Microstructural Damage Research Articles

Diffusion tensor imaging features of white matter pathways in the brain after COVID-19 infection.

To determine whether there is adifference in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values in white matter pathways in the subacute period after COVID-19 infection and to evaluate the correlation between diffusion tensor imaging (DTI) metrics and laboratory findings. The study included 64 healthy controls and 91patients. Patients were classified as group1 (all patients, n = 91), group2 (outpatients, n = 58), or group3 (inpatients, n = 33). The ADC and FA values were calculated from 10distinct neuroanatomic localizations; DTI values were compared between groups. Decreased FA values in the cingulum, corpus callosum splenium and genu (CCS-CCG), forceps major, inferior fronto-occipital fasciculus (IFOF), and middle cerebellar peduncle (MCP) observed in group1 compared with the control group. Group1 showed elevated ADC values in CCG. Lower FA and higher ADC values in CCG were shown in group3. The FA values for CCS, IFOF, and MCP in group3 were lower than those in the control group. Group3 had the highest ADC values in the CCS. Additionally, the FA values of the CCG were lower in group3 than in group2. Oxygen saturation levels and FA values in the CCG and SFOF exhibited apositive correlation. We speculate that DTI changes in white matter pathways may be associated with axonal damage and demyelination due to impaired white matter integrity following COVID-19 infection during the subacute period. Our study showed with DTI findings that there is microstructural damage in white matter pathways in the subacute period of COVID-19 infection and that this damage is related to oxygen saturation levels. Many studies in the literature show that microstructural damage in white matter pathways can lead to clinical neurocognitive dysfunction. We suggest that these cases require more comprehensive studies investigating whether chronic white matter damage is reversible and examining its relationship with neurocognitive dysfunctions in the future. Neurological involvement is not rare in COVID-19 infection. We examined various white matter pathways with DTI during the subacute period of COVID-19 infection. We showed changes in DTI parameters indicating adecrease in white matter integrity and microstructural damage in the subacute period follow-up of cases with COVID-19. We found that there was apositive correlation between oxygen saturation levels and decreased FA values in white matter tracts.

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

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

Brain tissue integrity in neuromyelitis optica spectrum disorder through T1-w/T2-w ratio, MTR and DTI.

The presence of diffuse brain damage in normal-appearing white matter (NAWM) and gray matter (NAGM) in neuromyelitis optica spectrum disorder (NMOSD) remains controversial. We aimed to address this controversy by applying a multiparametric MRI approach. Additionally, the association between MRI metrics and clinical variables was explored. In this cross-sectional study, we prospectively evaluated aquaporin-4-IgG positive NMOSD patients and healthy controls (HC) matched for age and sex. The clinical variables of interest were collected for each participant. The mean values of T1-w/T2-w ratio, magnetization transfer ratio (MTR), fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) were obtained in NAWM, NAGM, as well as in global and hypointense lesion masks. Global lesions refer to those typically associated with aquaporin-4-IgG positive NMOSD. Hypointense lesions were defined as areas of hypointense signal in both T1-w and fluid-attenuated inversion recovery (FLAIR) images. In total, we included 105 participants (59 NMOSD patients and 46 HC). T1-w/T2-w ratio was lower in NAWM of NMOSD patients versus HC (1.83 ± 0.14 vs 1.89 ± 0.14; p = 0.029), while no significant differences were found in NAWM or NAGM across the other metrics: (p range: 0.079 to 0.973). Hypointense lesions showed lower T1-w/T2-w ratio, MTR, and FA, and higher diffusivity metrics as compared to global lesion masks (p < 0.001). T1-w/T2-w ratio in NAWM was inversely correlated with time to start immunosuppressive therapy (r = - 0.278; p = 0.036) and with MD (r = - 0.325; p = 0.014). Microstructural integrity loss seems to be confined to focal tissue damage in NMOSD. Decreased T1-w/T2-w ratio in NAWM may reflect subclinical water accumulation due to astrocyte and blood-brain barrier dysfunction. Hypointense lesions have shown a severe degree of microstructural damage.

Unveiling lotus root processing under vacuum microwave: starch-malic acid interactions based on moisture, structure, and in vitro digestibility.

This study evaluated the effects of malic acid vacuum microwave preconditioning (MVMP) on lotus root (LR) by examining its moisture content, dielectric properties, microstructure, and starch characteristics, including modifications in starch structure and composition. Dielectric properties and LF-NMR indicated that the dielectric constant (ε') was closely associated to moisture content and state, while changes in water migration depended on microwave power and the dielectric loss factor (ε″). Increased microwave power and malic acid concentration resulted in microstructural damage (indentation and breakage of starch granules) and starch hydrolysis into smaller particles. MVMP preserved higher levels of phenolic and flavonoid compounds. FT-IR analysis revealed an additional absorption peak at 1740cm-1. The maximum degree of substitution was 0.131. Starch from MVMP-treated LR exhibited higher crystallinity, with a maximum resistant starch (RS) content of 68.3%. In addition, microwave power considerably influenced amylose content, solubility, swelling power, and thermal enthalpy.

Predilection for Perplexion: Preoperative microstructural damage is linked to postoperative delirium.

Postoperative delirium is the most common postsurgical complication in older adults and is associated with an increased risk of long-term cognitive decline and Alzheimer's disease (AD) and related dementias (ADRD). However, the neurological basis of this increased risk- whether postoperative delirium unmasks latent preoperative pathology or leads to AD-relevant pathology after perioperative brain injury-remains unclear. Recent advancements in neuroimaging techniques now enable the detection of subtle brain features or damage that may underlie clinical symptoms. Among these, Neurite Orientation Dispersion and Density Imaging (NODDI) can help identify microstructural brain damage, even in the absence of visible macro-anatomical abnormalities. To investigate potential brain microstructural abnormalities associated with postoperative delirium and cognitive function, we analyzed pre- and post-operative diffusion MRI data from 111 patients aged ≥60 years who underwent non-cardiac/non-intracranial surgery. Specifically, we investigated preoperative variation in diffusion metrics within the posterior cingulate cortex (PCC), a region in which prior work has identified glucose metabolism alterations in the delirious brain, and a key region in the early accumulation of amyloid beta (Aβ) in preclinical AD. We also examined the relationship of preoperative PCC NODDI abnormalities with preoperative cognitive function. Compared to patients who did not develop postoperative delirium (n=99), we found increased free water (FISO) and neurite density index (NDI) and decreased orientation dispersion index (ODI) in the dorsal PCC before surgery among those who later developed postoperative delirium (n=12). These FISO differences before surgery remained present at six weeks postoperatively, while these NDI and ODI differences did not. Preoperative dorsal PCC NDI and ODI values were also positively associated with preoperative attention/concentration performance, independent of age, education level, and global brain atrophy. Yet, these diffusion metrics were not correlated with cerebrospinal fluid Aβ positivity or levels. These results suggest that preoperative latent brain abnormalities within the dorsal PCC may underlie susceptibility to postoperative delirium, independent of AD-related (i.e., Aβ) neuropathology. Furthermore, these preoperative microstructural differences in the dorsal PCC were linked to preoperative deficits in attention/concentration, a core feature of postoperative delirium. Our findings highlight microstructural vulnerability within the PCC, a key region of the default mode network, as a neuroanatomic locus that can help explain the link between preoperative attention/concentration deficits and increased postoperative delirium risk among vulnerable older surgical patients.

Microstructural Damage and Repair in the Spinal Cord of Patients With Early Multiple Sclerosis and Association With Disability at 5 Years.

The dynamics of microstructural spinal cord (SC) damage and repair in people with multiple sclerosis (pwMS) and their clinical relevance have yet to be explored. We set out to describe patient-specific profiles of microstructural SC damage and change during the first year after MS diagnosis and to investigate their associations with disability and SC atrophy at 5 years. We performed a longitudinal monocentric cohort study among patients with relapsing-remitting MS: first relapse <1 year, no relapse <1 month, and high initial severity on MRI (>9 T2 lesions on brain MRI and/or initial myelitis). pwMS and age-matched healthy controls (HCs) underwent cervical SC magnetization transfer (MT) imaging at baseline and at 1 year for pwMS. Based on HC data, SC MT ratio z-score maps were computed for each person with MS. An index of microstructural damage was calculated as the proportion of voxels classified as normal at baseline and identified as damaged after 1 year. Similarly, an index of repair was also calculated (voxels classified as damaged at baseline and as normal after 1 year). Linear models including these indices and disability or SC cross-sectional area (CSA) change between baseline and 5 years were implemented. Thirty-seven patients and 19 HCs were included. We observed considerable variability in the extent of microstructural SC damage at baseline (0%-58% of SC voxels). We also observed considerable variability in damage and repair indices over 1 year (0%-31% and 0%-20%), with 18 patients showing predominance of damage and 18 predominance of repair. The index of microstructural damage was associated positively with the Expanded Disability Status Scale score (r = 0.504, p = 0.002) and negatively with CSA change (r = -0.416, p = 0.02) at 5 years, independent of baseline SC lesion volume. People with early relapsing-remitting MS exhibited heterogeneous profiles of microstructural SC damage and repair. Progression of microstructural damage was associated with disability progression and SC atrophy 5 years later. These results indicate a potential for microstructural repair in the SC to prevent disability progression in pwMS.

MR study on white matter injury in patients with acute diquat poisoning

To explore the microstructural damage of white matter in acute diquat (DQ) poisoning patients using diffusion kurtosis imaging (DKI) and Tract-based Spatial Statistics (TBSS). This study included 19 DQ poisoning patients and 19 age-matched controls. MRI was performed using a 3.0 T Philips Achieva scanner with sequences including 3D T1WI, T2WI, DWI, 3D T2WI-FLAIR, and DKI (3 b-values, 15 directions). DICOM to NIFTI image form conversion was done using MRIcron's Dcm2niigui, followed by motion and eddy current correction with FSL to create a brain mask. Scalar indicators (MK, AK, RK, FAK) were calculated with DKE software. TBSS was used for spatial normalization, skeletonization, and projection of DKI indices for group analysis with TFCE for multiple comparison correction (P < 0.025). After the screening and enrollment process, 19 DQ-poisoned patients and 19 healthy volunteers were analyzed. No significant age or sex differences were found between groups. For Mean Kurtosis (MK), the right corticospinal tract showed a significant difference with a mean difference of 0.21 (95 % CI: 0.15-0.27) and P = 0.000503. Axial Kurtosis (AK) in the left superior longitudinal fasciculus had a mean difference of 0.18 (95 % CI: 0.12-0.24) and P = 0.0024. Fractional Anisotropy of Kurtosis (FAK) in the right corticospinal tract showed a mean difference of 0.19 (95 % CI: 0.13-0.25) and P = 0.0000318. Axial Kurtosis (AK) positively correlated with blood drug levels (r = 0.52, P < 0.05). Seven patients developed subcortical leukodystrophy, mainly in the frontal parietal lobe, with possible insular lobe involvement. DQ poisoning primarily damages the right corticospinal tract, right cingulate gyrus, and left superior longitudinal fasciculus, potentially causing movement and visual impairments. The injury involves demyelination and axonal degeneration, with asymmetrical damage between hemispheres. The left superior longitudinal fasciculus injury is dose-dependent, and unlike prior studies, dopaminergic nuclei were unaffected. The frontal parietal lobe is predominantly affected, with some insular lobe involvement in DQ poisoning patients.

Multi-Analytical Study of Damage to Marine Ballast Tank Coatings After Cyclic Corrosion Testing

Seawater ballast tanks in vessels are subject to severe service conditions caused by repeated filling/emptying, as well as temperature variation. Consequently, relatively thick, barrier-type coatings are used for corrosion protection of their internals. These are generally formulated with solvent-based epoxy binders and contain a range of flake pigments designed to limit environmental entry. Here, we report on a detailed study of damage processes in order to understand the mechanisms of failure after hygro-thermal cyclic corrosion testing. Similar formulations were cured using variant phenalkamine cross-linkers. Visual observation after corrosion testing shows minimal changes and no sign of corrosion damage. However, high-resolution analytical microscopy and nanoscale tomography reveal the onset of microstructural and chemical damage processes inside the coating. Thus, kaolin and talc pigments in the coating remained stable under hygro-thermal cycling; however, dolomite and barium sulphate dissolved slightly, causing voids. Galvanic protection of the substrate by aluminium flake pigments was disproven as no electrical connection was evident. Vibrational spectroscopy revealed a decrease in residual epoxy functionality after exposure for the coating cured with the more stable phenalkamine. This was correlated with an increase in glass transition temperature (Tg) and no observable corrosion of aluminium flakes. In contrast, the less stable phenalkamine cross-linker caused the binder Tg to decrease and aluminium flakes and substrate corrosion to become evident.

Studying the Mechanical Behavior and Strengthening of RCSACC after Exposure to Elevated Temperatures

Rapid calcium sulfoaluminate cement concrete (RCSACC) has received increased attention of late because it can be manufactured with less CO2 emissions than ordinary Portland cement. In previous studies, RCSACC performed poorly when subjected to elevated temperatures, to which fiber-reinforced concrete (FRC) is a potential alternative. This study investigated the impact of incorporating two types of fibers, i.e., copper-plated steel microfilament (CPM) and shear corrugated steel (SC), on the engineering, mechanical, and microstructural features of RCSACC after exposure to elevated temperatures. Pore size distribution, microstructure, and mechanical properties were tested after exposure to temperatures of 100, 200, and 300 °C. The content of each type of fibers represented 1% of the concrete. The results showed that the mechanical properties were affected by the addition of either type of steel fibers. Adding CPM or SC steel fibers could ensure an adequate resistance of RCSACC when exposed to high temperatures, in addition to improving its residual mechanical behavior, spalling resistance, and ductility after heating. Steel fibers contribute to enhancing both mechanical properties and resistance to heating effects. However, adding steel fibers also appears to increase microstructure damage with heat, reduce workability, entrap air and water, and reduce cracking related to drying shrinkage.

Brain microstructural damage through serial diffusion tensor imaging and outcomes in Susac syndrome: A prospective cohort study.

Susac syndrome (SuS) is a rare immune-mediated microangiopathy with potential disabling evolution. We aimed to analyze brain microstructural damage through diffusion tensor imaging (DTI) in SuS and determine its association with poor outcomes. CarESS study is a prospective multicenter national cohort study of patients with SuS. Patients included at the principal investigator's center with at least two available brain magnetic resonance imaging (MRI) with DTI were analyzed. Mean diffusivity (MD) and fractional anisotropy (FA) were measured in fibers crossing three regions of interest (ROIs): the corpus callosum as a whole, the genu of the corpus callosum, and the splenium of the corpus callosum. The primary outcome was work resumption. Twenty-two patients (36 (25;42) years, 16 (73%) females) were studied. The triad (i.e., brain, eye, and ear involvement) was complete in 21 (95%) patients. All but one patients received steroids alone or in combination with immunosuppressive drugs (n = 11) and/or IVIg (n = 7). Over a median follow-up of 6 (5;8) years, 15 (68%) patients went back to work. FA and MD were longitudinally measured in 123 DTI MRI accounting for a median of 5.6 [4.2; 7] MRI per patient. Microstructural damages in the corpus callosum as a whole, the genu of the corpus callosum, and the splenium of the corpus callosum increased during follow-up and were significantly associated with the inability to return to work. Brain DTI identified microstructural damage in fibers crossing the corpus callosum that are associated with long-term disability in SuS. ClinicalTrials.gov portal identifier: NCT01481662 (https://clinicaltrials.gov/ct2/show/NCT01481662?term=caress&draw=2&rank=5).

EFFECT OF DRILLING PARAMETERS ON THRUST FORCE AND DELAMINATION DAMAGE OF DRILLED RAMIE WOVEN – COIR FIBER HYBRID COMPOSITES

This study examines the effect of spindle speed and feed rate variations on the delamination mechanism and thrust force of hybrid composite materials reinforced with ramie weave and coir fibers. The specimen was made with a volume fraction of 30%, consisting of 6 layers of woven ramie, with the remainder being coir. The drilling process is divided into four main phases, showing changes in thrust force at each stage. The results indicate that an increase in feed rate tends to increase thrust force and cause microstructural damage such as delamination and fiber pull-out. At a feed rate of 0.26 mm/rev and a spindle speed of 1500 RPM, the maximum thrust force is reached, indicating the most severe damage. The delamination factor is higher on the exit side compared to the entry side, especially at higher spindle speeds. Tensile tests show a significant decrease in the tensile strength of the composite material due to drilling, with the highest tensile stress achieved at a spindle speed of 1500 RPM and a feed rate of 0.1 mm/rev, although still lower than the sample without holes. The combination of high feed rate and high spindle speed increases the risk of material damage, but the proper selection of drilling parameters can help minimize damage and maintain the mechanical integrity of the composite material. This study provides important insights for industrial applications where mechanical strength and drilling efficiency are crucial.

Neuroanatomical and clinical correlates of prodromal dementia with Lewy bodies: a systematic literature review of neuroimaging findings.

Prodromal Dementia with Lewy bodies (pro-DLB) has been recently defined; however, the neuroanatomical and functional correlates of this stage have not yet been univocally established. This study aimed to systematically review neuroimaging findings focused on pro-DLB. A literature search of works employing MRI, PET, and SPECT was performed. Forty records were included: 15 studies assessed gray matter (GM) and white matter (WM) integrity, and 31 investigated metabolism, perfusion, and resting-state connectivity. Results showed that, in pro-DLB, frontal lobe areas were characterized by decreased function, cortical atrophy, and WM damage. Volumetric reductions were found in the insula, which also showed heightened metabolism. A pattern of hypofunction and structural damage was observed in the lateral and ventral temporal lobe; instead, the parahippocampal cortex and hippocampus exhibited greater function. Hypofunction marked parietal and occipital regions, with additional atrophy in the medial occipital lobe and posterior parietal cortex. Subcortically, atrophy and microstructural damage in the nucleus basalis of Meynert were reported, and dopamine transporter uptake was reduced in the basal ganglia. Overall, structural and functional damage was already present in pro-DLB and was coherent with the possible clinical onset. Frontal and parieto-occipital alterations may be associated with deficits in attention and executive functions and in visuo-perceptual/visuo-spatial abilities, respectively. Degeneration of cholinergic and dopaminergic transmission appeared substantial at this disease stage. This review provided an updated and more precise depiction of the brain alterations that are specific to pro-DLB and valuable to its differentiation from physiological aging and other dementias.

Eco-friendly recovery of pure and long carbon fibres from aged epoxy matrix composites by H2O2 as an oxidant

In this study, we focused on the chemical recovery of carbon fibres from epoxy matrix composite wastes. First, we laminated and cured composite panels from carbon fibre-reinforced prepregs (CFRP) and then aged them under controlled circumstances to simulate their lifespan. Fibre recovery was then carried out by hydrogen peroxide (H2O2) at 6 bar and between 60 and 150 °C. We chose this material because it results in a rapid, cost-efficient, and environmentally friendly process. Besides, we expected it would allow the removal of the polymer matrix without fragmenting the fibres. We aimed to investigate the matrix decomposition in H2O2, the purity of the obtained fibres and the retention of their mechanical properties. The purity and the structure of the obtained carbon fibres were then characterised by using scanning electronic microscopy (SEM), X-ray diffraction (XRD), thermogravimetry (TGA), infrared spectroscopy (IR), and X-ray photoelectron spectroscopy (XPS). We found that H2O2 was effective in recovering carbon fibres, especially at 150 °C. The mechanical results showed that the retention of the modulus was complete, while the tensile strength and elongation at break decreased by 35% due to microstructural damages. The fibres still have better properties than glass or basalt fibres; therefore, good-quality composites can be made using them.Graphical

Connectivity-based striatal subregion microstructural changes in sporadic amyotrophic lateral sclerosis patients: Relation to motor disability, cognitive deficits, and serum biomarkers.

To date, no previous studies have used multishell diffusion MRI to identify striatal microstructural damage invivo in amyotrophic lateral sclerosis (ALS) patients. Thus, in the present study, we aimed to comprehensively explore connectivity-based selective striatal subregion microstructural damage in sporadic ALS patients and its associations with motor disability, cognitive deficits, and serum biomarkers. In this retrospective study, 79 ALS patients and 53 healthy controls (HCs) who underwent clinical assessment, serum neurofilament light (NfL) measurement, genetic testing, and multishell diffusion MRI scanning were included. Using a probabilistic tractography approach, the striatum was segmented into six subregions based on their corticostriatal connectivity. Three neurite orientation dispersion and density imaging (NODDI) parameters, the neurite density index (NDI), orientation dispersion index (ODI), and isotropic volume fraction (ISO), of the connectivity-based striatal subregions were measured. Compared with HCs, ALS patients had a significantly lower NDI in the bilateral motor and right frontal subregions, a significantly lower ODI in the right motor and frontal subregions, and a significantly higher ISO in the bilateral motor and frontal subregions of the striatum after familywise error (p < 0.05). Moreover, striatal subregion microstructural damage was significantly correlated with motor disabilities, cognitive deficits, and serum NfL levels in ALS patients (p = 0.020-0.002). Our study provides clear evidence demonstrating that connectivity-based selective striatal subregion microstructural damage is a definite feature of sporadic ALS patients and suggesting that striatal damage may play an important role in motor disability and cognitive deficits in ALS patients.

Coupling x-ray computed tomography and gray-level co-occurrence matrix to assess the evolution of microstructural damage in coal treated with supercritical CO2 fluid

The reliability of segmentation of x-ray computed tomography (CT) images based on user-selected thresholds is important for analyzing supercritical CO2 (ScCO2)-water-induced microstructural damage in coal. In this study, a novel approach is introduced by integrating the gray-level co-occurrence matrix (GLCM) method with CT to analyze the evolution of microstructural damage in coal treated by ScCO2-water. The factors influencing GLCM calculation are also examined. GLCM heat maps and statistics were employed to visualize and quantitatively analyze the evolution of microstructural damage. The results show that the application of image grayscale registration and noise reduction to GLCM statistics did not produce directional bias, with noise reduction having a more significant impact. The pixel pairings depicted in GLCM heat maps provide insights into the spatial distribution of pore-fracture (in the low-density quadrant) and mineral components (in the high-density quadrant) within CT images, elucidating the evolution of micro-damage in coal samples. After the ScCO2-water treatment, a conspicuous rise in pixel pair counts within the low-density quadrant can be observed, accompanied by significant dissolution of the highest-density minerals, leading to a maximal reduction in pixel values within the high-density quadrant. Moreover, GLCM statistics show that the maximum damage location after ScCO2-water treatment does not completely match the initial coal. An accurate description of the evolution of GLCM statistics in the structural damage behavior induced by CO2 injection into deep coal-rock reservoirs is crucial, suggesting that these GLCM statistics have the potential to predict structural damage and reservoir instability during the geological sequestration of CO2.

γ-Glutamylcysteine restores glucolipotoxicity-induced islet β-cell apoptosis and dysfunction via inhibiting endoplasmic reticulum stress.

The impaired function of islet β-cell is associated with the pathogenesis of type 2 diabetes mellitus (T2DM). γ-glutamylcysteine (γ-GC), an immediate precursor of glutathione (GSH), has antioxidant and neuroprotective functions. Its level has been reported to be down-regulated in hyperglycemia. However, whether γ-GC has a protective effect on islet β-cell dysfunction remains elusive. Recently, we explore the molecular mechanism by which γ-GC protects islet β-cell from glucolipotoxicity-induced dysfunction. In vivo mice models and in vitro cell models were established to examine the therapeutic effects and molecular mechanisms of γ-GC. db mice develop impaired glucose-stimulated insulin secretion (GSIS) due to reduced islet number and damaged islet microstructure. Serious oxidative damage, apoptosis and lipid accumulation are also observed in β-cell stimulated by glucolipotoxicity. Mechanistic studies suggest that glucolipotoxicity inhibits PDX-1 nuclear translocation by inducing endoplasmic reticulum (ER) stress, which leads to impaired insulin (INS) secretion in β-cell. Nevertheless, γ-GC as an inhibitor of ER stress can alleviate the damage of islet microstructure in db mice. Importantly, γ-GC promotes INS gene expression and GSIS through driving nuclear translocation of PDX-1, thereby enhancing intracellular INS content. Moreover, treatment with γ-GC can also mitigate oxidative damage, apoptosis and lipid accumulation of β-cell, resulting in ameliorating islet β-cell dysfunction induced by glucolipotoxicity. Our results support the use of γ-GC as an inhibitor of ER stress for prevention and treatment of T2DM in the future.

A Brief Review of the Impact of Neutron Irradiation Damage in Tungsten and Its Alloys

Neutron irradiation poses a substantial challenge in the development and application of tungsten (W) and its alloys, predominantly in the framework of nuclear fusion and fission environments. Although W is well-acknowledged for its unique properties like its high melting temperature and higher resistance to sputtering, transmutation products, such as Re and Os, form and impact the alloy properties as a result of neutron irradiation. This transmutation effect accompanied by significant microstructure damage due to neutron irradiation can lead to the significant degradation of mechanical properties. This review surveys the literature focusing on the microstructural modifications post-irradiation and its impacts on the irradiation hardening. This review provides insights into the elaborative understanding on the neutron radiation damage on W and W alloys by exploring the microstructural evolution and hardness changes post-irradiation. The gaps and future opportunities for understanding neutron radiation damage in W are briefly summarized

Disease Severity Staging System for NOTCH3-Associated Small Vessel Disease, Including CADASIL

Typical cysteine-altering NOTCH3 (NOTCH3cys) variants are highly prevalent (approximately 1 in 300 individuals) and are associated with a broad spectrum of small vessel disease (SVD), ranging from early-onset stroke and dementia (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy [CADASIL]) to nonpenetrance. A staging system that captures the full NOTCH3-SVD severity spectrum is needed and currently lacking. To design a simple disease severity staging system that captures the broad clinicoradiological NOTCH3-SVD severity spectrum. A cohort study was performed in which the NOTCH3-SVD severity staging system was developed using a discovery cohort (2019-2020) and validated in independent international CADASIL cohorts (1999-2023) and the UK Biobank. Clinical and imaging data were collected from participants originating from 23 international CADASIL cohorts and from the UK Biobank. Eligibility criteria were presence of a NOTCH3cys variant, availability of brain magnetic resonance imaging, and modified Rankin Scale score. The discovery cohort consisted of 195 NOTCH3cys-positive cases from families with CADASIL; the validation set included 1713 NOTCH3cys-positive cases from 15 countries. The UK Biobank cohort consisted of 101 NOTCH3cys-positive individuals. Data from 2-year (2019-2023) and 18-year (1999-2017) follow-up studies were also analyzed. Data analysis was performed from July 2023 to August 2024. Percentage of cases following the sequence of events of the NOTCH3-SVD stages, and the association between the stages and ischemic stroke, intracerebral hemorrhage, global cognition, processing speed, brain volume, brain microstructural damage, and serum neurofilament light chain (NfL) level. The NOTCH3-SVD staging system encompasses 9 disease stages or substages, ranging from stage 0 (premanifest stage) to stage 4B (end stage). Of all 1908 cases, which included 195 in the discovery cohort (mean [SD] age, 52.4 [12.2] years) and 1713 in the validation cohorts (mean [SD] age, 53.1 [13.0] years), 1789 (94%) followed the sequence of events defined by the NOTCH3-SVD staging system. The NOTCH3-SVD stages were associated with neuroimaging outcomes in the NOTCH3cys-positive cases in the CADASIL cohorts and in the UK Biobank and with cognitive outcomes and serum NfL level in cases from the CADASIL cohorts. The NOTCH3-SVD staging system captured disease progression and was associated with 18-year survival. The NOTCH3-SVD staging system captures the full disease spectrum, from asymptomatic individuals with a NOTCH3cys variant to patients with end-stage disease. The NOTCH3-SVD staging system is a simple but effective tool for uniform disease staging in the clinic and in research.

The Effect of Cold Work and Irradiation on the Dealloying Behavior of Ni-Cr Alloys in Molten Fluoride Salts

Molten salt nuclear reactor (MSR) environments present several challenges to structural materials, such as corrosion coupled with radiation damage occurring at high homologous temperatures. When a corrosion driving force exists, such as the presence of an oxidizing impurity with a half-cell redox potential higher than those of the alloying elements, selective dealloying of the less noble element (LN) in a multi-component structural alloy can occur [1]. This process can result in interesting corrosion morphologies such as the formation of a relatively uniform penetrating bicontinuous porous structures in grain interiors and penetrating dealloying along grain boundaries. Irradiation can induce solute segregation and/or saturation of non-equilibrium defects that interact with the corrosion front [2]. Currently, it remains uncertain how irradiation damage within an alloy impacts the process of molten salt dealloying, rendering the morphological instability.In this work, the corrosion dealloying behavior of Ni20Cr alloy (wt.%) was studied in molten LiF-NaF-KF (or FLiNaK) salts at 600°C. Ni20Cr alloys were subjected to two different conditions of Ni ion radiation, one carried out at 25°C and the other at 600°C, creating a peak damage depth nearing ~3µm at approximately 60 dpa. As a surrogate for microstructural damage by radiation, a separate set of Ni20Cr alloys were cold-worked to achieve reductions of thickness of 10%, 30%, and 50% which induce lattice defects in the form of dislocations. Additional samples were subjected to the identical potentiostatic holds attempted previously in molten FLiNaK in carefully selected electrochemical potential regimes where only Cr dealloying occurs in FLiNaK [2]. A porous Ni-rich ligament was formed that undergoes coarsening and densification. Electrochemical impedance spectroscopy (EIS) was used to quantify the porous structures. The pre-irradiated then post-corrosion samples were examined by scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) techniques to characterize micro and nanoscale changes in structure and composition. Irradiation produced deeper dealloying depths than observed on annealed samples. Furthermore, the roles of dislocation array and grain boundaries dislocation pile ups, which serve as short-circuit paths for outward Cr transport, during the dealloying process, were closely examined. Acknowledgment Research is primarily supported as part of the fundamental understanding of transport under reactor extremes (FUTURE), an Energy Frontier Research Center (EFRC) funded by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES). This work was performed in the Department of Materials Science and Engineering (DMSE) in the Center for Electrochemical Science and Engineering (CESE) at the University of Virginia. Utilization of the Malvern-Panalytical Empyrean diffractometer was supported by Nanoscale Materials Characterization Facility (NMCF) with National Science Foundation (NSF) under award CHE-2102156. H.C. acknowledges the National Science Foundation Graduate Research Fellowship (GRFP), GRANT#: 1842490.

Microstructural Evolution and Damage Mechanism of Water-Immersed Coal Based on Physicochemical Effects of Inorganic Minerals.

Coal seam water injection technology enables seam permeability enhancement and facilitates outburst risk reduction. This study investigated the microscale effects of water infiltration on coal and the evolution mechanisms of its mechanical properties. To this end, we systematically analyzed dynamic changes (such as mineral composition, pore structure, and mechanical performance) in coal soaked for various durations using X-ray diffraction, low-field nuclear magnetic resonance (NMR), and uniaxial compression testing. The results indicate: (1) the coal NMR T2 spectrum displays three characteristic peaks, corresponding to rapid water absorption, uniform transition, and stabilization stages of soaking traditionally divided according to peak area variation trends. (2) The coal strength decreases with progressive soaking, influenced by water content, pore volume, mineral composition, etc. Its compressive strength and elastic modulus drop by 22.4% and 19.5%, respectively, compared to the initial values. (3) The expansion of clay minerals during immersion reduces average pore size. In contrast, quartz particle displacement, pore water movement, and soluble mineral dissolution increase pore volume, reducing the overall structure strength. (4) The dominant factors driving the degradation of mechanical properties vary across immersion stages, including water content and specific mineral concentration. This work offers new insights into how hydraulic technology alters coal seams, providing theoretical support for optimizing water injection strategies in the seam.