Physicochemical Research Articles

Exploring the impact of key physicochemical properties of rice on taste quality and instant rice processing

Exploring the impact of key physicochemical properties of rice on taste quality and instant rice processing

Defect Passivation of Mn2+-Doped CsPbX3(X=Cl,Br) Perovskite Nanocrystals as Electrocatalyst for Overall Water Splitting.

Mn doping has been used to improve the physical chemistry of lead halide perovskite nanocrystals such as CsPbX3, where X is a halogen ion. In this paper, a two-phase method for Mn-doped CsPbX3 nanosheets (where X=Br, Cl), namely water-hexane system, is reported. Compared to conventional catalyst arrays, the band gap of CsPbBr3 nanocrystalline is easily tuned, the carrier diffusion distance is remote, the band edge position of the band structure is favorable for a wide range of electrocatalytic redox reactions, and the catalytic active site is maximally exposed, providing a larger electrolyte contact area. The porous hierarchical structure also accelerates the release of hydrogen bubbles. The results showed that the optimized Mn : CsPbBr3 catalyst exhibited excellent electrolytic performance of aquatic hydrogen in alkaline electrolyte (1 mol/L KOH). The overpotentials of the oxygen evolution reaction (OER) at the current densities of 10 and 100 mA cm-2 are only 114.4 and 505.4 mV, respectively, with a Tafel slope of 43 mV dec-1. At a current density of 10 mA cm-2, the excess potential required for the hydrogen evolution reaction (HER) is 158.6 mV and it exhibits excellent electrochemical stability. The Mn : CsPbBr3 nanocrystalline consists of two electrodes for hydrolysis of water, requiring only a voltage of 1.45 V. This provides implications for the optimization of electrocatalysts in alkaline electrolytes with the aim of developing next generation 2D electrocatalysts for overall water splitting.

IMPACT OF LIGAND CONJUGATION OF PHYSICOCHEMICAL ATTRIBUTES OF POLYMERIC NANOPARTICLES OF ATYPICAL ANTIPSYCHOTIC DRUG FOR NOSE-TO-BRAIN DELIVERY

Objective: To formulate and characterize the ligand-conjugated chitosan nanoparticles of Ziprasidone Hydrochloride (ZH) and compare with its plain chitosan nanoparticles. Methods: Transferrin (Tf) conjugated Chitosan Nanoparticles (CH-NP) containing ZH were prepared by ionotropic gelation method by using modified chitosan and Tf. Physicochemical attributes of nanoparticles which can potentially impact the nose-to-brain delivery were evaluated. Results: The Tf-CH-NP has demonstrated 207.1 nm mean particle size, 87.6% entrapment efficiency with a release of 89.34% at 24 h and has shown about 2.22 times more release than drug suspension and about 4.5% more than plain CH-NP. The similar trend was observed in Ex vivo nasal permeation study. Its acceptability was shown in histomorphology study, where a minimal inflammation seen, that might be due to the pH of the formulation. There is deeper penetration with Tf-CH-NP, which is more promising for penetration into brain. Conclusion: The formulated Tf-CH-NP has a greater potential due to ligand conjugation to reach the brain and, facilitate targeted delivery and enables better treatment of schizophrenia at minimal doses.

Cross-linked Arenga pinnata (Wurmb.) Merr. starch and chitosan with sodium trimetaphosphate: Structure, physicochemical properties and in vitro digestibility.

The inherent limitations of native starch considerably restrict its applications in the food industry. To enhance its processing properties, Arenga pinnata (Wurmb.) Merr. starch (APS) was subjected to dual modification with low levels of sodium trimetaphosphate (0%, 1%, and 3%) and chitosan (1%) to investigate its physicochemical, thermal, pasting, and in vitro digestibility. The dual modification of APS significantly increased the degree of cross-linked (CLD) to 84.69%, resulting in a rougher surface texture. This process led to the formation of phosphate bonds, the weakening of hydrogen bonds, and a decrease in relative crystallinity, all while preserving the starch's crystalline structure. Additionally, the modification impeded paste formation, reduced swelling power, and lowered pasting enthalpy, while increasing the content of slowly digestible starch and resistant starch. These findings provided a basis to enhance the functional properties of starch-based materials, which could be applied to improve the texture and stability of food products such as sauces, dressings, and desserts in the food industry.

Novel Less Toxic, Lymphoid Tissue-Targeted Lipid Nanoparticles Containing a Vitamin B5-Derived Ionizable Lipid for mRNA Vaccine Delivery.

Following their approval by the Food and Drug Administration, lipid nanoparticles (LNPs) have emerged as promising tools for delivering mRNA vaccines and therapeutics. Ionizable lipids are among the essential components of LNPs, as they play crucial roles in encapsulating mRNA and facilitating its release into the cytosol. In this study, 17 innovative ionizable lipids using vitamin B5 are designed as the core structure, aiming to reduce toxicity, to maintain vaccine efficiency, and to ensure synthetic feasibility. The top-performing LNP in terms of mRNA vaccine delivery in the mouse model is LNP 5097, which is generated by incorporating ionizable lipid I97. mRNA⊂LNP 5097 demonstrates favorable structural and physicochemical properties, high mRNA transfection efficiency, and long-term stability. Moreover, mRNA⊂LNP 5097 specifically delivers the mRNA to the spleen and lymph nodes in model mice, induces balanced Th1/Th2 immune responses, and elicits the production of high levels of neutralizing antibodies with low toxicity. The findings here suggest the high utility of LNP 5097, which includes novel vitamin B5-derived ionizable lipids with reduced toxicity, in mRNA vaccine research for both infectious diseases and cancer.

Amino Acid Adsorption Onto Magnetic Nanoparticles Reveals Correlations With Physicochemical Parameters

AbstractWe analyze the adsorption of the proteinogenic amino acids (AAs) glutamine, glutamic acid, lysine, tyrosine, proline, and valine onto bare iron oxide nanoparticles (approx. 10 nm). Aiming to identify the governing principles of low molecular weight coronae, which remain underinvestigated, our study covers broad concentration ranges up to the solubility limit of the AAs. Isothermal experiments reveal that the highly soluble AAs valine, proline, and lysine form extensive multilayers on the nanoparticle surface, and infrared measurements indicate intermolecular interactions, particularly with valine and lysine, for higher AA contents. Conversely, the low solubility of tyrosine and glutamic acid restricts their adsorption capacity, despite their higher partitioning on the solid surface. Parameters derived from fitting a classic saturation model seem to align with well‐documented physicochemical properties such as the hydrophobicity and the complexity indices – a promising first step towards formulating design principles. Scaling these parameters by the AA solubility reveals a clear correlation with the adsorption behavior. In adsorption experiments with AA model mixtures, sequential incubation increases the adsorption capacity for valine and proline, whereas simultaneous incubation with these AAs reduces tyrosine's capacity. Future studies should seek to elucidate adsorption patterns to advance our understanding of corona growth and evolution mechanisms.

Physicochemical Properties and Valorization of the Mucilage Byproduct from Colombian Coffea arabica L. as a Powdered Food Hydrocolloid

Physicochemical Properties and Valorization of the Mucilage Byproduct from Colombian <i>Coffea arabica</i> L. as a Powdered Food Hydrocolloid

Physicochemical Properties and Metal Ion-Binding Capacity of Thermal-Induced Antarctic Krill Protein Aggregates under Different pH Conditions.

Protein properties can be modified by thermal treatment at different pH values, resulting in the formation of protein aggregates with diverse morphologies and functionalities. This study investigated the morphology of aggregates of Antarctic krill protein (AKPS) formed by thermal treatment (90 °C, 15 min) at pH 2, 3, 4, and 6-12, characterized the different morphologies of AKPS, and determined the metal ion (Ca2+, Fe2+, and Zn2+)-binding capacities. Results showed that heat treatment with different pH values generated various AKPS with distinct morphology and metal ion-binding abilities. AKPS have formed fibrils at pH ≤ 3, particles at pH 4-7, and amorphous aggregates at pH ≥ 8. Fibrous AKPS (pH 2) exhibited a high solubility (80.36%) and strong reducing effect on iron. The binding capacities of Ca2+ and Fe2+ reached 36.08% and 66.75%. Particulate AKPS (pH 6 and 7) primarily only showed Zn2+-binding capacity similar to that of casein phosphopeptide (17.33%). Amorphous AKPS (pH 9-11) displayed the optimal capacity to bind Zn2+ and Fe2+ (26.90% and 74.94%). The alterations in morphology and functional characteristics of AKPS permit the design of various nanostructures for food-derived mineral supplements, thus developing their potential for application in functional foods.

Pred-AHCP: Robust Feature Selection-Enabled Sequence-Specific Prediction of Anti-Hepatitis C Peptides via Machine Learning.

Every year, an estimated 1.5 million people worldwide contract Hepatitis C, a significant contributor to liver problems. Although many studies have explored machine learning's potential to predict antiviral peptides, very few have addressed the problem of predicting peptides against specific viruses such as Hepatitis C. In this study, we demonstrate the application and fine-tuning of machine learning (ML) algorithms to predict peptides that are effective against Hepatitis C virus (HCV). We developed a fine-tuned and explainable ML model that harnesses the amino acid sequence of a peptide to predict its anti-hepatitis C potential. Specifically, features were computed based on sequence and physicochemical properties. The feature selection was performed using a combined strategy of mutual information and variance inflation factor. This facilitated the removal of redundant and multicollinear features, enhancing the model's generalizability in predicting anti-hepatitis C peptides (AHCPs). The model using the random forest algorithm produced the best performance with an accuracy of about 92%. The feature analysis highlights that the distributions of hydrophobicity, polarizability, coil-forming residues, frequency of glycine residues and the existence of dipeptide motifs VL, LV, and CC emerged as the key predictors for identifying AHCPs targeting different components of HCV. The developed model can be accessed through the Pred-AHCP web server, provided at http://tinyurl.com/web-Pred-AHCP. This resource facilitates the prediction and re-engineering of AHCPs for designing peptide-based therapeutics while also proposing an exploration of similar strategies for designing peptide inhibitors effective against other viruses. The developed ML model can also be used for validating peptide sequences generated using generative artificial intelligence methods for further optimization.

Rice husk biochar resuscitates the microecological functions of heavy–metal contaminated soil after washing by enriching functional bacteria

Biochar has great potential for simultaneously improving soil ecological functions and eliminating environmental pollutants. However, studies on this strategy in the restoration of ecological functions in chelator–washed soil are lacking, and the effect of biochar on the structure, functions, and microbial interactions of washed soil microbiomes are unclear. Hence, the effect of rice husk biochar (RHB, 2 %) on the physicochemical properties, heavy metal fractions, and microbial community structure of glutamate–N, N–diacetic acid (GLDA)– and ethylenediaminetetraacetic acid (EDTA)– washed remediated soil were investigated. Results showed that the RHB addition restored the washed soil physical structure (pores and agglomerates) and meanwhile, the soil colloidal sheet sweeps increased by 20.49 % and 102.07 % in the z–axis, respectively. Additionally, RHB significantly increased washed soil pH (P < 0.05) and alkaline phosphatase and urease activities, while decreased acid phosphatase and glucosidase activities. The Observed–species and Shannon index were significantly higher in soil treated by RHB combined with GLDA and EDTA than those treated with GLDA and EDTA alone (P < 0.05). GLDA washing coupled RHB treatment enriched key bacterial groups such as MND1, Chelativorans, and Ellin6067, while EDTA washing coupled RHB treatment enriched Sreroidobacter, Micromonospora, and Reyranella, that both related to C–, N–, and P– cycles. Importantly, RHB addition could enrich functional bacteria by increasing bacterial resistance, including glucose metabolic homeostasis and metal ion resistance. The observed enrichment of functional bacteria provided evidence for the enhancement of soil nutrient cycles, indicative of improved soil functions by combination of chelator washing and biochar amended.

Microbial Succession and Effect of Fermentation on the Proximate Composition of Sweet Potato Tubers, Leaves and Vines

This study was aimed at determining the effect of fermentation on the proximate composition of sweet potato tubers, leaves and vines. The study involved the spontaneous fermentation of the substrates for five days (120h). Physico-chemical properties and microbial counts were determined during the fermentation period. Lactic acid bacteria and yeasts were isolated and characterized. Proximate composition of the substrates were determined at the end of the fermentation period. The results obtained show that the aerobic plate counts range from 6.80x105±1.00x105- 8.40x106±1.00x105CFU/g, lactic acid bacteria count range from 1.70x105±1.30x105- 1.60x107±6.00x106 CFU/g and fungal count range from 2.50x105±8.00x104- 7.75x106±5.50x105 CFU/g. The counts were significantly different in most cases (p≤0.05). The lactic acid bacteria and yeast isolated and identified from the study include Lactobacillus plantarum, L. buchneri, L. delbrueckii, L. brevis, L. lactis, L. fructovorans, L. colloides, L. pentosus, Leuconostoc mesenteroides, Weisella confusa, Candida krusei, C. utilis, C. ciferii, C. spherical, C. rugosa, C. zeylanoides, C. guilliermondii, C. lipolytica, C. tropicalis, C. boidinii, Saccharomyces cerevisiae, Rhodoturulaminuta, R. glutinis, Kodamaeaohmeri, Kloekerasp. The results of the proximate composition show that there was increase in both Nitrogen free extract and metabolisable energy and decrease in protein content and ash content after fermentation. Findings from this study imply that fermentation of these substrates is characterized by a wide variety of lactic acid bacteria and yeasts with positive effect on the proximate composition of the substrates.

Superstatistical functions of modified shifted Morse potential for diatomic molecules

The application of the molecular potential model to the study of different thermodynamic systems has been a focus of interest in recent time due to its importance in molecular and chemical physics. Hence, the asymptotic iteration method and the Laguerre polynomials are employed to obtain the eigensolutions of the Schrödinger equation with the modified shifted Morse potential model. Vibrational energy results for different diatomic molecules have been presented numerically, and these results are compared with experimental data and other results from available literature. The variation of normalised wave function and probability density of modified shifted Morse potential for some selected diatomic molecules at the ground- and first-excited states have been considered. Results obtained show that the equally spaced sinusoidal wave curves and varying nodes depend on the level of electron concentrations in the diatomic molecules considered. Partition function and other superstatistical function expressions of modified shifted Morse potential for some diatomic molecules within the modified Dirac delta distribution are obtained, using the Poisson summation formula. The superstatistical plots show a high level of dependence on the temperature parameter, maximum vibrational quantum number and deformation parameter. The superstatistical functions for a deformation parameter of zero correspond to the conventional thermodynamic functions.

Formation of bone tissue apatite on starch-based nanofiber-capped nanohydroxyapatite and reduced graphene oxide: a preliminary study.

In the present study, blends of polyvinyl alcohol (PVA), starch (SH), nanohydroxyapatite (Nano-HA), and reduced graphene oxide (r-GO) were used to fabricate an electrospun nano scaffold (ENS), via electrospinning for their potential application in oral and maxillofacial bone soft and hard tissue regeneration. The scaffold was characterized for its physicochemical and mechanical properties. An invitro study was carried out using human osteoblast MG-63 bone cells. Surface characterization, particularly the analysis of calcium content, was performed before and after immersion in the simulated body fluid (SBF). Additionally, the impact of surface treatment on antimicrobial activity was investigated. The results demonstrated that the tensile strength (18.12 ± 0.14MPa), elongation at break (19.23 ± 0.11%), and flexing index (20.15 ± 0.13%) of the ENS were outstanding, indicating promising performance. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assays demonstrated the biocompatible nature of the ENS. The bioactivity test result of ENS showed excellent deposition of bone apatite crystals. The ENS exhibited antimicrobial properties against E. coli (3.41 ± 0.03mm) and S. aureus (3.12 ± 0.08mm). The ENS, possessing the desired properties, has the potential to be tested in large animals for oral and maxillofacial bone and soft tissue regeneration after obtaining the necessary approvals. The developed ENS offers a promising solution for bone tissue regeneration in the oral and maxillofacial region.

Exceptions, Paradoxes, and Their Resolutions in Chemical Reactivity.

Progress in chemistry has primarily been framed through inductive processes, leading to the frequent emergence of exceptions and unexpected reactivities. These anomalies─ranging from surprising reactivity trends and paradoxical understandings to unanticipated parameter influences and unexpected successes or failures in synthetic methods─offer valuable insights that can drive scientific discovery. While it is commonly accepted that such exceptions can drive progress, many have been passively accepted without being explored for opportunities. Although numerous chemists have addressed exceptions and refined chemical models and theories, employing a systematic framework for actively exploring and understanding the underlying causes of exceptions could resolve paradoxes in broader contexts and create a greater impact than treating anomalies as isolated occurrences. This perspective demonstrates a proactive epistemic approach to uncovering the opportunities presented by exceptions and promotes deliberate, thoughtful engagement with paradoxes and anomalies. While the examples primarily focus on physical organic chemistry, the concepts are broadly applicable across various fields in chemical science. The thinking framework presented here is neither exhaustive nor prescriptive, but it outlines one of many potentially possible ways to inspire further development in how these anomalies could be harnessed for advancement.

Enhancing the Cumulene Character of One-Dimensional Acetylene-Based Systems by Stimuli-Induced Planarization of Their Two Pro-diradicaloid Cyclopenta[h,i]aceanthrylene Units.

Acetylene/polyynes -(C≡C-)n and cumulenes =(C=)n are connectors widely used for the realization of one-dimensional (1-D) π-conjugates. Although both π-moieties are constituted by sp carbon atoms, their different bond connectivity confers distinct physicochemical properties to the resulting systems. In this context, while many acetylene/polyyne- and cumulene-based derivatives have been prepared and studied, no reports have tackled the possibility to reversibly alter the acetylene/polyyne-cumulene electronic character of these derivatives using mild conditions. Herein, we present a novel approach to enhance the cumulene character of 1-D acetylene-based conjugates consisting in the preparation of derivatives featuring an acetylene moiety connecting two pro-diradicaloid species, namely cyclopenta[h,i]aceanthrylene (CPA), at their pro-radical positions. A thoughtful spectroscopic study of the prepared dimers, complemented by theoretical calculations, suggest a high π-electronic delocalization of the pro-diradicaloid CPAs through the central acetylene spacer upon the dimers' planarization which, in turn, increases the cumulenic character of the acetylenic π-bridge, a feature enhanced for one of the two dimers at low temperature and in methylcyclohexane due to an aggregation-induced planarization process. We reckon that the proposed approach offers an interesting avenue towards the realization of 1-D systems which cumulenic character of the acetylenic π-connector could be altered in response to external stimuli.

Microfluidic Synthesis of Magnetic Nanoparticles for Biomedical Applications.

Magnetic nanoparticles have attracted great attention and become promising candidates in the biomedicine field due to their special physicochemical properties. They are generally divided into metallic and non-metallic magnetic nanoparticles, according to their compositions. Both of the two types have shown practical values in biomedicine applications, such as drug delivery, biosensing, bioimaging, and so on. Research efforts are devoted to the improvement of synthesis strategies to achieve magnetic nanoparticles with controllable morphology, diverse composition, active surface, or multiple functions. Taking high repeatability, programmable operation, precise fluid control, and simple device into account, the microfluidics system can expand the production scale and develop magnetic nanoparticles with desired features. This review will first describe different classifications of promising magnetic nanoparticles, followed by the advancements in microfluidic synthesis and the latest biomedical applications of these magnetic nanoparticles. In addition, the challenges and prospects of magnetic nanoparticles in the biomedical field are also discussed.

LOW-TEMPERATURE SYNTHESIS OF FINE-POROUS CORUNDUM BASED ON INCORPORATED GRAPHENE NANOSTRUCTURES

In the present paper, the effect of the addition of graphene nanostructures and 3 mass % TiO2 on the microstructure and properties of sintered corundum ceramics were studied. Fine-porous corundum ceramics were obtained by the method of solid-phase sintering at relatively low temperatures of 1450oC, by adding graphene nanostructures in an amount of 2 % or 20 %. To lower the synthesis temperature, 3 mass % TiO2 was added to the initial ceramic blends. As a result of the solid solution formed between Al2O3 and TiO2, a well-sintered corundum ceramic is obtained at synthesis temperature lower than that of pure corundum - 1450oС. For the characterization of the initial blends and the ceramic samples, the methods of X-ray phase analysis, infrared spectroscopy, SEM, TEM EDS and visual microscopy were used. Besides, the basic physicochemical properties of the samples synthesized based on corundum were determined, e.g. water absorption (WA, %), apparent density (AD, %) and apparent (open) porosity (Pa, %).

Investigating the effects of various irrigation methods on bacterial communities in paddy soil

Different irrigation methods can impact the micro-ecological environment of paddy soil, affecting crop growth. This study focuses on County A, a key grain production area on China’s East Coast, where 20 plots each of intermittent and flood irrigation were selected and labeled as Group I and Group F, respectively. Soil's basic physicochemical properties and heavy metal content were measured in the laboratory, and high-throughput sequencing was used to analyze soil bacterial communities. The study evaluated the impact mechanisms of different irrigation methods on these bacterial communities. Results indicate: (1) Intermittent irrigation significantly increased bacterial richness, evenness, and diversity, enhancing microbial community diversity and stability. (2) Intermittent irrigation notably raised the abundance of 9 bacterial genera (e.g., Nitrospira, H16) while reducing the abundance of 7 genera (e.g., Geobacter, Sphingomonas). (3) The soil environment in Group I was stable, with bacterial communities influenced by SMC, pH, and Cu; Group F was affected by multiple environmental factors. Intermittent irrigation provides a stable environment that supports bacterial diversity and abundance, contributing to a richer community structure. (4) Intermittent irrigation optimizes moisture, significantly enhancing bacterial functions such as energy production, cell wall biosynthesis, repair, and signal transduction. These findings suggest that intermittent irrigation improves bacterial community stability and diversity, which is crucial for enhancing the overall quality of paddy fields.

Nanoparticles in Subunit Vaccines: Immunological Foundations, Categories, and Applications.

Subunit vaccines, significant in next-generation vaccine development, offer precise targeting of immune responses by focusing on specific antigens. However, this precision often comes at the cost of eliciting strong and durable immunity, posing a great challenge to vaccine design. To address this limitation, recent advancements in nanoparticles (NPs) are utilized to enhance antigen delivery efficiency and boost vaccine efficacy. This review examines how the physicochemical properties of NPs influence various stages of the immune response during vaccine delivery and analyzes how different NP types contribute to immune activation and enhance vaccine performance. It then explores the unique characteristics and immune activation mechanisms of these NPs, along with their recent advancements, and highlights their application in subunit vaccines targeting infectious diseases and cancer. Finally, it discusses the challenges in NP-based vaccine development and proposes future directions for innovation in this promising field.

PHYSICO-CHEMICAL PROPERTIES OF MALIN-UROTROPIN- COPPER SULFATE SYSTEM

Before seed treatment, the seed must contain several active ingredients. Because the mail significant part of the saved crop depends on the correct seed dressing technology. Seed dressing, or seed treatment with pesticides, is an activity aimed at protecting plants from pests and diseases, using special preparations. In this study, the physicochemical properties of the formalin-urotropine-copper sulfate system were investigated at 25 oC. It is established that the isotherms of the system confirmed that the density, viscosity, pH of the solution medium and the crystallization temperature are characterized by inflection points corresponding to concentrations. Analysis of the “composition - properties” diagram of the system shows that the isotherms of the refractive index, density, viscosity and pH of the medium are characterized by two inflection points corresponding to 30 % formalin and 15 % urotropine that equals molar ratio of 1:1:1. Thus, it can be assumed that the interaction of formalin with copper sulfate in aqueous solutions results in the formation of a complex compound of the composition [30 % CH2O +15 % C6H12N4]-CuSO4·5H2O. Based on the data obtained, a solubility diagram was constructed, identified by X-ray phase, IR spectroscopic and thermogravimetric. Comparison of the value of the degree of crystallinity of the studied samples shows that the degree of crystallinity increases in the samples.