bluuebunny/crossref_metadata_2025 huggingface dataset:
Short Landing for Flying-Wing Unmanned Aircraft with Thrust Vector
Authors: Lyu Huitao , Yin Yong , Gong Zheng , Chen Yongliang , Bai Yalei , Liu Xueqiang
Published: March 2023

The task of achieving a safe and short landing for a flying-wing unmanned aircraft with a three-bearing-swivel thrust vector is highly challenging. The process is further complicated due to the need to switch between multiple control modes, while also ensuring the protection of the flight boundaries from environmental disturbances and model uncertainties to ensure flight safety. To address this challenge, this paper proposes a short-landing strategy that employs mixed control using lift fans, thrust vectors, and aerodynamic control surfaces. The extended state observer (ESO) is integrated into the inner angular rate control and outer sink rate control to account for environmental disturbances and model uncertainties. To ensure flight safety, the attainable linear and angular acceleration is calculated through a trim analysis to determine the command value of velocity and angle of attack during a short landing. Additionally, a flight boundary protection method is employed which includes an additional command value of the angle of attack, resulting in a higher probability of a successful landing. This paper provides a detailed description of the short-landing strategy, including the control objectives for each phase. Finally, a Monte Carlo simulation is conducted to evaluate the effectiveness and robustness of the short-landing strategy, and the landing accuracy is assessed using the circular error probability metric.
Analysis and Visualization of Production Bottlenecks as Part of a Digital Twin in Industrial IoT
Authors: Arff Benjamin , Haasis Julian , Thomas Jochen , Bonenberger Christopher , Höpken Wolfram , Stetter Ralf
Published: March 2023

In the area of industrial Internet of Things (IIoT), digital twins (DTs) are a powerful means for process improvement. In this paper the concept of a DT is explained and analysis possibilities throughout the life-cycle of a product and its production system are explored. The main part of this paper is focused on an approach to the analysis of manufacturing layouts and their parameters. The approach, which is based on a state of the art bottleneck detection method, allows an intelligent representation of the temporal process characteristics. The presented method is widely applicable for any type of manufacturing layout and time-span. The use of elementary heuristics leads to traceable results that can be used for further analysis or optimization. The results of this analysis method can be integrated in a DT and combined with machine learning and explainable artificial intelligence (XAI). The concept for a self-learning DT is explained and implementation possibilities are elucidated.
Numerical and Experimental Determination of the Wind Speed Value Causing Catastrophe of the Scissor Lift
Authors: Augustyn Marcin , Barski Marek , Chwał Małgorzata , Stawiarski Adam
Published: March 2023

The current work is devoted to the numerical determination of the wind speed value, which can cause the overturning of the mobile elevating work platform of the scissor lift type. In the first step of the analysis, the scaled model of the real vehicle is prepared. In the second step, the model is used in the aerodynamic tunnel to determine the aerodynamic force values and moment, which act on the vehicle. The three different configurations of the work platform are considered, namely: (a) The work platform raised to the maximum height with an additional bridge extended, (b) the work platform raised to the maximum height, and (c) the work platform half raised. In each position, the direction of the wind is changed from the range from 0° to 180° with an increment equal to 15°. In the next step of the analysis, the CFD simulations are carried out. The ANSYS Fluent R22 software is used. As a model of turbulent airflow, the standard k-ε with standard wall function is adopted. The obtained experimental results are used to verify the numerical model. A very good agreement between the results of the experiment and the results of numerical simulations is obtained. As the main result of the numerical study, the values of the tipping moment and corresponding wind speed that cause the overturning of the analyzed real scissor lift are determined. It occurred that the lowest value of the wind speed is obtained for the first variant of the vehicle configuration V1crt = 22.315 m/s for the angle of the wind speed direction β = 30° and the highest one for the third variant V3crt = 34.534 m/s and β = 15°, without any persons on the work platform. The presence of human beings on the work platform is also considered.
Extraction of Flaw Signals from the Mixed 1-D Signals by Denoising Autoencoder
Authors: Lee Seung-Eun , Park Jinhyun , Kim Hak-Joon , Song Sung-Jin
Published: March 2023

Ultrasonic testing (UT) is one of the most popular non-destructive evaluation (NDE) techniques used in many industries to evaluate structural integrity. The commonly used NDE techniques are basic inspection techniques, such as visual testing (VT), penetration testing (PT), and magnetic testing (MT), and advanced inspection techniques, such as UT, radiography testing (RT), eddy current testing (ECT), and phased array ultrasonic testing (PAUT). Among the numerous advanced techniques, ultrasonic testing (UT) is usually used for the inspection of welds in various industries. However, the application of UT still has some shortcomings to overcome. One major shortcoming that reduces the precision of UT is the extra signals from the geometrical interface of a specimen. UT uses the reflection indications of the ultrasonic beam. However, the reflection signals from the welding interface and geometry along with the target flaw signal produce mixed signals. The inspectors use a 1-D reflection outcome called the ultrasonic A-scan to evaluate the welding integrity. The mixed ultrasonic A-scan signals are often very difficult to analyze because inspectors must distinguish the target flaw signal of welding from the mixed ultrasonic A-scan signal, which includes the flaw indication as well as the background signal. Therefore, a method to distinguish between the flaw signal and the background signal must be developed for the efficiency of UT. Autoencoder is an artificial neural network that is made for feature extraction from the input. Denoising autoencoder (DAE) is one of the derivative models of the autoencoder which adds or eliminates random noise signals to extract the prominent features. DAE is already widely used in the denoising of images and sound data. The characteristics of DAE are used in this research to distinguish the ultrasonic flaw signal from the mixed ultrasonic A-scan signal. For the training, 2463 mixed A-scan signals were obtained from 45 different standard blocks in which 5 different types of flaws were embedded. For testing, we used 1000 mixed A-scan signals. The performance of the network was evaluated using a point-by-point comparison method. The autoencoder was trained to denoise the background signal from the mixed ultrasonic A-scan, and the target flaw signal was extracted from the original A-scan signal.
A Systematic Review on Low-Level Laser Therapy in the Management of Shoulder Impingement Syndrome
Authors: Castaldo Marco , De Angelis D’Ossat Andrea , Gnessi Pablo , Galeoto Giovanni
Published: March 2023

Background: Conservative therapy is currently the elective treatment for shoulder impingement syndrome according to the scientific literature. The success of conservative therapy is due to physiotherapy and the application of its methods. The aim of this systematic review was to evaluate low-level laser therapy, a physiotherapeutic method for pain reduction and increasing the range of motion. Methods: This systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The screening of the literature was carried out on the Cochrane, PEDro, PubMed/Medline, and Scopus databases up until December 2021. All studies were randomized controlled trials (RCTs), and five articles met the inclusion criteria and were included in this study. The risk of bias was evaluated with PEDro and Jadad scales. Results: In this study, we reviewed five RCTs that compared low-level laser therapy with other physiotherapy treatments to reduce pain and improve range of motion in patients with shoulder impingement syndrome. Conclusions: Low-level laser therapy for shoulder impingement syndrome requires further investigation in future studies.
Augmented and Virtual Reality to Enhance the Didactical Experience of Technological Heritage Museums
Authors: Bachiller Carmen , Monzo Jose M. , Rey Beatriz
Published: March 2023

The way that the new generations approach cultural contents changed dramatically. The audiovisual language substituted traditional media. Museums face now an important challenge to survive as cultural referents in this new paradigm: the introduction of new audiovisual languages in their exhibitions and the provision of attractive online content. The work presents a case study of the use of augmented reality and virtual reality (AR/VR) in a technological heritage museum, with a double approach: on the one hand the development of AR to enhance the real visit to the museum; and on the other, the provision of VR to ease online visits to the museum for those that do not want to or cannot visit it. The results show that young visitors massively appreciate the use of these technologies. Using AR contents also contributes to the preservation of the original artifacts without damage. Furthermore, multimedia content provides some contextual information, improving the learning experience. Regarding the VR application, it is thought as a complement to the AR experience. It was developed as a virtual reproduction of the museum visit that can be experienced from any location, thus contributing to a higher diffusion of the museum contents.
Dynamic Behavior of Aluminum Plates Subjected to Sequential Fragment Impact and Blast Loading: An Experimental Study
Authors: Atoui Oussama , Maazoun Azer , Aminou Aldjabar , Belkassem Bachir , Pyl Lincy , Lecompte David
Published: March 2023

This paper presents a study on the dynamic behavior of thin aluminum plates subjected to consecutive fragment impact and blast loading. To this end, two separate experimental setups are used. In the first setup, 2 mm thick aluminum plates EN-AW-1050A-H24 were subjected to the ballistic impact of fragment-simulating projectiles (FSPs). Experiments were carried out for FSP calibers of 7.62 mm and 12.7 mm considering both single impact and triple impacts with variations in the spacing of the impact locations. The out-of-plane displacement and in-plane strain fields were measured using digital image correlation (DIC) coupled to a pair of high-speed cameras in a stereoscopic setup. In the second setup, a subsequent blast loading was applied to the perforated plates using an explosive-driven shock tube (EDST). After the plates are perforated, the strain field around the holes depended on the caliber, the impact orientation of the FSP, and the distance between the impact locations. When the blast loading was applied, cracks tended to appear in areas of strain concentration between the perforated holes. It was found that the relative distance between the holes significantly influences the target’s response mode.
The Effect of Cutting Tool Geometry on Surface Integrity: A Case Study of CBN Tools and the Inner Surface of Bearing Rings
Authors: Cepova Lenka , Cep Robert , Chalko Leszek , Dvorackova Stepanka , Trochta Miroslav , Rucki Miroslaw , Beranek Libor , Mizera Ondrej , Chyshkala Volodymyr
Published: March 2023

In this paper, a practical issue of the application of cubic boron nitride (CBN) cutting tools for the machining of steel 100Cr6 thin-walled bearing rings is addressed. Three geometries of the commercially available CBN cutting inserts were tested at different machining parameters. The effect of geometry was assessed in terms of surface integrity, considering 2D profile parameters, 3D topography of the surface, and residual stresses in the surface layer. The results were sometimes contradictory, since the same cutting inserts provided the largest and the lowest values of the topography parameters, dependent on different cutting conditions. In general, CBN cutting inserts with XCEL geometry ensured the smallest profile parameters Ra and Rz, and the spatial parameters of Smr1 exhibited the largest values among all tested tools, suggesting reduced wear resistance. Residual stresses analysis did not reveal any inacceptable or potentially dangerous surface layer state after machining.
The Effect of a Single Session of Balance and Coordination Training on Cognitive Function in Older Adults
Authors: Dunsky Ayelet , Unger Liat , Carasso Refael , Fox Orly
Published: March 2023

The cognitive decline that is characteristic of older adults has led researchers to seek methods for improving cognitive functions in this population in the short and long term. One broadly studied aspect relates to physical activity interventions and their impact on cognitive functions in older adults. This study examines the effect of a single session of balance and coordination exercises on the cognitive functions in older adults compared to that of a single session of aerobic exercises or a single control session of reading. The study included 30 physically active participants (23 females), with an average age of 73 (±5) years. The participants completed computerized cognitive tests to assess attention and executive functions in five separate sessions: two without interventions and three with interventions (aerobic exercise; balance and coordination and reading while sitting). The interval between each session was at least two weeks. The order of interventions between participants was random. While no differences were seen between the three types of intervention in executive function scores, our findings indicate that a single session of aerobic exercises and a single session of balance and coordination exercises led to higher scores on the attention test than in the control condition. This suggests that older adults may benefit from a single 30-min session of aerobic exercises or balance and coordination exercises prior to performing attention-demanding tasks.
Do the Culturable Microbial Groups Present in Cutaway Bogs Change According to Temporal Variation? Pilot Study Based on the Midlands in the Republic of Ireland
Authors: Atapattu Gouri Nilakshika , Battersby Tara , Giltrap Michelle , Tian Furong
Published: March 2023

Cutaway peatlands in the midlands of the Republic of Ireland are rarely the focus of scientific studies. The soil quality and related microenvironment have been severely impacted by peat extraction. Returning them to a ‘near-natural state’ would require greater insights into this ecological niche. The current research took the initiative to study the microbiology of vast cutaway sites in the midlands of Ireland. Peat was collected over two seasons in January, February and April. Homogenised peat was aseptically cultured on a range of specific and non-specific culture media. Microbial enumeration, Gram staining and other microscopic observations of morphologically distinct microorganisms were performed. The total viable bacterial and fungal numbers were highest in February (1.33 × 105 CFU ml−1 and 5.93 × 106 CFU ml−1, respectively) and were lowest in April (1.14 × 103 CFU ml−1 and 5.57 × 106 CFU ml−1). Penicillium spp. and Trichoderma spp. were common in all the sites. The highest values of phosphate solubilisation index were recorded in peat collected in April (SI = 3.167 & 3.000). Overall, there is a statistically significant difference (p ≤ 0.0001) among the microbial numbers across the three months. This variation could be due to the temperature and pH differences across peat soil.
A Visual–Emotional Analysis of Perception in the Homes of Chronic Patients during Confinement by COVID-19 in Spain
Authors: Navas-Martín Miguel Ángel , Cuerdo-Vilches Teresa
Published: March 2023

One of the highest risk groups the highest during COVID-19 were chronic patients. In addition to being a population at risk, in the lockdown they had to combine the pandemic with their own disease. Through a qualitative study of visual–emotional analysis, the perception of patients and their social environment (immediate support network) about the domestic confinement in Spain was requested during the State of Alarm in the Spring of 2020. For this, 33 participants filled out an online questionnaire with narratives and images describing their experiences. They were asked to share their experiences about quarantine from several perspectives of the housing spaces: the workplace (or alternatively, if they did not work, the most used occupational space), the least pleasant spaces or aspects of the dwelling and the most pleasant or comfortable area. The results suggested the importance for participants of natural and adequate lighting in spaces and tidiness, with both being linked to well-valued spaces. Moreover, rest was the activity most undertaken, for those who did not telework. Likewise, the narratives provided by participants were mostly positive, despite their condition, maybe due to their own coping with the disease. Dwellings were the adaptive means to tackle the situation of physical isolation as a place of protection against an external threat. The living room and bedrooms were chosen as the most prominent places. The characteristics of the dwellings conditioned the experiences lived during the quarantine of chronic patients.
Becoming (Un)Masked: Semiotics of Identification in Nick Cave’s Hy-Dyve
Authors: Albu Cristina
Published: March 2023

Displayed in a Kansas City neighborhood with a history of blockbusting, Nick Cave’s 14-channel video installation Hy-Dyve confronted viewers with a visceral sense of entrapment in traumatizing spaces of racism. The immersive environment portrayed deeply moving experiences of confinement and concealment, connecting narratives of the Middle Passage to present fears of racial profiling. Shown at different scales on the dilapidated walls of a deconsecrated church, the video images enabled visitors to sense what it feels like to be exposed to a scrutinizing and categorizing gaze. Building on Gilles Deleuze’s theory of close-up operations, I explore how Cave both showcases and subverts the visual rhetoric of surveillance, inviting viewers to suspend processes of individuation and embrace alterity. I offer a semiotic analysis of the visual motifs in Hy-Dyve and show how their unstable meanings heighten the potential for immersion in conjunction with the projection mapping technique. The entanglement of video images with crumbling architectural features destabilizes perception and fosters reflection on the imbrication of past and present realities of racial discrimination. Placing Hy-Dyve in the broader context of Cave’s body of work, I suggest that it conjoins two different sides of his practice: a post-black approach to issues of identity which is consonant with his Soundsuits and a more radical activist stance which addresses the particularities of black experience and the burdening history of racial abuse.
Effects of Wave-Mean Flow Interaction on the Multi-Time-Scale Variability of the AO Indices: A Case Study of Winters 2007/08 and 2009/10
Authors: Liang Sujie , Liu Yanju , Ding Yihui
Published: March 2023

Wave-mean flow interaction is usually regarded as accounting for the origin of the Arctic Oscillation/Northern Hemisphere Annular Mode (AO/NAM). It is inferred that the combination of the local wave-mean flow interactions at the AO/NAM’s three regional centers of action on three important time scales contributes to the main behavior of the AO/NAM index. To discuss the variations of the AO/NAM indices on the three prominent time scales, we take the 2007/08 and 2009/10 winters as two comparative examples to analyze the local wave-mean flow interactions at the AO/NAM’s three centers. The following three facets are identified: (1) Synoptic-scale wave breakings in the North Atlantic can explain the variances of the AO/NAM index on a time scale of 10–20 days. In the 2007/08 winter, there were both cyclonic and anticyclonic synoptic wave breakings, while in the 2009/10 winter, cyclonic synoptic wave breaking was dominant, and the flow characteristics were strikingly similar to the blocking. (2) In the 2007/08 and 2009/10 winters, the signals of the AO/NAM indices on the time scale of 30–60 days are mainly from the interactions between the upward propagating quasi-stationary waves and the polar vortex in the stratosphere. (3) This work also demonstrates that the AO/NAM is linked to the El Niño–Southern Oscillation (ENSO) by the Pacific–North American pattern (PNA) on the winter mean time scale. In the 2007/08 (2009/10) winter, La Niña (El Niño) forced the Pacific jet to shift poleward (equatorward), in favor of weakening (enhancing) the polar waveguide; thus, the polar vortex became stronger (weaker), corresponding to the positive (negative) winter mean AO/NAM index.
Separation of Ambient Radio Noise and Radio Signals Received via Ionospheric Propagation
Authors: Witvliet Ben A. , Alsina-Pagès Rosa M. , Altadill David , van Maanen Erik , Laanstra Geert Jan
Published: March 2023

Systems for atmospheric research and wireless communication use the High Frequency (HF) radio spectrum. At these frequencies, typically up to 20 MHz, the ambient electromagnetic noise is stronger than the noise generated by the receiver itself, thereby limiting the sensitivity of the instruments. Especially in urban areas, the noise level is high. In remote rural environments, where artificial noise sources are absent, a much lower noise level is observed. It has been shown that this noise arrives via ionospheric propagation and consists of impulsive noise from lightning and a background component that resembles additive white Gaussian noise. To establish the absolute field strength of this background noise component, a direction- and polarization-agnostic antenna is realized by adding the power of two orthogonal antenna elements in the digital domain. To suppress radio signals arriving via ionospheric propagation—of which the spectral and temporal aspects are not known a priori—a novel adaptive filter is demonstrated that separates the background noise from the radio signals in the joint frequency-time domain. This method is demonstrated using measurements from a polarimetric experiment on 7 MHz in a remote rural area in Catalonia. The results are submitted to the International Telecommunication Union for the validation of ambient noise models.
Identification and Characteristics of Historical Extreme High-Temperature Events over the China–Pakistan Economic Corridor
Authors: Li Tao , Bao Anming
Published: March 2023

Recently, there has been an increase in the occurrence of extreme high-temperature events across the China–Pakistan Economic Corridor (CPEC). Regional spatiotemporal identification and evaluation of extreme high temperatures are essential for accurate forecasting of future climate changes. When such events generate a meteorological hazard, it is important to understand their temporal and spatial features, return period, and identification criteria. Accurately identifying extreme events can help assess risk and predict their spatial–temporal variation. While past studies have focused on individual sites, extreme heat events generally manifest as spatially and temporally continuous regional events. In this study, we propose an objective identification technique based on gridded data and spatiotemporal continuity to reveal the spatiotemporal characteristics of intensity, frequency, and duration events of extreme heat events in the CPEC from May to October between 1961 and 2015. Furthermore, we estimate the return period of extreme heat in the study region using the generalized Pareto distribution (GPD). Our findings indicate that the historical extreme temperature events (intensity, frequency, and duration) in the CPEC have significantly increased. Areas with a high incidence of extreme heat events are concentrated in eastern Balochistan, northern Sindh, and southeastern Punjab. These findings suggest that disaster prevention and mitigation plans should be targeted towards areas with a high frequency of extreme heat events in the CPEC, allowing policy makers to better prepare for and respond to future events.
Spatiotemporal Analysis of Extreme Rainfall Frequency in the Northeast Region of Brazil
Authors: Morales Fidel Ernesto Castro , Rodrigues Daniele Torres , Marques Thiago Valentim , Amorim Ana Cleide Bezerra , Oliveira Priscilla Teles de , Silva Claudio Moises Santos e , Gonçalves Weber Andrade , Lucio Paulo Sergio
Published: March 2023

Climate extreme events are becoming increasingly frequent worldwide, causing floods, drought, forest fires, landslides and heat or cold waves. Several studies have been developed on the assessment of trends in the occurrence of extreme events. However, most of these studies used traditional models, such as Poisson or negative binomial models. Thus, the main objective of this study is to use a space–time data counting approach in the modeling of the number of days with extreme precipitation as an alternative to the commonly used statistical methods. The study area is the Northeast Brazil region, and the analysis was carried out for the period between 1 January 1980 and 31 December 2010, by assessing the frequency of extreme precipitation represented by the R10 mm, R20 mm and R* indices.
Surface Wave Mixing Modifies Projections of 21st Century Ocean Heat Uptake
Authors: Kousal Joshua , Walsh Kevin J. E. , Song Zhenya , Liu Qingxiang , Qiao Fangli , Babanin Alexander V.
Published: March 2023

Climate models do not explicitly account for the smaller scale processes of ocean surface waves. However, many large-scale phenomena are essentially coupled with the waves. In particular, waves enhance mixing in the upper ocean and thereby accelerate the ocean response to atmospheric changes. Here, we introduced a representation of wave-induced turbulent mixing into the one-way coupled ACCESS-OM2-025 ocean model to study its effect on ocean heat content throughout the 21st century under the RCP4.5 scenario. We made two projections on ocean heat uptake for the end of the century: one which accounts for wave-induced mixing (the ‘modified’ projection) and the other which does not (the ‘standard’ projection). Both projections showed upper ocean heat content to increase by more than 2.2 × 1022 J. This projected ocean heat uptake was reduced by about 3% in the modified projection. Whilst the inclusion of wave-induced mixing reduces projected ocean heat uptake globally, some areas are expected to warm considerably faster, particularly the North Atlantic sub-tropics, the Tasman Sea, the Sea of Japan, and parts of the South Atlantic.
Solid Electrolytes in the N-Propyl-N-methyl-pyrrolidinium Tetrafluoroborate—Lithium Tetrafluoroborate System
Authors: Ulihin Artem , Novozhilov Dmitry , Uvarov Nikolai
Published: March 2023

Solid electrolytes prepared by the addition of LiBF4 to the plastic phase of [N13pyr]BF4 were prepared, and their physical and electrical properties were investigated. The electrolytes [N13pyr]BF4-LiBF4 containing 8–20 wt% LiBF4 are solid at temperatures below 80 °C and have a high ionic conductivity ~10−3–10−2 S cm−1 at 60 °C. Based on the results of DSC and conductivity studies, the phase diagram of the [N13pyr]BF4-LiBF4 binary system was plotted, and the formation of a new compound, 3[N13pyr]BF4·2LiBF4 was proposed. The existence of the new phase was supported by X-ray diffraction data. Electrochemical measurements of cells with lithium electrodes were carried out to test the applicability of these materials in lithium batteries. The electrochemical window was determined to be more than 5 V. In contrast to earlier data obtained for similar systems, the preconditioning effect was not observed. Nevertheless, the solid electrolyte [N13pyr]BF4-LiBF4 system has high ionic conductivity and may be used in solid-state lithium-ion batteries.
The Role of the Precursor on the Electrochemical Performance of N,S Co-Doped Graphene Electrodes in Aqueous Electrolytes
Authors: Braga Rodrigo , Fernandes Diana M. , Adán-Más Alberto , Silva Teresa M. , Montemor M. F.
Published: March 2023

The introduction of pillared agents or dopants to the graphene used as the electroactive material in supercapacitor electrodes can be an efficient way to facilitate ion transfer, mitigate re-stacking, and improve electrochemical performance. We evaluated the effect of different precursors containing nitrogen (N) and sulfur (S) atoms to dope graphene flake (GF) lattices. The electrochemical performance of the doped GF was assessed in 1 M KOH and 1 M Na2SO4 electrolytes. N- and S-doped GF flakes were synthesized via mechanochemical synthesis, also known as ball milling. After being ground, the materials were calcined under N2. The physicochemical characterization of the materials evidenced the co-doping of both S and N into the graphene backbone, as corroborated by the results of Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). As shown by the results, the nature of the precursors influences the ratio of S and N in the doped graphene flakes and, consequently, the response of the electroactive electrode material. The co-doping obtained using 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole revealed a specific capacitance of 48 F.g−1 at 1.0 A∙g−1 and over 90% capacitance retention after 10,000 cycles at 10.0 A∙g−1 in Na2SO4.
Stimulation of Nuclear Factor (Erythroid-Derived 2)-like 2 Signaling by Nucleus Targeted Irradiation with Proton Microbeam
Authors: Wang Jun , Oikawa Masakazu , Konishi Teruaki
Published: March 2023

Nuclear factor (erythroid-derived 2)-like 2 (NRF2), well-known as a master antioxidative response regulator in mammalian cells, is considered as a potential target for radiation protection and cancer therapy sensitization. We examined the response of NRF2 signaling in normal human lung fibroblast WI-38 cells to nucleus targeted irradiation by 3.4 MeV proton microbeam. Nucleus targeted irradiation stimulated the nucleus accumulation of NRF2 and the expression of its target gene, heme oxygenase 1 (HO-1). The nucleus accumulation of NRF2 increased from 3 h to 12 h post 500 proton irradiation. In the 500 protons range, higher number of protons resulted in increased NRF2 nucleus accumulation. Activating NRF2 with tert-butylhydroquinone reduced DNA double-strand break (DSB) formation in nucleus targeted irradiation by 15%. Moreover, ATM phosphorylation was found in nucleus targeted irradiation. Inhibiting ATM with ku55933 prevented NRF2 nucleus accumulation. Furthermore, nucleus targeted irradiation activated ERK 1/2, and ROS-ERK 1/2 signaling regulated NRF2 nucleus accumulation. Taken together, NRF2 signaling was activated by nucleus targeted irradiation and mitigated DNA DSB. The discovery of ATM and ERK 1/2 as upstream regulators of NRF2 signaling in nucleus targeted cells revealed new information regarding radiation protection.
Physiologic Response Evaluation of Human Foetal Osteoblast Cells within Engineered 3D-Printed Polylactic Acid Scaffolds
Authors: Rizzo Maria Giovanna , Palermo Nicoletta , Alibrandi Paola , Sciuto Emanuele Luigi , Del Gaudio Costantino , Filardi Vincenzo , Fazio Barbara , Caccamo Antonella , Oddo Salvatore , Calabrese Giovanna , Conoci Sabrina
Published: March 2023

Large bone defect treatments have always been one of the important challenges in clinical practice and created a huge demand for more efficacious regenerative approaches. The bone tissue engineering (BTE) approach offered a new alternative to conventional bone grafts, addressing all clinical needs. Over the past years, BTE research is focused on the study and realisation of new biomaterials, including 3D-printed supports to improve mechanical, structural and biological properties. Among these, polylactic acid (PLA) scaffolds have been considered the most promising biomaterials due to their good biocompatibility, non-toxic biodegradability and bioresorbability. In this work, we evaluated the physiological response of human foetal osteoblast cells (hFOB), in terms of cell proliferation and osteogenic differentiation, within oxygen plasma treated 3D-printed PLA scaffolds, obtained by fused deposition modelling (FDM). A mechanical simulation to predict their behaviour to traction, flexural or torque solicitations was performed. We found that: 1. hFOB cells adhere and grow on scaffold surfaces; 2. hFOB grown on oxygen plasma treated PLA scaffolds (PLA_PT) show an improvement of cell adhesion and proliferation, compared to not-plasma treated scaffolds (PLA_NT); 3. Over time, hFOB penetrate along strands, differentiate, and form a fibrous matrix, tissue-like; 4. 3D-printed PLA scaffolds have good mechanical behaviour in each analysed configuration. These findings suggest that 3D-printed PLA scaffolds could represent promising biomaterials for medical implantable devices in the orthopaedic field.
How Do Motor and Sensory Function Correlate with Daily Performance Recovery after Post-Stroke Robotic Intervention? A Secondary Analysis of a Non-Randomized Controlled Trial
Authors: Rodríguez-Pérez Mª Pilar , Sánchez-Herrera-Baeza Patricia , Montes-Montes Rebeca , Cano-de-la-Cuerda Roberto , Martínez-Piédrola Rosa M. , Serrada-Tejeda Sergio , Obeso-Benítez Paula , Pérez-de-Heredia-Torres Marta
Published: March 2023

New technologies have been developed to complement conventional interventions to better target the specific needs of people with stroke, and they have been shown to improve both function and performance. However, it is unknown whether the baseline levels of sensorimotor function and performance interrelate with the improvement in upper limb and daily performance. Thus, the aim of this study was to examine the relationship between baseline levels of sensorimotor function and daily performance and its impact on post-intervention improvement in people with stroke following a robotic intervention. A single-blind, non-randomized, controlled clinical trial was conducted. Participants in the experimental group (n = 9) received a robotic intervention in addition to conventional treatment. Sensorimotor function was measured with Semmes-Weinstein Monofilaments® and the Fugl-Meyer Assessment Upper Extremity Scale. Upper limb and daily performance were measured with the MAL and SIS-16 scales. The multivariate regression models showed that baseline levels of upper limb performance and motor function predicted >95% of the variance in upper limb performance (p < 0.001), while pre-intervention levels of daily performance explained >75% of the post-intervention variance (p < 0.05). These findings indicate that basal upper limb motor function is associated with improved performance following a combined intervention of conventional treatment and robotic intervention.
Bag-1 Protects Nucleus Pulposus Cells from Oxidative Stress by Interacting with HSP70
Authors: Suyama Kaori , Sakai Daisuke , Hayashi Shogo , Qu Ning , Terayama Hayato , Kiyoshima Daisuke , Nagahori Kenta , Watanabe Masahiko
Published: March 2023

Bcl-2-associated athanogene 1 (Bag-1) is a multifunctional prosurvival protein that binds to several intracellular targets and promotes cell survival. HSP70 and Raf-1 are important targets of Bag-1; however, the protective function of Bag-1 in nucleus pulposus (NP) cells remains unclear. In this study, we determined the effects of Bag-1 on NP cells under oxidative stress induced by treatment with hydrogen peroxide (H2O2). We found that Bag-1 was bound to HSP70, but Bag-1–Raf1 binding did not occur in NP cells. Bag-1 overexpression in NP cells enhanced cell viability and mitochondrial function and significantly suppressed p38/MAPKs phosphorylation during oxidative stress, although NP cells treated with a Bag-1 C-terminal inhibitor, which is the binding site of HSP70 and Raf-1, decreased cell viability and mitochondrial function during oxidative stress. Furthermore, the phosphorylation of the ERK/MAPKs was significantly increased in Bag-1 C-terminal inhibitor-treated NP cells without H2O2 treatment but did not change with H2O2 exposure. The phosphorylation of Raf-1 was not influenced by Bag-1 overexpression or Bag-1 C-terminal binding site inhibition. Overall, the results suggest that Bag-1 preferentially interacts with HSP70, rather than Raf-1, to protect NP cells against oxidative stress.
Chronic Treatment with Somatostatin Analogues in Recurrent Type 1 Gastric Neuroendocrine Tumors
Authors: Sebastian-Valles Fernando , Bernaldo Madrid Blanca , Sager Carolina , Carrillo López Elena , Mera Carreiro Sara , Ávila Antón Laura , García Noelia Sánchez-Maroto , Sampedro-Nuñez Miguel Antonio , Díaz Pérez Jose Ángel , Marazuela Mónica
Published: March 2023

Background: Type 1 gastric neuroendocrine tumors (GC-1) represent an uncommon subtype of neoplasms. Endoscopic resection has been proposed as the treatment of choice; active surveillance may be performed in those smaller than 1 cm, while gastric surgery may be performed for those with frequent recurrences. The antiproliferative effect of somatostatin analogues (SSA) is well known, and their action on GC-1s has been postulated as a chronic treatment to reduce recurrence. Methods: A two-centered, retrospective, observational study that included nine patients (55.6% women) diagnosed with GC-1, receiving long-term treatment with SSA, with a median follow-up from baseline of 22 months, was undertaken. Endoscopic follow-up, extension study, and analytical values of chromogranin A (Cg A) and gastrin were collected. Results: In total, 88.9% of patients presented partial or complete response. Treatment with SSA was the only independent factor with a trend to prevent tumor recurrence (Odds Ratio 0.054; p = 0.005). A nonsignificant tendency toward a decrease in CgA and gastrin was observed; lack of significance was probably related to concomitant treatment with proton pump inhibitors in some patients. Conclusions: Chronic treatment with SSA is a feasible option for recurrent GC-1s that are difficult to manage using endoscopy or gastrectomy. Randomized clinical trials to provide more scientific evidence are still needed.
Association between Systemic Immune Inflammation Index and Cognitive Impairment after Acute Ischemic Stroke
Authors: Bao Yuanfei , Wang Lingling , Du Chaopin , Ji Yan , Dai Yiwei , Jiang Wei
Published: March 2023

Background and Aims: Post-stroke cognitive impairment (PSCI) is one of the major complications after ischemic stroke. PSCI has been shown to be associated with low-grade systemic inflammation. As a novel inflammatory marker, the systemic immune-inflammation (SII) index could reflect clinical outcomes in severe cardiovascular diseases. We therefore performed a prospective study to investigate the correlation between the SII index and the risk of PSCI in patients with ischemic stroke. Methods: We prospectively enrolled 254 patients with ischemic stroke with symptoms onset <72 h. The SII index was detected within 24 h after admission. The Montreal Cognitive Scale (MoCA) was utilized to evaluate cognitive function, and PSCI was defined as a MoCA score of <25 points. Results: During the 3-month follow-up, 70 participants (27.6%) had mild cognitive impairment and 60 (23.6%) had severe cognitive impairment. In binary logistic regression analysis, each one-standard deviation increase in the SII index was significantly associated with the prevalence of PSCI after adjusting for age, sex, and other confounders (odds ratio 2.341; 95% confidence interval, 1.439–3.809, p = 0.001). Similar significant findings were observed when SII was defined as a categorical variable. In addition, the multiple-adjusted spline regression model showed a linear association between the SII index and cognitive impairment (p = 0.003 for linearity). Conclusions: Our study indicated that an increased SII index was closely related to PSCI at 3 months in patients with ischemic stroke. Further research is required to evaluate the efficacy of inflammation management in these patients.
Application of Immersive Virtual Reality for Assessment and Intervention in Psychosis: A Systematic Review
Authors: Chan Karen Chui-Shan , Hui Christy Lai-Ming , Suen Yi-Nam , Lee Edwin Ho-Ming , Chang Wing-Chung , Chan Sherry Kit-Wa , Chen Eric Yu-Hai
Published: March 2023

Virtual reality (VR) has emerged as a safe and non-invasive technology for the assessment of psychotic symptoms, social and cognitive impairments, and psychosocial intervention in improving outcomes in psychosis. This study systematically reviewed the current state of evidence in applying semi- and fully immersive VR for assessing and treating patients with psychosis. A systematic review was conducted adhering to the PRISMA statement and was conducted in Embase, PsycINFO, and PubMed databases for articles published between January 2013 and April 2022, which identified 28 eligible studies, including 12 for assessment and 16 for intervention. In the assessment studies, not all VR tasks could distinguish the differences between patients and healthy controls regarding their physiological responses, paranoid ideation, and certain aspects of cognitive functioning such as memory bias on the object tasks. Comparatively, VR-based interventions are more promising, especially for improving cognitive impairments, social skills, agoraphobic avoidance, negative and positive affective states, auditory verbal hallucination, paranoid ideation and persecutory delusions, and other psychiatric symptoms in patients. We conclude that more rigorous studies are needed to confirm treatment effectiveness and to understand the underlying mechanism of VR-based intervention for psychotic disorders. Future studies should also improve the reliability and validity of VR-based assessments for psychotic disorders.
The Factors Influencing Users’ Trust in and Loyalty to Consumer-to-Consumer Secondhand Marketplace Platform
Authors: Jang Yumi , Kim Seongcheol
Published: March 2023

This study investigates the factors influencing users’ trust in and loyalty to Karrot, a Korean consumer-to-consumer secondhand marketplace platform. This research develops a model with key variables based on the dual model of post-adoption phenomena and adds variables reflecting the specific context of Karrot. An online survey of 305 Karrot users was conducted in South Korea during 19–23 May 2022; the data obtained were analyzed by SEM. The results reveal that two types of trust—trust in Karrot and mutual trust among Karrot users—are direct antecedents of loyalty. Mutual trust among Karrot users is an essential predictor of trust in Karrot. Economic benefits and perceived platform functionality are positively associated with trust in Karrot. Psychological ownership and information interactions were shown to be the important determinants of mutual trust among Karrot users. This study contributes to extending the horizons of post-adoption research by understanding users’ affective and practical motivations for trust and loyalty and by confirming the significant role of two types of trust in forming loyalty. Moreover, this study also provides implications for practitioners of C2C secondhand market platforms to develop their management strategies and expand their customer base.
Proof of Concept and Preliminary Validation of an Analytical Model of an Energy Dissipator for Tension Loads with Self-Centering Capacity
Authors: Maureira-Carsalade Nelson , Balboa-Constanzo Esteban , Sanhueza-Cartes Marcelo , Sanhueza Claudio , Núñez Eduardo , Roco-Videla Ángel
Published: March 2023

A novel energy dissipation device is proposed to protect structures against dynamic loads. A conceptual model of the device is presented, describing the fundamental components of its operation. This model has a linear elastic element and a frictional damper. The equilibrium equations that lead to the relationship that governs its behavior are proposed. A functional model of the device was built on a 3D printer with PLA filament. Experimental trials were carried out to characterize its elastic component and the coefficient of friction of the damping parts. Proofs of concept load-unload tests were also carried out on the device, subjecting it to cyclical movement sequences. The results of the first two types of tests allowed the parameters of the previously developed analytical model to be calibrated. The results of the load-unload tests were compared with the predictions of the analytical model using the calibrated parameters. Consistency was observed between the experimental and analytical results, demonstrating the basic attributes of the device: self-centering capacity, dissipation capacity and force proportional to the displacement demand. It is concluded that the proposed device has the potential to be used effectively in the protection of structures under dynamic loads.
Experimental Study of Envelope Airtightness in New Egyptian Residential Dwellings
Authors: Raafat Rana , Marey Ahmed , Goubran Sherif
Published: March 2023

In residential buildings, air infiltration impacts energy, indoor air quality, and thermal comfort considerably. While air infiltration in residential buildings has been the focus of many studies, most published field-testing results pertain to developed countries, with little or no data on air infiltration in developing nations. This paper presents the results of one of the first field investigations into envelope infiltration in the residential buildings of the hot-arid climatic area of Egypt. To analyze the air permeability of the building envelope, the fan pressurization method, often known as the blower door test (BDT), is used, following ISO 9772. The study focuses on 20 residential dwellings built with heavy construction materials and subjects them to extensive characterization and testing. The average air leakage and the air permeability rate for the tested sample were 6.14 h−1 and 17.3 m3/(h∙m2), respectively. However, significant variations in airtightness were observed across the dwelling, leading the team to test several building-related parameters statistically to study their impact on airtightness. Fenestration quality appeared to be a critical factor in determining air infiltration, showing a strong correlation with the air change and leakage. A further investigation underscored that the specific aperture factor and the fenestration quality can predict the infiltration rates to a large degree. Thus, we recommend further investigation of these characteristics in heavy construction material building. Finally, we strongly recommend that building codes in developing countries such as Egypt include minimum performance requirements for fenestration.