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A biodegradable catalyst based on natural deep eutectic solvents (NaDESs) designed from Betaine and natural acids (Betaine: Citric Acid: H2O) with a molar ratio of (1:1.5:1) has been utilized in one-pot multi-component reaction for the synthesis of Isoxazol-5-ones derivatives in a mild, green and efficient manner. The reaction was carried out under different conditions that are, at 400C, ultrasonic and microwave. The developed method provided many advantages, including an excellent yield of up to 98% in a shorter reaction time, avoiding the use of toxic solvents and an easy handling process. Additionally, the use of NaDESs enabled the conservation of resources due to their simple preparation. The developed process adheres to the requirements of green chemistry by employing a bio-sourced and recyclable catalyst. [ABSTRACT FROM AUTHOR]

AbstractThe release of 21 elemental ions from lead crystal ware and metallic hip flasks into different food simulants as well as alcoholic beverages was investigated in this study. For this purpose, an ICP-MS method including a sample pre-treatment based on microwave-assisted digestion was developed and validated. Elemental ion release from lead crystal glasses into artificial tap water, 0.5% citric acid solution and white wine, respectively, was only analysed for Pb. Within 24 h, Pb release from crystal glass was shown to increase with time. To account for repeated use, at least three consecutive release experiments were performed, which showed – with one remarkable exception – constant or decreasing levels of element ion release. However, after four months resting period, Pb release from crystal glass was higher than before. In contrast, all 21 elemental ions were detected to be released from the hip flasks into 0.5% citric acid solution, apple liqueur and herb liqueur, respectively. Release of Cd, Cr, Ni, As, TI, Sn and most prominently Pb from hip flasks was in the range of and above the respective release limit (SRL) as set by the Council of Europe (CoE). When focussing on the third repetition, only one out of six hip flasks met the suggested SRL for all determined elements in all test solutions. This demonstrates both, that the SRLs of the CoE can be met and that producers of hip flasks may have to review their manufacturing processes. [ABSTRACT FROM AUTHOR]

AbstractPurposeMaterials and methodsResultsConclusionCancer diagnosis involves a multi-step process. Accurate identification of the tumor, staging and development of cancer cells is crucial for selecting optimal treatments to minimize disease recurrence. Quantum dots (QDs) represent an exciting class of fluorescent nanoprobes in molecular detection and targeted tumor imaging.In this study, graphene quantum dots (GQDs) were synthesized by pyrolysis of citric acid (CA) as a carbon precursor under high temperatures. The morphology of the obtained GQDs was first characterized using physical (TEM and DLS) and spectroscopic (fluorescence, FTIR and UV–Vis) methods. In the following,99mTc-labeled GQDs were prepared in the presence of SnCl2.2H2O as a reducing agent between 95 and 100 °C. The biodistribution and tumor targeting efficiency of radiolabeled GQDs as a novel agent for C6 glioma tumor scintigraphy in an animal model were evaluated. Furthermore, organ uptake, human serum albumin binding and tumor accumulation were measured.The TEM image of the prepared GQDs showed a relatively uniform size distribution in the range of diameter 6-9 nm and spherical shape. Radiolabeled GQDs showed a radiochemical yield of >97% (n = 3). Through incubation in human serum, almost 15% of 99mTc-labeled GQDs degraded after 6 h. The amount of uptake in xenograft models of glioma C6 rats was 1.10 ± 0.36% of injection dose per gram after 1 h. The kidneys, intestinal and glioma tumor sites were observed via scintigraphy imaging.Our data suggest that 99mTc-labeled GQDs, as a new radiotracer, efficiently accumulate in the tumor site and could be included as a radiotracer for detecting glioma tumors. [ABSTRACT FROM AUTHOR]

AbstractIn this work, we have studied the stability constants of ternary cobalt(II) complexes with the primary ligands: pyridine-2,3-dicarboxylic acid (H22,3-Dipic, H2L) and pyridine-3,4-dicarboxylic acid (H23,4-Dipic, H2L) and secondary ligands representing low molecular mass components of blood serum: lactic acid (HLac), oxalic acid (H2Ox), citric acid (H3Cit), and phosphoric acid (H3PO4). Potentiometric data were analyzed using the least squares computational program LETAGROP. Ionic strength and temperature were both kept constant using 1.0 mol dm−3 NaNO3 as ionic medium at 25 °C. Species distribution diagrams were generated to determine the speciation variations with respect to pH. [ABSTRACT FROM AUTHOR]

This article presents a new method for synthesizing quinoxalines, a versatile class of compounds with applications in medicine, agriculture, and materials science. The authors demonstrate that their method, which uses meglumine sulfate as a catalyst, is simple, efficient, and produces high-quality products. The article includes experimental details and characterization data for the synthesized compounds, which include various quinoxaline derivatives. The document also includes acknowledgments and a disclosure statement. [Extracted from the article]

The main objective of this work is to synthesize multifunctional nanodendritic structural molecules that can effectively encapsulate hydrophilic as well as hydrophobic therapeutic agents. Four different types of fourth-generation lysine-citric acid based dendrimer have been synthesized in this work: PE-MC-Lys-CA-PEG, TMP-MC-Lys-CA-PEG, PE-MS-Lys-CA-PEG, and TMP-MS-Lys-CA-PEG. The antibacterial drug cefotaxime (CFTX) was further conjugated to these dendrimers. The dendrimer and drug-dendrimer conjugate structures were characterized with the help of FTIR,1H-NMR, and 13C-NMR spectroscopy. Zeta sizer, AFM, and HR-TEM techniques were used to investigate the particle size, surface topography, and structural characteristics of drug-dendrimer conjugates. In vitro drug release was then investigated using dialysis method. Various kinetic drug release models were examined to evaluate the type of kinetic drug release mechanism of the formulations. Cytotoxicity study revealed that the dendrimers encapsulated with CFTX exhibited 2-3% toxicity against healthy epithelial cells, indicating their safe use. Plain dendrimers show 10-15% hemolytic toxicity against red blood cells (RBC), and the toxicity was reduced to 2-3% when CFTX was conjugated to the same dendrimers. The 3rd and 4th generation synthesized drug-dendrimer conjugates exhibit a significantly effective zone of inhibition (ZOI) against both Gram-positive and Gram-negative bacteria. For Gram-positive bacteria, the lower concentration of 0.1 mg/mL showed more than 98% inhibition of drug-dendrimer conjugate samples against B. subtilis and more than 50% inhibition against S. aureus using 0.2 mg/mL, respectively. Moreover, samples with concentrations of 0.5 and 1.0 mg/mL exhibited more than 50% inhibition against S. typhimurium and E. coli, respectively. [ABSTRACT FROM AUTHOR]

Sphagnum palustre L. is a Chinese herbal medicine with a long history, however, few studies have been performed on its chemical composition and active effects. In this study, we investigated the composition and antibacterial and antioxidant capacities of extracts obtained from Sphagnum palustre L. phytosomes extracted with conventional solvents (water, methanol, and ethanol) and two different hydrogen bond donors (citric acid and 1,2-propanediol) modified with choline chloride-type deep eutectic solvents (DESs). The results show that Sphagnum palustre extracts contained 253 compounds, including citric acid, ethyl maltol, and thymol. The highest total phenolic content (TPC) was obtained with a DES extraction method combining 1,2-propanediol and choline chloride (39.02 ± 7.08 mg gallic acid equivalent/g dried weight (DW). This shows the composition of Sphagnum palustre as a natural product and the application of DESs in the extraction of active ingredients, demonstrating the potential of peat moss extracts in cosmetics and health products. [ABSTRACT FROM AUTHOR]

Achieving the clean utilization of coal is the priority of the coal industries. This paper proposed an efficient electrochemical technology for coal desulfurization before combustion. It was explored that citric acid can chemically provide enough acidic conditions for desulfurization reactions, and the ultrasonic-enhanced treatment physically helps to remove sulfur from coal due to its cavitation effect and mechanical effect. So the experiments of ultrasound-assisted electrochemical desulfurization using citric acid as the electrolyte solution were conducted. They combined physical and chemical methods to effectively remove sulfur from coal. The optimal operating parameters of the desulfurization effect were achieved by qualitative and quantitative analysis of coal samples(coal slurry concentration of 66 g/L, electrolysis time of 8 h, electrolyte concentration of 1.5 mol/L, electrolysis voltage of 4 V, electrolysis temperature of 30°C, ultrasonic strengthening time of 1 h and ultrasonic intensity of 320 W.). The total sulfur removal efficiency reached 45.09%. The electrolytic desulfurization experiments removed samples' sulfur contents, ash contents, and water. The crystal structures of gypsum, white iron ore, zinc sulfide, and the molybdenite mineral composition were also destroyed for purification. Gaussian simulations showed that C-S bonds and S-S bonds contained in non-thiophene organic sulfur are easier to remove, and S-S bonds are more likely to break than C-S bonds. This study realized the promotion of desulfurization with the ultrasonic wave and citric acid solution. It provides a new idea of synergistic desulfurization and is beneficial to reduce atmospheric sulfur pollution. [ABSTRACT FROM AUTHOR]

Citric acid can be used as a bio-based binding agent in composites made from lignocellulosic material due to its crosslinking ability with hydroxyl groups via ester formation. Even though plenty of research has investigated diverse manufacturing conditions, with a focus on citric acid content and pressing temperature, an apparent knowledge gap persists regarding their effect on the properties of particleboards made from softwood sawdust. Furthermore, the optimal temperature for particleboards crafted from mostly non-wood lignocellulosic materials was found to be 180–200°C which is lower than that observed for softwood material in a prior study. This study aimed to systematically examine the effects of citric acid content and pressing temperature on particleboards derived from softwood sawdust. Results highlighted a positive correlation of both citric acid content and pressing temperature with mechanical and hygroscopic properties of the particleboards, the best results being achieved at 20 wt% citric acid and 220°C, exhibiting a thickness swelling of 9%, internal bonding strength of 0.77 MPa and a modulus of rupture of 4.3 MPa. This study served as a foundational framework for future investigations into the addition of other chemicals, offering a comprehensive understanding of their interactions with citric acid in particleboard manufacturing. [ABSTRACT FROM AUTHOR]

Wood, a fundamental material in construction, confronts durability and weathering challenges, notably UV-induced degradation leading to colour changes. This study investigated a novel treatment using citric acid and urea to enhance the UV stability of wood. The reaction between these compounds generates water-soluble fluorescent species and insoluble particles upon thermal treatment which may provide wood with UV protection. Specimens were treated with two different treatment methods and then exposed to 2016 h of accelerated weathering, during which colour was measured regularly. Citric acid and urea were either pressure impregnated into the wood and thermally reacted in situ during heat treatment or pre-reacted in the absence of wood with subsequent implementation into melamine formaldehyde (MF) and water-based surface coatings. The results showed that water-soluble fluorophore compounds were formed with both treatment methods. Accelerated weathering tests revealed significant colour changes over time, where specimens coated with a mixture of MF and fluorescent particles from the reaction between citric acid and urea, exhibiting the least alteration. The lowest colour change ΔE of 5.9 was observed for specimens coated with a MF-based coating containing 1 wt% of citric acid and urea thermally pre-reacted at a temperature of 180 °C, showcasing potential wood protection applications. [ABSTRACT FROM AUTHOR]

Diacerein (DCN) is used mainly to treat degenerative diseases, such as osteoarthritis. DCN is marketed commercially in solid dosage forms. Liquid formulations of diacerein (DCN) have been hindered by its poor chemical stability in aqueous media. This work aims to develop a novel, stable, oral, liquid preparation of DCN having a concentration of 50 mg/5 ml. Solid lipid nanoparticles (SLNs) of DCN were prepared using cetyl alcohol as the lipid matrix and Tween 80® as a surfactant. A quality-by-design approach was utilized to optimize DCN-SLNs. The optimum DCN-SLNs were dispersed in a structured vehicle to formulate the liquid dosage form. This liquid preparation was subjected to accelerated stability studies at 40 °C and 75% RH for 6 months. The potential of the liquid preparation to minimize the diarrheal effect of DCN was assessed. Optimum concentrations of cetyl alcohol (2%) and Tween 80® (0.9%) were chosen to obtain the desired characteristics of SLNs. Interestingly, we determined that 0.05% of citric acid was the maximum concentration that can be added to the liquid preparation of diacerein to modify its pH without compromising its stability. The results of the stability studies show that the liquid preparation was robust and it withstood storage conditions (40 °C, 75% RH) for 6 months. The encapsulation of diacerein helps to protect it from degradation and significantly reduced the occurrence of diarrhea as a side effect (p < 0.0001). Liquid preparations of DCN-SLNs can thus be marketed as a new dosage form. [ABSTRACT FROM AUTHOR]

Boswellia serrata ole-gum-resin extracts (BSEs) are commonly used as food supplements, especially in osteoarthritis management. The quality standard is established by determining 11-keto-β-boswellic acid (KBA) and acetyl-11-keto-boswellic acid (AKBA) content using high-performance liquid chromatography (HPLC) or assessing the total boswellic acid (TBA) content by titrimetry. The limited geographical distribution of Boswellia species and increasing industrial demand could increase the risk of adulteration in Boswellia-containing products. In this study, 14 BSEs from commercial sources, used in food supplements, were analyzed in comparison with a USP Reference Standard extract. The KBA and AKBA content was determined by HPLC, whereas the TBA content was determined by titration. Targeted UHPLC-high-resolution mass spectrometry (HRMS) was applied to identify the carboxylic acid content in the samples. The 1H NMR spectra of extracts were also analyzed. Only two products met the criteria for KBA and AKBA content. Although, the TBA content complied with the expected amount, 10 extracts contained citric acid levels of 6–11% even though citric acid is not a cha-racteristic component of BSEs. Our results suggest undeclared addition of citric acid to comply with declared contents of TBA when using titration methods. Incorporation of citric acid to industrial samples – in order to alter the outcomes of the titration analysis – was demonstrated for the first time. [ABSTRACT FROM AUTHOR]

In this study, the removal of RhB from water by furfural residue (FR) biochar was prepared by hydrothermal carbonization (HTC) and citric acid (CA) modification and named this biochar as CHFR (C refers to citric acid, H refers to hydrothermal carbonization and FR is furfural residue). The CHFR were characterized by SEM, FT-IR and XPS, and CHFR was investigated by the effects of initial concentration, adsorbent dosage, pH, and contact time on the removal of RhB, and the experimental data were analyzed using the adsorption isotherm models, the adsorption kinetic models and thermodynamics, et al. The results showed that CHFR has strong adsorption performance, and the theoretical maximum adsorption capacity of RhB was 39.46 mg·g−1 under the reaction conditions of pH3, the dosage of 1.5 g·L−1, and 120 min contact time, with a removal efficiency close to 100%. the adsorption of RhB by CHFR is spontaneous and endothermic, which is consistent with the Freundlich adsorption, and the isotherm model fits well with the pseudo-second-order model, and the adsorption rate could still be as high as 92.74% after five regenerations, therefore, CHFR is an environmentally friendly and efficient adsorbent with excellent adsorption regeneration performance. [ABSTRACT FROM AUTHOR]

Membrane fouling during the filtration process is a perennial issue and could lead to reduced separation efficiency. In this work, poly(citric acid)-grafted graphene oxide (PGO) was incorporated into a matrix of single-layer hollow fibre (SLHF) and dual-layer hollow fibrr (DLHF) membranes, respectively, aiming to improve membrane antifouling properties during water treatment. Different loadings of PGO ranging from 0 to 1 wt% were first introduced into the SLHF to identify the best PGO loading for the DLHF preparation with its outer layer modified by nanomaterials. The findings showed that at the optimized PGO loading of 0.7 wt%, the resultant SLHF membrane could achieve higher water permeability and bovine serum albumin rejection compared to the neat SLHF membrane. This is due to the improved surface hydrophilicity and increased structural porosity upon incorporation of optimized PGO loading. When 0.7 wt% PGO was introduced only to the outer layer of DLHF, the cross-sectional matrix of the membrane was altered, forming microvoids and spongy-like structures (more porous). Nevertheless, the BSA rejection of the membrane was improved to 97.7% owing to an inner selectivity layer produced from a different dope solution (without the PGO). The DLHF membrane also demonstrated significantly higher antifouling properties than the neat SLHF membrane. Its flux recovery rate is 85%, i.e. 37% better than that of a neat membrane. By incorporating hydrophilic PGO into the membrane, the interaction of the hydrophobic foulants with the membrane surface is greatly reduced. [ABSTRACT FROM AUTHOR]

Ferric ion (Fe3+) serves as an essential and indispensable inorganic element in various biological process. Excess Fe3+ is harmful for biological systems and human health. Herein, highly sensitive carbon quantum dots (Fe-CQDs) for ferric ions were synthesized by a high-efficiency, one-step hydrothermal route utilizing L-arginine and citric acid. The prepared Fe-CQDs exhibited good water solubility, high photostability, and bright blue florescence with relatively high quantum yields (QYs) over 21.33% and a Stokes shift exceeding 100 nm. The functionalized Fe-CQDs offer rapid, sensitive, and selective recognition of Fe3+ with a linear relationship from 0.6 to 80 μM and a low detection limit of 0.2 μM. Moreover, the synthesized Fe-CQDs illustrated strong anti-interference properties in samples and buffer solutions. The developed sensor demonstrated high biocompatibility and was successfully applied for intracellular Fe3+ determination in SHSY5Y and HT22 cells, illustrating excellent imaging application. The present work provides a promising platform for the early clinical diagnosis of Fe3+-associated diseases. [ABSTRACT FROM AUTHOR]

Saccharomycopsis fibuligera (Lindner) Klocker 1907 is frequently employed in the fermentation of metabolites such as citric acid, ethanol, mannitol, and pyruvate. Its heat tolerance and alcohol-producing capabilities during fermentation make it a desirable option for bread and wine production. To date, the mitochondrial genome of S. fibuligera has not been sequenced. In the present study, we obtained the full mitochondrial genome of S. fibuligera, which is 57,302 bp long and has a GC content of 24.40%. This genome contained 14 core protein-coding genes, 3 independent ORFs, 21 intronic ORFs, 25 tRNAs, and 2 rRNA genes. By utilizing the Bayesian inference phylogenetic method, we constructed phylogenetic trees for 24 Saccharomycotina fungi, which indicated that S. fibuligera is closely related to S. capsularis. [ABSTRACT FROM AUTHOR]

A solid phase extraction-electrospray ionization-ion mobility spectrometry (SPE-ESI-IMS) method was developed to determine six organic acids in cucumber leaves. The multiplexing IMS using correlation technique was adopted to optimize the signal-to-noise ratio (SNR) and resolution. 90% methanol/water was selected to be the solvent, the flow rate was 120 µL·h−1, the stop frequency of ion gate was 5000 Hz, the ion gate opening period was 0.1 ms, the air flow velocity was 2.0 L·min−1, the electrospray voltage was 3.5 kV, and the drift tube temperature was 90 °C. The cucumber leaves were treated with ultrasound in 50% methanol/water. The analytes were subsequently eluted from an SPE cartridge with 0.1 mol·L−1 HCl, and the extract was neutralized to pH 2–3 with ammonia before freeze-drying. SPE-ESI-IMS enabled the effective determination of citric acid, fumaric acid, lactic acid, malic acid, pyruvic acid, and succinic acid based upon the drift time. The limits of detection were from 0.008 µg·mL−1 to 0.2 µg·mL−1, and the recoveries of spiked samples were from 87.00% to 107.20%. The convenient, sensitive, and efficient developed SPE-ESI-IMS method may be applicable for the determination of organic acids in leaves. [ABSTRACT FROM AUTHOR]

There are abundant low-rank coal resources in China. However, its higher AAEMs (alkali and alkaline earth metals) content and the release of AAEMs during combustion cause serious fouling and slagging problems. In this paper, a method of removing AAEMs and ash from low-rank coal to produce clean coal by organic acid leaching was proposed. The leaching effects of four organic acids were compared, the leaching mechanism of citric acid was analyzed, and the removal behavior of AAEMs and ash was investigated. The results show the effect of citric acid is better than others. During the leaching process, the citric acid ionizes H+, which reacts with inorganic minerals of AAEMs, completes ion exchange with AAEMs Organics. Under the relative optimized experimental conditions, the content of Na2O in coal ash is 0.9%, which is in line with the standard of power coal in China. The removal efficiency of alkaline earth metals Ca and Mg are significantly lower than those of alkali metals Na and K. The trend in the removal efficiency of Ca and ash are consistent. Citric acid leaching is an effective and promising method to produce clean coal from low-rank coal. [ABSTRACT FROM AUTHOR]

One of the potassium (K) sources for plant growth are the soil clay minerals (such as vermiculite) that have K element in their structure. The purpose of this research was the investigation of non-exchangeable K release from vermiculite clay soil to citric acid and calcium chloride extractants. Treatments included two vermiculite clay soil samples (with carbonatic (CV) and non-carbonatic (NCV)) and two extractants (0.01 M CaCl2 and citric acid). Thirteen successive extractions of K were done during 1, 2, 4, 6, 16, 24, 48, 72, 120, 168, 312, 384 and 552 h. Cumulative K release was determined and data was fitted to five kinetic equations. Results showed that there was a significant difference between treatments and extractants in K release. Cumulative K release to CaCl2 for CV and NCV was 3161 and 2935 mg kg−1, respectively while this was for citric acid 2172 and 1503 mgkg−1, respectively. The best kinetic models describing K release to CaCl2 and citric acid were Elovich (r = 0.98 and 0.80, p <.01) and power function equations (r = 0.96 and 0.76, p <.01). Maximum K release was observed in carbonatic vermiculite extracted with CaCl2 (1873 mgkg−1). Results of X-ray diffraction analysis showed that the peak intensity of vermiculite reduced with extraction time and no complete conversion were observed but its peaks showed the presence of mixed minerals such as mica-vermiculite and chlorite-vermiculite. Scanning electron microscopy analysis revealed that vermiculite clay soil structure was changed and more voids were observed in the mineral structure with extraction time. It's recommended that release experiment is done in longer time for better monitoring of vermiculite structural changes. The present study showed that vermiculite clay soil taken from Jiroft mine can be used as a natural source of potash fertilizer in sustainable agriculture. [ABSTRACT FROM AUTHOR]

Cu-Mo composite powders were produced by combining solution combustion synthesis and self-propagating high-temperature synthesis. In the first stage a homogeneous nanocomposite powder comprising molybdenum dioxide and copper with average particle size of 50 nm was produced using ammonium heptamolybdate, copper nitrate as precursors and citric acid as a chelating reagent. At the second stage Cu-Mo nanocomposite preparation was performed by reduction of MoO2+Cu mixture with Mg + C combined reducer at a relatively moderate thermal conditions. The relationship between combustion peculiarities, phase composition and microstructural features were examined. Highlights: Novel approach for preparation of Cu-Mo nanocomposite was invented. MoO2 and copper powders mixture was prepared by solution combustion synthesis. A mixture of MoO2 and Cu was reduced in the combustion mode by Mg/С combined reducer. Cu-Mo composite powder with particle size of 50–70 nm was produced. [ABSTRACT FROM AUTHOR]

Undersized fraction from aged municipal solid waste (UFAMSW), as a kind of soil-like material, has been proved effective in providing a large amount of organic matter and nutrients for soil and plants. The characteristics and effectiveness of heavy metal pollution removal in UFAMSW attracted tremendous research interest from scientists recently. In this study, the heavy metal removal efficiencies and bioavailability of washing on contaminated UFAMSW were evaluated with three washing reagents including ethylene diamine tetra acetic acid (EDTA), citric acid (CA), and humic acid (HA). The effects of chelating agent concentration, pH, and washing time on metal removal were investigated and response surface methodology (RSM) was employed to optimize the washing conditions. The results indicated that the removal efficiencies of Cu, Zn, and Mn could be 53.68%, 52.12%, and 30.63% by EDTA/HA washing and 42.36%, 39.67% and 28.49% by CA/HA washing, respectively. The European Community Bureau of Reference (BCR) sequential extraction was applied to analyze the fraction change of heavy metals in UFAMSW before and after washing, and it was found that chelating agent combined with HA could contribute to the removal of the exchangeable fraction. Physical and chemical properties of UFAMSW were improved to some extent after washing with mixed HA and chelating agent and could achieve the quality standard of landscape gardening soil. Accordingly, the mixture of HA and other chelating agents could be a promising washing process for preparation of landscape gardening soil using UFAMSW. Implications: Our manuscript studies the removal of heavy metals from the contaminated undersized fraction from aged municipal solid waste (UFAMSW). UFAMSW, as a kind of soil-like material, has been proved effective in providing a large amount of organic matter and nutrients for soil and plants however often limited by heavy metal pollution. The UFAMSW used in this experiment was collected after the excavation and screening-sorting of aged refuse from Changshankou Domestic Waste Sanitary Landfill in Wuhan City, Hubei Province, Southern China. This study investigated the effects of EDTA, CA, HA, mixed EDTA/HA, and mixed CA/HA washing on heavy metal removal (Cu, Zn, and Mn), bioavailability of residual heavy metal and properties. The effects of chelating agent concentration, pH, and washing time on metal removal were investigated and then response surface methodology was employed to optimize the washing conditions. The results showed that washing by CA/HA and EDTA/HA, had a higher removal efficiency of heavy metals (Cu, Zn, and Mn) in UFAMSW compared to single HA. Meanwhile, HA has a higher removal for exchangeable fraction of heavy metals, the exchangeable concentration of Cu, Zn, and Mn in CA/HA and EDTA/HA washed UFAMSW were lower compared with UFAMSW washed by single CA and EDTA. Thus, mixing HA with EDTA or CA makes a less risk to environmental and the removal efficiency is acceptable. Additionally, CA/HA and EDTA/HA washing tend to improve soil physicochemical properties and soil fertility. Thus, mixing HA with different washing agent are potential methods for preparation of landscape gardening soil using UFAMSW. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the impact of water deficit stress during fruit cultivation on the δ13C values of citric acid and malic acid in Japanese apricots at different ripeness stages and their resulting liqueurs. Our experiments show that water deficit stress increases the δ13C values of citric acid and malic acid in tree-ripened fruits, counteracting the typical decrease during ripening. However, water deficit treatment has a minimal effect on the δ13C values of organic acids in green fruits. Regardless of fruit ripeness or water status, the δ13C values of organic acids in fruits are directly reflected in the resulting liqueurs. Overall, water deficit stress during fruit cultivation has the potential to promote similarity in the δ13C values of organic acids across fruits at different ripeness levels, reducing variations among liqueurs derived from fruits of varying ripeness levels. [ABSTRACT FROM AUTHOR]

ZnO nanorods (NRs) were synthesized with Zn(NO3)2, citric acid, and NaOH as precursors and Spirulina platensis as a capping agent. The sol-gel-hydrothermal method was used to synthesize ZnO-NRs with pH adjustment of the reaction to modify its morphology. Furthermore, the products of ZnO-NRs were characterized by FT-IR, UV-Vis UV-DRS, XRD, SEM, and EDS instruments. The characterization result shows crystal and particle size differences when the biosynthetic pH ranges from 7 to 13. The ZnO bandgap energy changed at a certain pH ranging from 3.13 to 3.17 eV. FTIR analysis shows that the stretching of Zn-O occurs at wave number 436 cm−1. The morphological patterns of SEM-EDX showed that the ZnO-NPs were spherical, cube, and nanorods. However, the dominant morphology is nanorods form, where the particle sizes ranged from 120 to 180 nm. The result of the antimicrobial activity test against Staphylococcus epidermidis shows that the maximum inhibition of ZnO-pH 9 was 6–16 mm. The antioxidant test also shows that ZnO-pH 9 had the highest antioxidant content, accounting for 72.1%. [ABSTRACT FROM AUTHOR]

To improve the resistance of wood to biological decay the Maillard reaction between introduced amines and wood cell-wall polymers can be utilised. However, initial studies in wood modification showed almost complete leaching of bicine and tricine from treated wood and the loss of beneficial effects. The objective of this study was to assess whether possible reactions of bicine or tricine with wood could be further enhanced and reaction products stabilised through the addition of glucose and/or citric acid. Thus, Scots pine sapwood specimens were impregnated with tricine or bicine, with or without glucose and citric acid, and then heated to a temperature of 160°C. The dimensional stability, degree of chemical leaching and mechanical properties were assessed. Overall, it was concluded that neither the presence of glucose nor citric acid did appear to enhance the reactivity of tricine or bicine. Anti-swelling efficiency (ASE) of 50% was observed for combined treatments of bicine/tricine and citric acid but the leaching resistance originated mainly from citric acid and glucose, with no indication for the retention of bicine or tricine. The presence of citric acid led to a strongly reduced modulus of rupture. [ABSTRACT FROM AUTHOR]

Based on the growth-promoting effect of plant growth promoting bacteria on plants and the mobilization of Cd by citric acid, an experiment was designed in which the combined treatment of Bacillus megaterium and citric acid promoted ryegrass to repair Cd-contaminated soil. This study aimed to evaluate the effects of different treatments on the antioxidant enzyme activity, photosynthesis intensity, Cd accumulation, and rhizosphere cadmium migration under cadmium contamination conditions. And the soil morphology and structure changes were studied by infrared spectroscopy FourierTransformInfrared(FT-IR) and scanning electron microscope Energy Dispersive Spectrometer(SEM-EDS) before and after different treatments. The results show that the combined treatment of Bacillus megaterium and citric acid significantly improved the oxidative stress defense and plant photosynthesis and increased of rye biomass. rye biomass 1.28 times higher than CK treatment. Joint treatment significantly increased the amount of shoot accumulation of Cd, 2.31 times higher than CK treatment, increased the migration and accumulation of cadmium. FTIR and SEM-EDS also showed that the organic constituents such as O-H, C-O and C-N in soils as a major mechanism for mobilization of the heavy metal Cd. Thus, the combined treatment of Bacillus megaterium and citric acid can promote plant growth, improve the damage to ryegrass caused by single organic acid addition, and improve the plant extraction efficiency, which is a feasible way to repair Cd-contaminated soil through activated extraction system. The novelty of this study is the combined application of bacteria and chelating agents to ryegrass to improve phytoremediation efficiency. Bacillus giganosus has a good role in promoting the growth of ryegrass. As citrate, a small molecule chelate, can activate heavy metal cadmium and detoxify heavy metals, so it was selected. This study revealed in detail the response of ryegrass to the heavy metal Cd after exogenous addition of Bacillus gigansus and citrate, which is important for the application of cadmium removal by phytoremediation. Exogenous Bacillus megaterium has a pro-growth effect on ryegrass. The combined treatment of Bacillus megaterium and citric acid significantly improved oxidative defense mechanisms in ryegrass to alleviate Cd stress in plants. FTIR and SEM-EDS showed that the joint treatment significantly improved the soil nutrient content. Combined application of citric acid and Bacillus megaterium showed the highest removal rate of cadmium. [ABSTRACT FROM AUTHOR]

Flake silver powder was prepared by liquid phase reduction method with silver nitrate as silver source, ferrous sulfate heptahydrate as reducing agent, citric acid and gum acacia as surfactants. The effects of reducing agent dosage, citric acid dosage, gum acacia dosage, silver nitrate dosage and reaction temperature on the properties of silver powder were studied. The results show that when the dosage of silver nitrate is 0.08 mol·L−1, the molar ratio of silver nitrate to ferrous sulfate heptahydrate is 1:2, the oxidizing solution is added to the reducing solution at the rate of 100 ml·min−1, the citric acid is added to the oxidizing solution at 7.5% of the mass of silver nitrate, the gum acacia is added equally dispersed to the oxidizing solution and the reducing solution, the addition amount is 20% of the mass of silver nitrate and the reaction temperature is 30 °C, the silver powder obtained is flake with good dispersion and narrow particle size distribution. [ABSTRACT FROM AUTHOR]

Soil leaching remediation has attracted extensive attention because of its good removal effect, short operation period and stable removal effect of heavy metals. The key to reduce the harm of heavy metal contaminated soil to the environment and human health is to use appropriate leachate to repair heavy metal contaminated soil. In this study, citric acid (CA), iron nitrate (Fe(NO3)3) and polyepoxysuccinic acid (PESA) with different concentrations were used as research reagents to explore the best combination of leaching effects of heavy metals (Cu, Zn, Pb, Cd) in contaminated soil. The effects of concentration of eluent, liquid to solid ratio and leaching time on leaching efficiency of heavy metals and the changes of soil physical and chemical properties before and after leaching were studied. The results showed that 0.5 mol/L CA and 0.05 mol/L PESA were combined according to the volume ratio of 7:3, and the leaching effect was the best when the liquid–solid ratio was 15 and the leaching time was 240 min. Under the optimal leaching condition, the four heavy metals in the soil had significant removal effects, and the removal rates were, respectively, 86.06% Cu, Zn 74.55%, Pb 67.88% and Cd 91.63%. The X-ray spectrum and Fourier infrared spectrum analysis of soil before and after leaching showed that CA-PESA combined leaching had little effect on soil structure change. This study provided theoretical support for the development and application of suitable leaching agents for the remediation of heavy metal-contaminated soil. [ABSTRACT FROM AUTHOR]

In this study, Cht/PS-CA/HNT biocomposite adsorbent was synthesized using halloysite nanotube as nanomaterial, chitosan which is a biodegradable and biocompatible biopolymer, pistachio shell as biomass source, citric acid as biomass modifier. The removal of methylene blue dyestuff on the synthesized new Cht/PS-CA/HNT from the aqueous medium by adsorption method was investigated. Experimental parameters such as dye concentration, contact time, amount of adsorbent, solution pH and temperature, which affect the adsorption process, were investigated. The adsorption experimental data were analyzed with the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms, which are widely used in aqueous solutions, and it was decided that Langmuir is the most suitable isotherm. The maximum adsorption capacity of the monolayer was calculated to be 111.14 mg/g. Optimum contact time and adsorbent dose were determined as 90 min and 1 g/L. Adsorption experimental data were applied for Pseudo-first-order and Pseudo-second-order kinetic models and it was decided that the most suitable kinetic model was pseudo-second-order. Thermodynamic evaluation of adsorption showed that adsorption is endothermic and adsorption is spontaneous. In the present study, it was determined that chitosan beads prepared using citric acid modified pistachio shells and HNT have strong adsorption properties for dyestuff removal, which is one of the important causes of environmental pollution. The novelty of this work is based on the development of a new composite adsorbent that can be synthesized in a simple and fast method and does not require expensive reagents or complex equipment. Another innovation is that MB dyestuff, which has a highly harmful effect, can be easily removed from polluted water by using simple biowaste-based adsorbents by adopting appropriate procedures. [ABSTRACT FROM AUTHOR]

Recycling postharvest tomato wastes will reduce the carbon footprints of greenhouse facilities. This study investigated the effects of tomato postharvest waste as a growing medium (TSW; tomato stalk waste and PTSW; pretreated tomato stalk waste) in soilless culture on tomato growth, development, yield and quality. Tomato wastes were compared with cocopeat and peat-perlite mixture media and economic analyses were made for potential use of tomato waste as a growing medium. The highest stomatal conductance (138.7 mmol m−2 s−1), average fruit weight (86.7 g), yield (3.96 kg plant−1) and soluble solids content (SSC; 4.8%) values were obtained from the cocopeat medium. PTSW, cocopeat and peat + perlite media yielded similar stomatal conductance values. The best fruit skin color values (hue; 0.54) were obtained from peat + perlite medium. The highest titratable acidity (4.9 g citric acid 100 mL−1) and vitamin C (21.7 mg 100 g−1) values were obtained from the TSW medium. PTSW (Pretreated tomato waste) had similar yield and quality traits with commercial growing media. It was concluded that PTSW was better than other growing media. [ABSTRACT FROM AUTHOR]

An eco-friendly citric acid leaching of uranium (VI) from Abu Zeneima carbonaceous shale, as well as its extraction using humic acid, has been studied. Excess of chloride anions in the leachate solution became an offending object for uranium recovery due to its adverse effect on quaternary ammonium resins. To overcome this serious problem, humic acid extraction of uranium (VI) has been studied. The prepared citrate leach liquor was found to assay in g/L: 0.39 U, 4.4 Cl, 1.4 Fe and 0.12 REE. The obtained results indicated that 97.3% of U (VI) was efficiently extracted compared to other associated elements (i.e. Cl, Fe and REE) at pH 5 with stirring time of 45 min. [ABSTRACT FROM AUTHOR]

Citric acid has a very important role in the extraction process of uranium from the matrix such as hydrous oxide cake formed after alkali breakdown of Egyptian Rosetta monazite mineral concentrate. This manner involved leaching of uranium selectively (94%) using 150 g L−1 citric acid concentration at solid liquid (S/L) ratio of 1:5 at room temperature for 120 min. The kinetics of the concerning leaching process and the reaction mechanism between citric acid and uranium have been discussed in detail. From the latter, it was found that the reaction was diffusion controlled and the calculated apparent activation energy value was 12.724 KJ mole−1. The work then explained the separation of Th and REEs from hydrous oxide as conventional techniques in published data. [ABSTRACT FROM AUTHOR]

As a gastrointestinal malignancy, colorectal cancer (CRC) is a main cause of cancer-related deaths worldwide. Mex-3 RNA-binding family member A (MEX3A) is upregulated in multiple types of tumors and plays a critical role in tumor proliferation and metastasis. However, the function of MEX3A in CRC angiogenesis has not been fully understood. Hence, the aim of this study was to explore the role of MEX3A in CRC angiogenesis and investigate its underlying mechanisms. MEX3A expression in CRC was first investigated by bioinformatics means and then measured by qRT-PCR and Western blot. CCK-8 assay was employed to test cell viability. Angiogenesis assay was used to assess angiogenesis. The protein levels of VEGF, FGF and SDF-1 were evaluated using Western blot. The expression levels of MYC, HK2 and PGK1 were investigated by qRT-PCR. Extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) were determined by Seahorse XP 96. The levels of pyruvate, lactate, citric acid and malate were measured by corresponding kits. Bioinformatics analysis demonstrated high MEX3A expression in CRC tissues and MEX3A enrichment in glycolysis and angiogenesis pathways. Cell assays showed high MEX3A expression in CRC cells and its promoting effects in CRC cell proliferation and glycolysis as well as angiogenesis. Rescue experiment confirmed that glycolysis inhibitor 2-DG could offset the promoting effects of MEX3A on the proliferation, angiogenesis and glycolysis of CRC cells. In conclusion, MEX3A could facilitate CRC angiogenesis by activating the glycolytic pathway, suggesting that MEX3A may be a novel therapeutic target for CRC. [ABSTRACT FROM AUTHOR]

The microwave-assisted hydrogen peroxide-citric acid desulfurization of coal was optimized by response surface methodology, and the samples were characterized before and after desulfurization by proximate analysis, ultimate analysis, sulfur forms determination, X-ray diffraction (×RD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (×PS), and scanning electron microscopy (SEM) and so on. The quantum chemical calculations were selected to investigate desulfurization mechanism of microwave-assisted hydrogen peroxide-citric acid, and data analysis shows that the citric acid dose is the main factor affecting the desulfurization rate. Under optimized conditions, the actual desulfurization rate can reach 72.23%, the sulfur removal rate of pyrite up to 92.19%. The mineral content of the coal sample was significantly reduced. The oxygen-containing functional groups in the coal sample increased, and more inorganic sulfur and sulfoxide in the low valence state were oxidized to sulfone and sulfate in the high valence state. The microwave effect of pyrite will react with hydrogen ions to produce Fe2+, Fe2+ and citric acid reaction to form a complex. Quantum chemical calculations prove that the addition of an applied electric field can reduce the energy required for the coordination reaction and facilitate the reaction. [ABSTRACT FROM AUTHOR]

The failure of mineral oils to work in machinery and engines under intense pressure, heat, and corrosion has prompted researchers to consider the development of synthetic lubricating oils that are appropriate for these demanding conditions. This research was conducted to synthesize new esters by reaction of citric acids (CA) with mono-alcohols (hexanol, octanol, decanol and 2-ethylhexanol), then the products were reacted with propanoic acid, valeric acid, and octanoic acid separately using 1:1 molar ratio. The resulting esters were characterized using nuclear magnetic resonance spectroscopy (NMR), Fourier-transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA). The rheological properties were studied, and it was found that the prepared esters have high thermal stabilities as the degradation takes place in the range of 175 °C - 425 °C. The prepared esters show Newtonian behaviors as their viscosities do not change by changing shear rate. The physicochemical characteristic of prepared esters were also determined which showed improved low temperature properties (PP) -36 °C for ester (2R)-1,2-bis(2-ethylhexyl) 3-nonyl 2-(pentanoyloxy)propane-1,2,3-tricarboxylate (COEV) and viscosity index (VI) at 195 for ester (2R)-1-decyl 3-(2-ethylhexyl) 2-heptan-3-yl 2-(propionyloxy)propane-1,2,3-tricarboxylate (CDEP). The stabilities of the prepared esters were confirmed via the computational analysis and their stabilities were ranked as CDEP>COEP>COEO>COEV. [ABSTRACT FROM AUTHOR]

Abstract \nHerein, we report the fabrication of graphite oxide (GO) nanosheets using the modified Hummer’s method. The prepared GO nanosheets were anchored with citrate functionality to develop a new nanocatalyst for potential organic conversions. The prepared native, as well as functionalized nanostructures, were characterized using advanced analytical techniques. The citrate functionalized GO nanosheets were then used as a nanocatalyst for the organic synthesis of an imidazole derivative through an aldehyde-amine condensation route. The hence produced imidazole derivative was elucidated using electrospray ionization mass spectrometry and thermogravimetric analysis. The nanocatalyst showed good catalytic activity and reusability for an aldol condensation reaction. We suggest that the prepared nanocatalyst could further be investigated for other condensation reactions.We report the fabrication of citric acid-functioned graphite oxide nanosheets as a novel nanocatalyst for the synthesis of an imidazole derivative through an aldehyde-amine condensation route.Both nanocatalyst and the condensed product were characterized using advanced analytical approaches.The nanocatalyst expressed good catalytic activity and reusability for an aldol condensation reaction. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs) were produced through citric acid (CA) pyrolysis. For the first time, we searched for the optimum CA pyrolysis duration and temperature. As a basic quality criterion of quantum dots, photoluminescence quantum yield (QY) was chosen. For this purpose, the pyrolysis products were analysed with UV–Vis spectroscopy and fluorescence (FL) spectroscopy. The optimum pyrolysis time was accepted to be 240 min, whereas the optimum pyrolysis temperature was approved as 200 °C. The pyrolysis products obtained at the optimum conditions were further subjected to dialysis. Finally, the purified CQDs were characterised with FL spectroscopy, transmission electron microscopy, dynamic light scattering, Raman spectroscopy, and Fourier transform infra-red spectroscopy. The produced CQDs were shown to be stable in water solution. Their PL QY (6.1%) was decreased to 1.2% after CQDs exposure to daylight for 90 days. Luminescent polymer composites were produced when CQDs were embedded in the poly(vinyl alcohol) and bacterial cellulose matrices. The prepared composites can be used for fabrication of transparent, flexible, and luminescent films and for production of anti-counterfeiting paper for confidential documents, labels, and banknotes. [ABSTRACT FROM AUTHOR]

The work mentioned in the title of this comments-typed paper contains several calculations that disagree with some basic chemistry concepts. These misleading calculations mainly include (i) both kinetic and isotherm modeling through linear equations and (ii) calculating the thermodynamic parameters for the adsorption processes. Thus, we remind how to correct ways allowing to make these calculations. In our opinion, it is a source of confusion for the scientific community to continue using inappropriate methods as applied in the original paper. [ABSTRACT FROM AUTHOR]

Light-emitting diodes (LED) have emerged as a non-polluting and energy-saving technology in fruit postharvest. The aim of this work was to evaluate the effect of different LED light pulses during raspberries´ and blackberries´ postharvest under cold storage. Fruit was exposed to short LED light pulses (Green, Blue, Red, and Red+Blue) of 15 min every 2 h for 7 and 14 d of storage at 4°C. Raspberries were more susceptible to water loss. Short LED light pulses decreased internal breakdown in raspberries, and minor effects of LED treatments were observed in blackberries. After 7 d of cold storage, in raspberries, Green, Blue, and Red light treatments increased the content of quinic and malic acids, and only Green and Blue LED sources also increased ascorbic acid content. In addition, Blue, Green, and Blue+Red LED light treatments exhibited a higher level of citric acid at 14 d. In blackberries, fruit changes were mainly because of the cold storage. Overall, these results showed that short LED light pulses can extend the postharvest life of raspberries, decreasing internal breakdown and increasing the content of ascorbic acid, suggesting that different Rubus species have distinct physiological processes underlying ripening and light interactions. [ABSTRACT FROM AUTHOR]

Dy substituted Ni ferrite nanoparticles with composition NiFe1.95Dy0.05O4 were synthesized by using the citric acid sol–gel auto combustion method. The samples were sintered at temperatures of 400°C, 700°C, and 900°C. The X-ray diffraction measurements clearly showed the formation of a cubic spinel structure along with a small orthoferrite phase for all the sintered samples. The crystallite size increases from 17.79 to 39.36 nm while the grain size increases from 50.70 nm to 83.05 nm. The lattice parameter and lattice volume decrease with increasing sintering temperature was observed. The Spinel ferrite structure of prepared samples has been confirmed from FTIR spectra. With increasing sintering temperature saturation magnetization increases from 25.80 emu/gm to 49.48 emu/gm while the coercivity value decreases from 207.95 Oe to 165.43 Oe. Increasing saturation magnetization and decreasing coercivity values with increasing sintering temperature make the synthesized nanoparticles suitable for high-density data storage devices. [ABSTRACT FROM AUTHOR]

Wood chips can be stored in a variety of ways and the choice of method can affect their properties. Because mold fungi are common in landfills and in the case of advanced growth the wood material can be classified as low quality, the presented research was carried out to determine the impact of the method of wood chips short-term storage on the development of mold fungi. Chips stored in silo, on unpaved yard, paved yard with and without the roof were analyzed. The genera and species of fungi were identified, their growth was assessed with a visual method, and the concentrations of ergosterol, citric acid, and oxalic acid were determined. The research have shown that from the point of view of mold fungi development, the most advantageous is to store the chips in a silo and the least favorable on the unpaved yard. The effect of roofing of the paved yard probably would be more noticeable during the short-term storage. [ABSTRACT FROM AUTHOR]

In this study the three natural dyes of madder, curcumin and gardenia blue were used as sensitizers to treat the nano-TiO2 which was prepared with the sol-gel method improved by plant honeysuckle extract, and then oxalic acid (OA) and citric acid (CA) were compounded as crosslinkers to modify the cotton fabric, The carboxyl groups on the modified cotton fabric can anchor the dye-sensitized nano-TiO2 to give it self-cleaning performance. Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) showed that the dye-sensitized nano-TiO2 was successfully loaded on the surface of the cotton fabrics, and basically did not change their crystalline structure. UV-Visible diffuse reflectance spectra (UV-Vis-DRS) and Photoluminescence Spectroscopy (PL) spectra showed that, compared with nano-TiO2 photocatalytic cotton fabrics, the photocatalytic cotton fabric prepared from our dye-sensitized nano-TiO2 had a narrower band gap energy and a decrease in the recombination rate of electron-hole pairs. The cross-linked cotton fabric treated with dye-sensitized nano-TiO2 had excellent photocatalytic performance and washing resistance. In addition, the cross-linking treatment greatly improved the wrinkle recovery of the cotton fabrics, and the load of dye-sensitized nano-TiO2 endowed the fabric with excellent hydrophilic properties. but it also led to a certain degree of decrease in its breaking strength. [ABSTRACT FROM AUTHOR]

A highly efficient protocol was developed for the ipso hydroxylation of arylboronic acids using citric acid as an effective organocatalyst. The sustainable methodology offers good to excellent yields with in the rapid reaction time in water as a solvent media and 30% H2O2 as an oxidant. The reaction proceeds without the aid of any metal catalyst or base and is simple, safe, and clean. The current protocol enables the access to variety of phenols and is found to be tolerable to the diverse electronic substrates. Even, the devised reaction conditions have been found to be effective in the gram-scale synthesis of an API, Mequinol. [ABSTRACT FROM AUTHOR]

This study aims to visually inspect the effects of oxidized starch (OS) adhesives prepared with two cross-linkers namely citric acid (CA) and blocked-polymeric MDI (B-pMDI) on the extent of surface-inhabiting molds growth on the surface of medium-density fiberboard (MDF). Five surface-inhabiting molds namely Aspergillus niger (ASN), Penicillium funiculosum (PEC), Rhizopus oryzae (RHO), Aureobasidium pullulans (AUP), and Trichoderma virens (TRV) were inoculated onto MDF samples for four weeks at 26 ± 2°C and 70–80% relative humidity to enable them grow on the surface. The extent of mycelium growth on the MDF surface was assessed by visual inspection after incubation at four time intervals. The results showed that MDF samples bonded with OS adhesives were more susceptible to the surface-inhabiting molds than the control MDF samples bonded with urea-formaldehyde (UF) resins. The resistance of mold growth on MDF-OS/CA was comparable to MDF-control, particularly against AUP, which was around 0.7 after four weeks, indicating less mold growth on the surface of MDF. The susceptibility of MDF samples to mold increased in the order of MDF-control, MDF-OS/CA, and MDF-OS/B-pMDI. [ABSTRACT FROM AUTHOR]

Mussel-inspired tissue adhesives have been widely studied in recent years because of their excellent underwater adhesion. Our recent study has synthesized a series of tissue adhesives with citric acid, dopamine, 1,8-octanediol and poly(ethylene oxide) (PEO), and found that amphiphilic adhesives showed an efficient underwater adhesion mechanism. Poly(propylene oxide)-poly(ethylene oxide) block copolymer (PEO-PPO-PEO) is a thermosensitive amphiphilic material, widely used in medical field. Herein, we replaced PEO with PEO-PPO-PEO to introduce temperature-sensitivity into adhesives, and utilized the hydrophilic-to-hydrophobic transition of PEO-PPO-PEO to reduce the swelling at human temperature. Fortunately, we got positive results that all the synthetized adhesives showed obvious temperature-sensitivity. The transition from low temperature to room temperature of the high concentrated uncured adhesive dispersion made it potentially injectable. After crosslinking, the swelling ratio of cured adhesives showed a significant decrease from 4°C to 37°C. And all the swelling ratios under 37°C were low, ranging from 8.4% to 22.5%. Additionally, the lap-shear adhesion strength on wet porcine skin was in the range of 29.2–67.1 kPa, which was higher than that of commercial fibrin glue (9–15 kPa). By selecting different (PEO)y(PPO)x(PEO)y, we could obtain adhesives with wide mechanical properties and broaden the scope of use of the adhesives. [ABSTRACT FROM AUTHOR]

A series of MoP catalysts (MoP-CAx) were synthesized by adding citric acid (CA) to solutions of (NH4)6Mo7O24·4H2O and (NH4)2HPO4 with a fixed molar ratio of Mo:P:CA = 1:1: x (x = 0, 1, 4, 8) followed by drying and reduction in H2. The addition of CA had a significant effect on the microstructure (surface area and particle dispersion) and performance of MoP for dry reforming of methane (DRM). Among these MoP-CAx catalysts, the MoP-CA8 was found to show the highest catalyst stability, which should be attributed to the best matching of oxidation resistance ability and methane dissociation ability of MoP. [ABSTRACT FROM AUTHOR]

Enrichment of organic residues with mineral fertilizers is a sustainable route to produce high agronomic value organomineral fertilizers (OMFs). OMFs agronomic value was conditioned by the properties and nutrients pools accessed by chemical analysis. Partial least squares (PLS) regression based on infrared analysis is a fast and alternative technique to assess the properties of OMFs, while replacing laborious, non-environmental-friendly, time-consuming, and high-cost conventional lab analytical procedures. OMFs were produced by composting of mixtures of different proportions of low-grade and soluble P sources with chicken manure and coffee husk for 150 days. After composting, the OMFs were dried and analyzed for: pH in CaCl2, electrical conductivity, total contents of C, P, N, and K, and C soluble in water, as well as for fertilizer-P soluble in water, citric acid, and neutral ammonium citrate. The compost MAP-based OMFs had a greater agronomic value than low-grade rock P-based OMFs. PLS regression models based on the ATR-FTIR spectral signature were a suitable tool to predict all OMFs chemical properties and nutrient pools evaluated through lab conventional analytical procedures. The good performance, robustness, and non-random correlation of PLS regression models were attested by their high coefficient of determination (R2) to calibration (0.92–0.99), cross-validation (0.87–0.99), and prediction capacity (0.89–0.99) combined with the lowest values of the root-mean-square error (RMSE) and reduced values of R2 (0.19–0.44), and to high values of RMSE to y-randomization. PLS based on ATR-FTIR is a rapid and alternative chemometric approach to assess the properties and nutrients pools of OMFs. [ABSTRACT FROM AUTHOR]

Electrolyte is one of the critical factors for the efficient and green implementation of electrokinetic remediation (EK). Modelling of enhanced EK in the complex heavy metal contaminated soils was designed. Enhanced electrokinetic remediation experiments with composite electrolyte (citric acid + calcium chloride) were conducted to investigate their influence on the removal of cadmium (Cd) and lead (Pb), depletion of soil cations, and electric energy consumption. The results indicated that the removal efficiency of lead and cadmium rose from 10.8% and 14% to 15.1% and 22.5%, at the same time, the power consumption increased from 140.4 to 402 Wh since calcium chloride was added to citric acid. With the extension of time, the highest removal of Pb and Cd were 58% and 99.2%, respectively, in the section of S1 where soil pH was 2.5. The dominant cations (detected) in the pore water of the soil were Ca2+, Mg2+, and Mn2+, which was more evident with the extension of time. Lead-cadmium transmission efficiency under the electric field was lowered because the ratio of the heavy metal ions to the total amount of cations was very low, especially with the addition of calcium chloride. [ABSTRACT FROM AUTHOR]

Acid soils (0-20 cm) from five different locations namely Jibanpur, Kamalpur, Washabarie, Hansqua (from the state of West Bengal) and Padu (Meghalaya) were collected to evaluate the efficiency of organic acids in dissolving phosphorus which was conducted in the laboratory. The extracted P by different organic acids varied from soil to soil and least was in the soil of Padu followed by Jibanpur. These two soils are collected from bare land having low P content. Citric acid is most effective in releasing inorganic P in these soils. On the other hand, the other three soils, were known to have fertilized regularly over 100 years under tea plantation and thus bearing high amount of total P, extracted higher amount P with oxalic acid at comparable level of acid addition. The time-depended P release data were fitted to different models and the data were better model by Elovich and Power functional equations based on the values of the coefficient of determination (r2) and the standard errors of the estimates (S.E). The dissolution and complexation of the Fe3+/Al3+or Ca2+compounds that bind most P in soils may be the possible mechanisms for its release by low molecular weight organic acids according to the well fitted Elovich and Power function models in kinetic experiment. [ABSTRACT FROM AUTHOR]

Soybean crop is used as both legume and oil seed contributing for 23% of total vegetable oil production of the country. Soybean productivity and fertilizer P use efficiency (FPUE) is low due to its higher fixation with iron, aluminum and/or calcium minerals in the soil. In order to make the fixed P bioavailable, plant roots secretes low-molecular weight organic acids (LMWOAs) which act as ligands and compete with the PO43– site of Fe2+, Al3+, and/or Ca2+. But the LMWOAs secreted by crops are of very low concentration and also these LMWOAs undergo rapid degradation in the soil. Therefore, present study was undertaken to know the impact of extraneous application of LMWOAs (oxalic and citric acid) on yield of soybean. Results showed that the application of LMWOAs significantly increased the soil Olsen P concentration and soybean yield. Application of LMWOAs (10 mg LMWOAs kg−1) along with 9 mg P kg−1 can reduce about half of the recommended dose of P fertilizers (RDPF i.e., 18 mg P kg−1) through increased FPUE without compromising the yield. By enhancing FPUE, LMWOAs indirectly reduce cost of cultivation and avoid environmental imbalance. However, higher concentration of oxalic acid drastically reduced yield of soybean by damaging its root system. [ABSTRACT FROM AUTHOR]

The electrochemical and surface properties of mild steel in stagnant aerated solutions containing 5 mM citric acid at pH 5 and pH 9 were investigated by open circuit potential, potentiodynamic polarization and electrochemical impedance measurements combined with X-ray photoelectron spectroscopy (XPS) characterization. The results show that the active dissolution behavior of steel in the citric acid solution at pH 5 is well described using a kinetic model consisting of a modified consecutive mechanism, in parallel with a catalytic path involving the divalent intermediate Fe[(OH)2)]ads. The surface film is composed of FeO, Fe(OH)2, FeOOH and Fe-citrate. Also, the analysis of in-depth distribution of composition indicates a high coverage of the organic layer. In the pH 9 citrate solution, a thin bilayer passive film was formed (with Fe(II) and Fe(III) located mainly in the inner and outer regions, respectively). Its overall composition is Fe3O4/FeOOH. Electrochemical measurements revealed the low protective ability of this film and this was confirmed by a modest XPS intensity ratio of Fe(III)/Fe(II). Moreover, no clear presence of Fe-citrate was detected in the passive film, and so the poor passivation behavior was correlated to insufficient adsorption of the tri-ionized citrate anion. The importance of solution flow to stimulate the adsorption of citrate anion is emphasized. [ABSTRACT FROM AUTHOR]