Rab8a Is a Key Target That Melatonin Prevents Lipid Disorder from Atrazine.

Atrazine (ATZ), a widely used herbicide, disrupts mitochondrial function and lipid metabolism in the liver. Melatonin (MLT), a naturally synthesized hormone, combats mitochondrial dysfunction and alleviates lipid toxicity. However, the mechanisms behind ATZ-induced lipid metabolism toxicity and the protective effects of MLT remain unexplored. Mice were randomly assigned to four groups: control (Con), 5 mg/kg MLT, 170 mg/kg ATZ, and a cotreatment group receiving 170 mg/kg ATZ with 5 mg/kg MLT (ATZ+MLT). Additionally, we analyzed the effects of MLT and Rab8a on mRNA and proteins related to mitochondrial function and lipid metabolism disrupted by ATZ in AML12 cells. In conclusion, ATZ induced mitochondrial stress and disrupted fatty acid metabolism in mouse hepatocytes and AML12 cells. Exogenous MLT restores Rab8a levels, regulating fatty acid utilization in mitochondria and mitochondrial function. Notably, targeting Rab8a does not significantly affect mitochondrial function but prevents ATZ-induced lipid metabolism disorders in hepatocytes.

Calibration of Discrete Element Method Parameters for a High-Fidelity Lunar Regolith Simulant Considering the Effects of Realistic Particle Shape.

The Discrete Element Method (DEM) is an important tool for investigating the geotechnical properties of lunar regolith. The accuracy of DEM simulations largely depends on precise particle modeling and the appropriate selection of mesoscopic parameters. To enhance the reliability and accuracy of the DEM in lunar regolith studies, this paper utilized the high-fidelity IRSM-1 lunar regolith simulant to construct a DEM model with realistic particle shapes and conducted an angle of repose (AoR) simulation test. The optimal DEM parameters were calibrated using a combination of the Plackett-Burman test, steepest ascent test, and Box-Behnken design. The results indicate that the sliding friction coefficient, rolling friction coefficient, and surface energy significantly influence the simulation AoR. By optimizing against the measured AoR using a second-order regression model, the optimal parameter values were determined to be 0.633, 0.401, and 0.2, respectively. Under these optimal parameters, the error between the simulation and experimental AoR was 2.1%. Finally, the calibrated mesoscopic parameters were validated through a lifting cylinder test, showing an error of 6.3% between the simulation and experimental results. The high similarity in the shape of the AoR further confirms the accuracy and reliability of the parameter calibration method. This study provides a valuable reference for future DEM-based research on the mechanical and engineering properties of lunar regolith.

Self-doped Na-carbon materials derived from a lyocell fiber for a high-performance trimethylamine gas sensor at room temperature.

In this study, biomass-derived carbon material obtained from Lyocell fibers was first utilized as a gas sensor. The impacts of varying pyrolytic carbonization temperatures and pregrinding treatments on the structure, surface morphology, elemental composition, and gas sensitivity of the samples were thoroughly examined. The CL-500 sensor can realize rapid detection of trimethylamine with a high response (12.79k%, 500 ppm) and high selectivity at room temperature; the response/recovery times are 10 s and 2 s, respectively, and the theoretical detection limit is 3.96 ppm. Moreover, after four months, the response of the CL-500 sensor to trimethylamine fluctuated by less than 9.7 % compared with that of the fresh sensor, indicating good stability. It also shows good recovery after seven consecutive response-recovery cycles. Additionally, the CL-500 sensor has promising applications in real-life fish freshness monitoring. Theoretical calculations indicate that the introduction of trace amounts of Na enhances the sensing performance of this sensor for target gases. This study serves as a guide for developing cost-effective, high-performance gas sensors, promoting the efficient and high-value utilization of biomass waste.

Fabrication and Properties of Hydrogel Dressings Based on Genipin Crosslinked Chondroitin Sulfate and Chitosan.

Multifunctional hydrogel dressings remain highly sought after for the promotion of skin wound regeneration. In the present study, multifunctional CHS-DA/HACC (CH) hydrogels with an interpenetrated network were constructed using hydroxypropyl trimethyl ammonium chloride modified chitosan (HACC) and dopamine-modified chondroitin sulfate (CHS-DA), using genipin as crosslinker. The synthesis of HACC and CHS-DA was effectively confirmed using Fourier transform infrared (FT-IR) analysis and 1H nuclear magnetic resonance (1H NMR) spectroscopy. The prepared CH hydrogels exhibited a network of interconnected pores within the microstructure. Furthermore, rheological testing demonstrated that CH hydrogels exhibited strong mechanical properties, stability, and injectability. Further characterization investigations showed that the CH hydrogels showed favorable self-healing and self-adhesion properties. It was also shown that increasing HACC concentration ratio was positively correlated with the antibacterial activity of CH hydrogels, as evidenced by their resistance to Escherichia coli and Staphylococcus aureus. Additionally, Cell Counting Kit-8 (CCK-8) tests, fluorescent images, and a cell scratch assay demonstrated that CH hydrogels had good biocompatibility and cell migration ability. The multifunctional interpenetrated network hydrogels were shown to have good antibacterial properties, antioxidant properties, stable storage modulus and loss modulus, injectable properties, self-healing properties, and biocompatibility, highlighting their potential as wound dressings in wound healing applications.

The clinical characteristics analysis of serum markers for the cardiovascular system in early-stage COVID-19 patients.

Background: This study aimed to investigate alterations in serum markers [creatine kinase-MB (CKMB), cardiac troponin T (cTnT), myoglobin (Myo), B-type natriuretic peptide (BNP), D-dimer (DD), procalcitonin (PCT) and interleukin-6 (IL6)] in early Omicron variant infection and analyzed their correlation with clinical parameters. Methods: Retrospective analysis of 1,138 mild/asymptomatic cases at Tianjin First Central Hospital, including age, gender, serum markers and nucleic acid test results. Statistical analysis used SPSS software, version 24.0. Results: Elevated cTnT, BNP (125-400), and DD (0.55-1.10) levels were prevalent at 12.92%, 15.64%, and 14.50%, respectively. Females had significantly higher proportions with slightly elevated BNP (19.34%) and DD (19.69%) levels. Patients over 35 had a higher proportion of slight elevation in BNP (20.00%). Abnormal levels of serum markers were significantly associated with older age, increased PCT and IL6 levels, as well as delayed nucleic acid clearance. Additionally, levels of immunoglobulin G (IgG) were notably reduced in these cases. Patients with prolonged nucleic acid clearance (>14 days) had higher BNP and DD levels upon admission. Logistic regression identified PCT (OR = 237.95) as the most significant risk factor for abnormal serum markers for cardiovascular system injury. Conclusion: Early Omicron infection might do subclinical damage to the cardiovascular system. Elevated cTnT, BNP and DD levels were correlated with age, gender, inflammatory factors, and IgG. Notably, high PCT level emerged as the most robust predictor of abnormal serum biomarkers.

CD3ζ-Mediated Signaling Protects Retinal Ganglion Cells in Glutamate Excitotoxicity of the Retina.

Excessive levels of glutamate activity could potentially damage and kill neurons. Glutamate excitotoxicity is thought to play a critical role in many CNS and retinal diseases. Accordingly, glutamate excitotoxicity has been used as a model to study neuronal diseases. Immune proteins, such as major histocompatibility complex (MHC) class I molecules and their receptors, play important roles in many neuronal diseases, while T-cell receptors (TCR) are the primary receptors of MHCI. We previously showed that a critical component of TCR, CD3ζ, is expressed by mouse retinal ganglion cells (RGCs). The mutation of CD3ζ or MHCI molecules compromises the development of RGC structure and function. In this study, we investigated whether CD3ζ-mediated molecular signaling regulates RGC death in glutamate excitotoxicity. We show that mutation of CD3ζ significantly increased RGC survival in NMDA-induced excitotoxicity. In addition, we found that several downstream molecules of TCR, including Src (proto-oncogene tyrosine-protein kinase) family kinases (SFKs) and spleen tyrosine kinase (Syk), are expressed by RGCs. Selective inhibition of an SFK member, Hck, or Syk members, Syk or Zap70, significantly increased RGC survival in NMDA-induced excitotoxicity. These results provide direct evidence to reveal the underlying molecular mechanisms that control RGC death under disease conditions.

High-Performance Trimethylamine Sensor Based on an Imine Covalent Organic Framework.

As trimethylamine (TMA) is widely used in agriculture and industry, inhalation of TMA can cause very serious negative effects on human health. However, most of the current gas sensors for detecting TMA are commonly performed at high temperatures and cannot meet market needs. Inspired by this, we prepared imine covalent organic frameworks (TB-COF) synthesized from two monomers, 1,3,5-tris(4-aminophenyl)benzene (TAPB) and 1,3,5-benzotricarboxaldehyde (BTCA), using acetic acid as a catalyst at room temperature. Based on this, three sensors were prepared for gas sensitivity testing, namely, TA, BT, and TB-COF sensors. The three sensors were tested for 15 different gases at room temperature. From the whole gas sensitivity data, the TB-COF sensor made by compositing TA and BT has a higher sensitivity (6845.9%) to TMA at 500 ppm, which is 6.1 and 5.4 times higher than the response of TA and BT sensors, respectively. The TB-COF sensor adsorbs and desorbs TMA in a controlled 23 s cycle with a low detection limit of 28.6 ppb. This result indicates that TB-COF prepared at room temperature can be used as a gas-sensitive sensing material for real-time monitoring of TMA. The gas sensing results demonstrate the great potential of COFs for sensor development and application and provide ideas for further development of COFs-based gas sensors.

Melatonin Mitigates Atrazine-Induced Renal Tubular Epithelial Cell Senescence by Promoting Parkin-Mediated Mitophagy.

The accumulation of senescent cells in kidneys is considered to contribute to age-related diseases and organismal aging. Mitochondria are considered a regulator of cell senescence process. Atrazine as a triazine herbicide poses a threat to renal health by disrupting mitochondrial homeostasis. Melatonin plays a critical role in maintaining mitochondrial homeostasis. The present study aims to explore the mechanism by which melatonin alleviates atrazine-induced renal injury and whether parkin-mediated mitophagy contributes to mitigating cell senescence. The study found that the level of parkin was decreased after atrazine exposure and negatively correlated with senescent markers. Melatonin treatment increased serum melatonin levels and mitigates atrazine-induced renal tubular epithelial cell senescence. Mechanistically, melatonin maintains the integrity of mitochondrial crista structure by increasing the levels of mitochondrial contact site and cristae organizing system, mitochondrial transcription factor A (TFAM), adenosine triphosphatase family AAA domain-containing protein 3A (ATAD3A), and sorting and assembly machinery 50 (Sam50) to prevent mitochondrial DNA release and subsequent activation of cyclic guanosine 5'-monophosphate-adenosine 5'-monophosphate synthase pathway. Furthermore, melatonin activates Sirtuin 3-superoxide dismutase 2 axis to eliminate the accumulation of reactive oxygen species in the kidney. More importantly, the antisenescence role of melatonin is largely determined by the activation of parkin-dependent mitophagy. These results offer novel insights into measures against cell senescence. Parkin-mediated mitophagy is a promising drug target for alleviating renal tubular epithelial cell senescence.

CircVDAC3 sequesters microRNA-592 and elevates EIF4E3 expression to inhibit the progression of gastric cancer.

BACKGROUND: Accumulating evidence has shown that circular RNAs (circRNAs) are involved in gastric cancer (GC) tumorigenesis. However, specific functional circRNAs in GC remain to be discovered, and their underlying mechanisms remain to be elucidated. METHODS: CircRNAs that were differentially expressed between GC tissues and controls were analyzed using a circRNA microarray dataset. The expression of circVDAC3 in GC was determined using quantitative real-time PCR (qRT-PCR), and the structural features of circVDAC3 were validated. Cell function assays and animal experiments were conducted to explore the effects of circVDAC3 on GC. Finally, bioinformatics analysis, fluorescent in situ hybridization, and dual luciferase assays were used to analyze the downstream mechanisms of circVDAC3. RESULTS: Our results showed that circVDAC3 was downregulated in GC and inhibited the proliferation and metastasis of GC cells. Mechanistically, circVDAC3 acts as a competing endogenous RNA (ceRNA) of miR-592 and deregulates the repression of EIF4E3 by miR-592. EIF4E3 is downregulated in GC and overexpression of miR-592 or knockdown of EIF4E3 in circVDAC3-overexpressing cells weakens the anticancer effect of circVDAC3. CONCLUSION: Our study provides evidence that circVDAC3 affects the growth and metastasis of GC cells via the circVDAC3/miR-592/EIF4E3 axis. Our findings offer valuable insights into the mechanisms underlying GC tumorigenesis and suggest novel therapeutic strategies.

Treatment of hemolymphangioma by robotic surgery: A case report.

BACKGROUND: Hemolymphangioma of the jejunum is rare and lacks clinical specificity, and can manifest as gastrointestinal bleeding, abdominal pain, and intestinal obstruction. Computed tomography, magnetic resonance imaging, and other examinations show certain characteristics of the disease, but lack accuracy. Although capsule endoscopy and enteroscopy make up for this deficiency, the diagnosis also still requires pathology. CASE SUMMARY: A male patient was admitted to the hospital due to abdominal distension and abdominal pain, but a specific diagnosis by computed tomography examination was not obtained. Partial resection of the small intestine was performed by robotic surgery, and postoperative pathological biopsy confirmed the diagnosis of hemolymphangioma. No recurrence in the follow-up examination was observed. CONCLUSION: Robotic surgery is an effective way to treat hemolymphangioma through minimally invasive techniques under the concept of rapid rehabilitation.

Seeded growth of single-crystal black phosphorus nanoribbons.

Two-dimensional materials have emerged as an important research frontier for overcoming the challenges in nanoelectronics and for exploring new physics. Among them, black phosphorus, with a combination of a tunable bandgap and high mobility, is one of the most promising systems. In particular, black phosphorus nanoribbons show excellent electrostatic gate control, which can mitigate short-channel effects in nanoscale transistors. Controlled synthesis of black phosphorus nanoribbons, however, has remained an outstanding problem. Here we report large-area growth of black phosphorus nanoribbons directly on insulating substrates. We seed the chemical vapour transport growth with black phosphorus nanoparticles and obtain uniform, single-crystal nanoribbons oriented exclusively along the [100] crystal direction. With comprehensive structural calculations, we discover that self-passivation at the zigzag edges holds the key to the preferential one-dimensional growth. Field-effect transistors based on individual nanoribbons exhibit on/off ratios up to ~104, confirming the good semiconducting behaviour of the nanoribbons. These results demonstrate the potential of black phosphorus nanoribbons for nanoelectronic devices and also provide a platform for investigating the exotic physics in black phosphorus.

Quantitative ultrasound image assessment of the optic nerve subarachnoid space during 90-day head-down tilt bed rest.

The elevation in the optic nerve sheath (ONS) pressure (ONSP) due to microgravity-induced headward fluid shift is the primary hypothesized contributor to SANS. This longitudinal study aims to quantify the axial plane of the optic nerve subarachnoid space area (ONSSA), which is filled with cerebrospinal fluid (CSF) and expands with elevated ONSP during and after head-down tilt (HDT) bed rest (BR). 36 healthy male volunteers (72 eyes) underwent a 90-day strict 6° HDT BR. Without obtaining the pre-HDT data, measurements were performed on days 30, 60, and 90 during HDT and at 6 recovery time points extended to 180-days (R + 180) in a supine position. Portable B-scan ultrasound was performed using the 12 MHz linear array probe binocularly. The measurements of the ONS and the calculation of the ONSSA were performed with ImageJ 1.51 analysis software by two experienced observers in a masked manner. Compared to R + 180, the ONSSA on HDT30, HDT60, and HDT90 exhibited a consistently significant distention of 0.44 mm2 (95% CI: 0.13 to 0.76 mm2, P = 0.001), 0.45 mm2 (95% CI: 0.15 to 0.75 mm2, P = 0.001), and 0.46 mm2 (95% CI: 0.15 to 0.76 mm2, P < 0.001), respectively, and recovered immediately after HDT on R + 2. Such small changes in the ONSSA were below the lateral resolution limit of ultrasound (0.4 mm) and may not be clinically relevant, possibly due to ONS hysteresis causing persistent ONS distension. Future research can explore advanced quantitative portable ultrasound-based techniques and establish comparisons containing the pre-HDT measurements to deepen our understanding of SANS.

Flow-tub model: A modified bathtub flood model with hydraulic connectivity and path-based attenuation.

Global climate change and sea level rise are increasing the risks of flooding for coastal communities. Probabilistic coastal flood risk analysis at regional or global scales requires flood models with relatively low data requirements and low computational costs. Bathtub inundation models, which compute flood depth as the difference between water level and ground elevation, are well-suited for large-scale flood risk analysis. However, these models may overestimate floods because they do not capture some of the relevant underlying hydrodynamic processes that govern flood propagation on land. We present Flow-Tub, a modified bathtub inundation model that integrates two hydrodynamic processes to improve the accuracy of the bathtub inundation model while retaining computational efficiency: hydraulic connectivity and path-based attenuation.1.Hydraulic connectivity ensures that inundation is restricted to areas connected to the water source.2.Path-based attenuation ensures that the modeled flood water depths are reduced along the flow paths to represent the effects of surface friction and the temporary nature of storm surges. We validate the Flow-tub model against a hydrodynamic model. We also compare results of the bathtub model and the Flow-Tub model, highlighting the improved accuracy in the estimation of flood depths in the latter.

EAAT3 impedes oligodendrocyte remyelination in chronic cerebral hypoperfusion-induced white matter injury.

BACKGROUND: Chronic cerebral hypoperfusion-induced demyelination causes progressive white matter injury, although the pathogenic pathways are unknown. METHODS: The Single Cell Portal and PanglaoDB databases were used to analyze single-cell RNA sequencing experiments to determine the pattern of EAAT3 expression in CNS cells. Immunofluorescence (IF) was used to detect EAAT3 expression in oligodendrocytes and oligodendrocyte progenitor cells (OPCs). EAAT3 levels in mouse brains were measured using a western blot at various phases of development, as well as in traumatic brain injury (TBI) and intracerebral hemorrhage (ICH) mouse models. The mouse bilateral carotid artery stenosis (BCAS) model was used to create white matter injury. IF, Luxol Fast Blue staining, and electron microscopy were used to investigate the effect of remyelination. 5-Ethynyl-2-Deoxy Uridine staining, transwell chamber assays, and IF were used to examine the effects of OPCs' proliferation, migration, and differentiation in vivo and in vitro. The novel object recognition test, the Y-maze test, the rotarod test, and the grid walking test were used to examine the impact of behavioral modifications. RESULTS: A considerable amount of EAAT3 was expressed in OPCs and mature oligodendrocytes, according to single-cell RNA sequencing data. During multiple critical phases of mouse brain development, there were no substantial changes in EAAT3 levels in the hippocampus, cerebral cortex, or white matter. Furthermore, neither the TBI nor ICH models significantly affected the levels of EAAT3 in the aforementioned brain areas. The chronic white matter injury caused by BCAS, on the other hand, resulted in a strikingly high level of EAAT3 expression in the oligodendroglia and white matter. Correspondingly, blocking EAAT3 assisted in the recovery of cognitive and motor impairment as well as the restoration of cerebral blood flow following BCAS. Furthermore, EAAT3 suppression was connected to improved OPCs' survival and proliferation in vivo as well as faster OPCs' proliferation, migration, and differentiation in vitro. Furthermore, this study revealed that the mTOR pathway is implicated in EAAT3-mediated remyelination. CONCLUSIONS: Our findings provide the first evidence that abnormally high levels of oligodendroglial EAAT3 in chronic cerebral hypoperfusion impair OPCs' pro-remyelination actions, hence impeding white matter repair and functional recovery. EAAT3 inhibitors could be useful in the treatment of ischemia demyelination.

Melatonin inhibits atrazine-induced mitochondrial impairment in cerebellum of mice: Modulation of cGAS-STING-NLRP3 axis-dependent cell pyroptosis.

The global prevalence of Neurological disorders has increased alarmingly in response to environmental and lifestyle changes. Atrazine (ATZ) is a difficult to degrade soil and water pollutant with well-known neurotoxicity. Melatonin (MT), an antioxidant with chemoprotective properties, has a potential therapeutic effect on cerebellar damage caused by ATZ exposure. The aim of this study was to explore the effects and underlying mechanisms of MT on the cerebellar inflammatory response and pyroptosis induced by ATZ exposure. In this study, C57BL/6J mice were treated with ATZ (170 mg/kg BW/day) and MT (5 mg/kg BW/day) for 28 days. Our results revealed that MT alleviated the histopathological changes, ultrastructural damage, oxidative stress and decrease of mitochondrial membrane potential (ΔΨm) in the cerebellum induced by ATZ exposure. ATZ exposure damaged the mitochondria leading to release of mitochondrial DNA (mtDNA) to the cytoplasm, MT activated the cyclic GMP-AMP synthetase interferon gene stimulator (cGAS-STING) axis to alleviate inflammation and pyroptosis caused by ATZ exposure. In general, our study provided new evidence that the cGAS-STING-NLRP3 axis plays an important role in the treatment of ATZ-induced cerebellar injury by MT.

Exogenous Melatonin Alleviates Atrazine-Induced Glucose Metabolism Disorders in Mice Liver via Suppressing Endoplasmic Reticulum Stress.

Atrazine (ATZ) is a widely used herbicide that has toxic effects on animals. Melatonin (MLT) is a natural hormone with strong antioxidant properties. However, the effect of MLT on the glucose metabolism disorder caused by ATZ is still unclear. Mice were divided into four groups randomly and given 21 days of gavage: blank control group (Con), 5 mg/kg MLT group (MLT), 170 mg/kg ATZ group (ATZ), and 170 mg/kg ATZ and 5 mg/kg MLT group (ATZ + MLT). The results show that ATZ alters mRNA levels of metabolic enzymes related to glycogen synthesis and glycolysis and increased metabolites (glycogen, lactate, and pyruvate). ATZ causes abnormalities in glucose metabolism in mouse liver, interfering with glycemia regulation ability. MLT can regulate the endoplasmic reticulum to respond to disordered glucose metabolism in mice liver. This study suggested that MLT has the power to alleviate the ATZ-induced glycogen overdeposition and glycolytic deficit.

Holistic Assessment Based On Hepatocyte Mitochondria: Lycopene Repairs Oxidized mtDNA to Alleviate Mitochondrial Stress Induced by Atrazine.

Atrazine (ATZ) is a highly persistent herbicide that harms organism health. Lycopene (LYC) is an antioxidant found in plants and fruits. The aim of this study is to investigate the mechanisms of atrazine-induced mitochondrial damage and lycopene antagonism in the liver. The mice were divided into seven groups by randomization: blank control (Con group), vehicle control (Vcon group), 5 mg/kg lycopene (LYC group), 50 mg/kg atrazine (ATZ1 group), ATZ1+LYC group, 200 mg/kg atrazine (ATZ2 group), and ATZ2+LYC group. The present study performed a holistic assessment based on mitochondria to show that ATZ causes the excessive fission of mitochondria and disrupts mitochondrial biogenesis. However, the LYC supplementation reverses these changes. ATZ causes increased mitophagy and exacerbates the production of oxidized mitochondrial DNA (Ox-mtDNA) and mitochondrial stress. This study reveals that LYC could act as an antioxidant to repair Ox-mtDNA and restore the disordered mitochondrial function caused by ATZ.

High-Performance Ethylene Glycol Sensor Based on Imine Covalent Organic Frameworks.

The colorless and odorless ethylene glycol is prone to unknowingly causing poisoning, making preventive monitoring of ethylene glycol necessary. In this paper, scandium (III) trifluoromethanesulfonate was used as a catalyst to successfully prepare covalent organic framework (COF) nanospheres linked by imines at room temperature. The COF nanospheres were characterized by XRD, SEM, TEM, FT-IR, UV-Vis and BET. The results show that COF nanospheres have rough surfaces and a large number of mesoporous structures, which greatly increase the active sites on the surface of the sensing material and enhance the gas sensing performance. The sensing results showed that the prepared imine-conjugated COF nanospheres exhibited a good response-recovery ability for 10 consecutive response-recovery cycles for ethylene glycol at room temperature and had a theoretical detection limit of 40 ppb. In addition, the responses of COF nanospheres to nearly 20 interfering gases, including HCl, HNO3, phenol, formaldehyde and aniline, are relatively low compared to the response to ethylene glycol, indicating that the COF nanospheres have high selectivity towards ethylene glycol. The COF nanospheres show good sensitivity and selectivity for the detection of ethylene glycol, which should be attributed to the large specific surface area, hydrogen bonding interactions, and high defects. This work provides an effective method for the detection of ethylene glycol and expands the application field of COF materials.

An Anisotropic Peridynamic Model for Simulating Crack Propagation in Isotropic and Anisotropic Rocks.

In this work, we present a peridynamic-based simulation method for modeling quasi-static fracture propagation in isotropic and anisotropic rock within the framework of peridynamic least square minimization (PDLSM). The original isotropic elastic PDLSM is further extended to investigate fracture propagation in anisotropic materials in this study. The proposed AN-PDLSM model integrates an anisotropic model in fracture mechanics to analyze the failure process of anisotropic rocks. An important advancement in this research lies in the incorporation of the maximum energy release rate criterion (MERR) into the PDLSM framework for the first time. This enhancement enables accurately determining crack propagation and the associated crack angles. The proposed model utilizes the energy release rate calculated through the J-integral method to assess bond breakage, and it employs a mesh-independent, piecewise linear fracture model to describe crack propagation. The proposed method fully combines the merits of traditional fracture mechanics with the unique capabilities of peridynamics. To demonstrate the effectiveness of the proposed model, a simulation of fracture evolution in isotropic plates subjected to semi-circular bending tests is presented and compared with experimental results. It is shown that the proposed model accurately replicates fracture trajectories in isotropic specimens. In the context of anisotropic rock, the effect of a weak coefficient on crack morphology is discussed in order to obtain a suitable value. Additionally, the impact of bedding angles on fracture paths through our proposed model is also explored, revealing excellent agreement with experimental results. The findings in this research demonstrate that the proposed AN-PDLSM model is exceptionally proficient at capturing the intricate, oscillating crack paths observed in anisotropic rock materials.

Correlation study and clinical value analysis between cerebral microbleeds and white matter hyperintensity with high-field susceptibility-weighted imaging.

This study aimed to investigate the relationship between white matter hyperintensity (WMH) and cerebral microbleeds (CMBs) using susceptibility-weighted imaging (SWI) with high resolution. Additionally, it sought to analyze the clinical significance of SWI with high resolution and its potential to guide intravenous thrombolysis in stroke patients. In this retrospective analysis, we examined 96 patients with hypertension after acute stroke in our hospital using SWI. Demographic and medical data of these 96 patients were collected. Spearman correlation analysis was performed to investigate the relationship between CMBs and the grading of WMH. A significant positive correlation was observed between CMBs and the grade of WMH (R = 0.593, P < .05). The data also revealed a superior ROC area under the curve for the modified Fazekas grading of WMH, which was 0.814 (P < .05). There is a positive correlation between CMBs and the grading of leukoaraiosis in patients with acute stroke and hypertension. The higher the degree of WMH, the more severe the microvascular lesions, increasing the likelihood of intracranial hemorrhage. SWI can provide valuable guidance for administering intravenous thrombolysis in patients with acute stroke.