Free Water Content Research Articles

Determining the effects of LFHV-PEF treatment on the water distribution and vigor of aged rice seeds using LF-NMR

This study aimed to investigate the effect of low-frequency high-voltage pulsed electric field (LFHV-PEF) treatment on the germination of aged rice seeds. Aged rice seeds were subjected to LFHV-PEF treatment with different electric field strengths, and low-field nuclear magnetic resonance (LF-NMR) was performed to acquire the LF-NMR data of rice seeds at different germination periods during a standard seed germination test to analyze their internal patterns of water state and distribution. Optimal treatment conditions were determined based on the physicochemical data collected during germination, and the improvements in seed vigor were verified. The findings indicated that during germination, the contents of bound and semi-bound water within the aged rice seeds initially increased and then decreased, whereas free water and total water contents increased continuously and rapidly. Side peaks were also observed within the seeds. Under the LFHV-PEF treatment, the semi-bound water within the seeds was more easily converted to free water, and the water absorption rate, germination potential, germination rate, germination index, and vigor index of these seeds improved. Further, the optimal electrical field strength was 12 kV. By analyzing the internal patterns of water state and distribution in seeds, the mechanism by which electric field treatment improved seed vigor was elucidated, thus, providing theoretical support and data evidence for research on water absorption during the germination of rice seeds, and methods for improving seed vigor. Keywords: aged rice seeds, germination, water phase, seed vigor, LF-NMR, LFHV-PEF DOI: 10.25165/j.ijabe.20221504.7590 Citation: Cheng E S, Song P, Hou T G, Wu L Y, Zhang B H. Determining the effects of LFHV-PEF treatment on the water and vigor of aged rice seeds using LF-NMR. Int J Agric & Biol Eng, 2022; 15(4): 190–196.

Influence of the flocculation effect on the rheological properties of cement slurry

The rheological properties have an important impact on the migration and diffusion of cement slurry in grouting reinforcement applications. The microscopic interaction between particles affects the macroscopic rheological behaviors of cement slurry. However, the detailed influence mechanisms still remain unclear. In this work, five different fineness cements were selected to investigate the rheological properties. The focused beam reflectance measurement (FBRM) system was used to detect the in-situ flocculation characteristics under different water-to-cement ratios, cement fineness, and shear rates. In addition, the initial and time-dependent rheological properties under various conditions were measured by a rotary viscometer. The results reveal that these three factors influence the number and particle size distribution of flocculent particles, and the degree of flocculation increases linearly with time. Cement slurry with a water-to-cement ratio ranging from 0.6:1 to 1.6:1 follows the Bingham model. The yield strength and plastic viscosity decrease with increasing water-to-cement ratio, and increase with increasing cement fineness. The apparent viscosity is reversible with the change of shear rate. The influence of water-to-cement ratio, cement fineness, and shear rate on the flocculation effect is consistent with the influence on rheological parameters. Three factors and time affect the rheological properties by influencing the formation and destruction of the flocculation structure, and then changing the content of free water and intergranular force in cement slurry. Our study has revealed the evolution of rheological properties from a microscopic point of view, which can provide theoretical guidance for the design and application of cement slurry.

AN OPERATIONAL EVALUATION OF A TECHNOLOGICAL LINE FOR INDUSTRIAL DRIED CHERRY PRODUCTION BY THE OSMOTIC-CONVECTION METHOD, COMPARED TO A LABORATORY SCALE

Background. Pre-osmotic dehydration of fruits may significantly reduce free water content. It also causes fruit penetration by solution components, increasing the efficiency of products manufactured by the osmotic-convection method. A study was carried out on a laboratory and industrial scale to perform an operational evaluation of a technological line for dried cherry production. Frozen pitted cherries (Łutówka variety) were the research material. Sucrose solution, concentrated apple juice, and sucrose and glucosefructose syrup mixture (1:1) were used for OD; with 70±2 °Brix at 40, 55 °C (an industrial scale), and 50 °C (a laboratory scale) to obtain ≥ 60 °Brix of fruit extract. Industrial convection drying was carried out at 70 °C until the water activity of < 0.6 was reached. Results and conclusion. Increasing the osmoactive solution temperature enhanced the efficiency of a process aimed at fruit saturation by an osmotic substance and shortened the treatment time. Higher dehydration efficiency resulted in shorter convective drying time. No impact of the osmotic solution type on most mass exchange indices in dehydrated fruits was found. Despite the significantly higher process efficiency of the pre-dehydration in apple juice concentrate and drying stages, there was no significant impact of the solution type on the total process efficiency expressed as the ratio of dried mass to raw material mass. In spite of the same variants of osmotic dehydration of cherries in both production scales, the dehydration time under industrial conditions was even 11times longer. The technical condition of the tested line was determined as operable. The osmotic dehydration and drying equipment was working correctly. The complexity of repair processes and time-consuming equipment cleaning were demonstrated.

PERBANDINGAN AKTIVITAS EKSTRAK DAUN TAPAK DARA (Catharanthus Roseus) DAN TBHQ SEBAGAI ANTIOKSIDAN MINYAK GORENG TERHADAP FOTOOKSIDASI UV-C

Cooking oil is one of the sources of human energy with a total consumption of 290 million tons/year by the public. The largest use of cooking oil is the household sector which generally gets its oil from traditional markets. The oil that is traded in the market is often not covered properly so that it is easily exposed to sunlight. The light that hits the oil can cause damage, including the formation of peroxide compounds. Efforts to overcome the damage include adding natural antioxidants as an alternative to synthetic antioxidants. This study aims to determine the impact of 254nm ultraviolet photooxidation on the containment of oil oxidation by the addition of tapak Dara leaf extract and TBHQ. The oil was photo oxidized with variations of 1, 3, 6, and 12 hours to determine the hold. To determine the quality of the oil, three parameters of sample testing were carried out, namely free fatty acid content, peroxide number, and water content. The results of photooxidation showed that cooking oil with tapak Dara leaf extract had lower holding activity than TBHQ. This value was measured on the peroxide number and free fatty acid content, while the measurement of the water content of the measured containment activity was better with a value that met SNI, namely <0.1%

Effect of multi-frequency ultrasound assisted thawing on the quality of large yellow croaker (Larimichthys crocea)

The effects of mono-, dual- and tri-frequency ultrasound-assisted thawing (UAT) on the physicochemical quality, water-holding capacity, moisture migration and distribution and myofibrillary structure of frozen large yellow croaker (Larimichthys crocea) were detected. The results indicated that multifrequency UAT treatment significantly increased the thawing rate, maintained the stability of myofibrils and reduced the lipid oxidation. The multifrequency UAT samples had better water-holding capacity (higher water-holding capacity values, lower thawing loss and cooking loss) and physicochemical quality (higher hardness, springiness, resilience, chewiness and lower total volatile basic nitrogen (TVB-N) values, thiobarbituric acid reactive substances (TBARS) values), higher immobilized water content, and lower free water content. Therefore, the results provide a further understanding of the quality stability of frozen large yellow croaker treated by the multifrequency UAT.

Inhibitory Effects of CaCl2 and Pectin Methylesterase on Fruit Softening of Raspberry during Cold Storage

Quality of raspberry fruit experiences a rapid decline after harvest due to its vulnerable texture and high moisture content. Application of calcium chloride (CaCl2) combined with pectin methylesterase (PME) is efficient in delaying fruit softening. In this study, the effects of exogenous CaCl2 alone or in combination with PME on the structure of the cell wall, the molecular properties of pectin, and the amount of free water of raspberry during postharvest storage were investigated. The results showed that CaCl2 combined with PME treatment could maintain fruit firmness and inhibit weight loss. The treatment of CaCl2+PME maintained the cell wall structure via sustaining middle lamella integrity and reducing the activities of cell wall-degrading enzymes, such as polygalacturonase, pectin methylesterase, β-galactosidase, α-L-arabinofuranosidase, and β-xylosidase. In addition, CaCl2+PME treatment could effectively increase the content of chelate-soluble pectin (CSP) and develop a cross-linked structure between Ca2+ and CSP. Moreover, CaCl2+PME treatment was of benefit in maintaining free water content. CaCl2 in combination with PME treatment could be a promising method for inhibiting softening and maintaining the quality of postharvest raspberry during cold storage.

Moisture Distribution and Structural Properties of Frozen Cooked Noodles with NaCl and Kansui.

The effects of NaCl (1–3%) and kansui (0.5–1.5%) on the quality of frozen cooked noodles (FCNs) were investigated, which provided a reference for alleviating the quality deterioration of FCNs. Textural testing illustrated that the optimal tensile properties were observed in 2% NaCl (N-2) and the maximum hardness and chewiness were reached at 1% kansui (K-1). Compared to NaCl, the water absorption and cooking loss of recooked FCNs increased significantly with increasing kansui levels (p < 0.05). Rheological results confirmed NaCl and kansui improved the resistance to deformation and recovery ability of thawed dough; K-1 especially had the highest dough strength. SEM showed N-2 induced a more elongated fibrous protein network that contributed to the extensibility, while excessive levels of kansui formed a deformed membrane-like gluten network that increased the solid loss. Moisture analysis revealed that N-2 reduced the free water content, while K-1 had the lowest freezable water content and highest binding capacity for deeply adsorbed water. The N-2 and K-1 induced more ordered protein secondary structures with stronger intermolecular disulfide bonds, which were maximally improved in K-1. This study provides more comprehensive theories for the strengthening effect of NaCl and kansui on FCNs quality.

Effects of Multi-Shell Free Water Correction on Glioma Characterization.

Diffusion MRI is a useful tool to investigate the microstructure of brain tumors. However, the presence of fast diffusing isotropic signals originating from non-restricted edematous fluids, within and surrounding tumors, may obscure estimation of the underlying tissue characteristics, complicating the radiological interpretation and quantitative evaluation of diffusion MRI. A multi-shell regularized free water (FW) elimination model was therefore applied to separate free water from tissue-related diffusion components from the diffusion MRI of 26 treatment-naïve glioma patients. We then investigated the diagnostic value of the derived measures of FW maps as well as FW-corrected tensor-derived maps of fractional anisotropy (FA). Presumed necrotic tumor regions display greater mean and variance of FW content than other parts of the tumor. On average, the area under the receiver operating characteristic (ROC) for the classification of necrotic and enhancing tumor volumes increased by 5% in corrected data compared to non-corrected data. FW elimination shifts the FA distribution in non-enhancing tumor parts toward higher values and significantly increases its entropy (p ≤ 0.003), whereas skewness is decreased (p ≤ 0.004). Kurtosis is significantly decreased (p < 0.001) in high-grade tumors. In conclusion, eliminating FW contributions improved quantitative estimations of FA, which helps to disentangle the cancer heterogeneity.

Characteristics of hydrate formation, decomposition, and phase equilibrium in the transition area formed by the high-pressure jet breaking and sand filling method

Marine hydrates mainly occur in clayey silt sediments, and their occurrence environment has the characteristics of a high clay content and low permeability, which seriously inhibit an increase in the gas production rate. This study presents a new method, the high-pressure jet breaking and sand filling method, to transform the natural gas hydrate (NGH) reservoir near the production well, whereby a water jet is used to form an area of sediment with large particle diameters and high permeability. Based on indoor experiments, we report the characteristics of hydrate formation, decomposition, and phase equilibrium in the transition area formed by this method under different sand particle sizes and mass fractions. The addition of sand at a high mass fraction with a large particle diameter significantly shortened the time required for rapid hydrate formation, prolonged slow hydrate formation, and reduced the increase in temperature. With an increase in the mass fraction of large-diameter sand, the free water content of pores increased, which made it easier to form hydrates with large particles, thus delaying the hydrate decomposition rate. The phase equilibrium curves of hydrates in clayey silt sediments with sand added at mass fractions of 30% and 50% were close to that of bulk hydrate in pure water at lower temperatures. As the temperature increased, the phase equilibrium curves gradually approached those of hydrates in clayey silt sediments.

The Effects of Different Addition of Wine on Water Migration and Edible Quality of Braised Pork

In order to explore the effect of adding different wines on the eating quality and water migration of braised pork, braised pork cooked with rice wine, papaya wine, beer and mixed wine was taken as the research object, low-field nuclear magnetic resonance(lLF-NMR) and texture analyzers, calorimeters, etc. were used to detect changes in the edible quality, texture characteristics, nutritional content and internal moisture relaxation time of braised pork in this experiment. The results showed that through sensory evaluation, the overall acceptability of braised pork in the rice wine group was higher; the braised pork in papaya wine group had the highest fat, protein and calorie content, which were 51.95, 38.55 g/100 g and 623.50 kcal/100 g, respectively; the water content of beer group was the highest, up to 31.55 g/100 g; the hardness and shear force of braised meat in rice wine group were the lowest, which were 31.54 and 2.06 N, respectively, and the meat sample reached ideal taste and tenderness; the L*(brightness) value and a*(redness) value of the yellow wine group were higher, and the color was more red and bright. Through low-field NMR analysis, it was found that the beer group had the shortest relaxation time T21, and the water was more tightly bound to the substrate, and it was not easy to lose. The relaxation time(T22) and peak area T22 of papaya wine group were the longest, and the free water content of braised meat was the highest. To sum up, in the process of cooking braised pork, the braised pork with rice wine was the best in all aspects, followed by the mixed wine(rice wine+beer) group. The research results of this article would provide a reference for the standardized industrial production of braised pork, and also provide a basis for further exploring the mechanism of wine's influence on the texture and taste of traditional Chinese dishes.

Study on the regulation of sludge dewatering by hydrophobically associating cationic polyacrylamide coupled with framework materials

To further improve the performance of sludge dewatering, this study used the UV-light-initiated aqueous micellar polymerization method to obtain hydrophobic associating cationic polyacrylamide (HACPAM) as a flocculant and coupled it with quartz sand and fly ash to investigate sludge flocculation and dewatering. The results show that the flocculation of HACPAM is interfered with by the framework material quartz sand and fly ash, which leads to significant changes in the sludge floc particle size, capillary suction time (CST), settlement performance and other indicators. This is the result of the coupling between HACPAM and the framework materials. The larger the molecular weight of HACPAM, the larger the particle size of the sludge flocs is, and the better the dehydration performance. The dosage of 7.5784 kg/ton (T) dry solids (DS) is the optimum dosage level when the sludge dewatering performance is the best. It is represented by the largest sludge floc size (2280 μm), the highest removal free water content (90.9%) and the inflection point of CST change (59.3 s). When HACPAM is coupled with quartz sand and fly ash flocculated sludge, different characteristics of dewatering performance are showed. Both low-dose HACPAM 3 coupled with fly ash and high-dose HACPAM 3 coupled with quartz sand can achieve better dehydration effects, but the former has more advantages than the latter. The 3D scanning structure explains why HACPAM 3 is more suitable for coupling fly ash to improve the dewatering performance of sludge. In addition, the mechanism is also discussed.

Effects and underlying mechanisms of insoluble dietary fiber and ferulic acid on the crumb structure of steamed bread

This study investigated the effects and underlying mechanisms of insoluble dietary fiber (IDF) and ferulic acid (FA) on the crumb structure of steamed bread. Both IDF and FA had significant (p < 0.05) adverse effects on the crumb structure of steamed bread, except for small doses of FA (0.3 g), while the simultaneous addition of IDF and FA exacerbated the adverse effects. IDF reduced the bound water and free water content of the dough and increased the immobilized water content due to physical filling and strong water absorption, which hindered the formation of gluten. Moreover, IDF mainly reduced the extractability of low molecular weight glutenin subunit (LMW-GS), thereby promoting glutenin polymerization, which further limited the extensibility and fermentation of the dough. The fermentation height and CO2 production of the dough with FA added decreased rapidly to 0 mm and 4 mL, and then remained stable. This was attributed to the fact that FA resulted in a denser gluten network structure. The extractability of glutenin indicated that FA reduced the extractabilities of glutenin subunits and increased the extractabilities of gliadin subunits. The extractability of LMW-GS with 1.8 g of FA was reduced by 25.03% compared with the control sample, which far exceeded the 6.39% reduction of high molecular weight glutenin subunit. This revealed that FA was mainly through cross-linking with LMW-GS to promote gluten polymerization. Moreover, the addition of IDF + FA exacerbated the gluten polymerization through the formation of macromolecular polymers, which further affected the crumb structure of steamed bread.

Influence of Drought Stress and Rehydration on Moisture and Photosynthetic Physiological Changes in Three Epilithic Moss Species in Areas of Karst Rocky Desertification

The drought resistance mechanism of typical mosses in the karst area was studied, and the water and photosynthetic physiological adaptation of mosses to karst environmental change was analyzed in this paper, which provided the basis for the restoration and control of karst rocky desertification ecological environment. Three superior plants in the rocky desertification area of Guizhou province were selected; they are, respectively, Erythrodontium julaceum (Schwaegr.) Par., Barbula unguiculata Hedw., and Bryum argenteum Hedw. Results show that the three kinds of plant rock mosses of leaf water potential (Ψs), free water content ( V a ), total water content, and relative water content (RWC) decreased; bound water ( V s ), water saturation deficit (WSD), and V s / V a ratio increased; transpiration rate (Tr) fell slightly, under drought stress. The physiological indexes of water have different degrees of recovery after rehydration. The total chlorophyll content shows a trend of first increasing followed by falling and then rising. RWC was negatively related to qN and positively related to F v / F m , yield, ETR, and qP. After rewetting, the fluorescence parameters are returned to average level under mild-to-moderate stress. At the same time, it is hard to get back to the control level under severe pressure. The water use efficiency (WUE) decreased with stress and recovered to different degrees after rehydration.

Feasibility of producing cement-based sacrificial materials with strontium ferrite: A preliminary study

The safety of nuclear power plant can be improved via core catcher, and cement-based sacrificial materials are widely used in most core catchers because of their simple construction process and the low manufacturing cost. This paper carried out a preliminary investigation to explore the feasibility of using strontium ferrite to prepare cement-based sacrificial materials. The effects of strontium ferrite on the room temperature and high temperature properties of cement mortar were systematically studied in the work. In addition, the damage evolution of cement mortar containing strontium ferrite subjected to elevated temperatures was also identified according to the damage mechanics theory. It was found that, (1) the addition of strontium ferrite led to the deterioration of the mechanical properties, microstructure and pore structure of cement mortar; (2) it was feasible to prepare cement-based sacrificial materials containing strontium ferrite that met the requirements on basic properties like mechanical properties, free water content, volume stability, and the high temperature integrity by controlling the content of strontium ferrite; (3) the correlation between the internal damage of cement mortar and the temperature could be described by Weibull Distribution Model, which provided a basis for the identification and evaluation of serious nuclear power accidents.

Effects of different metal ions on the physicochemical properties and microstructure of egg white gel.

To ameliorate egg white gel's salinity and undesirable texture characteristics during curing, different metal ions (K+ , Mg2+ , Ca2+ , Zn2+ ) were used to replace sodium chloride (NaCl) to simulate salted eggs partially. The effects of these ions on the physicochemical properties, microstructure, and gel characteristics of egg white protein were studied. Low field nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) analysis showed that adding K+ , Mg2+ , Ca2+ , and Zn2+ could decrease immobile water content and increase free water content in egg white gel. Circular dichroism/fluorescence spectrophotometry (CD/FL) analysis showed that substitutive addition of K+ , Mg2+ , Ca2+, and Zn2+ changed the conformational structure of the protein, which was not conducive to the formation of the three-dimensional mesh gel structure. Differential scanning calorimetry (DSC) results show that the addition of four metal ions could reduce the thermal denaturation temperature of egg white gel. Scanning electron microscopy (SEM) showed that the gel structure of egg white in the zinc chloride (ZnCl2 ) group was rougher and more chaotic, the crosslinking degree was worse, so it was not suitable for low sodium salted egg preparations. The gel strength of the calcium chloride (CaCl2 ) group was significantly higher than other groups (P < 0.05), while the gel strength of the potassium chloride (KCl) group was similar to the NaCl group (P > 0.05). CaCl2 and KCl could be used as partial NaCl substitutes to study the addition level and ratio further and improve salted egg white quality. © 2021 Society of Chemical Industry.

Free water in T2 FLAIR white matter hyperintensity lesions

AbstractBackgroundWhite matter (WM) free water (FW) is likely associated with cerebral small vessel disease (CSVD). FW is the fraction of unconstrained water within an image voxel, which can be estimated from diffusion‐weighted images. T2‐weighted Fluid‐Attenuated Inversion Recovery (FLAIR) white matter hyperintensity (WMH) is a widely used index to assess the damages caused by CSVD. It is critical to characterize how FW content is altered in WMH lesions. In this work, we proposed a data processing framework to assess FW distributions in WMH and normal‐appearing WM as well as in different WM fiber tracts.MethodSingle‐shell diffusion‐weighted image (SS‐DWI) and T2 FLAIR image data of 133 cognitively normal (CN) adults (Table 1) were obtained from the ADNI dataset (http://adni.loni.usc.edu). FW maps were generated from SS‐DWI images using the DIPY software package (https://dipy.org/). WMH lesions were identified with the lesion segmentation toolbox implemented in SPM. We co‐registered FW and WMH maps of individual subjects in the MNI space. Then we derived group WM fiber tracts using the tract‐based spatial statistics (TBSS). Finally, we examined the localization of WMH and FW in the major WM tracts.ResultFigure 1 shows the FW map, FLAIR image, and WMH lesion from a representative subject. Figure 2 shows group average and individual FW distributions in WMH and normal‐appearing WM. Two sample T‐Test found that FW content in WMH is significantly higher than that in normal‐appearing WM (mean FW and standard deviation FW in WMH are 0.430 and 0.112, mean FW and standard deviation FW in normal‐appearing WM are 0.203 and 0.06, P &lt; 1×10‐30). TBSS based analysis showed that: 1) WMH lesions are mainly located in the corona radiata, posterior thalamic radiation, tapetum, superior fronto‐occipital fasciculus, superior longitudinal fasciculus, corpus callosum, and sagittal stratum; 2) Compared with mean FW in normal‐appearing WM, elevated FW content is mainly at the fornix, tapetum, cingulum hippocampus, superior fronto‐occipital fasciculus, corpus callosum, sagittal stratum, and posterior thalamic radiation.ConclusionWe developed an image processing pipeline to estimate FW changes in WMH lesions and normal‐appearing WM. Free water content is elevated in WMH lesions, which is likely driven by CSVD.

Diffusion models reveal white matter microstructural changes with aging, pathology, and cognition

AbstractBackgroundWhite matter microstructure undergoes progressive changes during the life‐span but the neurobiological underpinnings related to aging and disease remains unclear. We used an advanced diffusion MRI, Neurite Orientation Dispersion and Density Imaging (NODDI), to investigate the microstructural alterations due to demographics, common age‐related pathological processes (amyloid, tau, and white matter hyperintensities (WMH)), and cognition. We also compared NODDI findings to the older Diffusion Tensor Imaging (DTI) model based findings.Method328 participants (264 cognitively unimpaired, 57 mild cognitive impairment (MCI), and 7 dementia with a mean age of 68.3 ±13.1 years) from the Mayo Clinic Study of Aging with multi‐shell diffusion imaging, FLAIR‐MRI as well as amyloid and tau PET scans were included in this study. White matter (WM) tract level diffusion measures (Figure 1) were calculated from DTI and NODDI. Pearson correlation and multiple linear regression analyses were performed with diffusion measures as the outcome and age, sex, education/occupation, WMH, amyloid, and tau as predictors. Analyses were also performed with each dMRI measure as a predictor of cognitive outcomes.ResultAge and WMH were the strongest predictors of all WM diffusion measures with low associations with amyloid and tau (Figure 1). However, neurite density decrease from NODDI was observed with amyloidosis specifically in the temporal lobes (Figure 2). WM integrity (mean diffusivity and free water) in the corpus callosum showed the greatest associations with cognitive measures (Table 1). All diffusion measures provided information about WM aging and WM disease processes and were associated with cognition.ConclusionNODDI and DTI are two different biophysical models that provide distinct information about variation in WM microstructural integrity. NODDI provides additional information about synaptic density, organization, and free water content which may aid in providing mechanistic insights into disease progression.

Neurite density and free water concentration are associated with synaptic density in the hippocampus as assessed through NODDI and [C‐11]UCB‐J PET

AbstractBackgroundNeurite Orientation Dispersion and Density Imaging (NODDI), derived through multi‐shell diffusion MRI, allows for the estimation of markers pertaining to multiple distinct components of neural tissue microstructure. Lower neurite density index (NDI), lower orientation dispersion index (ODI), and higher volume fraction of isotropic water (Viso), have all been significantly associated with biomarkers of AD pathology, as well as increase diagnostic model predictability. Recent studies employing [C‐11]UCB‐J PET to study synaptic vesicle glycoprotein 2A (SV2A) have found strong reductions in individuals with AD. Here we explore regional associations between cortical tissue microstructure (indexed by NODDI) and synaptic density (measured through [C‐11]UCB‐J PET). We hypothesize that increased NDI and ODI, and decreased Viso will associate with higher [C‐11]UCB‐J binding.MethodParticipants (N=24) included cognitively unimpaired and impaired older adults (Table 1) from the Wisconsin Alzheimer’s Disease Research Center who underwent [C‐11]UCB‐J PET and multi‐shell diffusion MRI. NODDI measures (including NDI, ODI, and Viso) were estimated and [11‐C]UCB‐J binding was quantified by calculating distribution volume ratios (DVR) using SRTM2 with the whole cerebellum as a reference region. Pearson correlations were conducted within Desikan‐Killiany‐derived regions of interest (ROI) including the hippocampus, entorhinal cortex, and parahippocampal gyrus, regions previously associated with altered NODDI metrics and [C‐11]UCB‐J binding in the AD population.ResultSignificant associations were found between [C‐11]UCB‐J DVR and both NDI and Viso in the hippocampus (NDI: r = 0.45, p=0.047; Viso: r = ‐0.46, p = 0.043). A trend was identified between [C‐11]UCB‐J DVR and ODI in the parahippocampus (r = 0.39, p = 0.098). No significant associations or trends were found in the entorhinal cortex.ConclusionThis preliminary analysis identified associations between increased synaptic density and metrics of cortical tissue microstructure. Both NDI and Viso were correlated with [C‐11]UCB‐J DVR in the hippocampus, indicating dendritic complexity and synaptic density are possibly linked. Future analyses will include more participants, determine whether hippocampal [C‐11]UCB‐J DVR in addition to NODDI may increase diagnostic model predictability, as well as estimate the temporal progression of synaptic and dendritic loss in AD.

Perfusion and free water show opposite trends across tissue layers surrounding white matter hyperintensities in participants with dementia and mild cognitive impairment

AbstractBackgroundWhite matter hyperintensities (WMH) are associated with an increased risk of cognitive impairment and AD. While WMHs are thought to reflect vascular disease, the physiological basis of WMHs remain unclear. New imaging biomarkers are needed to understand the cascade of events leading to the development of WMH. The present MRI study aims to investigate changes in both Free Water (FW) and Cerebral Blood Flow (CBF) in WMH and its penumbra elderly cohort with and without cognitive impairment.MethodFluid‐attenuated inversion recovery, diffusion tensor imaging, and pulsed arterial spin labeling (ASL) perfusion images were acquired in participants with dementia (n=17), MCI (n=41), and normal cognition (n=130) with an 8‐channel coil on a 3 Tesla MRI (Siemens Tim Trio). ASL scan parameters included TR/TE: 4000/13ms, inversion time=1800, voxel size: 4x4x10mm3. CBF maps, calculated using the FMRIB software library, and FW maps were co‐registered into structural space. WMHs were segmented from fluid‐attenuated inversion recovery and T1‐weighted images using an automated protocol. For each subject, individual WMH lesions were identified and successively dilated by 1mm to create 4 WM layers surrounding the lesion core (Figure 1). For each biomarker (CBF and FW), linear mixed‐effect models were used to compare (1) normal WM to WMHs and their surrounding layers; and (2) WMHs to their surrounding layers (lme4 in R software). All models specified individual lesions per participant as a nested random effect as random effects, and age and cognitive diagnosis as fixed effects.ResultCBF in WMHs and Layers 1‐4 were lower than the reference WM (p&lt;0.001, Figure 2A). CBF reduced inlayer 1 (p=0.013) and increased toward normal values in layers 2‐4 (p&lt;0.001) compared the WMH core (Figure 2B). In contrast, the mean FW content was higher in the WMHs and layers 1‐2 compared to the WM (p&lt;0.001). The WMH core had higher FW content than the surrounding layers 1‐4 (p&lt;0.001, Figure 3A, B).ConclusionDecreased CBF and increased FW was observed in tissue surrounding WMHs, suggestive of vascular and microstructural damage in a penumbra region beyond the WMH core. FW and CBF measures provide complementary information to understand the pathological mechanisms of WMH.

Structural and rheological properties of meat analogues from Haematococcus pluvialis residue-pea protein by high moisture extrusion

Meat analogues, a kind of healthy promising meat substitute, are gaining more and more attention due to its eco-friendly, personal satisfactory and low cost benefits. In this study, Haematococcus pluvialis residue (HPR) was used for preparing pea protein-based meat analogues by high moisture extrusion. Mixed raw material with HPR contents ranging from 10 g/100g to 40 g/100g can successfully be extruded under high moisture of 50 g/100g. The reddish color of HPR made the extrudates look like dried red meat. HPR could markedly improve the textural properties by loosening the layered and the fibrous structures of meat analogues. The fibrous degree of meat analogues with 10 g/100g (dry basis) HPR content reached the maximum (1.28 ± 0.05). Even though the HPR content increased to 40 g/100g (dry basis), the fibrous degree of meat analogues was 1.15 ± 0.03, which was higher than the extrudates without HPR (1.08 ± 0.05). The mechanism of forming meat analogues with better texture was mainly caused by the increased free water content and β-Sheet structure of extrudates after adding HPR. On the whole, HPR can be used as a raw material for high moisture extrusion to enhance the physical properties of meat analogues.