bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Description of Pore and Fracture Distribution Heterogeneity Using Mercury Removal Curve and Applicability of Fractal Models
Authors: Chong Huasheng , Liu Xiao , Xi Danyang , Zhang Junjian , Vandeginste Veerle , Wang Dongdong , Yao Peng
Published: May 2024

Many studies have used fractal theory to characterize pore structure distribution heterogeneity through mercury intake curves. However, there is relatively little research on the fractal model calculation of mercury removal curves. In this study, a high-pressure mercury intrusion test is used to describe the pore and fracture distribution heterogeneity (PFDH). The fractal physical meaning of the mercury removal curve was determined by calculating the change in the curve’s fractal dimension value. The results are as follows. (1) According to mercury removal efficiency and porosity, samples can be divided into types A (mercury removal efficiency above 35%) and B (mercury removal efficiency below 35%). In general, type A sample belongs to micro-pore-developed types, and type B samples belong to the macro-pore-developed type. (2) The Menger model (M) represents the complexity of a specific surface area, while the Sierpinski model (S) represents the roughness of the pore volume. Among all the samples, the lower-pore-volume region controls PFDH. (3) According to the calculation results of the single fractal model, it can be seen that the PFDH of type B is stronger than that of type A, which is similar to the results of mercury intrusion. According to the calculation structure of the multifractal model, it can be seen that the volume distribution heterogeneity of type B under various pores is significantly stronger than that of type A. This is opposite to the result of mercury injection. (4) DM has a relationship with the pore volume percentage at different stages, so the M model at the mercury inlet stage can better characterize PFDH at the mercury inlet stage.
Study on the Damage Mechanism of Coal under Hydraulic Load
Authors: Li Hongyan , Li Yaolong , Wang Weihua , Li Yang , Sun Zhongxue , He Shi , Fan Yongpeng
Published: May 2024

Hydraulic fracturing is extensively utilized for the prevention and control of gas outbursts and rockbursts in the deep sections of coal mines. The determination of fracturing construction parameters based on the coal seam conditions and stress environments merits further investigation. This paper constructs a damage analysis model for coal under hydraulic loads, factoring in the influence of the intermediate principal stress, grounded in the octahedron strength theory analysis approach. It deduces the theoretical analytical equation for the damage distribution of a coal medium subjected to small-flow-rate hydraulic fracturing in underground coal mines. Laboratory experiments yielded the mechanical parameters of coal in the study area and facilitated the fitting of the intermediate principal stress coefficient. Leveraging these datasets, the study probes into the interaction between hydraulic loads and damage radius under assorted influence ranges, porosity, far-field crustal stresses, and brittle damage coefficients. The findings underscore that hydraulic load escalates exponentially with the damage radius. Within the variable range of geological conditions in the test area, the effects of varying influence range, porosity level, far-field stress, and brittle damage coefficient on the outcomes intensify one by one; a larger hydraulic load diminishes the impact of far-field stress variations on the damage radius, inversely to the influence range, porosity, and brittle damage. The damage radius derived through the gas pressure reduction method in field applications corroborates the theoretical calculations, affirming the precision of the theoretical model. These findings render pivotal guidance for the design and efficacy assessment of small-scale hydraulic fracturing in underground coal mines.
Growth Substrate Geometry Optimization for the Productive Mechanical Dry Transfer of Carbon Nanotubes
Authors: Butzerin Andre , Weikert Sascha , Wegener Konrad
Published: May 2024

The selection of growth substrate geometries for the mechanical dry transfer of carbon nanotubes to device substrates depends on the precision of the assembly equipment. Since these geometries play a decisive role in the overall efficiency of the process, an investigation of the most important geometry parameters is carried out. The substrate geometry affects the number of carbon nanotubes suspended during the growth process and the speed of mechanical assembly at the same time. Since those two criteria are interlinked and affect productivity, a meta-model for the growth and selection of the nanotubes is simulated and a time study of the resulting assembly motions is subsequently performed. The geometry parameters are then evaluated based on the total number of suspended carbon nanotubes and the throughput rate, measured in transfers per hour. The accuracy specifications are then taken into account. Depending on the overall accuracy that can be achieved, different offset angles and overlaps between the growth and receiving substrate can be reached, which affect productivity differently for different substrate geometries. To increase the overall productivity, growth substrate designs are adapted to allow fully automated operation. This measure also reduces the frequency of substrate exchanges once all carbon nanotubes have been harvested. The introduction of substrates with multiple, polygonally arranged edges increases the total number of nanotubes that can be harvested. The inclusion of polygonally arranged edges in the initial analysis shows a significant increase in overall productivity.
YOLOv8-LMG: An Improved Bearing Defect Detection Algorithm Based on YOLOv8
Authors: Liu Minggao , Zhang Ming , Chen Xinlan , Zheng Chunting , Wang Haifeng
Published: May 2024

In industrial manufacturing, bearings are crucial for machinery stability and safety. Undetected wear or cracks can lead to severe operational and financial setbacks. Thus, accurately identifying bearing defects is essential for maintaining production safety and equipment reliability. This research introduces an improved bearing defect detection model, YOLOv8-LMG, which is based on the YOLOv8n framework and incorporates four innovative technologies: the VanillaNet backbone network, the Lion optimizer, the CFP-EVC module, and the Shape-IoU loss function. These enhancements significantly increase detection efficiency and accuracy. YOLOv8-LMG achieves a mAP@0.5 of 86.5% and a mAP@0.5–0.95 of 57.0% on the test dataset, surpassing the original YOLOv8n model while maintaining low computational complexity. Experimental results reveal that the YOLOv8-LMG model boosts accuracy and efficiency in bearing defect detection, showcasing its significant potential and practical value in advancing industrial inspection technologies.
Lithium Silicate-Based Glass Ceramics in Dentistry: A Narrative Review
Authors: Al-Johani Hanan , Haider Julfikar , Satterthwaite Julian , Silikas Nick
Published: May 2024

Considering the rapid evolution of lithium silicate-based glass ceramics (LSCs) in dentistry, this review paper aims to present an updated overview of the recently introduced commercial novel LSCs. The clinical and in vitro English-language literature relating to the microstructure, manufacturing, strengthening, properties, surface treatments and clinical performance of LSC materials was obtained through an electronic search. Findings from relevant articles were extracted and summarised for this manuscript. There is considerable evidence supporting the mechanical and aesthetic competency of LSC variants, namely zirconia-reinforced lithium silicates and lithium–aluminium disilicates. Nonetheless, the literature assessing the biocompatibility and cytotoxicity of novel LSCs is scarce. An exploration of the chemical, mechanical and chemo-mechanical intaglio surface treatments—alternative to hydrofluoric acid etching—revealed promising adhesion performance for acid neutralisation and plasma treatment. The subtractive manufacturing methods of partially crystallised and fully crystallised LSC blocks and the additive manufacturing modalities pertaining to the fabrication of LSC dental restorations are addressed, wherein that challenges that could be encountered upon implementing novel additive manufacturing approaches using LSC print materials are highlighted. Furthermore, the short-term clinical performance of zirconia-reinforced lithium silicates and lithium–aluminium disilicates is demonstrated to be comparable to that of lithium disilicate ceramics and reveals promising potential for their long-term clinical performance.
Recent Trends and Innovations in Bead-Based Biosensors for Cancer Detection
Authors: Cheng Hui-Pin , Yang Tai-Hua , Wang Jhih-Cheng , Chuang Han-Sheng
Published: May 2024

Demand is strong for sensitive, reliable, and cost-effective diagnostic tools for cancer detection. Accordingly, bead-based biosensors have emerged in recent years as promising diagnostic platforms based on wide-ranging cancer biomarkers owing to the versatility, high sensitivity, and flexibility to perform the multiplexing of beads. This comprehensive review highlights recent trends and innovations in the development of bead-based biosensors for cancer-biomarker detection. We introduce various types of bead-based biosensors such as optical, electrochemical, and magnetic biosensors, along with their respective advantages and limitations. Moreover, the review summarizes the latest advancements, including fabrication techniques, signal-amplification strategies, and integration with microfluidics and nanotechnology. Additionally, the challenges and future perspectives in the field of bead-based biosensors for cancer-biomarker detection are discussed. Understanding these innovations in bead-based biosensors can greatly contribute to improvements in cancer diagnostics, thereby facilitating early detection and personalized treatments.
Directional Multi-Resonant Micro-Electromechanical System Acoustic Sensor for Low Frequency Detection
Authors: Ivancic Justin , Alves Fabio
Published: May 2024

This paper reports on the design, modeling, and characterization of a multi-resonant, directional, MEMS acoustic sensor. The design builds on previous resonant MEMS sensor designs to broaden the sensor’s usable bandwidth while maintaining a high signal-to-noise ratio (SNR). These improvements make the sensor more attractive for detecting and tracking sound sources with acoustic signatures that are broader than discrete tones. In-air sensor characterization was conducted in an anechoic chamber. The sensor was characterized underwater in a semi-anechoic pool and in a standing wave tube. The sensor demonstrated a cosine-like directionality, a maximum acoustic sensitivity of 47.6 V/Pa, and a maximum SNR of 88.6 dB, for 1 Pa sound pressure, over the bandwidth of the sensor circuitry (100 Hz–3 kHz). The presented design represents a significant improvement in sensor performance compared to similar resonant MEMS sensor designs. Increasing the sensitivity of a single-resonator design is typically associated with a decrease in bandwidth. This multi-resonant design overcomes that limitation.
Data-Monitoring Solution for Desalination Processes: Cooling Tower and Mechanical Vapor Compression Hybrid System
Authors: Hernández-Baño Paula , Molina-García Angel , Vera-García Francisco
Published: May 2024

The advancement of novel water treatment technologies requires the implementation of both accurate data measurement and recording processes. These procedures are essential for acquiring results and conducting thorough analyses to enhance operational efficiency. In addition, accurate sensor data facilitate precise control over chemical treatment dosages, ensuring optimal water quality and corrosion inhibition while minimizing chemical usage and associated costs. Under this framework, this paper describes the sensoring and monitoring solution for a hybrid system based on a cooling tower (CT) connected to mechanical vapor compression (MVC) equipment for desalination and brine concentration purposes. Sensors connected to the data commercial logger solution, Almemo 2890-9, are also discussed in detail such as temperature, relative humidity, pressure, flow rate, etc. The monitoring system allows remote control of the MVC based on a server, GateManager, and TightVNC. In this way, the proposed solution provides remote access to the hybrid system, being able to visualize gathered data in real time. A case study located in Cartagena (Spain) is used to assess the proposed solution. Collected data from temperature transmitters, pneumatic valves, level sensors, and power demand are included and discussed in the paper. These variables allow a subsequent forecasting process to estimate brine concentration values. Different sample times are included in this paper to minimize the collected data from the hybrid system within suitable operation conditions. This solution is suitable to be applied to other desalination processes and locations.
A Multimodal Feature Fusion Brain Fatigue Recognition System Based on Bayes-gcForest
Authors: Zhou You , Chen Pukun , Fan Yifan , Wu Yin
Published: May 2024

Modern society increasingly recognizes brain fatigue as a critical factor affecting human health and productivity. This study introduces a novel, portable, cost-effective, and user-friendly system for real-time collection, monitoring, and analysis of physiological signals aimed at enhancing the precision and efficiency of brain fatigue recognition and broadening its application scope. Utilizing raw physiological data, this study constructed a compact dataset that incorporated EEG and ECG data from 20 subjects to index fatigue characteristics. By employing a Bayesian-optimized multi-granularity cascade forest (Bayes-gcForest) for fatigue state recognition, this study achieved recognition rates of 95.71% and 96.13% on the DROZY public dataset and constructed dataset, respectively. These results highlight the effectiveness of the multi-modal feature fusion model in brain fatigue recognition, providing a viable solution for cost-effective and efficient fatigue monitoring. Furthermore, this approach offers theoretical support for designing rest systems for researchers.
Automatic Shrimp Fry Counting Method Using Multi-Scale Attention Fusion
Authors: Peng Xiaohong , Zhou Tianyu , Zhang Ying , Zhao Xiaopeng
Published: May 2024

Shrimp fry counting is an important task for biomass estimation in aquaculture. Accurate counting of the number of shrimp fry in tanks can not only assess the production of mature shrimp but also assess the density of shrimp fry in the tanks, which is very helpful for the subsequent growth status, transportation management, and yield assessment. However, traditional manual counting methods are often inefficient and prone to counting errors; a more efficient and accurate method for shrimp fry counting is urgently needed. In this paper, we first collected and labeled the images of shrimp fry in breeding tanks according to the constructed experimental environment and generated corresponding density maps using the Gaussian kernel function. Then, we proposed a multi-scale attention fusion-based shrimp fry counting network called the SFCNet. Experiments showed that our proposed SFCNet model reached the optimal performance in terms of shrimp fry counting compared to CNN-based baseline counting models, with MAEs and RMSEs of 3.96 and 4.682, respectively. This approach was able to effectively calculate the number of shrimp fry and provided a better solution for accurately calculating the number of shrimp fry.
Wireless Power Transfer Efficiency Optimization Tracking Method Based on Full Current Mode Impedance Matching
Authors: Xu Yuanzhong , Zhang Yuxuan , Wu Tiezhou
Published: May 2024

Wireless power transfer (WPT) technology is a contactless wireless energy transfer method with wide-ranging applications in fields such as smart homes, the Internet of Things (IoT), and electric vehicles. Achieving optimal efficiency in wireless power transfer systems has been a key research focus. In this paper, we propose a tracking method based on full current mode impedance matching for optimizing wireless power transfer efficiency. This method enables efficiency tracking in WPT systems and seamless switching between continuous conduction mode and discontinuous mode, expanding the detection capabilities of the wireless power transfer system. MATLAB was used to simulate the proposed method and validate its feasibility and effectiveness. Based on the simulation results, the proposed method ensures optimal efficiency tracking in wireless power transfer systems while extending detection capabilities, offering practical value and potential for widespread applications.
How Italians Transgress: A Survey on Rough Sexual Behaviors in a Sample of Italians
Authors: Daminato Luca , Riboli Greta , Nese Mattia , Brighetti Gianni , Giunti Daniel , Borlimi Rosita
Published: May 2024

Surveys of the Italian population typically assess general sexual behaviors (e.g., oral, vaginal and anal intercourse). However, little is known about other sexual behavior such as rough sexual behaviors, choking and slapping. Thus, an online cross-sectional survey of 4618 Italian participants was conducted. In the past month, the most prevalent sexual behaviors were solo masturbation (93.6%), partner masturbation (80.0%), oral sex (71.4% received, 75.9% performed), penile–vaginal intercourse (75.7%) and anal intercourse (12.5% received, 7.1% performed). Regarding rough sexual behaviors, the most common behaviors performed were spanking (23.3% received, 55.5% performed), choking (13.2% receive, 60.0% performed), slapping (30.1% received, 20.9% performed) and name calling (44.5% received, 37.0% performed). Our results suggest a gender difference where men and transgender/non-binary individuals perform more rough sexual behaviors compared to women. Moreover, regarding the role of consent in behaviors such as choking and slapping, our results highlight the importance of sexual and affective education to implement sexual assertiveness. In conclusion, this study adds knowledge to the limited literature on this topic, especially with respect to the Italian population.
The Impact of the COVID-19 Pandemic in the Inclusion of Refugee Students in Greek Schools: Pre-Service Teachers’ Views about Distance Learning
Authors: Samsari Eleni , Palaiologou Nektaria , Nikolaou Georgios
Published: May 2024

Over the last two years, the prolonged massive school closure due to COVID-19 has provoked significant constraints for refugee children. The present study aimed to investigate the perceptions of Greek pre-service teachers on refugee education during the COVID-19 pandemic. A questionnaire was addressed to 32 native university students (n = 32) who attended Education Departments in Western Macedonia in Greece. The results showed that the prevalence of distance education affected pre-service teachers’ perceptions. The access to devices with internet capability as well as the cultural barriers was considered to be crucial factors for the school attendance of refugee children. Participants’ perceptions of the level of teacher preparation in a distance learning environment were related to their level of self-efficacy for supporting refugee students. The findings suggest that in the aftermath of COVID-19 pandemic, the international community should make efforts to ensure the school attendance of all refugee students.
On Non-Occurrence of the Inspection Paradox
Authors: Rauwolf Diana , Kamps Udo
Published: May 2024

The well-known inspection paradox or waiting time paradox states that, in a renewal process, the inspection interval is stochastically larger than a common interarrival time having a distribution function F, where the inspection interval is given by the particular interarrival time containing the specified time point of process inspection. The inspection paradox may also be expressed in terms of expectations, where the order is strict, in general. A renewal process can be utilized to describe the arrivals of vehicles, customers, or claims, for example. As the inspection time may also be considered a random variable T with a left-continuous distribution function G independent of the renewal process, the question arises as to whether the inspection paradox inevitably occurs in this general situation, apart from in some marginal cases with respect to F and G. For a random inspection time T, it is seen that non-trivial choices lead to non-occurrence of the paradox. In this paper, a complete characterization of the non-occurrence of the inspection paradox is given with respect to G. Several examples and related assertions are shown, including the deterministic time situation.
15-Year Experience in Maxillofacial Surgical Navigation with Tracked Instruments
Authors: Novelli Giorgio , Santamato Filippo , Piza Moragues Alejandro Juan , Filippi Andrea , Valsecchi Federico , Canzi Gabriele , Sozzi Davide
Published: May 2024

(1) Introduction and Aim: Surgical navigation has evolved as a vital tool in maxillofacial surgery, offering precise and patient-specific data. This study explores the clinical applications and accuracy of intraoperative tool tracking in maxillofacial surgery. (2) Materials and Methods: The research includes 42 patients with various pathologies who underwent surgeries assisted by a surgical navigation system using tracked instruments. Four representative cases are exhibited in the study: the first case involving coronoid hyperplasia with mouth opening deficit, the second case addressing naso-orbital-ethmoidal-frontal ossifying fibroma resection, the third case showcasing a subapical osteotomy (Köle) for a class III dentoskeletal malocclusion, and the fourth one exposing the treatment of a recurrent ameloblastoma. (3) Results: The results indicate that surgical navigation with tracked instruments provides high precision (<1.5 mm error), reduced surgical time, and a less invasive approach. (4) Conclusions: This study highlights the potential for reproducible outcomes and increased safety, especially in complex cases. Despite some limitations, the synergy between surgical navigation and tracked instruments offers a promising approach in maxillofacial surgery, expanding its applications beyond current practices.
Assessing Green Practices on Eco-Friendly Hotel Customer Loyalty: A Partial Least Squares Structural Equation Modeling and Fuzzy-Set Qualitative Comparative Analysis Hybrid Approach
Authors: Chang Ruiqi , Chanda Razib Chandra , Vafaei-Zadeh Ali , Hanifah Haniruzila , Gui Anderes
Published: May 2024

With a global focus on environmental sustainability, hotels worldwide are actively transitioning their services from conventional to eco-friendly practices. This study aims to comprehensively understand the factors that contribute to visitors’ satisfaction in eco-friendly hotels and how this satisfaction influences customers’ future reactions towards such environmentally conscious establishments. Employing the Stimulus-Organism-Response theory, this study collected data from 277 respondents using a robust quantitative research strategy. A combined approach of Partial Least Squares Structural Equation Modeling (PLS-SEM) and Fuzzy-Set Qualitative Comparative Analysis (fsQCA) was employed, to uncover deep insights into visitors’ satisfaction and their reactions towards eco-friendly hotels. The PLS-SEM results reveal significant associations between customers’ satisfaction towards eco-friendly hotel services and service quality, green practices, perceived value, and environmental sensitivity. Moreover, this study highlights a positive correlation between satisfaction and crucial outcomes like revisit intention (RVI), willingness to pay a premium (WTPP), and word-of-mouth intention (WOMI). Complementing these findings, the fsQCA analysis uncovers intricate causal relationships among antecedents that influence customer satisfaction in eco-friendly hotels. By offering critical marketing insights, this study provides guidance for hotels, the tourism industry, and policymakers on attracting customers to eco-friendly hotels, to meet the increasing demands for environmental sustainability.
What Is Necessary for Digital Transformation of Large Manufacturing Companies? A Necessary Condition Analysis
Authors: Zhang Ziye , Wu Meiying , Yin Jiajie
Published: May 2024

Digital transformation is of significant importance to the sustainable development of manufacturing companies and the construction of the digital economy. However, this major change is often hindered by numerous complex antecedents. What are the key factors in the digital transformation of manufacturing companies, and what is their relative importance? Accordingly, this paper identifies the key factors for digital transformation in large manufacturing companies from the “Ability–Motivation–Opportunity” (AMO) perspective. This study uses a necessary condition analysis (NCA) to conduct a necessity causality study on data collected from 67 listed Chinese manufacturing companies between 2016 and 2020. The results show that the digital transformation of large manufacturing companies is influenced by four necessary conditions: managerial myopia, industry concentration (very large effect), dynamic capabilities, and industrial digitalization (large effect). Managerial myopia and industry concentration have a negative necessary impact on digital transformation. The types of conditions and the level of bottlenecks required at different stages of digital transformation vary significantly. This study reveals the necessary causal relationships between organizational abilities, motivation, external opportunities, and digital transformation, providing empirical evidence to promote the digital transformation practices of manufacturing companies.
Strong and Weak Convergence Theorems for the Split Feasibility Problem of (β,k)-Enriched Strict Pseudocontractive Mappings with an Application in Hilbert Spaces
Authors: Razzaque Asima , Saleem Naeem , Agwu Imo Kalu , Ishtiaq Umar , Aphane Maggie
Published: May 2024

The concept of symmetry has played a major role in Hilbert space setting owing to the structure of a complete inner product space. Subsequently, different studies pertaining to symmetry, including symmetric operators, have investigated real Hilbert spaces. In this paper, we study the solutions to multiple-set split feasibility problems for a pair of finite families of β-enriched, strictly pseudocontractive mappings in the setup of a real Hilbert space. In view of this, we constructed an iterative scheme that properly included these two mappings into the formula. Under this iterative scheme, an appropriate condition for the existence of solutions and strong and weak convergent results are presented. No sum condition is imposed on the countably finite family of the iteration parameters in obtaining our results unlike for several other results in this direction. In addition, we prove that a slight modification of our iterative scheme could be applied in studying hierarchical variational inequality problems in a real Hilbert space. Our results improve, extend and generalize several results currently existing in the literature.
Potential Spatial Accessibility to Cardiovascular Hospitals in Romania
Authors: Cioclu Alexandra , Dumitrache Liliana , Nae Mariana , Mareci Alina
Published: May 2024

Cardiovascular diseases (CVDs) represent the leading cause of death globally. Romania recorded the highest mortality rate due to CVDs in the EU in 2022, with 162,984 deaths, while the number of registered patients with CVDs surpassed 4 million. This study aims to measure the population’s potential spatial accessibility to cardiovascular hospitals in Romania, as timely access to such healthcare facilities is crucial to minimise avoidable mortality due to CVDs. Although distance is an essential parameter of spatial accessibility, time-based analysis is more reflective of real-world scenarios due to the unpredictability of travel. The potential spatial accessibility was measured using the Application Program Interface (API) offered through the Google Maps platform and a personal car as the transportation mode. The country’s cardiovascular hospital network comprises 161 units, of which 84 can provide complex care. Because all of them are located in urban areas, three different time slots were considered to distinguish between high and low traffic congestion situations. We created hierarchies of ten-minute and five km intervals for travel time and distance, respectively, to emphasize the population percentages with better or low potential spatial accessibility. Results showed that only 15% of the population can reach the nearest cardiovascular hospital in less than 20 min, and 23% must travel for over 60 min, while 45.7% live farther than 20 km from a cardiovascular hospital. Inhabitants living in remote areas, especially rural ones, are the most vulnerable, having to travel for the longest time and distance. Actions like improving the existing transport infrastructure and upgrading healthcare facilities and equipment are needed to ensure better medical care and an adequate response to population needs. This study can support local authorities in optimising spatial accessibility to cardiovascular care by identifying the most burdened hospitals in the context of low medical specialised staff and large catchment areas.
Arterial Input Function (AIF) Correction Using AIF Plus Tissue Inputs with a Bi-LSTM Network
Authors: Huang Qi , Le Johnathan , Joshi Sarang , Mendes Jason , Adluru Ganesh , DiBella Edward
Published: May 2024

Background: The arterial input function (AIF) is vital for myocardial blood flow quantification in cardiac MRI to indicate the input time–concentration curve of a contrast agent. Inaccurate AIFs can significantly affect perfusion quantification. Purpose: When only saturated and biased AIFs are measured, this work investigates multiple ways of leveraging tissue curve information, including using AIF + tissue curves as inputs and optimizing the loss function for deep neural network training. Methods: Simulated data were generated using a 12-parameter AIF mathematical model for the AIF. Tissue curves were created from true AIFs combined with compartment-model parameters from a random distribution. Using Bloch simulations, a dictionary was constructed for a saturation-recovery 3D radial stack-of-stars sequence, accounting for deviations such as flip angle, T2* effects, and residual longitudinal magnetization after the saturation. A preliminary simulation study established the optimal tissue curve number using a bidirectional long short-term memory (Bi-LSTM) network with just AIF loss. Further optimization of the loss function involves comparing just AIF loss, AIF with compartment-model-based parameter loss, and AIF with compartment-model tissue loss. The optimized network was examined with both simulation and hybrid data, which included in vivo 3D stack-of-star datasets for testing. The AIF peak value accuracy and ktrans results were assessed. Results: Increasing the number of tissue curves can be beneficial when added tissue curves can provide extra information. Using just the AIF loss outperforms the other two proposed losses, including adding either a compartment-model-based tissue loss or a compartment-model parameter loss to the AIF loss. With the simulated data, the Bi-LSTM network reduced the AIF peak error from −23.6 ± 24.4% of the AIF using the dictionary method to 0.2 ± 7.2% (AIF input only) and 0.3 ± 2.5% (AIF + ten tissue curve inputs) of the network AIF. The corresponding ktrans error was reduced from −13.5 ± 8.8% to −0.6 ± 6.6% and 0.3 ± 2.1%. With the hybrid data (simulated data for training; in vivo data for testing), the AIF peak error was 15.0 ± 5.3% and the corresponding ktrans error was 20.7 ± 11.6% for the AIF using the dictionary method. The hybrid data revealed that using the AIF + tissue inputs reduced errors, with peak error (1.3 ± 11.1%) and ktrans error (−2.4 ± 6.7%). Conclusions: Integrating tissue curves with AIF curves into network inputs improves the precision of AI-driven AIF corrections. This result was seen both with simulated data and with applying the network trained only on simulated data to a limited in vivo test dataset.
Toxoplasma gondii in a Remote Subsistence Hunting-Based Indigenous Community of the Peruvian Amazon
Authors: Menajovsky María Fernanda , Espunyes Johan , Ulloa Gabriela , Calderon Maritza , Diestra Andrea , Malaga Edith , Muñoz Carmen , Montero Stephanie , Lescano Andres G. , Santolalla Meddly L. , Cabezón Oscar , Mayor Pedro
Published: May 2024

Toxoplasma gondii is a ubiquitous zoonotic protozoan parasite that infects a wide variety range of warm-blooded animals. This study describes the epidemiological scenario of T. gondii in an indigenous community that relies on subsistence hunting in a well-conserved and isolated area of the Peruvian Amazon. The high seropositivity against T. gondii in humans (83.3% IgG and 6.1% IgM), wild mammals (30.45%, 17 species), peri-domestic rodents (10.0% Rattus sp.), and domestic animals (94.1% dogs and 100% cats) indicates the existence of a sylvatic cycle in the community under study. Individual age was found to be positively associated with IgG detection against T. gondii but not with IgM. It is estimated that each family consumed 5.67 infected animals per year with terrestrial species having higher infective rates than arboreal species. The main risk factors included improper handling and cooking of wild meat, poor hygiene practices, and feeding uncooked offal to domestic animals. This scenario results in a continuous process of infection and reinfection within the indigenous community with cats, dogs, and peri-domestic animals becoming infected through the ingestion of infected raw viscera. Our results emphasize the need to promote safe food handling practices and disposal of waste materials from hunted animals in such communities.
Resistance Mutation Patterns among HIV-1-Infected Children and Features of the Program for Prevention of Mother-to-Child Transmission in Vietnam’s Central Highlands and Southern Regions, 2017–2021
Authors: Thu Huynh Hoang Khanh , Schemelev Alexandr N. , Ostankova Yulia V. , Reingardt Diana E. , Davydenko Vladimir S. , Tuong Vi Nguyen , Ngoc Tu Le , Tran Ton , Thi Xuan Lien Truong , Semenov Aleksandr V. , Totolian Areg A.
Published: May 2024

The Vietnam Ministry of Health (MOH) has intensified efforts in its aim to eliminate AIDS by 2030. Expanding the program for prevention of mother-to-child transmission (PMTCT) is a significant step towards achieving this goal. However, there are still HIV-exposed children who do not have access to PMTCT services, and some who have participated in the program but still contracted HIV. This study focused on assessing the prevalence and profile of HIV mutations among children under 18 months of age who had recently tested positive for HIV, while gaining insights into the implementation of early infant diagnostic (EID) tests. Between 2017 and 2021, 3.43% of 5854 collected dry blood spot (DBS) specimens from Vietnam’s Central and Southern regions showed positive EID results. This study identified a high prevalence of resistance mutations in children, totaling 62.9% (95% CI: 53.5–72.3). The highest prevalence of mutations was observed for NNRTIs, with 57.1% (95% CI: 47.5–66.8). Common mutations included Y181C and K103N (NNRTI resistance), M184I/V (NRTI resistance), and no major mutations for PI. The percentage of children with any resistance mutation was significantly higher among those who received PMTCT interventions (69.2%; 95% CI: 50.5–92.6%) compared with those without PMTCT (45.0%; 95% CI: 26.7–71.1%) with χ2 = 6.06, p = 0.0138, and OR = 2.75 (95% CI: 1.13–6.74). Mutation profiles revealed that polymorphic mutations could be present regardless of whether PMTCT interventions were implemented or not. However, non-polymorphic drug resistance mutations were predominantly observed in children who received PMTCT measures. Regarding PMTCT program characteristics, this study highlights the issue of late access to HIV testing for both mothers and their infected children. Statistical differences were observed between PMTCT and non-PMTCT children. The proportion of late detection of HIV infection and breastfeeding rates were significantly higher among non-PMTCT children (p < 0.05). Comparative analysis between children with low viral load (≤200 copies/mL) and high viral load (>200 copies/mL) showed significant differences between the mothers’ current ART regimens (p = 0.029) and the ARV prophylaxis regimen for children (p = 0.016). These findings emphasize the need for comprehensive surveillance to assess the effectiveness of the PMTCT program, including potential transmission of HIV drug-resistance mutations from mothers to children in Vietnam.
Genetic Diversity and Detection of Respiratory Viruses Excluding SARS-CoV-2 during the COVID-19 Pandemic in Gabon, 2020–2021
Authors: Ondo Georgelin , Ushijima Yuri , Abe Haruka , Mahmoudou Saïdou , Bikangui Rodrigue , Nkoma Anne , Mbadinga Marien , More Ayong , Agbanrin Maradona , Pemba Christelle , Beh Mba Romuald , Adegnika Ayola Akim , Lell Bertrand , Yasuda Jiro
Published: May 2024

Acute respiratory infections are a major global burden in resource-limited countries, including countries in Africa. Although COVID-19 has been well studied since the pandemic emerged in Gabon, Central Africa, less attention has been paid to other respiratory viral diseases, and very little data are available. Herein, we provide the first data on the genetic diversity and detection of 18 major respiratory viruses in Gabon during the COVID-19 pandemic. Of 582 nasopharyngeal swab specimens collected from March 2020 to July 2021, which were SARS-CoV-2 negative, 156 were positive (26%) for the following viruses: enterovirus (20.3%), human rhinovirus (HRV) (4.6%), human coronavirus OC43 (1.2%), human adenovirus (0.9%), human metapneumovirus (hMPV) (0.5%), influenza A virus (IAV) (0.3%), and human parainfluenza viruses (0.5%). To determine the genetic diversity and transmission route of the viruses, phylogenetic analyses were performed using genome sequences of the detected viruses. The IAV strain detected in this study was genetically similar to strains isolated in the USA, whereas the hMPV strain belonging to the A2b subtype formed a cluster with Kenyan strains. This study provides the first complete genomic sequences of HRV, IAV, and hMPV detected in Gabon, and provides insight into the circulation of respiratory viruses in the country.
Correlation between the Cycle Threshold Values in Detection of Severe Fever with Thrombocytopenia Syndrome Virus Using PowerChekTM SFTSV Real-Time PCR Kit and Viral Load: Prognostic Implications
Authors: Kim Misun , Heo Sang Taek , Kim Hee Cheol , Kang Myeong Jin , Kim Sora , Lee Keun Hwa , Yoo Jeong Rae
Published: May 2024

Background: This study aimed to analyze the correlation between the cycle threshold (Ct) values of severe fever with thrombocytopenia syndrome (SFTS) virus small (S) and middle (M) segments and the SFTS viral load, aiming to estimate the initial viral load and predict prognosis in the early clinical course. Method: A retrospective study was conducted with confirmed SFTS patients at Jeju National University Hospital (2016–2022). Patients were categorized into non-fatal and fatal groups. Results: This study included 49 patients with confirmed SFTS (non-fatal group, n = 42; fatal group, n = 7). A significant negative correlation (−0.783) was observed between the log SFTS viral load and Ct values (p < 0.001). This negative correlation was notably stronger in the fatal group (correlation coefficient −0.940) than in the non-fatal group (correlation coefficient −0.345). Conclusion: In this study, we established a correlation between SFTS viral load and Ct values for estimating the initial viral load and early predicting prognosis. These results are expected to offer valuable insights for SFTS patient treatment and prognosis prediction.
The Significance of the 98th Amino Acid in GP2a for Porcine Reproductive and Respiratory Syndrome Virus Adaptation in Marc-145 Cells
Authors: Chen Yao , Huo Zhantang , Jiang Qi , Qiu Zhiheng , Shao Zheng , Ma Chunquan , Zhang Guihong , Li Qi
Published: May 2024

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important pathogens in the pig industry. Marc-145 cells are widely used for PRRSV isolation, vaccine production, and investigations into virus biological characteristics. Despite their significance in PRRSV research, Marc-145 cells struggle to isolate specific strains of the North American virus genotype (PRRSV-2). The involvement of viral GP2a, GP2b, and GP3 in this phenomenon has been noted. However, the vital amino acids have not yet been identified. In this study, we increased the number of blind passages and successfully isolated two strains that were previously difficult to isolate with Marc-145 cells. Both strains carried an amino acid substitution in GP2a, specifically phenylalanine to leucine at the 98th amino acid position. Through a phylogenetic and epidemiologic analysis of 32 strains, those that were not amenable to isolation widely exhibited this mutation. Then, by using the PRRSV reverse genetics system, IFA, and Western blotting, we identified the mutation that could affect the tropism of PRRSV-2 for Marc-145 cells. Furthermore, an animal experiment was conducted. Through comparisons of clinical signs, mortality rates, and viral load in the organs and sera, we found that mutation did not affect the pathogenicity of PRRSV-2. In conclusion, our study firmly establishes the 98th amino acid in GP2a as a key determinant of PRRSV-2 tropism for Marc-145 cells.
piRNA-Guided Transposon Silencing and Response to Stress in Drosophila Germline
Authors: Ho Samantha , Theurkauf William , Rice Nicholas
Published: May 2024

Transposons are integral genome constituents that can be domesticated for host functions, but they also represent a significant threat to genome stability. Transposon silencing is especially critical in the germline, which is dedicated to transmitting inherited genetic material. The small Piwi-interacting RNAs (piRNAs) have a deeply conserved function in transposon silencing in the germline. piRNA biogenesis and function are particularly well understood in Drosophila melanogaster, but some fundamental mechanisms remain elusive and there is growing evidence that the pathway is regulated in response to genotoxic and environmental stress. Here, we review transposon regulation by piRNAs and the piRNA pathway regulation in response to stress, focusing on the Drosophila female germline.
Phylogenomic Characterization of Ranavirus Isolated from Wild Smallmouth Bass (Micropterus dolomieu)
Authors: Quail Hannah , Viadanna Pedro H. O. , Vann Jordan A. , Hsu Hui-Min , Pohly Andrea , Smith Willow , Hansen Scott , Nietlisbach Nicole , Godard Danielle , Waltzek Thomas B. , Subramaniam Kuttichantran
Published: May 2024

In September 2021, 14 smallmouth bass (SMB; Micropterus dolomieu) with skin lesions were collected from Green Bay waters of Lake Michigan and submitted for diagnostic evaluation. All the skin samples tested positive for largemouth bass virus (LMBV) by conventional PCR. The complete genome of the LMBV (99,328 bp) isolated from a homogenized skin sample was determined using an Illumina MiSeq sequencer. A maximum likelihood (ML) phylogenetic analysis based on the 21 core iridovirus genes supported the LMBV isolated from SMB (LMBV-WVL21117) as a member of the species Santee-Cooper ranavirus. Pairwise nucleotide comparison of the major capsid protein (MCP) gene showed that LMBV-WVL21117 is identical to other LMBV reported from the United States and nearly identical to doctor fish virus and guppy virus 6 (99.2%) from Southeast Asia, as well as LMBV isolates from China and Thailand (99.1%). In addition, ML phylogenetic analysis based on the MCP gene suggests three genotypes of LMBV separated by region: genotype one from the United States, genotype two from Southeast Asia, and genotype three from China and Thailand. Additional research is needed to understand the prevalence and genetic diversity of LMBV strains circulating in wild and managed fish populations from different regions.
Immunological Response against Breast Lineage Cells Transfected with Human Papillomavirus (HPV)
Authors: Santos Daffany Luana , São Marcos Bianca de França , de Sousa Georon Ferreira , Cruz Leonardo Carvalho de Oliveira , Barros Bárbara Rafaela da Silva , Nogueira Mariane Cajuba de Britto Lira , Oliveira Talita Helena de Araújo , Silva Anna Jessica Duarte , Santos Vanessa Emanuelle Pereira , de Melo Cristiane Moutinho Lagos , de Freitas Antonio Carlos
Published: May 2024

Breast cancer is the most common neoplasm worldwide. Viral infections are involved with carcinogenesis, especially those caused by oncogenic Human Papillomavirus (HPV) genotypes. Despite the detection of HPV in breast carcinomas, the virus’s activity against this type of cancer remains controversial. HPV infection promotes remodeling of the host’s immune response, resulting in an immunosuppressive profile. This study assessed the individual role of HPV oncogenes in the cell line MDA-MB-231 transfected with the E5, E6, and E7 oncogenes and co-cultured with peripheral blood mononuclear cells. Immunophenotyping was conducted to evaluate immune system modulation. There was an increase in CD4+ T cell numbers when compared with non-transfected and transfected MDA-MB-231, especially in the Treg profile. Pro-inflammatory intracellular cytokines, such as IFN-γ, TNF-α, and IL-17, were impaired by transfected cells, and a decrease in the cytolytic activity of the CD8+ and CD56+ lymphocytes was observed in the presence of HPV oncogenes, mainly with E6 and E7. The E6 and E7 oncogenes decrease monocyte expression, activating the expected M1 profile. In the monocytes found, a pro-inflammatory role was observed according to the cytokines released in the supernatant. In conclusion, the MDA-MB-231 cell lineage transfected with HPV oncogenes can downregulate the number and function of lymphocytes and monocytes.
Epigenetic Modifications of White Blood Cell DNA Caused by Transient Fetal Infection with Bovine Viral Diarrhea Virus
Authors: Van Campen Hana , Bishop Jeanette V. , Brink Zella , Engle Terry E. , Gonzalez-Berrios Carolina L. , Georges Hanah M. , Kincade Jessica N. , Murtazina Dilyara A. , Hansen Thomas R.
Published: May 2024

Bovine viral diarrhea virus (BVDV) infections cause USD 1.5–2 billion in losses annually. Maternal BVDV after 150 days of gestation causes transient fetal infection (TI) in which the fetal immune response clears the virus. The impact of fetal TI BVDV infections on postnatal growth and white blood cell (WBC) methylome as an index of epigenetic modifications was examined by inoculating pregnant heifers with noncytopathic type 2 BVDV or media (sham-inoculated controls) on Day 175 of gestation to generate TI (n = 11) and control heifer calves (n = 12). Fetal infection in TI calves was confirmed by virus-neutralizing antibody titers at birth and control calves were seronegative. Both control and TI calves were negative for BVDV RNA in WBCs by RT-PCR. The mean weight of the TI calves was less than that of the controls (p < 0.05). DNA methyl seq analysis of WBC DNA demonstrated 2349 differentially methylated cytosines (p ≤ 0.05) including 1277 hypomethylated cytosines, 1072 hypermethylated cytosines, 84 differentially methylated regions based on CpGs in promoters, and 89 DMRs in islands of TI WBC DNA compared to controls. Fetal BVDV infection during late gestation resulted in epigenomic modifications predicted to affect fetal development and immune pathways, suggesting potential consequences for postnatal growth and health of TI cattle.