Search

Rapeseed (Brassica napus L.) is a major oilseed crop in the middle and lower reaches of the Yangtze River in China. However, it is susceptible to waterlogging stress. This study aimed to investigate the physiological characteristics, cellular changes, and gene expression patterns of rapeseed under waterlogging stress, with the goal of providing a foundation for breeding waterlogging-tolerant rapeseed. The results revealed that waterlogging-tolerant rapeseed exhibited higher levels of soluble sugars and antioxidant enzyme activity, particularly in the roots. Conversely, waterlogging-sensitive rapeseed displayed greater changes in malondialdehyde, proline, and hydrogen peroxide levels. Cellular observations showed that after experiencing waterlogging stress, the intercellular space of rapeseed leaf cells expanded, leading to disintegration of mitochondria and chloroplasts. Moreover, the area of the root xylem increased, the number of vessels grew, and there were signs of mitochondrial disintegration and vacuole shrinkage, with more pronounced changes observed in waterlogging-sensitive rapeseed. Furthermore, significant differences were found in the transcription levels of genes related to anaerobic respiration and flavonoid biosynthesis, and different varieties demonstrated varied responses to waterlogging stress. In conclusion, there are differences in the response of different varieties to waterlogging stress at the levels of morphology, physiological characteristics, cell structure, and gene transcription. Waterlogging-tolerant rapeseed responds to waterlogging stress by regulating its antioxidant defense system. This study provides valuable insights for the development of waterlogging-tolerant rapeseed varieties. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION This study applied a combined pretreatment method involving microwave and acetic acid (AA) soaking to monitor oil absorption of fried potato chips based on texture and microstructure characteristics.Results demonstrated that medium–low microwave combined with 4 h of AA soaking significantly improved the texture profile of potato chips, and reduced oil content by approximately 53.25%. Higher microwave intensity led to greater surface roughness of samples, whereas AA soaking for 1–4 h effectively reduced surface roughness. The decrease in Fm and Nwr, along with the increase in Fwr and Wc with prolonged AA soaking time for 1–4 h indicated that medium–low microwave intensity combined with AA pretreatment enhanced hardness and brittleness of samples. Microscopic examination of cell structure revealed that this combined pretreatment facilitated pectin gelation between the cell walls of potato chips, resulting in a more intact cell structure with fewer gaps. Additionally, the color of pretreated potato chips became brighter.The combination of medium–low microwave intensity and AA soaking pretreatment resulted in a decrease in the oil content and improved the texture profile of fried potato chips. This study provides new strategies and insights for producing low‐fat potato chips based on low‐cost pretreatment. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

With the advancement of society, the issue of oil pollution is escalating, therefore we propose a straightforward and efficient approach for fabricating fully biodegradable poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) foams with exceptional selective oil-absorption capabilities through the integration of melt blending and supercritical CO2 (scCO2) foaming techniques. The PLA90 foams, activated at 11 MPa and temperatures ranging from 105 ℃ to 110 ℃, exhibit an expansion ratio of 44 and a highly interconnected open-cell structure with an open-cell content exceeding 80%, effectively mitigating cell shrinkage occurrences. The 105 ℃-triggered PLA90 foam displays pronounced lipophilicity/hydrophobicity, accelerated oil-absorption kinetics, and elevated oil-absorption capacity. Specifically, the equilibrium absorption capacities for cyclohexane and silicone are 12.8 g/g and 20.1 g/g, respectively. Moreover, the maximum absorption capacity decline rate for silicone oil stands at a mere 13.4% over 10 absorption–desorption cycles. The findings presented in this study establish a theoretical framework and offer empirical evidence to support the development of fully biodegradable, high-performance, and reusable oil-absorption materials. [ABSTRACT FROM AUTHOR]

Abstract Rapeseed (Brassica napus L.) is a major oilseed crop in the middle and lower reaches of the Yangtze River in China. However, it is susceptible to waterlogging stress. This study aimed to investigate the physiological characteristics, cellular changes, and gene expression patterns of rapeseed under waterlogging stress, with the goal of providing a foundation for breeding waterlogging-tolerant rapeseed. The results revealed that waterlogging-tolerant rapeseed exhibited higher levels of soluble sugars and antioxidant enzyme activity, particularly in the roots. Conversely, waterlogging-sensitive rapeseed displayed greater changes in malondialdehyde, proline, and hydrogen peroxide levels. Cellular observations showed that after experiencing waterlogging stress, the intercellular space of rapeseed leaf cells expanded, leading to disintegration of mitochondria and chloroplasts. Moreover, the area of the root xylem increased, the number of vessels grew, and there were signs of mitochondrial disintegration and vacuole shrinkage, with more pronounced changes observed in waterlogging-sensitive rapeseed. Furthermore, significant differences were found in the transcription levels of genes related to anaerobic respiration and flavonoid biosynthesis, and different varieties demonstrated varied responses to waterlogging stress. In conclusion, there are differences in the response of different varieties to waterlogging stress at the levels of morphology, physiological characteristics, cell structure, and gene transcription. Waterlogging-tolerant rapeseed responds to waterlogging stress by regulating its antioxidant defense system. This study provides valuable insights for the development of waterlogging-tolerant rapeseed varieties.

Ethylene–vinyl acetate copolymer (EVA), a crucial elastomeric resin, finds extensive application in the footwear industry. Conventional chemical foaming agents, including azodicarbonamide and 4,4′-oxybis(benzenesulfonyl hydrazide), have been identified as environmentally problematic. Hence, this study explores the potential of physical foaming of EVA using supercritical nitrogen as a sustainable alternative, garnering considerable interest in both academia and industry. The EVA formulations and processing parameters were optimized and EVA foams with densities between 0.15 and 0.25 g/cm3 were produced. Key findings demonstrate that physical foaming not only reduces environmental impact but also enhances product quality by a uniform cell structure with small cell size (50–100 μm), a wide foaming temperature window (120–180 °C), and lower energy consumption. The research further elucidates the mechanisms of cell nucleation and growth within the crosslinked EVA network, highlighting the critical role of blowing agent dispersion and localized crosslinking around nucleated cells in defining the foam's cellular morphology. These findings offer valuable insights for producing EVA foams with a more controllable cellular structure, utilizing physical foaming techniques. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In actual production processes, pure ethyl vinyl acetate (EVA) foams have a high shrinkage rate, and the foaming matrix is prone to plastic deformation, even causing the collapse of bubbles. This limits the further application of EVA foams. In this study, we incorporated styrene butadiene rubber (SBR) and butadiene rubber (BR) into EVA to improve the mechanical properties and dimensional stability of EVA composite foams without sacrificing their low-density characteristics of low density. We used a melting index meter, rotorless vulcanizing meter and dynamic mechanical analysis (DMA) to characterize the changes in viscosity and energy storage modulus of the composite matrix. Scanning electron microscopy (SEM) was used to study the microscopic morphology of foams. The mechanical properties test results showed that the addition of SBR reduced the density of EVA/SBR/BR composite foams, and the addition of BR improved the mechanical properties and dimensional stability of the foams. By combining the advantages of both, the density of products is comparable to pure EVA, the tensile strength and the compressive strength are increased by 11% and 6.3% relative to pure EVA, respectively. [ABSTRACT FROM AUTHOR]

In previous studies, the effect of cell structures of polypropylene (PP) foam materials on flammability behavior had been largely overlooked. In this work, ammonium polyphosphate and pentaerythritol were used as intumescent flame retardants (IFR) for PP, and then the PP‐IFR flame retardant foams were prepared by using injection foaming technology with two different weight reduction methods (same mold volume before foaming and after foaming). The results showed that the average cell size of all the PP‐IFR flame retardant foams in the 10% to 30% weight reduction was less than 100 μm. The PP‐IFR flame retardant foams with an average cell diameter of 26.22 μm and cell density of 7.88 × 106 cells/cm3 had the best limiting oxygen index (LOI) of 27.9%. In addition, the PP‐IFR flame retardant foams with better foaming quality had a higher LOI and a denser foam carbon layer whatever the weight reduction methods, resulting in better flame retardant properties. The escape of gases from the foamed and un‐foamed areas not only reduced the concentration of flammable gases but also led to the collapse and rupture of the foam carbon layer during the combustion process. Hence, it provides guidance for preparing PP foam materials with excellent flame retardancy. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a naturally occurring toxic heavy metal that adversely affects plant germination, growth, and development. While the effects of Cd have been described on many crop species including rice, maize, wheat and barley, few studies are available on cadmium's effect on Tartary buckwheat which is a traditional grain in China. We examined nine genotypes and found that 30 µM of Cd reduced the root length in seedlings by between 4 and 44% and decreased the total biomass by 7 to 31%, compared with Cd-free controls. We identified a significant genotypic variation in sensitivity to Cd stress. Cd treatment decreased the total root length and the emergence and growth of lateral roots, and these changes were significantly greater in the Cd-sensitive genotypes than in tolerant genotypes. Cd resulted in greater wilting and discoloration in sensitive genotypes than in tolerant genotypes and caused more damage to the structure of root and leaf cells. Cd accumulated in the roots and shoots, but the concentrations in the sensitive genotypes were significantly greater than in the more tolerant genotypes. Cd treatment affected nutrient uptake, and the changes in the sensitive genotypes were greater than those in the tolerant genotypes, which could maintain their concentrations closer to the control levels. The induction of SOD, POD, and CAT activities in the roots and shoots was significantly greater in the tolerant genotypes than in the sensitive genotypes. We demonstrated that Cd stress reduced root and shoot growth, decreased plant biomass, disrupted nutrient uptake, altered cell structure, and managed Cd-induced oxidative stress differently in the sensitive and tolerant genotypes of Tartary buckwheat. [ABSTRACT FROM AUTHOR]

In this work, a facile in situ precuring and supercritical CO2 (sc‐CO2) foaming technology is proposed to fabricate silicone rubber foam (SRF) with a tunable cell structure. Uncured silicone rubber is put into the autoclave to saturate sc‐CO2 directly, which not only shorts the saturation time but also accelerates the curing reaction in the precuring process. In the foaming process, cell nucleation is triggered by rapid release of pressure. The cell structure of SRF samples with cell size range of 9.45 to 128.09 μm, cell density range of 3.5 × 105 cells/cm3 to 5.7 × 108 cells/cm3, and porosity range of 28.35% to 77.28% are successfully fabricated by controlling of precuring time, saturation pressure and foaming temperature. To guarantee the dimensional stability and optimize surface quality of SRF samples, in situ post‐curing process is implemented within the foaming mold. With the increase of cell size from 9.91 to 128.09 μm, the compressive stress at strain of 75% decreases from 2.19 to 0.61 MPa, while the energy loss coefficient reduces from 35.4% to 16.9%, exhibiting excellent compression recovery steady. The new technique integrates the precuring, foaming process and post‐curing into an autoclave to simplify the SRF procedure. [ABSTRACT FROM AUTHOR]

Anthracyclines are broad-spectrum anticancer drugs, but their clinical use is limited due to their severe cardiotoxicity. Anthracycline-induced cardiotoxicity (AIC) remains a significant cause of heart disease-related mortality in many cancer survivors. The underlying mechanisms of AIC have been explored over the past few decades. Reactive oxygen species and drug-induced inhibition of topoisomerase II beta are well-studied mechanisms, with mitochondria being a prominently investigated organelle. Emerging mechanisms such as ferroptosis, Ca2+ overload, autophagy and inflammation mediators have been implicated in recent years. In this review, our goal is to summarize and update the roles of various mechanisms in AIC, focusing on different cellular levels and further explore promising therapeutic approaches targeting these organelles or pathways.

To investigate the effects of chitosan and ε-polylysine on the cell structure and cytoprotective enzymes of Carbibacterium divergens to explore their inhibition mechanism against Carbibacterium divergens, the broth dilution method was used to determine the minimum inhibitory concentrations (MICs) of chitosan and ε-polylysine against Carbibacterium divergens. Their effects on the cellular structure of Carbibacterium divergens were then assessed by several indexes, such as growth curves, electronic conductivity, extracellular nucleic acids, extracellular proteins, and alkaline phosphatase (AKP) activity, and the microstructure of bacteria were also observed by scanning electron microscopy (SEM). In addition, their role in oxidative stress was analyzed by detecting changes in catalase (CAT) activity and superoxide dismutase (SOD) activity. The results showed that the MIC of chitosan and ε-polylysine against Carbibacterium divergens was 0.1953 and 0.1563 mg/mL, respectively. The intracellular components (AKP, proteins, nucleic acids, and ions) leaked after treatment with MIC and 2MIC chitosan and ε-polylysine. The mass concentrations of chitosan and ε-polylysine were negatively correlated with enzyme activity, and the activities CAT and SOD significantly decreased (P

This study aimed to investigate the inactivation effect of HPTS combining with egg white lysozyme on the spores of Bacillus subtilis. The spores were treated with pressure 200 MPa at 25, 65 °C and 75 °C, and egg white lysozyme at 0.05%, 0.1% and 0.3%. After treatment, the inactivation rate of Bacillus subtilis spores, leakage of nucleic acid and protein, the change in the cell membrane ATPase activity, the changes in inner membrane permeability of spores and the damage on protein of the spores were determined. The results showed that HPTS and egg white lysozyme synergistically inactivated the spores, and the survival concentration of spores decreased by 3.91 lg (CFU/mL) after 200 MPa/75 °C combining with 0.3% lysozyme treatment. HPTS combining with lysozyme treatment significantly increased the protein and nucleic acid leakage and conductivity of the spores, significantly decreased the Na+/K+-ATPase activity, decreased the stability of the budding spore proteins, and significant increases in the permeability of the inner membrane of the spores. In summary, HPTS combining with egg white lysozyme treatment inhibited the activity of key enzymes in the spore metabolic pathway, while disrupting the spore wall, inner membrane and other structures of Bacillus subtilis budding spores, changed the physiological properties of spores, and eventually led to spore inactivation. [ABSTRACT FROM AUTHOR]

Digested wastewater contains pathogenic microorganisms and high ammonia concentrations, which can pose a potential risk to public health. Effective removal of pathogens and nitrogen is crucial for the post-treatment of digested wastewater. Partial nitrification-anammox is an energy-saving nitrogen removal process. Free nitrous acid (FNA), an intermediate product of partial nitrification, has the potential to inactivate microorganisms. However, the efficiency and mechanisms of FNA-related inactivation in pathogens during partial nitrification remains unclear. In this study, Enterococcus and Escherichia coli (E. coli) were selected to investigate the efficiency and mechanisms of FNA-related inactivation in partial nitrification process. The results revealed that 83% ± 13% and 59% ± 27% of E. coli and Enterococcus were removed, respectively, in partial nitrification process at FNA concentrations of 0.023–0.028 mg/L. When the concentration of FNA increased from 0 to 0.5 mg/L, the inactivation efficiencies of E. coli and Enterococcus increased from 0 to 99.9% and 89.9%, respectively. Enterococcus exhibited a higher resistance to FNA attack compared to E. coli. 3D-laser scanning microscopy (3D-LSM) and scanning electron microscopy (SEM) revealed that FNA exposure caused the surface collapse of E. coli and Enterococcus, as well as visible pore formation on the surface of E. coli cells. 4′,6-Diamidino-2-phenylindole dihydrochloride n-hydrate (DAPI)/propidium iodide (PI) and biomolecule leakage confirmed that inactivation of E. coli and Enterococcus occurred due to breakdown of cell walls and cell membranes. These findings indicate that partial nitrification process can be used for the removal of residual pathogenic microorganisms. [ABSTRACT FROM AUTHOR]

Copyright of Biology Teaching is the property of East China Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT This paper presents two low-cost hands-on activities designed to enhance student understanding and address the pedagogical challenges faced by microbiology professors in teaching concepts related to cell structure and gene regulation. In the first activity, we used Shrinky Dinks and Jeopardy-style game questions to explore the differences between prokaryotic and eukaryotic cells. Students have to collect pieces and physically build their cell models. The second activity uses origami organelles sets from Edvotek to illustrate the regulation of gene expression in the lac and trp operons, incorporating mutation scenarios for analysis. The intended audience comprises undergraduate students in microbiology, including biology, pre-medical studies, and health profession majors. The activities were deployed in three microbiology lectures, and students were surveyed. Students’ feedback highlights the efficacy of the hands-on approach and increased class participation, as two of the recurring words in the students’ survey were “helpful” and “fun.”

For mechanical metamaterials and their vibration isolation ability, a new corset type structure (CTS) is designed from the inward hexagonal steel structure by applying fillet at the inward corners. Ten CTS cells are born by using the different fillet radius. The fillet radius is 10 mm to 100 mm, but the cell mass remains constant when the plate has the same thickness. The static deformation, vibration modality and harmonic response of these NPR structures are analyzed in this paper. These CTS cells are modeled by using the finite element method (FEM) with a uniform grids. In static analysis, a surface load and a point load on the top plate are respectively considered to study the elastic deformation, the NPR and the stiffness of CTS cells with different fillet radii and thicknesses. These CTS cells have a greater NPR and a higher stiffness than the original inward hexagonal steel structure. In modal analysis, the natural frequency, the eigenmode and the fixed modality are numerically computed. These frequency values and displacement distributions of CTS cells show that these CTS cells have a higher vibration frequency than the origin inward hexagonal structure cell. In harmonic response analysis, the frequency domain is from 1 Hz to 1000 Hz, and the excitation force is on the top surface of the upper plate. All displacement responses of these CTS cells are analyzed. The harmonic response analysis result shows that the resonance magnitude can be significantly suppressed by these new CTS cells. The analysis result presents the characteristics of this new CTS, and it is beneficial for the vibration isolation in engineering application. [ABSTRACT FROM AUTHOR]

A basic knowledge of the features of modern microorganisms can be useful for interpreting microfossils in bacterial-paleontological studies. This article analyzes the diversity of morphological forms of prokaryotic microorganisms, provides data on their size range in comparison with eukaryotic microorganisms and viruses, and describes the principles of modern prokaryotic taxonomy. The paper also discusses some aspects of prokaryotic cytology that play a key role in the formation of biomarkers (“molecular fossils”) and mineral precipitation. [ABSTRACT FROM AUTHOR]

In the present work, we applied acetic acid pretreatment (ACP) to reduce the oil absorption and improve the quality characteristics of potato chips (PC) and we explored the underlying mechanism. The variation of water distribution in fresh potato slices pretreated with acetic acid for 1–8 hours and the variations of the water and oil contents, oil composition and distribution, pore diameter, color and texture of PC made from the pretreated potato samples were studied. After ACP, both oil and water contents of PC were significantly decreased (P < 0.05). An ACP time of 4 h gave the lowest oil content of PC (17%). Microscopic observation of the cell structure of PC revealed that pectin gelation occurred between the cell walls, and the cell structure remained relatively intact with few empty spaces after ACP. Moreover, ACP significantly improved the sensory characteristics of PC, endowing it with a brighter color and better crispness. This study provides a new strategy for the production of low-fat potato chips.

Ethylene–vinyl acetate copolymer (EVA), a crucial elastomeric resin, finds extensive application in the footwear industry. Conventional chemical foaming agents, including azodicarbonamide and 4,4′-oxybis(benzenesulfonyl hydrazide), have been identified as environmentally problematic. Hence, this study explores the potential of physical foaming of EVA using supercritical nitrogen as a sustainable alternative, garnering considerable interest in both academia and industry. The EVA formulations and processing parameters were optimized and EVA foams with densities between 0.15 and 0.25 g/cm3 were produced. Key findings demonstrate that physical foaming not only reduces environmental impact but also enhances product quality by a uniform cell structure with small cell size (50–100 μm), a wide foaming temperature window (120–180 °C), and lower energy consumption. The research further elucidates the mechanisms of cell nucleation and growth within the crosslinked EVA network, highlighting the critical role of blowing agent dispersion and localized crosslinking around nucleated cells in defining the foam’s cellular morphology. These findings offer valuable insights for producing EVA foams with a more controllable cellular structure, utilizing physical foaming techniques.

Cadmium (Cd) is a naturally occurring toxic heavy metal that adversely affects plant germination, growth, and development. While the effects of Cd have been described on many crop species including rice, maize, wheat and barley, few studies are available on cadmium’s effect on Tartary buckwheat which is a traditional grain in China. We examined nine genotypes and found that 30 µM of Cd reduced the root length in seedlings by between 4 and 44% and decreased the total biomass by 7 to 31%, compared with Cd-free controls. We identified a significant genotypic variation in sensitivity to Cd stress. Cd treatment decreased the total root length and the emergence and growth of lateral roots, and these changes were significantly greater in the Cd-sensitive genotypes than in tolerant genotypes. Cd resulted in greater wilting and discoloration in sensitive genotypes than in tolerant genotypes and caused more damage to the structure of root and leaf cells. Cd accumulated in the roots and shoots, but the concentrations in the sensitive genotypes were significantly greater than in the more tolerant genotypes. Cd treatment affected nutrient uptake, and the changes in the sensitive genotypes were greater than those in the tolerant genotypes, which could maintain their concentrations closer to the control levels. The induction of SOD, POD, and CAT activities in the roots and shoots was significantly greater in the tolerant genotypes than in the sensitive genotypes. We demonstrated that Cd stress reduced root and shoot growth, decreased plant biomass, disrupted nutrient uptake, altered cell structure, and managed Cd-induced oxidative stress differently in the sensitive and tolerant genotypes of Tartary buckwheat.

This study investigates a prospective and straightforward method for producing graphene material derived from biomass, examining the influence of plant cell composition and functions. The experimental outcomes highlight ultrasound's crucial role in synthesizing graphene material sourced from biomass. Ultrasound, a pivotal element in the experiment, significantly affects graphene production from biomass by working synergistically with the liquid components in the solvent system. Notably, the ethanol content reduces the solution’s surface tension, facilitating the effective dispersion of biochar and graphene oxide sheets throughout the process. Simultaneously, the water content maintains the solution’s polarity, enhancing the cavitation effect induced by ultrasound. Biomass-derived graphene is exfoliated utilizing an ultrasonic bath system (134.4 W, 40 kHz, 0.5 W/cm2) from biochar. The as-synthesized graphene oxide exhibits a structure comprising a few layers while remaining intact, featuring abundant functional groups. Interestingly, the resulting product displays nanopores with an approximate diameter of 100 nm. These nanopores are attributed to preserving specific cell structures, particularly those with specialized cell wall structures or secondary metabolite deposits from biomass resources. The study's findings shed light on the impact of cellular structure on synthesizing graphene material sourced from biomass, emphasizing the potential application of ultrasound as a promising approach in graphene production.

ABSTRACTHigh hydrostatic pressure (HHP) influences the life processes of organisms living at depth in the oceans. While filamentous fungi are one of the essential members of deep-sea microorganisms, few works have explored their piezotolerance to HHP. Here, we obtained three homogeneous Aspergillus sydowii from terrestrial, shallow, and hadal areas, respectively, to compare their pressure resistance. A set of all-around evaluation methods including determination of growth rate, metabolic activity, and microscopic staining observation was established and indicated that A. sydowii DM1 from the hadal area displayed significant piezotolerance. Global analysis of transcriptome data under elevated HHP revealed that A. sydowii DM1 proactively modulated cell membrane permeability, hyphae morphology, and septal quantities for seeking a better livelihood under mild pressure. Besides, differentially expressed genes were mainly enriched in the biosynthesis of amino acids, carbohydrate metabolism, cell process, etc., implying how the filamentous fungi respond to elevated pressure at the molecular level. We speculated that A. sydowii DM1 could acclimatize itself to HHP by adopting several strategies, including environmental response pathway HOG-MAPK, stress proteins, and cellular metabolisms.IMPORTANCEFungi play an ecological and biological function in marine environments, while the physiology of filamentous fungi under high hydrostatic pressure (HHP) is an unknown territory due to current technologies. As filamentous fungi are found in various niches, Aspergillus sp. from deep-sea inspire us to the physiological trait of eukaryotes under HHP, which can be considered as a prospective research model. Here, the evaluation methods we constructed would be universal for most filamentous fungi to assess their pressure resistance, and we found that Aspergillus sydowii DM1 from the hadal area owned better piezotolerance and the active metabolisms under HHP indicated the existence of undiscovered metabolic strategies for hadal fungi. Since pressure-related research of marine fungi has been unexpectedly neglected, our study provided an enlightening strategy for them under HHP; we believed that understanding their adaptation and ecological function in original niches will be accelerated in the perceivable future.

AbstractIn the present study, text presentation in biology textbooks was analyzed with respect to misconception and elements of conceptual change towards the learning of “Cell Structure”. Content analysis of the lesson “Cell Structure” in five biology textbooks of Grades 11 and 12 across selected educational boards in Asia like the International Baccalaureate Diploma Program (IBDP), Cambridge Advanced Subsidiary and Advanced Level (AS-A Level), Advanced Placements Board (AP Board), Central Board of Secondary Education (CBSE) and Tamil Nadu Board of Higher Secondary Education (TNBHSE) was carried out to identify the differences in text-presentation with respect to misconceptions and elements of conceptual change towards the learning of “Cell Structure”. Analysis for elements of conceptual change was carried out by applying “Posner’s Model of Conceptual Change” needed for the replacement of these misconceptions. The results of the analysis indicate that all four elements needed for conceptual change learning were found only in biology textbooks of international boards. The study further reports that the text presentation in these biology textbooks is non-expository with refutational characteristics fostering conceptual understanding by “reasoning and inquiry”. In contrast, text presentation in biology textbooks of Indian educational boards is expository, fostering conceptual understanding by “memorization”.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Our experiment revealed that the addition of Janus nanosheets to polypropylene (PP) has a significant impact on the viscoelasticity of the composite system. Specifically, when 0.10 wt% of Janus nanosheets were added, the complex viscosity of the composite system increased. However, when we added less than 0.05 wt% of Janus nanosheets, there was a reduction in complex viscosity, which is known as the non-Einstein phenomenon. The Cole–Cole plot showed that the nanosheet network structure did not have a significant effect on the viscosity of the composite system. Additionally, we used carbon dioxide as a foaming agent to autoclave foaming using modified PP from Janus nanosheets, and the results demonstrated that increasing the number of Janus nanosheets decreased the apparent density and strengthened the cell structure of foaming beads, resulting in improved closed porosity. [ABSTRACT FROM AUTHOR]

Due to advantages of low cost and intrinsic flame retardancy, urea−formaldehyde (UF) foams with electromagnetic shielding function present a promising application prospect in the fields of construction, transportation and electronics. In this study, by using carbon nanotubes (CNTs) as conductive filler and thermo‐expandable microspheres (EMs) as physical foaming agent, a series of UF/CNT composite foams with perfect and polygonal closed cellular structure were prepared for electromagnetic shielding. By adding 6 wt% EMs, the composite foam exhibited a uniform cell wall thickness, while the local accumulation of CNTs was inhibited and CNTs were distributed evenly within the cell walls. With increasing CNT content the dispersion of CNTs transformed from a scattered and 'island‐like' structure to an interconnected structure, and for samples with CNT content higher than 1.34 vol% a continuous conductive network was constructed within the cell walls, thus significantly improving the electrical conductivity and electromagnetic shielding effectiveness for the foams, which reached 34.5 dB and satisfied the requirement of commercial applications. Moreover, the contribution of absorption to the electromagnetic shielding effectiveness was much larger than that of reflection for composite foams, indicating that absorption was the dominant shielding mechanism. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The development of lightweight insulation materials has become one of the effective ways to improve the performance of solid rocket motors (SRMs). In this paper, porous structure was introduced into ethylene propylene diene monomer (EPDM) insulation materials through rubber foaming technology to prepare lightweight insulation materials. The influence of foaming agent content and pre-curing temperature on morphology and properties of EPDM rubber foams were investigated. With the increase in pre-curing temperature, the cell size decreases significantly and the cell becomes more uniform, resulting in an increase in mechanical properties. As the foaming agent content increases, the cell density increases gradually without significant change in cell diameter. Meanwhile, the mechanical properties of insulation materials gradually decrease. EPDM rubber foams have optimum ablation resistance when the pre-curing temperature is 120 °C and the content of foaming agent is 6phr. Its charring ablation rate is 0.186 mm/s, only increasing by 16% compared with that of basic formula. On this basis, carbon nanotubes (CNTs) and carbon fibers (CF) were added to reinforce EPDM rubber foams. The tensile strength of the reinforced formula increases by 36.4% compared to the foaming formula, which is 19.2% lower than that of the basic formula. The charring rate of the reinforced formula decreases by 35.5% compared to the foaming formula, which is only 5.3% higher than that of the basic formula. • A lightweight EPDM insulation material is prepared through rubber foaming. • Effects of pre-cure temperature and foaming agent content on EPDM composites are revealed. • EPDM composites have optimum properties when pre-cure temperature is 120 °C and foaming agent content is 6phr. • Tensile strength and charring rate of EPDM composites are reinforced by CNTs and CF. [ABSTRACT FROM AUTHOR]

The foaming of PP has encountered challenges because of its low melt strength and semi-crystalline characteristics. Introducing long chain branching (LCB) onto the PP backbone and the addition of particles as cell nucleating agent are the commonly used methods to improve the cell structure of PP foams. In this paper, clay-supported sodium benzoate (NaB-OMMT) was prepared from Na-montmorillonite (Na-MMT) via the partial ion exchange reaction with surfactant and subsequent reaction with benzoic acid. The as prepared NaB-OMMTs were then applied to prepare LCBPP/NaB-OMMT nanocomposites and their foams. The dispersion state of clay, crystallization behaviors and rheological properties of the nanocomposites, as well as the cell structure and compression properties of the foams were investigated. The results show that clay layers are mostly exfoliated in the nanocomposites with low NaB-OMMT content, while intercalated layers dominant with the content reaches 2% or higher. The melting temperature of the nanocomposites decreases and the crystallinity increases, while the spherulite size decreases compared to LCBPP. The melt viscosity and elasticity of nanocomposites increase significantly when the content of NaB-OMMT reaches 2% or higher. LCBPP/NaB-OMMT nanocomposites foams exhibit higher cell density, smaller cell size and its standard deviation. Therein, the foam with 1% of NaB-OMMT shows the maximum cell density and the minimum cell size. It is concluded that the cell structure of the foam is highly dependent on the content, dispersion state and structure of the cell nucleating agent. When NaB is supported on well dispersed and exfoliated clay layers, the cell nucleation efficiency is significantly enhanced. The compression properties of the foams depend on their cell structures and exhibit the similar variation trend with the latter with the content of NaB-OMMT increasing. Graphical Abstract [ABSTRACT FROM AUTHOR]

Fenlong-ridging (FL) is a new type of conservation tillage. In many crops, FL increases crop yield and quality; however, the cytology and molecular mechanisms of crops under FL is not completely understood. This study investigated soil physical and chemical properties under FL and conventional tillage (CK) during 2018–2019 (plant cane) and 2019–2022 (first stubble), and analyzed the agronomic trait, physiology, leaf anatomical structure, and gene expression related to photosynthesis between FL and CK of sugarcane (Guitang 42). Soil bulk density significantly increased, and soil porosity, water storage, and content of available nitrogen and phosphorus under FL were significantly higher than those under CK. Plant height, stem diameter, single stem weight, effective stem number and yield significantly increased under FL compared to under CK. Sugar content significantly increased in plant cane under FL. Chlorophyll content and the photosynthetic rate increased, with significantly higher activity of photosynthetic enzymes including NADP-malate dehydrogenase (NADP-MDH), phosphoenolpyruvate carboxylase (PEPC), and ribulose-1,5-bisphosphate carboxylase (RuBPC) under FL compared to CK. Fenlong-ridging cytology results showed that the mesophyll cells were large and arranged well, the Kranz anatomy was noticeable, and there were a high number of large chloroplasts in mesophyll cell and in the vascular bundle sheath. Furthermore, the bundle sheath in FL was larger than that in CK. Transcriptomics results showed that 19,357 differentially genes (DEGs) were up-regulated and 28,349 DEGs were down-regulated in sugarcane leaves under FL vs. CK. The Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that abundant DEGs were enriched in photosynthesis, photosynthesis-antenna protein, carotenoid biosynthesis, and other pathways associated with photosynthesis. Most expression was up-regulated, thus, facilitating photosynthesis regulation. Quantitative real-time polymerase chain reaction analysis revealed the up-regulation of genes related to photosynthesis (PsaH and PsbS) under FL. Overall, this study provides insights into the role of FL in increased sugarcane yield by integrating physiology, cytology, and proteomics analysis. These findings could be used to further improve its application and promotion. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper compared the effects of air and nitrogen on the freezing characteristics, color, and cell structures of chestnut kernels at different rates of heat transfer and adopted liquid nitrogen spray quick-freezing (NF−40 °C/−60 °C/−80 °C/−100 °C) and still air freezing (AF−20 °C/−40 °C) as the freezing methods. The ratio of heat transfer coefficients in N2 groups was two times as high as those in air groups, and NF−100 °C and NF−80 °C showed better freezing characteristics, good protection for cytoskeletons, and the color was similar to those of the fresh group. Taking both Multivariate Analysis of Variance (Principal Components Analysis and Cluster Analysis) and economic factors, NF−80 °C can be used as a suitable method for chestnut kernel freezing. When the ambient freezing temperature was lower than Tg, both NF and AF treatment groups presented poor quality. The rate and medium of heat transfer jointly influenced the freezing characteristics and quality. The former had a greater effect than the latter, however. [ABSTRACT FROM AUTHOR]

Thioflavin T, a cationic benzothiazole dye, is typically used to detect amyloid fibrils. In this study, we analyzed the staining properties of Bacillus subtilis cells using several fluorescent dyes, including thioflavin T analogs, 2- (4 '-methylaminophenyl) benzothiazole (BTA-1), and 2- (4-aminophenyl) benzothiazole (APBT). Thioflavin T stained vegetative cells in the early log phase and outer layer structures of forespores and mature spores. The inner parts of forespores and heat-killed mature spores were also stained with thioflavin T. Congo red, auramine O, and rhodamine B stained forespores and mature spores similar to thioflavin T. In contrast, APBT and BTA-1 fluorescence was detected in the outer layers of vegetative cells, mother cells, forespores, and mature spores, indicating that they bind to the cell membrane and/or cell wall. The combination of the fluorescent dyes used in this study will help analyze morphogenetic processes during the sporulation and the damage mechanisms of vegetative cells and spores. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A significant weather hazard for flying an airplane is icing. In this context, ice accumulation has recently been recognized as a risk to flight safety. A briefly review on the models used for investigating the icing phenomena is performed. The review topics are ice accretion models, icing phenomena, such as phase change material problem, and ice as porous medium. The results of the review show that a model at meso-scale level of ice melting or solidification is needed. Enthalpy porosity and volume of fluid models are employed to investigate the behaviour of air and ice during its melting at pore scale level. A numerical investigation based on air forced convection in phase change materials cell structures is accomplished. Ansys-Fluent code is employed to perform the numerical simulations. A validation for the combination of the two models is performed using a comparison with an experimental study. By means of the numerical investigation a permeability estimation of the porous medium during melting process is made. The results show that the comparisons between the permeability values by steady-state regime on assigned geometries are a good estimation of the permeability values of the solid matrix of the porous medium during the melting process.

SO 2 -depolarized electrolysis (SDE) is the key step of the hybrid sulfur (HyS) process, which is one of the simplest thermochemical cycles for producing hydrogen by water splitting. Exploration and optimization of flow field/structure design is essential for improving the efficiency of SDE. In this work, graphite plates with different flow channels, together with porous graphite felts or carbon papers as diffusion layers are adopted to fabricate SDE cells with different structures. Evaluation of the cell structures is carried out, by comparing the SDE performance and taking into account the fluid resistance (pressure drop) of anode side. The effects of graphite felt compression ratio, hydrophilicity or hydrophobicity of carbon papers, anodic fluid flow rate, and operating temperature on the SDE performance are investigated. Square porous flow fields provided by graphite felts show excellent performance. Serpentine channel covered by hydrophobic carbon paper reveals advantages when adopted on the cathode side. Combination of above two flow fields and using them on anode and cathode sides respectively, could achieve excellent SDE performance. Under the condition of 40 °C and 360 mL/min anolyte flow rate, the current density could reach 760 mA/cm2 at the cell voltage of 1.19 V. • 16 SDE cells are fabricated with different flow field plates and diffusion layers. • Performance of electrolytic cells with different structure varies greatly. • Anodic fluid resistance used to assist analysis of performance difference of cells. • Effects of felt compression ratio and carbon paper hydrophobicity are discussed. • High performance achieved by arranging GF & hydrophobic carbon paper properly. [ABSTRACT FROM AUTHOR]

We present a model useful for interpretation of indentation experiments on animal cells. We use finite element modeling for a thorough representation of the complex structure of an animal cell. In our model, the crucial constituent is the cell cortex—a rigid layer of cytoplasmic proteins present on the inner side of the cell membrane. It plays a vital role in the mechanical interactions between cells. The cell cortex is modeled by a three-dimensional solid to reflect its bending stiffness. This approach allows us to interpret the results of the indentation measurements and extract the mechanical properties of the individual elements of the cell structure. During the simulations, we scan a broad range of parameters such as cortex thickness and Young's modulus, cytoplasm Young's modulus, and indenter radius, which define cell properties and experimental conditions. Finally, we propose a simple closed-form formula that approximates the simulated results with satisfactory accuracy. Our formula is as easy to use as Hertz's function to extract cell properties from the measurement, yet it considers the cell's inner structure, including cell cortex, cytoplasm, and nucleus. [ABSTRACT FROM AUTHOR]

Regulation of fruit ripening is one of the most important topics in postharvest storage. Effects of 1-methylcyclopropene (1-MCP) greatly depend on the responsiveness of fruit cultivar to this molecule. Although 1-MCP has been used in postharvest preservation of many fruit species, its effects on ripening process, including ethylene production, and softening of banana, mango, and papaya are still not very clear. In the present study, we comparatively investigated the effects of 1-MCP fumigation treatment (1 μL L−1 for 20 h) on ripening behavior and texture qualities of the three fruits during storage at 15 °C. Results showed that 1-MCP treatment not only suppressed the production but also delayed the peak points of ethylene in banana and mango. However, it only significantly delayed the emergence of peak, but didn't suppress the production of ethylene in papaya. Meanwhile, 1-MCP treated papayas showed the lowest malondialdehyde (MDA) content, cell membrane permeability (CMP) and activities of polygalacturonase (PG) and cellulose (CX), accompanied by the highest firmness and protopectin content. Furthermore, 1-MCP treatment slowed down the changes of pulp cell structure in three kinds of fruit. Thus, the findings suggest that postharvest application of 1-MCP has potential in banana and mango fruits due to both prolonging storage-life and ensuring the texture quality, whereas it is not suitable for papaya fruit because of the abnormal softening and the poor texture. [ABSTRACT FROM AUTHOR]

In recent years, bamboo has been well exploited in the pulp and paper industry. Moso bamboo (Phyllostachys edulis (Carriere) J. Houzeau; hereafter M), originated from China with a long history of cultivation as the most abundant resource with the widest distribution area among bamboo plants in China. In this study, Moso bamboo (M) and nine bamboo varieties were selected in the bamboo germplasm resources storage bank of the Anhui Taiping Experimental Station of ICBR. The characteristics of their cell structures were compared, and the differences were analyzed from a genetic perspective. The results showed that M had the highest fiber cell length, fiber cell width, length, and parenchyma width, while GJ showed the lowest of these measurements [P. edulis 'Kikko-chiku',G.H.Lai]. The fiber wall thickness of Q [P. edulis f. obliquinoda (Z.P.Wang et N.X.Ma) Ohrnberger] was the smallest, while its fiber lumen diameter was the highest in the group. The parenchyma wall thickness and parenchyma lumen diameter of Q were the smallest in the group. The fiber cells of M and Q had better flexibility, which is conducive to improving the tensile strength, break resistance, and folding resistance of paper made from these materials. SY and GJ may be more suitable for ornamental items because of their special appearances. The purpose of this study was to explore the genetic variation patterns of various cell structure indicators among Moso bamboo and its varieties, as well as to develop a strategy of bamboo growing and lumbering based on the local conditions, providing reference data for the utilization of non-woody forest resources. [ABSTRACT FROM AUTHOR]

Developing in silico models that accurately reflect a whole, functional cell is an ongoing challenge in biology. Current efforts bring together mathematical models, probabilistic models, visual representations, and data to create a multi-scale description of cellular processes. A realistic whole-cell model requires imaging data since it provides spatial constraints and other critical cellular characteristics that are still impossible to obtain by calculation alone. This review introduces Soft X-ray Tomography (SXT) as a powerful imaging technique to visualize and quantify the mesoscopic (~25 nm spatial scale) organelle landscape in whole cells. SXT generates three-dimensional reconstructions of cellular ultrastructure and provides a measured structural framework for whole-cell modeling. Combining SXT with data from disparate technologies at varying spatial resolutions provides further biochemical details and constraints for modeling cellular mechanisms. We conclude, based on the results discussed here, that SXT provides a foundational dataset for a broad spectrum of whole-cell modeling experiments. [ABSTRACT FROM AUTHOR]

In order to reduce the adverse effects of materials and manufacturing technology on the environment, it is of great practical significance to study the mechanical properties of wood-based sandwich cell structure to adapt to the rapid growth of reconstructed houses and prefabricated building sites. In this paper, three kinds of wood-based interlocking grid cell structures with the same structural form but different combined materials are designed and prepared. The static compression experiments are carried out, and the compression strength, mass load ratio and specific energy absorption characteristics are analyzed by theoretical analysis and numerical simulation. The results show that the mechanical properties of the three cell structures are higher than those of their combined materials, and they are light and high-strength materials. It can be concluded that the core layer of wood-based interlocking grid sandwich cell structure is the main body to bear the external force, the material of the panel plays an important role in the bearing capacity of the cell structure. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of the viscosity and content of vinyl silicone oil and fireproof fillers with different shape on the cell structure and fire resistance of condensed silicone rubber foam materials were stu-died. The foaming rate and crosslinking rate of silicone rubber foam during the foaming process was characterized by the rubber processing analyzer. At the same time, the effects of the shape of aluminum hydroxide, mica and wollastonite on the fire resistance of silicone rubber foam were also investigated. The results showed when no vinyl silicone oil was added, storage modulus of silicone rubber foam whose cell structure of was mainly closed was lower. The addition of vinyl silicone oil increased the crosslinking rate and storage modulus of silicone rubber foam, and caused easily more open cell structures, and also had an impact on the cell size distribution of silicone rubber foam. The addition of lamellar mica was likely to result in the collapse and rupture of cell. However, the integrity of the cell structure and the ablation surface were well maintained after the flame ablation, and the complete ceramic barrier layer could play a good role in the fire prevention. In the other hand, silicone rubber foam materials with aluminum hydroxide and wollastonite were seriously cracked after the flame ablation.

This study aimed to explore the effect of osmotic methods on the cell structure and quality of freeze-dried mango. This experiment uses jade as the raw material, mango was treated by solid osmotic (SSD) and liquid osmotic (LOD) at 20 and 30 ℃, and then vacuum freeze-dried. By measuring the soluble solids and cell morphology of fresh mango samples after osmosis treatment, and analyzing the changes of elastic modulus, porosity, cell wall structure, color and VC, total phenols, and β-carotene retention index of freeze-dried mangoes. The results showed that the increasing of soluble solids in solid osmotic mango was higher than that in liquid osmotic. There was no significant difference between the cell morphology of liquid osmotic mango and fresh sample (CK). The content of soluble solids and the shrinkage degree of cell morphology increased with the increasing of sucrose, the solid osmotic reduced the intercellular porosity and increased the elastic modulus of mango. Moreover, results of infrared spectroscopy showed that the stretching vibration absorption peak of O-H increased with the increasing of sucrose content. Low sucrose solid osmotic helps to maintain the color of mango. The retention rates of VC and total phenol in solid osmotic were higher than those in liquid osmotic at ambient temperature of 20 and 30 ℃, and the highest retention rates of SSD20 VC and total phenol in solid state infiltration were 37.75% and 33.37%, respectively. The retention rate of β-carotene in vacuum freeze-dried mango SSD20 treated with solid osmotic treatment was higher than that of liquid osmotic treatment LOD30, but the retention rate of β-carotene decreases gradually with the increasing of sucrose supplementation in solid osmotic treatment. The results of this study showed that low sucrose solid osmotic could effectively improve the comprehensive quality of vacuum freeze-dried mango, which would provide a theoretical reference for improving the quality of dried mango products.

Dislocation cell structures significantly influence the fatigue failure process. Research on the cell structures in multiple-slip-oriented copper single crystals has focused primarily on the [ 1 ‾ 11 ] orientation, whereas formation mechanisms and development processes of cell structures in [001] and [011] copper single crystals remain unclear. Therefore, this study examines the dislocation structures of near-[001] and near-[011] copper single crystals under cyclic deformation at high strain amplitudes. The cyclic stress–strain curve of the [011] crystals showed a distinct plateau at plastic shear strain amplitudes ≤7.5 × 10−3. In the plateau region, the dislocation structures consisted of cell structures along the (111) primary slip plane and matrix wall structures. Furthermore, (111) cell structures were formed in the single-slip deformation bands (DBs). After the plateau region, several types of new DBs could be observed due to the activation of multiple-slip systems. Multiple-slip DBs have a higher degree of plastic strain concentration than single-slip DBs, leading to the preferential formation of cell structures. For the near-[001] crystals, (111) cell structures were uniformly formed throughout the matrix, without the formation of DBs. The formation mechanism of the (111) cell boundary was independent of the stress axis and resulted from the interaction between the primary and coplanar slip systems. • Cell structures in [001] and [011] copper single crystals were characterized. • First analysis of fatigue behavior in [011] crystals after plateau region. • Formation mechanism of the (111) cell boundary is independent of the stress axis. • Multiple-slip deformation bands bear higher strain than those of single-slip. • Activated slip systems and formation sites mutually influence cell formation. [ABSTRACT FROM AUTHOR]

Poor surface appearance and decreased mechanical performance are critical factors limiting the broad application of Microcellular injection molding (MIM) in foamed polymer products. Herein, in-situ polytetrafluoroethylene (PTFE) nanofibrils reinforced polypropylene (PP) foams with high strength, impact resistance, and enhanced surface quality were prepared by mold opening microcellular injection molding (MOMIM). PTFE nanofibers with different diameters were introduced into the PP matrix via twin screw extrusion and significantly enhanced the crystallinity and viscoelasticity of the PP matrix with the enhancement being more pronounced for the finer PTFE fibers. High-density oriented cellular structures were formed in the MOMIM PP/PTFE foams owing to the heterogeneous nucleation of PTFE and the stretching effect of the mold opening process. The optimum MOMIM PP/PTFE foam fabricated possesses a high cell orientation angle close to 90° and a large cell aspect ratio of 5.3, which reached a 34.37 % increase in tensile strength and a 73.08 % increase in impact strength owing to the synergetic effects of the PTFE network and the highly oriented fine cell structure, which effectively dissipated the tensile stress and impact stress by cell wall twisting and folding deformation. Furthermore, the MOMIM PP/PTFE foam showed a significantly enhanced surface quality compared to the MIM foam due to the reduced dragging flow in MOMIM, which greatly hindered cell rupture on the foam surface. Therefore, this work provides insights into the MOMIM of polymer composites containing fibrous fillers and the enhancement of tensile properties, impact resistance, and surface quality of foam products. In-situ PTFE nanofibrils-reinforced PP foams were fabricated by MOMIM. PTFE nanofibers were introduced enhancing the crystallinity and viscoelasticity of PP. Optimum MOMIM PP/PTFE foam showed 34.37 % higher tensile strength and 73.08 % higher impact strength owing to the synergetic effects of the PTFE network and the highly oriented fine cell structure. [Display omitted] • In-situ fibrillated PP/PTFE nanocomposite foams were prepared by MOMIM. • PTFE nanofibrils with finer size enhanced the crystallinity and viscoelasticity. • Cells with high orientation angle and large aspect ratio were obtained. • PTFE nanofibrils and oriented cells synergized stress dissipation of the foams. [ABSTRACT FROM AUTHOR]

Lightweight and excellent mechanical properties rigid polyurethane foams (RPUFs) play an irreplaceable role in aerospace, construction and transportation fields. Microstructure is an important factor in controlling properties of RPUFs. In this study, RPUFs with different cell structures were fabricated by adjusting foaming agent. The relationship between cell structure parameters (cell size, wall thickness, closed cell rate and cell anisotropy) and density was determined based on SEM analysis. The compressive, bending, impact, heat insulation and sound insulation properties were tested. The results showed that cell structure was related to mechanical properties, which was reflected in the linear relationship between log (density) and log (mechanical properties). RPUF 0.4 with a density of 148 kg/m3 possessed excellent compressive strength, flexural strength, flexural modulus and impact strength of 2.89 MPa, 2.60 MPa, 35.41 MPa and 1.06 kJ/m2. Thermal and sound insulation properties were depended on cell size and closed cell rate, the thermal conductivity of RPUFs ranged from 0.0398 to 0.0515 W/(m·K), and the sound transmission loss of RPUF 1.4 exceeded 25 dB in 500–5000 Hz. The comprehensive properties were regulated by adjusting cell structure, which provides a theoretical basis for the design of RPUFs with specific properties. [Display omitted] • The rigid polyurethane foams (RPUFs) with different cell sizes were fabricated through adjusting H 2 O content. • The mechanical, thermal and sound insulation properties of RPUFs were studied based on the cell structure and density. • The relationship between density and mechanical properties was constructed to predict the properties of RPUFs. • The RPUFs exhibited excellent comprehensive properties, which were expected to serve as building materials. [ABSTRACT FROM AUTHOR]