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Mattresses' pressure relief performance and comfort largely affect sleep quality. Mattress filling materials have been proven to affect the interface pressure distribution and comfort, but the effect of mattress structure is unclear. In this paper, the interface pressure distribution and subjective comfort of 10 subjects were assessed in the different bedding layer structures of mattresses, after mattress support performance was tested. The results show that the mattresses with bedding material hardness gradually increasing from the top layer to the bottom layer (BMH-ITTB) structure have a softer surface layer, a better support core layer, and higher fitness. This enables the mattress to achieve a better decompression effect. The low-pressure area (PAI ≤0.67kPa) increased, while the high-pressure area (PAI ≥2.67kPa and PAI ≥4.00kPa), maximum pressure (P 95), average pressure (P 50), and pressure index (PI) decreased. This also enables the mattress to achieve higher subjective comfort scores. • Mattresses with the same material but different structures provide different support. • A mattress with a BMH-ITTB structure achieves a better decompression effect. • A mattress with a BMH-ITTB structure achieves higher subjective comfort scores. • The correlations between the mattress support, pressure and comfort were reported. • Some indicators are considered important in mattress pressure relief design. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Luffa sponge cell wall has a two-layer secondary wall. • 10%NaOH-20%CH 3 COOH treatment can help to obtain brilliant mechanical properties. • 10%NaOH-20%CH 3 COOH treatment made the luffa sponge fibrils arranged compactly. • 5%NaOH-5%H 2 O 2 treatment can help to control moisture regain. Abstract Luffa sponge (LS) is a resourceful natural plant fiber with polyporous structure, which can be effectively used for reinforcement of light weight composite materials. However, reduction in the moisture absorption tendency and enhancement in the mechanical properties of LS fiber bundles by chemical modifications are highly desirable in order to utilize LS as reinforcement material. In this study, three chemical treatments including the use of 5% sodium hydroxide and 5% hydrogen peroxide (5%NaOH-5%H 2 O 2), 10% NaOH and 20% acetic acid (10%NaOH-20%CH 3 COOH), and 18% NaOH and 1.6% carbamide (18%NaOH-1.6%CO(NH 2) 2) were used to modify the LS fiber bundles. And the effect of the three chemical treatment methods on the micro/nano structures, moisture absorption and mechanical properties of LS fiber bundles was investigated by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarized light microscopy (PLM), fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis, moisture regain (MR) and tensile strength test. The results showed that the treatment with 10%NaOH-20%CH 3 COOH could significantly improve the mechanical properties of LS fiber bundles, the increase of the tensile strength was 121.3%. However, the treatment with 5%NaOH-5%H 2 O 2 could sharply decrease the mechanical properties of fiber bundles, the reduction of the tensile strength was 75.0%. Furthermore, the treatment with all the three above mentioned chemical combinations could reduce the moisture absorption of LS fiber bundles. The decrease in the moisture regain was found to be 29.0, 16.9, and 12.4%, respectively. [ABSTRACT FROM AUTHOR]

Objectives: Depressive symptoms are prevalent and cause adverse outcomes in heart failure. Previous studies have linked depressive symptoms with socioeconomic status. However, little is known about the mechanisms underlying this relationship. This study aimed to evaluate the association between socioeconomic status and depressive symptoms, and to examine whether access to healthcare, health literacy and social support mediated this relationship in patients with heart failure.Methods: Cross-sectional design was used to study 321 patients with heart failure recruited from a general hospital. Demographics, clinical data, depressive symptoms, socioeconomic status (i.e., education, employment, income, and subjective social status), access to healthcare, health literacy, and social support were collected by patient interview, medical record review or questionnaires. A series of logistic regressions and linear regressions were conducted to examine mediation.Results: The mean age of patients with heart failure was 63.6±10.6years. Fifty-eight patients (18%) had depressive symptoms. Lower subjective social status (OR=1.321, p=0.012) and lower health literacy (OR=1.065, p<0.001) were separately associated with depressive symptoms. When subjective social status and health literacy were entered simultaneously, the relationship between subjective social status and depressive symptoms became non-significant (OR=1.208, p=0.113), demonstrating mediation. Additionally, lower social support was associated with depressive symptoms (OR=1.062, p=0.007).Conclusions: In patients with heart failure, health literacy mediated the relationship between subjective social status and depressive symptoms. Lower social support was associated with depressive symptoms. Interventions should take these factors into account. [ABSTRACT FROM AUTHOR]

Xylooligosaccharide (XOS) has tremendous prebiotic potentials for gut health, but the relevant mechanisms are unclear. Herein, we confirmed the positive effects of dietary XOS enhancing gut barrier in a pig model via suppressing the expression of pro-inflammatory cytokines (IL-6 and IL-8). Meanwhile, XOS increased beneficial microbes Lactobacillus and decreased potential pathogenic bacteria. Moreover, XOS augmented microbiota-derived metabolites (mainly butyrate, propionate, and secondary bile acid) to strengthen the gut barrier and regulate gut immunity through activating host G-protein coupled receptors 109a or inhibiting histone deacetylases. Furthermore, XOS attenuated IgA-production and antigen cross-presentation processes. In addition, XOS supplementation led to the alteration of cell proliferation, remodeling of the energy metabolism, activation processes of serial genes or proteins, increased molecular chaperones, and the enhanced ubiquitin-proteasome pathway in cecal cells. Collectively, these results suggest that XOS enhances gut barrier and modulates gut immunity by optimizing gut microbiota and their metabolites, which is associated with alterations of biological processes. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: This study presents an in vivo investigation of the arylpropylsulfonamide α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor positive modulator (R,R)-N,N-(2,20-[biphenyl-4-40-diyl]bis[propane-2,1-diyl])dimethanesulfonamide (PIMSD). The pharmacokinetics of the drug were examined in male C57BL/6J mice and the drug concentration in blood plasma determined after subcutaneous injection of 1mg/kg b.w. This analysis revealed a rapid increase of the plasma concentration, peaking within 30min after administration with a T 1/2 of approximately 30min and a peak plasma concentration of about 2μM. Analysis of brain tissue homogenates also indicated blood–brain barrier permeability of the compound. Cognitive enhancing effects of the drug were then studied on place learning in male C57BL/6J mice in a water maze. In order to elucidate the potential positive effects of PIMSD on spatial learning the muscarinergic antagonist scopolamine was utilized, which is known to impair spatial learning ability. The mice were divided into four groups and subjected to two sequential subcutaneous injections administered 25min prior to behavioural testing: (1) vehicle/vehicle; (2) PIMSD/vehicle; (3) scopolamine/vehicle; (4) PIMSD/scopolamine. PIMSD at a dose of 3mg/kg b.w. was able to partially reverse the impairment given by 0.5mg/kg b.w. scopolamine. These results suggest that arylpropylsulfonamides such as PIMSD may have a therapeutic use in the enhancement of cognitive function and support the hypothesis that AMPA receptor potentiation is one mechanism that can be targeted for diseases of cognitive impairment. [Copyright &y& Elsevier]

For promoting the recycling of industrially discarded luffa resources and preventing environmental pollution caused by the incineration of luffa waste, abundant luffa scraps and environmentally friendly polyester fibers were used as raw materials to produce luffa fiber sound absorbing composites by the clean hot-pressing technology. Results revealed that the polyester fiber surface becomes rougher, with a large number of porous structures, affording a three-dimensional network after hot-pressing. Within the range of the test design, the sound absorption coefficient of the samples increased with increasing density, thickness, and distance of the back air gap. With the increase in the thickness from 2 cm to 6 cm, the average sound absorption coefficient of the material increased from 0.442 to 0.684, and the maximum sound absorption coefficient increased from 0.907 (4000 Hz) to 0.991 (1000 Hz). At back air gap distances of 0 cm, 1 cm, and 2 cm, their average sound absorption coefficients were 0.602, 0.606, and 0.645, respectively. At a density of 0.09 g/cm3, a thickness of 4 cm, and a back air gap distance of 2 cm, the average sound absorption coefficient of the luffa fiber composite reached 0.645, revealing a high-efficiency sound absorbing material. In addition to exhibiting a good sound absorption performance, the luffa fiber composite exhibited a soft surface and good buffer performance. Moreover, compared to other plant fiber composites, the luffa fiber composite exhibited better performance for hygroscopic and moisture dissipation. Raw materials as well as the processing of the novel sound absorbing material comprising luffa and polyester fibers. Image 1 • The composite overcomes the inhomogeneity of luffa scraps and remains highly porous. • Polyester fibers combined with luffa fibers, affording a three-dimensional network. • Pores and folds were generated on the polyester fiber surface after hot-pressing. • The average sound absorption coefficient of the composite reached 0.645. • The composite performs well on buffering, hygroscopicity and moisture dissipation. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the natural Luffa vine (LV) fiber to be effectively used as cellulose fiber reinforcing material for lightweight and decay-resistance composite materials. The physical, chemical, thermal, and morphological properties of the LV fibers, together with their microstructure are investigated. The test results conclude that the LV density, microscopic characteristics, and mechanical properties show that this crop is a lightweight (200–550 kg/m3) natural fiber with a porous structure and a high specific modulus (1.18–2.04 MPa∙ m3/kg). The chemical, X-ray diffraction and the Fourier transform infrared spectroscopy analyses indicate that the LV has a high lignin content (25.18%) and a relatively high relative crystallinity (37.18%) of cellulose, and it contains saponins, which increase its erosion resistance and hardness. The thermogravimetric analysis reveals that the fibers can stand up to 315.4 °C. Moreover, due to their kinetic activation energy of 63.9 kJ/mol, they can be used as reinforcement materials in thermoplastic green composites with a working temperature below 300°. • Luffa vine (LV) have a multi-level porous structure and a high specific modulus. • The presence of saponins help LV develop corrosion-resistant composites. • The LV lignin is mostly guajacyl lignin and only a small amount of syringyl lignin. • The LV thermal properties meet to a working temperature of composites below 300 °C. [ABSTRACT FROM AUTHOR]

In ovarian follicle development, estrogen acts as a regulatory molecule to mediate proliferation and differentiation of follicular cells. ERα (estrogen receptor α) exerts regulatory function classically by binding directly to the estrogen response element, recruiting co-factors and activating or repressing transcription in response to E2. In this study, we used ChIP-seq to map ERα-binding sites in ovaries of Hy-line Brown commercial hens at 45 d, 90 d and 160 d. In total, 24,886, 21,680 and 23,348 binding sites were identified in the ovaries of hens at 45 d, 90 d and 160 d, which are linked to 86, 83 and 74 genes, respectively. The PPI network contains 47 protein nodes and 164 interaction edges, among which, AKT1 (V-Akt Murine Thymoma Viral Oncogene Homolog 1) and ACTN2 (Actinin Alpha 2) with the highest weight in the network, followed by CREB1 (CAMP Responsive Element Binding Protein 1), and EPHA5 (EPH Receptor A5) were identified. These genes are likely related to sexual maturity in hens. This study also provides insight into the regulation of the ERα target gene networks and a reference for understanding ERα-regulated transcription. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dual-emissive CDs have been synthesized by hydrothermal treatment of mulberry leaves and sodium hydroxide. • CDs-based nonenzymatic fluorescent platform for pesticides sensing was developed. • Dual-channel strategy was developed for simultaneously detecting parathion-methyl and glyphosate. • Parathion-methyl and glyphosate were detected in real samples sensitively, selectively, and accurately. • Combination of dual-emission CDs and OR logic gate can predict food, herbal, or environmental safety. Simultaneous and high-performance detection of pesticides is still a considerable challenge and urgent need. Herein, a dual-emission carbon dots (CDs)-based nonenzymatic fluorescent sensing platform has been developed, which shows excellent sensitivity and selectivity in simultaneously detecting parathion-methyl (MP) and glyphosate. CDs with emissions at 440 nm (bCDs) and 660 nm (rCDs) were prepared by hydrothermal treatment of mulberry leaves and sodium hydroxide. bCDs response to hydrolyzed MP via inner filter effect, while rCDs sense glyphosate with the aid of Cu2+ by static quenching effect. Excellent linear correlations were found for MP (0.3–65.0 μM) and glyphosate (1.0–110.0 μM) with limits of detection at 0.14 and 0.60 μM. Notably, the presented dual-channel strategy was successfully applied in simultaneously detecting MP and glyphosate in food/herbal samples with acceptable recoveries, good precision, and high selectivity. Moreover, an OR logic gate was achieved for estimating food, herbal, or environmental safety. [ABSTRACT FROM AUTHOR]

Exploration of the application prospects of cattail fibers (CFs) in natural composites, and other fields is important for the sustainable development of new, green, light-weight, functional biomass materials. In this study, the physical and chemical properties, micro/nano structure, and mechanical characteristics of CFs were investigated. The CFs have a low density (618.0 kg m−3). The results of transmission electron microscopy and tensile testing data indicated that the cattail trunk fiber (CTF) bundle is composed of parenchyma cells and solid stone cells, demonstrating high specific modulus (10.1 MPa∙m3·kg−1) and high elongation at break (3.9%). In turn, the cattail branch fiber (CBF) bundle is composed of parenchyma cells with specific "half-honeycomb" shape. The inner diaphragms divide these cells into the open cavities. This structural feature endows the CTF bundles with stable structure, good oil absorption and storage capacities. The chemical component and the Fourier transform infrared spectroscopy analyses show that the CFs have higher lignin content (20.6%) and wax content (11.5%), which are conducive to the improvement of corrosion resistance, thermal stability and lipophilic–hydrophobic property of CF. Finally, the thermogravimetric analysis indicates that its final degradation temperature is 404.5 °C, which is beneficial to the increase in processability of CFs-reinforced composites. • The cattail fiber (CF) has lower density and multi-cavity structure. • Higher wax content endows CF with lipophilic-hydrophobic potential. • The cattail branch fiber (CBF) has "half-honeycomb" shape and inner diaphragms. • The CBF structural feature gives CF stable structure and good oil storage capacities. • The cattail trunk fiber bundles exhibit excellent mechanical properties. [ABSTRACT FROM AUTHOR]

The exploration of modified luffa sponge (LS) cellulose fiber in the field of polymer composite can contribute to the development of high-performance and lightweight composites. In this study, two chemical treatments (10%NaOH–20%CH 3 COOH (Method 1) and 10%NaOH–5%Na 2 SO 3 (Method 2)) and two drying methods (air drying and freeze-drying) were used to treat LS. The microscopic characteristics and physical properties showed that Methods 1 and 2 caused shrinkage of the LS fibers and increased their fiber density by 30.6% and 15.0%. Meanwhile, freeze-drying kept the cells of modified LS fibers full and decreased their fiber density by 5.0% and 21.0%, respectively. The tensile properties test analyses indicated that freeze-drying further increased the elongation at break values of modified LS fibers by 25.3% and 17.7%, respectively. The moisture absorption analyses showed that freeze-drying could further decrease the moisture absorption ratios of modified LS fibers by 25.8% and 35.8%, respectively, which was useful for improving the dimensional stability of composite materials. Moreover, the thermogravimetric analysis reveals that freeze-drying increased onset degradation temperatures of the modified fibers by 24.0 °C and 6.7 °C, which was beneficial to improve the thermal stability of the composite material. • Freeze-drying can further decrease the water absorption of modified LS fiber. • Freeze-drying can further increase the toughness of modified LS cellulose fiber. • Freeze-drying can improve the thermal stability of modified LS cellulose fiber. [ABSTRACT FROM AUTHOR]

Measuring student growth and providing diagnostic feedback are core components of cognitive diagnostic assessment. However, most current cognitive diagnostic models solely rely on data from a single occasion to diagnose student skill states, overlooking the substantial long-term information encapsulated in the learning history from multiple occasions. In this paper, we propose a long short-term attentional cognitive diagnostic (LS-ENCD) model for skill growth assessment in intelligent tutoring systems. Specifically, we first embed exercise and student features into high-dimensional vectors. Then, we use a measurement module with a bilayer architecture to establish the interaction between students and exercises, considering guessing and slipping factors. To capture long short-term dependencies on historical data, we design the long short-term learning transfer module based on the attention mechanism, which computes state transfer weights by incorporating occasion time and mastery state. Finally, extensive experimental results on four public datasets demonstrate the superiority and good interpretability of our proposed model. [ABSTRACT FROM AUTHOR]

Nanozyme-based assays present favorable prospects in sensitive determination of pesticides in food samples yet are constrained with little or even no catalytic activities at neutral pH, lack of selectivity, and interference by sample color. Here, a facile and novel photothermal system for rapid, specific, sensitive, and background-free detection of dichlorvos was developed based on peroxidase-like activity of coordinated carbon dots-Fe (CDs-Fe). CDs-Fe was prepared and fabricated based on the redox and coordination chemistry between CDs and Fe species. Catalytic mechanism investigations illustrate that CDs-Fe with outstanding peroxidase-like activity at neutral pH comes from the synergistic effect of •OH production and electron transfer process. More interestingly, dichlorvos can specifically complex with CDs-Fe through electrostatic attraction and π-π stacking interactions, which then cement substrates affinity and improve electron transfer efficiency to enhance the catalytic activity. Oxidized 3,3′,5,5′-tetramethylbenzidine (oxTMB) presents photothermal effect by absorption of near-infrared (808 nm) laser-driven light, which eliminates the color interference from real samples. Accordingly, a background-free photothermal strategy was established. Furthermore, a portable hydrogel kit was fabricated by embedding CDs-Fe and TMB into agarose hydrogel for on-site rapid detection of dichlorvos. A good relationship was observed in the range of 5.00–650 μg L−1 with a satisfactory detection limit at 4.85 μg L−1, and a good recovery (90.56–107.0 %) with excellent anti-interference capacity was achieved for real sample analysis. The work presents a novel nanozyme enhancement strategy for specific and background-free detecting dichlorvos in food samples. [Display omitted] [ABSTRACT FROM AUTHOR]

Mold infestation-induced degradation of quality and performance of bamboo remains a persistent and unresolved issue in the bamboo engineering industry. Herein, an effective strategy was proposed to prepare mold resistant bamboo by luffa seed oil (LSO) microcapsules impregnation method. First, microcapsules were prepared by ionic gelation method, with LSO as the core and chitosan as the shell. Second, the microwave-pretreated bamboo slices were vacuum impregnated with the microcapsules. Microcapsules exhibited good slow-release properties, with a maximum embedding ratio of 17.65% and an average particle size of less than 500 nm. Microcapsules got adsorbed, bonded to, or fused with the bamboo fiber cell wall, and they exhibited less effect on the moisture absorption ratio, moisture desorption ratio, and mechanical properties of bamboo. However, the microcapsule impregnation treatment led to significant improvement in the mold resistance of the bamboo slices, so that the infection level was still level 1 after 30 d of inoculation with mold. This strategy lays a strong foundation for further research on mold-resistant bamboo materials and encourages new applications in green engineering. [Display omitted] • Luffa seed oil (LSO) microcapsules with particle size below 500 nm were prepared. • LSO microcapsules exhibited good slow-release property. • Microcapsules achieved deep impregnation in bamboo through pores in bamboo slices. • Microcapsule treatment significantly improved the mold resistance of bamboo slices. • Microcapsule treatment preserves excellent mechanical properties of bamboo slices. [ABSTRACT FROM AUTHOR]

In this study, agricultural waste luffa vines (LVs) were used to develop solar evaporators by surface carbonization and KOH treatment combined with freeze-drying method. Scanning electron microscopy (SEM), solar absorption, solar thermal management and salt dissolution tests showed that the water vapor generation rate of a single column of LV-based solar evaporator after surface carbonization was as high as 3.26 kg m−2 h−1 under 1 sun, and its evaporation efficiency (118%) even exceeded the theoretical valve. After 36 h of continuous use, there was almost no salt deposition. Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), contact angle, thermal conductivity, evaporation enthalpy, and low field nuclear magnetic resonance (LF-NMR) analyses indicated that the high evaporation efficiency of LV-based solar evaporators after surface carbonization was mainly due to high water transport capacity, low water evaporation enthalpy, and high light absorption rate (91%) of LV. The excellent salt-deposition resistance benefitted from the natural multilayered gradient porous structures of LV, forming spontaneous salt backflowing systems. The desalinization rate of LV-based solar evaporators exceeded 99.9%, which was even higher than those of many membrane elements and thermal desalination systems. They also had excellent removal effects on dyes and oily wastewater. After 30 d of continuous soaking, the compressive strength of 2–cm LVs was still 9.4 MPa. KOH-freeze-drying treatment further improved the salt-deposition resistance of LV-based solar evaporators, but reduced their evaporation efficiency and mechanical performance. This work suggests that LVs with carbonized surface have significant potential for development of environmentally friendly biomass solar evaporators with efficient evaporation, excellent resistance to salt deposition, and good durability. • Luffa vine (LV) solar evaporator has high evaporation rate (3.26 kg m−2 h−1) and efficiency (118%). • Natural LV pore structures give the solar evaporator high resistance to salt deposition. • Baking carbonization can make the surface carbon layer and microstructure of LV more stable. • KOH freeze-drying treatment of LV is helpful to improve the salt tolerance of solar evaporator. • The structure of LVs arranged separately help form a cold steamed surface to efficient evaporation. [ABSTRACT FROM AUTHOR]

The utilization potential of bamboo is enormous; however, its use is hampered in furniture and building materials applications due to its hydrophilic and mildew-prone properties. For the first time, bamboo was subjected to microwave treatment followed by impregnation with luffa seed oil (LSO), rich in high levels of bioactive substances. The synergistic effects of microwave treatment and LSO impregnation on the chemical, physical, mildew resistance, and mechanical properties of bamboo materials and their interrelationships were systematically investigated. The results showed that microwave treatment could increase the porosity of bamboo slices. The LSO content reached a higher saturation in bamboo slices when impregnated for 8 h, the contact angle of bamboo slices increased by 318.9%, and the short-term mildew resistance was significantly enhanced. LSO not only penetrated the bamboo fiber cell wall and cell cavity to form a physical bond, but also possibly formed a chemical connection. The mechanical strength of bamboo slices impregnated with LSO after microwave treatment was improved, and the ultimate load and elastic modulus when loaded on the yellow side of bamboo were 426.8 N and 9379.4 MPa, respectively. [Display omitted] • Microwave treatment synergistic luffa seed oil (LSO) treated bamboo slices. • LSO reduced the hydrophilicity and porosity of bamboo slices. • Synergistic modification resulted in less mold-induced corrosion of bamboo fibers. • Physical and chemical connections exist between LSO and bamboo fiber tissue. • LSO treatment can regulate the mechanical properties of bamboo slices. [ABSTRACT FROM AUTHOR]

• Digital image (DI) can reflect wood-plastic composites (WPCs) apparent crack growth. • Finite element method does not reflect the late fracture process of WPCs well. • Acoustic emission (AE) can reflect the internal damage and crack growth of WPCs well. • The R-square of the crack growth model based on AE cumulative count of WPCs is 0.97. • Change trend of AE cumulative count highly agrees with the crack growth rate of WPCs. To evaluate non-destructive methods for the characterization of highly-filled wood-plastic composites (WPCs), current work investigates the damage and crack propagation of highly-filled WPCs during three-point bending using digital image correlation (DIC), acoustic emission (AE), and finite element method (FEM). Herein, DIC can assess crack propagation, whereas FEM cannot provide insights into the late fracture process. Furthermore, AE shows that the WPCs crack propagation rate is closely related to the AE signal. Especially it is highly consistent with the slope changes of the strain-cumulative ringing count curve, indicating that AE can accurately evaluate the damage and crack propagation evolution within a material. [ABSTRACT FROM AUTHOR]

In this study, abundant, inexpensive, and underutilized natural luffa seed oil (LSO) was used for modifying polyurethane viscoelastic foam (PVF) to prepare LSO-modified PVF (LSVF). Scanning electron microscopy and porosity measurement results show that the addition of LSO endowed LSVF with a rich porous structure and rough cell surface. With the increase in LSO addition, the cell diameter and porosity of LSVF increased from 0.33 to 0.58 mm and 50.68–87.69%, respectively. Addition of LSO increased the viscosity of LSVF reaction mixture system, thus prolonging the cell expansion time in foaming process. Moreover, the addition of LSO reduced the indentation hardness, compression deflection coefficient, and hysteresis loss rate, and improved the flexibility of LSVF. Notably, LSO could significantly improve the sound absorption performance of LSVF. LSVF-30 (30% LSO added amount) acted as a high-efficiency sound-absorbing material, and the LSVF containing LSO exhibited a significantly improved ability to absorb sound waves in the frequency range of 2000–5000 Hz (the most sensitive range for the human ear). Compared to LSVF-0 without LSO, the sound absorption performance of LSVF-30 in this frequency range improved by nearly 100% on average. The addition of LSO significantly improved the moisture dissipation of conventional PVF. The moisture dissipation rate of LSVF-30 increased by 17.67% in 72 h compared to that of LSVF-0. These results show that the addition of LSO is beneficial to improve the properties and service life of foam, reduce the polyurethane foam waste from the source, and help reduce environmental pollution. • Luffa seed oil modified polyurethane viscoelastic foam (LSVF) has good flexibility. • Luffa seed oil (LSO) can increase the viscosity of the LSVF reaction mixture system. • LSO endows LSVF with a rich porous structure and rough cell surface. • LSVF-30 has a nearly 100% increase in high-frequency sound absorption performance. • The LSVF performs well on moisture dissipation than conventional viscoelastic foam. [ABSTRACT FROM AUTHOR]

• Luffa seeds are a vegetable oil raw material with high extraction yield (39.48 %). • Luffa seed oil (LSO) has a high content of unsaturated fatty acids (70.97–75.03 %). • The sufficient reaction sites provide LSO with good chemical modification potential. • The rich bioactive compounds endow LSO with a wide range of potential applications. • The LSO has the potential to develop polyurethanes with good elasticity. Luffa seeds are rich in resources, although they are considered as agricultural waste and thus underutilized. The main objective of this study was to investigate the application prospect of luffa seed oil (LSO) in natural polymer composites, cosmetics, functional materials, and other fields. The extraction yield, fatty acid composition, bioactive components, thermal stability, and physicochemical properties of LSO were systematically investigated. The results of extraction yield and gas chromatography–mass spectrometry analysis indicated that the extraction yield of LSO is high (36.24–39.48 %) and is rich in unsaturated fatty acids (70.97–75.03 %). Moreover, LSO is rich in bioactive substances (31 types) such as squalene, (E)-2-decenal, etc. These results indicate that LSO has promising applications in polymer composites and bioactive substance utilization. 1H NMR, 13C NMR, and FTIR spectroscopy analyses showed that LSO contains sufficient chemical reaction sites (e.g. ester groups, unsaturated double bonds, etc.), and the average double bond number of LSO molecules is 2.69–3.29. These results further indicate its greater potential for the development of polymer composites, in particular, more elastic polyurethane foams. Moreover, analysis of the thermogravimetric and physicochemical properties of LSO revealed that LSO has a relatively high iodine value (83.17 g I 2 /100 g), and high peak degradation temperature (371.89–422.5 °C) and final degradation temperature (490.36–501.80 °C), which is favorable for its thermal polymerization at high temperature for the preparation of polymers. [ABSTRACT FROM AUTHOR]

• Luffa vine (LV) is a low-density natural plant fiber with a porous structure. • The secondary wall of LV fiber cell contains two layers with spiral thickening. • Sclerenchyma cell of LV exhibits excellent micromechanical properties. • The microscopic characteristics endow LV with good processability. • The pit pairs on cell walls provide good permeability to LV fibers. The exploration of luffa vine (LV) in the polymer composites field can contribute to the development of lightweight composites and expand their use in new wide scale applications. In this study, the physical and chemical properties and the microstructure of the LV fibers were investigated by various techniques. The results of LV density and microscopic characteristics indicated that this crop is a lightweight (with density mainly concentrated in 0.30–0.45 g cm−3) natural fiber with a porous structure (the ratio of wall to lumen: 0.2–0.3). Transmission electron microscopy and nanoindentation analyses showed that the secondary wall of the LV sclerenchyma cell is made up of two layers with spiral thickening and exhibiting a high nanoindentation modulus (7.8–10.4 GPa) and a high nanoindentation hardness (0.40–0.58 GPa). The chemical composition and X-ray diffraction analysis indicated that the LV has high lignin content (20–25%) and a relatively high relative crystallinity index of cellulose, which are conducive to increase the hardness of the LV fiber. Moreover, microscopic characteristics analysis also revealed that the LV fiber cells have a relatively high aspect ratio (30.3), there are pit pairs on the LV fiber cell walls, and the core fiber cells of the LV have relatively high flexibility coefficient (0.8), which are beneficial to increase the processability of composite materials with the LV fibers as reinforcement. [ABSTRACT FROM AUTHOR]