Size Range Research Articles

Comparison of the Characteristics of Circulating Small Extracellular Vesicles Isolated by Ultracentrifugation and a Commercial Kit.

The market offers a wide range of extracellular vesicles (EVs) isolation products, but their lack of standardization is a concern. Therefore, it is important to carefully assess the quality of the EVs obtained using these products. In this study, we compared the EXOCIB kit with the ultracentrifuge method, which is considered the gold standard for small EV isolation. After overnight fasting, small plasma EVs were extracted from four individuals using both the ultracentrifuge and the EXOCIB kit methods. The pooled EVs were then compared for the presence of the cluster of differentiation 63 (CD63) protein using the western blot analysis, and their size and zeta potential were performed by Dynamic Light Scattering (DLS). In addition, the size and morphology of small EVs were determined by using the Transmission Electron Microscopy (TEM) technique. An average hydrodynamic size of 135.7 nm and a zeta potential of -6.33 Mv at 25°C was found for small EVs isolated by the ultracentrifuge, whereas the kit method resulted in small EVs with a hydrodynamic size of 102.8 nm and a zeta potential of -0.907. Notably, the size of the particles in the kit samples was smaller compared to those obtained through the ultracentrifuge (P < 0.001). The western blot method confirmed the expression of CD63 in both methods, so the ultracentrifuge yielded small EVs with a higher level of purity compared to the kit-based approach (P = 0.036). The DLS findings revealed the existence of vesicles within the appropriate size range for small EVs like exosomes in both isolation techniques. The results of the western blot analysis, in conjunction with DLS, displayed that the ultracentrifuge method extracted small EVs with a greater degree of purity than the kit-based approach.

Optical spectra of silver clusters and nanoparticles from 4 to 923 atoms from the TDDFT+U method

The localized surface-plasmon resonances of coinage-metal clusters and nanoparticles enable many applications, the conception and necessary optimization of which require precise theoretical description and understanding. However, for the size range from few-atom clusters through nanoparticles of a few nanometers, where quantum effects and atomistic structure play a significant role, none of the methods employed previously has been able to provide high-quality spectra for all sizes. The main problem is the description of the filled shells of d electrons which influence the optical response decisively. We show that the DFT+U method, employed with real-time time-dependent density-functional theory calculations (RT-TDDFT), provides spectra in good agreement with experiment for silver clusters ranging from 4 to 923 atoms, the latter representing a nanoparticle of 3 nm. Both the electron-hole-type discrete spectra of the smallest clusters and the broad plasmon resonances of the larger sizes are obtained. All calculations use the value of the effective U parameter that provides good results in bulk silver. The agreement with experiment for all sizes shows that the U parameter is surprisingly transferable. Our results open the pathway for calculations of many practically relevant systems including clusters coupled to bio-molecules or to other nano-objects.

Influence of Aqueous Phase Salt and Oil Phase Surfactants and Viscosity on the Dynamic Interfacial Tension and Coalescence Timescales.

Liquid-liquid separation is a critically important process in the treatment of emulsions that can occur in our environment, such as oily stormwater, shipboard bilgewater, or off-shore oil spill treatment. Effective filtration systems, including coalescing filters, are essential for mitigating these environmental pollutants. Achieving this requires a comprehensive understanding of liquid-liquid interface dynamics influenced by additives and surfactants. Furthermore, understanding the impact of surfactants on emulsion stability in saline environments is vital for optimizing filtration processes and ensuring the protection of marine and freshwater ecosystems. In this work, these effects are highlighted using measurements performed across a range of droplet size, surfactant concentration, viscosity ratios, and saline presence. Dynamic IFT measurements are conducted using the pendant drop method for water in light mineral oil, with and without salt in the water phase. The effect of salt addition is also highlighted by using microfluidic coalescence experiments, in which it was found that the addition of salt increases the dimensionless drainage time below the critical micelle concentration. The second focus of this work is to study the effect of bulk phase viscosity on the stability. Dynamic IFT measurements are performed at both millimeter and micrometer scales using pendant drop experiments and microfluidic tensiometry, respectively, involving light and heavy mineral oils with varying SPAN80 surfactant concentrations. The surfactant diffusivity and interfacial adsorption and desorption rates are then extracted by fitting a surfactant diffusion and equation of state equations to the dynamic IFT measurements. The results of the IFT decay, surfactant diffusivity, and adsorption rates are compared at two different viscosity ratios. This study also compares the times required for IFT relaxation with the film drainage times in water-in-oil systems. The comparison aids in comprehending the impact of competing timescales during film drainage. The findings presented in this paper offer valuable insights into the design and optimization of liquid-liquid filtration systems, especially when operating under challenging environmental conditions, such as in saline environments. The principles explored here can be applied to improving industrial water treatment and in the design of advanced filtration technologies for chemical and petrochemical industries, particularly those involving flow, contributing to more sustainable and efficient practices in handling emulsified waste streams.

Skeletal muscle size and quality in healthy kidney donors, normal range and clinical associations

The gold standard to estimate muscle mass and quality is computed tomography (CT) scan. Lower mass and density (intramuscular fat infiltration) of skeletal muscles are markers of sarcopenia, associated with increased mortality risk, impaired physical function, and poorer prognosis across various populations and medical conditions. We aimed to describe standard reference values in healthy population, prospective kidney donors, and correlate clinical parameters to muscle mass and density. Included in the cohort 384 consecutive kidney donors. Mean age was 44.6 ± 11.5 (range 18.4–74.2), 46% were female and mean BMI was 25.6 ± 3.8 kg/m2. Our quantified reference values for psoas cross -sectional area (CSA) index at L3 level (males/females respectively) were 6.3 ± 1.8 and 4.8 ± 1.9 cm2 /m2, and density was 46.1 ± 5 and 41 ± 5 HU at that level. Older age (standardized beta coefficient − 0.12, p = 0.04), sex (− 0.32, p < 0.001) and BMI (0.17, p = 0.002) were significantly associated with CSA index of psoas at L3. Density, however, was associated with triglycerides level (− 0.21, p < 0.001), in addition to age (− 0.22, p < 0.0001), sex (− 0.27, p < 0.001) and BMI (− 0.1, p = 0.05). Our study validates the normative values of psoas muscle mass and density in healthy individuals and suggests correlations with clinical parameters. We demonstrate the significance of measuring not only the mass of the muscle, but also its density, as it has a valid association with metabolic parameters, including BMI and lipid level, even in healthy individuals and in the normal range of the tests.

The Fragility of Statistical Significance in the Use of Aspirin in Prevention of Venous Thromboembolism Events Following Total Joint Arthroplasty: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background/Objectives: Comparative studies often use the p value to convey statistical significance, but fragility indices (FI) and fragility quotients (FQ) may better signify statistical strength. The use of aspirin as venous thromboembolism (VTE) chemoprophylaxis following elective arthroplasty has been debated between the orthopedic and cardiac fields. The purpose of this study was to apply both the FI and FQ to evaluate the degree of statistical fragility in the total joint arthroplasty (TJA) literature regarding aspirin (ASA) use for VTE prevention. Methods: We performed a systematic search for TJA clinical trials from 2004 to 2023 reporting comparisons between ASA and other chemoprophylaxis methods for VTE. The FI of each outcome was calculated through reversal of a single outcome event until significance was reversed. The FQ was calculated by dividing each fragility index by study sample size and interquartile range (IQR) was calculated. SPSS Meta-analysis function was used to calculate the Mean Effect Size Estimate and 95% Confidence Intervals for each outcome. Results: Of 245 articles screened, 39 met search criteria, with 10 RCTs included for analysis (n = 11,481 patients). There were 38 outcome events reported, with three significant (p < 0.05) outcomes and 35 non-significant (p > 0.05) outcomes identified. The overall FI and FQ for all 38 outcomes were 6 (IQR: 5-7) and 0.059 (IQR: 0.044-0.064), respectively. Seven studies (70%) reported a loss-to-follow-up (LTF) greater than the overall FI. There was no increased risk of DVT, PE, or mortality with use of ASA (all p > 0.2). Conclusions: Despite showing non-inferiority in preventing venous thromboembolic events in TJA overall, the highest-level peer-reviewed literature concerning aspirin use following total joint arthroplasty is considered statistically fragile due to high loss-to-follow-up. In addition to the reporting of the p value, the fragility index and quotient can further provide insight into the strength and trustworthiness of outcome measures.

Enhancing late postmortem interval prediction: a pilot study integrating proteomics and machine learning to distinguish human bone remains over 15 years

BackgroundDetermining the postmortem interval (PMI) accurately remains a significant challenge in forensic sciences, especially for intervals greater than 5 years (late PMI). Traditional methods often fail due to the extensive degradation of soft tissues, necessitating reliance on bone material examinations. The precision in estimating PMIs diminishes with time, particularly for intervals between 1 and 5 years, dropping to about 50% accuracy. This study aims to address this issue by identifying key protein biomarkers through proteomics and machine learning, ultimately enhancing the accuracy of PMI estimation for intervals exceeding 15 years.MethodsProteomic analysis was conducted using LC–MS/MS on skeletal remains, specifically focusing on the tibia and ribs. Protein identification was performed using two strategies: a tryptic-specific search and a semitryptic search, the latter being particularly beneficial in cases of natural protein degradation. The Random Forest algorithm was used to model protein abundance data, enabling the prediction of PMI. A thorough screening process, combining importance scores and SHAP values, was employed to identify the most informative proteins for model’s training and accuracy.ResultsA minimal set of three biomarkers—K1C13, PGS1, and CO3A1—was identified, significantly improving the prediction accuracy between PMIs of 15 and 20 years. The model, based on protein abundance data from semitryptic peptides in tibia samples, achieved sustained 100% accuracy across 100 iterations. In contrast, non-supervised methods like PCA and MCA did not yield comparable results. Additionally, the use of semitryptic peptides outperformed tryptic peptides, particularly in tibia proteomes, suggesting their potential reliability in late PMI prediction.ConclusionsDespite limitations such as sample size and PMI range, this study demonstrates the feasibility of combining proteomics and machine learning for accurate late PMI predictions. Future research should focus on broader PMI ranges and various bone types to further refine and standardize forensic proteomic methodologies for PMI estimation.

Particle size and band gap evaluation of green gold nanoparticles (AuNPs) with potential applications

Abstract The present study was aimed towards green synthesis of gold nanoparticles (AuNPs) using fungal strain (SGSK-7) with assessment of their size using different techniques viz., X-ray diffractormeter, Dynamic light scattering, Atomic force microscopy, FE-Scanning Electron Microscopy and Fourier transform Infrared Spectroscopy. The intense characteristic diffraction peaks at angle 2Ѳ (38.13˚) presented the crystalline nature of the reduced gold solution and calculation of crystalline size (12 nm) using Scherer’s equation further confirmed synthesis of gold nanoparticles while dynamic light scattering analysis indicated the particle size range of gold nanoparticles between 2 nm to 50 nm. Field Emission Scanning Electron Microscopic (FESEM) and Atomic Force Microscopy (AFM) analysis of extracellular gold nanoparticles depicts spherical shape of AuNPs of approximately 40 nm. Fourier transform Infrared (FTIR) Spectroscopy depicted the presence of the gold nanoparticles along with the other biomolecules secreted by fungus which plays vital role in reduction, capping and stabilization of gold nanoparticles. Energy dispersive X-ray, mapping analysis, Zeta potential and UV-Vis spectrophotometery analysis further confirmed the presence and stability of gold nanoparticles, respectively. Zeta potential of gold nanoparticles leads to conclude the neutral nature (-10 mV to 10mV) of the particles. The UV-Visible spectrophotometeric analysis also confirmed the formation of gold nanoparticles with an absorption peak at 547 nm. On the basis of UV-Visible spectra the optical band gap of 2.44 eV is examined. The phylogenetic relatedness of SGSK-7 revealed 99% homology with Aspergillus tamari after sequencing of the ITS region followed by BLAST.

The Emboless® venous chamber efficiently reduces air bubbles: a randomized study of chronic hemodialysis patients

Abstract Background When blood passes the extracorporeal circuit, air microbubbles (MBs) contaminate the blood. Some MBs will end up as microemboli in the lung, heart, and brain. MB exposure has no medical purpose and is considered as bio-incompatibility. Selecting venous chambers with high removal rate of MBs is warranted to reduce the risks of air bio-incompatibility. The primary aim was to compare the Fresenius 5008 (F5008-VC) and the Emboless® (Emboless-VC) venous chambers regarding the elimination of MBs in the return bloodline during hemodialysis (HD). Methods Twenty patients underwent 80 sessions of cross-over HD using both the F5008-VC and the Emboless-VC randomized such that half started with the F5008-VC and half with the Emboless-VC. For 32 of the 80 sessions measurements were also performed during hemodiafiltrations (HDF) after the initial HD. MBs were measured with an ultrasound device (within the size range of 20-500µm) at the ‘Inlet’ and ‘Outlet’ bloodline of the venous chambers. The Wilcoxon pairwise test compared the percentage of MB elimination between venous chambers. Results During HD, the median reduction of MBs for the Outlet was 39% with the F5008-VC and 76% with the Emboless-VC (p&amp;lt;0.001). During HDF, the reduction was 28% with the F5008-VC and 70% with the Emboless-VC (p&amp;lt;0.001). Conclusion Fewer MBs and subsequently fewer microemboli entered the bloodline of the patient using the Emboless-VC compared to the F5008-VC venous chamber during HD and during HDF. Venous chambers with a high removal rate of MBs will reduce the extent of air emboli.

Assessment of fly ash based sand as a perspective alternate backfill material for stowing in mining activity

Due to the paucity of river sand and increased regulations on sand mining, mine fill voids are kept emptied, fostering the demand for alternate backfilling material. This study attempts to develop fly ash based sand (FAB Sand) using abundantly available fly ash alone as resource material and explores its suitability as a stowing material in mine void applications, including both underground and open mining activity. Since sand within particle sizes from 4.75 to 0.075 mm is explicitly used for stowing applications, FAB Sand is developed within the same particle size range. Its applicability is evaluated in terms of physical, chemical, mechanical, morphological and mineralogical properties, and suitability is assessed by comparing vis-à-vis with river sand. Towards environmental acceptability, leaching characteristics and human health risks of FAB Sand are examined comprehensively. The findings of the study reveal that FAB Sand is not only doable and promising but could also become a sustainable alternate backfilling material for stowing in mining activities. Results pertaining to environmental acceptability endorse that FAB Sand poses no threat to ecology and human health. Overall, the proposed novel alternate backfill material and its employability alleviates the mining of sand from rivers while concurrently accentuating sustainable solutions for mining practices.

Space use of polar bears (&lt;i&gt;Ursus maritimus&lt;/i&gt;) in Davis Strait in relation to sea ice and harp seals (&lt;i&gt;Pagophilus groenlandicus&lt;/i&gt;)

Polar bears (&lt;i&gt;Ursus maritimus&lt;/i&gt;) rely on seals as their primary prey, yet predator-prey spatial relationships are poorly understood. We examined the spatial relationship between Davis Strait polar bears and harp seals (&lt;i&gt;Pagophilus groenlandicus&lt;/i&gt;), using satellite-telemetry for both species. We analyzed sea ice trends using remote sensing (1979-2021) to examine how their environment may be changing using four sea ice seasons (freeze-up, winter, break-up, and summer). Sea ice cover decreased and summer season lengthened over time. Polar bears (n=23) tracked in 1991-2001 for 7-12 months had a mean 95% minimum convex polygon home range size (MCP) of 102,864 km&lt;sup&gt;2&lt;/sup&gt; (SE=15,236 km&lt;sup&gt;2&lt;/sup&gt;) and a mean 95% kernel density home range size (KDE) of 66,215 km&lt;sup&gt;2&lt;/sup&gt; (SE=59,688 km&lt;sup&gt;2&lt;/sup&gt;). Harp seals (n=29) tracked for 5-8 months in 1993-2005 had a mean 95% MCP of 464,330 km&lt;sup&gt;2&lt;/sup&gt; (SE=47,009 km&lt;sup&gt;2&lt;/sup&gt;) and a mean 95% KDE of 256,016 km&lt;sup&gt;2&lt;/sup&gt; (SE=31,566 km&lt;sup&gt;2&lt;/sup&gt;). During freeze-up, the core-use areas of both species did not overlap, but the broad-use areas did. During break-up, the broad-use areas overlapped more than the core-use areas. The space use of both species was influenced by the sea ice seasons and these seasons have changed over time.

Phylogenetic relatedness, not geographic origin, shapes traits across ontogenetic stages for common native and exotic plants in subtropical China

Abstract Functional traits, which shift as a plant develops from seed to adult and may be phylogenetically conserved, are widely acknowledged to be associated with exotic species invasion. However, existing studies comparing functional traits between native and invasive species often focus on a single ontogenetic stage, yielding mixed results. It remains unclear whether the functional trait differences and their relationship with invasiveness (e.g. range size) of exotic species remain consistent across ontogenetic stages. In this study, we experimentally compared 18 traits across the seed, early growth and adult stages of 127 native and exotic species from 19 families. These species are common and often co‐occur in the subtropical region of China. We also explored the linkage between these traits, alongside their phylogenetic relatedness with native species and exotic species' range size in China. Our results show that only seed mass differed between native and exotic species. Moreover, the compositions of traits across all stages and the entire lifespan were primarily influenced by phylogenetic relatedness rather than geographic origin. Further, the range size of exotic species in China positively correlated with their mean phylogenetic distance to native species, with no association with individual functional traits or functional distinctiveness. Synthesis. Our results emphasize the importance of comparing functional traits across ontogenetic stages between native and exotic species to improve our understanding of the role of functional traits in shaping plant invasion. Our findings also underscore the pivotal role of phylogenetic relatedness in shaping plant functional traits and the distribution of exotic species in their new ranges.

Advancing the Understanding of Microplastic Weathering: Insights from a Novel Polarized Light Scattering Approach.

Weathering is a significant process that alters the properties of microplastics (MPs) and consequently affects their environmental behaviors. In this study, we introduced a novel approach based on polarized light scattering technique, which offers advantages in terms of rapid, high-throughput, and submicron-sized detection. This technique was successfully applied to characterize the weathered MPs after a 180-day laboratory simulation of coastal environments. By employing polarization measurements, we obtained a 46-dimensional matrix data set for the weathered MP fragments and subsequently processed them using a backpropagation neural network. The successful extraction of effective polarization pulses confirmed the presence of MP fragments within the size range of 0.2-60 μm, yielding total accuracies for size classification ranging from 78.9 to 86.9%. Furthermore, this technique achieved an overall accuracy of 93.8% in classifying MPs with different weathering degrees and polymer types, revealing polarization parameters associated with size and morphological changes play a dominant role in characterizing the weathering process of MPs. Compared with conventional approaches, the novel polarized light scattering approach holds great promise for rapid, high-throughput, and accurate characterization of MPs with small sizes. The findings of this study provided new insights into how MPs change after long-term weathering in aquatic environments.

Synthesis and Characterization of ZnO Nanoparticles by Pulsed Laser Ablation in Liquid Using Different Wavelengths for Antibacterial Application

In this paper, the synthesis of colloidal solution of ZnO nanoparticles by PLAL using an Nd: YAG laser with 1064 nm and 532 nm wavelengths is described. The optical, morphological, structural, wettability and antibacterial activities were studied. The XRD analysis showed the hexagonal wurtzite structure while the UV-vis indicated the blue shift of the absorption peak due to the surface plasmon of the nanoparticle, which showed significant changes in color behavior. The FE-SEM revealed a uniformed spherical shape with a partial size range of 20.50–21.48 nm for ZnO at 1064 and 57.08–59.87 nm for ZnO at 532nm. Also, the concentration measurement indicated that the concentration of ZnO prepared at 1064 nm is 26.7 μg ml-1 and 63 μg ml-1 at 532 nm due to the relevance of high energy to the Zn plate and little distortion in the water and high absorption of short wavelength. Finally, the optical density of the antibacterial activity has been investigated, and both concentrations have good antibacterial activity at 12 h. The ZnO prepared at 532 nm has higher antibacterial activity because it has a high concentration of nanoparticles for both S. aureus and E. coli. Finally, the cell viability for ZnO synthesis with both 1064 nm and 532 nm indicates that this material has high biocompatibility and could be used for medical applications.

Nano Hydroxyapatite (Nano-HA) Based on Pholas Orientalis Shells and Degradation Analysis

Millions of tons of seashells are produced every day as waste around the world. These underutilized seashells waste was executed as calcium precursor by researcher to synthesis the nano-hydroxyapatite (nano-HA). Nano-HA was successfully synthesised from Pholas Orientalis seashells waste via the chemical precipitation method. Different sintering temperatures were implemented to evaluate the physicochemical criteria of nano-HA. The obtained powders were examined by various physicochemical methods such as XRD, FTIR, FESEM, EDX and degradation analysis. The peaks in XRD and FTIR analysis the HA is successfully produced. The FESEM images on the other hand showing the HA particle in nano size range with rice-like structure. Meanwhile, a variation of Ca/P ratio can be observed in respect to sintering temperatures. The Ca/P ratio for HA-WS, HA-S500 and HA-S700 sample is 1.78, 2.03 and 1.57 respectively. Different sintering temperatures result in different crystallinity value which consequently affects its degradation profile.

Development and characterization of mesoporous silica-MgSO4-MgCl2 binary salt composites for low-grade heat storage in fluidized bed systems

Achieving nearly zero-energy buildings requires the efficient utilization and storage of renewable energy. Salt-hydrate-based thermochemical energy storage (TCES) systems are promising due to their high heat storage capacity and minimal seasonal heat loss. However, challenges remain in their commercialization and large-scale application. For instance, TCES systems using magnesium sulphate (MgSO4) provide low temperature lifts due to slow reaction kinetics. Incorporating deliquescent salts like magnesium chloride (MgCl2) can enhance sorption performance but may introduce stability issues such as agglomeration and decomposition. This study presents a novel binary-salt composite combining MgSO4 and MgCl2 within commercial mesoporous silica (CMS) to address these challenges and enhance overall performance. The binary-salt composite powder, with a particle size range of 150–300 μm, is well-suited for use in fluidized-bed reactors, where fast mass and heat transfer promote efficient moisture adsorption, prevent uneven temperature distribution, and reduce agglomeration. Thermogravimetric analysis (TGA) was employed to evaluate the water sorption and desorption behaviour of MgCl2-MgSO4@CMS binary-salt composites with a total salt content of 50 wt% and salt mixing ratios of 3:1, 1:1, and 1:3. The corresponding water sorption capacities were 0.95, 0.68, and 0.57 g/g, respectively. In comparison, the MgSO4@CMS single-salt composite showed a lower water adsorption capacity of 0.47 g/g and required temperatures exceeding 150 °C for complete regeneration. Reactor-scale experiments demonstrated that the MgCl2-MgSO4@CMS composite with a 1:1 salt mixing ratio could be fluidized at low gas velocities on the order of 10−2 m/s, achieving a maximum temperature lift of 24.7 °C and an energy density of 1018 kJ/kg during hydration at 80% relative humidity and 30 °C. Additionally, the binary-salt composite showed good cyclic stability with less particle agglomeration compared to the MgCl2@CMS single-salt composite.

Enhanced Cooperative Compressive Spectrum Sensing in Cognitive Radio Networks

ABSTRACTThe demand for bandwidth in cognitive radio networks (CRNs) is growing as applications become increasingly data intensive. Techniques such as compressed spectrum sensing (CSS) and cooperative spectrum sensing (C‐SS) are employed to address this challenge. C‐SS enhances overall detection accuracy and reliability by enabling multiple nodes to share and combine their local sensing data. Conversely, CSS effectively reduces the required information for spectrum usage decision making, thereby improving bandwidth utilization. Integrating these two methods allows CRNs to utilize the spectrum reliably and efficiently, leading to increased spectral efficiency. To further improve reconstruction performance, we leverage the sparsity concept to transcend hardware constraints and merge restrictions from both real and synthesized channels. This approach involves the virtual synthesis of channels, which linearly enhances the signal‐to‐noise ratio (SNR) within the network's size range. Simulation results demonstrate that our proposed method offers significant advantages over single‐node recovery, as validated by simulations and software defined radio (SDR) Implementation. The integration of spectral estimations from various local CR detectors enhances spatial diversity gain and sensing quality, particularly in fading channels. Compared to traditional approaches, our method achieves superior performance, evidenced by an increase in (from 93.97% to 96.52%) with almost the same .

Impact of pupil size and corneal spherical aberrations on the performance of monofocal intraocular lenses: an experimental model

In this study, an in vitro comparison of the optical performances of three models (spherical, aberration-neutral, and aberration-correcting) of monofocal intraocular lenses (IOLs) is proposed. A comprehensive model is employed, encompassing a wide range of corneal models and aperture sizes, reflecting the high variability of corneal spherical aberrations (SA) and pupil sizes in both normal and postoperative refractive corneal surgery populations. Analysis of average through-focus modulation transfer function (MTF) curves reveals significant differences in optical performance attributable to pupil size and corneal SA. These differences depend on the IOL model and affects MTFmax (representing contrast at best focus), depth of focus, refractive error tolerance, and the effective power of the lens.

Characterization of bacteriophage vB_AbaS_SA1 and its synergistic effects with antibiotics against clinical multidrug-resistant Acinetobacter baumannii isolates.

Acinetobacter baumannii is a major cause of nosocomial infections globally. The increasing prevalence of multidrug-resistant (MDR) A. baumannii has become an important public health concern. To combat drug resistance, alternative methods such as phage therapy have been suggested. In total, 30 MDR A. baumannii strains were isolated from clinical specimens, and their antibiotic susceptibilities were determined. The Acinetobacter phage vB_AbaS_SA1, isolated from hospital sewage, was characterized. In addition to its plaque size, particle morphology, and host range, its genome sequence was determined and annotated. Finally, the antibacterial effects of phage alone, antibiotics alone, and phage/antibiotic combinations were assessed against the A. baumannii strains. Phage vB_AbaS_SA1 had siphovirus morphology, showed a latent period of 20 minutes, and a 250 PFU/cell (plaque forming unit/cell) burst size. When combined with antibiotics, vB_AbaS_SA1 (SA1) showed a significant phage-antibiotic synergy (PAS) effect and reduced the overall effective concentration of antibiotics in time-kill assessments. The genome of SA1 is a linear double-stranded DNA of 50,108bp in size with a GC content of 39.15%. Despite the potent antibacterial effect of SA1, it is necessary to perform additional research to completely elucidate the mechanisms of action and potential constraints associated with utilizing this bacteriophage.

Optimizing revision arthroplasty: the role of customized articulating spacers

Introduction The advancement of surgery is set against a backdrop of continuous development and surgical innovations have transformed the way clinical care is delivered. Revision surgery might be required to address complications of primary arthroplasty. The first stage of revision arthroplasty would involve removal of an implant and placement of an antibiotic-impregnated cement spacer to maintain the joint space and stability, prevent soft tissue retraction, provide local antibiotic release and preserve bone tissue for revision implantation at the final stage of revision. Custom-made articulating spacers are a promising tool for optimizing the first stage of revision arthroplasty.The objective was to summarize the current data and present comprehensive information about spacers used in two-stage revision arthroplasty including manufacturing techniques, physical and chemical properties, clinical applications, the possibility of customization within the first stage of revision arthroplasty, current and promising directions for research.Material and methods The original literature search was conducted on key resources including Scientific Electronic Library (www.elibrary.ru), the National Library of Medicine (www.pubmed.org), the Cochraine Library (www.cochranelibrary.com) between 2018 and 2023 using search words and phrases: total arthroplasty, complications, revision arthroplasty, articulating spacer, periprosthetic joint infection, additive manufacturing, 3D printing.Results A comparative analysis of factory supplied, home-made, dynamic and static spacer models showed that the choice of articulating spacers for revision arthroplasty of major joints is of great relevance. Advantages of factory-made spacers include standardized range of sizes, the reliability and availability for medical institutions. They are characterized by limited use in repair of severe bone defects.Discussion Custom-made articulating spacers enable specific tailoring to accommodate individual defects. Despite high expectations from custom-made spacers, development of optimal technologies for rapid prototyping is essential. Investments in research and development in this area have the potential to create innovative solutions that can significantly improve the results of revision arthroplasty.Conclusion The paper explores the importance of systemization of knowledge about spacers and the role of new research in improving the design and functionality. Progress in the field of materials science, additive technologies and a personalized approach to spacer manufacturing can expand possibilities of revision arthroplasty and the effectiveness. Personalized approaches and improved methods of local drug delivery that provide controlled release of antibiotics can improve the results of treatment of periprosthetic joint infections.

Retention and interfacial failure mechanism of single diamond grains in resin-bonded grinding tools

Abrasive grains and the associated bonding agent are the two significant components in the manufacturing of fixed abrasive machining tools. The material properties and interfacial bonding behavior between the grains and the bonding matrix determine machining performance. In precision machining processes with diamond abrasives, the primary failure modes of fixed abrasive tools are grain dislodgement and premature loss, leading to abrupt change in machining load and ultimately causing inaccurate and inefficient machining performance. This study develops a comprehensive model for understanding abrasive grain retention and interfacial failure mechanisms in resin-bonded diamond tools. Finite element analysis of a single diamond grain embedded in a resin matrix was conducted to examine the influence of the grain shape, protruding height, and orientation angle on critical interfacial failure force. A series of single diamond scratching experiments validated the model, revealing that the maximum retention force reached 43.56 N for grains with a 0.9 mm protruding height and a 60° orientation angle. The results also show that, within a specific grain size range, grain shape—quantified by the sphere deviation coefficient proposed in this paper, has the greatest impact on retention and failure behavior. Protruding height plays a secondary role, while the contribution of orientation angle is minimal. These findings provide valuable insights for the design, manufacture, and optimization of precision abrasive machining tools, particularly for applications requiring high precision and reliability.