Significant Suppressive Effect Research Articles

Alkaloids and Iridoids From Phlogacanthus curviflorus.

Four unreported pyridine alkaloids, curviflorines A-D (1-4), two undescribed iridoids, curviridoids A and B (5 and 6), and one known iridoid glycoside (7), were isolated from the twigs and leaves of Phlogacanthus curviflorus. The structures of these compounds were established by detailed interpretation of MS and NMR data, with the absolute configurations being assigned via comparison of experimental and calculated electronic circular dichroism spectra. Notably, it is the first report of alkaloidal constituents (1-4) from the genus Phlogacanthus. Compounds 1-7 did not show obvious inhibitory activities against α-glucosidase and NO production (in RAW264.7 macrophages), nor did they exhibit anti-oxidant activity and cytotoxicity towards MDA-MB231, A549 and HeLa cancer cell lines. Nevertheless, alkaloids 1-4 did exert a significant suppressing effect on TGF-β1-induced upregulation of the fibrotic marker protein fibronectin in HK-2 cells, indicating their antifibrotic potential.

Attempt to Improve MIP Image of Cerebrovascular MRA by Subtraction Method: Efficient Acquisition of Mask Images Using Segmented TOF and Compressed Sensing

The aim of this study was to investigate imaging conditions that allow for the rapid acquisition of mask images used in the subtraction method, one of the depiction improvement methods for brain magnetic resonance angiography, by employing compressed sensing (CS) combined with segmented time-of-flight (TOF). The experiment was performed on healthy volunteers using 3.0T-MRI. We examined the blood flow signal suppression effects in arteries and veins at different numbers of segments. We determined the flip angle at which the signal value of fat in the mask image became equivalent to that in the angio image. We visually assessed the impact of mask images with varying CS factors on subtraction images and determined the optimal CS factor. Effective blood flow signal suppression in arteries and veins was achieved with segment numbers of 12 or fewer, and a flip angle of 18° resulted in equivalent fat signal values. Even with a CS factor set to its maximum value of 12, no degradation in image quality was observed in the maximum intensity projection images. Using segmented TOF with CS, optimal imaging conditions for acquiring mask images for the subtraction method were determined to be segment number 9, flip angle 18°, and CS factor 12.

Assessment of the Anticancer Effects of Simvastatin on Human Osteosarcoma and Colorectal Cancer Cell Lines

Background: Colorectal cancer (CRC) and osteosarcoma (OS) and all other cancers represents one of the most challenger issues to the humanity for long time, due to their associated sever health lesions, emotional and psychological hardships, and significant economic encumbrances. Adding to that, the poor curing fate achieved with current therapeutic strategies of cancer. The invention of new drugs for cancer treatment required long time reaching to years as well as consuming the huge money budget, so that the focusing on the aspect of the repositioning of conventional drugs (like simvastatin) has gradually take a large consideration as they can participate in the alleviation of cancer treatment burden in view of this work promising results and preceding hopeful findings and conclusions have been obtained from the studies conducted in this field. The Aim: assessment of the cytotoxic effects of a lipid lowering drug, simvastatin, in human CRC and OS cells. Methods: SW480 (CRC) and MG-63 (OS) cell lines were utilized in this work and have been treated with various doses of simvastatin, then its cytotoxic effects have been evaluated by MTT assay. Thereafter, the VEGF and GDF-15 suppression effects of simvastatin have been measured in SW480 and MG-63 cells. Results: exposure of CRC and OS cells to simvastatin resulted in significant cellular growth inhibition, and VEGF and GDF-15 suppression effects. Conclusions: Simvastatin has a promising antineoplastic potential and its role in cancer therapy cannot be underestimated, and encourage the utilization and surveying of other preexisting drugs in cancer treatment path.

Effects of chronic empathic stress on synaptic efficacy, as well as short-term and long-term plasticity at the Schaffer collateral/commissural- CA1 synapses in the dorsal hippocampus of rats.

Empathy, the ability to comprehend and share others' emotional states, impacts brain functions. This invivo electrophysiological study explored the influence of chronic empathic stress on synaptic efficacy, as well as short-term and long-term plasticity at the Schaffer collateral/Commissural - CA1 synapses in the dorsal hippocampus of rats, in situations of social equality and inequality. Forty-eight male rats were randomized into six groups: control, pseudo-observer, pseudo-demonstrator, observer, demonstrator, and co-demonstrator(Co, Pse-Ob, Pse-De, Ob, De, Co-De) groups. Stress induction(2h/day, 21 days) was performed in situations of equality and inequality. Serum corticosterone levels, slope, amplitude, and area under the curve(AUC) of field excitatory postsynaptic potentials(fEPSPs) were assessed in the hippocampal CA1 area using input-output(I/O) functions, paired-pulse(PP) responses with different interpulse intervals(IPIs), and long-term potentiation (LTP) after high-frequency stimulation (HFS). The fEPSP slope, amplitude, and AUC significantly decreased in all stress groups, especially in the De and Pse-De groups. These parameters were significantly increased in the Co-De and Ob groups compared to theDe group. Notably, the corticosterone levels strongly confirmed the electrophysiological findings. Chronic empathic stress could disrupt synaptic efficacy and plasticity in the CA1 area. Empathic stress, involving the presence of cagemates in situations of social equality and inequality, can modify long-term plasticity and serum corticosterone levels in demonstrators and co-demonstrators. Under empathic stress related to situations of inequality, freely moving observers may influence the demonstrators' stress experience. Therefore, the presence of a conspecific in the social inequality conditions had significant suppressive effects on long-term plasticity, while conversely, under equality conditions, long-term plasticity was favorably improved through social buffering.

Study on the Resonance Characteristics and Active Damping Suppression Strategies of Multi-Inverter Grid-Connected Systems Under Weak Grid Conditions

When a multi-inverter grid-connected system is influenced by the parasitic parameters of LCL-type inverters and the impedance of the connected system’s lines, its resonance characteristics become more complex and difficult to predict. For LCL-type multi-inverter grid-connected systems, a mathematical model that considers the effects of parasitic parameters and line impedance has been established, leading to the derivation of the system’s Norton equivalent circuit and a general expression for the inverter output current. The resonance characteristics of multi-inverter grid-connected systems composed of inverters with the same and different parameters were analyzed under the influence of parasitic parameters and line impedance. To suppress the resonance in multi-inverter grid-connected systems and address the issue of traditional PI control not meeting grid requirements for LCL-type grid-connected inverters, a strategy combining superhelical sliding mode control with active damping was adopted. To verify the practical performance of the adopted resonance suppression strategy in complex environments, a grid-connected system model containing two LCL-type inverters was constructed using the MATLAB/Simulink software platform, followed by simulation analysis. The simulation results strongly confirm the feasibility and effectiveness of the adopted resonance suppression strategy, considering the effects of parasitic parameters and line impedance. This strategy demonstrates significant suppression effects in addressing resonance issues caused by parasitic parameters and line impedance, effectively enhancing the quality of grid-connected electrical energy.

Efficacy of L-arabinose in managing cucumber Fusarium wilt and the underlying mechanism of action.

Cucumber Fusarium wilt (CFW), triggered by Fusarium oxysporum f. sp. cucumerinum, leads to substantial yield reductions in global cucumber (Cucumis sativus L.) production. Common management strategies for CFW include soil fumigation, grafting, and crop rotation. However, these methods have limitations regarding safety and efficacy stability, necessitating the development of new, cost-effective, and eco-friendly control strategies. Our prior research demonstrated that L-arabinose, an inexpensive and safe sugar commonly used in food and beverages, effectively suppressed bacterial wilt in tomatoes. This study explores the potential of L-arabinose in managing CFW and investigates its mechanism of action. Soil applications of L-arabinose, ranging from 0.00001 to 0.01%, effectively suppressed CFW. The most significant suppressive effect was observed at 0.01%, reducing the disease severity index by 67.5% compared to the control treatment. Microscopic examination of transverse root sections showed that pathogen hyphae colonized the epidermis but seldom penetrated the cortical layer of roots in L-arabinose-treated seedlings. In contrast, the entire root tissue of control seedlings was colonized by the pathogen. Quantitative real-time PCR revealed a significant increase in the expression of defense-related genes dependent on salicylic acid, jasmonic acid, and ethylene in L-arabinose-treated plants compared to control plants, 6 and 10 days post pathogen inoculation. This study demonstrated that soil application of L-arabinose can effectively suppress CFW by priming root tissues for multiple defense signaling pathways. Therefore, L-arabinose holds potential as a new fungicide for managing CFW. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Integrative Gut Microbiota and Metabolomic Analyses Reveal the PANoptosis- and Ferroptosis-Related Mechanisms of Chrysoeriol in Inhibiting Melanoma.

Chrysoeriol, a natural flavonoid, has shown potential in inhibiting melanoma. However, the detailed molecular mechanisms of its action still need to be clarified. In this study, chrysoeriol showed significant suppressive effects on melanoma progression in a mouse model. The integrative gut microbiota and metabolomic analyses revealed that chrysoeriol modulates multiple pathways associated with apoptosis, necroptosis, pyroptosis, and ferroptosis. Morphological changes in chrysoeriol-treated melanoma cells showed PANoptosis- and ferroptosis-related characteristics. Additionally, chrysoeriol induced apoptosis, altered mitochondrial membrane potential, increased ROS production, promoted necroptosis, and also upregulated molecules linked to pyroptosis and ferroptosis. Molecular-level experiments confirmed that chrysoeriol promoted the upregulation of crucial proteins associated with the PANoptosis and ferroptosis pathways. Inhibition of PANoptosis and ferroptosis pathways by inhibitors or gene knockdown significantly attenuated the inhibitory effects of chrysoeriol on melanoma cell viability. This study provides robust evidence that chrysoeriol triggers both PANoptosis and ferroptosis in melanoma cells, underscoring its promise as a treatment option for melanoma.

Revealing the flame inhibition effect of phytic acid (PA) by PIV measurements and detailed chemical kinetic modeling of counterflow CH4/PA/air flames

As industrialization continues to deepen, polymers have become ubiquitous in daily life. However, their flammable characteristics pose significant safety risks. Therefore, supporting the global goal of sustainable development necessitates the development of high-performance, environmentally friendly flame retardants. Biomass phytic acid (PA) has emerged as a promising option because of its high phosphorus content and excellent biocompatibility. However, its combustion behaviors and chemical kinetic mechanisms remain unclear. In this study, quantum chemical calculation methods were used to construct a detailed PA chemical reaction kinetic model. A series of experiments were conducted to validate the model and evaluate PA's flame suppression effect. Utilizing a counterflow flame burner and particle image velocimetry (PIV), the inhibitory effect of various PA concentrations was examined based on the laminar flame speed of CH4/PA/Air mixture. The results revealed that a merely 0.2 % addition of PA could reduce the laminar flame speed by 38.9 %, demonstrating its significant flame suppression effect. Building on the foundational GRI-Mech 3.0 and integrating PA's pyrolysis and reaction mechanism, this study developed for the first time a detailed chemical model of CH4/PA/Air combustion. This model integrated PA's thermal decomposition module and thermodynamic data via ab-initio quantum chemical calculations, thereby accurately predicting global kinetic indicators such as laminar flame speed. Results suggested that the key reactions, such as PO2+H + M→HOPO + M, HOPO2+H→PO2+H2O, and HOPO + OH→PO2+H2O primarily influenced the laminar flame speed. Moreover, the CFD simulation elucidated the complex interaction between PA and flame structures. A detailed analysis of the spatial distribution of key parameters such as temperature, combustion radicals, and effective inhibition radicals unveiled the PA's flame suppression mechanism in support of the practical application of this eco-friendly flame retardant.

Experimental exploration of methane-coal dust explosion suppression by expandable graphite: From the point of view of pressure, flame, spectrum, and flow field

Expandable graphite (EG) has been proposed as a more efficient material for suppressing methane-coal dust explosions. The suppression effect was evaluated based on pressure, flame, spectrum, and flow field. The influence of particle size, expansion ratio, and suppressant concentration on the suppression effect was considered, and the suppression mechanism was analyzed. The explosion characteristics and OH* emission spectrum indicated that EG effectively suppressed methane-coal dust explosions. Higher concentrations, smaller particle sizes, and higher expansion ratios resulted in a stronger suppression effect. The influence of EG parameters on suppression effectiveness was ranked from highest to lowest in terms of the concentration, particle size, and expansion ratio. Schlieren imaging showed that EG can partially suppress the initial flame. However, the significant suppression effect occurs during the pressure-increase stage. The flow field was also analyzed using proper orthogonal decomposition. The results showed that EG suppressed flow-field fluctuations, with the mode coefficient trends aligned closely with the pressure-change curve.

Precursor-Directed Biosynthesis of Panepoxydone Derivatives with Nitric Oxide Production Inhibitory Activity.

Panepoxydone is a natural NF-κB inhibitor isolated from basidiomycetes belonging to the genus Panus and Lentinus. It is biosynthesized from prenylhydroquinone through successive hydroxylation, epoxidation, and reduction reactions. In this study, we establish an efficient precursor-directed biosynthesis strategy for the structural expansion of panepoxydone based on its biosynthetic pathway. Supplementation of the panepoxydone-producing strain, Panus rudis, with various prenylhydroquinone analogues enabled the production of fourteen previously undescribed panepoxydone derivatives, panepoxyquinoid A-N (2-14). The obtained panepoxydone derivatives together with their parental molecules were evaluated for their inhibitory activity on LPS-induced NO production in RAW 264.7 cells. Compounds 1, 5-6, 10-11, and 14-15 displayed significant suppressive effects on LPS-induced NO production with IC50 values ranging from 4.3 to 30.1 μM.

Influence of suppressed blistering by heavy ion pre-damage on deuterium retention in tungsten

Surface damage and fuel retention are one of the major threats to the performance of plasma-facing materials (PFMs) in ITER and future fusion reactors. This work aims to investigate the influence of suppressed blistering by heavy ion pre-damage on deuterium (D) retention in tungsten (W). Recrystallized W samples were irradiated with 3.5 MeV iron (Fe13+) ions at room temperature to create displacement damage with a peak damage level of 0.1 dpa. Afterwards, a series of low-energy (38 eV) D plasma exposures were performed at 500 K. Three exposure fluences below and above the blistering threshold (5 × 1024 ∼ 3 × 1025 D m−2) of the pre-damaged W are selected to decouple and couple the damage-induced defects and blistering-induced defects, respectively. Surface observations show that no blisters are formed in un-damaged W after low-fluence D exposure (5 × 1024 D m−2), whereas severe blistering (surface coverage ratio: 34.2 %) occurs in the high-fluence case (3 × 1025 D m−2). In contrast, only a small number of blisters (4.2 %) are formed in Fe-damaged W when D fluence reaches 3 × 1025 D m−2. Moreover, Fe pre-damage increases D retention by a factor of 3.33 and 1.20 at the low-fluence (5 × 1024 D m−2) and medium-fluence (1 × 1025 D m−2) D exposure, respectively. While in the high-fluence case (3 × 1025 D m−2), the enhancement effect of D retention in Fe-damaged W is significantly weakened, such that retention is lower for damaged W, probably due to the significant suppression effect on surface blistering and its accompanying defect formation. This work highlights the suppressed blistering-induced D retention by pre-existing damage in W.

The suppression effect of a vertical baffle on three-dimensional swirling and chaotic sloshing in a laterally excited square-based tank

In order to systematically investigate the suppression effect of a vertical baffle on three-dimensional (3D) swirling and chaotic sloshing in a square-based tank subjected to horizontal harmonic excitation, hundreds of experiments are conducted in a clean tank and baffled tanks with three different configurations. Specifically, the vertical baffle is mounted on the tank bottom parallel to the longitudinal direction, the transverse direction, or the diagonal direction. This experimental work finds that there are four sloshing wave regimes in a clean tank—planar, square-like, swirling, and chaotic—which can be described by the asymptotic multimodal theory. Furthermore, there are only two wave regimes in a longitudinal-baffle tank, the planar and swirling regimes, and the occurrence of swirling requires that the excitation amplitude is sufficiently large. It is confirmed that the longitudinal baffle has a significant suppression effect on the swirling and chaotic motions of the sloshing waves, even though it is parallel to the direction of tank movement. Furthermore, the suppression effect of the diagonal baffle is similar to but somewhat smaller than that of the longitudinal baffle. However, when the transverse baffle is mounted on the bottom of the tank, it is difficult to excite the rotation of the sloshing wave. Therefore, the suppression effect of a bottom-mounted baffle depends largely on the included angle between the vertical baffle and the tank movement direction.

Discovery of 2-Aryl-4-aminoquinazolin-Based LSD1 Inhibitors to Activate Immune Response in Gastric Cancer.

LSD1 (histone lysine-specific demethylase 1) has been gradually disclosed to act as an immunomodulator to enhance antitumor immune response. Despite the identification of numerous potent LSD1 inhibitors, there remains a lack of LSD1 inhibitors approved for marketing. Novel LSD1 inhibitors with different mechanisms are therefore needed. Herein, we reported a series of novel quinazoline-based LSD1 inhibitors. Among them, compound Z-1 exhibited the best LSD1 inhibitory activity (IC50 = 0.108 μM). Z-1 also acted as a selective and cellular active as an LSD1 inhibitor. Furthermore, Z-1 promoted response of gastric cancer cells to T-cell killing effect by decreasing PD-L1 expression and further attenuated the PD-1/PD-L1 interaction. In vivo, Z-1 exhibited significant suppression effect on the growth of gastric cancer cells without obvious toxicity. Therefore, Z-1 represents a potential novel immunomodulator that targets LSD1, providing a lead compound with new function mechanism for gastric cancer treatment.

Emotional exhaustion behind the badge: Examining the effects of affective commitment, surface acting, and gender among police personnel

Public service organizations, such as the police, place great value on employee commitment because the public interest is at stake. While previous literature establishes a negative association between affective commitment and emotional exhaustion, the underlying mechanism remains insufficiently explored. Drawing on the perspective of emotional labor, this paper investigates whether surface acting, which refers to the feigning of expected emotions, mediates the impact of affective commitment on emotional exhaustion among police personnel. Furthermore, the study aims to explore whether this mediating effect is influenced by gender. The dataset utilized in this research comprises responses obtained from a survey administered to 465 police officers employed by the Taipei City Police Department. Our findings reveal a significant suppression effect of surface acting in the affective commitment-emotional exhaustion relationship, suggesting that surface acting, as a result of low affective commitment, has a detrimental impact on emotional well-being. Interestingly, the effects of affective commitment and surface acting on emotional exhaustion are stronger in male police officers compared to their female counterparts. In summary, the results of this study contribute to the existing literature and have broader implications for high-stress work environments. The findings provide insights into how organizations can better support the well-being of their employees by promoting commitment and addressing surface acting. Moreover, the study underscores the importance of considering gender differences in understanding the impact of these variables on emotional exhaustion among police personnel.

Tri-source integrated adenosine triphosphate complexed copper ions anchored to boron nitride surfaces for enhancing flame protection of waterborne epoxy coatings

The abundant C, P, and N elements in the structure of adenosine triphosphate (ATP) can act as carbon, acid, and gas sources, and thus can be used as an efficient intumescent flame retardant. Here, a layer of polydopamine (PDA) with polyhydroxyl groups was firstly loaded on the surface of BN to provide a bridging effect for the surface modification of BN. Then, ATP-Cu was immobilized on the BN surface by complexation of ATP with Cu2+, resulting in an efficient inorganic-organic-metal composite flame retardant (BNP@ATP-Cu). This composite flame retardant effectively combined the high barrier effect of BN, the high swelling property of ATP and the catalytic carbon formation activity of Cu2+. The experimental results revealed that the EP loaded with BNP@ATP-Cu showed the lowest backside temperature (171.2 °C), indicating the highest thermal barrier effect. Moreover, BNP@ATP-Cu/EP exhibited the most significant swelling characteristics (22.7 mm, 17.46) and smoke suppression effect (42.8 %). In contrast, the carbon residue of BNP@ATP-Cu/EP (30.8 %) was significantly higher than that of the other coated samples, which was related to the combined effect of BN and ATP-Cu. The above relevant results fully demonstrated the effectiveness of the composite flame retardants in improving the fire resistance of epoxy coatings.

Modulation of M1/M2 Cytokines and Inflammatory Enzymes by Persicaria Species Leaf Extracts in Lipopolysaccharide-stimulated RAW 264.7 Cell Macrophages.

Investigating the impacts of plant-based substances on the regulation of pro-inflammatory M1 and anti-inflammatory M2 cytokines could have significant implications for immune-related health conditions. Seven Persicaria plant species from sub-Saharan Africa were specifically selected for analysis, based on their traditional use in treating inflammation. To investigate the inhibitory effects of methanol leaf extracts from selected plants on enzymes involved in chronic inflammation. The inhibition of nitric oxide production, acetylcholinesterase activity, and 15-lipoxygenase activity was assessed using the Griess reagent method, Ellman's colorimetric method, and the ferrous oxidation-xylenol orange assay. The quantity of M1/M2 cytokines released was quantified using a flow cytometer. At a concentration of 50 µg/mL, the methanol extracts of P. limbata exhibited the highest NO inhibition (97.67%), followed by P. nepalensis (93.06%) and P. setosula (92.78%). The NO inhibition caused by the plant extracts was correlated directly with the decrease in NO release by the LPS-stimulated macrophages. Furthermore, the pro-inflammatory enzyme assays indicated that the methanol extracts of P. setosula exhibited the highest enzyme inhibitory activity (LOX 89.59%, AChE 72.12 %). This was followed by P. limbata (with 92.76% for LOX and 56.93% for AChE) and P. nepalensis (with 88.16% for LOX and 47.17% for AChE). Cytokine assays revealed that the extracts of P. limbata had significant dose-dependent suppressive effects on IFN-γ and TNF-α expression while promoting the secretion of IL-2, IL-4, IL-6, and IL-10. Extracts of P. limbata contain immunomodulatory compounds that could be further explored as potential remedies to target the molecular drivers of chronic inflammation.

Modeling and compensation of a hollow XY stage based on hybrid reluctance actuators

In the field of beam pointing and optoelectronic imaging, there is a growing demand for control mechanisms that offer large stroke, and high bandwidth. These are precisely the characteristics of hybrid reluctance actuator, which therefore is increasingly being used in XY stage to replace piezo-actuator and voice coil motor. This study presents a hollow XY stage utilizing hybrid resistance actuators, aiming to adapt to optical applications with inherent nonlinearity and biaxial coupling, which are further modeled and compensated to mitigate their impacts. Firstly, the basic composition and working principle of the hollow XY stage are described, and the impact of its nonlinearity and biaxial coupling characteristics is elucidated. Secondly, the sources of nonlinearity and biaxial coupling are analyzed, and an analytical model of hybrid reluctance actuators is established. The magnetic leakage coefficient of the model is determined, and the accuracy of the model is verified by Finite Element Method (FEM) and experiment, demonstrating consistency with the analytical model's results. Furthermore, based on the nonlinear and biaxial coupling model, a compensator based on feedback linearization method is established, and verified through experiment. The results show that this method has a significant suppression effect on nonlinear and biaxial coupling, and the tracking error and cross-talk is obviously reduced, which proves the effectiveness of this compensation method.

A novel biomarker GATM suppresses proliferation and malignancy of cholangiocarcinoma cells by modulating the JNK/c-Jun signalling pathways

BackgroundCholangiocarcinoma (CCA) is the second most common primary malignancy of the liver and is associated with poor prognosis. Despite the emerging role of glycine amidinotransferase (GATM) in cancer development, its function in CCA remains elusive. This study investigated the biological significance and molecular mechanisms of GATM in CCA. MethodGATM expression was measured using immunohistochemistry and western blotting. Cell proliferation, migration, and invasion were assessed through CCK-8, EdU, clone formation, wound healing, and Transwell assays. Rescue experiments were performed to determine whether the JNK/c-Jun pathway is involved in GATM-mediated CCA development. Immunoprecipitation and mass spectrometry were performed to screen for proteins that interact with GATM. The role of GATM in vivo was investigated according to the xenograft experiment. ResultGATM expression was downregulated in CCA tissues and cells (p < 0.05) and had a significant suppressive effect on CCA cell proliferation, migration, and invasion in vitro as well as on tumour growth in vivo (p < 0.05); conversely, GATM knockdown promoted these phenotypes (p < 0.05). Notably, GATM inhibited the JNK/c-Jun pathway, and JNK activation abrogated GATM's antitumor effects (p < 0.05). Isocitrate dehydrogenase 1 (IDH1) interacts with GATM, and IDH1 knockdown significantly attenuated GATM protein degradation. Overexpression of IDH1 restored the biological function of CCA by reversing the inhibition of JNK/c-Jun pathway phosphorylation by GATM (p < 0.05). ConclusionGATM acts as a tumour suppressor in CCA by regulating the phosphorylation of the JNK/c-Jun pathway. IDH1 interacted with GATM to regulate CCA progression.

EFFECT OF ADDING N2/H2O TO ETHYLENE LAMINAR DIFFUSION FLAME ON SOOT FORMATION

Abstract The method of adding exhaust gas to fuel to reduce soot and NOX is called Exhaust Gas Recirculation (EGR). This paper was carried out to investigate the effect of adding N2 and H2O to the fuel side to dilute ethylene on soot generation in laminar diffusion flame by combining experiment and numerical simulation. In the experiment, the flame was optically detected, and the volume fraction of soot and temperature was reconstructed. The numerical simulation adopts a simplified GRI-Mech 3.0 ethylene 23-step combustion reaction mechanism. It introduces virtual species FX (F1H2O, F2H2O, F3H2O) to isolate the effects of H2O addition on thermal, transport, chemical, and density effects. The results show that the numerical values agree well with the experimental results. At the same dilution ratio, the direct involvement of H2O in the reaction affects the flame temperature and intermediate products, leading to a more significant suppressing effect on soot than N2 dilution. After decoupling the effects of H2O, it was found that there are two main reasons for the decrease of soot caused by the addition of H2O. The first is the dilution effect and thermal effect, which hinder the HACA reaction by reducing the concentration of intermediate component C2H2, greatly inhibiting the surface growth rate of soot, and playing a decisive role in reducing the formation of soot. The second is the chemical effect, which mainly enhances the oxidation process of soot by increasing the concentration of OH free radicals during combustion through the elementary reaction OH+H2↔H+H2O. Additionally, the degree of influence of various effects on soot was qualitatively determined as follows: dilution effect &amp;gt; chemical effect &amp;gt; thermal effect &amp;gt; density effect &amp;gt; transport effect.

Investigation on vibration control of TetraSpar floating offshore wind turbine

The stability of offshore wind turbines during operation is crucial, and as an emerging technology, the TetraSpar floating offshore wind turbine demonstrates commendable stability. Moreover, it can effectively reduce the levelized cost of energy (LCOE) in production and installation. However, There is relatively scarce research on its dynamic response and reliability under complex ocean conditions. To reduce the vibration response of floating offshore wind turbines in complex marine environments and improve the stability of the turbines, it is necessary to establish a fully coupled dynamic model to study the multi-field coupled dynamic response and vibration control of the turbines. In light of this, this paper establishes a multi-physical field coupled dynamic model for TetraSpar floating offshore wind turbine through an F2A coupling framework, integrating aerodynamics, servo-elasticity, hydrodynamics, and mooring dynamics. The study analyzes the vibration suppression effects of different Tuned Mass Dampers (TMDs) on the wind turbine system. Using the two main response frequencies, 0.0367Hz and 0.57Hz, in the front and rear directions of the wind turbine as the tuning frequencies for TMD. The best vibration reduction effect was achieved by comparing multiple sets of TMD with different parameters. Analysis shows that TMD can significantly reduce the standard deviation of bending moment and tension of steel bars before and after tower foundation, with maximum values of 38.76% and 73.02%, respectively. At the same time, TMDs also impose a burden on wind turbines, such as a maximum increase of 2.23% in the average values of tower base bending moment, platform pitch, and tower top longitudinal displacement, which also slightly increase under extreme sea conditions. However, compared to the significant vibration suppression effect of TMD, it can be ignored.