The production of cement mortar has resulted in significant environmental issues. Many scientists have attempted to reduce environmental pollution by using agricultural waste as a substitute for ...mortar raw materials. This study creatively investigated the physical and mechanical properties of the new green cement mortar made from macadamia nutshell(MN), including compressive strength, flexural strength, and apparent density of 7d, 14d, and 28d. The effects of cement-sand ratio (c/s), nutshell particle size, and MN substitution rate on cement mortar's physical properties were studied using three-factor and three-level orthogonal test design methods. The digital image correlation (DIC) technique was used to analyze the crack development of macadamia nutshell cement mortar (MNM) at different loading stages. The analysis of variance (ANOVA) showed that the cement-sand ratio was the most significant factor affecting the strength of MNM. In addition, adding MN can increase the compressive strength of the mortar compared to the control group. The apparent density of the mortar decreases with the increase of MN addition.
•The influence of adding varying particle sizes of the nutshell on the strength of mortar was studied.•The density and flexural strength of mortar decreased with the increase of macadamia nutshell addition.•Macadamia nutshell could be used as an eco-friendly supplementary natural aggregate material.
Lamb waves are being investigated extensively for structural health monitoring (SHM) because of their characteristics of traveling long distances with little attenuation and sensitivity to minor ...local damage in structures. However, Lamb waves are dispersive, which results in the complex overlap of waveforms in the damage detection applications of the SHM community. This paper proposes a sparse representation strategy based on an l1-norm optimization algorithm for guided-Lamb-wave-based inspections. A comprehensive dictionary is designed containing various waveforms under diverse conditions so that the received waveform can be decomposed into a spatial domain for the identification of damage location. Furthermore, the l1-norm optimization algorithm is employed to pursue the sparse solution related to the physical damage location. The functionality of the created dictionary is validated by both metal beam and composite wind turbine experiments. The results indicate a great potential for the proposed sparse representation using a dictionary algorithm, which provides an effective alternative approach for damage detection.
Exploring efficient and stable electrocatalysts for the bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is vital to developing renewable energy technologies. However, ...due to the substantial and intricate design space associated with these bifunctional OER/ORR electrocatalysts, their development presents a formidable challenge, resulting in their cost-prohibitive nature in both experimental and computational studies. Herein, using the defect physics method, we systematically investigate the formation energies and bifunctional overpotential (η
) of 4d-transition-metal (4d-TM, 4d-TM = Zr, Nb, Mo, Ru, Rh, Pd, and Ag)-doped monolayer supercell g-C
N
(4d-TM@C
N
) based on the density functional theory (DFT) calculations. Under N-rich and C-rich conditions, we find that the formation energies of Rh
@C
N
(Rh occupation N) and Pd
@C
N
(Pd occupation N) are smaller than that of other 4d-TM
@C
N
(4d-TM occupation N site); for the 4d-TM
@C
N
(4d-TM interstitial site occupation), the lowest-formation energy defects are Pd
@C
N
. These results indicate that they have better stabilities. Interestingly, for these formation energy lower systems, Pd
@C
N
(η
= 1.00 V) and Rh
@C
N
(η
= 0.73 V) have ultralow overpotential and can be great candidates for bifunctional OER/ORR electrocatalysts. We find the reason is that adjusting the charge states of 4d-TM@C
N
can tune the interaction strength between the oxygenated intermediates and the 4d-TM@C
N
, which plays a crucial role in the activity of reactions. Additionally, the data obtained through machine learning (ML) application suggest that the electronegativity (
) and bond length of 4d-TM and coordination atoms (
) are primary descriptors characterizing the OER and ORR activities, respectively. The charged defect tuning of the bifunctional OER/ORR activity for 4d-TM@C
N
would enable electrocatalytic performance optimization and the development of potential electrocatalysts for renewable energy applications.
Agar/maltodextrin (A/M) emulsion films incorporated with beeswax (BW), shortening (SH), and liquid paraffin (LP), respectively, at different concentrations (0, 10%, 20%) were prepared using the ...solution casting method, and their physicochemical properties were investigated. Fourier transform infrared spectra indicated that the intermolecular hydrogen bonds weakened with the increase in the concentration of hydrophobic agents. Differential scanning calorimetry and scanning electron microscopy analyses revealed good compatibility between agar and maltodextrin. Phase separation occurred when the hydrophobic agents were incorporated in the A/M films. SEM images of the composite films showed incompatibility between the A/M matrix and hydrophobic agents, causing an irregular and heterogeneous structure. Incorporation of hydrophobic agents significantly improved the hydrophobicity of the A/M films. A/M-10% BW and A/M-10% LP films achieved the lowest water vapor permeability (6.86 × 10−13 g·m−1·s−1·Pa−1) and oxygen permeability (1.17 × 10−17 cm2·s−1 Pa−1), respectively. The tensile strength (TS), elongation at break (EAB) and Young's Modulus (YM) of the A/M films simultaneously increased in the presence of hydrophobic agents. The TS and YM of A/M-20% BW film was 112% and 179% higher than A/M film, respectively. The EAB of A/M-20% LP film was 240% higher than A/M film. These results revealed that the A/M-hydrophobic agent films with high barrier and mechanical properties show promising potential for food packaging.
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•Agar/maltodextrin emulsion films were prepared.•Addition of lipids significantly improved the hydrophobicity of the films.•The TS and EAB of the films simultaneously increased in the presence of lipids.
Although photothermal therapy (PTT) has thrived as a promising treatment for drug-resistant bacterial infections by avoiding the abuse of antibiotics, the remaining challenges that limit the ...treatment efficiency are the poor targeting properties of infected lesions and low penetration to the cell membrane of Gram-negative bacteria. Herein, we developed a biomimetic neutrophil-like aggregation-induced emission (AIE) nanorobot (CM@AIE NPs) for precise inflammatory site homing and efficient PTT effects. Due to their surface-loaded neutrophil membranes, CM@AIE NPs can mimic the source cell and thus interact with immunomodulatory molecules that would otherwise target endogenous neutrophils. Coupled with the secondary near-infrared region absorption and excellent photothermal properties of AIE luminogens (AIEgens), precise localization, and treatment in inflammatory sites can be achieved, thereby minimizing damage to surrounding normal tissues. Moreover, CM@AIE NP-mediated PTT was stimulated in vivo by a 980 nm laser irradiation, which contributed to the extent of the therapeutic depth and limited the damage to skin tissues. The good biocompatibility and excellent in vitro and in vivo antibacterial effects prove that CM@AIE NPs can provide a strategy for broad-spectrum antibacterial applications.
•Synthesis of La-CQDs from ATP and LaCl3·2H2O are achieved by solvothermal process.•The La-CQDs shows high selectivity for detecting Hg2+.•The La-CQDs enables the optical monitoring of the cells and ...tissue multicolor fluorescence.•The La-CQDs have an enhanced antibacterial effect.•It is a multifunctional platform with low cytotoxicity.
This work describes a hydrothermal method for the preparation of multi-functional carbon quantum dots of the type La-CQDs. The La-CQDs are 4.3±0.3nm in diameter and have a good dispersion and exhibit excellent emission property and high stability, as well as excitation-dependent emission behavior with typical excitation/emission peaks at 350/460nm. They can also be used as an effective fluorescent probe for the quenchometric determination of mercury ion in aqueous solution with a detection limit of 0.1µM. The particles are readily internalized by liver epithelial HepG2 cells and enable multi-color fluorescence imaging by displaying green and red emission if excited with 488 and 543nm light, respectively. Intravenous injection of the quantum dots in nude mice, in turn, enabled tissue imaging. The La-CQDs possess abundant phosphate, hydroxyl, pyridinic, pyridine-like and pyrrole-like nitrogen groups. Therefore, they can exhibit strong fluorescence, improve the accuracy as an optical monitoring code both in vitro and in vivo, and enhance blood compatibility. In vitro investigations show that La-CQDs do not exhibit significant apoptotic effects on NIH3T3 cells even at a high concentration (2.5mg/mL) while they exhibit improved antibactericidal capacity of the La-CQDs against gram-positive S. aureus and gram-negative E. coli bacteria was also observed. No apparent pathological damages are observed in all organs during the 30-day period, which suggests that La-CQDs do not produce detectable long-term toxicological responses.
In this work, the fermentation properties and quality attributes of fresh and ultrasonicated dough and the hierarchical structure of starches isolated from ultrasonicated dough were evaluated to ...understand the causal relations. It can be observed that ultrasound treatment could improve the dough fermentation performance, including the maximum height, total CO2 volume, and CO2 retention volume, by controlling the irradiation time (within 20 min), consequently enhancing the specific volume of steamed bread and decreasing its hardness. And these changes may be attributed to the pores and cracks that emerged on granular structure, relatively polydisperse semicrystalline lamellae, lessened amounts of crystallites, reduced short-range ordered degree and double helix fractions, which facilitated the interaction between yeast and starch granules, eventually improving the dough fermentation performance and developing high-quality steamed bread. These results indicate that ultrasound treatment is beneficial for designing steamed bread with tailored quality through rationally controlling the intrinsic starch structure in dough.
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•Ultrasound treatment improved the fermentation performance of dough.•Ultrasound treatment enhanced quality attributes of steamed bread.•Ultrasound treatment resulted in disordering for starch hierarchical structures.•Structural destructions facilitated the CO2 production during dough fermentation.•Relationship between fermentation properties and starch structure was revealed.
In the past decades, advances in nanoparticles (NPs) synthesis and engineering have greatly propelled the application of nanoscale agents for therapeutic and diagnostic functions, promoting an ...emerging field of “nanotheranostics”. In particular, they are being increasingly exploited for cancer management, in which diagnosis and therapy are combined to address clinical challenges. In this work, core–shell-structured amorphous zinc oxide (a-ZnO) on gold NPs (Au-His@a-ZnO) was produced using histidine (His) to control the shell growth under hydrothermal conditions. Subsequently, Au-His@a-ZnO NPs were integrated onto the planar structure of PEGylated graphene oxide (PEG-GO) via carbodiimide cross-linker chemistry. More importantly, strong absorption and near-infrared (NIR) emission in the range of 700 to 900 nm was observed with preferential uptake at tumors and high photothermal conversion efficiency (η = 38%). Both in vitro and in vivo studies showed that the GO@Au-His@a-ZnO NCs were biocompatible with low toxicity. Moreover, GO@Au-His@a-ZnO NCs were further conjugated with the antibody of epidermal growth factor receptor aptamer (anti-EGFR Apt) and doxorubicin (DOX), yielding Apt@GO@Au-His@a-ZnO@DOX NCs, which were then applied toward the synergetic treatment of lung cancer. The prepared Apt@GO@Au-His@a-ZnO@DOX NCs showed a high loading capacity of DOX, as well as NIR/pH-sensitive drug release in which the metal–drug complex dissociated to release antitumor Zn2+ ions into the acidic endosome/lysosome. In addition, these materials also showed good biostability and anti-EGFR Apt-promoted binding specificity for lung cancer cells. The specific binding facilitated the cellular uptake into EGFR-mutated cancer sites, as compared with nontargeted controls. In particular, human pulmonary adenocarcinoma cell (A549)-tumor bearing mice were selected as the animal model, and efficient targeted drug delivery and the high anticancer efficacy of Apt@GO@Au-His@a-ZnO NCs in vivo were demonstrated. Taken together, our multifunctional NCs, Apt@GO@Au-His@a-ZnO@DOX NCs, have shown high efficacy in targeted, photothermal, and chemotherapy when applied to lung cancer. This proof-of-principle example suggests a fascinating perspective for these functional NCs for future clinical use.
Abstract Purpose For the custom‐built construction of eye plaques, the iodine (I‐125) seeds of different source strengths are recycled in our eye plaque program. To return I‐125 seeds to the correct ...lot, we developed a novel 3D‐printed conical plaque QA holder for relative assay for eye plaques. Materials and methods A universal 3D‐printed conical plaque holder was designed to accommodate six plaque sizes and fit reproducibly in a well‐type dose calibrator. A reproducibility test was used to compare the plaque placement consistency in the holder versus without the holder. Plaque assays were performed for assembled plaques both before implant and after explant. The explant reading was compared with the implant reading adjusted for decay, and the relative error was calculated. The plaque response fraction (PRF) is defined as the fraction of well chamber implant reading over the total seed strength for a plaque. The PRF was aggregated for each individual plaque to confirm the seed lot before implant. Results The reproducibility test showed the chamber reading's relative standard deviation of 0.40% with the QA holder compared to 0.68% without it. The batch relative assay was performed for 251 plaques. The absolute value of measurement deviation between explant and decay‐corrected implant readings is 0.89% ± 0.86% (mean ± standard deviation). The PRFs for individual plaques range from 36.49% to 49.87%, with a maximum standard deviation of 2%. Conclusions This novel 3D‐printed QA holder provides reproducible setup for assaying assembled eye plaques in a well chamber. Batch relative assay can validate the seed batch used and plaque integrity during the implant without assaying individual seeds, saving valuable physicist time and radiation exposure from seed handling.
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