Formation Of Network Structure Research Articles

Improving the Stability of Water-in-Oil Emulsions with Medium Internal Phase by the Introduction of Gelatin.

The water-in-oil (W/O) emulsion with a medium aqueous phase may be limited in food and cosmetics due to its poor stability and high cost. Herein, this work proposed a facile strategy to improve the W/O emulsion stability by introducing gelatin. The influence of different gelatin concentrations (0, 0.5%, 1.0%, 2.0%, and 4.0%) on the stability and properties of W/O emulsions was mainly investigated. Results showed that the obtained emulsions still belonged to W/O emulsions after adding gelatin to the aqueous phase. As the gelatin concentration increased (0~4.0%), the interfacial tension decreased, which is conducive to promoting the interface adsorption of polyglycerol polyricinoleate (PGPR). Furthermore, introducing gelatin also improved the water-holding capacity (WHC) (33.50~6.32%) and viscosity of W/O emulsions and reduced the droplet size (37.47~8.75 μm) of emulsions. The enhanced interfacial adsorption and aqueous gelation induced by gelatin addition promoted the formation of a tight overall emulsion network structure by the interaction between the interfacial adsorbed PGPR, as well as PGPR and gelatin in the aqueous phase. The enhancement of the overall network effectively improved the storage stability (35 d), thermal stability (20 min, 80 °C), and freeze-thaw stability (10 cycles) of emulsions, especially at 4.0% gelatin concentration. Hence, this study can provide guidance for the improvement and regulation of the stabilities of W/O emulsions.

Structural characteristics, component interactions and functional properties of gelatins from three fish skins extracted by five methods

Fish skin gelatin is an important functional product used in food, medicine and other industries. However, the structure and function of gelatins extracted with different methods differ significantly, thus limiting its production and application. This study used dry-salting, wet-salting, pepsin, acid and heat methods to extract gelatins from the skins of tilapia, grass carp and sea perch. Then, their structural characteristics (micro- and ultra-structure, amyloid-like fibril, etc.) and functional properties (viscosity, emulsifying performance, antioxidant abilities, etc.) were analyzed, and interaction between gelatin components were also explored. According to the results, the gelatins extracted with dry-salting and wet-salting methods had better reticular structure, larger fiber length/height, and higher viscosity properties, emulsifying and antioxidant capacity. The gelatin extracted by applying heat has the highest gel strength, and the gelatin extracted using pepsin had better thermal stability, water absorption capacity, and fat absorption capacity. Further analysis of component interaction showed that 11 types of collagens detected in the gelatins might promote the conversion of collagen to gelatin through self-assembly ability. The co-assembly of different types of collagens enhanced the properties of gelatin. Decorin had a positive effect on gelatin network structure, but Metallopeptidase inhibited the formation of network structure. Different methods can produce personalized gelatin products according to specific needs. The mining of component interaction would reveal the mechanism of gelatin formation and promote the development of gelatin synthetic biology.

Using nanocellulose to improve heat-induced cull cow meat myofibrillar protein gels: effects of particle morphology and content.

Enhancing protein gel properties is essential to improve the texture of meat products. In this study, the improvement effects of three types of nanocellulose, i.e. rod-like cellulose nanocrystals (CNC), long-chain cellulose nanofibers (CNF) and spherical cellulose nanospheres (CNS) with different concentrations (1, 3, 5, 10, 15 and 20 g kg-1 ), on cull cow meat myofibrillar protein (MP) gel were investigated. Compared with needle-shaped CNC and spherical CNS, the addition of 10 and 20 g kg-1 long-chain CNF had the most significant improvement effect on gel hardness and water-holding capacity, respectively (P < 0.05), increasing to 160.1 g and 97.8%, respectively. In addition, the incorporation of long-chain CNF shortened the T2 relaxation time and induced the formation of the densest network structure and promoted the phase transition of the gel. However, excessive filling of nanocellulose would destroy the structure of the gel, which was not conducive to the improvement of gel properties. Fourier transform infrared results showed that there was no chemical reaction between the three nanocellulose types and MP, but the addition of nanocellulose was conducive to gel formation. The improvement of MP gel properties by adding nanocellulose mainly depends on its morphology and concentration. Nanocellulose with higher aspect ratio is more beneficial to the improvement of gel properties. For each nanocellulose type, there is an optimal addition amount for MP gel improvement. © 2023 Society of Chemical Industry.

Effect of surfactants on the interfacial behaviors of diacylglycerol-based solid lipid nanoparticles and physical stability of W/O emulsion

The influence of surfactants (Span 80, Span 60, PGPR and sodium caseinate) on the stability of W/O emulsions stabilized by diacylglycerol (DAG)-based solid Lipid nanoparticles (SLN) was investigated. DAG-based SLN showed phase separation at high NaCl concentration and acidic pH although the SLN-stabilized W/O emulsion was minimally affected. Span 80 increased the hydrophobicity whereas Span 60 increased the hydrophilicity of SLN. With concentration close to CMC, both Span surfactants caused detachment of SLN from interface and reduced emulsion stability. Nonetheless, addition of a small amount (0.1 wt%) of Span surfactants increased the interfacial modulus. The co-adsorption of SLN and PGPR at the oil-water interface promoted the formation of denser network structure and higher interfacial elasticity, which enhanced the emulsion rigidity and freeze-thaw stability. Sodium caseinate (NaCAS) showed intense competition with particles for adsorption at the interface and caused emulsion destabilization. Consequently, the NaCl release rate was directly influenced by the emulsion stability and the interaction between surfactants with SLN. The results have important implications for applying DAG nanoparticles as stabilizers in W/O emulsions with tailoring interfacial rigidity and water-soluble component release behaviors.

Antibacterial film based on κ-carrageenan with benzyl isothiocyanate-β-cyclodextrin inclusion complex: Characterization and application in chicken preservation

To effectively utilize the potent antibacterial capacity of benzyl isothiocyanate (BITC), attempts have been made to apply it in the natural biopolymeric film by solving its high volatility. In this study, we encapsulated BITC in the carrier β-cyclodextrin (βCD) to form an inclusion complex to protect BITC from volatilization and then introduced the complex to κ-carrageenan (KC) to fabricate an antibacterial food packaging film. The addition of the BITC-βCD complex enhanced the storage modulus and promoted a denser network structure formation for KC hydrogel by rheological measurements and microstructure observations, respectively. In terms of antibacterial capacity, BITC-βCD-KC film displayed favorable antibacterial potential against both Staphylococcus aureus and Listeria monocytogenes after co-incubation for 18 h, with the inhibition zone diameters of 25.7 mm and 16.7 mm, respectively. As an active packing material, the BITC-βCD-KC film exhibited a sustained inhibition effect against the proliferation of these two bacteria on the chicken meat surface at 25 °C. Moreover, the chicken breasts packaged with BITC-βCD-KC film had a total viable count of 4.7 Log CFU/g, obviously lower than that of the unpackaged sample (9.8 Log CFU/g) after storage at 4 °C for 8 days. These results suggested that the KC film with the BITC-βCD inclusion complex might have promising potential as an antibacterial food packaging material for food preservation.

Sialylation shapes mucus architecture inhibiting bacterial invasion in the colon

In the intestine, mucin 2 (Muc2) forms a network structure and prevents bacterial invasion. Glycans are indispensable for Muc2 barrier function. Among various glycosylation patterns of Muc2, sialylation inhibits bacteria-dependent Muc2 degradation. However, the mechanisms by which Muc2 creates the network structure and sialylation prevents mucin degradation remain unknown. Here, by focusing on two glycosyltransferases, St6 N-acetylgalactosaminide α-2,6-sialyltransferase 6 (St6galnac6) and β-1,3-galactosyltransferase 5 (B3galt5), mediating the generation of desialylated glycans, we show that sialylation forms the network structure of Muc2 by providing negative charge and hydrophilicity. The colonic mucus of mice lacking St6galnac6 and B3galt5 was less sialylated, thinner, and more permeable to microbiota, resulting in high susceptibility to intestinal inflammation. Mice with a B3galt5 mutation associated with inflammatory bowel disease (IBD) also showed the loss of desialylated glycans of mucus and the high susceptibility to intestinal inflammation, suggesting that the reduced sialylation of Muc2 is associated with the pathogenesis of IBD. In mucins of mice with reduced sialylation, negative charge was reduced, the network structure was disturbed, and many bacteria invaded. Thus, sialylation mediates the negative charging of Muc2 and facilitates the formation of the mucin network structure, thereby inhibiting bacterial invasion in the colon to maintain gut homeostasis.

LONDON AS A CENTER OF ATTRACTION FOR FOREIGN TRANSNATIONAL CORPORATIONS

The assessment of the role of large cities as hubs of foreign TNCs is of particular importance in economic geography in the context of the formation of global business network structures. Based on the Forbes Global 2000 rating data, the range of presence of the world’s largest foreign TNCs’ affiliates in the London agglomeration, their industrial and geographic structure, and the pattern of location were assessed. As a result of the analysis, the historical stages of the formation of foreign corporate segment of the city’s economy were identified. London is highly attractive for foreign corporations, in their numbers it competes equally with New York and the world’s “gateway cities”. The maximum number of foreign TNCs’ affiliates was recorded in the sphere of financial and professional services, and, to a lesser extent, in mechanical engineering, chemical and mining industries. A relatively narrow geography of corporate links is revealed with a clear dominance of US companies. A pronounced “centric” model of foreign TNCs’ affiliates’ location is argued with two key clusters - in the City and Westminster areas.

Mechanical properties and micro-mechanism of cement-based materials strengthened by in-situ organic-inorganic polymerization

Ordinary cement-based materials face defects in practical applications, such as poor tensile strength, brittleness, and high cracking risk. Compound modification has great potential to improve cement-based material structural and mechanical performance. In this paper, cement-based materials with a three-dimensional (3D) plug-in network structure are formed by in-situ organic-inorganic polymerization. Partial acrylamide (AM) monomer is inserted into the zirconium phosphate (ZrP) interlayer, and zirconium phosphate-acrylamide (ZrP-AM) composite materials are successfully prepared. During cement hydration, AM undergoes in-situ self-polymerization and co-polymerization with ZrP-AM, forming a complete plug-in network with ZrP distributed on the polymer network. Meanwhile, the plug-in network structure is closely bound to the cement matrix due to the formation of chemical bonds. In the best mix ratio design, the ZrP-PAM-modified sample with 1 wt% ZrP and 3 wt% AM has a 105% higher flexural strength than the cement paste. Moreover, due to the enhancing effect of ZrP on the cement matrix and polymer network, the flexural and compressive strengths of the modified sample increased by 28.5% and 17%, respectively, compared to the single AM modified sample with respect to the same dosage. The formation of the plug-in network structure and chemical bonds greatly enhances the mechanical strength of cement-based materials. This synergistic modification method fully exploits the modifying effects of polymers and nanomaterials and provides a novel strategy to improve the mechanical properties of cement-based materials.

P-345 GM-CSF drives endometrial repair via p-STAT3 mediating angiogenesis

Abstract Study question Does granulocyte macrophage colony-stimulating factor (GM-CSF) play a role in endometrial angiogenesis and can it be used as a new application for treating endometrial regeneration? Summary answer GM-CSF improves endometrial repair via promoting endometrial angiogenesis and may provide a novel insight and therapeutics for endometrial injury. What is known already GM-CSF is a cytokine normally expressed in the female reproductive tract and plays key roles in embryo implantation and subsequent development. Our previous study found that intraperitoneally （i.p.）injection of GM-CSF can significantly improve endometrial repair by promoting endometrial glandular cells proliferation and stromal cells migration, increasing the thickness of endometrium and embryo implantation in mice. However, whether GM-CSF is involved in endometrial angiogenesis is unknown. Study design, size, duration To observe whether angiogenesis is promoted by GM-CSF, the expression of angiogenic factor CD31 was evaluated after injection of GM-CSF into endometrial injured mice model. The effect of GM-CSF on vascular g regeneration was also explored by zebrafish embryo model of intersegmental vascular injury. Human umbilical vein vascular endothelial cells (HUVECs) were cultured in vitro, and the role of GM-CSF on HUVECs were examined through EdU, Tube formation, Scratch repair and Transwell assays. Participants/materials, setting, methods 20μl 90% ethanol was used to establish endometrial injured mice model. After modeling, compared with i.p. injection of GM-CSF and saline, observing whether GM-CSF had the effect of repairing angiogenesis of injured endometrium, by evaluating expression of CD31. Real-time PCR, Western Blot were used to verify differentially expressed levels of mRNA and protein. Western Blot was used to confirm protein location. ChIP was used to analyze stat3 regulation of GM-CSF. Main results and the role of chance GM-CSF promoted expression of angiogenic factor CD31 in the mice model of endometrial injury. GM-CSF can repair and regenerate the zebrafish embryo model of intersegmental vascular injury caused by Sorafenib. GM-CSF can promote angiogenesis by HUVECs proliferation and migration, and significantly increase the formation of vascular-like network structures In GM-CSF treatment group, the mRNA expression of VEGF, MMP2, Ang1, Ang2 and Tie2 mRNA in HUVECs cells increased significantly; GM-CSF can activate the phosphorylation expression levels of p-FAK, p-Src, p-ERK 1/2, p-STAT3, p-p38 MAPK, pc-Jun, p-CREB, p-Akt, and p-eNOS. And it can increase the expression of downstream VEGF and MMP2 proteins. GM-CSF treatment for 30 min can promote phosphorylation and translocation of STAT3 from cytoplasm to nucleus, thereby regulating the expression of VEGF and MMP2 downstream. While FAK inhibitors (PF573228) and STAT3 knockdown can abrogate GM-CSF effect on HUVECs. Limitations, reasons for caution The results at the cellular and animal level can’t be completely mimic human endometrial injury. In future, well-designed clinical trials are needed to investigate the efficacy and safety of GM-CSF for treatment of human endometrial vascular injury. Wider implications of the findings GM-CSF can promote the vascular regeneration in mice model of endometrial injury through p-STAT3. Our findings provide new ideas for clinical treatment of endometrial injury. Trial registration number Not applicable

Ab-Initio molecular dynamics simulations of binary NaCl-ThCl4 and ternary NaCl-ThCl4-UCl3 molten salts

Molten salt reactor (MSR) with Thorium (Th) fuel cycle has attracted growing attention due to its merits such as safety, low radioactive waste production, and non-proliferation. The design and safe operation of MSR rely on a thorough understanding of the thermophysical properties of molten salts over a wide range of composition and temperature. However, experimental data of Th-based molten salts are limited due to the inherent challenges of dealing with corrosive molten salts and the radioactive nature of actinides. In this work, thermophysical properties including density, heat capacity, thermal expansion coefficient, and mixing energy of binary NaCl-ThCl4 and ternary NaCl-ThCl4-UCl3 molten salts are explored using ab-initio molecular dynamic simulations (AIMD) with the dDsC dispersion correction. The calculated mixing energy of binary NaCl-ThCl4 exhibits a minimum close to the eutectic composition. The heat capacity of the mixtures is linearly dependent on the mole fraction of each component. 7-fold and 6-fold coordinated Th complexes are dominant in the mixtures. 8-fold coordinated Th complex increases with ThCl4 fraction due to the formation of network structures. The average coordination number of Th exhibits a minimum near the eutectic composition. The minimum mixing energy for the ternary mixtures is observed in systems with a composition close to [NaCl]0.5[ThCl4]0.25[UCl3]0.25. The density positively deviates from the ideal solution in mixtures near this composition. These results are important to fill the data and knowledge gap of ThCl4 molten salts.

Synthesis and adsorption behaviors of dendrimeric cross-linked networks with bio-based phytic acid groups obtained by UV curing

The treatment of wastewater, which has become a major environmental concern as industry has grown, is an important research topic. In this study, a dendrimeric cross-linked network had been designed as a new adsorbent for the removal of Crystal violet dye (CV) from aqueous solutions. First, dendrimers of the polyamidoamine (PAMAM) type with an ethylene diamine core were developed. Then, glycidyl metacrylate (GMA) was independently used to modify bio-based phytic acid and PAMAM dendrimer. The formation of a polymeric network structure with phosphoric acid groups that may be employed as an adsorbent (PG-PAG) was then accomplished using the UV curing. Nuclear Magnetic Resonance Spectroscopy (NMR), and Fourier-Transform Infrared-Attenuated Total Reflection (FTIR-ATR) were employed to characterize the polyester polymers. Differential Scanning Calorimetry (DSC), SEM-EDX (Scanning Electron Microscope-Energy Dispersion Spectroscopy), and Brunauer-Emmet-Teller surface measurement analysis (BET) were used to analyze the polymeric networks. The adsorbent’ adsorption and desorption behavior were examined. In this adsorption mechanism, which conforms to the Langmuir isotherm model, the theoretical capacity was calculated as 250 mg/g. In addition, kinetically suitable for the pseudo-second-order model was determined. According to the findings, this novel adsorbent may be used regardless of the pH of the aqueous media. Furthermore, in contrast to previously studied bio-based adsorption materials, the materials used in this study have extraordinarily high adsorptive capabilities. According to the pseudo-second-order model, theoretical 555.55 mg/g and experimental 530.43 mg/g capacities were found.

BaO–reinforced SiO2–Na2O–Ca(O/F2)–Al2O3 glasses for radiation safety: On the physical, optical, structural and radiation shielding properties

This paper reports on a study aimed at investigating the physical properties and radiation shielding capability of a low-cost, high-transparency silicate glassy system reinforced with barium oxide. The prepared glasses' elementary and modified network structures were analyzed using X-ray diffraction and Raman spectroscopy, confirming their glass nature and revealing the progressive network depolymerization with BaO inclusion. Differential scanning calorimetry was employed to determine the glass transition temperature, which showed an increase with increasing BaO content. Tauc's plot was used to study the direct optical bandgap, which was observed to increase from 3.91 to 4.75 eV with BaO content from 0 to 30 mol%, linked to an increase in the average oxygen bond chain length and non-bridging oxygen atoms' creation. The density, molar volume, and oxygen packing density of the glass were found to increase with BaO addition, indicating that barium oxide promotes the formation of a compact network structure collapsing into a closely packed arrangement. At an X-ray energy of 40 keV, the mass attenuation coefficient increased from 0.67 to 11.48 cm2/g with BaO content. To assess the efficacy of theoretical calculations, we have conducted an experimental setup to measure the linear attenuation coefficient using an 241Am (59.5 keV) radiation source. Finally, the gamma shielding effectiveness was evaluated, and the sample containing 30 mol% of BaO showed superior radiation protection compared to concrete and was comparable to RS360 commercial glass.

Freeze-casted tungsten skeleton reinforced copper matrix composites

Copper-tungsten (Cu-W) composites with a copper content larger than 50 vol% are expected to have a good combination of electrical conductivity and mechanical properties. However, it is difficult to synthesize these types of composites using the conventional manufacturing routes. In this paper, W skeletons with a high porosity up to 80 ± 0.8% and well-aligned microstructures were prepared by directional solidification of aqueous slurries of W followed by ice sublimation and heat treatment. Tungsten reinforced copper matrix composites (e.g., Cu-15 vol% W composites) were fabricated by infiltration of Cu into the W skeleton structures, and their microstructure, electrical conductivity and mechanical properties were studied. The synthesized Cu-15 vol% W composites exhibited alternately patterned Cu and W microstructures and showed a good combination of electrical conductivity of 78 ± 2% IACS and hardness of 136 ± 6HV. The strengthening mechanisms of these Cu-15 vol% W composites were identified as the formation of tungsten network structures which support and strengthen the copper matrix. Residual pores in the W lamellae and weak interfaces of copper-tungsten caused the initiation and propagation of cracks, and the fracture mode of Cu-15 vol% W composite was polymerization induced ductile fracture.

The effect of high-voltage electrostatic field on the interactions between duck myofibrillar protein and inulin: An underlying mechanisms study

This study investigated the effect of high-voltage electrostatic field (HVEF) treatment on the interactions between duck myofibrillar protein (MP) and inulin, as well as explored the gel properties of adding inulin to duck MP. Hence, different inulin content (0–30 mg mL−1) were added to duck MP and HVEF treatment was applied in the gelation process.The results revealed that HVEF combined with the addition of 30 mg mL−1 inulin treatment significantly increased (P < 0.05) the water holding capacity and gel strength by 0.20 and 2.61 times, respectively. Moreover, the rheological characteristics and the formation of the three-dimensional network structure was promoted after added inulin and applied HVEF treatment. The HVEF treatment in modifying MP-inulin interaction promoted the conversion of α-helix to β-sheet, β-turn and random coil, significantly increased (P < 0.05) the content of R–SH groups and surface hydrophobicity, thus revealing the underlying mechanisms of the enhancement of duck MP gel performance. Principal component analysis revealed these interrelationships. This data demonstrated that inulin addition combined with HVEF treatment might be a new and effective strategy to enhance the duck MP gel properties.

Simulation of fracture propagation law in fractured shale gas reservoirs under temporary plugging and diversion fracturing

Natural fractures (NFs) are developed in shale gas reservoirs, which can easily cause frac hits during hydraulic fracturing and reduce the productivity of infill wells and parent wells. Temporary plugging diverting fracturing (TPDF) can hinder the single forward extension of fracture transition and avoid the communication of hydraulic fractures (HFs) or NFs adjacent to wells. In order to explore the fracture propagation law of TPDF in fractured shale gas reservoirs, this study systematically evaluates the main factors such as stress difference, displacement, and fracturing fluid viscosity on the fracture temporary plugging diversion (TPD) law by means of true triaxial hydraulic fracturing simulation device and cohesive element model in ABAQUS. The findings reveal that (1) the law of fracture initiation and propagation at the engineering scale is similar to that in indoor experiments. Upon the primary fracturing (PF), the smaller the horizontal stress difference, the larger the pumping displacement, and the smaller the viscosity of the fracturing fluid is, the greater the corresponding fracture breakdown pressure and the stronger the rock compression resistance. (2) After TPD secondary fracturing, a small horizontal stress difference and a large pumping displacement facilitate the formation of a vertical complex fracture network structure on the primary fracture. Because of the small size of the indoor rock, viscosity has little effect on the fracture propagation of the TPDF, but the numerical simulation results reveal that the higher the viscosity, the greater the width of the new fracture. In addition, (3) the smaller the angle between the new fracture opened after PF and TPDF, the better the propagation effect of the new fracture. Meanwhile, the farther the temporary plugging zone is from the fracture front end, the wider the new fracture opened after TPDF. The field construction results reveal that the TPDF technology can avoid the effect of HFs, thus preventing frac hits during shale gas reservoir reconstruction. This study not only posits a physical and numerical simulation method for simulating the fracture propagation law of TPDF in fractured shale gas reservoirs but also provides theoretical guidance for applying TPDF to field construction.

Fabrication of surface modified antibacterial Ti6Al4V alloy powder reinforced gelatin/chitosan composite scaffold for tissue engineering applications

The present work attempted to modify Ti6Al4V (Ti64) alloy powder to induce biocompatibility and antimicrobial properties by incorporating Ca2+ and Ag+ ions, respectively using a simple chemical treatment followed by ion exchange method. Thus functionally modified Ti64 alloy powders characterized using FE-SEM and Raman spectroscopic techniques indicate the formation of fine porous network structure along with the evolution of different phases of titania upon heat treatment in presence of Ca2+ and Ag+ ions. The incorporation of Ca2+ ions and transformation of Ag+ ions into AgNPs and their decoration on the nano porous network structure have been confirmed by the HR-TEM and EDX results. Optimized concentration of AgNPs decorated Ti64 alloy powder not only found to induce antimicrobial activity against both Gram-positive S. aureus and Gram-negative E. coli bacteria and also compatible with MG-63 cell lines. Surface functionalized Ti64 alloy powder was subsequently used as reinforcement for the fabrication of gelatin - chitosan composite scaffolds using the lyophilization technique. Thus fabricated composite scaffold was analyzed for its pore morphology and pore distribution along with its in-vitro cell toxicity towards MG-63 cell lines using MTT assay. Taken together, surface modified Ti64 alloy powder reinforced gelatin-chitosan composite scaffold with biocompatible and antimicrobial properties is expected to be suitable for tissue engineering applications.

Effects of casein phosphopeptides on thermal stability and sensory quality of whey protein emulsions containing calcium beta-hydroxy-beta-methylbutyrate

This study aimed to elucidate the effect of casein phosphopeptides (CPP) on the thermal stability and sensory quality of whey protein emulsions containing calcium beta-hydroxy-beta-methylbutyrate (WPEs-HMB-Ca). The interaction mechanism among CPP, HMBCa, and WP in the emulsions before and after autoclaving (121 °C, 15 min) was systematically investigated from macroscopic external and microscopic molecular perspectives. It was found that WPEs-HMB-Ca treated by autoclaving resulted in an increase in droplet size (d4,3 = 24.09 μm) due to aggregation/flocculation of proteins, along with a stronger odor with higher viscosity, compared to those without autoclaving. When CPP:HMB-Ca = 1:25 (w/w) in the emulsion, the droplets exhibited a more uniform and consistent state in the emulsion. In addition, CPP was able to inhibit the formation of complex spatial network structures of proteins during autoclaving by binding with Ca2+, thus improving the thermal stability and storage stability of WPEs-HMB-Ca. This work might provide theoretical guidance for developing functional milk drinks with good thermal stability and flavor.

Hydrogelation from Self-Assembled and Scaled-Down Chitin Nanofibers by the Modification of Highly Polar Substituents.

Chitin nanofibers (ChNFs) with a bundle structure were fabricated via regenerative self-assembly at the nanoscale from a chitin ion gel with an ionic liquid using methanol. Furthermore, the bundles were disentangled by partial deacetylation under alkaline conditions, followed by cationization and electrostatic repulsion in aqueous acetic acid to obtain thinner nanofibers called scaled-down ChNFs. This review presents a method for hydrogelation from self-assembled and scaled-down ChNFs by modifying the highly polar substituents on ChNFs. The modification was carried out by the reaction of amino groups on ChNFs, which were generated by partial deacetylation, with reactive substituent candidates such as poly(2-oxazoline)s with electrophilic living propagating ends and mono- and oligosaccharides with hemiacetallic reducing ends. The substituents contributed to the formation of network structures from ChNFs in highly polar dispersed media, such as water, to produce hydrogels. Moreover, after the modification of the maltooligosaccharide primers on ChNFs, glucan phosphorylase-catalyzed enzymatic polymerization was performed from the primer chain ends to elongate the amylosic graft chains on ChNFs. The amylosic graft chains formed double helices between ChNFs, which acted as physical crosslinking points to construct network structures, giving rise to hydrogels.

Atomistic simulation for initiation of crystal slip deformation from surface of nanoscale copper single-crystal nanowires

In nano/micrometer-scale materials, dislocations accounting for crystal slip deformation are introduced from the surface because of lack of pre-existing dislocations inside the materials. The dislocation emission from the surface must play an important role in the formation of dislocation network structures in the nano/micrometer-scale materials under cyclic loading, which should differ from that in macroscale materials. The purpose of this study is to investigate the effect of the atomic-level structure of surfaces on the initiation of crystal slip deformation. We create copper single-crystal nanowire models with different surface structures by varying the cross-section shape and crystal orientation. To observe the initiation of the slip deformation from the surface, we conduct atomistic simulations of tensile deformation for these models. We also discuss the effect of the surface structure on the critical shear stress for slip occurrence from the surface. Our analyses reveal that the orientation of surface steps and the normal stress on the active slip plane are important factors affecting the slip occurrence. Thus, the slip occurs in a slip system so as to reduce the height of a surface step. The active slip system is affected by the cross-section shape and crystal orientation because the slip system is dependent on the relationship between slip planes and the orientation of the surface step. Our results also suggest that the cross-section shape and crystal orientation affect the critical shear stress because of the difference of the normal stress on the active slip plane according to these factors.

Automatic Multiscale Method of Building up a Cross-linked Polymer Reaction System: Bridging SMILES to the Multiscale Molecular Dynamics Simulation

An automatic method is introduced to generate the initial configuration and input file from SMILES for multiscale molecular dynamics (MD) simulation of cross-linked polymer reaction systems. Inputs are a modified version of SMILES of all the components and conditions of coarse-grained (CG) and all-atom (AA) simulations. The overall process comprises the following steps: (1) Modified SMILES inputs of all the components are converted to 3-dimensional coordinates of molecular structures. (2) Molecular structures are mapped to the coarse-grained scale, followed by a CG reaction simulation. (3) CG beads are backmapped to the atomic scale after the CG reaction. (4) An AA productive run is finally performed to analyze volume shrinkage, glass transition, and atomic detail of network structure. The method is applied to two common epoxy resin reactions, that is, the cross-linking process of DGEVA (diglycidyl ether of vanillyl alcohol) and DHAVA (dihydroxyaminopropane of vanillyl alcohol) and that of DGEBA (diglycidyl ether of bisphenol A) and DETA (diethylenetriamine). These components form network structures after the CG cross-linking reaction and are then backmapped to calculate properties in the atomic scale. The result demonstrates that the method can accurately predict volume shrinkage, glass transition, and all-atom structure of cross-linked polymers. The method bridges from SMILES to MD simulation trajectories in an automatic way, which shortens the time of building up cross-linked polymer reaction model and suitable for high-throughput computations.