MDPI - Publisher of Open Access Journals

26 pages, 1828 KiB

Open AccessReview

Navigating the Intersection: Sarcopenia and Sarcopenic Obesity in Inflammatory Bowel Disease

by Valentin Calvez, Guia Becherucci, Carlo Covello, Giulia Piccirilli, Irene Mignini, Giorgio Esposto, Lucrezia Laterza, Maria Elena Ainora, Franco Scaldaferri, Antonio Gasbarrini and Maria Assunta Zocco

Biomedicines 2024, 12(6), 1218; https://doi.org/10.3390/biomedicines12061218 (registering DOI) - 30 May 2024

Abstract

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, [...] Read more.

Inflammatory bowel diseases (IBDs) are intricate systemic conditions that can extend beyond the gastrointestinal tract through both direct and indirect mechanisms. Sarcopenia, characterized by a reduction in muscle mass and strength, often emerges as a consequence of the clinical course of IBDs. Indeed, sarcopenia exhibits a high prevalence in Crohn’s disease (52%) and ulcerative colitis (37%). While computed tomography and magnetic resonance imaging remain gold-standard methods for assessing muscle mass, ultrasound is gaining traction as a reliable, cost-effective, and widely available diagnostic method. Muscle strength serves as a key indicator of muscle function, with grip strength test emerging nowadays as the most reliable assessment method. In IBDs, sarcopenia may arise from factors such as inflammation, malnutrition, and gut dysbiosis, leading to the formulation of the ‘gut–muscle axis’ hypothesis. This condition determines an increased need for surgery with poorer post-surgical outcomes and a reduced response to biological treatments. Sarcopenia and its consequences lead to reduced quality of life (QoL), in addition to the already impaired QoL. Of emerging concern is sarcopenic obesity in IBDs, a challenging condition whose pathogenesis and management are still poorly understood. Resistance exercise and nutritional interventions, particularly those aimed at augmenting protein intake, have demonstrated efficacy in addressing sarcopenia in IBDs. Furthermore, anti-TNF biological therapies showed interesting outcomes in managing this condition. This review seeks to furnish a comprehensive overview of sarcopenia in IBDs, elucidating diagnostic methodologies, pathophysiological mechanisms, and clinical implications and management. Attention will also be paid to sarcopenic obesity, exploring the pathophysiology and possible treatment modalities of this condition. Full article

(This article belongs to the Section Immunology and Immunotherapy)

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42 pages, 7808 KiB

Open AccessArticle

Getting Hold of the Tobamovirus Particle—Why and How? Purification Routes over Time and a New Customizable Approach

by Tim Wendlandt, Beate Britz, Tatjana Kleinow, Katharina Hipp, Fabian J. Eber and Christina Wege

Viruses 2024, 16(6), 884; https://doi.org/10.3390/v16060884 (registering DOI) - 30 May 2024

Abstract

This article develops a multi-perspective view on motivations and methods for tobamovirus purification through the ages and presents a novel, efficient, easy-to-use approach that can be well-adapted to different species of native and functionalized virions. We survey the various driving forces prompting researchers [...] Read more.

This article develops a multi-perspective view on motivations and methods for tobamovirus purification through the ages and presents a novel, efficient, easy-to-use approach that can be well-adapted to different species of native and functionalized virions. We survey the various driving forces prompting researchers to enrich tobamoviruses, from the search for the causative agents of mosaic diseases in plants to their increasing recognition as versatile nanocarriers in biomedical and engineering applications. The best practices and rarely applied options for the serial processing steps required for successful isolation of tobamoviruses are then reviewed. Adaptations for distinct particle species, pitfalls, and ‘forgotten’ or underrepresented technologies are considered as well. The article is topped off with our own development of a method for virion preparation, rooted in historical protocols. It combines selective re-solubilization of polyethylene glycol (PEG) virion raw precipitates with density step gradient centrifugation in biocompatible iodixanol formulations, yielding ready-to-use particle suspensions. This newly established protocol and some considerations for perhaps worthwhile further developments could serve as putative stepping stones towards preparation procedures appropriate for routine practical uses of these multivalent soft-matter nanorods. Full article

(This article belongs to the Special Issue Tobamoviruses: Molecular Aspects and Resistance Regulation—a Special Issue Commemorating 125 Years of Research on Tobamoviruses)

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Graphical abstract

19 pages, 12740 KiB

Open AccessArticle

Theoretical Analysis of Plate-Type Thermoelectric Generator for Fluid Waste Heat Recovery Using Thermal Resistance and Numerical Models

by Yongfei Jia, Ruochen Wang and Jie Chen

World Electr. Veh. J. 2024, 15(6), 240; https://doi.org/10.3390/wevj15060240 - 30 May 2024

Abstract

In current research, there are excessive assumptions and simplifications in the mathematical models developed for thermoelectric generators. In this study, a comprehensive mathematical model was developed based on a plate-type thermoelectric generator divided into multiple thermoelectric units. The model takes into account temperature-dependent [...] Read more.

In current research, there are excessive assumptions and simplifications in the mathematical models developed for thermoelectric generators. In this study, a comprehensive mathematical model was developed based on a plate-type thermoelectric generator divided into multiple thermoelectric units. The model takes into account temperature-dependent thermoelectric material parameters and fluid flow. The model was validated, and a maximum error of 6.4% was determined. Moreover, the model was compared and analyzed with a numerical model, with a maximum discrepancy of 7.2%. The model revealed the factors and their degree of influence on the performance of the thermoelectric generator unit. In addition, differences in temperature distribution, output power, and conversion efficiency between multiple thermoelectric units were clearly studied. This study can guide modeling and some optimization measures to improve the overall performance of thermoelectric generators. Full article

(This article belongs to the Special Issue Electric Vehicle Technology Development, Energy and Environmental Implications, and Decarbonization)

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19 pages, 7279 KiB

Open AccessArticle

Decoupled Adaptive Motion Control for Unmanned Tracked Vehicles in the Leader-Following Task

by Jingjing Fan, Pengxiang Yan, Ren Li, Yi Liu, Falong Wang, Yingzhe Liu and Chang Chen

World Electr. Veh. J. 2024, 15(6), 239; https://doi.org/10.3390/wevj15060239 - 30 May 2024

Abstract

As a specific task for unmanned tracked vehicles, leader-following imposes high-precision requirements on the vehicle’s motion control, especially the steering control. However, due to characteristics such as the frequent changes in off-road terrain and steering resistance coefficients, controlling tracked vehicles poses significant challenges, [...] Read more.

As a specific task for unmanned tracked vehicles, leader-following imposes high-precision requirements on the vehicle’s motion control, especially the steering control. However, due to characteristics such as the frequent changes in off-road terrain and steering resistance coefficients, controlling tracked vehicles poses significant challenges, making it difficult to achieve stable and precise leader-following. This paper decouples the leader-following control into speed and curvature control to address such issues. It utilizes model reference adaptive control to establish reference models for the speed and curvature subsystems and designs corresponding parameter adaptive control laws. This control method enables the actual vehicle speed and curvature to effectively track the response of the reference model, thereby addressing the impact of frequent changes in the steering resistance coefficient. Furthermore, this paper demonstrates significant improvements in leader-following performance through a series of simulations and experiments. Compared with the traditional PID control method, the results shows that the maximum following distance has been reduced by at least approximately 12% (ensuring the ability to keep up with the leader), the braking distance has effectively decreased by 22% (ensuring a safe distance in an emergency braking scenario and improving energy recovery), the curvature tracking accuracy has improved by at least 11% (improving steering performance), and the speed tracking accuracy has increased by at least 3.5% (improving following performance). Full article

(This article belongs to the Special Issue Intelligent Electric Vehicle Control, Testing and Evaluation)

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21 pages, 2220 KiB

Open AccessArticle

Investigation of the Coupling Schemes between the Discrete and the Continuous Phase in the Numerical Simulation of a 60 kW_th Swirling Pulverised Solid Fuel Flame under Oxyfuel Conditions

by Hossein Askarizadeh, Stefan Pielsticker, Hendrik Nicolai, Reinhold Kneer, Christian Hasse and Anna Maßmeyer

Fire 2024, 7(6), 185; https://doi.org/10.3390/fire7060185 - 30 May 2024

Abstract

Detailed numerical analyses of pulverised solid fuel flames are computationally expensive due to the intricate interplay between chemical reactions, turbulent multiphase flow, and heat transfer. The near-burner region, characterised by a high particle number density, is particularly influenced by these interactions. The accurate [...] Read more.

Detailed numerical analyses of pulverised solid fuel flames are computationally expensive due to the intricate interplay between chemical reactions, turbulent multiphase flow, and heat transfer. The near-burner region, characterised by a high particle number density, is particularly influenced by these interactions. The accurate modelling of these phenomena is crucial for describing flame characteristics. This study examined the reciprocal impact between the discrete phase and the continuous phase using Reynolds-averaged Navier–Stokes (RANS) simulations. The numerical model was developed in Ansys Fluent and equipped with user-defined functions that adapt the modelling of combustion sub-processes, in particular, devolatilisation, char conversion, and radiative heat transfer under oxyfuel conditions. The aim was to identify the appropriate degree of detail necessary for modelling the interaction between discrete and continuous phases, specifically concerning mass, momentum, energy, and turbulence, to effectively apply it in high-fidelity numerical simulations. The results of the numerical model show good agreement in comparison with experimental data and large-eddy simulations. In terms of the coupling schemes, the results indicate significant reciprocal effects between the discrete and the continuous phases for mass and energy coupling; however, the effect of particles on the gas phase for momentum and turbulence coupling was observed to be negligible. For the investigated chamber, these results are shown to be slightly affected by the local gas phase velocity and temperature fields as long as the global oxygen ratio between the provided and needed amount of oxygen as well as the thermal output of the flame are kept constant. Full article

(This article belongs to the Special Issue Combustion and Fire I)

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11 pages, 304 KiB

Open AccessArticle

Matrix-Wigner Distribution

by Long Wang, Manjun Cui, Ze Qin, Zhichao Zhang and Jianwei Zhang

Fractal Fract. 2024, 8(6), 328; https://doi.org/10.3390/fractalfract8060328 - 30 May 2024

Abstract

In order to achieve time–frequency superresolution in comparison to the conventional Wigner distribution (WD), this study generalizes the well-known

τ

-Wigner distribution (

τ

-WD) with only one parameter

τ

to the multiple-parameter matrix-Wigner distribution (M-WD) with the parameter matrix

M

. According [...] Read more.

In order to achieve time–frequency superresolution in comparison to the conventional Wigner distribution (WD), this study generalizes the well-known

τ

-Wigner distribution (

τ

-WD) with only one parameter

τ

to the multiple-parameter matrix-Wigner distribution (M-WD) with the parameter matrix

M

. According to operator theory, we construct Heisenberg’s inequalities on the uncertainty product in M-WD domains and formulate two kinds of attainable lower bounds dependent on

M

. We solve the problem of lower bound minimization and obtain the optimality condition of

M

, under which the M-WD achieves superior time–frequency resolution. It turns out that the M-WD breaks through the limitation of the

τ

-WD and gives birth to some novel distributions other than the WD that could generate the highest time–frequency resolution. As an example, the two-dimensional linear frequency-modulated signal is carried out to demonstrate the time–frequency concentration superiority of the M-WD over the short-time Fourier transform and wavelet transform. Full article

19 pages, 21797 KiB

Open AccessArticle

Safety and Security-Specific Application of Multiple Drone Sensors at Movement Areas of an Aerodrome

by Béla Kovács, Fanni Vörös, Tímea Vas, Krisztián Károly, Máté Gajdos and Zsófia Varga

Drones 2024, 8(6), 231; https://doi.org/10.3390/drones8060231 - 30 May 2024

Abstract

Nowadays, the public service practice applicability of drones and remote sensing sensors is being explored in almost all industrial and military areas. In the present research, in collaboration with different universities, we investigate the applicability of drones in airport procedures, assessing the various [...] Read more.

Nowadays, the public service practice applicability of drones and remote sensing sensors is being explored in almost all industrial and military areas. In the present research, in collaboration with different universities, we investigate the applicability of drones in airport procedures, assessing the various potential applications. By exploiting the data from remote sensing sensors, we aim to develop methodologies that can assist airport operations, including managing the risk of wildlife threats to runway safety, infrastructure maintenance, and foreign object debris (FOD) detection. Drones equipped with remote sensing sensors provide valuable insight into surface diagnostics, helping to assess aprons, taxiways, and runways. In addition, drones can enhance airport security with effective surveillance and threat detection capabilities, as well as provide data to support existing air traffic control models and systems. In this paper, we aim to present our experience with the potential airport applications of UAV high-resolution RGB, thermal, and LiDAR sensors. Through interdisciplinary collaboration and innovative methodologies, our research aims to revolutionize airport operations, safety, and security protocols, outlining a path toward a safer, more efficient airport ecosystem. Full article

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14 pages, 754 KiB

Open AccessArticle

The Development of an Optimal Operation Algorithm for Food Delivery Using Drones Considering Time Interval between Deliveries

by Young Kwan Ko, Hyeseon Han, Yonghui Oh and Young Dae Ko

Drones 2024, 8(6), 230; https://doi.org/10.3390/drones8060230 - 30 May 2024

Abstract

These days, many attempts are being made worldwide to use drones for food delivery. Especially in the case of food, fast delivery is required, while maintaining its temperature and taste to the maximum. Therefore, using drones is suitable for food delivery because they [...] Read more.

These days, many attempts are being made worldwide to use drones for food delivery. Especially in the case of food, fast delivery is required, while maintaining its temperature and taste to the maximum. Therefore, using drones is suitable for food delivery because they can move through the air without being affected by traffic congestion. In this study, the purpose is to develop an optimal algorithm that can complete the delivery of customer food orders in the shortest time using drones. We have applied mathematical-model-based optimization techniques to develop an algorithm that reflects the given problem situation. Since the delivery capacity of drones is limited, and especially small, multiple drones may be used to deliver the food ordered by a particular customer. What is important here is that the drones assigned to one customer must arrive consecutively within a short period of time. This fact is reflected in this mathematical model. In the numerical example, it can be confirmed that the proposed algorithm operates optimally by comparing a case where the arrival time of multiple drones assigned to one customer is limited to a certain time and a case when it is not. Full article

(This article belongs to the Special Issue Advances of Drones in Logistics)

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22 pages, 3840 KiB

Open AccessArticle

Remediation of Methyl Orange Dye in Aqueous Solutions by Green Microalgae (Bracteacoccus sp.): Optimization, Isotherm, Kinetic, and Thermodynamic Studies

by Ahmad Al Shra’ah, Abdullah T. Al-Fawwaz, Mohammed M. Ibrahim and Eid Alsbou

Separations 2024, 11(6), 170; https://doi.org/10.3390/separations11060170 - 30 May 2024

Abstract

This study aims to assess the ability of old, immobilized fresh, and free fresh green microalgae (a Bracteacoccus sp.) to remove methyl orange (MO) dye from aqueous solutions. The effects of four factors, including initial MO concentration (5–25 mg L⁻¹), adsorbent [...] Read more.

This study aims to assess the ability of old, immobilized fresh, and free fresh green microalgae (a Bracteacoccus sp.) to remove methyl orange (MO) dye from aqueous solutions. The effects of four factors, including initial MO concentration (5–25 mg L⁻¹), adsorbent dose (0.02–0.10 g mL⁻¹), temperature (4–36 °C), and contact time (5–95 min), were examined. The Box–Behnken design (BBD) was used to determine the number of required experiments and the optimal conditions expected to provide the highest removal percentage of MO dye from aqueous solutions. The experimental data were applied to four isotherm models (Langmuir, Freundlich, Dubinin–Radushkevich (D–R), and Temkin isotherm models) and three kinetic models (pseudo–first–order, pseudo–second–order, and Elovich kinetic models). The results indicate that the highest removal of MO (97%) could be obtained in optimal conditions consisting of an initial MO concentration of 10.0 mg L⁻¹, an adsorbent dose of 0.10 g mL⁻¹, a temperature of 20 °C, and a contact time of 75 min. Moreover, the experimental data were best fitted by the Langmuir and Temkin isotherm models and followed a pseudo-second-order kinetic model. The interaction between MO and the Bracteacoccus sp. was confirmed by UV and ESI/MS analyses, indicating that MO removal occurred via both sorption and degradation processes. Full article

(This article belongs to the Special Issue Adsorption and Remediation of Emerging Pollutants from Water and Soil)

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16 pages, 329 KiB

Open AccessArticle

The Effective Potential of Scalar Pseudo-Quantum Electrodynamics in (2 + 1)D

by Leandro O. Nascimento, Carlos A. P. C. Junior and José R. Santos

Condens. Matter 2024, 9(2), 25; https://doi.org/10.3390/condmat9020025 - 30 May 2024

Abstract

The description of the electron–electron interactions in two-dimensional materials has a dimensional mismatch, where electrons live in (2 + 1)D while photons propagate in (3 + 1)D. In order to define an action in (2 + 1)D, one may perform a dimensional reduction [...] Read more.

The description of the electron–electron interactions in two-dimensional materials has a dimensional mismatch, where electrons live in (2 + 1)D while photons propagate in (3 + 1)D. In order to define an action in (2 + 1)D, one may perform a dimensional reduction of quantum electrodynamics in (3 + 1)D (QED4) into pseudo-quantum electrodynamics (PQED). The main difference between this model and QED4 is the presence of a pseudo-differential operator in the Maxwell term. However, besides the Coulomb repulsion, electrons in a material are subjected to several microscopic interactions, which are inherent in a many-body system. These are expected to reduce the range of the Coulomb potential, leading to a short-range interaction. Here, we consider the coupling to a scalar field in PQED for explaining such a mechanism, which resembles the spontaneous symmetry breaking (SSB) in Abelian gauge theories. In order to do so, we consider two cases: (i) by coupling the quantum electrodynamics to a Higgs field in (3 + 1)D and, thereafter, performing the dimensional reduction; and (ii) by coupling a Higgs field to the gauge field in PQED and, subsequently, calculating its effective potential. In case (i), we obtain a model describing electrons interacting through the Yukawa potential and, in case (ii), we show that SSB does not occur at one-loop approximation. The relevance of the model for describing electronic interactions in two-dimensional materials is also addressed. Full article

(This article belongs to the Special Issue PQED: 30 Years of Reduced Quantum Electrodynamics)

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21 pages, 13335 KiB

Open AccessArticle

Coordinated Transport by Dual Humanoid Robots Using Distributed Model Predictive Control

by Shengjun Wen, Zhaoyuan Shi and Hongjun Li

Biomimetics 2024, 9(6), 332; https://doi.org/10.3390/biomimetics9060332 - 30 May 2024

Abstract

Dual humanoid robot collaborative control systems possess better flexibility and adaptability in complex environments due to their similar structures to humans. This paper adopts a distributed model predictive controller based on the leader–follower approach to address the collaborative transportation control issue of dual [...] Read more.

Dual humanoid robot collaborative control systems possess better flexibility and adaptability in complex environments due to their similar structures to humans. This paper adopts a distributed model predictive controller based on the leader–follower approach to address the collaborative transportation control issue of dual humanoid robots. In the dual-robot collaborative control system, network latency issues may arise due to unstable network conditions, affecting the consistency of dual-robot collaboration. To solve this issue, a communication protocol was constructed through socket communication for dual-robot collaborative consistency, thereby resolving the problem of consistency in dual humanoid robot collaboration. Additionally, due to the complex structure of humanoid robots, there are deficiencies in position tracking accuracy during movement. To address the poor accuracy in position tracking, this paper proposes a distributed model predictive control that considers historical cumulative error, thus enhancing the position tracking accuracy of dual-robot collaborative control. Full article

(This article belongs to the Special Issue Bio-Inspired Approaches—a Leverage for Robotics)

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Graphical abstract

24 pages, 1612 KiB

Open AccessArticle

A Grey Wolf Optimizer Algorithm for Multi-Objective Cumulative Capacitated Vehicle Routing Problem Considering Operation Time

by Gewen Huang, Yuanhang Qi, Yanguang Cai, Yuhui Luo and Helie Huang

Biomimetics 2024, 9(6), 331; https://doi.org/10.3390/biomimetics9060331 - 30 May 2024

Abstract

In humanitarian aid scenarios, the model of cumulative capacitated vehicle routing problem can be used in vehicle scheduling, aiming at delivering materials to recipients as quickly as possible, thus minimizing their wait time. Traditional approaches focus on this metric, but practical implementations must [...] Read more.

In humanitarian aid scenarios, the model of cumulative capacitated vehicle routing problem can be used in vehicle scheduling, aiming at delivering materials to recipients as quickly as possible, thus minimizing their wait time. Traditional approaches focus on this metric, but practical implementations must also consider factors such as driver labor intensity and the capacity for on-site decision-making. To evaluate driver workload, the operation times of relief vehicles are typically used, and multi-objective modeling is employed to facilitate on-site decision-making. This paper introduces a multi-objective cumulative capacitated vehicle routing problem considering operation time (MO-CCVRP-OT). Our model is bi-objective, aiming to minimize both the cumulative wait time of disaster-affected areas and the extra expenditures incurred by the excess operation time of rescue vehicles. Based on the traditional grey wolf optimizer algorithm, this paper proposes a dynamic grey wolf optimizer algorithm with floating 2-opt (DGWO-F2OPT), which combines real number encoding with an equal-division random key and ROV rules for decoding; in addition, a dynamic non-dominated solution set update strategy is introduced. To solve MO-CCVRP-OT efficiently and increase the algorithm’s convergence speed, a multi-objective improved floating 2-opt (F2OPT) local search strategy is proposed. The utopia optimum solution of DGWO-F2OPT has an average value of two fitness values that is 6.22% lower than that of DGWO-2OPT. DGWO-F2OPT’s average fitness value in the algorithm comparison trials is 16.49% less than that of NS-2OPT. In the model comparison studies, MO-CCVRP-OT is 18.72% closer to the utopian point in Euclidean distance than CVRP-OT. Full article

(This article belongs to the Special Issue Nature-Inspired Metaheuristic Optimization Algorithms 2024)

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17 pages, 10191 KiB

Open AccessArticle

Evolutionary Approach to Optimal Oil Skimmer Assignment for Oil Spill Response: A Case Study

by Yong-Hyuk Kim, Hye-Jin Kim, Dong-Hee Cho and Yourim Yoon

Biomimetics 2024, 9(6), 330; https://doi.org/10.3390/biomimetics9060330 - 30 May 2024

Abstract

We propose a genetic algorithm for optimizing oil skimmer assignments, introducing a tailored repair operation for constrained assignments. Methods essentially involve simulation-based evaluation to ensure adherence to South Korea’s regulations. Results show that the optimized assignments, compared to current ones, reduced work time [...] Read more.

We propose a genetic algorithm for optimizing oil skimmer assignments, introducing a tailored repair operation for constrained assignments. Methods essentially involve simulation-based evaluation to ensure adherence to South Korea’s regulations. Results show that the optimized assignments, compared to current ones, reduced work time on average and led to a significant reduction in total skimmer capacity. Additionally, we present a deep neural network-based surrogate model, greatly enhancing efficiency compared to simulation-based optimization. Addressing inefficiencies in mobilizing locations that store oil skimmers, further optimization aimed to minimize mobilized locations and was validated through scenario-based simulations resembling actual situations. Based on major oil spills in South Korea, this strategy significantly reduced work time and required locations. These findings demonstrate the effectiveness of the proposed genetic algorithm and mobilized location minimization strategy in enhancing oil spill response operations. Full article

(This article belongs to the Special Issue Nature-Inspired Metaheuristic Optimization Algorithms 2024)

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24 pages, 7372 KiB

Open AccessArticle

Bioinspired Control Architecture for Adaptive and Resilient Navigation of Unmanned Underwater Vehicle in Monitoring Missions of Submerged Aquatic Vegetation Meadows

by Francisco García-Córdova, Antonio Guerrero-González and Fernando Hidalgo-Castelo

Biomimetics 2024, 9(6), 329; https://doi.org/10.3390/biomimetics9060329 - 30 May 2024

Abstract

Submerged aquatic vegetation plays a fundamental role as a habitat for the biodiversity of marine species. To carry out the research and monitoring of submerged aquatic vegetation more efficiently and accurately, it is important to use advanced technologies such as underwater robots. However, [...] Read more.

Submerged aquatic vegetation plays a fundamental role as a habitat for the biodiversity of marine species. To carry out the research and monitoring of submerged aquatic vegetation more efficiently and accurately, it is important to use advanced technologies such as underwater robots. However, when conducting underwater missions to capture photographs and videos near submerged aquatic vegetation meadows, algae can become entangled in the propellers and cause vehicle failure. In this context, a neurobiologically inspired control architecture is proposed for the control of unmanned underwater vehicles with redundant thrusters. The proposed control architecture learns to control the underwater robot in a non-stationary environment and combines the associative learning method and vector associative map learning to generate transformations between the spatial and velocity coordinates in the robot actuator. The experimental results obtained show that the proposed control architecture exhibits notable resilience capabilities while maintaining its operation in the face of thruster failures. In the discussion of the results obtained, the importance of the proposed control architecture is highlighted in the context of the monitoring and conservation of underwater vegetation meadows. Its resilience, robustness, and adaptability capabilities make it an effective tool to face challenges and meet mission objectives in such critical environments. Full article

(This article belongs to the Special Issue Bio-Inspired Underwater Robots: 2nd Edition)

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18 pages, 1873 KiB

Open AccessArticle

Autocatalysis, Autopoiesis, and the Opportunity Cost of Individuality

by Nemanja Kliska and Chrystopher L. Nehaniv

Biomimetics 2024, 9(6), 328; https://doi.org/10.3390/biomimetics9060328 - 30 May 2024

Abstract

Ever since Varela and Maturana proposed the concept of autopoiesis as the minimal requirement for life, there has been a focus on cellular systems that erect topological boundaries to separate themselves from their surrounding environment. Here, we reconsider whether the existence of such [...] Read more.

Ever since Varela and Maturana proposed the concept of autopoiesis as the minimal requirement for life, there has been a focus on cellular systems that erect topological boundaries to separate themselves from their surrounding environment. Here, we reconsider whether the existence of such a spatial boundary is strictly necessary for self-producing entities. This work presents a novel computational model of a minimal autopoietic system inspired by dendrites and molecular dynamic simulations in three-dimensional space. A series of simulation experiments where the metabolic pathways of a particular autocatalytic set are successively inhibited until autocatalytic entities that could be considered autopoietic are produced. These entities maintain their distinctness in an environment containing multiple identical instances of the entities without the existence of a topological boundary. This gives rise to the concept of a metabolic boundary which manifests as emergent self-selection criteria for the processes of self-production without any need for unique identifiers. However, the adoption of such a boundary comes at a cost, as these autopoietic entities are less suited to their simulated environment than their autocatalytic counterparts. Finally, this work showcases a generalized metabolism-centered approach to the study of autopoiesis that can be applied to both physical and abstract systems alike. Full article

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19 pages, 597 KiB

Open AccessReview

Factors Affecting the Quality of Probiotic Plant-Based Frozen Desserts—The Authors’ Own Experiments in the Context of the Literature

by Aleksandra Szydłowska, Dorota Zielińska, Barbara Sionek and Danuta Kołożyn-Krajewska

Fermentation 2024, 10(6), 291; https://doi.org/10.3390/fermentation10060291 - 30 May 2024

Abstract

Recently, there has been worldwide growth in consumer nutrition awareness, which has resulted in a market-driven increase in the demand for “functional food”, which, in addition to traditional nutrients, also contains ingredients with specific properties that have a beneficial effect on human health. [...] Read more.

Recently, there has been worldwide growth in consumer nutrition awareness, which has resulted in a market-driven increase in the demand for “functional food”, which, in addition to traditional nutrients, also contains ingredients with specific properties that have a beneficial effect on human health. One of the types of functional food is so-called “probiotic food”, which includes, for example, frozen desserts. These products appear attractive to the consumer because of their sensory, nutritional and refreshing qualities. Due to progress in science, genetics, the acquisition of new sources of probiotic microorganisms and new plant varieties, the beneficial effects of the characteristic metabolites of the microbiome—so-called postbiotics—and also aspects of NGPs (Next Generation Probiotics), work is under way to optimize the technology used during the production of such products. At the same time, there is an observed market-based increase in the supply of new formulations based only on plant-origin materials with different technological modifications, including prebiotic enrichment, which allows for the production of a synbiotic product. Therefore, the objective of this study is a narrative review, in combination with the authors’ own experiments, concerning the impact of various factors on functional, plant-origin frozen desserts, from the point of view of maintaining their quality. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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18 pages, 2864 KiB

Open AccessArticle

Bioproduction of 2-Phenylethanol by Yarrowia lipolytica on Sugar Beet Molasses as a Low-Cost Substrate

by Sara Mitri, Nicolas Louka, Tristan Rossignol, Richard G. Maroun and Mohamed Koubaa

Fermentation 2024, 10(6), 290; https://doi.org/10.3390/fermentation10060290 - 30 May 2024

Abstract

2-phenylethanol (2-PE) is a valuable aromatic alcohol with diverse applications in cosmetics, food, beverages, and pharmaceutical industries. Currently, 2-PE is produced either through chemical synthesis or by extraction from plant materials. However, both conventional production methods have their own limitations. Therefore, there is [...] Read more.

2-phenylethanol (2-PE) is a valuable aromatic alcohol with diverse applications in cosmetics, food, beverages, and pharmaceutical industries. Currently, 2-PE is produced either through chemical synthesis or by extraction from plant materials. However, both conventional production methods have their own limitations. Therefore, there is a need for more eco-friendly and cost-effective approaches to produce natural 2-PE. Biotechnological routes, particularly microbial fermentations, hold promise for natural 2-PE production, especially when using low-cost substrates. In this study, 2-PE was produced by de novo synthesis via the shikimate pathway, using the yeast Yarrowia lipolytica in a medium composed of sugar beet molasses (SBM) and yeast extract (YE) as carbon and nitrogen sources, respectively. A genetically engineered strain was generated, in which the SUC2 gene was transformed, expressing the invertase enzyme, enabling Y. lipolytica to efficiently utilize SBM as a cost-effective substrate. A central composite design allowed for the optimization of the concentrations of the carbon and nitrogen sources, resulting in approximately 0.71 g_(2-PE)/L_{(culture medium)}. The results obtained highlight the potential of utilizing SBM as a low-cost substrate for 2-PE production, advancing biotechnological approaches in fragrance synthesis. Full article

(This article belongs to the Special Issue Production of Added-Value Products from Renewable Resources and Engineered Cell Factories)

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18 pages, 2014 KiB

Open AccessReview

Harnessing the Potential of Sludge Fermentation Liquid to Induce Partial Nitrification

by Xu Wang, Cancan Jiang, Danhua Wang, Lijing Fan, Yang Yang, Tiancheng Yang, Jiang Peng, Xinyuan Zhang and Xuliang Zhuang

Fermentation 2024, 10(6), 289; https://doi.org/10.3390/fermentation10060289 - 30 May 2024

Abstract

Extra energy consumption, inefficient nitrogen removal, and excessive sludge production are major challenges faced by wastewater treatment plants (WWTPs) that rely on the traditional activated sludge process. Fermentation of wasted activated sludge (WAS) and novel nitrogen removal technologies based on partial nitrification (PN) [...] Read more.

Extra energy consumption, inefficient nitrogen removal, and excessive sludge production are major challenges faced by wastewater treatment plants (WWTPs) that rely on the traditional activated sludge process. Fermentation of wasted activated sludge (WAS) and novel nitrogen removal technologies based on partial nitrification (PN) have emerged as promising solutions to these issues. Recent studies have revealed an innovative strategy that integrates these two processes by supplementing fermentation liquid into activated sludge to induce PN. This review summarizes the research progress on PN establishment induced by the fermentation process. The microbiology and establishment methods of PN are briefly introduced, followed by a detailed discussion on the process, influencing factors, and product characteristics of WAS fermentation. The core section focuses on the side-stream and main-stream approaches of fermentation-induced PN, comparing their performance and application prospects. The potential mechanisms are explored, with an emphasis on the roles of free ammonia for the side-stream approach and the high tolerance of ammonium oxidizers to in-site fermentation stress for the main-stream approach. Finally, the limitations of the current research and future perspectives are discussed, highlighting the need for further investigation into microbial ecology, process optimization, and long-term stability. This review aims to provide insights into the synergistic integration of WAS fermentation and PN for sustainable and energy-efficient wastewater treatment. Full article

(This article belongs to the Special Issue Treatment of Municipal Wastewater by Anaerobic Biotechnology)

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10 pages, 2019 KiB

Open AccessArticle

Identification and Characterization of Yeast Species Isolated from Cornus kousa Fruits in Japan

by Norihiro Otani, Kieu D. M. Nguyen, Atsushi Hirokawa, Yasuharu Kanki, Hyun-Sik Yun, Yoshiaki Maeda, Wenchao Gu, Yoichiro Takahashi and Takehito Sugasawa

Fermentation 2024, 10(6), 288; https://doi.org/10.3390/fermentation10060288 - 30 May 2024

Abstract

The Cornus kousa tree, which is of Asian origin, is often cultivated for ornamental purposes and used in traditional medicine. The tree produces sugar-rich fruits, which are potential habitats for natural yeasts. The identification of new yeast strains has many advantages for the [...] Read more.

The Cornus kousa tree, which is of Asian origin, is often cultivated for ornamental purposes and used in traditional medicine. The tree produces sugar-rich fruits, which are potential habitats for natural yeasts. The identification of new yeast strains has many advantages for the industry and research. This study aimed to isolate and identify yeast species from C. kousa fruits and to understand their microbial ecology. Ripe and rotten fruits, which had fallen on the ground naturally, were collected and soaked in culture media, followed by plate spreading for colony growth. The morphological examination revealed three distinct colony types, including two from the ripe fruits and one from the rotten fruits. The analysis of the internal transcribed spacer 1 region indicated three yeast strains corresponding to the three colony types: Torulaspora delbrueckii and Pichia kluyveri from the ripe fruits and Saccharomyces cerevisiae from the rotten fruits. The metabolic characterizations demonstrated that all three yeasts efficiently consumed glucose and produced alcohol. S. cerevisiae exhibited the strongest fermentation ability and the highest growth rate. These findings showed that Cornus kousa fruit is a source of diverse yeast species, with distinct species associated with different states of fruit decomposition. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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23 pages, 5300 KiB

Open AccessArticle

Half-Curcuminoids Encapsulated in Alginate–Glucosamine Hydrogel Matrices as Bioactive Delivery Systems

by Florentina Monica Raduly, Valentin Raditoiu, Alina Raditoiu, Cristian Andi Nicolae, Maria Grapin, Miruna Silvia Stan, Ionela Cristina Voinea, Raluca-Ioana Vlasceanu, Cristina Doina Nitu, Dan F. Mihailescu, Speranta Avram and Maria Mernea

Gels 2024, 10(6), 376; https://doi.org/10.3390/gels10060376 - 30 May 2024

Abstract

The therapeutic effects of curcumin and its derivatives, based on research in recent years, are limited by their low bioavailability. To improve bioavailability and develop the medical field of application, different delivery systems have been developed that are adapted to certain environments or [...] Read more.

The therapeutic effects of curcumin and its derivatives, based on research in recent years, are limited by their low bioavailability. To improve bioavailability and develop the medical field of application, different delivery systems have been developed that are adapted to certain environments or the proposed target type. This study presents some half-curcuminoids prepared by the condensation of acetylacetone with 4-hydroxybenzaldehyde (C1), 4-hydroxy-3-methoxybenzaldehyde (C2), 4-acetamidobenzaldehyde (C3), or 4-diethylaminobenzaldehyde (C4), at microwaves as a simple, solvent-free, and eco-friendly method. The four compounds obtained were characterized in terms of morphostructural and photophysical properties. Following the predictions of theoretical studies on the biological activities related to the molecular structure, in vitro tests were performed for compounds C1–C3 to evaluate the antitumor properties and for C4’s possible applications in the treatment of neurological diseases. The four compounds were encapsulated in two types of hydrogel matrices. First, the alginate–glucosamine network was generated and then the curcumin analogs were loaded (G1, G3, G5–G7, and G9). The second type of hydrogels was obtained by loading the active compound together with the generation of the hydrogel carrier matrices, by simply dissolving (G4 and G10) or by chemically binding half-curcuminoid derivatives to glucosamine (G2 and G8). Thus, two types of curcumin analog delivery systems were obtained, which could be applied in various types of medical treatments. Full article

(This article belongs to the Special Issue Advances in Hydrogels for Biomedical Applications)

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19 pages, 4232 KiB

Open AccessArticle

Control of Fusarium Head Blight of Wheat with Bacillus velezensis E2 and Potential Mechanisms of Action

by Jianing Ma, Chen Gao, Meiwei Lin, Zhenzhong Sun, Yuhao Zhao, Xin Li, Tianyuan Zhao, Xingang Xu and Weihong Sun

J. Fungi 2024, 10(6), 390; https://doi.org/10.3390/jof10060390 - 30 May 2024

Abstract

Wheat plants are impacted by Fusarium head blight (FHB) infection, which poses a huge threat to wheat growth, development, storage and food safety. In this study, a fungal strain was isolated from diseased wheat plants and identified as Fusarium asiaticum F1, known to [...] Read more.

Wheat plants are impacted by Fusarium head blight (FHB) infection, which poses a huge threat to wheat growth, development, storage and food safety. In this study, a fungal strain was isolated from diseased wheat plants and identified as Fusarium asiaticum F1, known to be a member of the Fusarium graminearum species complex, agents causally responsible for FHB. In order to control this disease, new alternatives need to be developed for the use of antagonistic bacteria. Bacillus velezensis E2 (B. velezensis E2), isolated from a previous investigation in our laboratory, showed a notable inhibitory effect on F. asiaticum F1 growth and deoxynivalenol (DON) synthesis in grains. The spore germination of F. asiaticum F1 was significantly reduced and the spores showed vesicular structures when treated with B. velezensis E2. Observations using scanning electron microscopy (SEM) showed that the hyphae of F. asiaticum F1 were shrunken and broken when treated with B. velezensis E2. The RNA-seq results of F1 hyphae treated with B. velezensis E2 showed that differentially expressed genes (DEGs), which were involved in multiple metabolic pathways such as toxin synthesis, autophagy process and glycan synthesis, especially the genes associated with DON synthesis, were significantly downregulated. In summary, those results showed that B. velezensis E2 could inhibit F. asiaticum F1 growth and reduce the gene expression of DON synthesis caused by F1. This study provides new insights and antagonistic mechanisms for the biological control of FHB during wheat growth, development and storage. Full article

(This article belongs to the Special Issue Fungal Metabolism in Filamentous Fungi: 2nd Edition)

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20 pages, 2533 KiB

Open AccessReview

The Easily Overlooked Effect of Global Warming: Diffusion of Heavy Metals

by Wenqi Xiao, Yunfeng Zhang, Xiaodie Chen, Ajia Sha, Zhuang Xiong, Yingyong Luo, Lianxin Peng, Liang Zou, Changsong Zhao and Qiang Li

Toxics 2024, 12(6), 400; https://doi.org/10.3390/toxics12060400 - 30 May 2024

Abstract

Since industrialization, global temperatures have continued to rise. Human activities have resulted in heavy metals being freed from their original, fixed locations. Because of global warming, glaciers are melting, carbon dioxide concentrations are increasing, weather patterns are shifting, and various environmental forces are [...] Read more.

Since industrialization, global temperatures have continued to rise. Human activities have resulted in heavy metals being freed from their original, fixed locations. Because of global warming, glaciers are melting, carbon dioxide concentrations are increasing, weather patterns are shifting, and various environmental forces are at play, resulting in the movement of heavy metals and alteration of their forms. In this general context, the impact of heavy metals on ecosystems and organisms has changed accordingly. For most ecosystems, the levels of heavy metals are on the rise, and this rise can have a negative impact on the ecosystem as a whole. Numerous studies have been conducted to analyze the combined impacts of climate change and heavy metals. However, the summary of the current studies is not perfect. Therefore, this review discusses how heavy metals affect ecosystems during the process of climate change from multiple perspectives, providing some references for addressing the impact of climate warming on environmental heavy metals. Full article

(This article belongs to the Section Metals and Radioactive Substances)

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14 pages, 2061 KiB

Open AccessArticle

Multi-Omics Analysis Reveals the Toxicity of Polyvinyl Chloride Microplastics toward BEAS-2B Cells

by Chengzhi Liu, Shuang Chen, Jiangliang Chu, Yifan Yang, Beilei Yuan and Huazhong Zhang

Toxics 2024, 12(6), 399; https://doi.org/10.3390/toxics12060399 - 30 May 2024

Abstract

Polyvinyl chloride microplastics (PVC-MPs) are microplastic pollutants widely present in the environment, but their potential risks to human lung health and underlying toxicity mechanisms remain unknown. In this study, we systematically analyzed the effects of PVC-MPs on the transcriptome and metabolome of BEAS-2B [...] Read more.

Polyvinyl chloride microplastics (PVC-MPs) are microplastic pollutants widely present in the environment, but their potential risks to human lung health and underlying toxicity mechanisms remain unknown. In this study, we systematically analyzed the effects of PVC-MPs on the transcriptome and metabolome of BEAS-2B cells using high-throughput RNA sequencing and untargeted metabolomics technologies. The results showed that exposure to PVC-MPs significantly reduced the viability of BEAS-2B cells, leading to the differential expression of 530 genes and 3768 metabolites. Further bioinformatics analyses showed that PVC-MP exposure influenced the expression of genes associated with fluid shear stress, the MAPK and TGF-β signaling pathways, and the levels of metabolites associated with amino acid metabolism. In particular, integrated pathway analysis showed that lipid metabolic pathways (including glycerophospholipid metabolism, glycerolipid metabolism, and sphingolipid metabolism) were significantly perturbed in BEAS-2B cells following PVC-MPs exposure. This study provides new insights and targets for a deeper understanding of the toxicity mechanism of PVC-MPs and for the prevention and treatment of PVC-MP-associated lung diseases. Full article

(This article belongs to the Special Issue State-of-the-Art Environmental Chemicals Exposomics and Metabolomics)

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