Simulated Conditions Research Articles

Effectiveness of Adult Chest Compressions during Resuscitation Performed by Children Aged 10–14 Years under Simulated Conditions

Introduction: Numerous educational programs recommend implementing the teaching principles of BLS from an early age. The aim of this study was to evaluate selected parameters of the quality of resuscitation performed by children aged 10–14 years during simulated circulatory arrest in an adult. Materials and Methods: The project involved four stages, culminating in students performing thoracic compressions on an adult simulator for 2 min. A digital analysis of the quality, depth, relaxation and rate of compressions allowed us to formulate results and conclusions. The authors’ proprietary questionnaire form allowed for the correlation of criteria such as age, gender, body mass and past experience in first aid training of the participant. Results: A total of 149 girls and 130 boys were studied. The mean age was 12 years (SD ± 1.41). A directly proportional increase in body mass with participant age was observed (p < 0.000). Children as young as 10 years old achieved only 24.13% quality, while those at the age of 14 demonstrated a more than doubled value (67.61%). The minimum depth of chest compressions recommended for an adult (5–6 cm) was not reached in any age group. Girls from all grades achieved a mean quality of 44.69% (SD ± 32.57), while boys achieved a score of 60.23% (SD ± 31.74). On the other hand, in the case of evaluating thoracic relaxation, a significantly better result was achieved by girls compared to boys (66.14% vs. 56.78%; rho-Spearman test for p = 0.011). Conclusions: Age, sex and body mass play important roles in the quality of resuscitation provided by children. None of the age groups studied achieved the minimum mean depth during adult thoracic compressions under simulated conditions. It is recommended to modify school-based BLS classes to better match the exercises to students’ predispositions.

Eco-friendly encapsulation: Investigating plant-based protein-alginate shells for efficient delivery and digestion of hemp seed oil encapsulated via supercritical CO2 dispersion

In this study, supercritical carbon dioxide solution-enhanced dispersion (SEDS) was used to encapsulate hemp seed oil (HSO) within matrices of hemp seed protein isolate (HPI), pea protein (PPI) and soy protein (SPI) (0.5 % w/v) in complex with alginate (AL) (0.01 % w/v). The effects of different pH levels (3–9), NaCl concentrations (0–200 mmol/L) and simulated gastrointestinal conditions on HSO release and digestion patterns were analyzed. The findings revealed that SPI/AL microcapsules effectively maintained structural integrity and controlled oil release across diverse pH levels and salt concentrations. During gastrointestinal phases, minimal oil release was observed during oral digestion (<25 % for all samples), while significant (P < 0.05) gastric release occurred in PPI/AL (55.4 %) and SPI/AL (78.1 %) microcapsules. Surprisingly, HPI/AL microcapsules exhibited delayed and sustained release (27.9 %), indicating their potential as ideal wall material for delivering sensitive food and pharmaceutical ingredients to the intestinal stage while minimizing damage in the harsh gastric environment.

Compositing of rGO to TiO2 by Low-Temperature Treatment and Their Photocatalytic Properties

Reduced graphene oxide (rGO)/TiO2 nanocomposites were prepared by low-temperature and low-pressure heat treatment. The structure and photocatalysis performance of the composites were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and UV-visible diffuse reflectance spectrum (UV-Vis DRS). The photocatalytic degradation performance of methyl orange (MO) by composites with different raw material ratios was studied under simulated solar-irradiation conditions. Results indicated that graphene oxide (GO) was reduced to graphene during heat treatment and bonded well with TiO2. Compared with TiO2, GO addition greatly improved its photocatalytic efficiency. Under simulated sunlight irradiation, the samples exhibited good photocatalysis performance. Within 50[Formula: see text]min, MO can be rapidly degraded by TiO2/40% rGO composite.

The Impact of Hydrogen on Flame Characteristics and Pollutant Emissions in Natural Gas Industrial Combustion Systems

To improve energy savings and emission reduction in industrial heating furnaces, this study investigated the impact of various molar fractions of hydrogen on natural gas combustion and compared the results of the Non-Premixed Combustion Model with the Eddy Dissipation Combustion Model. Initially, natural gas combustion in an industrial heating furnace was investigated experimentally, and these results were used as boundary conditions for CFD simulations. The diffusion flame and combustion characteristics of natural gas were simulated using both the non-premixed combustion model and the Eddy Dissipation Combustion Model. The results indicated that the Non-Premixed Combustion Model provided simulations more consistent with experimental data, within acceptable error margins, thus validating the accuracy of the numerical simulations. Additionally, to analyze the impact of hydrogen doping on the performance of an industrial gas heater, four gas mixtures with varying hydrogen contents (15% H2, 30% H2, 45% H2, and 60% H2) were studied while maintaining constant fuel inlet temperature and flow rate. The results demonstrate that the Non-Premixed Combustion Model more accurately simulates complex flue gas flow and chemical reactions during combustion. Moreover, hydrogen-doped natural gas significantly reduces CO and CO2 emissions compared to pure natural gas combustion. Specifically, at 60% hydrogen content, CO and CO2 levels decrease by 70% and 37.5%, respectively, while NO emissions increase proportionally; at this hydrogen content, NO concentration in the furnace chamber rises by 155%.

Influence of light-polymerizing units and zirconia on the physical, chemical and biological properties of self-adhesive resin cements

BackgroundSelf-adhesive resin cements (SARCs) are widely used for fixed prostheses, but incomplete cleaning near the gingival margin can cause inflammation. However, the factors influencing cement properties and the biological response of gingival fibroblasts to cement eluates are not well understood. This study examines the impact of two light-polymerizing units (LPUs) on the physical and chemical properties of two SARCs under simulated clinical conditions, as well as the subsequent response of human gingival fibroblasts (hGFs) to these eluates.MethodsDental cement discs of SARCs were polymerized using Kerr DemiPlus and 3 M Elipar DeepCure-S LED LPUs with or without a 2-mm thick zirconia screen. Physical properties (microhardness, surface roughness, residual monomers) were evaluated. hGFs’ cell viability, wound healing potency, and gene expression were assessed.ResultsBoth Maxcem and RelyX exhibited reduced microhardness and increased surface roughness when polymerized through zirconia or with DemiPlus LPU. Higher residual monomers (HEMA and GDMA in Maxcem; TEGDMA in RelyX) concentration was observed with DemiPlus and zirconia polymerization. Maxcem polymerized with DemiPlus exhibited lower cell viability, impaired healing, and altered gene expression in hGFs compared to those polymerized with Elipar LPU. Gene expression changes included downregulated NRF2 and HO-1 and upregulated CCR-3.ConclusionsLight-polymerizing Maxcem through zirconia with DemiPlus LPU compromised SARCs’ properties, leading to higher residual monomers and negatively impacting hGFs’ viability, healing, and gene expression. Careful material selection and polymerization techniques are crucial to minimize adverse effects on surrounding tissues.Clinical significanceClinicians should exercise caution when using LPUs and SARCs, especially when polymerizing through zirconia. This will help optimize the physical and chemical properties of SARCs and minimize potential adverse effects on the surrounding gingival soft tissues.

B-027 CLSI-Based Result Precision on the cobas ISE neo and cobas c 703 Analytical Units Across Two Sites in Europe

Abstract Background Novel cobas® pro integrated solutions analytical units, the cobas® ISE neo and cobas c 703 analytical units (all Roche Diagnostics International Ltd, Rotkreuz, Switzerland), were assessed at two sites in Europe (Aalst, Belgium and Heidelberg, Germany). During the system design validation, precision was evaluated under intended use conditions in a routine simulation setting. Methods Quality control (QC) materials at two analyte concentrations were measured per site for selected assays (ion selective electrodes [ISEs], general chemistries and specific proteins, and immunochemistry assays); analyte recovery per QC was closely monitored. Precision was evaluated at both study sites based on Clinical and Laboratory Standards Institute EP05-A3 guidelines over 21 days for 53 applications representing the entire assay menu: six ISE serum/plasma and urine applications; 40 clinical chemistry serum/plasma and urine applications (four were measured using cobas c 503 at one site only); and seven immunochemistry serum/plasma applications. Reproducibility under various stressed routine-like conditions, including provocations, was tested using routine simulation imprecision experiments. To test the interaction of new and existing analytical units under routine conditions, two test configurations were used: the first configuration comprised one cobas ISE neo, two cobas c 703, and one cobas e 801 analytical units; and the second configuration comprised one cobas ISE neo, one cobas c 703, one cobas c 503, and one cobas e 801 analytical units. The precision of batch type measurements was compared with the precision under routine simulated random access conditions. Random access coefficients of variance (CVs) that exceeded 1.5× reference batch CVs, or single measurements deviating by &amp;gt;10% from the batch mean, triggered in-depth analysis of the system components that contributed to the result. CVs for intermediate precision comprised measurements from ≤4 cobas c 703 reagent disks, dependent on the system set-up and application assignment. CVs for reproducibility were calculated across four ISE measuring units, ≤3 cobas c 703 reagent disks, or ≤4 cobas e 801 measuring cells. Results Using four analytical units, n=511 CVs for repeatability, intermediate precision, and reproducibility were calculated. For repeatability, the median CV for ISE (n=24) was 0.8%, for clinical chemistry (cobas c 703: n=146; cobas c 503: n=8) was 0.9%, and for immunochemistry (n=28) was 1.0%. For intermediate precision, the median CV for ISE (n=24) was 1.1%, for clinical chemistry (cobas c 703: n=146; cobas c 503: n=8) was 1.2%, and for immunochemistry (n=28) was 1.5%. For reproducibility, the median CV for ISE (n=12) was 0.9%, for clinical chemistry (cobas c 703: n=73) was 1.6%, and for immunochemistry (n=14) was 1.7%. Conclusions The novel cobas ISE neo and cobas c 703 analytical units demonstrated robust precision, comparable to the existing cobas pro integrated solutions analytical units, over a prolonged period.

A circular economy approach for utilization of tannery fleshing hydrolysate and kitchen wastes into organic fertilizer through enzymatic decomposition

This study presents a sustainable method for converting tannery fleshing waste (FH) into organic fertilizer using enzymatic decomposition with crude protease. After extracting fat from the enzymatic hydrolysis, the enzyme-rich residue was mixed with dried kitchen waste (KW) and allowed to decompose for 45 days, producing nutrient-rich fertilizer. FT-IR spectroscopy confirmed the presence of important functional groups, including hydroxyl, aliphatic hydrocarbons, esters, and amide-I linkages. The organic fertilizers had higher nutrient content, with nitrogen (1.08-1.67%), phosphorus (0.78–0.98 %), potassium (0.1–0.76 %), and magnesium (239–259.5 ppm) which is higher than commercial fertilizers. FESEM-EDX analysis revealed a dense, porous structure with a high surface concentration of calcium, which enhances nutrient release in the soil. Dissolution tests showed that nutrients from the organic fertilizer were released gradually over 36 hours, whereas commercial NPK fertilizers released nutrients within 150 minutes in simulated soil-water conditions. Field trials with a Randomized Complete Block Design (RCBD) demonstrated improved growth in Malabar spinach, particularly with fertilizer sample S-5, which had an optimal flesh to kitchen waste (FH to KW) ratio of 1:10. Although S-5 had a lower nitrogen content (1.08 %), it contained higher levels of phosphorus (0.98 %), potassium (0.765 %), and magnesium (259.5 ppm), contributing to enhanced plant growth. The organic fertilizer resulted in a shoot length of 38.8 ± 2.0 cm, root length of 16.33 cm, 31 ± 3 leaves, and 95.12 % dry matter of the plant. Heavy metal analysis of the plant confirmed that levels of chromium (Cr), iron (Fe), nickel (Ni), cadmium (Cd), copper (Cu), and lead (Pb) were within WHO safety limits. Phytotoxicity tests of the fertilizer also showed no negative impact on Malabar spinach seed germination.

B-028 Result Precision on the New cobas pro integrated solutions cobas ISE neo and cobas c 703 Analytical Units Under Routine-Like Conditions Across Two Sites in Europe

Abstract Background The precision of the new cobas® pro integrated solutions cobas® ISE neo and cobas c 703 analytical units (Roche Diagnostics International Ltd, Rotkreuz, Switzerland) was measured under intended use conditions in a routine simulation setting. Methods The interaction of hardware, software, assays, and samples was tested at two sites (Aalst, Belgium and Heidelberg, Germany) between October and December 2023. Reproducibility under various stressed routine-like conditions, including provocations, was tested using routine simulation imprecision experiments. To test the interaction of new and existing analytical units under routine conditions, test configurations including commercially available cobas c 503 and cobas e 801 analytical units were used. The first configuration comprised one cobas ISE neo analytical unit, two cobas c 703 analytical units, and one cobas e 801 analytical unit. The second configuration comprised one cobas ISE neo analytical unit, one cobas c 703 analytical unit, one cobas c 503 analytical unit, and one cobas e 801 analytical unit. The precision of batch type measurements was compared with the precision under routine simulated random access conditions. Random access coefficients of variance (CVs) that exceeded 1.5× reference batch CVs, or single measurements deviating by &amp;gt;10% from the batch mean, triggered in-depth analysis of the system components that contributed to the result. Results Overall, 56 applications were measured during the reference and random parts of seven routine simulation imprecision runs: six ion selective electrodes (ISE; three serum, three urine), 35 clinical chemistry applications on cobas c 703 (27 serum, eight urine), seven clinical chemistry applications on cobas c 503 (five serum, one urine, one whole blood) and eight immunochemistry (serum) applications. Of six ISE (serum and urine) applications, the mean reference and random CVs were 0.8% and 0.9%, respectively. Of 42 clinical chemistry (serum, urine, and whole blood) applications, the mean reference CV was 0.9% and the mean random CV was 1.0%. Of eight immunochemistry (serum only) applications, mean reference and random CVs were 1.1% and 1.4%, respectively. Conclusions The findings from this study demonstrate that the new cobas ISE neo and cobas c 703 analytical units show consistent results over a prolonged time period, with most CVs in this setting below 0.9%. These results also show the successful integration of the new analytical units into the cobas pro integrated solutions, with seamless interaction of existing and analytical units under stressed conditions.

How Shell Add-On Products Influence Varsity Football Helmet Performance?

PurposeThe study purpose was to investigate the laboratory-based performance of three commercially available shell add-on products under varsity-level impact conditions.MethodsPendulum impact tests were conducted at multiple locations (front, front boss, rear, side) and speeds (3.1, 4.9, 6.4 m/s) using two helmet models. Tests were performed with a single add-on configuration for baseline comparisons and a double add-on configuration to simulate collisions with both players wearing shell add-ons. A linear mixed-effect model was used to evaluate peak linear acceleration (PLA), peak rotational acceleration (PRA), and concussion risk, which was calculated from a bivariate injury risk function, based on shell add-on and test configuration.ResultsAll shell add-ons decreased peak head kinematics and injury risk compared to controls, with the Guardian NXT producing the largest reductions (PLA: 7.9%, PRA: 14.1%, Risk: 34.1%) compared to the SAFR Helmet Cover (PLA: 4.5%, PRA: 9.3%, Risk: 24.7%) and Guardian XT (PLA: 3.2%, PRA: 5.0%, Risk: 15.5%). The same trend was observed in the double add-on test configuration. However, the Guardian NXT (PLA: 17.1%; PRA: 11.5%; Risk: 62.8%) and SAFR Helmet Cover (PLA: 12.2%; PRA: 9.1%; Risk: 52.2%) produced larger reductions in peak head kinematics and injury risk than the Guardian XT (PLA: 5.7%, PRA: 2.2%, Risk: 21.8%).ConclusionIn laboratory-based assessments that simulated varsity-level impact conditions, the Guardian NXT was associated with larger reductions in PLA, PRA, and injury risk compared to the SAFR Helmet Cover and Guardian XT. Although shell add-ons can enhance head protection, helmet model selection should be prioritized.

Combining clinostating and proton irradiation for modeling the space environment: a case study with a Chernobyl accession of Arabidopsis thaliana

Purpose The study of mechanisms of plant responses to extreme conditions, particularly, microgravity and ionizing radiation, is crucial for space exploration. Modern space biology of plants focuses on increasing plant tolerance to harsh conditions of space environment. Given the limited access to the International Space Station, we designed and assembled the 3D clinostat for mimicking microgravity, which, in combination with proton irradiation, allows simulating space conditions. As a case study for testing the device, we studied the effect of clinostating on Arabidopsis thaliana accession originating from the Chernobyl exclusion zone. Materials and Methods Using the combined clinostating and proton irradiation, we simulated the conditions of long-term space flight for Arabidopsis thaliana plants of the Chernobyl accession – progeny of chronically irradiated plants, grown from field-collected (Masa-0) and laboratory-cultivated (Masa-0-1) seeds, and for wild-type Col-8. The clinostating and irradiation of plants were also carried out separately. Plant responses were studied as photosynthetic and phenotypic endpoints of seedlings. Results and Conclusions Parameters of chlorophyll fluorescence estimated immediately after exposure showed that Masa-0-1 plants were resistant to the simulated space conditions, while Masa-0 demonstrated modulation of non-photochemical fluorescence quenching. Proton irradiation generally inhibited photosynthesis of Masa-0, Masa-0-1, and Col-8 seedlings. The combined effect of irradiation and clinostating modulated the photosynthetic activity of Col-8 seedlings. The leaf area of seedlings did not change after exposure to simulated conditions. The 3D clinostat model and software are published along with this article for researchers interested in the field of space biology.

Study on a novel thermal management system and heat recovery strategy of range extend electric vehicle

The integrated thermal management system (ITMS) can effectively improve the pure electric range of the vehicle. This work proposes a ITMS based on a super bottle. In this work, the power battery temperature is subdivided into five stages and a control strategy for heating the battery and cabin with dual heat sources in a low-temperature environment is developed. Then a numerical integrated simulation model of the ITMS is developed and experimentally verified in an environmental chamber. The experimental and simulation conditions used throughout the study are set to an ambient temperature of 0°C. At the same time, due to the better sampling of data under 40 km/h, a constant speed of 40 km/h is used. At 0 °C, through 660 s of 40 km/h conditions, the results show that the ITMS can heat the battery to 15 °C in about 20 minutes at a low temperature of 0°C, and heat the cabin to 22 °C in 10 min. The ITMS also improves battery warm-up efficiency by 16.7% and reduces energy consumption by 5.5% compared to the original system. The ITMS is 17% more expensive than the original system. In addition, the low-temperature electric range has been increased by 3.3 km, and the cost of increasing the range by integrating the thermal management components is approximately 28 ¥/km.

A high-resolution method for direction of arrival estimation based on an improved self-attention module.

The high-resolution direction of arrival (DOA) estimation is a prominent research issue in underwater acoustics. The existing high-resolution methods include subspace methods and sparse representation methods. However, the performance of subspace methods suffers from low signal-to-noise ratio (SNR) and limited snapshots conditions, and the computational complexity of sparse representation methods is too high. The neural network methods are emerging high-resolution methods. However, insufficient support for big data is frequently observed in underwater acoustics, and conventional network structures present challenges in further enhancing performance. To address the aforementioned problems, we propose a neural network method based on an improved self-attention module to achieve high accuracy and robust DOA estimation. First, we design a multi-head self-attention module with large-scale convolutional kernels and residual structures to improve the estimated accuracy. Second, we propose an improved input feature to enhance the robustness to non-uniform noise and unequal-intensity targets. The simulations demonstrate that the proposed method exhibits superior angle resolution compared to sparse representation methods under the same simulation conditions. The proposed method demonstrates exceptional accuracy and robustness in DOA estimation under challenging conditions of low SNR, limited snapshots, and unequal-intensity targets. The experimental results further prove the effectiveness of the proposed method.

Polymeric artificial heart valves derived from modified diol-based polycarbonate polyurethanes

A series of polycarbonate silicone polyurethanes (SiPCUs) have been synthesized to develop elastomers with the mechanical properties, biostability, and biocompatibility required for artificial heart valve manufacturing. In these SiPCUs, the polar functional group 4,4′-dicyclohexylmethane diisocyanate (HMDI) was incorporated into the soft segment 1,6-poly (hexamethylene carbonate) diol (PCDL) to form the modified macromolecular diol, PCDL-HMDI-PCDL. The hard segment consisted of HMDI and the chain extenders 1,4-butanediol and 1,3-bis(4-hydroxybutyl)-1,1,3,3-tetramethyl disiloxane (BHTD). The synthesized PHC-PCUB improves the excessive microphase separation caused by the introduction of PDMS. This material possesses good physicochemical properties, long-term oxidative degradation stability, and comparatively low mechanical performance loss after degradation. Compared to the commercially available bioprosthetic heart valve (BHV) material Glut-PP, PHC-PCUB demonstrated enhanced biocompatibility, good thromboresistant properties, less calcification, and higher endothelial cell adhesion. Furthermore, valve prototypes fabricated with PHC-PCUB showed improved hemodynamic performance under various simulated conditions, highlighting the potential of PHC-PCUB as an advanced material for valve leaflets. Statement of SignificanceArtificial heart valves are crucial for treating valve diseases, and polyurethane-based valves present a promising alternative due to their durability, strong biocompatibility, and customizable properties. This study improves the biostability and post-degradation mechanical properties of siloxane polyurethanes by reducing the content of polydimethylsiloxane (PDMS) and adding modified diol (PCDL-HMDI-PCDL). By integrating hexamethylene diisocyanate (HMDI) and chain extenders, we developed polycarbonate siloxane polyurethanes (SiPCUs) that improve phase mixing, mechanical strength, and oxidative stability. These SiPCUs also exhibit good thromboresistance and calcification resistance, low cytotoxicity, and promote cell adhesion, positioning them as highly promising materials for heart valve leaflets, effectively addressing the limitations of current mechanical and bioprosthetic valves.

Introduction of Formal Training of Interns in Breaking Bad News in an Empathetic Manner through a Structured Module

Background: Due to lack of formal training, young doctors cannot deliver bad news in a way that is expected by patients and their attendants, thereby jeopardizing doctor–patient relationship. Aim: The aim of this study was to train interns about “breaking bad news” to the patients using a structured module. Materials and Methods: A workshop comprising interactive lectures and videos followed by debriefing, and discussion was conducted for interns. Pre/posttest, workshop feedback evaluation, and a group activity based on article case were conducted, followed by discussion. An assessment of skills based on a checklist was done after 15 days of workshop in simulated conditions. Results: There was a significant difference in scores of written tests taken by all 56 participants before and after the session (P &lt; 0.0001). Almost all of them agreed that their ability to break bad news has improved, and they feel confident in breaking bad news after attending this session. During the assessment of the skill of breaking bad news, most of them fell into the category of beginner after attending the workshop with a median of 2. Conclusions: A structured module is an effective method in improving the skills of the interns in sharing bad news with the patients.

Heat transfer performance of regenerative cooling in the presence of supersonic combustion based on two-way decoupling method

As a promising active cooling method for aero engines, regenerative cooling with endothermic hydrocarbon fuel plays an important role in thermal protection systems. However, simply assuming the thermal boundary conditions for the numerical simulation of regenerative cooling as either Dirichlet or Neumann boundary conditions is often unsuitable, as the combustion process exhibits complex three-dimensional (3D) characteristics. We propose a novel multi-step iterative calculation method in this work to simulate the coupled flow and heat transfer between supersonic combustion in the combustor and regenerative cooling outside. The method captures the main features of the supersonic combustion including different shockwave structures, and generates a realistic 3D distribution of heat flux as the boundary condition for the regenerative cooling study. With improved simulation, the result shows that regenerative cooling significantly reduces the peak temperature of the combustor by 58.5% with a mass flow rate of 1 g/s. A local high-temperature region is observed on the coupled wall inside the combustor near the injector, where the flame is primarily concentrated. Increasing the mass flow rate by 100%, from 1 g/s to 2 g/s, leads to a reduction in the maximum wall temperature by up to 15.7%.

Influence of the number of guide vane blades on the energy conversion characteristics of gas-liquid mixing pumps

Abstract To investigate the optimal number of guide vanes for peak performance efficiency in a mixing pump, this study employs a self-engineered gas-liquid mixing pump to the principal subject of analysis. adopts SST κ -ω turbulence model, Euler multiphase flow model and SIMPLEC algorithm, and conducts three-dimensional flow field numerical simulation under five operating conditions with the number of guide vane of the gas-liquid mixing pump as 5, 7, 9, 11, 13, 15, and 17, and the volume gas content as 10% to 50%, respectively. Volume gas content were 10% ∼ 50% of the five conditions for three-dimensional flow field numerical simulation, the experimental findings indicate that: with an increase in the number of guide vane blades, the efficiency of the pump’s secondary impeller varies in a cubic function relationship. When the gas content at the inlet is between 10% and 20%, efficiency is highest with 9 blades. When the gas content at the inlet is between 30% and 50%, efficiency is highest with 15 blades. Additionally, when there are 9 blades, the head of the secondary impeller reaches its maximum at different gas contents at the inlet.

Enhanced Zinc-air battery performance and local electrochemical evaluation of atomically dispersed Co and Ni in S, N-codoped carbon nanofibers via scanning electrochemical microscopy

This study reports the successful synthesis of a novel electrocatalyst for oxygen reduction reactions (ORR), comprising S,N dual-doped carbon nanofibers with atomically dispersed Co/Ni species (denoted as Co,Ni-SAs/S,N-CNFs), leveraging electrostatic spinning to achieve a unique spatial architecture that maximizes both active site density and mass transport efficiency. Density functional theory (DFT) analysis identified the initial proton-electron transfer to adsorbed O2 as the rate-limiting step, with CoN3S1-NiN3S1 emerging as the pivotal active site structure catalyzing this critical reaction. The fabricated Co,Ni-SAs/S,N-CNFs electrocatalyst exhibited remarkable ORR performance, characterized by a high half-wave potential of 0.84 V and a low Tafel slope of 57.9 mV dec-1. To gain a comprehensive understanding of its catalytic behavior, a tailored temperature-controlled scanning electrochemical microscopy (SECM) was employed, enabling the mapping of reactivity distribution under simulated operating conditions while preserving structural integrity. Liquid zinc-air batteries (ZABs) with this electrocatalyst excelled, reaching 175 mW/cm2 power density and enduring 1240 cycles. The electrospun membrane catalyst enabled both button and flexible ZABs, adaptable to diverse environments. This study advances non-precious metal electrocatalyst design and offers insights for ZAB applications, fostering green energy prospects.

Preparation, characterization, and stability of chitosan-tremella polysaccharide layer-by-layer encapsulated astaxanthin nanoemulsion delivery system

In this study, a layer-by-layer (LBL) encapsulated astaxanthin (Ast) nanoemulsion delivery system based on chitosan (CS) and tremella polysaccharide (TP) was successfully developed. The system constructed an Ast-CS-TP emulsion with high encapsulation efficiency and an excellent stability profile by utilizing the opposite charge properties of CS and TP. This study evaluated the effects of different stresses (including temperature, salt addition, pH, UV irradiation, and centrifugal force) on the emulsion's stability. To further investigate the protective mechanism of the emulsions, we performed antioxidant activity experiments after UV treatment. Additionally, an in vitro digestion experiment was conducted to assess the behavior of Ast emulsion under simulated gastrointestinal conditions. The stability correlation coefficients were calculated using the Python database Pandas. The results showed that Ast-CS-TP emulsions exhibited turbidity and enhanced homogeneity with a small particle size of around 400 nm and a high absolute zeta potential of 35 mV and exhibited excellent stability under various stresses. The Ast-CS-TP emulsions also exhibited pH-responsive release at pH ≥ 7, consistent with pH changes in the gastrointestinal tract, and were stable in highly concentrated salt solutions. We found that the CS and TP layers significantly improved the photostability of Ast. CS and TP significantly enhanced Ast's oral bioavailability. The stability correlation coeffcients showed that pH and salt concentration were the largest factors that affected the stability of the emulsion. This study provided important insights into the encapsulation and targeting of Ast, providing a theoretical foundation and technical guidance for the comprehensive utilization of Ast.

In Vitro Evaluation of a Continuous Potassium Monitoring System in Simulated Dialysis Conditions

In Vitro Evaluation of a Continuous Potassium Monitoring System in Simulated Dialysis Conditions

Development of vitamin D3 and Spirulina platensis protein hydrolysates co-loaded nanoliposomes and coated by sodium caseinate

The objective of this study was to investigate the co-loading of vitamin D3 (VitD3) and Spirulina platensis protein hydrolysates (SPH) within coated nanoliposomes (NLPs) by sodium caseinate, with the intention of developing a novel nutritional supplement. The coated NLPs exhibited particle size, PDI, and zeta potential values of 185.30 ± 29.62 nm, 0.22±0.04, and +18.70 ± 3.44 mV, respectively. Moreover, the encapsulation efficiencies of the coated NLPs for VitD3 and SPH were 83.24 ± 4.22 % and 89.41 ± 4.36 %, respectively. The improving effect of the surface coating by sodium caseinate on the stability and function of the NLPs was exhibited through analysis of chemical structure, thermal stability, and crystalline structure. The transmission electron microscopy pictures of the developed NLPs revealed a spherical morphology with a thin layer around the vesicle. The loaded VitD3 and SPH in the coated NLPs showed controlled release profiles during incubation in the simulated gastrointestinal condition. Moreover, the VitD3/SPH co-loaded NLPs and their coated form had no considerable cell toxicity. To conclude, the developed nanosystem demonstrated the suitable characteristics of a nanocarrier for reaping the nutritional benefits of VitD3 and SPH.