Volatile Inhibitors Research Articles

Exposure to volatile ferroptosis inhibitor, TEMPO, reduced cutaneous ischemia-reperfusion injury progression to pressure ulcer formation in a mouse model

BackgroundIschemia– reperfusion (I/R) injury-induced oxidative stress is a key factor in the pathogenesis of pressure ulcer formation. Ferroptosis is an iron-dependent programmed cell death that connects oxidative stress and inflammation in various diseases. Recent studies revealed the protective effect of inhibition of ferroptosis in I/R injury. However, the role of ferroptosis in cutaneous I/R injury remains elusive. ObjectiveTo assess the role of ferroptosis in the progression of cutaneous I/R injury. MethodsCutaneous I/R injury experiments and histopathological studies were performed in wild-type mice with or without exposure to volatile ferroptosis inhibitor, TEMPO (2,2,6,6-Tetramethylpiperidine-1-oxyl). The suppressive effects of TEMPO on ferroptosis inducing cell death and oxidative stress were examined in vitro. ResultsInhibition of ferroptosis with TEMPO significantly reduced ulcer formation after cutaneous I/R injury. Fluctuated ferroptosis markers, such as GPX4, ACSL4, and 4-HNE expression in the I/R skin site, were reversed by TEMPO treatment. Inhibition of ferroptosis reduced apoptosis, CD3+ infiltrating lymphocytes, and improved vascularity in the I/R skin site. Inhibition of ferroptosis also suppressed the enhancement of Nrf2 activation. In vitro, ferroptosis and the activation of ferroptosis-related gene expression by RSL3 stimulation were markedly ameliorated by TEMPO treatment in mouse fibroblasts. Inhibiting ferroptosis also suppressed the elevation of the mRNA levels of NOX2 and HO-1 caused by ferroptosis. ConclusionCutaneous I/R injury-induced ferroptosis likely promotes cell death, vascular loss, infiltration of inflammatory cells, and oxidative stress. The inhibition of ferroptosis with TEMPO might have potential clinical application as novel therapeutic agent for cutaneous I/R injury.

Mechanism of isoflurane‑mediated breast cancer growth in vivo.

Use of volatile anesthetics is associated with worse outcome following tumor resection surgery compared with the use of intravenous anesthetics. However, the underlying mechanism has not been clearly delineated yet in vivo. The EO771 cell-based congenic breast cancer model was used in the present study. Isoflurane directly binds to and inhibits two adhesion molecules, leukocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1). Similarly, exposure to sevoflurane, another volatile anesthetic and LFA-1 inhibitor, is associated with an increase in breast cancer size compared with non-exposure. Thus, the present study first examined the role of LFA-1 and Mac-1 in the EO771 breast cancer model. Both LFA-1 deficiency and inhibition enhanced tumor growth, which was supported by cytokine and eicosanoid data profiles. By contrast, Mac-1 deficiency did not affect tumor growth. The exposure to isoflurane and sevoflurane was associated with an increase in breast cancer size compared with non-exposure. These data suggested that isoflurane enhanced tumor growth by interacting with LFA-1. Isoflurane exposure did not affect tumor growth in LFA-1-deficient mice. In summary, the present data showed that LFA-1 deficiency facilitated breast cancer growth, and isoflurane, an LFA-1 inhibitor, also increased breast cancer growth.

Black cumin and clove: Litholytic volatile compounds and inhibitors of inflammation-induced gallstone

Gallstones are a serious and widespread disease of the biliary system, which remain a costly disease and the major cause of hospital admissions for gastrointestinal problems. Natural products are a rich source of different volatile compounds such as terpenes that were found to be good dissolving solvents. Whereas, the potential of essential oils and their aromatic constituents has been rarely reported. Herein, we studied for the first time the litholytic activity of essential oils from Nigella sativa and Syzygium aromaticum, and their main compounds; p-cymene (49.25 %) and eugenol (49.92 %), respectively. The gallstone samples were classified as cholesterol and pigment types, using FTIR spectroscopy and UV-spectrophotometer analyses. All samples caused a deterioration in the morphological appearance of cholesterol gallstones with no effect on pigment gallstones. These volatile compounds, seem promising litholytic solvents as they reproduce better or close dissolving capacity to Methyl tertbutyl ether (MTBE) standard. Black cumin essential oil manifested with remarkable litholytic activity reached to a dissolution capacity of 90.07 ± 5.58 %, higher than that of clove with 59.52 ± 5.86 %, and that of MTBE standard (84.86 ± 2.93 %). Fascinating, p-cymene produced the most remarkable litholytic activity of 97.68 ± 2.11 %, leading to almost a total dissolution of the cholesterol gallstone sample, while that of eugenol was of 75.92 ± 6.02 %. The in-silico study suggested a strong lipoxygenase-inhibitory of eugenol compared with zileuton standard. The molecular docking experiments revealed that the important affinity of eugenol involving both hydrophobic and hydrogen bond interactions with human 5-lipoxygenase (5-LOX). Our study highlights for the first time the importance of aromatic structures from essential oils in gallstone dissolution. Eugenol and p-cymene contributed mainly to the activity of their essential oils, and could be effective litholytic agents able also to prevent gallstone formation through their potential anti-inflammatory intervention in the gallbladder.

Vapor–Gas Deposition of Polymer Coatings on Metals from Azeotropic Solutions of Organosilanes

The mechanism of the vapor–gas deposition of vinyltrimethoxysilane (VS) and ethylene glycol (EG) from azeotropic solutions is investigated, which allows a reduction of the evaporation temperature of the components of working mixtures. The need for such studies is associated with the development of a new direction in the technology of vapor–gas deposition of polymer coatings. Methods have been developed for monitoring the chemical composition of working solutions in evaporators using optical spectroscopy, which makes it possible to calculate the partial pressures of vapor-phase components. Based on these studies, compositions of working solutions are proposed that allow the equalization of the partial pressures of the components of working mixtures with a large difference in the boiling point. With the aid of vapor–gas deposition, siloxane coatings on low-carbon steel were obtained, the protective properties of which exceeded the treatment with volatile inhibitors of the adsorption type by two to three orders of magnitude. A new method of vapor–gas deposition of non-volatile powder inhibitors on metals is proposed. Chemical compositions of siloxane coatings were determined using XPS, and mechanisms of interaction of VS with the polymerization promoters ethylene glycol and 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP) were proposed.

Small Volatile Inhibitors Targeting LncRNA in Radioresistant Non-small Cell Lung Cancer

Background and objectivesRadiotherapy is the most crucial nonsurgical therapeutic method in the multidisciplinary care of non-small cell lung cancer (NSCLC) patients. However, radiation resistance continues to be a significant clinical issue, negatively affecting cancer prognosis in patients. The small molecules that target these RNAs offer therapeutic modulation of multiple biological processes. The study aims to identify the genes and a long non-coding RNA (lncRNA) regulating their expression and binding potential of small volatile inhibitors to the lncRNA to overcome radioresistance in NSCLC.

Experimental Investigation to Quantify Gas Hydrate Formation during Shutdown in the Wellbore Near the Wellhead: Impact of Thermodynamic Inhibitors

In most cases, concerns about gas hydrates in hydrocarbon production are often associated with shut-in and restart of the production system associated with the fluids in the wellhead and the main flowline. The exposure of the wellhead to cold temperatures during shutdown can cause severe hydrate formation even with stagnant fluid in the wellbore. Similar conditions may exist at the top of the gas line in flowlines for hydrate formation when gas is saturated with water. This study investigated the hydrate deposition kinetics and morphology at 10 MPa (ca. 1400 psi), with the goal of preventing severe solid hydrate formation from the vapor or supercritical phase near the wellhead or a vertical conduit exposed to cold conditions such as road overpass or river crossing during shutdown and providing operating guidelines for hydrate management by understanding the impact of volatile (methanol) and non-volatile (monethylene glycol, MEG) thermodynamic hydrate inhibitors (THIs). These results may also apply to top of line hydrate and its inhibition. It was verified that non-volatile THI is ineffective in preventing hydrate deposition near the wellhead, showing growth behavior of hydrate formation in the presence of MEG similar to that with lower pressure without inhibitors. However, volatile THI prevents hydrate deposition in a cold wellhead even though the experimental condition provides sufficient convection and water condensation. In the warm wellhead, volatile THI does not prevent hydrate formation, but it delays the growth of hydrate deposits. In the presence of volatile THI, the dissociation and reformation of hydrate deposits on the vertical wall are observed. This study provides a quantifiable method for hydrate growth in real-time and insight into better management strategies for THI usage to mitigate hydrate blockage risk near the wellhead.

Oil compositions modified with volatile inhibitor to protect metals against atmospheric corrosion

Новые технологии, Химическая промышленность, Химическая технология, Научные журналы, Защита от коррозии, Технология металлов, Свойства материалов, Технические журналы, Наука и технологии, Справочная литература, Научные разработки

2,2,6,6-Tetramethylpiperidine-1-oxyl acts as a volatile inhibitor of ferroptosis and neurological injury.

Ferroptosis, a type of oxidative stress cell death, has been implicated in cell injury in several diseases, and treatments with specific inhibitors have been shown to protect cells and tissues. Here we demonstrated that a treatment with the nitroxide radical, 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), prevented the ferroptotic cell death in an airborne manner. Other TEMPO derivatives and lipophilic antioxidants, such as Trolox and ferrostatin-1, also prevented cell death induced by erastin and RSL3; however, only TEMPO exhibited inhibitory activity from a physically distant location. TEMPO vaporized without decomposing and then dissolved again into a nearby water solution. Volatilized TEMPO inhibited glutamate-induced cell death in mouse hippocampal cell lines and also reduced neuronal cell death in a mouse ischemia model. These results suggest that TEMPO is a unique cell protective agent that acts in a volatility-mediated manner.

Study of operating properties of aanticorrosion packing papers

Metal products are subjected to atmospheric corrosion during transportation and storing. An important way to prevent this negative phenomenon is application of special packing materials, in particular materials, containing volatile inhibitors of corrosion, which protect metal against various corrosion agents. To protect metal effectively it is necessary to provide a definite level of operating characteristics of packing materials. The purpose of the work was the study of operating properties of inhibited crepe, inhibited and laminated polyethylene film, inhibited crepe and reinforced by polypropylene web papers, manufactured by OJSC “PP TechnoKhim”, Magnitogorsk, used for packing of metals. Structural and dimensional, sorption, deformation and strength characteristics, of the studied anticorrosion papers are presented, the characteristics being calculated based on the results of measurements. To determine their physical-mechanical and anticorrosion properties, standard methods and methodologies were used. To evaluate impact of moisture and transportation conditions, indices of water adsorption and wear of the studied papers were determined. Inhibitor content in these materials was determined by thermogravimetric analysis method. Their protective ability was studied on samples of low carbon steel strip. For accelerated corrosion tests the strip samples were degreased by alcohol, dried in air and packed in the studied anticorrosion papers, after that they were exposed under increased temperatures and moisture conditions. It was determined, that among the materials under the study, the inhibited crepe paper, reinforced by polypropylene web, hhas the best complex of physical-mechanical and anticorrosion properties. It provides a higher level of prevention corrosion of metal l and surpasses other materials in a number of deformation and strength characteristics. Recommendations were proposed to improve qquality of produced anticorrosion papers.

Volatile self-inhibitor of spore germination in pathogenic Mucorale Rhizopus arrhizus.

Rhizopus arrhizus is a common pathogenic Mucoralean mold that exists as a saprophyte, and is disseminated through sporangiospores, which germinate to form mycelia under suitable environmental or infection settings. Such morphological transitions are often mediated by self-produced effector molecules in a density-dependent fashion. This study aimed to elucidate if a quorum-dependent, cell-density-driven phenomenon exists in R. arrhizus, and identify the molecule(s) involved. The germination of R. arrhizus was observed to be reliant on the seeding density, with nearly 71% and 47% germination in Sabouraud dextrose and glucose asparagine media respectively at 1× 105-1× 106 spores/mL, and only 10% and 1% germination respectively with 1× 108 spores/mL. The late-growth-stage supernatant also hindered the spore germination and liquid-culture biomass in a dose-dependent way. These effects were being mediated by a volatile inhibitor present in the headspace and supernatant of R. arrhizus cultures, identified as 2-methyl-2-butene by gas chromatography and electron ionization-quadrupole mass spectrometry. The compound was present in a density-dependent manner and considerably impaired fungal germ-tube emergence and elongation during germination. Spore swelling remained unaffected. Multiple thin protrusions comprising of F-actin and microtubules were seen emanating from the treated cells, suggestive of filopodia-like and cytoneme-like extensions. The same compound was also detected in Rhizomucor pusillus.

Assessment of the protective effectiveness of a volatile inhibitor in atmospheric corrosion of steel under conditions of increased concentrations of carbon dioxide, ammonia and hydrogen sulfide by electrochemical methods

Assessment of the protective effectiveness of a volatile inhibitor in atmospheric corrosion of steel under conditions of increased concentrations of carbon dioxide, ammonia and hydrogen sulfide by electrochemical methods

Chromosomal mutations in Escherichia coli that improve tolerance to nonvolatile side-products from dilute acid treatment of sugarcane bagasse.

Lignocellulosic biomass provides attractive nonfood carbohydrates for the production of ethanol, and dilute acid pretreatment is a biomass-independent process for access to these carbohydrates. However, this pretreatment also releases volatile and nonvolatile inhibitors of fermenting microorganisms. To identify unique gene products contributing to sensitivity/tolerance to nonvolatile inhibitors, ethanologenic Escherichia coli strain LY180 was adapted for growth in vacuum-treated sugarcane bagasse acid hydrolysate (VBHz) lacking furfural and other volatile inhibitors. A mutant, strain AQ15, obtained after approximately 500 generations of growth in VBHz, grew and fermented the sugars in a medium with 50% VBHz. Comparative genome sequence analysis of strains AQ15 and LY180 revealed 95 mutations in strain AQ15. Six of these mutations were also found in strain SL112, an independent inhibitor-tolerant derivative of strain LY180. Among these six mutations, null mutations in mdh and bacA were identified as contributing factors to VBHz tolerance in strain AQ15, based on the genetic and physiological analysis. The deletion of either gene in strain LY180 increased tolerance to VBHz from approximately 30-50% (vol/vol). Considering the location and physiological role of the two enzymes in the cell, it is likely that the two enzymes contribute to the VBHz sensitivity of ethanologenic E. coli by different mechanisms.

Loss of Methanol and Monoethylene Glycol in VLE and LLE: Prediction of Hydrate Inhibitor Partition

Phase equilibria of water–alcohol–hydrocarbons are important when it comes to flow assurance issues in the petroleum industry. Thermodynamic inhibitors [usually alcohols and glycols, such as methanol and monoethylene glycol (MEG)] change the thermodynamic equilibrium, thus avoiding the hydrate zone. Accurate results for the loss of the volatile inhibitor in the gas or condensate phase (partition) are of extreme importance for the oil and gas industry. In this work, a flash algorithm using the cubic-plus-association (CPA) equation of state was developed to estimate the partition of each component (water, hydrate-forming gas, and inhibitor) in any phase over a wide range of temperatures and pressures in vapor–liquid equilibrium and liquid–liquid equilibrium. Different temperature-dependent functions were optimized and evaluated for the CPA binary interaction parameters. The flash algorithm was applied to several systems with water, methane, ethane, propane, carbon dioxide, methanol, and monoethylene glycol ...

Estimation of protective ability, physical and mechanical properties of polymer inhibited films

Metal products are subjected to atmosphere corrosion during transporting and longtime storing. Utilization of packing materials eliminating the access of water vapor and aggressive gases to the metal products surface is an important ways of struggling against the corrosion. Among the methods of metal products protection against the corrosion, application of volatile inhibitors is one of most effective one. As a carrier of the volatile corrosion inhibitors, polyethylene films can be used. Study of strength and barrier properties of polyethylene films with a volatile corrosion inhibitor and without it accomplished. As an object of the study, the films, produced under laboratory conditions by extrusion with blowing of low-density polyethylene and mixture of low-density polyethylene and IFKhAN volatile inhibitor, developed by the Institute of Physical Chemistry (Academy of Sciences of RF). For accelerated corrosion tests, samples of 08пс cold rolled steel used. The prepared samples packed in the studied films, a part of the closed airtight, and another part – not compact. It was traced, that the samples packed in the polyethylene film without the volatile inhibitor, had a point corrosion. The airtight sealed polymer film casings protect the carbon steel much better, comparing with the not compact casings. The surface of samples corrosion worms, which were airtight packed, was 0.15%, not compact ones – 0.33%. When inhibited polymer film was used for not compact packing, the corrosion had a uniform character, no local corrosion worms (pitting) was observed. The corrosion products were spongy, weekly cohered with the basic metal, easily peeling off. During the test period, the samples airtight packed in polyethylene film, containing IFKhAN volatile inhibitors, had no areas of corrosion. It was found, that input of inhibitor into the polyethylene matrix results in decreasing the film strength properties due to formation structure defects at the sub-molecular level during the extrusion, and also as a result of inhibitor desorption.

Universality of volatile corrosion inhibitors applied requirements of agricultural production

Aqualitative and quantitative system of criteria for evaluating the universality of volatile metal corrosion inhibitors (VCIs) applied to agricultural production conditions was developed. The system of qualitative criteria for universalism includes: 1- an assessment of the effectiveness of corrosion inhibition of metals under the conditions of the action of corrosion-specific stimulants present in the vapor- gas phase separately or together; 2 - suppression of various types of local corrosion caused by them in the composition of a corrosive medium; 3 - suppression in specific conditions of general and local corrosion of contacting metallic structural materials of various nature; 4 - observance of acceptable specific characteristics of VCI: ecological, class-related hazards, influence on chemical oxygen consumption (COC) and biochemical oxygen demand for the biodegradation of substances by microorganisms (BOD5). The system of quantitative criteria for universalism of the VCIs includes quantitative parameters for all the proposed qualitative items. A simplified assessment, taking into account only a part of the criteria for characterizing partially universal inhibitors, is proposed to be applied to the conditions of agricultural production. The experimental data for the volatile inhibitor IFKhAN-114 are given as an example of the effectiveness of the proposed criteria. It was shown that IFKhAN-114 is a partially universal inhi-bitor.

Evaluation of the Protective Efficiency of IFKhAN-114 Volatile Inhibitor against Atmospheric Corrosion of Copper by Polarization Measurements

To simulate conditions for evaluating the inhibition efficiency of an IFKhAN-114 volatile inhibitor under atmospheric corrosion of copper in the presence in the air of two corrosion promoters CO2 + NH3 or H2S + NH3, polarization measurements were performed. For this purpose, 0.1 M NaCl solution containing, in a wide range of concentrations, the products of the hydrolysis of ammonium carbonate or ammonium sulfide was used. Comparison of the data obtained through weight loss tests (the first method) and polarization measurements (the second method) showed that the latter approach allows obtaining only qualitative data, which, however, requires significantly less time than the first one.

Suppression of local corrosion of steel, brass and copper with IFKhAN-114 volatile inhibitor

Suppression of local corrosion of steel, brass and copper with IFKhAN-114 volatile inhibitor

Защитная эффективность летучих ингибиторов ИФХАН-118 и ИФХАН-114 по отношению к атмосферной коррозии стали, латуни и меди в присутствии в воздухе повышенных концентраций CO2, H2S и NH3

Защитная эффективность летучих ингибиторов ИФХАН-118 и ИФХАН-114 по отношению к атмосферной коррозии стали, латуни и меди в присутствии в воздухе повышенных концентраций CO2, H2S и NH3

The Influence of the Volatile Ifhan-114 Inhibitor on the Efficiency of a Number of Contact Galvanic Metal Pairs and Rate of Corrosion of Their Constituents in the Atmosphere of Livestock Premises

The protective ability of the volatile IFHAN-114 inhibitor in the corrosion of models of macrogalvanic steel/brass, steel/copper, and copper/brass pairs under conditions simulating the atmosphere of livestock premises is studied. The content of CO2, NH3, and H2S (corrosion stimulators) was 0.2–0.6 vol %, 20–60 mg/m3, and 10–30 mg/m3, respectively. The ability of IFHAN-114 to suppress the generation of the faradaic current by the models of galvanic pairs is investigated. It is shown that the surface of metals forming the galvanic pairs undergoes intensive pitting and ulcer corrosion when there is no inhibitor under the effect of one corrosion stimulator (CS) or simultaneous effect of two or three corrosion stimulators. In most cases, the introduction of IFHAN-114 into the gas phase completely suppresses the local corrosion of metals forming the galvanic pairs and reduces the rate of their general corrosion (which is uniform when the volatile corrosion inhibitor is used) by 2–5 times. The inhibitor introduced into the 0.1 M KCl solution significantly suppresses the density of the current generated by the models of galvanic steel/brass and copper/brass pairs. However, this effect is observed only after 200 min of exposure of the pair models to corrosion.

Influence of the volatile inhibitor ifhan-114 on the efficiency of a number of contact galvanic metal pairs and the rate of corrosion of their constituents in the atmosphere of livestock buildings

Influence of the volatile inhibitor ifhan-114 on the efficiency of a number of contact galvanic metal pairs and the rate of corrosion of their constituents in the atmosphere of livestock buildings