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Preserving Mesoporosity in Type III Porous Liquids through Dual-layer Surface Weaving. Angew Chem Int Ed Engl 2024:e202405288. [PMID: 38588044 DOI: 10.1002/anie.202405288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/10/2024]
Abstract
The fundamental limitation for pore preservation in a Type III porous liquid (T3PL) is the need for a small aperture from the porous filler to realize size exclusion of a bulky solvent. We present a dual-layer surface weaving strategy that can disregard this limitation and achieve micro- and mesoporous metal-organic framework (MOF)-based T3PLs even with apertures much larger than the solvent molecules. By first weaving a tight network of poly(tert-butyl methacrylate) on the MOF surface, the poly(dimethylsiloxane) (PDMS) solvent can be effectively excluded from the pores while smaller guest molecules such as CO2, C2H4, and H2O can freely access the interior, as confirmed by low-pressure adsorption isotherms. Further application of a PDMS-containing polymer coating helps lower the viscosity of the PL due to increased particle dispersibility. This strategy has resulted in the successful construction of T3PLs with aperture sizes up to 3.1 nm.
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Understanding Gut Sensations: Irritable Bowel Syndrome and Diagnostic Fluidity in Danish Clinical Practice. Med Anthropol 2024; 43:174-187. [PMID: 37682635 DOI: 10.1080/01459740.2023.2248354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Irritable bowel syndrome (IBS) is a prevalent health challenge in a Danish welfare context. Drawing on ethnographic fieldwork at two Danish gastroenterology clinics, and inspired by Charles E. Rosenberg's idea of styles of explaining widespread diseases, we outline three styles of understanding and treating gut trouble in daily clinical work: "The microbial gut," "the mindful gut," and "the lifestyled gut." Moreover, we suggest the concept of fluidity to characterize IBS as a diagnostic category that allows clinicians and patients to operate through complex understandings of permeable boundaries between body, mind, and environment to negotiate personalized solutions for embodied gut sensations.
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Biophysical Interaction Landscape of Mycobacterial Mycolic Acids and Phenolic Glycolipids with Host Macrophage Membranes. ACS APPLIED BIO MATERIALS 2023; 6:5555-5562. [PMID: 38015441 DOI: 10.1021/acsabm.3c00748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Lipidic adjuvant formulations consisting of immunomodulatory mycobacterial cell wall lipids interact with host cells following administration. The impact of this cross-talk on the host membrane's structure and function is rarely given enough consideration but is imperative to rule out nonspecific perturbation underlying the adjuvant. In this work, we investigated changes in the plasma membranes of live mammalian cells after exposure to mycobacterial mycolic acid (MA) and phenolic glycolipids, two strong candidates for lipidic adjuvant therapy. We found that phenolic glycolipid 1 softened the plasma membrane, lowering membrane tension and stiffness, but MA did not significantly change the membrane characteristics. Further, phenolic glycolipid 1 had a fluidizing impact on the host plasma membrane, increasing the fluidity and the abundance of fluid-ordered-disordered coexisting lipid domains. Notably, lipid diffusion was not impacted. Overall, MA and, to a lesser extent, phenolic glycolipid 1, due to minor disruption of host cell membranes, may serve as appropriate lipids in adjuvant formulations.
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The asymmetric plasma membrane-A composite material combining different functionalities?: Balancing Barrier Function and Fluidity for Effective Signaling. Bioessays 2023; 45:e2300116. [PMID: 37712937 DOI: 10.1002/bies.202300116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 09/16/2023]
Abstract
One persistent puzzle in the life sciences is the asymmetric lipid composition of the cellular plasma membrane: while the exoplasmic leaflet is enriched in lipids carrying predominantly saturated fatty acids, the cytoplasmic leaflet hosts preferentially lipids with (poly-)unsaturated fatty acids. Given the high energy requirements necessary for cells to maintain this asymmetry, the question naturally arises regarding its inherent benefits. In this paper, we propose asymmetry to represent a potential solution for harmonizing two conflicting requirements for the plasma membrane: first, the need to build a barrier for the uncontrolled influx or efflux of substances; and second, the need to form a fluid and dynamic two-dimensional substrate for signaling processes. We hence view here the plasma membrane as a composite material, where the exoplasmic leaflet is mainly responsible for the functional integrity of the barrier and the cytoplasmic leaflet for fluidity. We reinforce the validity of the proposed mechanism by presenting quantitative data from the literature, along with multiple examples that bolster our model.
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Effects of kidney perfusion on renal stiffness and tissue fluidity measured with tomoelastography in an MRI-compatible ex vivo model. Front Bioeng Biotechnol 2023; 11:1236949. [PMID: 38026891 PMCID: PMC10665518 DOI: 10.3389/fbioe.2023.1236949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/27/2023] [Indexed: 12/01/2023] Open
Abstract
Stiffness plays a vital role in diagnosing renal fibrosis. However, perfusion influences renal stiffness in various chronic kidney diseases. Therefore, we aimed to characterize the effect of tissue perfusion on renal stiffness and tissue fluidity measured by tomoelastography based on multifrequency magnetic resonance elastography in an ex vivo model. Five porcine kidneys were perfused ex vivo in an MRI-compatible normothermic machine perfusion setup with adjusted blood pressure in the 50/10-160/120 mmHg range. Simultaneously, renal cortical and medullary stiffness and fluidity were obtained by tomoelastography. For the cortex, a statistically significant (p < 0.001) strong positive correlation was observed between both perfusion parameters (blood pressure and resulting flow) and stiffness (r = 0.95, 0.91), as well as fluidity (r = 0.96, 0.92). For the medulla, such significant (p < 0.001) correlations were solely observed between the perfusion parameters and stiffness (r = 0.88, 0.71). Our findings demonstrate a strong perfusion dependency of renal stiffness and fluidity in an ex vivo setup. Moreover, changes in perfusion are rapidly followed by changes in renal mechanical properties-highlighting the sensitivity of tomoelastography to fluid pressure and the potential need for correcting mechanics-derived imaging biomarkers when addressing solid structures in renal tissue.
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In-Line Detection of Bed Fluidity in Gas-Solid Fluidized Beds Using Near-Infrared Spectroscopy. Pharmaceutics 2023; 15:2246. [PMID: 37765215 PMCID: PMC10537685 DOI: 10.3390/pharmaceutics15092246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/23/2023] [Accepted: 08/28/2023] [Indexed: 09/29/2023] Open
Abstract
A novel approach was developed to detect bed fluidity in gas-solid fluidized beds using diffuse reflectance near-infrared (NIR) spectroscopy. Because the flow dynamics of gas and solid phases are closely associated with the fluidization state, the fluidization quality can be evaluated through hydrodynamic characterization. In this study, the baseline level of NIR spectra was used to quantify the voidage of the fluidized bed. Two indicators derived from the NIR baseline fluctuation profiles were investigated to characterize bed fluidity, named bubble proportion and skewness. To establish a robust fluidity evaluation method, the relationships between the indicators and bed fluidity were investigated under different conditions firstly, including static bed height and average particle size. Then, a generalized threshold was identified to distinguish poor and good bed fluidity, ensuring that the probability of the α- and β-errors was less than 15% regardless of material conditions. The results show that both indicators were sensitive to changes in bed fluidity under the investigated conditions. The indicator of skewness was qualified to detect bed fluidity under varied conditions with a robust threshold of 1.20. Furthermore, the developed NIR method was successfully applied to monitor bed fluidity and for early warning of defluidization in a laboratory-scale fluidized bed granulation process.
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Effect of Low Light on Photosynthetic Performance of Tomato Plants-Ailsa Craig and Carotenoid Mutant Tangerine. PLANTS (BASEL, SWITZERLAND) 2023; 12:3000. [PMID: 37631211 PMCID: PMC10459318 DOI: 10.3390/plants12163000] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/20/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023]
Abstract
The effects of a five-day treatment with low light intensity on tomato plants-Ailsa Craig and tangerine mutant-at normal and low temperatures and after recovery for three days under control conditions were investigated. The tangerine tomato, which has orange fruits, yellowish young leaves, and pale blossoms, accumulates prolycopene rather than all-trans lycopene. We investigated the impact of low light at normal and low temperatures on the functioning and effectiveness of photosynthetic apparatuses of both plants. The photochemical activities of Photosystem I (PSI) and Photosystem II (PSII) were assessed, and the alterations in PSII antenna size were characterized by evaluating the abundance of PSII-associated proteins Lhcb1, Lhcb2, CP43, and CP47. Alterations in energy distribution and interaction of both photosystems were analyzed using 77K fluorescence. In Aisla Craig plants, an increase in thylakoid membrane fluidity was detected during treatment with low light at a low temperature, while for the tangerine mutant, no significant change was observed. The PSII activity of thylakoids from mutant tangerine was more strongly inhibited by treatment with low light at a low temperature while low light barely affected PSII in Aisla Craig. The obtained data indicated that the observed differences in the responses of photosynthetic apparatuses of Ailsa Craig and tangerine when exposed to low light intensity and suboptimal temperature were mainly related to the differences in sensitivity and antenna complexes of PSII.
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Molecular and biophysical features of hippocampal "lipid rafts aging" are modified by dietary n-3 long-chain polyunsaturated fatty acids. Aging Cell 2023; 22:e13867. [PMID: 37254617 PMCID: PMC10410061 DOI: 10.1111/acel.13867] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/25/2023] [Accepted: 04/29/2023] [Indexed: 06/01/2023] Open
Abstract
"Lipid raft aging" in nerve cells represents an early event in the development of aging-related neurodegenerative diseases, such as Alzheimer's disease. Lipid rafts are key elements in synaptic plasticity, and their modification with aging alters interactions and distribution of signaling molecules, such as glutamate receptors and ion channels involved in memory formation, eventually leading to cognitive decline. In the present study, we have analyzed, in vivo, the effects of dietary supplementation of n-3 LCPUFA on the lipid structure, membrane microviscosity, domain organization, and partitioning of ionotropic and metabotropic glutamate receptors in hippocampal lipid raffs in female mice. The results revealed several lipid signatures of "lipid rafts aging" in old mice fed control diets, consisting in depletion of n-3 LCPUFA, membrane unsaturation, along with increased levels of saturates, plasmalogens, and sterol esters, as well as altered lipid relevant indexes. These changes were paralleled by increased microviscosity and changes in the raft/non-raft (R/NR) distribution of AMPA-R and mGluR5. Administration of the n-3 LCPUFA diet caused the partial reversion of fatty acid alterations found in aged mice and returned membrane microviscosity to values found in young animals. Paralleling these findings, lipid rafts accumulated mGluR5, NMDA-R, and ASIC2, and increased their R/NR proportions, which collectively indicate changes in synaptic plasticity. Unexpectedly, this diet also modified the lipidome and dimension of lipid rafts, as well as the domain redistribution of glutamate receptors and acid-sensing ion channels involved in hippocampal synaptic plasticity, likely modulating functionality of lipid rafts in memory formation and reluctance to age-associated cognitive decline.
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A molecular rotor FLIM probe reveals dynamic coupling between mitochondrial inner membrane fluidity and cellular respiration. Proc Natl Acad Sci U S A 2023; 120:e2213241120. [PMID: 37276406 PMCID: PMC10268597 DOI: 10.1073/pnas.2213241120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 04/13/2023] [Indexed: 06/07/2023] Open
Abstract
The inner mitochondrial membrane (IMM), housing components of the electron transport chain (ETC), is the site for respiration. The ETC relies on mobile carriers; therefore, it has long been argued that the fluidity of the densely packed IMM can potentially influence ETC flux and cell physiology. However, it is unclear if cells temporally modulate IMM fluidity upon metabolic or other stimulation. Using a photostable, red-shifted, cell-permeable molecular-rotor, Mitorotor-1, we present a multiplexed approach for quantitatively mapping IMM fluidity in living cells. This reveals IMM fluidity to be linked to cellular-respiration and responsive to stimuli. Multiple approaches combining in vitro experiments and live-cell fluorescence (FLIM) lifetime imaging microscopy (FLIM) show Mitorotor-1 to robustly report IMM 'microviscosity'/fluidity through changes in molecular free volume. Interestingly, external osmotic stimuli cause controlled swelling/compaction of mitochondria, thereby revealing a graded Mitorotor-1 response to IMM microviscosity. Lateral diffusion measurements of IMM correlate with microviscosity reported via Mitorotor-1 FLIM-lifetime, showing convergence of independent approaches for measuring IMM local-order. Mitorotor-1 FLIM reveals mitochondrial heterogeneity in IMM fluidity; between-and-within cells and across single mitochondrion. Multiplexed FLIM lifetime imaging of Mitorotor-1 and NADH autofluorescence reveals that IMM fluidity positively correlates with respiration, across individual cells. Remarkably, we find that stimulating respiration, through nutrient deprivation or chemically, also leads to increase in IMM fluidity. These data suggest that modulating IMM fluidity supports enhanced respiratory flux. Our study presents a robust method for measuring IMM fluidity and suggests a dynamic regulatory paradigm of modulating IMM local order on changing metabolic demand.
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Comprehensive Evaluation of the Performance and Benefits of SSA-GGBS Geopolymer Mortar. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16114137. [PMID: 37297270 DOI: 10.3390/ma16114137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 05/12/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023]
Abstract
The activity of sewage sludge ash (SSA) is not high; ground granulated blast slag (GGBS) has a high calcium oxide content that can accelerate polymerization rates and exhibit better mechanical performance. In order to improve the engineering application of SSA-GGBS geopolymer, it is necessary to conduct a comprehensive evaluation of its performance and benefits. In this study, the fresh properties, mechanical performance and benefits of geopolymer mortar with different SSA/GGBS, modulus and Na2O contents were studied. Taking the economic and environmental benefits, working performance and mechanical performance of mortar as evaluation indexes, the entropy weight TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) comprehensive evaluation method is used to evaluate the geopolymer mortar with different proportions. The results show that as SSA/GGBS increases, the workability of mortar decreases, the setting time first increases and then decreases, and the compressive strength and flexural strength decrease. By appropriately increasing the modulus, the workability of the mortar decreases and more silicates are introduced, resulting in increased strength in the later stage. By appropriately increasing the Na2O content, the volcanic ash activity of SSA and GGBS is better stimulated, the polymerization reaction is accelerated, and the early strength increases. The highest Ic (integrated cost index, Ctfc28) of geopolymer mortar is 33.95 CNY/m3/MPa, and the lowest is 16.21 CNY/m3/MPa, which is at least 41.57% higher than that of ordinary Portland cement (OPC). The minimum Ie (embodied CO2 index, Ecfc28) is 6.24 kg/m3/MPa, rising up to 14.15 kg/m3/MPa, which is at least 21.39% lower than that of OPC. The optimal mix ratio is a water-cement ratio of 0.4, a cement-sand ratio of 1.0, SSA/GGBS of 2/8, a modulus content of 1.4, and an Na2O content of 10%.
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Effect of Ultrasonic Vibration on Microstructure and Fluidity of Aluminum Alloy. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16114110. [PMID: 37297244 DOI: 10.3390/ma16114110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 05/12/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
The effect of ultrasonic vibration on the fluidity and microstructure of cast aluminum alloys (AlSi9 and AlSi18 alloys) with different solidification characteristics was investigated. The results show that ultrasonic vibration can affect the fluidity of alloys in both solidification and hydrodynamics aspects. For AlSi18 alloy without dendrite growing solidification characteristics, the microstructure is almost not influenced by ultrasonic vibration, and the influence of ultrasonic vibration on its fluidity is mainly in hydrodynamics aspects. That is, appropriate ultrasonic vibration can improve fluidity by reducing the flow resistance of the melt, but when the vibration intensity is high enough to induce turbulence in the melt, the turbulence will increase the flow resistance greatly and decrease fluidity. However, for AlSi9 alloy, which obviously has dendrite growing solidification characteristics, ultrasonic vibration can influence solidification by breaking the growing α (Al) dendrite, consequently refining the solidification microstructure. Ultrasonic vibration could then improve the fluidity of AlSi9 alloy not only from the hydrodynamics aspect but also by breaking the dendrite network in the mushy zone to decrease flow resistance.
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The effect of fatigue on climbing fluidity and hand movements. Sports Biomech 2023:1-13. [PMID: 36846867 DOI: 10.1080/14763141.2023.2182703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 02/15/2023] [Indexed: 03/01/2023]
Abstract
In rock climbing, climbers use their arms to regulate their posture on the wall, which can lead to localised muscle fatigue. Evidence shows fatigue is the primary cause of falls, but little is known about how fatigue specifically affects climbing rhythm and hand movements. The present study examined climbing fluidity and hand movements on an indoor climbing wall before and after a specific fatiguing protocol. Seventeen climbers completed three repetitions of a challenging climbing route (21 on Ewbank scale) with different levels of localised arm fatigue. Climbers' movements were tracked using 3D motion capture, and their hand actions assessed using notational analysis. Seventy markers were used to create 15 rigid body segments and the participants' centre of mass. The global entropy index was calculated on the path of the participants' centre of mass. Climbers fell more often when fatigued, but there were no significant differences in hip jerk or global entropy index when fatigued. No significant differences were found between the number of exploratory or performatory hand movements with different amounts of fatigue. The results suggest that localised arm fatigue affects a climber's ability to prevent themselves from falling, but it does not specifically affect their fluidity.
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Development of Cemented Paste Backfill with Superfine Tailings: Fluidity, Mechanical Properties, and Microstructure Characteristics. MATERIALS (BASEL, SWITZERLAND) 2023; 16:ma16051951. [PMID: 36903066 PMCID: PMC10004122 DOI: 10.3390/ma16051951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/22/2023] [Accepted: 02/26/2023] [Indexed: 05/27/2023]
Abstract
Previous studies have shown that the effectiveness of superfine tailings cemented paste backfill (SCPB) is influenced by multiple factors. To optimize the filling effect of superfine tailings, the effects of different factors on the fluidity, mechanical properties, and microstructure of SCPB were investigated. Before configuring the SCPB, the effect of cyclone operating parameters on the concentration and yield of superfine tailings was first investigated and the optimal cyclone operating parameters were obtained. The settling characteristics of superfine tailings under the optimum cyclone parameters were further analyzed, and the effect of the flocculant on its settling characteristics was shown in the block selection. Then the SCPB was prepared using cement and superfine tailings, and a series of experiments were carried out to investigate its working characteristics. The flow test results showed that the slump and slump flow of SCPB slurry decreased with increasing mass concentration, which was mainly because the higher the mass concentration, the higher the viscosity and yield stress of the slurry, and thus the worse its fluidity. The strength test results showed that the strength of SCPB was mainly affected by the curing temperature, curing time, mass concentration, and cement-sand ratio, among which the curing temperature had the most significant effect on the strength. The microscopic analysis of the block selection showed the mechanism of the effect of the curing temperature on the strength of SCPB, i.e., the curing temperature mainly affected the strength of SCPB by affecting the hydration reaction rate of SCPB. The slow hydration process of SCPB in a low temperature environment leads to fewer hydration products and a loose structure, which is the fundamental reason for the strength reduction of SCPB. The results of the study have some guiding significance for the efficient application of SCPB in alpine mines.
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Antimicrobial Activity of Quercetin, Naringenin and Catechin: Flavonoids Inhibit Staphylococcus aureus-Induced Hemolysis and Modify Membranes of Bacteria and Erythrocytes. Molecules 2023; 28:molecules28031252. [PMID: 36770917 PMCID: PMC9920354 DOI: 10.3390/molecules28031252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 01/19/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
Search for novel antimicrobial agents, including plant-derived flavonoids, and evaluation of the mechanisms of their antibacterial activities are pivotal objectives. The goal of this study was to compare the antihemolytic activity of flavonoids, quercetin, naringenin and catechin against sheep erythrocyte lysis induced by α-hemolysin (αHL) produced by the Staphylococcus aureus strain NCTC 5655. We also sought to investigate the membrane-modifying action of the flavonoids. Lipophilic quercetin, but not naringenin or catechin, effectively inhibited the hemolytic activity of αHL at concentrations (IC50 = 65 ± 5 µM) below minimal inhibitory concentration values for S. aureus growth. Quercetin increased the registered bacterial cell diameter, enhanced the fluidity of the inner and surface regions of bacterial cell membranes and raised the rigidity of the hydrophobic region and the fluidity of the surface region of erythrocyte membranes. Our findings provide evidence that the antibacterial activities of the flavonoids resulted from a disorder in the structural organization of bacterial cell membranes, and the antihemolytic effect of quercetin was related to the effect of the flavonoid on the organization of the erythrocyte membrane, which, in turn, increases the resistance of the target cells (erythrocytes) to αHL and inhibits αHL-induced osmotic hemolysis due to prevention of toxin incorporation into the target membrane. We confirmed that cell membrane disorder could be one of the direct modes of antibacterial action of the flavonoids.
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Synthesis and Characteristics of a pH-Sensitive Sol-Gel Transition Colloid for Coal Fire Extinguishing. Gels 2023; 9:gels9010069. [PMID: 36661835 PMCID: PMC9858249 DOI: 10.3390/gels9010069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 12/31/2022] [Accepted: 01/11/2023] [Indexed: 01/18/2023] Open
Abstract
Coal fires, most of which are triggered by the spontaneous combustion of coal, cause a huge waste of resources and release poisonous and harmful substances into the environment, seriously threatening the safety of industrial production. Gel flame retardant plays a core role in coal fire prevention and extinguishing. Most gel flame retardants used in coal fires possess good sealing and oxygen isolation properties, but it is difficult for them to flow deep into fire areas due to their low fluidity. Some fire extinguishing agents with good fluidity lack leak-blocking performance. In order to simultaneously improve the fluidity, leakage sealing, and oxygen isolation effects of coal fire extinguishing colloids, a novel, pH-sensitive, sol-gel transition colloid was prepared using low methoxyl pectin (LMP), calcium bentonite (Ca-Bt), sodium bentonite (Na-Bt), and water as the main components. When the initial sol-state colloid absorbed acid gas products from coal combustion, the pH value decreased and a large amount of Ca2+ in Ca-Bt precipitated, thus immediately growing calcium bridges with LMP molecules that formed a three-dimensional network structure for gelation. The optimum ratio of the new colloid was determined through X-ray diffraction, tube inversion, shock shear-temperature scanning, and genetic algorithm. By testing the fire extinguishing performance of the colloid, the findings proved that the product had good oxygen isolation performance, strong adhesion ability, high thermal stability, and strong inhibition effects on coal combustion.
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Investigation on Roles of Packing Density and Water Film Thickness in Synergistic Effects of Slag and Silica Fume. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8978. [PMID: 36556782 PMCID: PMC9781019 DOI: 10.3390/ma15248978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/28/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
Abstract
The ternary blended cement with finer slag and silica fume (SF) could improve the packing density (PD) through the filling effect. The excess water (water more than needed for filling into voids between the cement particles) can be released to improve the fresh properties and densify the microstructure which is beneficial for improving the hardened properties. To verify the hypothesis and reveal how and why (cement + slag + SF) the ternary blends could bring such advantages, the binder pastes incorporating slag and SF with various water-to-binder ratios were produced to determine the PD experimentally. To evaluate the optimum water demand (OWD) for maximum wet density, the influence of the dispersion state of the binder on PD was investigated using the wet packing density approach. The effect of PD of various binary and ternary binder systems on water film thickness (WFT), fluidity, setting time, and compressive strength development of cement paste was also investigated. The results show that the ternary blends could improve the PD and decrease the water film thickness (WFT). The enhanced PD and altered WFT are able to increase fluidity and compressive strength. The ternary blends could improve the compressive strengths by increasing PD and exerting nucleation and pozzolanic effects.
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[An evaluation method for physical properties of medicinal film and its application in screening film formulation of Trillium tschonoskii total saponins]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 2022; 47:6615-6623. [PMID: 36604910 DOI: 10.19540/j.cnki.cjcmm.20220705.303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
At present, the evaluation methods for pharmaceutical properties of Chinese medicinal films have many problems, such as poor objectivity for the indexes and no quantitative and standardized evaluation methods. This study established a new method using three important physical property parameters, i.e., flow index, weight loss rate, and elongation rate, which were closely related to the pharmaceutical properties of films. On this basis, the above parameters were taken as indicators to optimize the film formulation of Trillium tschonoskii total saponins and verify the feasibility and suitability of the established method and parameters in formulation optimization. A self-made flow distance detection device and a viscometer were used to measure and characterize the fluidity, where the flow index refers to the ratio of the flow distance per unit time to the viscosity. The weight loss rate was measured by the 3 M transpore~(TM) surgical tape. The film-forming property was characterized by the weight loss rate of the sample within a certain period of time. An electronic tension machine was employed to measure the elongation rate after drying, which was used to characterize the ductility of the film. The results showed that the established method for the determination of flow index, weight loss rate, and elongation rate was stable and reliable. The optimal film formulation of T. tschonoskii total saponins could be obtained by optimization with those indicators. As demonstrated, the above evaluation indicators(flow index, weight loss rate, and elongation rate) can guide the optimization and design of formulation, and the new evaluation method constructed based on this shows a good application prospect in formulation optimization and formulation quality evaluation of medicinal films.
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Preparation and Investigation of Spherical Powder Made from Corrosion-Resistant 316L Steel with the Addition of 0.2% and 0.5% Ag. MATERIALS (BASEL, SWITZERLAND) 2022; 15:7887. [PMID: 36431378 PMCID: PMC9695185 DOI: 10.3390/ma15227887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 10/27/2022] [Accepted: 11/05/2022] [Indexed: 06/16/2023]
Abstract
The paper describes the production and study of spherical powder made from corrosion-resistant 316L steel with the addition of 0.2% and 0.5% Ag. The study of granulometric composition, morphology, fluidity and bulk density, phase composition, microhardness and impurity composition of the spherical powders was carried out. The study showed compliance of the spherical powders with the requirements for powders used for additive manufacturing. The fluidity of the powders was 17.9 s, and the bulk density was 3.76 g/cm3. The particles have a spherical shape with a minimum number of defects and an austenitic-ferritic structure. The study of the phase composition of ingots, wires and powders showed that the ingot structure of all samples consists of austenite. According to the results of studies of the phase composition of the wire, there is a decrease in γ-Fe and an increase in α-Fe and σ-NiCr in going from wire No. 1 to wire No. 3. According to the results of studies of the phase composition of the powder particles, there are three phases, γ-Fe, α-Fe, and Fe3O4. The study of microhardness showed a decrease in HV depending on the increase in silver. The hardness of the powder is lower than that of the ingot by 16-24% due to the presence of a ferritic phase in the powder. As a result of plasma spraying, an increase in residual oxygen is observed, which is associated with the oxidation of the melt during plasma dispersion. The amount of nitrogen and sulfur does not change, while the amount of carbon and hydrogen decreases, and the impurities content corresponds to the standards for corrosion-resistant steel. Qualitative and quantitative analysis of the silver content in the samples indicates that it was not affected by the stages involved in obtaining the spherical powder.
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Effect of Distigmasterol-Modified Acylglycerols on the Fluidity and Phase Transition of Lipid Model Membranes. MEMBRANES 2022; 12:membranes12111054. [PMID: 36363609 PMCID: PMC9698068 DOI: 10.3390/membranes12111054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/18/2022] [Accepted: 10/25/2022] [Indexed: 05/10/2023]
Abstract
Plant sterols are known for their health-promoting effects, lowering blood cholesterol levels and alleviating cardiovascular disease. In this work, we continue our research on the asymmetric acylglycerols in which fatty acid residues are replaced by two stigmasterol residues in sn-1 and sn-2 or sn-2 and sn-3 positions as new thermostable carriers of phytosterols for their potential application in foods or as components of new liposomes in the pharmaceutical industry. The aim of this manuscript was to compare and analyze the effects of four distigmasterol-modified acylglycerols (dStigMAs) on the fluidity and the main phase transition temperature of the model phospholipid membrane. Their properties were determined using differential scanning calorimetry (DSC), steady-state fluorimetry and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The determination of the effect of the tested compounds on the mentioned physicochemical parameters of the model membranes will allow for the determination of their properties and stability, which is essential for their practical application. The results indicated that all compounds effect on the physicochemical properties of the model membrane. The degree of these changes depends on the structure of the compound, especially the type of linker by which stigmasterol is attached to the glycerol backbone, as well as on the type of hydrocarbon chain.
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Investigation of Fluidity and Strength of Enhanced Foam-Cemented Paste Backfill. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15207101. [PMID: 36295169 PMCID: PMC9605369 DOI: 10.3390/ma15207101] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 05/27/2023]
Abstract
To solve the problems of high cement dosage and poor fluidity of conventional cemented paste backfill (CPB) materials, the fluidity and strength properties of foam-cemented paste backfill (FCPB) were studied in combination. Based on determining the optimum contents of a foaming agent and a foam stabilizer, FCPB density was measured. To investigate the fluidity and strength of FCPB under different foam contents (0%, 5%, 10%, 15%, 20%, 25%, 30%, and 40%), different solid contents (75 wt.% and 77 wt.%), and different cement-tailing ratios (1:4 and 1:5), spread tests and unconfined compressive strength (UCS) tests were conducted. In addition, the FCPB microstructure was analyzed by scanning electron microscopy (SEM). The results indicate that the optimum combination dosages of sodium lauryl sulfate (K12) and sodium carboxymethyl cellulose (CMC) are 0.5 g/L and 0.2 g/L. The density decreases with the foam content (FC), but the fluidity and strength of the FCPB increase first and then decrease with the FC. In addition, the microstructure analysis explains the enhanced strength of FCPB by adding foam. These results contribute to further understanding the effect of foam content on the fluidity and strength of the FCPB.
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Novel O-Methylglucoside Derivatives of Flavanone in Interaction with Model Membrane and Transferrin. MEMBRANES 2022; 12:978. [PMID: 36295737 PMCID: PMC9609356 DOI: 10.3390/membranes12100978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 10/05/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Flavonoids were biotransformed using various microorganisms, in order to obtain new compounds with potentially high biological activity. The aim of this work was to determine and compare the biological activity of four novel 6-methylflavanone O-methylglucosides. The tested compounds have the same flavonoid core structure and an attached O-methylglucose and hydroxyl group at different positions of ring A or B. The studies on their biological activity were conducted in relation to phosphatidylcholine membrane, erythrocytes and their membrane, and with human transferrin. These studies determined the compounds' toxicity and their impact on the physical properties of the membranes. Furthermore, the binding ability of the compounds to holo-transferrin was investigated. The obtained results indicate that used compounds bind to erythrocytes, change their shape and decrease osmotic fragility but do not disrupt the membrane structure. Furthermore, the used compounds ordered the area of the polar heads of lipids and increased membrane fluidity. However, the results indicate the binding of these compounds in the hydrophilic region of the membranes, like other flavonoid glycosides. The used flavanones formed complexes with transferrin without inducing conformational changes in the protein's structure. The relationship between their molecular structure and biological activity was discussed.
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Effects of Capsule Type on the Characteristics of Cement Mortars Containing Powder Compacted Capsules. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6773. [PMID: 36234114 PMCID: PMC9571192 DOI: 10.3390/ma15196773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/14/2022] [Accepted: 09/24/2022] [Indexed: 06/16/2023]
Abstract
Several studies have been reported on self-healing concrete using bacteria, admixtures, and microcapsules. Among these self-healing techniques, encapsulating cement-based materials is advantageous in that large amounts of self-healing material can be contained in a capsule and released at the cracked site for a targeted reaction. This study produced a powder compacted capsule (PCC) using the droplet and blended manufacturing methods to encapsulate cementitious materials. This study refers to the PCCs as droplet-PCC (D-PCC) and blended-PCC (B-PCC) according to the manufacturing method used. The fluidity, compressive strength, carbonation, drying shrinkage, and water permeability of cement mortar with PCCs were evaluated. The test results show that the flow of the mortar sample using D-PCC was slightly higher than that of the mortar using B-PCC. The compressive strength of the mortar sample with B-PCC was generally higher than that of the mortar sample with D-PCC. The compressive strength of the B-PCC2 sample (with 0.2% of B-PCC) was the highest at all curing ages. This may be because the B-PCC fracture load was higher than that of the D-PCC. In addition, more hydrates were observed in the B-PCC sample than in the D-PCC sample. A crack healing effect was observed in the samples with PCC, regardless of the PCC type. The effect was the greatest in the B-PCC6 sample (with 0.6% of B-PCC). The results of this study provide a reference for the PCC type and mix ratio that would yield the best mechanical properties and crack healing effect.
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Animal-Protein-Based and Synthetic-Based Foamed Mixture Lightweight Soil Doped with Bauxite Tailings: Macro and Microscopic Properties. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6377. [PMID: 36143688 PMCID: PMC9503447 DOI: 10.3390/ma15186377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/13/2022] [Accepted: 05/23/2022] [Indexed: 06/16/2023]
Abstract
In order to explore the effect of the foaming agent type on the properties of foamed mixture lightweight soil mixed with bauxite tailings (FMLSB), low-density (437.5 kg/m3 and 670 kg/m3) and high-density (902.5 kg/m3 and 1170 kg/m3) FMLSB were prepared using protein-based and synthetic-based foaming agents (AF and SF, respectively). The foam stability, micro characteristics, compressive strength, fluidity, and volume of water absorption of the FMLSB were investigated. The results showed that the foam made from AF had better strength and stability compared to SF. The internal pore sizes of both AF- and SF-FMLSB at low density were large, but at high density the internal pore sizes and area porosity of AF-FMLSB were smaller than those of SF-FMLSB. In terms of compressive strength, the compressive strength of AF-FMLSB was improved by 17.5% to 43.2% compared to SF-FMLSB. At low density, the fluidity of AF- and SF-FMLSB is similar, while at high density the fluidity of AF-FMLSB is much higher than that of SF-FMLSB. In addition, the stable volume of water absorption of SF-FMLSB is smaller than that of AF-FMLSB at low density, and the corresponding water resistance is better, but the situation is reversed at high density.
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Multi-frequency magnetic resonance elastography of the pancreas: measurement reproducibility and variance among healthy volunteers. Gastroenterol Rep (Oxf) 2022; 10:goac033. [PMID: 35910246 PMCID: PMC9336557 DOI: 10.1093/gastro/goac033] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/08/2022] [Accepted: 07/05/2022] [Indexed: 12/13/2022] Open
Abstract
Background Patients with chronic pancreatitis often have irreversible pancreatic insufficiency before a clinical diagnosis. Pancreatic cancer is a fatal malignant tumor in the advanced stages. Patients having high risk of pancreatic diseases must be screened early to obtain better outcomes using new imaging modalities. Therefore, this study aimed to investigate the reproducibility of tomoelastography measurements for assessing pancreatic stiffness and fluidity and the variance among healthy volunteers. Methods Forty-seven healthy volunteers were prospectively enrolled and underwent two tomoelastography examinations at a mean interval of 7 days. Two radiologists blindly and independently measured the pancreatic stiffness and fluidity at the first examination to determine the reproducibility between readers. One radiologist measured the adjacent pancreatic slice at the first examination to determine the reproducibility among slices and measured the pancreas at the second examination to determine short-term repeatability. The stiffness and fluidity of the pancreatic head, body, and tail were compared to determine anatomical differences. The pancreatic stiffness and fluidity were compared based on sex, age, and body mass index (BMI). Results Bland–Altman analyses (all P > 0.05) and intraclass correlation coefficients (all >0.9) indicated near perfect reproducibility among readers, slices, and examinations at short intervals. Neither stiffness (P = 0.477) nor fluidity (P = 0.368) differed among the pancreatic anatomical regions. The mean pancreatic stiffness was 1.45 ± 0.09 m/s; the mean pancreatic fluidity was 0.83 ± 0.06 rad. Stiffness and fluidity did not differ by sex, age, or BMI. Conclusion Tomoelastography is a promising and reproducible tool for assessing pancreatic stiffness and fluidity in healthy volunteers.
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Fluidity-Guided Assembly of Au@Pt on Liposomes as a Catalase-Powered Nanomotor for Effective Cell Uptake in Cancer Cells and Plant Leaves. ACS NANO 2022; 16:9019-9030. [PMID: 35709532 DOI: 10.1021/acsnano.2c00327] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The fluidity of the liposomes is essential to nanoparticle-membrane interactions. We herein report a liposomal nanomotor system by controlling the self-assembly behavior of gold core-platinum shell nanoparticles (Au@Pt) on liposomes. Au@Pt can aggregate immediately on fluid-phase dioleoyl-sn-glycero-3-phosphocholine (DOPC) liposomes, forming an uneven distribution. By control of the lipid phase and fluidity, either using pure 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) above its phase transition temperature or adding cholesterol as an adjuvant to DPPC lipids, we precisely control the assembly of Au@Pt on liposomes. Au@Pt maintained high catalase-like activity on the liposomal surface, promoting the decomposition of H2O2 and the movement of the liposomal nanomotors. Finally, we demonstrate that liposomal nanomotors are biocompatible and they can speed up the cellular uptake in mammalian HepG2 cancer cells and Nicotiana tabacum (Nb) plant leaves. This liposomal nanomotor system is expected to be further investigated in biomedicine and plant nanotechnology.
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Preparation and Comprehensive Properties of a High-Radiation-Shielding UHPC by Using Magnetite Fine Aggregate. MATERIALS 2022; 15:ma15030978. [PMID: 35160924 PMCID: PMC8838137 DOI: 10.3390/ma15030978] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/09/2022] [Accepted: 01/18/2022] [Indexed: 02/04/2023]
Abstract
Nuclear technology benefits humans, but it also produces nuclear radiation that harms human health and the environment. Based on the modified Andreasen and Andersen particle packing model for achieving a densely compacted cementitious matrix, a new magnetite ultra-high-performance concrete (MUHPC) was designed using magnetite fine aggregate as a substitute for river sands with 0%, 20%, 40%, 60%, 80%, and 100% replacement ratios. The comprehensive properties of the developed MUHPC were tested and evaluated. These properties were fluidity, static and dynamic compressive strengths, high-temperature performance, antiradiation behaviors, hydration products, and micropore structures. Experimental results indicate that the developed MUHPC has high work performance and static and dynamic mechanical properties. The gamma ray shielding performance of MUHPC substantially improves with increased magnetite fine aggregate. Corresponding with 100% magnetite fine aggregate substitution, the linear attenuation coefficient of MUHPC is enhanced by 56.8% compared with that of ordinary concrete. Magnetite addition does not change the type of cement hydration products but improves the micropore structures of MUHPC and effectively reduces its total porosity and average pore diameter, thereby contributing to its mechanical and radiation shielding properties. The compressive strength and linear attenuation coefficient of the MUHPC can reach 150 MPa and 0.2 cm−1, respectively. In addition, the MUHPC also exhibits superior mechanical and radiation shielding performance at elevated temperatures (<400 °C). Finally, high strength and antiradiation performance support the use of MUHPC in radiation protection materials in the future.
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Study on the Influence of Silica Fume (SF) on the Rheology, Fluidity, Stability, Time-Varying Characteristics, and Mechanism of Cement Paste. MATERIALS (BASEL, SWITZERLAND) 2021; 15:90. [PMID: 35009234 PMCID: PMC8746081 DOI: 10.3390/ma15010090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/08/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
In this study, the rheology, fluidity, stability, and time-varying properties of cement paste with different substitute contents of silica fume (SF) were investigated. The result showed that the effects of SF on macro-fluidity and micro-rheological properties were different under different water-cement ratios. The addition of SF increased the yield stress and plastic viscosity in the range of 2.61-18.44% and 6.66-24.66%, respectively, and reduced the flow expansion in the range of 4.15-18.91%. The effect of SF on cement paste gradually lost its regularity as the w/c ratio increased. The SF can effectively improve the stability of cement paste, and the reduction range of bleeding rate was 0.25-4.3% under different water-cement ratios. The mathematical models of rheological parameters, flow expansion, and time followed the following equations: τ(t) = τ0 + k0t, η(t) = η0eat, and L(t) = L0 - k1t, L(t) = L0 - k1t - a1t2. The SF slowly increased the rheological parameters in the initial time period and reduced the degree of fluidity attenuation, but the effect was significantly enhanced after entering the accelerated hydration period. The mechanism of the above results was that SF mainly affected the fluidity and rheology of the paste through the effect of water film thickness. The small density of SF particles resulted in a low sedimentation rate in the initial suspended paste, which effectively alleviated the internal particle agglomeration effect and enhanced stability. The SF had a dilution effect and nucleation effect during hydration acceleration, and the increase of hydration products effectively increased the plastic viscosity.
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Evaluation of the Physico-Chemical Properties of Liposomes Assembled from Bioconjugates of Anisic Acid with Phosphatidylcholine. Int J Mol Sci 2021; 22:13146. [PMID: 34884953 PMCID: PMC8658227 DOI: 10.3390/ijms222313146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 11/29/2021] [Accepted: 12/02/2021] [Indexed: 12/25/2022] Open
Abstract
The aim of this work was the evaluation of the physico-chemical properties of a new type of liposomes that are composed of DPPC and bioconjugates of anisic acid with phosphatidylcholine. In particular, the impact of modified anisic acid phospholipids on the thermotropic parameters of liposomes was determined, which is crucial for using them as potential carriers of active substances in cancer therapies. Their properties were determined using three biophysical methods, namely differential scanning calorimetry (DSC), steady-state fluorimetry and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). Moreover, temperature studies of liposomes composed of DPPC and bioconjugates of anisic acid with phosphatidylcholine provided information about the phase transition, fluidity regarding chain order, hydration and dynamics. The DSC results show that the main phase transition peak for conjugates of anisic acid with phosphatidylcholine molecules was broadened and shifted to a lower temperature in a concentration- and structure-dependent manner. The ATR-FTIR results and the results of measurements conducted using fluorescent probes located at different regions in the lipid bilayer are in line with DSC. The results show that the new bioconjugates with phosphatidylcholine have a significant impact on the physico-chemical properties of a membrane and cause a decrease in the temperature of the main phase transition. The consequence of this is greater fluidity of the lipid bilayer.
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Response to 'Transgender medicalization and the attempt to evade psychological distress' (Withers 2020) and to Herdzik's (2021) response to Withers. THE JOURNAL OF ANALYTICAL PSYCHOLOGY 2021; 66:837-843. [PMID: 34758136 DOI: 10.1111/1468-5922.12715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Psyche is non-binary and multiple and clinical work in the analytic container must be held in the fluidity of multiplicity. Analysts are called to bring Queer energy to analytical attitude. Queer energy is intrinsically non-conforming and desires to confront a priori concepts in service to the unfolding of the Self. A Queer analytic attitude seeks to blur narrative, deconstruct language and listen deeply for what is emergent in the field. Queer energy is also deeply activating and often results in polarizations of attitude and a failure to hold what is emergent. This response to Withers (2020) and to (Herdzik 2021) is an invitation for all of us to engage our activated complexes around work with transgender issues and the fluidity of the Queer experience. The multiplicity of the Self seeks to be known through analytic process. Consciously held authentic experience of what is emergent and thus unknown is at the core of this process. An analysis capable of holding Queer energy offers a theatre for the exploration of gender identity and its expression.
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Adaptive Membrane Fluidity Modulation: A Feedback Regulated Homeostatic System Hiding in Plain Sight. In Vivo 2021; 35:2991-3000. [PMID: 34697130 PMCID: PMC8627736 DOI: 10.21873/invivo.12594] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 09/26/2021] [Accepted: 09/28/2021] [Indexed: 11/10/2022]
Abstract
The structure of the plasma membrane affects its function. Changes in membrane fluidity with concomitant effects on membrane protein activities and cellular communication often accompany the transition from a healthy to a diseased state. Although deliberate modulation of membrane fluidity with drugs has not been exploited to date, the latest data suggest the "druggability" of the membrane. Azelaic acid esters (azelates) modulate plasma membrane fluidity and exhibit a broad range of immunomodulatory effects in vitro and in vivo. Azelates represent a new class of drugs, membrane active immunomodulators (MAIMs), which use the entire plasma membrane as the target, altering the dynamics of an innate feedback regulated homeostatic system, adaptive membrane fluidity modulation (AMFM). A review of the literature data spanning >200 years supports the notion that molecules in the MAIMs category including known drugs do exert immunomodulatory effects that have been either neglected or dismissed as off-target effects.
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Lipidomic landscape in cancer: Actionable insights for membrane-based therapy and diagnoses. Med Res Rev 2021; 42:983-1018. [PMID: 34719798 DOI: 10.1002/med.21868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 08/18/2021] [Accepted: 10/24/2021] [Indexed: 01/17/2023]
Abstract
Cancer cells display altered cellular lipid metabolism, including disruption in endogenous lipid synthesis, storage, and exogenous uptake for membrane biogenesis and functions. Altered lipid metabolism and, consequently, lipid composition impacts cellular function by affecting membrane structure and properties, such as fluidity, rigidity, membrane dynamics, and lateral organization. Herein, we provide an overview of lipid membranes and how their properties affect cellular functions. We also detail how the rewiring of lipid metabolism impacts the lipidomic landscape of cancer cell membranes and influences the characteristics of cancer cells. Furthermore, we discuss how the altered cancer lipidome provides cues for developing lipid-inspired innovative therapeutic and diagnostic strategies while improving our limited understanding of the role of lipids in cancer initiation and progression. We also present the arcade of membrane characterization techniques to cement their relevance in cancer diagnosis and monitoring of treatment response.
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Enhanced Fluidity of ZL205A Alloy with the Combined Addition of Al-Ti-C and La. MATERIALS 2021; 14:ma14206169. [PMID: 34683760 PMCID: PMC8541223 DOI: 10.3390/ma14206169] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/09/2021] [Accepted: 10/15/2021] [Indexed: 12/03/2022]
Abstract
The effects of Al–Ti–C and La on the fluidity of a ZL205A alloy after separate and combined addition were studied by conducting a fluidity test. The fluidity of the ZL205A alloy first increased and then decreased with the increasing addition of Al–Ti–C and La; it peaked at 0.3% and 0.1% for Al–Ti–C and La, respectively. The combined addition of Al–Ti–C and La led to better fluidity, which increased by 74% compared with the base alloy. The affecting mechanism was clarified through microstructure characterization and a DSC test. The heterogeneous nucleation aided by Al–Ti–C and La, the number of particles in the melt, and the evolution of the solidification range all played a role. Based on the evolution of the fluidity and grain size, the optimal levels of Al–Ti–C and La leading to both high fluidity and small grain size were identified.
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Added Value of Tomoelastography for Characterization of Pancreatic Neuroendocrine Tumor Aggressiveness Based on Stiffness. Cancers (Basel) 2021; 13:cancers13205185. [PMID: 34680334 PMCID: PMC8533708 DOI: 10.3390/cancers13205185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 10/03/2021] [Accepted: 10/13/2021] [Indexed: 12/12/2022] Open
Abstract
Simple Summary The prediction of pancreatic neuroendocrine tumor (PNET) aggressiveness is important for treatment planning. The aim of this study was to evaluate the diagnostic performance of magnetic resonance elastography (MRE) with tomoelastography postprocessing (tomoelastography) in differentiating PNET from healthy pancreatic tissue and to correlate PNET stiffness with aggressiveness using asphericity derived from positron emission tomography (PET) as reference. In this prospective study we showed in a group of 13 patients with PNET that tomoelastography detected PNET by increased stiffness (p < 0.01) with a high diagnostic performance (AUC = 0.96). PNET was positively correlated with PET derived asphericity (r = 0.81). Tomoelastography provides quantitative imaging markers for the detection of PNET and the prediction of greater tumor aggressiveness by increased stiffness. Abstract Purpose: To evaluate the diagnostic performance of tomoelastography in differentiating pancreatic neuroendocrine tumors (PNETs) from healthy pancreatic tissue and to assess the prediction of tumor aggressiveness by correlating PNET stiffness with PET derived asphericity. Methods: 13 patients with PNET were prospectively compared to 13 age-/sex-matched heathy volunteers (CTR). Multifrequency MR elastography was combined with tomoelastography-postprocessing to provide high-resolution maps of shear wave speed (SWS in m/s). SWS of pancreatic neuroendocrine tumor (PNET-T) were compared with nontumorous pancreatic tissue in patients with PNET (PNET-NT) and heathy pancreatic tissue (CTR). The diagnostic performance of tomoelastography was evaluated by ROC-AUC analysis. PNET-SWS correlations were calculated with Pearson’s r. Results: SWS was higher in PNET-T (2.02 ± 0.61 m/s) compared to PNET-NT (1.31 ± 0.18 m/s, p < 0.01) and CTR (1.26 ± 0.09 m/s, p < 0.01). An SWS-cutoff of 1.46 m/s distinguished PNET-T from PNET-NT (AUC = 0.89; sensitivity = 0.85; specificity = 0.92) and a cutoff of 1.49 m/s differentiated pancreatic tissue of CTR from PNET-T (AUC = 0.96; sensitivity = 0.92; specificity = 1.00). The SWS of PNET-T was positively correlated with PET derived asphericity (r = 0.81; p = 0.01). Conclusions: Tomoelastography provides quantitative imaging markers for the detection of PNET and the prediction of greater tumor aggressiveness by increased stiffness.
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Impact of Silibinin A on Bioenergetics in PC12APP sw Cells and Mitochondrial Membrane Properties in Murine Brain Mitochondria. Antioxidants (Basel) 2021; 10:antiox10101520. [PMID: 34679655 PMCID: PMC8533090 DOI: 10.3390/antiox10101520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/21/2021] [Accepted: 09/22/2021] [Indexed: 12/02/2022] Open
Abstract
Age-related multifactorial diseases, such as the neurodegenerative Alzheimer’s disease (AD), still remain a challenge to today’s society. One mechanism associated with AD and aging in general is mitochondrial dysfunction (MD). Increasing MD is suggested to trigger other pathological processes commonly associated with neurodegenerative diseases. Silibinin A (SIL) is the main bioactive compound of the Silymarin extract from the Mediterranean plant Silybum marianum (L.) (GAERTN/Compositae). It is readily available as a herbal drug and well established in the treatment of liver diseases as a potent radical scavenger reducing lipid peroxidation and stabilize membrane properties. Recent data suggest that SIL might also act on neurological changes related to MD. PC12APPsw cells produce low levels of human Aβ and thus act as a cellular model of early AD showing changed mitochondrial function. We investigated whether SIL could affect mitochondrial function by measuring ATP, MMP, as well as respiration, mitochondrial mass, cellular ROS and lactate/pyruvate concentrations. Furthermore, we investigated its effects on the mitochondrial membrane parameters of swelling and fluidity in mitochondria isolated from the brains of mice. In PC12APPsw cells, SIL exhibits strong protective effects by rescuing MMP and ATP levels from SNP-induced mitochondrial damage and improving basal ATP levels. However, SIL did not affect mitochondrial respiration and mitochondrial content. SIL significantly reduced cellular ROS and pyruvate concentrations. Incubation of murine brain mitochondria with SIL significantly reduces Ca2+ induced swelling and improves membrane fluidity. Although OXPHOS activity was unaffected at this early stage of a developing mitochondrial dysfunction, SIL showed protective effects on MMP, ATP- after SNP-insult and ROS-levels in APPsw-transfected PC12 cells. Results from experiments with isolated mitochondria imply that positive effects possibly result from an interaction of SIL with mitochondrial membranes and/or its antioxidant activity. Thus, SIL might be a promising compound to improve cellular health when changes to mitochondrial function occur.
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Fluidity Investigation of Pure Al and Al-Si Alloys. MATERIALS 2021; 14:ma14185372. [PMID: 34576593 PMCID: PMC8472160 DOI: 10.3390/ma14185372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/09/2021] [Accepted: 09/13/2021] [Indexed: 11/17/2022]
Abstract
Fluidity tests of pure aluminum 1070 and Al-Si alloys with Si contents of up to 25% were conducted using a die cast machine equipped with a spiral die. The effects of the channel gap, die temperature, and injection speed on the fluidity were investigated. When the channel gap was small (0.5 mm), the flow length of the 1070 was minimized, and the fluidity increased monotonically at a gradual rate with increasing Si content. In contrast, larger gaps yielded convex fluidity–Si content curves. Additionally, heating the die had less of an influence on the fluidity of the 1070 than on that of the Al-Si alloy. These results are discussed in the context of the peeling of the solidification layer from the die based on the thicknesses of foils and strips cast by melt spinning and roll casting, respectively. At lower Si contents, heat shrinkage was greater and the latent heat was lower. When the heat shrinkage was greater, the solidification layer began to peel earlier, and the heat transfer between the solidification layer and the die became smaller. As a result, the fluidity of the 1070 was greatest when the channel gap was 0.8 mm.
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Mass spectrometry-based untargeted lipidomics reveals new compositional insights into membrane dynamics of Candida albicans under magnesium deprivation. J Appl Microbiol 2021; 132:978-993. [PMID: 34424599 DOI: 10.1111/jam.15265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/16/2021] [Accepted: 08/18/2021] [Indexed: 11/29/2022]
Abstract
AIMS There is growing appreciation in adopting new approaches to disrupt multidrug resistance in human fungal pathogen, Candida albicans. The plasma membrane of C. albicans comprises potential lipid moieties that contribute towards the survival of pathogen and could be utilized as antifungal targets. Considering promising applications of developments in mass spectrometry (MS)-based lipidomics technology, the aim of the study was to analyse lipidome profile and expose lipid-dependent changes in response to Mg deprivation. METHODS AND RESULTS We found that both phosphatidylcholine (PC) and lysophosphatidylcholine (LysoPC) were decreased. Increased flip (inward translocation) in the fluorophore labelled NBD-PC was ascribed to enhanced PC-specific flippase activity. Furthermore, a decrease in phosphatidylethanolamine (PE) leading to altered membrane fluidity and loss of cellular material was prominent. Additionally, we observed decreased phosphatidylglycerol (PG) and phosphatidylinositol (PI) leading to genotoxic stress. Besides, we could detect enhanced levels of phosphatidylserine (PS), diacylglycerol (DAG) and triacylglycerides (TAG). The altered gene expressions of lipid biosynthetic pathway by RT-PCR correlated with the lipidome profile. Lastly, we explored abrogated ionic (Na+ and K+ ) transport across the plasma membrane. CONCLUSIONS We propose that C. albicans exposed to Mg deprivation could reorganize plasma membrane (lipid species, membrane fluidity and ionic transport), and possibly redirected carbon flux to store energy in TAGs as an adaptive stress response. This work unravels several vulnerable targets governing lipid metabolism in C. albicans and pave way for better antifungal strategies. SIGNIFICANCE AND IMPACT OF THE STUDY This study demonstrates that magnesium availability is important when one considers dissecting drug resistance mechanisms in Candida albicans. Through mass spectrometry (MS)-based lipidomics technology, the study analyses lipidome profile and exposes lipid-dependent changes that are vulnerable to magnesium availability and presents an opportunity to employ this new information in improving treatment strategies.
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Ex vivo interaction study of NaYF 4 :Yb,Er nanophosphors with isolated mitochondria. Biotechnol Appl Biochem 2021; 69:920-929. [PMID: 33830536 DOI: 10.1002/bab.2163] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 03/09/2021] [Indexed: 12/14/2022]
Abstract
Ex vivo interaction of NaYF4 :Yb,Er nanophosphors with isolated mitochondria has been investigated. The nanophosphors were synthesized using the hydrothermal method. The synthesized NaYF4 :Yb,Er nanophosphors were characterized for physicochemical properties. The NaYF4 :Yb,Er nanophosphors showed successful upconversion with excitation wavelength lying in the near-infrared region. The effect of synthesized NaYF4 :Yb,Er nanophosphors on mitochondria isolated from the chicken heart tissue was examined through ROS generation capacity, membrane fluidity, and complex II activity. The exposer of NaYF4 :Yb,Er nanophosphors to isolated mitochondria inhibits ROS generation activity as compared to control. The mitochondria membrane fluidity of the lipid bilayer and complex-II activity of mitochondria was observed to be unaltered after the interaction with NaYF4 :Yb,Er nanoparticles. The results confirm that synthesized NaYF4 :Yb,Er nanoparticles can be used as a safe contrast agent.
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Influence of Particle Morphology of Ground Fly Ash on the Fluidity and Strength of Cement Paste. MATERIALS 2021; 14:ma14020283. [PMID: 33430518 PMCID: PMC7826750 DOI: 10.3390/ma14020283] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 11/23/2022]
Abstract
The grinding process has become widely used to improve the fineness and performance of fly ash. However, most studies focus on the particle size distribution of ground fly ash, while the particle morphology is also an important factor to affect the performance of cement paste. This article aims at three different kinds of ground fly ash from the ball mill and vertical mill, and the particle morphology is observed by scanning electron microscopy (SEM) to calculate the spherical destruction (the ratio of spherical particles broken into irregular particles in the grinding process of fly ash), which provides a quantification of the morphology change in the grinding process. The fluidity of cement paste and the strength of cement mortar are tested to study the relation of spherical destruction and fluidity and strength. The results show that the spherical destruction of ground fly ash in a ball mill is more than 80% and that in a vertical mill with a separation system is only 11.9%. Spherical destruction shows a significant relation with the fluidity. To different addition of ground fly ash, the fluidity of cement paste decreases with the increase of spherical destruction. To the strength of cement paste, particle size distribution and spherical destruction are both the key factors. Therefore, spherical destruction is an important measurement index to evaluate the grinding effect of the fly ash mill.
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Influence of Traditional Sporting Games on the Development of Creative Skills in Team Sports. The Case of Football. Front Psychol 2020; 11:611803. [PMID: 33424723 PMCID: PMC7786199 DOI: 10.3389/fpsyg.2020.611803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/25/2020] [Indexed: 11/13/2022] Open
Abstract
The aim of this present study is to investigate the influence of three learning contexts on the development of motor creativity of young footballers (8-9 years old). In team sport, creativity is a fundamental issue because it allows players to adapt in an environment of high social uncertainty. To carry out this work, we suggest a method for assessing motor creativity into ecological situations based on the analysis of praxical communications. Creativity originates from an interaction between divergence and convergence. In our case, the number of communications (fluidity) and the diversity of updated communications (flexibility) are our divergence indicators. Convergence, understood as the ability to make good decisions, is assessed by two expert judges (R > 0.90). Sixty boys' football players (M = 8.67; SD = 0.3) coming from three football clubs participated in this research. The study lasted 2 years. Each year, a team of 10 players from each club participated in the research twice a week for 32 weeks (8 months), these groups attended different training sessions: (a) the control group (n = 20) followed a classical learning; (b) the decoding group (n = 20) attended training focused on learning the praxemes of football; (c) the traditional sporting games group (n = 20) followed a training session that was jointly focused on praxemes and the practice of traditional sporting games. The motor creativity of players and groups was assessed both at the beginning and at the end of the year during football matches. Compared to the control group, in the post-test, the group with the highest fluidity is the decoding group (p < 0.001) and the one with the highest fluidity is the traditional sporting games group. The latter group is also the one with the best convergence (p < 0.001). The results showed that traditional games can help develop players' creative abilities. This research invites us to investigate the complementarity between the different offered training.
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Size of Cells and Physicochemical Properties of Membranes are Related to Flavor Production during Sake Brewing in the Yeast Saccharomyces cerevisiae. MEMBRANES 2020; 10:membranes10120440. [PMID: 33352892 PMCID: PMC7766171 DOI: 10.3390/membranes10120440] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/17/2022]
Abstract
Ethyl caproate (EC) and isoamyl acetate (IA) are key flavor components of sake. Recently, attempts have been made to increase the content of good flavor components, such as EC and IA, in sake brewing. However, the functions of EC and IA in yeast cells remain poorly understood. Therefore, we investigated the effects of EC and IA using cell-sized lipid vesicles. We also investigated lipid vesicles containing EC and/or caproic acid (CA) as well as IA and/or isoamyl alcohol (IAA). CA and IAA are precursors of EC and IA, respectively, and are important flavors in sake brewing. The size of a vesicle is influenced by flavor compounds and their precursors in a concentration-dependent manner. We aimed to establish the conditions in which the vesicles contained more flavors simultaneously and with different ratios. Interestingly, vesicles were largest in a mixture of 50% of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) with 25% EC and 25% CA or a mixture of 50% DOPC with 25% IA and 25% IAA. The impact of flavor additives on membrane fluidity was also studied using Laurdan generalized polarization. During the production process, flavors may regulate the fluidity of lipid membranes.
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Effect of water bath-assisted water extraction on physical and chemical properties of soybean oil body emulsion. Food Sci Nutr 2020; 8:6380-6391. [PMID: 33312524 PMCID: PMC7723176 DOI: 10.1002/fsn3.1921] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 01/11/2023] Open
Abstract
Soybean oil body (SOB), rich in polyunsaturated fatty acids and biologically active substances, is used as a natural emulsifier in food processing. In addition, SOB is healthier than synthetic emulsifiers. However, the physical and chemical properties of the SOB emulsion directly affect its application in food processing. In order to study the effect of water bath extraction (WBAE) on SOBs, the effects of WBAE method on the composition of SOBs, the zeta potential, average particle size, oxidation stability, and viscosity characteristics of SOB emulsions were researched. It was found that both protein and moisture contents of SOB decreased with increasing WBAE temperature; however, lipid content increased. These results were attributed to the exogenous proteins gradually denatured and dissociated with extraction temperature from 60°C to 100°C. Increasing the extraction temperature, the average particle size of the SOB emulsions increased, the oxidative stability was improved, the Zeta potential and viscosity decreased, and the fluidity of emulsions was improved. The SOB extracted at 100°C has broad application prospects in food, and this research is meaningful for supplying fundamental information for selecting proper extraction temperature of SOBs.
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Abstract
Purpose/Aim: The amount of membrane-bound α-crystallin increases significantly with age and cataract formation, accompanied by a corresponding decline in the level of α-crystallin in the lens cytoplasm. The purpose of this research is to evaluate the binding affinity of α-crystallin to the phospholipid membranes as well as the physical properties of the membranes after α-crystallin binding. Materials and Methods: The continuous wave and saturation recovery electron paramagnetic resonance (EPR) methods were used to obtain the information about the binding affinity and the physical properties of the membrane. In this approach, the cholesterol analog spin label CSL was incorporated in the membrane and the binding of α-crystallin to the membrane was monitored by this spin label. Small uni-lamellar vesicles were prepared from 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) with 1% of CSL. The measured membrane properties included the mobility parameter, fluidity, and the oxygen transport parameter. Results: The binding affinity (Ka ) of α-crystallin with the POPC membrane was estimated to be 4.9 ± 2.4 µM-1. The profiles of mobility parameter showed that mobility parameter decreased with an increase in the binding of α-crystallin. The profiles of spin-lattice relaxation rate showed that the spin-lattice relaxation rate decreased with an increase in binding. These results show that the binding of α-crystallin makes the membrane more immobilized near the head group region of the phospholipids. Furthermore, the profiles of the oxygen transport parameter indicated that the oxygen transport parameter decreased with an increase of binding, indicating the binding of α-crystallin forms a barrier for the passage of non-polar molecules which supports the barrier hypothesis. Conclusions: The binding of α-crystallin to the membrane alters the physical properties of the membranes, and this plays a significant role in modulating the integrity of the membranes. EPR techniques are useful in studying α-crystallin membrane interactions.
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The Structural Integrity of the Model Lipid Membrane during Induced Lipid Peroxidation: The Role of Flavonols in the Inhibition of Lipid Peroxidation. Antioxidants (Basel) 2020; 9:E430. [PMID: 32429305 PMCID: PMC7278707 DOI: 10.3390/antiox9050430] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 04/29/2020] [Accepted: 05/13/2020] [Indexed: 01/06/2023] Open
Abstract
The structural integrity, elasticity, and fluidity of lipid membranes are critical for cellular activities such as communication between cells, exocytosis, and endocytosis. Unsaturated lipids, the main components of biological membranes, are particularly susceptible to the oxidative attack of reactive oxygen species. The peroxidation of unsaturated lipids, in our case 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), induces the structural reorganization of the membrane. We have employed a multi-technique approach to analyze typical properties of lipid bilayers, i.e., roughness, thickness, elasticity, and fluidity. We compared the alteration of the membrane properties upon initiated lipid peroxidation and examined the ability of flavonols, namely quercetin (QUE), myricetin (MCE), and myricitrin (MCI) at different molar fractions, to inhibit this change. Using Mass Spectrometry (MS) and Fourier Transform Infrared Spectroscopy (FTIR), we identified various carbonyl products and examined the extent of the reaction. From Atomic Force Microscopy (AFM), Force Spectroscopy (FS), Small Angle X-Ray Scattering (SAXS), and Electron Paramagnetic Resonance (EPR) experiments, we concluded that the membranes with inserted flavonols exhibit resistance against the structural changes induced by the oxidative attack, which is a finding with multiple biological implications. Our approach reveals the interplay between the flavonol molecular structure and the crucial membrane properties under oxidative attack and provides insight into the pathophysiology of cellular oxidative injury.
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Effects of Temperature on Fluidity and Early Expansion Characteristics of Cement Asphalt Mortar. MATERIALS 2020; 13:ma13071655. [PMID: 32260063 PMCID: PMC7178426 DOI: 10.3390/ma13071655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 03/19/2020] [Accepted: 03/23/2020] [Indexed: 11/18/2022]
Abstract
In order to solve the problems of the sudden loss of fluidity and low expansion rate of CAM I (cement asphalt mortar type I) in a construction site with high environmental temperature, this paper studies the effect of temperature on the fluidity, expansion ratio and pH value of CAM I. The mechanism of action was analyzed by IR (infrared spectrometry), SEM (scanning electron microscopy) and other test methods. The results showed that a high temperature accelerates aluminate formation in cement paste. Aluminate adsorbs emulsifiers leading to demulsification of emulsified asphalt, and wrapped on the surface of cement particles, this causes CAM I to lose its fluidity rapidly. The aluminum powder gasification reaction is inhibited, resulting in an abnormal change in the expansion ratio. Based on findings, the application of an appropriate amount of superplasticizers can effectively improve the workability and expansion characteristics of CAM I at a high temperature.
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Fluidity of Poly (ε-Caprolactone)-Based Material Induces Epithelial-to-Mesenchymal Transition. Int J Mol Sci 2020; 21:E1757. [PMID: 32143443 PMCID: PMC7084864 DOI: 10.3390/ijms21051757] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND We propose the potential studies on material fluidity to induce epithelial to mesenchymal transition (EMT) in MCF-7 cells. In this study, we examined for the first time the effect of material fluidity on EMT using poly(ε-caprolactone-co-D,L-lactide) (P(CL-co-DLLA)) with tunable elasticity and fluidity. METHODS The fluidity was altered by chemically crosslinking the polymer networks. The crosslinked P(CL-co-DLLA) substrate showed a solid-like property with a stiffness of 261 kPa, while the non-crosslinked P(CL-co-DLLA) substrate of 100 units (high fluidity) and 500 units (low fluidity) existed in a quasi-liquid state with loss modulus of 33 kPa and 30.8 kPa, respectively, and storage modulus of 10.8 kPa and 20.1 kPa, respectively. RESULTS We observed that MCF-7 cells on low fluidic substrates decreased the expression of E-cadherin, an epithelial marker, and increased expression of vimentin, a mesenchymal marker. This showed that the cells lose their epithelial phenotype and gain a mesenchymal property. On the other hand, MCF-7 cells on high fluidic substrates maintained their epithelial phenotype, suggesting that the cells did not undergo EMT. CONCLUSION Considering these results as the fundamental information for material fluidity induced EMT, our system could be used to regulate the degree of EMT by turning the fluidity of the material.
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Isolate Specific Cold Response of Yersinia enterocolitica in Transcriptional, Proteomic, and Membrane Physiological Changes. Front Microbiol 2020; 10:3037. [PMID: 32038527 PMCID: PMC6990146 DOI: 10.3389/fmicb.2019.03037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 12/17/2019] [Indexed: 12/24/2022] Open
Abstract
Yersinia enterocolitica, a zoonotic foodborne pathogen, is able to withstand low temperatures. This psychrotrophic ability allows it to multiply in food stored in refrigerators. However, little is known about the Y. enterocolitica cold response. In this study, isolate-specific behavior at 4°C was demonstrated and the cold response was investigated by examining changes in phenotype, gene expression, and the proteome. Altered expression of cold-responsive genes showed that the ability to survive at low temperature depends on the capacity to acclimate and adapt to cold stress. This cold acclimation at the transcriptional level involves the transient induction and effective repression of cold-shock protein (Csp) genes. Moreover, the resumption of expression of genes encoding other non-Csp is essential during prolonged adaptation. Based on proteomic analyses, the predominant functional categories of cold-responsive proteins are associated with protein synthesis, cell membrane structure, and cell motility. In addition, changes in membrane fluidity and motility were shown to be important in the cold response of Y. enterocolitica. Isolate-specific differences in the transcription of membrane fluidity- and motility-related genes provided evidence to classify strains within a spectrum of cold response. The combination of different approaches has permitted the systematic description of the Y. enterocolitica cold response and gives a better understanding of the physiological processes underlying this phenomenon.
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Loss of Dynamic RNA Interaction and Aberrant Phase Separation Induced by Two Distinct Types of ALS/FTD-Linked FUS Mutations. Mol Cell 2019; 77:82-94.e4. [PMID: 31630970 DOI: 10.1016/j.molcel.2019.09.022] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 08/19/2019] [Accepted: 09/20/2019] [Indexed: 12/13/2022]
Abstract
FUS is a nuclear RNA-binding protein, and its cytoplasmic aggregation is a pathogenic signature of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). It remains unknown how the FUS-RNA interactions contribute to phase separation and whether its phase behavior is affected by ALS-linked mutations. Here we demonstrate that wild-type FUS binds single-stranded RNA stoichiometrically in a length-dependent manner and that multimers induce highly dynamic interactions with RNA, giving rise to small and fluid condensates. In contrast, mutations in arginine display a severely altered conformation, static binding to RNA, and formation of large condensates, signifying the role of arginine in driving proper RNA interaction. Glycine mutations undergo rapid loss of fluidity, emphasizing the role of glycine in promoting fluidity. Strikingly, the nuclear import receptor Karyopherin-β2 reverses the mutant defects and recovers the wild-type FUS behavior. We reveal two distinct mechanisms underpinning potentially disparate pathogenic pathways of ALS-linked FUS mutants.
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Understanding toward the Biophysical Interaction of Polymeric Proanthocyanidins (Persimmon Condensed Tannins) with Biomembranes: Relevance for Biological Effects. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:11044-11052. [PMID: 31545599 DOI: 10.1021/acs.jafc.9b04508] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Persimmon condensed tannins (PT) are highly polymerized (mDP = 26) and highly galloylated (72%) proanthocyanidins. Its pleiotropic effects in oxidation resistance, neuroprotection, hypolipidemia, and cardio-protection both in vitro and in vivo were widely reported. Because large proanthocyanidins are unlikely to be absorbed in the gastrointestinal tract, it is believed that the interaction of PT with biological membranes may play a crucial role in its biological activities. In the present study, the capacities of PT adsorbing to membrane, partitioning into membrane, and its influence on the membrane fluidity were investigated by fluorescence quenching, isothermal titration calorimetry (ITC) and fluorescence anisotropy measurements in a biomembrane-mimetic system composed of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC), 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE), sphingomyelin (SPM), and cholesterol (CHOL). Besides, the effects of PT on the morphology and integrity of the cell membrane were studied by scanning electron microscopy (SEM) and fluorescence staining in the 3T3-L1 cell model. The results suggested that PT could affect cell membrane rafts domains, destroy the cell membrane morphology, and regulate cell membrane fluidity, which might contribute to its biological effects.
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Effect of Micro-Scale Er on the Microstructure and Fluidity of ZL205A Alloy. MATERIALS 2019; 12:ma12101688. [PMID: 31137642 PMCID: PMC6566755 DOI: 10.3390/ma12101688] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 05/07/2019] [Accepted: 05/21/2019] [Indexed: 11/16/2022]
Abstract
The effect of Er addition on the fluidity and microstructure transformation of the as-cast and T5 heat-treated ZL205A alloys was investigated by optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). The fluidity of the liquid metal after adding Er was tested and the fracture characteristics of the material were analyzed. The results indicated that Er was mainly dissolved into an α-Al matrix near the grain boundaries (GBs). It is easily segregated and enriched in the intersection of the GBs or the interface between the α and θ phase, which caused the intermetallic compounds to be distributed along the GBs to the neck and to fuse. Er could also inhibit the diffusion of Cu atoms in the process of solid solution, so that increased the residual eutectic structures in the crystal, while accelerating the precipitation progress of the Guinier-Preston (GP) zone and θ' phase and increasing precipitation of the θ phase. A small amount of precipitation of θ phase and micro-scale Er (0.1-0.5 wt %) can significantly increase the fluidity and reduce the casting defects, which can effectively improve the castability of the ZL205A alloy. The interface between the (Al8Cu4Er) phase and matrix is the main area of microcracks, through analyzing the fracture morphology.
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Effect of Lithium-Slag in the Performance of Slag Cement Mortar Based on Least-Squares Support Vector Machine Prediction. MATERIALS 2019; 12:ma12101652. [PMID: 31117276 PMCID: PMC6566977 DOI: 10.3390/ma12101652] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 05/11/2019] [Accepted: 05/16/2019] [Indexed: 12/01/2022]
Abstract
There is a universally accepted view that environmental pollution should be controlled while improving cement mortar natural abilities. The purpose of this study is to develop a green cement mortar that has better compressive strength and anti-chloride ion permeability. Two industrial wastes, lithium-slag and slag, were added to cement mortar, and the role of lithium-slag was to activate slag. In addition, to save economic and time costs, this paper also used the least-squares support vector machine (LS-SVM) method to predict the property changes of cementitious-based materials. Then multiple natural abilities of samples, including compressive strength, anti-chloride ion permeability, and fluidity, were tested. In addition, LS-SVM and traditional support vector machine (SVM) were used to train and forecast the performance, including compressive strength. The results show that lithium-slag can activate slag to improve the compressive strength, anti-chloride ion permeability of mortar, and LS-SVM sharpens accuracy by 11% compared to SVM.
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