Search Results (17)

Better mechanistic understanding of desmosome disruption and acantholysis in Grover’s disease (GD) may improve management of this disease. Recent molecular studies highlighted promising pathways to be explored by directly comparing GD and selected features of associated skin diseases. The association between GD and cutaneous keratinocyte carcinomas, the most prevalent non-melanoma skin cancers (NMSC), is not completely characterized. To review the medical literature regarding GD-associated cutaneous keratinocyte cancers, focusing on molecular features, pathophysiological mechanisms, and disease associations, to help guide future research and patient management. GD has been associated with a variety of skin conditions, but its association with skin cancers has been rarely reported. Between 1983 and 2024, only nine scientific papers presented data supporting this association. Interestingly, we found that GD may mimic multiple NMSCs, as few authors reported GD cases misdiagnosed as multiple cutaneous squamous cell carcinomas for more than 4 years or the presence of superficial basal cell carcinoma-like areas associated with focal acantholysis. In conclusion: (a) GD may be an imitator of multiple NMSCs, and (b) the relationship between GD and NMSCs may reveal promising pathways for the mechanistic understanding of desmosome disruption and acantholysis in GD and may even lead to its reclassification as a distinctive syndrome. Full article

The additive processes used in the manufacture of components for unmanned aerial vehicles (UAVs), from composite filaments, have an important advantage compared to classical technologies. This study focused on three-dimensional design, preliminary aerodynamic analysis, fabrication and assembly of thermoplastic extruded composite components, flight testing and search-rescue performance of an UAV. The UAV model was designed to have the highest possible structural strength (the fuselage has a structure with stiffening frames and the wing is a tri-spar), but also taking into account the limitations of the thermoplastic extrusion process. From the preliminary aerodynamic analysis of the UAV model, it was found that the maximum lift coefficient of 1.2 and the maximum drag coefficient of 0.06 were obtained at the angle of attack of 12°. After conducting flight tests, it can be stated that the UAV model, with components manufactured by the thermoplastic extrusion process, presented high stability and maneuverability, a wide range of speeds and good aerodynamic characteristics. The lack of this type of aircraft, equipped with electric motors, a traffic management system, and a thermal module designed for search-and-rescue missions, within the additive manufacturing UAV market, validates the uniqueness of the innovation of the UAV model presented in the current paper. Full article

The aim of the research was to identify the effect of 4vs.4 small-sided games (SSGs) with goalkeepers (4vs.4+GK), applied twice a week, for 8 weeks, on U18 football players’ physical ability, compared to that of the athletes who performed specific aerobic endurance training. The research included 40 football players U18, divided into two groups: 20 in the experiment group (EG) aged 17.49 ± 0.61 years and 20 in the control group (CG) aged 17.66 ± 0.54 years. From the initial test (IT) to final tests (FT) performed on the parameters, maximum oxygen consumption (VO_2max) and 10 m and 20 m sprint and agility with and without a ball showed a significant increase for both groups. The first and last SSG training was monitored, using total distance (TD), high-intensity distance (HSR—high-speed running) and maximum intensity distance (VHSR—very-high-speed running). Comparative analyses of EG and CG parameters at the FT shows that the differences between the means of two groups are statistically significant in favor of the experimental group in terms of all parameters, except 10 m sprint (p < 0.05). Referring to SSGs, the experimental group had a 7.78% increase rate in TD (p < 0.0005), a 30.90% (p < 0.0005) increase rate with HSR and no significant differences (p > 0.05) with VHSR. The experimental training program of 4vs.4+GK SSGs, applied to U18 football players, produced significant progress in the physical, and functional parameters. Full article

This article investigates the perspectives of Romanian academics on implementing Artificial Intelligence (AI) in Higher Education (HE). The article analyzes the pros and cons of AI in HE, based on the views of eighteen academics from five Romanian universities. There is a large and heated debate about the proliferation of AI in many domains, with strong supporters and determined deniers. Studies that research the implications of AI enrich the evidence-based literature on the advantages, disadvantages, threats, or opportunities that AI creates for us, for businesses, or for societies. Though many aspects are still less well known, attitudes toward AI are still under construction. HE is a domain where the implications of AI create passionate discussions. HE is, eventually, the sector that shapes the masterminds of societies’ leaders. There is a quest to find the perspectives of those who will apply AI, who will work with or for AI, and those who are opposed to or in favor of implementing AI in HE. The conclusions revealed by this study are in line with similar studies that exist in the literature. The positive aspects of AI implementation in HE are related, in the view of academics, to gains in the learning–teaching process, improvements in students skills and competences, better inclusion, and greater efficiency in administrative costs. Similarly, the negative aspects revealed by the research are linked to psychosocial effects, data security, ethical aspects, and unemployment threats. However, there are some aspects (mostly negative) related to implementing AI in HE that are less exposed by the interviewed academics, which are mostly related to the costs and efforts of implementing AI in HE. The possible explanation of this situation is related to the lack of strategic vision on what, in fact, the implementation of AI in HE means, what this process involves, and the fact that digitalization in Romanian universities (as well as in the Romanian economy) is in its infancy. The contribution of the results of this research is mainly empirical and practical. These opinions should be used as resources for managers of HE institutions to develop better policies concerning the implementation of AI in HE and for strategic vision toward AI, with the ultimate purpose of achieving progress and prosperity for the entire society. Full article

Metallic additive manufacturing technology is seeing increasing use from aviation companies manufacturing prototypes or components with complex geometric shapes, which are then tested and put into operation. This paper presents the design, fabrication via a selective laser sintering process, and testing of the mechanical performance by performing three-point bending and tensile tests on A6 steel specimens. After performing the mechanical tests on specimens made from A6 steel manufactured via the SLS process, the following performances were obtained: the maximum three-point bending strength was 983.6 MPa and the maximum tensile strength was 398.6 MPa. In the microscopic analysis of the specimens manufactured by the selective laser sintering process, a homogeneous structure with defects specific to additive processes (voids) was revealed. Additionally, the feasibility of designing, manufacturing through the selective laser sintering process and subsequent testing of some components (rotor, right case, left case and motor mount) from a brushless motor made from A6 steel material was demonstrated. After testing the brushless motor, the main performances showed stable behavior of the motor and a linear dependence with the increase in electronic speed control signal or motor electrical speed, resulting in a maximum thrust force of 4.68 kgf at 7800 RPM. Full article

Fused Filament Fabrication (FFF) is one of the frequently used material extrusion (MEX) additive manufacturing processes due to its ability to manufacture functional components with complex geometry, but their properties depend on the process parameters. This paper focuses on studying the effects of process parameters, namely infill density (25%, 50%, 75%, and 100%), on the mechanical and thermal response of the samples made of poly(lactic acid) (PLA) reinforced with short glass fibers (GF) produced using FFF process. To perform a comprehensive analysis, tensile, flexural, compression, differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA) tests were used. The paper also aims to manufacture by FFF process of composite structures of the fuselage section type, as structural elements of an unmanned aerial vehicle (UAV), and their testing to compression loads. The results showed that the tensile, flexural and compression strength of the additive manufactured (AMed) samples increased with the increase of infill density and therefore, the samples with 100% infill density provides the highest mechanical characteristics. The AMed samples with 50% and 75% infill density exhibited a higher toughness than samples with 100% infill. DSC analyses revealed that the glass transition (Tg), and melting (Tm) temperature increases slightly as the infill density increases. Thermogravimetric analyses (TGA) show that PLA-GF filament loses its thermal stability at a temperature of about 311 °C and the increase in fill density leads to a slight increase in thermal stability and the complete degradation temperature of the AMed material. The compression tests of the fuselage sections manufactured by FFF made of PLA-GF composite showed that their stiffening with stringers oriented at an angle of ±45° ensures a higher compression strength than the stiffening with longitudinal stringers. Full article

This study concerns the use of the fused filament fabrication technique to create models of the landing gear of an unmanned aircraft. These components are made of filament with short fibers (chopped fibers) of carbon fiber and fiberglass. In order to identify the material with the high mechanical strength, the designed models were subjected to a finite element analysis and to a three-point bending test, followed by a microscopic examination of the tested components. Following a comparative study, both the finite element analysis results and the three-point bending test results provided similar results, with a relative error of 2%, which is acceptable in the aviation field. After analyzing all the results, it was found that the carbon fiber-reinforced polymer material has the highest mechanical performance, with a bending strength of 1455 MPa. Among the fused filament fabricated landing gears, the one with the best mechanical performance was polyethylene terephthalate with short carbon fiber, which had a bending strength of 118 MPa. Microscopic analysis of the landing gear models, manufactured by the fused filament fabrication process, indicated the typical defects of composite filaments: voids and interlayer voids. Full article

Additive manufacturing, through the process of thermoplastic extrusion of filament, allows the manufacture of complex composite sandwich structures in a short time with low costs. This paper presents the design and fabrication by Fused Filament Fabrication (FFF) of composite sandwich structures with short fibers, having three core types C, Z, and H, followed by mechanical performance testing of the structures for compression and bending in three points. Flatwise compression tests and three-point bending have clearly indicated the superior performance of H-core sandwich structures due to dense core structures. The main modes of failure of composite sandwich structures were analyzed microscopically, highlighting core shear buckling in compression tests and face indentation in three-point bending tests. The strength–mass ratio allowed the identification of the structures with the best performances considering the desire to reduce the mass, so: the H-core sandwich structures showed the best results in compression tests and the C-core sandwich structures in three-point bending tests. The feasibility of the FFF process and the three-point bending test of composite wing sections, which will be used on an unmanned aircraft, have also been demonstrated. The finite element analysis showed the distribution of equivalent stresses and reaction forces for the composite wing sections tested for bending, proving to validate the experimental results. Full article

In three-dimensional (3D) printing, one of the main parameters influencing the properties of 3D-printed materials is the infill density (ID). This paper presents the influence of ID on the microstructure, mechanical, and thermal properties of carbon fiber-reinforced composites, commercially available, manufactured by the Fused Filament Fabrication (FFF) process. The samples were manufactured using FFF by varying the infill density (25%, 50%, 75%, and 100%) and were subjected to tensile tests, three-point bending, and thermal analyses by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). It was shown that the samples with 100% ID had the highest values of both tensile, 90.8 MPa, and flexural strengths, 114 MPa, while those with 25% ID had the lowest values of 56.4 MPa and 62.2 MPa, respectively. For samples with infill densities of 25% and 50%, the differences between the maximum tensile and flexural strengths were small; therefore, if the operating conditions of the components allow, a 25% infill density could be used instead of 50%. After DSC analysis, it was found that the variation in the ID percentage determined the change in the glass transition temperature from 49.6 °C, for the samples with 25% ID, to 32.9 °C, for those with 100% ID. TGA results showed that the samples with IDs of 75% and 100% recorded lower temperatures of onset degradation (approximately 344.75 °C) than those with infill densities of 25% and 50% (348.5 °C, and 349.6 °C, respectively). Full article

Organ-on-chips (OOCs) are microfluidic devices used for creating physiological organ biomimetic systems. OOC technology brings numerous advantages in the current landscape of preclinical models, capable of recapitulating the multicellular assemblage, tissue–tissue interaction, and replicating numerous human pathologies. Moreover, in cancer research, OOCs emulate the 3D hierarchical complexity of in vivo tumors and mimic the tumor microenvironment, being a practical cost-efficient solution for tumor-growth investigation and anticancer drug screening. OOCs are compact and easy-to-use microphysiological functional units that recapitulate the native function and the mechanical strain that the cells experience in the human bodies, allowing the development of a wide range of applications such as disease modeling or even the development of diagnostic devices. In this context, the current work aims to review the scientific literature in the field of microfluidic devices designed for urology applications in terms of OOC fabrication (principles of manufacture and materials used), development of kidney-on-chip models for drug-toxicity screening and kidney tumors modeling, bladder-on-chip models for urinary tract infections and bladder cancer modeling and prostate-on-chip models for prostate cancer modeling. Full article

Background: COVID-19 vaccination started in Romania in December 2020. Child vaccination started in 2021 with children aged 12–15 years in August. For children aged 5–11 years, vaccination started in January 2022. The aim of our study was to describe COVID-19 vaccination hesitancy in Romanian children and vaccine acceptability in the general population. As parental consent is required for child vaccination in Romania, these aspects have a significant association. Methods: An analytical cross-sectional survey was conducted in October and November 2021 during the peak of the 4th COVID-19 wave. Results: After validation, 1645 participants formed the main study group: median age 35 years, 72.83% women, and 35.44% from the medical domain. In total, 1311 (79.70%) participants were vaccinated against COVID-19 and 188 (11.42%) had vaccinated their 12–18-year-old children against COVID-19. Parents’ level of education, geographic area of residence, and COVID-19 vaccination status were significantly associated with COVID-19 vaccination. The hesitancy factors of child vaccination included the novelty of COVID-19 vaccines (62, 47.32%), fear of adverse reactions (32, 24.42%), and anti-vaccinism in general (29, 22.13%). In the studied group, only 188 (11.42%) participants recommended vaccination of 5–11-year-old children. Vaccine acceptability was higher in the general population (1311, 79.70%) than in the medical domain (326 out of 583, 55.91%). General vaccine hesitancy was based mainly on beliefs regarding inefficiency (131, 39.22%) and fears about the side effects of the vaccine (76, 22.75%). Conclusions: Overall, the acceptability of COVD-19 vaccines in the Romanian population was influenced by the level of education, area of residence, and being a COVID-19-vaccinated parent. Public health intervention programs are essential. Full article

Background: In December 2020, the first doses of COVID-19 vaccines arrived in Romania and were made available to medical and social staff. Vaccine hesitancy appeared as a barrier to effectively ending the pandemic. The opinions of medical and social staff influence the opinion of the general population. This study assesess the attitudes, knowledge, and opinion of medical and social personnel toward COVID-19 vaccines and vaccination and the influencing factors. Methods: 1025 persons participated in an online cross-sectional study from March until July 2021. Results: Out of 1021 eligible responders, 719 (70.42%) had been vaccinated: 227 with one dose (22.23%) and 492 with two doses (48.18%). There were 302 responders who were not vaccinated at all. Out of them, 188 refused vaccinations. The participants showed a good understanding and knowledge of SARScoV-2 transmission and treatment. Geographic area, medical profession, and medical experience influenced COVID-19 vaccination (p < 0.001). There were no associations between willingness to vaccinate and vaccine/virus knowledge. Most of the responders who were vaccinated or wanted to be vaccinated indicated an mRNA vaccine as their first choice. The variables that were significantly associated with reporting COVID-19 vaccine acceptance after logistic regression were: living in an urban area (Ora = 1.58, 95% CI: 0.98–2.56), being female (Ora = 1.59; 95% CI:1.03–2.44), and being a medical doctor (Ora = 3.40; 95% CI: 1.84–6.26). Conclusions: These findings show that vaccine hesitancy persists in medical and social personnel in Romania, and, hence, it may be reflected in the hesitancy of the general population toward vaccination. Full article

Background and Objectives: Endometrial hyperplasia (EH) is a precursor lesion to endometrial cancer (EC), and when cellular atypia is present, in 40% of cases, they are diagnosed with EC on hysterectomy. Usually, EH is clinically manifested by uterine bleeding. In patients with oral anticoagulant therapy (OAT), the uterus is the second most common source of bleeding. The aim of the study was to show that uterine bleeding in postmenopausal patients undergoing OAT may reveal precancerous endometrial lesions with atypia, or neoplastic lesions in patients with an initial diagnosis of endometrial hyperplasia without atypia (non-atypical endometrial hyperplasia, NAEH) on dilation and curettage (D&C). We will be able to estimate the risk of a postmenopausal female patient with uterine bleeding during an OAT to have a precancerous endometrial lesion. Materials and Methods: The subjects of the study were 173 female patients with uterine bleeding, who have had total hysterectomy with bilateral salpingoovarectomy, of whom 99 underwent an OAT. There were 101 female patients initially diagnosed with NAEH, of which 60 did not have anticoagulant treatment (mean age 57.36 ± 6.51) and 41 had anticoagulant treatment (mean age 60.39 ± 7.35) (p = 0.006). From the pathology diagnosis moment, the surgery was performed at 42.09 ± 14.54 days in patients without OAT and after 35.39 ± 11.29 days in those who received such treatment (p = 0.724). Results: Initial diagnosis of NAEH established at D&C was changed at the final diagnosis after hysterectomy in EH with cellular atypia (atypical endometrial hyperplasia AEH) or EC in 18.18% of patients without OAT, and in 40.54% of patients who received this treatment. Conclusions: Based on a logistic regression model, it is estimated that female patients with an initial histopathological diagnosis of NAEH and who underwent OAT have, on average, 4.85 times greater odds (OR = 4.85, 95% CI 1.79–14.06) than the others of being identified postoperatively with more advanced lesions. Full article