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1.
J Cardiothorac Surg ; 19(1): 438, 2024 Jul 13.
Article in English | MEDLINE | ID: mdl-39003452

ABSTRACT

BACKGROUND: This study examined the efficacy of del Nido cardioplegia compared with traditional blood cardioplegia in adult cardiac surgery for isolated coronary artery bypass grafting by evaluating the early postoperative outcomes. METHODS: A total of 119 patients who underwent isolated conventional coronary artery bypass grafting were enrolled and divided into two groups (del Nido cardioplegia group [n = 36] and blood cardioplegia group [n = 50]) based on the type of cardioplegia used. This study compared the preoperative characteristics, intraoperative data, and early postoperative outcomes. Further subgroup analyses were conducted for high-risk patient groups. RESULTS: The 30-day mortality and morbidity rates were not significantly different between groups. The del Nido cardioplegia group exhibited advantageous myocardial protection outcomes, demonstrated by a significantly smaller rise in Troponin I levels post-surgery (2.8 [-0.4; 4.2] vs. 4.5 [2.9; 7.4] ng/mL, p = 0.004) and fewer defibrillation attempts during weaning off of cardiopulmonary bypass (0.0 ± 0.2 vs. 0.4 ± 1.1 times, p = 0.011) when compared to the blood cardioplegia group. Additionally, the del Nido group achieved a reduction in surgery duration, as evidenced by the reduced aortic cross-clamping time (64.0 [55.5; 75.5] vs. 77.5 [65.0; 91.0] min, p = 0.001) and total operative time (287.5 [270.0; 305.0] vs. 315.0 [285.0; 365.0] min, p = 0.008). Subgroup analyses consistently demonstrated that the del Nido cardioplegia group had a significantly smaller postoperative increase in Troponin I levels across all subgroups (p < 0.05). CONCLUSIONS: del Nido cardioplegia provided myocardial protection and favorable early postoperative outcomes compared to blood cardioplegia, making it a viable option for conventional coronary artery bypass grafting. Establishing a consensus on the protocol for Del Nido cardioplegia administration in adult surgeries is needed.


Subject(s)
Cardioplegic Solutions , Coronary Artery Bypass , Heart Arrest, Induced , Humans , Heart Arrest, Induced/methods , Coronary Artery Bypass/methods , Male , Female , Middle Aged , Aged , Retrospective Studies , Treatment Outcome , Postoperative Complications/prevention & control , Coronary Artery Disease/surgery , Troponin I/blood , Potassium Chloride , Mannitol , Lidocaine , Solutions , Electrolytes , Magnesium Sulfate , Sodium Bicarbonate
2.
Int J Mol Sci ; 25(13)2024 Jul 05.
Article in English | MEDLINE | ID: mdl-39000514

ABSTRACT

The peculiar behavior of arsenoplatin-1, ([Pt(µ-NHC(CH3)O)2ClAs(OH)2], AP-1), in aqueous solution and the progressive appearance of a characteristic and intense blue color led us to carry out a more extensive investigation to determine the nature of this elusive chemical species, which we named "AsPt blue". A multi-technique approach was therefore implemented to describe the processes involved in the formation of AsPt blue, and some characteristic features of this intriguing species were revealed.


Subject(s)
Oxidation-Reduction , Water/chemistry , Solutions , Organoplatinum Compounds/chemistry
3.
Anim Sci J ; 95(1): e13977, 2024.
Article in English | MEDLINE | ID: mdl-38982658

ABSTRACT

Hard meat has low market value; hence, we used bittern as a novel meat tenderizer for bovine M. semitendinosus, one of a hard muscle. We investigated the effects of beef immersion in bittern, a basic solution primarily comprising MgCl2, on textural properties and water-holding capacity. Muscle samples from M. semitendinosus of Holstein steers were immersed in seven different solutions (RO, NaCl, MgCl2, red wine, pH 3, bittern, and pH 8) and heated at 80°C for 5min. The pH of the beef and immersion solutions, water-holding capacity, and maximum load of the meat were measured. Although beef immersed in red wine (pH 3) had a lower pH and water-holding capacity, that immersed in bittern (pH 8.4) had a higher pH and higher water holding capacity. These results indicate that immersion in acidic red wine may harden beef and that immersion in basic bittern may be more effective in maintaining water-holding capacity and softening beef.


Subject(s)
Food Handling , Red Meat , Water , Wine , Animals , Cattle , Hydrogen-Ion Concentration , Wine/analysis , Food Handling/methods , Red Meat/analysis , Immersion , Food Quality , Muscle, Skeletal , Chemical Phenomena , Male , Solutions , Hot Temperature , Meat/analysis , Hardness
4.
Eur J Pharm Biopharm ; 201: 114377, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38955284

ABSTRACT

Drug product development of therapeutic antibody formulations is still dictated by the risk of protein particle formation during processing or storage, which can lead to loss of potency and potential immunogenic reactions. Since structural perturbations are the main driver for irreversible protein aggregation, the conformational integrity of antibodies should be closely monitored. The present study evaluated the applicability of a plate reader-based high throughput method for Intrinsic Tryptophan Fluorescence Emission (ITFE) spectroscopy to detect protein aggregation due to protein unfolding in high-concentrated therapeutic antibody samples. The impact of fluorophore concentration on the ITFE signal in microplate readers was investigated by analysis of dilution series of two therapeutic antibodies and pure tryptophan. At low antibody concentrations (< 5 mg/mL, equivalent to 0.8 mM tryptophan), the low inner filter effect suggests a quasi-linear relationship between antibody concentration and ITFE intensity. In contrast, the constant ITFE intensity at high protein concentrations (> 40 mg/mL, equivalent to 6.1 mM tryptophan) indicate that ITFE spectroscopy measurements of IgG1 antibodies are feasible in therapeutically relevant concentrations (up to 223 mg/mL). Furthermore, the capability of the method to detect low levels of unfolding (around 1 %) was confirmed by limit of detection (LOD) determination with temperature-stressed antibody samples as degradation standards. Change of fluorescence intensity at the maximum (ΔIaM) was identified as sensitive descriptor for protein degradation, providing the lowest LOD values. The results demonstrate that ITFE spectroscopy performed in a microplate reader is a valuable tool for high-throughput monitoring of protein degradation in therapeutic antibody formulations.


Subject(s)
Immunoglobulin G , Spectrometry, Fluorescence , Tryptophan , Tryptophan/chemistry , Spectrometry, Fluorescence/methods , Immunoglobulin G/chemistry , Protein Aggregates , Protein Unfolding , Antibodies, Monoclonal/chemistry , High-Throughput Screening Assays/methods , Solutions
5.
Yakugaku Zasshi ; 144(7): 715-732, 2024.
Article in Japanese | MEDLINE | ID: mdl-38945846

ABSTRACT

An aqueous solution of 2,3-cis gallate type catechin (-)-epigallocatechin-3-O-gallate (EGCg) and caffeine afforded a precipitate of Creaming-down Phenomenon, which crystallized slowly for about three months to give a colorless block crystal. By X-ray crystallographic analysis, the crystal was determined to be a 2 : 2 complex of EGCg and caffeine, in which caffeine molecules were captured in a hydrophobic space formed with three aromatic A, B, and B' rings of EGCg. It was considered that the solubility of the 2 : 2 complex in water rapidly decreased and the 2 : 2 complex precipitated from aqueous solution. The hydrophobic spaces of EGCg captured a variety of heterocyclic compounds, and the molecular capture abilities of heterocyclic compounds using EGCg from the aqueous solutions were evaluated. Since the C ring of EGCg has two chiral carbon atoms, C2 and C3, the hydrophobic space of EGCg was a chiral space. EGCg captured diketopiperazine cyclo(Pro-Xxx) (Xxx=Phe, Tyr) and pharmaceuticals with a xanthine skeleton, proxyphylline and diprophylline, in the hydrophobic space, and recognized their chirality.


Subject(s)
Caffeine , Catechin , Hydrophobic and Hydrophilic Interactions , Solubility , Tea , Catechin/chemistry , Catechin/analogs & derivatives , Tea/chemistry , Caffeine/chemistry , Crystallography, X-Ray , Stereoisomerism , Water/chemistry , Crystallization , Solutions , Heterocyclic Compounds/chemistry , Xanthines/chemistry
6.
J Oleo Sci ; 73(7): 1015-1026, 2024.
Article in English | MEDLINE | ID: mdl-38945920

ABSTRACT

Herein, we evaluated friction dynamics of human skin treated with polyacrylic acid aqueous solutions or gel creams using a sinusoidal motion friction evaluation system to demonstrate the effect of treatment with polymer aqueous solutions on human skin. A polymer aqueous solution or gel cream was applied to the inner forearms of 10 subjects to evaluate temporal changes in friction force under sinusoidal motion. Water content, skin viscoelasticity, and transepidermal water loss were also simultaneously measured to determine the effects on skin conditions. When human skin was treated with the polymer aqueous solution, the friction coefficient immediately after treatment was 0.69-0.99 and the delay time δ, a normalized parameter of the time difference in the delayed response of friction to the movement of the contact probe divided by the friction time T 0 for one round trip, was 0.171-0.179, which was greater than that of untreated skin. This increase was caused by the swelling and softening of the stratum corneum caused by the penetration of water in the polymer aqueous solution, which increased true contact area between the skin and contact probe. A significant difference was observed in the friction coefficient of the skin immediately after treatment with different polymer aqueous solutions. Among polymers (P1-P4), P4, which has a low-salt resistance and low yield stress, had the lowest friction coefficient because of collapsing of the polymer network structures by shearing and reduced viscosity owing to salts on human skin. The skin treated with a gel cream also exhibited a greater friction coefficient than the untreated skin immediately after treatment and 90 min later. This phenomenon can be caused by the occlusive effect of the oil in the gel cream.


Subject(s)
Acrylic Resins , Friction , Solutions , Water , Humans , Viscosity , Acrylic Resins/chemistry , Skin/drug effects , Elasticity , Adult , Female , Male , Polymers/chemistry , Skin Cream/chemistry , Gels , Water Loss, Insensible/drug effects
7.
Nat Methods ; 21(6): 928, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38866985
8.
Sci Rep ; 14(1): 13957, 2024 06 17.
Article in English | MEDLINE | ID: mdl-38886515

ABSTRACT

Heteropolysaccharides are among the most widely distributed compounds in nature, acting as both tissue building blocks and as a source of nutrients. Their physicochemical and biological properties have been studied thoroughly; however, the microstructural properties of heteropolysaccharides are still poorly understood. This study aims to investigate the micro-structural peculiarities of agarose, gum arabic, hyaluronic and alginic acids by means of confocal laser scanning microscopy (CLSM) and cryogenic scanning electron microscopy (cryo-SEM). Herein, attention is paid to layered complexity of the microstructure differentiating surface, under surface, inner, and substrate interface layers. The scale and pattern of the polysaccharide's microstructure depend on the concentration, changing from lamellae to cell-like porous structures. This work provides the insight into micro- and nanoscale mechanisms of self-healing and substrate-induced reorganisation. Thus, investigation of the self-healing mechanism revealed that this diffusion-based process starts from the fibres, turning into lamellae, following by cell-like structures with smaller dimensions. Investigation of the substrate-induced reorganisation ability showed that nano-to-micro (scale) porous substrate causes reorganisation in the interface layer of the studied heteropolysaccharides. This work contributes to understanding the structural peculiarities of heteropolysaccharides by looking at them through a supramolecular, micro-level prism.


Subject(s)
Polysaccharides , Polysaccharides/chemistry , Microscopy, Confocal , Solutions , Alginates/chemistry , Microscopy, Electron, Scanning , Gum Arabic/chemistry , Sepharose/chemistry , Hyaluronic Acid/chemistry , Cryoelectron Microscopy
9.
Int J Biol Macromol ; 272(Pt 2): 132912, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38851617

ABSTRACT

The unique molecular structure of cellulose makes it challenging to dissolve at room temperature (R.T.), and the dissolution mechanism remains unclear. In this study, we employed ZnCl2 aqueous solution for cellulose dissolution at R.T., proposing a novel four-stage dissolution mechanism. The efficient dissolution of cellulose in ZnCl2 aqueous solution at R.T. involves four indispensable stages: rapid migration of hydrated Zn2+ ions towards cellulose, sufficient penetration between cellulose sheets, strong interaction with cellulose hydroxyl groups, and effective dispersion of separated cellulose chains. The proposed four-stage dissolution mechanism was validated through theoretical calculations and experimental evidence. The hydrated Zn2+ ions in ZnCl2 + 3.5H2O solvent exhibited ideal migration, penetration, interaction, and dispersion abilities, resulting in efficient cellulose dissolution at R.T. Moreover, only slight degradation of cellulose occurred in ZnCl2 + 3.5H2O at R.T. Consequently, the regenerated cellulose materials obtained from ZnCl2 + 3.5H2O (R.T.) exhibited better mechanical properties. Notably, the solvent recovery rate reached about 95 % based on previous usage during five cycles. The solvent is outstanding for its green, low-cost, efficiency, simplicity, R.T. conditions and recyclability. This work contributes to a better understanding of the cellulose dissolution mechanisms within inorganic salt solvents at R.T., thereby guiding future development efforts towards greener and more efficient cellulosic solvents.


Subject(s)
Cellulose , Chlorides , Solubility , Temperature , Water , Zinc Compounds , Cellulose/chemistry , Zinc Compounds/chemistry , Chlorides/chemistry , Water/chemistry , Solutions , Solvents/chemistry , Zinc/chemistry
10.
Environ Sci Technol ; 58(26): 11791-11801, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38871647

ABSTRACT

The effect of aqueous solution chemistry on the ionic hydration structure and its corresponding nanofiltration (NF) selectivity is a research gap concerning ion-selective transport. In this study, the hydration distribution of two typical monovalent anions (Cl- and NO3-) under different aqueous solution chemical conditions and the corresponding transmembrane selectivity during NF were investigated by using in situ liquid time-of-flight secondary ion mass spectrometry in combination with molecular dynamics simulations. We demonstrate the inextricable link between the ion hydration structure and the pore steric effect and further find that ionic transmembrane transport can be regulated by breaking the balance between the hydrogen bond network (i.e., water-water) and ion hydration (i.e., ion-water) interactions of hydrated ion. For strongly hydrated (H2O)nCl- with more intense ion-water interactions, a higher salt concentration and coexisting ion competition led to a larger hydrated size and, thus, a higher ion rejection by the NF membrane, whereas weakly hydrated (H2O)nNO3- takes the reverse under the same conditions. Stronger OH--anion hydration competition resulted in a smaller hydrated size of (H2O)nCl- and (H2O)nNO3-, showing a lower observed average hydration number at pH 10.5. This study deepens the long-overlooked understanding of NF separation mechanisms, concerning the hydration structure.


Subject(s)
Filtration , Water/chemistry , Ions , Molecular Dynamics Simulation , Solutions , Anions/chemistry
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 320: 124611, 2024 Nov 05.
Article in English | MEDLINE | ID: mdl-38852304

ABSTRACT

Trimethine cyanine dyes are widely used as probes for the detection, study and quantification of biomolecules. In particular, cationic trimethine cyanines noncovalently interact with DNA with growing fluorescence. However, their use is often limited by the tendency to self-association - to the formation of aggregates. Disubstituted trimethine cyanines with hydrophobic substituents are especially prone to aggregation. In this work, we studied the interaction of a number of substituted trimethine cyanines with DNA (in aqueous buffer solutions) and showed that their aggregation strongly interfered with their use as fluorescent probes for DNA. To eliminate this drawback, preliminary heating of dye solutions with DNA to 60-70 °C was used, followed by cooling to room temperature. Compared to the experiments without heating, an increase in the dye fluorescence intensity was observed due to the partial thermal decomposition of the aggregates and the interaction of the resulting monomers with DNA. To decompose aggregates, another method was also used - protonation of the dyes with amino substituents in buffer solutions with pH 5.0, which also led to growing the dye fluorescence intensity in the presence of DNA. Complexes of the dyes with DNA were modeled using molecular docking. Effective binding constants of the dyes to DNA and detection limits when using the dyes as probes for DNA (LOD and LOQ) were determined. It is shown that dye 3 with heating in neutral buffer and dye 1 in acidic buffer may be recommended as sensitive probes for DNA. It is concluded that the method of preliminary heating may be applied to dyes prone to aggregation, for improving their properties as biomolecular probes. Another possible means to reduce the interfering effects of dye aggregates is to use easily protonated dyes (with amino substituents) in slightly acidic media.


Subject(s)
Carbocyanines , DNA , Fluorescent Dyes , Spectrometry, Fluorescence , DNA/chemistry , Carbocyanines/chemistry , Hydrogen-Ion Concentration , Fluorescent Dyes/chemistry , Molecular Docking Simulation , Solutions , Hot Temperature , Animals
12.
Int J Biol Macromol ; 273(Pt 1): 132992, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38857718

ABSTRACT

ß-D-galactosidase is a hydrolase enzyme capable of hydrolyzing lactose in milk-based foods. Its free form can be inactivated in solution during the production of low-dosage lactose foods. Then, it is important to study strategies for avoiding the free enzyme inactivation with the aim of circumventing this problem. The stabilization of ß-D-galactosidase in aqueous solution after interactions with chitosan/eucalyptus sawdust composite membrane proved to be a potential strategy when optimized by central composite rotatable (CCR) design. In this case, the best experimental conditions for ß-D-galactosidase partitioning and stability in an aqueous medium containing the chitosan-based composite membrane reinforced with eucalyptus sawdust were i) enzyme/buffer solution ratio of 0.0057, ii) pH 5.6, iii) membrane mass of 50 mg, and iv) temperature lower than 37 °C. Significance was found for the linear enzyme/buffer solution ratio, linear temperature, and quadratic pH (p < 0.05) in the interval between 0 and 60 min of study. In the interval between 60 and 120 min, there was significance (p < 0.12) for linear temperature, the temperature-enzyme/buffer solution ratio interaction and the interaction between linear pH and linear enzyme/buffer solution ratio. The Pareto charts and response surfaces clearly showed all the effects of the experimental variables on the stabilization of ß-D-galactosidase in solution after interactions with the chitosan composite membrane. In this case, industrial food reactors covered with chitosan/eucalyptus sawdust composite membrane could be a strategy for the hydrolysis of lactose during milk-producing processes.


Subject(s)
Chitosan , Enzyme Stability , beta-Galactosidase , Chitosan/chemistry , beta-Galactosidase/chemistry , beta-Galactosidase/metabolism , Hydrogen-Ion Concentration , Membranes, Artificial , Solutions , Temperature , Lactose/chemistry
13.
Int J Biol Macromol ; 273(Pt 1): 133015, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38857731

ABSTRACT

Cosmetics, textiles, foodstuffs, and medicines frequently contain the yellow dye tartrazine. It has carcinogenic properties and can trigger allergies. In this study, a unique NH2-MIL-101(Cr)/chitosan composite (MIL/chitosan composite) was created using a hydrothermal process. The effectiveness of this composite in removing Tartrazine (TZ) from aqueous solutions was investigated. It was characterized via FT-IR, XPS, XRD, and BET analysis. The surface area of the MIL/chitosan nanoadsorbent sample was 1256.64 m2/g, where after five times recycling, it was reduced to 1068.14 m2/g. The study analyzed the impact of dye concentration, pH, temperature, and MIL/chitosan composite dosage. Experimental measurements were taken for the equilibrium isotherms of dye adsorption. The kinetic models and adsorption isotherm were used to analyze the results. The adsorption process was found to match Langmuir and pseudo-second-order kinetic models. Chemisorption was the mechanism of the adsorption process. Based on thermodynamic parameters, it was determined that the adsorption process was endothermic. The MIL/chitosan composite was recycled up to five cycles. Using the MIL/chitosan composite towards the adsorption of the tartrazine from the real sample has been checked. The interaction process between the MIL/chitosan nanoadsorbent and Tartrazine adsorbate has been investigated. The TZ electrical characteristics, reactivity, and shape were ascertained through the application of density functional theory (DFT). The placement of electrophilic and nucleophilic attack sites is in good agreement with the molecular orbitals (HOMO and LUMO) and MEP results, according to DFT. The optimization of adsorption results was accomplished using Box-Behnken design (BBD).


Subject(s)
Chitosan , Metal-Organic Frameworks , Tartrazine , Water Pollutants, Chemical , Chitosan/chemistry , Tartrazine/chemistry , Metal-Organic Frameworks/chemistry , Adsorption , Kinetics , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Hydrogen-Ion Concentration , Water Purification/methods , Temperature , Thermodynamics , Coloring Agents/chemistry , Coloring Agents/isolation & purification , Water/chemistry , Solutions
14.
Int J Biol Macromol ; 273(Pt 2): 133150, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38878930

ABSTRACT

The extraction of Li+ from liquid lithium resources is a pivotal focus of current research endeavors. Attapulgite (ATP), characterized by its distinctive layered structure and inherent ion exchange properties, emerges as an exceptional material for fabricating lithium-ion sieve. Ion-imprinted chitosan/ATP composite materials are successfully synthesized, demonstrating efficacy in selectively absorbing Li+. The results emphasize the rich functional groups present in H-CTP-2, enhancing its absorbability and selectivity, with an adsorption capacity of 37.56 mg•g-1. The adsorption conforms to the Langmuir and pseudo-second-order kinetic model. Li+ coordination involves amino and hydroxyl group, indicating a chemisorption process. Furthermore, the substantial pore structure and significant specific surface area of ATP significantly promote Li+ adsorption, suggesting its participation not only in chemisorption but also in physical adsorption. The fabricated ion-imprinted materials boast substantial adsorption capacity, exceptional selectivity, and rapid kinetics, highlighting their potential for effectively separating Li+ from aqueous solution.


Subject(s)
Chitosan , Lithium , Magnesium Compounds , Silicon Compounds , Chitosan/chemistry , Lithium/chemistry , Adsorption , Kinetics , Magnesium Compounds/chemistry , Silicon Compounds/chemistry , Water/chemistry , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/isolation & purification , Ions , Solutions , Surface Properties , Hydrogen-Ion Concentration
15.
Int J Biol Macromol ; 273(Pt 2): 133141, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38878935

ABSTRACT

Forests are a major source of wealth for Canadians, and cellulose makes up the "skeleton" of wood fibers. Concentrated H2SO4 and NaOH/urea aqueous solutions are two efficient solvents that can rapidly dissolve cellulose. Our preliminary experiment obtained regenerated wood cellulose films with different mechanical properties from these two solvents. Therefore, herein, we aim to investigate the effects of aqueous solvents on the structure and properties of wood cellulose films. Regenerated cellulose (RC) films were produced by dissolving wood cellulose in either 64 wt% H2SO4 solution (RC-H4) or NaOH/urea aqueous solution (RC-N4). RC-H4 showed the higher tensile strength (109.78 ± 2.14 MPa), better folding endurance (20-28 times), and higher torsion angle (42°) than RC-N4 (62.90 ± 2.27 MPa, un-foldable, and 12°). The increased cellulose contents in the H2SO4 solutions from 3 to 5 wt% resulted in an improved tensile strength from 102.61 ± 1.99 to 132.93 ± 5.64 MPa and did not affect the foldability. RC-H4 also exhibited better water vapor barrier property (1.52 ± 0.04 × 10-7 g m-1 h-1 Pa-1), superior transparency (~90 % transmittance at 800 nm), but lower thermal stability compared to RC-N4. This work provides special insights into the regenerated wood cellulose from two aqueous solvents and is expected to facilitate the development of high-performance RC films from abundant forestry resources.


Subject(s)
Cellulose , Sodium Hydroxide , Sulfuric Acids , Tensile Strength , Urea , Wood , Cellulose/chemistry , Sodium Hydroxide/chemistry , Sulfuric Acids/chemistry , Wood/chemistry , Urea/chemistry , Water/chemistry , Solvents/chemistry , Solutions , Solubility
16.
Biomacromolecules ; 25(7): 4063-4073, 2024 Jul 08.
Article in English | MEDLINE | ID: mdl-38832755

ABSTRACT

Processing cellulose from 4-methyl morpholine n-oxide (NMMO)-water solutions is a completely circular route that produces biodegradable cellulose fibers or films while recovering reusable NMMO [Guo, Y.; Cai, J.; Sun, T.; Xing, L.; Cheng, C.; Chi, K.; Xu, J.; Li, T. The purification process and side reactions in the N-methylmorpholine-N-oxide (NMMO) recovery system. Cellulose 2021, 28(12), 7609-7617]. Despite proven success in two-dimensional applications, challenges in transitioning to three-dimensional objects arise from the critical changes that cellulose undergoes during deposition, regeneration, and postregeneration stages. While emphasizing the critical diffusion-driven precipitation during regeneration, this investigation explores the influence of extrusion temperature, printing alignment, regeneration, and drying processes on interfilament fusion, bonding, shape integrity, and mechanical properties. Three distinct drying processes: ambient, vacuum, and freeze-drying were investigated. Tensile and flexural bending tests provided insight into the delamination of dried specimens. Ambient and vacuum drying enhanced the properties of specimens, while freeze-drying resulted in a more stable shape. The findings contribute to advancing the understanding of 3D-printing cellulose from NMMO solutions, addressing crucial aspects of the extrusion, regeneration, and drying stages for enhanced applications in sustainable manufacturing.


Subject(s)
Cellulose , Printing, Three-Dimensional , Water , Cellulose/chemistry , Water/chemistry , Cyclic N-Oxides/chemistry , Morpholines/chemistry , Solutions , Desiccation/methods
17.
Ultrason Sonochem ; 108: 106937, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38896895

ABSTRACT

This study explores the reduction of carbamates (CAs) and pyrethroids (PYs) - commonly used pesticides - in lettuce using various immersion solutions and ultrasonic processing. It also examines the role of machine learning and molecular docking in understanding the mechanisms of pesticide reduction. The results revealed that the highest reduction of both CAs and PYs exceeded 80 % on lettuce leaves. In most samples, the reduction increased with the power of ultrasonic processing and processing time. The results of machine learning models (XGBoost and SHAP) showed that during the immersion cleaning of CAs and PYs, as well as during both immersion cleaning and ultrasonic processing of CAs + PYs, the reduction was most influenced by the initial pesticide levels and immersion time. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of lettuce's wax layer identified 24 compounds, including fatty alcohols, fatty acids, fatty acid esters, and triterpenoids. Despite the absence of active sites, the lipophilic nature of long-chain aliphatic compounds aids in pesticide binding, while triterpenoids form strong hydrogen bonds with pesticides, indicating a robust adsorption on the lettuce surface. This study aims to offer insights into the efficient removal of chemical pesticide residues from fruits and vegetables, addressing critical concerns for food safety and human health.


Subject(s)
Lactuca , Lactuca/chemistry , Molecular Docking Simulation , Pesticides/chemistry , Solutions , Sonication , Ultrasonic Waves , Machine Learning , Carbamates/chemistry , Pyrethrins/chemistry , Pyrethrins/isolation & purification , Food Contamination/analysis
18.
Phys Chem Chem Phys ; 26(27): 18614-18628, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38919134

ABSTRACT

A partition analysis based on segments is developed for density functional theory defining solute dipole moments of functional groups, and the corresponding induced solvent dipoles representing solvent screening. The accuracy of dipoles from the fragment molecular orbital method is evaluated in comparison to unfragmented values. The analysis is applied to evaluate dipole moments of side chains, amino and carbonyl groups in common polypeptide motifs, α-helixes, ß-turns, and random coils in solution. The membrane domain of the ATP synthase (1B9U) is analyzed, revealing the effect of the bend splitting of the α-helix into two pieces.


Subject(s)
Peptides , Peptides/chemistry , Density Functional Theory , Solutions , Solvents/chemistry , Amino Acid Motifs , Models, Molecular
19.
Environ Sci Technol ; 58(27): 12237-12248, 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38934294

ABSTRACT

Pertechnetate (99TcO4-), a physiologically toxic radioactive anion, is of great concern due to its high mobility in environmental contamination remediation. Although the soluble oxyanion can be photoreduced to sparingly soluble TcO2·nH2O, its effective removal from a strongly acidic aqueous solution remains a challenge. Here, we found that low-crystalline nitrogen-doped titanium oxide (N-TiO2, 0.6 g L-1) could effectively uptake perrhenate (ReO4-, 10 mg L-1, a nonradioactive surrogate for TcO4-) with 50.8% during 360 min under simulated sunlight irradiation at pH 1.0, but P25 and anatase could not. The nitrogen active center formed by trace nitrogen doping in N-TiO2 can promote the separation and transfer of photogenerated carriers. The positive valence band value of N-TiO2 is slightly higher than those of P25 and anatase, which means that the photogenerated holes have a stronger oxidizability. These holes are involved in the formation of strong reducing •CO2- radicals from formic acid oxidation. The active radicals convert ReO4- to Re(VI), which is subsequently disproportionated to Re(IV) and Re(VII). Effective photocatalytic reduction/removal of Re(VII)/Tc(VII) is performed on the material, which may be considered a potential and convenient strategy for technetium decontamination and extraction in a strongly acidic aqueous solution.


Subject(s)
Titanium , Catalysis , Titanium/chemistry , Oxidation-Reduction , Rhenium/chemistry , Water/chemistry , Hydrogen-Ion Concentration , Solutions
20.
J Vis Exp ; (207)2024 May 17.
Article in English | MEDLINE | ID: mdl-38829127

ABSTRACT

In recent years, solution processes have gained considerable traction as a cost-effective and scalable method to produce high-performance thermoelectric materials. The process entails a series of critical steps: synthesis, purification, thermal treatments, and consolidation, each playing a pivotal role in determining performance, stability, and reproducibility. We have noticed a need for more comprehensive details for each of the described steps in most published works. Recognizing the significance of detailed synthetic protocols, we describe here the approach used to synthesize and characterize one of the highest-performing polycrystalline p-type SnSe. In particular, we report the synthesis of SnSe particles in water and the subsequent surface treatment with CdSe molecular complexes that yields CdSe-SnSe nanocomposites upon consolidation. Moreover, the surface treatment inhibits grain growth through Zenner pinning of secondary phase CdSe nanoparticles and enhances defect formation at different length scales. The enhanced complexity in the CdSe-SnSe nanocomposite microstructure with respect to SnSe promotes phonon scattering and thereby significantly reduces the thermal conductivity. Such surface engineering provides opportunities in solution processing for introducing and controlling defects, making it possible to optimize the transport properties and attain a high thermoelectric figure of merit.


Subject(s)
Cadmium Compounds , Selenium Compounds , Thermal Conductivity , Selenium Compounds/chemistry , Cadmium Compounds/chemistry , Tin/chemistry , Solutions/chemistry , Surface Properties , Crystallization/methods
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