pH-Controllable Redox Responsive Amphiphilic Viologens for Switchable Emulsions.

A pH and redox dual responsive amphiphilic viologen is synthesized, which can be reversibly transformed among the zwitterionic (SVa), monovalent anionic (SV+), and divalent anionic (SVH2+) forms upon pH variation, exhibiting pH-controllable redox responsive properties. Switchable Pickering emulsions with different droplet size and viscosity are prepared by the mixture of hydrophilic silica nanoparticles and the viologens (SV+ or SVH2+) at acidic conditions, while such combination yielded an oil-in-dispersion emulsion at neutral pH value. Not only can rapid reversible demulsification/stabilization of the Pickering emulsions be achieved by redox reactions, but the rate of redox-demulsification can also be controlled by pH trigger. The dual-responsive amphiphilic viologens have potential applications in developing intelligent colloid materials and molecular logic systems.

Circ_100549 promotes tumor progression in lung adenocarcinoma through upregulation of BIRC6.

Lung adenocarcinoma (LUAD) is a subtype of lung cancer with high incidence and mortality globally. Emerging evidence suggests that circular RNAs (circRNAs) exert critical functions in human cancers, including LUAD. CircRNA_100549 (circ_100549) has been reported to be significantly upregulated in non-small cell lung cancer (NSCLC) samples, while its role in modulating LUAD progression remains to be explored. The current study aims at investigating the functional roles of circ_100549 in LUAD and its downstream molecular mechanism. First, we found that the expression of circ_100549 was higher in LUAD cell lines. Loss-of-function assays verified that depletion of circ_100549 repressed LUAD cell proliferation but accelerated cell apoptosis. Furthermore, in vivo experiments demonstrated that silencing of circ_100549 suppressed tumor growth. Subsequently, based on database analysis, we carried out a series of experiments to explore the mechanisms and effects of circ_100549 underlying LUAD progression, including RNA-binding protein immunoprecipitation (RIP), RNA/DNA pull-down, luciferase reporter, and chromatin immunoprecipitation (ChIP) assays. The results indicated that circ_100549 serves as a ceRNA by sponging miR-95-5p to upregulate BPTF expression, thus upregulating BIRC6 expression at a transcriptional level in LUAD. In summary, our study demonstrated that circ_100549 facilitates LUAD progression by upregulating BIRC6 expression.

Unveiling the Structural Origins of Dynamic Diversity in Pd-Based Metallic Glasses.

The ß-relaxation is one of the major dynamic behaviors in metallic glasses (MGs) and exhibits diverse features. Despite decades of efforts, the understanding of its structural origin and contribution to the overall dynamics of MG systems is still unclear. Here two palladium-based Pd─Cu─P and Pd─Ni─P MGs are reported with distinct different ß-relaxation behaviors and reveal the structural origins for the difference using the advanced X-ray photon correlation spectroscopy and absorption fine structure techniques together with the first-principles calculations. The pronounced ß-relaxation and fast atomic dynamics in the Pd─Cu─P MG mainly come from the strong mobility of Cu atoms and their locally favored structures. In contrast, the motion of Ni atoms is constrained by P atoms in the Pd─Ni─P MG, leading to the weakened ß-relaxation peak and sluggish dynamics. The correlation of atomic dynamics with microscopic structures provides a way to understand the structural origins of different dynamic behaviors as well as the nature of aging in disordered materials.

Anomalous temperature dependence of elastic limit in metallic glasses.

Understanding the atomistic mechanisms of inelastic deformation in metallic glasses (MGs) remains challenging due to their amorphous structure, where local carriers of plasticity cannot be easily defined. Using molecular dynamics (MD) simulations, we analyzed the onset of inelastic deformation in CuZr MGs, specifically the temperature dependence of the elastic limit, in terms of localized shear transformation (ST) events. We find that although the ST events initiate at lower strain with increasing temperature, the elastic limit increases with temperature in certain temperature ranges. We explain this anomalous behavior through the framework of an energy-strain landscape (ESL) constructed from high-throughput strain-dependent energy barrier calculations for the ST events identified in the MD simulations. The ESL reveals that the anomalous behavior is caused by the transition of ST events from irreversible to reversible with increasing temperature. An analytical formulation is developed to predict this transition and the temperature dependence of the elastic limit.

Progression of enlarged perivascular spaces contributes to occurrence of silent lacunar infarction in the elderly.

INTRODUCTION: This study aims to assess the effect of enlarged perivascular spaces (EPVS) in patients using the methods of scale score and 3D volume quantification and to determine whether EPVS progression is related to the occurrence of silent lacunar infarction (SLI). METHOD: Three hundred sixty-seven elderly patients with EPVS were screened by MRI on the day of admission and 2 years later; 295 patients were included in the final study, among which 136 patients had EPVS with SLI (EL); and 159 patients had EPVS without SLI (EOL). Both scale score and 3D volume quantification method were used to evaluate EPVS. The 295 patients were divided into three groups based on EPVS progression state: Group 1 (no progression), Group 2 (0-50% EPVS progression), and Group 3 (≥ 50% EPVS progression). Multiple logistic regression analysis was used to analyze the risk of occurrence of SLI. RESULTS: The EPVS scores and ΔEPVS scores were not significantly different between the EL and EOL groups (p > 0.05). EPVS volumes and their progression were significantly higher in EL compared with EOL (p < 0.001). The incidence of SLI was increased in Groups 2 and 3 compared with those in Group 1, and the trend test showed statistically significant (p = 0.032). Multiple logistic regression analysis showed that the risk of occurrence of SLI was significantly increased in Group 2 (OR 2.24; p = 0.024) and Group 3 (OR 3.31; p = 0.037) versus that in Group 1. CONCLUSION: 3D volume quantification allows for a more sensitive assessment of EPVS changes, and the progression of EPVS volume may contribute to the occurrence of SLI.

Alkali-Ion Batteries by Carbon Encapsulation of Liquid Metal Anode.

Gallium-based metallic liquids, exhibiting high theoretical capacity, are considered a promising anode material for room-temperature liquid metal alkali-ion batteries. However, electrochemical performances, especially the cyclic stability, of the liquid metal anode for alkali-ion batteries are strongly limited because of the volume expansion and unstable solid electrolyte interphase film of liquid metal. Here, the bottleneck problem is resolved by designing carbon encapsulation on gallium-indium liquid metal nanoparticles (EGaIn@C LMNPs). A superior cycling stability (644 mAh g-1 after 800 cycles at 1.0 A g-1 ) is demonstrated for lithium-ion batteries, and excellent cycle stability (87 mAh g-1 after 2500 cycles at 1.0 A g-1 ) is achieved for sodium-ion batteries by carbon encapsulation of the liquid metal anode. Morphological and phase changes of EGaIn@C LMNPs during the electrochemical reaction process are revealed by in situ transmission electron microscopy measurements in real-time. The origin for the excellent performance is uncovered, that is the EGaIn@C core-shell structure effectively suppresses the non-uniform volume expansion of LMNPs from ≈160% to 127%, improves the electrical conductivity of the LMNPs, and exhibits superior electrochemical kinetics and a self-healing phenomenon. This work paves the way for the applications of room-temperature liquid metal anodes for high-performance alkali-ion batteries.

Smart Emulsions Stabilized by a Multi-headgroup Surfactant Tolerant to High Concentrations of Acids and Salts.

Retaining emulsions stable at high acidity and salinity is still a great challenge. Here, we report a novel multi-headgroup surfactant (C3 H7 -NH+ (C10 COOH)2 , di-UAPAc) which can be reversibly transformed among cationic, anionic and zwitterionic forms upon pH variation. Stable oil-in-dispersion (OID) emulsions in strong acidity (pH=2) can be co-stabilized by low concentrations of di-UAPAc and silica nanoparticles. High salinity at pH=2 improves the adsorption of di-UAPAc on silica particles through hydrogen bonding, resulting in the transformation of OID emulsions into Pickering emulsions. Moreover, emulsification/demulsification and interconversion between OID and Pickering emulsions together with control of the viscosity and droplet size can be triggered by pH. The present work provides a new protocol for designing surfactants for various applications in harsh aqueous media, such as strong acidity and high salinity, involved in oil recovery and sewerage treatments.

Preparation of ß-ionone microcapsules by gelatin/pectin complex coacervation.

ß-ionone has a unique violet odor and good biological activity, which is an essential fragrance component and potential anticancer drug. In this paper, ß-ionone was encapsulated using complex coacervation of gelatin and pectin, followed by cross-linking with glutaraldehyde. The pH value, wall material concentration, core-wall ratio, homogenization conditions, and curing agent content were investigated in the single-factor experiments. For example, the encapsulation efficiency increased with the homogenization speed, which reached a relatively high value at 13000 r/min for 5 min. The gelatin/pectin ratio (3:1, w/w) and pH value (4.23) significantly affected the size, shape, and encapsulation efficiency of the microcapsule. The fluorescence microscope and SEM were used to characterize the morphology of the microcapsules, in which the microcapsule has a stable morphology, uniform size, and spherical multinuclear structure. FTIR measurements confirmed the electrostatic interactions between gelatin and pectin during complex coacervation. Thermogravimetric analysis (TGA) revealed that the microcapsules could maintain good thermal stability over 260 °C. The release rate of ß-ionone microcapsule was only 20.6 % after 30 days at the low temperature of 4 °C. These findings provide an effective carrier to deliver flavors like ß-ionone and could be useful in the fields of daily chemicals and textiles.

CO2-switchable emulsions with controllable size and viscosity.

CO2-responsive emulsions have attracted considerable attention in recent years because of their biocompatibility and easy removal of CO2. However, most CO2-responsive emulsions are only used in stabilization and demulsification processes. In this paper, we report CO2-switchable oil-in-dispersion (OID) emulsions co-stabilized with silica nanoparticles and anionic NCOONa, in which the required concentrations of NCOONa and silica particles were as low as 0.01 mM and 0.0001 wt%, respectively. Besides reversible emulsification/demulsification, the aqueous phase containing the emulsifiers was recycled and reused with the CO2/N2 trigger. More importantly, the properties of the emulsions, such as droplet sizes (40-1020 µm) and viscosities (6-2190 Pa s), were intelligently controlled by the CO2/N2 trigger, and meanwhile reversible conversion between OID emulsions and Pickering emulsions was achieved. The present method offers a green and sustainable way to regulate the emulsion states, which enables smart control of emulsions and widens their potential applications.

Identification of Novel Biomarkers for Abdominal Aortic Aneurysm Promoted by Obstructive Sleep Apnea.

BACKGROUND: We sought to find new biomarkers for abdominal aortic aneurysms (AAA) caused by chronic intermittent hypoxia (CIH). METHODS: The AAA mice model was created using Ang II. The mice were divided into normoxic and CIH groups. The structure of AAA was observed using abdominal ultrasonography, Elastica van Gieson (EVG), and hematoxylin and eosin (HE) staining. The expression of ɑ-SMA was investigated using immunohistochemistry. The novel biomarkers were screened using bioinformatics analysis. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to verify the expression of novel genes in both normal oxygen and CIH. RESULTS: CIH appears to cause greater aortic dilation, higher AAA incidence, lower survival rate, thicker vessel wall, and more brittle elastic lamellae when compared to controls. The immunohistochemistry results showed that the expression of ɑ-SMA in the CIH group was reduced significantly. Four novel genes, including Homer2, Robo2, Ehf, and Asic1, were found to be differentially expressed between normal oxygen and CIH using qRT-PCR, indicating the same trend as bioinformatics analysis. CONCLUSIONS: We discovered that CIH could hasten the occurrence and progression of AAA. Four genes (Homer2, Robo2, Ehf, and Asic1) may be novel biomarkers for AAA, which could aid in the search for new therapies for patients with AAA caused by CIH.

Plasticity Improvement in a Co-Rich Co40Fe25Cr20Ni15 High-Entropy Alloy via Al Alloying.

The mechanical properties of high-entropy alloys (HEAs) can be regulated by altering the stacking fault energy (SFE) through compositional modulation. The Co-rich HEAs, exhibiting deformation twinning and even strain-induced martensitic transformation at room temperature, suffer from insufficient ductility at high strength. In this work, we developed Co-rich (Co40Fe25Cr20Ni15)100-xAlx (x = 0 and 5 at.%) HEAs and investigated their tensile behaviors at room temperature. The addition of Al resulted in a massive improvement in the strength-ductility product, even at similar grain sizes, and also altered the fracture mode from quasi-cleavage to ductile dimple fracture. Interestingly, both alloys were deformed by mechanical twinning, which was also verified by molecular dynamics (MD) simulations. The MD simulations revealed the SFE increased upon Al addition; however, the slip energy barrier was reduced, which favored the mobility of dislocations and twinning propensity to prolong strain hardening. The present findings provide further insights into the regulation of mechanical properties of HEAs by Al-alloying.

Recyclable Nonionic-Anionic Bola Surfactant as a Stabilizer of Size-Controllable and pH-Responsive Pickering Emulsions.

A novel nonionic-anionic Bola surfactant (abbreviated as CH3O(EO)7-R11-COOH) was designed and synthesized by condensation of methyl polyoxyethylene (7) ether with 12-bromododecanoic acid. In neutral aqueous solution, the surfactant behaves as a nonionic one and can stabilize oil-in-water (O/W) conventional emulsions alone and costabilize O/W Pickering emulsions with positively charged alumina nanoparticles with n-decane as the oil. In alkaline solution, the carboxylic acid group is deprotonated, becoming anionic and the surfactant is converted to Bola form, which is an inferior emulsifier and does not adsorb on particle surfaces, resulting in demulsification of both kinds of emulsions. With strong hydrophilicity, both the Bola surfactant and the bare particles return to the aqueous phase after demulsification, which is therefore recyclable and reusable in accordance with sustainable chemistry and engineering. In acidic media between pH 3 and 6, the ethyleneoxy groups tend to desorb from particle surfaces, slightly reducing the hydrophobicity of the particles. However, Pickering emulsions are still stable but their droplet size increases on lowering the pH. The Pickering emulsions are therefore pH-responsive and size-controllable. This newly designed Bola surfactant is effective in preparing smart emulsions, which are extensively applied in heterogeneous catalysis, oil product transportation, emulsion polymerization, and new material preparation.

Charge Density Overcomes Steric Hindrance of Ferrocene Surfactant in Switchable Oil-in-Dispersion Emulsions.

A ferrocene surfactant can be switched between single and double head form (FcN+ C12 /Fc+ N+ C12 ) triggered by redox reaction. FcN+ C12 can neither stabilize an O/W emulsion alone nor an oil-in-dispersion emulsion in combination with alumina nanoparticles due to the steric hindrance of the ferrocene group. However, such steric hindrance can be overcome by increasing the charge density in Fc+ N+ C12 , so that oil-in-dispersion emulsions can be co-stabilized by Fc+ N+ C12 and alumina nanoparticles at very low concentrations (1×10-7  M (≈50 ppb) and 0.001 wt %, respectively). Not only can reversible formation/destabilization of oil-in-dispersion emulsions be achieved by redox reaction, but also reversible transformation between oil-in-dispersion emulsions and Pickering emulsions can be obtained through reversing the charge of alumina particles by adjusting the pH. The results provide a new protocol for the design of surfactants for stabilization of smart oil-in-dispersion emulsions.

Temperature and chemical effects on the interfacial energy between a Ga-In-Sn eutectic liquid alloy and nanoscopic asperities.

The interfacial energies between a eutectic Ga-In-Sn liquid alloy and single nanoscopic asperities of SiO x , Au, and PtSi have been determined in the temperature range between room temperature and 90 °C by atomic force spectroscopy. For all asperities used here, we find that the interfacial tension of the eutectic Ga-In-Sn liquid alloy is smaller than its free surface energy by a factor of two (for SiO x ) to eight (for PtSi). Any significant oxide growth upon heating studied was not detected here, and the measured interfacial energies strongly depend on the chemistry of the asperities. We also observe a weak increase of the interfacial energy as a function of the temperature, which can be explained by the reactivity between SiO x and Ga and the occurrence of chemical segregation at the liquid alloy surface.

Soft and Stretchable Liquid Metal-Elastomer Composite for Wearable Electronics.

Soft devices, especially capacitive stress (or strain) sensors, are important for applications, including wearable medical monitoring, electronic skin, and soft robotics. The incorporation of liquid metal particles (LMPs) into highly deformable elastomers as inclusions ameliorates the mechanical compliance caused by a rigid filler. The high dielectric constant and liquid feature of LMPs are suitable for soft sensors with high sensitivity and a large real-time dynamic detection range. Here, a class of LM-elastomer composites are introduced with elastic and high dielectric properties, making them uniquely suitable for the application of soft stress sensors. The prepared stretchable soft stress sensor can detect the bending degree of the finger, monitor physiological signals in real time, and distinguish the vibration from the pronunciation of different letters. The nanoscale X-ray computational tomography (nano-CT) measurements indeed detect the changes of LMPs under stress, i.e., LMPs in the matrix distribute from uneven to relatively uniform, agglomerate, and even connect each other to have a conduction path in the composition with high LMP contents, which cause the changes in the physical properties of devices under operation. The cognition of LMP changes in composites under stress is instructive for promoting their further applications in the field of soft devices.

Oil-in-Water emulsions stabilized by alumina nanoparticles with organic electrolytes: Fate of particles.

HYPOTHESIS: Oil-in-dispersion emulsions can be stabilized by like charged particles and surfactant. Surfactant adsorbs at the oil-water interface to reduce the interfacial tension and endow the interface with charge, while particles remain dispersed in the aqueous phase to provide electrostatic repulsion between droplets and particles. Can weakly surface-active organic electrolytes adsorb at the oil-water interface and behave like surfactants in stabilizing oil-in-dispersion emulsions with like charged particles? EXPERIMENTS: Symmetrical organic electrolytes, tetraalkylammonium bromides (R4NBr), with either no or very low interfacial activity endowing oil droplets with charge were combined with alumina nanoparticles to stabilize emulsions. The effect of R chain length (varying from methyl to butyl) on the type and stability of emulsions was investigated. FINDINGS: Mixtures of high concentrations of short chain R4NBr salts (R = methyl or ethyl) and alumina particles stabilise oil-in-water Pickering emulsions, whereas longer chain (R = propyl or butyl) analogues stabilize oil-in-dispersion emulsions assisted by alumina particles. Tetrapropylammonium and tetrabutylammonium cations adsorb at the oil-water interface reducing the interfacial tension and endowing the interface with charge. The stability of the oil-in-dispersion emulsions is dominated by the electrostatic repulsion between the droplets and between droplets and particles in the continuous aqueous phase.

Extra plasticity governed by shear band deflection in gradient metallic glasses.

Inspired by gradient materials in nature, advanced engineering components with controlled structural gradients have attracted substantial research interests due to their exceptional combinations of properties. However, it remains challenging to generate structural gradients that penetrate through bulk materials, which is essential for achieving enhanced mechanical properties in metallic materials. Here, we report practical strategies to design controllable structural gradients in bulk metallic glasses (BMGs). By adjusting processing conditions, including holding time and/or controlling temperatures, of cryogenic thermal cycling and fast cooling, two different types of gradient metallic glasses (GMGs) with spatially gradient-distributed free volume contents can be synthesized. Both mechanical testing and atomistic simulations demonstrate that the spatial gradient can endow GMGs with extra plasticity. Such an enhanced mechanical property is governed by the gradient-induced deflection of shear deformation that fundamentally suppresses the unlimited shear localization on a straight plane that would be expected in BMGs without such a gradient.

pH-Responsive Liquid Marbles Based on Dihydroxystearic Acid.

Herein, we report pH-responsive liquid marbles stabilized by 9,10-dihydroxystearic acid (DHSA). The particle morphology and the pH-responsive behavior of the liquid marbles were investigated. The rolling time during the preparation of liquid marbles has a great influence on the thickness of powder adsorption and the stability of the marbles. Compared with the liquid marbles stabilized by other fatty acids (e.g., stearic acid and docosoic acid), the liquid marbles prepared by DHSA have a much higher mechanical robustness. The increase in the number of hydroxyl groups on the carbon chain of fatty acids improves the mechanical robustness of the liquid marbles. Such liquid marbles immediately disintegrated on the surface of an alkaline solution or after exposure to NH3 gas, which extends their applications in the NH3 sensor and chemical reactions.

Recyclable and re-usable smart surfactant for stabilization of various multi-responsive emulsions alone or with nanoparticles.

A novel multi-responsive surfactant (abbreviated as N+-8P8-N) was synthesized, in which one octyl trimethylamine group (quaternary ammonium) and one octyl dimethylamine group are connected to a benzene ring through ether bonds. This novel surfactant can stabilize conventional oil-in-water (O/W) emulsions alone, and O/W Pickering emulsions and novel oil-in-dispersion emulsions together with oppositely and similarly charged nanoparticles, respectively. In all cases rapid demulsification can be achieved through either pH or CO2/N2 triggers, by which the surfactant is reversibly converted between a normal cationic surfactant form (N+-8P8-N) and a strongly hydrophilic and surface-inactive bola form (N+-8P8-NH+). Notably, the bola form N+-8P8-NH+ dissolves in the aqueous phase alone or together with nanoparticles after demulsification without contamination of the oil phase, and the aqueous phase can be recycled many times triggered by pH or CO2/N2 in accordance with the principle of green chemistry. This newly designed re-usable smart surfactant is significant for the development of various temporarily stable emulsions, which are extensively applied in emulsion polymerization, new material synthesis, heterogeneous catalysis and oil transportation.

Conversion of bile salts from inferior emulsifier to efficient smart emulsifier assisted by negatively charged nanoparticles at low concentrations.

Bile salts (BS), one of the biological amphiphiles, are usually used as solubilizing/emulsifying agents of lipids or drugs. However, BS such as sodium deoxycholate (NaDC) can't stabilize an oil-in-water (O/W) emulsion alone due to its unusual molecular structure. In this paper we report that these emulsifiers with poor emulsifying ability can be transformed to highly efficient emulsifiers by combining with negatively charged particles (silica or montmorillonite). Both together can synergistically co-stabilize oil-in-water emulsions at extremely low concentrations (minimum 0.01 mM NaDC plus 0.003 wt% particles). Moreover, the emulsions can be reversibly switched between stable and unstable triggered by CO2/N2 at room temperature. This strategy is universal for emulsions containing different oils (alkanes, aromatic hydrocarbons and triglycerides) and for different BS and offers a generic model for a variety of BS of different molecular structure, which will extend their applications in more technical fields such as emulsion polymerization, biphasic catalysis and emulsion extraction.