Multiscale Bayes Adaptive Threshold Wavelet Transform Geomagnetic Basemap Denoising Taking Residual Constraints into Account.

To achieve high-precision geomagnetic matching navigation, a reliable geomagnetic anomaly basemap is essential. However, the accuracy of the geomagnetic anomaly basemap is often compromised by noise data that are inherent in the process of data acquisition and integration of multiple data sources. In order to address this challenge, a denoising approach utilizing an improved multiscale wavelet transform is proposed. The denoising process involves the iterative multiscale wavelet transform, which leverages the structural characteristics of the geomagnetic anomaly basemap to extract statistical information on model residuals. This information serves as the a priori knowledge for determining the Bayes estimation threshold necessary for obtaining an optimal wavelet threshold. Additionally, the entropy method is employed to integrate three commonly used evaluation indexes-the signal-to-noise ratio, root mean square (RMS), and smoothing degree. A fusion model of soft and hard threshold functions is devised to mitigate the inherent drawbacks of a single threshold function. During denoising, the Elastic Net regular term is introduced to enhance the accuracy and stability of the denoising results. To validate the proposed method, denoising experiments are conducted using simulation data from a sphere magnetic anomaly model and measured data from a Pacific Ocean sea area. The denoising performance of the proposed method is compared with Gaussian filter, mean filter, and soft and hard threshold wavelet transform algorithms. The experimental results, both for the simulated and measured data, demonstrate that the proposed method excels in denoising effectiveness; maintaining high accuracy; preserving image details while effectively removing noise; and optimizing the signal-to-noise ratio, structural similarity, root mean square error, and smoothing degree of the denoised image.

Organoboron based photochromic gelator.

A series of tetra-coordinate boron-peptide conjugates has been reported. The incorporation of a photochromic organoboron unit into the gelator endows photoactivity to the supramolecular gels. While the structural transformation of the gelator upon UV irradiation minimally impacts the formed self-assembled structures, it indeed influences their rheological properties.

Spatiotemporal-Dependent Confinement Effect of Bubble Swarms Enables a Fractal Hierarchical Assembly with Promoted Chirality.

The submarine-confined bubble swarm is considered an important constraining environment for the early evolution of living matter due to the abundant gas/water interfaces it provides. Similarly, the spatiotemporal characteristics of the confinement effect in this particular scenario may also impact the origin, transfer, and amplification of chirality in organisms. Here, we explore the confinement effect on the chiral hierarchical assembly of the amphiphiles in the confined bubble array stabilized by the micropillar templates. Compared with the other confinement conditions, the assembly in the bubble scenario yields a fractal morphology and exhibits a unique level of the chiral degree, ordering, and orientation consistency, which can be attributed to the characteristic interfacial effects of the rapidly formed gas/water interfaces. Thus, molecules with a balanced amphiphilicity can be more favorable for the promotion. Not limited to the pure enantiomers, chiral amplification of the enantiomer-mixed assembly is observed only in the bubble scenario. Beyond the interfacial mechanism, the fast formation kinetics of the confined liquid bridges in the bubble scenario endows the assembly with the tunable hierarchical morphology when regulating the amphiphilicity, aggregates, and confined spaces. Furthermore, the chiral-induced spin selectivity (CISS) effect of the fractal hierarchical assembly was systematically investigated, and a strategy based on photoisomerization was developed to efficiently modulate the CISS effect. This work provides insights into the robustness of confined bubble swarms in promoting a chiral hierarchical assembly and the potential applications of the resulting chiral hierarchical patterns in solid-state spintronic and optical devices.

Grafting of Poly(ionic liquid) Brushes through Fe0-Mediated Surface-Initiated Atom Transfer Radical Polymerization for Marine Antifouling.

Surface-tethered poly(ionic liquid) brushes have attracted considerable attention in widespread fields, from bioengineering to marine antifouling. However, their applications have been constrained due to the poor polymerization efficiency and sophisticated operation process. In this work, we efficiently synthesized the poly(ionic liquid) brushes with unparalleled speed (up to 98 nm h-1) through Fe0-mediated surface-initiated atom transfer radical polymerization (Fe0 SI-ATRP) while consuming only microliter of monomer solution under ambient conditions. We also demonstrated that poly(ionic liquid) brushes with gradient thickness and wettability were easily accessible by regulating the distance between the opposite plates of Fe0 SI-ATRP. Moreover, the resultant poly(ionic liquid) brushes presented excellent antibacterial activities against Escherichia coli (99.2%) and Bacillus subtilis (88.1%) after 24 h and low attachment for proteins and marine algae (≤5%) for over 2 weeks. This research provided pathways to the facile and controllable fabrication of poly(ionic liquid) materials for marine antifouling applications.

Galvanic-Replacement-Assisted Synthesis of Nanostructured Silver-Surface for SERS Characterization of Two-Dimensional Polymers.

Surface-enhanced Raman scattering (SERS) spectroscopy is a powerful technology in trace analysis. However, the wide applications of SERS in practice are limited by the expensive substrate materials and the complicated preparation processes. Here we report a simple and economical galvanic-replacement-assisted synthesis route to prepare Ag nanoparticles on Cu(0) foil (nanoAg@Cu), which can be directly used as SERS substrate. The fabrication process is fast (ca. 10 min) and easily scaled up to centimeters or even larger. In addition, the morphology of the nanoAg@Cu (with Ag particles size from 30 nm to 160 nm) can be adjusted by various additives (e.g., amino-containing ligands). Finally, we show that the as-prepared nanoAg@Cu can be used for SERS characterization of two-dimensional polymers, and ca. 298 times relative enhancement of Raman intensity is achieved. This work offers a simple and economical strategy for the scalable fabrication of silver-based SERS substrate in thin film analysis.

Precise Preparation of Triarylboron-Based Graphdiyne Analogues for Gas Separation.

A series of triarylboron-based graphdiyne analogues (TAB-GDYs) with tunable pore size were prepared through copper mediated coupling reaction. The elemental composition, chemical bond, morphology of TAB-GDYs were well characterized. The crystallinity was confirmed by selected area electron diffraction (SAED) and stacking modes were studied in combination with high resolution transmission electron microscope (HRTEM) and structure simulation. The absorption and desorption isotherm revealed relatively high specific surface area of these TAB-GDYs up to 788 m2 g-1 for TMTAB-GDY, which decreased as pore size enlarged. TAB-GDYs exhibit certain selectivity for CO2 /N2 (21.9), CO2 /CH4 (5.3), CO2 /H2 (41.8) and C2 H2 /CO2 (2.3). This work has developed a series of boron containing two-dimensional frameworks with clear structures and good stability, and their tunable pore sizes have laid the foundation for future applications in the gas separation field.

Exosomes-derived miR-548am-5p promotes colorectal cancer progression.

Exosomes are vital modulators in intercellular communication and microRNAs (miRNAs) are enriched within exosomes. MiRNAs are important participants in affecting colorectal cancer (CRC) progression, but the influence and latent mechanism of cancer-secreted exosomal miRNAs in colorectal cancer are not fully understood. miR-548am-5p has been reported to be differentially expressed in colon cancer and is indicated as a biomarker for colon cancer diagnosis at the early stage. In this study, we aimed to explore the role of exosomes-derived miR-548am-5p in CRC development. ISH and FISH were implemented to assess miR-548am-5p expression and location in CRC. CRC cells-secreted exosomes were identified via transmission electron microscopy and western blot. Colony formation, sphere formation and flow cytometry assessed the changes in proliferation, stemness and apoptosis of CRC cells. Bioinformatic analyses and mechanical experiments verified the binding of miR-548am-5p and RAR-related orphan receptor A (RORA). Our study identified miR-548am-5p was highly expressed in CRC tissues and cells. Tumor-derived exosomes expedited CRC cell proliferation and stemness along with secreted miR-548am-5p. Moreover, miR-548am-5p inhibition suppressed CRC cell proliferation and stemness while promoting cell apoptosis. RORA was the target mRNA of miR-548am-5p. Down-regulation of RORA was discovered in CRC and its expression was repressed by CRC cell-derived exosomes. As a result, our work elucidated that tumor-derived exosomal miR-548am-5p promoted CRC cell proliferation and stemness via targeting RORA, providing a valuable sight for CRC therapy.

Comparing Safety Profiles: Low-Temperature Plasma Excision vs. Traditional Adenoidectomy for Adenoid Hypertrophy.

Objective: This study compares the efficacy of low-temperature plasma excision and adenoidectomy performed under a nasal endoscope (NE) to treat adenoid hypertrophy (AH). The goal is to offer valuable insights and guidance for future treatments. Methods: We selected a cohort of 83 children diagnosed with AH admitted to our hospital between August 2019 and August 2022. The observation group included 45 children treated with low-temperature plasma excision under NE, while the control group consisted of 38 children treated with adenoidectomy under NE. We compared various parameters, including operative time, intraoperative bleeding, the time for white film disappearance, and the duration of hospitalization between the two groups. Additionally, we assessed levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), nasal pharyngeal volume (NPV), total inspiratory resistance (TIR), and total expiratory resistance (TER). Pain and sleep were evaluated using the Visual Analogue Scale (VAS) and the Pittsburgh Sleep Quality Index (PSQI). Finally, we recorded perioperative complications in both groups. Results: No significant difference was observed in the time of albuginea regression between the two groups (P > .05). However, the observation group demonstrated shorter operative time, quicker dietary recovery, and reduced hospital stay compared to the control group (P < .05). After treatment, the two groups had no significant differences in NPV, TIR, and TER (P > .05). Nevertheless, the observation group exhibited higher levels of SOD and GSH-Px, while MDA, CRP, TNF-α, IL-6, VAS, and PSQI scores were lower (P < .05). Furthermore, the incidence of complications in the observation group was significantly lower than in the control group (P < .05). Conclusions: Low-temperature plasma excision performed under NE for AH demonstrates superior outcomes and improved surgical safety and is strongly recommended for the treatment of adenoid hypertrophy.

Unraveling Triplet Formation Mechanisms in Acenothiophene Chromophores.

The evolution of molecular platforms for singlet fission (SF) chromophores has fueled the quest for new compounds capable of generating triplets quantitatively at fast time scales. As the exploration of molecular motifs for SF has diversified, a key challenge has emerged in identifying when the criteria for SF have been satisfied. Here, we show how covalently bound molecular dimers uniquely provide a set of characteristic optical markers that can be used to distinguish triplet pair formation from processes that generate an individual triplet. These markers are contained within (i) triplet charge-transfer excited state absorption features, (ii) kinetic signatures of triplet-triplet annihilation processes, and (iii) the modulation of triplet formation rates using bridging moieties between chromophores. Our assignments are verified by time-resolved electron paramagnetic resonance (EPR) measurements, which directly identify triplet pairs by their electron spin and polarization patterns. We apply these diagnostic criteria to dimers of acenothiophene derivatives in solution that were recently reported to undergo efficient intermolecular SF in condensed media. While the electronic structure of these heteroatom-containing chromophores can be broadly tuned, the effect of their enhanced spin-orbit coupling and low-energy nonbonding orbitals on their SF dynamics has not been fully determined. We find that SF is fast and efficient in tetracenothiophene but that anthradithiophene exhibits fast intersystem crossing due to modifications of the singlet and triplet excited state energies upon functionalization of the heterocycle. We conclude that it is not sufficient to assign SF based on comparisons of the triplet formation kinetics between monomer and multichromophore systems.

Changes in the Texture and Flavor of Lotus Root after Different Cooking Methods.

The changes in the texture and flavor of lotus root were determined before and after boiling, steaming and frying. Compared to fresh lotus root, all three kinds of cooking decreased the hardness and springiness, and frying significantly enhanced the gumminess, chewiness and cohesiveness. The flavor components, such as flavor amino acids, nucleotides and their taste character in lotus roots, were determined by liquid chromatography and electronic tongue. The amino acids and nucleotide contents of fresh lotus root were 20.9 and 0.07 µg/kg, respectively. The content of flavor substances in lotus roots decreased obviously, and the texture characteristics decreased after boiling and steaming. After deep-frying for 2 min, the free amino acids and nucleotide contents of lotus root were 32.09 and 0.85 µg/kg, respectively, which were the highest in all cooking methods. The contents of volatile flavor components and their smell character in lotus roots were determined by GC-MS and electronic nose. There were 58 kinds of flavor compounds identified in fresh lotus root, mainly alcohols, esters and olefins. The total amount of volatile flavor compounds decreased, and new compounds, such as benzene derivatives, were produced in lotus roots after boiling and steaming. After deep-frying, the content of volatile flavor compounds in lotus root increased significantly, especially the aldehyde volatile flavor compounds. The production of pyran, pyrazine and pyridine volatile flavor compounds made the lotus root flavor unique and delicious. The taste and smell character of lotus roots before and after cooking were effectively separated by an electronic tongue, nose and PCA analysis; the results suggested the boiled lotus root exhibited the most natural and characteristic taste and smell among the four groups.

Mitigation of Thermal Instability for Electrical Properties in CaZrO3-Modified (Na, K, Li) NbO3 Lead-Free Piezoceramics.

Lead-free ceramics 0.96(Na0.52K0.48)0.95Li0.05NbO3-0.04CaZrO3 (NKLN-CZ) are prepared by using the solid-state procedure and two-step synthesis technique. The crystal structure and thermal stability of NKLN-CZ ceramics sintered at 1140-1180 °C are investigated. All the NKLN-CZ ceramics are ABO3-type perovskite phases without impure phases. With the increase in sintering temperature, a phase transition occurs in NKLN-CZ ceramics from the orthorhombic (O) phase to the concomitance of O-tetragonal (T) phases. Meanwhile, ceramics become dense because of the presence of liquid phases. In the vicinity of ambient temperature, an O-T phase boundary is obtained above 1160 °C, which triggers the improvement of electrical properties for the samples. The NKLN-CZ ceramics sintered at 1180 °C exhibit optimum electrical performances (d33 = 180 pC/N, kp = 0.31, dS/dE = 299 pm/V, εr = 920.03, tanδ = 0.0452, Pr = 18 µC/cm2, Tc = 384 °C, Ec = 14 kV/cm). The relaxor behavior of NKLN-CZ ceramics was induced by the introduction of CaZrO3, which may lead to A-site cation disorder and show diffuse phase transition characteristics. Hence, it broadens the temperature range of phase transformation and mitigates thermal instability for piezoelectric properties in NKLN-CZ ceramics. The value of kp for NKLN-CZ ceramics is held at 27.7-31% (variance of kp < 9%) in the range from -25 to 125 °C. The results indicate that lead-free ceramics NKLN-CZ is one of the hopeful temperature-stable piezoceramics for practical application in electronic devices.

Fluorenylidene-Cyclopentadithiophene Based Asymmetric Bistricyclic Aromatic Ene Compounds: Synthesis and Substituents Effects.

Low band gap materials have always been a focus of attention due to their potential applications in various fields. In this work, a series of asymmetric bistricyclic aromatic ene (BAE) compounds with fluorenylidene-cyclopentadithiophene (FYT) skeleton were facially synthesized, which were modified with different substituents (-OMe, -SMe). The FYT core exhibit twisted C=C bond with dihedral angles around 30°, and the introduction of -SMe group can provide additional S⋅⋅⋅S interaction between molecules, which is conducive to the charge transporting. The UV-Vis spectra, electrochemistry and photoelectron spectroscopy revealed that these compounds have relatively narrow band gaps, particularly, the -SMe modified compounds have slightly lower HOMO and Fermi energy levels than that of the -OMe modified compounds. Furthermore, PSCs devices were fabricated with the three compounds as HTMs, and FYT-DSDPA exhibit the best performance among them, revealing the fine-tuning band structure could influence properties of HTMs.

Internal B ← O Bond Facilitated Photo/Thermal Isomerization of Tetra-Coordinated Boranes.

A new series of O∧C-chelate tetra-coordinated boranes with naphtha-aldehyde as the chelate backbone have been synthesized. Their photophysical and photochemical properties have been examined, which show that all of the compounds can undergo both photo and thermal transformations, generating aryl-migrated [1,2]oxaborinine derivatives as the major products. 1,3-Sigmatropic shifts and an intramolecular nucleophilic addition mechanism are proposed for the photochemical and thermal conversion pathways, respectively.

Bubble wall confinement-driven molecular assembly toward sub-12 nm and beyond precision patterning.

Patterning is attractive for nanofabrication, electron devices, and bioengineering. However, achieving the molecular-scale patterns to meet the demands of these fields is challenging. Here, we propose a bubble-template molecular printing concept by introducing the ultrathin liquid film of bubble walls to confine the self-assembly of molecules and achieve ultrahigh-precision assembly up to 12 nanometers corresponding to the critical point toward the Newton black film limit. The disjoining pressure describing the intermolecular interaction could predict the highest precision effectively. The symmetric molecules exhibit better reconfiguration capacity and smaller preaggregates than the asymmetric ones, which are helpful in stabilizing the drainage of foam films and construct high-precision patterns. Our results confirm the robustness of the bubble template to prepare molecular-scale patterns, verify the criticality of molecular symmetry to obtain the ultimate precision, and predict the application potential of high-precision organic patterns in hierarchical self-assembly and high-sensitivity sensors.

Engineering of Graphdiyne-Based Functional Coatings for the Protection of Arbitrary Shapes of Copper Substrates.

Copper-based materials are very important for many application fields from marine industry to energy management and electronic devices. For most of these applications, the copper objects require long-term contact to a wet and salty environment, which leads to serious corrosion of copper. In this work, we report a thin graphdiyne layer directly grown on arbitrary shapes of copper objects at mild conditions, which could function as a protective coating for the copper substrates in artificial seawater with corrosion inhibition efficiency of ∼99.75%. To further improve the protective performance of the coating, the graphdiyne layer is fluorinated and followed by infusion with a fluorine-containing lubricant (i.e., perfluoropolyether). As a result, a slippery surface is obtained, which shows enhanced corrosion inhibition efficiency of ∼99.99% as well as excellent antibiofouling properties against microorganisms, such as protein and algae. Finally, the coatings are successfully applied in the protection of a commercial copper radiator from long-term attack of artificial seawater without disturbing its thermal conductivity. These results demonstrate the great potential of graphdiyne-based functional coatings for the protection of copper devices in aggressive environments.

Optimal design of dual air-gap closed-loop TMR current sensor based on minimum magnetic field uniformity coefficient.

Advanced sensor technology provides accurate information for transparent monitoring and real-time control of the power grid. Tunnel magnetoresistance (TMR) elements with high sensitivity and linearity provide a new technical means for current measurement in medium-voltage DC power distribution systems. This paper proposes a dual air-gap closed-loop TMR current sensor and its optimal design method based on the magnetic field's minimum uniformity coefficient. The dual air-gap structure reduces the measurement error caused by the eccentricity of the wire, and the theory and modelling of the minimum magnetic field uniformity coefficient optimise the key parameters, such as the inner radius of the magnetic core, the distance of the air-gap and the area size of the section side. Finally, a sensor prototype with a rated measurement current of ± 50 A was developed. The experiment results show that the relative error of the proposed TMR current sensor is less than 0.2% under the rated current. The conclusion can be drawn that the proposed sensor with the optimised design effectively improves the measurement accuracy.

Synthesis and Structure-Property Relationships in Regioisomeric Alternating Borane-Terthiophene Polymers.

Main-chain boron-containing π-conjugated polymers are attractive for organic electronic, sensing, and imaging applications. Alternating terthiophene-borane polymers were prepared and the effects of regioisomeric attachment of the conjugated linker and variations in the electronic effect of the pendent aryl groups (2,4,6-tri-tert-butylphenyl, Mes*; 2,4,6-tris(trifluoromethyl)phenyl, FMes) examined. Pd2 dba3 /P(t-Bu)3 -catalyzed Stille polymerization of arylbis(2-thienyl)borane and arylbis(3-thienylborane) with 2,5-bis(trimethylstannyl)thiophene at 120 °C gave polymers with appreciable molecular weight but MALDI-TOF MS analyses showed evidence of unusually prominent homocoupling. These defects could be suppressed by using brominated rather than iodinated monomers, more hindered 2,5-bis(tri-n-butylstannyl)thiophene as comonomer, and Pd2 dba3 /P(o-tol)3 as the catalyst at 100 °C. Under these conditions, macrocyclic species with n=3-10 repeating units formed preferentially according to MALDI-TOF MS analyses. Photophysical studies revealed a prominent effect of the regiochemistry and the nature of the pendent aryl groups on the absorption and emission, giving rise to orange, yellow-green, blue-green, and blue emissive materials respectively. The electronic effects were rationalized through DFT calculations on bis(terthiophene) model systems.

Quantum interference effects elucidate triplet-pair formation dynamics in intramolecular singlet-fission molecules.

Quantum interference (QI)-the constructive or destructive interference of conduction pathways through molecular orbitals-plays a fundamental role in enhancing or suppressing charge and spin transport in organic molecular electronics. Graphical models were developed to predict constructive versus destructive interference in polyaromatic hydrocarbons and have successfully estimated the large conductivity differences observed in single-molecule transport measurements. A major challenge lies in extending these models to excitonic (photoexcited) processes, which typically involve distinct orbitals with different symmetries. Here we investigate how QI models can be applied as bridging moieties in intramolecular singlet-fission compounds to predict relative rates of triplet pair formation. In a series of bridged intramolecular singlet-fission dimers, we found that destructive QI always leads to a slower triplet pair formation across different bridge lengths and geometries. A combined experimental and theoretical approach reveals the critical considerations of bridge topology and frontier molecular orbital energies in applying QI conductance principles to predict rates of multiexciton generation.

Tinware-Inspired Aerobic Surface-Initiated Controlled Radical Polymerization (SI-Sn0CRP) for Biocompatible Surface Engineering.

Surface anchored polymer brushes prepared by surface-initiated controlled radical polymerization (SI-CRP) have raised considerable interest in biomaterials and bioengineering. However, undesired residues of noxious transition metal catalysts critically restrain their widespread biomedical applications. Herein, we present a robust and biocompatible surface-initiated controlled radical polymerization catalyzed by a Sn(0) sheet (SI-Sn0CRP) under ambient conditions. Through this approach, microliter volumes of vinyl monomers with diverse functions (heterocyclic, ionic, hydrophilic, and hydrophobic) could be efficiently converted to homogeneous polymer brushes. The excellent controllability of SI-Sn0CRP strategy is further demonstrated by the exquisite fabrication of predetermined block and patterned polymer brushes through chain extension and photolithography, respectively. Additionally, in virtue of intrinsic biocompatibility of Sn, the resultant polymer brushes present transcendent affinity toward blood and cell, in marked contrast to those of copper-based approaches. This strategy could provide an avenue for the controllable fabrication of biocompatible polymer brushes toward biological applications.

Expanding new chemistry of aza-boracyclophanes with unique dipolar structures, AIE and redox-active open-shell characteristics.

π-Conjugated macrocycles involving electron-deficient boron species have received increasing attention due to their intriguing tunable optoelectronic properties. However, most of the reported B(sp2)-doped macrocycles are difficult to modify due to the synthetic challenge, which limits their further applications. Motivated by the research of non-strained hexameric bora- and aza-cyclophanes, we describe a new class of analogues MC-BN5 and MC-ABN5 that contain charge-reversed triarylborane (Ar3B) units and oligomeric triarylamines (Ar3N) in the cyclics. As predicted by DFT computations, the unique orientation of the donor-acceptor systems leads to an increased dipole moment compared with highly symmetric macrocycles (M1, M2 and M3), which was experimentally represented by a significant solvatochromic effect with large Stokes shifts up to 12 318 cm-1. Such a ring-structured design also allows the easy peripheral modification of aza-boracyclophanes with tetraphenylethenyl (TPE) groups, giving rise to a change in the luminescence mechanism from aggregation-caused quenching (ACQ) in MC-BN5 to aggregation-induced emission (AIE) in MC-ABN5. The open-shell characteristics have been chemically enabled and were characterized by UV-Vis-NIR spectroscopy and electron paramagnetic resonance (EPR) for MC-BN5. The present study not only showed new electronic properties, but also could expand the research of B/N doped macrocycles into the future scope of supramolecular chemistry, as demonstrated in the accessible functionalization of ring systems.