Water Diffusion Research Articles

Eliminating adverse effects of fouling layer using composite membranes with dense surface layers for sustainable membrane distillation of high-strength wastewater

This study explored composite membranes (CMs) with dense and water-permeable surface layers for the deep-concentration of high-strength wastewater using membrane distillation (MD). Compared to conventional microporous MD membranes, coating a dense PVA surface layer avoided the detrimental effects of landfill leachate (LFL) foulants (e.g., membrane pore blockage and deformation) during MD concentration. The hydrophilicity and water/salt separation capability of surface layers enhanced the dispersion of water diffusion on membrane surfaces and altered the solute distribution on membrane cross-sections, resulting in inorganic crystallization mitigation and transforming the fouling layer structure to a more porous and water-permeable state. This ensured the membrane efficiency was little affected by membrane fouling even as LFL was highly concentrated (water flux decline: PVDF ∼49 % vs. CM ∼14 % as concentration factor increased to 20). The resistance of foulant intrusion and in-pore deposition, which easily occurred on microporous membranes, and the decrease in membrane-foulant interactions by the surface layer endowed the CM with a high foulant-release capability (clean efficiency: ∼97 %). The surface layer also exhibited an ammonia/water sieving effect which enhanced volatile ammonia rejection (∼1.6 times). This work provides insight into the construction of high-sustainable MD membranes for high-strength wastewater treatment, promoting the practical implementation of MD.

Do Electrostatics Control the Diffusive Dynamics of Solitary Water? NMR and MD Studies of Water Translation and Rotation in Dipolar and Ionic Solvents.

NMR-based measurements of the diffusion coefficients and rotation times of solitary water and benzene at 300 K are reported in a diverse collection of 13 conventional organic solvents and 10 imidazolium ionic liquids. Proton chemical shifts of water are found to be correlated to water OH-stretching frequencies, confirming the importance of electrostatic interactions in these shifts. However, the influence of magnetic interactions in aromatic solvents renders chemical shifts a less reliable indicator of electrostatics. Diffusion coefficients (DB) and rotational correlation times (τB) of benzene in the solvents examined are accurately described as functions of viscosity (η) by DB ∝ η-0.81 and τB ∝ η0.64. Literature values of DB and τB in alkane and normal alcohols, which were not included among the solvents studied here, are systematically faster than predicted by these correlations, indicating that factors beyond solvent viscosity play a role in determining the friction on benzene. In contrast to benzene, water diffusion and rotation are poorly described in terms of viscosity alone, even in the dipolar and ionic solvents measured here. The present data and the substantial literature data already available on dilute water diffusion show a systematic dependence of DW on solvent polarity among isoviscous solvents. The aspect of solvent polarity most relevant to water dynamics is the ability of a solvent to accept hydrogen bonds from water, as conveniently quantified by the frequency of water's OH stretching band, ΔνOH. The friction on translation, ζtr = kBT/DW, and rotation, ζrot = kBTτW, are both well correlated by functions of the form ζ(η, ΔνOH) = a1ηa2 exp (a3ΔνOH), where the ai are adjustable parameters. Molecular dynamics simulations reveal a strong coupling between electrostatic and nonelectrostatic water-solvent interactions, which makes it impossible to dissect the friction on water into additive dielectric and hydrodynamic components. Simulations also provide a tentative explanation for the unusual form of the correlating function ζ(η, ΔνOH), at least in the case of ζrot.

Study of the drying kinetics of black mulberry (Morus nigra L.) leaves

Black mulberry leaves have been used to promote health and prevent diseases due to their biological properties. Drying leaves allows greater stability during storage and marketing. However, studying this operation is important to ensure that the properties are maintained. Therefore, the objective of this study was to use mathematical modeling to define the model that best fits to the experimental data of the drying kinetics at temperatures of 40, 50, 60, and 70°C. Liquid diffusion, leaf surface area, the relationship between temperature increase and diffusion coefficient, and energy activation were also determined. Among the mathematical models studied, the Page model was the one that best described the drying process of black mulberry leaves. As for the diffusion coefficient, the values increase as the drying temperature increases. The activation energy was 65.418 kJ mol-1, and it was observed that the lower the activation energy, the greater the water diffusivity in the product. The drying kinetics data of black mulberry leaves allowed a better understanding of this operation in a matrix with wide application potential. Drying black mulberry leaves at different temperatures altered their color. Considering the evaluations, temperatures of 40 and 50°C are the most indicated for drying black mulberry leaves.

Glymphatic System Dysfunction Underlying Schizophrenia Is Associated With Cognitive Impairment.

Despite the well-documented structural and functional brain changes in schizophrenia, the potential role of glymphatic dysfunction remains largely unexplored. This study investigates the glymphatic system's function in schizophrenia, utilizing diffusion tensor imaging (DTI) to analyze water diffusion along the perivascular space (ALPS), and examines its correlation with clinical symptoms. A cohort consisting of 43 people with schizophrenia and 108 healthy controls was examined. We quantified water diffusion metrics along the x-, y-, and z-axis in both projection and association fibers to derive the DTI-ALPS index, a proxy for glymphatic activity. The differences in the ALPS index between groups were analyzed using a 2-way ANCOVA controlling for age and sex, while partial correlations assessed the association between the ALPS index and clinical variables. People with schizophrenia showed a significantly reduced DTI-ALPS index across the whole brain and within both hemispheres (F = 9.001, P = .011; F = 10.024, P = .011; F = 5.927, P = .044; false discovery rate corrected), indicating potential glymphatic dysfunction in schizophrenia. The group by cognitive performance interaction effects on the ALPS index were not observed. Moreover, a lower ALPS index was associated with poorer cognitive performance on specific neuropsychological tests in people with schizophrenia. Our study highlights a lower ALPS index in schizophrenia, correlated with more pronounced cognitive impairments. This suggests that glymphatic dysfunction may contribute to the pathophysiology of schizophrenia, offering new insights into its underlying mechanisms.

Investigating exchange, structural disorder, and restriction in gray matter via water and metabolites diffusivity and kurtosis time-dependence

Abstract Water diffusion-weighted MRI is a very powerful tool for probing tissue microstructure, but disentangling the contribution of compartment-specific structural disorder from cellular restriction and inter-compartment exchange remains an open challenge. In this work, we use diffusion-weighted MR spectroscopy (dMRS) of water and metabolite as a function of diffusion time in vivo in mouse gray matter to shed light on: i) which of these concomitant mechanisms (structural disorder, restriction, and exchange) dominates the MR measurements and ii) with which specific signature. We report the diffusion time-dependence of water with excellent SNR conditions as provided by dMRS, up to a very long diffusion time (500 ms). Water kurtosis decreases with increasing diffusion time, showing the concomitant influence of both structural disorder and exchange. However, despite the excellent experimental conditions, we were not able to clearly identify the nature of the structural disorder (i.e., 1D versus 2D/3D short-range disorder). Measurements of purely intracellular metabolites diffusion time-dependence (up to 500 ms) show opposite behavior to water, with metabolites kurtosis increasing as a function of diffusion time. We show that this is a signature of diffusion restricted in the intracellular space, from which cellular microstructural features such as soma’s and cell projections’ size can be estimated. Finally, by comparing water and metabolite diffusion time-dependencies, we attempt to disentangle the effect of intra/extracellular exchange and structural disorder of the extracellular space (both impacting water diffusion only). Our results suggest a relatively short intra/extracellular exchange time (~1-50 ms) and short-range disorder (still unclear if 1D or 2D/3D) most likely coming from the extracellular compartment. This work provides novel insights to help interpret water diffusion-time dependent measurements in terms of the underlying microstructure of gray matter and suggests that diffusion-time dependent measurements of intracellular metabolites may offer a new way to quantify microstructural restrictions in gray matter.

Nitrocellulose for Prolonged Permeation of Levofloxacin HCl-Salicylic Acid In Situ Gel.

Currently, the application of solvent exchange-induced in situ gel is underway for drug delivery to the body target site. Nitrocellulose was attempted in this research as the matrix-forming agent in solvent exchange-induced in situ gel for acne and periodontitis treatments. The gel incorporated a combination of 1% w/w levofloxacin HCl and 2% w/w salicylic acid as the active compounds. In order to facilitate formulation development, the study explored the matrix-forming behavior of different concentrations of nitrocellulose in N-methyl pyrrolidone (NMP). Consequently, their physicochemical properties and matrix-forming behavior, as well as antimicrobial and anti-inflammatory activities, were evaluated using the agar cup diffusion method and thermal inhibition of protein denaturation in the egg albumin technique, respectively. All prepared formulations presented as clear solutions with Newtonian flow. Their contact angles on agarose gel were higher than on a glass slide due to matrix formation upon exposure to the aqueous phase of agarose, with an angle of less than 60° indicating good spreadability. Nitrocellulose concentrations exceeding 20% initiated stable opaque matrix formation upon contact with phosphate buffer pH 6.8. The high hardness and remaining force of the transformed gel indicated their robustness after solvent exchange. Fluorescence tracking using sodium fluorescein and Nile red confirmed the retardation of NMP and water diffusion by the nitrocellulose matrix. From the Franz cell permeation study, these drugs could permeate through neonate porcine skin and tissue of porcine buccal from the nitrocellulose in situ forming gel. Their accumulation in these tissues might enable the inhibition of the invading bacterial pathogens. The developed in situ gels effectively inhibited Staphylococcus aureus, Staphylococcus epidermidis, Propionibacterium acnes, and Porphyromonas gingivalis. Furthermore, the formulations demonstrated an anti-inflammatory effect. The low viscosity of LvSa25Nc makes it appropriate for injectable treatments targeting periodontitis, while the higher viscosity of LvSa40Nc renders it appropriate for topical applications in acne treatment. Therefore, the nitrocellulose in situ gel loaded with combined levofloxacin HCl and salicylic acid emerges as a promising dosage form for treating acne and periodontitis.

In-vitro dehydration kinetics coefficient of Kalifilcon A and other contact lens materials

In contact lens (CL) wear, dehydration needs to be tailored to avoid dryness and related symptoms. In this view, this work aims to assess and compare the in-vitro dehydration kinetics of five CL materials, including the newly developed Kalifilcon A CL. At 36 °C and 60% relative humidity, the in-vitro dehydration kinetics of the different CLs were compared using a gravimetric method. CLs were analyzed either after a rinse of a few seconds in preservative-free saline solution or after a 24-h incubation in the same solution. A model based on the Fick diffusion equation was employed to deduce a water kinetics coefficient, providing insights into water diffusion within the polymeric matrix. The study reveals that all materials exhibit a non-Fickian dehydration behavior, with significant differences in dehydration kinetics coefficients and dehydration rate slopes. Etafilcon A and Omafilcon A, both hydrogel CLs, exhibit a similar behavior, different compared to the pattern shown by Senofilcon A and Delefilcon A, silicone-hydrogel CLs. Notably, Kalifilcon A, despite being a silicone-hydrogel, displays a hydration behavior reminiscent of hydrogel CLs.

Synthesis of struvite-enriched slow-release fertilizer using magnesium-modified biochar: Desorption and leaching mechanisms

To improve the retention and slow-release abilities of nitrogen (N) and phosphorus (P), an 82 %-purity struvite fertilizer (MAP-BC) was synthesized using magnesium-modified biochar and a solution with a 2:1 concentration ratio of NH4+ to PO43− at a pH of 8. Batch microscopic characterizations and soil column leaching experiments were conducted to study the retention and slow-release mechanisms and desorption kinetics of MAP-BC. The slow-release mechanism revealed that the dissolution rate of high-purity struvite was the dominant factor of NP slow release. The re-adsorption of NH4+ and PO43− by biochar and unconsumed MgO prolonged slow release. Mg2+ ionized by MgO could react with PO43− released from struvite to form Mg3(PO4)2. The internal biochar exhibited electrostatic attraction and pore restriction towards NH4+, while magnesium modification and nutrient loading formed a physical antioxidant barrier that ensured long-term release. The water diffusion experiment showed a higher cumulative release rate for PO43− compared to NH4+, whereas in soil column leaching, the trend was reversed, suggesting that soil's competitive adsorption facilitated the desorption of NH4+ from MAP-BC. During soil leaching, cumulative release rates of NH4+ and PO43− from chemical fertilizers were 3.55–3.62 times faster than those from MAP-BC. The dynamic test data for NH4+ and PO43− in MAP-BC fitted the Ritger-Peppas model best, predicting release periods of 163 days and 166 days, respectively. The leaching performances showed that MAP-BC reduced leaching solution volume by 5.58 % and significantly increased soil large aggregates content larger than 0.25 mm by 24.25 %. The soil nutrients retention and pH regulation by MAP-BC reduced leaching concentrations of NP. Furthermore, MAP-BC significantly enhanced plant growth, and it is more suitable as a NP source for long-term crops. Therefore, MAP-BC is expected to function as a long-term and slow-release fertilizer with the potential to minimize NP nutrient loss and replace part of quick-acting fertilizer.

High angular resolution diffusion imaging (HARDI) of porcine menisci: a comparison of diffusion tensor imaging and generalized q-sampling imaging.

Diffusion magnetic resonance imaging (MRI) allows for the quantification of water diffusion properties in soft tissues. The goal of this study was to characterize the 3D collagen fiber network in the porcine meniscus using high angular resolution diffusion imaging (HARDI) acquisition with both diffusion tensor imaging (DTI) and generalized q-sampling imaging (GQI). Porcine menisci (n=7) were scanned ex vivo using a three-dimensional (3D) HARDI spin-echo pulse sequence with an isotropic resolution of 500 µm at 7.0 Tesla. Both DTI and GQI reconstruction techniques were used to quantify the collagen fiber alignment and visualize the complex collagen network of the meniscus. The MRI findings were validated with conventional histology. DTI and GQI exhibited distinct fiber orientation maps in the meniscus using the same HARDI acquisition. We found that crossing fibers were only resolved with GQI, demonstrating the advantage of GQI over DTI to visualize the complex collagen fiber orientation in the meniscus. Furthermore, the MRI findings were consistent with conventional histology. HARDI acquisition with GQI reconstruction more accurately resolves the complex 3D collagen architecture of the meniscus compared to DTI reconstruction. In the future, these technologies have the potential to nondestructively assess both normal and abnormal meniscal structure.

Comparative analysis of glymphatic system alterations in multiple sclerosis and neuromyelitis optica spectrum disorder using MRI indices from diffusion tensor imaging.

The glymphatic system is a glial-based perivascular network that promotes brain metabolic waste clearance. Glymphatic system dysfunction has been observed in both multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD), indicating the role of neuroinflammation in the glymphatic system. However, little is known about how the two diseases differently affect the human glymphatic system. The present study aims to evaluate the diffusion MRI-based measures of the glymphatic system by contrasting MS and NMOSD. This prospective study included 63 patients with NMOSD (n = 21) and MS (n = 42) who underwent DTI. The fractional volume of extracellular-free water (FW) and an index of diffusion tensor imaging (DTI) along the perivascular space (DTI-ALPS) were used as indirect indicators of water diffusivity in the interstitial extracellular and perivenous spaces of white matter, respectively. Age and EDSS scores were adjusted. Using Bayesian hypothesis testing, we show that the present data substantially favor the null model of no differences between MS and NMOSD for the diffusion MRI-based measures of the glymphatic system. The inclusion Bayes factor (BF10) of model-averaged probabilities of the group (MS, NMOSD) was 0.280 for FW and 0.236 for the ALPS index. Together, these findings suggest that glymphatic alteration associated with MS and NMOSD might be similar and common as an eventual result, albeit the disease etiologies differ. Previous literature indicates important glymphatic system alteration in MS and NMOSD. We explore the difference between MS and NMOSD using diffusion MRI-based measures of the glymphatic system. We show support for the null hypothesis of no difference between MS and NMOSD. This suggests that glymphatic alteration associated with MS and NMOSD might be similar and common etiology.

Development and performance evaluation of chitosan-graft-poly (N-vinyl pyrrolidone) as a dual-function inhibitor for hydrate decomposition and reformation

In the process of drilling and producing natural gas hydrates, the hydrate is prone to decomposition, leading to wellbore instability and well control problems, and the natural gas produced by the decomposition is prone to form hydrate again in the low-temperature and high-pressure wellbore, creating flow obstacles. The existing inhibitors, however, fail to effectively inhibit the decomposition and reformation of hydrates. In this work, N-vinylpyrrolidone was used to modify chitosan, and an inhibitor namely DFHI with a dual function of inhibiting hydrate decomposition and reformation was developed. The inhibitory effects of DFHI were analyzed using the optimized experimental method for evaluating hydrate decomposition and reformation, and the mechanism was analyzed. The results showed that the memory effect of hydrate reformation gradually weakened or even disappeared with the rising ambient temperature during hydrate decomposition. The inhibitory performance of DFHI exhibited a positive correlation with its concentration. 0.5% DFHI resulted in a 74.7% delay in the decomposition time of methane hydrate, along with an extension of the induction time for both hydrate formation and reformation by 137.2% and 262.1%, respectively, significantly weakening the memory effect of hydrate reformation. The mechanism of DFHI inhibiting hydrate decomposition primarily involves surface adsorption on hydrates and thickening effects that retard mass and heat transfer processes. During the process of hydrate formation and reformation, DFHI molecules tend to aggregate at the surface of methane bubbles, hindering gas–water contact and diffusion, particularly when numerous micro-nano bubbles generated by hydrate dissolution are present; furthermore, the adsorption of DFHI molecules on the surface of hydrates delays their nucleation and growth.

Mobility of water and ions in partially water-saturated compacted MX-80 bentonite in relation with swelling pressure

Many countries are planning to host long-lived high- and intermediate-level radioactive waste in disposal facilities sited in deep argillaceous formations. Bentonite, as a swelling material, is often chosen as engineered buffers due to its low permeability and high swelling capacity. However, its properties can be influenced by the hydraulic/gas conditions prevailing in-situ that are expected to change throughout the duration of the repository. The objective of this work is to estimate the effect of partially water-saturated conditions on the mobility of water and ions in compacted MX-80 bentonite in relation to the evolution of its swelling pressure. For that purpose, (i) diffusion of water and ions (I− and Na+) and (ii) the swelling pressure of compacted bentonite samples partially water-saturated were studied by means of the osmotic technique that allows controlling the suction from 9 to 0 MPa.Results showed that (i) water diffusivity remained unchanged independently of the degrees of saturation (70, 84 and 100%) and (ii) iodide diffusivity decreased by a factor of 12 (from 100 to 70%), while (iii) Na+ diffusion was reduced by a factor of more than 70 (from 100 to 70%), associated to a drop of the distribution factor by a factor of 16. Comparison of these results with diffusion data already acquired in clayey materials whose porous structure evolves little with suction (i.e. compacted kaolinite and intact Collovo-oxfordian clay-rocks) underlined how the bentonite porous structure whose organization evolved with the degree of saturation is a key parameter. This statement is supported by mechanical tests, which indicated a distinct evolution of the swelling pressure curves depending on the degree of saturation. At 70% saturation, mechanical tests indicate (i) a preservation of the large inter-aggregate porosity where water can diffuse in both vapor and liquid phases, and (ii) a final swelling pressure 1.5 to 2 times lower than at full water saturation, meaning that a part of swelling clay particles was not accessible to water ingress and so to 22Na+. Conversely, at 84 % and 100 % saturation, change in swelling pressure curves was explained by a collapse of bentonite inter-aggregate porosity, in favor of expanding the inter-particle and interlayer porosities where 22Na + diffusion is enhanced by surface diffusion phenomenon.

Расчет режимов релаксации обезвоженного поверхностного слоя путассу в процессе сушки

During cold drying of fish, the surface layers, which have lost a significant part of the water, become compacted and prevent the diffusion of water from the inner layers of the fish to the surface. In order to restore the diffusion properties of the surface layer of fish, it is necessary to create conditions for the redistribution of moisture along the thickness of the object, for example, temporarily limit external mass transfer. To do this, reduce the temperature, the speed of air movement in the drying chamber and increase its relative humidity. Due to diffusion, water from the central layers of the fish will flow to the dehydrated surface layer and moisten it. As a result, the mass-conducting properties of the surface layer will increase. The purpose of this work is to study the effect of relaxation processes on changes in the thickness of the dehydrated surface layer of fish for the subsequent development of scientifically sound rational drying regimes. The calculation of moisture redistribution in this work was carried out under the condition (assumption) that there is no external mass transfer of moisture from the surface of the processing object. The kinetics curve and water distribution curves in the processing facility were constructed during the production of dried fish products in 2; 2.5; 13.5; 55 hours respectively. The average humidity of the whiting after dehydration lasting 2 hours was 333% in terms of dry matter. The thickness of the dehydrated layer S = 1.6 mm. After 1.5 hours of relaxation, the moisture on the surface of the fish increased from 272 to 330% and approached the average humidity of the sample. During dehydration of fish lasting 13.5 hours, the average moisture content of the sample per dry mass was 217%, the thickness of the dehydrated surface layer S = 0.9 mm. After 2.5 hours of relaxation, the moisture content on the surface of the layer was 174%. It was found that at the beginning of the drying process, the dry dehydrated layer has 
 a positive tendency to restore the lost moisture-conducting (diffusion) properties, but at the end of the drying process it takes more time to restore them. The paper proposes a method for calculating relaxation curves, which can be used to study the processes of moisture redistribution in the processing object in order to create rational drying modes.

Measurement of the rotational relaxation time of intracellular water in dried yeast and Jurkat cells by near infrared spectroscopy

Molecular mobility of intracellular water is a crucial parameter in the study of the mechanism of desiccation tolerance. As one of the parameters that reflecting molecular mobility, the viscosity of intracellular water has been found intimately related with the protection of the phospholipid membrane because it quantifies the diffusion ability of water and mass in the intracellular environment. In this work we measured the intracellular water relaxation time, which can be translated into water viscosity, by using a previously established NIR-dielectric method to monitor the drying process of baker's yeast and Jurkat cells with different desiccation tolerance. We found that intracellular saccharide can significantly decrease the intracellular water viscosity. Also, the intracellular water diffusion coefficient obtained from this method were found in good agreement with other reports.

Spatial Distribution and Diffusion Characterisation of Water in Coal Samples: An Experimental Study

Comprehending the water absorption process inherent to coal, including the associated spatial distribution patterns of water, proves indispensable in the design and evaluation of coal pillar dams in underground water reservoirs. To better understand this process, a series of NMR (nuclear magnetic resonance) tests were carried out on cylindrically shaped coal samples immersed in water for varying durations, with the upper and lower surfaces of the samples sealed. A method involving image digital processing and finite element simulation was used to quantitatively characterise the water absorption process, as well as the spatial distribution of water in the samples. The results showed that NMR imaging colour brightness differences were positively correlated with water content and that the wetted ring gradually increased in width as the water immersion time increased. The expectation and sum of squared deviations of the pixel greyscale values of the NMR images, which were used to characterise the water saturation and spatial distribution of the coal samples, represented positive and negative exponential functions of the water immersion time, respectively. This indicated that the water saturation gradually increased and became more uniformly distributed. Furthermore, based on the set threshold value of the target variable rate of change, the limiting expectation of the pixel greyscale values was obtained, and the limiting water absorption time of the coal sample was predicted. The water diffusion equation was then used to characterise the water absorption process of the coal samples, and a water diffusion model was developed to accurately obtain the wet ring boundary data. A reasonable value of the diffusion coefficient was determined by comparing and correcting the results of the numerical simulation and physical experiments with full consideration of the non-homogeneity of the numerical model. This water diffusion model can better characterise the water transport phenomena in the macroscopic barrier zone of coal pillar dams. Finally, the application prospects in terms of practical engineering were investigated.

Ultra-high b-value DWI accurately identifies isocitrate dehydrogenase genotypes and tumor subtypes of adult-type diffuse gliomas.

To distinguish isocitrate dehydrogenase (IDH) genotypes and tumor subtypes of adult-type diffuse gliomas based on the fifth edition of the World Health Organization classification of central nervous system tumors (WHO CNS5) in 2021 using standard, high, and ultra-high b-value diffusion-weighted imaging (DWI). This prospective study enrolled 70 patients with adult-type diffuse gliomas who underwent multiple b-value DWI. Apparent diffusion coefficient (ADC) values including ADCb500/b1000, ADCb500/b2000, ADCb500/b3000, ADCb500/b4000, ADCb500/b6000, ADCb500/b8000, and ADCb500/b10000 in tumor parenchyma (TP) and contralateral normal-appearing white matter (NAWM) were calculated. The ADC ratios of TP/NAWM were assessed for correlations with IDH genotypes, tumor subtypes, and Ki-67 status; diagnostic performances were compared. All ADCs were significantly higher in IDHmutant gliomas than in IDH wild-type gliomas (p < 0.01 for all); ADCb500/b8000 had the highest area under the curve (AUC) of 0.866. All ADCs were significantly lower in glioblastoma than in astrocytoma (p < 0.01 for all). ADCs other than ADCb500/b1000 were significantly lower in glioblastoma than in oligodendroglioma (p < 0.05 for all). ADCb500/b8000 and ADCb500/b10000 were significantly higher in oligodendroglioma than in astrocytoma (p = 0.034 and 0.023). The highest AUCs were 0.818 for ADCb500/b6000 when distinguishing glioblastoma from astrocytoma, 0.979 for ADCb500/b8000 and ADCb500/b10000 when distinguishing glioblastoma from oligodendroglioma, and 0.773 for ADCb500/b10000 when distinguishing astrocytoma from oligodendroglioma. Additionally, all ADCs were negatively correlated with Ki-67 status (p < 0.05 for all). Ultra-high b-value DWI can reliably separate IDH genotypes and tumor subtypes of adult-type diffuse gliomas using WHO CNS5 criteria. Ultra-high b-value diffusion-weighted imaging can accurately distinguish isocitrate dehydrogenase genotypes and tumor subtypes of adult-type diffuse gliomas, which may facilitate personalized treatment and prognostic assessment for patients with glioma. • Ultra-high b-value diffusion-weighted imaging can accurately distinguish subtle differences in water diffusion among biological tissues. • Ultra-high b-value diffusion-weighted imaging can reliably separate isocitrate dehydrogenase genotypes and tumor subtypes of adult-type diffuse gliomas. • Compared with standard b-value diffusion-weighted imaging, high and ultra-high b-value diffusion-weighted imaging demonstrate better diagnostic performances.

On Local Structure Equilibration of Ca2+ in Solution by Ab Initio Molecular Dynamics.

Analyzing the stable isotopic ratio of Ca offers valuable insights into a wide range of applications from climate reconstruction to bone cancer diagnosis and agricultural nutrient improvement. While the first hydration shell of Ca in solution is expected to play a major role in its fractionation properties, the coordination of Ca in water remains a subject of debate. In this work, Ca2+ in water has been modeled by means of ab initio molecular dynamics simulations using various exchange and correlation functionals and at different temperatures. Results show a significant effect of the functional on the average Ca2+ coordination, depending on its tendency to over- or understructure liquid water. The BLYP functional with Grimme-D2 correction was judged as the most accurate among those tested based on its accuracy to reproduce water structural and diffusion properties. Using this functional, the effect of temperature has been systematically investigated, focusing on means to limit the uncertainty in our assessments of the average coordination of Ca2+ ions by (1) estimating the number of water exchanges in the simulations and (2) implementing a statistical approach based on Markov chains. The findings indicate, especially, that our simulations at 300, 350, and 400 K do not yield converged results due to potential equilibration problems. These observations impose substantial constraints on the trustworthiness of numerous estimates in the existing literature that depend on trajectories with insufficient exchanges. We estimate Ca2+ coordination values of 6.8 ± 0.1, 6.8 ± 0.1, 6.7 ± 0.2, and 6.7 ± 0.2 at 600, 550, 500, and 450 K respectively. At lower temperatures (300, 350, and 400 K), while obtaining definitive values for Ca2+ coordination remains challenging, our research does indicate a potential temperature-related influence on coordination with an average Ca2+ coordination at 300 K as low as 6.2.

Effect of PFDS on the immobilization of Cs+ by metakaolin-based geopolymers in complex environments

Metakaolin-based geopolymers are very promising materials for improving the safety of low and intermediate level radioactive waste disposal, with respect to ordinary Portland cement, due to their excellent immobilization performance for Cs+ and superior chemical stability. However, their application is limited by the fact that the leaching behavior of Cs+ is susceptible to the presence of other ions in the environment. Here, we propose a way to modify a geopolymer using perfluorodecyltriethoxysilane (PDFS), successfully reducing the leaching rate of Cs+ in the presence of multiple competitive cations due to blocking the diffusion of water. The leachability index of the modified samples in deionized water and highly concentrated saline water reached 11.0 and 8.0, respectively. The reaction mechanism between PDFS and geopolymers was systematically investigated by characterizing the microstructure and chemical bonding of the material. This work provides a facile and successful approach to improve the immobilization of Cs ions by geopolymers in real complex environments, and it could be extended to further improve the reliability of geopolymers used in a range of applications.

A micro‐nanohierarchical composite fabric for efficient water transport and outstanding flame retardancy

AbstractTextiles with outstanding moisture transport characteristics and excellent flammability is of vital importance for human beings. In this work, the poly(arylene sulfide sulfone)–polydopamine/polyphenylene sulfide–polydopamine/poly(arylene sulfide sulfone) (PASS‐PDA/PPS‐PDA/PASS) composite fibric with multigradient porous structures from macro to submicron levels prepared via micrometer and nanometer fibers for water transport and evaporation has been fabricated. The introduction of PDA can effectively improve the hydrophilicity of the composite membrane. Meanwhile, superhydrophobic PASS layer with beaded structure was obtained by electrospray as the inner layer. It is found that PASS‐PDA‐72 fabric exhibited outstanding water diffusion property (spreading diameter = 10.47 cm) and ultrafast the water evaporation (0.20 g h−1). Meanwhile, the beaded‐structure PASS fabrics with high hydrophobicity (water contact angle is 130°C) was selected to absorb water from the surface of human skin and transport it to the other side to evaporate quickly, giving the surface of human skin a comfortable and dry environment. What is more, the PASS‐PDA/PPS‐PDA/PASS composite membrane exhibited excellent thermal stability (Tdmax = 544°C) and flame retardancy, which will have potential for the application in the field of fire protection.

Solar drying of oregano leaves (Plectranthus amboinicus, Lour): Analysis of experimental performance under a tropical climate

Despite the multiple applications of the oregano ( Plectranthus amboinicus (Lour)), an important herbaceous plant because of its medicinal and culinary properties, limited research has been conducted on this species’ solar drying. Thus, the experimental drying of oregano leaves in a tropical climate was performed using direct and indirect solar drying and an electric oven in this research work. Also, mathematical modeling of the drying process, moisture diffusivity, activation energy, and colorimetric analysis (as a quality parameter) were accomplished to complement the experimental evaluation and understand the drying process behavior. The results show a shorter drying time obtained with the electric oven with 210 min reached at 65°C; however, the minimum solar drying time (250 min) was achieved with a maximum drying rate of 0.025 g water/g dry matter per minute and minimum final moisture between 0.28 and 0.13 g water/g dry matter was obtained with indirect solar dryer. Moreover, the models that better represented the experimental data were Modified Page, Page, and Logarithmic, with a maximum value of R2 obtained of 0.9980 corresponding to the Logarithmic model. Furthermore, a maximum effective diffusivity value of 1.81E-9 was obtained with direct solar dryer natural convection, while for the electric oven, were 1.14E-10, 2.280E-10, and 1.026E-09 for 45, 55, and 65°C, respectively. The activation energy for water diffusion in oregano leaves was 55.66 and 97.78 kJ/g mol for solar dryers and electric ovens, respectively, which were values very close to those reported in the literature. Finally, the colorimetric analysis exhibited a minimum color change value of 17.1 obtained for the indirect solar dryer, allowing better oregano preservation and maintaining its quality for the market, which makes it ideal for drying oregano in tropical climates and promotes solar drying use for sustainable growth of the region.