ACS Omega最新文献

Risks of water-related mine incidents are related to water source, pathways, and water inrush intensity. This study aims to clarify the evolution of overburden fractures under repeated mining in closely spaced coal seams and to identify the presence of a connection between the damaged overburden and the overlying highly water-rich aquifer. Longfeng Coal Mine in northern Guizhou was taken as a case study. A coupled UDEC-DIC methodology was applied to identify fracture evolution and the development of water-conducting fracture zones during the downward mining of closely spaced coal seams. This approach allows an integrated study of fracture patterns, displacement, stress, and strain fields. Four key strata from the working face upward were identified, with breaking intervals of 22.72, 22.78, 24.08, and 100.79 m, respectively. The uppermost layer is a highly water-rich aquifer. During the early mining stage, risks of overburden collapse and fracture development were relatively minor. However, after advancing 30 m, overburden collapse, subsidence, and the vertical and horizontal development of fractures gradually intensified. After 110 m, fracture development gradually stabilized. The combination of UDEC numerical simulation and DIC digital speckle technology showed increasing vertical displacement and vertical stress of the overburden with the advance of the working face. During the evolution process, the overburden showed “saddle”- and “arch”-shaped patterns. The amplitudes of both the stress peak and displacement peak first showed a rapid increase, followed by a slow increase, and then finally a rapid increase. However, the displacement peak eventually stabilized, whereas the stress peak continued to increase. The strain peak fluctuated between increasing and decreasing trends over two cycles. The height of the water-conducting fracture zone first gradually increased, then rapidly increased, and lastly followed a stable increasing pattern. With the downward advance of the mine shaft, the increase in the fracture zone height showed a temporary halt and progressed again after the overburden of the lower coal seam collapsed and connected to the upper goaf. During the mining of the #5 coal seam, fracture height reached 41.7–42.8 m, thereby connecting to the highly water-rich Changxing Formation aquifer, resulting in a water inrush risk. Subsequent to the mining of the #5 and #9 coal seams, fracture height ultimately reached 90.2–91.2 m, connecting two highly water-rich aquifers and presenting a serious water hazard risk. The research findings hold significant theoretical and practical importance for water hazard prevention and water resource protection in coal mines.

In this work, lightweight aggregates were developed from mixtures of bauxite residue and clay, using a nonlinear programming model to determine the optimum composition. The aggregates were characterized using TGA/DTG/DSC analysis, X-ray diffraction, scanning electron microscopy and physical tests of apparent density, porosity and water absorption, carried out on three samples (BR50, BR30.50 and BR0). The results showed that the bauxite residue favored the formation of amorphous and porous phases, reducing the density of the aggregates. A nonlinear programming model was developed to determine the optimal composition of a lightweight aggregate, resulting in a mixture containing 30.50% bauxite residue and 69.50% clay. This composition yielded a material with a density of 0.78 ± 0.03 g/cm³, porosity of 14.54 ± 1.13%, and water absorption of 14.05 ± 1.72%, confirming its classification as a lightweight aggregate. The reference sample, with 100% clay (BR0), had a density of 2.20 ± 0.02 g/cm³ and a more compact structure. The proposed model proved effective in maximizing density and porosity without compromising the integrity of the aggregate, indicating that the use of bauxite residue is a promising and sustainable alternative to produce materials for use in civil construction.

Alzheimer’s disease (AD) is a prevalent neurodegenerative degenerative disorder among the elderly, featured by progressive cognitive decline and memory impairment. Due to its complex pathogenesis, there is still no effective therapeutic drug to date. Recently, selective BChE inhibition has been regarded as a potent approach for treating AD. In this work, we conducted structural optimization and structure–activity relationship studies on the previously obtained lead compound EMC-4f, and obtained the potential selective BChE inhibitor 12a (eqBChE, IC₅₀ = 1.3 μM; huBChE, IC₅₀ = 0.95 μM). The in vitro results exhibited that 12a showed good BBB permeability. Moreover, 12a demonstrated significant neuroprotective effects on l-Glu/Aβ_25–35-induced HT22 cells injury. Further, the in vivo tests suggested that 12a remarkably alleviated mice cognitive impairment induced by scopolamine. Therefore, these data present that 12a is a promising BChE inhibitor against AD.

The plants can be a source of compounds that prevent UV-induced DNA damage involved in the genesis of skin cancer and aging. This work was aimed to evaluated the safety and the antigenotoxic effect of Rosa centifolia flower ethanolic extract and of selected flavonoid constituents against UVB radiation in MRC-5 human fibroblasts. The cytotoxicity and genotoxicity of the phytochemicals were evaluated using trypan blue exclusion and Comet assays, respectively. The assays revealed that R. centifolia extract, kaempferol, kaempferol-3-glucoside, and quercetin exhibited cytotoxic effects at concentrations of 363 μg/mL, 393 μM, 379 μM, and 141.1 μM, respectively. Additionally, R. centifolia extract and quercetin demonstrated genotoxic effects at the highest tested concentrations. The antigenotoxic effects of R. centifolia extract, kaempferol, and kaempferol-3-glucoside against UVB radiation were subsequently evaluated. These phytochemicals significantly reduced UVB-induced DNA damage in human fibroblasts at noncytotoxic concentrations. Therefore, these compounds represent promising candidates for sunscreen formulations for human photoprotection.

As the global population ages, the prevalence of neurodegenerative diseases (NDDs)─including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, Multisystem Atrophy (multiple system atrophy), and amyotrophic lateral sclerosis─continues to rise, largely driven by environmental, metabolic, and lifestyle risk factors. Advances in computational technologies, particularly machine learning (ML) and deep learning, are reshaping research in this field. This review summarizes the major features of these diseases and emphasizes the role of ML in drug discovery, virtual screening, drug repurposing, and drug combination optimization. Representative approaches include support vector machines for classification, convolutional neural networks|convolutional neural network for imaging analysis, recurrent neural networks for temporal biomedical data, and transformers for multimodal integration. These methods highlight the potential of computational strategies to improve therapeutic development. In addition, the review underscores the substantial incidence rates and socioeconomic burden of these conditions, which have made them focal points for algorithmic innovation. With research evolving rapidly, the development of AI-driven approaches is expected to enable more effective, targeted interventions and improve patient outcomes. This Perspective provides a concise overview of current progress and identifies promising future directions in the fight against NDDs.

To address the severe interlayer interference and insufficient sweep efficiency during CO₂ flooding in reverse-rhythm reservoirs, this study conducted miscible CO₂ flooding experiments using a self-designed three-layer heterogeneous two-dimensional (2D) visual physical model under two production schemes: sequential layered production and simultaneous layered production. Through image monitoring and a gas/oil ratio control system, the evolution characteristics of displacement front advancement, miscible layer expansion, and interlayer interference under different schemes were revealed. The results indicate that high-permeability layers tend to form gas channeling paths and exhibit a gravity override, which significantly suppresses oil recovery from medium- and low-permeability layers. In contrast, the simultaneous layered production scheme enables collaborative exploitation of multiple layers, significantly improving sweep efficiency and miscible layer continuity in lower-permeability layers and effectively mitigating interlayer interference. The overall oil recovery factor increased from 68.63 to 79.24%. Further analysis shows that shutting the production end of the high-permeability layer enhances vertical mass transfer of CO₂ and delays gas breakthrough, making the medium-permeability layer the dominant contributor to recovery. This study clarifies the controlling mechanisms of permeability contrast and gravitational differentiation on interlayer interference, confirms the crucial role of layered production in controlling displacement paths and enhancing oil recovery, and provides theoretical insights and engineering guidance for the development of CO₂-EOR in reverse-rhythm reservoirs.

Fluoride contamination in drinking water is a major global concern, affecting millions of individuals with varying degrees of fluorosis. The Great Rift Valley, encompassing Tanzania, Kenya, Malawi, Ethiopia, Sudan, Uganda, and Rwanda, is among the most severely impacted regions. In this work, we report a synthesis method to produce a low-cost material for fluoride detection based on defect engineering and coordinative postsynthetic modification of metal–organic frameworks (MOFs) using Rhodamine B. The method was optimized under varying conditions to enhance the material’s response to fluoride ions and to elucidate the design parameters that augment sensing capabilities. The MOFs that exhibited the best response to fluoride were thoroughly characterized, and the kinetics of dye release in the presence of fluoride ions were investigated, including analyses in commercial mineral water and groundwater samples from Tanzania. The proposed methodologies were validated against standard quantification methods employing ion-selective electrodes below the maximum levels recommended by the World Health Organization (WHO) and the U.S. Environmental Protection Agency (US EPA).

Time-resolved optical Kerr effect (OKE) spectroscopy was employed to investigate the low-frequency vibrational dynamics of aqueous acetate solutions. While the isotropic OKE spectrum of neat water is broad and featureless, acetate solutions display a distinct band near 200 cm^–1. This feature increases systematically with acetate concentration, is absent in methyl acetate, and shows negligible dependence on the countercation, establishing it as the vibrational fingerprint of acetate–water hydrogen bonds. Comparison with hydroxide solutions demonstrates that the band is spectrally distinct from other anion–water vibrations. Quantum-chemical calculations further support the assignment, reproducing polarized vibrational modes in the same frequency region. Together, these results resolve long-standing ambiguities in the interpretation of acetate hydration and highlight the power of ultrafast OKE spectroscopy to isolate solute-specific hydrogen-bond vibrations in aqueous solutions. Beyond spectroscopy, these findings have implications for understanding electrolyte behavior in energy storage systems (e.g., lithium-ion batteries) and biological buffering processes.

Electrochemical immunosensors are emerging as promising tools for cancer detection due to their simplicity, portability, and high sensitivity. Colorectal cancer (CRC), the third most common cancer in the United States, remains challenging to diagnose early, as the standard method, colonoscopy, is invasive and often avoided. To address this gap, a graphene-gold-based immunosensor was developed for the early detection of CRC by targeting colon cancer-secreted protein-2 (CCSP-2), a biomarker overexpressed in CRC patients. The sensor was fabricated by attaching graphene oxide (GO) to a gold (Au) electrode using 4-aminothiophenol (4-ATP) as a linker, followed by immobilization of CCSP-2 antibodies (Anti-CCSP-2) and blocking with bovine serum albumin (BSA). Characterization of the immunosensor using linear sweep voltammetry (LSV), Raman spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) confirmed successful modifications. The attachment of graphene oxide contributed to an enhancement in current response, likely due to partial reduction and improved electron transfer at the modified surface. The sensor demonstrated a good linear response (R² = 0.979) to CCSP-2 antigen (CCSP-2) concentrations ranging from 1 ng/μL to 100 ng/μL, with a limit of detection (LOD) of 0.17 ng/μL and a sensitivity of 0.031 (ng/μL)⁻¹. Selectivity was validated using CRC cell extracts (CACO-2) and human kidney extracts (HEK), showing a more significant signal for CACO-2. These findings suggest that the developed immunosensor is a reliable and sensitive platform for CCSP-2 detection, with the potential for adaptation as a point-of-care device for early CRC screening.

Inspired by the self-healing capabilities of skeletal tissues, advanced osteoinductive treatments, such as calcium phosphate ceramics, have been developed to improve bone repair. Hydroxyapatite (HAP), renowned for its osteoconductive and osteoinductive properties, is commonly used in dental and orthopedic implants. However, HAP’s mechanical limitations under load-bearing conditions drive the need for composites that incorporate reinforcing materials. Graphene, with its superior surface area, conductivity, mechanical strength, and biocompatibility, is an ideal candidate for enhancing HAP composites. This study explores the development of graphene oxide (GO)-based nano HAP (n-HAP/GO) composite coating via electrophoretic deposition (EPD) on titanium (Grade-2) surfaces, optimizing deposition voltages (60–90 V) and time (3 min) to achieve uniform, adherent, and crack-free coatings. Various characterization techniques, including high-resolution transmission electron microscopy (HR-TEM), high-resolution scanning electron microscopy (HR-SEM), optical microscope, contact angle measurement, and electrochemical analyses (open circuit potential (OCP), potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS)), were employed to assess morphology, bioactivity, and corrosion resistance. Results indicate that coatings deposited at 80 V for 3 min exhibited better characteristics including reduced porosity, enhanced hydrophilicity, and improved corrosion resistance, which records the highest corrosion potential (E_corr) (−164.16 mV vs SCE) and the lowest corrosion current density (i_corr) (39.848 nA/cm²). COMSOL Multiphysics software was used to analyze changes in coating thickness due to variations in coating parameters (voltages, time, and bath concentration). The results demonstrate that adjusting the coating voltage to 80 V produced a more controlled and desirable coating thickness of 21.0 to 22.5 μm, which aligns with experimental findings. Additionally, antibacterial tests confirmed enhanced activity against S. aureus and E. coli. The findings of the study suggest that n-HAP/GO composite coatings prepared by EPD at 80 V for 3 min significantly improve the bioactivity and corrosion resistance of titanium implants, offering promising applications in bone implants and infection prevention.