Search Results (340)

The deformation characteristics of the surrounding rock in tunnel groups are considered critical for the design of support structures and the assurance of the long-term safety of deep-buried diversion tunnels. The deformation behavior of surrounding rock in tunnel groups was investigated to guide structural support design. Field tests and numerical simulations were performed to analyze the distribution of ground stress and the ground reaction curve under varying conditions, including rock type, tunnel spacing, and burial depth. A solid unit–structural unit coupled simulation approach was adopted to derive the two-liner support characteristic curve and to examine the propagation behavior of concrete cracks. The influences of surrounding rock strength, reinforcement ratio, and secondary lining thickness on the bearing capacity of the secondary lining were systematically evaluated. The following findings were obtained: (1) The tunnel group effect was found to be negligible when the spacing (D) was ≥65 m and the burial depth was 1600 m. (2) Both P_0.3 and P_max of the secondary lining increased linearly with reinforcement ratio and thickness. (3) For surrounding rock of grade III (IV), 95% u_lim and 90% u_lim were found to be optimal support timings, with secondary lining forces remaining well below the cracking stress during construction. (4) For surrounding rock of grade V in tunnels with a burial depth of 200 m, 90% u_lim is recommended as the initial support timing. Support timings for tunnels with burial depths between 400 m and 800 m are 40 cm, 50 cm, and 60 cm, respectively. Design parameters should be adjusted based on grouting effects and monitoring data. Additional reinforcement is recommended for tunnels with burial depths between 1000 m and 2000 m to improve bearing capacity, with measures to enhance impermeability and reduce external water pressure. These findings contribute to the safe and reliable design of support structures for deep-buried diversion tunnels, providing technical support for design optimization and long-term operation. Full article

The efficiency of coalbed methane (CBM) extraction is closely related to the drilling response of coal seams, which is significantly influenced by natural fracture development of coal seams. This work investigated 11 coal samples from the Baode, Xinyuan, and Huolinhe mines, employing quantitative fracture characterization, acoustic wave testing, drilling experiments, and cuttings analysis to systematically reveal the relationships and mechanisms between fracture parameters and coal drilling response characteristics. The result found that acoustic parameters (average wave velocity v and drilling surface wave velocity v₀) exhibit significant negative correlations with fracture line density (ρ₁) and area ratio (ρ₂) (|r| > 0.7), while the geological strength index (GSI) positively correlates with acoustic parameters, confirming their utility as indirect indicators of fracture development. Fracture area ratio (ρ₂) strongly correlates with drilling cuttings rate q (r = 0.82), whereas GSI negatively correlates with drilling rate w, indicating that highly fractured coal is more friable but structural stability constrains drilling efficiency, while fracture parameters show limited influence on drill cuttings quantity Q. Cuttings characteristics vary with fracture types and density. Type I coal (low-density coexisting exogenous fractures and cleats) produces cuttings dominated by fine particles with concentrated size distribution (average particle size d ≈ 0.52 mm, crushability index n = 0.46–0.61). Type II coal (exogenous-fracture-dominant) exhibits coarser particle sizes in cuttings (d ≈ 0.8 mm, n = 0.43–0.53). Type III coal (dense-cleat-dominant) drill cuttings are mainly coarse particles and are concentrated in distribution (d ≈ 1.53 mm, n = 0.72–0.98). Additionally, drilling response differences are governed by the coupling effects of vitrinite reflectance (R_o), density, and firmness coefficient (f), with Huolinhe coal being easier to drill due to its lower R_o, f, and density. This study elucidates the mechanism by which fracture development affects coal drilling response through multi-parameter correlation analysis, while also providing novel insights into the optimization of fracturing sweet spot selection for CBM development. Full article

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias encountered globally, characterized by a pro-inflammatory pattern. This analysis evaluated the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in patients with AF alongside chronic kidney disease (CKD) and/or type 2 diabetes mellitus (T2DM). This retrospective cohort study included 6077 patients admitted to the Third Medical Clinic of Saint Spiridon Hospital in Iasi from 2018 to 2023, all diagnosed with AF, CKD, and T2DM. After applying the exclusion criteria, 1066 AF patients remained eligible. For a multivariate comparative analysis, the patients were divided into groups: I. control group (non-AF patients); II. AF patients; III. T2DM group; IV. CKD-only group; V. AF+CKD group; VI. AF+T2DM group; and VII. AF+T2DM+CKD group. The Mann–Whitney/Kruskal–Wallis test demonstrated a statistically significant difference in NLR and PLR values between the AF group and the non-AF group (H = 70.627, p < 0.001). The receiver operating characteristic (ROC) analysis identified statistical significance and predictive power for NLR (AUC = 0.722; sensitivity = 63.6%; specificity = 76.9%) and neutrophil count in diagnosing AF, T2DM, and CKD. In conclusion, this study illustrated the utility of NLR and PLR as readily available and predictive biomarkers of inflammation in patients with AF, with or without comorbidities. Full article

This study aims to evaluate the tolerance of an endophytic fungus isolated from the fibrous roots of Gentiana yunnanensis Franch. to arsenic (As) and elucidate the underlying physiological and molecular mechanisms. The filamentous fungus is identified as Cladosporium cladosporioides based on morphological characteristics and phylogenetic tree analysis, belonging to the family Moniliaceae and Phyla Hyphomycetes. The tolerance of C. cladosporioides to As(V) was assessed by measuring its biomass under varying concentrations of As(V). The fungus exhibited remarkable As(V) tolerance, with an EC₅₀ value of 2051.94 mg/L, and accumulated high concentrations of As in its mycelium. Subcellular distribution analysis revealed that As was predominantly localized in the cell wall fraction, with levels 4.06 times higher than those in the non-cell wall fraction. Notably, the concentrations of total organic As and As(III) in the mycelium were 852.75 μg/g and 24.94 μg/g, respectively, with conversion ratios of 76.64% and 2.24%. The organic As levels significantly surpassed both As(V) and As(III) concentrations in all cellular fractions (cell wall and non-cell wall components), demonstrating particularly efficient As transformation in C. cladosporioides. Under As(V) stress, the membrane antioxidant system, including superoxide dismutase (SOD), metallothionein (MT), glutathione (GSH), and melanin, was activated and significantly enhanced to mitigate oxidative damage. Transcriptomic analysis identified 4771 differentially expressed genes (DEGs; 2527 upregulated), including highly expressed As-responsive genes (CcArsH_1, CcARR_1, CcARR_3, CcGST_1, and CcGST_3). Strong correlations emerged between As speciation (total/organic/As(V)/As(III)), antioxidant levels, and DEG expression patterns. Taken together, these findings demonstrate that C. cladosporioides employs a multi-faceted As detoxification strategy involving subcellular distribution and reductive transformation (As(V) to As(III)/organic As), antioxidant system enhancement, transcriptomic adaptations, and integrated defense strategy. This work highlights C. cladosporioides potential for As bioremediation and elucidates As accumulation mechanisms in G. yunnanensis. Full article

The effect of low-molecular-weight dissolved organic matter (LDOM) on antimony enrichment in groundwater remains unclear. In this study, the spectroscopic and molecular characteristics of high- and low-Sb groundwater are compared using optical spectrophotometry, ultrafiltration, and Fourier transform ion cyclotron resonance mass spectrometry. The results demonstrated that although the mean DOM concentration in LDOM groundwater (3.98 mg/L) accounted for only 69.22% of the mean DOM concentration, the proportion of Sb(V) within the total Sb varied between 80.29% and 99.56%. LDOM was characterized by higher biological and fluorescence index values, a greater H/C ratio, and reduced double-bond equivalent values compared with high-molecular-weight dissolved organic matter. High abundances of LDOM can enhance the primary enrichment of Sb(V) within the total Sb concentration via competitive adsorption and, as energy and electron acceptors for microbial communities facilitate Sb(III), oxidation within groundwater systems. This study provides new perspectives on understanding how DOM influences the migration and speciation transformation of Sb in groundwater environments. Full article

Microplastics (MPs) are ubiquitous in aquatic environments, soils, and beach sediments, demonstrating a remarkable ability to adsorb dissolved organic matter (DOM). Although there are methods for extracting DOM from water, the approaches for directly extracting DOM from microplastics have not been thoroughly investigated, and the characterization of DOM adsorbed on microplastics is also insufficient. In this study, five different types of microplastic samples were collected from each of five environmental media (water and sediment), and finally 25 samples were obtained. This paper comparatively assessed the extraction efficiency of DOM from MPs with various solvents by using total organic carbon (TOC), culminating in the development of a sodium pyrophosphate-NaOH solution extraction method optimized for DOM. The morphology, material and environmental medium of microplastics were the three primary factors affecting the adsorption of DOM on microplastics, with the highest enrichment ratio of 1.4–1.8 times for extruded polyethylene microplastics (EPE-MPs) characterized by their porous structure in the flowing water environment. The molecular weight of DOM adsorbed on microplastics showed a multi-modal distribution pattern with great dissimilarities among the different environmental media. Gel permeation chromatography (GPC) indicated that the weight-average molecular weight (M_w) of DOM was 2750–4552 Da for river MPs, 2760–5402 Da for Qiantang River MPs, 1233–5228 Da for East China Sea MPs, 440–7302 Da for soil sediment MPs and 438–6178 Da for beach sediment MPs, respectively. Excitation-emission matrix-parallel factor analysis (EEM-PARAFAC) identified that tyrosine-like substances with high excitation in region IV and low excitation in region I were predominantly adsorbed on MPs, followed by tryptophan-like substances with low excitation in region II and protein-like substances in region IV, while humic- and fulvic-like substances in regions V and III, respectively, exhibited the least adsorption affinity. The findings underscored the critical need to comprehensively consider the interactions between MPs and DOM and their environmental impacts in pollution control strategies. Full article

Contiguous destitute areas (CDAs) in China, characterized by deep poverty and difficulty in alleviating it, have garnered attention for their spatial–temporal development. Using nighttime light (NTL) data from 2000 to 2020, we developed a novel method to identify spatiotemporal changes in CDAs. This is the first classification method based on multi-period continuous threshold judgement to objectively classify counties into expansion, shrinkage, or stability types, and quantify the intensity and ratio of these changes. The results showed that: (1) From 2000 to 2020, 345 counties expanded, 176 remained stable, and 11 shrank, accounting for 64.85%, 33.08%, and 1.07%, respectively. Dabie Mountains (VI), Luoxiao Mountains (XI), and Wuling Mountains (VII) had higher proportions of expanding counties, while shrinkage was concentrated in Tsinling-Daba mountains (V), VII, Lvliang Mountains (III), and Rocky Desertification Area (X). (2) The peak of expansions occurred between 2008 and 2011. (3) Both expansion and shrinkage intensities and ratios were generally low, with strong expansion primarily in IV and VI. We also found that there is the risk of returning to poverty in the development of the CDAs, such as space shrinking, lack of development impetus, coexisting expansion and shrinkage, and low intensity. It provides reference information for China’s future targeted and sustained poverty reduction policies and systems. Full article

Marine–continental transitional shale is a focus of global energy exploration, offering significant but underexplored hydrocarbon potential. Unlike well-studied marine shales, these deposits pose challenges due to complex interactions between marine and continental influences. The lower Xujiahe Formation in the southeastern Sichuan Basin exemplifies this uncertainty, with its depositional environment debated as either continental or transitional. Resolving this issue is critical for refining facies models and improving exploration strategies. This study aims to determine the depositional environment of the lower Xujiahe Formation by integrating sedimentological, paleontological, and geochemical evidence. Field observations identify tidal rhythmites, reverse cross-stratification, and double mud drapes, indicative of tidal influence. Fossil assemblages, including Sulcusicystis sp. and marine-influenced sporopollen sequences, further support marine influence and align with records from the Tanba and Qilixia sections in northeastern Sichuan. Geochemical analysis reveals Sr concentrations (24.47–194.43 ppm), Sr/Ba ratios (0.11–0.65), m-values (4.37–33.08), and CaO/(Fe + CaO) ratios (0.03–0.80), suggesting freshwater to brackish conditions. V/Cr (0.92–2.22) and U/Th (0.18–0.48) ratios indicate a weakly oxidizing environment. Kerogen analysis classifies the organic matter as type II₂–III, suggesting periodic marine influence during deposition. These findings confirm that the lower Xujiahe Formation represents a marine–continental transitional facies, refining previous facies interpretations and providing a basis for more targeted shale gas exploration in the Sichuan Basin and comparable basins worldwide. Full article

Background: Early detection of pancreatic cancer using existing tumor markers is challenging, and novel biomarkers are needed. Apolipoprotein A2 (APOA2), which is not directly produced by tumors, may help detect pancreatic cancer through mechanisms distinct from carbohydrate antigen 19-9 (CA 19-9). This study aimed to evaluate the diagnostic performance of the APOA2-isoform (APOA2-i) Index in patients with pancreatic cancer. Methods: Serum levels of the APOA2-i Index and CA 19-9 were measured in 76 patients with pancreatic cancer (Stage 0, n = 5; I, n = 4; II, n = 15; III, n = 19; and IV, n = 33) and 98 patients with non-pancreatic cancer (intraductal papillary mucinous neoplasm, n = 36; chronic pancreatitis, n = 33; pancreatic neuroendocrine neoplasm, n = 8; autoimmune pancreatitis, n = 9; and others, n = 12) to evaluate diagnostic performance. Results: APOA2 showed lower accuracy for advanced (stages II–IV) pancreatic cancer compared to CA 19-9 (sensitivity, 50.7% vs. 83.6%; sensitivity, 77.6% vs. 87.9%), but it provided superior accuracy for early-stage (stages 0 and I) detection (sensitivity, 33.3% vs. 22.2%; specificity, 66.7% vs. 59.4%). Three early-stage pancreatic cancer cases negative for CA 19-9 were detected with the APOA2-i Index, demonstrating high diagnostic accuracy for early-stage pancreatic cancer when both biomarkers are combined (sensitivity, 44.4%; specificity, 46.7%). The multivariate analysis revealed pancreatic cancer to be an independent risk factor for APOA2-i Index positivity (odds ratio [OR]: 3.48, p < 0.001), CA 19-9 positivity (OR: 25.5, p < 0.001), and positivity for either marker (OR: 13.3, p < 0.001). Conclusions: The APOA2-i Index, combined with CA 19-9, may improve early-stage pancreatic cancer detection, especially in challenging cases and for high-risk patient surveillance. Full article

Muscle atrophy, a physiological decline in muscle mass and strength due in ageing, occurs through an imbalance between protein breakdown and synthesis. The purpose of this study was to verify whether amino acid complex supplementation (ACS) can prevent and treat muscle loss in a dexamethasone (Dexa, 800 μg/kg)-induced rat model of sarcopenia. Sprague Dawley rats (6 weeks old) were assigned to seven groups: (i) normal control, (ii) positive control (high-dose ACS, 500 mg), (iii) Dexa only, (iv) Dexa + high-dose ACS (500 mg), (v) Dexa + medium-dose ACS (300 mg), (vi) Dexa + low-dose ACS (100 mg), or (vii) Dexa + liquid amino acid complex formulation (LF, 2 mL), administered orally for 4 weeks. Exercise capacity tests were performed five times using a treadmill test (TT) and forced swimming test (FST). The body weight increase in each group was less than that of the normal group. The blood biochemical indices, AST levels, and AST/ALT ratio significantly increased in the Dexa-treated medium-dose ACS group. The total muscle protein also significantly increased in all ACS groups. In the Dexa-treated LF group, CK decreased below the normal level. Exercise capacity, assessed by TT and FST, increased the most in the positive control and Dexa-treated high-dose ACS groups. In the TT, the Dexa-only group increased by about 18%, but the Dexa-treated high-dose ACS group increased by about 110%. Additionally, in the FST, Dexa-treated rats receiving a high dose of ACS demonstrated significantly increased exercise time and capacity. Electron microscopic (EM) and hematoxylin and eosin (H&E) observations of muscle tissue revealed muscle fiber atrophy in the gastrocnemius muscles of the Dexa-only group. In the EM findings of the Dexa-treated high-dose ACS group, the M-line and Z-line were clearer than in the Dexa-only group, and the mitochondria were partially preserved. In conclusion, the ACS-treated rats showed a clear recovery from muscle damage based on serum indices, total muscle protein mass, and the microscopic findings on muscle tissue. Notably, a high dose of ACS demonstrated the most effective protection and recovery of muscle tissue in the Dexa-induced sarcopenia rat model. Full article

There are two sets of hydrocarbon source rock formations developed in the Paleogene of the Zhu-1 Depression: the Wenchang Formation of semi deep lacustrine facies and the Enping Formation of lacustrine facies. Their basic geochemical characteristics, chemical structures, kerogen components, sedimentary paleoenvironments, etc., are not the same. High quality hydrocarbon source rocks are the basic conditions for oil and gas generation. This article comprehensively evaluates the key depression Paleogene hydrocarbon source rocks in the Zhu-1 Depression, and studies the development mechanism and controlling factors of hydrocarbon source rocks in this area, which is of great significance for understanding the development conditions, quality, and predicting potential high-quality hydrocarbon source rocks. After conducting rock pyrolysis, major and trace element analysis, and infrared spectroscopy experiments on the samples, it was found that the main source rock type of the Wenchang Formation is type II₁, which has a high HI value; the Enping Formation is mainly composed of II₂-III types with low HI values (with a small number of II₁ types), and the source rocks of the Wenchang Formation have a strong hydrocarbon producing aliphatic structure, with the sapropelic and shell formations being larger than the Enping Formation source rocks. By using methods such as CIA values, C values, and Mo-U covariant models, it can be concluded that during the Wenchang to Enping periods, the climate changed from warm and dry to cool and humid, and the overall environment was characterized by freshwater, weak oxidation weak reduction, and gradually decreasing paleo-productivity. At the same time, it was analyzed that the formation of organic rich sediments in the source rocks of the Zhu-1 Depression played an important role in the relative oxygen phase. The ratio of V/(V + Ni) to V/Cr can better indicate the redox environment of the water body and show a good correlation with TOC. Two sets of development models of source rocks controlled by paleooxygen phase were initially established, providing sufficient scientific basis for oil and gas exploration in the area. Full article

The Jiepailing deposit in southern Hunan is a typical large to super-large polymetallic tin deposit enriched in beryllium and other rare metals. To enhance the understanding of the mineralization processes of the Jiepailing deposit, detailed mineralogical, in situ geochemical, and sulfur isotopic analyses were conducted on pyrite closely associated with tin–polymetallic mineralization. Five types of pyrite have been identified in the deposit: (1) euhedral to subhedral medium- to coarse-grained pyrite (PyI) in tungsten–tin ore; anhedral fine-grained pyrite (PyII) in tin polymetallic–fluorite ore; anhedral fine-grained or aggregate pyrite (PyIII) in lead–zinc ore; euhedral to subhedral coarse-grained pyrite (PyIV) in beryllium–fluorite mineralization; and subhedral to anhedral fine-grained pyrite (PyV) in carbonate veinlets developed in the wall rock. Backscattered electron imaging indicates consistent structural features across the five types of pyrite. In situ trace element analysis reveals differences in trace element concentrations among the pyrite types. PyI is relatively enriched in Sn, Cu, and Co. In contrast, PyIII is enriched in Pb, Zn, Sn, and Ti, while PyIV and PyV are enriched in Ag and Sb. PyI has a Co/Ni ratio more than 1, while the Co/Ni ratios in the other four types of pyrite are less than 1. LA-MC-ICP-MS in situ sulfur isotope analysis shows δ³⁴S values ranging from 2.5‰ to 5.8‰ (average 4.3‰, PyI), 2.5‰ to 5.8‰ (average 4.3‰, PyII), −7.6‰ to 9.5‰ (average 3.9‰, PyIII), −3.7‰ to 10.6‰ (average 3.6‰, PyIV), and 6.8‰ to 14.1‰ (average 9.2‰, PyV). Based on previous studies, regional geological background, deposit characteristics, and the in situ trace element and sulfur isotope compositions of pyrite, it is inferred that the various ore bodies in the Jiepailing deposit are products of Late Cretaceous magmatic–hydrothermal activity. The early ore-forming fluid originated from magmatic sources and during the migration into the wall rock and shallow formations, mixed with fluids primarily derived from atmospheric precipitation. Temperature, pressure, and composition changed of the ore-forming fluid which carried a large amount of substances, leading to tungsten–tin, tin polymetallic–fluorite, lead–zinc, and beryllium–fluorite mineralization, followed by carbonation during the late-stage mineralization. Full article

Wet etching is the mainstream fabrication method for single-bar quantum cascade lasers (QCLs). Different etching solutions result in varying etching effects on III-V semiconductor materials. In this study, an efficient and nearly ideal etching solution ratio was proposed for simultaneously etching both InP and GaInAs/AlInAs, and the surface chemical reactions induced by each component of the etching solution during the process were investigated. Using univariate and single-component experiments, coupled with various characterization techniques such as atomic force microscopy (AFM), stylus profilometer, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), we found that the ratio of HBr to hydrogen peroxide significantly determines the etching rate, while the ratio of HCl to hydrogen peroxide affects the interface roughness. The aim of this study was to provide a comprehensive understanding of the effects of different etching solution components, thereby enhancing the understanding of the wet etching process for InP/GaInAs/AlInAs materials. These findings offer valuable insights into efficient QCL fabrication processes and contribute to the advancement of the field. Full article

Background: Multiphoton tomography (MPT) is a femtosecond laser imaging technique that enables high-resolution virtual biopsies of human skin. It provides a non-invasive method for analyzing cellular metabolism, structural changes, and responses to cosmetic products, providing insights into cell–cosmetic interactions. This review explores the principles, historical development, and key applications of MPT in cosmetic research. Methods: The latest MPT device combines five modalities: (i) two-photon fluorescence: visualizes cells, elastin, and cosmetic ingredients; (ii) second harmonic generation (SHG): maps the collagen network; (iii) fluorescence lifetime imaging (FLIM): differentiates eumelanin from pheomelanin and evaluates the impact of cosmetics on cellular metabolic activity; (iv) reflectance confocal microscopy (RCM): images cell membranes and cosmetic particles; and (v) white LED imaging for dermoscopy. Results: MPT enables in-depth examination of extracellular matrix changes, cellular metabolism, and melanin production. It identifies skin responses to cosmetic products and tracks the intratissue distribution of sunscreen nanoparticles, nano- and microplastics, and other cosmetic components. Quantitative measurements, such as the elastin-to-collagen ratio, provide insights into anti-aging effects. Conclusions: MPT is a powerful in vivo imaging tool for the cosmetic industry. Its superior resolution and metabolic information facilitate the evaluation of product efficacy and support the development of personalized skincare solutions. Full article

In this work, a cylindrical gate-all-around junctionless field effect transistor (JLFET) was investigated. Junctions and doping concentration gradients are unavailable in JLFET. According to the results, the suggested device has a novel architecture that significantly enhances transistor performance while exhibiting a decreased vulnerability to short-channel effects (SCEs). The Atlas 3D device simulator has been used to analyze the proposed JLFET’s performance, especially for low-power applications for different channel lengths ranging from 10 nm to 60 nm with Al_0.30Ga_0.60As as III-V materials. The comparative simulated study has been based on various performance parameters, including subthreshold slope (SS), drain-induced barrier lowering (DIBL), transconductance, threshold voltage, and I_ON to I_OFF ratio. The results of the simulations demonstrated that the III-V JLFET exhibited a favorable SS and decreased DIBL compared to other circuit topologies. In the suggested study, gallium arsenide (GaAs) and its compound materials have demonstrated a strong correlation between the SS and DIBL values. The SS is approximately 63 mV/dec, extremely near the ideal 60 mV/dec value. Gallium arsenide (GaAs) and aluminum gallium arsenide (AlGaAs) exhibit DIBL of approximately 30 mV/V and an SS value of around 64 mV/dec. Full article