406, p = 0.008), thrombectomy (β = 0.481, p = 0.002), and infarct volume (β = 0.292, p = 0.051) as predictive of stroke severity based on NIHSS. ConclusionsGiven its short processing time, MAP MRI is a valuable alternative with potential for clinical use in AIS.

Improving gel properties of silver carp (Hypophthalmichthys molitrix) myosin with flavonols: Unveiling the advantages of isorhamnetin

This study explores the impact of flavonols (kaempferol, quercetin, kaempferitrin, and isorhamnetin) on the gel properties of myosin derived from silver carp (Hypophthalmichthys molitrix). Before employing a two-stage heating process, myosin samples are pretreated with flavonols, which enhance the structural stability of myosin and aid in the dispersion of myosin molecules. These pretreatments prepare the samples for subsequent thermal processing, where flavonols facilitate myosin unfolding and enhance intermolecular aggregation, thereby improving gel strength. This process also transforms free water within the gel to bound water, significantly increasing the water-holding capacity. Both macroscopic and microscopic rheological analyses suggest that flavonols, particularly isorhamnetin, notably enhance the elasticity and viscosity of myosin during the gelation process. Further, microstructural examinations employing techniques such as small-angle X-ray scattering and micro-computed tomography demonstrate that samples treated with flavonols develop denser and more uniform gel networks. Analytical studies reveal that flavonols, especially methylated derivatives like isorhamnetin, effectively promote gelation through strengthening hydrophobic interactions, disulfide bonds, and ionic interactions among myosin molecules. This research underscores the potential of flavonols as natural additives to enhance the quality and functional properties of surimi products, thereby elevating the processing standards of aquatic products.

Mechanism of improved cellulase production by Trichoderma reesei in water-supply solid-state fermentation.

High production cost of cellulases limits its commercial application on lignocellulose. Solid-state fermentation (SSF) has special advantages of water and energy conservation, however, the lack of free water and water loss during fermentation limits its application. In this paper, a constructed water-supply SSF was used to improve carboxymethyl cellulose activity and filter paper activity of 1.7-fold and 2.3-fold by Trichoderma reesei Rut-C30, respectively. The dynamic changes in substrate physical prosperities and water characteristics during fermentation indicated that water supply by superabsorbent polymers could improve substrate utilization. Transcriptome results showed that the cells were more active at the early water-supply SSF, accumulating a lot of energy and precursors for cellulase production. Cellulase activity-related genes were significantly up-regulated, especially the glycoside hydrolase family and major facilitator superfamily. These findings provide a mechanism for SAPs to promote high cellulase activity production in solid-state fermentation.

Validation of diffusivity along the perivascular space as a biomarker for vascular cognitive impairment and dementia

AbstractBackgroundTo validate the index of diffusivity along the perivascular space (ALPS index) as a biomarker for vascular cognitive impairment and dementia (VCID).MethodThe participants and MRI data used in this study were acquired as part of the MarkVCID consortium, which consisted of seven sites. A total of 578 participants (72.5±7.2 years old, 232 Male) who received baseline and follow‐up cognitive evaluations (Montreal Cognitive Assessment (MoCA), Principal Component Analysis derived General Cognitive Function (GCF_PCA), and composite score of Executive Function (EFC)) and MRI examinations were included in this study. The diffusion tensor imaging (DTI) data were processed by using an in‐house automatic processing pipeline with FMRIB Software Library 6.0.6. The mean free water (mFW) and peak width of skeletonized mean diffusivity (PSMD) were computed in the white matter (WM). The ALPS index was defined as the average of bilateral ALPS indices which were calculated by the ratio of mean of x‐axis diffusivity in the projection fibers (Dxxproj) and x‐axis diffusivity in the association fibers (Dxxassoc) to the mean of y‐axis diffusivity in the projection fibers (Dyyproj) and z‐axis diffusivity in the association fibers (Dzzassoc). The WM hyperintensity volumes (WMHV) were calculated on FLAIR images and normalized by intracranial volume (ICV). Univariate correlation (Pearson or Spearman) was used to examine the associations between imaging markers (ALPS index, mFW, PSMD, and WMHV). Linear regression models were used to evaluate the associations of baseline ALPS index with baseline and longitudinal changes of cognitive outcomes, regressing out three types of covariates: 1) age, sex, and education, 2) added vascular risk factors (VRFs), including diabetes, hypertension and smoking, 3) further added mFW, PSMD and WMHV. SAS 9.4 software was used for all statistical analyses, and P&lt;0.05 was regarded as statistical significance.ResultThe baseline ALPS index was significantly correlated with existing biomarkers of cerebral small vessel disease (cSVD)‐related VCID, i.e., mFW and WMHV (P&lt;0.01) (Figure 1), and baseline cognitive performances, i.e., MoCA total score, GCF_PCA score, and EFC score (P&lt;0.05) after adjusting for the demographics, VRFs, and existing biomarkers (Figure 2).Conclusionthe ALPS index is an independent contributor to the cognitive decline in cSVD.

A diffusion kurtosis MRI signature of subjective cognitive decline

AbstractBackgroundDiffusion weighted imaging (DWI) of brain white matter is better at predicting future cognitive decline and medial temporal lobe atrophy than cerebrospinal fluid biomarkers in subjective cognitive decline (SCD)1. However, few studies have investigated gray matter DWI in SCD, despite the importance of regional gray matter changes as a biomarker for Alzheimer’s Disease and related dementias.Method316 cognitively normal participants from Cam‐CAN2 (123 SCD) older than 55 were included in the analysis. Participants were placed in the SCD group if they endorsed problems with their memory. Imaging data was collected on a 3T Siemens Trio scanner2. Diffusion imaging included 0, 1000 and 2000 s/mm2 b‐values and 30 gradient directions, and were processed using MrTrix3, PyDesigner, and AMICO to apply diffusion tensor (DTI), diffusion kurtosis (DKI), and neurite orientation density and dispersion (NODDI) models. FreeSurfer with T1w and T2w images was used to segment subcortical and cortical regions (Figure 1B&amp;C), then calculate regional volume and cortical thickness. Segmentations were also registered to diffusion images to generate regional averages of the diffusion metrics. Uncorrected p&lt;0.05 according to Wilcoxon tests were considered significant.ResultThe metric with the most regional group differences was kurtosis fractional anisotropy (KFA) from DKI, an indicator of structural complexity. KFA was significantly lower in SCD in 17 of 84 gray matter regions, including hippocampus (Figure 2‐3B). DTI showed reduced fractional anisotropy (Figure 2‐3C) and increased mean diffusivity (Figure 2‐3D) in SCD, but for fewer regions than KFA. NODDI showed increased free water (Figure 2‐3E), increased orientation dispersion (Figure 2‐3F), and increased neurite density (Figure 3G) in SCD. Volume and thickness were higher in SCD in 5 regions, but lower in 3 regions (Figure 2‐3A). Only KFA showed group differences in hippocampus.ConclusionKFA was more sensitive to SCD and more consistent than regional gray matter volume, cortical thickness, and all other diffusion metrics. This may indicate KFA is a biomarker signature of SCD across the whole brain gray matter.Selnes P, Aarsland D, Bjornerud A, et al. J Alzheimers Dis. 2013;33(3):723‐36.Shafto MA, Tyler LK, Dixon M, et al. BMC Neurol. 2014;14(1):1‐25.

EFFECTS OF AQUEOUS EXTRACT OF Andira inermis STEM BARK ON SOME REPRODUCTIVE PARAMETERS OF MALE WISTAR RATS

Andira inermis stem bark has been used by herbal practitioners in the treatment of many ailments. Its Pharmacological activities include Anti-oxidant activity, haematological activities, hypoglycaemic activity and antiplasmodia activities. This study seeks to evaluate the effect of aqueous stem bark extract of Andira inermis on some gonadal hormones, sperm count and sperm motility. Thirty-two male Wistar rats weighing 100-120g were randomized into Four (4) groups consisting eight (8) rats each. The animals were allowed to undergo acclimatization for 14days. Animals in group 1 served as the control, group 2, 3 and 4 were the treatment groups. Group 1 received free animal feed and water. Group 2, 3 and 4 received 100, 250 and 500mg/kg aqueous extract of Andira inermis stem bark administered orally daily for 90days. Twenty-four hours after the last administration, rats were sacrificed and cardiac puncture was used to collect the blood for centrifugation. The extract produced a significant (P&lt;0.05) increase in serum testosterone, follicle stimulating hormone, and luteinizing hormone respectively at 100mg/kg body weight but had no significant effect on luteinizing hormone and testosterone hormone at 250mg/kg and 500mg/kg bodyweight compared to normal control. At 250mg/kg and 500mg/kg treatment, follicle stimulating hormone was significantly decreased compared to control. Sperm counts decreased significantly from 22.13±0.53million/ml to 13.00±1.16 million/ml and sperm motility from 11.25±0.41 million/ml to 8.00 ± 0.59 million/ml after treatment. Data was expressed as the mean ± SEM. Statistical comparisons between various treatment groups was determined using one-way analysis of variance (ANOVA).

Dynamic interfacial pH regulation with chitosan gel electrolyte for enhanced high-temperature Zn anode stability

Aqueous zinc-ion batteries (AZIBs) are promising for high-temperature energy storage due to their high safety, low cost, and energy density. However, their reversibility and cycling stability at elevated temperatures remain challenging. We introduce a novel dynamic interfacial pH regulation strategy specifically designed for high-temperature conditions to mitigate proton and by-product formation on zinc anodes. This strategy involves a chitosan gel electrolyte that not only reduces proton generation from water decomposition but also impedes zinc ion dissociation at elevated temperatures. The amino and hydroxyl groups in chitosan act as proton traps, releasing functional groups that form complexes with zinc ions, thereby reducing zinc ion activity and preventing hydrolysis. Furthermore, chitosan's hydrogen bonding sites decrease free water activity, inhibiting its decomposition and further suppressing proton generation. These unique features work together to enhance the stability and efficiency of zinc plating/stripping, achieving a coulombic efficiency of 99.3 % at 25 °C and 98.5 % at 60 °C. Zn||PANI cells using this chitosan-based electrolyte demonstrated remarkable long-term stability, retaining 68.7 % of their initial capacity after 2000 cycles at 60 °C and 5 A g-1.

The risk of sodium overcorrections in severe hyponatremia and the utility of Desmopressin: a large retrospective study

Abstract Background The suggested narrow rate of serum sodium (sNa) correction in hyponatremia can be difficult to respect, leading to overcorrections. Our ability to anticipate the rapidity of correction according to the mechanism of hyponatremia is uncertain. While desmopressin is often used to pause a rapid rise in sNa, its dose-related effect is also not well-described. We studied the rate of hyponatremia overcorrections, its prediction and the utility of desmopressin in its management. Methods We retrospectively reviewed all cases of severe hyponatremia (sNa &amp;lt; 120) in a large university hospital that occurred over ten years. We assessed investigations, causes and treatments. We compared all sNa separated by at least 8 hours and calculated correction rates. Significant overcorrection rates were defined by any rise of sNa &amp;gt;9 mmol/L per day sustained over at least 24 hours. Results After exclusions, we found 355 episodes of severe hyponatremia. Low, appropriate and inappropriate ADH-defined mechanisms accounted for 17, 24 and 29% of etiologies, with the remaining 25% secondary to diuretics and 5% of uncertain causes. First urinary sodium and osmolality were consistent with the final diagnosis in 73%. Significant overcorrections were seen in 45% and were frequent in the setting of low ADH. Desmopressin was given in 82 episodes, more often as a rescue than a preventive measure, with the subsequent sNa dropping by ≥5 mmol/L by 12 hours in 8 instances. The dose of desmopressin (≥2 µg versus 1 µg) and a higher volume of intravenous free water coadministration resulted in a clinically meaningful greater reduction in sNa in the following 12 hours. Conclusions Overcorrections in severe hyponatremia are common, mainly when ADH is low. Initial urinary measurements anticipate this risk. Desmopressin effectively halted the rate of correction in a dose-dependent manner. Caution should be given when coadministrating water, which can significantly lower the sNa.

Epigenetic age acceleration predicts subject-specific white matter degeneration in the human brain.

Epigenetic clocks provide powerful tools for estimating health and lifespan but their ability to predict brain degeneration and neuronal damage during the aging process is unknown. In this study, we use GrimAge, an epigenetic clock correlated to several blood plasma proteins, to longitudinally investigate brain cellular microstructure in axonal white matter from a cohort of healthy aging individuals. A specific focus was made on white matter hyperintensities, a visible neurological manifestation of small vessel disease, and the axonal pathways throughout each individual's brain affected by their unique white matter hyperintensity location and volume. 98 subjects over 55 years of age were scanned at baseline with 41 returning for a follow-up scan 2 years later. Using diffusion MRI lesionometry, we reconstructed subject-specific networks of affected axonal tracts and examined the diffusion cellular microstructure composition of these areas, both at baseline and longitudinally, for evidence of cellular degeneration. A chronological age-adjusted version of GrimAge was significantly correlated with baseline WMH volume and markers of neuronal decline, indicated by increased extracellular free water, increased intracellular signal, and decreased axonal signal within WMH. By isolating subject-specific axonal regions "lesioned" by crossing through a WMH, age-adjusted GrimAge was also able to predict longitudinal development of similar patterns of neuronal decline throughout the brain. This study is the first to demonstrate WMH lesionometry as a subject-specific precision imaging technique to study degeneration in aging and the first to establish a relationship between accelerated epigenetic GrimAge and brain cellular microstructure in humans.

An Experimental Investigation of the Hydrate Formation Mechanism in the Throttling of Carbon Dioxide-Containing Trace Moisture

Carbon capture, utilization and storage are facilitated through carbon dioxide (CO2) transport. Pipe transportation is the main method for transporting CO2. However, hydrate blockages reduce transport efficiency in the pipelines, and the throttling devices are the main location of hydrate blockages. In this paper, the mechanism of hydrate formation in the throttling of CO2-containing trace moisture was investigated. The throttling device in a pipe was mimicked using a cylindrical orifice plate. The work also studied the effects of moisture content, upstream pressure and upstream temperature on hydrate formation. The results indicate that the Joule–Thomson cooling effect is a key contributor, and promotes the condensation of trace moisture, resulting in the free water necessary for hydrate nucleation. Under the effect of gas flow back-mixing, it is easy for the hydrate to adhere to the inner surface of the pipe behind the orifice plate. When the moisture content in the gas increases from 123 μmol/mol to 1024 μmol/mol, the hydrate induction time decreases from infinity to 792 s. However, the moisture content has no effect on the adhesion strength of the hydrate to the inner surface of the pipe. When the initial upstream pressure increases from 2.0 MPa to 3.5 MPa, the hydrate induction time decreases from infinity to 306 s. When the upstream temperature decreases from 291.15 K to 285.15 K, the hydrate induction time decreases from infinity to 330 s. With the decrease in the initial upstream temperature, the adhesion of hydrate particles to the inner surface of the pipe is promoted. This study provides experimental evidence for the characteristics of hydrate formation in the process of CO2 throttling.

Octenyl succinic anhydride starch enhanced 3D printability of corn starch-based emulsion-filled gels incorporating egg yolk

This work investigated the effect of octenyl succinic anhydride starch (OSAS) on the 3D printing performance of corn starch-based emulsion-filled gels containing egg yolk. The influence of OSA-S concentration on emulsion droplet size, ζ-potential and stability, as well as the printing performance, rheological properties and microstructure of gel were discussed. The results indicated that the addition of OSA-S significantly improved the accuracy of the printed objects, with the best accuracy of the models printed using OSA-1.6 and OSA-2.0 inks. Emulsion tests showed that increasing the OSA-S content reduced the droplet size, increased its ζ-potential, and enhanced the stability of the emulsion. Rheological analyses showed that the energy storage modulus, loss modulus, and apparent viscosity of the gels were slightly enhanced with increasing OSA-S content. Microstructural analysis showed that OSA-S increased the density of the gel microstructural network. In addition, the addition of OSA-S enhanced the thermal stability of the gels and facilitated the transition of water molecule states from free water to bound water. The melting temperature of the gel gradually increased from 135.72 °C to 147.52 °C with the increase of OSA content. This study aims to develop promising 3D printing ink to facilitate its industrial applications.

Effect of ultrasound-assisted water-holding agent on the quality of frozen stored beef

Beef was soaked in an ultrasonic-assisted water-holding agent to increase its water-holding capacity without sacrificing its quality. Storage at -18 °C for 0, 7, 14, 21 and 28 days, the effects of the water-holding agent and ultrasound on the quality of the beef were discussed, along with the centrifugal loss rate, pH, texture, water distribution, and thiobarbituric acid reactive substances (TBARS) and other indexes. The centrifugal loss of the control group was found to be 14.33 %, while the chitosan treatment had the lowest centrifugal loss. The centrifugal losses of compound phosphate, soybean dietary fiber, and chitosan were found to be 10.77 %, 11.86 %, and 12.10 %, respectively, over the 28-days freezing time. Furthermore, there was less water migration and a lower free water P22 value in the chitosan and compound phosphate treatment groups, indicating improved water maintenance capabilities. The highest TBARS value in the control group was 1.17 mg/kg, and the lowest value of compound phosphate was 0.91 mg/kg, indicating that the compound phosphate had a good effect on lipid peroxidation. The findings of this study offer valuable insights into the water-holding properties of water-holding agents in frozen beef and serve as a guide for using these agents in the food industry.

Acetamide-based hydrated eutectic electrolytes for supercapacitors with high voltage and low self-discharge

Hydrated eutectic electrolytes (HEEs) hold promise as green, safe and affordable electrolytes for high-voltage electrochemical energy storage. The water molecules in HEEs participate in the solvation structure of cations, which is critical to the electrolyte performance. We hereby report HEEs consisting of NaClO4, N-methyl acetamide (NMAc) and water. By adjusting the ratio of the ingredients, the optimized HEEs-5 shows a wide electrochemical potential window, lowered viscosity and non-flammability. Spectroscopic analysis and molecular dynamics simulations reveal that NMAc and H2O form the inner solvation shell of Na+, while the free ClO4– result in enhanced ionic conductivity. Moreover, NMAc molecules form a protective barrier on the surface of carbon upon charging, inhibiting the activation-controlled faradaic self-discharge reactions caused by free water molecules. The supercapacitor with HEEs-5 electrolyte shows a high voltage of 2.3 V, ultra-long cycle life and low self-discharge. This work reveals the crucial roles of NMAc, but also shed light on the design and optimization of other HEEs.

Utilizing spodumene slag as a supplementary cementitious material: A quantitative study

This study investigates the potential of spodumene slag (SPS) as a supplementary cementitious material (SCM). Firstly, the comprehensive characterization results show that SPS consists of quartz, gypsum, calcite, lazurite, and alumino-silicates, with 34 % amorphous content. Next, the hydration characterization indicates that SPS has limited self-cementing properties; however, it inhibits the initial dissolution of C3S, C3A, and C4AF due to the gypsum. This inhibition for C3S is counteracted by the dilution effect of SPS. Over time, the hydration degrees of the clinker phases improve as SPS provides additional nucleation sites and retains more free water for cement hydration. Additionally, thermodynamic modelling was established and validated by experimental data to capture the reaction process and phase changes. AFt forms in all systems, but AFm phases decrease and disappear at 40 % and 50 % SPS levels. Engineering tests reveal that 50 % SPS addition extends initial setting time by 60 %, and reduces fluidity by 20 %. Compressive strength remains acceptable up to 20 % SPS replacement, with an activity index of more than 80 %. Overall, SPS shows potential as a supplementary cementitious material, but careful adjustment of replacement levels is essential to minimize its disadvantages.

White matter integrity and cognitive performance in the subacute phase after ischemic stroke in young adults

IntroductionReduced white matter integrity outside the stroke lesion may be a potential contributor of post-stroke cognitive impairment. We aimed to investigate how a stroke lesion affects the integrity of surrounding white matter, and whether the integrity of the non-lesioned part of white matter tracts is associated with cognitive performance after ischemic stroke in young adults. MethodsPatients from the ODYSSEY study, aged 18–49 years, with a first-ever ischemic stroke, underwent 3T MRI and cognitive assessment within six months after the index event. Using TractSeg and free water imaging, we analyzed free water corrected fractional anisotropy (FAT), free water corrected mean diffusivity (MDT), and free water (FW) of all white matter tracts outside the stroke lesion. We calculated FAT and FW in the lesioned white matter tracts at 2 mm incremental distances from the lesion, extending up to 10 mm, represented as Z-scores using the diffusion measures of controls. We categorized patients as no/mild or major vascular cognitive disorder (VCD) and compared with a stroke-free control group (n = 23). Group differences in diffusion measures were examined. We investigated associations between FAT, FW and cognitive performance across seven domains. ResultsAmong 66 patients (median age 40.3 years (IQR 31.3–46.2); 54.5 % women), 22 had major VCD. In the different lesion expansions, we found differences in FAT (p = 0.009) and FW (p = 0.049). Patients with major VCD had lower FAT [range of Cohen’s d (0.65; 1.65)] and higher FW [Cohen’s d (−1.40; −0.64)] values compared to controls, both in the hemisphere affected by the lesion and the unaffected hemisphere. Performance in processing speed correlated with FAT across eight tracts in the affected hemisphere [range of R2adj (0.30; 0.37)], and with FW in four tracts in the affected and three in the unaffected hemisphere [R2adj (0.28; 0.38)]. DiscussionIn the first months after a stroke, we observed a trend of microstructural changes remote from the lesion that diminish as the distance from the lesion increases. Tissue changes in the white matter outside the lesion are present in both hemispheres, but are more pronounced in the hemisphere affected by the stroke, and may contribute to worse cognitive performance.