The 2023 MDPI Annual Report has
been released!
 
23 pages, 5506 KiB  
Article
An Adaptive Control Scheme Based on Non-Interference Nonlinearity Approximation for a Class of Nonlinear Cascaded Systems and Its Application to Flexible Joint Manipulators
by Zhangxing Liu, Hongzhe Jin and Jie Zhao
Sensors 2024, 24(10), 3178; https://doi.org/10.3390/s24103178 (registering DOI) - 16 May 2024
Abstract
Control design for the nonlinear cascaded system is challenging due to its complicated system dynamics and system uncertainty, both of which can be considered some kind of system nonlinearity. In this paper, we propose a novel nonlinearity approximation scheme with a simplified structure, [...] Read more.
Control design for the nonlinear cascaded system is challenging due to its complicated system dynamics and system uncertainty, both of which can be considered some kind of system nonlinearity. In this paper, we propose a novel nonlinearity approximation scheme with a simplified structure, where the system nonlinearity is approximated by a steady component and an alternating component using only local tracking errors. The nonlinearity of each subsystem is estimated independently. On this basis, a model-free adaptive control for a class of nonlinear cascaded systems is proposed. A squared-error correction procedure is introduced to regulate the weight coefficients of the approximation components, which makes the whole adaptive system stable even with the unmodeled uncertainties. The effectiveness of the proposed controller is validated on a flexible joint system through numerical simulations and experiments. Simulation and experimental results show that the proposed controller can achieve better control performance than the radial basis function network control. Due to its simplicity and robustness, this method is suitable for engineering applications. Full article
(This article belongs to the Special Issue Advanced Sensing and Control Technologies for Autonomous Robots)
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16 pages, 1971 KiB  
Article
Extraction and Biological Activity of Lignanoids from Magnolia officinalis Rehder & E.H.Wilson Residual Waste Biomass using Deep Eutectic Solvents
by Ying Lu, Haishan Tang, Feng Chen, Wufei Tang, Wubliker Dessie, Yunhui Liao and Zuodong Qin
Molecules 2024, 29(10), 2352; https://doi.org/10.3390/molecules29102352 (registering DOI) - 16 May 2024
Abstract
Lignanoids are an active ingredient exerting powerful antioxidant and anti-inflammatory effects in the treatment of many diseases. In order to improve the efficiency of the resource utilization of traditional Chinese medicine waste, Magnolia officinalis Rehder & E.H.Wilson residue (MOR) waste biomass was [...] Read more.
Lignanoids are an active ingredient exerting powerful antioxidant and anti-inflammatory effects in the treatment of many diseases. In order to improve the efficiency of the resource utilization of traditional Chinese medicine waste, Magnolia officinalis Rehder & E.H.Wilson residue (MOR) waste biomass was used as raw material in this study, and a series of deep eutectic solvents (ChUre, ChAce, ChPro, ChCit, ChOxa, ChMal, ChLac, ChLev, ChGly and ChEG) were selected to evaluate the extraction efficiency of lignanoids from MORs. The results showed that the best conditions for lignanoid extraction were a liquid–solid ratio of 40.50 mL/g, an HBD-HBA ratio of 2.06, a water percentage of 29.3%, an extract temperature of 337.65 K, and a time of 107 min. Under these conditions, the maximum lignanoid amount was 39.18 mg/g. In addition, the kinetics of the extraction process were investigated by mathematic modeling. In our antioxidant activity study, high antioxidant activity of the lignanoid extract was shown in scavenging four different types of free radicals (DPPH, ·OH, ABTS, and superoxide anions). At a concentration of 3 mg/mL, the total antioxidant capacity of the lignanoid extract was 1.795 U/mL, which was equal to 0.12 mg/mL of Vc solution. Furthermore, the antibacterial activity study found that the lignanoid extract exhibited good antibacterial effects against six tested pathogens. Among them, Staphylococcus aureus exerted the strongest antibacterial activity. Eventually, the correlation of the lignanoid extract with the biological activity and physicochemical properties of DESs is described using a heatmap, along with the evaluation of the in vitro hypoglycemic, in vitro hypolipidemic, immunomodulatory, and anti-inflammatory activity of the lignanoid extract. These findings can provide a theoretical foundation for the extraction of high-value components from waste biomass by deep eutectic solvents, as well as highlighting its specific significance in natural product development and utilization. Full article
(This article belongs to the Special Issue Study on Extraction and Chemical Constituents of Natural Extracts)
21 pages, 7668 KiB  
Article
Navigating the Maze: Exploring Non-Oncological Complexities in Non-Small-Cell Lung Cancer
by Angela-Ștefania Marghescu, Silviu Vlăsceanu, Mădălina Preda, Mirela Țigău, Ștefan Dumitrache-Rujinski, Diana Gabriela Leonte, Elena Doina Măgheran, Adrian Tudor, Ioana Anca Bădărău, Livia Georgescu and Mariana Costache
Cancers 2024, 16(10), 1903; https://doi.org/10.3390/cancers16101903 (registering DOI) - 16 May 2024
Abstract
Pulmonary oncological pathologies are an important public health problem and the association with other pulmonary lesions may pose difficulties in diagnosis and staging or require different treatment options. To address this complexity, we conducted a retrospective observational study at the Marius Nasta Institute [...] Read more.
Pulmonary oncological pathologies are an important public health problem and the association with other pulmonary lesions may pose difficulties in diagnosis and staging or require different treatment options. To address this complexity, we conducted a retrospective observational study at the Marius Nasta Institute of Pneumophthisiology, Bucharest, Romania. Our study focused on patients admitted in 2019 with non-small-cell lung carcinoma and associated pulmonary lesions identified through surgical resection specimens. Among the 314 included patients, multiple pulmonary nodules were observed on macroscopic examination, with 12% (N = 37) exhibiting nonmalignant etiologies upon microscopic examination. These findings underscore the challenge of preoperative staging. Patients with coexisting nonmalignant lesions were similar in age, smoking habits, and professional or environmental exposure by comparison with those who presented only malignant lesions. The presentation of coexisting malignant and nonmalignant lesions may pose difficulties in diagnosing and staging pulmonary cancer. Full article
(This article belongs to the Special Issue Pathology, Diagnosis and Treatment in Non-small Cell Lung Cancer)
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17 pages, 3606 KiB  
Article
Prescribed Performance Fault-Tolerant Attitude Tracking Control for UAV with Actuator Faults
by Qilong Wu and Qidan Zhu
Drones 2024, 8(5), 204; https://doi.org/10.3390/drones8050204 (registering DOI) - 16 May 2024
Abstract
This paper proposes a prescribed performance fault-tolerant control based on a fixed-time extended state observer (FXTESO) for a carrier-based unmanned aerial vehicle (UAV). First, the attitude motion model of the UAV is introduced. Secondly, the proposed FXTESO is designed to estimate the total [...] Read more.
This paper proposes a prescribed performance fault-tolerant control based on a fixed-time extended state observer (FXTESO) for a carrier-based unmanned aerial vehicle (UAV). First, the attitude motion model of the UAV is introduced. Secondly, the proposed FXTESO is designed to estimate the total disturbances including coupling, actuator faults and external disturbances. By using the barrier Lyapunov function (BLF), it is proved that under prescribed performance control (PPC), the attitude tracking error is stable within the prescribed range. The simulation results for tracking the desired attitude angle show that the average overshoot and stabilization time of PPC-FXTESO is 0.00455rad and 6.2s. Comparatively, the average overshoots of BSC-ESO and BSC-FTESO are 0.035rad and 0.027rad, with stabilization times of 14.97s and 12.56s, respectively. Therefore, the control scheme proposed in this paper outperforms other control schemes. Full article
27 pages, 2043 KiB  
Article
A Qualitative Study on the Consumer Behaviour Related to Food Waste: Romanian Perspectives through Word Cloud and Sentiment Analysis
by Maria-Georgeta Moldovan, Dan-Cristian Dabija, Liana Stanca and Cristina Bianca Pocol
Sustainability 2024, 16(10), 4193; https://doi.org/10.3390/su16104193 (registering DOI) - 16 May 2024
Abstract
In emerging countries like Romania, research on food loss and waste remains relatively scarce. This is mainly because the phenomenon, along with its repercussions and ramifications, is inadequately understood by all stakeholders within the agri-food chain. Consumer behaviour, with a specific focus on [...] Read more.
In emerging countries like Romania, research on food loss and waste remains relatively scarce. This is mainly because the phenomenon, along with its repercussions and ramifications, is inadequately understood by all stakeholders within the agri-food chain. Consumer behaviour, with a specific focus on sustainability and waste reduction, has undergone a noticeable transformation on a global scale. Researchers have been emphasising the imperative for effective awareness and education strategies in this respect. Diverse studies contribute valuable insights into household food behaviour, identifying possible drivers and suggesting counteractive techniques. This study poses inquiries about consumer feelings regarding the food waste phenomenon and perceptions of the Romanian agri-food chain, as well as the influence of education on their awareness and adoption of sustainable eating habits. The paper delineates the semi-structured interview-based methodology, shows results through word-cloud and sentiment analysis, and engages in discussions on consumer behaviour through four distinct clusters, concluding with limitations, managerial implications and outlining future research directions. The findings underscore the relevance of emotions and sentiments in understanding consumer behaviour, shedding light on the nuanced factors influencing food waste. Notably, the accuracy of interpretation is higher when drawn from interviews rather than online comments or reviews made by unknown individuals. This distinction increases the credibility of the insights gained from the qualitative study. By analysing consumer sentiments, the study aids in implementing strategies to improve customer satisfaction and reduce food waste, fostering a more sustainable and consumer-centric approach in the agri-food sector worldwide. Full article
16 pages, 1591 KiB  
Article
Enhanced Chromium (VI) Removal by Micron-Scale Zero-Valent Iron Pretreated with Aluminum Chloride under Aerobic Conditions
by Xuejun Long, Rui Li, Jun Wan, Zhenxing Zhong, Yuxuan Ye, Jiazhi Yang, Jun Luo, Jin Xia and Yaomeng Liu
Molecules 2024, 29(10), 2350; https://doi.org/10.3390/molecules29102350 (registering DOI) - 16 May 2024
Abstract
Micron-scale zero-valent iron (ZVI)-based material has been applied for hexavalent chromium (Cr(VI)) decontamination in wastewater treatment and groundwater remediation, but the passivation problem has limited its field application. In this study, we combined aluminum chloride solution with ZVI (pcZVI-AlCl3) to enhance [...] Read more.
Micron-scale zero-valent iron (ZVI)-based material has been applied for hexavalent chromium (Cr(VI)) decontamination in wastewater treatment and groundwater remediation, but the passivation problem has limited its field application. In this study, we combined aluminum chloride solution with ZVI (pcZVI-AlCl3) to enhance Cr(VI) removal behavior under aerobic conditions. The optimal pre-corrosion conditions were found to be 2.5 g/L ZVI, 0.5 mM AlCl3, and a 4 h preconditioning period. Different kinds of techniques were applied to detect the properties of preconditioned ZVI and corrosion products. The 57Fe Mössbauer spectra showed that proportions of ZVI, Fe3O4, and FeOOH in pcZVI-AlCl3 were 49.22%, 34.03%, and 16.76%, respectively. The formation of Al(OH)3 in the corrosion products improved its pHpzc (point of zero charge) for Cr(VI) adsorption. Continuous-flow experiments showed its great potential for Cr(VI) removal in field applications. The ZVI and corrosion products showed a synergistic effect in enhancing electron transfer for Cr(VI) removal. The mechanisms underlying Cr(VI) removal by pcZVI-AlCl3 included adsorption, reduction, and precipitation, and the contribution of adsorption was less. This work provides a new strategy for ZVI pre-corrosion to improve its longevity and enhance Cr(VI) removal. Full article
18 pages, 1333 KiB  
Article
The Influence of Diatomite Addition on the Properties of Geopolymers Based on Fly Ash and Metakaolin
by Marek Nykiel, Kinga Korniejenko, Kinga Setlak, Mykola Melnychuk, Nina Polivoda, Barbara Kozub, Maria Hebdowska-Krupa and Michał Łach
Materials 2024, 17(10), 2399; https://doi.org/10.3390/ma17102399 (registering DOI) - 16 May 2024
Abstract
Geopolymer materials, considered to be an alternative to Portland cement-based concretes, can be produced from various types of waste aluminosilicate raw materials. This article presents the results of research related to the use of diatomite as an additive in geopolymers. The results of [...] Read more.
Geopolymer materials, considered to be an alternative to Portland cement-based concretes, can be produced from various types of waste aluminosilicate raw materials. This article presents the results of research related to the use of diatomite as an additive in geopolymers. The results of testing geopolymer composites with 1%, 3%, and 5% additions of diatomite with a grain size of 0–0.063 mm after and without thermal treatment were presented. This article presents the physical properties of the diatomite additive, the morphology of diatomite particles SEMs, thermal analysis, and compressive strength test results. In this research, diatomite was treated as a substitute for both fly ash and metakaolin (replaced in amounts of 1 and 3%) and as a substitute for sand introduced as a filler (in this case, 5% of diatomite was added). As a result of this research, it was found that the addition of diatomite instead of the main geopolymerization precursors in amounts of 1 and 3% had a negative impact on the strength properties of geopolymers, as the compressive strength was reduced by up to 28%. The introduction of crushed diatomite instead of sand in an amount of 5% contributed to an increase in strength of up to 24%. Full article
(This article belongs to the Special Issue Geopolymers and Fiber-Reinforced Concrete Composites)
20 pages, 736 KiB  
Review
Associations between “Cancer Risk”, “Inflammation” and “Metabolic Syndrome”: A Scoping Review
by Elsa Vitale, Alessandro Rizzo, Kazuki Santa and Emilio Jirillo
Biology 2024, 13(5), 352; https://doi.org/10.3390/biology13050352 (registering DOI) - 16 May 2024
Abstract
Background: Individuals with metabolic syndrome exhibit simultaneously pro-thrombotic and pro-inflammatory conditions which more probably can lead to cardiovascular diseases progression, type 2 diabetes mellitus, and some types of cancer. The present scoping review is aimed at highlighting the association between cancer risk, [...] Read more.
Background: Individuals with metabolic syndrome exhibit simultaneously pro-thrombotic and pro-inflammatory conditions which more probably can lead to cardiovascular diseases progression, type 2 diabetes mellitus, and some types of cancer. The present scoping review is aimed at highlighting the association between cancer risk, inflammation, and metabolic syndrome. Methods: A search strategy was performed, mixing keywords and MeSH terms, such as “Cancer Risk”, “Inflammation”, “Metabolic Syndrome”, “Oncogenesis”, and “Oxidative Stress”, and matching them through Boolean operators. A total of 20 manuscripts were screened for the present study. Among the selected papers, we identified some associations with breast cancer, colorectal cancer, esophageal adenocarcinoma, hepatocellular carcinoma (HCC), and cancer in general. Conclusions: Cancer and its related progression may also depend also on a latent chronic inflammatory condition associated with other concomitant conditions, including type 2 diabetes mellitus, metabolic syndrome, and obesity. Therefore, prevention may potentially help individuals to protect themselves from cancer. Full article
21 pages, 551 KiB  
Article
“Pay Attention! Pay Attention! Pay Attention!!!”: The Pivotal Role of Educators and the Educational System as Experienced by Survivors of Child Sexual Abuse
by Laura I. Sigad, Dafna Tener, Efrat Lusky-Weisrose, Jordan Shaibe and Carmit Katz
Behav. Sci. 2024, 14(5), 419; https://doi.org/10.3390/bs14050419 (registering DOI) - 16 May 2024
Abstract
 Educational institutions and educators are significant in children’s lives, and they have a crucial role in implementing policies, practices, and sexual education to enhance children’s safety. Such policies and practices should be based on the voices of CSA survivors. This study explored child [...] Read more.
 Educational institutions and educators are significant in children’s lives, and they have a crucial role in implementing policies, practices, and sexual education to enhance children’s safety. Such policies and practices should be based on the voices of CSA survivors. This study explored child sexual abuse (CSA) survivors’ viewpoints on their past experiences with educators and the educational system. A qualitative thematic approach was used to analyze 61 written testimonies collected in 2020–2021 by the Israeli Independent Public Inquiry on CSA. Two interrelated themes arose: 1) CSA survivors’ retrospective perspectives of educators and the educational system’s responses to signs of their CSA, described as ranging from abusive to life-saving. Specifically, they shared three types of responses: a) harmful and hurtful; b) dismissive and ignoring; and c) accepting and attending. 2) The second theme described the survivors’ messages to educators to promote constructive change. The survivors conveyed expectations that educators should play a central role in CSA prevention, detection, and intervention and, specifically, the need for educators to receive professional training, provide beneficial sexual education, and identify and respond to CSA. The findings promoted moving beyond individual-level interventions to focus on improving educational institutional and organizational cultures related to CSA in both national and international contexts. Full article
12 pages, 427 KiB  
Article
Financial Toxicity in Japanese Patients with Metastatic Renal Cell Carcinoma: A Cross-Sectional Study
by Go Kimura, Yasuhisa Fujii, Kazunori Honda, Takahiro Osawa, Yosuke Uchitomi, Miki Kondo, Ariko Otani, Tetsuya Wako, Daisuke Kawai, Yoshihide Mitsuda, Naotaka Sakashita and Nobuo Shinohara
Cancers 2024, 16(10), 1904; https://doi.org/10.3390/cancers16101904 (registering DOI) - 16 May 2024
Abstract
Information on the financial toxicity experienced by Japanese patients with metastatic renal cell carcinoma (mRCC) is lacking, even though Japan has its own unique public health insurance system. Thus, a web-based survey was conducted to evaluate the financial toxicity experienced by Japanese mRCC [...] Read more.
Information on the financial toxicity experienced by Japanese patients with metastatic renal cell carcinoma (mRCC) is lacking, even though Japan has its own unique public health insurance system. Thus, a web-based survey was conducted to evaluate the financial toxicity experienced by Japanese mRCC patients using the COmprehensive Score for financial Toxicity (COST) tool. This study enrolled Japanese patients who underwent, or were undergoing, systemic therapy for mRCC. The outcomes evaluated were the distribution of COST scores, the correlation between COST and quality of life (QOL) assessed by the Functional Assessment of Cancer Therapy-General (FACT-G) scale, and demographic factors associated with financial toxicity. The median (range) COST score was 19.0 (3.0–36.0). The Pearson correlation coefficient for COST and FACT-G total scores was 0.40. Univariate analysis revealed that not having private health insurance and lower household income per year were significantly associated with lower COST scores. Multivariate analyses showed that age < 65 years and not having private health insurance were significantly associated with lower COST scores. This study revealed that Japanese mRCC patients experience adverse financial impacts even under the universal health insurance coverage system available in Japan, and financial toxicity negatively affects their QOL. Full article
(This article belongs to the Section Cancer Survivorship and Quality of Life)
14 pages, 977 KiB  
Article
Selective Recovery of Gold from E-Waste Recycling Plants’ Waste Fractions: Waste-to-Resource Transition
by Svetlana Zueva, Nicolò Maria Ippolito, Marco Passadoro, Pietro Romano, Francesco Ferella and Francesco Vegliò
Minerals 2024, 14(5), 518; https://doi.org/10.3390/min14050518 (registering DOI) - 16 May 2024
Abstract
Electronic waste grows globally at a rate of 5% annually, which makes electronic waste recycling (WEEE recycling) an urgent task aimed at achieving (i) environmental protection and (ii) the preservation of mineral resources through the re-introduction of strategic metals into the market. As [...] Read more.
Electronic waste grows globally at a rate of 5% annually, which makes electronic waste recycling (WEEE recycling) an urgent task aimed at achieving (i) environmental protection and (ii) the preservation of mineral resources through the re-introduction of strategic metals into the market. As it turns out, WEEE recycling produces further waste, called WEEE secondary waste, which still contains valuable metals such as gold, silver, and copper. This study assessed the economic viability of recovering these metals and identified the most promising targets and approaches. WEEE secondary waste produced at a plant in southern Europe was sampled and examined for this purpose. The study methods included an ANOVA (analysis of variance) and an OCCP (orthogonal central composition plan). Over 90% gold, silver, and copper extraction was achieved with hydrochloric acid leaching in sodium hypochlorite with sodium chlorite as an oxidizing agent at 60 °C. The significance of the variation in the response for each factor, calculated using the Yates algorithm, demonstrates that by excluding sodium chloride and optimizing the doses of hydrochloric acid and sodium hypochlorite, gold can be selectively recovered through the leaching process. The scenario of HCl (2.5M)/NaClO (5%) leaching results in the maximum extraction effect of Au (91.6%) at the lowest concentrations of Ag and Cu (37–44%). Full article
(This article belongs to the Section Mineral Processing and Extractive Metallurgy)
13 pages, 1523 KiB  
Article
A Comparison of RML Prion Inactivation Efficiency by Heterogeneous and Homogeneous Photocatalysis
by Ioannis Paspaltsis, Eirini Kanata, Sotirios Sotiriadis, Susana Silva Correia, Matthias Schmitz, Inga Zerr, Dimitra Dafou, Konstantinos Xanthopoulos and Theodoros Sklaviadis
Pathogens 2024, 13(5), 420; https://doi.org/10.3390/pathogens13050420 (registering DOI) - 16 May 2024
Abstract
Prions are proteinaceous pathogens responsible for a variety of devastating diseases in mammals, including scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt–Jakob disease (CJD) in humans. They are characterized by their exceptional persistence to common inactivation procedures. This applies [...] Read more.
Prions are proteinaceous pathogens responsible for a variety of devastating diseases in mammals, including scrapie in sheep and goats, chronic wasting disease in cervids, and Creutzfeldt–Jakob disease (CJD) in humans. They are characterized by their exceptional persistence to common inactivation procedures. This applies to all possible sources of prion contamination as prions may be present in the tissues and biological fluids of infected individuals. Hence, efficient prion inactivation procedures are still being sought to minimize the risk of intra- or inter-species transmission. In the past, photocatalytic treatment has been proven to be capable of efficiently oxidizing and inactivating prions. In the present study, the efficacy of homogeneous photo-Fenton-based photocatalysis as well as heterogeneous photocatalysis with TiO2 in reducing RML mouse scrapie infectivity was evaluated. Prion inactivation was assessed by means of a bioassay, and the results were confirmed by in vitro experiments. While the prion infectivity of the RML mouse scrapie was reduced after treatment with the photo-Fenton reagent, the heterogeneous photocatalytic treatment of the same prion strain completely eliminated prion infectivity. Full article
18 pages, 787 KiB  
Article
Plateau-Adapted Single-Pump, Single-Bed Vacuum Pressure Swing Adsorption Oxygen Generation Process Simulation and Optimization
by Yingying Zhang, Yanbin Li, Zhenxing Song, Hongyun Sun, Bolun Wen, Junming Su, Jun Ma and Yanjun Zhang
Processes 2024, 12(5), 1015; https://doi.org/10.3390/pr12051015 (registering DOI) - 16 May 2024
Abstract
To enhance the oxygen guarantee capacity in high altitude areas and address the challenges of traditional pressure swing adsorption oxygen generation fixed equipment with large volume and multiple device modules, a novel single-reversible-pump single-bed vacuum pressure swing adsorption (VPSA) oxygen generation process was [...] Read more.
To enhance the oxygen guarantee capacity in high altitude areas and address the challenges of traditional pressure swing adsorption oxygen generation fixed equipment with large volume and multiple device modules, a novel single-reversible-pump single-bed vacuum pressure swing adsorption (VPSA) oxygen generation process was proposed and simulated. This study investigated the effects of purge on oxygen productivity, purity, recovery, and energy consumption, determining that the optimum ratio of total oxygen in the purge gas to the total oxygen in the feed gas (P/F) was 0.176. A set of principle prototypes was developed and validated in plains. The process performance was then simulated and studied at altitudes of 3000 m, 4000 m, and 5000 m. Finally, the optimization was carried out by adjusting the product flow rate and feed flow rate, revealing that the best performance can be achieved when the oxygen purity exceeded 90% with lower energy consumption or larger productivity than the optimization goal. This study serves as a valuable reference for the optimization of the VPSA oxygen generation process in a plateau environment. Full article
16 pages, 548 KiB  
Review
Cyclic Fatigue of Different Ni-Ti Endodontic Rotary File Alloys: A Comprehensive Review
by Dina Abdellatif, Alfredo Iandolo, Michela Scorziello, Giuseppe Sangiovanni and Massimo Pisano
Bioengineering 2024, 11(5), 499; https://doi.org/10.3390/bioengineering11050499 (registering DOI) - 16 May 2024
Abstract
Introduction: Modern endodontics aims to decrease the bacterial load from the complex endodontic space. Over the years, improvements in the operative phases have led to a considerable increase in the success rate of endodontic treatments. The shaping phase has seen the development of [...] Read more.
Introduction: Modern endodontics aims to decrease the bacterial load from the complex endodontic space. Over the years, improvements in the operative phases have led to a considerable increase in the success rate of endodontic treatments. The shaping phase has seen the development of new techniques supported by technological innovations that have led to higher treatment predictability. Endodontic instruments have experienced a series of changes that have led to modifications in their design, surface treatments, and heat treatments. The clinical use of rotating nickel–titanium instruments has become widespread and consolidated, a success due primarily to the alloy’s mechanical characteristics, which are superior to steel ones, but also to innovations in instrument design. The advent of the Ni-Ti alloy has kept the concepts and requirements of shaping the same but has modified its implementation in endodontics. Aim: The following review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) protocol. The research question focused on Ni-Ti endodontic instruments whose cyclic fatigue was evaluated by analyzing cyclic fatigue strength and the incidence of fracture. Results: At the end of the research, 10 systematic reviews and 1 randomized controlled trial were included in this comprehensive review. The most frequently analysed alloys were M-wire, conventional Ni-Ti, and CM-wire. In seven articles, instruments made of M-wire alloy were used; in eight articles, instruments made of conventional Ni-Ti; and in seven articles, instruments made of CM-wire alloy. Conclusions: The technological evolution of Ni-Ti alloys has led to the development of increasingly high-performance endodontic files that are resistant to cyclic fatigue during clinical practice and have greater resistance to sterilisation practices, making treatment easier and more predictable over time. In particular, heat-treated nickel-titanium root canal instruments present greater resistance to cyclic fatigue than untreated ones and those used with reciprocating kinematics concerning continuous rotation. Full article
(This article belongs to the Special Issue Modern Approaches in Adhesive Dentistry)
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29 pages, 408 KiB  
Article
Three-Body 3D-Kepler Electromagnetic Problem—Existence of Periodic Solutions
by Vasil Georgiev Angelov
AppliedMath 2024, 4(2), 612-640; https://doi.org/10.3390/appliedmath4020034 (registering DOI) - 16 May 2024
Abstract
The main purpose of the present paper is to prove the existence of periodic solutions of the three-body problem in the 3D Kepler formulation. We have solved the same problem in the case when the three particles are considered in an external inertial [...] Read more.
The main purpose of the present paper is to prove the existence of periodic solutions of the three-body problem in the 3D Kepler formulation. We have solved the same problem in the case when the three particles are considered in an external inertial system. We start with the three-body equations of motion, which are a subset of the equations of motion (previously derived by us) for any number of bodies. In the Minkowski space, there are 12 equations of motion. It is proved that three of them are consequences of the other nine, so their number becomes nine, as much as the unknown trajectories are. The Kepler formulation assumes that one particle (the nucleus) is placed at the coordinate origin. The motion of the other two particles is described by a neutral system with respect to the unknown velocities. The state-dependent delays arise as a consequence of the finite vacuum speed of light. We obtain the equations of motion in spherical coordinates and split them into two groups. In the first group all arguments of the unknown functions are delays. We take their solutions as initial functions. Then, the equations of motion for the remaining two particles must be solved to the right of the initial point. To prove the existence–uniqueness of a periodic solution, we choose a space consisting of periodic infinitely smooth functions satisfying some supplementary conditions. Then, we use a suitable operator which acts on these spaces and whose fixed points are periodic solutions. We apply the fixed point theorem for the operators acting on the spaces of periodic functions. In this manner, we show the stability of the He atom in the frame of classical electrodynamics. In a previous paper of ours, we proved the existence of spin functions for plane motion. Thus, we confirm the Bohr and Sommerfeld’s hypothesis for the He atom. Full article
13 pages, 4812 KiB  
Article
Fe-Co Co-Doped 1D@2D Carbon-Based Composite as an Efficient Catalyst for Zn–Air Batteries
by Ziwei Deng, Wei Liu, Junyuan Zhang, Shuli Bai, Changyu Liu, Mengchen Zhang, Chao Peng, Xiaolong Xu and Jianbo Jia
Molecules 2024, 29(10), 2349; https://doi.org/10.3390/molecules29102349 (registering DOI) - 16 May 2024
Abstract
A Fe-Co dual-metal co-doped N containing the carbon composite (FeCo-HNC) was prepared by adjusting the ratio of iron to cobalt as well as the pyrolysis temperature with the assistance of functionalized silica template. Fe1Co-HNC, which was formed with 1D carbon nanotubes [...] Read more.
A Fe-Co dual-metal co-doped N containing the carbon composite (FeCo-HNC) was prepared by adjusting the ratio of iron to cobalt as well as the pyrolysis temperature with the assistance of functionalized silica template. Fe1Co-HNC, which was formed with 1D carbon nanotubes and 2D carbon nanosheets including a rich mesoporous structure, exhibited outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic activities. The ORR half-wave potential is 0.86 V (vs. reversible hydrogen electrode, RHE), and the OER overpotential is 0.76 V at 10 mA cm−2 with the Fe1Co-HNC catalyst. It also displayed superior performance in zinc–air batteries. This method provides a promising strategy for the fabrication of efficient transition metal-based carbon catalysts. Full article
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43 pages, 1100 KiB  
Review
Hive Products: Composition, Pharmacological Properties, and Therapeutic Applications
by Roberto Bava, Fabio Castagna, Carmine Lupia, Giusi Poerio, Giovanna Liguori, Renato Lombardi, Maria Diana Naturale, Rosa Maria Bulotta, Vito Biondi, Annamaria Passantino, Domenico Britti, Giancarlo Statti and Ernesto Palma
Pharmaceuticals 2024, 17(5), 646; https://doi.org/10.3390/ph17050646 (registering DOI) - 16 May 2024
Abstract
Beekeeping provides products with nutraceutical and pharmaceutical characteristics. These products are characterized by abundance of bioactive compounds. For different reasons, honey, royal jelly, propolis, venom, and pollen are beneficial to humans and animals and could be used as therapeutics. The pharmacological action of [...] Read more.
Beekeeping provides products with nutraceutical and pharmaceutical characteristics. These products are characterized by abundance of bioactive compounds. For different reasons, honey, royal jelly, propolis, venom, and pollen are beneficial to humans and animals and could be used as therapeutics. The pharmacological action of these products is related to many of their constituents. The main bioactive components of honey include oligosaccharides, methylglyoxal, royal jelly proteins (MRJPs), and phenolics compounds. Royal jelly contains jelleins, royalisin peptides, MRJPs, and derivatives of hydroxy-decenoic acid, particularly 10-hydroxy-2-decenoic acid (10-HDA), which possess antibacterial, anti-inflammatory, immunomodulatory, neuromodulatory, metabolic syndrome-preventing, and anti-aging properties. Propolis has a plethora of activities that are referable to compounds such as caffeic acid phenethyl ester. Peptides found in bee venom include phospholipase A2, apamin, and melittin. In addition to being vitamin-rich, bee pollen also includes unsaturated fatty acids, sterols, and phenolics compounds that express antiatherosclerotic, antidiabetic, and anti-inflammatory properties. Therefore, the constituents of hive products are particular and different. All of these constituents have been investigated for their properties in numerous research studies. This review aims to provide a thorough screening of the bioactive chemicals found in honeybee products and their beneficial biological effects. The manuscript may provide impetus to the branch of unconventional medicine that goes by the name of apitherapy. Full article
(This article belongs to the Special Issue Therapeutic Effects of Natural Products and Their Clinical Research)
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16 pages, 13893 KiB  
Article
ZPD Retrieval Performances of the First Operational Ship-Based Network of GNSS Receivers over the North-West Mediterranean Sea
by Andrea Antonini, Luca Fibbi, Massimo Viti, Aldo Sonnini, Simone Montagnani and Alberto Ortolani
Sensors 2024, 24(10), 3177; https://doi.org/10.3390/s24103177 (registering DOI) - 16 May 2024
Abstract
This work presents the design and implementation of an operational infrastructure for the monitoring of atmospheric parameters at sea through GNSS meteorology sensors installed on liners operating in the north-west Mediterranean Sea. A measurement system, capable of operationally and continuously providing the values [...] Read more.
This work presents the design and implementation of an operational infrastructure for the monitoring of atmospheric parameters at sea through GNSS meteorology sensors installed on liners operating in the north-west Mediterranean Sea. A measurement system, capable of operationally and continuously providing the values of surface parameters, is implemented together with software procedures based on a float-PPP approach for estimating zenith path delay (ZPD) values. The values continuously registered over a three year period (2020–2022) from this infrastructure are compared with the data from a numerical meteorological reanalysis model (MERRA-2). The results clearly prove the ability of the system to estimate the ZPD from ship-based GNSS-meteo equipment, with the accuracy evaluated in terms of correlation and root mean square error reaching values between 0.94 and 0.65 and between 18.4 and 42.9 mm, these extreme values being from the best and worst performing installations, respectively. This offers a new perspective on the operational exploitation of GNSS signals over sea areas in climate and operational meteorological applications. Full article
(This article belongs to the Special Issue GNSS Software-Defined Radio Receivers: Status and Perspectives)
14 pages, 12382 KiB  
Article
Environmentally Relevant Concentrations of Triphenyl Phosphate (TPhP) Impact Development in Zebrafish
by Benjamin Schmandt, Mfon Diduff, Gabrielle Smart and Larissa M. Williams
Toxics 2024, 12(5), 368; https://doi.org/10.3390/toxics12050368 (registering DOI) - 16 May 2024
Abstract
A common flame-retardant and plasticizer, triphenyl phosphate (TPhP) is an aryl phosphate ester found in many aquatic environments at nM concentrations. Yet, most studies interrogating its toxicity have used µM concentrations. In this study, we used the model organism zebrafish (Danio rerio [...] Read more.
A common flame-retardant and plasticizer, triphenyl phosphate (TPhP) is an aryl phosphate ester found in many aquatic environments at nM concentrations. Yet, most studies interrogating its toxicity have used µM concentrations. In this study, we used the model organism zebrafish (Danio rerio) to uncover the developmental impact of nM exposures to TPhP at the phenotypic and molecular levels. At concentrations of 1.5–15 nM (0.5 µg/L–5 µg/L), chronically dosed 5dpf larvae were shorter in length and had pericardial edema phenotypes that had been previously reported for exposures in the µM range. Cardiotoxicity was observed but did not present as cardiac looping defects as previously reported for µM concentrations. The RXR pathway does not seem to be involved at nM concentrations, but the tbx5a transcription factor cascade including natriuretic peptides (nppa and nppb) and bone morphogenetic protein 4 (bmp4) were dysregulated and could be contributing to the cardiac phenotypes. We also demonstrate that TPhP is a weak pro-oxidant, as it increases the oxidative stress response within hours of exposure. Overall, our data indicate that TPhP can affect animal development at environmentally relevant concentrations and its mode of action involves multiple pathways. Full article
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16 pages, 6070 KiB  
Article
RsRbohD1 Plays a Significant Role in ROS Production during Radish Pithiness Development
by Qiong Gong, Chaonan Wang, Weiqiang Fan, Shuiling Li, Hong Zhang, Zhiyin Huang, Xiaohui Liu, Ziyun Ma, Yong Wang and Bin Zhang
Plants 2024, 13(10), 1386; https://doi.org/10.3390/plants13101386 (registering DOI) - 16 May 2024
Abstract
Pithiness is one of the physiological diseases of radishes, which is accompanied by the accumulation of reactive oxygen species (ROS) during the sponging of parenchyma tissue in the fleshy roots. A respiratory burst oxidase homolog (Rboh, also known as NADPH oxidase) is a [...] Read more.
Pithiness is one of the physiological diseases of radishes, which is accompanied by the accumulation of reactive oxygen species (ROS) during the sponging of parenchyma tissue in the fleshy roots. A respiratory burst oxidase homolog (Rboh, also known as NADPH oxidase) is a key enzyme that catalyzes the production of ROS in plants. To understand the role of Rboh genes in radish pithiness, herein, 10 RsRboh gene families were identified in the genome of Raphanus sativus using Blastp and Hmmer searching methods and were subjected to basic functional analyses such as phylogenetic tree construction, chromosomal localization, conserved structural domain analysis, and promoter element prediction. The expression profiles of RsRbohs in five stages (Pithiness grade = 0, 1, 2, 3, 4, respectively) of radish pithiness were analyzed. The results showed that 10 RsRbohs expressed different levels during the development of radish pithiness. Except for RsRbohB and RsRbohE, the expression of other members increased and reached the peak at the P2 (Pithiness grade = 2) stage, among which RsRbohD1 showed the highest transcripts. Then, the expression of 40 genes related to RsRbohD1 and pithiness were analyzed. These results can provide a theoretical basis for improving pithiness tolerance in radishes. Full article
(This article belongs to the Special Issue The Growth and Development of Vegetable Crops)
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13 pages, 1110 KiB  
Article
High-Resolution Millimeter-Wave Radar for Real-Time Detection and Characterization of High-Speed Objects with Rapid Acceleration Capabilities
by Yair Richter and Nezah Balal
Electronics 2024, 13(10), 1961; https://doi.org/10.3390/electronics13101961 (registering DOI) - 16 May 2024
Abstract
In this study, we present a novel approach for the real-time detection of high-speed moving objects with rapidly changing velocities using a high-resolution millimeter-wave (MMW) radar operating at 94 GHz in the W-band. Our detection methodology leverages continuous wave transmission and heterodyning of [...] Read more.
In this study, we present a novel approach for the real-time detection of high-speed moving objects with rapidly changing velocities using a high-resolution millimeter-wave (MMW) radar operating at 94 GHz in the W-band. Our detection methodology leverages continuous wave transmission and heterodyning of the reflected signal from the moving target, enabling the extraction of motion-related attributes such as velocity, position, and physical characteristics of the object. The use of a 94 GHz carrier frequency allows for high-resolution velocity detection with a velocity resolution of 6.38 m/s, achieved using a short integration time of 0.25 ms. This high-frequency operation also results in minimal atmospheric absorption, further enhancing the efficiency and effectiveness of the detection process. The proposed system utilizes cost-effective and less complex equipment, including compact antennas, made possible by the low sampling rate required for processing the intermediate frequency signal. The experimental results demonstrate the successful detection and characterization of high-speed moving objects with high acceleration rates, highlighting the potential of this approach for various scientific, industrial, and safety applications, particularly those involving targets with rapidly changing velocities. The detailed analysis of the micro-Doppler signatures associated with these objects provides valuable insights into their unique motion dynamics, paving the way for improved tracking and classification algorithms in fields such as aerospace research, meteorology, and collision avoidance systems. Full article
(This article belongs to the Special Issue Advances in Terahertz Radiation Sources and Their Applications)
9 pages, 209 KiB  
Article
The Ill-Thought-Through Aim to Eliminate the Education Gap across the Socio-Economic Spectrum
by Ognjen Arandjelović
Knowledge 2024, 4(2), 280-288; https://doi.org/10.3390/knowledge4020015 (registering DOI) - 16 May 2024
Abstract
Background: In an era of dramatic technological progress, the consequent economic transformations, and an increasing need for an adaptable workforce, the importance of education has risen to the forefront of the social discourse. The concurrent increase in the awareness of issues pertaining to [...] Read more.
Background: In an era of dramatic technological progress, the consequent economic transformations, and an increasing need for an adaptable workforce, the importance of education has risen to the forefront of the social discourse. The concurrent increase in the awareness of issues pertaining to social justice and the debate over what this justice entails and how it ought to be effected, feed into the education policy more than ever before. From the nexus of the aforementioned considerations, concern about the so-called education gap has emerged, with worldwide efforts to close it. Methods: I analyze the premises behind such efforts and demonstrate that they are founded upon fundamentally flawed ideas. Results: I show that in a society in which education is delivered equitably, education gaps emerge naturally as a consequence of differentiation due to talents, the tendency for matched mate selection, and the heritability of intellectual traits. Conclusion: I issue a call for a redirection of efforts away from the ill-founded idea of closing the education gap to the understanding of the magnitude of its unfair contributions, as well as to those social aspects that can modulate it in accordance with what a society deems fair according to its values. Full article
20 pages, 5055 KiB  
Article
Evaluation of Density Functional Theory-Generated Data for Infrared Spectroscopy of Novel Psychoactive Substances Using Unsupervised Learning
by Christiano dos Santos and Aline Thais Bruni
Psychoactives 2024, 3(2), 265-284; https://doi.org/10.3390/psychoactives3020017 (registering DOI) - 16 May 2024
Abstract
Novel psychoactive substances (NPSs) are compounds plotted to modify the chemical structures of prohibited substances, offering alternatives for consumption and evading legislation. The prompt emergence of these substances presents challenges in health concerns and forensic assessment because of the lack of analytical standards. [...] Read more.
Novel psychoactive substances (NPSs) are compounds plotted to modify the chemical structures of prohibited substances, offering alternatives for consumption and evading legislation. The prompt emergence of these substances presents challenges in health concerns and forensic assessment because of the lack of analytical standards. A viable alternative for establishing these standards involves leveraging in silico methods to acquire spectroscopic data. This study assesses the efficacy of utilizing infrared spectroscopy (IRS) data derived from density functional theory (DFT) for analyzing NPSs. Various functionals were employed to generate infrared spectra for five distinct NPS categories including the following: amphetamines, benzodiazepines, synthetic cannabinoids, cathinones, and fentanyls. PRISMA software was conceived to rationalize data management. Unsupervised learning techniques, including Hierarchical Cluster Analysis (HCA), Principal Component Analysis (PCA), and t-distributed stochastic neighbor embedding (t-SNE), were utilized to refine the assessment process. Our findings reveal no significant disparities among the different functionals used to generate infrared spectra data. Additionally, the application of unsupervised learning demonstrated adequate segregation of NPSs within their respective groups. In conclusion, integrating theoretical data and dimension reduction techniques proves to be a powerful strategy for evaluating the spectroscopic characteristics of NPSs. This underscores the potential of this combined methodology as a diagnostic tool for distinguishing IR spectra across various NPS groups, facilitating the evaluation of newly unknown compounds. Full article
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