Two-step Method Research Articles

Electrodeposited CoMnS/NiCo2S4 nanocomposite for high performance supercapacitors

In this work, we report a facile two-step electrodeposition method to fabricate a CoMnS/NiCo2S4/NF (CMS/NCS/NF) composite on nickel foam (NF) for application of supercapacitor electrode. The electrochemical performance of this composite material has been extensively investigated, revealing superior performance compared to individual CMS/NF and NCS/NF materials. The CMS/NCS/NF composite exhibits an exceptionally high specific capacity of 707 C/g at a current density of 1 A/g in a three-electrode system. Remarkably, the material retains 92 % of its specific capacitance after 5000 cycles, indicating excellent cyclic stability and durability. To further explore its practical applications, we constructed a two-electrode symmetric supercapacitor using the CMS/NCS/NF electrode. This symmetric cell demonstrates an outstanding energy density of 97.5 Wh/kg and a peak power density of 12 kW/kg, underscoring its potential for high-performance energy storage applications. These comprehensive studies indicate that the synthesized CMS/NCS/NF is a highly promising candidate for supercapacitor electrodes, offering both high capacity and long-term stability. This work paves the way for the development of efficient and durable energy storage devices.

YOLOv8s-DDA: An Improved Small Traffic Sign Detection Algorithm Based on YOLOv8s

In the realm of traffic sign detection, challenges arise due to the small size of objects, complex scenes, varying scales of signs, and dispersed objects. To address these problems, this paper proposes a small object detection algorithm, YOLOv8s-DDA, for traffic signs based on an improved YOLOv8s. Specifically, the C2f-DWR-DRB module is introduced, which utilizes an efficient two-step method to capture multi-scale contextual information and employs a dilated re-parameterization block to enhance feature extraction quality while maintaining computational efficiency. The neck network is improved by incorporating ideas from ASF-YOLO, enabling the fusion of multi-scale object features and significantly boosting small object detection capabilities. Finally, the original IoU is replaced with Wise-IoU to further improve detection accuracy. On the TT100K dataset, the YOLOv8s-DDA algorithm achieves mAP@0.5 of 87.2%, mAP@0.5:0.95 of 68.3%, precision of 85.2%, and recall of 80.0%, with a 5.4% reduction in parameter count. The effectiveness of this algorithm is also validated on the publicly available Chinese traffic sign detection dataset, CCTSDB2021.

Engineering Thermoresponsive Poly(N-isopropylacrylamide)-Based Films with Enhanced Stability and Reusability for Efficient Bone Marrow Mesenchymal Stem Cell Culture and Harvesting.

Poly(N-isopropylacrylamide) (PNIPAM) offers a promising platform for non-invasive and gentle cell detachment. However, conventional PNIPAM-based substrates often suffer from limitations including limited stability and reduced reusability, which hinder their widespread adoption in biomedical applications. In this study, PNIPAM copolymer films were formed on the surfaces of glass slides or silicon wafers using a two-step film-forming method involving coating and grafting. Subsequently, a comprehensive analysis of the films' surface wettability, topography, and thickness was conducted using a variety of techniques, including contact angle analysis, atomic force microscopy (AFM), and ellipsometric measurements. Bone marrow mesenchymal stem cells (BMMSCs) were then seeded onto PNIPAM copolymer films prepared from different copolymer solution concentrations, ranging from 0.2 to 10 mg·mL-1, to select the optimal culture substrate that allowed for good cell growth at 37 °C and effective cell detachment through temperature reduction. Furthermore, the stability and reusability of the optimal copolymer films were assessed. Finally, AFM and X-ray photoelectron spectroscopy (XPS) were employed to examine the surface morphology and elemental composition of the copolymer films after two rounds of BMMSC adhesion and detachment. The findings revealed that the surface properties and overall characteristics of PNIPAM copolymer films varied significantly with the solution concentration. Based on the selection criteria, the copolymer films derived from 1 mg·mL-1 solution were identified as the optimal culture substrates for BMMSCs. After two rounds of cellular adhesion and detachment, some proteins remained on the film surfaces, acting as a foundation for subsequent cellular re-adhesion and growth, thereby implicitly corroborating the practicability and reusability of the copolymer films. This study not only introduces a stable and efficient platform for stem cell culture and harvesting but also represents a significant advance in the fabrication of smart materials tailored for biomedical applications.

Oxygen reduction reaction on Ag nanocatalysts prepared by the microemulsion method

The microemulsion (water-in-oil) method is used to prepare novel silver catalysts onto three different carbon supports (multi-walled carbon nanotubes (MWCNT), mesoporous carbon (MC) and Vulcan carbon (C)). It allows to control the Ag particle growth and produces particles that range between 2 and 3 nm. The Ag-based catalysts are characterised by scanning transmission electron microscopy (STEM) with energy-dispersive X-ray spectroscopy (EDS). The electrocatalytic activity towards the oxygen reduction reaction (ORR) in 0.1 M KOH is studied using the rotating disc electrode method. High-angle annular dark-field (HAADF) STEM images reveal the Ag particle size range between 1.8 and 2.4 nm, and the EDS mapping shows uniform Ag distribution on the substrates used. Ag1/MC (two-step synthesis) and Ag2/MC (one-step synthesis) catalysts prepared onto the MC support show the highest mass activity of 30–37 A g−1. The two-step synthesis method is preferred to prepare Ag/MWCNT and Ag/C catalysts. The mass activity of the Ag1/MWCNT catalyst is more than two times higher than that of Ag2/MWCNT. Ag1/MWCNT shows the highest electrochemical stability after the accelerated durability test, with only a 6 mV shift in half-wave potential. The microemulsion method is very promising for the production of highly stable Ag-based catalysts with Ag particles smaller than 3 nm in size.

Characterization of Peptide Profiles and the Hypoallergenic and High Antioxidant Activity of Whey Protein Hydrolysate Prepared Using Different Hydrolysis Modes.

Food proteins and peptides are generally considered a source of dietary antioxidants. The aim of this study was to investigate the antioxidant activity, allergenicity, and peptide profiles of whey protein hydrolysates (WPHs) using different hydrolysis methods. The results demonstrated that the degrees of hydrolysis of the hydrolysates with one-step (O-AD) and two-step (T-AD) methods reached 16.25% and 17.64%, respectively. The size exclusion chromatography results showed that the O-AD had a higher content of >5 and <0.3 kDa, and the distribution of peptide profiles for the two hydrolysates was significantly different. Furthermore, 5 bioactive peptides and 15 allergenic peptides were identified using peptidomics. The peptide profiles and the composition of the master proteins of the O-AD and T-AD were different. The DPPH and ABTS radical scavenging abilities of WPHs were measured, and hydrolysates were found to exhibit a strong radical scavenging ability after being treated using different hydrolysis methods. An enzyme-linked immunosorbent assay showed that the sensitization of WPHs was significantly reduced. This study may provide useful information regarding the antioxidant properties and allergenicity of WPHs.

Improved adsorption and charge transfer capacity by coupling g-C3N4 and NH2-MIL-125 for efficient degradation of sulfamethoxazole in water: Characterization, degradation efficiency, influence factors, and mechanism

Photocatalysis is an advanced oxidation process that shows excellent promise in degrading organic pollutants present in water. However, electrons and holes tend to combine easily during the transfer process, and the adsorption capacity of single-phase photocatalytic materials is weak, resulting in a low degradation rate. Therefore, a new composite semiconductor photocatalyst g-C3N4/NH2-MIL-125 was constructed using a two-step solvothermal method. The morphology, elemental composition, structure, photoelectric properties, and photocatalytic activity of g-C3N4/NH2-MIL-125 were characterized. The photocatalytic degradation of Sulfamethoxazole (SMX) in water was also carried out. Results indicated that g-C3N4/NH2-MIL-125 had been synthesized successfully, and g-C3N4/NH2-MIL-125 had a broader photoresponse range, higher adsorption capacity, and higher separation efficiency of photogenerated carriers. When pH was 4.0 and catalyst dosage was 0.15 g/L, g-C3N4/NH2-MIL-125 showed the highest degradation rate for SMX. It was confirmed that the main active groups in SMX degradation were OH, h+, and O2−. 15 kinds of intermediates of SMX and the possible degradation pathways were identified by high-performance liquid chromatography-mass spectrometry and DFT calculation. Toxicity analysis revealed that the intermediate products have a lower developmental toxicity than SMX. This work demonstrated that g-C3N4/NH2-MIL-125 has great potential in eliminating antibiotics from water.

Non-invasive mass flow and local heat transfer coefficient measurements in pulsating heat pipes

A single loop Pulsating Heating Pipe (PHP) experimental setup was developed for non-invasive measurement of the local heat transfer coefficient and the mass flow along the PHP evaporator. These measurements are valuable to validate modeling tools used in the design of PHP. A two-step differential heat input method was used for measurement of mass flow and the results were compared with the optical and theoretical results. The conditions tested in the PHP were 50, 60 and 70% filling ratio, R134a as working fluid, internal diameter of 2 mm, saturation temperature of between 30 to 40 °C, inclination angles from 30 to 90° (vertical bottom heat mode) and heat loads on the evaporator from 10 up to 68 W. The results indicate a high performance in heat transfer of the PHP, with minimum internal thermal resistance values close to 0.008 K/W as well as local heat transfer coefficients greater than 10 kW/m2K for observed values of mass velocities between 60 and 140 kg/m2s. The results were compared with correlations from the literature and these were able to predict the results with a 20% average error margin, suggesting many similarities with convective boiling mechanisms.

Exploring the charge transfer enhancement mechanism in selective SERS detection with Mo1−xWxS2@Ag2S nanosheets

In order to solve the problem of poor sensitivity and selectivity of conventional SERS substrates, we synthesized Mo1−xWxS2@Ag2S nanosheets in this paper by a two-step hydrothermal method. The structure and morphology of the synthesized Mo1−xWxS2@Ag2S nanosheets were characterized by XRD and SEM,respectively. The results show that the Mo1−xWxS2@Ag2S nanosheet has an irregular layered structure. Further, the SERS properties of Mo1−xWxS2@Ag2S nanosheets were tested by using rhodamine 6G (R6G), crystalline violet (CV), and 4-mercaptobenzoic acid (4-MBA) as probe molecules, respectively. The test results demonstrated that the nanosheets were specific to R6G and CV probe molecules, and the mechanism of selectivity was due to CT enhancement. In addition, Mo1−xWxS2@Ag2S exhibits ultrahigh sensitivity in R6G and CV, with the corresponding detection limit of both reached 10−8 M. And linear fitting of the peak intensities was carried out, with the R2 coefficient of 0.981 and 0.951, respectively. Finally, the relative standard deviations (RSDs) of this Mo1-xWxS2@Ag2S nanosheets was obtained to be 8.56 % by test 1 × 10−4 M R6G at the characteristic peak 613 cm−1, which represents excellent detection repeatability. The Mo1−xWxS2@Ag2S nanosheets are rich in edge-active sites favorable for charge transfer, which can enhance the SERS signals of the target molecules better. Besides, the Raman detection of the surface of Mo1−xWxS2@Ag2S nanosheets using nitrofurantoin (NFT) also reached a detection limit of 10−8 M. Mo1−xWxS2@Ag2S nanosheets substrates can find applications in medicine and provide new strategies for improving the SERS performance.

Mechanistic insights into ultrafast degradation of electron-rich emerging pollutants by waste cyanobacteria resource utilization

Biochar has the issues with inadequate stability and low catalytic activity. In this study, two-step ball milling method was applied to synthesis carbon nitride co-modified cyanobacteria biochar (CN-BC). The optimized CN-BC can effectively activate peroxymonosulfate (PMS) to degrade emerging pollutants. The degradation rate constant of enrofloxacin in the CN-BC/PMS system reached 0.506 min−1, and 95 % of enrofloxacin could be effectively degraded within 10 min. Free radical quenching experiments and electrochemical experiments confirmed that the electron transfer and 1O2 were the main pathways in the CN-BC/PMS system. The CN-BC/PMS system has selective degradation of electron-rich pollutants, and the pollutants containing electron-donating groups are more easily degraded than those containing electron-withdrawing group. The selective degradation pathway of pollutants by CN-BC was further analyzed using density functional theory (DFT). Continuous flow CN-BC/PMS membrane system showed long-term abatement of emerging pollutants. This study improves the understanding of the mechanism of PMS activation by cyanobacterial biochar catalysts and provides a new pathway for membrane-based domain-limited catalysis.

Highly sensitive site-specific SUMOylation proteomics in Arabidopsis.

SUMOylation-the attachment of a small ubiquitin-like modifier (SUMO) to target proteins-plays roles in controlling plant growth, nutrient signalling and stress responses. SUMOylation studies in plants are scarce because identifying SUMOylated proteins and their sites is challenging. To date, only around 80 SUMOylation sites have been identified. Here we introduce lysine-null SUMO1 into the Arabidopsis sumo1 sumo2 mutant and establish a two-step lysine-null SUMO enrichment method. We identified a site-specific SUMOylome comprising over 2,200 SUMOylation sites from 1,300 putative acceptors that function in numerous nuclear processes. SUMOylation marks occur on several motifs, differing from the canonical ψKxE motif in distant eukaryotes. Quantitative comparisons demonstrate that SUMOylation predominantly enhances the stability of SUMO1 acceptors. Our study delivers a highly sensitive and efficient method for site-specific SUMOylome studies and provides a comprehensive catalogue of Arabidopsis SUMOylation, serving as a valuable resource with which to further explore how SUMOylation regulates protein function.

Accelerated Lanthanide Intercalation into Graphite Catalyzed by Na.

Lanthanides (Ln) are notoriously difficult to intercalate into graphite. We investigated the possibility of using Na to catalyze the formation of Ln-intercalated graphite and successfully synthesized LnC6 (Ln = Sm, Eu, and Yb) significantly rapidly in high yields. The synthesis process involves the formation of the reaction intermediate NaCx, through the mixing of Na and C, which subsequently reacts with Ln upon heating to form LnC6. Well-sintered LnC6 pellets with low residual Na concentrations (Ln:Na ≈ 98:2) were fabricated by the two-step method. The pellets enabled the evaluation of LnC6 by powder X-ray diffraction and electrical resistivity measurements. This study highlights the versatility of the Na-catalyzed method and lays the foundation for the rapid mass production of LnC6, with potential applications in superconducting and rechargeable battery materials.

Development of water-based micro-particle enhanced phase change material for cool thermal energy storage systems

ABSTRACT Building accounts over one-third of global energy consumption, mainly for cooling/heating the space, contributing to enormous emission of greenhouse gases. Extensive usage of air-conditioning system in tropical countries demands cool thermal energy storage system for energy management that essentially demands development of novel energy storage materials. In this study, micro-particle enhanced phase change materials (MePCMs) were prepared through two-step method with deionized water as base PCM and natural graphite flakes (NGF) as additive. Heat transfer characteristics of the MePCMs were experimentally analyzed during solidification in a spherical capsule. High specific surface area of the NGF creates more nucleation sites that lead to elimination of subcooling in the MePCM. As a result of enhanced thermal conductivity of MePCM, solidification duration was reduced to 40% with 5 wt.% NGF, compared to base PCM. Accelerated mode of charging was seen in MePCMs, storing 96% of energy during 70% of corresponding solidification duration. In addition to the above fascinating advantages, abundant availability and low cost of the NGF make the MePCM as potential energy storage material for space cooling applications.

Comparison of gestational diabetes one-step and two-step screening methods: incidence of gestational diabetes and associated pregnancy outcomes

Comparison of gestational diabetes one-step and two-step screening methods: incidence of gestational diabetes and associated pregnancy outcomes

Degradation of phenol by metal-free electro-fenton using a carbonyl-modified activated carbon cathode: Promoting simultaneous H2O2 generation and activation

The low yield of hydrogen peroxide, narrow pH application range, and secondary pollution due to iron sludge precipitation are the major drawbacks of the electro-Fenton (EF) process. Metal-free electro-Fenton technology based on carbonaceous materials is a promising green pollutant degradation technology. Activated carbon cathodes enriched with carbonyl functional groups were prepared using a two-step annealing method for the degradation of phenol pollutants. The •OH in the activation process of H2O2 were identified using the EPR test technique. The action mechanism of carbonyl groups on H2O2 activation was investigated in conjunction with density functional theory (DFT) calculations. The EPR tests demonstrated that the modified activated carbon could promote the in-situ activation of H2O2 to •OH. And the results of material analysis and DFT showed that C=O could facilitate the activation of hydrogen peroxide through the electron transfer mechanism as an electron-donating group. Electrochemical tests showed that both the oxygen reduction activity and 2e−ORR selectivity of the modified activated carbons were significantly improved. Compared with the original activated carbon cathode and EF, the degradation efficiency of phenol in the ACNH-1000/GF cathode was increased by 58.10% and 45.61%, respectively. Compared with EF, ACNH-1000/GF metal-free electro-Fenton effectively expands the pH application range, and is proven to be less affected by solution initial pH, while avoiding secondary pollution. The metal-free electro-Fenton system can save more than a quarter of the cost of EF system. This study has a deep understanding of the reaction mechanism of the carbonyl modified activated carbon, and provides valuable insights for the design of metal-free catalysts, so as to promote its application in the degradation of organic pollutants.

Ultra-High-Voltage Construction Projects and Total Factor Energy Efficiency: Empirical Evidence on Cross-Regional Power Dispatch in China

Optimizing cross-regional energy dispatch is crucial for addressing regional energy resource imbalances and significantly enhancing energy utilization efficiency. This study aims to analyze the potential impact of China’s ultra-high-voltage (UHV) construction on firms’ total factor energy efficiency and provide empirical evidence supporting the role of cross-regional energy dispatch in improving firms’ energy efficiency. The construction of UHV infrastructure has become a vital part of China’s “New Infrastructure” projects, presenting a “Chinese solution” to the global challenge of regional energy resource mismatches. This study employs an enhanced two-step stochastic frontier method to quantify firms’ total factor energy efficiency and utilizes a difference-in-differences model to evaluate the impact of inter-regional electricity dispatch on this efficiency. The empirical analysis results indicate that UHV construction projects increase the total factor energy efficiency of regional firms by an average of 0.45%, which significantly contributes to firms’ total factor productivity. This conclusion remains valid after a series of robustness tests. Furthermore, the heterogeneity analysis results indicate that the UHV construction project increases the total factor energy efficiency of non-energy-intensive industries by 0.49%, and significantly enhances the total factor energy efficiency of the manufacturing industry by 0.94%. However, it has no significant effect on energy-intensive industries or non-manufacturing enterprises. Additionally, the mechanism analysis shows that UHV construction projects affect total factor energy efficiency through three pathways: industrial structure adjustment, urban innovation, and clean energy transition. This study offers insights for addressing regional energy spatial mismatches and provides policy recommendations for developing a new energy system aligned with regional needs.

Fabrication of high-performance graphene fiber: Structural evolution strategy from a two-step green reduction method

Graphene fibers (GFs) have a bright future in a variety of applications ascribing to their excellent performance. However, strict preparation conditions with extremely high graphitization temperature or toxic chemical reagents severely restrict their extensive implementation. Meanwhile, researchers are seeking easily scalable and eco-friendly GFs production methods. Here, we propose a green two-step reduction strategy involving L-ascorbic acid (LAA) chemical reduction followed by low-temperature annealing for the preparation of high-performance GFs. Benefiting from the elimination of macro-, micro- and nano-scaled defects and recombination of graphene nanosheets, the prepared GFs demonstrated amazing tensile strength of 778.49 MPa, Young's modulus of 92.61 GPa and an outstanding electrical conductivity of 3.2 × 104 S m−1, outperforming most of the chemically reduced GFs. This two-step green reduction strategy provides a new insight for constructing integrated high-performance GFs for sustainable application in many fields.

Extending Shelf-life of Two-step Method Precursor Solutions through Targeted Regulation for Highly Efficient and Reproducible Perovskite Solar Cells.

Precursor solution aging process can cause significant influence on the photovoltaic performance of perovskite solar cells (PVSCs). Notably, we first observe that the aging phenomenon is more severe in the precursor of two-step sequential method compared to that in one-step method due to that the protic solvent isopropanol facilitates amine-cation side reaction and iodide ions oxidation. Herein, we report a novel approach for selectively stabilizing both organic amine salt and lead iodide (PbI2) precursor solutions in two-step method. The introduction of benzene-1,3-dithiol into organic amine salt solution can mitigate amine-cation side reactions due to the formation of an acidic and reducing environment. Simultaneously, decamethylferrocene (FcMe10/FcMe+10) pair can act as a redox shuttle in PbI2 solution to concurrently oxidize Pb0 and reduce I2 in cyclic manner. Consequently, the PVSCs device fabricated from ameliorative precursor solutions demonstrates superior power conversion efficiency of 25.31%, retaining 95% of its efficiency after 21 days of solution aging. Moreover, the unencapsulated devices maintain 85% of primitive efficiency for 1500 h at maximum power point tracking under continuous illumination. This work establishes a fundamental guidance and scientific direction for the stabilization of two-step perovskite precursor solutions.

Evaluation of the geometric and dosimetric accuracies of deformable image registration of targets and critical organs in prostate CBCT-guided adaptive radiotherapy.

Kilovoltage cone beam computed tomography (kVCBCT)-guided adaptive radiation therapy (ART) uses daily deformed CT (dCT), which is generated automatically through deformable registration methods. These registration methods may perform poorly in reproducing volumes of the target organ, rectum, and bladder during treatment. We analyzed the registration errors between the daily kVCBCTs and corresponding dCTs for these organs using the default optical flow algorithm and two registration procedures. We validated the effectiveness of these registration methods in replicating the geometry for dose calculation on kVCBCT for ART. We evaluated three deformable image registration (DIR) methods to assess their registration accuracy and dose calculation effeciency in mapping target and critical organs. The DIR methods include (1) default intensity-based deformable registration, (2) hybrid deformable registration, and (3) a two-step deformable registration process. Each technique was applied to a computerized imaging reference system (CIRS) phantom (Model 062M) and to five patients who received volumetric modulated arc therapy to the prostate. Registration accuracy was assessed using the 95% Hausdorff distance (HD95) and Dice similarity coefficient (DSC), and each method was compared with the intensity-based registration method. The improvement in the dCT image quality of the CIRS phantom and five patients was assessed by comparing dCT with kVCBCT. Image quality quantitative metrics for the phantom included the signal-to-noise ratio (SNR), uniformity, and contrast-to-noise ratio (CNR), whereas those for the patients included the mean absolute error (MAE), mean error, peak signal-to-noise ratio (PSNR), and structural similarity index measure (SSIM). To determine dose metric differences, we used a dose-volume histogram (DVH) and 3.0%/0.3mm gamma analysis to compare planning computed tomography (pCT) and kVCBCT recalculations with restimulated CT images used as a reference. The dCT images generated by the hybrid (dCTH) and two-step (dCTC) registration methods resulted in significant improvements compared to kVCBCT in the phantom model. Specifically, the SNR improved by 107% and 107.2%, the uniformity improved by 90% and 75%, and the CNR improved by 212.2% and 225.6 for dCTH and dCTC methods, respectively. For the patient images, the MAEs improved by 98% and 94%, the PSNRs improved by 16.3% and 22.9%, and the SSIMs improved by 1% and 1% in the dCTH and dCTC methods, respectively. For the geometric evaluation, only the two-step registration method improved registration accuracy. The dCTH method yielded an average HD95 of 12mm and average DSC of 0.73, whereas dCTC yielded an average HD95 of 2.9mm and average DSC of 0.902. The DVH showed that the dCTC-based dose calculations differed by <2% from the expected results for treatment targets and volumes of organs at risk. Additionally, gamma indices for dCTC-based treatment plans were >95% at all points, whereas they were <95% for kVCBCT-based treatment plans. The two-step registration method outperforms the intensity-based and hybrid registration methods. While the hybrid and two-step-based methods improved the image quality of kVCBCT in a linear accelerator, only the two-step method improved the registration accuracy of the corresponding structures among the pCT and kVCBCT datasets. A two-step registration process is recommended for applying kVCBCT to ART, which achieves better registration accuracy for local and global image structures. This method appears to be beneficial for radiotherapy dose calculation in patients with pelvic cancer.

Validation of DDC-3D code system for neutronics and thermal-hydraulics coupling analysis using BEAVRS benchmark

The direct whole-core calculations can provide accurate results and insights to the physics phenomena of the reactor. It can also capture the local effects of temperature and density fields on fuel depletion. However, the computational cost of the direct whole-core calculations is expensive. To compromise between computational cost and accuracy, the DDC-3D code system has been developed to perform neutronics and thermal-hydraulics coupling analysis. The DDC-3D code system couples the open-source codes DRAGON & DONJON based on two-step method and subchannel code COBRA-EN. The Picard iteration method is applied to ensure the stability of numerical calculation. Then the BEAVRS benchmark is used to validate the computational capabilities of DDC-3D code system. The critical boron concentrations, control rod worths and fission rate distributions are calculated in HZP condition. The results show a good agreement with measured data. The results demonstrate that the two-step method is applicable and valid for multiphysics simulations. For the result of HFP condition for cycle 1, the results also agree well with measured data, including the trend of the critical boron concentrations and power distributions throughout the cycle 1. Although the detailed thermal–hydraulic experimental values are not available, the thermal-hydraulics analysis of the hot fuel assemblies indicates that the calculation results are reasonable. In general, the results demonstrate the feasibility and accuracy of DDC-3D code system for neutronics and thermal-hydraulics coupling calculations and life cycle simulation of PWRs.

Isolation and quantification of human urinary exosomes using a Tween-20 elution solvent from polyester, capillary-channeled polymer fiber columns

BackgroundExosomes, a subset of extracellular vesicles (EVs), are a type of membrane-secreted vesicle essential for intercellular communication. There is a great deal of interest in developing methods to isolate and quantify exosomes to study their role in intercellular processes and as potential therapeutic delivery systems. Polyester, capillary-channeled polymer fiber columns and spin-down tips are highly efficient, low-cost means of exosome isolation. As the methodology evolves, there remain questions as to the optimum elution solvent for specific end-uses of the recovered vesicles; fundamental biochemistry, clinical diagnostics, or therapeutic vectors. ResultsWhile both acetonitrile and glycerol have been proven highly successful in terms of EV recoveries in the hydrophobic interaction chromatography workflow, many biological studies entail the use of the non-ionic detergent, Tween-20, as a working solvent. Here we evaluate the use of Tween-20 as the elution solvent for the recovery of exosomes. A novel 10-min, two-step gradient elution method, employing 0.1 % v/v Tween-20, efficiently isolated EVs at a concentration of ∼1011 EV mL−1 from a 100 μL urine injection. Integration of absorbance and multi-angle light scattering detectors in standard HPLC instrumentation enables a comprehensive single-injection determination of eluted exosome concentration and sizes. Transmission electron microscopy verifies the retention of the vesicular structure of the exosomes. The micro-bicinchoninic acid protein quantification assay confirmed high-purity isolations of exosomes (∼99 % removal of background proteins) SignificanceThe effective use of Tween-20 as an elution solvent for exosome isolation/purification using capillary-channeled polymer fiber columns adds greater versatility to the portfolio of the approach. The proposed method holds promise for a wide range of fundamental biochemistry, clinical diagnostics, and therapeutic applications, marking a significant advancement in EV-based methodologies.