bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant Genetic Variants Modify Echocardiography Indices in Long COVID
Authors: Asanin Milika , Ercegovac Marko , Krljanac Gordana , Djukic Tatjana , Coric Vesna , Jerotic Djurdja , Pljesa-Ercegovac Marija , Matic Marija , Milosevic Ivana , Viduljevic Mihajlo , Stevanovic Goran , Ranin Jovan , Simic Tatjana , Bukumiric Zoran , Savic-Radojevic Ana
Published: June 2023

Although disturbance of redox homeostasis might be responsible for COVID-19 cardiac complications, this molecular mechanism has not been addressed yet. We have proposed modifying the effects of antioxidant proteins polymorphisms (superoxide dismutase 2 (SOD2), glutathione peroxidase 1 (GPX1), glutathione peroxidase 3 (GPX3) and nuclear factor erythroid 2-related factor 2, (Nrf2)) in individual susceptibility towards the development of cardiac manifestations of long COVID-19. The presence of subclinical cardiac dysfunction was assessed via echocardiography and cardiac magnetic resonance imaging in 174 convalescent COVID-19 patients. SOD2, GPX1, GPX3 and Nrf2 polymorphisms were determined via the appropriate PCR methods. No significant association of the investigated polymorphisms with the risk of arrhythmia development was found. However, the carriers of variant GPX1*T, GPX3*C or Nrf2*A alleles were more than twice less prone for dyspnea development in comparison with the carriers of the referent ones. These findings were even more potentiated in the carriers of any two variant alleles of these genes (OR = 0.273, and p = 0.016). The variant GPX alleles were significantly associated with left atrial and right ventricular echocardiographic parameters, specifically LAVI, RFAC and RV-EF (p = 0.025, p = 0.009, and p = 0.007, respectively). Based on the relation between the variant SOD2*T allele and higher levels of LV echocardiographic parameters, EDD, LVMI and GLS, as well as troponin T (p = 0.038), it can be proposed that recovered COVID-19 patients, who are the carriers of this genetic variant, might have subtle left ventricular systolic dysfunction. No significant association between the investigated polymorphisms and cardiac disfunction was observed when cardiac magnetic resonance imaging was performed. Our results on the association between antioxidant genetic variants and long COVID cardiological manifestations highlight the involvement of genetic propensity in both acute and long COVID clinical manifestations.
A Comparison of Two Interaction Paradigms for Training Low Cost Automation Assembly in Virtual Environments
Authors: Manuri Federico , Decataldo Federico , Sanna Andrea , Brizzi Paolo
Published: June 2023

Virtual environments have been widely adopted for design and training tasks in the industrial domain. Low-cost automation (LCA) is a technology that automatizes some activities using mostly standard automation mechanisms available off the shelf. However, LCA systems should adapt to existing standard production lines and workstations. Thus, workers must customize standard LCA templates and perform adaptation and customization steps. This activity can be very time consuming with physical LCA systems, and in case of errors, it may be necessary to rebuild many parts from scratch. Thus, LCA systems would greatly benefit from a design and prototyping step experienced in a virtual simulation environment. An immersive virtual reality (IVR) application for rapid and easy prototyping of LCA solutions has been investigated in previous work; the assessment of the system usability proved that the users highly appreciated the proposed solutions. This research explores further improvements to exploit the existing IVR application as a training tool for LCA prototyping trainees. The proposed application now provides users with two different interaction paradigms based on the VIVE controllers and the Manus Prime II data gloves. The application’s interface has been revised to allow a proper comparison of the two interaction models. The two interfaces have been compared, involving 12 participants in an LCA building task. The System Usability Scale (SUS) and the NASA Task Load Index (TLX) questionnaires have been used to assess the usability and workload of the two solutions.
Development and Reproduction of a Japanese Strain of Ctenolepisma calvum (Ritter, 1910) at Room Temperature
Authors: Watanabe Hiroki , Shimada Megumi , Sato Yoshinori , Kigawa Rika
Published: June 2023

Ctenolepisma calvum (Ritter, 1910) (Zygentoma: Lepismatidae) is a primitive wingless insect that causes damage to paper, and it is regarded as a pest of collections in museums, archives, and libraries. This species was recently discovered in Japan for the first time and may have already spread over large areas of Japan, but, currently, no information is available on the biological characteristics of C. calvum in Japan. In this study, we observed the processes of development and reproduction of C. calvum found in Japan at room temperature. Oviposition was observed from April to November, with a peak in early June. The average egg period was 56.9 days at average temperatures above 24.0 °C, and was 72.4 days at average temperatures below 24.0 °C. The 1st, 2nd, and 3rd instars lasted 4.7 days, 13.2 days, and 26.1 days on average, respectively, at average temperatures above 22.0 °C. Average instar periods were 23–28 days in 4th–7th instars and tended to increase in later instars. Instar periods also increased when the average temperature was 22.0 °C or lower. In individual rearing, the longest-living individual lived for approximately two years, up to the 15th instar. The head width grew at an approximate ratio of 1.1 per molt. First oviposition occurred at the 10th or 11th instar. Individually observed females oviposited once or twice a year, laying 6–16 eggs at one time, but females at least two years old laid 78.2 eggs per year on average in a mass-culture cage. Through this study, only females were found, and the mature females produced their progenies parthenogenetically.
Bone Morphogenic Protein and Mesenchymal Stem Cells to Regenerate Bone in Calvarial Defects: A Systematic Review
Authors: Torres-Guzman Ricardo A. , Avila Francisco R. , Maita Karla C. , Garcia John P. , De Sario Gioacchino D. , Borna Sahar , Eldaly Abdullah S. , Quinones-Hinojosa Alfredo , Zubair Abba C. , Ho Olivia A. , Forte Antonio J.
Published: June 2023

Background: The use of bone morphogenic protein and mesenchymal stem cells has shown promise in promoting bone regeneration in calvarial defects. However, a systematic review of the available literature is needed to evaluate the efficacy of this approach. Methods: We comprehensively searched electronic databases using MeSH terms related to skull defects, bone marrow mesenchymal stem cells, and bone morphogenic proteins. Eligible studies included animal studies that used BMP therapy and mesenchymal stem cells to promote bone regeneration in calvarial defects. Reviews, conference articles, book chapters, and non-English language studies were excluded. Two independent investigators conducted the search and data extraction. Results: Twenty-three studies published between 2010 and 2022 met our inclusion criteria after a full-text review of the forty-five records found in the search. Eight of the 23 studies used mice as models, while 15 used rats. The most common mesenchymal stem cell was bone marrow-derived, followed by adipose-derived. BMP-2 was the most popular. Stem cells were embedded in Scaffold (13), Transduction (7), and Transfection (3), and they were delivered BMP to cells. Each treatment used 2 × 104–1 × 107 mesenchymal stem cells, averaging 2.26 × 106. Most BMP-transduced MSC studies used lentivirus. Conclusions: This systematic review examined BMP and MSC synergy in biomaterial scaffolds or alone. BMP therapy and mesenchymal stem cells in calvarial defects, alone, or with a scaffold regenerated bone. This method treats skull defects in clinical trials. The best scaffold material, therapeutic dosage, administration method, and long-term side effects need further study.
Circulating Anti-GB3 Antibody as a Biomarker of Myocardial Inflammation in Patients with Fabry Disease Cardiomyopathy
Authors: Frustaci Andrea , Verardo Romina , Magnocavallo Michele , Scialla Rossella , Sansone Luigi , Russo Matteo Antonio
Published: June 2023

Background: Fabry disease cardiomyopathy (FDCM) has manifested some resistance to enzyme replacement therapy (ERT), particularly in its advanced phase. Recently, myocardial inflammation of autoimmune origin has been demonstrated in FDCM. Aims: The objective of this study was the assessment of circulating anti-globotriaosylceramide (GB3) antibodies as potential biomarkers of myocardial inflammation in FDCM, defined by the additional presence of ≥CD3+ 7 T lymphocytes/low-power field associated with focal necrosis of adjacent myocytes. Its sensitivity was based on the evidence of overlapping myocarditis at left ventricular endomyocardial biopsy. Methods and Results: From January 1996 to December 2021, 85 patients received a histological diagnosis of FDCM in our department and 48 (56.5%) of them had an overlapping myocardial inflammation with negative PCR for common cardiotropic viruses, positive antiheart, and antimyosin abs. The presence of anti-GB3 antibodies was evaluated with an in-house ELISA assay (BioGeM scarl Medical Investigational Research, MIR—Ariano Irpino, Italy), along with antiheart and antimyosin abs, in the FDCM patients and compared with control healthy individuals. The correlation between levels of circulating anti-GB3 autoantibody myocardial inflammation and FDCM severity was assessed. Anti-Gb3 antibodies were above the positivity cut-off in 87.5% of FDCM subjects with myocarditis (42 out of 48), while 81.1% of FDCM patients without myocarditis were identified as negative for Gb3 antibodies. Positive anti-Gb3 abs correlated with positive antiheart and antimyosin abs. Conclusions: The present study suggests a potential positive role of anti-GB3 antibodies as a marker of overlapping cardiac inflammation in patients with FDCM.
Intravascular Ultrasound Guided Intervention in Calcified Coronary Lesions Showed Good Clinical Outcomes during One Year Follow-Up
Authors: Doan Khanh-Hung , Liu Tai-Li , Yun Won-Sik , Kim Yi-Sik , Yun Kyeong Ho , Oh Seok Kyu , Park Jong-Pil , Rhew Jay Young , Lee Sang-Rok
Published: June 2023

Background: Calcified coronary lesions can cause stent under-expansion, malapposition, and polymer degradation, hence increasing the risk of adverse clinical outcomes. Percutaneous coronary intervention (PCI) guided by intravascular ultrasound (IVUS) has been used regularly to improve outcomes. Our primary aim was to evaluate the clinical efficacy of IVUS-guided PCI in calcified coronary lesions. Methods: From August 2018 to December 2021, we prospectively included 300 patients in the CAPIRO study (CAlcified plaque in patients receiving Resolute Onyx®) at three educational hospitals in Jeonbuk Province. We studied 243 patients (265 lesions) who were followed up for over a year. Based on coronary calcification by IVUS analysis, the patient population was categorized into two groups (Group I: non/mild calcification; Group II: moderate/severe calcification (maximum calcium arc >180° and calcium length > 5 mm)). One-to-one Propensity Score Matching was used to match the baseline characteristics. The stent expansion rate was analyzed by recent criteria. The primary clinical outcome was Major Adverse Cardiac Events (MACE), which included Cardiac death, Myocardial Infarction (MI), and Target Lesion Revascularization (TLR). Results: After follow-up time, the MACE rate in Group I was 1.99%, comparable to Group II’s 1.09% (p = 0.594). The components of MACE did not significantly differ between the two groups. Based on absolute MSA or MSA/MVA at MSA site criteria, the stent expansion rate in Group II was lower than that of Group I. Nevertheless, based on recent relative criteria, the stent expansion rate in both groups was comparable. Conclusions: After more than a year of follow-up, IVUS-guided PCI in moderate/severe calcification lesions was associated with good clinical outcomes, which was comparable with non/mild calcification lesions. Future studies with a larger sample size and a more extended follow-up period are required to clarify our findings.
Immunosuppressant Adherence Factors Differentiating Compliant and Non-Compliant Kidney Transplant Recipients
Authors: Ostrowski Piotr , Kargul Michał , Gurazda Klaudia , Skoryk Anastasiia , Ostrowski Marek , Myślak Marek , Różański Jacek , Skwirczyńska Edyta
Published: June 2023

The purpose of this study is to find out the psychological factor characteristic of non-adherence patients. The study population comprised kidney transplant recipients aged between 18 and 82 years at least 3 months post-transplant who voluntarily agreed to answer a couple of fully anonymous questionnaires that questions pertaining to basic data, type of immunosuppressive drugs taken, and standardized questionnaires. Participants were recruited using direct routine, free-of-charge visits to specialist doctors in transplant clinics. There was no significant difference in the percentage of men and women in both adherence and non-adherence groups. Non-adherence patients were significantly younger compared to adherence patients. There was also a significant difference in the patient’s level of education. Adherence patients were better educated. No significant differences in criteria such as place of residence, having children or a partner, or way of living were observed. However, the emotion scale correlated negatively with the level of life orientation in both groups, but the level of the emotions scale and distractions subscale was negatively correlated with the level of self-esteem only for the adherence group. In future research, it would be worthwhile to focus on lifestyle and health-promoting behaviors in juxtaposition with the propensity for adherence.
Uncovering Predictors of Lipid Goal Attainment in Type 2 Diabetes Outpatients Using Logic Learning Machine: Insights from the AMD Annals and AMD Artificial Intelligence Study Group
Authors: Masi Davide , Zilich Rita , Candido Riccardo , Giancaterini Annalisa , Guaita Giacomo , Muselli Marco , Ponzani Paola , Santin Pierluigi , Verda Damiano , Musacchio Nicoletta
Published: June 2023

Identifying and treating lipid abnormalities is crucial for preventing cardiovascular disease in diabetic patients, yet only two-thirds of patients reach recommended cholesterol levels. Elucidating the factors associated with lipid goal attainment represents an unmet clinical need. To address this knowledge gap, we conducted a real-world analysis of the lipid profiles of 11.252 patients from the Annals of the Italian Association of Medical Diabetologists (AMD) database from 2005 to 2019. We used a Logic Learning Machine (LLM) to extract and classify the most relevant variables predicting the achievement of a low-density lipoprotein cholesterol (LDL-C) value lower than 100 mg/dL (2.60 mmol/L) within two years of the start of lipid-lowering therapy. Our analysis showed that 61.4% of the patients achieved the treatment goal. The LLM model demonstrated good predictive performance, with a precision of 0.78, accuracy of 0.69, recall of 0.70, F1 Score of 0.74, and ROC-AUC of 0.79. The most significant predictors of achieving the treatment goal were LDL-C values at the start of lipid-lowering therapy and their reduction after six months. Other predictors of a greater likelihood of reaching the target included high-density lipoprotein cholesterol, albuminuria, and body mass index at baseline, as well as younger age, male sex, more follow-up visits, no therapy discontinuation, higher Q-score, lower blood glucose and HbA1c levels, and the use of anti-hypertensive medication. At baseline, for each LDL-C range analysed, the LLM model also provided the minimum reduction that needs to be achieved by the next six-month visit to increase the likelihood of reaching the therapeutic goal within two years. These findings could serve as a useful tool to inform therapeutic decisions and to encourage further in-depth analysis and testing.
Evolutionary Palaeoecological and Morphological Response of Globorotalia menardii to Environmental Stress Conditions Preceding the Tortonian–Messinian Boundary in the Mediterranean Basin
Authors: Besiou Evangelia , Kontakiotis George , Vasiliev Iuliana , Moissette Pierre , Cornée Jean-Jacques , Antonarakou Assimina
Published: June 2023

The Tortonian–Messinian transition is associated with important climatic and oceanographic changes in the Mediterranean Basin, which have shaped both the biotic and abiotic nature of this setting. The morphological variability of the planktonic foraminifera Globorotalia menardii, a species that is highly sensitive to water column structure, has been investigated from the sedimentary archive of three Cretan sections across a west–east transect covering the Tortonian–Messinian Boundary. The present work explicitly focuses on test-size and coiling direction changes occurring during the 7.36–7.24 Ma time slice. On such a short timescale, the most important morphological differentiation accounts for the average size of G. menardii, which is mostly associated with evolutionary adaptation to new ecological niches during the latest Tortonian as a response to the environmental perturbations and ecological stress conditions preceding the Tortonian–Messinian Boundary. A combined thermal and/or salinity-driven stratification and thermocline development hypothesis has been suggested to explain the observed size variability. To ameliorate the accuracy of the proposed model and further determine which environmental parameter reflects the optimum conditions of the analysed species, additional sea surface temperature and salinity data derived from the same sampling intervals of the studied or additional Mediterranean sites are needed. The coiling direction of this species within the study time interval remained constant and not environmentally controlled.
Estimate of Cetacean and Shark Depredations in the Small-Scale Longline Fishery in the Southeastern Waters of Taiwan
Authors: Liu Kwang-Ming , Su Kuan-Yu , Chin Chien-Pang
Published: June 2023

Cetacean and shark depredations in a small-scale longline fishery in the southeastern Taiwan waters were estimated based on interviews of 21 fishermen and logbooks of 12 sampling vessels, including 649 operations (681,310 hooks) from October 2009 to December 2010. Cetacean depredations were more serious than shark depredations, with damage rates of 19.26% and 11.56%, respectively. The depredation rates in number and weight from cetaceans were estimated to be 2.21% and 3.23%, respectively, and were significantly higher than those from sharks, which were estimated to be 0.51% and 0.47%, respectively. The depredation indices from cetacean and shark were estimated to be 0.93 and 0.22 per 1000 hooks, respectively. The dolphinfish and yellowfin tuna were the top two species depredated by cetaceans and sharks. The annual economic loss of the small-scale longline fishery due to cetacean and shark depredations was estimated to be USD 441.9 thousand and USD 58.8 thousand, respectively, which corresponded to 4.5% and 0.6% of the total sales of the longline fishery at Hsinkang fishing port, southeastern Taiwan. The catch in number of dolphinfish and the operation depth were significant factors that affected cetacean depredations.
Ectomycorrhizal Fungal Community and Ascoma Production in a Declining Tuber borchii Plantation
Authors: Ori Francesca , Leonardi Marco , Puliga Federico , Lancellotti Enrico , Pacioni Giovanni , Iotti Mirco , Zambonelli Alessandra
Published: June 2023

Tuber borchii is an edible ectomycorrhizal mushroom of considerable economic value. Its cultivation has become popular in recent years, but there are few studies on the factors affecting its productivity. In this work, the ascoma production and the ectomycorrhizal (ECM) community of a T. borchii plantation, established in an intensive farming area where this truffle is not naturally present, were studied. Tuber borchii production drastically declined from 2016 to 2021, and ascomata of other Tuber species (T. maculatum and T. rufum) were found from 2017. Molecular characterization of ectomycorrhizae carried out in 2016 identified 21 ECM fungal species, of which T. maculatum (22%) and Tomentella coerulea (19%) were the most abundant. Tuber borchii ectomycorrizae (16%) were almost entirely confined to the fruiting points. The diversity and structure of the ECM community on Pinus pinea were significantly different from those observed on hardwood trees. The obtained results suggest that T. maculatum (a native of the study site) tends to replace T. borchii through a mechanism of competitive exclusion. Although T. borchii cultivation is possible in suboptimal environments, particular care should be taken to limit competition with ECM fungi more suitable for local conditions.
Antibody Therapeutics as Interfering Agents in Flow Cytometry Crossmatch for Organ Transplantation
Authors: Kueht Michael L. , Dongur Laxmi Priya , Mujtaba Muhammad A. , Cusick Matthew F.
Published: June 2023

Donor–recipient matching is a highly individualized and complex component of solid organ transplantation. Flowcytometry crossmatching (FC-XM) is an integral step in the matching process that is used to detect pre-formed deleterious anti-donor immunoglobulin. Despite high sensitivity in detecting cell-bound immunoglobulin, FC-XM is not able to determine the source or function of immunoglobulins detected. Monoclonal antibody therapeutic agents used in a clinic can interfere with the interpretation of FC-XM. We combined data from the prospectively maintained Antibody Society database and Human Protein Atlas with a comprehensive literature review of PubMed to summarize known FC-XM-interfering antibody therapeutics and identify potential interferers. We identified eight unique FC-XM-interfering antibody therapeutics. Rituximab (anti-CD20) was the most-cited agent. Daratumuab (anti-CD38) was the newest reported agent. We identified 43 unreported antibody therapeutics that may interfere with FC-XM. As antibody therapeutic agents become more common, identifying and mitigating FC-XM interference will likely become an increased focus for transplant centers.
First Results of Concurrent Chemoradiation with Two Courses of 5 × 25 mg/m2 Cisplatin for Locally Advanced Head and Neck Cancer
Authors: Zwaan Inga , Soror Tamer , Idel Christian , Pries Ralph , Bruchhage Karl L. , Hakim Samer G. , Yu Nathan Y. , Rades Dirk
Published: June 2023

Many patients with squamous cell carcinoma of the head and neck (SCCHN) receive cisplatin-based chemoradiation. Cisplatin 100 mg/m2 every three weeks is toxic and alternative cisplatin regimens are desired. Two courses of 20 mg/m2/day 1–5 (cumulative 200 mg/m2) were shown to be similarly effective and better tolerated than 100 mg/m2 every three weeks. Previous studies suggested that cumulative doses >200 mg/m2 may further improve outcomes. In this study, 10 patients (group A) receiving two courses of 25 mg/m2/day 1–5 (cumulative 250 mg/m2) in 2022 were retrospectively matched and compared to 98 patients (group B) receiving two courses of 20 mg/m2/day 1–5 or 25 mg/m2/day 1–4 (cumulative 200 mg/m2). Follow-up was limited to 12 months to avoid bias. Group A achieved non-significantly better 12-month loco-regional control (100% vs. 83%, p = 0.27) and metastases-free survival (100% vs. 88%, p = 0.38), and similar overall survival (89% vs. 88%, p = 0.90). No significant differences were found regarding toxicities, completion of chemotherapy, and interruption of radiotherapy. Given the limitations of this study, chemoradiation with two courses of 25 mg/m2/day 1–5 appears an option for carefully selected patients as a personalized treatment approach. Longer follow-up and a larger sample size are needed to properly define its role.
Testbed Facilities for IoT and Wireless Sensor Networks: A Systematic Review
Authors: Judvaitis Janis , Abolins Valters , Elkenawy Amr , Balass Rihards , Selavo Leo , Ozols Kaspars
Published: June 2023

As the popularity and complexity of WSN devices and IoT systems are increasing, the testing facilities should keep up. Yet, there is no comprehensive overview of the landscape of the testbed facilities conducted in a systematic manner. In this article, we provide a systematic review of the availability and usage of testbed facilities published in scientific literature between 2011 and 2021, including 359 articles about testbeds and identifying 32 testbed facilities. The results of the review revealed what testbed facilities are available and identified several challenges and limitations in the use of the testbed facilities, including a lack of supportive materials and limited focus on debugging capabilities. The main contribution of this article is the description of how different metrics impact the uasge of testbed facilities, the review also highlights the importance of continued research and development in this field to ensure that testbed facilities continue to meet the changing needs of the ever-evolving IoT and WSN domains.
Response of Spontaneous Plant Communities to Sedum mexicanum Cover and Water Availability in Green Roof Microcosms
Authors: Schrieke Dean , Williams Nicholas S. G. , Farrell Claire
Published: June 2023

Lack of maintenance can lead to ‘weedy’ spontaneous vegetation on green roofs. Aspects of green roof design, including substrate depth and roof height, have been shown to influence the composition of spontaneous vegetation. In drier climates, Sedum species are often planted on shallow substrate ‘extensive’ green roofs and irrigated during summer to maintain cover. However, the response of spontaneous vegetation to Sedum cover and water availability is unclear. Understanding this relationship could help minimise maintenance and maintain Sedum vegetation cover. We hypothesised that increasing Sedum (Sedum mexicanum) cover and reduced water availability would reduce the abundance, biomass, species and functional richness, and the community weighted mean specific leaf area (SLA; CWM by abundance) of spontaneous plant communities. We conducted a 10-month experiment in green roof microcosms planted with S. mexicanum (0%, 25%, 50%, 75% and 100% total cover), subjected to a well-watered or water-deficit irrigation treatment, and sown with a mix of 14 plant species that commonly occur as spontaneous on green roofs. We measured spontaneous species abundance, community biomass, and functional traits (specific leaf area, leaf dry matter content, and relative growth rate), and calculated species and functional richness. Increasing S. mexicanum cover reduced spontaneous species abundance and species and functional richness but did not affect community biomass. Species richness was affected by the interaction of S. mexicanum cover and watering treatment and was greatest in well-watered microcosms with 0% S. mexicanum cover. Increased water availability increased spontaneous plant biomass but did not affect functional richness. The SLA of spontaneous communities was affected by the interaction of S. mexicanum cover and watering and was significantly greater in well-watered treatments where S. mexicanum cover was <100%. Therefore, maximising Sedum cover and limiting water availability on green roofs will likely limit the abundance, biomass, and diversity of spontaneous vegetation. Conversely, for green roofs where substrate is left to be naturally colonised, increasing water availability could encourage establishment and increase functional richness of spontaneous vegetation.
Evolution of Grain Structure and Dynamic Precipitation during Hot Deformation in a Medium-Strength Al-Zn-Mg-Er-Zr Aluminum Alloy
Authors: Chen Jiongshen , Rong Li , Wei Wu , Qi Peng , Wang Meng , Wang Zezhong , Zhou Li , Huang Hui , Nie Zuoren
Published: June 2023

The hot deformation behavior of Al-Zn-Mg-Er-Zr alloy was investigated through an isothermal compression experiment at a strain rate ranging from 0.01 to 10 s−1 and temperature ranging from 350 to 500 °C. The constitutive equation of thermal deformation characteristics based on strain was established, and the microstructure (including grain, substructure and dynamic precipitation) under different deformation conditions was analyzed. It is shown that the steady-state flow stress can be described using the hyperbolic sinusoidal constitutive equation with a deformation activation energy of 160.03 kJ/mol. Two kinds of second phases exist in the deformed alloy; one is the η phase, whose size and quantity changes according to the deformation parameters, and the other is spherical Al3(Er, Zr) particles with good thermal stability. Both kinds of particles pin the dislocation. However, with a decrease in strain rate or increase in temperature, η phases coarsen and their density decreases, and their dislocation locking ability is weakened. However, the size of Al3(Er, Zr) particles does not change with the variation in deformation conditions. So, at higher deformation temperatures, Al3(Er, Zr) particles still pin dislocations and thus refine the subgrain and enhance the strength. Compared with the η phase, Al3(Er, Zr) particles are superior for dislocation locking during hot deformation. A strain rate ranging from 0.1 to 1 s−1 and a deformation temperature ranging from 450 to 500 °C form the safest hot working domain in the processing map.
Quad-Band Metamaterial Perfect Absorber with High Shielding Effectiveness Using Double X-Shaped Ring Resonator
Authors: Jahan MST Ishrat , Faruque Mohammad Rashed Iqbal , Hossain Md Bellal , Khandaker Mayeen Uddin , Elsayed Fahmi , Salman Mohammad , Osman Hamid
Published: June 2023

This study assesses quad-band metamaterial perfect absorbers (MPAs) based on a double X-shaped ring resonator for electromagnetic interference (EMI) shielding applications. EMI shielding applications are primarily concerned with the shielding effectiveness values where the resonance is uniformly or non-sequentially modulated depending on the reflection and absorption behaviour. The proposed unit cell consists of double X-shaped ring resonators, a dielectric substrate of Rogers RT5870 with 1.575 mm thickness, a sensing layer, and a copper ground layer. The presented MPA yielded maximum absorptions of 99.9%, 99.9%, 99.9%, and 99.8% at 4.87 GHz, 7.49 GHz, 11.78 GHz, and 13.09 GHz resonance frequencies for the transverse electric (TE) and transverse magnetic (TM) modes at a normal polarisation angle. When the electromagnetic (EM) field with the surface current flow was investigated, the mechanisms of quad-band perfect absorption were revealed. Moreover, the theoretical analysis indicated that the MPA provides a shielding effectiveness of more than 45 dB across all bands in both TE and TM modes. An analogous circuit demonstrated that it could yield superior MPAs using the ADS software. Based on the findings, the suggested MPA is anticipated to be valuable for EMI shielding purposes.
Incorporating Industrial By-Products into Geopolymer Mortar: Effects on Strength and Durability
Authors: Lam Tang Van , Nguyen May Huu
Published: June 2023

In recent years, the reuse of industrial waste has become increasingly important for sustainable development. Therefore, this study investigated the application of granulated blast furnace slag (GBFS) as a cementitious replacement material in fly-ash-based geopolymer mortar containing silica fume (GMS). The performance changes in the GMS samples manufactured with different GBFS ratios (0–50 wt%) and alkaline activators were evaluated. The results indicated that GBFS replacement from 0 wt% to 50 wt% significantly affects GMS performance, including improving the bulk density from 2235 kg/m3 to 2324 kg/m3, flexural-compressive strength from 5.83 MPa to 7.29 MPa and 63.5 MPa to 80.2 MPa, respectively; a decrease in water absorption and chloride penetration, and an improvement in the corrosion resistance of GMS samples. The GMS mixture containing 50 wt% GBFS demonstrated the best performances with notable results regarding strength and durability. Owing to the increased production of C-S-H gel, the microstructure of the GMS sample containing more GBFS was denser, as obtained via the scanning electron micrograph analysis results. Incorporating the three industrial by-products into geopolymer mortars was verified when all samples were determined to be in accordance with the relevant Vietnamese standards. The results demonstrate a promising method to manufacture geopolymer mortars that aid sustainable development.
Evolution of the Microstructure and Mechanical Performance of As-Sprayed and Annealed Silicon Coating on Melt-Infiltrated Silicon Carbide Composites
Authors: Guo Mengqiu , Cui Yongjing , Wang Changliang , Jiao Jian , Bi Xiaofang , Tao Chunhu
Published: June 2023

In this study, silicon coating was deposited on melt-infiltrated SiC composites using atmospheric plasma spraying and then annealed at 1100 and 1250 °C for 1–10 h to investigate the effect of annealing on the layer. The microstructure and mechanical properties were evaluated using scanning electron microscopy, X-ray diffractometry, transmission electron microscopy, nano-indentation, and bond strength tests. A silicon layer with a homogeneous polycrystalline cubic structure was obtained without phase transition after annealing. After annealing, three features were observed at the interface, namely β-SiC/nano-oxide film/Si, Si-rich SiC/Si, and residual Si/nano-oxide film/Si. The nano-oxide film thickness was ≤100 nm and was well combined with SiC and silicon. Additionally, a good bond was formed between the silicon-rich SiC and silicon layer, resulting in a significant bond strength improvement from 11 to >30 MPa.
Experimental and Numerical Study of Non-Explosive Simulated Blast Loading on Reinforced Concrete Slabs
Authors: Xiong Zhixiang , Wang Wei , Yu Guocai , Ma Jian , Zhang Weiming , Wu Linzhi
Published: June 2023

This study presents a non-explosive method for simulating blast loading on reinforced concrete (RC) slabs. The method involves using a newly developed blast simulator to apply a speedy impact load on the slab, which generates a pressure wave similar to that of an actual blast. Both experimental and numerical simulations were carried out to evaluate the effectiveness of the method. The experimental results showed that the non-explosive method can produce a pressure wave with a peak pressure and duration analogous to those of an actual blast. The numerical simulations also showed good agreement with the experimental results. Additionally, parameter studies were conducted to evaluate the effects of the rubber shape, the impact velocity, the bottom thickness, and the upper thickness on the impact loading. The results indicate that pyramidal rubber is more suitable as an impact cushion for simulating blast loading than planar rubber. The impact velocity has the widest range of regulation for peak pressure and impulse. As the velocity increases from 12.76 to 23.41 m/s, the corresponding range of values for peak pressure is 6.457 to 17.108 MPa, and for impulse, it is 8.573 to 14.151 MPa∙ms. The variation in the upper thickness of the pyramidal rubber has a more positive effect on the impact load than the bottom thickness. With the upper thickness increasing from 30 mm to 130 mm, the peak pressure decreased by 59.01%, and the impulse increased by 16.64%. Meanwhile, when the bottom part’s thickness increased from 30 mm to 130 mm, the peak pressure decreased by 44.59%, and the impulse increased by 11.01%. The proposed method provides a safe and cost-effective alternative to traditional explosive methods for simulating blast loading on RC slabs.
Structural, Magnetic, and Magneto-Optical Properties of Thin Films of BaM Hexaferrite Grown by Laser Molecular Beam Epitaxy
Authors: Krichevtsov Boris , Korovin Alexander , Suturin Sergey , Levin Aleksandr A. , Lobov Ivan , Telegin Andrey , Badalyan Andrey , Sakharov Vladimir , Serenkov Igor , Dorogov Maxim , Sokolov Nikolai
Published: June 2023

Thin films of BaM hexaferrite (BaFe12O19) were grown on α-Al2O3(0001) substrates by laser molecular beam epitaxy. Structural, magnetic, and magneto-optical properties were studied using medium-energy ion scattering, energy dispersive X-ray spectroscopy, atomic force microscopy, X-ray diffraction, magneto-optical spectroscopy, and magnetometric techniques, and the dynamics of magnetization by ferromagnetic resonance method. It was shown that even a short time annealing drastically changes the structural and magnetic properties of films. Only annealed films demonstrate magnetic hysteresis loops in PMOKE and VSM experiments. The shape of hysteresis loops depends on thickness of films showing practically rectangular loops and high value of remnant magnetization (Mr/Ms~99%) for thin films (50 nm) and much broader and sloped loops in thick (350–500 nm) films. The magnitude of magnetization 4πMs ≈ 4.3 kG in thin films corresponds to that in bulk BaM hexaferrite. Photon energy and sign of bands in magneto-optical spectra of thin films correspond to ones observed earlier in bulk samples and films of BaM hexaferrite. FMR spectra of 50 nm films at 50 GHz consist of a number of narrow lines. The width of main line ΔH~20 Oe is lower than has been reported up to now.
Thermal Deformation Behavior and Dynamic Softening Mechanisms of Zn-2.0Cu-0.15Ti Alloy: An Investigation of Hot Processing Conditions and Flow Stress Behavior
Authors: Xie Guilan , Kuang Zhihao , Li Jingxin , Zhang Yating , Han Shilei , Li Chengbo , Zhu Daibo , Liu Yang
Published: June 2023

Through isothermal hot compression experiments at various strain rates and temperatures, the thermal deformation behavior of Zn-2.0Cu-0.15Ti alloy is investigated. The Arrhenius-type model is utilized to forecast flow stress behavior. Results show that the Arrhenius-type model accurately reflects the flow behavior in the entire processing region. The dynamic material model (DMM) reveals that the optimal processing region for the hot processing of Zn-2.0Cu-0.15Ti alloy has a maximum efficiency of about 35%, in the temperatures range (493–543 K) and a strain rate range (0.01–0.1 s−1). Microstructure analysis demonstrates that the primary dynamic softening mechanism of Zn-2.0Cu-0.15Ti alloy after hot compression is significantly influenced by temperature and strain rate. At low temperature (423 K) and low strain rate (0.1 s−1), the interaction of dislocations is the primary mechanism for the softening Zn-2.0Cu-0.15Ti alloys. At a strain rate of 1 s−1, the primary mechanism changes to continuous dynamic recrystallization (CDRX). Discontinuous dynamic recrystallization (DDRX) occurs when Zn-2.0Cu-0.15Ti alloy is deformed under the conditions of 523 K/0.1 s−1, while twinning dynamic recrystallization (TDRX) and CDRX are observed when the strain rate is 10 s−1.
Hydrothermal Synthesis of MoS2/SnS2 Photocatalysts with Heterogeneous Structures Enhances Photocatalytic Activity
Authors: Ma Guansheng , Pan Zhigang , Liu Yunfei , Lu Yinong , Tao Yaqiu
Published: June 2023

The use of solar photocatalysts to degrade organic pollutants is not only the most promising and efficient strategy to solve pollution problems today but also helps to alleviate the energy crisis. In this work, MoS2/SnS2 heterogeneous structure catalysts were prepared by a facile hydrothermal method, and the microstructures and morphologies of these catalysts were investigated using XRD, SEM, TEM, BET, XPS and EIS. Eventually, the optimal synthesis conditions of the catalysts were obtained as 180 °C for 14 h, with the molar ratio of molybdenum to tin atoms being 2:1 and the acidity and alkalinity of the solution adjusted by hydrochloric acid. TEM images of the composite catalysts synthesized under these conditions clearly show that the lamellar SnS2 grows on the surface of MoS2 at a smaller size; high-resolution TEM images show lattice stripe distances of 0.68 nm and 0.30 nm for the (002) plane of MoS2 and the (100) plane of SnS2, respectively. Thus, in terms of microstructure, it is confirmed that the MoS2 and SnS2 in the composite catalyst form a tight heterogeneous structure. The degradation efficiency of the best composite catalyst for methylene blue (MB) was 83.0%, which was 8.3 times higher than that of pure MoS2 and 16.6 times higher than that of pure SnS2. After four cycles, the degradation efficiency of the catalyst was 74.7%, indicating a relatively stable catalytic performance. The increase in activity could be attributed to the improved visible light absorption, the increase in active sites introduced at the exposed edges of MoS2 nanoparticles and the construction of heterojunctions opening up photogenerated carrier transfer pathways and effective charge separation and transfer. This unique heterostructure photocatalyst not only has excellent photocatalytic performance but also has good cycling stability, which provides a simple, convenient and low-cost method for the photocatalytic degradation of organic pollutants.
Analysis and Minimization of Race Tracking in the Resin-Transfer-Molding Process by Monte Carlo Simulation
Authors: Agogué Romain , Shakoor Modesar , Beauchêne Pierre , Park Chung Hae
Published: June 2023

A numerical analysis of the influence of race tracking on dry spots formation and the accuracy of permeability measurement during the resin-transfer-molding process is presented. In the numerical simulation of the mold-filling process, defects are randomly generated, and their effect is assessed by a Monte Carlo simulation method. The effect of race tracking on the unsaturated permeability measurement and dry spots formation is investigated on flat plates. It is observed that the race-tracking defects located near the injection gate increase up to 40% of the value of the measured unsaturated permeability. The race-tracking defects located near the air vents are more likely to generate dry spots, whereas those near the injection gates have a less significant influence on dry spots generation. Depending on vent location, it has for instance been shown that the dry spot area can increase by a factor of 30. Dry spots may be mitigated by placing an air vent at a suitable location based on the numerical analysis results. Moreover, those results may be helpful to determine optimal sensor locations for the on-line control of mold-filling processes. Finally, the approach is successfully applied to a complex geometry.
HAPC Model of Crowd Behavior during Crises
Authors: Pompa Marcello , Cerasa Antonio , Panunzi Simona , De Gaetano Andrea
Published: June 2023

The dynamics of pedestrian crowds during exceptional tragic events are very complex depending on a series of human behaviors resulting from combinations of basic interaction principles and self-organization. The Alert–Panic–Control (APC) model is one of the mathematical models in the literature for representing such complicated processes, mainly focusing on psychologists’ points of view (i.e., emotion contagion). This work proposes a Hybrid APC (HAPC) model including new processes, such as the effect of resonance, the victims caused by people in state of panic, new interactions between populations based on imitation and emotional contagion phenomena and the ability to simulate multiple disaster situations. Results from simulated scenarios showed that in the first 5 min 54.45% of population move towards a state of alert, 13.82% enter the control state and 31.73% pass to the state of panic, highlighting that individuals respond to a terrible incident very quickly, right away after it occurs.
Authenticated Key Exchange under Bad Randomness, Revisited
Authors: Cui Hui , Mudra Glen
Published: June 2023

A bad randomness may cause catastrophic results in security; thus, it is of importance to make cryptographic systems secure against bad randomness. In this paper, we focus on a practical situation where an adversary is able to force participants in an authenticated key exchange (AKE) system to reuse the random values and the functions of these values, called related randomness attack (RRA). Following the existing randomness resetting security model of AKE and the RRA security model of public-key encryption, we present a model of RRA security for authenticated key exchange, as well as the necessary restrictions on the related randomness functions used to obtain the security definition. Then we show how a related randomness attack adversary breaks the security of some existing AKE protocols, and propose some constructions of RRA-secure authenticated key exchange in the random oracle model and standard model, respectively.
Joint Optimization of Condition-Based Maintenance and Performance Control for Linear Multi-State Consecutively Connected Systems
Authors: Wang Jun , Wang Yuyang , Fu Yuqiang
Published: June 2023

Industrial systems such as signal relay stations and oil pipeline systems can be modeled as linear multi-state consecutively connected systems, which comprise sequentially ordered elements and fail if the first and the final elements are not connected. The performance level of each element is controllable, which determines how many elements an element can connect and affects its degradation rate. Accumulated degradation can cause element failure, which may lead to costly system failure. This paper aims to minimize long-term maintenance-related costs, including system failure costs. We provide optimal maintenance planning and performance control for every system degradation state through Markov decision process modeling and a dynamic programming algorithm. Load-sharing, restricted maintenance capacity, maintenance setup costs, and the structural characteristics of the system are considered in the model, all of which influence the optimal maintenance and performance control policy. Regarding degradation management, reducing the difference in degradation levels between elements, e.g., replacing more-degraded elements first, can be cost-effective. However, increasing the difference in degradation by maintenance or performance control can also lower maintenance-related costs in specific situations, which is discussed in numerical experiments. We also illustrate structural insights regarding the proposed model, including sensitivity analyses of maintenance capacity, setup costs, and the difference between preventive and corrective replacement costs.
Neuroadaptive Dynamic Surface Asymptotic Tracking Control of a VTOL Aircraft with Unknown Dynamics and External Disturbances
Authors: Yang Xianhao , Deng Xiongfeng , Tao Liang , Xu Binzi
Published: June 2023

This work studies the asymptotic tracking control problem of a vertical take-off and landing (VTOL) aircraft with unknown dynamics and external disturbances. The unknown nonlinear dynamics of the VTOL aircraft are approximated via the introduction of radial basis function neural networks. Then, the weight update laws are designed. Furthermore, the parameter update control laws are presented to deal with the errors generated during the approximation process and the external disturbances of the aircraft system. Moreover, first-order filters are introduced to avoid repeated differentiation of the designed virtual control laws, thereby effectively eliminating the “complexity explosion” problem caused by traditional backstepping control. Based on the application of the neural network control method, dynamic surface control technique, weight update laws and parameter update control laws, neuroadaptive dynamic surface control laws for the aircraft system are finally proposed. Theoretical analysis shows that the proposed control law can ensure that the aircraft system asymptotically tracks the reference trajectories and the tracking errors can converge to a small neighborhood of zero by choosing the appropriate designed parameters. Finally, simulation examples are provided to verify the effectiveness of proposed control laws.