Size Parameters Research Articles

Anatomical study of the C6 pedicle and lateral mass in children aged 0–14 years based on CT imaging

ObjectiveThis study aims to investigate the anatomical structure of the C6 pedicle and lateral mass in children aged 0–14 years using CT imaging, providing detailed insights into their growth and development.MethodsWe conducted a comprehensive measurement of C6. Measurements included width, length, and height of the pedicles, as well as the length, width, and thickness of the lateral masses, and several angular metrics. Regression analysis was performed to understand the growth trends, and statistical analyses were carried out to identify differences between age groups, genders, and sides.ResultsIn children younger than four years, the pedicle width exceeds its height, influencing the diameter of the pedicle screws. By age two to three, the pedicle height and lateral mass thickness reaches 3.0 mm, allowing for the use of 3.0 mm diameter screws. The pedicle transverse angle remains stable. Most parameters showed no significant differences between the left and right sides. Size parameters exhibited significant larger in males than females at ages 0–1, 3–7, and 10–12 years. Regression analysis revealed that the growth trends of size parameters follow cubic or polynomial curves. Most angular metrics follow cubic fitting curves without a clear trend of change with age.ConclusionThis study provides a detailed analysis of the anatomical development of the C6 pedicle and lateral masses in children, offering valuable insights for pediatric cervical spine surgeries. The findings highlight the importance of considering age-specific anatomical variations when planning posterior surgical fixation, specifically at C6. It is necessary for us to perform thin-layer CT scans on children and carefully measure various indicators before surgery.

Photoluminescence, cytotoxic and oxygen evolution reaction kinetics studies of silver doped haematite nanoparticles

Fe2O3: Ag(1–9 mol %) nanoparticles (NPs) have been synthesized through the co-precipitation method. Crystallite size, phase, crystallinity, and structural parameters were analyzed by using powder X-ray diffraction. The Bragg reflections confirm that the synthesized NPs crystallize in hexagonal crystal structure with space group R-3c. Surface morphology consists of agglomerated irregular size and roughly spherical-shaped NPs. Energy Dispersive Analysis of X-ray confirms the presence of Fe, O, and Ag elements and also the purity of the sample. Crystallite size decreased with the increase in dopant concentration. Direct band gap energy is found to increase with an increase in dopant concentration. Photoluminescence and anticancer properties were studied in detail. The CIE coordinates confirm red emission in the visible region. CIE and CCT co-ordinate values indicate cool light emission, hence, the synthesized nanophosphor material meets the demand of display technology. Further anticancer properties were investigated on HeLa cells and compared with the standard drug cisplatin for biomedical applications. Further, Oxygen evolution reaction kinetics was investigated for Fe2O3:Ag (1 mol %) nanoparticles. demonstrates enhanced oxygen evolution reaction performance with a low overpotential of 348 mV, as shown by linear sweep voltammetry. It also exhibits a favorable Tafel slope of 83 mV/dec, indicating efficient electron transfer kinetics, making it a promising candidate for OER applications.

Impact of Multi-Scattered LiDAR Returns in Fog.

In the context of autonomous driving, the augmentation of existing data through simulations provides an elegant solution to the challenge of capturing the full range of adverse weather conditions in training datasets. However, existing physics-based augmentation models typically rely on single scattering approximations to predict light propagation under unfavorable conditions, such as fog. This can prevent the reproduction of important signal characteristics encountered in a real-world environment. Consequently, in this work, Monte Carlo simulations are employed to assess the relevance of multiple-scattered light to the detected LiDAR signal in different types of fog, with scattering phase functions calculated from Mie theory considering real particle size distributions. Bidirectional path tracing is used within the self-developed GPU-accelerated Monte Carlo software to compensate for the unfavorable photon statistics associated with the limited detection aperture of the LiDAR geometry. To validate the Monte Carlo software, an analytical solution of the radiative transfer equation for the time-resolved radiance in terms of scattering orders is derived, thereby providing an explicit representation of the double-scattered contributions. The results of the simulations demonstrate that the shape of the detected signal can be significantly impacted by multiple-scattered light, depending on LiDAR geometry and visibility. In particular, double-scattered light can dominate the overall signal at low visibilities. This indicates that considering higher scattering orders is essential for improving AI-based perception models.

Modeling aerosol transmission spectra from n(λ) and k(λ) infrared optical constants measurements of organic liquids and solids

The effects of light scattering and refraction play significantly different roles for aerosols than for bulk materials, making it challenging to identify aerosolized chemicals using traditional spectral methods or spectral reference libraries. Due to a potentially infinite number of particle morphologies, sizes, and compositions, constructing a database of laboratory-measured aerosol spectra is not a practical solution. Here, as an alternative approach, the measured n/k optical vectors of two example organic materials (diethyl phthalate and D-mannitol) are used in combination with particle absorption / scattering theory (Mie theory and FDTD) and the Beer-Lambert law to generate a series of synthetic infrared transmission / scattered light spectra. The synthetic spectra show significant differences versus simple slab transmission spectra, even for small changes in particle size (e.g., 5 vs. 10 µm) for both single particles and ensembles, potentially serving as useful reference data for aerosol sensing. For spherical single particles with diameters of 1 to 10 µm, FDTD simulations predict changes in the magnitudes of spectral shifts and the shapes of the peaks vs. particle size with only small deviations from Mie theory predictions, yet reliably capture the direction of the shifts. Typical spectral peak shifts in the longwave infrared correspond to Δλ ∼0.20 µm (∼34 cm-1) when compared to corresponding slab transmission spectra. Additionally, synthetic spectra generated from the n/k values derived using two different methods (KBr pellet transmission and single-angle reflectance) are compared using the Mie theory model.

Influence of Mg+2 on the structure, microstructure, and magnetic interactions of zinc ferrite nanoparticles synthesized via co-precipitation route

Evolution of the structural, morphological and magnetic properties of Zn1-xMgxFe2O4 (X = 0.00, 0.10 and 0.20) nanoparticles are discussed in detail and relation between cation disorder and magnetic interactions are prospected. The synthesized samples sintered at 500 °C temperature under examination display cubic crystal structure possesses Fd-3m as space group. The average crystallite size and lattice parameter shows variation as revealed from scherrer equation with the addition of Mg dopant at zinc site. Rietveld refinement presented single phase formation. Raman spectroscopy was utilized to convey different Raman modes and their associated vibrations. Scanning electron microscopy was utilized to survey the morphological attributes. Magnetization studies reveal weak ferromagnetism at low temperature (5 K) due to cation disorder for all samples. Zero field cooled and field cooled curves from magnetization vs temperature reveal the blocking temperature and its dependence on cation disorder and particle size. These results provide information about the possible applications of zinc ferrite nanoparticles in magnetic sensors, nanomedicine, optoelectronics, and memory devices.

Cutting-Based Manufacturing and Surface Wettability of Microtextures on Pure Titanium.

Pure titanium is a preferred material for medical applications due to its outstanding properties, and the fabrication of its surface microtexture proves to be an effective method for further improving its surface-related functional properties, albeit imposing high demands on the processing accuracy of surface microtexture. Currently, we investigate the fabrication of precise microtextures on pure titanium surfaces with different grid depths using precision-cutting methods, as well as assess its impact on surface wettability through a combination of experiments and finite element simulations. Specifically, a finite element model is established for pure titanium precision cutting, which can predict the surface formation behavior during the cutting process and further reveal its dependence on cutting parameters. Based on this, precision-cutting experiments were performed to explore the effect of cutting parameters on the morphology of microtextured pure titanium with which optimized cutting parameters for high-precision microtextures and uniform feature size were obtained. Subsequent surface wettability measurement experiments demonstrated from a macroscopic perspective that the increase in the grid depth of the microtexture increases the surface roughness, thereby enhancing the hydrophilicity. Corresponding fluid-solid coupling finite-element simulation is carried out to demonstrate from a microscopic perspective that the increase in the grid depth of the microtexture decreases the cohesive force inside the droplet, thereby enhancing the hydrophilicity.

High-order Autler–Townes splitting in electrically tunable photonic molecules

Whispering gallery mode optical microresonators represent a promising avenue for realizing optical analogs of coherent light–atom interactions, circumventing experimental complexities. All-optical analogs of Autler–Townes splitting have been widely demonstrated, harnessing coupled optical microresonators, also known as photonic molecules, wherein the strong coupling between resonant fields enables energy level splitting. Here, we report the characterizations of Autler–Townes splitting in waveguide-coupled microring dimers featuring mismatched sizes. By exploiting backscattering-induced coupling via Rayleigh and Mie scatterers in individual rings, high-order Autler–Townes splitting has been realized, yielding supermode hybridization in a multi-level system. Upon resonance detuning using an integrated phase shifter, intra-cavity coupling-induced splitting becomes almost indistinguishable at the zero-detuning point where the strong inter-cavity coupling counteracts the imbalance of backscattering strengths in individual rings. Through demonstrations on the maturing silicon photonics platform, our findings establish a framework of electrically tunable photonic molecules for coupling-mediated Autler–Townes splitting, offering promising prospects for on-chip signal generation and processing across classical and quantum regimes.

Determination of the effects of size parameters and lean angle on Bovet-based Francis turbine runner performance

Abstract In global hydropower generation, the Francis turbine is widely used because of its ability to work efficiently in a wide range of conditions like varying head and flow rates. Turbine’s meridional profile can be developed using traditional design approaches, like the Bovet method which uses empirical relations based on hydrological factors, that can be refined through optimization. Runner performance evaluation considers factors such as efficiency, erosion resistance, resistance to cavitation, and many more. Adjusting design parameters can enhance a turbine’s performance at a particular site. In this paper, a Bovet-based Francis runner design was obtained for Damile Micro Hydro located at Pharping, Nepal and the effect of variation of size parameters and lean angle on the runner performance was investigated. Initially, In-house MATLAB codes were used to design 99 meridional profile of different sizes by changing the size parameters as indicated by Bovet method and numerical simulation was performed to select the best meridional profile based on efficiency. After obtaining best meridional profile, the effect of lean angle was studied by varying it from -10° to 10°. Among the 99 designs based on different sizes, the simulation results indicate that the maximum efficiency was found to be 92.3% whereas the minimum efficiency was found to be 87.84%. The corrected lean angle of -5° showed the maximum efficiency and better pressure distribution along the blade.

Predicting cachexia in hepatocellular carcinoma patients: a nomogram based on MRI features and body composition.

Approximately half of all patients with hepatocellular carcinoma (HCC) develop cachexia during the course of the disease. It is important to be able to predict which patients will develop cachexia at an early stage. To develop and validate a nomogram based on the magnetic resonance imaging (MRI) features of HCC and body composition for potentially predicting cachexia in patients with HCC. A retrospective two-center study recruited the pretreatment clinical and MRI data of 411 patients with HCC undergoing abdominal MRI. The data were divided into three cohorts for development, internal validation, and external validation. Patients were followed up for six months after the MRI scan to record each patient's weight to diagnose cachexia. Logistic regression analyses were performed to identify independent variables associated with cachexia in the development cohort used to build the nomogram. The multivariable analysis suggested that the MRI parameters of tumor size > 5 cm (P = 0.001), intratumoral artery (P = 0.004), skeletal muscle index (P < 0.001), and subcutaneous fat area (P = 0.004) were independent predictors of cachexia in patients with HCC. The nomogram derived from these parameters in predicting cachexia reached an area under receiver operating characteristic curve of 0.819, 0.783, and 0.814 in the development, and internal and external validation cohorts, respectively. The proposed multivariable nomogram suggested good performance in predicting the risk of cachexia in HCC patients.

Imbibition models quantifying interfacial interactions: Based on nuclear magnetic resonance investigation and coupled structural characteristics

An investigation into spontaneous imbibition in porous media is of paramount scientific significance in various projects. However, a precise understanding of the interaction mechanisms between media structural characteristics and imbibition remains elusive, and quantitative analysis of the interfacial interaction is lacking. Therefore, to mitigate the influence of dispersion, this study first investigates cyclic imbibition experiments of coal samples to explore the interaction mechanism between pore-fracture structure (PFS) and imbibition. Nuclear magnetic resonance is used to visualize water transport during imbibition across all scales. Subsequently, the slake durability index is suggested to clarify the coupling relationship between water–coal interactions and imbibition. Two more comprehensive and accurate imbibition models are established, based on pore size and comprehensive seepage parameters, respectively. The results demonstrate that both new models exhibit superior conformity with experimental data compared to traditional models. The memory factor quantifies interface interaction within these models. Sensitivity analysis reveals that strong interface interaction diminishes the effective imbibition ratio, while the structural characteristics of porous media significantly influence the interaction. Furthermore, the fractal dimension quantitatively characterizes the PFS features of coal samples. An exploration of the relationship between fractal dimension and memory factor indicates the influence of porous media heterogeneity on imbibition.

Study on the mechanical properties of micropore organic polymer membranes

Abstract Micropore organic polymer membranes are indispensable for membrane filtration with well-established selectivity and permeability. Pressure-driven conditions in harsh acidic or alkaline environments can influence the mechanical properties of these materials. Diminished mechanical properties may include a shortened membrane lifespan, reduced filtration effectiveness, and increased filtration cost. Understanding of the intricate mechanisms influencing the mechanical properties of organic polymer membranes remains incomplete. In this study, a comprehensive investigation was carried out to characterize the mechanical properties of different membrane materials with similar and varying pore size parameters. The influence of different methods of membrane preparation on the mechanical properties of these materials was also explored. Results showed that the PTFE membranes demonstrated excellent Young’s modulus and tensile strength, while PVDF membranes excelled in elongation at break. Organic filter membranes prepared by the phase transition method exhibited a more structured fiber filament arrangement, a smoother surface, reduced crack formation and extension, and uniform pore size and distribution when compared to materials prepared using the tensile method. The results of this study expanded our understanding of the factors that can influence the mechanical properties of organic filtration membranes.

Scattering properties of protoplanetary dust analogs with microwave analogy: Rough compact grains

Context. Scattering simulations of perfect spheres are not sufficient to explain the observations of scattered light from protoplanetary and debris disks, especially when the dust sizes are on the same order of magnitude as the wavelength used to perform the observations. Moreover, examples of grains collected from the Solar System have proved that the morphology of interstellar dust is irregular. These pieces of evidence lead us to consider that the morphologies of the dust that participates in these circumstellar disks are more complex than those of spheres. Aims. We aim to measure and simulate the scattering properties of six rough compact grains to identify how their morphology affects their scattering properties. These grains are intended to be dust analogs of protoplanetary and debris disks. Their convexity ranges from 75% to 99%. Methods. Grains were 3D printed using stereolithography, and their shape and refractive index were controlled. These analogs were measured with our microwave-scattering experiment (microwave analogy) at wavelengths ranging from 16.7 mm to 100 mm, leading to size parameters from X = 1.07 to X = 7.73. In parallel, their scattering properties were simulated with our finite-element method (FEM), which contained the same geometric file as the 3D printed grains. Results. We retrieved five scattering properties of these grains, that is, the phase function, the degree of linear polarization (DLP), and three other Mueller matrix elements 〈Sij〉. Two types of studies were performed. First, a study of the scattering properties averaged over several orientations of grains at different wavelengths. Second, a study of the same scattering properties, for which a power-law size distribution effect was applied. Conclusions. The very good correspondence between the measured and simulated Mueller matrix elements demonstrated the accuracy of our measurement setup and the efficiency of our FEM simulations. For the first study, DLP proved to be a good indicator of the grain morphology in terms of convexity and shape anisotropy. For the second study, backscattering enhancements of the phase function were related to the grain convexity. The maximum DLP and its negative polarization branches as well as the 〈S22〉/〈S11〉 levels were related to the shape anisotropy of our grains.

Optimising design and operation of sewage source heat pump: techno-economic and environmental assessment

ABSTRACT Heat pump can be used to recover abundant thermal energy contained in the discharge of municipal wastewater treatment plants. While there are some design standards for common heat pump systems, the design of a sewage source heat pump (SSHP) system is still often based on a fixed heat load and neglects the interdependencies between the equipment sizing and operating parameters. To address the issue that previous design methods have not balanced investment and operational costs well from a global optimisation perspective, this work formulates the simultaneous optimisation of SSHP design and operation as a non-linear programming problem. The proposed model features the consideration of multiple working conditions caused by the impact of ambient temperature variation on the heat load of the SSHP system. The feasibility and potential benefits of the optimised SSHP system are also evaluated by incorporating techno-economic performances and environmental impact analyses into the mathematical framework. A case study is carried out to demonstrate the effectiveness of the proposed methodology. The results show that the total annual cost of the optimally designed and operated SSHP in Harbin could be 9% lower than in Beijing and 39% lower than in Shanghai, suggesting that constructing and running the SSHP system in severe cold regions with great heating demands might be more economical than in less cold regions. The CO2, SO2, and NOx emissions of the SSHP could be approximately 50% less than that of coal-fired boiler heating, and 80% less than that of direct electric heating with coal-fired electricity.

К вопросу оценки качества сырья из каспийской атерины (Atherina boyeri caspia (Risso, 1810))

The purpose of this work was to establish the informative value of methods of structural analysis of biological fluids in determining the prospects of using atherina (Atherina boyeri caspia (Risso, 1810)) as a source of dietary protein in aquaculture. For the first time, solid-phase structures of atherina muscle homogenates were studied. It is known that the solid phase of biological fluids formed under conditions of wedge-shaped dehydration is a visualization of biochemical processes occurring in an organism or organ. The study of the morphological picture of a dried drop (facies) makes it possible to establish associative links between the features of the structuring of the studied liquid and its composition, as well as to determine the nature of the impact of environmental factors on a living system. The results of the study made it possible to establish the main type of homogenate facies and its morphological parameters, which indicate the consistency of biochemical processes and the presence of high-grade protein in the muscle tissue of the Caspian atherina, caught both in the spring and autumn seasons. The size and weight parameters of fish, the content of water-soluble protein in muscle tissue are characterized. For the first time, a comparative analysis of the level of water-soluble protein and solid-phase structures of muscle homogenates of Caspian atherina caught in different seasons in the coastal waters of Dagestan was carried out. Atherina is a food component for many fish living in the Caspian Sea. It was determined that in October, the content of muscle water-soluble protein in atherina tended to increase relative to March. During the feeding period, the accumulated part of the protein components turns into lipid components, which accumulate intensively, therefore, there are no significant seasonal differences in the content of water-soluble protein. It has been established that the biochemical processes occurring in muscle tissues are reflected in the solid-phase structures of biological fluids formed under conditions of wedge-shaped dehydration. The obtained results of the trend towards an increase in water-soluble muscle proteins in the body and an increase in the population in recent years indicate the importance of the use of Caspian atherina in the quality of live feed at fish farms.

Investigating the impact of anthropogenic radiofrequency electromagnetic fields on animals and plants in the environment: analysis from a systematic map

ABSTRACT Radiofrequency electromagnetic fields (RF EMF) from anthropogenic sources have become ubiquitous in the environment. International guidelines have been set by expert scientific bodies to protect human health from excessive exposure. There are no specifically established exposure guidelines to protect plants and animals. A previous systematic map identified 334 studies investigating the effects of RF EMF exposure from anthropogenic sources on animals and plants. This study aimed to analyse the effect of RF EMF and its relationship to different exposure parameters and the quality of those studies. Statistically significant inverse relationships were found between effect size and exposure-level parameters for studies investigating effects in animals. The results indicated that quality score is more indicative of the magnitude of the effect size than exposure-level parameters or exposure duration. This highlights the need for further, high-quality research on the effects of RF EMF exposure on plants and animals.

Los colores del cielo

This manuscript describes the Olbers paradox, the Purkinje effect, and the Rayleigh and Mie theories of light scatte-ring, explaining their link with the black of the night, the white of the stars, the blue of a clear day sky, the yellowish co-lors of the Sun, the reddish of sunsets, and the milky appearance of clouds

Investigation on selective laser-melted AlSi10Mg micro-struts: influence of processing parameters on dimensional accuracy, molten pool morphology and microhardness

PurposeThis study aims to address the limited understanding of the complex correlations among strut size, structural orientation and process parameters in selective laser melting (SLM)-fabricated lattice structures. By investigating the effects of crucial process parameters, strut diameter and angle on the microstructure and mechanical performance of AlSi10Mg struts, the research seeks to enhance the surface morphologies, microstructures and mechanical properties of AM lattice structures, enabling their application in various engineering fields, including medical science and space technologies.Design/methodology/approachThis comprehensive study investigates SLM-fabricated AlSi10Mg strut structures, examining the effects of process parameters, strut diameter and angle on densification behavior and microstructural characteristics. By analyzing microstructure, geometrical properties, melt pool morphology and mechanical properties using optical microscopy, scanning electron microscope, energy dispersive X-ray spectroscopy and microhardness tests, the research addresses existing gaps in knowledge on fine lattice strut elements and their impact on surface morphology and microstructure.FindingsThe study revealed that laser energy, power density and strut inclination angle significantly impact the microstructure, geometrical properties and mechanical performance of SLM-produced AlSi10Mg struts. Findings insight enable the optimization of SLM process parameters to produce lattice structures with enhanced surface morphologies, microstructures and mechanical properties, paving the way for applications in medical science and space technologies.Originality/valueThis study uniquely investigates the effects of processing parameters, strut diameter and inclination angle on SLM-fabricated AlSi10Mg struts, focusing on fine lattice strut elements with diameters as small as 200 µm. Unlike existing literature, it delves into the complex correlations among strut size, structural orientation and process parameters to understand their impact on microstructure, geometrical imperfections and mechanical properties. The study provides novel insights that contribute to the optimization of SLM process parameters, moving beyond the typically recommended guidelines from powder or machine suppliers.

Numerical simulation study on opening blood–brain barrier by ultrasonic cavitation

Experimental studies have shown that ultrasonic cavitation can reversibly open the blood–brain barrier (BBB) to assist drug delivery. Nevertheless, the majority of the present study focused on experimental aspects of BBB opening. In this study, we developed a three-bubble-liquid-solid model to investigate the dynamic behavior of multiple bubbles within the blood vessels, and elucidate the physical mechanism of drug molecules through endothelial cells under ultrasonic cavitation excitation. The results showed that the large bubbles have a significant inhibitory effect on the movement of small bubbles, and the vibration morphology of intravascular microbubbles was affected by the acoustic parameters, microbubble size, and the distance between the microbubbles. The ultrasonic cavitation can significantly enhance the unidirectional flux of drug molecules, and the unidirectional flux growth rate of the wall can reach more than 5 %. Microjets and shock waves emitted from microbubbles generate different stress distribution patterns on the vascular wall, which in turn affects the pore size of the vessel wall and the permeability of drug molecules. The vibration morphology of microbubbles is related to the concentration, arrangement and scale of microbubbles, and the drug permeation impact can be enhanced by optimizing bubble size and acoustic parameters. The results offer an extensive depiction of the factors influencing the blood–brain barrier opening through ultrasonic cavitation, and the model may provide a potential technique to actively regulate the penetration capacity of drugs through endothelial layer of the neurovascular system by regulating BBB opening.

Comparison of experimental, empirical, and CFD pressure losses of lab-scale sampling cyclones

Significant efforts remain to be undertaken to achieve efficient separation of particulate matter. Devices widely used for this purpose are cyclone separators. This study investigates the pressure loss phenomena and flow structures within cyclone devices, aiming to elaborate and optimize their performance. Traditional cyclone models: (i) Muschelknautz, (ii) Stairmand, and (iii) PM1 Sharp Cut, are evaluated alongside the innovative vortex limiter cyclone (VL) to distinguish their advantages and limitations. The focus is on describing the relation between pressure loss and flow characteristics of the different cyclones with the same design separation diameter of 1μm. Empirical pressure loss correlations analyze how pressure losses vary within different cyclone devices. It was proven that predictions depend on cyclone size and operational parameters. Computational Fluid Dynamics (CFD) simulations further elucidate pressure loss mechanisms, highlighting the complexities inherent in modeling cyclonic behavior accurately. In conclusion, this study contributes to advancing the understanding of cyclone performance by elucidating the intricate interplay between pressure loss phenomena and flow structures. Such insights hold profound indications for optimizing cyclone separator design and operation in diverse industrial applications.

Release of ions enhanced the antibacterial performance of laser-generated, uncoated Ag nanoparticles

Identifying the antibacterial mechanisms of elemental silver at the nanoscale remains a significant challenge due to the intertwining behaviors between the particles and their released ions. The open question is which of the above factor dominate the antibacterial behaviors when silver nanoparticles (Ag NPs) with different sizes. Considering the high reactivity of Ag NPs, prior research has primarily concentrated on coated particles, which inevitably hinder the release of Ag+ ions due to additional chemical agents. In this study, we synthesized various Ag NPs, both coated and uncoated, using the laser ablation in liquids (LAL) technique. By analyzing both the changes in particle size and Ag+ ions release, the impacts of various Ag NPs on the cellular activity and morphological changes of gram-negative (E. coil) and gram-positive (S. aureus) bacteria were evaluated. Our findings revealed that for uncoated Ag NPs, smaller particles exhibited greater ions release efficiency and enhanced antibacterial efficacy. Specifically, particles approximately 1.5 nm in size released up to 55 % of their Ag+ ions within 4 h, significantly inhibiting bacterial growth. Additionally, larger particles tended to aggregate on the bacterial cell membrane surface, whereas smaller particles were more likely to be internalized by the bacteria. Notably, treatment with smaller Ag NPs led to more pronounced bacterial morphological changes and elevated levels of intracellular reactive oxygen species (ROS). We proposed that the bactericidal activity of Ag NPs stems from the synergistic effect between particle-cell interaction and the ionic silver, which is dependent on the crucial parameter of particle size.