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1.
Biomaterials ; 313: 122771, 2025 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-39190940

RESUMO

The notorious tumor microenvironment (TME) usually becomes more deteriorative during phototherapeutic progress that hampers the antitumor efficacy. To overcome this issue, we herein report the ameliorative and adaptive nanoparticles (TPASIC-PFH@PLGA NPs) that simultaneously reverse hypoxia TME and switch photoactivities from photothermal-dominated state to photodynamic-dominated state to maximize phototherapeutic effect. TPASIC-PFH@PLGA NPs are designed by incorporating oxygen-rich liquid perfluorohexane (PFH) into the intraparticle microenvironment to regulate the intramolecular motions of AIE photosensitizer TPASIC. TPASIC exhibits a unique aggregation-enhanced reactive oxygen species (ROS) generation feature. PFH incorporation affords TPASIC the initially dispersed state, thus promoting active intramolecular motions and photothermal conversion efficiency. While PFH volatilization leads to nanoparticle collapse and the formation of tight TPASIC aggregates with largely enhanced ROS generation efficiency. As a consequence, PFH incorporation not only currently promotes both photothermal and photodynamic efficacies of TPASIC and increases the intratumoral oxygen level, but also enables the smart photothermal-to-photodynamic switch to maximize the phototherapeutic performance. The integration of PFH and AIE photosensitizer eventually delivers more excellent antitumor effect over conventional phototherapeutic agents with fixed photothermal and photodynamic efficacies. This study proposes a new nanoengineering strategy to ameliorate TME and adapt the treatment modality to fit the changed TME for advanced antitumor applications.


Assuntos
Fluorocarbonos , Nanopartículas , Fotoquimioterapia , Fármacos Fotossensibilizantes , Espécies Reativas de Oxigênio , Microambiente Tumoral , Nanopartículas/química , Microambiente Tumoral/efeitos dos fármacos , Animais , Fotoquimioterapia/métodos , Espécies Reativas de Oxigênio/metabolismo , Fluorocarbonos/química , Fluorocarbonos/farmacologia , Linhagem Celular Tumoral , Fármacos Fotossensibilizantes/uso terapêutico , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/química , Humanos , Camundongos , Neoplasias/terapia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Camundongos Endogâmicos BALB C , Terapia Fototérmica/métodos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Fototerapia/métodos , Feminino
2.
Meat Sci ; 220: 109703, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39489001

RESUMO

The present work mainly investigated the changes of gel characteristics, rheological properties and ultrastructure of myofibrillar protein (MP) gels with varying amounts (2, 4, 6, and 8 %, w/w) of cross-linked tapioca starch (CTS) or acetylated tapioca starch (ATS). The findings showed that CTS or ATS notably improved the gelling characteristics (such as gel strength and water retention) of mixed MP gels in a dose-dependent manner (P < 0.05), which was clearly verified by the results of rheological behavior tests under different modes. Moreover, compared to ATS, CTS rendered higher gel strength and promoted the formation of a more uniform and smoother mixed MP gel matrix, which was mainly attributed to the higher peak viscosity of CTS. Furthermore, the images of iodine staining indicated that in mixed MP gels, the continuous phase supported by MP was gradually transited to being starch supported as the amounts of CTS or ATS increased between 2 % and 8 %. Additionally, hydrophobic interactions and disulfide bonds were the principal chemical forces of mixed MP gels, which could promote the occurrence phase transition. Briefly, our present work provided some vital understanding of the molecular interactions between MP and modified tapioca starches, which could efficiently modulate the quality profiles of meat products.

3.
Int J Biol Macromol ; : 137109, 2024 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-39486694

RESUMO

Despite the remarkable potential of phase change fibers for energy storage, their practical deployment has been hindered by two crucial challenges: inadequate external thermal stimulation to induce phase transition and leakage of the phase-change material. In this study, we successfully incorporated carbon nanotubes (CNTs) into a solution of sodium alginate grafted polyethylene glycol monomethyl ether (SA-g-mPEG) and utilized wet spinning processing to fabricate CNTs/SA-g-mPEG hybrid fibers with enhanced photo-thermal conversion and robust solid-solid phase change capabilities. Upon exposure to sunlight for merely 60 s, the hybrid fibers achieved a remarkable peak temperature of 40 °C. Upon cessation of sunlight exposure, these fibers demonstrated a gradual release of thermal energy, thereby underlining their exceptional photothermal conversion and temperature regulation capabilities. Furthermore, DSC analysis revealed that, at an optimal grafting ratio of 36.6 %, the hybrid fibers exhibited ΔHc and ΔHm values of 48.23 J/g and 50.83 J/g, respectively. Notably, hybrid fibers with a grafting ratio of 20.2 % demonstrated substantial enhancements in tensile properties, achieving a maximum breaking strength of approximately 2.02 cN/dtex-an impressive 11.3 % increase compared to SA-g-mPEG composite fibers. Our findings suggest that CNTs/SA-g-mPEG hybrid fibers hold immense promise for applications in body heat storage, fabric temperature regulation, and related fields.

4.
Nano Lett ; 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39485267

RESUMO

The intermediate behavior near a quantum phase transition is crucial for understanding the quantum criticality of various competing phases and their separate origins, yet it remains unexplored for the multiple Yu-Shiba-Rusinov (YSR) states. Here, we investigated the detailed spectroscopic change of the exchange-coupling-dependent YSR states near a quantum phase transition. The initially developed one pair of YSR states, induced by the Fe vacancy in monolayer Fe(Te,Se) superconductor, are clearly resolved with high resolution showing an evolution into two pairs of YSR peaks yet with dichotomy in their spectral features as they enter the quantum phase transition region. Spectral-weight analysis suggests that the double YSR pairs occur as a result of field splitting by the magnetic anisotropy. Our findings unveil the intermediate region of a quantum phase transition with a magnetic anisotropy-induced splitting of the YSR resonance, and highlight a prospect for developing functional electronics based on the flexibly controllable multiple quantum states.

5.
EMBO Rep ; 2024 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-39482488

RESUMO

The first step of successful infection by any intracellular pathogen relies on its ability to invade its host cell membrane. However, the detailed structural and molecular understanding underlying lipid membrane modification during pathogenic invasion remains unclear. In this study, we show that a specific Leishmania donovani (LD) protein, KMP-11, forms oligomers that bridge LD and host macrophage (MΦ) membranes. This KMP-11 induced interaction between LD and MΦ depends on the variations in cholesterol (CHOL) and ergosterol (ERG) contents in their respective membranes. These variations are crucial for the subsequent steps of invasion, including (a) the initial attachment, (b) CHOL transport from MΦ to LD, and (c) detachment of LD from the initial point of contact through a liquid ordered (Lo) to liquid disordered (Ld) membrane-phase transition. To validate the importance of KMP-11, we generate KMP-11 depleted LD, which failed to attach and invade host MΦ. Through tryptophan-scanning mutagenesis and synthesized peptides, we develop a generalized mathematical model, which demonstrates that the hydrophobic moment and the symmetry sequence code at the membrane interacting protein domain are key factors in facilitating the membrane phase transition and, consequently, the host cell infection process by Leishmania parasites.

6.
Molecules ; 29(19)2024 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-39407624

RESUMO

Axitinib (AXTN) is an oral tyrosine kinase inhibitor for the treatment of early to advanced renal cell carcinoma. In this work, solvates of AXTN were prepared in five solvents and subjected to desolvation treatment. The crystal form A of AXTN can form solvates in acetonitrile, DMF, acetic acid, acetic acid + water, and methanol. Different ratios of AXTN and acetic acid will form different products (solvate or directly crystallized into another crystal form (form IV)). The characterization results of thermal analyses confirmed the types of the five solvates. The obtained solvates were desolvated using methods of solid-phase desolvation (heating, exposure to solvent steam, microwave) and solvent-mediated phase transformation (SMPT). The desolvated solids were characterized by PXRD, TGA, DSC, FT-IR, and SEM, and it was ultimately inferred that a new crystal form (form Z) of AXTN could be formed after desolvation. In addition, the solvates obtained in this work experienced mutual transformation via SMPT, which depends on the type of solvents or mixed solvents. The phase transformations of different solid forms were summarized. This study is instructive for exploring solvates and polymorphs of AXTN and understanding phase transitions under different environments.

7.
Int J Mol Sci ; 25(19)2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39408768

RESUMO

This study reveals the pH-responsive behavior of collagen hydrogels prepared using ultraviolet (UV) irradiation with riboflavin as a photosensitizer. By varying the UV exposure time, we modulated the crosslinking density, thereby influencing the mechanical properties and pH responsiveness. Rheological analysis confirmed successful network formation, whereas swelling studies revealed significant pH-dependent behavior, with maximum swelling at a pH of four and minimal swelling above a pH of six, demonstrating partial reversibility over multiple pH cycles. Mechanical testing showed a pH-dependent elastic modulus, which increased 10 fold from a pH of 6 to 10. Fibroblast proliferation assays confirmed the biocompatibility of the hydrogels, with cell growth positively correlating with the UV exposure time. This research demonstrates the potential of UV-crosslinked collagen hydrogels in biomedical applications, such as tissue engineering and drug delivery, where pH responsiveness is essential.


Assuntos
Colágeno , Hidrogéis , Riboflavina , Raios Ultravioleta , Riboflavina/química , Riboflavina/farmacologia , Hidrogéis/química , Concentração de Íons de Hidrogênio , Colágeno/química , Fibroblastos/efeitos dos fármacos , Animais , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Materiais Biocompatíveis/química , Camundongos , Engenharia Tecidual/métodos , Reologia
8.
Cell ; 2024 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-39426376

RESUMO

Synucleinopathies, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy, are triggered by α-synuclein aggregation, triggering progressive neurodegeneration. However, the intracellular α-synuclein aggregation mechanism remains unclear. Herein, we demonstrate that RNA G-quadruplex assembly forms scaffolds for α-synuclein aggregation, contributing to neurodegeneration. Purified α-synuclein binds RNA G-quadruplexes directly through the N terminus. RNA G-quadruplexes undergo Ca2+-induced phase separation and assembly, accelerating α-synuclein sol-gel phase transition. In α-synuclein preformed fibril-treated neurons, RNA G-quadruplex assembly comprising synaptic mRNAs co-aggregates with α-synuclein upon excess cytoplasmic Ca2+ influx, eliciting synaptic dysfunction. Forced RNA G-quadruplex assembly using an optogenetic approach evokes α-synuclein aggregation, causing neuronal dysfunction and neurodegeneration. The administration of 5-aminolevulinic acid, a protoporphyrin IX prodrug, prevents RNA G-quadruplex phase separation, thereby attenuating α-synuclein aggregation, neurodegeneration, and progressive motor deficits in α-synuclein preformed fibril-injected synucleinopathic mice. Therefore, Ca2+ influx-induced RNA G-quadruplex assembly accelerates α-synuclein phase transition and aggregation, potentially contributing to synucleinopathies.

9.
Angew Chem Int Ed Engl ; : e202416290, 2024 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-39387848

RESUMO

O3-type layered oxides are highly promising cathodes for sodium-ion batteries (SIBs), however they undergo complex phase transitions and exhibit high sensibility to air, leading to subpar cycling performance and commercial viability. In this work, we report a layered cathode material (NaNi0.29Cu0.1Mg0.05Li0.05Mn0.2Ti0.2Sn0.11O2) with a sate-of-the-art high-entropy compositional design. We unveil that such a configuration featuring inhomogeneous coordination environment of transition metal (TM) elements, can enable enhanced gliding energy (-0.38 vs -0.58 eV) of TMO2 slabs upon desodiation both theoretically and experimentally, which underlies the fundamental origin of the outstanding structural stability of HEO materials. As a consequence, the complex phase transitions (O3-O'3-P3-P'3-P3'-O3') of conventional O3-type cathode have been eliminated, and the as-obtained material demonstrates exceptional structural robustness and integrity with an ultra-long cycle life in a quasi-solid-state cell (maintaining 73.2% capacity after 1000 cycles at 2 C). Moreover, the material presents satisfactory air stability, with minimal structural and electrochemical degradation when directly exposed to the air. An Ah-scale pouch cell based on the cathode material is constructed, demonstrating a capacity retention of 83.6% after 500 cycles, signaling substantial promise for commercial applications.

10.
Adv Sci (Weinh) ; : e2410099, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39412082

RESUMO

Developing strategies to systematically increase the critical current, the threshold current below which the superconductivity exists, is an important goal of materials science. Here, the concept of quantum phase transition is employed to enhance the critical current of a kagome superconductor CsV3Sb5, which exhibits a charge density wave (CDW) and superconductivity that are both affected by hydrostatic pressure. As the CDW phase is rapidly suppressed under pressure, a large enhancement in the self-field critical current (Ic, sf) is recorded. The observation of a peak-like enhancement of Ic, sf at the zero-temperature limit (Ic, sf(0)) centered at p* ≈ 20 kbar, the same pressure where the CDW phase transition vanishes, further provides strong evidence of a zero-temperature quantum anomaly in this class of pressure-tuned superconductor. Such a peak in Ic, sf(0) resembles the findings in other well-established quantum-critical superconductors, hinting at the presence of enhanced quantum fluctuations associated with the CDW phase in CsV3Sb5.

11.
J Fungi (Basel) ; 10(10)2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39452639

RESUMO

Talaromyces marneffei is a thermally dimorphic fungus that can cause life-threatening systemic mycoses, particularly in immunocompromised individuals. Fungal homeobox transcription factors control various developmental processes, including the regulation of sexual reproduction, morphology, metabolism, and virulence. However, the function of homeobox proteins in T. marneffei has not been fully explored. Here, we searched the T. marneffei genome for the total homeobox transcription factors and predicted their biological relevance by performing gene expression analysis in different cell types, including conidia, mycelia, yeasts, and during phase transition. RfeB is selected for further computational analysis since (i) its transcripts were differentially expressed in different phases of T. marneffei, and (ii) this protein contains the highly conserved protein-protein interaction region (IR), which could be important for pathobiology and have therapeutic application. To assess the structure-function of the IR region, in silico alanine substitutions were performed at three-conserved IR residues (Asp276, Glu279, and Gln282) of RfeB, generating a triple RfeB mutated protein. Using 3D modeling and molecular dynamics simulations, we compared the protein complex formation of wild-type and mutated RfeB proteins with the putative partner candidate TmSwi5. Our results demonstrated that the mutated RfeB protein exhibited increased free binding energy, elevated protein compactness, and a reduced number of atomic contacts, suggesting disrupted protein stability and interaction. Notably, our model revealed that the IR residues primarily stabilized the RfeB binding sites located in the central region (CR). This computational approach for protein mutagenesis could provide a foundation for future experimental studies on the functional characterization of RfeB and other homeodomain-containing proteins in T. marneffei.

12.
Artigo em Inglês | MEDLINE | ID: mdl-39454620

RESUMO

Efficient and better energy storage materials are of utmost technological importance to reduce energy dependence on the fossil fuels. Li2MnO3is one such material having potential to meet most of the requirements for energy storage. This material has been synthesized using solid state synthesis route. High pressure structural and vibrational studies on this material have been carried out upto~ 22 and 26 GPa respectively. These investigations show occurrence of a hitherto unknown second order phase transition to a new low symmetry phase whose symmetry is constrained to be monoclinic with space group P21/n at pressure of ~ 2.3 GPa in Li2MnO3. The bulk modulus and its derivative determined by fitting the P-V data with third order Birch-Murnaghan (B-M) equation of state (EOS) are 113.3 ± 13.1 GPa and 4.1 ± 1.2 respectively. Mode Grüneisen parameter calculated for all the Raman modes show positive values which indicates the absence of any soft mode in this material. A microscopic mechanism based on bond-charge transfer is invoked and applied to understand the spectroscopic changes occurring in this material which also manifests second order structural phase transition. Enhancement in covalent character of Li-O bonds in the Li-O polyhedra is inferred based on the spectroscopic observation and above mechanism. .

13.
Microsc Res Tech ; 2024 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-39462904

RESUMO

In the present work, the photocatalytic activity against the natural dye extracted from the novel fruits has been studied by the BaTiO3 nanoparticles (NPs) under a ultra-violet (UV) light source. The large concentrations of an essential phenolic agent present in this phytochemical extract superimposed with cloths fibers make strong stain and degrade into another form of toxic, which is excluded from the many textiles industries as the colorful waste waters without recycling and removal of that dye pigments have been investigated using both photodegradation and photoluminescence techniques. The entitled nanoparticles (NPs) were prepared using the soft chemical root-modified solvothermal synthesis combo method and exposure to heat treatment such that the annealing process has been done for different temperatures ranging from 100°C to 250°C. As for as concern the characterization, as a start, structural and morphology studies have been reported here that highly crystalline oriented peaks data using powder x-ray diffraction techniques (PXRD) as well as the surface morphology including the size, shape, and mass distribution using the field emission scanning electron microscopy (FESEM) techniques, which purely belong to rutile tetragonal structure of the crystal system and circular and noncircular flakes like rough surface morphology materials respectively. The lattice dissociation constant 'ε' value of the BaTiO3 NPs has determined to be ~2.71 × 10-3 using the Williamson-Hall (W-H plot) analysis of crystallographic data. In the UV visible spectroscopy findings, since the extreme quantum confinement of BaTiO3 nanoflakes/nanodisc, the optical energy bandgap has been estimated to be a range of 1.98 to 2.67 eV (~2.48 eV) found from the Tauc plot analysis, which contributes to the significantly owing to the enhanced photocatalytic efficiency with excellent performance along exciton formation, superoxide ions, and hydroxyl free radicals generations under UV-vis light irradiation resulting in efficient degradation of typical novel fruit organic dye. Photoluminescence spectra observed at room temperature and low temperature have been observed for the BaTiO3 nanoflakes, which exhibit the blue emission due to the crystalline defects such as the appearance of Ba vacancies leads to the conceivable beginning of p-type conductivity and the origination of free exciton emission reveals the direct bandgap transition nature of nanoflakes. RESEARCH HIGHLIGHTS: According to our findings, 89.71% of the natural syzygium cumin is degraded by photocatalysis reaction. As a plausible mechanism for the destruction of natural dyes under solar light, photocatalytic destruction has been proposed. The reaction between these reactive free radical species leads to high efficiency photodegradation with a short decay time. In addition to water treatment and environmental cleaning applications, the excellent performance of this photocatalyst makes it a promising candidate for other applications. Hence, the synthesized BaTiO3 nanoflakes showcase a highly significant advancement towards the development of a textiles dye recycling method.

14.
Artigo em Inglês | MEDLINE | ID: mdl-39465985

RESUMO

The self-similar fractal morphology mediated by nonequilibrium processes is widely observed in low-dimensional materials grown by various techniques. Understanding how these fractal geometries affect the physical and chemical properties of materials and devices is crucial for both fundamental studies and various applications. In particular, the interplay between superconducting phase fluctuations and disorder can give rise to intriguing phenomena depending on the dimensionality. However, current experimental studies on low-dimensional superconductors are limited to two- and one-dimensional systems, leaving fractional dimensional systems largely unexplored. Here, we use chemical vapor deposition to successfully synthesize ultrathin NbC crystals with a well-defined fractal geometry at the nanoscale. By performing electrical transport measurements, we find that both the superconducting and normal-state properties are strongly affected in the fractal samples, where the intrinsic and geometric disorder is induced. In contrast to the 2D crystal, the fractal NbC crystals show a significant low-temperature resistive upturn before the onset of superconducting transition, which can be attributed to the disorder-enhanced electron-electron interaction effect. From transport data analysis, we demonstrate that the superconducting transition in NbC is correlated to the strength of disorder and the fractional dimensions, revealing that nanoscale fractal structures can significantly modify the electronic properties of low-dimensional superconductors. Our work paves the way for the explorations of mesoscopic transport and intriguing superconducting phenomena in fractional dimensions.

15.
Artigo em Inglês | MEDLINE | ID: mdl-39466260

RESUMO

This study introduces a discovery of pressure-induced new semiconductor electronic phase transitions. A novel semiconductor family that exhibits pressure-induced nonmonotonic changes in band gaps was found and meets the definition of phase transitions, challenging the traditional understanding of linear and monotonic band gap modification through pressurization. Our findings suggest a complex interplay of atomic spacing and electron orbital contributions under varying pressure conditions, resulting in the variation of band gaps. This behavior, which includes three distinct steps: first, narrowing, second, broadening, and third, narrowing again and ultimately metalizing; some compounds could bypass step 1, has potential applications in piezoelectric and semiconductor technologies. We propose two new semiconductor electronic phase transitions (SEPT) associated with specific inflection points in the pressure-dependent band gap curve. Our results open avenues for further research into the electronic properties of crystals under high pressure, with the ultimate goal of uncovering the more profound physical principles governing these phenomena.

16.
Materials (Basel) ; 17(20)2024 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-39459778

RESUMO

This work investigated the structure, microstructure, and ferroelectric and dielectric behavior of (Pb0.97Ba0.03)(Zr0.98Ti0.02)1-xSnxO3 (PBZT_xSn) solid solution with variable tin content in the range x = 0.00-0.08. Synthesis was carried out using the powder calcination method, and sintering was carried out using the hot-pressing method. For all the PBZT_xSn samples at room temperature, X-ray diffractograms confirmed the presence of an orthorhombic (OR) crystal structure with space group Pnnm, and the microstructure is characterized by densely packed and properly shaped grains with an average size of 1.36 µm to 1.73 µm. At room temperature, PBZT_xSn materials have low permittivity values ε' ranging from 265 to 275, whereas, at the ferroelectric-paraelectric phase transition temperature (RE-C), the permittivity is high (from 8923 to 12,141). The increase in the tin dopant in PBZT_xSn lowers permittivity and dielectric loss and changes the scope of occurrence of phase transitions. The occurring dispersion of the dielectric constant and dielectric loss at low frequencies, related to the Maxwell-Wagner behavior, decreases with increasing tin content in the composition of PBZT_xSn. Temperature studies of the dielectric and ferroelectric properties revealed anomalies related to the phase transitions occurring in the PBZT_xSn material. With increasing temperature in PBZT_xSn, phase transitions occur from orthorhombic (OR) to rhombohedral (RE) and cubic (C). The cooling cycle shifts the temperatures of the phase transitions towards lower temperatures. The test results were confirmed by XRD Rietveld analysis at different temperatures. The beneficial dielectric and ferroelectric properties suggest that the PBZT_xSn materials are suitable for micromechatronic applications as pulse capacitors or actuator elements.

17.
Bioresour Technol ; 415: 131650, 2024 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-39419406

RESUMO

Algal biomass harvesting is one of key technical hurdles impeding the commercialization of algae-based biorefinery. The goal of this work is to develop an innovative technology for algae cell harvesting. Thermoresponsive polymers (TRPs) such as poly(N-isopropylacrylamide) (PNIPAM) and its derivatives were studied on their properties and potential applications for microalgae harvesting. Various PNIPAM was synthesized, and the effects of charge, molecular weight (MW), amine content, and polymer concentration on the polymer phase transition temperature, the degree of phase separation, and the harvesting of microalgae (Chlorella vulgaris) were investigated. The lower critical solution temperature (LCST) of PNIPAM decreased with the increase of polymer concentration, while the decline rate reduced under high MW. The amine content didn't significantly affect the LCST of TRPs. Approx. 92 % of algae cells were harvested by PNIPAM-300 kDa. Modified TRPs showed few benefits in enhancing algae harvesting. TRPs are a promising class of polymers for microalgae harvesting.

18.
Adv Colloid Interface Sci ; 334: 103309, 2024 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-39393254

RESUMO

When n-alkanes or n-alcohols coexist with surfactants that have similar chain lengths, they can form mixed surface-frozen films at the oil-water interface. In this review, we first explain the basic characteristics of this surface freezing transition mainly from a thermodynamic viewpoint. Then, we discussed the effect of surface freezing of a cationic surfactant (cetyltrimethylammonium chloride: CTAC) with tetradecane, hexadecane, or hexadecanol on the kinetic stability of the oil-in-water (O/W) emulsions. We show that the surface frozen film not only increases the kinetic stability of the O/W emulsions but also stably encapsulates coexisting organic molecules in the oil core. Finally, we will introduce one of our recent works in which we observed that the exchange between silica nanoparticles and CTAC molecules occurs at the surface of Pickering emulsions when the oil-water interfacial tension is lowered by the surface freezing. The resulting detachment of silica particles from the oil-water interface broke the Pickering emulsion. The advantages of controlling the stability of O/W emulsions via the use of surface-frozen film are discussed in comparison with normal surfactant emulsifiers in the conclusion part of the review.

19.
J R Soc Interface ; 21(219): 20240232, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39378983

RESUMO

Biological processes that are able to discriminate between different molecules consume energy and dissipate heat, using a mechanism known as proofreading. In this work, we thoroughly analyse the thermodynamic properties of one of the most important proofreading mechanisms, namely Hopfield's energy-relay proofreading. We discover several trade-off relations and scaling laws between several kinetic and thermodynamic observables. These trade-off relations are obtained both analytically and numerically through Pareto optimal fronts. We show that the scheme is able to operate in three distinct regimes: an energy-relay regime, a mixed relay-Michaelis-Menten (MM) regime and a Michaelis-Menten regime, depending on the kinetic and energetic parameters that tune transitions between states. The mixed regime features a dynamical phase transition in the error-entropy production Pareto trade-off, while the pure energy-relay regime contains a region where this type of proofreading energetically outperforms standard kinetic proofreading.


Assuntos
Termodinâmica , Cinética , Modelos Biológicos
20.
Chemistry ; : e202403362, 2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-39468633

RESUMO

Thermo-responsive dielectric switching hybrid halides, displaying reversible dielectric bistability, have recently made them highly versatile and attractive for their structural tunability and rich functional properties. However, the substantial improvement of the dielectric switching operating range is limited near room temperature, and obtaining ultra-wide dielectric switching temperature region is a major challenge. Herein, a remarkable dielectric switching effect is reported with ultra-wide dielectric switching temperature region in a hybrid halide system, caused by dipolar orientational polarization ascribing order-disorder phase transitions. The new A2BX4 hybrid halide [C6H5(CH2)4NH3]2ZnBr4 (4PBA-ZnBr4) with an ultra-wide dielectric hysteresis loop of about 55 K near room temperature is designed successfully through halogen substitution. Meanwhile, structurally similar hybrid materials 4PBA-ZnI4 were designed as controls. More interestingly, the crystal structure, phase transition temperature (Tc), dielectric and semiconductor properties exhibit significant discrepancies as the halogen atoms vary from Br to I. This discovery provides an efficiently regulated anionic framework to construct hybrid halides with ultra-wide high dielectric switching and reliable cycling stability by assembling with various cations, making them potentially excellent candidates for highly responsive room temperature smart switches or transducer devices.

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