Size Control Research Articles

Hydrophobic iron oxide nanoparticles: Controlled synthesis and phase transfer via flash nanoprecipitation

Iron oxide nanoparticles (IONPs) synthesized via thermal decomposition find diverse applications in biomedicine owing to precise control of their physico-chemical properties. However, use in such applications requires phase transfer from organic solvent to water, which remains a bottleneck.Through the thermal decomposition of iron oleate (FeOl), we systematically investigate the impact of synthesis conditions such as oleic acid (OA) amount, temperature increase rate, dwell time, and solvent on the size, magnetic saturation, and crystallinity of IONPs. Solvent choice significantly influences these properties, manipulating which, synthesis of monodisperse IONPs within a tunable size range (10-30 nm) and magnetic properties (75 to 42 Am2Kg-1) is obtained.To enable phase transfer of IONPs, we employ flash nanoprecipitation (FNP) for the first time as a method for scalable and precise size control, demonstrating its potential over conventional methods. Poly(lactic-co-glycolic acid) (PLGA)-coated IONPs with hydrodynamic diameter (Hd) in the range of 250 nm, high colloidal stability and high IONPs loadings up to 43% were obtained, such physicochemical properties being tuned exclusively by the size and hydrophobicity of starting IONPs. They showed no discernible cytotoxicity in human dermal fibroblasts, highlighting the applicability of FNP as a novel method for the functionalization of hydrophobic IONPs for biomedicine.

On the adaptive solution of phase‐field problems with A‐stable explicit last‐stage diagonally implicit Runge–Kutta (ELDIRK) methods

AbstractRunge–Kutta algorithms with adaptive step size control provide reliable tools for the solution of initial value problems with diagonally implicit Runge‐Kutta (DIRK) methods as the most common approach. In this contribution, the new low‐order explicit last‐stage diagonally implicit Runge–Kutta (ELDIRK) methods are investigated, combining implicit schemes with an additional explicit evaluation as an explicit last stage. This results in Butcher tableaus with two solutions of different convergence orders suitable for embedded methods, where the higher‐order solution is achieved by additional explicit evaluations. Thus, the iterative solution of non‐linear systems is omitted for the additional stage, presenting a major reduction in computational cost for the determination of a local error estimate. The key contribution is the application of the novel Butcher tableaux to phase‐field problems, solved with the finite‐element method, leading to substantial numerical investigations with an efficient approach for DIRK schemes. The most important aspects are the investigations of stability properties which lead to the novel class of A‐stable ELDIRK methods. In accordance, the study of the convergence orders is presented. A local error estimator is presented, such that adaptive step size control for the new low‐order embedded schemes based on an empirical approach for error estimation is achieved. A suitable parallel algorithm is presented with conclusive two‐dimensional phase‐field simulations based on a Kobayashi‐Warren‐Carter model. The higher‐order convergence suggested by the novel schemes is confirmed, and their effective results are demonstrated, resulting in a valuable semi‐explicit addition to the family of Runge–Kutta time integration schemes.

Enhanced Lithium Extraction from Brines: Prelithiation Effect of FePO4 with Size and Morphology Control.

Extracting lithium resources from seawater and brine can promote the development of the new energy materials industry. The electrochemical method is green and efficient. Iron phosphate (FePO4) crystal, with its 1D ion channel, holds significant potential as a primary lithium extraction electrode material. Li+ encounters a substantial concentration disadvantage in brines, and the co-intercalation of Na+ diminishes Li+ selectivity. To address this issue, this work enhances the energy barrier for Na+ insertion through prelithiation strategies applied to the 1D channels of FePO4 crystal, thereby improving Li+ selectivity, and further investigating the prelithiation effect with particle size and morphology control. The results indicate that the Li(4C-40%)FePO4// Activated carbon(AC) system enhances selectivity of lithium. The Li(4C-40%)FePO4 with size diameter of 2500nm demonstrates an energy consumption of 0.79Whmol-1 and a purity of 97.94% for lithium extraction at a unit lithium extraction of 5.93mmolg-1 in simulated brine. Li(4C-40%)FePO4-nanoplates demonstrate the most optimal lithium extraction performance among the three morphologies due to their lamellar structure's short ion diffusion path in the [010] channel, favoring Li+ diffusion. The diffusion energy barriers of Li+ and Na+ are calculated using Density Functional Theory (DFT) before and after prelithiation, showing good agreement with experimental results.

Incubation of Amyloidogenic Peptides in Reverse Micelles Allow Active Control of Oligomer Size and Study of Protein-Protein Interactions.

Studies of the structure and dynamics of oligomeric aggregates of amyloidogenic peptides pose challenges due to their transient nature. This concept article provides a brief overview of various nucleation mechanisms with reference to the classical nucleation theory and illustrates the advantages of incubating amyloidogenic peptides in reverse micelles (RMs). The use of RMs not only facilitates size regulation of oligomeric aggregates but also provides an avenue to explore protein-protein interactions among the oligomeric aggregates of various amyloidogenic peptides. Additionally, we envision the feasibility of preparing brain tissue-derived oligomeric aggregates using RMs, potentially advancing the development of monoclonal antibodies with enhanced potency against these pathological species in vivo.

A non-classical synthetic strategy for organic mesocrystals.

Mesocrystals are ordered nanoparticle superstructures, often with internal porosity, which receive much recent research interest in catalysis, energy storage, sensors, and biomedicine area. Understanding the mechanism of synthetic routes is essential for precise control of size and structure that affect the function of mesocrystals. The classical synthetic strategy of mesocrystal was formed via self-assembly of nanoparticles with a faceted inorganic core but a denser (or thicker) shell of organic molecules. However, the potential materials and synthetic handles still need to be explored to meet new applications. In this work, we develop a non-classical synthetic strategy for organic molecules, such as tetrakis (4-hydroxyphenyl) ethylene (TPE-4OH), tetrakis (4-bromophenyl) ethylene (TPE-4Br), and benzopinacole, to produce mesocrystals with composed of microrod arrays via co-solvent-induced crystal transformation. The aligned nanorods are grown epitaxially onto organic microplates, directed by small lattice mismatch between plates and rods. Thus, the present work offers general synthetic handle for establishing well-organized organic mesocrystals.

WOX11-mediated cell size control in Arabidopsis attenuates growth and fecundity of endoparasitic cyst nematodes.

Cyst nematodes establish permanent feeding structures called syncytia inside the host root vasculature, disrupting the flow of water and minerals. In response, plants form WOX11-mediated adventitious lateral roots at nematode infection sites. WOX11 adventitious lateral rooting modulates tolerance to nematode infections; however, whether this also benefits nematode parasitism remains unknown. Here, we report on bioassays using a 35S::WOX11-SRDX transcriptional repressor mutant to investigate whether WOX11 adventitious lateral rooting promotes syncytium development and thereby female growth and fecundity. Moreover, we chemically inhibited cellulose biosynthesis to verify if WOX11 directly modulates cell wall plasticity in syncytia. Finally, we performed histochemical analyses to test if WOX11 mediates syncytial cell wall plasticity via reactive oxygen species (ROS). Repression of WOX11-mediated transcription specifically enhanced the radial expansion of syncytial elements, increasing both syncytium size and female offspring. The enhanced syncytial hypertrophy observed in the 35S::WOX11-SRDX mutant could be phenocopied by chemical inhibition of cellulose biosynthesis and was associated with elevated levels of ROS at nematode infection sites. We, therefore, conclude that WOX11 restricts radial expansion of nematode-feeding structures and female growth and fecundity, likely by modulating ROS-mediated cell wall plasticity mechanisms. Remarkably, this novel role of WOX11 in plant cell size control is distinct from WOX11 adventitious lateral rooting underlying disease tolerance.

Sequence-Dependent Single-Molecule DNA Sensing Using Covalent Organic Framework Nanopores.

Enzyme-free single-molecule sequencing has the potential to significantly expand the application of nanopore technology to DNA, proteins, and saccharides. Despite their advantages over biological nanopores and natural suitability for enzyme-free single-molecule sequencing, conventional solid-state nanopores have not yet achieved single-molecule DNA sequencing. The biggest challenge for the accuracy of single-molecule sequencing using solid-state nanopores lies in the precise control of the pore size and conformity. In this study, we fabricated nanopore devices by covering the tip of a quartz nanopipette with ultrathin two-dimensional (2D) covalent organic framework (COF) nanosheets (pore size ≈ 1.1 nm). The size of the periodically arranged nanopores in COF is comparable to that of protein nanopores, and the structure of each COF nanopore is consistent at the atomic scale. The COF nanopore device could roughly distinguish dAMP, dCMP, dGMP, and dTMP. Furthermore, a certain percentage of the current blockades originating from 150 nucleotides model DNA molecules (13.5% for dA50dC50dA50 and 11.1% for dC50dA50dC50) show distinct DNA sequence-specific concave and convex resistive current patterns. The finite element simulation confirmed that the current blockade pattern of a DNA molecule passing through a COF nanopore is dependent on the relative location of the nanopore with respect to the wall of the nanopipette. Our study is a significant step toward single-molecule DNA sequencing by solid-state nanopores.

Low Silver/Copper Exchange in a Copper-Phosphate Enzyme Nanoflower Hybrid Extremely Enhanced Antimicrobial Efficacy against Multidrug Resistant Bacteria.

Infections caused by bacteria that are resistant to many drugs are a major threat to public health in many countries around the world. Here we demonstrate the creation of heterogeneous catalytic nanomaterials with outstanding antimicrobial properties against several superbugs. We have shown that replacing a small amount of copper in a generated copper-phosphate-enzyme nanoflower hybrid with silver drastically increases the antimicrobial capacity of the nanomaterial. In this sense, it has been confirmed that the exchange generated silver phosphate nanoparticles on the Cu nanoflowers, with control of the nanoparticle diameter size. The Fenton catalytic activity of the Ag-containing nanobiohybrids was affected, showing better performance with lower amounts of silver in the final hybrid. This effect was confirmed by their antimicrobial efficacy against Escherichia coli, where the Ag4Cu32@CALB hybrid displayed a log reduction of 3.9, an efficiency more than 5000 times higher than that obtained with copper nanoflowers (Cu36@CALB). The hybrid also showed excellent efficacy against other bacteria such as Klebsiella pneumoniae, Pseudomonas aeruginosa, and Mycobacterium smegmatis with log reductions of 7.6, 4.3, and 1.8, respectively.

An improved Takagi–Sugeon–Kang-based FxLMS algorithm and its active noise control in electric bus driving position

This paper proposed an improved filtered-x least mean square (FxLMS) algorithm based on the fuzzy control rule of Takagi–Sugeon–Kang (TSK) to solve the drawback of slow convergence for standard FxLMS algorithm. The TSK-FxLMS is a control framework with two inputs and three outputs constructed by the error signal and its integral as input variables. To validate its effectiveness and applicability, in-vehicle active noise control (ANC) modelling and adaptive noise reduction at the driver’s position of an electric bus are thoroughly investigated. Firstly, the four noise signals for the different working conditions at 50 km/h, acceleration, coasting and braking are collected, and their spectral analyses are performed. Secondly, the effects of step size and fuzzy control parameters of ANC model on weight convergence and noise reduction effect are analysed and determined. Finally, the results of calculating and comparing the residual signals’ waveforms, frequency spectra, sound pressure levels and tracking performance indicate that the proposed TSK-FxLMS algorithm outperforms the standard FxLMS algorithm with faster convergence and better noise reduction effect.

Quantitative label-free digital holographic imaging of cardiomyocyte optical volume, nucleation, and cell division

Cardiac regeneration in newborn rodents depends on the ability of pre-existing cardiomyocytes to proliferate and divide. This capacity is lost within the first week of postnatal development when these cells rapidly switch from hyperplasia to hypertrophy, withdraw from the cell cycle, become binucleated, and increase in size. How these dynamic changes in cell size and nucleation impact cardiomyocyte proliferative potential is not well understood. In this study, we innovate the application of a commercially available digital holographic imaging microscope, the Holomonitor M4, to evaluate the proliferative responses of mononucleated and binucleated cardiomyocytes after CHIR99021 treatment, a model proliferative stimulus. This system enables long-term label-free quantitative tracking of primary cardiomyocyte dynamics in real-time with single-cell resolution. Our results confirm that chemical inhibition of glycogen synthase kinase 3 with CHIR99021 promotes complete cell division of both mononucleated and binucleated cardiomyocytes with high frequency. Quantitative tracking of cardiomyocyte volume dynamics during these proliferative events revealed that both mononucleated and binucleated cardiomyocytes reach a similar size-increase threshold prior to attempted cell division. Binucleated cardiomyocytes attempt to divide with lower frequency than mononucleated cardiomyocytes, which may be associated with inadequate increases in cell size. By defining the interrelationship between cardiomyocyte size, nucleation, and cell cycle control, we may better understand the cellular mechanisms that drive the loss of mammalian cardiac regenerative capacity after birth.

Sustainable synthesis of iron oxide nanopigments: Enhancing pigment quality through combined air oxidation and cavitation techniques

This study investigates the synthesis and characterization of iron oxide pigments through various methods, including air oxidation, co-precipitation, and hydrodynamic cavitation. The infrared (IR) spectral analysis revealed key functional groups and metal-oxide bonds indicative of goethite, with bands associated with O–H stretching and Fe–O vibrations. The study also explores how different conditions, such as temperature, pH, and reactant ratios, affect the color, yield, and particle size of the pigments produced. Through batch and continuous synthesis processes, it was found that cavitation offers a more controlled particle size distribution compared to other methods. The experiments highlight the influence of parameters like temperature, pH, and NaOH concentration on the final pigment properties, with optimized conditions yielding high-quality pigments. The comparison of synthetic methods demonstrates the trade-offs in terms of reaction complexity, particle size control, and yield, emphasizing the potential of hydrodynamic cavitation for efficient and scalable pigment production. The study concludes by summarizing the versatile reactions of FeSO4 and NaOH in producing various iron oxide and oxyhydroxide materials, which are valuable in industrial and environmental applications.

From personality types to social labels: the impact of using MBTI on social anxiety among Chinese youth.

As the Myers-Briggs Type Indicator (MBTI) gains popularity among Chinese young people, it has undergone a gradual transition from being perceived as a personality assessment tool to being regarded as a social label. The objective of this study was to ascertain whether the use of the MBTI as a social label has an impact on social anxiety among Chinese youth groups. A questionnaire survey was conducted on social media platforms to recruit Chinese youth aged 18 to 35. A total of 247 males and 222 females participated in the study, and the data was analyzed quantitatively using SPSS software and the Process macro plugin. The study found no strong correlation between MBTI as a social label and social anxiety. Moreover, this study introduced ego identity, belonging, and impression management as mediating variables and found that, under the influence of ego identity and impression management, the use of MBTI has a significant impact on social anxiety. The research reveals the complex role of MBTI among Chinese youth and provides a new perspective for understanding the impact of online social labels on the mental health of youth groups. Of course, this study also has limitations in terms of sample size and variable control. Future research should expand the sample size, introduce more potential influencing factors, and further validate and expand the existing conclusions.

Inducing high-concentration Tb3+ with free oxygen via atomic layer deposition

Precise preparation and control of trivalent states in rare earth metal oxide films are crucial for their optical and magnetic applications. In this study, compact and continuous terbium-doped nanofilms were deposited on silica substrates using atomic layer deposition (ALD). The average nanoparticle size varied from 17.9 to 78.5 nm with increasing growth cycles. X-ray photoelectron spectroscopy showed that the Tb3+/Tb4+ ratio increased from 0.98 to 1.42. A valence reduction mechanism involving free oxygen was introduced to analyze the reasons for the enhanced Tb3+ concentration in the nanofilms. The enhanced photoluminescence of Tb3+ (5D4→7F5) ions and the increased magnetization in terbium oxide nanofilms both reveal that free oxygen ions are the effective active sites responsible for the transition from the tetravalent to the trivalent state, in excellent agreement with theoretical analysis. Size control and free oxygen induction are promising strategies for enhancing the optical and magnetic properties of multivalent rare earth oxides.

Piecewise modified Prandtl-Ishlinskii model for precise nano-positioning

Piezoelectric ceramic, an indispensable micro-nano actuator, has advantages of small size, high sensitivity and strong controllability, which is widely applied in various fields like micro-nano processing, medicine, chemistry and materials. However, its nonlinear and asymmetric hysteresis features directly affect its positioning accuracy. The classical and generalized Prandtl-Ishlinskii models with linear symmetry operators are commonly used to deal with these issues, but they still face difficulties in asymmetric systems. Therefore, a piecewise modified Prandtl-Ishlinskii (PMPI) model is proposed to compensate nonlinear and asymmetric hysteresis in this paper. The new nonlinear operator and piecewise nonlinear envelope function are introduced into the PMPI model. Independent right and left parts are adopted to describe hysteresis increasing and decreasing stages, while the threshold and weight vectors correspond to them. Weight vectors are extended and a new diagonal matrix is constructed for avoiding excessive parameters and computation. Simulations and experiments are shown that the PMPI model has good compensation performance and effectiveness, which has better fitting, higher accuracy, fewer parameters and computation, and can be well applied to the precise nano-positioning systems with less nonlinear and asymmetric errors.

Computational Thermodynamics and Kinetics of Aluminum Nitride Precipitation in Steel—An Overview with Emphasis on Austenitic Grain Size Control

Computational Thermodynamics and Kinetics of Aluminum Nitride Precipitation in Steel—An Overview with Emphasis on Austenitic Grain Size Control

Green Capping Agents and Digestive Ripening for Size Control of Magnetite for Magnetic Fluid Hyperthermia

Background: Magnetite is the most recognized iron oxide candidate used for various biological applications. Objective: This work is a complete study that addresses the synthesis of magnetic nanoparticles and investigates the feasibility of using green tea and ascorbic acid as capping agents. Methods: Synthesis of magnetite by two wet chemical methods namely: coprecipitation and solvothermal methods. The samples were characterized using X-ray diffraction (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM). Results: The results reveal the impact of coating on the size and morphology of the particles. The study also proves that autoclaving the samples prepared by coprecipitation results in smaller particle size and narrower size distribution due to digestive ripening. In addition, a novel and facile methodology for coating magnetite with polyethylene glycol is presented. The potential of the particles to be used for magnetic fluid hyperthermia is assessed by measuring the specific absorption rate (SAR) of the samples. Conclusión: The results show that all the prepared magnetite samples showed a promising capacity to be used as magnetic fluid hyperthermia agents.

Toward Understanding Mechanistic Regulation of Body Size and Growth Control in Bivalve Mollusks

ABSTRACTBivalves possess a pair of valves connected to a stretchable ligament that facilitates the opening and closing of the shell. The growth bioprocess commences when the supplemental materials secreted from the edge are added to the early‐constructed shell. Here, we endeavor to provide a glimpse into physiological responses, mechanistic control, and omics applications toward understanding this complex trait. In the first section, we review studies that have been performed to investigate the effects of food availability, temperature, salinity, contaminants, and climate change in natural ecosystems and under experimental conditions. These conditions affect some internal promotors and alter the concentration of particular neuropeptides and neurotransmitters that induce neuroendocrinal signals crucial for regulating this peculiar process. Besides, we provide a predicted concept for organs' size control and maintaining body size homeostasis via intertwining networks, including the Hippo pathway. On the other hand, we discuss the findings of studies employing genomics, transcriptomics, proteomics, and metabolomics approaches to uncover the mechanistic modulation of growth‐related traits in different bivalve species. We recommend further research to decipher organ size control and its intricate relationship with the entire body homeostasis. Future genetic dissection studies are also recommended to identify new key genes with a major effect that profoundly influences this trait, facilitating their potential editing to develop new strains with enhanced growth rates.

Facile‐Prepared Size‐Controllable Nanogels for Enhancing Bidirectional Translocation, Control Efficiency, and Security of Nanopesticide

AbstractNanopesticides have been acknowledged by International Union of Pure and Applied Chemistry as a critical tool for revolutionizing future agricultural practices. However, the existing nanopesticides are often plagued by high costs, strict preparation conditions, uncontrollable size, and poor stability. Herein, taking the non‐systemic insecticide lambda‐cyhalothrin (LC) as a model pesticide, a series of LC‐loaded poly(octyl acrylate) nanogel formulations (LONFs) simultaneously featuring easy‐preparation, size‐controllable, and targeted delivery using microemulsion polymerization are developed. By adjusting the ratio of surfactants, the size of LONFs can be accurately designed to be 20, 50, 100, and 200 nm, exhibiting good stability under unconventional storage conditions (0 °C, 54 °C, ultraviolet radiation). Furthermore, reducing the particle diameter enhances the bidirectional translocation of LONFs in Vicia faba L., potentially reaching an optimal diameter (≈20 nm) for unique and rapid transport. LONFs increase the acute toxicity of LC to Aphis craccivora compared to conventional microemulsions (with a maximum reduction of 82.40% in LC50 at 24 h). Additionally, LONFs alter the lethal process of LC in human embryonic kidney 293T cells, with minimal cytotoxicity at a concentration of general application (40 mg L−1). This strategy simultaneously considers convenience, size controllability, and efficiency, providing a feasible method for the industrial development of nanopesticides.

Individual differences in baseline eye movement indices: Examining the relationships between baseline pupil size, inhibitory control, and fixation stability.

The relationship among baseline pupil size, fixation stability, and inhibitory control were examined in this study. Participants performed a baseline eye measure in which they were instructed to stare at a fixation dot on screen for 2 min. Following the baseline eye measure, participants completed an antisaccade task to measure inhibitory control ability. We found a correlation between baseline pupil size variability and inhibitory control, as well as between fixation stability and inhibitory control. We showed that participants with better inhibitory control exhibited larger variability in pupil size, and those with better fixation stability showed superior inhibitory control ability. Overall, our results indicate that there are significant correlations between inhibitory control and baseline pupil size, as well as between inhibitory control and fixation stability.

Expandable rotational origami nano-boxes made by giant shape amphiphile

Dynamic cavity is widespread in living matter and supramolecular scaffolds. Generally speaking, flexible building block as a segment is used to realize dynamic cavities building in artificial molecules and materials. However, the incorporation of rigid synthetic supramolecular scaffolds with flexible cavity motion remains rare. Inspired by rotational origami patterns, giant shape amphiphile (GSA), POSS-NDI-POSS (PNP), assembled into an origami nano-box with feature of rotational expansion. The open/close of cavity and size control of PNP host can be adjusted by rotational offset between adjacent PNP in supramolecule entities. The rotational offset of 150°, 130° and 0° were observed when the host nano-box presented close, half-open and fully-open state, respectively. The rotational expansion of PNP trigged by gaseous arenes makes PNP as a novel nonporous crystal. Compared with conformation change in flexible building segment, rotational expansion in acyclic host (PNP) provides a new strategy for the development of rigid segment to build adaptive host-guest recognition.