Stability Limit Research Articles

A third-order compact finite volume scheme on unstructured grid for fluid flows

The large reconstruction stencil is one of the biggest obstacles in design and implementation of high-order finite volume schemes on unstructured grid. To tackle this problem, a third-order compact reconstruction scheme on unstructured grid is developed on the basis of compact least-squares (CLS) finite volume method. In building the reconstruction polynomial, the general boundary condition is adopted to ensure the unified third-order accuracy in both the internal and boundary cells. The reconstruction polynomial is solved in a semi-implicit sense to ensure high computational efficiency without solving the global linear algebraic equations. The theoretical accuracy order and stability limit are firstly verified by the Fourier analysis. The numerical accuracy and efficiency are then verified and validated with several incompressible and compressible flow cases. This work provides a reference to design and analysis of high-order compact finite volume schemes on unstructured grid with unified accuracy.

Voltage stability assessment of the power system using novel line voltage collapse index

Nowadays, for the maximum utilization of the power available, power systems are operated at their maximum stability limit due to the scarcity of natural resources. In this situation, quick monitoring and control of the power systems are very necessary for the electrical operators. This paper presents a novel line voltage stability index based on V-Q sensitivity. The index is created utilizing the network’s ABCD parameters and is based on an exact transmission system model. The new index is evaluated in terms of ABCD parameters from the reactive power equation of the power system. The proposed line index can predict the voltage collapse under heavy MVA loading, heavy reactive loading, randomly chosen heavy reactive loading, and different N-1 contingencies conditions. This has also the capability to predict voltage stability under different contingencies. The proposed method is compared with four existing methods named line stability index (Lmn), fast voltage stability index (FVSI), line stability factor (Lqp), and line voltage stability index (LVSI). Results show that the critical situation of the power system that has been investigated by the proposed approach is more accurate than these four existing methods under different operating scenarios. The accuracy and applicability of the proposed method are investigated on IEEE 14-bus and IEEE 118-bus systems.

DAP1-2: a synthetic peptide targeting IL-1R1 receptor effectively suppresses IL-1β in vitro.

The pathological manifestation of the inflammatory process primarily stems from the heightened release of pro-inflammatory cytokines, with IL-1β standing out as a pivotal cytokine. The excessive presence of IL-1β disrupts immune signaling, thereby assuming a pathogenic and exacerbating role in the pathophysiology of numerous inflammatory diseases. Regulating IL-1β levels becomes crucial, and the IL-1Ra molecule serves this purpose by binding to the IL-1R1 receptor, thereby impeding the binding of IL-1β. Several pharmaceuticals have entered the market, aiming to neutralize IL-1β's biological function through diverse mechanisms. However, the existing IL-1β inhibitors are recombinant proteins, characterized by a high production cost and limited stability. Therefore, this study aimed to predict a peptide, named DAP1-2, based on the IL-1Ra molecule. DAP1-2 was designed to attenuate responses triggered by IL-1β by blocking the IL-1R1 receptor. The selection of amino acids from the IL-1Ra molecule (PDB: I1RA) that interact with the three domains of the IL-1R1 receptor was performed using Swiss PDB Viewer. After prediction, chemical synthesis was made using the Fmoc-Synthesis technique. The efficacy of DAP1-2 was assessed using RAW 264.7 cells, which were exposed to LPS (5μg/mL) for 24h to induce IL-1β expression and treated with the peptides in different concentrations. IL-1β levels were assessed using ELISA, and the gene expression of IL-1β was measured by RT-qPCR, additionally to the viability test. Results revealed a significant reduction in IL-1β levels and gene expression in cells stimulated by LPS and treated with DAP1-2 in different concentrations. Furthermore, the MTT assay confirmed the nontoxic nature of the peptides on the cell lineage. This alternative approach shows promise as an IL-1 inhibitor, due to the stability, ease of production, and cost-effectiveness provided by the use of synthetic peptides.

Revolutionizing Antimicrobial Biomaterials: Integrating an Enzyme Degradation-Resistant Sequence into Self-Assembled Nanosystems to Overcome Stability Limitations of Peptide-Based Drugs

Revolutionizing Antimicrobial Biomaterials: Integrating an Enzyme Degradation-Resistant Sequence into Self-Assembled Nanosystems to Overcome Stability Limitations of Peptide-Based Drugs

The influence of professional identity and occupational well-being on retention intention of rural teachers in China

Rural teachers are fundamental to rural education. Currently, the high turnover rate of rural teachers is a bottleneck that restricts the improvement of rural education quality. However, most existing studies focus on why rural teachers cannot stay but do not pay enough attention to the reasons for them to stay. Therefore, from the perspective of retention, this study breaks through the limitations of teacher stability represented by teacher turnover in the past and further enriches the theoretical understanding of rural teacher retention. This study adopts a questionnaire survey of 588 rural teachers in Yulin City, Shaanxi province, China. It found that the overall retention intention (emotional retention and interest retention) of rural teachers was not very strong, and it shows statistically significant differences in terms of age, address on their ID card, marital status, educational level, years of teaching in rural areas, and the type of house they currently live in. The following three strategies are proposed in the hope of stabilizing the rural teacher team: (i) Focus on key groups and accurately meet the real needs of rural teachers, (ii) Strengthen professional identity to improve benefit retention intention, and (iii) Promote occupational happiness to further enhance the emotional retention intention of rural school teachers.

A Virtual Resistance Optimization Method Based on Hybrid Index in Low-voltage Microgrid

Introduction: The introduction of virtual resistance can effectively suppress the circulating current between micro-sources and improve power allocation in low-voltage microgrid, but it also causes the voltage deviation of micro-sources’ inverters. An optimization method of virtual resistance based on hybrid index is proposed in order to suppress circulating current and improve voltage deviation at the same time in this paper. The gradient descent method is used to design the virtual resistance optimization process, aiming at the optimization of hybrid index composed of circulating current and voltage deviation. The constraints are deduced with power quality requirements, capacity limitation and static stability, and then virtual resistance values are optimized. The effects of switching load and micro-source on the optimization results are analyzed through the simulation of low-voltage microgrid, and the simulation results show that the virtual resistance optimization method can significantly suppress circulating current while improving power quality. When distributed generators are connected to utility grid through inverters and feeders, differences in feeder parameters and inverter control strategies easily cause circulating current and uneven power distribution among micro-sources. The introduction of virtual resistance can effectively suppress the circulating current between micro-sources and improve power allocation in low-voltage microgrids, but it also causes the voltage deviation of micro-sources’ inverters. An optimization method of virtual resistance based on hybrid index is proposed in order to suppress circulating current and improve voltage deviation. Methods: The gradient descent method is used to design the virtual resistance optimization process, aiming at the optimization of hybrid index composed of circulating current and voltage deviation. The constraints are deduced with power quality requirements, capacity limitation and static stability, and then virtual resistance values are optimized. Results: In the simulation scenario of two micro-sources and three micro-sources, the virtual resistance obtained by the method proposed in this paper has more obvious improvement on the system operation index, and is not affected by the load type. Conclusion: The method of optimizing virtual resistance based on the hybrid index can achieve the effect of restraining circulating current and improving power sharing degree on the premise of guaranteeing power quality and satisfying system stability. The optimization of virtual resistance is affected by the number of feeders. It is necessary to re-optimize the virtual resistance after changing the number of feeders, but the process of switching micro-source and adjusting load does not affect the optimized resistance value.

Development of a Closed-Loop Controller for an Arduino-Based DC Chopper using Proteus and LabVIEW

This research focuses on developing a DC-DC converter voltage regulation system using an Arduino microcontroller, addressing the instability inherent in renewable energy sources like solar panels and wind turbines. Utilizing Proteus and LabVIEW, the study employs a quantitative deductive approach to experimentally simulate and model the system over four months at the Control and Automation Laboratory of Politeknik ATI Makassar. Key challenges of conventional converters, including limited PWM flexibility, output stability, and ripple reduction, are addressed through a closed-loop control system with voltage feedback. The methodology involves extensive parameter calculations derived from literature review and expected testing scenarios to ensure precise component selection and system performance. Specific calculations guide the determination of minimum component values, facilitating the desired input and output voltage levels with minimal ripple. Simulation testing validates the system's effectiveness, demonstrating successful integration between LabVIEW and Proteus through additional library utilization. The resulting DC-DC converter voltage regulation system enables more robust control through Arduino microcontroller, enhancing stability and efficiency in renewable energy applications.

Eclipse-timing study of new hierarchical triple star candidates in the northern continuous viewing zone of TESS

Aims. We compiled a list of more than 3500 eclipsing binaries located in and near the northern continuous viewing zone (NCVZ) of the TESS space telescope that have sufficient TESS photometry to search for additional hidden components in these systems. In addition to discovering their hierarchical nature, we also determined their orbital parameters and analyzed their distributions. Methods. We obtained the TESS light curves of all targets in an automated way by applying convolution-aided differential photometry on the TESS full-frame images from all available sectors up to sector 60. Using a new self-developed Python GUI, we visually confirmed all of these light curves, determined the eclipsing periods of the objects, and calculated their eclipse-timing variations (ETVs). The ETV curves were used in order to search for nonlinear variations that could be attributed to a light travel-time effect (LTTE) or dynamical perturbations caused by additional components in these systems. We preselected 351 such candidates and modeled their ETVs with the analytic formulae of pure LTTE or with a combination of LTTE and dynamical perturbations. Results. We were able to fit a model solution for the ETVs of 135 hierarchical triple candidates, 10 systems of which were known from the literature, and the remaining 125 systems are new discoveries. These systems include some more noteworthy ones, such as five tight triples that are very close to their dynamical stability limit with a period ratio lower than 20, and three newly discovered triply eclipsing triples. We point out that dynamical perturbations occur in GZ Dra, which we found to be a triple, and that the system is one of the most strongly inclined systems known in the literature, with im = 58° ±7°. We also compared the distributions of some orbital parameters from our solutions with those from a previous Kepler sample. Finally, we verified the correlations between the available parameters for systems that have Gaia non-single star orbital solutions with those from our ETV solutions.

Sweet potato (Ipomoea batatas L.) genotype selection using advanced indices and statistical models: A multi-year approach

In Bangladesh, sweet potato holds the fourth position as a crucial carbohydrate source, trailing rice, wheat, and potato. However, locally grown sweet potato varieties often display limited stability and yield. To tackle this challenge, diverse selection methods and statistical models were utilized to pinpoint sweet potato genotypes showcasing both stability and superior yield and quality traits. In the initial two years, multiple selection methods were employed to narrow down the collections based on preferences for yield and its contributing traits. Subsequently, a multi-environment trial (MET) was conducted in the following year to pinpoint superior and stable genotypes with desirable yield and quality characteristics. An integrated approach involving the Multi-Trait Genotype Ideotype Distance Index (MGIDI), Factor Analysis and Ideotype-Design (FAI-BLUP), and Smith-Hazel Index (SH) led to the identification of 71 superior sweet potato genotypes out of a total of 351 in the initial growing season. In the subsequent season, the MGIDI selection index was applied to the 71 genotypes, resulting in the selection of 11 top-performing genotypes. This selection process was complemented by a detailed analysis of the strengths and weaknesses of the selected genotypes. In the MET, the mixed effect model, specifically the linear mixed model (LMM), identified significant genotypic and genotype-environment interaction (GEI) variances. This points to elevated heritability and selection accuracy, ultimately boosting the model's reliability. By combining the strengths of LMM and additive main effects and multiplicative interaction (AMMI), the best linear unbiased prediction (BLUP) index identified H20 as the top-performing genotype for marketable root yield (MRY), H37 for dry weight of root (DW), H8 for beta carotene (BC) and H41 for vitamin c (VC). These genotypes surpassed the overall average in the WAAS index. For simultaneous stability and high performance, the WAASBY index selected H37 for MRY, H6 for DW, H61 for BC, and H3 for VC. Finally, genotypes H3 and H20 were selected using multi-trait stability index (MTSI), as they possessed high performance and stability. Based on the selection sense, the objective has been achieved with regards to the trait MRW, which serves as a major criterion for a superior variety of sweet potato.

Biodynamer Nano-Complexes and -Emulsions for Peptide and Protein Drug Delivery.

Therapeutic proteins and peptides offer great advantages compared to traditional synthetic molecular drugs. However, stable protein loading and precise control of protein release pose significant challenges due to the extensive range of physicochemical properties inherent to proteins. The development of a comprehensive protein delivery strategy becomes imperative accounting for the diverse nature of therapeutic proteins. Biodynamers are amphiphilic proteoid dynamic polymers consisting of amino acid derivatives connected through pH-responsive dynamic covalent chemistry. Taking advantage of the amphiphilic nature of the biodynamers, PNCs and DEs were possible to be prepared and investigated to compare the delivery efficiency in drug loading, stability, and cell uptake. As a result, the optimized PNCs showed 3-fold encapsulation (<90%) and 5-fold loading capacity (30%) compared to DE-NPs. PNCs enhanced the delivery efficiency into the cells but aggregated easily on the cell membrane due to the limited stability. Although DE-NPs were limited in loading capacity compared to PNCs, they exhibit superior adaptability in stability and capacity for delivering a wider range of proteins compared to PNCs. Our study highlights the potential of formulating both PNCs and DE-NPs using the same biodynamers, providing a comparative view on protein delivery efficacy using formulation methods.

Water at negative pressure: nuclear quantum effects

Various condensed phases of water, spanning from the liquid state to multiple ice phases, have been systematically investigated under extreme conditions of pressure and temperature to delineate their stability boundaries. This study focuses on probing the mechanical stability of liquid water through path-integral molecular dynamics simulations, employing the q-TIP4P/F potential to model interatomic interactions in flexible water molecules. Temperature and pressure conditions ranging from 250 to 375 K and − 0.3 to 1 GPa, respectively, are considered. This comprehensive approach enables a thorough exploration of nuclear quantum effects on various physical properties of water through direct comparisons with classical molecular dynamics results employing the same potential model. Key properties such as molar volume, intramolecular bond length, H–O–H angle, internal and kinetic energy are analysed, with a specific focus on the effect of tensile stress. Particular attention is devoted to the liquid-gas spinodal pressure, representing the limit of mechanical stability for the liquid phase, at several temperatures. The quantum simulations reveal a spinodal pressure for water of − 286 and − 236 MPa at temperatures of 250 and 300 K, respectively. At these temperatures, the discernible shifts induced by nuclear quantum motion are quantified at 15 and 10 MPa, respectively. These findings contribute valuable insights into the interplay of quantum effects on the stability of liquid water under diverse thermodynamic conditions.

Water Absorption, Thermal, and Mechanical Properties of Bamboo Fiber with Chopped Glass Fiber Filler-Reinforced Polyester Composites

This study explores the investigations of bamboo fiber-reinforced polyester composites with chopped glass fiber (CGF) filler, focusing on addressing the challenges of low mechanical properties, limited thermal stability, and high moisture absorption. The two types of composites were fabricated using the hand layup method, that is, long unidirectional 0° bamboo fiber (BF) and randomly oriented short bamboo fiber (BP) reinforced a polyester matrix with chopped glass fiber (CGF) filler. By incorporating CGF filler, significant improvements in mechanical properties were achieved across both types of bamboo fiber, surpassing the limitations of unfilled composites. Notably, the composite formulation consisting of 40% wt. of unidirectional 0° BF and 5% wt. of CGF filler exhibited superior ultimate tensile strength, flexural strength, impact strength, water absorption, and thermal stability. This composite demonstrated remarkable enhancements, with increases of up to 131.22 MPa, 128.76 MPa, 113.3 kJ/m2, 1.94% water absorption, and up to 255°C (representing a 10% improvement) in thermal stability compared to the unfilled composite. Statistical analysis revealed quadratic models for the mechanical properties of long unidirectional 0° bamboo fiber composites, while water absorption exhibited a linear two-factor interaction model. For randomly oriented short bamboo fiber, the models for tensile, flexural, and water absorption properties were linear, while the impact energy model showed a quadratic relationship. These statistical models provide valuable insights into predicting the properties of bamboo fiber-reinforced polyester composites. This research underscores the significance of bamboo fiber-reinforced polyester composites in wall partition systems. This study paves the way for improved performance in these areas. The findings highlight the potential of incorporating CGF filler, enabling enhanced mechanical strength, increased thermal stability, and improved resistance to moisture-related issues. The derived statistical models offer valuable guidance for predicting the properties of these composites, facilitating their application and adoption in the construction industry.

An ultrasensitive NO2 gas sensor based on a NiO-SnO2 composite with a sub-ppb detection limit at room temperature

The highly sensitive detection of ppb-level NO2 at room temperature (RT, 25 °C) remains a challenge hindering the detection of metal oxides due to their chemical inactivity. Herein, a strategy for constructing mixed metal oxides with high specific surface areas and highly active surfaces is proposed. In this work, we synthesized NiO-SnO2 using the solvothermal and calcination methods with Ni/Sn bimetallic organic frameworks (Ni/Sn-BTC MOFs, BTC: benzene-1,3,5-tricarboxylic) as sacrificial templates. The characterization shows that NiO-SnO2 has a high porosity (0.343 m3/g) and a large specific surface area (74.73 m2/g), which can produce abundant permeability pathways for NO2, maximize the number of active sites, and enhance the capacity for NO2 capture. The sensing test results indicate that the NiO-SnO2 sensor exhibits an excellent sensing response of 693.1% (ΔR/Ra) to 150 ppb NO2, a fast response/recovery time (86.8/29.4 s), a distinct selectivity, a lower detection limit (25 ppb) and good long-term stability at RT and 60% RH (RH: relative humidity). The outstanding sensing performance can be attributed to the microstructure characteristics, oxygen vacancies and p-n heterojunctions formed between NiO and SnO2. The current work provides a versatile platform for designing sensitive materials with heterogeneous structures and opens up a new pathway for the development of room temperature gas sensors based on metal oxide.

Bismuth (Bi3+) based lead-free halide perovskitoid for light driven applications: A potential low-toxic alternative for lead (Pb2+)

Bismuth-based perovskite-like materials are recognised as feasible optoelectronic alternatives to lead-based perovskites. High toxicity and limited environmental stability of Pb-based perovskite are the principal hurdles for their practical use, whereas Bismuth (Bi3+) based materials exhibit relatively low toxicity. In this study, we fabricated (FPEA)BiI4 (FPEA = Fluorophenylethyl amine, as a hydrophobic aromatic spacer) and explored its compatibility in the field of photocatalysis and solar cells. UV–Vis, photoluminescence (PL) and time-correlated single photon counting (TCSPC) techniques were used to understand the optoelectronic properties of the material. These fabricated thin films were used towards toxic MBT remediation. Solar cells (in n-i-p configuration) were also fabricated using (FPEA)BiI4 and their photo conversion efficiency (PCE) was tested under AM1.5 illumination.

Nanotubes from Lanthanide-Based Misfit-Layered Compounds: Understanding the Growth, Thermodynamic, and Kinetic Stability Limits.

Gaining insights into the kinetics and the thermodynamic limits of nanostructures in high-temperature reactions is crucial for controlling their unique morphology, phase, and structure. Nanotubes from lanthanide-based misfit-layered compounds (MLCs) have been known for more than a decade and were successfully produced mostly via a chemical vapor transport protocol. The MLC nanotubes show diverse structural arrangements and lattice disorders, which could have a salient impact on their properties. Though their structure and charge transfer properties are reasonably well understood, a lack of information on their thermodynamic and kinetic stability limits their scalable synthesis and their applicability in modern technologies. In this study, the growth, thermodynamic stability, and decomposition kinetics of lanthanide-based misfit nanotubes of two model compounds, i.e., (LaS)1.14TaS2 and (SmS)1.19TaS2 are elucidated in detail. The nanotubes were carefully analyzed via atomic resolution electron microscopy imaging and synchrotron-based X-ray and electron diffraction techniques, and the information on their morphology, phase, and structures was deduced. The key insights gained would help to establish the parameters to explore their physio-chemical properties further. Furthermore, this study sheds light on the complex issue of the high-temperature stability of nanotubes and nanostructures in general.

Recent Advances in Catalytic Compounds Developed by Thermal Treatment of (Zr-Based) Metal–Organic Frameworks

Metal–organic frameworks (MOFs) have been the subject of extensive scientific investigation in the last three decades and, currently, they make up one of the types of compounds most studied for their potential application in a wide range of distinct catalytic processes. Pristine MOF compounds provide several intriguing benefits for catalytic applications, including large interior surface areas and high densities of active sites; high catalytic reaction rates per volume; post-synthesis modifications with complementary catalytic groups; and the ability for multiple functional groups to catalyze the reaction. For most large-scale catalytic applications, including those in fuel processing, gas emission reduction, and chemical synthesis, pristine MOFs often show limited stabilities and opportunities for regeneration at high temperatures. As a result, the real applications of MOFs in these technologies are likely to be constrained, and a controlled thermal modification to prepare MOF-derivative compounds has been applied to induce crystalline structural changes and increase the structural stability of the MOFs, enhancing their potential applicability in more severe catalytic processes. Recent advances concerning the use of this strategy to boost the catalytic potential of MOF-derivative compounds, particularly for stable Zr-based MOFs, are outlined in this short review article.

Stable Ga2O3 soft x-ray detector with ultrahigh responsivity

Soft x-ray detectors play crucial roles in biology, chemistry, and lithography. Current soft x-ray detectors suffer from insufficient responsivity (R), excessively large cell area, and limited stability. Here, the β-Ga2O3 soft x-ray detector is constructed, and the effects of varying the sensitive layer thickness and voltage on the soft x-ray detection characteristics of the device are explored. Meanwhile, the mechanism of the multiplication ionization process from soft x-ray and the photoconductivity gain on the photoresponse performance of the device are analyzed. The device obtains the R up to 3.05 × 103 A/W under 300 eV soft x-ray irradiation at the synchrotron beamline, which is about 1.19 × 104 times higher than that of the conventional device. The Ga2O3 device also maintains stable operation under long-term irradiation and multicycle switching. These results indicate that Ga2O3 is an ideal candidate material for soft x-ray detection, which has great potential for applications such as imaging of biological cells.

Nanocarriers for natural polyphenol senotherapeutics.

Senescence is a heterogenous and dynamic process in which various cell types undergo cell-cycle arrest due to cellular stressors. While senescence has been implicated in aging and many human pathologies, therapeutic interventions remain inadequate due to the absence of a comprehensive set of biomarkers in a context-dependent manner. Polyphenols have been investigated as senotherapeutics in both preclinical and clinical settings. However, their use is hindered by limited stability, toxicity, modest bioavailability, and often inadequate concentration at target sites. To address these limitations, nanocarriers such as polymer nanoparticles and lipid vesicles can be utilized to enhance the efficacy of senolytic polyphenols. Focusing on widely studied senolytic agents-specifically fisetin, quercetin, and resveratrol-we provide concise summaries of their physical and chemical properties, along with an overview of preclinical and clinical findings. We also highlight common signaling pathways and potential toxicities associated with these agents. Addressing challenges linked to nanocarriers, we present examples of senotherapeutic delivery to various cell types, both with and without nanocarriers. Finally, continued research and development of senolytic agents and nanocarriers are encouraged to reduce the undesirable effects of senescence on different cell types and organs. This review underscores the need for establishing reliable sets of senescence biomarkers that could assist in evaluating the effectiveness of current and future senotherapeutic candidates and nanocarriers.

Optimizing Individual Wound Closure Practice Using Augmented Reality: A Randomized Controlled Study.

Background Suturing requires repeated practice with guidance to prevent skill deterioration; however, guidance is often limited by expert availability. There is evidence that augmented reality (AR) may assist procedural skill acquisition among learners. This study examines the use of an AR suture guidance application to assist the independent practice of suturing. Methodology A novel suture guidance application was designed for the Microsoft HoloLens. The guidance system included a calibration system and holograms that projected over a suture pad in a stepwise manner. To assess the application, 30 medical students were recruited and randomly assigned to two groups. The control group (n = 16) was given 30 minutes of independent suture practice, while the experimental group (n = 14) utilized the suture guidance application. Both groups completed a pre- and post-test wound closure assessment. After the post-test, the control group trialed the suture guidance application. All participants completed a feedback survey on the application. Statistical analysis was completed using Stata (StataCorp., College Station, TX, USA) with paired Student's t-tests and Welch's t-tests with a significance of 95%. Results Both groups demonstrated a significant improvement in total time and time per stitch during the post-test. Additionally, comparing pre- and post-test assessments in the experimental group revealed a significant improvement in the total number of stitches (p = 0.007), the ratio of bisecting stitches (p = 0.02), and the symmetry of stitch bite (p = 0.03). The feedback survey supported the application for guiding suture placement and spacing. Participants identified limitations in the hologram stability and neck positioning. Conclusions This study suggests the potential to use AR to facilitate the independent practice of wound closure within simulation environments.

Subacute toxicity of isoliquiritigenin-zein phosphatidylcholine nanoparticles on biochemical, hematological, and histopathological parameters in Sprague-Dawley rats

Aim: Isoliquiritigenin (ISL) is a natural flavonoid found in many natural plants, which exhibits numerous pharmacological properties including anti-inflammatory, antioxidant, antitumor, and antiviral activities. However, the low bioavailability and stability of ISL limit its application in clinical practice. To overcome these limitations, ISL-zein phosphatidylcholine hybrid nanoparticles (ISL@ZLH NPs) have been developed to improve the bioavailability and stability of ISL. The present study aimed to evaluate the acute and subacute toxicity of ISL@ZLH NPs in Sprague-Dawley (SD) rats. Methods: The ISL@ZLH NPs were prepared by the solvent evaporation method. The acute toxicity was evaluated by administering a single dose of 110 mg/kg and 160 mg/kg of ISL@ZLH NPs extracted in distilled water via oral gavage in rats and mice, respectively. The subacute toxicity was evaluated by administering doses of 27.5 mg/(kg∙day), 55 mg/(kg∙day), and 110 mg/(kg∙day) of ISL@ZLH NPs for 30 days and 90 days. The biochemical, hematological, and histopathological parameters were analyzed in both studies. Results: In the acute toxicity study, no mortality or significant changes in the biochemical and hematological parameters were observed in both Kunming (KM) mice and SD rats. In the subacute toxicity study, no toxic reactions were observed in both species at all doses tested. Moreover, no significant changes in the biochemical, hematological and histopathological parameters were observed in both species. Conclusions: The results of this study suggest that ISL@ZLH NPs are safe and non-toxic in both KM mice and SD rats. The nanoparticles (NPs) did not induce any adverse effects on the biochemical, hematological, and histopathological parameters in both acute and subacute toxicity studies. These results indicate that ISL@ZLH NPs are safe for prolonged consumption. Further studies are needed to evaluate the long-term toxicity and efficacy of these NPs in vivo.