Sodium Solutions Research Articles

Atorvastatin improved ulcerative colitis in association with gut microbiota-derived tryptophan metabolism

AimsAtorvastatin is a commonly used cholesterol-lowering drug that possesses non-canonical anti-inflammatory properties. However, the precise mechanism underlying its anti-inflammatory effects remains unclear. Materials and methodsThe acute phase of ulcerative colitis (UC) was induced using a 5 % dextran sulfate sodium (DSS) solution for 7 consecutive days and administrated with atorvastatin (10 mg/kg) from day 3 to day 7. mRNA-seq, histological pathology, and inflammatory response were determined. Intestinal microbiota alteration, tryptophan, and its metabolites were analyzed through 16S rRNA sequencing and untargeted metabolomics. Key findingsAtorvastatin relieved the DSS-induced UC in mice, as evidenced by colon length, body weight, disease activity index score and pathological staining. Atorvastatin treatment reduced the level of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). Atorvastatin also relieved the intestinal microbiota disorder caused by UC and decreased the proliferation of pernicious microbiota such as Akkermansia and Bacteroides. Atorvastatin dramatically altered tryptophan metabolism and increased the fecal contents of tryptophan, indolelactic acid (ILA), and indole-3-acetic acid (IAA). Furthermore, atorvastatin enhanced the expression level of aryl hydrocarbon receptor (AhR) and interleukin-22 (IL-22) and further promoted the expression level of intestinal tight junction proteins, such as ZO-1 and occludin, in colitis mice. SignificanceThese findings indicated that atorvastatin could alleviate UC by regulating intestinal flora disorders, promoting microbial tryptophan metabolism, and repairing the intestinal barrier.

Protective effect of Albizia chinensis saponin on ethanol-induced gastric mucosal injury in rats focus on mucus and mucosal barriers

This study aims to explore the protective effect of Albizia chinensis saponin on ethanol-induced acute gastric ulcer in rats and elucidate its mechanisms. SD rats were deprived of water for 24 hours before the experiment. The control group and model group were administered water by gavage, and the positive drug group received rabeprazole sodium solution(40 mg·kg~(-1)) by gavage. The experimental groups were given different doses of Albizia chinensis saponin solution(3, 10, and 30 mg·kg~(-1)). After 30 minutes, the control group received 1.5 mL of water by gavage, while the other groups were administered an equal volume of 95% ethanol for modeling. After six hours, the rats were killed by cervical dislocation, and the stomachs were collected. The ulcer area was measured, and the ulcer index was calculated. Hematoxylin-eosin(HE) staining was performed to assess histopathological changes in gastric tissue. Periodic acid-Schiff(PAS) staining was used to evaluate the distribution of gastric mucosal surface mucus. Enzyme-linked immunosorbent assay(ELISA) was employed to measure the levels of phospholipids and aminohexose in the gastric mucosa. Western blot was performed to determine the expression levels of the bicarbonate transporter, matrix metalloproteinase, and tight junction-associated proteins in gastric tissue. Immunohistochemistry(IHC) staining was conducted to quantify the number of positive cells for secreted mucin and tight junction-associated proteins. The results showed that the gastric tissue surface of rats in the control group was smooth without ulceration, and the gastric ulcer index of rats in the model group was 35±11. Albizia chinensis saponin at doses of 3, 10, and 30 mg·kg~(-1) resulted in inhibition rates of gastric ulcer of 46%(P<0.01), 85%(P<0.001), and 100%(P<0.001), respectively. Severe disruption of gastric mucosal structure and absence of the mucus layer were observed in the model group. Compared with the model group, the Albizia chinensis saponin group showed intact gastric mucosal surface mucus layer, significantly increased levels of phospholipids and aminohexose in the mucus, increased number of MUC5AC positive cells, and upregulated expression levels of the bicarbonate transporter SLC26A3 and CFTR. It also showed decreased phosphorylation of JNK and c-Jun, reduced expression levels of MMP-8, elevated expression of TIMP-1, and increased expression levels of Occludin and ZO-1. In conclusion, Albizia chinensis saponin enhances the function of the mucus-bicarbonate barrier by upregulating the content of MUC5AC, phospholipids, and aminohexose and increasing the expression levels of the bicarbonate transporter SLC26A3 and CFTR. Moreover, Albizia chinensis saponin exerts its protective effects on gastric ulcers by inhibiting the JNK signaling pathway to prevent excessive activation of MMP-8, thereby reducing the degradation of Occludin and ZO-1 and enhancing the mucosal barrier function. In summary, Albizia chinensis saponin exerts its anti-gastric ulcer effects by simultaneously enhancing the mucus barrier and the mucosal barrier.

Chinese Bayberry Extract Regulates the Permeability of Blood-cerebrospinal Fluid Barrier and Ameliorates Experimental Colitis-Related Brain Comorbidities in Mice

Abstract Objectives The anxiety, depression symptoms, and cognitive decline related to inflammatory bowel disease (IBD) are recognized to have an impact on patients’ health. The blood-cerebrospinal fluid barrier (BCSFB) is important in somatic disease-related psychiatric and cognitive disorders, however, few treatments show efficacy. The objective of this research was to seek the protective effect of Chinese bayberry extract on inflammatory bowel disease-related brain comorbidities. Materials and Methods C57BL/6J mice were induced with dextran sulfate sodium (DSS) solution to establish the experimental model, followed by the administration of Chinese bayberry extract. Oxidative stress indexes, immunofluorescence of choroid plexus, and BCSFB permeability were further investigated. Results Chinese bayberry extract improved behavioral markers and reduced the level of oxidative stress in the brain. In addition, administration of the bayberry extract increased the tight junction proteins in the choroid plexus and a significant decrease in the permeability of the BCSFB. Conclusions Chinese bayberry extract has the potential therapeutic effect of relieving inflammatory bowel disease-related brain comorbidities. The underlying mechanism is associated with a decrease in oxidative stress in the brain and a decrease in the permeability of the BCSFB.

Highly precisive digital polymerase chain reaction based on inkjet printer

BackgroundTo eliminate the indeterminate droplet partitions that highly obfuscate the distinguishment of the positive and the negative partitions in digital polymerase chain reaction (dPCR), the highly precisive droplets array of dPCR was developed via the inkjet printer coupled with the X-Y stage. ResultsThe highly precisive droplets could be generated by the inkjet printer and the droplets array would be arranged by the movable X-Y stage at the same time. The highly precisive droplets array in a volume of at least 20,000 droplets could be obtained with a coefficients of variation (CV) of 1.57 % for the decided droplets in a diameter of 145.16 μm. The CV of the fluorescence intensities of droplets in array could be lowered to 3.17 % for the droplets of 5 μM fluorescein sodium solution, which guaranteed the clear identification of the positive droplets in the absolute quantification of dPCR. In addition, the thermal amplification in dPCR was designed to implement at the same sheet to avoid the delivery of the droplet partitions. The highly precisive dPCR was demonstrated through the wide linear range of more than 103 in the measurement of the model GAPDH gene with a low limitation of detection (LOD) of 0.60 copies/μL. Finally, the practicality of developed dPCR was confirmed by the measurement of the human mammaglobin (hMAM) gene in MCF-7 cell as well. Significance and noveltyThe successful development of the highly precisive droplet array through the inkjet printer coupled with X-Y stage eliminated the indeterminate positive droplet partitions in dPCR. It paved a way to develop the compact and highly sensitive dPCR.

Liquid-phase microextraction approach using supramolecular solvent formed in aqueous systems based on di(2-ethylhexyl)phosphoric acid salt: Spectrophotometric determination of antipyrine in saliva

In this study, di(2-ethylhexyl)phosphoric acid salt was investigated as a double-chain anionic surfactant for supramolecular solvent formation in a liquid-phase microextraction procedure for the first time. Inorganic electrolytes (sodium salts) were shown to be coacervation agents, due to their salting-out property in solution of sodium di(2-ethylhexyl)phosphate, obtained by deprotonation of the acid. The physico-chemical properties of the newly synthesised solvents were studied. Sodium carbonate and sodium phosphate were found to be the most suitable coacervation agents, due to their alkaline nature and low viscosity of the supramolecular solvent phases they produce. The extraction ability of the novel solvent was demonstrated in liquid-phase microextraction of a colored derivative of antipyrine from saliva for further spectrophotometric determination. The extraction recovery was found to be 70 %. The proposed green sample preparation technique enabled the exclusion of traditional toxic solvents and reduction of reagent consumption. The satisfactory analytical performance of the procedure was validated with real sample analysis. The calibration graph was linear over the concentration range of 0.03 to 0.5 mmol/L. The limit of detection (3σ) and limit of quantification (10σ), calculated from blank tests, were 0.01 and 0.03 mmol/L, respectively.

INVESTIGATION OF THE NA+, K+ || VO3–, SO42– TERNARY RECIPROCAL SYSTEM AND MEASUREMENT OF THE NONVARIANT COMPOSITIONS MELTING ENTHALPY

Functional compositions based on multicomponent systems of oxygen-containing salts of s1-elements are widely used in various fields of industry, science and technology: electrometallurgy of light, refractory and heavy metals, as well as metallothermy, pyrometallurgy, promising fluxes for welding and soldering metals, chemical power sources. In the work the triangulation of the Na+, K+ || VO3–, SO42– ternary reciprocal system of sulfates and metavanadates of sodium and potassium on simplices was carried out. The phase states of the Na+, K+ || VO3–, SO42– ternary reciprocal system was investigated by differential thermal analysis (DTA). T–x diagram of the stable secant K2SO4–NaVO3 was constructed, which is the diagonal of the system composition square and which has a eutectic with a melting point of the quasi-double eutectic of 575 °C and a specific melting enthalpy value of 206 kJ/kg. In the NaVO3–Na2SO4–K2SO stable triangle, a minimum of solid solutions with a temperature of 559 °C and an enthalpy of 190 kJ/kg was determined. In the NaVO3–KVO3–K2SO4 stable triangle, the three-component eutectic with a minimum melting point in the system of 474 °C has a minimum specific melting enthalpy of 183 kJ/kg. Compositions of the triple peritectic Р 482 °С and the three-component minimum of solid solutions M 559 °С were determined. The maximum crystallization fields of the system composition square correspond to potassium sulfate and continuous solid solutions of sodium and potassium sulfates. Low-melting mixtures of quasi-double eutectic, ternary eutectic, and ternary minimum can be used as molten electrolytes for medium-temperature chemical current sources and as heat storage materials. For citation: Istomova M.A., Garkushin I.K. Investigation of the Na+, K+ || VO3–, SO42– ternary reciprocal system and measurement of the nonvariant compositions melting enthalpy. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 6. P. 38-44. DOI: 10.6060/ivkkt.20246706.6983.

Quantitative investigation of drug-drug interaction between bergenin and vilazodone in rats through UPLC-MS/MS assay

In this study, we firstly established and verified a method by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the analysis of vilazodone and its metabolite M10 in rat plasma, then this method was used to explore the pharmacokinetics of vilazodone and M10 present or absence of 80 mg/kg bergenin in rats. Protein precipitation with acetonitrile was used to prepare the samples in this research. The mobile phase for liquid chromatography was consisted of 0.1% formic acid aqueous solution and acetonitrile. Brexpiprazole was used as the internal standard (IS), and the multiple reaction monitoring (MRM) mode was used for detection. The verification items required by the US Food and Drug Administration (FDA) guidelines such as selectivity, sensitivity, linearity, stability, recovery and matrix effect of this method were all met the standards. Besides, rats were used to explore the drug-drug interaction between vilazodone and bergenin, which were divided into two groups, and separately gavaged with the same-volume of carboxymethyl cellulose sodium (CMC-Na) solution and 80 mg/kg bergenin, respectively. The results showed that bergenin significantly affected the metabolism of vilazodone. It suggested that there was a potential drug-drug interaction between bergenin and vilazodone in rats. In clinical application, we should pay attention to the dose of vilazodone when in combination with bergenin.

Reducing operational risks during suspensions separation in rare metals technology

The work presents the results of studies of the solid-liquid separation processes of different mineralogical and granulometric compositions, different viscosity and concentrations of uranium, zirconium, nitric acid, soda, sodium nitrate. It has been shown that the process of industrial filtration is impossible for finely dispersed phases due to the low separation rate. Requirements for the purity of technological solutions of uranium and zirconium for the extraction process are limited by the technological ability of the filter fabric to retain the smallest particles, including chemical compounds with a particle size of 1–5 μm. The control filtration process is only possible under pressure, for which a new disk press filter was created, which reduced the concentration of the solid phase in the filtrate to 0.06 g/L. For difficult-to-filter suspensions, a screw centrifuge was developed, which ensured minimum sediment moisture after separating the finely dispersed phase from a solution of soda and sodium silicate and created conditions for maximum extraction of zirconium and hafnium from the solid phase. The separation of water-soluble sodium silicate ensured the stability of the process of extraction separation of zirconium and hafnium and made it possible to isolate silicon oxide.

Thermochemical and structural study of sodium, iron, and niobium phosphate NASICON solid solutions

Solid solutions NaxFe0.5+0.5xNb1.5-0.5x(PO4)3 (0 ≤ x ≤ 1; x = 2) of NASICON structure (sp.gr. R3-c) and NbOPO4 were prepared via solid-state reaction and characterized by electron microprobe analysis, powder X-ray and neutron diffraction, and differential thermal analysis. The decrease of the a- and b-unit cell parameter prevails over the increase in c-parameters, resulting in nonlinear decrease of the unit cell volume with Na content. Enthalpies of drop solution in molten sodium molybdate solvent at 700 °C were measured by high temperature oxide melt solution calorimetry and were used to derive the enthalpies of formation. Strongly negative enthalpies of formation from elements and from constituent oxides indicate high thermodynamic stability. The mixing enthalpies of solid solutions show negative deviation from the ideality. Negative mixing enthalpies and negative mixing volumes indicate short-range ordering of cations in the structure.

Influence of concentration of causid sodium solution on the structure formation of cement matrix from flow dust from mineral wool production

One of the ways to utilize mineral wool production waste is to use it in an alkaline hydraulic binder. However, this requires an assessment of the structure of the raw material and the effect of the alkaline activator on it. The article presents the results of a study of the influence of caustic soda solution concentrations of 5,6,7,8,9,10 mol/l on the properties of a cement-sand solution from dust-flying gas purification system of a cupola furnace of mineral wool production. The features of the formation of a cement matrix with changes in concentration have been studied. The maximum compressive strength of 28 MPa and flexural strength of 7.1 MPa were obtained at a concentration of 6 mol/l. It has been established that when dust is mixed with water, the mineral calcium silicate hydrate – gismondine – is formed. During the geopolymerization reaction, gismondin is significantly reduced due to the formation of N-A-S-H gel and ziolites.

Novel liquid dosimeters for low-energy electron beam irradiation in low and medium dose ranges

Low-energy electron beam irradiation, which refers to the treatment of matter with accelerated electrons at energies below 300 keV, is gaining attention for many applications in life sciences. In the scope of vaccine production, low-energy electron irradiation is an efficient and chemical free technology to inactivate viruses. Low-energy electron beam irradiation has also been proposed to be a powerful technique for its use in biotechnological processes. As biotechnological applications operate in an aqueous environment, there is an urgent need for accurate dose quantification in liquids, especially for low (< 500 Gy) and medium doses (500–5000 Gy). This study investigated dye solutions of xylenol orange tetrasodium, 1,9-dimethylmethylene blue, resazurin sodium, and tartrazine for their suitability as radiochromic liquid dosimeters. The solutions were evaluated regarding their dose–response characteristics and storage stability prior to irradiation over a range of pH values and concentrations. The radiochromic dosimeters were irradiated with electrons with maximal energies of 200 keV and dose rates of 6.5 Gy/s to 45 Gy/s. Then, the absorbance was measured and response curves were plotted. The dye solutions of 1,9-dimethylmethylene blue and resazurin sodium covered a low to medium dose range from 100–1500 Gy and 100–1000 Gy, respectively. Tartrazine at pH 4 was suitable for quantification of doses from 100 Gy to 3500 Gy, which covers a wide dose range of biotechnological applications.

Sijunzi decoction alleviates inflammation and intestinal epithelial barrier damage and modulates the gut microbiota in ulcerative colitis mice.

As a representative classical prescription, Sijunzi decoction has powerful therapeutic effects on spleen-stomach qi insufficiency. Ulcerative colitis (UC) is a chronic, diffuse, and non-specifically inflammatory disorder, the etiology of which still remains unclear. In the traditional Chinese medicine (TCM) perspective, splenic asthenia is the primary cause of UC. Based on this, Sijunzi decoction has been extensively used in TCM clinical practice to alleviate UC in recent years. However, the pharmacological mechanism of Sijunzi decoction in modern medicine is still not completely clear, which limits its clinical application. The purpose of this study was to investigate the Sijunzi decoction's curative effect on acute UC mice and probe into its potential pharmacological mechanism. The UC mouse model was set up by freely ingesting a 3% dextran sulfate sodium (DSS) solution. The relieving role of Sijunzi decoction on UC in mice was analyzed by evaluating the changes in clinical parameters, colon morphology, histopathology, inflammatory factor content, intestinal epithelial barrier protein expression level, and gut microbiota balance state. Finally, multivariate statistical analysis was conducted to elucidate the relationship between inflammatory factors, intestinal epithelial barrier proteins, and gut microbiota. First, the research findings revealed that Sijunzi decoction could visibly ease the clinical manifestation of UC, lower the DAI score, and attenuate colonic damage. Moreover, Sijunzi decoction could also significantly inhibit IL-6, IL-1β, and TNF-α while increasing occludin and ZO-1 expression levels. Subsequently, further studies showed that Sijunzi decoction could remodel gut microbiota homeostasis. Sijunzi decoction was beneficial in regulating the levels of Alistipes, Akkermansia, Lachnospiraceae_NK4A136_group, and other bacteria. Finally, multivariate statistical analysis demonstrated that key gut microbes were closely associated with inflammatory factors and intestinal epithelial barrier proteins. Sijunzi decoction can significantly prevent and treat UC. Its mechanism is strongly associated with the improvement of inflammation and intestinal epithelial barrier damage by regulating the gut microbiota.

Phase behavior of sodium and potassium salts in their aqueous solutions: Experiment and computational thermodynamics

AbstractWith the rapid development of the semiconductor industry, the demand for ultraclean and high‐purity electronic chemicals, especially ultrapure water as a general solvent for cleaning semiconductor chips, has increased dramatically. The distillation process is a good choice for large‐scale production of ultrapure water that can be used to clean semiconductor chips, but there is a lack of basic thermodynamic theory for removing ionic impurities. In this work, the temperature and vapor–liquid phase composition of sodium and potassium salts aqueous solutions at vapor–liquid equilibrium (VLE) were investigated by experiments. The microstructure of each inorganic salt aqueous solution was explored by molecular dynamics simulation and quantum chemical calculation, and the interaction between each ion and water molecule was analyzed. A volatilization mechanism of inorganic salts was proposed, and it was found that the volatilization of inorganic salts in an aqueous solution was affected by the strength of interaction between the dissociated anions and cations and water molecules. Finally, the conductor‐like screening model segment activity coefficient (COSMO‐SAC) model predicted the VLE values of inorganic salt aqueous solutions. The prediction at low concentrations (xs &lt; 0.06) was in good agreement with the experimental data.

Protective effects of sinomenine against dextran sulfate sodium-induced ulcerative colitis in rats via alteration of HO-1/Nrf2 and inflammatory pathway.

Dextran Sulfate Sodium (DSS) induces ulcerative colitis (UC), a type of inflammatory bowel disease (IBD) that leads to inflammation, swelling, and ulcers in the large intestine. The aim of this experimental study is to examine how sinomenine, a plant-derived alkaloid, can prevent or reduce the damage caused by DSS in the colon and rectum of rats. Induction of ulcerative colitis (UC) in rats was achieved by orally administering a 2% Dextran Sulfate Sodium (DSS) solution, while the rats concurrently received oral administrations of sinomenine and sulfasalazine. The food, water intake was estimated. The body weight, disease activity index (DAI), colon length and spleen index estimated. Antioxidant, cytokines, inflammatory parameters and mRNA expression were estimated. The composition of gut microbiota was analyzed at both the phylum and genus levels in the fecal samples obtained from all groups of rats. Sinomenine treatment enhanced the body weight, colon length and reduced the DAI, spleen index. Sinomenine treatment remarkably suppressed the level of NO, MPO, ICAM-1, and VCAM-1 along with alteration of antioxidant parameters such as SOD, CAT, GPx, GR and MDA. Sinomenine treatment also decreased the cytokines like TNF-α, IL-1, IL-1β, IL-6, IL-10, IL-17, IL-18 in the serum and colon tissue; inflammatory parameters viz., PAF, COX-2, PGE2, iNOS, NF-κB; matrix metalloproteinases level such as MMP-1 and MMP-2. Sinomenine significantly (P < 0.001) enhanced the level of HO-1 and Nrf2. Sinomenine altered the mRNA expression of RIP1, RIP3, DRP3, NLRP3, IL-1β, caspase-1 and IL-18. Sinomenine remarkably altered the relative abundance of gut microbiota like firmicutes, Bacteroidetes, F/B ratio, Verrucomicrobia, and Actinobacteria. The results clearly indicate that sinomenine demonstrated a protective effect against DSS-induced inflammation, potentially through the modulation of inflammatory pathways and gut microbiota.

A Low-Carbon Optimal Operation Method for an Industrial Park Multi-Energy Coupling System Utilizing By-Product Hydrogen

To enhance the utilization efficiency of by-product hydrogen and decrease the power supply expenses of industrial parks, local utilization of by-product hydrogen plays a crucial role. However, the methods of utilizing by-product hydrogen in industrial parks are relatively limited. In response to this issue, an optimization method for a multi-energy system with by-product hydrogen considering the production process of chlor-alkali plants was proposed in this paper. Firstly, on the source side, models were established for hydrogen production using the ion exchange membrane electrolyzer and for the energy consumption during the caustic soda solution evaporation process. Secondly, on the load side, this paper explored the potential for local utilization of by-product hydrogen, including its participation in the production of downstream chemical products, combustion when mixed with natural gas, and utilization in hydrogen fuel cells. Next, this paper considered the influence of correlations among various loads within the factory and wind power generation, proposing a method for generating scenarios that takes into account the spatiotemporal correlation of source-load variables. Then, aiming to minimize the system operation cost and carbon trading cost, an operation strategy for a multi-energy system in a low-carbon industrial park, considering local utilization of by-product hydrogen, was proposed. Finally, the effectiveness of the scenario generation method proposed in this paper, considering spatiotemporal correlation, and the economic and environmental benefits of the proposed operation model utilizing the by-product hydrogen are verified through arithmetic simulation, based on the operation data of a chlor-alkali chemical park.

Removal of molybdenum by TBP-TRPO extraction in sodium isopolytungstate solution

A new process was proposed for extracting molybdenum from tungsten solutions in acidic tungsten-molybdenum mixed solution. The extraction ratio of molybdenum reached 70 % and the tungsten-molybdenum separation factors reached 400 with the hydrogen peroxide dosage of nH2O2/n(Mo) = 2 (nH2O2/n(W + Mo) = 0.3) for the molybdenum-containing isopolytungstate sodium solution. The experimental conditions resulted in the yield of only 20 % of the traditional method (nH2O2/n(W + Mo) = 1.5–2). The organic phases consisted of 2 % TRPO and 60 % TBP. The saturated extraction capacity of molybdenum was found to be 10 g/L. The solution of 0.3 mol/L sodium bicarbonate was used as the stripping agent. With the temperature of 25 ℃, stripping time of 6 min, and the phase ratio of (O/A)2, the stripping ratio of molybdenum was 90 % and that of tungsten was 70 %. The extraction mechanism of TBP-TRPO and the hydrogen peroxide coordination were analyzed using Raman and infrared analyses. The process has a high industrial potential due to its low hydrogen peroxide dosage, high molybdenum extraction ratio, high separation factor, and low cost.

Corrosion failure of stainless-steel in caustic soda lines

Abstract The paper deals with the case studies of stainless steel piping corrosion in caustic soda transfer lines at a hydrocarbon processing plant, in the Asian region. The lines were in service of transferring the caustic soda solution from the storage tank farm to different process units, for subsequent use in reaction vessels. To maintain a minimum temperature of the fluid to avoid its precipitation, the lines were accompanied by a steam heat-tracer, throughout the line route. The material of construction (MOC) of the line was stainless steel type 316. After a period of about 3.5 years, 2” caustic line suffered fluid leakage, which was noticed through significant salt accumulation over insulation at one location. A valve was also noticed to leak through a weld at a 1.5” distribution line. The affected components were removed from service and subjected to detailed inspection and laboratory investigation, using advanced tools of metallurgical analysis and characterization. It was found that leakage in 2” line had occurred due to poor workmanship used during the repair of a manufacturing defect at the affected location and leakage of the valve had taken place due to the use of improper welding practice (in the case of subjected weld). In addition, the significant role of metallurgical defects in the parent metal was also disclosed to result in the observed failures. In addition, the contribution of process excursions can’t be completely ruled out. Finally, remedial measures are given to avoid the recurrence of such failure.

Determination of the isotonicity 1 % solution of sodium 2-((4-amino-5-thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate

The aim of the work is to justify the composition of a 1 % aqueous solution of sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate for parenteral use. Materials and methods. The osmolality study of a 1 % solution of sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate was conducted using the cryoscopic method according to the State Pharmacopoeia of Ukraine (2.2.35). The calculations were based on measuring the depression of the crystallization temperature of the 1 % solution of sodium 2-((4-amino-5-(thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate, 0.9 % NaCl solution, and high-purity water (Q3). The measurements of crystallization temperature were performed using a Beckman TL-1 thermometer, which allows for research with high precision up to ± 0.005 °C, making it valuable and most effective for studying isotonic concentration. Results. Temperature measurements of the crystallization of a 1 % solution under investigation, a 0.9 % NaCl solution, and high-quality purified water were conducted. Calculations of isotonic concentration were performed based on the measurement results. Conclusions. Based on the obtained experimental data on the depression of the crystallization temperature and the calculations, the amount of sodium chloride necessary for the preparation of an isotonic 1 % aqueous solution of AFI sodium 2-((4-amino-5-thiophen-2-ylmethyl)-4H-1,2,4-triazole-3-yl)thio)acetate for parenteral use was established.

Cationic effect in the formation of toxic and antiviral properties of Keggon heteropoly compounds

The Cytotoxicity indices (IC50) of Keggin’s phosphorus-molybdenum heteropoly acids (HPCAs) and their sodium and potassium salts on dog kidney cells (MDSC) were determined. The antiviral activity of these compounds against topical strains of influenza A (H3N2 and H1N1) was revealed. The dependence of the biological properties of polyoxometalates (POMs) on the elemental composition of their molecules has been confirmed. It has been shown that when some of the molybdenum atoms are replaced by vanadium atoms, HPCA and their salts acquire higher cytotoxicities, which increase monotonically as the number of substitutions increases. For the first time, the dependence of the biological activity of HPCA and their salts on the mass of cations has been established and interpreted. In vivo (on white outbred mice) the values of semi-lethal doses (DL50) of these compounds were established. For aqueous solutions of sodium and potassium salts of GPCA in a wide range of concentrations (from 0.05 μM to 15 μM), the values of the toxicity index (It) were determined on the model of motile cells. It has been established that GPCA and their salts are classified as moderately dangerous toxic substances and have selective antiviral activity, which at low concentrations (less than 15 μM) for influenza A strains is manifested mainly by a decrease in hemagglutination activity (HA).

The application of a 4D-printed chitosan-based stem cell carrier for the repair of corneal alkali burns

BackgroundCorneal alkali burns can lead to ulceration, perforation, and even corneal blindness due to epithelial defects and extensive cell necrosis, resulting in poor healing outcomes. Previous studies have found that chitosan-based in situ hydrogel loaded with limbal epithelium stem cells (LESCs) has a certain reparative effect on corneal alkali burns. However, the inconsistent pore sizes of the carriers and low cell loading rates have resulted in suboptimal repair outcomes. In this study, 4D bioprinting technology was used to prepare a chitosan-based thermosensitive gel carrier (4D-CTH) with uniform pore size and adjustable shape to improve the transfer capacity of LESCs.MethodsPrepare solutions of chitosan acetate, carboxymethyl chitosan, and β-glycerophosphate sodium at specific concentrations, and mix them in certain proportions to create a pore-size uniform scaffold using 4D bioprinting technology. Extract and culture rat LESCs (rLESCs) in vitro, perform immunofluorescence experiments to observe the positivity rate of deltaNp63 cells for cell identification. Conduct a series of experiments to validate the cell compatibility of 4D-CTH, including CCK-8 assay to assess cell toxicity, scratch assay to evaluate the effect of 4D-CTH on rLESCs migration, and Calcein-AM/PI cell staining experiment to examine the impact of 4D-CTH on rLESCs proliferation and morphology. Establish a severe alkali burn model in rat corneas, transplant rLESCs onto the injured cornea using 4D-CTH, periodically observe corneal opacity and neovascularization using a slit lamp, and evaluate epithelial healing by fluorescein sodium staining. Assess the therapeutic effect 4D-CTH-loaded rLESCs on corneal alkali burn through histological evaluation of corneal tissue paraffin sections stained with hematoxylin and eosin, as well as immunofluorescence staining of frozen sections.ResultsUsing the 4D-CTH, rLESCs were transferred to the alkali burn wounds of rats. Compared with the traditional treatment group (chitosan in situ hydrogel encapsulating rLESCs), the 4D-CTH-rLESC group had significantly higher repair efficiency of corneal injury, such as lower corneal opacity score (1.2 ± 0.4472 vs 0.4 ± 0.5477, p < 0.05) and neovascularization score (5.5 ± 1.118 vs 2.6 ± 0.9618, p < 0.01), and significantly higher corneal epithelial wound healing rate (72.09 ± 3.568% vs 86.60 ± 5.004%, p < 0.01).ConclusionIn summary, the corneas of the 4D-CTH-rLESC treatment group were similar to the normal corneas and had a complete corneal structure. These findings suggested that LESCs encapsulated by 4D-CTH significantly accelerated corneal wound healing after alkali burn and can be considered as a rapid and effective method for treating epithelial defects.Graphical abstract