Amount Of Acid Research Articles

A green and efficient method to prepare oleic acid–modified CaCO3/reHDPE composites

Industrial recycling of waste plastics frequently utilizes mechanical recovery and recycling. However, plastics recycled through mechanical recovery tend to have reduced properties, limiting their applications. In this study, modified calcium carbonate (OA-CaCO3) was prepared using different amounts of oleic acid (OA) (0.5, 1.0, and 2.0 wt%). Infrared spectroscopic characterization showed OA was successfully adsorbed on the CaCO3 surface. Particle size, micromorphology, oil absorption value, and activation tests indicated that CaCO3 modified with 1.0 wt% OA yielded optimal results. Melt blending 1.0 wt% OA-modified CaCO3 with recycled high-density polyethylene (reHDPE) produced composites. Scanning electron microscopy results showed OA modification enhanced interfacial compatibility between the two phases. Mechanical property tests revealed at high filling levels, the impact strength of OA-modified composites increased considerably, reaching 42.6 kJ/m2 with 40 wt% OA-CaCO3 filling. Melt flow rate test results showed that OA-modified composites had increased melt flow and modified processing properties. Filling OA-CaCO3 to compensate for reHDPE properties caused by mechanical recycling is essential to expand mechanical recycling applications in plastics recycling.

Research on the modification technology of beta molecular sieve

The influence of temperature and time of the acid washing and hydrothermal treatment on Beta zeolite properties was examined in detail, the results revealed that acid washing at 2h and 80℃and 2h hydrothermal treatment at 650℃are the best modification operating conditions. The different SiO2/Al2O3ratio of Beta zeolite are systematically modified using optimized modification operating conditions. Beta zeolite modified from higher SiO2/Al2O3ratio of the starting Beta also has higher SiO2/Al2O3 ratio. Crystallinity of starting Beta zeolite has less effect on the modified Beta zeolite. As the SiO2/Al2O3 ratio of starting Beta increased, total acid amount of modified Beta decreased. When the SiO2/Al2O3 ratio of starting Beta is bigger, the surface area and pore volume is higher.

Development and Characterization of Sodium Bicarbonate-Based Gel for Cytolytic Vaginosis.

Background/Objectives: Cytolytic vaginosis or, classically, Doderlein's cytolysis is characterized by significant growth of species of the Lactobacillus genus, which leads to high amounts of lactic acid in the vaginal environment. Lactobacillus crispatus has been proposed as a key pathogen in this clinical condition. The symptomatology of cytolytic vaginosis is commonly confused with that of vulvovaginal candidosis, leading to inadequate and ineffective azole therapies. Nevertheless, historically, the use of sodium bicarbonate intimate baths was an effective way to reduce the symptoms of cytolytic vaginosis. Methods: In this study, four HPMC gel prototypes were developed, containing sodium bicarbonate concentrations ranging from 4% to 7% (w/w). These gels were evaluated for their physicochemical properties, antimicrobial activity, interference with lactobacilli adhering to cells, and cellular and tissue biocompatibility. Results: The gels presented pH values of around 9.0, and osmolality between 706 mOsm/kg (F4) and 1065 mOsm/kg (F7). The viscosity upon heating to physiologic temperature and dilution with simulated vaginal fluid was highly affected by the concentration of sodium bicarbonate. Gels with higher sodium bicarbonate concentrations (F6 and F7) were not shown to be stable in these conditions. All formulations exhibited effective antimicrobial activity against seven L. crispatus strains, with MIC values ranging from 6.25% to 25% (v/v) in terms of dilution. Additionally, the 4% (w/w) gel significantly interfered with the adhesion of L. crispatus to epithelial cells in competition and exclusion assays, reducing adhesion by more than 90% in relation to the control. Cytotoxicity tests on the Hec-1A, HeLa, and VK2/E6E7 cell lines indicated that the F4 and F5 gels demonstrated lower cytotoxicity levels compared to those with higher concentrations. Furthermore, ex vivo assays using porcine vaginal tissue confirmed that the 4% gel was non-toxic at a 25% (v/v) dilution. Conclusions: Based on these results, the 4% (w/w) sodium bicarbonate gel (F4) emerges as a promising therapeutic option for cytolytic vaginosis, offering effective bacterial interference, favourable physicochemical properties, and biocompatibility suitable for vaginal application.

Antioxidant activity of Micractinium sp. (Chlorophyta) extracts against H2O2 induced oxidative stress in human breast adenocarcinoma cells

In response to the growing demand for high-value bioactive compounds, microalgae cultivation has gained a significant acceleration in recent years. Among these compounds, antioxidants have emerged as essential constituents in the food, pharmaceutical, and cosmetics industries. This study focuses on Micractinium sp. ME05, a green microalgal strain previously isolated from hot springs flora in our laboratory. Micractinium sp. cells were extracted using six different solvents, and their antioxidant capacity, as well as total phenolic, flavonoid, and carotenoid contents were evaluated. The methanolic extracts demonstrated the highest antioxidant capacity, measuring 7.72 and 93.80 µmol trolox equivalents g−1 dry weight (DW) according to the DPPH and FRAP assays, respectively. To further characterize the biochemical profile, reverse phase high-performance chromatography (RP-HPLC) was employed to quantify twelve different phenolics, including rutin, gallic acid, benzoic acid, cinnamic acid, and β-carotene, in the microalgal extracts. Notably, the acetone extracts of Micractinium sp. grown mixotrophically contained a high amount of gallic acid (469.21 ± 159.74 µg g−1 DW), while 4-hydroxy benzoic acid (403.93 ± 20.98 µg g−1 DW) was the main phenolic compound in the methanolic extracts under heterotrophic cultivation. Moreover, extracts from Micractinium sp. exhibited remarkable cytoprotective activity by effectively inhibiting hydrogen peroxide-induced oxidative stress and cell death in human breast adenocarcinoma (MCF-7) cells. In conclusion, with its diverse biochemical composition and adaptability to different growth regimens, Micractinium sp. emerges as a robust candidate for mass cultivation in nutraceutical and food applications.

The Role of Freeze-Drying as a Multifunctional Process in Improving the Properties of Hydrogels for Medical Use.

Background/Objectives: Freeze-drying is a dehydration method that extends the shelf life and stability of drugs, vaccines, and biologics. Recently, its role has expanded beyond preservation to improve novel pharmaceuticals and their carriers, such as hydrogels, which are widely studied for both drug delivery and wound healing. The main aim of this study was to explore the multifunctional role of freeze-drying in improving the physicochemical properties of sodium alginate/poly(vinyl alcohol)-based hydrogels for medical applications. Methods: The base matrix and hydrogels containing a nanocarrier-drug system, were prepared by chemical cross-linking and then freeze-dried for 24 h at -53 °C under 0.2 mBa. Key analyses included determination of gel fraction, swelling ratio, FT-IR, SEM, TG/DTG, in vitro drug release and kinetics, and cytotoxicity assessment. Results: Freeze-drying caused an increase in the gel fraction of the hydrogel with the dual drug delivery system from 55 ± 1.6% to 72 ± 0.5%. Swelling ability was pH-dependent and remained in the same range (175-282%). Thermogravimetric analysis showed that freeze-dried hydrogels exhibited higher thermal stability than their non-freeze-dried equivalents. The temperature at 10% weight loss increased from 194.0 °C to 198.9 °C for the freeze-dried drug-loaded matrix, and from 188.4 °C to 203.1 °C for the freeze-dried drug-free matrix. The average pore size of the freeze-dried hydrogels was in the range of 1.07 µm ± 0.54 to 1.74 µm ± 0.92. In vitro drug release revealed that active substances were released in a controlled and prolonged way, according to the Korsmeyer-Peppas model. The cumulative amount of salicylic acid released at pH = 9.0 after 96 h was 63%, while that of fluocinolone acetonide reached 73%. Both hydrogels were non-toxic to human fibroblast cells, maintaining over 90% cell viability after 48 h of incubation. Conclusions: The results show a high potential for commercialisation of the obtained hydrogels as medical dressings.

Lactobacillus johnsonii CCFM1376 improves hypercholesterolemia in mice by regulating the composition of bile acids

Aim: Strains with high bile salt hydrolase (BSH) activity have the potential to regulate cholesterol metabolism. This study aimed to assess the alleviating effect of Lactobacillus johnsonii (L. johnsonii ) CCFM1376, a strain with high BSH activity, on mice with hypercholesterolemia and explore the mechanism of its effect through the modulation of bile acid metabolism. Methods: The BSH activity was measured using the ninhydrin method. C57BL/6J mice were given a high-cholesterol diet to induce hypercholesterolemia with simultaneous gavage of L. johnsonii CCFM1376 for 8 weeks. The biochemical parameters in the serum and liver of hypercholesterolemic mice were measured to assess the alleviating effect of L. johnsonii CCFM1376 on hypercholesterolemia. Bile acid content in the mouse liver, serum, distal ileum contents, and feces was determined using liquid chromatograph mass spectrometer (LC-MS). RNA was extracted from mouse ileum and liver, and the expression levels of relative genes implicated in bile acid metabolism were measured by quantitative real-time PCR (qPCR). Results: Compared to the model group, the group treated with L. johnsonii CCFM1376 exhibited significantly reduced levels of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), along with a significant increase in high density lipoproteins cholesterol (HDL-C) level. Moreover, hepatic levels of TC and LDL-C in the CCFM1376 group also decreased significantly. Furthermore, the content and amount of unconjugated bile acids in the hepatic-enteric circulation of the L. johnsonii CCFM1376 group significantly increased, and the total bile acid content in the feces also significantly increased. In the L. johnsonii CCFM1376 group, the relative expression levels of ileal farnesoid X receptor (FXR) and fibroblast growth factor 15 (FGF15) were downregulated, while the relative expression level of CYP7A1 was upregulated. Conclusion: These results indicated L. johnsonii CCFM1376 improves hypercholesterolemia in mice by regulating the composition of bile acids. This provides a reference for probiotic strategy to regulate cholesterol metabolism.

Closed-Loop Process of Extracting and Separating Zinc Impurities from Industrial Cobalt Products—Pilot Test Study

The cobalt-containing products of an enterprise were selected as the object of this study. The separation effect of Cyanex 272 on Zn and Co was studied through a pilot test. The results showed that Cyanex 272 had a high extraction rate for Zn at pH 3–3.4, up to 99.8%. The extracted Zn2+ was enriched in the organic phase, and the Zn2+ in the organic phase was extracted back into the aqueous phase in the stripping stage by adding strong acid. Addition amounts of strong acid of 50 g·L−1, 80 g·L−1, and 100 g·L−1 were set. The results showed that the addition amounts of 80 g·L−1 and 100 g·L−1 could significantly reduce the pH of the back-extraction solution and effectively enrich Zn2+ in the solution. There was a large amount of Zn2+ in the back-extraction solution, which could be used twice to prepare zinc carbonate products through neutralization and precipitation. By comparing the extraction effect, economic cost, and resource loss under different strong acid addition amounts, it was found that the 80 g·L−1 strong acid addition amount was more suitable for the actual production process. This study provides data support and practical evidence for the selection of industrial extraction process parameters for Zn2+ separation in actual cobalt products.

Effects of lambda-cyhalothrin on gut microbiota and related bile acid metabolism in mice

Since the gut microbiota plays a crucial role in host metabolism and homeostasis, its alterations induced by xenobiotics such as pesticides, could pose a risk to host health. The pyrethroid insecticides were frequently detected in surface water (up to 13 mg/L worldwide), sediments, and agricultural products; additionally, some previous studies indicated that pyrethroid insecticides could cause disruption of gut homeostasis. Hence herein, the normally used pyrethroid lambda-cyhalothrin (LCT) was selected and studied for its effects on the intestinal microbial community and its related bile acid metabolism using mice as the model species. Results showed that the total amount of bile acids in plasma and fecal samples from LCT treated mice markedly increased compared to controls, which could be mainly ascribed to the significantly raised proportions of taurine conjugated bile acids in plasma, and the increase in fecal secondary bile acids. In gut microbial profiles, a significantly increased richness of Prevotellacea and a depletion of Lachnospiraceae were found at the family level upon the treatment with lambda-cyhalothrin. In conclusion, results obtained on bacterial and bile acid profiles corroborate that the treatment of mice with LCT could affect gut microbial community with accompanying changes in bile acid homeostasis.

Amino acid assisted-construction of 2D-hierarchical MFI zeolites for adsorption of rhodamine B

Hierarchical and two-dimensional (2D) zeolites have drawn much attention in catalysis and separation process due to their fast mass transfer. However, the facile manipulation in controllable mesopore volumes and morphologies for hierarchical nanozeolites is full of challenges. Herein, a facile strategy is presented for the synthesis of single-crystalline 2D hierarchical MFI zeolite nanosheets (HNSs) with tunable mesopore volumes through the amino acid-assisted crystallization of nucleated amorphous silicon precursors (NASPs). The tailored synthesis of HNSs with controllable aspect ratios ((Lc + La)/Lb), b-axis thicknesses (a few tens of nanometers) and mesopore volumes is achieved by adjusting the preparation of the NASPs and the amount of amino acid in the synthesis mixture. The HNSs exhibit large BET surface area (>400 m2 g-1), high micropore volume (0.16–0.18 cm3 g−1) as well as rich mesopore volume (>0.10 cm3 g−1), indicating the high crystallinity of the hierarchical zeolite nanosheets. Specially, the higher adsorption capability and faster adsorption rate for the dye (Rhodamine B) adsorption demonstrate the excellent performance of the hierarchical zeolite nanosheets, which exhibits the maximum adsorption capacity of 115.7 mg g−1. The controllable manipulation of mesoporous volumes and morphologies in MFI zeolites represents a significant contribution to the field of zeolite microstructure engineering.

Investigation of Chemical Composition and Biological Activity of Salix aegyptiaca L. Roots

The root of Salix aegyptiaca L. was extracted using their yield percentage, total condensed tannin concentration, antimicrobial, antioxidant activity and to determine chemical composition by LC-MS/MS. The root extraction was carried out together with water, ethanol and methanol. Accelerated solvent extraction (ASE), conventional extraction (CE), and microwave extraction (ME) were the extraction methods applied during the investigation. The LC-MS/MS methanol extract was used to detect phenolics. The antioxidant activities and total condensed tannin concentrations of root extracts have been done by UV-visible spectroscopy from 517 to 580 nm, severally. The disk diffusion method was used for antimicrobial activity. The maximum extraction yield (17.2%) was obtained in methanol by the ASE technique whereas, the conventional extraction technique obtained the minimum extraction efficiency (9.1%). By triplicate measurement, the total condensed tannin analysis result was found 35.14 mg/L. Using the ASE technique, the methanol extract was the maximum inhibitory zone (26 mm) against Candida albicans ATCC 10231. However, in water extract by conventional extraction, a minimum inhibitory zone (11 mm) was obtained against Staphylococcus aureus Cowan 1. The highest and lowest DPPH scavenging activity was determined in methanol (ASE) (98.8%) and ethanol (97.5%) extract respectively. The maximum amounts of quinic acid (63895 µg/g) were discovered using LC-MS/MS.

Effects of a Mouthrinse Containing Silver Nanoparticles on Polymicrobial Oral Biofilms.

To investigate the antimicrobial effects of a mouthrinse containing silver nanoparticles (AgNP) on polymicrobial biofilms in vitro. Polymicrobial biofilms were grown on glass cover slips following the method of Exterkate. Saliva collected from a healthy human was added to McBain medium (including 0.2% sucrose) to achieve a 50-fold dilution. Glass coverslips were attached to the lid of a 24-well culture plate and suspended in the medium of each well. After 24 h of cultivating, coverslips with biofilms were immersed in each of four treatment solutions or sterile deionized water for 5 min. The control and four treatment groups were as follows: 1) control: sterile deionized water; 2) nanosilver (NS): mouthrinse containing AgNP; 3) 0.05C: 0.05% chlorhexidine gluconate; 4) 0.2C: 0.2% chlorhexidine gluconate; 5) Xyl: 25% xylitol. The biofilms were further regrown for 48 h. After removing the biofilms ultrasonically, they were cultured on blood agar, viable cells were counted, and the amount of lactic acid in the biofilms was analysed using a colorimetric assay. Mouthrinse containing AgNP suppressed viable cells in the biofilm to the same degree or more than with chlorhexidine gluconate. Amounts of lactic acid after 72 h cultivation of biofilms treated with 0.2C and NS showed consistently low values. The mouthrinse containing AgNP suppressed viable cells in polymicrobial biofilms to the same level as 0.2% chlorhexidine or higher.

INFLUENCE OF CONSUMPTION OF ACIDIFYING AND COAGULATING AGENTS ON THE PROCESS OF SEPARATING RUBBER FROM LATEX

The presented work is devoted to improving the stage of separating crumbs of emulsion styrene-butadiene synthetic rubber. A comprehensive assessment of the influence of the consumption of the high-molecular cationic reagent VPK-10, the acidifying component and temperature on the process of reducing the aggregative stability of latex dispersion was carried out. The work investigated the effect of the amount of introduced sulfuric acid on the yield of released rubber at temperatures of 0, 20 or 60 °C. Anomalous behavior of the process was discovered when studying the effect of coagulation temperature on rubber yield depending on the amount of added acid. When introducing sulfuric acid in an amount of 15 kg/t of rubber, an increase in temperature required an increase in the amount of added coagulant to achieve complete recovery of rubber. Reducing the amount of sulfuric acid to 10 kg/t of rubber required an increase in the required amount of coagulant. At the same time, the increase in temperature also required an increase in the amount of added coagulant for maximum effect in releasing rubber. A distinctive feature when reducing the dosage of sulfuric acid to 5 kg/t of rubber was the reverse effect of the temperature of the coagulation process. The highest coagulant consumption was achieved not at 1 °C, but at 60 °C. At the same time, the amount of coagulant required for maximum extraction of rubber crumbs from latex decreased with increasing temperature. The change in the temperature regime of the process of separating rubber from latex with a decrease in the acidity of the coagulated system is possibly due to the fact that with a lack of sulfuric acid, incomplete conversion of latex carboxylic acid soaps into carboxylic acids occurs. Therefore, there is no significant destabilization of latex globules and the protective layer based on an anionic surfactant does not undergo global destruction. For citation: Pisareva I.A., Nikulina N.S., Sannikova N.Yu., Misin V.M., Vlasova L.A., Nikulin S.S. Influence of consumption of acidifying and coagulating agents on the process of separating rubber from latex. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 11. P. 114-121. DOI: 10.6060/ivkkt.20246711.7048.

Preparation and Characterization of Superabsorbents Based on Durian Seed Starch (Durio zibethinus) and Carboxymethyl Cellulose Using Citric Acid Crosslinking

Superabsorbents are materials that can absorb a liquid beyond its initial volume. Natural polymer-based superabsorbents can be obtained by combining CMC and durian seed starch. The combination of these two materials was cross-linked using varying amounts of citric acid: 0.0 grams, 0.2 grams, 0.4 grams, and 0.6 grams. The resulting superabsorbent has a cross-linking degree of about 41%, shows the presence of OH and CH groups, has a rough and dense surface, and a maximum water absorption capacity of 4130% with a water absorption rate of 41.3 g/g. Durian seed starch has potential as a superabsorbent material.

Anti‐mold properties of fermented apple juice in bread

AbstractBackground and ObjectivesBread may be spoiled by mold, which results in major economic losses. The aim of this study was to optimize the anti‐mold properties of apple juice fermented with Propionibacterium freudenreichii to get high levels of propionic acid with lesser amounts of acetic acid, which impairs bread taste.FindingsAfter fermentation for 7 days at 35°C, apple juice (half‐diluted to about 4% fermentable sugars; with 1% yeast extract; pH adjusted to 6.0) contained 1.0% propionic acid and little amounts of acetic acid (about 0.35%).ConclusionsIn bread, the anti‐mold activity of fermented apple juice (5%, fb) was similar to that of apple cider vinegar (2.44%, fb).Significance and NoveltyFermented apple juice is a novel mold inhibitor for bread that may replace apple cider vinegar and part of calcium propionate.

High-intensity ultrasound modification of techno-functional and structural properties of white finger millet protein fractions.

In this study, albumin, globulin, and glutelin were extracted from white finger millet, and their amino acid content, functional and structural properties were investigated. The protein concentration of albumin, globulin, and glutelin were 76.01%, 74.32%, and 69.55%, respectively. The results showed that all the fractions had a significant amount of essential amino acids. Aqueous protein dispersions (10%, w/v) were treated for 12min at different ultrasound power levels (100, 200, and 300W). The solubility, emulsifying, and foaming properties of albumin and glutelin were significantly (p<0.05) improved after ultrasound treatment (20kHz) which indicates that ultrasound could unfold protein aggregates. A decrease in particle size, increase in surface hydrophobicity, and zeta potential correlated with improved functional properties. Ultrasound treatment reduced the size of all proteins except for fractions at 300W and also sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a significant change in the molecular weight of albumin and glutelin at 300W. Scanning electron microscopy of treated protein fraction showed distinctive microstructure with irregular structure compared to untreated protein fraction. Although Fourier transform infrared spectroscopy spectra of proteins were similar after ultrasonication, a partial increase in the intensity of the Amide A band was observed. In conclusion, the ultrasound-treated protein fraction can be used as a high-value plant-based emulsifier.

Unveiling the nutritional treasure trove: A comparative analysis of two Azolla species for potential food applications

The study investigates the nutritional potential of Azolla pinnata and Azolla caroliniana for its food applications. Nutritional evaluation revealed it as a valuable source of major and minor nutrients. Both species exhibited an abundance of vitamins as well as essential macro and micro mineral components. The essential amino acid profile ranged from 41.96% to 42.91%, and non-essential amino acids comprising of 57.1–58.02%. Fatty acid analysis indicated a significant amount of polyunsaturated fatty acids (26.96% - 28.06%) and Monounsaturated fatty acids were present in the range of 8.34–8.81%. The ω3:ω6 ratio favored a healthy balance in both species indicating a ratio of 4:1. Protein quality indices showed encouraging values with regard to Protein Efficiency Ratio (PER), Essential Amino Acid Index (EAAI), Nutritional Index (NI), Biological Value (BV), and Chemical Score (CS) for both species. Findings suggested Azolla species as promising candidate for its food applications. A balanced and varied diet is essential for human health, and to meet this, Azolla can be explored as a complementary source of nutrient along with other major dietary sources.

Evaluating the thermal stability of hazelnut oil in comparison with common edible oils in Turkey using ATR infrared spectroscopy

Hazelnut oil (HO), a high-quality nutrient rich in monounsaturated fatty acids and antioxidants, is not commonly used due to a lack of awareness of its nutritional benefits. The purpose of the current study is to evaluate the stability of HO during the heating process in comparison with Riviera olive, sunflower and corn oils, the most commonly used edible oils in Turkey, by using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR). The oils were heated at 180 °C for 24h, divided into 8-h periods over the course of three days and the measurements were performed on oil samples taken every 2h. Thermogravimetric analysis-differential thermal analysis (TGA-DTA) and the measurement of the specific absorbance of conjugated dienes and trienes by using UV-visible spectroscopy were also performed to confirm the ATR-FTIR data. The spectroscopic results showed that the heating process led to an increase in the amount of primary and secondary oxidation products, a decrease in the amount of cis fatty acids and an increase in the amount of trans fatty acids in all oils. Based on the results of linear regression analysis, HO has the lowest slope value for all parameters, indicating that it is the most resistant to thermal oxidation. Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and TGA-DTA results confirmed that HO has a higher thermal stability than the other oils. These findings revealed that HO has the highest thermal stability among the oils compared and can be utilized as a healthy alternative for cooking. This study also showed that ATR-FTIR spectroscopy holds significant promise in oil analysis, competing with routine quality control techniques.

Tetrahedral DNA nanostructures-assisted electrochemical assay for detecting circulating tumor DNA by combining a masking tactic with 3D-hybridization chain reactions

Circulating tumor DNA (ctDNA) is a remarkable noninvasive tumor marker that plays a crucial role in tumor diagnosis, prognosis and treatment. However, detecting low-abundance ctDNA from a substantial amount of nucleic acids originating from healthy cells is challenging. Herein, we proposed a tetrahedral DNA nanostructures (TDNs)-assisted electrochemical biosensor for ctDNA detection. This biosensor combines a masking tactic with 3D-hybridization chain reactions. Masking hairpins (MHs) were initially introduced to prevent interference from wild-type (WT) DNA. Then, the initiator sequence was transferred to the electrode surface modified with TDNs by the target ctDNA. The initiator sequence triggers the 3D self-assembly of hairpin strands, leading to the formation of DNA networks or even DNA hydrogels (long reaction time). This process generates numerous evenly distributed biotin molecules that can bind to streptavidin peroxidase to considerably amplify the signal. This method exhibits high sensitivity (the minimum concentration for detecting ctDNA is 1 aM, which corresponds to 60 ctDNA molecules in 100 μl sample) and excellent specificity (single mismatch). More importantly, this high-performance sensor can detect ctDNA with other mutation sites and their mixtures by modifying the corresponding capture probes on the TDNs. Furthermore, this ultrasensitive sensor effectively detects target ctDNA (0.001%) at high levels of WT DNA and in complex matrices such as serum. These findings suggest that the sensor has promising potential as a noninvasive tool for early tumor diagnosis.

Sulfamic Acid Catalyzed One‐Pot Three‐Component Synthesis of Spiro‐Oxindole Fused Dihydroquinazolinone Derivatives in Aqueous Medium

AbstractA simple, efficient, and straightforward protocol has been developed for the synthesis of spiro‐oxindole fused dihydroquinazolinone derivatives from one‐pot three‐component reactions of isatoic anhydride, various primary anilines, and substituted isatins using a catalytic amount of sulfamic acid as an organocatalyst in water under refluxed conditions. All the synthesized compounds were formed within just 2 h and isolated pure by simple filtration with excellent yields (89%–94%). Gram scale production, use of commercially available low‐cost organocatalyst, green solvent, reusability of the medium, one‐pot three‐component reaction strategy, no column chromatography, and high atom economy are some of the major benefits of this newly developed protocol.

Dietary Eicosapentaenoic Acid Improves Ozone-Induced Pulmonary Inflammation in C57BL/6 Mice

BackgroundAmbient concentrations of the air pollutant, ozone, are rising with increasing global temperatures. Ozone is known to increase incidence and exacerbation of chronic lung diseases, which will increase as ambient ozone levels rise. Studies have identified diet as a variable that is able to modulate the pulmonary health effects associated with ozone exposure. Eicosapentaenoic acid (EPA) is an n–3 (ω-3) PUFA consumed through diet, which lowers inflammation through conversion to oxylipins including hydroxy-eicosapentaenoic acids (HEPEs). However, the role of dietary EPA in ozone-induced pulmonary inflammation is unknown. ObjectiveTherefore, we hypothesized increasing dietary EPA will decrease ozone-induced pulmonary inflammation and injury through the production of HEPEs. Methods: To test this, male C57BL/6J mice were fed a purified control diet or EPA-supplemented diet for 4 wk and then exposed to filtered air or 1 part per million ozone for 3 h. 24 or 48 h after exposure, bronchoalveolar lavage fluid was collected to assess airspace inflammation/injury and lung tissue was collected for targeted liquid chromatography-mass spectrometry lipidomics. ResultsFollowing ozone exposure, EPA supplementation did not alter markers of lung injury but decreased ozone-induced airspace neutrophilia. Targeted liquid chromatography-mass spectrometry lipidomics revealed dietary EPA supplementation increased pulmonary EPA-derived metabolites including 5-HEPE and 12-HEPE. Additionally, EPA supplementation decreased pulmonary amounts of proinflammatory arachidonic acid–derived metabolites. To evaluate whether dietary EPA reduces ozone-induced pulmonary inflammation through increased pulmonary HEPEs, C57BL/6J mice were administered 5-HEPEs and 12-HEPEs systemically before filtered air or ozone exposure. Pretreatment with 5-HEPEs and 12-HEPEs reduced ozone-driven increases in airspace macrophages. ConclusionsTogether, these data indicate that an EPA-supplemented diet protects against ozone-induced airspace inflammation which is, in part, due to increasing pulmonary amounts of 5-HEPEs and 12-HEPEs. These findings suggest that dietary EPA and/or increasing EPA-derived metabolites in the lung can reduce ozone-driven incidences and exacerbations of chronic pulmonary diseases.