Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.543
Filtrar
1.
Food Microbiol ; 125: 104657, 2025 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-39448167

RESUMEN

Acetobacter is one of the main species producing fruit vinegar and its tolerance mechanism to citric acid has not been fully studied. This limits fruit vinegar production from high-citric-acid fruits, which are excellent materials for fruit vinegar production. This study analyzed the metabolic differences between two strains of A. tropicalis with different citric acid tolerances using non-targeted metabolomics. Differential metabolites and metabolic pathways analysis showed that the enhanced amino acid metabolism significantly improved the citric acid tolerance of A. tropicalis and the deamination of amino acids may also play a role. In addition, the up-regulated phosphatidylcholine (PC) and N-heptanoylhonoserine lactone indicated decreased membrane permeability and enhanced quorum sensing (QS), respectively. The analysis of the interaction between pathways and metabolites indicated that Gln, Cys, and Tyr contribute to improving citric acid tolerance, which was also confirmed by the exogenous addition. After adding the amino acids, the down-regulated qdh, up-regulated ggt, and improved glutathione reductase (GR) activity in J-2736 indicated that glutathione metabolism played an important role in resisting citric acid, and cellular antioxidant capacity was increased. This study provides a theoretical basis for efficient fruit vinegar production from citric-acid-type fruits.


Asunto(s)
Ácido Acético , Acetobacter , Antioxidantes , Ácido Cítrico , Glutatión , Acetobacter/metabolismo , Acetobacter/efectos de los fármacos , Ácido Cítrico/metabolismo , Ácido Acético/metabolismo , Ácido Acético/farmacología , Antioxidantes/metabolismo , Glutatión/metabolismo , Frutas/microbiología , Frutas/metabolismo , Aminoácidos/metabolismo , Percepción de Quorum , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Metabolómica , Redes y Vías Metabólicas
2.
Food Chem ; 463(Pt 4): 141477, 2024 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-39357312

RESUMEN

The highly efficient red-emissive carbon dots (R-CDs) were synthesized from citric acid, polyethyleneimine, and benzil via a facile solvothermal process. The R-CDs displayed maximum fluorescence properties at excitation and emission wavelengths of 550 and 631 nm, respectively, which fall within the red wavelength range. Moreover, the R-CDs exhibited a high fluorescence quantum yield of 11.3 %, and this fluorescence was effectively quenched by Sunset Yellow (SY). Consequently, a novel fluorescent probe was developed for SY detection. This probe exhibited a linear range of 0.085-11.31 µg/mL and limit of detection of 0.026 µg/mL. The R-CDs were validated for SY quantification in various food samples, including carbonate beverages, powdered beverage, cider vinegar, fruit flavored drinks, chocolate, and hard candy samples, achieving recovery rates of 91.2-122 % and a relative standard deviation of 1.0-3.5 %. The synthesized R-CDs therefore show promise for application as a probe for the detection of SY in foods.

3.
J Environ Manage ; 370: 122739, 2024 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-39368388

RESUMEN

INTRODUCTION: Microbial fuel cell (MFC) is a variant of the bio-electro-chemical system that uses microorganisms as biocatalysts to generate bioenergy by oxidizing organic matter. Due to its two-prong feature of simultaneously treating wastewater and generating electricity, it has drawn extensive interest by scientific communities around the world. However, the pollution purifying capacity and power production of MFC at the laboratory scale have tended to remain steady, and there have been no reports of a performance breakthrough. PROBLEM STATEMENT: This research was conducted to produce electricity and evaluate the efficiency of chemical oxygen demand (COD) removal from wastewater containing Citric Acid using a two-chamber microbial fuel cell without an intermediary. METHODOLOGY: In this research, citric acid factory wastewater was used as the substrate, graphite as the electrode, Nafion membrane for proton transfer from anode to cathode, and grape waste as a carbon source. These Experiments were performed at room temperature and neutral pH. Also, the effect of three independent variables mixed liquor suspended solid (MLSS), Carbon: Nitrogen: Phosphorus stoichiometric ratio (COD:TKN:P), and grape waste on electricity production and wastewater treatment was investigated. Then, the optimal values of each variable were determined under favorable conditions for electricity generation and COD reduction. RESULTS: The MFC was conducted at the optimal values of MLSS 1400 mg/L, the stoichiometric ratio of COD:TKN:P 140:10:1, and the grape waste dose of 1.4 g/L. At these conditions, the obtained maximum power density and current density were 18228.10 mW/m2 and 244.44 mA/m2, respectively. The maximum COD removal was 72% achieved in the values of MLSS 1400 mg/L, the stoichiometric ratio of COD:TKN:P equal to 260:10:1, and 1.4 g/L of grape waste. The maximum open circuit voltage was also recorded as 678 mV, obtained at MLSS 3000 mg/L, the stoichiometric ratio of COD:TKN:P equal to 200:10:1, and for a grape waste dose of 2 g/L. CONCLUSION: The results of this research showed that the use of grape waste to supply glucose to microorganisms in the MFC system has a significant effect on increasing energy production and COD removal, and it is recommended to conduct additional research in the future to improve the efficiency. However, scalability and practical application potential of these integrated technologies are the challenges towards their real-world applications in small scale trials.

4.
Microbiol Spectr ; : e0190624, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39377610

RESUMEN

For over a century, the filamentous Ascomycete fungus Aspergillus niger has played a pivotal role in the industrial production of citric acid. A critical fermentation parameter that sustains high-yield citric acid accumulation is the suboptimal concentration of manganese(II) ions in the culture broth at the early stages of the process. However, the requirement for this deficiency has not been investigated on a functional genomics level. In this study, we compared the transcriptome of the citric acid hyper-producer A. niger NRRL2270 strain grown under citric acid-producing conditions in 6-L scale bioreactors at Mn2+ ion-deficient (5 ppb) and Mn2+ ion-sufficient (100 ppb) conditions at three early time points of cultivation. Of the 11,846 genes in the genome, 963 genes (8.1% of the total) were identified as significantly differentially expressed under these conditions. Disproportionately high number of differentially regulated genes encode predicted extracellular and membrane proteins. The most abundant gene group that was upregulated in Mn2+ ion deficiency condition encodes enzymes acting on polysaccharides. In contrast, six clusters of genes encoding secondary metabolites showed downregulation under manganese deficiency. Mn2+ deficiency also triggers upregulation of the cexA gene, which encodes the citrate exporter. We provide functional evidence that the upregulation of cexA is caused by the intracellular accumulation of citrate or acetyl-CoA and is a major factor in triggering citrate overflow. IMPORTANCE: Citric acid is produced on industrial scale by batch fermentation of the filamentous fungus Aspergillus niger. High-yield citric acid production requires a low (<5 ppb) manganese(II) ion concentration in the culture broth. However, the requirement for this deficiency has not been investigated on a functional genomics level. Here, we compared the transcriptome of a citric acid hyper-producer A. niger strain grown under citric acid-producing conditions in 6-L scale bioreactors at Mn2+ ion-deficient (5 ppb) and Mn2+ ion-sufficient (100 ppb) conditions at three early time points of cultivation. We observed that Mn2+ deficiency triggers an upregulation of the citrate exporter gene cexA and provides functional evidence that this event is responsible for citrate overflow. In addition to the industrial relevance, this is the first study that examined the role of Mn2+ ion deficiency in a heterotrophic eukaryotic cell on a genome-wide scale.

5.
Environ Geochem Health ; 46(11): 473, 2024 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-39400738

RESUMEN

The novel brominated flame retardant decabromodiphenyl ethane (DBDPE) has biological toxicity, persistence, long-range migration and bioaccumulation ability. However, there is currently little research on the phytotoxicity of DBDPE in plants. The perennial herbaceous plant tall fescue (Festuca elata Keng ex E. B. Alexeev) was selected as the model organism for use in seed germination experiments, and the phytotoxicity of DBDPE in the soil of tall fescue was studied. The results indicated that DBDPE had a significant effect on the germination and growth of tall fescue seedlings. Citric acid reduced the stress caused by DBDPE in plants, effectively alleviating the phytotoxicity of DBDPE in tall fescue. The root vitality and protein content significantly increased after the application of citric acid, increasing by 74.93-183.90%, 146.44-147.67%, respectively. The contents of proline and soluble sugars significantly decreased after the application of citric acid, decreasing by 45.18-59.69% and 23.03%, respectively (P < 0.05). There was no significant difference in superoxide dismutase (SOD) or peroxidase (POD) activity in tall fescue seedlings, and the catalase (CAT) activity and malondialdehyde (MDA) content were significantly lower after the application of citric acid, decreasing by 64.62-67.91% and 29.10-49.80%, respectively (P < 0.05). Tall fescue seedlings bioaccumulated DBDPE, with biological concentration factors (BCFs) ranging from 4.28 to 18.38 and transfer factors (TFs) ranging from 0.43 to 0.54. This study provides theoretical support for the study of the toxicity of DBDPE to plants and offers a research foundation for exploring the phytoremediation of DBDPE-contaminated soil by tall fescue.


Asunto(s)
Ácido Cítrico , Festuca , Germinación , Plantones , Contaminantes del Suelo , Plantones/metabolismo , Plantones/efectos de los fármacos , Festuca/metabolismo , Festuca/efectos de los fármacos , Ácido Cítrico/metabolismo , Germinación/efectos de los fármacos , Contaminantes del Suelo/toxicidad , Contaminantes del Suelo/metabolismo , Bromobencenos/toxicidad , Retardadores de Llama/toxicidad , Retardadores de Llama/metabolismo , Semillas/efectos de los fármacos , Semillas/metabolismo , Raíces de Plantas/metabolismo , Raíces de Plantas/efectos de los fármacos
6.
J Dent Res ; : 220345241279555, 2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39394783

RESUMEN

Nonresolving inflammation causes irreversible damage to periodontal ligament stem cells (PDLSCs) and impedes alveolar bone restoration. The impaired tissue regeneration ability of stem cells is associated with abnormal mitochondrial metabolism. However, the impact of specific metabolic alterations on the differentiation process of PDLSCs remains to be understood. In this study, we found that inflammation altered the metabolic flux of the tricarboxylic acid cycle and induced the accumulation of fumarate through metabolic testing and metabolic flux analysis. Transcriptome sequencing revealed the potential of fumarate in modulating epigenetics. Specifically, histone methylation typically suppresses the expression of genes related to osteogenesis. Fumarate was found to impede the osteogenic differentiation of PDLSCs that exhibited high levels of H3K9me3. Various techniques, including assay for transposase-accessible chromatin with high-throughput sequencing, chromatin immunoprecipitation sequencing, and RNA sequencing, were used to identify the target genes regulated by H3K9me3. Mechanistically, accumulated fumarate inhibited lysine-specific demethylase 4B (KDM4B) activity and increased H3K9 methylation, thus silencing asporin gene transcription. Preventing fumarate from binding to the histone demethylase KDM4B with α-ketoglutarate effectively restored the impaired osteogenic capacity of PDLSCs and improved alveolar bone recovery. Collectively, our research has revealed the significant impact of accumulated fumarate on the regulation of osteogenesis in stem cells, suggesting that inhibiting fumarate production could be a viable therapeutic approach for treating periodontal diseases.

7.
Angew Chem Int Ed Engl ; : e202414484, 2024 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-39395025

RESUMEN

Hydrometallurgy remains a major challenge to simplify its complex separation and precipitation processes for spent lithium-ion batteries (LIBs). Herein, we propose a Fischer-lactonisation-driven mechanism for the cascade reaction of leaching and chelation of spent LIBs. Citric acid undergoes a two-step dissociation of the carboxylic acid (-COOH) and complexes with the leached metal ion, while the residual -COOH is attacked by H protons to form a protonated carboxyl ion (-COO^-). Subsequently, the lone pair of electrons in the hydroxyl of the same molecule attack the carbon atom in -COO^- to facilitate ester bonding, leading to the formation of a lactonized gel. The leaching rates of Li, Ni, Co and Mn are 99.3, 99.1, 99.5 and 99.2%, respectively. The regenerated monocrystalline LiNi0.5Co0.2Mn0.3O2 (NCM523) has a uniform particle size distribution and complete lamellar structure, with a capacity retention rate of 70.6% after 250 cycles at 0.5 C. The mechanism achieves a one-step chelation reaction, and the energy consumption and carbon emissions are only 26% and 44%, respectively, of that of the conventional hydrometallurgical. The strategy achieves a double breakthrough in simplifying the process and improving environmental friendliness, offering a sustainable approach to the re-utilization of spent LIBs.

8.
Int J Biol Macromol ; 281(Pt 2): 136385, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39383914

RESUMEN

Citric acid-modified starch functions as a resistant starch, while the combined effects of its fine molecular structure and degree of substitution on gut microbiota are not well understood. To this end, citric acid-modified starches with varying degrees of substitution were synthesized from rice starches with distinct molecular structures and their impact on gut microbiota composition and short-chain fatty acid (SCFA) production was analyzed. Notably, rice starch with a higher degree of substitution significantly reduced acetate production, while promoted butyrate production. Correlation analysis further suggested that amylopectin chains with 12 < DP ≤ 36 and amylose chains with 100 < DP ≤ 500 alter the growth of Faecalibacterium_prausnitzii and Bacteroides_vulgatus, consequentially determining the production of SCFAs. Collectively, these findings indicate that citric acid-modified rice starch with different degrees of substitution can target specific gut bacteria and SCFA production, thus conferring beneficial impact on human health.

9.
Int J Biol Macromol ; 281(Pt 3): 136339, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39383909

RESUMEN

Lignocellulose (LC) is a natural polymer material that holds immense potential for various applications. However, extracting LC from biomass wastes with high-starch content has been challenging due to low selectivity and yield. In this study, LC was prepared from cassava residue (CR) via a combination of mechanical activation pretreatment and a citric acid (CA)-enhanced ternary deep eutectic solvent (TDES) consisting of choline chloride (ChCl), lactic acid (LA), and CA. The mechanical activation reduces the size of CR, greatly promoting the removal ability for starch, lignin and hemicellulose using TDES, and thus improving yield and selectivity of LC through this method. The CA esterified LC to prevent its excessive hydrolysis and increased a significantly higher LC content (82.52 wt%) compared to mechanical activation only and DES without CA, increasing by 6.97 times and 1.26 times, respectively. The extraction temperature significantly affected the structure, composition, thermal stability of LC and the properties of recovered TDES. The LC extracted at 90 °C (LC-90) had the highest cellulose content (82.52 wt%), crystallinity index (44.82 %), and higher degradation temperature (339.7 °C). The properties of the recovered TDES and extraction mechanism were analyzed. This study provides a strategy for the high-value utilization of biomass waste.

10.
Int J Biol Macromol ; 281(Pt 3): 136338, 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39374719

RESUMEN

Wheat straw, as a non-wood fiber waste, is available worldwide and can be used in cellulosic matric production, promoting the application of sustainable materials. However, poor fiber properties and water drainage are the primary obstacles to its utilization. In this study, wheat straw pulp fibers were chemically crosslinked by citric acid (CA) in an environmentally friendly process. X-ray photoelectron spectroscopy and Fourier transform infrared spectra confirmed that the chemical treatment introduced carboxylic groups to cellulose fibers. Meanwhile, X-ray diffraction patterns showed that the crystallinity of cellulose was reduced. The average fiber length and water retention value of the pulp decreased with increasing CA dosage under the conditions of 3 mL/g CA4 (4 wt% CA), and the drainage performance of the cellulose pulp improved by 21 %. Also, the crosslinking of fibers contributed to the mechanical properties of the cellulosic matrix, increasing the dry and wet strength by 21 % and 282 %, respectively. These results demonstrated that citric acid could be a sustainable method for improving the properties of wheat straw fibers, thereby promoting its application in fabricating sustainable materials.

11.
Cureus ; 16(9): e69963, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39445300

RESUMEN

BACKGROUND: Non-carious cervical lesions (NCCLs) present themselves as smooth saucer lesions with variable height and depth. Treatment of choice for these lesions should be aimed at conservative management by restoring the teeth. The present study aims to evaluate the micro-tensile bond strength in NCCLs after various surface pre-treatments. MATERIALS AND METHODS: Sixty-six human permanent maxillary first premolars were subjected to artificial wedge-shaped lesions on the buccal aspect of the cervical regions of all the teeth. Samples were divided into two groups (n = 33 per group). Group 1 received a 37% orthophosphoric acid treatment for 30 seconds and a 17% ethylene diamine tetraacetic acid (EDTA) application for 10 seconds. Group 2 received a 10% citric acid treatment for 30 seconds, followed by a 17% EDTA application for 10 seconds. These groups were further subdivided according to the bonding agent applied as subgroup A: 3M™ Single Bond™; Subgroup B: Prime & Bond Universal group; and Subgroup C: Tetric N-Bond Universal. Samples were subjected to incremental restoration and then segmented to fit into Geraldelli jig with cyanoacrylate adhesive. A universal testing machine was used to assess the micro-tensile bond strength and the data obtained were subjected to statistical analysis. RESULTS: In this study, statistically significant differences in micro-tensile strength were observed between the pre-treatment groups and the effect of the bonding agent. Consequently, the null hypothesis was rejected, and the research hypothesis was accepted. The micro-tensile strength for both groups was compared with various pre-conditioning methods. It was noted that the micro-tensile strength was maximum when Tetric N Bond was used along with 37% orthophosphoric acid followed by Prime Bond with highly statistically significant values (p = 0.000). Contrary to this, in the 10% citric acid group, the micro-tensile strength was equally comparable in the 3M ESPE and Tetric N bond groups compared to the Prime Bond group, with highly statistically significant differences (p = 0.000). CONCLUSION: Surface pre-treatment in NCCLs improves the bonding strength of the restoration used. Analysis using scanning electron microscopy and long-term assessment of the failure of restoration should be carried out in future studies.

12.
Molecules ; 29(19)2024 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-39407550

RESUMEN

In the present work, the phytotoxic effects of secondary metabolites extracted from lichen Ramalina celastri (usnic acid) and lichen Stereocaulon ramulosum (a naturally occurring mixture of atranorin and perlatolic acid, approx. 3:1) on cultures of the aposymbiotically grown lichen photobiont Asterochloris erici were evaluated. Algae were cultivated on the surface of glass microfiber disks with applied crystals of lichen extracts for 14 days. The toxicity of each extract was tested at the two selected doses in quantities of 0.01 mg/disk and 0.1 mg/disk. Cytotoxicity of lichen extracts was assessed using selected physiological parameters, such as growth (biomass production) of photobiont cultures, content of soluble proteins, chlorophyll a fluorescence, chlorophyll a integrity, contents of chlorophylls and total carotenoids, hydrogen peroxide, superoxide anion, TBARS, ascorbic acid (AsA), reduced (GSH) and oxidized (GSSG) glutathione, and composition of selected organic acids of the Krebs cycle. The application of both tested metabolic extracts decreased the growth of photobiont cells in a dose-dependent manner; however, a mixture of atranorin and perlatolic acid was more effective when compared to usnic acid at the same dose tested. A higher degree of cytotoxicity of extracts from lichen S. ramulosum when compared to identical doses of extracts from lichen R. celastri was also confirmed by a more pronounced decrease in chlorophyll a fluorescence and chlorophyll a integrity, decreased content of chlorophylls and total carotenoids, increased production of hydrogen peroxide and superoxide anion, peroxidation of membrane lipids (assessed as TBARS), and a strong decrease in non-enzymatic antioxidants such as AsA, GSH, and GSSG. The cytotoxicity of lichen compounds was confirmed by a strong alteration in the composition of selected organic acids included in the Krebs cycle. The increased ratio between pyruvic acid and citric acid was a very sensitive parameter of phytotoxicity of lichen secondary metabolites to the algal partner of symbiosis. Secondary metabolites of lichens are potent allelochemicals and play significant roles in maintaining the balance between mycobionts and photobionts, forming lichen thallus.


Asunto(s)
Alelopatía , Líquenes , Metabolismo Secundario , Líquenes/metabolismo , Líquenes/química , Líquenes/crecimiento & desarrollo , Benzofuranos/farmacología , Benzofuranos/metabolismo , Benzofuranos/química , Clorofila A/metabolismo , Clorofila/metabolismo , Ascomicetos/metabolismo , Ascomicetos/efectos de los fármacos , Carotenoides/metabolismo , Hidroxibenzoatos
13.
Int J Biol Macromol ; : 136909, 2024 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-39471931

RESUMEN

A new type of polycarboxylic acid crosslinking agent 2-(2,4,5-tricarboxybenzyloxy)-1,2,3-propanetricarboxylic acid (TBPTA) with the morphology similar to the regular arrangement of the foliar morphology of Araucaria was synthesized by dissolving carboxylic acid system of 1, 2, 3, 4-butane tetracarboxylic acid (PMDA) and citric acid (CA) in the molar ratio of 1: 1 in tetrahydrofuran (THF) at 68 °C. On this basis, a novel adsorbent TEMPO-derived nanocellulose (CNF)/TBPTA with excellent adsorption properties for methylene blue (MB) was prepared by mixing CNF, TBPTA as raw materials and sodium hypophosphite (SHP) as catalyst in various proportions. The X-ray diffraction (XRD) spectra showed that the cross-linking effect of TBPTA transformed the crystal structure of CNF from type I to type II. The MB adsorption results suggested that the maximum adsorption capacity of CNF/TBPTA was 1152 mg g-1, which was 321.58 % higher than that of CNF without TBPTA esterification crosslinking modification. The adsorption process can be described by Langmuir isothermal adsorption model and pseudo-second-order kinetic model, involving electrostatic force, hydrogen bond and π-π conjugation effect. CNF/TBPTA demonstrates a strong potential for reuse, maintaining 92 % of its initial MB adsorption efficiency after undergoing 7 successive adsorption-desorption cycles.

14.
Front Bioeng Biotechnol ; 12: 1483025, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39420967

RESUMEN

This study investigated the biphasic phenoxyethanol-citric acid (PECA) pretreatment for bamboo residues (BRs) and its corresponding effects on the enzymatic hydrolysis performance. It is found that increasing the concentration of citric acid in the pretreatment system from 2.5% to 15% greatly enhanced the delignification and xylan removal for BRs. Consequently, the enzymatic hydrolysis yield of pretreated BRs significantly enhanced, increasing from 12.4% to 58.2% and 28.0%72.4% when the concentration of citric acid was increased from 2.5% to 15.0% at 160°C and 170°C, respectively. The characterization results from cellulose crystallinity, accessibility, and hydrophobicity of pretreated bamboo residues indicated that their changes possessed a beneficial performance on the enzymatic hydrolysis yield, which could result from the synergistic removal of lignin and xylan. The Chrastil model analysis showed that pretreatment at higher conditions resulted in the pretreated BRs possessing weaker diffusion resistance for cellulase, which is attributed to its higher enzymatic hydrolysis yield.

15.
Membranes (Basel) ; 14(10)2024 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-39452825

RESUMEN

Composite polymer membranes were obtained using the so-called dry phase inversion and were used for desalination of diluted saline water solutions by pervaporation (PV) method. The tests used a two-layer backing, porous, ultrafiltration commercial membrane (PS20), which consisted of a supporting polyester layer and an active polysulfone layer. The active layer of PV membranes was obtained in an aqueous environment, in the presence of a surfactant, by cross-linking a 5 wt.% aqueous solution of polyvinyl alcohol (PVA)-using various amounts of cross-linking substances: 50 wt.% aqueous solutions of glutaraldehyde (GA) or citric acid (CA) or a 40 wt.% aqueous solution of glyoxal. An ethylene glycol oligomer (PEG 200) was also used to prepare active layers on PV membranes. Witch its help a chemically cross-linked hydrogel with PVA and cross-linking reagents (CA or GA) was formed and used as an active layer. The manufactured PV membranes (PVA/PSf/PES) were used in the desalination of water with a salinity of 35‱, which corresponds to the average salinity of oceans. The pervaporation method was used to examine the efficiency (productivity and selectivity) of the desalination process. The PV was carried at a temperature of 60 °C and a feed flow rate of 60 dm3/h while the membrane area was 0.005 m2. The following characteristic parameters of the membranes were determined: thickness, hydrophilicity (based on contact angle measurements), density, degree of swelling and cross-linking density and compared with the analogous properties of the initial PS20 backing membrane. The physical microstructure of the cross-section of the membranes was analyzed using scanning electron microscopy (SEM) method.

16.
Environ Pollut ; 363(Pt 1): 125061, 2024 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-39374758

RESUMEN

Green rust (GR), as a vital intermediate product during the formation of various iron oxides, exists with organic matters and metals contaminants in natural environments. Understanding the effects of these natural factors on the transformation process of GR into iron oxides and the environmental behaviors of heavy metals and organic matters during process are critical for environmental quality management, but the fundamental identification of the interaction mechanisms between them and GR is still challenging. In this study, the transformation mechanisms of Co-bearing green rust (GR-Co) synthesized by co-precipitation, and the redistribution behaviors of Co(II) in an environment containing oxalic acid (OA) and citric acid (CA) were clarified. The findings indicated that OA promoted the Fe(II) dissolution and the transformation of GR-Co to goethite, while CA decreased the Fe(II) dissolution and the proportion of non-extractable Co. Furthermore, in the presence of CA, the transformation products of GR-Co were ferrihydrite, magnetite, lepidocrocite and goethite instead of only lepidocrocite and goethite. Meanwhile, CA prohibited ferrihydrite from transforming into more highly crystalline iron minerals. The finding of this study improves the understanding of the interaction mechanisms between GR-Co and organic matter, and the environmental geochemical behaviors of Co and organic carbon during the transformation processes in nature.

17.
Sci Rep ; 14(1): 25729, 2024 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-39468231

RESUMEN

Swelling of shale in clastic reservoirs poses a significant challenge, causing instability in wellbores. Utilizing water-based drilling mud with shale inhibitors is preferable for environmental reasons over oil-based mud. Ionic liquids (ILs) have garnered interest as shale inhibitors due to their customizable properties and strong electrostatic features. However, widely used imidazolium-based ILs in drilling fluids are found to be toxic, non-biodegradable, and expensive. Deep Eutectic Solvents (DES), considered a more economical and less toxic alternative to ILs, still fall short in terms of environmental sustainability. The latest advancement in this field introduces Natural Deep Eutectic Solvents (NADES), renowned for their genuine eco-friendliness. This study explores NADES formulated with citric acid (as a Hydrogen Bond Acceptor) and glycerine (as a Hydrogen Bond Donor) as additives in drilling fluids. The NADES based drilling mud was prepared according to API 13B-1 standards and their efficacy was compared with KCl, imidazolium based ionic liquid, and Choline Chloride: Urea-DES based mud. A thorough physicochemical characterization of the in-house prepared NADES is detailed. The research evaluates rheological, filtration and shale inhibition properties of the mud, demonstrating that NADES enhanced the yield point to plastic viscosity ratio (YP/PV), reduced mudcake thickness by 26%, and decreased filtrate volume by 30.1% at a 3% concentration. Notably, NADES achieved an impressive 49.14% inhibition of swelling and improved shale recovery by 86.36%. These outcomes are attributed to NADES' ability to modify surface activity, zeta potential, and clay layer spacing which are discussed to understand the underlying mechanism. This sustainable drilling fluid promises to reshape the drilling industry by offering a non-toxic, cost-effective, and highly efficient alternative to conventional shale inhibitors, paving the way for environmentally conscious drilling practices.

18.
Viruses ; 16(9)2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39339927

RESUMEN

The recent incursion of highly pathogenic influenza viruses into dairy cattle opens new insights for influenza virus ecology and its interspecies transmission and may have a significant impact on public health and agriculture. The aim of this study was to determine the stability of a bovine highly pathogenic avian influenza H5N1 virus isolate in the milk byproduct lactose and to evaluate two inactivation methods using industrial procedures. The bovine isolate of the highly pathogenic avian influenza H5N1 virus was stable for 14 days in a concentrated lactose solution under refrigerated conditions. Heat or citric acid treatments successfully inactivated the virus in lactose. This study highlights the persistence of HPAIV in lactose and its efficient inactivation under industrial standards.


Asunto(s)
Subtipo H5N1 del Virus de la Influenza A , Lactosa , Leche , Inactivación de Virus , Lactosa/farmacología , Animales , Bovinos , Leche/virología , Subtipo H5N1 del Virus de la Influenza A/efectos de los fármacos , Calor , Ácido Cítrico/farmacología
19.
ACS Appl Bio Mater ; 7(10): 6665-6681, 2024 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-39300902

RESUMEN

Biological scaffolds are plagued by poor biomechanical properties and untimely degradation. These limitations have yet to be addressed without compromising their biocompatibility. It is desirable to avoid inflammation and have degradation with concomitant host collagen deposition or even site-appropriate in situ regeneration for the successful outcome of an implanted biological scaffold. This work aims to achieve this by utilizing a biocompatible method to modify acellular scaffolds by impregnating alkaline-catalyzed citric acid (CA) cross-linking between the extracellular matrix proteins and silk fibroin (SF)/SF-gelatin (SFG) blends. Combinatorial detergent decellularization was employed to prepare a decellularized porcine liver scaffold (DPL). After proving the decellularization efficiency, the scaffold underwent modification by vacuum impregnation with CA containing SF (SF100DPL) and SFG blends (SFG5050DPL and SFG3070DPL) following pre-cross-linking, drying, and post-cross-linking. The subsequent strength augmentation was demonstrated by significant improvement in tensile strength from 2.4 ± 0.4 MPa (DPL) to, 3.8 ± 0.7 MPa (SF100DPL), 3.4 ± 0.7 MPa (SFG5050DPL), and 3.5 ± 0.2 MPa (SFG3070DPL); Young's modulus from 8.7 ± 1.8 MPa (DPL) to 20 ± 1.9 MPa (SF100DPL), 13.3 ± 2.6 MPa (SFG5050DPL), and 16 ± 1.2 MPa (SFG3070DPL); and suture retention strength from 0.9 ± 0.08 MPa (DPL) to 2.3 ± 0.2 MPa (SF100DPL), 2.8 ± 1.2 MPa (SFG5050DPL), and 2.6 ± 0.9 MPa (SFG3070DPL). The degradation resistance of the modified scaffolds was also markedly improved. Being cytocompatible, its ability to incite tolerable inflammatory and immune responses was confirmed by rat subcutaneous implantation for 14, 30, and 90 days, in terms of inflammatory cell infiltration, neoangiogenesis, and in vitro cytokine release to assess B-cell and T-cell activation. Such ECM composite scaffolds with appropriate strength and biocompatibility offer great promise in soft tissue repair applications such as skin grafting.


Asunto(s)
Materiales Biocompatibles , Fibroínas , Ensayo de Materiales , Andamios del Tejido , Fibroínas/química , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Andamios del Tejido/química , Porcinos , Tamaño de la Partícula , Resistencia a la Tracción , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Humanos
20.
Heliyon ; 10(16): e36309, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39253192

RESUMEN

Contamination of agricultural soils with heavy metals (HMs) poses a significant environmental threat, especially because industrial discharges often irrigate agricultural lands. A prominent source of HM(s) pollution occurs from tannery effluents containing high concentrations of chromium (Cr) in both Cr3+ and Cr6+ forms along with other toxic materials. Cr is known for its carcinogenic and mutagenic properties in biological systems. Microbe-assisted phytoremediation has emerged as a promising and environmentally friendly approach for detoxifying Cr-contaminated environments. This study aimed to evaluate the performance of citric acid (CA) and a Cr-reducing bacterial strain (Staphylococcus aureus) on the phytoextraction potential of Lemna minor within a Constructed Wetland System treated with tannery wastewater. Various combinations of tannery wastewater (0, 50, and 100 %), CA (0, 5 and 10 mM), and microbial inoculants were applied to the test plants. The mitigative effects of Staphylococcus aureus strain K1 were examined in combination with different concentrations of CA (0, 5, 10 mM). Data on growth and yield attributes highlighted the beneficial effects of bacterial inoculation and CA in ameliorating Cr toxicity in L. minor, as evidenced by increased foliar chlorophyll and carotenoid contents, enhanced antioxidant enzyme activities (SOD, POD, APX, CAT), and improved nutrient uptake. Specifically, CA application resulted in an enhancement of Cr ranging from 12% to 15% and 23%-31% in concentration, and 134%-141% and 322%-337% in Cr accumulation, respectively. When combined with the S. aureus inoculation treatment, CA application (5 and 10 mM) further increased the concentration and accumulation of Cr in L. minor. The enhancement in Cr ranged from 12% to 23% and 27%-41% in concentration, 68%-75%, and 179%-185% in accumulation, respectively. These results demonstrated that L. minor is an effective choice for environmentally friendly Cr remediation due to its continued ability to grow in polluted wastewater. This study suggested that microbial-assisted phytoextraction combined with chelating agents such as CA could be a practical and effective approach for remediating tannery effluents.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...