Effect of rheological behaviors of polyacrylonitrile grafted sericin solution on film structure and mechanical properties.

Sericin protein possesses excellent biocompatibility, antioxidation, and processability. Nevertheless, manufacturing large quantities of strong and tough pure regenerated sericin materials remains a significant challenge. Herein, we design a lightweight structural sericin film with high ductility by combining radical chain polymerization reaction and liquid-solid phase inversion method. The resulting polyacrylonitrile grafted sericin films exhibit the ability to switch between high strength and high toughness effortlessly, the maximum tensile strength and Young's modulus values are 21.92 ± 1.51 MPa and 8.14 ± 0.09 MPa, respectively, while the elongation at break and toughness reaches up to 344.10 ± 35.40 % and 10.84 ± 1.02 MJ·m-3, respectively. Our findings suggest that incorporating sericin into regenerated films contributes to the transformation of their mechanical properties through influencing the entanglement of molecular chains within polymerized solutions. Structural analyses conducted using infrared spectroscopy and X-ray diffraction confirm that sericin modulates the mechanical properties by affecting the transition of condensed matter conformation. This work presents a convenient yet effective strategy for simultaneously addressing the recycling of sericin as well as producing regenerated protein-based films that hold potential applications in biomedical, wearable, or food packaging.

Twist-Angle Tuning of Electronic Structure in Two-Dimensional Dirac Nodal Line Semimetal Au2Ge on Au(111).

Topological semimetals have emerged as quantum materials including Dirac, Weyl, and nodal line semimetals, and so on. Dirac nodal line (DNL) semimetals possess topologically nontrivial bands crossing along a line or a loop and are considered precursor states for other types of semimetals. Here, we combine scanning tunneling microscopy/spectroscopy (STM/S) measurements and density functional theory (DFT) calculations to investigate a twist angle tuning of electronic structure in two-dimensional DNL semimetal Au2Ge. Theoretical calculations show that two bands of Au2Ge touch each other in Γ-M and Γ-K paths, forming a DNL. A significant transition of electronic structure occurs by tuning the twist angle from 30° to 24° between monolayer Au2Ge and Au(111), as confirmed by STS measurements and DFT calculations. The disappearing of DNL state is a direct consequence of symmetry breaking.

Individualized treatment decision model for inoperable elderly esophageal squamous cell carcinoma based on multi-modal data fusion.

BACKGROUND: This research aimed to develop a model for individualized treatment decision-making in inoperable elderly patients with esophageal squamous cell carcinoma (ESCC) using machine learning methods and multi-modal data. METHODS: A total of 189 inoperable elderly ESCC patients aged 65 or older who underwent concurrent chemoradiotherapy (CCRT) or radiotherapy (RT) were included. Multi-task learning models were created using machine learning techniques to analyze multi-modal data, including pre-treatment CT images, clinical information, and blood test results. Nomograms were constructed to predict the objective response rate (ORR) and progression-free survival (PFS) for different treatment strategies. Optimal treatment plans were recommended based on the nomograms. Patients were stratified into high-risk and low-risk groups using the nomograms, and survival analysis was performed using Kaplan-Meier curves. RESULTS: The identified risk factors influencing ORR were histologic grade (HG), T stage and three radiomic features including original shape elongation, first-order skewness and original shape flatness, while risk factors influencing PFS included BMI, HG and three radiomic features including high gray-level run emphasis, first-order minimum and first-order skewness. These risk factors were incorporated into the nomograms as independent predictive factors. PFS was substantially different between the low-risk group (total score ≤ 110) and the high-risk group (total score > 110) according to Kaplan-Meier curves (P < 0.05). CONCLUSIONS: The developed predictive models for ORR and PFS in inoperable elderly ESCC patients provide valuable insights for predicting treatment efficacy and prognosis. The nomograms enable personalized treatment decision-making and can guide optimal treatment plans for inoperable elderly ESCC patients.

Interface Structure, Dielectric Behavior and Temperature Stability of Ba(Mg1/3Ta2/3)O3/PbZr0.52Ti0.48O3 Thin Films.

Multilayer films can achieve advanced properties and a wide range of applications. The heterogeneous interface plays an important role in the performances of multilayer films. In this paper, the effects of the interface of Ba(Mg1/3Ta2/3)O3/PbZr0.52Ti0.48O3 (BMT/PZT) thin films on dielectric behavior and temperature stability are investigated. The heterogeneous interface structures are characterized by Auger electron spectroscopy (AES). The PZT-BMT interface is different from the BMT-PZT interface in thickness. For the PZT-BMT interface, the PZT thin films are diffused to the whole BMT layers, and the interface thickness is about 90 nm, while the BMT-PZT interface's thickness is only about 8.6 nm. The presence of heterogeneous interfaces can improve the performances of BMT/PZT thin films and expand their applications. The dielectric constant of BBPP thin films is significantly lower than BPBP thin films, while the dielectric loss is exactly the opposite. The more interfaces there are, the greater the dielectric constant. The relationship between the electric-field-dependent dielectric constant curve and the P-E curve is established. The equivalent interface barrier of the diode is used to show that the dielectric peaks under the positive and negative voltage are different. Similarly, heterogeneous interfaces show a certain improvement in dielectric tunability and temperature stability.

Fully Physically Crosslinked Conductive Hydrogel with Ultrastretchability, Transparency, and Self-Healing Properties for Strain Sensors.

Currently, conductive hydrogels have received great attention as flexible strain sensors. However, the preparation of such sensors with integrated stretchability, transparency, and self-healing properties into one gel through a simple method still remains a huge challenge. Here, a fully physically crosslinked double network hydrogel was developed based on poly(hydroxyethyl acrylamide) (PHEAA) and κ-carrageenan (Car). The driving forces for physical gelation were hydrogen bonds, ion bonding, and electrostatic interactions. The resultant PHEAA-Car hydrogel displayed stretchability (1145%) and optical transparency (92%). Meanwhile, the PHEAA-Car hydrogel exhibited a self-healing property at 25 °C. Additionally, the PHEAA-Car hydrogel-based strain sensor could monitor different joint movements. Based on the above functions, the PHEAA-Car hydrogel can be applied in flexible strain sensors.

Two-Dimensional Artificial Ge Superlattice Confining in Electronic Kagome Lattice Potential Valleys.

Constructing two-dimensional (2D) artificial superlattices based on single-atom and few-atom nanoclusters is of great interest for exploring exotic physics. Here we report the realization of two types of artificial germanium (Ge) superlattice self-confined by a 37×37 R25.3° superstructure of bismuth (Bi) induced electronic kagome lattice potential valleys. Scanning tunneling microscopy measurements demonstrate that Ge atoms prefer to be confined in the center of the Bi electronic kagome lattice, forming a single-atom superlattice at 120 K. In contrast, room temperature grown Ge atoms and clusters are confined in the sharing triangle corner and the center, respectively, of the kagome lattice potential valleys, forming an artificial honeycomb superlattice. First-principle calculations and Mulliken population analysis corroborate that our reported atomically thin Bi superstructure on Au(111) has a kagome surface potential valley with the center of the inner Bi hexagon and the space between the outer Bi hexagons being energetically favorable for trapping Ge atoms.

Tunable non-volatile memories based on 2D InSe/h-BN/GaSe heterostructures towards potential multifunctionality.

Floating-gate memories based on two-dimensional van der Waal (2D vdW) heterostructures play an important role in the development of next-generation information technology. The diversity of 2D vdW materials and their heterostructures provides flexibility in the design of novel storage architectures. However, 2D InSe/h-BN/GaSe heterostructures are rarely reported in the field of tunable non-volatile memories, probably due to the quality limitation of materials and complex interfaces from stackings. Herein, a floating-gate 2D InSe/h-BN/GaSe memory with high performance and atmosphere stability is demonstrated. It exhibits both a large ON/OFF current ratio of ∼105 and a good extinction ratio of ∼103, with an estimated maximum storage capacity of 5.1 × 1012 cm-2. Moreover, the storage performance can be regulated by optimizing the thickness of the insulating h-BN layer. Different device configurations have been explored to validate the working mechanism. Furthermore, a simulation of biological synaptic behavior is achieved on the same prototype device. The enhanced non-volatile characteristics enable the exploration of the integrated 2D memory and potential multifunctionality.

Realization of black phosphorus-like PbSe monolayer on Au(111) via epitaxial growth.

Lead selenide (PbSe) has been attracted a lot attention in fundamental research and industrial applications due to its excellent infrared optical and thermoelectric properties, toward reaching the two-dimensional limit. Herein, we realize the black phosphorus-like PbSe (α-phase PbSe) monolayer on Au(111) via epitaxial growth, where a characteristic rectangular superlattice of 5 Å × 9 Å corresponding to 1 × 2 reconstruction with respect to the pristine ofα-phase PbSe is observed by scanning tunneling microscopy. Corresponding density functional theory calculation confirmed the reconstruction and revealed the driven mechanism, the coupling between monolayer PbSe and Au(111) substrate. The metallic feature of differential conductance spectra as well as the transition of the density of states from semiconductor to metal further verified such coupling. As the unique anisotropic structure, our study provides a pathway towards the synthesis of BP-PbSe monolayer. In addition, it builds up an ideal platform for studying fundamental physics and also excellent prospects in PbSe-based device applications.

Influence of Fermentation by Lactobacillus helveticus on the Immunoreactivity of Atlantic Cod Allergens.

Fermentation techniques may induce alterations in fish allergen immunoreactivity. In this study, the influence of fermentation with three different strains of Lactobacillus helveticus (Lh187926, Lh191404, and Lh187926) on the immunoreactivity of Atlantic cod allergens was investigated via several methods. Gradually reduced protein composition and band intensity due to the fermentation by strain Lh191404 were found in SDS-PAGE analysis, and decreased immunoreactivity of fish allergens was confirmed by Western blotting and ELISA analysis due to the fermentation of strain Lh191404. Additionally, results from nLC-MS/MS and immunoinformatics tools analysis demonstrated that the protein polypeptide and allergen composition of Atlantic cod showed evident alterations after fermentation, with the epitopes of the main fish allergens being heavily exposed and destroyed. These results indicated that the fermentation of L. helveticus Lh191404 could destroy the structure and linear epitopes of the allergens from Atlantic cod and may have considerable potential in mitigating the allergenicity of fish.

TIGAR Protects Against Adenine-Induced Ferroptosis in Human Proximal Tubular Epithelial Cells by Activating the mTOR/S6KP70 Axis.

TP53-induced glycolysis and apoptosis regulator (TIGAR) acts as a switch for nephropathy, but its underlying mechanism is still unclear. The purpose of this study was to explore the potential biological significance and underlying mechanism of TIGAR in modulating adenine-induced ferroptosis in human proximal tubular epithelial (HK-2) cells. HK-2 cells under- or overexpressing TIGAR were challenged with adenine to induce ferroptosis. The levels of reactive oxygen species (ROS), iron, malondialdehyde (MDA), and glutathione (GSH) were assayed. Expression of ferroptosis-associated solute carrier family seven-member 11 (SLC7A11) and glutathione peroxidase 4 (GPX4) at the level of mRNA and protein were measured by quantitative real-time-PCR and western blotting. The phosphorylation levels of proteins in the mTOR/S6KP70 pathway were determined by western blotting. Adenine overload triggered ferroptosis in HK-2 cells, as evidenced by reduced levels of GSH, SLC7A11, and GPX4, and increased levels of iron, MDA, and ROS. TIGAR overexpression repressed adenine-induced ferroptosis and induced mTOR/S6KP70 signaling. Inhibitors of mTOR and S6KP70 weakened the ability of TIGAR to inhibit adenine-induced ferroptosis. TIGAR inhibits adenine-induced ferroptosis in human proximal tubular epithelial cells by activating the mTOR/S6KP70 signaling pathway. Therefore, activating the TIGAR/mTOR/S6KP70 axis may be a treatment for crystal nephropathies.

Hydroxypropyl methyl cellulose reinforced conducting polymer hydrogels with ultra-stretchability and low hysteresis as highly sensitive strain sensors for wearable health monitoring.

Conducting polymer hydrogels have emerged as promising materials to fabricate highly sensitive strain sensors. However, due to weak bindings between conducting polymer and gel network, they usually suffer from limited stretchability and large hysteresis, failing to achieve wide-range strain sensing. Herein, we combine hydroxypropyl methyl cellulose (HPMC), poly (3,4-ethylenedioxythiophene):poly (styrene sulfonic acid) (PEDOT: PSS) with chemically cross-linked polyacrylamide (PAM) to prepare a conducting polymer hydrogel for strain sensors. Owing to abundant hydrogen bonds between HPMC, PEDOT:PSS and PAM chains, this conducting polymer hydrogel exhibits high tensile strength (166 kPa), ultra-stretchability (>1600 %) and low hysteresis (<10 % at 1000 % cyclic tensile strain). The resultant hydrogel strain sensor shows ultra-high sensitivity, wide strain sensing ranges of 2-1600 %, and excellent durability and reproducibility. Finally, this strain sensor can be used as wearable sensor to monitor vigorous human movement and fine physiological activity, and services as bioelectrodes for electrocardiograph and electromyography monitoring. This work provides new horizons to design conducting polymer hydrogels for advanced sensing devices.

Cyclic-anion salt for high-voltage stable potassium-metal batteries.

Electrolyte anions are critical for achieving high-voltage stable potassium-metal batteries (PMBs). However, the common anions cannot simultaneously prevent the formation of 'dead K' and the corrosion of Al current collector, resulting in poor cycling stability. Here, we demonstrate cyclic anion of hexafluoropropane-1,3-disulfonimide-based electrolytes that can mitigate the 'dead K' and remarkably enhance the high-voltage stability of PMBs. Particularly, even using low salt concentration (0.8 M) and additive-free carbonate-based electrolytes, the PMBs with a high-voltage polyanion cathode (4.4 V) also exhibit excellent cycling stability of 200 cycles with a good capacity retention of 83%. This noticeable electrochemical performance is due to the highly efficient passivation ability of the cyclic anions on both anode and cathode surfaces. This cyclic-anion-based electrolyte design strategy is also suitable for lithium and sodium-metal battery technologies.

Ionic conductive hydroxypropyl methyl cellulose reinforced hydrogels with extreme stretchability, self-adhesion and anti-freezing ability for highly sensitive skin-like sensors.

Ionically-conductive hydrogels are attracting increasing interest as skin-like sensors, however, the fabrication of ion-conductive hydrogels with excellent mechanical properties, high conductivity, self-adhesion and anti-freezing ability for high-performance sensors remains a challenge. Herein, a highly ion-conductive hydrogel is prepared by introducing LiCl into polyacrylamide/hydroxypropyl methyl cellulose (PAM/HPMC) composite hydrogel. The introduction of LiCl simultaneously endows the PAM/HPMC/LiCl hydrogel with outstanding stretchability (1453 %), high tensile strength (135 kPa), skin-like elasticity (9.18 kPa), high conductivity (7.85 S/m), good adhesiveness and wide operating temperature range. Impressively, this ion-conductive hydrogel can be utilized in skin-like sensor, which achieves high strain sensitivity (GF = 11.19) with wide sensing ranges (up to 600 %), and excellent endurance over 250 consecutive stretching. As a result, the wearable sensor assembled from the hydrogels can be used to detect complex human activities with high stability even at -40 °C. This work promotes the development of ion-conductive hydrogels with broad operating temperature in advanced sensory platform.

Nanopore-Patterned CuSe Drives the Realization of the PbSe-CuSe Lateral Heterostructure.

Monolayer PbSe has been predicted to be a two-dimensional (2D) topological crystalline insulator (TCI) with crystalline symmetry-protected Dirac-cone-like edge states. Recently, few-layered epitaxial PbSe has been grown on the SrTiO3 substrate successfully, but the corresponding signature of the TCI was only observed for films not thinner than seven monolayers, largely due to interfacial strain. Here, we demonstrate a two-step method based on molecular beam epitaxy for the growth of the PbSe-CuSe lateral heterostructure on the Cu(111) substrate, in which we observe a nanopore-patterned CuSe layer that acts as the template for lateral epitaxial growth of PbSe. This further results in a PbSe-CuSe lateral heterostructure with an atomically sharp interface. Scanning tunneling microscopy and spectroscopy measurements reveal a fourfold symmetric square lattice of such PbSe with a quasi-particle band gap of 1.8 eV, a value highly comparable with the theoretical value of freestanding PbSe. The weak monolayer-substrate interaction is further supported by both density functional theory (DFT) and projected crystal orbital Hamilton population, with the former predicting the monolayer's anti-bond state to reside below the Fermi level. Our work demonstrates a practical strategy to fabricate a high-quality in-plane heterostructure, involving a monolayer TCI, which is viable for further exploration of the topology-derived quantum physics and phenomena in the monolayer limit.

Bio-Inspired Antibacterial Hydrogel Adhesives with High Adhesion Strength.

Traditional adhesives such as cyanoacrylate glue are mostly solvent-based. They are facing the problem of insufficient adhesion to some substrates, and also from the drawback of volatilization and release of small organic molecules in the process of usage. Therefore, a novel adhesive with non-irritating, high adhesive strength, and antibacterial properties is highly required. In this study, a full physically crosslinked zwitterionic poly(betaine sulfonate methacrylate) (PSBMA) hydrogel is proposed. The physical crosslinking interactions endow the hydrogel with good self-healing properties. Furthermore, the pure physical crosslinking hydrogel can form PSBMA powder adhesive after lyophilization and return to the hydrogel state after hydration. The mechanical properties of PSBMA adhesive can be modulated via adjusting the solid content and initiator dosage. Following the cure process similar to that of snail mucus or insect exoskeletons in nature, the adhesion of the PSBMA adhesive is improved at least 100 times than its wet state. In addition, the PSBMA adhesive is easy to be removed due to the dissociation of cross-linked structures in saltwater environments. Moreover, PSBMA adhesive with antifouling properties can effectively prevent the adhesion of proteins and bacteria, which shows potential applications in the assembly of medical devices.

Spectroscopic Visualization of Flat Bands in Magic-Angle Twisted Monolayer-Bilayer Graphene: Coexistence of Localization and Delocalization.

Recent transport studies have demonstrated the great potential of twisted monolayer-bilayer graphene (TMBG) as a new platform to host moiré flat bands with a higher tunability than twisted bilayer graphene (TBG). However, a direct visualization of the flat bands in TMBG and its comparison with the ones in TBG remain unexplored. Here, via fabricating on a single sample with exactly the same twist angle of ∼1.13°, we present a direct comparative study between TMBG and TBG using scanning tunneling microscopy and spectroscopy. We observe a sharp density of states peak near the Fermi energy in tunneling spectroscopy, confirming unambiguously the existence of flat electronic bands in TMBG. The bandwidth of this flat-band peak is found to be slightly narrower than that of the TBG, validating previous theoretical predictions. Remarkably, by measuring spatially resolved spectroscopy, combined with continuum model calculation, we show that the flat-band states in TMBG exhibit a unique layer-resolved localization-delocalization coexisting feature, which offers an unprecedented possibility to utilize their cooperation on exploring novel correlation phenomena. Our work provides important microscopic insight of flat-band states for better understanding the emergent physics in graphene moiré systems.

Metagenomic study of humic acid promoting the dechlorination of polychlorinated biphenyls.

Polychlorinated biphenyls (PCBs) are persistent organic pollutants that degrade slowly in the environment. Humic acid (HA), the main component of soil organic matter, or more specifically, the quinone moieties in HA, is generally regarded as an "electron shuttle" between pollutants and microorganisms, which could promote microbial remediation of contamination. In this study, we examined the dechlorination of PCB153 by adding HA and anthraquinone-2,6-disulfonate (AQDS, a model compound of quinones) to systems containing PCB dechlorinators, analyzed the composition and functional gene network of the microbial community by metagenomics, and explored the role of HA by modifying or substituting carbon sources or electron donors. However, this study found that HA accelerated microbial dechlorination of PCBS, while AQDS did not. Moreover, HA without quinone activity still promoted dechlorination, but not without carbon source or electron donor. Metagenomic analysis showed that HA did not promote the growth of PCB dechlorinator (Dehalococcoides), but the transmembrane electron carriers in the HA group were higher than those in the AQDS group and the control group, so HA may have promoted the electron transport process. This study is helpful for microbial remediation of PCB contamination, and provides new insights into the role that HA plays in the biogeochemical cycle.

Electronic Tuning in WSe2/Au via van der Waals Interface Twisting and Intercalation.

The transition metal dichalcogenide (TMD)-metal interfaces constitute an active part of TMD-based electronic devices with optimized performances. Despite their decisive role, current strategies for nanoscale electronic tuning remain limited. Here, we demonstrate electronic tuning in the WSe2/Au interface by twist engineering, capable of modulating the WSe2 carrier doping from an intrinsic p-type to n-type. Scanning tunneling microscope/spectroscopy gives direct evidence of enhanced interfacial interaction induced doping in WSe2 as the twist angle with respect to the topmost (100) lattice of gold changing from 15 to 0°. Taking advantage of the strong coupling interface achieved this way, we have moved a step further to realize an n-p-n-type WSe2 homojunction. The intrinsic doping of WSe2 can be recovered by germanium intercalation. Density functional theory calculations confirm that twist angle and intercalation-dependent charge transfer related doping are involved in our observations. Our work offers ways for electronically tuning the metal-2D semiconductor interface.

Enhanced perchloroethene dechlorination by humic acids via increasing the dehalogenase activity of Dehalococcoides strains.

Perchloroethene (PCE) is a widely used chlorinated solvent. PCE is toxic to humans and has been identified as an environmental contaminant at thousands of sites worldwide. Several Dehalococcoides mccartyi strains can transform PCE to ethene, and thus contribute to bioremediation of contaminated sites. Humic acids (HA) are ubiquitous redox-active compounds of natural aquatic and soil systems and have been intensively studied because of their effect in electron transfer. In this study, we observed the dechlorination of PCE was accelerated by HA in mixed cultures containing Dehalococcoides strains. Anthraquinone-2,6-disulfonic acid (AQDS), a humic acid analogue, inhibited PCE dechlorination in our cultures and thus induced an opposite effect on PCE dehalogenation than HA. We observed the same effect on PCE dechlorination with the pure culture of Dehalococcoides mccartyi strain CBDB1. Not only in mixed cultures but also in pure cultures, growth of Dehalococcoides was not influenced by HA but inhibited by AQDS. Enzymatic activity tests confirmed the dehalogenating activity of strain CBDB1 was increased by HA, especially when using hydrogen as electron donor. We conclude that HA enhanced PCE dechlorination by increasing the reaction speed between hydrogen and the dehalogenase enzyme rather than acting as electron shuttle through its quinone moieties.

Highly Sensitive Detection of Iron Ions in Aqueous Solutions Using Fluorescent Chitosan Nanoparticles Functionalized by Rhodamine B.

Detection of iron ions in aqueous solutions is of significant importance because of their important role in the environment and the human body. Herein, a fluorescent rhodamine B-functionalized chitosan nanoparticles probe is reported for the efficient detection of iron ions. The chitosan nanospheres-rhodamine B (CREN) was prepared by grafting rhodamine B onto the surface of chitosan nanospheres through an amidation reaction. The as-prepared CREN fluorescent probes exhibit high fluorescence intensity under ultraviolet light. When iron ions are added to the CREN solution, they can be coordinated with weak-field ligands such as N and O on the surface of chitosan nanoparticles (CSNP) by a high-spin method. The self-assembly of Fe3+ on the surface of the CREN led to the generation of single electrons and the presence of high paramagnetism, resulting in fluorescence quenching. The quenching effect of Fe3+ on the CREN fluorescent probe can achieve the efficient detection of Fe3+, and the detection limit reaches 10-5 mol/mL. Moreover, this fluorescence quenching effect of Fe3+ on the CREN fluorescent probe is specific, which could not be disturbed by other metal ions and counteranions.