All articles published by MDPI are made immediately available worldwide under an open access license. No special
permission is required to reuse all or part of the article published by MDPI, including figures and tables. For
articles published under an open access Creative Common CC BY license, any part of the article may be reused without
permission provided that the original article is clearly cited. For more information, please refer to
https://www.mdpi.com/openaccess.
Feature papers represent the most advanced research with significant potential for high impact in the field. A Feature
Paper should be a substantial original Article that involves several techniques or approaches, provides an outlook for
future research directions and describes possible research applications.
Feature papers are submitted upon individual invitation or recommendation by the scientific editors and must receive
positive feedback from the reviewers.
Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world.
Editors select a small number of articles recently published in the journal that they believe will be particularly
interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the
most exciting work published in the various research areas of the journal.
This study investigates the efficacy of a novel low-cost phosphate adsorbent, denoted as SH-CGCS, derived from coal gasification coarse slag (CGCS) via an alkali activation method. SH-CGCS is a mesoporous material with a specific surface area (64 m2/g) approximately six times
[...] Read more.
This study investigates the efficacy of a novel low-cost phosphate adsorbent, denoted as SH-CGCS, derived from coal gasification coarse slag (CGCS) via an alkali activation method. SH-CGCS is a mesoporous material with a specific surface area (64 m2/g) approximately six times larger than CGCS (11 m2/g), which enhances its adsorption capacity compared with CGCS. Furthermore, SH-CGCS achieves a phosphate adsorption capacity of 38.5 mg/g in strongly acidic water (pH 3) and demonstrates robust acid resistance, which makes it particularly effective for phosphate removal from acidic wastewater. Results from coexisting anion experiments affirm the good adsorption selectivity of SH-CGCS for phosphate. Moreover, SH-CGCS exhibits proficiency in treating water containing low phosphate concentrations under flowing conditions. The maximum phosphate adsorption capacity of SH-CGCS calculated using the Langmuir model is 23.92 mg/g, surpassing that of other reported adsorbents. Importantly, saturated SH-CGCS can be regenerated and reused, which contributes to its practical applicability. The adsorption mechanisms of SH-CGCS for phosphate involve ligand exchange, inner-sphere complexation, surface precipitation, and electrostatic adsorption. Thus, this study not only enhances the overall utility of CGCS but also presents a simple and efficient method for removing phosphate. Our findings indicate that SH-CGCS holds considerable potential as a phosphate adsorbent, offering a promising solution for wastewater treatment.
Full article
The authors investigated the impact of active learning STEM and STEAM approaches on secondary school students’ general engineering knowledge, intrinsic relevance, and creativity. Three out-of-school sensor-based courses were held successively. Every sensor-based course involved the final project development. A structured questionnaire was administered
[...] Read more.
The authors investigated the impact of active learning STEM and STEAM approaches on secondary school students’ general engineering knowledge, intrinsic relevance, and creativity. Three out-of-school sensor-based courses were held successively. Every sensor-based course involved the final project development. A structured questionnaire was administered to 379 students and consisted of two critical factors: creativity and intrinsic relevance. The third factor was dedicated to the students’ engineering learning outcomes. Two factors were addressed to secondary school students, while the third factor was addressed to the tutors’ observations of the students’ general sensor-based knowledge. Clustering validation analysis quantified the obtained results and justified the significant differences in all estimated factors for different educational modes. Moreover, the study showcases the value of the arts in sensor-based learning-by-doing courses when tackling complex issues like engineering topics. The authors suggest that broader research be undertaken, involving a larger sample, a greater scale, and a diversity of factors.
Full article
Basic motor skills are recognized as fundamental movements that allow children to interact with their environment and are identified as the basic structure on which more complex movements are built. Objective: to identify the level of motor development of children from 3 to
[...] Read more.
Basic motor skills are recognized as fundamental movements that allow children to interact with their environment and are identified as the basic structure on which more complex movements are built. Objective: to identify the level of motor development of children from 3 to 10 years of age according to sex and age group. Methodology. We studied a sample with a total of 328 participants (girls = 170; boys = 158) at preschool (n = 154) and school levels (n = 174). The ages of the students ranged from 3 to 10 years, with a mean of 5.94 years (±2.53). TGMD2 was applied to identify motor development. Results: boys and girls present low levels of physical activity, with most of them in the very poor, poor, and low-average categories (n = 182, 55.5%). Levels of motor development in locomotion, manipulation, and general development by age show significant differences (p = 0.000). However, levels of development by sex are not significant in manipulation, locomotion, and gross motor skills tests, respectively (p = 0.150, p = 0.208, and p = 0.210), and in relation to chronological age and motor development age show significant differences (p = 0.000).
Full article
Inflammatory Bowel Disease (IBD) is a complex and challenging health problem that exerts a significant impact on the quality of life of millions of individuals worldwide [...]
Full article
by
Natália Lopes Castilho, Daniella R. Barbosa Martelli, Renato Assis Machado, Zêus Araujo Cunha, Claudiojanes dos Reis, Priscila Regina Queiroz, Dayane de Sá Silva, Eduardo Araujo Oliveira, Ricardo D. Coletta and Hercílio Martelli-Júnior
COVID-19, a respiratory illness with a global impact on millions, has recently been linked to manifestations affecting various bodily systems, including the oral cavity. Studies highlight oral issues, like ulcers, blisters, and white patches, alongside olfactory and gustatory dysfunction, influencing an individual’s quality
[...] Read more.
COVID-19, a respiratory illness with a global impact on millions, has recently been linked to manifestations affecting various bodily systems, including the oral cavity. Studies highlight oral issues, like ulcers, blisters, and white patches, alongside olfactory and gustatory dysfunction, influencing an individual’s quality of life. In this context, our study aimed to assess the frequency of oral lesions, olfactory and gustatory disorders, and xerostomia resulting from COVID-19. An observational study was conducted with 414 patients to evaluate the frequency of oral symptoms resulting from COVID-19. Patients were diagnosed with mild symptoms and evaluated through clinical examination of the oral cavity and a questionnaire to assess functional alterations. The findings showed that 139 out of 414 patients presented clinical manifestations, with oral lesions being the most prevalent (19.1%), followed by gustatory disorders (18.1%), xerostomia (14.2%), and olfactory dysfunction (14%). The most prevalent oral lesions were ulcerations (n = 51), candidiasis (n = 8), and erythema or red plaques (n = 7). Unfortunately, 50 (12.1%) patients died during this study. Therefore, oral lesions, olfactory and gustatory dysfunctions, and xerostomia are common symptoms associated with COVID-19.
Full article
Vascular endothelial cells form a monolayer in the vascular lumen and act as a selective barrier to control the permeability between blood and tissues. To maintain homeostasis, the endothelial barrier function must be strictly integrated. During acute inflammation, vascular permeability temporarily increases, allowing
[...] Read more.
Vascular endothelial cells form a monolayer in the vascular lumen and act as a selective barrier to control the permeability between blood and tissues. To maintain homeostasis, the endothelial barrier function must be strictly integrated. During acute inflammation, vascular permeability temporarily increases, allowing intravascular fluid, cells, and other components to permeate tissues. Moreover, it has been suggested that the dysregulation of endothelial cell permeability may cause several diseases, including edema, cancer, and atherosclerosis. Here, we reviewed the molecular mechanisms by which endothelial cells regulate the barrier function and physiological permeability.
Full article
The coastal zone is constantly under pressure from human activities. One of these pressures is the concentration of solid waste that has escaped from the sanitation system in place. The Togolese coastline, mainly the segment from Aflao to Kpogan, is overrun by waste
[...] Read more.
The coastal zone is constantly under pressure from human activities. One of these pressures is the concentration of solid waste that has escaped from the sanitation system in place. The Togolese coastline, mainly the segment from Aflao to Kpogan, is overrun by waste from households and various socioeconomic activities and is faced with the challenges of unregulated solid waste management. This situation is contributing to the degradation of the urban landscape and is giving rise to environmental and health risks. The aim of this study is to carry out a physical characterisation and analyse the perception of the potential environmental and health risks involved. The methodology included documentary research, site mapping, physical characterisation of waste using the MODECOM approach, principal component analysis and a survey of 300 households in our study area. The results show the poor waste management that prevails along the Lomé coastline, with the anarchic proliferation of waste dumps: 13 categories of waste including a predominance of flexible plastic waste out of a total of 510 kg collected. The results show that the environment is deteriorating, with unsightly, unpleasant smells and the presence of pests. These environmental risks expose the population to diseases such as malaria, lung infection, diarrhoea, typhoid fever and skin diseases.
Full article
Photocatalysis represents a sustainable strategy for addressing energy shortages and global warming. The main challenges in the photocatalytic process include limited light absorption, rapid recombination of photo-induced carriers, and poor surface catalytic activity for reactant molecules. Defect engineering in photocatalysts has been proven
[...] Read more.
Photocatalysis represents a sustainable strategy for addressing energy shortages and global warming. The main challenges in the photocatalytic process include limited light absorption, rapid recombination of photo-induced carriers, and poor surface catalytic activity for reactant molecules. Defect engineering in photocatalysts has been proven to be an efficient approach for improving solar-to-chemical energy conversion. Sulfur vacancies can adjust the electron structure, act as electron reservoirs, and provide abundant adsorption and activate sites, leading to enhanced photocatalytic activity. In this work, we aim to elucidate the role of sulfur vacancies in photocatalytic reactions and provide valuable insights for engineering high-efficiency photocatalysts with abundant sulfur vacancies in the future. First, we delve into the fundamental understanding of photocatalysis. Subsequently, various strategies for fabricating sulfur vacancies in photocatalysts are summarized, along with the corresponding characterization techniques. More importantly, the enhanced photocatalytic mechanism, focusing on three key factors, including electron structure, charge transfer, and the surface catalytic reaction, is discussed in detail. Finally, the future opportunities and challenges in sulfur vacancy engineering for photocatalysis are identified.
Full article
by
Andrés Jiménez-Sánchez, José Luis Pereira-Cunill, María Luisa Limón-Mirón, Amelia López-Ladrón, Francisco Javier Salvador-Bofill and Pedro Pablo García-Luna
Nutrients2024, 16(12), 1824; https://doi.org/10.3390/nu16121824 (registering DOI) - 11 Jun 2024
Background: Reduced muscle strength (dynapenia) and mass (atrophy) are prognostic factors in oncology. Measuring maximal handgrip strength with dynamometers is feasible but limited by the cost of the reference device (JAMAR). Methods: A cross-sectional study was conducted on colorectal cancer outpatients treated with
[...] Read more.
Background: Reduced muscle strength (dynapenia) and mass (atrophy) are prognostic factors in oncology. Measuring maximal handgrip strength with dynamometers is feasible but limited by the cost of the reference device (JAMAR). Methods: A cross-sectional study was conducted on colorectal cancer outpatients treated with chemotherapy or under active surveillance in our center from September 2022 to July 2023. Accuracy, reliability, and concordance were compared for two handheld dynamometers: the JAMAR Plus (the gold-standard device) and the Camry EH101 (a low-cost index device). A simultaneous nutritional diagnosis with GLIM criteria and bioelectrical impedance analysis (BIA) was carried out. Results: A total of 134 participants were included. The median of maximal strength for the JAMAR Plus had a non-significant difference of 1.4 kg from the Camry EH101. The accuracy and reliability of the devices were high. Bland–Altman analysis showed a 0.8 kg bias and −4.1 to 5.6 kg limits of agreement (LoA); a 0.1 kg bias and −5.3 to 5.4 kg LoA in men; a 1.5 kg bias and −2.2 to 5.3 kg LoA in women. In total, 29.85% of the participants were malnourished. Prevalence of dynapenia increased from 3.67% with the JAMAR Plus to 5.14% with the Camry EH101. Both devices had a moderate and significant correlation with BIA-estimated muscle mass. Conclusions: The Camry EH101 was a cost-effective alternative to JAMAR Plus in our sample.
Full article
This paper investigates the cooperative formation trajectory tracking problem for heterogeneous unmanned aerial vehicle (UAV) and multiple unmanned surface vessel (USV) systems with input quantization performance. Firstly, at the kinematic level, a distributed guidance law based on an extended state observer (ESO) is
[...] Read more.
This paper investigates the cooperative formation trajectory tracking problem for heterogeneous unmanned aerial vehicle (UAV) and multiple unmanned surface vessel (USV) systems with input quantization performance. Firstly, at the kinematic level, a distributed guidance law based on an extended state observer (ESO) is designed to compensate for the unknown speed of neighbor agents for expected trajectory tracking, and subsequently at the dynamic level, an ESO is utilized to estimate model uncertainties and environmental disturbances. Following that, a linear analytic model is employed to depict the input quantization process, and the corresponding adaptive quantization controller is designed without necessitating prior information on quantization parameters. Based on the input-to-state stability, the stability of the proposed control structure is proved, and all the signals in the closed-loop system are ultimately bounded. Finally, a simulation study is provided to show the efficacy of the proposed strategy.
Full article
This paper introduces a novel type of prefabricated semi-rigid concrete beam–column joint, aiming to examine its load-carrying capacity and seismic performance in comparison with a traditional cast-in-place joint. This study utilized the ABAQUS 2020 software to establish finite element models for both types
[...] Read more.
This paper introduces a novel type of prefabricated semi-rigid concrete beam–column joint, aiming to examine its load-carrying capacity and seismic performance in comparison with a traditional cast-in-place joint. This study utilized the ABAQUS 2020 software to establish finite element models for both types of joints and conducted finite element analysis under low circumferential reciprocating displacement loads. When comparing the energy dissipation capacity, ductility, ultimate load-carrying capacity, stress mechanism, and damage mode, a comprehensive evaluation of the two types of joints was performed. Furthermore, this study investigated the impacts of various factors such as the axial compression ratio, concrete strength, reinforcement strength, and connector strength on the ultimate load-carrying capacity, ductility, and energy dissipation performance of the joints. Based on the findings, the newly combined joint exhibited a substantial 31.7% increase in its ultimate load-carrying capacity, along with a notable 7.23% enhancement in ductility and an improved energy dissipation capacity when compared with the cast-in-place joint. As a result, it can be concluded that the seismic performance of the new joint surpasses that of cast-in-place joints. Additionally, this study examined the impact of modifying relevant parameters on the seismic performance of the new prefabricated semi-rigid concrete beam–column joint.
Full article
Aluminum–air (Al–air) batteries are considered one of the most promising next-generation energy storage devices. In this paper, we carry out an orthogonal experimental study on the SLM printing process parameters in 3D-printed Al–air battery anodes. The surface roughness, densification, and discharge performance of
[...] Read more.
Aluminum–air (Al–air) batteries are considered one of the most promising next-generation energy storage devices. In this paper, we carry out an orthogonal experimental study on the SLM printing process parameters in 3D-printed Al–air battery anodes. The surface roughness, densification, and discharge performance of the electrodes under different process parameters are observed to reveal the effects of different process parameters on the forming quality and discharge performance of aluminum–air battery anodes. The results show that the laser power is the most important factor affecting the surface roughness of the porous aluminum anode, and the scanning spacing is the most important factor affecting the densification. The best printing parameters for the porous aluminum anode can be obtained when the laser power is 325 W, the scanning speed is 1000 mm/s, the scanning spacing is 0.12 mm, and the thickness of the powder spread is 0.03 mm. At this time, the surface roughness of the porous aluminum anode obtained by this process parameter is 15.01 μm, the densification is 94.97%, and the discharge is stable with a high value. In addition, we also carry out data validation to ensure that the data we obtain are optimal and valid.
Full article
Mainstream semi-supervised learning (SSL) techniques, such as pseudo-labeling and contrastive learning, exhibit strong generalization abilities but lack theoretical understanding. Furthermore, pseudo-labeling lacks the label enhancement from high-quality neighbors, while contrastive learning ignores the supervisory guidance provided by genuine labels. To this end, we
[...] Read more.
Mainstream semi-supervised learning (SSL) techniques, such as pseudo-labeling and contrastive learning, exhibit strong generalization abilities but lack theoretical understanding. Furthermore, pseudo-labeling lacks the label enhancement from high-quality neighbors, while contrastive learning ignores the supervisory guidance provided by genuine labels. To this end, we first introduce a generalized bias-variance decomposition framework to investigate them. Then, this research inspires us to propose two new techniques to refine them: neighbor-enhanced pseudo-labeling, which enhances confidence-based pseudo-labels by incorporating aggregated predictions from high-quality neighbors; label-enhanced contrastive learning, which enhances feature representation by combining enhanced pseudo-labels and ground-truth labels to construct a reliable and complete symmetric adjacency graph. Finally, we combine these two new techniques to develop an excellent SSL method called GBVSSL. GBVSSL significantly surpasses previous state-of-the-art SSL approaches in standard benchmarks, such as CIFAR-10/100, SVHN, and STL-10. On CIFAR-100 with 400, 2500, and 10,000 labeled samples, GBVSSL outperforms FlexMatch by 3.46%, 2.72%, and 2.89%, respectively. On the real-world dataset Semi-iNat 2021, GBVSSL improves the Top-1 accuracy over CCSSL by 4.38%. Moreover, GBVSSL exhibits faster convergence and enhances unbalanced SSL. Extensive ablation and qualitative studies demonstrate the effectiveness and impact of each component of GBVSSL.
Full article
Background: The aim of this study was to evaluate different preoperative immune, inflammatory, and nutritional scores and their best cut-off values as predictors of poorer overall survival (OS) and disease-free survival (DFS) in patients who underwent curative gastric cancer resection. Methods: This was
[...] Read more.
Background: The aim of this study was to evaluate different preoperative immune, inflammatory, and nutritional scores and their best cut-off values as predictors of poorer overall survival (OS) and disease-free survival (DFS) in patients who underwent curative gastric cancer resection. Methods: This was a retrospective observational multicentre study based on data of the Spanish EURECCA Esophagogastric Cancer Registry. Time-dependent Youden index and log-rank test were used to obtain the best cut-offs of 18 preoperative biomarkers for OS and DFS. An adjusted Cox model with variables selected by bootstrapping was used to identify the best preoperative biomarkers, which were also analysed for every TNM stage. Results: High neutrophil-to-lymphocyte ratio (NLR), high monocyte systemic inflammation index (moSII), and low prognostic nutritional index (PNI) were identified as independent predictors of poor outcome: NLR > 5.91 (HR:1.73; 95%CI [1.23–2.43]), moSII >2027.12 (HR:2.26; 95%CI [1.36–3.78]), and PNI >40.31 (HR:0.75; 95%CI [0.58–0.96]) for 5-year OS and NLR > 6.81 (HR:1.75; 95%CI [1.24–2.45]), moSII > 2027.12 (HR:2.46; 95%CI [1.49–4.04]), and PNI > 40.31 (HR:0.77; 95%CI [0.60,0.97]) for 5-year DFS. These outcomes were maintained in the whole cohort for NLR and moSII (p < 0.05) but not in stage II and for PNI in all tumoral stages. The associations of NLR-PNI and moSII-PNI were also a relevant prognostic factor for OS. Conclusions: High NLR, high moSII (for stages I and III), and low PNI (regardless of tumour stage) were the most promising preoperative biomarkers to predict poor OS and DFS in gastric cancer patients treated with curative intent.
Full article
This paper delves into the integration of Factories of the Future (FoF) and digital twin technologies within urban contexts, marking a significant leap in Smart Cities development. We present a thorough exploration of the principles and a scientifically grounded framework designed for seamlessly
[...] Read more.
This paper delves into the integration of Factories of the Future (FoF) and digital twin technologies within urban contexts, marking a significant leap in Smart Cities development. We present a thorough exploration of the principles and a scientifically grounded framework designed for seamlessly blending advanced manufacturing systems with the urban environment’s digital and physical aspects. Our detailed analysis has identified core principles crucial for this integration, focusing on interoperability, sustainability, adaptability, stakeholder collaboration, and strong data governance. We propose a structured framework that puts these principles into action, outlining strategic routes for incorporating digital twin and Building Information Modeling (BIM) technologies into FoF, establishing public-private partnerships, enhancing education and workforce development, and setting up mechanisms for ongoing evaluation and enhancement. The potential of this integration to transform urban development is vast, providing a model for boosting operational efficiency, driving economic growth, and enhancing urban livability. Although challenges exist in realizing this vision, our research offers practical insights and strategies for cities and industries to effectively navigate the complexities of the digital era. This contribution enriches the growing field of urban science, advocating for a harmonious integration of industrial production with urban development in the Smart Cities framework.
Full article
Vascular dementia, the second most common type of dementia, currently lacks a definitive cure. In the pursuit of therapies aimed at slowing its progression and alleviating symptoms, transcranial direct current stimulation (tDCS) emerges as a promising approach, characterized by its non-invasive nature and
[...] Read more.
Vascular dementia, the second most common type of dementia, currently lacks a definitive cure. In the pursuit of therapies aimed at slowing its progression and alleviating symptoms, transcranial direct current stimulation (tDCS) emerges as a promising approach, characterized by its non-invasive nature and the ability to promote brain plasticity. In this study, the primary objective was to investigate the effects of a two-week cycle of tDCS on the dorsolateral prefrontal cortex (DLPFC) and neurophysiological functioning in thirty patients diagnosed with vascular dementia. Each participant was assigned to one of two groups: the experimental group, which received anodal tDCS to stimulate DPCFL, and the control group, which received sham tDCS. Neurophysiological functions were assessed before and after tDCS using P300 event-related potentials (ERPs), while neuropsychological function was evaluated through a Mini-Mental State Examination (MMSE). The results showed a reduction in P300 latency, indicating a faster cognitive process; an increase in P300 amplitude, suggesting a stronger neural response to cognitive stimuli; and a significant improvement in MMSE scores compared to the control group, indicating an overall enhancement in cognitive functions. These findings suggest that tDCS could represent a promising therapeutic option for improving both neurophysiological and cognitive aspects in patients with vascular dementia.
Full article
by
Dina Bugybayeva, Ekachai Dumkliang, Veerupaxagouda Patil, Ganesh Yadagiri, Raksha Suresh, Mithilesh Singh, Jennifer Schrock, Sara Dolatyabi, Olaitan C. Shekoni, Hadi M. Yassine, Praneet Opanasopit, Harm HogenEsch and Gourapura J. Renukaradhya
Vaccines2024, 12(6), 647; https://doi.org/10.3390/vaccines12060647 (registering DOI) - 11 Jun 2024
This study focuses on the development and characterization of an intranasal vaccine platform using adjuvanted nanoparticulate delivery of swine influenza A virus (SwIAV). The vaccine employed whole inactivated H1N2 SwIAV as an antigen and STING-agonist ADU-S100 as an adjuvant, with both surface adsorbed
[...] Read more.
This study focuses on the development and characterization of an intranasal vaccine platform using adjuvanted nanoparticulate delivery of swine influenza A virus (SwIAV). The vaccine employed whole inactivated H1N2 SwIAV as an antigen and STING-agonist ADU-S100 as an adjuvant, with both surface adsorbed or encapsulated in mannose–chitosan nanoparticles (mChit-NPs). Optimization of mChit-NPs included evaluating size, zeta potential, and cytotoxicity, with a 1:9 mass ratio of antigen to NP demonstrating high loading efficacy and non-cytotoxic properties suitable for intranasal vaccination. In a heterologous H1N1 pig challenge trial, the mChit-NP intranasal vaccine induced cross-reactive sIgA antibodies in the respiratory tract, surpassing those of a commercial SwIAV vaccine. The encapsulated mChit-NP vaccine induced high virus-specific neutralizing antibody and robust cellular immune responses, while the adsorbed vaccine elicited specific high IgG and hemagglutinin inhibition antibodies. Importantly, both the mChit-NP vaccines reduced challenge heterologous viral replication in the nasal cavity higher than commercial swine influenza vaccine. In summary, a novel intranasal mChit-NP vaccine platform activated both the arms of the immune system and is a significant advancement in swine influenza vaccine design, demonstrating its potential effectiveness for pig immunization.
Full article
For a class of fractional-order singular multi-agent systems (FOSMASs) with local Lipschitz nonlinearity, this paper proposes a closed-loop -type iterative learning formation control law via input sharing to achieve the stable formation of FOSMASs in a finite time. Firstly, the formation
[...] Read more.
For a class of fractional-order singular multi-agent systems (FOSMASs) with local Lipschitz nonlinearity, this paper proposes a closed-loop -type iterative learning formation control law via input sharing to achieve the stable formation of FOSMASs in a finite time. Firstly, the formation control issue of FOSMASs with local Lipschitz nonlinearity under the fixed communication topology (FCT) is transformed into the consensus tracking control scenario. Secondly, by virtue of utilizing the characteristics of fractional calculus and the generalized Gronwall inequality, sufficient conditions for the convergence of formation error are given. Then, drawing upon the FCT, the iteration-varying switching communication topology is considered and examined. Ultimately, the validity of the -type learning method is showcased through two numerical cases.
Full article
Micro-milling, widely employed across various fields, faces significant challenges due to the small diameter and limited stiffness of its tools, making the process highly susceptible to cutting chatter and premature tool breakage. Ensuring stable and safe cutting processes necessitates the prediction of chatter
[...] Read more.
Micro-milling, widely employed across various fields, faces significant challenges due to the small diameter and limited stiffness of its tools, making the process highly susceptible to cutting chatter and premature tool breakage. Ensuring stable and safe cutting processes necessitates the prediction of chatter by considering the tool breakage. Crucially, the modal parameters of the spindle–holder–tool system are important prerequisites for such stability prediction. In this paper, the FRFs of the micro-milling tool are calculated by direct frequency response functions (FRFs) of the micro-milling cutter and cross-FRFs between a point on the shank and one on the tool tip. Additionally, by utilizing a cutting force model specific to micro-milling, the bending stress experienced by the tool is computed, and the tool breakage curve is subsequently determined based on the material’s permissible maximum allowable stress. The FRFs of the micro-milling tool, alongside the tool breakage curve, are then integrated to generate the final stability lobe diagrams (SLDs). The effectiveness and reliability of the proposed methodology are confirmed through a comprehensive series of numerical and experimental validations.
Full article
The maximum linear (or translational) velocity achievable by an omnidirectional platform is not uniform as it depends on the angular orientation of the motion. This velocity is limited by the maximum angular velocity of the motors driving the wheels and also depends on
[...] Read more.
The maximum linear (or translational) velocity achievable by an omnidirectional platform is not uniform as it depends on the angular orientation of the motion. This velocity is limited by the maximum angular velocity of the motors driving the wheels and also depends on the mechanical configuration and orientation of the wheels. This paper proposes a procedure to compute an upper bound for the translational velocity, named the consistent velocity of the omnidirectional platform, which is defined as the minimum of the maximum translational velocities achievable by the platform in any angular orientation with no wheel slippage. The consistent velocity is then a uniform translational velocity always achievable by the omnidirectional platform regardless of the angular orientation of the motion. This paper reports the consistent velocity for a set of omnidirectional platforms with three omni wheels that have the same radius and angular distribution but different angular orientations. Results have shown that these platforms can achieve different maximum velocities in different angular orientations although the consistent velocity is the same for all of them. Results have also shown that the consistent velocity has a linear relation with the angular velocity of the motion. The consistent velocity of a mobile platform can be used by its path-planning algorithm as an upper bound that guarantees the execution of any omnidirectional motion at a uniform and maximum translational velocity.
Full article
The compound 15-deacetylcalonectrin (15-deCAL) is a common pathway intermediate in the biosynthesis of Fusarium trichothecenes. This tricyclic intermediate is metabolized to calonectrin (CAL) by trichothecene 15-O-acetyltransferase encoded by Tri3. Unlike other trichothecene pathway Tri gene mutants, the Δtri3 mutant
[...] Read more.
The compound 15-deacetylcalonectrin (15-deCAL) is a common pathway intermediate in the biosynthesis of Fusarium trichothecenes. This tricyclic intermediate is metabolized to calonectrin (CAL) by trichothecene 15-O-acetyltransferase encoded by Tri3. Unlike other trichothecene pathway Tri gene mutants, the Δtri3 mutant produces lower amounts of the knocked-out enzyme’s substrate 15-deCAL, and instead, accumulates higher quantities of earlier bicyclic intermediate and shunt metabolites. Furthermore, evolutionary studies suggest that Tri3 may play a role in shaping the chemotypes of trichothecene-producing Fusarium strains. To better understand the functional role of Tri3p in biosynthesis and evolution, we aimed to develop a method to produce 15-deCAL by using transgenic Fusarium graminearum strains derived from a trichothecene overproducer. Unfortunately, introducing mutant Tri3, encoding a catalytically impaired but structurally intact acetylase, did not improve the low 15-deCAL production level of the ΔFgtri3 deletion strain, and the bicyclic products continued to accumulate as the major metabolites of the active-site mutant. These findings are discussed in light of the enzyme responsible for 15-deCAL production in trichothecene biosynthesis machinery. To efficiently produce 15-deCAL, we tested an alternative strategy of using a CAL-overproducing transformant. By feeding a crude CAL extract to a Fusarium commune strain that was isolated in this study and capable of specifically deacetylating C-15 acetyl, 15-deCAL was efficiently recovered. The substrate produced in this manner can be used for kinetic investigations of this enzyme and its possible role in chemotype diversification.
Full article
The ‘Fit for 55’ policy package was presented in the European Commission’s Green Deal framework, comprising a set of proposals to improve existing energy and climate legislation. Among its main proposals was a revision of the European Union’s Emission Trading System to expand
[...] Read more.
The ‘Fit for 55’ policy package was presented in the European Commission’s Green Deal framework, comprising a set of proposals to improve existing energy and climate legislation. Among its main proposals was a revision of the European Union’s Emission Trading System to expand its sectoral coverage. Anticipating the possible loss of competitiveness with carbon pricing within the EU—which may lead to ‘carbon leakage’—a carbon border adjustment mechanism (CBAM) was included in the package. This scheme takes the form of an export tax levied by the European Union on some goods manufactured in non-carbon-taxing countries. In this paper, we provide a first-order estimate of the potential impact of CBAM on Morocco’s exports using an input–output approach. Our main findings suggest that the scheme would yield a carbon bill ranging from USD 20 to 34 million annually to Moroccan exporters in its initial phase. Morocco can mitigate such economic losses by instituting a national Emission Trading System, a tax reform, or speeding up the decarbonization of its economy.
Full article
In today’s dynamic organizational landscape, characterized by rapid technological advancements and evolving workplace dynamics, understanding the factors influencing employee well-being is paramount. This study investigates the interplay between ethical leadership, organizational climate, role overload, and job burnout in public healthcare organizations across northern
[...] Read more.
In today’s dynamic organizational landscape, characterized by rapid technological advancements and evolving workplace dynamics, understanding the factors influencing employee well-being is paramount. This study investigates the interplay between ethical leadership, organizational climate, role overload, and job burnout in public healthcare organizations across northern Jordan. By focusing on ethical leadership, organizational climate, and role overload as determinants of job burnout, this research provides insights into strategies for enhancing employee well-being. Drawing on ethical leadership theory, social exchange theory, and the job demands–resources model, this study employs PLS-SEM to analyze data collected from 260 employees working in Jordanian government hospitals. The findings reveal negative associations between ethical leadership and job burnout, highlighting the importance of ethical leadership behaviors in mitigating employee burnout. Additionally, a positive organizational climate is associated with lower levels of burnout, underscoring the impact of the broader organizational context on employee well-being. The study also explores the mediating role of organizational climate and the moderating effect of role overload in the relationship between ethical leadership and job burnout, providing insights into the complex dynamics at play in healthcare organizations. These findings enrich our understanding of the factors influencing employee well-being in healthcare contexts and underscore the importance of fostering ethical leadership and supportive organizational climates to mitigate job burnout.
Full article