Engineering Technology Research Articles

Students and Lecturers of Kaunas Polytechnic Institute in the KGB Spotlight (1951–1989)

The KGB branch at the Council of Ministers of the Lithuanian SSR paid particular attention to schools of higher education in Kaunas who were supposed to train intelligentsia loyal to the Soviet government. During the interwar period Kaunas was the temporary capital of Lithuania and the majority of schools of higher education in Kaunas stemmed from the Lithuanian University (Vytautas Magnus University) founded in 1922. Therefore, there were a number of representatives of the national intelligentsia in Kaunas who exerted a significant influence on the younger generation. During the Soviet period, the KGB monitored political sentiments, research and foreign relations of lecturers and students of all schools of higher education, including Kaunas Polytechnic Institute (KPI). The KGB carried out the surveillance using a network of trusted people and agents and was assisted in this by functionaries of the Communist Party and the All-Union Leninist Young Communist League (Komsomol). In 1951–1973, the KGB in Lithuania disclosed the underground organisations in which KPI students and teachers were involved. In order to identify anti-Soviet organisations, the KGB agents used provocateurs and later – listening devices. Seeking to “re-educate” KPI students and teachers who were involved in anti-Soviet organisations, the KGB applied typical methods: arrest, courts, detention and forced labour in Soviet labour camps. “Less serious crimes” of students, such as singing of anti-Soviet songs, belonging to a religious group or asking inappropriate questions at ideological sciences lectures, were punished with preventive conversations, public discussions of their behaviour, reprimands, removal from the Komsomol, and expulsion from the Institute. Although the functionaries of the KGB and the Communist Party applied measures aimed at suppressing national consciousness and statehood aspirations and ideological censorship, there were frequent manifestations of dissatisfaction with the Soviet occupation at KPI and some students and lecturers continued to participate in the anti-Soviet resistance. In order to protect young people from the negative influence, the KGB sought to prevent the former deportees or prisoners from studying and working at the schools of higher education. Prof. Kazimieras Baršauskas, Rector of KPI, disobeyed prohibitions by KGB leaders, and the Institute had a number of students who were former deportees and political prisoners. The KGB sought to expand its network of agents at KPI, but their reports indicate that there were too few agents. The KGB tried to use some KPI lecturers who travelled abroad for their sabbatical as their agents at the institute and for technical espionage abroad. In order to control research work related to military orders and trips abroad, the 1st Unit and the Foreign Relations Unit were set up at the institute; these were actually led by KGB officers. The KGB monitored whether the enemies from the capitalist countries were interested in what was developed at KPI laboratories or in researchers who wrote dissertations on the so-called classified topics. In the 1980s, the KGB mainly focused on the KPI Scientific Centre Vibrotechnika, the Ultrasound Laboratory, and faculties of Automation, Radio Electronics, Computer Technology and Mechanical Engineering, the Nemunas song and dance ensemble, tourist society and the society for regional studies.

An Overview of the Basic Theory of Probability Theory and its Commercial Application

Abstract. Probability theory is a key field of mathematics that focus on developing theoretical models and mathematical frameworks to describe and analyze random events or processes. As a part of basic science, probability theory holds a central place in pure mathematics while also serving a crucial function across various domains, including natural science, social science and engineering technology. This paper summarizes the main concepts, basic theories and commercial applications of probability theory. Probability theory encompasses ideas such as random experiment, sample space, event, probability, conditional probability, independence, Bayes Theorem, random variable, probability distribution, expected value and variance, law of large numbers and central limit theorem. This paper provides an overview of key concepts and theorems from probability theory, along with their practical applications in everyday life, in order to make people deeply recognize the broad and profound contents and research fields of probability theory and its wide application in various fields as an academic tool, which has a great relation with people.

“She does a good job for a woman” – the challenges for women enablers in the era of internet histories

This article explores issues of gender imbalance in the historical record of the period of technological development of the internet. It revisits the approach by authors, mostly women, who have criticised the lack of representation of women in the recorded history of technologies. It suggests that women in the period 1980s – 2000s may have been considered as not relevant to the technological record of that period because they were mostly working in invisible support roles, or leading on governance and commercial development matters. Overcoming centuries of discriminatory treatment women enablers have made significant contributions to the growth of new technology organisations but their involvement has been largely hidden from view by gatekeepers seeking to focus on and celebrate the mostly male led engineering and information technology achievements. Illustrated with exemplars from women collected especially for this article, it recommends further study about the roles of the women enablers to complement the already well documented histories in the era of the internet.

International Journal of Scientific Research in Computer Science, Engineering and Information Technology

This paper explores decentralized finance (DeFi), a fast-growing area powered by blockchain technology that offers a new alternative to traditional financial systems. DeFi removes the need for intermediaries like banks, making transactions more transparent, accessible, and often cheaper. This shift not only reduces costs but also helps improve financial access, particularly for people who are underserved by traditional banking systems. Key elements of DeFi, such as smart contracts and oracles, play a central role in automating processes and enabling peer-to-peer exchanges without needing middlemen. Despite its advantages, DeFi faces several challenges. Smart contracts can have security vulnerabilities, oracles may not always provide accurate data, and there is little consumer protection in place, which raises risks for users. Furthermore, DeFi’s decentralized and often anonymous structure creates regulatory difficulties, especially when it comes to complying with anti-money laundering (AML) and know-your-customer (KYC) standards, which are crucial for ensuring financial safety and preventing illegal activities. This paper examines these issues and proposes potential solutions, such as decentralized oracle networks, regulatory tools embedded within DeFi platforms, and improved scalability techniques. These solutions aim to enhance DeFi’s security while maintaining its core decentralized benefits. The paper concludes by discussing the future of DeFi, stressing the importance of balanced regulations that protect users without stifling innovation. Ultimately, DeFi holds the potential to reshape global finance, making it more inclusive, efficient, and accessible.

Preface

The 2nd International Symposium on Frontiers of Mechanical and Material Engineering (MME2024) is a globally recognized event to be organized by the Hubei Digital Textile Equipment Key Laboratory, China, in collaboration with the Wuhan Textile University, China, Zhongnan University, East-Siberian State University of Technology and Management, Russia, Rongzhi Sciences and Technology Center, China, was held from 21-22 September 2024 in Hangzhou, China. Since its inception in 2014, MME has successfully encompassed a wide spectrum of cuttingedge research domains, developed into a premier international event held in China and which gathered the best scientists and world class experts to share leading edge and multidisciplinary research in various fields related to mechanical engineering, materials science and modern technologies. MME serves as a prestigious international platform, this conference will continue to facilitate the dissemination of cutting-edge advancements across a spectrum of disciplines, converge students, experts, researchers, scholars, and industry professionals from different nations to share and deliberate on their latest work. This volume comprises select proceedings of 18 papers from 56 contributions submitted to MME2024. All the papers underwent a meticulous peer-review process, with each paper being evaluated by at least one expert in the relevant field. It introduces latest advancements in the subjects of mechanical engineering, materials science and advanced manufacturing technology, et al. It will be beneficial for readers from both academia and industry to understand and tackle the challenges in an efficient manner and to adopt appropriate solutions in the mentioned fields above. We would like to extend our heartfelt gratitude to invited keynote speakers: Dr. Valeriy Buryachenko, Micromechanics & Composites LLC, Cincinnati, Ohio, USA; Prof. David BASSIR, French University of Technology UTBM, France; Prof. Raul Duarte Salgueiral Gomes Campilho, Department of Mechanical Engineering, ISEP - School of Engineering, Portugal, and Dr. Ghulam Yasin, Oxford Brookes University, UK, for their brilliant speeches. Thanks to all the international reviewers and program committee members for their valuable contributions and dedication. List of Conference Chair, Conference Co-Chair, Honorary Chair, Editors and Technical Program Committees are available in this Pdf.

Bioavailability Improvement by Atomic Layer Coating: Fenofibrate A Case Study

Biopharmaceutical Classification Systems (BCS) class II drugs show poor solubility and high permeability in the body. Fenofibrate (FF) is a classic example of a BCS class II drug, used to treat high cholesterol and triglyceride (fat-like substances) levels in the blood. Atomic layer coating (ALC) is a surface engineering technology adapted from the semiconductor industry, where metal oxides are coated one atomic layer at a time over the active pharmaceutical ingredients (API) particles. ALC coating was proven to improve the processability, alter the hydrophilicity, improve the stability, and fine-tune the release of drugs. Herein, we report the intervention of ALC coating in enhancing the bioavailability of a poorly water-soluble drug (fenofibrate) in the animal model. The physical properties of uncoated fenofibrate were compared with those of zinc oxide-coated and silicon oxide-coated fenofibrate. Following the application of the coatings, the structural integrity (both chemical stability and solid-state stability) of the active pharmaceutical ingredient (API) remained uncompromised, as corroborated by 1H NMR and powder X-ray diffraction analyses. Notably, zinc oxide-coated fenofibrate exhibited favorable flow characteristics, whereas no discernible enhancement in flow behavior was observed for silicon oxide-coated fenofibrate. The results from contact angle measurements suggest that the silicon oxide-coated fenofibrate exhibits superior wetting behavior, as indicated by a contact angle nearing 0°. The application of ALC demonstrates an enhanced dissolution rate when compared to the uncoated active pharmaceutical ingredient (API) while leaving its equilibrium solubility unaffected. Coating the API with silicon oxide improves particle hydrophilicity and wetting properties, whereas zinc oxide coating aids in particle de-agglomeration, thereby enhancing their interaction with an aqueous medium. In vivo bioavailability studies conducted on rodents and larger animal (dog) models indicate a substantial increase in bioavailability (approximately 2 times) for the silicon oxide-coated API in comparison to the uncoated API, as determined by the area under the curve (AUC). Furthermore, the Cmax values for the silicon oxide-coated API also demonstrate a significant increase (approximately 3 times) over the uncoated API. Notably, an oral subacute toxicity study of ALC silicon-coated fenofibrate revealed no toxic effects attributable to the coating. This study underscores the potential of ALC in augmenting the bioavailability of BCS(II) drugs.

Multiomics analysis reveals the involvement of OnDIVARICATA 3 in controlling dynamic flower coloring of Oncidium hybridum

Flower color is one of the main quality and economic traits of ornamental plants, and a large amount of research on flower color mainly focuses on the differences between varieties, while there were few reports on the change of flower color at different developmental stages. In this study, the metabolome and transcriptome of a new strain 'XM-1' with dynamic color changes of Oncidium were analyzed. The results showed that rutin, quercetin and carotenoids metabolism decreased significantly during the change of color from yellow to white. Analyzing the correlation network between metabolites and differential expressed genes, 25 key structural genes were detected and regulated by multiple MYB-related transcription factors. The MYB-related transcription factor Cluster-100966.1_OnDIVARICATA 3 was selected for further analysis. The phylogenetic tree of DIVARICATA in different species of Orchidaceae and Arabidopsis thaliana was constructed and the most closely related members were selected for sequence comparison. The results showed that OnDIVARICATA 3 contained MYB-like conserved domains. Subcellular localization results showed that OnDIVARICATA 3 was located in the nucleus. In overexpressing OnDIVARICATA 3 transgenic hairy roots, the expression of flower color related genes FLS, ZEP, and CHYB were significantly up-regulated. In summary, this study characterized the key metabolic pathways in the formation of the dynamic flower color of Oncidium hybridum, and constructed the regulatory network of the MYB-related. These results laid a theoretical foundation for the subsequent research on flower color and genetic engineering technology breeding of Oncidium hybridum.

Al modification layer method for enhancing InAlZnO transistors

In this work, a surface engineering method is proposed to boost electrical performance and stability of the InAlZnO (IAZO) transistors, of which an Al modification layer is deposited on surface of the IAZO channel layer. Through analysed by transmission electron microscope and X-ray photoelectron spectroscopy, the IAZO thin film with Al modification layer undergoes a reduction reaction to generate more oxygen vacancies. Hall effects measurement further demonstrates that IAZO thin films with Al modification layer exhibit higher carrier concentrations than the ones without Al modification layer. The IAZO transistors with Al modification layer exhibit better performance and stability, including a field-effect mobility of 4.36 cm2 V−1s−1 (an improvement of about three-fold), a small subthreshold swing of 105.23 mV/decade, a high on-to-off current ratio greater than 107, and a threshold voltage shift of less than 0.50 V under positive and negative gate bias stress. Moreover, the IAZO transistors with Al modification layer demonstrate high thermal stability under 400 °C for 120 min in air atmosphere. Based on this method, the IAZO inverters have been implemented with high voltage gain of 87.55 V/V. This surface engineering technology paves the way for application of high-performance oxide transistors for advanced monolithic three-dimensional integration.

Numerical Analysis of the Cell Droplet Loading Process in Cell Printing

Cell printing is a promising technology in tissue engineering, with which the complex three-dimensional tissue constructs can be formed by sequentially printing the cells layer by layer. Though some cell printing experiments with commercial inkjet printers show the possibility of this idea, there are some problems, such as cell damage due the mechanical impact during cell direct writing, which include two processes of cell ejection and cell landing. Cell damage observed during the bioprinting process is often simply attributed to interactions between cells and substrate. However, in reality, cell damage can also arise from complex mechanical effects caused by collisions between cell droplets during continuous printing processes. The objective of this research is to numerically simulate the collision effects between continuously printed cell droplets within the bioprinting process, with a particular focus on analyzing the consequent cell droplet deformation and stress distribution. The influence of gravity force was ignored, cell droplet landing was divided into four phases, the first phase is cell droplet free falling at a certain velocity; the second phase is the collision between the descending cell droplet and the pre-existing cell droplets that have been previously printed onto the substrate. This collision results in significant deformation of the cell membranes of both cell droplets in contact; the third phase is the cell droplet hitting a rigid body substrate; the fourth phase is the cell droplet being bounced. We conducted a qualitative analysis of the stress and strain of cell droplets during the cell printing process to evaluate the influence of different parameters on the printing effect. The results indicate that an increase in jet velocity leads to an increase in stress on cell droplets, thereby increasing the probability of cell damage. Adding cell droplet layers on the substrate can effectively reduce the impact force caused by collisions. Smaller droplets are more susceptible to rupture at higher velocities. These findings provide a scientific basis for optimizing cell printing parameters.

A Bibliometric Analysis of Research Trends in Hazard Mitigation Studies in Korea: Based on Articles from the Journal of Korean Society of Hazard Mitigation

This study conducts a bibliometric analysis to identify research trends in hazard mitigation, based on 3,074 papers published in the Journal of the Korean Society of Hazard Mitigation between 2010 and 2023. The findings revealed that research on climate change and disaster response was the most active, with key topics including natural disaster management, urban water resource management, fire analysis and prevention, and AI-based disaster management. A keyword analysis highlighted “disaster” and “climate change” as having the highest frequency and centrality within the network. Institutional analysis identified the Korea Institute of Civil Engineering and Building Technology as the leading institution in co-authorship, with high research productivity and a key role as an intermediary. The authors’ analysis revealed that certain authors were central to expanding the field through diverse cooperation. These insights highlight the evolution of hazard mitigation research in Korea and offer guidance for future research to tackle emerging challenges in disaster management.

The Influence of ISLE-based STEM Physics Learning on Students' Understanding of Physics Concepts

This research aims to provide an overview and determine the influence of ISLE (Investigative Science Learning Environment) based STEM (Science Technology Engineering and Mathematics) physics learning on students' understanding of physics concepts. This research is a quantitative descriptive study using the one group pretest-posttest method. The population in this study were students of class XI Science at MAN Ende for the 2024/2025 academic year and the sample was students of class. Sampling in this research used purposive sampling technique. The data collection method consists of administering tests and LKPD. The data obtained from the research sample was in the form of test scores on students' understanding of physics concepts on global warming materials. Normality test and t-test are the data analysis techniques used. From the results of data analysis, it is known that ISLE based STEM physics learning has an effect on students' ability to understand physics concepts according to the One-Sample Test carried out with sig. (One-Sided p) is 0.001 < 0.05. Students' ability to understand physics concepts increased after implementing ISLE-based STEM physics learning with an average pretest score of 57.119 and an average posttest of 89.381 with the difference between the posttest and pretest scores being 32.252 points. While working on the LKPD students are more active in working with their team in solving problems and students are trained to understand the procedures for working on them. Apart from that, by implementing this learning, it can encourage students to hone their own thinking patterns so that they are able to explain the students' own understanding of physics concepts based on what they have observed and understood.

Call for papers: Advanced technologies in concurrent engineering

Call for papers: Advanced technologies in concurrent engineering

Evaluation of Post-Processing on Additive Manufactured Bioresorbable Polymers for Medical Devices.

Additive manufacturing (AM) has seen massive growth in the medical device sector and an increase in the clearance of devices. Many challenges still exist in the design, development, and clinical use of AM-fabricated devices, notably the processing, annealing, and sterilization of resorbable polymers. In addition, the use of these materials continues to grow in medical devices and scaffold technologies for tissue engineering and regenerative medicine (TERM). Specifically, this study focused on the scaffold mechanical properties post-processing and throughout a simulated resorption (in vitro) study. Herein, we evaluated three (3) materials that span a range of mechanical properties and degradation rates relating to a range of tissue healing rates and mechanical properties affording the opportunity of biomimetic potentials, Caproprene 100M, Lactoflex 7415, and Lactoprene 100M. These bioresorbable polymers were additively manufactured into scaffold forms of Type V tensile bars to investigate post-processing parameters. A range of heat treatments were then performed after the AM process to induce a range of semicrystalline morphologies, and subsequently, two different sterilization techniques were performed, one based on super critical carbon dioxide and another using electron beam radiation. It was statistically shown that the heat treatment parameters and the sterilization method had statistically significant effects on the scaffold properties of each material. While material differences were responsible for the majority of the mechanical property breadth, techniques utilizing analysis of variance allowed the observation of significant effects and interactions associated with heat treatment, sterilization, and material parameters (alpha = 0.05). The characterization of the sample groups provided insight into the process-structure-property-performance relationships of the resorbable scaffold samples. It was established that the post-processing impacted the scaffold structures, and therefore, sterilization and heat treatment selections should be included within initial design considerations alongside material selection as critical for device development, especially when AM bioresorbable scaffolds for TERM.

Line-of-Sight Probability Models for 5G/6G Millimeter-Wave Networks: A Review

In the fifth-generation (5G) and future wireless networks, coverage planning for millimeter-wave (mm-wave) networks in a three-dimensional (3D) urban environment depends on the communication channel and line-of-sight (LoS) probability models. This is especially true when there are big stationary obstructions. The current literature lacks a complete review of the existing LoS probability models. To bridge this gap, this paper reviews modeling approaches and mathematical models of the LoS probability. We discovered that, due to the complexity of modeling a large number of 3D layouts, most existing models have focused on a few urban layouts. We developed a 3D synthetic urban layout generator that is based on game engine technology to simulate any ITU-R P.1410 urban layouts and collect the ray-tracing. We provided a proof-of-concept to show that the game technology could handle the complexity of simulating ray-tracing in 3D urban environments. Moreover, we addressed some of the biggest challenges and gaps in the current LoS probability literature and suggested some valid opportunities.

DIGITAL TRANSFORMATION THROUGH COOPERATIVE LEARNING

In today’s complex world, a continuous upgrade of knowledge is crucial. Digital literacy, as one of the key competencies of the 21st century, is becoming more critical since it enables an efficient use of digital devices and tools. The European Union has set five key competencies for digital literacy, including informational and data literacy, digital content creation and communication and collaboration. In education, communication is widely accepted as a crucial skill for achieving common goals. Collaborative learning has proven to be a practical approach to teaching since it encourages the active participation of learners, provides many valuable and innovative solutions, and enables the development of key competencies. The collaborative workability can be further enhanced through cross-curricular integration, where learners are taught independent learning, information-seeking skills and critical thinking. In the school context, combining digital competencies, collaborative learning, and cross-curricular integration is key to preparing students for life in the modern world. This research presents an example of developing digital competencies in technology engineering lessons. The example above is offered in three stages and covers a period of ten school lessons. In addition to digital competencies, students are developing other competencies that will benefit their daily lives. Research is aimed at teachers who want to build digital competencies in their students through experiential learning, collaborative work, and cross-curricular integration, as well as prepare them for future challenges. Keywords: digital competences, digital literacy, cross-curricular approaches, cooperative learning, technology and engineering learning, technology and engineering literacy

Identifying the policy configurational conditions for off-site construction development: a case of China

PurposeA series of policies have been formulated to promote off-site construction (OSC) development. However, the effectiveness of these policies has yet to be fully explored. This study aims to explore the practical policy configurational conditions for achieving a high level of OSC development.Design/methodology/approachData on policy configurational conditions and the OSC development level were collected from 28 provinces/municipalities in China using text mining. A mixed-method approach was used to conduct data analysis involving text analysis and qualitative comparative analysis (QCA). Text analysis was used to identify current policies with frequencies as independent variables and obtain the proportion of OSC projects in new construction projects as the dependent variable. QCA is employed to analyze the necessary and sufficient conditions of policy conditions for the high-level development of OSC by exploring the complex causal relationships between policy configurational conditions and the OSC development level.FindingsNine policies are obtained from the current policy framework for promoting OSC development using text analysis: industry supports, land policies, presale policies, reputation rewards, regulation controls, tax incentives, floor area rewards, financial subsidies, and loan subsidies. Four policy configurational conditions are identified that can achieve a high development level of OSC: three incentive-driven policy conditions with industry supports, presale policies, tax incentives, and floor area rewards as the core conditions, and one compulsory-driven policy conditions with land policies, financial supports, and loan supports as the core conditions using fuzzy set QCA. Moreover, our study found that a single policy cannot achieve a high level of OSC development as a necessary condition, and the policy configurational conditions that lead to high and nonhigh levels of OSC development are asymmetrical.Research limitations/implicationsThe study did not test the policy’s dynamic effects on the OSC development. A longitudinal study will be conducted to further identify the impact of policy on OSC implementation.Practical implicationsIt provides policymakers with four practical policy configurational conditions to promote OSC development and guides policymakers to optimize effective policies considering the interaction effects of effective policies such as industry supports, presale policies, tax incentives, and floor area rewards instead of their net effects.Originality/valueIt contributes to the existing literature concerning the effects of policy on emerging technology (i.e. OSC) promotion by elucidating configurative effects rather than net effects. Meanwhile, it enriches the research on the antecedent conditions that affect the implementation of other emerging technologies in the architecture engineering and construction industry.

The Application of Biomaterial-Based Spinal Cord Tissue Engineering.

Advancements in biomaterial-based spinal cord tissue engineering technology have profoundly influenced regenerative medicine, providing innovative solutions for both spinal cord organoid development and engineered spinal cord injury (SCI) repair. In spinal cord organoids, biomaterials offer a supportive microenvironment that mimics the natural extracellular matrix, facilitating cell differentiation and organization and advancing the understanding of spinal cord development and pathophysiology. Furthermore, biomaterials are essential in constructing engineered spinal cords for SCI repair. The incorporation of biomaterials with growth factors, fabrication of ordered scaffold structures, and artificial spinal cord assemblies are critical insights for SCI to ensure structural integrity, enhance cell viability, and promote neural regeneration in transplantation. In summary, this review summarizes the contribution of biomaterials to the spinal cord organoids progression and discusses strategies for biomaterial-based spinal cord engineering in SCI therapy. These achievements underscore the transformative potential of biomaterials to improve treatment options for SCI and accelerate future clinical applications.

Platelet membrane coated r-SAK to improve thrombolytic efficacy by targeting thrombus

Abstract Background Thrombolytic therapy is one of the most effective treatments to achieve rapid thrombus clearance and recanalization of blocked vessels in thrombotic diseases. However, the application of thrombolytic strategy has been limited due to unsatisfied thrombolytic efficacy, relatively higher bleeding complications, and consequently restricted indications.[1] With the development of nanotechnology and biotechnology, platelet membrane nanoparticles have been developed to enable the targeted delivery of thrombolytic agents to local thrombus sites.[2] Recombinant staphylokinase (r-SAK) is a third-generation thrombolytic agent produced by genetic engineering technology. In this study, platelet membrane coated r-SAK (PLT-r-SAK) was constructed, and its thrombolytic efficacy was evaluated in in-vitro and in-vivo experiments. Purpose We aimed to construct a thrombus-targeting agent of PLT-r-SAK and investigate its thrombolytic efficacy. Methods PLT-r-SAK was prepared by encapsulating r-SAK into platelet membrane vesicles using a membrane extrusion method. An in-vitro thrombolytic experiment was performed to examine the thrombolytic efficacy of PLT-r-SAK, and a totally occluded femoral artery thrombosis model of rabbit was developed to evaluate the in-vivo thrombolytic efficacy of PLT-r-SAK. The changes in femoral artery pressure were adopted to assess the vessel opening status. Besides, the effect of the antiplatelet drugs on the thrombolytic efficacy of PLT-r-SAK was explored. Finally, near-infrared fluorescence imaging system was used to verify the thrombus-targeting effect of PLT-r-SAK. Results PLT-r-SAK was firstly constructed, which exhibited a uniformly dispersed spherical morphology with a diameter of 185.8 ± 1.5 nm and a zeta potential of -26.1 ± 0.8 mV. In the in-vitro animal experiment, the thrombolysis rate of PLT-r-SAK was significantly higher than that of the same (low) dose and 4-fold (high) dose r-SAK (Figure 1a, 1b). In the in-vivo experiment, the initial recanalization time of PLT-r-SAK was significantly shorter than that of the low dose and high dose r-SAK, and the duration of the reperfusion time of PLT-r-SAK was prolonged compared to low dose and high dose r-SAK (Figure 1c). Another in-vitro experiment showed that the increased thrombolysis rate of PLT-r-SAK could be inhibited by platelet poor plasma (PPP) from aspirin- and ticagrelor-treated patients. Finally, both the in-vitro and in-vivo near-infrared fluorescence imaging showed significantly higher radiant efficiency in the PLT-r-SAK group as compared to the NS group (Figure 2). Conclusions Platelet membrane coating significantly improves the thrombolytic efficacy of r-SAK, which is related to the thrombus-targeting activity of the platelet membrane and can be inhibited by aspirin- and ticagrelor-treated plasma.Thrombolytic efficacy of PLT-r-SAKThrombus-targeting evidence of PLT-r-SAK

New Magnetic Materials and Technologies: Experiment and Theory

This article presents a brief review of works devoted to the latest research by a number of Russian groups involved in the development, creation, and study of the physical properties of new magnetic materials and the phenomena observed in them. These studies are of both great fundamental and practical interest for various fields of science, engineering, and new technologies.

Dynamic Response of a Rotor Supported on Hybrid Bearings in Air, Water, and Liquid Nitrogen: Measurements and Comparisons to Predictions

Abstract Modern liquid rocket engine turbopumps implement hybrid bearings, which combine hydrostatic and hydrodynamic fluid film principles, in compact and lightweight units known for their superior reusability, durability, and reliability. This study aims to provide extensive and reliable test data for the purpose of anchoring and benchmarking predictive tools for these bearings. This paper provides comprehensive dynamic response measurements of a rotor weighing 10.40 kg and approximately 60 mm in diameter at the bearing locations. The test rotor is supported on two hybrid journal bearings with a bearing length to bearing diameter ratio of approximately 0.42 and a bearing radial clearance to rotor radius ratio of around 0.0017. The bearings are tested with air, water, and liquid nitrogen, serving as surrogate test fluids for common propellants in liquid rocket engines. Rotor run-up and speed coast-down tests are conducted to measure shaft motion responses. The results clearly demonstrate that the rotordynamic characteristics of the test rotor supported on the hybrid journal bearings largely rely on properties of the test fluids and their feeding conditions. Notably, when air is pressurized into the test bearings, the shaft motion responses differ markedly from those observed with water and liquid nitrogen, primarily due to significantly lower stiffness and damping coefficients. Furthermore, rotor speed coast-down tests for each test fluid exhibit notable differences in coast-down speed over time characteristics, depending on the test fluid properties. The predicted rotor imbalance responses exhibit excellent correlation with the measurement data. The steady increase of demand and growth of the fluid film bearing technology for reusable rocket engines require accurate bearing design tools, the extensive component testing, and the implementation of the technology. The validated and developed bearing predictive models from previous research demonstrate well the characteristics of bearings under various operating fluids conditions. The findings and database presented in this work contribute not only to comprehending the performance of hybrid bearings but also to understanding and enhancing the dynamic characteristics of rotor systems supported on hybrid bearings.