Impact of signal-to-noise ratio and contrast definition on the sensitivity assessment and benchmarking of fluorescence molecular imaging systems.

Significance: Standardization of fluorescence molecular imaging (FMI) is critical for ensuring quality control in guiding surgical procedures. To accurately evaluate system performance, two metrics, the signal-to-noise ratio (SNR) and contrast, are widely employed. However, there is currently no consensus on how these metrics can be computed. Aim: We aim to examine the impact of SNR and contrast definitions on the performance assessment of FMI systems. Approach: We quantified the SNR and contrast of six near-infrared FMI systems by imaging a multi-parametric phantom. Based on approaches commonly used in the literature, we quantified seven SNRs and four contrast values considering different background regions and/or formulas. Then, we calculated benchmarking (BM) scores and respective rank values for each system. Results: We show that the performance assessment of an FMI system changes depending on the background locations and the applied quantification method. For a single system, the different metrics can vary up to ∼ 35 dB (SNR), ∼ 8.65 a . u . (contrast), and ∼ 0.67 a . u . (BM score). Conclusions: The definition of precise guidelines for FMI performance assessment is imperative to ensure successful clinical translation of the technology. Such guidelines can also enable quality control for the already clinically approved indocyanine green-based fluorescence image-guided surgery.

Development and antimicrobial activity of composite edible films of chitosan and nisin incorporated with perilla essential oil-glycerol monolaurate emulsions.

Aquatic products are highly susceptible to spoilage, and preparing composite edible film with essential oil is an effective solution. In this study, composite edible films were prepared using perilla essential oil (PEO)-glycerol monolaurate emulsions incorporated with chitosan and nisin, and the film formulation was optimized by response surface methodology. These films were applied to ready-to-eat fish balls and evaluated over a period of 12 days. The films with the highest inhibition rate against Staphylococcus aureus were acquired using a polymer composition of 6 µL/mL PEO, 18.4 µg/mL glycerol monolaurate, 14.2 mg/mL chitosan, and 11.0 µg/mL nisin. The fish balls coated with the optimal edible film showed minimal changes in appearance during storage and significantly reduced total bacterial counts and total volatile basic nitrogen compared to the control groups. This work indicated that the composite edible films containing essential oils possess ideal properties as antimicrobial packaging materials for aquatic foods.

Denitrification enhanced by composite carbon sources in AAO-biofilter: Efficiency and metagenomics research.

Nitrogen removal from domestic sewage is usually limited by insufficient carbon source and electron donor. An economical solid carbon source was developed by composition of polyvinyl alcohol, sodium alginate, and corncob, which was utilized as external carbon source in the anaerobic anoxic oxic (AAO)-biofilter for the treatment of low carbon-to-nitrogen ratio domestic sewage, and the nitrogen removal was remarkably improved from 63.2% to 96.5%. Furthermore, the effluent chemical oxygen demand maintained at 35 mg/L or even lower, and the total nitrogen was reduced to less than 2 mg/L. Metagenomic analysis demonstrated that the microbial communities responsible for potential denitrification and organic matter degradation in both AAO and the biofilter reactors were mainly composed of Proteobacteria and Bacteroides, respectively. The solid carbon source addition resulted in relatively high abundance of functional enzymes responsible for NO3--N to NO2--N conversion in both AAO and the biofilter reactors, thus enabled stable reaction. The carbon source addition during glycolysis primarily led to the increase of genes associated with the metabolic conversion of fructose 1.6P2 to glycerol-3P The reactor maintained high abundance of genes related to the tricarboxylic acid cycle, and then guaranteed efficient carbon metabolism. The results indicate that the composite carbon source is feasible for denitrification enhancement of AAO-biofilter, which contribute to the theoretical foundation for practical nitrogen removal application.

Wide-temperature-range pressure sensing by an aramid nanofibers/reduced graphene oxide flakes composite aerogel.

Aerogel-based conductive materials have emerged as a major candidate for piezoresistive pressure sensors due to their excellent mechanical and electrical performance besides light-weighted and low-cost characteristics, showing great potential for applications in electronic skins, biomedicine, robot controlling and intelligent recognition. However, it remains a grand challenge for these piezoresistive sensors to achieve a high sensitivity across a wide working temperature range. Herein, we report a highly flexible and ultra-light composite aerogel consisting of aramid nanofibers (ANFs) and reduced graphene oxide flakes (rGOFs) for application as a high-performance pressure sensing material in a wide temperature range. By controlling the orientations of pores in the composite framework, the aerogel promotes pressure transfer by aligning its conductive channels. As a result, the ANFs/rGOFs aerogel-based piezoresistive sensor exhibits a high sensitivity of up to 7.10 kPa-1, an excellent stability over 12,000 cycles, and an ultra-wide working temperature range from -196 to 200 °C. It is anticipated that the ANFs/rGOFs composite aerogel can be used as reliable sensing materials in extreme environments.

A self-healing composite solid electrolyte with dynamic three-dimensional inorganic/organic hybrid network for flexible all-solid-state lithium metal batteries.

Composite solid electrolytes (CSEs), which combine the advantages of solid polymer electrolytes and inorganic solid electrolytes, are considered to be promising electrolytes for all-solid-state lithium metal batteries. However, the current CSEs suffer from defects such as poor inorganic/organic interface compatibility, lithium dendrite growth, and easy damage of electrolyte membrane, which hinder the practical application of CSEs. Herein, a CSE (PBHL@LLZTO@DDB) with polyurethane (PBHL) as the polymer matrix and Li6.4La3Zr1.4Ta0.6O12 (LLZTO) modified by silane coupling agent (DDB) as inorganic fillers (LLZTO@DDB) has been prepared. Disulfide bond exchange reactions between PBHL and LLZTO@DDB enable PBHL@LLZTO@DDB to form a dynamic three-dimensional (3D) inorganic/organic hybrid network, which promotes the uniform dispersion of LLZTO in PBHL@LLZTO@DDB, improves the Li+ conductivity (1.24 ± 0.08 × 10-4 S cm-1 at 30 â„ƒ), and broadens the electrochemical stability window (5.16 V vs. Li+/Li). Moreover, a combination of hydrogen bonds and disulfide bonds endows PBHL@LLZTO@DDB with excellent self-healing properties. As such, both all-solid-state symmetric and full cells exhibit excellent cycle performance at ambient temperature. More importantly, the healed PBHL@LLZTO@DDB can almost completely restore its original electrochemical properties, indicating its application potential in flexible electronic products.

In situ construction of NiCo-layered double hydroxide nanobranches with adjustable layer spacing on micro-sized carbon plate for high-performance supercapacitors.

Binary layered double hydroxides (LDHs) are an emerging class of materials for supercapacitors owing to their tunable topological structure and excellent theoretical energy storage capacity. However, aggregation and restacking cause a decrease in the interlayer distance of LDHs, resulting in a considerable drop in real specific capacitance. To address this, large-sized anions are intercalated into the interlayer space. Herein, we constructed 3D top-tangled NiCo-LDH nanobranches in situ on a biomass micro-sized carbon plate (CP). By varying the amount of benzene-1,4-dicarboxylic acid (BDC), we prepared a BDC-intercalated CP/NiCo-LDH composite material with adjustable interlayer spacing. Remarkably, the CP/NiCo-LDH-BDC(0.03) composite exhibited excellent electrochemical properties (1530 F g-1/212.5 mAh/g at 1 A/g). It retained 88.36 % capacity after 5000 charge-discharge cycles. The constructed CP/NiCo-LDH-BDC(0.03)//CP asymmetric supercapacitor showed excellent gravimetric capacitance (123 F g-1/54.7 mAh/g at 1 A/g) and energy density (43.7 Wh kg-1 at 800 W kg-1). Furthermore, two asymmetric capacitors connected in series powered a small lightbulb for 2 min, even in a bent state. These findings show that the fabricated CP and CP/NiCo-LDH-BDC(0.03) electrode materials can be applied in flexible and wearable energy storage systems.

Enhanced electrochemical stability and ion transfer rate: A polymer/ceramic composite electrolyte for high-performance all-solid-state lithium-sulfur batteries.

All-solid-state (ASS) lithium-sulfur (LiS) batteries utilizing composite polymer electrolytes (CPEs) represent a promising avenue in the domain of electric vehicles and large-scale energy storage systems, leveraging the combined benefits of polymer electrolytes (PEs) and ceramic electrolytes (CEs). However, the inherent weak interface compatibility between PEs and CEs often leads to phase separation, thereby impeding the transposition of Li+. In this study, the trimethoxy-[3-(2-methoxyethoxy)propyl]silane (TM-MES) is introduced as a chemical agent to form bonds with polyethylene oxide (PEO) and Li10GeP2S12 (LGPS), resulting in the development of a novel composite polymer electrolyte (CPETM-MES). This innovative approach mitigates phase separation between PEs and CEs while concurrently enhancing the protective capabilities of LGPS against decomposition at the interfaces of both the Li anode and sulfur cathode. Moreover, the CPETM-MES exhibits superior mechanical toughness, an expanded electrochemical window, and elevated ionic conductivity. In the symmetric cell, it demonstrates an extended operational lifespan exceeding 1800 h, and the current density can reach up to 1.05 mA/cm2. Furthermore, the initial discharge capacity of ASS LiS batteries utilizing CPETM-MES attains 1227 mAh/g and maintains a capacity of 904 mAh/g after 100 cycles. Notably, a high-energy-density of 2454 Wh/kg is achieved based on the sulfur cathode.

Utilizing a synergistic strategy that combines electromagnetic and chemical enhancement to analyze the SERS effect of the Fe3O4@GO@Ag on PAHs detection.

A comprehensive understanding of the enhancement mechanism of the substrate material is crucial to ensure the repeatability and functionality of SERS detection technology. Therefore, this study introduces a theoretical analysis method that integrates electromagnetic and chemical enhancement to achieve a comprehensive understanding of the SERS effect on the magnetic composite substrate. The visual model is employed in this study to comprehensively analyze and illustrate the electric field enhancement and optical effects of composite substrate materials. The study also elucidated the adsorption and charge transfer between the substrate material and target molecules. Based on this theory, Fe3O4@GO@Ag material was prepared and used to detect hydrophobic organic molecules such as polycyclic aromatic hydrocarbons (PAHs), with a concentration as low as 0.5 nM. This study comprehensively analyzed the SERS enhancement effect of the composite substrate for the first time, and prepared a magnetic composite substrate material for the detection of hydrophobic organic molecules, opening up a new avenue for theoretical guidance and experimental exploration in SERS detection and analysis.

Magnetic field-assisted vertically aligned NiFe2O4 nanosheets in composite solid polymer electrolytes for advanced all solid-state lithium metal batteries.

Two-dimensional materials (2D Ms) as fillers have been applied in polyethylene oxide (PEO)-based electrolyte to enhance the low ionic conductivity and poor interface compatibility. However, the randomly dispersed fillers in PEO matrix result in anisotropy of Li+ transportation and insufficent ionic conductivity. Herein, NiFe2O4 (NFO) nanosheets are firstly introduced in polymer matrix to form vertically aligned NFO-PEO (ANFO-PEO) composite solid-state electrolytes (CSEs) through magnetic field-assisted alignment strategy. The vertically aligned NFO/PEO interface in CSEs can construct oriented Li+ transport channels and maximize the utilization of high in-plane conductivity. Meanwhile, the NFO nanosheets with abundant oxygen vacancies could effectively anchor TFSI- to promote the dissociation of Li salts. Furthermore, the optimized Li+ transport flux in CSEs enables homogeneous Li deposition and effectively mitigates the growth of dendrites. Owing to the synergistic effects, the ANFO-PEO CSEs exhibit high ionic conductivity (9.16 × 10-4 S cm-1 at 60 °C) and stable potential window up to 5.0 V vs Li/Li+. Therefore, LiFePO4 in the full cell and pouch cell with ANFO-PEO CSEs could deliver excellent cycling performance (92.78 % capacity retention after 1000 cycles at 0.5C; 96.88 % capacity retention after 105 cycles at 0.1C).

Enhancing deep visible-light photoelectrocatalysis with a single solid-state synthesis: Carbon nitride/TiO2 heterointerface.

Visible-light responsive, stable, and abundant absorbers are required for the rapid integration of green, clean, and renewable technologies in a circular economy. Photoactive solid-solid heterojunctions enable multiple charge pathways, inhibiting recombination through efficient charge transfer across the interface. This study spotlights the physico-chemical synergy between titanium dioxide (TiO2) anatase and carbon nitride (CN) to form a hybrid material. The CN(10%)-TiO2(90%) hybrid outperforms TiO2 and CN references and literature homologs in four photo and photoelectrocatalytic reactions. CN-TiO2 achieved a four-fold increase in benzylamine conversion, with photooxidation conversion rates of 51, 97, and 100 % at 625, 535, and 465 nm, respectively. The associated energy transfer mechanism was elucidated. In photoelectrochemistry, CN-TiO2 exhibited 23 % photoactivity of the full-spectrum measurement when using a 410 nm filter. Our findings demonstrate that CN-TiO2 displayed a band gap of 2.9 eV, evidencing TiO2 photosensitization attributed to enhanced charge transfer at the heterointerface boundaries via staggered heterojunction type II.

A semiconductor SERS sensor of corrosion-resistant PPy/GO composite film by electrochemical growth for detecting crystal violet residues in fresh fish tissue.

Crystal violet (CV) residues in Marine food have produced a severe health threat in human life. In this study, we proposed a semiconductor surface-enhanced Raman scattering (SERS) sensor of corrosion-resistant Polyaniline/Graphene oxide (PPy/GO) film by electrochemical growth method to detect CV residues in fresh fish tissue. A PPy/GO dispersion solution was one-step deposited on a stainless steel sheet surface by electrochemical polymerization process to form a PPy/GO composite film acting as a semiconductor SERS substrate. Since the substrate of PPy/GO film was mainly composed of GO sheet without other metals, it had a good corrosion resistance. The SERS enhancement factor and charge transfer intensity PCT of PPy/Go SERS substrate for CV molecules were up to 1.18 × 106 and 0.903, respectively. Furthermore, the limit of detection (LOD) of PPy/GO SERS substrate could reach 1.58 nM. In addition, SERS sensor of PPy/GO film could identify CV residues in fresh fish tissues, and its recovery rate was 91.8 %-107 %. This preparing method and detecting method we proposed PPy/GO SERS substrate provide a new pathway for detecting CV residues in Marine food.

Flexural behavior of over-reinforced beam with ECC layer: Experimental and numerical simulation study.

To optimize the brittle failure of reinforced conerete (RC) over-reinforeed beams and enhance their flexural performance, a novel structural form is proposed. To be specific, the Engineered Cementitious Composite (ECC) layer is installed on top of the RC over-reinforced beam (ERCOB). A total of six test beams are prepared, comprising one unreinforced beam and five reinforced beams. The variables comprised the depth of the ECC, reinforcement ratio, and whether the ECC is configured at the bottom. The test findings are subsequently compared with simulation outcomes to validate the model's precision. Next, the influence of various variables on ERCOB flexural performance, such as load-deflection response, bearing capacity, etc., is deeply analyzed. The research indicates that the ECC applied to both the top and bottom of the specimen exhibits enhanced bearing capacity and ductility. In comparison to CB-1, the maximum load and deflection ductility coefficient of EB-2 increased from 45.73 kN to 2.63-48.52 kN and 3.85, representing increases of 6.1 % and 29.6 %, respectively. It reveals that ECC layer improves the defects caused by excessive reinforcement of over-reinforced beams, and optimizes the tensile capacity of the steel bars, thus improving the bending capacity and ductility of the specimens. Finally, the prediction model of ERCOB flexural capacity is proposed to further verify the effectiveness of ERCOB. This study not only verifies the effectiveness of ECC reinforcement, but also helps to delay the failure process of structures, provide reference for future engineering application design.

Induction cladding of alloys and metal-matrix composite coatings: A review.

Induction cladding is a promising surface technology that combines the advantages of surface coatings and induction heating. It is an energy-efficient, environment-friendly, and cost-effective method that facilitates the fabrication of coatings with controllable thicknesses and ensures metallurgical bonding between the coating and the substrate. Owing to the high power-conversion efficiency of helical coil, induction cladding is particularly adaptable for the application of coatings on long shafts and rod parts, which find widespread use in mining and energy machinery. This paper provides a comprehensive overview of the state-of-the-art methods in induction cladding. Herein we focus on its mechanisms, cladding process and parameters, commonly used materials, simulations, innovative induction cladding technologies, industrial applications, problems, and future developments in this field.

Characterizing tensile and flexural properties of synthetic fibers-reinforced epoxy composite for foot prosthetic application.

Materials have a direct and critical impact on the performance of prosthetic feet. This study investigates the mechanical properties of E-glass and hybrid (E-glass/carbon) epoxy composites for prosthetic foot applications. Using ANSYS FEA software, four stacking sequences were analyzed for tensile and flexural strength, with stacking configuration the SS-3 ( [ 0 c / 90 / 45 ] s ) demonstrating the highest performance. The numerical results were validated against analytical MATLAB solutions, showing excellent agreement. Compared to Homo-polymer-polypropylene, the composite prosthetic foot exhibits superior performance, with increased deformation resistance, energy storage capacity, safety factor, and stiffness, while reducing weight by 30.62 %. This study suggests a cost-effective and efficient method for developing lightweight and durable prosthetic feet that match the comfort and performance constraints of current HPP designs. The selected composite for prosthetic foot production was suggested due to its enhanced mechanical properties and improved functionality.

Perfecting the Craft: Composite Restoration Elevated With the Stamp Technique.

The "stamp technique" for posterior composite restoration placements is a relatively simple method for duplicating occlusal anatomy with near perfection. Due to the sensitivity of proprioceptors in the stomatognathic system to pressure, even slight occlusal disparities resulting from direct restorations can cause discomfort for patients. This discomfort often leads patients to adjust to a new habitual occlusal position, potentially leading to significant long-term craniomandibular issues. It was initially designed to restore Class I cavities and eroded teeth, where the marginal ridge of the tooth remains undamaged. The method is suitable for teeth with preoperative intact anatomy unaffected by carious lesions. The stamp technique aims to deliver a precise and natural-looking restoration with accurate functional occlusion. This case study demonstrates the application of the stamp technique for a straightforward Class I composite restoration, with the goal of quickly replicating the occlusal anatomy by creating a model of the original, unprepared tooth structure within minutes.

The win ratio in cardiology trials: lessons learnt, new developments, and wise future use.

The win ratio method for analysing a composite clinical hierarchy of outcomes is growing in popularity especially in cardiovascular trials. This article gives a perspective on its use so far and the issues derived from that experience. Specifically, it focuses on the limitations of a conventional composite outcome; how does the win ratio work, what does it mean, and how to display its findings; guidance on choosing an appropriate clinical hierarchy of outcomes including clinical events, quantitative outcomes, and other options; the additional value of the win difference as a measure of absolute benefit: extension to stratified win ratio, subgroup analysis, matched win ratio, and covariate adjustment; determining trial size for a win ratio outcome; specific insights such as adaptive designs, use of repeat events, and use of margins and time averages for quantitative outcomes; a critique of potential misuses; availability of statistical software; and a statistical appendix on the methodological details. Throughout, each principle is illustrated by examples from specific cardiology trials. The article concludes with a set of recommendations for future use of the win ratio.

Effect of Newer Intraorifice Barriers on the Fracture Resistance of Endodontically Treated Teeth: An In Vitro Study.

AIM: This study aimed to assess and compare the fracture resistance of endodontically treated teeth using three new intraorifice barrier materials. MATERIALS AND METHODS: A total of 60 extracted human mandibular premolars having single roots were decoronated to 14 mm length, prepared up to rotary F3 ProTaper Gold files, and sealed with gutta-percha and AH Plus sealer. Specimens were divided into one control and three experimental groups (n  = 15): Group 1, control; Group 2, Biodentine (Septodont, Saint Maur des Fosses, France); Group 3, resin-modified glass ionomer cement (RMGIC, GC Gold Label 2 LC, GC Corporation, Tokyo, Japan); and Group 4, flowable nanohybrid composite (G-aenial Universal Flo, GC Corporation, Tokyo, Japan). A 3 mm coronal gutta-percha was replaced with respective intraorifice barrier materials in the experimental groups, and the fracture resistance of all the groups was tested using the universal testing machine. STATISTICAL ANALYSIS: One-way analysis of variance and Tukey's post-hoc test were conducted. RESULTS: The experimental groups showed higher mean load values than the control group. The flowable composite showed the highest mean loads followed by Biodentine and RMGIC. The mean fracture resistance of flowable nanohybrid composite and Biodentine was significantly higher than that of the control. No statistically significant difference was observed among the other groups. CONCLUSION: The flowable nanohybrid composite and Biodentine significantly improved resistance to fracture of endodontically treated teeth when compared to the control.

An in vitro wear behavior analysis of polymer composite for biomedical application.

The tribological performance of basalt fiber reinforced PEEK material especially used as a biomaterial in many biomedical and dental applications is of interest. The specimens of three different weight fractions of PEEK and basalt fiber are fabricated as per ASTM G99 standards. The prepared specimens are having PEEK and basalt fiber in the weight percentage of 90:10, 80:20 and 70:30 ratio and named as PBC 1, PBC 2 and PBC 3 respectively. The specimens are subjected to pin-on-disc test using EN31 steel as the sliding disc material. The hardness of PBC 2 specimen shows a better value of 50.74 HRB. Wear resistance is comparatively less when Basalt weight percentage increases from 10% to 20%, but further increase of basalt fiber in the composite, the wear resistance drops down. Similarly, the COF values also noted high for PBC 2 compared to pure PEEK, PBC 1 and PBC 3 composites. PBC 2 sample is found to be better with high wear resistance.

Copper-PANI-graphite HB2 composite for eco-friendly efficient degradation of textile dyes: Advancements in wastewater treatment enhanced by solar radiation.

This research aimed to assess the potential of Cu50PANI@UG composite for sunlight drive photocatalytic dye degradation, targeting specifically Thymol Blue (TB) and Black NT (BNT) dyes and their mixture (DM). The Cu50PANI@UG composite was successfully synthesized via electropolymerization in acetonitrile/sulfuric acid mixture under atmospheric conditions. Photocatalytic experiments were conducted by exposing aqueous dye solutions to sunlight. N,N-dimethyl-p-nitrosoaniline (RNO) served as a molecular probe for detecting hydroxyl radicals (•OH). Additionally, experiments capturing free radicals were performed to identify active components, with a concomitant proposal of plausible degradation reaction mechanism for the Photo-Fenton-Like degradation into the Cu50PANI@UG composite + H2O2 + hv reaction system. Various operating parameters affecting dye degradation were evaluated, including catalyst dosage (from 0.27 to 0.67 g L-1), H2O2 concentration (from 16 to 64 mM), pH (from 3.0 to 9.0), and dye concentration (from 25 to 100 mg L-1). Optimization of key parameters such as pH, catalyst dosage, and H2O2 concentration was conducted. The highest degradation efficiency, ca. 100% of DM dye, was achieved within 35 min under optimized conditions, using Cu50PANI@UG composite as a catalytic precursor. These conditions were determined as follows: Catalyst dosage = 0.67 g L-1, pH = 3.0-6.0, H2O2 = 32-64 mM, and irradiation time of 35 min. The degradation percentage under the Response Surface Methodology (RSM) was utilized as a statistical tool to correlate influential parameters. Four consecutive reusability trials were performed to assess catalyst stability.

Environmental sustainability and waste conversion of Prosopis juliflora fibre-reinforced ZnO nanofiller particulates PLA composite- mechanical and thermal analysis.

The presence of large quantities of Prosopis juliflora (PJ) fibers in natural habitats presents substantial threats to the environment and economies of numerous developing countries. Utilizing natural fibers in polymer composites can effectively enhance their characteristics. The primary objective of this study is to create a composite material by combining Prosopis Juliflora (PJ) fiber with a polylactic matrix that has been combined with zinc oxide nanofillers. The fabrication process will involve the hand layup technique. In order to have a comprehensive understanding of the mechanical characteristics, thermal behavior, and thermal stability of the PJ composite, it is necessary to undertake additional investigations. The results showed that the inclusion of zinc oxide filler enhanced the tensile strength (67.29 MPa), flexural strength (64.27 MPa), compressive strength (56.79 MPa), and impact energy (34 J) in sample S5. Additionally, the thermal properties, including thermal conductivity, thermal expansion, and short-term heat resistant capacity, were also improved by the addition of zinc oxide filler in sample S5. The deterioration temperature of the PJ composite was determined to be between 312 and 342 °C using thermogravimetric analysis. The failure mode of the PJ composite was investigated using scanning electron microscopy.