Formation Of Aggregates Research Articles

In2O3 synthesis and investigation of their impact on the structural and physical characteristics of polyvinyl alcohol films for optical applications

In2O3 nanoparticles were synthesized via the simple-polymerized-complex method and incorporated in the PVA matrix with different contents to obtain PVA-In2O3 films via the casting technique. The optical and structural characteristics of the synthesized PVA-In2O3 films were analyzed using Fourier transform infrared (FTIR), scanning electron microscope (SEM), UV-vis spectroscopy, and X-ray diffraction (XRD). These techniques help in understanding how the addition of In2O3 affects the PVA properties. The change in PVA’s structure upon increasing the In2O3 concentration was investigated through XRD and FTIR. XRD showed the change in the crystallinity of the PVA with increasing In2O3 concentration. SEM confirms the incorporation of In2O3 in the PVA matrix in the nanoscale with the formation of aggregations at higher concentrations. The PVA’s optical absorbance was investigated through the UV-visible spectrophotometer, and a change upon adding In2O3 nanoparticles was observed. The PVA’s direct bandgap changed from 5.41 eV to 3.5 eV, and the indirect bandgap from 4.61 eV to 2.5 eV upon adding 8% In2O3. Increasing In2O3 concentration in the PVA significantly enhances the refractive index and optical conductivity. These results highlight the potential of In2O3-filled PVA films for optical applications, showcasing their improved optical and structural properties.

Iron oxides promote physicochemical stabilization of carbon despite enhancing microbial activity in the rice rhizosphere.

Rice rhizosphere soil is a hotspot of microbial activity and a complex interplay between soil abiotic properties, microbial community and organic carbon (C). The iron (Fe) plaque formation in the rice rhizosphere promotes Fe-bound organic C formation and increases microbial activity. Yet, the overall impact of Fe on C storage via physicochemical stabilization and microbial mineralization of rhizodeposits (rhizo-C) and soil organic C (SOC) in the rice rhizosphere remain unclear. We conducted a microcosm experiment using 13C-CO2 pulse labeling to grow rice (Oryza sativa L.) with four levels of α-FeOOH addition (Control, Fe-10%, Fe-20%, Fe-40% w/w of α-FeOOH per total Fe in soil). This study aimed to evaluate the impact of Fe oxides on rhizo-C mineralization, the rhizosphere priming effect, and Fe-OM formation. Microbial community composition and localization of enzyme activities were also quantified through 16S rRNA sequencing and zymography. The hotspot area, as being indicated by zymography, increased by 20-50% in the presence of Fe compared to the soil without Fe addition. Despite being a hotspot, strong coprecipitation of Fe-OM in the rhizosphere promoted C immobilisation. Fe-20% and Fe-40% resulted in a 41% and 33% decrease of rhizodeposits derived 13C-CO2 emission and increased 13C stabilization mainly in 0.25-2mm soil aggregates due to coprecipitation and aggregate formation with α-FeOOH. Moreover, Fe addition led to a dominance of Fe-oxidizing bacteria genera such as Pseudomonas, which fostered coprecipitation of Fe-OM formation. We highlight larger physicochemical stabilization of organic C by α-FeOOH addition despite raised hotspot area of microbial activity in the rice rhizosphere.

Histopathological changes of nervous tissue in women over 60 years of age with Alzheimer's disease and their relationship with menopause.

Ageing is a natural and irreversible process that primarily manifests in older age, becoming more common after the age of 60. Currently, a significant increase has been observed in the elderly population, with forecasts indicating that this group will triple in size over the next 50 years. This phenomenon is evident in several countries, including Japan, Mexico, Brazil, and Colombia, where the growing population of older adults is accompanied by an increased risk of neurodegenerative diseases, such as Alzheimer's disease. Studies have shown differences in the onset and progression of the disease between men and women, highlighting menopause and hormonal factors as key determinants in women. An association has been identified between a lower exposure to endogenous oestrogens and a higher risk of dementia in women, linked to the action of the enzyme β-secretase (BACE1), which is involved in the formation of amyloid aggregates associated with Alzheimer's disease. These findings highlight the importance of thoroughly investigating and understanding the impact of ageing and related diseases on the current and future population. This study aims to describe the histopathological changes in nervous tissue in women over 60 years of age with Alzheimer's disease and their relationship to menopause. A comprehensive search was conducted in databases such as PubMed, ScienceDirect, Frontiers, Scopus, and Springer. Two hundred thirteen articles were selected for review and 45 full articles were chosen. Alzheimer's disease is characterised by a progressive loss of cognitive function due to brain lesions, including the accumulation of amyloid-beta plaques and neuronal apoptosis. Hormonal changes during menopause may contribute to the onset of the disease.

Nuclear Magnetic Resonance Study of Monoclonal Antibodies Near an Oil-Water Interface.

Monoclonal antibodies (mAb) represent an important class of biologic therapeutics that can treat a variety of diseases including cancer, autoimmune disorders or respiratory conditions (e.g. COVID-19). However, throughout their development, mAb are exposed to air-water or oil-water interfaces that may trigger mAb partial unfolding that can lead to the formation of proteinaceous aggregates. Using a combination of dynamic surface tensiometry and spatially resolved 1D 1H NMR spectroscopy, this study investigates if adsorption of a model IgG2a-κ mAb to the oil-water interface affects its structure. Localized NMR spectroscopy was performed using voxels of 375 µm, incrementally approaching the oil-water interface. Dynamic interfacial tension progressively decreases at the oil-water interface over time, confirming mAb adsorption to the interface. Localized NMR spectroscopy results indicate that, while the number of mAb-related chemical resonances and chemical shift frequencies remain unaffected, spectral line broadening is observed as voxels incrementally approach the oil-water interface. Moreover, the spin-spin (T2) relaxation of the mAb molecule was measured for a voxel centered at the interface and shown to be affected differentially across the mAb resonances, indicating a rotational restriction for mAb molecules due to presence of the interface. Finally, the apparent diffusion coefficient of the mAb for the voxel centered at the interface is lower than the bulk mAb. These results suggest that this specific mAb interacts with and may be in exchange with bulk mAb phase in the vicinity of the interface. As such, these localized NMR techniques offer the potential to probe and quantify alterations of mAb properties near interfacial layers.

Unveiling emissive H-aggregates of benzocoronenediimide, their photophysics and ultrafast exciton dynamics.

H- and J-aggregates of many molecules can be considered ordered mesoscopic structures that behave like a single entity. This is due to coherent electronic coupling between electronic excitations of aggregated molecules, resulting in distinct electronic properties compared to the monomer. H-aggregates are generally non-emissive and, due to this property, they are considered unfit for optoelectronics applications, but they have found applications in organic light-emitting transistors. Herein, we designed t-butyl-substituted benzocoronenediimide (t-But-BCDI) forming rare emissive H-aggregates. The tertiary butyl groups are placed to inhibit the formation of strong aggregates. Photophysical studies showed that t-But-BCDI forms H-aggregates in a concentrated solution in a THF/CHCl3 mixture. A blue shift in absorption along with a decrease in the A0-0/A0-1 ratio and red-shifted weaker emission are observed for the aggregate compared to the monomer. Ultrafast transient absorption studies revealed biphasic relaxation with lifetimes of 150 (±10) fs and 13 (±2) ps, which are attributed to a higher-to-lower state transition and vibrational cooling, respectively. The transient spectral signature suggests the Frenkel-type (localized to a monomer) character of the exciton. Faster evolution at the tens of picosecond timescale suggests relaxation of the exciton state within the H-type exciton band. An extraordinarily long emission lifetime from the H-aggregated state is observed.

Virus-mediated delivery of single-chain antibody targeting TDP-43 protects against neuropathology, cognitive impairment and motor deficit caused by chronic cerebral hypoperfusion.

Chronic cerebral hypoperfusion induced by permanent unilateral common carotid artery occlusion in mice was recently found to induce an age-dependent formation of insoluble cytoplasmic TDP-43 aggregates reminiscent of pathological changes found in human vascular dementia. In this model, the gradual deregulation of TDP-43 homeostasis in cortical neurons was associated with marked cognitive and motor deficits. To target the TDP-43-mediated toxicity in this model, we generated an adeno-associated virus vector encoding a single-chain antibody against TDP-43, called scFv-E6, designed for pan-neuronal transduction following intravenous administration. Injected prior to brain hypoperfusion, this tonic virus-mediated delivery of the scFv-E6 antibody reduced formation of cytoplasmic TDP-43 aggregates in cortical neurons, boosted levels of autophagy markers and attenuated microgliosis. Moreover, the novel object recognition and grip strength tests revealed that neuronal expression of scFv-E6 prevented the cognitive impairment and loss of motor performance caused by two-months of cerebral hypoperfusion. The robust protective effects of scFv-E6 antibody in this model suggest a key role of TDP-43 in neuronal damage and symptom phenotypes caused by chronic cerebral hypoperfusion. Accordingly, TDP-43 should be considered as a new therapeutic target in drug development, including antibody approaches, for treatment of vascular dementia.

A dual antibacterial action of soft quaternary ammonium compounds: bacteriostatic effects, membrane integrity, and reduced in vitro and in vivo toxicity.

Quaternary ammonium compounds (QACs) have served as essential antimicrobial agents for nearly a century due to their rapid membrane-disrupting action. However, the emergence of bacterial resistance and environmental concerns have driven interest in alternative designs, such as "soft QACs", which are designed for enhanced biodegradability and reduced resistance potential. In this study, we explored the antibacterial properties and mechanisms of action of our newly synthesized soft QACs containing a labile amide bond within a quinuclidine scaffold. Our findings revealed that these compounds primarily exhibit a bacteriostatic mode of action, effectively suppressing bacterial growth even at concentrations exceeding their minimum inhibitory concentrations (MICs). Unlike traditional QACs, fluorescence spectroscopy and microscopy demonstrated membrane preservation during treatment, with reduced membrane integration compared to cetylpyridinium chloride (CPC), as corroborated by parallel artificial membrane permeability assays. Additionally, molecular dynamics simulations revealed "hook-like" conformations that limit lipid bilayer penetration and promote the formation of larger aggregates, reducing their effective concentration and minimizing cytotoxic effects. Interestingly, secondary antibacterial mechanisms, including inhibition of protein synthesis, were observed, further enhancing their activity. Zebrafish embryotoxicity and in vitro cytotoxicity studies confirmed significantly lower toxicity compared to CPC. By addressing limitations associated with conventional QACs, including toxicity, resistance, and environmental persistence, these soft QACs provide a promising foundation for next-generation antimicrobials. This work advances the understanding of QAC mechanisms while paving the way for safer, eco-friendly applications in healthcare, agriculture, and industrial settings.

Modeling the navigating forces behind BSA aggregation in a microfluidic chip.

Microfluidic chips are powerful tools for investigating numerous variables including chemical and physical parameters on protein aggregation. This study investigated the aggregation of bovine serum albumin (BSA) in two different systems: a vial-based static system and a microfluidic chip-based dynamic system in which BSA aggregation was induced successfully. BSA aggregation induced in a microfluidic chip on a timescale of seconds enabled a dynamic investigation of the forces driving the aggregation process. This study employed a combination of experimental approaches, including biophysical and microscopic methods, and computational simulations using MATLAB and COMSOL Multiphysics. Obtained results revealed that Brownian movement, advective mixing, and laminar flow applied in favor of the formation of amyloid-like aggregates through the entire pathway. Furthermore, heating provided the necessary energy for the initial BSA's partial unfolding. In the following, space restriction and the cumulative effects of repulsive electrostatic and attractive van der Waals forces contributed to forming BSA clusters as a partially unfolded intermediate in the first few seconds of the aggregation process. Consequently, the synergistic effects of hydrodynamic forces (including shear force), hydrophobic interaction, and space restriction resulted in the deposition of larger aggregates on the channel sidewalls. Due to the elevated local concentration of BSA clusters alongside the strong shear force toward the channel sidewalls, the deposited structures underwent a structural conversion to form amyloid-like aggregates within a few seconds. In this study, we not only elucidated the molecular mechanisms underlying BSA aggregation but also highlighted the forces driving the aggregation process in microfluidic systems, explaining how it occurs within a timescale of seconds.

Preparation of a Stable Indomethacin Supersaturated Solution Using Hydrophobically Modified Hydroxypropylmethylcellulose and α-Cyclodextrin

In the present study, the stability of a supersaturated solution of indomethacin (IM) was evaluated in hydrophobically modified hydroxypropylmethylcellulose (HM-HPMC) solutions, with and without parent cyclodextrins (CDs). A highly supersaturated state of IM was maintained in the HM-HPMC solution and was further stabilized by the addition of α-CD and β-CD. Notably, the highest level of supersaturation was achieved in HM-HPMC/α-CD solution, which maintained a high concentration of IM for up to 120 h. IM concentrations in these solutions exceeded the amorphous solubility, indicating that phase separation had occurred. To explore this phase separation, Nile Red, a fluorescent probe sensitive to hydrophobic environments, was added to the supersaturated solutions. A higher fluorescence intensity was observed in the HM-HPMC/α-CD solution compared with the HM-HPMC solution, indicating a significant formation of colloidal amorphous aggregates in the supersaturated solution. Cryogenic transmission electron microscopy (Cryo TEM) analysis confirmed the presence of these aggregates, which appeared irregularly shaped. These findings suggest that the combination of HM-HPMC and α-CD effectively stabilized the colloidal amorphous aggregates in the IM supersaturated solution. The addition of α-CD facilitated the dissociation of HM-HPMC into smaller particles, increasing the number of hydrophobic stearyl moieties available for interactions with amorphous IM aggregates, thereby enhancing the stability of the supersaturated state. The combination of HM-HPMC and α-CD offers a promising approach to improving the oral bioavailability of drugs with poor water solubility.

Bioinspired programmable coacervate droplets and self-assembled fibers through pH regulation of monomers.

Phase separation and phase transitions pervade the biological domain, where proteins and RNA engage in liquid-liquid phase separation (LLPS), forming liquid-like membraneless organelles. The misregulation or dysfunction of these proteins culminates in the formation of solid aggregates via a liquid-to-solid transition, leading to pathogenic conditions. To decipher the underlying mechanisms, synthetic LLPS has been examined through complex coacervate formation from charged polymers. Nonetheless, temporal control over phase transitions from prebiotically relevant small organic synthons remains largely unexplored. Herein, we propose utilizing pH modulation to regulate the charge of small molecular building blocks, thereby controlling the LLPS process. Through a bio-inspired, enzyme-mediated pH-regulated reaction, we introduce temporal control over both LLPS and the transition from coacervates to supramolecular polymers. Additionally, by incorporating antagonistic pH modulators, we achieve transient LLPS and further temporal regulation of supramolecular polymer disassembly. Our investigation into pH-regulated LLPS provides a new avenue for exploring the stimuli-responsive, dynamic, and transient nature of LLPS.

Optogenetic control of cAMP oscillations reveals frequency-selective transcription factor dynamics in Dictyostelium.

Oscillatory dynamics and their modulation are crucial for cellular decision-making; however, analysing these dynamics remains challenging. Here, we present a tool that combines the light-activated adenylate cyclase mPAC with the cAMP biosensor Pink Flamindo, enabling precise manipulation and real-time monitoring of cAMP oscillation frequencies in Dictyostelium. High-frequency modulation of cAMP oscillations induced cell aggregation and multicellular formation, even at low cell densities, such as a few dozen cells. At the population level, chemotactic aggregation is driven by modulated frequency signals. Additionally, modulation of cAMP frequency significantly reduced the amplitude of the shuttling behaviour of the transcription factor GtaC, demonstrating low-pass filter characteristics capable of converting subtle oscillation changes, such as from 6 min to 4 min, into gene expression. These findings enhance our understanding of frequency-selective cellular decoding and its role in cellular signalling and development.

Focusing on the mechanism of glycinin-soybean lipophilic protein hybrid gels: Effect of ultrasonic, subunit interactions, and formation process analysis.

Heat facilitates aggregation and gel formation of soybean proteins. Ultrasonic reduces the size of protein aggregates. This study examined the impact of glycinin (11S) subunits on soybean lipophilic proteins (SLPs) gel formation and underlying mechanisms. Effects of protein dispersion pretreatment with 400W ultrasonic and associated mechanisms were assessed. Addition of the A- and B-subunits before and after ultrasonic minimally affected SLP secondary structure. A-subunit addition before ultrasonic negligibly affected SLP tertiary structure. Addition of the B-subunit after ultrasonic reduced hydrophobic thermal aggregation. However, the small B-subunit size was unfavorable for the formation of a gel matrix, which led to poor gel properties. In contrast, solubility of the A-subunit after ultrasonic was increased to 31.06±1.62%). Particle size was decreased to 43.33±1.36nm for A:SLP (1:2). Endogenous fluorescence spectroscopy demonstrated increased protein unfolding after ultrasonic and decreased disulfide bonds. These changes improved the gel state. Rheological and microstructural analyses revealed increased energy storage modulus and yield strain, accompanied by a more homogeneous microstructure following ultrasonic. Microscopic improvement resulted in increased encapsulated water within interstitial spaces of the A-SLP gel matrix. This enhanced water mobility in B-SLP gels, in turn weakening gel stability. The changes observed in B-SLP were primarily due to reduced hydrophobic interactions between the proteins. The findings clarify the effect of ultrasonic treatment on the formation of soybean globulin-SLP hybrid gels at the subunit level. The data provide a theoretical basis for the synergistic utilization of soybean proteins among different components.

Engineering Soil Quality and Water Productivity Through Optimal Phosphogypsum Application Rates

Water scarcity and soil degradation pose challenges to sustainable agriculture. Phosphogypsum, a low-cost solid waste, shows potential as a soil amendment, but its impact on water saving and soil quality need further study. This research assessed the effects of phosphogypsum application rates (CK: no phosphogypsum, 0.075%, 0.15%, 0.3% and 0.6%) on soil infiltration, water retention, salinity, soil quality, crop yield and irrigation water productivity (IWP) to identify the optimal rate. Phosphogypsum application altered pore structure and water potential gradients, slowing wetting front migration, increasing infiltration duration (102 to 158 min), cumulative infiltration (17.37 to 27.44 cm) (p < 0.05) and soil water content (18.25% to 24.33%) (p < 0.05) as the rate increased from CK to 0.6%. It also enhanced water retention by enhancing soil aggregation and reducing evaporation.By promoting the formation and stabilization of soil aggregates, phosphogypsum application (CK to 0.6%) reduced bulk density from 1.20 g/cm3 to 1.12 g/cm3 (p < 0.05), while porosity, available nitrogen and urease activity increased by 3.70%, 39.42% and 82.61%, respectively (p < 0.05). These enhancements provided a strong foundation for improved crop performance. Specifically, phosphogypsum enhanced yield through three pathways: (1) improving soil physical properties, which influenced soil nutrients and then improved enzyme activities; (2) directly affecting soil nutrients, which impacted enzyme activities and increased yield; and (3) directly boosting enzyme activities, leading to increased yield. The comprehensive benefits of phosphogypsum initially increased and then decreased, with an optimal application rate of 0.45% determined through TOPSIS, a method that ranks alternatives based on their proximity to an ideal solution, considering factors including soil quality, crop yield and IWP. These findings confirm the feasibility of phosphogypsum as an effective resource to enhance water efficiency and soil quality, promoting sustainable agricultural practices.

Engineered Polystyrene‐Zirconium Dioxide Nanocomposite With Enhanced Optical Properties

ABSTRACTThe demand for transparent polymers with high‐refractive indices (RIs) is increasing due to their versatility; however, low RIs also hold significance. Engineering the RI of polymer nanocomposites is crucial which benefits industry and research. The study investigates the influence of ZrO2 nanoparticles on the optical and surface properties of the polystyrene matrix. UV–Vis spectroscopy confirms that transparency is maintained with a light transmittance of 90 even with a ZrO2 loading of 16 wt%, while ellipsometry shows a steady increase in the RI due to the incorporation of nanoparticles. The RI of composites exceeds that of pure polystyrene (RI: 1.3–1.7) and utilizes the RI of ZrO2 (> 2.00) without altering the sample thickness. The microscopic image shows uniform distribution of particles up to 8 wt%, with slight agglomeration at higher contents. Scanning electron microscopy examination shows that the ZrO2 nanoparticles (20–150 nm) form loose agglomerated structures, while atomic force microscopy examination shows aggregate formation at 16 wt%. The addition of ZrO2 increases the surface roughness and water contact angle up to 4 wt%, which is related to the concentration of the nanofiller and the minimal interaction between ZrO2 and water. The results demonstrate the potential of ZrO2‐loaded nanocomposites for applications requiring high RIs and optical transparency.

Formation of Amyloid-Like Conformational States of β-Structured Membrane Proteins on the Example of the OmpF Porin from the <i>Yersinia pseudotuberculosis</i> Outer Membrane

The work presents the results of an in vitro and in silico study of the formation of amyloid-like structures under harsh denaturing conditions by the nonspecific OmpF porin of Yersinia pseudotuberculosis (YpOmpF), a membrane protein with a β-barrel conformation. It has been shown that in order to obtain amyloid-like porin aggregates, preliminary destabilization of its structure in a buffer solution with an acidic pH value at elevated temperature, followed by long-term incubation at room temperature is necessary. After heating at 95 °C in a solution with pH 4.5, significant conformational rearrangements are observed in the porin molecule at the level of the tertiary and secondary structure of the protein, which are accompanied by an increase in the content of the total β-structure and a sharp decrease in the value of the characteristic viscosity of the protein solution. Subsequent long-term exposure of the resulting unstable intermediate YpOmpF at room temperature leads to the formation of porin aggregates of various shapes and sizes that bind thioflavin T, a specific fluorescent dye for the detection of amyloid-like protein structures. Compared to the initial protein, early intermediates of the amyloidogenic porin pathway, oligomers, have been shown to have increased toxicity to Neuro-2aCCL-131™ mouse neuroblastoma cells. The results of computer modeling and analysis of changes in intrinsic fluorescence during protein aggregation suggest that during the formation of amyloid-like aggregates, changes in the structure of YpOmpF affect not only areas with an internally disordered structure corresponding to the external loops of the porin, but also the main framework of the molecule, which has a rigid spatial structure inherent to β-barrel.

Investigating the ROS Formation and Particle Behavior of Food-Grade Titanium Dioxide (E171) in the TIM-1 Dynamic Gastrointestinal Digestion Model.

Food-grade titanium dioxide (E171) is widely used in food, feed, and pharmaceuticals for its opacifying and coloring properties. This study investigates the formation of reactive oxygen species (ROS) and the aggregation behavior of E171 using the TNO Gastrointestinal (GI) model, which simulates the stomach and small intestine. E171 was characterized using multiple techniques, including electron spin resonance spectroscopy, single-particle inductively coupled plasma-mass spectrometry, transmission electron microscopy, and dynamic light scattering. In an aqueous dispersion (E171-aq), E171 displayed a median particle size of 79 nm, with 73-75% of particles in the nano-size range (<100 nm), and significantly increased ROS production at concentrations of 0.22 and 20 mg/mL. In contrast, when E171 was mixed with yogurt (E171-yog), the particle size increased to 330 nm, with only 20% of nanoparticles, and ROS production was inhibited entirely. After GI digestion, the size of dE171-aq increased to 330 nm, while dE171-yog decreased to 290 nm, with both conditions showing a strongly reduced nanoparticle fraction. ROS formation was inhibited post-digestion in this cell-free environment, likely due to increased particle aggregation and protein corona formation. These findings highlight the innate potential of E171 to induce ROS and the need to consider GI digestion and food matrices in the hazard identification/characterization and risk assessment of E171.

Impairment of lipid homeostasis causes lysosomal accumulation of endogenous protein aggregates through ESCRT disruption.

Protein aggregation increases during aging and is a pathological hallmark of many age-related diseases. Protein homeostasis (proteostasis) depends on a core network of factors directly influencing protein production, folding, trafficking, and degradation. Cellular proteostasis also depends on the overall composition of the proteome and numerous environmental variables. Modulating this cellular proteostasis state can influence the stability of multiple endogenous proteins, yet the factors contributing to this state remain incompletely characterized. Here, we performed genome-wide CRISPRi screens to elucidate the modulators of proteostasis state in mammalian cells, using a fluorescent dye to monitor endogenous protein aggregation. These screens identified known components of the proteostasis network and uncovered a novel link between protein and lipid homeostasis. Increasing lipid uptake and/or disrupting lipid metabolism promotes the accumulation of sphingomyelins and cholesterol esters and drives the formation of detergent-insoluble protein aggregates at the lysosome. Proteome profiling of lysosomes revealed ESCRT accumulation, suggesting disruption of ESCRT disassembly, lysosomal membrane repair, and microautophagy. Lipid dysregulation leads to lysosomal membrane permeabilization but does not otherwise impact fundamental aspects of lysosomal and proteasomal functions. Together, these results demonstrate that lipid dysregulation disrupts ESCRT function and impairs proteostasis.

Aprotic Electrolytes Beyond Organic Carbonates: Transport Properties of LiTFSI Solutions in S-Based Solvents.

This work illustrates a physico-chemical study of the structural, dynamic, and transport properties of electrolytes made of LiTFSI solutions in sulphoxide and sulphone solvent mixtures. Experimental measurements, by Raman and NMR spectroscopies, as well as electrochemical impedance spectroscopy, reveal the formation of a variety of ionic aggregates depending on the solvent composition that significantly affect the ion mobility and conductivity of the electrolyte. Mixtures containing tetrahydrothiophene-1-oxide exhibit a larger ion mobility due to a rapid exchange mechanism between solvent molecules, whereas the use of tetramethylene sulphone favors the formation of ionic aggregates due to the strong dipolar interactions between solvent molecules.

Benzoylmesaconine alters the native structure and activity of hen egg white lysozyme: revealing possible mechanism of aconitum-induced toxicity.

This study examines the interaction between benzoylmesaconine (BMA) and hen egg white lysozyme (HEWL) under various physiological conditions, aiming to determine how BMA affects the HEWL's structure and function. Several analytical techniques were used, including tryptophan assay, light scattering, thioflavin T (ThT)-binding assay, dynamic light scattering, 8-anilino-1-naphthalenesulfonic acid (ANS)-binding assay, circular dichroism (CD) spectroscopy, enzyme activity assay, and molecular docking. The tryptophan assay displayed a concentration-dependent decrease in tryptophan fluorescence, showing an interaction between BMA and HEWL. Light scattering and ThT-binding assays confirmed increased protein aggregation and amyloid fibril formation, while the ANS-binding assay demonstrated altered exposed hydrophobic regions, implying structural changes. CD spectroscopy showed a reduction in α-helix content, indicating conformational alterations, and enzyme activity assays showed a loss of lytic function due to structural distortion. Finally, molecular docking identified significant bonds and hydrophobic interactions between BMA and HEWL residues. BMA binding induces structural changes in proteins, forming small oligomers and amyloid fibrils that decrease HEWL enzymatic activity and disrupt functional integrity.

Preparation of cellulose-based fluorescent aggregations with various morphologies and their microstructure-correlated fluorescence behavior.

We provided an efficient method for preparing fluorescent materials with high specificity. Firstly, the cellulose-based aggregations with adjustable morphologies and sizes were obtained by cross-linking copolymerization and self-assembly. Then, after encapsulating the fluorescein isothiocyanate (FITC) into the hydrophobic microregions of the cellulose-based aggregations by ultrasound/dialysis method, a series of cellulose-based fluorescent aggregations with different morphologies was obtained. The flower-like, tentacle-like, microsphere, hollow sphere, coral-like and solid sphere fluorescent aggregations could be obtained by changing the mass ratio of cellulose to gelatin, the degree of alkylation and the length of the alkyl chain. Scanning electron microscope (SEM), Dynamic light scattering (DLS), UV-vis and Zeta potential confirmed the formation of the cellulose-based aggregations with different morphologies and sizes, which provided basis for the successful encapsulation of FITC. The flower-like fluorescent aggregation showed the maximum fluorescence intensity. This was due to the rigid structure of cellulose, electrostatic repulsion, hydrogen bonding, and the larger surface area in flower-like aggregation, which was conducive to inhibiting π-π stacking and hydrogen bonding interaction of FITC, thus promoting the electron radiative transition. Also, cellulose-based fluorescent aggregation could be processed into fluorescent fiber, coating and printing pattern, and had potential applications in information storage, scene warning, and special fiber.