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1.
Dig Dis Sci ; 2024 May 16.
Article in English | MEDLINE | ID: mdl-38753240

ABSTRACT

BACKGROUND: Severe acute pancreatitis (SAP) is a potential fatal gastrointestinal disease that is usually complicated by myocardial injury and dysfunction. Due to the lack of understanding of the mechanism of SAP-associated cardiac injury (SACI), there is still no complete treatment. AIMS: To explore the alleviative effect and anti-ferroptosis mechanism against SACI of glycyrrhizin (GL), an inhibitor of oxidative stress. METHODS: The SAP model was established by perfusing 5% sodium taurocholate into biliopancreatic duct in rats. H&E staining and serum assays were used to assess the injury changes of pancreas and heart. Echocardiography was used to evaluate the cardiac function. Transmission electron microscopy (TEM) and oxidative stress assays were used to investigate the ferroptosis-related morphological and biochemical changes. Western blot and immunofluorescence were performed to analyzed the expression of ferroptosis-related proteins. RESULTS: Significant myocardial impairment was found in SAP rats according to increased histopathological scores, serum creatine kinase-MB (CK-MB) and cardiac troponin-I (cTnI) levels, and a decreased fractional shortening and ejection fraction. The decreased mitochondrial cristae and significant expression changes of ferroptosis-related proteins confirmed the presence of ferroptosis in SACI. GL treatment attenuated above-mentioned cardiac tissues damage by inhibiting ferroptosis via restoring the expression of Nrf2 and HO-1 in vivo and in vitro. Treating with ML385 (a Nrf2 inhibitor) or transfecting with siRNA-Nrf2 reversed the protective effect of GL. CONCLUSIONS: Our findings demonstrate the involvement of ferroptosis in SACI and suggest a potential role for GL in the treatment of SACI by supressing ferroptosis via Keap1/Nrf2/HO-1 pathway.

2.
Sci Total Environ ; 935: 173195, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-38750752

ABSTRACT

The distribution fate of chlorothalonil (CHT) in the environment (soil and water) and fruits is controlled by the capacity of cuticles to adsorb and desorb CHT, which directly affects the safety of both the environment and fruits. Batch experiments were conducted to reveal the adsorption-desorption behaviors of CHT in the cuticles of apple and red jujube. The adsorption kinetics showed that both physisorption and chemisorption occurred during the adsorption process. Furthermore, the isothermal adsorption of CHT in the fruit cuticles followed the Freundlich model. The thermodynamic parameters (ΔG ≤ -26.16 kJ/mol, ΔH ≥ 31.05 kJ/mol, ΔS ≥ 0.20 kJ/(mol K) showed that the whole CHT adsorption process was spontaneous, and the hydrophobic interaction was predominant. The CHT adsorption capacity of the apple cuticle was higher than that of the red jujube cuticle, potentially due to the significantly higher alkanes content of apples than that of red jujubes. An appropriate ionic strength (0.01 moL/L) could induce a higher adsorption capacity. In addition, the desorption kinetics were shown to conform to a Quasi-first-order model, meaning that not all the adsorbed CHT could be easily desorbed. The desorption ratios in apple and red jujube cuticles were 41.38% and 35.64%, respectively. The results of Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy further confirmed that CHT could be adsorbed and retained in the fruit cuticles. Investigating the adsorption-desorption behavior of CHT in the apple and red jujube cuticles allowed to determine the ratio of its final distribution in the fruits and environment, providing a theoretical basis to evaluate the risk of residue pesticide.


Subject(s)
Fruit , Malus , Nitriles , Ziziphus , Adsorption , Ziziphus/chemistry , Malus/chemistry , Nitriles/chemistry , Fruit/chemistry , Kinetics , Fungicides, Industrial/chemistry
3.
Spectrochim Acta A Mol Biomol Spectrosc ; 316: 124326, 2024 Aug 05.
Article in English | MEDLINE | ID: mdl-38669978

ABSTRACT

Based on the fact that not all chemical substances possess good Raman signals, this article focuses on the Raman silent region signals of pesticides with cyano group. Under the optimized conditions of methanol-water (1:1, v/v) as the solvent, irradiation at 302 nm light source for 20 min, and the use of 0.5 mol/L KI as the aggregating agent, Surface-enhanced Raman spectroscopy (SERS) method for azoxystrobin detection was developed by the Raman silent region signal of 2230 cm-1, and verified by detecting the spiked grapes with different concentrations of azoxystrobin. Other four pesticides with cyano group also could be identified at the peak of 2180 cm-1, 2205 cm-1, 2125 cm-1, and 2130 cm-1 for acetamiprid, phoxim, thiacloprid and cymoxanil, respectively. When azoxystrobin or acetamiprid was mixed respectively with chlorpyrifos without cyano group, their SERS signals in the Raman silent region of chlorpyrifos were not interfered, while mixed with cymoxanil in different ratios (1:4, 1:1 and 4:1), respectively, each two pesticides with cyano group could be distinguished by the changes in the Raman silent region. In further, four pesticides with or without cyano group were mixed together in 1:1:1:1 (acetamiprid, cymoxanil, azoxystrobin chlorpyrifos), and each pesticide still could be identified even at 0.5 mg/L. The results showed that the SERS method combined with UV irradiation may provide a new way to monitor the pesticides with C≡N performance in the Raman silent region without interference from the food matrix.


Subject(s)
Pesticides , Spectrum Analysis, Raman , Strobilurins , Spectrum Analysis, Raman/methods , Pesticides/analysis , Strobilurins/analysis , Pyrimidines/analysis , Pyrimidines/chemistry , Vitis/chemistry , Methacrylates/chemistry , Methacrylates/analysis , Neonicotinoids/analysis
4.
Front Pharmacol ; 15: 1371929, 2024.
Article in English | MEDLINE | ID: mdl-38576483

ABSTRACT

Metabolic syndrome (MetS) is a clinical condition associated with multiple metabolic risk factors leading to type 2 diabetes mellitus and other metabolic diseases. Recent evidence suggests that modulating adipose tissue to adaptive thermogenesis may offer therapeutic potential for MetS. Xiasangju (XSJ) is a marketed drug and dietary supplement used for the treatment of metabolic disease with anti-inflammatory activity. This study investigated the therapeutic effects of XSJ and the underlying mechanisms affecting the activation of brown adipose tissue (BAT) in MetS. The results revealed that XSJ ameliorated MetS by enhancing glucose and lipid metabolism, leading to reduced body weight and abdominal circumference, decreased adipose tissue and liver index, and improved blood glucose tolerance. XSJ administration stimulated catecholamine biosynthesis, increasing noradrenaline (NA) levels and activating NA-mediated proteins in BAT. Thus, BAT enhanced thermogenesis and oxidative phosphorylation (OXPHOS). Moreover, XSJ induced changes in gut microbiota composition, with an increase in Oscillibacter abundance and a decrease in Bilophila, Candidatus Stoquefichus, Holdemania, Parasutterella and Rothia. XSJ upregulated the proteins associated with intestinal tight junctions corresponding with lower serum lipopolysaccharide (LPS), tumor necrosis factor α (TNF-α) monocyte chemoattractant protein-1 (MCP-1) and interleukin-6 (IL-6) levels to maintain NA signaling transport. In summary, XSJ may alleviate MetS by promoting thermogenesis in BAT to ultimately boost energy metabolism through increasing NA biosynthesis, strengthening intestinal barrier integrity and reducing low-grade inflammation. These findings suggest XSJ has potential as a natural therapeutic agent for the treatment of MetS.

5.
Chemosphere ; 353: 141561, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38417492

ABSTRACT

Carbofuran and acetamiprid pose the highest residual risk among pesticides found in wolfberries. This study aimed to degrade these pesticides in wolfberries using a multi-array dielectric barrier discharge plasma (DBD), evaluate the impact on safety and quality and explore their degradation mechanism. The results showed that DBD treatment achieved 90.6% and 80.9% degradation rates for carbofuran and acetamiprid, respectively, following a first-order kinetic reaction. The 120 s treatment successfully reduced pesticide contamination to levels below maximum residue limits. Treatment up to 180 s did not adversely affect the quality of wolfberries. QTOF/MS identification and degradation pathway analysis revealed that DBD broke down the furan ring and carbamate group of carbofuran, while replacing the chlorine atom and oxidizing the side chain of acetamiprid, leading to degradation. The toxicological evaluation showed that the degradation products were less toxic than undegraded pesticides. Molecular dynamics simulations revealed the reactive oxygen species (ROS) facilitated the degradation of pesticides through dehydrogenation and radical addition reactions. ROS type and dosage significantly affected the breakage of chemical bonds associated with toxicity (C4-O5 and C2-Cl1). These findings deepen insights into the plasma chemical degradation of pesticides.


Subject(s)
Carbofuran , Lycium , Neonicotinoids , Pesticides , Carbofuran/toxicity , Reactive Oxygen Species , Molecular Dynamics Simulation , Pesticides/analysis
6.
Small ; : e2309130, 2024 Jan 21.
Article in English | MEDLINE | ID: mdl-38247181

ABSTRACT

Various physical and chemical reaction processes occur in non-aqueous liquid systems, particularly in oil phase systems. Therefore, achieving efficient, accurate, controllable, and cost-effective movement and transfer of substances in the oil phase is crucial. Liquid-phase photothermal actuators (LPAs) are commonly used for material transport in liquid-phase systems due to their remote operability and precise control. However, existing LPAs typically rely on materials like hydrogels and flexible polymers, commonly unsuitable for non-aqueous liquids. Herein, a 3D porous poly(vinylidene fluoride) (PVDF)/Ti3 C2 Tx actuator is developed using a solvent displacement method. It demonstrates directional movement and controlled material transport in non-aqueous liquid systems. When subject to infrared light irradiation (2.0 W cm-2 ), the actuator achieves motion velocities of 7.3 and 6 mm s-1 vertically and horizontally, respectively. The actuator's controllable motion capability is primarily attributed to the foam's oil-wettable properties, 3D porous oil transport network, and the excellent photothermal conversion performance of Ti3 C2 Tx , facilitating thermal diffusion and the Marangoni effect. Apart from multidimensional directions, the actuator enables material delivery and obstacle avoidance by transporting and releasing target objects to a predetermined position. Hence, the developed controllable actuator offers a viable solution for effective motion control and material handling in non-aqueous liquid environments.

7.
J Hazard Mater ; 465: 133085, 2024 03 05.
Article in English | MEDLINE | ID: mdl-38070269

ABSTRACT

As an emerging contaminant in soil, the impact of microplastics (MPs) on the environmental behavior of other organic pollutants remains uncertain, potentially threatening the sustainability of agricultural production. In this study, the impact of two kinds of MPs on the environmental behaviors of herbicide atrazine in soil-plant system was investigated. The results showed that MPs significantly reduced the half-life 17.69 ∼ 21.86 days of atrazine in the soil, compared to the control group. Meanwhile, the introduction of MPs substantially increased atrazine adsorption. Additionally, MPs substantially enriched the diversity and functionality of soil microbiome, and the soil metabolic activity was stimulated. Regarding the crop growth, the accumulation of atrazine in maize were significantly decreased by approximately 48.4-78.5 % after exposure to MPs. In conclusion, this study reveals the impact of MPs on atrazine's environmental behaviors in soil and highlights their less effect on maize growth, providing valuable insights for managing MPs contamination in sustainable agriculture.


Subject(s)
Atrazine , Herbicides , Soil Pollutants , Atrazine/metabolism , Microplastics/metabolism , Soil , Plastics/metabolism , Adsorption , Bioaccumulation , Soil Pollutants/metabolism , Zea mays/metabolism
8.
Polymers (Basel) ; 15(15)2023 Jul 27.
Article in English | MEDLINE | ID: mdl-37571084

ABSTRACT

Piezoelectric nanogenerators have prospective uses for generating mechanical energy and powering electronic devices due to their high output and flexible behavior. In this research, the synthesis of the three-dimensional coral-like BaTiO3 (CBT) and its filling into a polyvinylidene fluoride (PVDF) matrix to obtain composites with excellent energy harvesting properties are reported. The CBT-based PENG has a 163 V voltage and a 16.7 µA current at a frequency of 4 Hz with 50 N compression. Simulations show that the high local stresses in the CBT coral branch structure are the main reason for the improved performance. The piezoelectric nanogenerator showed good durability at 5000 cycles, and 50 commercial light-emitting diodes were turned on. The piezoelectric nanogenerator generates a voltage of 4.68-12 V to capture the energy generated by the ball falling from different heights and a voltage of ≈0.55 V to capture the mechanical energy of the ball's movement as it passes. This study suggests a CBT-based piezoelectric nanogenerator for potential use in piezoelectric sensors that has dramatically improved energy harvesting characteristics.

9.
Bioact Mater ; 21: 194-208, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36101856

ABSTRACT

Tendinopathy is a common musculoskeletal disorder which results in chronic pain and reduced performance. The therapeutic effect of stem cell derived-small extracellular vesicles (sEVs) for tendinopathy has been validated in recent years. However, whether large extracellular vesicles (lEVs), another subset of extracellular vesicles, possesses the ability for the improvement of tendinopathy remains unknown. Here, we showed that lEVs secreted from iPSC-derived MSCs (iMSC-lEVs) significantly mitigated pain derived from tendinopathy in rats. Immunohistochemical analysis showed that iMSC-lEVs regulated the heterogeneity of infiltrated macrophages and several inflammatory cytokines in rat tendon tissue. Meanwhile, in vitro experiments revealed that the M1 pro-inflammatory macrophages were repolarized towards M2 anti-inflammatory macrophages by iMSC-lEVs, and this effect was mediated by regulating p38 MAPK pathway. Moreover, liquid chromatography-tandem mass spectrometry analysis identified 2208 proteins encapsulated in iMSC-lEVs, including 134 new-found proteins beyond current Vesiclepedia database. By bioinformatics and Western blot analyses, we showed that DUSP2 and DUSP3, the negative regulator of p38 phosphorylation, were enriched in iMSC-lEVs and could be transported to macrophages. Further, the immunomodulatory effect of iMSC-lEVs on macrophages was validated in explant tendon tissue from tendinopathy patients. Taken together, our results demonstrate that iMSC-lEVs could reduce inflammation in tendinopathy by regulating macrophage heterogeneity, which is mediated via the p38 MAPK pathway by delivery of DUSP2 and DUSP3, and might be a promising candidate for tendinopathy therapy.

10.
Front Plant Sci ; 13: 989931, 2022.
Article in English | MEDLINE | ID: mdl-36161000

ABSTRACT

Plant non-harvest changes element circulation and has a marked effect on element sinks in the ecosystem. In this study, a field investigation was conducted on the fixation of nitrogen and phosphorus in Miscanthus lutarioriparius, the most dominant plant species in the Dongting Lake wetlands. Further, to quantitatively compare the difference in nitrogen and phosphorus sinks between harvest and non-harvest, an in situ experiment on the release of the two elements from two types of litters (leaves and stems) was studied. The nitrogen concentrations in the plant had no significant relationship with the environmental parameters. The phosphorus concentrations were positively related to the plot elevation, soil organic matter, and soil total potassium and were negatively related to the soil moisture. The leaves demonstrated a higher decomposition coefficient than that of the stems in the in situ experiment. The half decomposition time was 0.61 years for leaves and 1.12 years for stems, and the complete decomposition time was 2.83 years for leaves and 4.95 years for stems. Except for the nitrogen concentration in the leaves, all the concentrations increased during the flood period. All concentrations unsteadily changed in the backwater period. Similarly, except for the relative release index of nitrogen in the leaves, all the relative release indices decreased in the flood period. At the end of the in situ decomposition experiment, the relative release indices of both the nitrogen and phosphors were greater than zero, indicating that there was a net release of nitrogen and phosphorus. Under the harvest scenario, the aboveground parts of the plant were harvested and moved from the wetlands, thus increasing the nitrogen and phosphorus sinks linearly over time. The fixed nitrogen and phosphorus in the aboveground parts were released under the non-harvest scenario, gradually accumulating the nitrogen and phosphorus sinks from the first year to the fifth year after non-harvest, reaching a maximum value after the fifth year. This study showed that the nitrogen and phosphorus sinks greatly decreased after the non-harvest of M. lutarioriparius compared to that after harvest. It is recommended to continue harvesting the plant for enhancing the capacity of element sinks.

11.
Compr Rev Food Sci Food Saf ; 21(5): 4402-4421, 2022 09.
Article in English | MEDLINE | ID: mdl-36037152

ABSTRACT

Drying is an important and influential process to prolong the shelf-life of food in the food industry. Recent studies have shown that cold plasma (CP) as an emerging drying pretreatment technology can improve drying performance, reduce drying energy consumption, and improve dried food quality. This paper comprehensively reviewed the mechanism of CP improving drying performance, related equipment, energy consumption, influencing factors, and impact on drying quality. This review also discusses the advantages and disadvantages and proposes possible challenges and suggestions for future research. Most studies indicated that CP pretreatment could improve the drying rate and quality and reduce the drying energy consumption. CP can promote moisture diffusion and improve drying efficiency by etching the surface and affecting the internal microstructure. In addition, CP can enhance the quality of dried products by reducing drying time and enzyme activity. Further research is needed to explore the drying mechanisms and equipment innovations to promote the application of CP in the food drying industry.


Subject(s)
Plasma Gases , Desiccation , Food Quality
12.
Food Chem ; 397: 133781, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-35940093

ABSTRACT

Research about biodegradable antimicrobial films continues to receive a lot of attention due to the plastic pollution crisis and the need for environment-friendly and safe food products. In this study, we developed chitosan-based antimicrobial films using a combination of encapsulated lemon essential oil (LEO) by ionic gelation and cranberry juice and evaluated the performance of the films. Our results indicated that the incorporation of LEO microspheres and cranberry juice into the chitosan films improved the UV barrier and thermal properties as well as antioxidant activity of the films. The increase in antioxidants was consistent with the chemical components in LEO and cranberry juice as determined by GC-MS; some of which possess antioxidant properties. Furthermore, following antimicrobial activity test, considerable inhibition halo of 11 and 20 mm were observed respectively against fungi Candida albicans and Penicillium roqueforti, particularly in presence of the film containing both LEO microspheres and cranberry juice.


Subject(s)
Anti-Infective Agents , Chitosan , Citrus , Oils, Volatile , Vaccinium macrocarpon , Anti-Bacterial Agents/pharmacology , Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Antioxidants/chemistry , Antioxidants/pharmacology , Chitosan/chemistry , Food Packaging/methods , Oils, Volatile/chemistry , Oils, Volatile/pharmacology
13.
Sci Rep ; 12(1): 12928, 2022 Jul 28.
Article in English | MEDLINE | ID: mdl-35902715

ABSTRACT

This paper investigated the preparation method and the dispersion behaviour of Modified Carbon Nanotube-fiber Reinforcements (MCNF), the change laws and the effect mechanisms of dynamic compressive strength of MCNF concretes. Electrophoresis method was used to prepare MCNF and its interfacial shear performance was tested by interfacial shear strength (IFSS) test. In addition, the dispersion behavior of MCNF in simulated concrete solution was verified by turbidity method. Split Hopkinson Pressure Bar (SHPB), Scanning Electron Microscope (SEM) and Mercury Intrusion Porosimetry (MIP) tests were carried on concrete samples with different volume fractions (0%, 0.1%, 0.2%, 0.3%, 0.4%) of MCNF. The results show that carbon nanotubes are easier to deposit to the negative electrode, and the higher the content of polycarboxylate superplasticizer, the more obvious the dispersity of MCNF in alkaline environment. The dynamic compressive strength of MCNF concrete was 14.0-35.5% higher than that of untreated concrete, and reached the maximum when the MCNF content was about 0.3%. The MCNF was wrapped in concrete matrix and promoted hydration reaction of interface between cement and MCNF from microscopic observation. The addition of MCNF could increase the porosity. The volume percentage of ≥ 100 nm pore decreased first and then increased. Reasons for the improvement strength of MCNF concrete is that the bridging effect is stronger with the increase of MCNF content (≤ 0.3%) and limited when the MCNF content is equal to 0.4%. MCNF concrete could be used in actual engineering with high requirements for dynamic load.

14.
Front Plant Sci ; 13: 864316, 2022.
Article in English | MEDLINE | ID: mdl-35685024

ABSTRACT

The distribution range of plants is usually related to their competitiveness. The competitive ability between common widespread, which are generally considered to be invasive, and common endemic species, is still not very clear. Five plant communities were monitored in the field to compare the competitive abilities of widespread species, Phragmites australis, and endemic species, Triarrhena lutarioriparia, in the Dongting Lake wetlands. The ratios of individual numbers of T. lutarioriparia to P. australis per square meter were found to be 9:0, 14:1, 10:5, 7:6, and 0:11 in the five respective communities. A manipulation experiment was then performed with five planting modes (T. lutarioriparia: P. australis was 4:0, 3:1, 2:2, 1:3, and 0:4, respectively). Results from field monitoring showed that the two plant species exhibited similar decreased survival percentages during flooding. P. australis had higher aboveground biomass before the flooding and a higher relative elongation rate, whereas T. lutarioriparia had higher aboveground biomass after flooding and a higher relative growth rate (RGR). P. australis had a higher competitive ability than T. lutarioriparia before and after the flooding. The manipulation experiment revealed that P. australis had a higher survival percentage than T. lutarioriparia, with no differences in plant biomass, RGR, and the relative elongation rate between the two species. P. australis was found to have a higher competitive ability than T. lutarioriparia in the early growing stage and a lower competitive ability in the middle and later stages. The relative yield total in the field monitoring and manipulation experiment was 1, indicating that T. lutarioriparia and P. australis occupied different niches in the experimental conditions. It was concluded that, compared with T. lutarioriparia, P. australis has a higher competitive ability in submerged habitats and a lower competitive ability in the non-submerged habitat. The niche differences between the two species enabled their coexistence in the Dongting Lake wetlands with seasonal flooding.

15.
ACS Omega ; 7(9): 7912-7919, 2022 Mar 08.
Article in English | MEDLINE | ID: mdl-35284708

ABSTRACT

Liquid metals (LMs) are playing an increasingly important role in the fields of flexible devices, electronics, and thermal management due to their low melting point and excellent thermal and electrical conductivity, and the transformation of LMs in deionized water has recently received much attention. In this paper, we investigate the transformation process of EGaIn microspheres in deionized water and propose a two-step process of microspherical transformation, whereby the microspheres are first deformed into a spindle shape and then into lamellar nanorods. It is also shown that the growth of GaOOH crystals drives the transformation. Based on this result, EGaIn microspheres with controllable transformation could be prepared, such as spindle or lamellar rod shapes, extending the application area of LMs.

16.
Mikrochim Acta ; 189(1): 46, 2022 01 05.
Article in English | MEDLINE | ID: mdl-34985727

ABSTRACT

Wearable film-based smart biosensors have been developed for real-time biomolecules detection. Particularly, interfacial co-assembly of reduced graphene oxide-prussian blue (PB-RGO) film through electrostatic interaction has been systematically studied by controllable pH values, achieving optimal PB-RGO nanofilms at oil/water (O/W) phase interface driven by minimization of interfacial free energy for wearable biosensors. As a result, as-prepared wearable biosensors of PB-RGO film could be easily woven into fabrics, exhibiting excellent glucose sensing performance in amperometric detection with a sensitivity of 27.78 µA mM-1 cm-2 and a detection limit of 7.94 µM, as well as impressive mechanical robustness of continuously undergoing thousands of bending or twist. Moreover, integrated wearable smartsensing system could realize remotely real-time detection of biomarkers in actual samples of beverages or human sweat via cellphones. Prospectively, interfacial co-assembly engineering driven by pH-induced electrostatic interaction would provide a simple and efficient approach for acquiring functional graphene composites films, and further fabricate wearable smartsensing devices in health monitoring fields.


Subject(s)
Biosensing Techniques , Electrochemical Techniques , Ferrocyanides/chemistry , Glucose/analysis , Graphite/chemistry , Wearable Electronic Devices , Delivery of Health Care , Humans , Particle Size , Surface Properties
17.
Sci Rep ; 12(1): 907, 2022 Jan 18.
Article in English | MEDLINE | ID: mdl-35042890

ABSTRACT

Three kinds of nano-concrete, i.e., 2.0% nano-SiO2 doped, 2.0% nano-CaCO3 doped and 1.0% nano-SiO2-1.0% nano-CaCO3 co-doped concretes (NS, NC, NSC) were prepared for a study on static property and dynamic property under different strain rates (50-130 s-1) using HYY series hydraulic servo test system and Φ100 mm split Hopkinson pressure bar test system, and a comparison with plain concrete (PC) as well. The results have shown that under static load, as compared with PC, NC has both strength and elastic modulus increased obviously, while NS has strength decreased and elastic modulus increased, and under dynamic load, there is an obvious strain rate effect for the dynamic compressive strength, impact toughness, energy dissipation and impact failure mode of concrete. Under the same strain rate, the dynamic compressive strength, peak strain, impact toughness and energy dissipation of NC are significantly increased, while its dynamic elastic modulus is decreased. Compared with PC, NS has dynamic compressive strength, peak strain, impact toughness and energy dissipation decreased, and dynamic elastic modulus increased, NC has static and dynamic mechanical properties improved, NS has static and dynamic mechanical properties weakened, and NSC is between PC and NC in static and dynamic mechanical properties, but generally improved. Doped with nano-CaCO3, NC has compactness improved, weak areas reduced, and pore size distribution optimized, while doped with nano-SiO2, NS has obvious internal weak areas, with pore structure degraded.

18.
Front Microbiol ; 12: 675020, 2021.
Article in English | MEDLINE | ID: mdl-34163451

ABSTRACT

Cronobacter sakazakii (C. sakazakii) is an emerging opportunistic foodborne pathogen that can cause neonatal necrotizing enterocolitis, meningitis, sepsis in neonates and infants with a relatively high mortality rate. Bacterial transcytosis across the human brain microvascular endothelial cells (HBMEC) is vital for C. sakazakii to induce neonatal meningitis. However, few studies focus on the mechanisms by which C. sakazakii translocates HBMEC. In this study, the translocation processes of C. sakazakii on HBMEC were explored. C. sakazakii strains could effectively adhere to, invade and intracellularly survive in HBMEC. The strain ATCC 29544 exhibited the highest translocation efficiency across HBMEC monolayer among four tested strains. Bacteria-contained intracellular endosomes were detected in C. sakazakii-infected HBMEC by a transmission electron microscope. Endocytosis-related proteins CD44, Rab5, Rab7, and LAMP2 were increased after infection, while the level of Cathepsin L did not change. C. sakazakii induced TLR4/NF-κB inflammatory signal pathway activation in HBMEC, with increased NO production and elevated mRNA levels of IL-8, IL-6, TNF-α, IL-1ß, iNOS, and COX-2. C. sakazakii infection also caused LDH release, caspase-3 activation, and HBMEC apoptosis. Meanwhile, increased Dextran-FITC permeability and decreased trans epithelial electric resistance indicated that C. sakazakii disrupted tight junction of HBMEC monolayers, which was confirmed by the decreased levels of tight junction-related proteins ZO-1 and Occludin. These findings suggest that C. sakazakii induced intracellular bacterial endocytosis, stimulated inflammation and apoptosis, disrupted monolayer tight junction in HBMEC, which all together contribute to bacterial translocation.

19.
Food Chem ; 351: 129284, 2021 Jul 30.
Article in English | MEDLINE | ID: mdl-33640773

ABSTRACT

Coating damage destroys the integrity features critical for maintaining the modified atmosphere inside the fruit. In this study, we developed a self-healing edible coating that maintains its barrier properties for extending the shelf life of strawberries. The coating was fabricated via the layer-by-layer assembly of chitosan (CS) and sodium alginate (SA). (SA/CS)3 formed by three assembly cycles could completely heal the visibly damaged area by treating water. The mechanical properties and the water and oxygen rates of the healed coating were 97%, 63%, and 95%, respectively, of the intact coating. (SA/CS)3 coating effectively delayed strawberry deterioration. Moreover, the coating reduced the impact of coating damage on strawberries by restoring the coating barrier properties. The present findings have important implications for solving the reduction in freshness caused by coating damage.


Subject(s)
Edible Films , Food Preservation/methods , Alginates/chemistry , Chitosan/chemistry , Food Quality , Fragaria/chemistry , Fragaria/metabolism , Fruit/chemistry , Fruit/metabolism , Hydrophobic and Hydrophilic Interactions , Oxygen/chemistry , Polyethylene Terephthalates/chemistry , Tensile Strength , Water/chemistry
20.
ACS Appl Mater Interfaces ; 13(5): 6699-6709, 2021 Feb 10.
Article in English | MEDLINE | ID: mdl-33523647

ABSTRACT

Driven by the evolution of electronic packaging technology for high-dense integration of high-power, high-frequency, and multi-function devices in modern electronics, thermal management materials have become a crucial component for guaranteeing the stable and reliable operation of devices. Because of its admirable in-plane thermal conductivity, graphene is considered as a desired thermal conductor. However, the promise of graphene films has been greatly weakened as the existence of grain boundaries lead to a high extent of phonon scattering. Here, a stitching strategy is adopted to fabricate an rGO/g-C3N4 film, where 2D g-C3N4 works as a linker to covalently connect adjacent rGO sheets for expanding the size of graphene and forming an in-plane rGO/g-C3N4 heterostructure. The in-plane thermal conductivity of the rGO/g-C3N4 film reaches 41.2 W m-1 K-1 at a g-C3N4 content of only 1 wt %, which increased by 17.3% compared to pristine rGO. The interfaced thermal resistance between rGO and g-C3N4 is further examined by non-equilibrium molecular dynamics simulations. Furthermore, owing to the unique light absorption and welding ability of g-C3N4, the rGO/g-C3N4 film presents superior solar-thermal and electric-thermal responses to controllably regulate the chip temperature against overcooling. This work provides a facile approach to construct a large-sized rGO sheet and combines heat dissipation and heating capability in the same thermal management material for future electronics.

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