Search Results (12,958)

The impact of invasive alien species (IAS) is one of the direct factors causing global biodiversity decline and economic losses, and predicting the potential invasion risks of invasive species is crucial for developing prevention and control strategies. In recent years, an increasing number of studies have shown that invasive species undergo rapid shifts in climate niche in invaded areas. Accurately quantifying the dynamic shifts in the climate niche of invasive species in invaded areas is crucial for developing a more accurate framework for early warning of invasive species risks. Pomacea canaliculata is a freshwater snail found in South America and has become one of the most aggressive aquatic species in the world. Since its introduction to China in 1981, it has rapidly spread and caused multiple serious damages to agriculture, ecology, and public health. Therefore, based on multi-source distribution data of P. canaliculata, this study calculated the climate niche overlap by Schoener’ s D, quantified the niche shifts between the P. canaliculata in native and invaded areas (China) via the COUE scheme (a unified terminology representing niche centroid shift, overlap, unfilling, and expansion), and analyzed their changes on a time scale. The results revealed that there have been significant climate niche shifts (Schoener’s D < 0.2, niche similarity tests p > 0.01, niche equivalence tests p < 0.01) between the native and invaded areas (China) of P. canaliculata, which does not support the climate niche conservation hypothesis. The minimum temperature of the coldest month (Bio 6) and precipitation seasonality (Bio 15) were the key climate variables driving the climatic niche shift, and P. canaliculata can survive in colder and more arid regions than their native counterparts. The changes in the niche shifts in P. canaliculata on a time scale show significant temporal heterogeneity, and its invasion behavior in China presents a discontinuous and phased expansion pattern, with strong adaptability to new environments. The results are of great significance for the future development of more accurate ecological niche model (ENM), the formulation of more targeted prevention and control strategies, and the study of adaptive evolution mechanisms of invasive species. Full article

Equine semen preservation is fundamental to modern equine reproduction, supporting breeding programs, genetic conservation, and industry sustainability. However, significant challenges persist, including temperature sensitivity, oxidative stress, bacterial contamination, individual variability, and lack of standardized preservation protocols. These factors contribute to reduced sperm viability and fertility following cryopreservation. This review examines critical obstacles in equine semen preservation, focusing on cryopreservation sensitivity, molecular damage mechanisms, economic constraints, and seasonal quality variations. We analyze the molecular and structural alterations (e.g., oxidative stress, membrane damage, and DNA fragmentation) and their impact on cryopreservation success. The review evaluates evidence-based enhancement strategies, including nutritional supplementation and genetic approaches, for improving semen quality. Nutritional interventions that utilize antioxidants, polyunsaturated fatty acids (PUFAs), and nutraceuticals have demonstrated promising results in enhancing sperm motility, preserving membrane integrity, and improving overall semen quality. Additionally, we discuss key candidate genes associated with equine semen-quality traits, including sperm motility, viability, and cryotolerance. The integration of nutritional supplementation and genetic selection strategies presents viable pathways for optimizing equine semen preservation techniques. These combined approaches offer potential solutions for overcoming current limitations, ultimately supporting sustainable breeding programs and advancing genetic conservation efforts in the equine industry. Full article

Preeclampsia (PE) is not merely a pregnancy complication but a clinical manifestation of underlying vascular dysfunction with long-term health implications. It is diagnosed after 20 weeks of gestation as new-onset hypertension with proteinuria or organ involvement. The condition arises from impaired placental development, particularly defective spiral artery remodeling, which leads to placental ischemia and the release of antiangiogenic factors such as soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng). These circulating factors contribute to systemic endothelial dysfunction, resulting in hypertension, inflammation, and multiorgan stress. Histopathological findings, including acute atherosis and abnormal vascular remodeling, further reflect the cardiovascular damage underlying PE. This review synthesizes emerging evidence on the vascular and histological mechanisms of PE, highlighting novel biomarkers such as microRNAs and neprilysin, and the potential of advanced diagnostic tools, including machine learning. Importantly, PE is now recognized not only as an obstetric disorder but also as an early marker of future cardiovascular disease. This paradigm shift emphasizes the need for personalized prevention strategies, close surveillance of high-risk women, and long-term cardiovascular follow-up. Pregnancy thus represents a critical window for early detection and intervention in women’s cardiovascular health. Full article

Fatigue damage failure is a process where the mechanical properties of different materials continuously degrade under the action of cyclic loads. The cumulative analysis of fatigue damage has a significant impact on the service structure of major equipment. This paper starts from the mechanism of fatigue damage evolution, comprehensively considers the influence of the order of high-low cycle load mixed cyclic loading on the fatigue life performance, and based on the Manson-Halford nonlinear fatigue damage accumulation theory and the mechanism of relative cumulative damage, a new nonlinear damage accumulation fatigue life model is established, and a fatigue damage accumulation influencing factor D_cr is introduced to improve the prediction accuracy of the model. The new model proposed in this paper is verified through multi-level fatigue load data. By comparing the prediction results with other models under the same experimental conditions, the fatigue life prediction error precision of the new model is the best in similar cases, generally with an error precision between 10% and 20%, which proves the effectiveness and accuracy of the nonlinear damage accumulation model proposed in this paper. At the same time, the improved method in this paper has better stability while ensuring prediction accuracy. Full article

Primary Sjögren’s syndrome (pSS) is a chronic, autoimmune rheumatic disease characterized by progressive lymphocytic infiltration of the exocrine glands, leading to inflammation and subsequent tissue damage. As a multifactorial disease, its etiology is complex, making it difficult to predict disease progression. Among the environmental factors implicated in pSS, the involvement of microorganisms has gained increasing attention. Since the launch of the Human Microbiome Project, growing evidence has highlighted the role of dysbiosis in the pathogenesis of various autoimmune diseases, including pSS. Shifts in the abundance of specific bacterial phyla can lead to corresponding changes in the levels of key microbial metabolites involved in tissue homeostasis and immune regulation—such as short-chain fatty acids (SCFAs), choline, taurine, serine, lactate, and tryptophan and their metabolites. Understanding the mechanisms by which these metabolites influence immune processes may provide deeper insights into the progression of the disease. Therefore, this review aims to explore the mechanisms through which microbiota-derived metabolites contribute to the pathophysiology of primary Sjögren’s syndrome. Full article

Background/Objectives: Leishmania spp. are protozoan parasites transmitted by female sandflies (Phlebotomus or Lutzomyia). Clinical manifestations depend on species and host immunity. While cutaneous and visceral forms prevail, mucocutaneous involvement—particularly isolated nasal septum leishmaniasis—is rare and frequently misdiagnosed as an inflammatory, infectious, or neoplastic condition. Risk factors associated with mucocutaneous leishmaniasis include systemic or local immunodeficiency, prior renal transplantation, treatment with chronic inhaled steroids, residence in endemic areas or travel to such regions, and previous Leishmania infections. Immunosuppressed patients are at higher risk for atypical presentations and delayed diagnosis, which can result in extensive tissue destruction. Early clinical suspicion, histopathological confirmation, and prompt therapy are essential to prevent permanent mucosal damage. Therefore, a multidisciplinary approach is needed for adequate evaluation and effective treatment. Methods: A 67-year-old man with rheumatoid arthritis on methotrexate reported a two-year history of right-sided nasal obstruction and ulceration that failed to respond to antibiotics. He did not present systemic symptoms. Results: Facial CT revealed a septal deviation; the patient underwent septoplasty, and biopsy confirmed Leishmania amastigotes. Serology (rK39 immunochromatographic test) was positive. He was treated with liposomal amphotericin B at 4 mg/kg/day for five days, followed by miltefosine at 100 mg/day orally for 14 days. At an eight-week follow-up, the nasal mucosa was fully healed, obstruction was resolved, and there was no evidence of recurrence. Conclusions: Although nasal septum leishmaniasis is uncommon, it should be considered in the differential diagnosis of chronic nasal lesions, especially in immunocompromised patients or those from endemic regions. Definitive diagnosis requires biopsy with histological or molecular confirmation. Combined liposomal amphotericin B and miltefosine therapy yields high cure rates and prevents mucosal destruction. Early recognition is critical to avoid diagnostic delays and long-term sequelae. Full article

In recent years, arresters in 10 kV distribution transformer areas of the Guangdong power grid have exhibited a rising trend of premature failures, posing a serious threat to distribution network reliability. This paper studied the failure causes of arresters through performance tests on failed arresters and through deterioration tests on new arresters and their prorated sections under typical operating stresses. The failed arresters and their internal varistors displayed varying degrees of physical damage and pronounced degradation in electrical performance, characterized by a strong polarity effect on the DC reference voltage (U_1mA), elevated DC leakage current (I_L) and resistive current (i_R), and excessive residual voltage (U_5kV). In the lightning impulse test, varistors primarily showed pinhole-type damage and significant polarity effects on ΔU_1mA. In the AC aging test, ΔU_5kV increased markedly. In the water immersion test, varistors exhibited salt deposits and aluminum electrode blackening, with ΔU_1mA decreasing, while I_L and Δi_R increased significantly. Overall, internal moisture superimposed on other operating stresses was identified as a major internal cause of arrester failure, while pollution flashover of the housing was considered the primary external factor. Corresponding improvement measures in material optimization, testing and inspection, and operation and maintenance are proposed to enhance arrester reliability. Full article

The cushion curves of cushioning materials play crucial roles in scientific and reliable cushioning designs and in reducing damage losses for fragile products during distributions. The construction methods of cushion curves of closed-cell foam materials (CFMs) mainly include the Janssen factor, Rusch curve, cushion factor, and energy absorption diagram. The construction principle of these methods is reviewed in detail, and their disadvantages are mainly discussed. According to relevant ASTM and GB/T experimental standards, the peak acceleration–static stress cushion curve is based on dynamic impacts, which are most consistent with the dropping situation of product packages, so this kind of cushion curve is the standard and most widely applied for product cushioning designs. However, when generating the peak acceleration–static stress cushion curves, the experimental work is extremely huge. Three methods, namely the dynamic factor method, dynamic stress–dynamic energy method, and dynamic cushion factor–dynamic energy method, can significantly reduce the experimental workload and simplify constructing cushion curves. The novel dynamic cushion factor–dynamic stress method is proposed to simplify constructing the cushion curves. The practical generation steps of constructing cushion curves based on the four simplified methods are created and presented in detail. Full article

Drought stress limits seedling growth, hindering morphological development and population establishment. Artocarpus nanchuanensis, a critically endangered species endemic to the karst regions of southwest China, exhibits poor population structure and limited natural regeneration in the wild, with water deficit during the seedling stage identified as a major factor contributing to its endangered status. Elucidating the physiological and molecular mechanisms underlying drought tolerance in A. nanchuanensis seedlings is essential for improving their drought adaptability and facilitating population recovery. In this study, 72 two-year-old seedlings were divided into two groups: drought (PEG) and ethephon (PEG + Ethephon), and subjected to drought-rehydration experiments. The results showed that exogenous application of 100 mg·L⁻¹ ethephon significantly improved stomatal conductance and photosynthetic pigment content in A. nanchuanensis seedlings. Under drought stress, the PEG + Ethephon group exhibited rapid stomatal closure, maintaining water balance and higher photosynthetic pigment levels. After rehydration, the PEG + Ethephon group significantly outperformed the PEG group in terms of photosynthetic rate. Ethephon treatment reduced H₂O₂ and MDA levels, enhanced antioxidant enzyme activity (SOD, CAT, POD, GR), and increased osmotic regulator activity (soluble sugars, soluble proteins, and proline), improving ROS-scavenging capacity and reducing oxidative damage. Ethephon application significantly enhanced ethylene accumulation in seedlings, while drought stress stimulated the concentrations of key ethylene biosynthetic enzymes (SAMS, ACS, and ACO), thereby further contributing to improved drought resistance. Transcriptomic data revealed that drought stress significantly upregulated key ethylene biosynthesis genes, with expression levels increasing with stress duration and rapidly decreasing after rehydration. WGCNA analysis identified eight key drought-resistance genes, providing valuable targets for future research. This study provides the first mechanistic insight into the physiological and molecular responses of A. nanchuanensis seedlings to drought and rehydration, underscoring the central role of endogenous ethylene in drought tolerance. Ethephon treatment effectively enhanced ethylene accumulation and biosynthetic enzyme activity, thereby improving drought adaptability. These findings lay a theoretical foundation for subsequent molecular functional studies and the conservation biology of this endangered species. Full article

Autologous platelet-rich plasma (PRP) has emerged as a promising regenerative therapy in various medical fields, including the treatment of stress urinary incontinence (SUI) in women. PRP promotes regeneration by delivering a concentrated dose of platelets to damaged tissues, triggering healing mechanisms such as hemostasis, revascularization, and connective tissue regeneration through the release of growth factors. Despite evidence supporting the short- and medium-term benefits of PRP, its long-term efficacy remains unclear, largely due to the limited duration of follow-up in existing studies. Furthermore, the lack of standardized protocols for both preparation and administration of PRP poses a significant challenge to accurately assessing and comparing its sustained therapeutic outcomes. This literature review utilized comprehensive searches of PubMed and Google Scholar databases to analyze current evidence regarding PRP’s role in managing SUI in women. SUI, often resulting from weakened pubo-urethral ligament or intrinsic sphincter dysfunction due to childbirth, aging, or hormonal changes, significantly impacts quality of life. PRP offers a safe, minimally invasive, and cost-effective treatment option; however, further large-scale, well-designed studies are necessary to define optimal protocols and confirm long-term benefits. Advancing understanding of PRP therapy could substantially improve clinical management and patient quality of life in SUI. Full article

In urban construction, the efficient demolition of concrete structures imposes high-precision requirements on blasting technology. The mesoscopic evolution mechanism of concrete blasting damage is the key to optimizing blasting parameters. In this study, a numerical model of concrete blasting is established using Particle Flow Code (PFC). By comparing it with an experimental model containing a blast hole and a horizontal single fissure, the rationality and reliability of the model in simulating blasting damage evolution are verified. On this basis, four groups of control variable schemes are designed (concrete particle size distribution, aggregate content, prefabricated fissure inclination angle, and fissure length) to systematically explore the effects of mesoscopic structures and macroscopic defects on blasting damage. The results show that larger concrete particles make it easier for damage cracks to avoid large particles, forming sparse and irregular crack networks. A higher aggregate content enhances the “obstruction-guidance” effect of aggregate distribution on damage. When the aggregate content is 40%, the vertical damage expansion is the most prominent, reaching up to 3.05 cm. Fissure inclination angle affects the damage direction by guiding the propagation path of stress waves. Fissures inclined at 30°~60° serve as preferential damage channels, while 90° vertical fissures make vertical damage more significant. An increased fissure length expands the damage range, and the damage degree is the highest for a 40 mm long fissure, being 1.29 times that of a 30 mm fissure. The research results reveal the mesoscopic evolution laws of concrete blasting damage, providing a theoretical basis for the optimization of engineering blasting parameters and safety control. Full article

Alcohol Use Disorder (AUD) poses global health challenges, and causes hematological alterations such as macrocytosis and oxidative stress. Disruption of protein structures by alcohol and/or its metabolites may exacerbate AUDs; proteomics can elucidate the underlying biological mechanisms. This study examined the proteins differentially expressed in the cytosol and membrane fractions of erythrocytes obtained from 30 male patients with AUD, comparing them to samples from 15 age- and BMI-matched social drinkers (SDs) and 15 non-drinkers (control). The analysis aimed to identify the molecular differences related to alcohol consumption. The AUD patient subgrouping was based on mean corpuscular volume (MCV), with 16 individuals classified as having a normal MCV and 14 having a high MCV. Proteins were separated via two-dimensional(2D)-gel electrophoresis, digested with trypsin, and identified via Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (TOF) mass spectrometry (MALDI-TOF/TOF). Additionally, levels of malondialdehyde and 4-hydroxyalkenals (MDA + HAE), reduced glutathione (GSH), oxidized glutathione (GSSG), serum carbohydrate-deficient transferrin (%CDT), disialotransferrin (%DST), and sialic acid (SA) were analyzed. The results showed increased MDA + HAE and decreased total thiols in AUD patients, with GSSG elevated and the GSH/GSSG ratio reduced in the AUD MCV-high subgroup. Serum %CDT, %DST, and SA were significantly higher in AUD. Compared to the control profiles, the AUD group exhibited differential protein expression. Few proteins, such as bisphosphoglycerate mutase, were downregulated in AUD versus control and SD, as well as in the MCV-high AUD subgroup. Conversely, endoplasmin and gelsolin were upregulated in AUD relative to control. Cytoskeletal proteins, including spectrin-alpha chain, actin cytoplasmic 2, were overexpressed in the AUD group and MCV-high AUD subgroup. Several proteins, such as 14-3-3 isoforms, alpha-synuclein, translation initiation factors, heat shock proteins, and others, were upregulated in the MCV-high AUD subgroup. Under-expressed proteins in this subgroup include band 3 anion transport protein, bisphosphoglycerate mutase, tropomyosin alpha-3 chain, uroporphyrinogen decarboxylase, and WD repeat-containing protein 1. Our findings highlight the specific changes in protein expression associated with oxidative stress, cytoskeletal alterations, and metabolic dysregulation, specifically in AUD patients with an elevated MCV. Understanding these mechanisms is crucial for developing targeted interventions and identifying biomarkers of alcohol-induced cellular damage. The complex interplay between oxidative stress, membrane composition, and cellular function illustrates how chronic alcohol exposure affects cellular physiology. Full article

Due to the shortage of construction aggregates, carbonate rock aggregates—including mainly limestone aggregates—have long been used in structural concrete in many countries worldwide. On the other hand, earlier tests on the shear fracture toughness of concretes with limestone aggregates were very limited and were even abandoned for many years. For the above reasons, in this paper, completely new fracture toughness tests were performed according to the mode II fracture for limestone concretes with different grain size distributions. Two types of aggregate grain were used, i.e., two with maximum grain sizes of 8 mm (M1 series concrete) and 16 mm (M2 series concrete). During the experiments, the critical stress-intensity factor (K_IIc) and critical unit work of failure (J_IIc) were determined. Based on the conducted studies, it was found that higher values of fracture mechanics parameters were noted as the grain sizes of the aggregate used increased. The increases in the analyzed fracture mechanics parameters were noticeably greater in the M2 series concrete compared to the results for the M1 series concrete, specifically by 27% for K_IIc and 35% for J_IIc. In addition to macroscopic tests, detailed microstructural analyses of the ITZ area between the coarse aggregate grains and the cement matrix were conducted. Based on the captured images, it was determined that, in the M1 series concrete, the contacts between the aggregate grains and the cement paste exhibit a loose structure with visible microcracks. In contrast, the M2 series concrete showed no visible damages within the ITZ area itself nor at their displacement at a distance of approximately a few μm away from this area. This microstructure of both materials resulted in the M1 series concrete being more prone to rapid and sudden fracture propagation, leading to its brittle behavior during the fracture process. In contrast, the large, well-developed limestone aggregate grains in the M2 series concrete facilitated improved stress transfer beyond the ITZ area into the cement matrix, preserving the continuity of the material structure and consequently leading to quasi-plastic behavior of the concrete during the fracture process. The novelty and utilitarianism of the research undertaken result from the fact that exploring the properties of concretes with limestone aggregates using mode II fracture is an important aspect of evaluating the durability and safety of concrete structures subjected mainly to shear forces. Full article

Ultrahigh dose rate (UHDR) radiotherapy, also known as FLASH radiotherapy (FLASH-RT), has shown potential for increasing tumor control while sparing normal tissue. In parallel, gold nanoparticles (GNPs) have been extensively explored as radiosensitizers due to their high atomic number and ability to enhance the generation of reactive oxygen species (ROS) through water radiolysis. In this study, we investigate the synergistic effects of UHDR electron beams and GNP-mediated radiosensitization using Monte Carlo (MC) simulations based on the Geant4-DNA code. A spherical water phantom with embedded GNPs of varying sizes (5–100 nm) was irradiated using pulsed electron beams (100 keV and 1 MeV) at dose rates of 60, 100, and 150 Gy/s. The chemical yield of ROS near the GNPs was quantified and compared to an equivalent water nanoparticle model, and the yield enhancement factor (YEF) was used to evaluate radiosensitization. Results demonstrated that YEF increased with smaller GNP sizes and at lower UHDR, particularly for 1 MeV electrons. A maximum YEF of 1.25 was observed at 30 nm from the GNP surface for 5 nm particles at 60 Gy/s. The elevated ROS concentration near GNPs under FLASH conditions is expected to intensify DNA damage, especially double-strand breaks, due to increased hydroxyl radical interactions within nanometric distances of critical biomolecular targets. These findings highlight the significance of nanoparticle size and beam parameters in optimizing ROS production for FLASH-RT. The results provide a computational basis for future experimental investigations into the combined use of GNPs and UHDR beams in nanoparticle-enhanced radiotherapy. Full article

This review aims to provide a comprehensive overview of how oxidative stress drives inflammation, structural remodeling, and clinical expression of childhood asthma, while critically appraising emerging redox-sensitive biomarkers and antioxidant-focused preventive and therapeutic strategies. Oxidative stress arises when reactive oxygen species (ROS) and reactive nitrogen species (RNS) outpace airway defenses. This surplus provokes airway inflammation: ROS/RNS activate nuclear factor kappa-B (NF-κB) and activator protein-1 (AP-1), recruit eosinophils and neutrophils, and amplify type-2 cytokines. Normally, an antioxidant network—glutathione (GSH), enzymes such as catalase (CAT) and superoxide dismutase (SOD), and nuclear factor erythroid 2-related factor 2 (Nrf2)—maintains redox balance. Prenatal and early exposure to fine particulate matter <2.5 micrometers (µm) (PM_2.5), aeroallergens, and tobacco smoke, together with polymorphisms in glutathione S-transferase P1 (GSTP1) and CAT, overwhelm these defenses, driving epithelial damage, airway remodeling, and corticosteroid resistance—the core of childhood asthma pathogenesis. Clinically, biomarkers such as exhaled 8-isoprostane, hydrogen peroxide (H₂O₂), and fractional exhaled nitric oxide (FeNO) surge during exacerbations and predict relapses. Therapeutic avenues include Mediterranean-style diet, regular aerobic exercise, pharmacological Nrf2 activators, GSH precursors, and mitochondria-targeted antioxidants; early trials report improved lung function and fewer attacks. Ongoing translational research remains imperative to substantiate these approaches and to enable the personalization of therapy through individual redox status and genetic susceptibility, ultimately transforming the care and prognosis of pediatric asthma. Full article