Network-like Structures Research Articles

A Bacterial Capturing, Neural Network-Like Carbon Nanotubes/Prussian Blue/Puerarin Nanocomposite for Microwave Treatment of Staphylococcus Aureus-Infected Osteomyelitis.

Staphylococcus aureus (S. aureus)-infected osteomyelitis is a deep tissue infection that cannot be effectively treated with antibiotics. Microwave (MW) thermal therapy (MTT) and MW dynamic therapy (MDT) based on MW-responsive materials are promising for the therapy of bacteria-infected osteomyelitis occurring in deep tissues that cannot be effectively treated with antibiotics. In this work, the MW-responsive system of carbon nanotubes (CNTs)/Prussian blue (PB)/puerarin (Pue) with stable network-like structures is constructed. The PB is grown in situ on the CNTs, and its introduction not only reduces the aggregation of the network-like structures of the CNTs, but the large specific surface area and mesoporous structure can also provide many active sites for the adsorption of oxygen and polar molecules. Pue is a natural anti-inflammatory material that reduces inflammation at the infection site. The composite of the CNTs and PB avoids the skin effect and thus can improve dielectric and reflection losses. The MW thermal response of CNTs/PB/Pue is mainly due to the occurrence of reflection loss, dielectric loss, multiple reflections and scattering, interface polarization, and dipole polarization. In addition, under MW irradiation, the CNTs/PB/Pue can produce reactive oxygen species (ROS), such as singlet oxygen (1O2), hydroxyl radical (·OH).

Transient microstructural behavior of methanol/n-heptane droplets under supercritical conditions

Supercritical fluids exist widely in nature and have enduringly attracted scientific and industrial interest. In power systems like liquid rocket engines, fluids undergo the trans-critical process transferred from the subcritical state to the supercritical state, and the phase change process exhibits different features distinguished from subcritical evaporation. In this work, we conducted a series of molecular dynamics studies on the behavior of methanol (MeOH), n-heptane (C7), and binary C7/MeOH droplets under supercritical nitrogen environments. The emphasis is on clarifying the transient characteristics and physical origins of the trans-critical evolution of droplets. During the trans-critical process, droplets are found to experience an unstable period without a spherical shape, where the droplet diameter no longer decreases, violating the traditional d2-law rule. The occurrence of nonspherical droplets is related to the microstructural behavior of trans-critical droplets. Two types of microscopic structures within the droplet are identified: large-scale thermally induced clusters for long-chain C7 and hydrogen-bond connected network-like structures for MeOH, which contains hydroxyl (–OH) groups. Based on these findings, the mechanism behind the evolution of trans-critical droplets is illustrated. Finally, we determine the boundary of ambient conditions in the form of dimensionless expressions Tr−1=a(pr−1)−b, which dictate whether droplets can maintain a spherical shape during the trans-critical process.

Abstract A035: 3D High-Density Collagen I Improves the Modeling of Aggressive Pancreatic Cancer

Abstract Background: Fibrillar collagen type I constitutes the majority of the extracellular matrix in pancreatic ductal adenocarcinoma (PDAC), yet most in vivo murine models involve the use of basement membrane extracts, which instead contain collagen type IV, as matrices to embed PDAC cells. Type I collagen in the PDAC tumor microenvironment has been associated with worse prognosis. Our hypothesis is that PDAC cells grown in 3D high-density collagen I (HDC) gels behave more aggressively compared to the same cells grown using conventional basement membrane matrix (BMM). Methods: The KPC1199 2D cell line was previously generated from a tumor-bearing male KPC mouse. KPC1199 cells were cultured in vitro in HDC or BMM for one week. Orthotopic tumors were established by embedding KPC1199 cells in HDC (N=10) or BMM (N=10) in the pancreatic tail of syngeneic C57BL/6J mice via laparotomy. Half of the tumors were collected five weeks after tumor implantation, and the other half utilized for a survival study. Collagen was imaged by second harmonic generation (SHG) microscopy. Results: In vitro imaging of single KPC1199 cells grown in HDC revealed an aggressive phenotype with clonal network-like structures compared to a spheroidal, non-aggressive phenotype for cells grown in BMM over the course of seven days. SHG imaging confirmed consistent formation and organization of collagen in HDC tumors but minimal to faint collagen formation in BMM tumors. Gross examination of HDC mice showed 60% with visible liver metastasis compared with none in the BMM mice. In the survival study, the entire HDC group died before the BMM group (p-value < 0.01). Conclusions: Our pilot study is the first, to our knowledge, to successfully generate orthotopic PDAC tumors using 3D high-density collagen I in a mouse model. KPC1199 cells embedded in HDC showed an aggressive phenotype in vitro, and resultant tumors demonstrated more robust collagen organization compared to the same cells grown in the BMM substrate. This aggressive phenotype translated to visible liver metastasis within five weeks in the HDC mice and prior to death from primary tumor burden. This is not typical for most KPC-derived cell lines but is typical for human PDAC patients. Our preliminary findings support the use of HDC as an alternative substrate for better modeling of this aggressive cancer. Citation Format: Kim Nguyen-Ta, Sural Ranamukhaarachchi, Jeffrey Turner, Utsav Joshi, Himangshu Sonowal, Jorge de la Torre Medina, Herve Tiriac, Stephanie Fraley, Rebekah White. 3D High-Density Collagen I Improves the Modeling of Aggressive Pancreatic Cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A035.

Ultrafine Network-Like Monolayer Structures of Amphiphilic Hyperbranched Copolymers Revealed by the Relative Aggregation Number Method.

The aggregation behavior of two amphiphilic hyperbranched copolymers of poly[oligo(ethylene glycol) methacrylate-co-lauryl methacrylate] (H-[P(OEGMA-co-LMA)]) at the air/water interface was investigated by using the Langmuir film balance technique and atomic force microscopy (AFM). At the air/water interface, H-[P(OEGMA-co-LMA)] copolymers spontaneously form the ultrafine network-like monolayer structures of micelles; each micelle consists of a tiny hydrophobic core of one or two carbon backbones and lauryl side groups and a short hydrophilic shell of oligo(ethylene glycol) (OEG) side groups, and the micellar cores are connected by the branching agent ethylene glycol dimethacrylate (EGDMA). These ultrafine micellar structures are successfully revealed by our relative aggregation number method presented in this work, which is based on our previous relative mass method and methylene number method. The surface pressure-molecular area isotherms of POEGMA29%-PLMA71% (weight percent) and POEGMA69%-PLMA31% are condensed and expanded, respectively, because the density/number of OEG side groups in the former shells is smaller than that in the latter case. Upon monolayer compression, the isotherms of the former are classified into regions I-IV, whereas those of the latter are classified into regions II and III based on their different variation trends of surface pressure. Subphase pH has little influence on the isotherms of the two copolymers because the stretching degrees of hydrophilic OEG side groups in the shells are probably limited by the connected cores, which is different from the large effects in our previous block copolymers containing POEGMA or poly[oligo(ethylene glycol) acrylate] blocks. Under neutral and alkaline conditions, in region III, the mean molecular area (mmA) values of the isotherms of the two copolymers at 20 °C are smaller than those at 10 °C due to the collapse of the OEG side groups above 15 °C. Furthermore, the isotherms of POEGMA69%-PLMA31% move to larger mmA values at 30 °C due to the increased thermal mobility and stretching degrees of more OEG side groups.

Fabrication of water-resistant and abrasion- resistant superhydrophilic coatings

Superhydrophilic coatings show promising applications in the anti-fogging and self-cleaning fields. However, the application of transparent superhydrophilic coatings faces two challenges: abrasion and water immersion leading to loss of superhydrophilicity. Herein, we contribute Halloysite nanotubes (HNTs) to enhancing abrasion resistance by integrating into network-like structures within coatings, and water resistance by adsorbing sodium alkenyl sulfonate (AOS) facilitated by the positive charge within their cavities, respectively. Hydrolyzed tetraethyl orthosilicate (TEOS) as crosslinking agents combines with the abundant hydroxyl groups (Si-OH) on the surface of HNTs nanotubes and glass substrate to form a three-dimensional network structure. The results demonstrate that the designed HNTs tube coatings have strong abrasion and water resistance accompanied by anti-fogging and self-cleaning properties, which can withstand 800 cycles of Taber abrasion under a load of 250 g, and 90 min of immersion in boiling water. Furthermore, the coated surface exhibited negligible contamination after 153 days in an outdoor environment, which indicates a commendable long-term self-cleaning capability. Therefore, the introduction of HNTs nanotubes can provide a useful strategy for the development of superhydrophilic coatings for anti-fogging and self-cleaning with excellent abrasion and water resistance.

Enhancing mechanical and corrosion properties of GO and Al2O3 reinforced Cu composite coatings

Despite their significant functions and properties, the performance characteristics of Al2O3 ceramic particles and graphene oxide (GO) within hybrid copper composite coatings have been seldom investigated. This study successfully fabricated a Cu-GO- Al2O3 composite coating featuring fine particulate spherical network-like structures on St37 low carbon steel using an ultrasonic-electroless coating method. The effects of Al2O3-decorated graphene oxide hybrid reinforcement on the texture and nanomechanical properties of the copper matrix were examined. The tribological performance of the Cu-GO- Al2O3 composite coating under dry sliding conditions was evaluated, and the wear mechanism was investigated in detail. Results demonstrate that the Cu-GO- Al2O3 composite coating effectively reduces the wear rate and friction of the GO/ Al2O3 hybrid reinforced composite coating. Potentiodynamic polarization tests indicated that the Cu-GO- Al2O3 composite coating exhibits higher corrosion resistance compared to the copper matrix. The enhanced mechanical, tribological, and corrosion properties of the Cu-GO- Al2O3 composite coating are primarily attributed to: (i) the fine particulate spherical network-like structure; (ii) the synergistic effect of the GO and ceramic particle hybrid with a decorated structure; (iii) the formation of graphene oxide/ Al2O3 nanorolls in tribofilms and the excellent self-lubrication properties of graphene oxide. The Cu-GO- Al2O3 composite coating significantly improves the frictional and electrochemical properties of the copper matrix, offering new perspectives for next-generation electrical contacts and nanoelectromechanical systems.

Three-Dimensional Cell Culture Scaffold Supports Capillary-Like Network Formation by Endothelial Cells Derived from Porcine-Induced Pluripotent Stem Cells.

Endothelial cells (EC) can be generated from porcine-induced pluripotent stem cells (piPSC), but poor efficiency in driving EC differentiation hampers their application and efficacy. Additionally, the culture of piPSC-derived EC (piPSC-EC) on three-dimensional (3D) scaffolds has not been fully reported yet. Here, we report a method to improve the generation of EC differentiation from piPSC and to facilitate their culture on 3D scaffolds, providing a potential resource for in vitro drug testing and the generation of tissue-engineered vascular grafts. We initiated the differentiation of piPSC into EC by seeding them on laminin 411 and employing a three-stage protocol, which involved the use of distinct EC differentiation media supplemented with CHIR99021, BMP4, VEGF, and bFGF. piPSC-EC not only expressed EC markers such as CD31, VE-cadherin, and von Willebrand factor (vWF) but also exhibited an upregulation of EC marker genes, including CD31, CD34, VEGFR2, VE-cadherin, and vWF. They exhibited functional characteristics similar to those of porcine coronary artery endothelial cells (PCAEC), such as tube formation and Dil-Ac-LDL uptake. Furthermore, when cultured on 3D scaffolds, piPSC-EC developed a 3D morphology and were capable of forming an endothelial layer and engineering capillary-like networks, though these lacked lumen structures. Our study not only advances the generation of EC from piPSC through an inhibitor and growth factor cocktail but also provides a promising approach for constructing vascular network-like structures. Importantly, these findings open new avenues for drug discovery in vitro and tissue engineering in vivo.

Durability of geopolymer cementitious materials synergistically stimulated by Ca2+ and Na+

Fewer studies related to the durability of multi-source solid waste geopolymer cementitious materials and the massive accumulation of industrial solid waste are urgent problems to be solved in practice in Inner Mongolia, China. In this paper, blast furnace slag (BFS), fly ash (FA), and calcium carbide slag (CCS) are used as the main raw materials to prepare geopolymer cementitious materials (BFCG) with Calcium Carbide Slag as the Ca-source alkali activator and NaOH as the Na-source alkali activator, considering their durability properties. By assessing the indicators of mechanical performance, engineering performance, and the synergistic mechanism of Ca2+ and Na+ in multi-source solid waste geopolymer, four sets of BFCG ratio optimization schemes are selected. XRD, FT-TR, SEM-EDS, and other testing methods are used to analyze its freeze–thaw resistance and acid–alkali-salt corrosion resistance. The following conclusions are drawn: the BFCG prepared under the synergistic excitation of Ca2+ and Na+ has better resistance to freezing and thawing, as well as acid-alkali-salt corrosion, both of which are in accordance with the standard specifications for road construction in China. After the freeze–thaw cycles, BFCG still has more three-dimensional network-like silica-aluminate structures, a compact micromorphology, and small pores. Its strength loss rate is 0.56 %–15.56 %, the mass loss rate is 0.19 %–1.26 %, and the relative dynamic modulus is 79.56 %–100.25 %. In a NaOH environment, the crystal type of BFCG did not change significantly, and the resistivity coefficients are 115.78 %–143.54 %. In a Na2SO4 environment, the decalcification or dealumination of C-A-S-H gel leads to the formation of a gel rich in silicon, magnesium, and aluminum phases, with a corrosion resistance coefficient of 101.8 %–119.96 %. In a HCl environment, HCl erosion inhibits the growth of hydration product crystals, with corrosion resistance coefficients ranging from 73.83 % to 97.24 %. BFCG-D has the best resistance to freezing and thawing as well as acid and alkali corrosion. BFCG-D has the best resistance to freezing and thawing as well as acid and alkali corrosion. These studies show that BFCG offers a promising solution for improving the durability of road base materials and reducing industrial solid waste.

Structural characterization and mechanical properties of bicontinuous dual-metal composites prepared by liquid metal dealloying

Most bicontinuous dual-metal composites (BDMCs) generated by liquid metal dealloying (LMD) exhibit lamellar microstructures at the grain boundaries of initial precursor alloys, resulting in little to no ductility. Herein, grain-boundary-defect-free bicontinuous Ni/Ag composites consisting of network-like dealloying structures (Ni phase) and solidified matrices of liquid metal corrosive media (Ag phase) are prepared. Then, a detailed study of their intrinsic structures and mechanical properties under uniaxial tension is conducted. This composite is found to be completely dense without visible holes or cracks. Both the Ni phase and Ag phase have independent open porous structures and are well bonded with clear interfaces, forming a dual-interlocking structure with phase-to-phase and grain-to-grain interlocking. This structure does not significantly affect the elastic modulus or tensile yield strength, but under specific conditions, it can enhance the tensile ductility because of the coordinated deformation between the two phases, thereby reducing the likelihood of stress concentration and delays necking. Moreover, these bicontinuous Ni/Ag composites display superior strain hardening rates in comparison to pure Ag. The high strength and ductility of this structure warrant the exploration of its practical application in many areas, if more defect-free systems are synthesized by optimizing the LMD process in the future.

Nanopore/pillar formation induced by ion irradiation with a controlled projected range via Au deposition on Ge

Nanopore/pillar formation on a Ge substrate can be induced by ion irradiation, which activates the ion beam sputtering and self-organization of point defects. Considering that the size and morphology of nanostructures are dependent on damage production, the irradiation parameters significantly affect nanostructuring. Here, the projected range of incident ions was selected as a parameter to be investigated. The projected range was modified by adding an Au buffer layer on the surface of the substrate, enabling the ions to stop in a shallower layer. The experimental results showed that the deposited Au layer affected the size and morphology of the nanostructures produced by ion irradiation. As a unique morphology, network-like structures were observed on the Au-deposited substrates. These structures were larger than ordinary porous structures.

Exploring the evolution of microstructure and mechanical property of a γʹ-strengthened Co-based single crystal superalloy during creep and thermal exposure at 1000 °C

The study provided a systematic investigation into the creep behavior of a γʹ-strengthened Co-based single crystal superalloy Co-7Al-8W-1Ta-4Ti (at.%) under compressive creep conditions at 1000 °C and 137 MPa. Simultaneously, the microstructural changes during thermal exposure at 1000 °C were thoroughly examined. The microstructure analysis of the creep samples revealed the presence of γ/γʹ rafts, twins, stacking faults, and dislocation networks. Statistical analyses were conducted to assess the dimensions and volume fractions of γʹ, alongside Vickers hardness tests and nanoindentation experiments. Results show that γʹ dissolution in the creep samples with substantially higher dissolution rates compared to thermal exposure. Localized Co depletion and Ti enrichment in twin is observed in creep sample, potentially initiating localized phase transformations. Concurrently, lattice rotation occurred during creep, resulting in a progressive deviation of crystal orientation away from the [001] direction. Stacking faults transitioned from network-like structures to parallel configurations, and twins played a significant role in creep deformation, particularly in samples subjected to 382 h creep. The study also explored the evolution of Vickers hardness and the elastic modulus, introducing a systematic linear model to describe Vickers hardness changes during both thermal exposure and creep conditions.

Neutrophil extracellular traps: a catalyst for atherosclerosis.

Neutrophil extracellular traps (NETs) are network-like structures released by activated neutrophils. They consist mainly of double-stranded DNA, histones, and neutrophil granule proteins. Continuous release of NETs in response to external stimuli leads to activation of surrounding platelets and monocytes/macrophages, resulting in damage to endothelial cells (EC) and vascular smooth muscle cells (VSMC). Some clinical trials have demonstrated the association between NETs and the severity and prognosis of atherosclerosis. Furthermore, experimental findings have shed light on the molecular mechanisms by which NETs contribute to atherogenesis. NETs play a significant role in the formation of atherosclerotic plaques. This review focuses on recent advancements in the understanding of the relationship between NETs and atherosclerosis. It explores various aspects, including the formation of NETs in atherosclerosis, clinical trials investigating NET-induced atherosclerosis, the mechanisms by which NETs promote atherogenesis, and the translational implications of NETs. Ultimately, we aim to propose new research directions for the diagnosis and treatment of atherosclerosis.

Tailoring robust luminescent-based BaSrY4O8: Eu3+ platform opens new avenues for screening diverge surface prompted cheiloscopy, WLED's, and dosimetric applications

The discovery, evaluation, and manipulation of material can open new avenues in different technological applications in a real-time practical implementation scenario is highly necessary. In this regard, the present work deals with the synthesis of a series amber-red color emitting BaSrY4O8:Eu3+(1–9 mol %) nanophosphors followed by a solution combustion route. X-ray diffraction studies of the prepared phosphors confirmed the orthorhombic phase with Pnma (62) space group. Scanning electron microscopy results revealed that the particles are dumbbells in shape with network-like structures. From diffuse reflectance spectroscopy data, the energy band gap was estimated and found to be ∼5.72–5.92 eV. The photoluminescence emission spectra of the prepared nanophosphors consist of intense and sharp peaks located at ∼ 578, 594, 612, 650, and 708 nm, which attributed to 5D0→7F0, 5D0→7F1,5D0→7F2,5D0→7F3 and 5D0→7F4 transitions of Eu3+ ions, respectively. The estimated Commission International de I'Eclairage color coordinates were found to be tuned from pink to amber-red region. Thermoluminescence glow curve of BaSrY4O8: Eu3+ (5 mol %) nanophosphor after irradiated with various γ –ray doses ranging from 1 to 8 KGy exhibits a broad band with maximum intensity at 340 °C. Thanks to intensive luminescence and nano-regime of the nanophosphor, which enable latent lip prints to visualize on various non-porous surfaces by revealing defined type I–V groove patterns without any background hindrance or color distraction under the excitation. The aforementioned results create new perspective avenues by demonstrating the versatility of the prepared nanophosphor as an excellent red component for white light-emitting diodes, dosimetry, and cheiloscopy applications.

Types and Genesis of Siderite in the Coal-Bearing Beds of the Late Permian Xuanwei Formation in Eastern Yunnan, China

The Late Permian strata of the Xuanwei Formation in the eastern Yunnan region exhibit extensive diverse morphological features within siderite deposits. These variations in siderite deposits suggest potential differences in their formation processes. In this study, fieldwork and comprehensive indoor studies revealed four distinct forms of siderite deposits: stratiform-laminated, lens-like nodule, sandstone cementation, and fracture filling. The stratiform-laminated siderite, varying in color from bluish-grey to dark grey, is composed of uniformly sized microcrystalline to fine-grained siderite along with detrital matter, displaying precise layering and banding structures that suggest direct deposition from cyclic iron-rich seawater under reducing conditions. Lens-like-nodule siderite, which appears grey-yellow, is composed of mud microcrystalline siderite, medium to coarse-grained pseudo-ooids, and glauconite. It shows conformable distribution characteristics resulting from the diagenetic differentiation of iron-rich sediments under reducing conditions during the diagenetic and early diagenetic periods. Siderite as sandstone cementation exhibits a yellow-brown color and consists of dispersed colloidal siderite and cemented siderite clumps that fill intergranular pores of detrital particles. It precipitated under reducing conditions within those intergranular pores. Siderite filling fractures typically appear as vein-like or network-like structures intersecting bedding at large angles. They exhibit grain structures with significant variations in size. These siderite deposits exhibit exceptional purity and result from siderite dissolution during sedimentary periods, followed by reprecipitation within regional extensional fractures during the diagenetic phase. The primary occurrence of siderite deposits in the study area is within coal-bearing strata, as revealed by the integration of sedimentary profiles and sedimentary facies analysis. The coal-bearing strata, influenced by the Emeishan large igneous province, underwent iron enrichment during and after volcanic eruptions while developing a reducing environment, which was facilitated by abundant vegetation. Consequently, geological processes led to siderite layers, lens-like siderite nodules, and siderite cementation. The Yanshan orogeny induced extensive high-angle fracture development in epigenetic coal-bearing strata, facilitating fluid circulation and the redistribution of soluble siderite. This geological activity resulted in the formation of vein-like structures composed of siderite.

Emerging exotic compositional order on approaching low-temperature equilibrium glasses

The ultimate fate of a glass former upon cooling has been a fundamental problem in condensed matter physics and materials science since Kauzmann. Recently, this problem has been challenged by a model with an extraordinary glass-forming ability effectively free from crystallisation and phase separation, two well-known fates of most glass formers, combined with a particle-size swap method. Thus, this system is expected to approach the ideal glass state if it exists. However, we discover exotic compositional order as the coexistence of space-spanning network-like structures formed by small-large particle connections and patches formed by medium-size particles at low temperatures. Therefore, the glass transition is accompanied unexpectedly by exotic compositional ordering inaccessible through ordinary structural or thermodynamic characterisations. Such exotic compositional ordering is found to have an unusual impact on structural relaxation dynamics. Our study thus raises fundamental questions concerning the role of unconventional structural ordering in understanding glass transition.

Neutrophil extracellular traps contributing to atherosclerosis: From pathophysiology to clinical implications.

Neutrophil extracellular traps (NETs) are network-like structures of chromatin filaments decorated by histones, granules, and cytoplasmic-derived proteins expelled by activated neutrophils under multiple pathogenic conditions. NETs not only capture pathogens in innate immunity but also respond to sterile inflammatory stimuli in atherosclerosis, such as lipoproteins and inflammatory cytokines. Atherosclerosis is a lipid-driven chronic inflammatory disease characterized by the accumulation and transformation of inflammatory cells, and smooth muscle cells in the intimal space. NETs-derived extracellular components possess toxic and proinflammatory properties leading to cellular dysfunction and tissue damage, which may establish a link among lipid metabolism, inflammatory immunity, and atherosclerosis. In this review, we discuss recent advances regarding the role of NETs engaged in the pathogenesis of atherosclerosis, particularly focusing on the interaction with lipids and inflammasomes, crosstalk with smooth muscle cells and inflammatory cells, and the association with aging. We also evaluate the current knowledge on the potential of NETs as biomarkers and therapeutic targets for atherosclerosis and its related diseases in clinical practice.

Synthesis, crystal structure and properties of Mn/Ni/Co 3D network structures based on 2, 5-bis(trifluoromethyl) terephthalic acid ligands

2,5-bis(trifluoromethyl)terephthalic acid (H2L1) as the main ligand and 1,10′-phenanthroline (L2) as the co-ligand were reacted with manganese chloride tetrahydrate (MnCl2·4H2O), nickel sulfate hexahydrate (NiSO4·6H2O) and cobalt nitrate hexahydrate (Co(NO3)2·6H2O) by solvothermal reaction to give the manganese complex [Mn2(L1) 2(L2)2]n (1), the nickel complex {[Ni3(L1)3(L2)2(H2O)4]·2DMF}n (2) and the cobalt complex {[Co2(L1)2(DMF)2]·H2O}n (3). The structures were characterized and their properties studied by means of single-crystal X-ray diffraction, infrared spectroscopy, elemental analysis, ultraviolet spectroscopy, fluorescence spectroscopy, thermogravimetric analysis. The single-crystal structure analysis showed that the complexes 1–3 are infinitely extended three-dimensional network-like structures of space groups P1-, P1-, P21/n, respectively. The results of fluorescence analysis and thermogravimetric analysis showed that complexes 1–3 have good thermal stability and fluorescence properties, respectively. Complex 3 can also maintain good thermal stability at 230 °C, and the maximum fluorescence emission wavelength is 370 nm.

Biophysical Properties of the Fibril Structure of the Toxic Conformer of Amyloid-β42: Characterization by Atomic Force Microscopy in Liquid and Molecular Docking.

Alzheimer's disease is associated with the aggregation of the misfolded neuronal peptide, amyloid-β42 (Aβ42). Evidence has suggested that several reasons are responsible for the toxicity caused by the aggregation of Aβ42, including the conformational restriction of Aβ42. In this study, one of the toxic conformers of Aβ42, which contains a Glu-to-Pro substitution (E22P-Aβ42), was explored using atomic force microscopy and molecular docking to study the aggregation dynamics. We proposed a systematic model of fibril formation to better understand the molecular basis of conformational transitions in the Aβ42 species. Our results demonstrated the formation of amorphous aggregates in E22P-Aβ42 that are stem-based, network-like structures, while the formation of mature fibrils occurred in the less toxic conformer of Aβ42, E22-Aβ42, that are sphere-like flexible structures. A comparison was made between the biophysical properties of E22P-Aβ42 and E22-Aβ42 that revealed that E22P-Aβ42 had greater stiffness, dihedral angle, number of β sheets involved, and elasticity, compared with E22-Aβ42. These findings will have considerable implications toward our understanding of the structural basis of the toxicity caused by conformational diversity in Aβ42 species.

Coacervate-Enhanced Deposition of Sprayed Pesticide on Hydrophobic/Superhydrophobic Abaxial Leaf Surfaces.

Deposition of high-speed droplets on inverted surfaces is important to many fundamental scientific principles and technological applications. For example, in pesticide spraying to target pests and diseases emerging on abaxial side of leaves, the downward rebound and gravity of the droplets make the deposition exceedingly difficult on hydrophobic/superhydrophobic leaf underside, causing serious pesticide waste and environmental pollution. Here, a series of bile salt/cationic surfactant coacervates are developed to attain efficient deposition on the inverted surfaces of diverse hydrophobic/superhydrophobic characteristics. The coacervates have abundant nanoscale hydrophilic/hydrophobic domains and intrinsic network-like microstructures, which endow them with efficient encapsulation of various solutes and strong adhesion to surface micro/nanostructures. Thus, the coacervates with low viscosity achieve high-efficient deposition on superhydrophobic abaxial-side of tomato leaves and inverted artificial surfaces with a water contact angle from 170° to 124°, much better than that of commercial agricultural adjuvants. Intriguingly, the compactness of network-like structures dominantly controls adhesion force and deposition efficiency, and the most crowded one leads to the most efficient deposition. The tunable coacervates can help comprehensively understand the complex dynamic deposition, and provide innovative carriers for depositing sprayed pesticides on abaxial and adaxial sides of leaves, thereby potentially reducing pesticide use and promoting sustainable agriculture.

Utilization of ovalbumin-propylene glycol alginate complex system for superior foam: The effect of pH-driven phase behavior

The complex system of ovalbumin (OVA) was constructed using propylene glycol alginate (PGA), and the mechanism linking pH-driven phase behavior of the complex system to foam performance was studied in this work. According to the pH-driven phase behavior of the OVA-PGA complex system determined by turbidity, three pH levels (pH 3.0: insoluble complex, pH 4.0: soluble complex and pH 7.0: co-soluble) were selected. The OVA-PGA complex system possessed better foaming properties compared with the OVA system at the same pH level. It exhibited excellent foaming ability (160.0%) and foaming stability (80.8%) at pH 3.0 and pH 4.0, respectively. At pH 3.0, the insoluble complexes enhanced the thermodynamic activity of the protein and interfacial stability to create abundant foams. The smaller OVA-PGA soluble complexes with moderate charge at pH 4.0, possessed network-like structures capable of forming thicker and moister bubble films to avoid foam instability. The FTIR confirmed the presence of electrostatic repulsion and hydrophobic interaction in the system of pH 7.0, while electrostatic attraction was predominant at pH 3.0. Besides that, the rheological and surface tension results further indicated that insoluble complexes diffused rapidly to the air/water interface at pH 3.0, and soluble complexes with lower interfacial tension presented viscoelasticity that stabilized the interface. However, the co-soluble state of the system at pH 7.0 was detrimental to the foaming properties due to competitive adsorption and unfolding of the OVA. This work provides the theoretical support for producing superior foam and regulating foam-based food systems precisely. • Foam performance was enhanced at various pH levels by adding polysaccharides. • The pH-driven phase behavior caused differences in aerated OVA-PGA complex system. • Soluble complexes formed network-like interface and greatly raised foam stability. • Excellent foaming ability was showed at pH 3.0 due to OVA-PGA insoluble complexes.