Reactive Capacity Research Articles

Impact of humidity on the adsorption and decomposition of mustard gas simulant on heteroatom-modified nanoporous carbon textiles.

Activated carbon textile (C-Text) was chemically modified to incorporate oxygen- (C-Text-O), nitrogen- (C-Text-ON), and/or sulfur- (C-Text-OS) containing surface functional groups, aiming to enhance their reactive adsorption capacity. The modified textiles were evaluated for their ability to detoxify 2-choloroethyl ethyl sulfide (CEES) in both vapor and liquid phases, under dry and humid conditions. The maximum amount of water adsorbed was directly affected by the surface area (R2 = 0.994) and total pore volume (R2 = 0.986) of the textiles. Pre-adsorbed water played an important role in the catalytic conversion of CEES through hydrolysis to form hydroxyethyl ethyl sulfide (HEES). Basic surface environment provided by nitrogen and sulfur groups promoted this process. Among the modified textiles, C-Text-ON adsorbed CEES with a 23 % increase compared to C-Text (238 mg/g), under humid conditions. Additionally, the presence of basic sites on the C-Text, C-Text-ON and C-Text-OS textiles stimulated the dehydrohalogenation of CEES, leading to the formation of ethyl vinyl sulfide (EVS). These results provide important insights into the interactions between CEES and water-exposed textiles, contributing to the design of more effective protective garments against chemical warfare agents.

A Multifunctional MIL-101-NH2(Fe) Nanoplatform for Synergistic Melanoma Therapy.

Melanoma is an aggressive form of skin cancer, and single-modality treatments often fail to prevent tumor recurrence and metastasis. Combination therapy has emerged as an effective approach to improve treatment outcomes. In this study, we developed a multifunctional nanoplatform, MIL@DOX@ICG, utilizing MIL-101-NH2(Fe) as a carrier to co-deliver the chemotherapeutic agent doxorubicin (DOX) and the photosensitizer indocyanine green (ICG). MIL-101-NH2(Fe) was synthesized via a hydrothermal method. Drug release was evaluated under different pH conditions, and the photothermal effect was tested under near-infrared (NIR) laser irradiation. Hydroxyl radical and reactive oxygen species generation capacities were quantified. Cellular studies using B16F10 cells assessed cytotoxicity, cellular uptake, migration inhibition, and colony formation suppression. In vivo experiments in melanoma-bearing mice evaluated antitumor efficacy and systemic safety through tumor growth inhibition, histological analyses, and toxicity assessments. MIL@DOX@ICG exhibited a uniform octahedral structure with a particle size of approximately 139 nm and high drug loading efficiencies for DOX (33.70%) and ICG (30.59%). The nanoplatform demonstrated pH-responsive drug release and potent photothermal effects. The generation of hydroxyl radicals via the Fenton reaction and reactive oxygen species production under NIR laser irradiation by MIL@DOX@ICG were confirmed. In vitro assessments revealed significant cytotoxicity of MIL@DOX@ICG against B16F10 cells under NIR laser irradiation, with improved efficacy in inhibiting cell proliferation and migration. In vivo studies confirmed the superior antitumor efficacy of MIL@DOX@ICG + NIR treatment, synergistically harnessing chemotherapy, photothermal therapy, photodynamic therapy, and chemodynamic therapy effects while maintaining excellent biocompatibility. Our findings underscore the potential of MIL-101-NH2(Fe) nanoparticles as a versatile and effective platform for synergistic melanoma therapy, offering a promising strategy for overcoming the limitations of conventional treatment modalities.

Preparation and Characterization of Biochar from Coconut Shell Biomass Activated Potassium Hydroxide (KOH)

Biochar made from coconut shell biomass contains constituent elements such as, Al, Si, P, S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ag, Cd, Zr, Br, and Rb. Where the largest components in this biochar are Potassium (K) of 2.17% and Aluminum (Al) of 1.51% and the presence of C-H and C-O groups with the presence of carbon, and has an amorphous material structure. After activation, the constituent components undergo an increase and chemical activation using KOH opens the pores and increases the surface area of biochar, thereby increasing its adsorption and reactivity capacity.

Comprehensive benefit optimization method for photovoltaic inverters participating in distribution network loss reduction by reactive compensation

When a large number of distributed photovoltaic (PV) systems are integrated into the distribution network, power flow becomes bidirectionally fluctuating, resulting in variable line losses. In the scenario of reverse flow, the increase in line loss is particularly significant. The bidirectional reactive power regulation of photovoltaic inverters is an effective approach to reduce losses in the distribution network. However, despite the benefits of reducing losses, reactive power regulation by photovoltaic inverters also incurs additional costs. Therefore, there is a need for research into a comprehensive benefit optimization method for inverters participation in reducing reactive power losses in distribution networks. Firstly, the cost quantification models for the investment, transformation, operation, and lifespan loss of the photovoltaic inverters involved in reactive power loss reduction are established. Secondly, the benefit quantification models for loss reduction and power factor improvement are developed. Thirdly, considering various operational scenarios of both photovoltaic systems and loads, a comprehensive benefit optimization method for photovoltaic inverters participating in reactive power loss reduction in distribution networks is proposed. Finally, through example analysis, the cost and benefit are calculated and fitted in different scenarios, and the optimization calculation is carried out. Compared to the scenario where the photovoltaic inverter operates at the maximum reactive power regulation capacity, the optimized comprehensive benefit is increased by 21.20%. The proposed method is validated to effectively enhance the comprehensive benefits of inverters participation in reactive power loss reduction.

Relevance of oxidative stress for small intestinal injuries induced by nonsteroidal anti-inflammatory drugs: A multicenter prospective study.

Several reports revealed that oxidative stress was involved in the mouse model of nonsteroidal anti-inflammatory drug (NSAIDs)-induced small intestinal mucosal injuries. Thus, we aimed to investigate in the prospective clinical study, that the relevance of oxidative stress balance in small intestinal mucosal injury in NSAIDs users. We prospectively included 60 patients who had been taking NSAIDs continuously for more than 3 months and exhibited obscure gastrointestinal bleeding (number UMIN 000011775). Small intestinal mucosal injuries were assessed by capsule endoscopy (CE), and reactive oxygen metabolites (d-ROMs) levels and oxidant capacity (OXY) adsorbent test were performed to investigate the relevance of oxidative stress balance. More than half of the patients (N = 32, 53%) had small intestinal mucosal injuries by CE, and 14 patients (24%) had ulcers. The incidence of ulcers was relatively higher in nonaspirin users. Serum OXY levels were significantly lower in the mucosal injury group (P = .02), and d-ROM levels were significantly higher in the ulcer group (P < .01). In aspirin users, d-ROM and OXY levels did not differ significantly with respect to mucosal injuries or ulcers. However, in nonaspirin users, OXY level was significantly lower in the mucosal injury group (P = .04), and d-ROM levels were significantly higher in the ulcer group (P = .02). Nonaspirin NSAIDs-induced intestinal mucosal injury is associated with antioxidant systems, resulting in increased oxidative stress.

Optimization and Chemical Characterization of Extracts Obtained from Ferula persica var. latisecta Aerial Parts and Roots and Their Neuroprotective Evaluation.

The genus Ferula has been traditionally used for the treatment of various illnesses, but the potential of Ferula persica var. latisecta against different Alzheimer's disease (AD) hallmarks has never been achieved. In this work, a pressurized liquid extraction (PLE) method was optimized to extract F. persica L. aerial parts and roots. Four different solvents (water, ethanol, ethyl acetate (EtAc), and cyclopentyl methyl ether (CPME)) were first tested, and the extraction yield, total phenolic content, reactive oxygen species scavenging capacity, and acetylcholinesterase (AChE) inhibition activity were evaluated. The results indicated that EtAc and CPME were the best solvents to be used, with the results obtained from the aerial parts being better than those obtained from the root samples. Thereafter, the PLE method was further optimized by combining these solvents in different percentages (100% EtAc, 100% CPME, and 50:50% (v/v) EtAc:CPME) and temperatures (50, 115, and 180 °C). Response surface methodology was then applied to analyze the data, and two optimum extraction conditions were obtained: EtAc:CPME (79:21%) at 180 °C for the aerial parts and 100% CPME at 180 °C for the roots. At these conditions, the total flavonoid content (TFC) and the inhibitory capacities against butyrylcholinesterase (BChE) and lipoxygenase (LOX) enzymes were also evaluated, indicating that the aerial part extracts had higher TFC and LOX inhibitory capacity than the root extracts but lower activity against BChE. The comprehensive LC/GC-MS chemical characterization allowed for the tentative identification of 222 compounds belonging to 66 chemical subclasses, the abundancies of which widely varied depending on the matrix and the extraction conditions used. The results obtained together with the application of advanced statistical analysis and molecular docking simulations suggested several sesquiterpenoids, such as selina-3,7(11)-diene, guaiol acetate, α-cyperone, and farnesyl acetate, as the molecules responsible of the in vitro results observed, with good neuroprotective potential against AD.

PP4.11 – 00077 Long-term antiretroviral treatment reduces the reactivation capacity of HIV-1 reservoir

PP4.11 – 00077 Long-term antiretroviral treatment reduces the reactivation capacity of HIV-1 reservoir

Carboxylic acid-assisted hydration for the preparation of mesoporous magnesium hydroxide/magnesium oxide with ultra-high adsorption performance and selective adsorption: Experiments and DFT investigations

Carboxylic acid-assisted hydration for the preparation of mesoporous magnesium hydroxide/magnesium oxide with ultra-high adsorption performance and selective adsorption: Experiments and DFT investigations

Kirkendall effect enhanced sustained-release Fe-C composites for long-term reductive dechlorination of trichloroethylene: Interfacial reactions and slow-release degradation

Kirkendall effect enhanced sustained-release Fe-C composites for long-term reductive dechlorination of trichloroethylene: Interfacial reactions and slow-release degradation

Construction of the Automatic Control System of a Single-Screw Extruder

The purpose of the work is to build the rational system for regulating technological parameters of the single-screw extruder using the frequency-regulated electric drive with limited use of sensors. This goal is achieved by the way of solving the following problems: development the method for controlling the technological parameters of the extruder with a controllable electric drive; development of a structural diagram of a model for estimating the speed of rotation a rotor of the engine without the use of velocity-type transducers; development of a functional diagram of the vector frequency-regulated electric drive with an observer that is built on the basis of a voltage equation corresponding to the main magnetic flux; development of a simulation model of the system of adjustable electric drive of the extruder and carrying out simulations with using the Matlab software package in the environment of Simulink. The most significant results of the researches are: the proposed algorithm for controlling the technological parameters (dynamic viscosity and pressure) by the way of calculating of the electrical power parameters of the adjustable electric drive of the extruder without the use velocity-type transducers; the functional diagram of the vector frequency-regulated electric drive of the single-screw extruder with the observer that was built on the basis of balance of the reactive capacity provides the necessary values of the technological parameters of the extruder. Changes in dynamic viscosity and pressure in the material, provides flexible adjustment without the use of speed sensors and rational use of electricity.

Green Synthesis and Characterization of Hydroxyapatite Nanorods with Enhanced Antibacterial and Anticancer Properties

This study reports the microwave synthesis of hydroxyapatite nanorods using Lantana camara L. flower extract (LCF-HA) and characterized by FTIR, XRD, TEM and SEM-EDX techniques. The extract coating on the hydroxyapatite nanorods improves the antibacterial efficacy against Gram-positive bacteria. The study also evaluates the mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS) and capacity to induce apoptosis of LCF-HA. It shows that LCF-HA efficiently inhibits the growth of osteosarcoma cells (MG-63) in a dose-dependent manner. The efficacy of LCF-HA in inducing apoptosis in osteosarcoma cells is established by dual acridine orange/ethidium bromide (AO/EB) fluorescence labelling. Additionally, LCF-HA induces an increase in reactive oxygen species (ROS) generation and a reduction in mitochondrial membrane potential (MMP) levels. The findings indicate that derived LCF-HA has significant anticancer efficacy by inducing apoptosis in osteosarcoma cells through enhanced ROS generation, suggesting that derived LCF-HA may serve as a promising therapeutic target for bone cancer cell lines. Furthermore, the study demostrates excellent compatibility with osteoblast cells, highlighting its potential for bone regeneration applications.

Antioxidant and anti-glycation activities of Mandevilla velutina extract and effect on parasitemia levels in Trypanosoma cruzi experimental infection: In vivo, in vitro and in silico approaches

Mandevilla velutina (Mart. Ex Stadelm.) Woodson, known in Brazil as "infalível" and "jalapa", is a medicinal plant native from the Cerrado region (Brazilian Savannah). The underground organ (xylopodium) of this species is prepared as ethanolic extract or infusion and it is commonly used in traditional medicine to treat snake venom. Although, locals and indigenous populations from Cerrado have used M. velutina for the treatment of infection by Trypanosoma cruzi (Chagas' disease). This study aimed to evaluate the in vitro antioxidant and anti-glycation activities of the crude hydroethanolic extract of M. velutina xylopodium. Besides, it aimed to evaluate its effect on parasitemia levels in vivo T. cruzi experimental infection. In addition, this study aimed to determine possible interactions between the main compound of the extract and molecular targets associated with survival and virulence of T. cruzi in silico approaches. Determination of total polyphenols, flavonoids and steroidal aglycones content were performed. In addition, high performance liquid chromatography (HPLC) was carried out to identify main compounds of the extract. Antioxidant activity was determined by DPPH radical scavenging, ferric ion reducing power (FRAP), Thiobarbituric acid reactive species (TBARS) and Oxygen Radical Absorbance Capacity (ORAC) methods. Anti-glycation activity was demonstrated through relative mobility in electrophoresis (RME), determination of free amino groups and inhibition of AGEs formation. Determination of the action of extract in parasitemia levels was performed by T. cruzi experimental infection of mice and nitrite levels were measured in the serum of animals evaluated in this study. Molecular docking analyses of the main compound (Velutinol A) with DNA and molecular targets associated with survival and virulence of T. cruzi. Phytoconstituents evaluation exhibited the presence polyphenols, flavonoids and steroidal aglycone, and HPLC identified the major presence of Velutinol A. Antioxidant and anti-glycation evaluations showed that the extract present significant activity in all methods evaluated. In addition, extract reduced the number of trypomastigotes and increased the survival of treated animals. The treatment using extract showed an interference in the synthesis of physiological nitric oxide as an immune response to infection. In silico assays demonstrated interaction between Velutinol A and DNA and molecular targets of T. cruzi. The results showed that the hydroethanolic extract of M. velutina xylopodium contains bioactive compounds including polyphenols, flavonoids and steroidal aglycones (mainly Velutinol A) of which may be responsible for the antioxidant, anti-glycation and anti-parasitic activity against T. cruzi. Trypanocidal activity of M. velutina compounds may be linked to their influence on NO synthesis during infection and/or their capacity to bind and inhibit molecules associated to virulence and survival of T. cruzi.

Beyond hemoglobin: Critical role of 2,3-bisphosphoglycerate mutase in kidney function and injury.

2,3-bisphosphoglycerate mutase (BPGM) is traditionally recognized for its role in modulating oxygen affinity to hemoglobin in erythrocytes. Recent transcriptomic analyses, however, have indicated a significant upregulation of BPGM in acutely injured murine and human kidneys, suggesting a potential renal function for this enzyme. Here we aim to explore the physiological role of BPGM in the kidney. A tubular-specific, doxycycline-inducible Bpgm-knockout mouse model was generated. Histological, immunofluorescence, and proteomic analyses were conducted to examine the localization of BPGM expression and the impact of its knockout on kidney structure and function. Invitro studies were performed to investigate the metabolic consequences of Bpgm knockdown under osmotic stress. BPGM expression was localized to the distal nephron and was absent in proximal tubules. Inducible knockout of Bpgm resulted in rapid kidney injury within 4 days, characterized by proximal tubular damage and tubulointerstitial fibrosis. Proteomic analyses revealed involvement of BPGM in key metabolic pathways, including glycolysis, oxidative stress response, and inflammation. Invitro, Bpgm knockdown led to enhanced glycolysis, decreased reactive oxygen species elimination capacity under osmotic stress, and increased apoptosis. Furthermore, interactions between nephron segments and immune cells in the kidney suggested a mechanism for propagating stress signals from distal to proximal tubules. BPGM fulfills critical functions beyond the erythrocyte in maintaining glucose metabolism in the distal nephron. Its absence leads to metabolic imbalances, increased oxidative stress, inflammation, and ultimately kidney injury.

Examining the relationship between subjective exercise tolerance and psychophysiological reactivity during physical stress.

It has been hypothesized that one's ability to control impulses aids in sustaining effort despite experiencing painful physical sensations. Physical exercise has been used extensively as an intervention to strengthen the inhibitory control system and protect an individual's cognitive plan of action. It is unclear, however, whether the high levels of exercise tolerance could facilitate inhibitory control under varied stressors. The present study explored the relationship between subjective exercise tolerance and psychophysiological characteristics that indicate reactivity capacity when exposed to the cold pressor test. Thirty-six participants were divided into two groups based on their subjective exercise tolerance profiles. During the test, participants' psychophysiological reactivity was monitored via heart rate variability. Participants were also required to answer questions about their perceptual and affective states at the beginning and immediately after the stress test. The study revealed insights into dominance perception and emotional states among individuals with varying subjective exercise tolerance levels. High-tolerant individuals endured physical discomfort longer (~50 s) and exhibited higher perceived dominance at the outset of the test when compared to their low-tolerant counterparts. Despite differences in task performance, both groups experienced more positive affective states post-task, potentially as a result of a heightened sense of self-accomplishment. Notably, both groups showed similar levels of psychophysiological reactivity, suggesting a protective effect of physical tolerance on ensuing biological responses. Overall, this study sheds light on the complex relationship between exercise tolerance, dominance perception, and psychophysiological reactivity during physically demanding tasks, enriching our understanding of how developing physical tolerance may impact inhibitory control under stress.

Gastrointestinal Self-Adaptive and Nutrient Self-Sufficient Akkermansia muciniphila-Gelatin Porous Microgels for Synergistic Therapy of Ulcerative Colitis.

To realize effective and long-term synergistic therapy of ulcerative colitis (UC) with probiotics, we developed gastrointestinal self-adaptive and nutrient self-sufficient Akkermansia muciniphila (AKK)-gelatin porous microgels (AKK@GPMGs). In AKK@GPMGs, AKK was covered with sequential layers of proanthocyanidins (PAs), mucin (MUC), and phosphatidylcholine (PC) to obtain AKK@PAs-MUC-PC (AKK@PMP), and then encapsulated within the methacrylate-modified gelatin porous microgels. AKK@GPMGs provide sufficient mucus as a nutrition source for AKK and boost resistance to stomach acid by 30.49-fold, and colonization in the intestines is enhanced by 83.46 times. The microgels can be dissociated by matrix metalloproteinase at the inflammatory sites of the intestine, and release AKK@PMP, which acts as "band-aid" that adheres to the inflamed colon for a long time and offers improved synergistic therapy for UC. Compared to uncoated AKK, AKK@GPMGs increase reactive oxygen species scavenging capacity by 26.47 times, improve the intestinal mucus layer thickness by 5.63 times, increase the goblet cells abundance by 3.93 times, reduce intestinal permeability by 5.60 times and significantly enhance beneficial gut microbiota while repressing harmful microbiota. These results indicate that AKK@GPMGs can restore mucus layer and tight junction integrity, reduce inflammation and oxidative stress, and regulate gut microbiota homeostasis to effectively treat intestinal inflammation.

Sputnik V-Induced Antibodies against SARS-CoV-2 Variants during the Dissemination of the Gamma Variant in Venezuela.

The COVID-19 pandemic was characterized by the emergence and succession of SARS-CoV-2 variants able to evade the antibody response induced by natural infection and vaccination. To evaluate the IgG reactivity and neutralizing capacity of the serum of individuals vaccinated with Sputnik V (105 volunteers vaccinated) against different viral variants. IgG reactivity to the Spike protein (S) was evaluated by ELISA. A plaque reduction neutralization test was performed using different viral variant isolates. At 42 days post-vaccination, the frequency of recognition and reactivity to the S protein of the Omicron variant was lower compared to that of the other variants. In general, a higher average neutralization titer was seen against the ancestral variant compared to the variants, especially Omicron. However, some sera exhibited a higher neutralization titer to the Gamma variant compared to the ancestral variant, suggesting unapparent exposure during the clinical trial. Antibodies induced by Sputnik V can recognize, persist, and neutralize SARS-CoV-2 variants, with Omicron being the one that best evades this response. These results represent a unique report on the humoral response induced by a globally lesser-studied vaccine in terms of efficacy and immune escape, offering insights into developing vaccines targeting unknown coronaviruses.

Study on photovoltaic primary frequency control strategy at different time scales

AbstractDuring the participation of photovoltaics in grid frequency regulation, different frequency regulation tasks are required at different time scales. The grid demands that photovoltaics (PVs) improve steady‐state frequency when facing short‐term load fluctuations, while also enhancing frequency response to long‐term environmental and load changes. Therefore, this study takes different time scales as the starting point. First, a two‐stage PV grid‐connected inverter generation system model is established, and an overall control strategy is proposed. Next, for short‐term time scales, a virtual inertia strategy based on direct current (DC) voltage droop control is proposed to utilize the energy storage effect of DC capacitors to suppress frequency fluctuations. For long‐term time scales, a strategy for controlling the variable reactive power reserve capacity is proposed to address the inadequacy of frequency regulation caused by traditional fixed de‐rating rate strategies and redundant standby power. Finally, the effectiveness of the proposed strategies is verified through model validation in MATLAB/Simulink. Simulation results demonstrate the effectiveness of the strategies at different time scales, aiding in improving grid frequency response.

Synthesis, characterization, theoretical, and experimental evaluation of novel imidazolone − based compounds as eco-friendly corrosion inhibitors for mild steel

Synthesis, characterization, theoretical, and experimental evaluation of novel imidazolone − based compounds as eco-friendly corrosion inhibitors for mild steel

Adaptive complex coefficient‐filtered extended states observer type three‐phase enhanced phase‐locked loop

AbstractThis paper proposes an adaptive complex coefficient filtered (CCF) full order extended state observer (ESO) type three phase enhanced phase locked loop (EPLL), which is employed in matrix reactance frequency converter (MRFC) for rotating vectors measurement estimation. EPLL phase detector was analysed first to track not only the rad frequency and transient phase, but also the amplitude of the rotating vectors. Full order ESO can filter out more high frequency disturbance, so it can track frequency and phase more accurately than proportion and integration algorithm. CCF modules were analysed in theory to attenuate the disturbance within two times of the EPLL's cut‐off frequency. The whole adaptive CCF‐ESO‐EPLL design, including stability and parameter tuning were then interpreted. The proposed CCF‐ESO‐EPLL adapts the estimated frequency with CCF to attenuate the MRFC switching non‐linear disturbance as well as unknown disturbance by the full order ESO. The MRFC topology necessary measured vectors, as well as the input side reactive power adjustment capacity, were discussed. The theoretical conclusion has been verified on a MRFC prototype. The proposed CCF‐ESO‐EPLL has less parameter tuning, less computation resource requirement, better steady and dynamic performance, and outstanding disturbance robustness.

Producing a siliceous ferroalloy from a mixture of amorphous rocks

Producing a siliceous ferroalloy from a mixture of amorphous rocks