ABSTRACT
JOURNAL/nrgr/04.03/01300535-202506000-00027/figure1/v/2024-08-05T133530Z/r/image-tiff Degenerative cervical myelopathy is a common cause of spinal cord injury, with longer symptom duration and higher myelopathy severity indicating a worse prognosis. While numerous studies have investigated serological biomarkers for acute spinal cord injury, few studies have explored such biomarkers for diagnosing degenerative cervical myelopathy. This study involved 30 patients with degenerative cervical myelopathy (51.3 ± 7.3 years old, 12 women and 18 men), seven healthy controls (25.7 ± 1.7 years old, one woman and six men), and nine patients with cervical spondylotic radiculopathy (51.9 ± 8.6 years old, three women and six men). Analysis of blood samples from the three groups showed clear differences in transcriptomic characteristics. Enrichment analysis identified 128 differentially expressed genes that were enriched in patients with neurological disabilities. Using least absolute shrinkage and selection operator analysis, we constructed a five-gene model (TBCD, TPM2, PNKD, EIF4G2, and AP5Z1) to diagnose degenerative cervical myelopathy with an accuracy of 93.5%. One-gene models (TCAP and SDHA) identified mild and severe degenerative cervical myelopathy with accuracies of 83.3% and 76.7%, respectively. Signatures of two immune cell types (memory B cells and memory-activated CD4+ T cells) predicted levels of lesions in degenerative cervical myelopathy with 80% accuracy. Our results suggest that peripheral blood RNA biomarkers could be used to predict lesion severity in degenerative cervical myelopathy.
ABSTRACT
Accurate description of nonadiabatic dynamics of molecules at metal surfaces involving electron transfer has been a long-standing challenge for theory. Here, we tackle this problem by first constructing high-dimensional neural network diabatic potentials including state crossings determined by constrained density functional theory, then applying mixed quantum-classical surface hopping simulations to evolve coupled electron-nuclear motion. Our approach accurately describes the nonadiabatic effects in CO scattering from Au(111) without empirical parameters and yields results agreeing well with experiments under various conditions for this benchmark system. We find that both adiabatic and nonadiabatic energy loss channels have important contributions to the vibrational relaxation of highly vibrationally excited CO(v_{i}=17), whereas relaxation of low vibrationally excited states of CO(v_{i}=2) is weak and dominated by nonadiabatic energy loss. The presented approach paves the way for accurate first-principles simulations of electron transfer mediated nonadiabatic dynamics at metal surfaces.
ABSTRACT
Personalized three-dimensional (3D) printed foods rich in probiotics were investigated. Lactiplantibacillus plantarum (Lp), as a representative of probiotics, was used to investigate the 3D printing of probiotic-rich dysphagia foods. Here, whey protein isolate nanofibrils (WPNFs) were coated and anchored on bacterial surfaces via biointerfacial supramolecular self-assembly, providing protection against environmental stress and the 3D printing process. The optimized composite gels consisting of High acyl gellan gum (0.25 g), whey protein isolate (1.25 g), fructooligosaccharides (0.75 g), Lp-WPNFs-Glyceryl tributyrate emulsion (Φ = 40%, 3.75 mL) can realize 3D printing, and exhibit high resolution, and stable shape. The viable cell count is higher than 8.0 log CFU/g. They are particularly suitable for people with dysphagia and are classified as level 5-minced & moist in the international dysphagia diet standardization initiative framework. The results provide new insights into the development of WPNFs-coating on bacterial surfaces to deliver probiotics and 3D printed food rich in probiotics.
ABSTRACT
Ferroptosis is a newly defined mode of cellular demise. The increasing investigation supports that ferroptosis is a crucial factor in the complex mechanisms of myocardial ischemia-reperfusion (I/R) injury. Hence, targeting ferroptosis is a novel strategy for treating myocardial injury. Although evidence suggests that trimetazidine (TMZ) is potentially efficacious against myocardial injury, the exact mechanism of this efficacy is yet to be fully elucidated. This study aimed to determine whether TMZ can act as a ferroptosis resistor and affect I/R-mediated myocardial injury. To this end, researchers have constructed in vitro and in vivo models of I/R using H9C2 cardiomyocytes, primary cardiomyocytes, and SD rats. Here, I/R mediated the onset of ferroptosis in vitro and in vivo, as reflected by excessive iron aggregation, GSH depletion, and the increase in lipid peroxidation. TMZ largely reversed this alteration and attenuated cardiomyocyte injury. Mechanistically, we found that TMZ upregulated the expression of Sirt3. Therefore, we used si-Sirt3 and 3-TYP to interfere with Sirt3 action in vitro and in vivo, respectively. Both si-Sirt3 and 3-TYP partly mitigated the inhibitory effect of TMZ on I/R-mediated ferroptosis and upregulated the expression of Nrf2 and its downstream target, GPX4-SLC7A11. These results indicate that TMZ attenuates I/R-mediated ferroptosis by activating the Sirt3-Nrf2/GPX4/SLC7A11 signaling pathway. Our study offers insights into the mechanism underlying the cardioprotective benefits of TMZ and establishes a groundwork for expanding its potential applications.
ABSTRACT
BACKGROUND: Bromhidrosis, characterized by foul-smelling sweat, is a prevalent condition that significantly affects patients' social and psychological well-being. METHODS: This review presents novel treatment approaches and discusses the pros and cons of various treatment options for axillary bromhidrosis. RESULTS: Extensive research has explored numerous treatment modalities for bromhidrosis. This article systematically reviews both surgical and nonsurgical interventions utilized in clinical practice. CONCLUSION: By synthesizing available evidence, this review aims to offer evidence-based recommendations for effectively managing bromhidrosis, considering factors such as treatment efficacy, safety profiles, patient preferences, and clinical outcomes.
Subject(s)
Axilla , Humans , Hyperhidrosis/therapy , Treatment Outcome , Sweat Gland Diseases/therapy , Sweat Gland Diseases/physiopathology , OdorantsABSTRACT
In-sensor and near-sensor computing architectures enable multiply accumulate operations to be carried out directly at the point of sensing. In-sensor architectures offer dramatic power and speed improvements over traditional von Neumann architectures by eliminating multiple analog-to-digital conversions, data storage, and data movement operations. Current in-sensor processing approaches rely on tunable sensors or additional weighting elements to perform linear functions such as multiply accumulate operations as the sensor acquires data. This work implements in-sensor computing with an oscillatory retinal neuron device that converts incident optical signals into voltage oscillations. A computing scheme is introduced based on the frequency shift of coupled oscillators that enables parallel, frequency multiplexed, nonlinear operations on the inputs. An experimentally implemented 3 × 3 focal plane array of coupled neurons shows that functions approximating edge detection, thresholding, and segmentation occur in parallel. An example of inference on handwritten digits from the MNIST database is also experimentally demonstrated with a 3 × 3 array of coupled neurons feeding into a single hidden layer neural network, approximating a liquid-state machine. Finally, the equivalent energy consumption to carry out image processing operations, including peripherals such as the Fourier transform circuits, is projected to be <20 fJ/OP, possibly reaching as low as 15 aJ/OP.
ABSTRACT
Li-rich layered oxides are promising candidates for high-capacity Li-ion battery cathode materials. In this study, we employ first-principles calculations to investigate the effect of F doping on Li-rich Li2MnO3 layered cathode materials. Our findings reveal that both Li2MnO3 and Li2MnO2.75F0.25 exhibit significant volume changes (greater than 10%) during deep delithiation, which could hinder the cycling of more Li ions from these two materials. For Li2MnO3, it is observed that oxygen ions lose electrons to compensate for charge during the delithiation process, leading to a relatively high voltage plateau. After F doping, oxidation occurs in both the cationic (Mn) and anionic (O) components, resulting in a lower voltage plateau at the beginning of the charge, which can be attributed to the oxidation of Mn3+ to Mn4+. Additionally, F doping can somewhat suppress the release of oxygen in Li2MnO3, improving the stability of anionic oxidation. However, the increase of the activation barriers for Li diffusion can be observed after F doping, due to stronger electrostatic interactions between F- and Li+, which adversely affects the cycling kinetics of Li2MnO2.75F0.25. This study enhances our understanding of the impact of F doping in Li2MnO3 based on theoretical calculations.
ABSTRACT
BACKGROUND: Previous researches have demonstrated that the traditional Chinese medicine could therapeutically treat inflammatory and hypoxic diseases by enhancing the functionality of mesenchymal stem cells. However, its mechanism was not yet clear. This research aimed to investigate the impact of the traditional Chinese medicine Sijunzi decoction and its herb monomer ginsenoside Rg1 on the proliferation and differentiation of human umbilical cord mesenchymal stem cells (hUC-MSCs) and explore the underlying mechanisms. METHODS: Different concentrations of Sijunzi decoction and Rg1 were applied to differentiating induced hUC-MSCs. The CCK-8 test was utilized to evaluate cell proliferation activity and identify suitable drug concentrations. Alizarin Red staining was employed to detect the formation of calcium nodules, and Oil Red O staining was used to assess the formation of lipid droplets. PCR was utilized to examine gene expression related to osteogenic differentiation, adipogenic differentiation, and the HIF-1α signaling pathway in hUC-MSCs. Western blot analysis was conducted to evaluate protein expression in osteogenic differentiation and HIF-1α. ELISA was performed to measure HIF-1α signaling factors and inflammatory cytokine expression. Biochemical assays were used to assess changes in oxidative stress indicators. RESULTS: The Sijunzi decoction and Rg1 both demonstrated a dose-dependent promotion of hUC-MSC proliferation. The Sijunzi decoction significantly increased the expression of genes and proteins relevant to osteogenesis, such as osterix, osteocalcin, RUNX2, and osteopontin, and activated the HIF-1α pathway in hUC-MSCs. (Pâ <â .05). Similar effects were observed at the gene level after treatment with Rg1. Simultaneously, Sijunzi decoction significantly reduced the secretion of pro-inflammatory cytokines TNF-α, IL-6, and IL-1ß, while increasing the secretion of the anti-inflammatory cytokine IL-10 during osteogenic differentiation (Pâ <â .05). Moreover, Sijunzi decoction lowered oxidative stress levels and enhanced the antioxidant capacity of hUC-MSCs during osteogenic differentiation (Pâ <â .05). However, the impact of Sijunzi decoction on hUC-MSCs toward adipogenic differentiation was not significant (Pâ >â .05). CONCLUSION: Sijunzi decoction promotes the proliferation and osteogenic differentiation of hUC-MSCs, potentially through the activation of the HIF-1α signaling pathway and by modulating the microenvironment via reducing inflammation and oxidative stress levels. Rg1 might be involved in this process.
Subject(s)
Cell Differentiation , Cell Proliferation , Drugs, Chinese Herbal , Ginsenosides , Hypoxia-Inducible Factor 1, alpha Subunit , Mesenchymal Stem Cells , Osteogenesis , Umbilical Cord , Humans , Mesenchymal Stem Cells/drug effects , Drugs, Chinese Herbal/pharmacology , Cell Proliferation/drug effects , Cell Differentiation/drug effects , Umbilical Cord/cytology , Osteogenesis/drug effects , Ginsenosides/pharmacology , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Adipogenesis/drug effects , Signal Transduction/drug effects , Cells, CulturedABSTRACT
Mitogenome data of Odonata is accumulating and widely used in phylogenetic analysis. However, noncoding regions, especially control region, were usually omitted from the phylogenetic reconstruction. In an effort to uncover the phylogenetic insights offered by the control region, we have amassed 65 Odonata mitogenomes and conducted an examination of their control regions. Our analysis discovered that species belonging to Anisoptera and Anisozygoptera exhibited a stem-loop structure, which was formed by a conserved polyC-polyG stretch located near the rrns gene (encoding 12S rRNA). Conversely, the polyC-polyG region was not a conserved fragment in Zygoptera. The length and number of repetitions within the control region were identified as the primary determinants of its overall length. Further, sibling species within Odonata, particularly those in the genus Euphaea, displayed similar patterns of repetition in their control region. Collectively, our research delineates the structural variations within the control region of Odonata and suggests the potential utility of this region in elucidating phylogenetic relationships among closely related species.
ABSTRACT
Ozone (O3) pollution is a severe environmental problem in China. The incomplete understanding of atmospheric photochemical reaction mechanisms prevents us from accurately understanding the chemistry of O3 production. Here, we used an improved dual-channel reaction chamber technique to measure net photochemical O3 production rate (P(O3)net) directly in Dongguan, a typical industrial city in China. The maximum P(O3)net was 46.3 ppbv h-1 during the observation period, which is at a relatively high level compared to previous observations under different environment worldwide. We employed an observation-based box model coupled with the state-of-the-art atmospheric chemical mechanism (MCM v3.3.1) to investigate the chemistry of O3 production. Under the base scenario, the modelling underestimates P(O3)net by ~30 %. Additionally considering HO2 uptake by ambient aerosols, inorganic deposition, and Cl chemistry only caused a small change (< 13 %) in the simulation of P(O3)net. Further analysis indicates that unmeasured reactive volatile organic compounds (VOCs), such as oxygenated VOCs and branched alkenes are potential contributors to the underestimation of P(O3)net. This study underscores the underestimation of P(O3)net in conventional atmospheric modelling setups, providing a crucial scientific foundation for further investigation aimed at promoting our understanding of photochemical O3 formation.
ABSTRACT
Hyperpolarization stands out as a technique capable of significantly enhancing the sensitivity of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Dynamic nuclear polarization (DNP), among various hyperpolarization methods, has gained prominence for its efficacy in real-time monitoring of metabolism and physiology. By administering a hyperpolarized substrate through dissolution DNP (dDNP), the biodistribution and metabolic changes of the DNP agent can be visualized spatiotemporally. This approach proves to be a distinctive and invaluable tool for non-invasively studying cellular metabolism in vivo, particularly in animal models. Biomarkers play a pivotal role in influencing the growth and metastasis of tumor cells by closely interacting with them, and accordingly detecting pathological alterations of these biomarkers is crucial for disease diagnosis and therapy. In recent years, a range of hyperpolarized DNP molecular bioresponsive agents utilizing various nuclei, such as 13C, 15N, 31P, 89Y, etc., have been developed. In this context, we explore how these magnetic resonance signals of nuclear spins enhanced by DNP respond to biomarkers, including pH, metal ions, enzymes, or redox processes. This review aims to offer insights into the design principles of responsive DNP agents, target selection, and the mechanisms of action for imaging. Such discussions aim to propel the future development and application of DNP-based biomedical imaging agents.
ABSTRACT
BACKGROUND: Telesurgery has the potential to overcome spatial limitations for surgeons, which depends on surgical robot and the quality of network communication. However, the influence of network latency and bandwidth on telesurgery is not well understood. METHODS: A telesurgery system capable of dynamically adjusting image compression ratios in response to bandwidth changes was established between Beijing and Sanya (Hainan province), covering a distance of 3000 km. In total, 108 animal operations, including 12 surgical procedures, were performed. Total latency ranging from 170 ms to 320 ms and bandwidth from 15-20 Mbps to less than 1 Mbps were explored using designed surgical tasks and hemostasis models for renal vein and internal iliac artery rupture bleeding. Network latency, jitter, frame loss, and bit rate code were systemically measured during these operations. National Aeronautics and Space Administration Task Load Index (NASA-TLX) and a self-designed scale measured the workload and subjective perception of surgeons. RESULTS: All 108 animal telesurgeries, conducted from January 2023 to June 2023, were performed effectively over a total duration of 3866 min. The operations were completed with latency up to 320 ms and bandwidths as low as 1-5 Mbps. Hemostasis for vein and artery rupture bleeding models was effectively achieved under these low bandwidth conditions. The NASA-TLX results indicated that latency significantly impacted surgical performance more than bandwidth and image clarity reductions. CONCLUSIONS: This telesurgery system demonstrated safety and reliability. A total of 320 ms latency is acceptable for telesurgery operations. Reducing image clarity can effectively mitigate the potential latency increase caused by decreased bandwidth, offering a new method to reduce the impact of latency on telesurgery.
ABSTRACT
C1R has been identified to have a distinct function in cutaneous squamous cell carcinoma that goes beyond its role in the complement system. However, it is currently unknown whether C1R is involved in the progression of hepatocellular carcinoma (HCC). HCC tissues were used to examine C1R expression in relation to clinical and pathological factors. Malignant characteristics of HCC cells were assessed through in vitro and in vivo experiments. The mechanism underlying the role of C1R in HCC was explored through RNA-seq, methylation-specific PCR, immuno-precipitation, and dual-luciferase reporter assays. This study found that the expression of C1R decreased as the malignancy of HCC increased and was associated with poor prognosis. C1R promoter was highly methylated through DNMT1 and DNMT3a, resulting in a decrease in C1R expression. Downregulation of C1R expression resulted in heightened malignant characteristics of HCC cells through the activation of HIF-1α-mediated glycolysis. Additionally, decreased C1R expression was found to promote xenograft tumor formation. We found that C-reactive protein (CRP) binds to C1R, and the free CRP activates the NF-κB signaling pathway, which in turn boosts the expression of HIF-1α. This increase in HIF-1α leads to higher glycolysis levels, ultimately promoting aggressive behavior in HCC. Methylation of the C1R promoter region results in the downregulation of C1R expression in HCC. C1R inhibits aggressive behavior in HCC in vitro and in vivo by inhibiting HIF-1α-regulated glycolysis. These findings indicate that C1R acts as a tumor suppressor gene during HCC progression, opening up new possibilities for innovative therapeutic approaches.
ABSTRACT
As a very common malignancy of the digestive system, the incidence and mortality rates of gastric cancer (GC) are increasing year by year. The critical role of ferroptosis in cancer development has been well-documented. The polyphenol compound curcumin shows prominent anti-tumor effects in multiple cancer types, including GC. However, whether curcumin participates in GC tumorigenesis by regulating ferroptosis remains unknown. Gastric cancer cells AGS and HGC-27 were treated with curcumin (0, 10, and 20 µM). Cell viability and death were evaluated through CCK-8 and LDH release assays. LC3B expression in cells was estimated through immunofluorescence staining. Intracellular ferrous iron (Fe2+), GSH, MDA, and lipid ROS levels were assessed by corresponding assay kits. The cellular levels of autophagy markers (ATG5, ATG7, Beclin 1, and LC3B), ferroptosis markers (ACSL4, SLC7A11, and GPX4), and phosphorylated (p)-PI3K, p-AKT, and p-mTOR were determined through western blotting. Curcumin attenuated cell viability but stimulated cell death in GC cells. Curcumin enhanced autophagy in GC cells, as demonstrated by the increased levels of ATG5, ATG7, Beclin 1, and LC3B. Besides, curcumin upregulated iron, MDA, GSH, and ACSL4 levels while downregulated lipid ROS, SLC7A11, and GPX4 levels, suggesting its stimulation on ferroptosis in GC cells. Curcumin decreased p-PI3K, p-AKT, and p-mTOR levels in cells. Importantly, the ferroptosis inhibitor ferrostatin-1 overturned the impacts of curcumin on GC cell viability, death, and ferroptosis. Curcumin suppresses GC development by inducing autophagy-mediated ferroptosis by inactivating the PI3K/AKT/mTOR signaling.
Subject(s)
Autophagy , Cell Survival , Curcumin , Ferroptosis , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Signal Transduction , Stomach Neoplasms , TOR Serine-Threonine Kinases , Stomach Neoplasms/drug therapy , Stomach Neoplasms/metabolism , Stomach Neoplasms/pathology , Ferroptosis/drug effects , Humans , Curcumin/pharmacology , TOR Serine-Threonine Kinases/metabolism , Autophagy/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Signal Transduction/drug effects , Cell Line, Tumor , Phosphatidylinositol 3-Kinases/metabolism , Cell Survival/drug effects , Antineoplastic Agents/pharmacologyABSTRACT
This article investigates adaptive output formation tracking control of nonlinear multiagent systems with time-varying actuator faults and unknown nonidentical control directions under double semi-Markovian switching topologies. Considering the dynamic changes of communication connections in uncertain environments, a double semi-Markov process is first introduced into the leader-follower structure to describe the random switching of communication topologies. Then, a novel adaptive distributed fault-tolerant output formation tracking control framework is established using the backstepping and Nussbaum gain technique to address matched/mismatched uncertainties and disturbances, time-varying actuator faults, and unknown nonidentical control directions. In this control framework, the independent variable of the Nussbaum function is designed as a non-negative function that monotonically increases with respect to time, thereby overcoming the presence of the absolute value of its derivative in the integration process. Based on the distributed structure, an adaptive fault-tolerant controller is further proposed to achieve the asymptotic output formation tracking in mean-square sense. The stability of the closed-loop nonlinear multiagent systems is analysed through the contradiction argument and Lyapunov theorem. The simulation example verifies the effectiveness of the proposed control strategy.
ABSTRACT
Purpose: The objective of this study was to investigate the effects of agrimonolide (AM) on mice with dextran sulfate sodium (DSS)-induced colitis and elucidate its protective mechanisms. Methods: A 3 % DSS solution was used to induce colitis, and intragastric administration of AM at doses of 25 and 50 mg/kg was performed. A comprehensive assessment was conducted to evaluate inflammatory responses and mucosal integrity in the colon. Inflammatory factors were quantified using enzyme-linked immunosorbent assay (ELISA). The proportions of T helper cell 17 (Th17) and regulatory T cells (Treg) cells in mesenteric lymph nodes (MLNs) was analyzed through RT-qPCR and flow cytometry. Proteins associated with the Notch and JAK2/STAT3 pathways were examined via RT-qPCR, western blotting, and immunofluorescence. Additionally, the impact of AM on Treg and Th17 cell differentiation was investigated in vitro. Results: Pre-treatment with AM significantly alleviated colon inflammation in mice, as evidenced by reduced body weight loss, shorter colon length, lower disease activity index (DAI) score, and decreased myeloperoxidase (MPO) content. Notably, AM pre-treatment attenuated the production of pro-inflammatory cytokines, including interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6, in mice with DSS-induced colitis. Additionally, AM pre-treatment significantly enhanced the expression of tight junction proteins (Occludin and ZO-1), thereby preserving gut barrier function. Moreover, we observed that AM administration decreased the ratio of Th17 cells while increasing the frequency of colonic Treg cells, thus modulating the Th17/Treg balance both in vivo and in vitro. Furthermore, in the AM-treated group, the expression of Notch-1, Jagged1, delta like 4 (DLL4), phospho-janus kinases 2 (p-JAK2)/JAK2, and p-signal transducer and activator of transcription 3 (STAT3)/STAT3 in colonic tissue was reduced compared to the DSS group. Remarkably, the therapeutic effects of AM in colitis mice were blocked by a Notch activator. Conclusion: These findings underscore the effectiveness of AM in alleviating symptoms and pathological damage in DSS-induced colitis mice by rebalancing Th17/Treg cell homeostasis through modulation of the Notch and JAK2/STAT3 signaling pathways. These insights into AM's mechanisms of action offer potential avenues for novel therapeutic strategies.
ABSTRACT
The Mg-Al-RE series heat-resistant magnesium alloys are applied in automotive engine and transmission system components due to their high-temperature performance. However, after serving at a high temperature for a long time, the Al11RE3 phase coarsened and even decomposed, while the Mg17Al12 phase grew and dissolved, which limits the service temperature of Mg-Al-RE series heat-resistant magnesium alloys to a maximum of 175 °C. In this study, a new preparation method for in situ AlN particles was presented. The AlN/Mg-4Al-4La-0.3Mn composites were prepared by a master alloy and casting method. The effects of various contents of AlN (0.5-3.0 wt.%) on the microstructure and mechanical properties of the Mg-4Al-4La-0.3Mn (AE44) alloy at room (25 °C) and high temperatures (150-250 °C) were investigated. Microstructure analysis revealed that the inclusion of AlN led to a reduction in both the grain size and second phase size in the AE44 alloy, while also improving the distribution of the second phase. The average grain size, Al11La3 phase, Al2La phase, and Al3La phase of the 2.0 wt.% AlN/AE44 composite were 135.7, 9.6, 1.9, and 12.6 µm, respectively, which were significantly lower than those of the AE44 matrix alloy (179.8, 12.6, 3.3, 17.8 µm). The refinement was attributed to the ability of AlN particles to serve as heterogeneous nucleation cores for α-Mg and, at the same time, impede the growth of the solid-liquid interface, eventually leading to grain refinement. With the increase in the AlN content, the mechanical properties of composites initially exhibited an increase at both room and high temperatures, followed by a subsequent decrease. When the AlN content was 2.0 wt.%, the composite exhibited optimal strength and plasticity matching. At room temperature, the TYS, UTS, and EL values of the 2.0 wt.% Mg-4Al-4La-0.3Mn composite were 96 MPa, 175 MPa, and 7.0%, respectively, which were increased by 26 MPa, 27 MPa, and 0.7% when compared with the base alloy. The TYS of the 2.0 wt.% Mg-4Al-4La-0.3Mn composite at 150 °C, 200 °C, and 250 °C were 17 MPa, 14 MPa, and 22 MPa higher than those of the matrix alloy, respectively. The main strengthening mechanisms were second phase strengthening, load transfer strengthening, and thermal mismatch strengthening. At elevated temperatures, AlN particles effectively pinned the grain boundaries, inhibiting their migration, and hindered dislocation climbing, resulting in excellent mechanical properties of the composites at high temperatures. This study contributes to the advancement of in situ AlN particle preparation methods and the exploration of effects of AlN on the properties and microstructure of Mg-Al-RE alloys at high temperatures (150-250 °C).
ABSTRACT
As the main pathogen associated with enzootic pneumonia (EP), Mycoplasma hyopneumoniae (Mhp) is globally prevalent and inflicts huge financial losses on the worldwide swine industry each year. However, the pathogenicity of Mhp has not been fully explained to date. Mhp invasion usually leads to long-term chronic infection and persistent lung colonization, suggesting that Mhp has developed effective immune evasion strategies. In this review, we offer more detailed information than was previously available about its immune evasion mechanisms through a systematic summary of the extant findings. Genetic mutation and post-translational protein processing confer Mhp the ability to alter its surface antigens. With the help of adhesins, Mhp can achieve cell invasion. And Mhp can modulate the host immune system through the induction of inflammation, incomplete autophagy, apoptosis, and the suppression of immune cell or immune effector activity. Furthermore, we offer the latest views on how we may treat Mhp infections and develop novel vaccines.
ABSTRACT
Previous research has established a correlation between PM2.5 exposure and aging-related cardiovascular diseases, primarily in blood vessels. However, the impact of PM2.5 on cardiomyocyte aging remains unclear. In this study, we observed that extractable organic matter (EOM) from PM2.5 exposure led to cellular senescence in H9c2 cardiomyoblast cells, as characterized by an increase in the percentage of ß-galactosidase-positive cells, elevated expression levels of p16 and p21, and enhanced H3K9me3 foci. EOM also induced cell cycle arrest at the G1/S stage, accompanied by downregulation of CDK4 and Cyclin D1. Furthermore, EOM exposure led to a significant elevation in intracellular reactive oxygen species (ROS), mitochondrial ROS, and DNA damage. Supplementation with the antioxidant NAC effectively attenuated EOM-induced cardiac senescence. Our findings also revealed that exposure to EOM activated the aryl hydrocarbon receptor (AhR) signaling pathway, as evidenced by AhR translocation to the nucleus and upregulation of Cyp1a1 and Cyp1b1. Importantly, the AhR antagonist CH223191 effectively mitigated EOM-induced oxidative stress and cellular senescence. In conclusion, our results indicate that PM2.5-induced AhR activation leads to oxidative stress, DNA damage, and cell cycle arrest, leading to cardiac senescence. Targeting the AhR/ROS axis might be a promising therapeutic strategy for combating PM2.5-induced cardiac aging.