Analysis of Transient Thermoacoustic Characteristics and Performance in Carbon Nanotube Sponge Underwater Transducers.

Recent advancements in marine technology have highlighted the urgent need for enhanced underwater acoustic applications, from sonar detection to communication and noise cancellation, driving the pursuit of innovative transducer technologies. In this paper, a new underwater thermoacoustic (TA) transducer made from carbon nanotube (CNT) sponge is designed to achieve wide bandwidth, high energy conversion efficiency, simple structure, good transient response, and stable sound response, utilizing the TA effect through electro-thermal modulation. The transducer has potential application in underwater acoustic communication. An electro-thermal-acoustic coupled simulation for the open model, sandwich model, and encapsulated model is presented to analyze the transient behaviors of CNT sponge TA transducers in liquid environments. The effects of key design parameters on the acoustic performances of both systems are revealed. The results demonstrate that a short pulse excitation with a low duty cycle could greatly improve the heat dissipation of the encapsulated transducer, especially when the thermoacoustic response time becomes comparable to thermal relaxation time.

Surface Passivation Method for the Super-repellence of Aqueous Macromolecular Condensates.

Solutions of macromolecules can undergo liquid-liquid phase separation to form droplets with ultralow surface tension. Droplets with such low surface tension wet and spread over common surfaces such as test tubes and microscope slides, complicating in vitro experiments. The development of a universal super-repellent surface for macromolecular droplets has remained elusive because their ultralow surface tension requires low surface energies. Furthermore, the nonwetting of droplets containing proteins poses additional challenges because the surface must remain inert to a wide range of chemistries presented by the various amino acid side chains at the droplet surface. Here, we present a method to coat microscope slides with a thin transparent hydrogel that exhibits complete dewetting (contact angles θ ≈ 180°) and minimal pinning of phase-separated droplets in aqueous solution. The hydrogel is based on a swollen matrix of chemically cross-linked polyethylene glycol diacrylate of molecular weight 12 kDa (PEGDA), and can be prepared with basic chemistry laboratory equipment. The PEGDA hydrogel is a powerful tool for in vitro studies of weak interactions, dynamics, and the internal organization of phase-separated droplets in aqueous solutions.

Isolation, identification and molecular docking of anti-inflammatory peptides from walnut (Juglans regia L.) meal hydrolysates.

The oil extraction residue of walnuts is rich in proteins and has been employed in the formulation of various functional food products. In this study, alcalase and neutrase were used to hydrolyze defatted walnut meal protein to obtain anti-inflammatory peptides. After separation by ultrafiltration and by using Sephadex G-25, the fraction with the highest anti-inflammatory activity was identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and 579 peptides were obtained. Then, four of the most stable binding tripeptides with the sequences Trp-Pro-Leu (WPL, MW: 414.2 Da), Trp-Ser-Leu (WSL, MW: 404.2 Da), Phe-Pro-Leu (FPL, MW: 375.2 Da) and Phe-Pro-Tyr (FPY, MW: 425.2 Da) were successfully identified by virtual screening. The anti-inflammatory activity determination of the synthetic peptide assay indicated that FPL (200 µM) exhibited excellent anti-inflammatory activity with inhibitory rates of 63.65 ± 2.64%, 68.25 ± 2.19%, 42.52 ± 2.01% and 59.39 ± 2.21% in terms of four inflammatory mediators (NO, TNF-α, IL-6 and IL-1ß), respectively. It was speculated that the anti-inflammatory activity of walnut peptides might be related to hydrophobic amino acids and aromatic amino acids. By molecular docking, further insight into the theoretical interaction mechanism of binding revealed that hydrophobic interactions and hydrogen bonds turned out to be the main interaction forces between the four peptides and iNOS. These results indicated that FPL screened in this study could be expected to be used as a natural anti-inflammatory active substance in the functional food and pharmaceutical industries.

Formulated chitosan-sodium tripolyphosphate nanoparticles for co-encapsulation of ellagic acid and anti-inflammatory peptide: characterization, stability and anti-inflammatory activity.

BACKGROUND: Chitosan (CS) and tripolyphosphate (TPP) can be combined in the development of a material with synergistic properties and promising potential for the conservation of food products. In this study, ellagic acid (EA) and anti-inflammatory peptide (FPL)-loaded CS nanoparticles (FPL/EA NPs) were prepared using the ionic gelation method and optimal preparation conditions were obtained through a single factor design. RESULTS: The synthesized nanoparticles (NPs) were characterized using a scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC). Nanoparticles were spherical, with an average size of 308.33 ± 4.61 nm, a polydispersity index (PDI) of 0.254, a zeta potential of +31.7 ± 0.08 mV, and a high encapsulation capacity (22.16 ± 0.79%). An in vitro release study showed that EA/FPL had a sustainable release from FPL/EA NPs. The stability of the FPL/EA NPs was evaluated for 90 days at 0, 25, and 37 °C. Significant anti-inflammatory activity of FPL/EA NPs was verified by nitric oxide (NO) and tumor necrosis factor-α (TNF-α) reduction. CONCLUSION: These characteristics support the use of CS nanoparticles to encapsulate EA and FPL and improve their bioactivity in food products. © 2023 Society of Chemical Industry.

Design and characteristic analysis of flexible CNT film patch for potential application in ultrasonic therapy.

Ultrasonic therapy has drawn increasing attention due to its noninvasiveness, great sensitivity and strong penetration capabilities. However, most of traditional rigid ultrasonic probes cannot achieve a solid interfacial contact with irregular nonplanar surfaces, which leads to unstable therapeutic effects and limitations of widespread use in practical applications. In this paper, a new flexible ultrasonic patch based on carbon nanotube (CNT) films is designed and fabricated to achieve a potential application in ultrasonic therapy. This patch is composed of a CNT film, a thermal protective layer and a heat sinking layer, and has the advantages of simple structure, soft, ultrathin and completely conforming to the treatment area. Theoretical and experimental studies are performed to investigate the acoustic and temperature fields before and after deformation. Effects of key design parameters of the patch on acoustic performances and temperature distributions are revealed. Numerical results indicate that the CNT film patch can produce ultrasounds over a wide frequency range and temperatures under the threshold of burn injury whether it is bent or not. Furthermore, it is also noted that the sound waves emitted from the bending patch are focused at the center of the bending patch, which demonstrates that the target treatment area can be controlled.

Hydroelastomers: soft, tough, highly swelling composites.

Inspired by the cellular design of plant tissue, we present an approach to make versatile, tough, highly water-swelling composites. We embed highly swelling hydrogel particles inside tough, water-permeable, elastomeric matrices. The resulting composites, which we call hydroelastomers, combine the properties of their parent phases. From their hydrogel component, the composites inherit the ability to highly swell in water. From the elastomeric component, the composites inherit excellent stretchability and fracture toughness, while showing little softening as they swell. Indeed, the fracture properties of the composite match those of the best-performing, tough hydrogels, exhibiting fracture energies of up to 10 kJ m-2. Our composites are straightforward to fabricate, based on widely-available materials, and can easily be molded or extruded to form shapes with complex swelling geometries. Furthermore, there is a large design space available for making hydroelastomers, since one can use any hydrogel as the dispersed phase in the composite, including hydrogels with stimuli-responsiveness. These features make hydroelastomers excellent candidates for use in soft robotics and swelling-based actuation, or as shape-morphing materials, while also being useful as hydrogel replacements in other fields.

The Synergistic Anti-inflammatory Activity and Interaction Mechanism of Ellagic Acid and a Bioactive Tripeptide (Phe-Pro-Leu) from Walnut Meal.

The anti-inflammatory effect of the interaction between ellagic acid (EA) and a bioactive tripeptide (FPL) from walnut meal was investigated in this study. We found that lipopolysaccharide (LPS) -induced expression of nitric oxide, tumor necrosis factor-α, interleukin-6, and interleukin-1ß were significantly inhibited by the interaction of EA and FPL in RAW264.7 macrophage cells. Cell viability assays and CompuSyn simulations predicted the highest synergistic effect of the combination at doses of EA-25 µM and FPL-100 µM, with the lowest combination index (CI) values reaching 0.56. Fluorescence spectra revealed the intrinsic fluorescence of phenylalanine in FPL was quenched by interaction with EA. Fourier transform infrared spectroscopy indicated FPL had electrostatic and hydrophobic interactions with EA through N-H, C = O, C-N bonds and the secondary structure of FPL had effectively changed, with a decrease in α-helix when interacting with EA. Our results demonstrated that the synergistic anti-inflammatory effect of EA and FPL as potential inflammatory inhibitors in food industry.

Separation, identification, and molecular docking of tyrosinase inhibitory peptides from the hydrolysates of defatted walnut (Juglans regia L.) meal.

Defatted walnut meal protein was hydrolyzed using alcalase to yield tyrosinase inhibitory peptides. After separation by ultrafiltration and Sephadex G-25, the fraction with the highest tyrosinase inhibitory activity was identified using liquid chromatography-tandem mass spectrometry and 606 peptides were obtained. Then, molecular docking was used to screen for tyrosinase inhibitory peptides and to clarify the theoretical interaction mechanism between the peptides and tyrosinase. A peptide with the sequence Phe-Pro-Tyr (FPY, MW: 425.2 Da) was identified and the synthesized peptide inhibited tyrosine monophenolase and diphenolase with IC50 values of 1.11 ± 0.05 and 3.22 ± 0.09 mM, respectively. The inhibition of tyrosinase by FPY was competitive and reversible. Good stability of FPY toward digestion was observed in an in vitro gastrointestinal digestion simulation experiment. These results indicated that FPY can be used as a potential tyrosinase inhibitor in the food, medicine, and cosmetics industries.

The immune-enhancing potential of peptide fractions from fermented Spirulina platensis by mixed probiotics.

Mixed fermentation with different microorganisms can facilitate fermentation metabolism and increase the low molecular metabolites accumulation, thereby enhancing the bioactive activity. In this study, we evaluated the immune-stimulating activities of Spirulina platensis and different extracts from fermented S. platensis (FS) by mixed probiotics in vitro, by measuring the proliferation and Th1/Th2 immunomodulatory potential on murine primary splenic lymphocytes. The results showed that mixed fermentation enhanced the immunomodulatory activity of S. platensis with higher lymphocyte proliferation compared with non-fermented S. platensis (NFS). Notably, the low molecular weight (<3 kDa) peptide fraction from fermented S. platensis (L-PFS), especially at 40 µg/ml, presented the strongest activity in promoting lymphocytes proliferation and modulating cytokines (IL-2 and IL-10) secretion. Meanwhile, L-PFS enhanced the relative mRNA expression of Th1 cytokine (IFN-γ) and Th2 cytokine (IL-4), along with inhibiting the relative mRNA expression of Th1 cytokines (IL-2 and TNF-α) and Th2 cytokine (IL-10) compared with Concanavalin A-treated lymphocytes. PRACTICAL APPLICATIONS: Fermentation with mixed probiotics could effectively improve the bioactive activity of S. platensis. In particular, L-PFS screened from the FS could significantly contribute to the immune-enhancing activity of lymphocytes, promote the Th1/Th2 balance, and provide insights for the investigation of FS as the potential immunomodulatory food products.

Mechanical Behavior of Natural Fiber-Based Bi-Directional Corrugated Lattice Sandwich Structure.

In this study, 11 kinds of composite material were prepared, and the compression behavior of a bi-directional corrugated lattice sandwich structure prepared using jute fiber and epoxy resin was explored. The factors affecting the mechanical behavior of single and double-layer structures were studied separately. The results shows that the fiber angle, length-to-diameter ratio of the struts, and the type of fiber cloth have the most significant influence on the mechanical behavior of the single-layer lattice structure when preparing the core layer. When the fiber angle of the core layer jute/epoxy prepreg is (90/90) the compressive strength and Young's modulus are 83.3% and 60.0% higher than the fiber angle of (45/45). The configuration of the core and the presence of the intermediate support plate of the double-layer structure have a large influence on the compression performance of the two-layer structure. After the configuration was optimized, the compressive strength and Young's modulus were increased by 40.0% and 28.9%, respectively. The presence of the intermediate support plate increases the compressive strength, and Young's modulus of the double-layer structure by 75.0% and 26.6%, respectively. The experimental failure is dominated by the buckling, fracture, and delamination of the core struts.

Analysis of simple sequence repeats in the Gaeumannomyces graminis var. tritici genome and the development of microsatellite markers.

Understanding the genetic structure of Gaeumannomyces graminis var. tritici is essential for the establishment of efficient disease control strategies. It is becoming clear that microsatellites, or simple sequence repeats (SSRs), play an important role in genome organization and phenotypic diversity, and are a large source of genetic markers for population genetics and meiotic maps. In this study, we examined the G. graminis var. tritici genome (1) to analyze its pattern of SSRs, (2) to compare it with other plant pathogenic filamentous fungi, such as Magnaporthe oryzae and M. poae, and (3) to identify new polymorphic SSR markers for genetic diversity. The G. graminis var. tritici genome was rich in SSRs; a total 13,650 SSRs have been identified with mononucleotides being the most common motifs. In coding regions, the densities of tri- and hexanucleotides were significantly higher than in noncoding regions. The di-, tri-, tetra, penta, and hexanucleotide repeats in the G. graminis var. tritici genome were more abundant than the same repeats in M. oryzae and M. poae. From 115 devised primers, 39 SSRs are polymorphic with G. graminis var. tritici isolates, and 8 primers were randomly selected to analyze 116 isolates from China. The number of alleles varied from 2 to 7 and the expected heterozygosity (He) from 0.499 to 0.837. In conclusion, SSRs developed in this study were highly polymorphic, and our analysis indicated that G. graminis var. tritici is a species with high genetic diversity. The results provide a pioneering report for several applications, such as the assessment of population structure and genetic diversity of G. graminis var. tritici.

Retrieval of colorectal polyps following snare polypectomy: Experience of the multiple-suction technique in 602 cases.

BACKGROUND: Retrieving colorectal polyp after endoscopic snare polypectomy is time consuming and possibly incurs a failure. The aim of the study was to assess the effectiveness of the multiple-suction (M-S) technique for retrieving a variety of polyps. MATERIALS AND METHODS: Four hundred and nine cases received endoscopic snare polypectomy from January 2003 to January 2007 were reviewed. The resected polyps were retrieved by M-S technique, in which suction regarded as the leading technique, was taken in combination with channel occlusion, trap, snare, and grasping forcep. Time of cecal intubation and of polypectomy, total examination time, shape, size, location, and number of polyp(s) were recorded. Retrieval time and polyp lost rate were also noted. RESULTS: A total of 602 polyps more than 3 mm in diameter underwent snare polypectomy. There were 96.7% (582/602) of polyps retrieved by the M-S technique. The mean retrieval time was 1.5 +/- 0.6 min. Time of polypectomy, retrieval time, and total examination time were significantly positive correlative with the number of polyps (P < 0.05). In a univariate analysis, longer retrieval time was significantly associated with larger polyps, more distant polyps from the anus, and a greater number of polyps, while higher polyp lost rate was significantly associated with sessile polyp, smaller polyps, and a greater number of polyps. In a multivariate analysis, retrieval time level (< or = 2.0 or >2.0 min) was linked to the number of polyps. CONCLUSIONS: The M-S technique is proved to be reliable when used in the majority cases of colorectal polyp retrieval. In retrieving too many polyps, the M-S technique is time consuming, and hence, additional methods should be applied to improve its retrieval effectiveness.