Original Structure Research Articles

Structural and electrical properties of mol% (100 − x)Li2SO4:xP2O5 solid electrolyte system (0 ≤ x ≤ 20)

Abstract Extensive research has been focused on solid electrolytes exhibiting high lithium ion conductivity, with the goal of advancing their use in solid-state lithium-ion batteries. This study investigates the influence of a glass former, P2O5, on the structure and ionic conductivity of the solid electrolyte Li2SO4. Quenching of Li2SO4 in the presence of P2O5 resulted in a glass–crystal composite with significant amorphous content. The XRD analysis of the 20 mol% glass ceramics detects the presence of Li4P2O7 without altering the original crystal structure. Notably, a conductivity value of 1.11 × 10−4 S cm−1 at 563 K was observed for 20 mol%, which is around two orders higher than that of polycrystalline Li2SO4. The introduction of a small amount of glass former P2O5 appears to loosen the structure of Li2SO4 creating an easier path for Li+ ion migration in the combined SO4–PO4 network structure.

Lattice Oxygen Redox Mechanisms in the Alkaline Oxygen Evolution Reaction

AbstractUnderstanding of fundamental mechanism and kinetics of the oxygen evolution reaction (OER) is pivotal for designing efficient OER electrocatalysts owing to its key role in electrochemical energy conversion devices. In the past few years, the lattice oxygen oxidation mechanism (LOM) arising from the anodic redox chemistry has attracted significant attention as it involves a direct O─O coupling and thus bypasses thermodynamic limitations in the traditional adsorbate evolution mechanism (AEM). Transition metal‐based oxyhydroxides are generally acknowledged as the real catalytic phase in alkaline media. In particular, their low‐dimensional layered structures offer sufficient structural flexibility to trigger the LOM. Herein, a comprehensive overview is provided for recent advances in anion redox from LOM‐based electrocatalysts. Based on analyses of electronic structure of electrocatalysts and LOM, a strategy is proposed to activate LOM. Possible identification techniques for corroboration of the oxygen redox are also reviewed. In addition, the structural reconstruction process induced by the LOM is focused and the importance of multiple in situ/operando characterizations is highlighted to unveil the structural and chemical origins of the LOM. To conclude, a prospect on the remaining challenges and future opportunities for LOM electrocatalysts is presented.

Mountain-valley crease reconfiguration of 4-crease origami vertices and tessellations

Reconfigurable origami-inspired folding has recently gained significant attention due to its potential to achieve multi-shape changes through crease topological morphing, resulting in multi-functionality from a single original structure. However, it is one of the major challenges to determine all possible mountain-valley crease (MV) assignments that ensure rigid foldability and obtain duplicate configurations in large 2D origami tessellations or 3D cellular structures. In this study, we developed a straightforward algorithm that combines graphic representation and motion compatibility conditions to assess the reconfigurability of origami structures with 4-crease vertices including double corrugated, Miura-ori, and symmetric Eggbox vertices, as well as their 2D and even 3D cellular tessellations. Our analysis has revealed three types of oligo-modal origami tessellations characterised by a consistent number of MV assignments independent of tessellation size, and pluri-modal cellular origami structures that exhibit negative, zero, and positive Poisson's ratios which were verified through experiment. This work could serve as a stepping stone towards developing multifunctional metamaterials and devices based on reconfigurable origami through mountain-valley crease assignment.

Zero-Sum Games between Mean-Field Teams: Reachability-Based Analysis under Mean-Field Sharing

This work studies the behaviors of two large-population teams competing in a discrete environment. The team-level interactions are modeled as a zero-sum game while the agent dynamics within each team is formulated as a collaborative mean-field team problem. Drawing inspiration from the mean-field literature, we first approximate the large-population team game with its infinite-population limit. Subsequently, we construct a fictitious centralized system and transform the infinite-population game to an equivalent zero-sum game between two coordinators. Via a novel reachability analysis, we study the optimality of coordination strategies, which induce decentralized strategies under the original information structure. The optimality of the resulting strategies is established in the original finite-population game, and the theoretical guarantees are verified by numerical examples.

Multiscale Low-Frequency Memory Network for Improved Feature Extraction in Convolutional Neural Networks

Deep learning and Convolutional Neural Networks (CNNs) have driven major transformations in diverse research areas. However, their limitations in handling low-frequency in-formation present obstacles in certain tasks like interpreting global structures or managing smooth transition images. Despite the promising performance of transformer struc-tures in numerous tasks, their intricate optimization com-plexities highlight the persistent need for refined CNN en-hancements using limited resources. Responding to these complexities, we introduce a novel framework, the Mul-tiscale Low-Frequency Memory (MLFM) Network, with the goal to harness the full potential of CNNs while keep-ing their complexity unchanged. The MLFM efficiently preserves low-frequency information, enhancing perfor-mance in targeted computer vision tasks. Central to our MLFM is the Low-Frequency Memory Unit (LFMU), which stores various low-frequency data and forms a parallel channel to the core network. A key advantage of MLFM is its seamless compatibility with various prevalent networks, requiring no alterations to their original core structure. Testing on ImageNet demonstrated substantial accuracy improvements in multiple 2D CNNs, including ResNet, MobileNet, EfficientNet, and ConvNeXt. Furthermore, we showcase MLFM's versatility beyond traditional image classification by successfully integrating it into image-to-image translation tasks, specifically in semantic segmenta-tion networks like FCN and U-Net. In conclusion, our work signifies a pivotal stride in the journey of optimizing the ef-ficacy and efficiency of CNNs with limited resources. This research builds upon the existing CNN foundations and paves the way for future advancements in computer vision. Our codes are available at https://github.com/AlphaWuSeu/MLFM.

SEA-GWNN: Simple and Effective Adaptive Graph Wavelet Neural Network

The utilization of wavelet-based techniques in graph neural networks (GNNs) has gained considerable attention, particularly in the context of node classification. Although existing wavelet-based approaches have shown promise, they are constrained by their reliance on pre-defined wavelet filters, rendering them incapable of effectively adapting to signals that reside on graphs based on tasks at hand. Recent research endeavors address this issue through the introduction of a wavelet lifting transform. However, this technique necessitates the use of bipartite graphs, causing a transformation of the original graph structure into a bipartite configuration. This alteration of graph topology results in the generation of undesirable wavelet filters, thereby undermining the effectiveness of the method. In response to these challenges, we propose a novel simple and effective adaptive graph wavelet neural network (SEA-GWNN) class that employs the lifting scheme on arbitrary graph structures while upholding the original graph topology by leveraging multi-hop computation trees. A noteworthy aspect of the approach is the focus on local substructures represented as acyclic trees, wherein the lifting strategy is applied in a localized manner. This locally defined lifting scheme effectively combines high-pass and low-pass frequency information to enhance node representations. Furthermore, to reduce computing costs, we propose to decouple the higher- order lifting operators and induce them from the lower-order structures. Finally, we benchmark our model on several real- world datasets spanning four distinct categories, including citation networks, webpages, the film industry, and large-scale graphs and the experimental results showcase the efficacy of the proposed SEA-GWNN.

Changing the structure of PFOA and PFOS: a chemical industry strategy or a solution to avoid thyroid-disrupting effects?

The family of perfluoroalkyl and polyfluoroalkyl substances (PFAS) raised concern for their proven bioaccumulation and persistence in the environment and animals as well as for their hazardous health effects. As a result, new congeners of PFAS have rapidly replaced the so-called "old long-chain PFAS" (mainly PFOA and PFOS), currently out-of-law and banned by most countries. These compounds derive from the original structure of "old long-chain PFAS", by cutting or making little conformational changes to their structure, thus obtaining new molecules with similar industrial applications. The new congeners were designed to obtain "safer" compounds. Indeed, old-long-chain PFAS were reported to exert thyroid disruptive effects in vitro, and in vivo in animals and humans. However, shreds of evidence accumulated so far indicate that the "restyling" of the old PFAS leads to the production of compounds, not only functionally similar to the previous ones but also potentially not free of adverse health effects and bioaccumulation. Studies aimed at characterizing the effects of new-PFAS congeners on thyroid function indicate that some of these new-PFAS congeners showed similar effects. The present review is aimed at providing an overview of recent data regarding the effects of novel PFAS alternatives on thyroid function. An extensive review of current legislation and of the shreds of evidence obtained from in vitro and in vivo studies evaluating the effects of the exposure to novel PFOA and PFOS alternatives, as well as of PFAS mixture on thyroid function will be provided.

SEIT: Structural Enhancement for Unsupervised Image Translation in Frequency Domain

For the task of unsupervised image translation, transforming the image style while preserving its original structure remains challenging. In this paper, we propose an unsupervised image translation method with structural enhancement in frequency domain named SEIT. Specifically, a frequency dynamic adaptive (FDA) module is designed for image style transformation that can well transfer the image style while maintaining its overall structure by decoupling the image content and style in frequency domain. Moreover, a wavelet-based structure enhancement (WSE) module is proposed to improve the intermediate translation results by matching the high-frequency information, thus enriching the structural details. Furthermore, a multi-scale network architecture is designed to extract the domain-specific information using image-independent encoders for both the source and target domains. The extensive experimental results well demonstrate the effectiveness of the proposed method.

Modification mechanism of soybean protein isolate-soluble soy polysaccharide complex by EGCG through covalent and non-covalent interaction: Structural, interfacial, and functional properties

Soybean protein isolate was modified with polysaccharides and polyphenols to prepare a natural emulsifier with antioxidant capacity. Physicochemical, structural, interfacial, and functional properties of SPI-SSPS complex were investigated after covalent and non-covalent interacted with EGCG. SPI-SSPS-EGCG ternary complex with low EGCG concentrations (0.0625 and 0.125 mg/mL) showed a significant increase in absolute potential value and a decrease in turbidity. EGCG destroyed the original rigid structure of SPI-SSPS complex, and the covalent complexes had an ordered structure, while the non-covalent interaction resulted in disordered. The ternary complex with high EGCG concentrations (0.25 and 0.5 mg/mL) exhibited stronger EGCG binding capacity and lower surface hydrophobicity, which in turn affected its interfacial properties. The EAI and ESI of SPI-SSPS-EGCG covalent complex increased significantly, while the non-covalent complex had a significant change in EAI but no significant change in ESI with increasing EGCG concentration. The ternary complex showed significantly enhanced antioxidant capacity. The SPI-SSPS-EGCG ternary complex, with excellent antioxidant capacity and emulsifying property, making it suitable for emulsion delivery systems.

Development and Initial Validation of the Shame Frequency Questionnaire in Medical Students.

This study presents the steps taken to develop and collect initial validity evidence for the Shame Frequency Questionnaire in Medical Students. The instrument was based on a 7-step survey design; validity evidence was collected from content, response process, internal structure, and relationship to other variables. A literature review and qualitative interviews led to the design of the initial 16-item scale. Expert review and cognitive interviewing led to minor modifications in the original structure. Initial pilot testing was conducted in August 2019 in Uniformed Services University (USU) medical students; reliability assessment and exploratory factor analysis were performed. The revised 12-item scale was tested in January 2022 in Duke University School of Medicine medical students; reliability assessment, exploratory factor analysis, and correlation analysis with depression, burnout, anxiety, emotional thriving, and emotional well-being were performed. A total of 336 of 678 USU students (50%) and 106 of 522 Duke students (20%) completed the survey. Initial exploratory factor analysis of the USU data revealed 1 factor (shame), and 4 items were dropped from the scale according to predefined rules. Subsequent exploratory factor analysis of the Duke data revealed 1 factor; no further items were removed according to predefined rules. Internal consistent reliability was 0.95, and all interitem correlations were less than 0.85 for USU and Duke samples. As predicted, mean shame scale scores were positively correlated with anxiety (r = 0.54, P < .001), burnout (r = 0.50, P < .001), and depression (r = 0.47, P < .001) and negatively correlated with emotional thriving (r = -0.46, P < .001) and emotional recovery (r = -0.46, P < .001). The Shame Frequency Questionnaire in Medical Students is a psychometrically sound instrument with strong internal reliability and multisource validity evidence, supporting its use in studying shame in medical students.

Abstract 6126: Understanding disparities in lung cancer using single cell RNA sequencing data transformed by the Gerchberg Saxton algorithm

Abstract Purpose An overarching goal of this study is to reduce disparities in lung cancer research commonly manifested by racial and/or gender under-representations. By employing the Gerchberg-Saxton (GS) algorithm, we aim to diminish data noise/bias in single-cell RNA sequencing (scRNA-seq) gene expression data, thereby enabling more equitable research outcomes. An immediate goal is to remove extensive data bias associated with scRNA-seq data thus enhancing downstream Machine Learning analyses. Background: We have successfully applied the GS algorithm for fairer mortality rate predictions across different racial groups [1]. In this study, we seek to apply the GS algorithm to the scRNA-seq data that interrogate the cellular landscapes of lung cancer and the tumor microenvironment. Methodology: The application of the GS algorithm to single cell RNA data involved a series of steps. Initially, all data frames were transposed, switching columns and rows to represent gene expressions and single cells, respectively. The algorithm was then meticulously applied to each column, allowing for the uniform distribution of certain specific gene expression information across all single cells within the data frame. This column-wise application was crucial to maintain the integrity of individual cell characteristics while ensuring a fair structural distribution of gene expression data. The process aimed to balance the representation of genes across all cells, addressing inherent biases and noises in the original data structure. Data: The study utilizes a previously unpublished scRNA-seq dataset comprising 14 lung cancer patients from Wake Forest Baptist Comprehensive Cancer Center, including 6 African American and 8 Caucasian patients. Results: One out of 14 preliminary clustering results are presented in Figure 2 using ScanPy [2]. The initial findings are based on a restricted set of cell marker genes, which will be further developed with additional markers in subsequent analyses. With the application of the Gerchberg-Saxton algorithm, the Shannon Entropy [3] analysis revealed a more uniform randomness across gene expressions (Figure 1), and the unsupervised clustering indicated a clearer separation of cell types, significantly enhancing the ability for downstream analyses. The data transformation will be applied to the whole dataset for comparative analyses of cellular landscapes between lung cancer from different races and genders, to be reported at the AACR 2024 Annual Meeting. Conclusions: Our preliminary studies showed that the Gerchberg-Saxton algorithm is effectiveness in normalizing data distribution for scRNA-seq data, which has led to enhanced resolution of cell type differentiations in clustering analysis. With this refined methodology, we are better poised to better address lung cancer health disparities revealed by single cell sequencing analysis. Citation Format: Seha Ay, Liang Liu, Elizabeth Forbes, Umit Topaloglu, Wei Zhang. Understanding disparities in lung cancer using single cell RNA sequencing data transformed by the Gerchberg Saxton algorithm [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6126.

Mechanical properties of hierarchical porous lattices with microscopic porosity fabricated by combination of lattice design and HSSH process

The hierarchical porous lattice implant with microscopic porosity, which resembles the original human bone structure, has significant potential application value. The microscopic porosity in the hierarchical porous lattice implant plays a crucial role in transporting nutrients and promoting tissue regeneration. However, it is difficult to fabricate microscopic pores smaller than 200 μm by powder bed fusion (PBF) processes due to the limitations of the laser spot size. In this study, the preparation of a hierarchical porous lattice implant with microscopic porosity is proposed by coupling structure design with the high scanning speed - short hatch spacing (HSSH) process formation. The structure-versus-process relationship is used to control the size and distribution of the microscopic pores, which meets the requirements of modulus and high biocompatibility. This proposed process breaks the inherent law where the higher the porosity, the higher the modulus of the lattice for the same lattice type. The modulus and porosity of the hierarchical porous implants could be flexibly tuned over a wide range (0.1–1.8 GPa and 63–84 %, respectively). The microscopic porosity is mainly distributed near the contour of the core rod, and the macroscopic porosity and microscopic porosity are approximately 73.70 % and 8.22 %, respectively. The problem of large errors in fitting the hierarchical porous lattice modulus calculation model according to the Gibson-Ashby equation has been solved. The mechanism of microscopic porosity formation was also analyzed. Furthermore, this method has the advantage of universal applicability, providing a feasible way for the development and application of porous materials.

Abstract 6769: Applications of a novel fibrous extracellular matrix for advanced in vitro cancer models

Abstract Compared to traditional in vitro two-dimensional (2D) planar cell culture system, three-dimensional (3D) mammalian cell culture can better recapitulate physiological environments and the complexity of natural tissues, hence they are crucial in modern biomedical research. Extracellular matrices (ECM) play a key role in in vitro mammalian cell culture systems. The role of the ECM on in vitro 3D cell culture are: 1) to simulate an in vivo-like physiological environment, 2) support cell-cell and cell-ECM interactions, 3) promote cell adhesion, migration, and communication, 4) aid in tissue development, morphogenesis, differentiation, and functioning. Although basal membrane extracts (BME) are the most popular type of ECM supporting 3D modeling in vitro, they often have significant limitations including limited long-term stability, significant batch to batch heterogeneity, restricted cell movement, and relatively high cost for culturing many cancer cell lines. In this investigation, we employ a novel micro-fibrous scaffold that closely mimics natural ECM, providing porous and interconnected networks for 3D culturing of hepatic cells, lung cancer, breast cancer, pancreatic cancer. As revealed by optical and scanning electron microscopy, the scaffold promotes significant cell-to-cell and cell-to-matrix interactions. Moreover, we observed improved cell growth in 3D culture over longer periods than 2D culture systems for all cell types examined. We also evaluated the anticancer efficiency of different drugs including Lapatinib, Cisplatin, Docetaxel, Doxorubicin and observed that 2D cultured cells were more sensitive to drugs treatment in comparison to 3D. Furthermore, ECM was observed to support 3D growth and structure formation with cell pools of primary cells achieved from disassociated human tumors. Tumor organoids were able to form within seven days and ready for anticancer screening within 14 days. We achieved an 80% success rate in developing breast cancer organoids from patient tissues. Additionally, tissue granules were also able to be cultured under the same condition, which allowed us to investigate the invasion of cancer cells into tissue. The primary cells from human tumors formed cell clusters resembling the original tumor tissue's structure. In conclusion, the novel micro-fibrous scaffold, closely mimicking natural extracellular matrixes, promotes significant cell-to-cell and cell-to-matrix interactions, while also facilitating cell growth over extended periods providing a more physiologically relevant platform for evaluating drug responses for various cancer cell types, further showing the importance of 3D culture systems in cancer research. Citation Format: Navneet Kaur, Dazhi Yang, Jamel Ali. Applications of a novel fibrous extracellular matrix for advanced in vitro cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6769.

Adaptation and Validation of the Self-Administered Foot Health Assessment Instrument for Portuguese Undergraduate Nursing Students

Background and Purpose:To translate and adapt the Self-Administered Foot Health Assessment Instrument from English to European Portuguese and explore its reliability and validity among undergraduate nursing students in Portugal.Methods:The study was divided into two phases. First, the translation and cross-cultural adaptation followed Beaton’s guidelines, with a pretesting of the final version with 30 students. The validation process used the content validity index with a minimum of 75% agreement between experts and Cronbach’s alpha for internal consistency. The second step provided the results of the principal component analysis and confirmatory factor analysis, which were performed to study the overall fit of the model and item correlations. The STROBE checklist was used.Results:The Portuguese version,Instrumento de Auto-Avaliação da Saúde do Pé(IAASP), showed an overall acceptable evidence regarding content validity and internal consistency. The factor analysis results suggested removing the “Foot pain” dimension from the original scale.Conclusions:IAASP is suggested to maintain the original 22-item structure, with four domains, “Skin health,” “Nail health,” “Foot structure,” and “Foot pain,” being an initial reliable version with interest to measure the current foot health of nursing students. Future studies should contribute to IAASP’s continuous improvement.

Production of resistant starch type 3 from cassava starch with high shear mixing and centrifugation treatment to increase its total dietary fibre content

SummaryCassava starch has a big potential to be a source material for producing low‐calorie starch by converting it to resistant starch. However, its original structure can prevent retrogradation of the amylose fraction to produce resistant starch so that reduce the total dietary fibre value. In this research, high shear mixing (HSM) is used to assist the gelatinisation process to provide disintegration of the cassava starch structure. Centrifugation was carried out to separate the top layers which have a high content of free amylose resulting in better retrogradation. The starch–water suspension was processed using HSM at a rotational speed of 9000–12 000 at 95 °C for 15 min. Then, the starch suspension was separated by centrifugation for 30 min. The product was then analysed using total dietary fibre (TDF), component carbohydrate analysis, scanning electron microscope (SEM) and x‐ray diffraction (XRD). From the analysis results, this method can increase the TDF content of the product up to 14.66% at 12 000 rpm.

Valvar bypass surgery to ameliorate persistent lower limb edema caused by post-thrombotic syndrome: a case report and literature review

Obstruction and/or reflux compromise during venous emptying can facilitate different pathophysiologies in chronic venous insufficiency (CVI). We present a patient with persistent lower limb CVI edema caused by post-thrombotic syndrome (PTS), who responded well to femoral vein valve therapy via axillary vein bypass after unsuccessful valvuloplasty, and led a normal life. During a 12 month observation period, bridging vessels completely restored original anatomical structures. In a literature study, no similar surgeries were reported, but we show that this operation may be feasible in selected patients.

Reliability and validity of the Greek version of the Short Gratitude Resentment and Appreciation Test (S-GRAT-GR)

Gratitude is a psychological notion that has been associated with numerous beneficial outcomes for individuals and communities. The Short Gratitude Resentment and Appreciation Test (S-GRAT), one of the most widely used measure to detect trait gratitude, comprises three subscales that assess lack of a sense of deprivation, appreciation for simple pleasures, and appreciation of others. The present study tested the psychometric properties of the Greek version of the S-GRAT scale. Using a sample of 681 adults from the general population and a smaller separate sample of fifty individuals we found that the scale demonstrated good internal consistency and high test-retest reliability. Explanatory and confirmatory factor analyses confirmed the original three-dimensional scale structure. Convergent and discriminant validity tests found S-GRAT-Gr total score was significantly correlated with Agreeableness, Intellect, Extraversion, Emotional Stability and Conscientiousness. S-GRAT-Gr also had positive correlations with the Gratitude Questionnaire (GQ-6), the Subjective Happiness Scale and the Satisfaction With Life Scale. S-GRAT-Gr score was found to have a unique impact on Life Satisfaction and Happiness beyond the basic taxonomies of personality and also beyond the GQ-6. Results indicate that the Greek version of the Revised Short Gratitude, Resentment, and Appreciation Test (S-GRAT-Gr) is a reliable and valid instrument for assessing dispositional gratitude in the Greek context.

Research on Safe Wearable Target Detection Technology for Power Production Scenarios based on YOLOv5-C3CA

Aiming at the establishment of a new generation of substation auxiliary equipment detection platform intelligence, this study proposes a power production industry personnel safety wear detection technology based on improved Yolov5-C3CA to meet the demand. First, the network performance is improved by adding the CA attention mechanism module to Yolov5s network; moreover, the CA module is modified to C3CA module and added to the model for more effective addition of the attention mechanism; finally, the AFPN network structure is used to replace the original feature pyramid network structure, which further effectively improves the utilization efficiency of shallow and deep features. The experimental results show that the mean average accuracy of the designed network is improved by 3.9% to 93.1% compared with the original network, and other evaluation indexes are also improved. It can be seen that the model modification in this paper has improved the performance of the detection network, and the improved network meets the requirements of the new generation of substation auxiliary equipment detection platform, which has a positive effect on the safety and reliability of the power production industry.

Discourse analysis of the social structure of the Gunung Kemukus society in Sragen Regency, Indonesia

As times change, a shift is observed in the background of economic stories or myths, which are created by social actors under the guise of prostitution as a means to fulfil a wish. The aim of this article is to examine the social structure of society within the Mount Kemukus Ritual Tourism Area. The writing methodology employed is a qualitative ethnographic approach, utilized to analyze findings from the community regarding changes in the structure of society. The subjects involved in this research encompass the community, tourist visitors, tourism services, academics, cultural activists, and relevant research. The research findings reveal that the social structure of society within the Mount Kemukus Ritual Tourism Area is characterised by a growing belief in the myth of the invisible quest for wealth. These beliefs stem from Javanese teachings or traditions, shaping the societal model around Mount Kemukus into a prismatic society. This signifies a societal model whose developmental trajectory is beginning to diverge from the original unified structure, yet has not fully transitioned to the modern divided structure. The orientation towards a prismatic society entails the coexistence of traditional and modern elements that complement each other.

New psychometric evidence for the thesis advisor abuse scale (EMAT) in Peruvian university students based on classic and modern procedures

Although evidence of mistreatment toward university students in the academic field has been reported for several years, its study in the context of the development of undergraduate research is still emerging. For this reason, it is necessary to have valid and reliable measurement instruments that allow assessing the magnitude of this problem. The objective of this study was to evaluate the psychometric properties of the Thesis Advisor Abuse Scale (EMAT, for its acronym in Spanish) in Peruvian university students. A total of 753 university students (women = 57.4%) from the 3 regions of Peru participated. The internal structure was analyzed under an analytical-factorial approach, and the discrimination and difficulty characteristics of the items were evaluated from the perspective of item response theory (IRT). The findings showed evidence supporting the original three-dimensional structure. Furthermore, all the items on the EMAT have good discriminatory power. Additionally, the EMAT proved to be strictly invariant according to sex, and the reliability coefficients reached high magnitudes. It is concluded that the EMAT is an instrument that has adequate psychometric properties to be used as a measure of mistreatment by advisors in the thesis preparation processes in Peruvian university students.