The 2023 MDPI Annual Report has
been released!
 
20 pages, 976 KiB  
Review
Synergistic Effects of Weight Loss and Catheter Ablation: Can microRNAs Serve as Predictive Biomarkers for the Prevention of Atrial Fibrillation Recurrence?
by Carola Y. Förster, Stephan R. Künzel, Sergey Shityakov and Stavros Stavrakis
Int. J. Mol. Sci. 2024, 25(9), 4689; https://doi.org/10.3390/ijms25094689 (registering DOI) - 25 Apr 2024
Abstract
In atrial fibrillation (AF), multifactorial pathologic atrial alterations are manifested by structural and electrophysiological changes known as atrial remodeling. AF frequently develops in the context of underlying cardiac abnormalities. A critical mechanistic role played by atrial stretch is played by abnormal substrates in [...] Read more.
In atrial fibrillation (AF), multifactorial pathologic atrial alterations are manifested by structural and electrophysiological changes known as atrial remodeling. AF frequently develops in the context of underlying cardiac abnormalities. A critical mechanistic role played by atrial stretch is played by abnormal substrates in a number of conditions that predispose to AF, including obesity, heart failure, hypertension, and sleep apnea. The significant role of overweight and obesity in the development of AF is known; however, the differential effect of overweight, obesity, cardiovascular comorbidities, lifestyle, and other modifiable risk factors on the occurrence and recurrence of AF remains to be determined. Reverse remodeling of the atrial substrate and subsequent reduction in the AF burden by conversion into a typical sinus rhythm has been associated with weight loss through lifestyle changes or surgery. This makes it an essential pillar in the management of AF in obese patients. According to recently published research, microRNAs (miRs) may function as post-transcriptional regulators of genes involved in atrial remodeling, potentially contributing to the pathophysiology of AF. The focus of this review is on their modulation by both weight loss and catheter ablation interventions to counteract atrial remodeling in AF. Our analysis outlines the experimental and clinical evidence supporting the synergistic effects of weight loss and catheter ablation (CA) in reversing atrial electrical and structural remodeling in AF onset and in recurrent post-ablation AF by attenuating pro-thrombotic, pro-inflammatory, pro-fibrotic, arrhythmogenic, and male-sex-associated hypertrophic remodeling pathways. Furthermore, we discuss the promising role of miRs with prognostic potential as predictive biomarkers in guiding approaches to AF recurrence prevention. Full article
(This article belongs to the Special Issue Current Research for Heart Disease Biology and Therapeutics)
16 pages, 290 KiB  
Article
Pinching Results for Doubly Warped Products’ Pointwise Bi-Slant Submanifolds in Locally Conformal Almost Cosymplectic Manifolds with a Quarter-Symmetric Connection
by Md Aquib, Ibrahim Al-Dayel, Mohd Aslam, Meraj Ali Khan and Mohammad Shuaib
Symmetry 2024, 16(5), 521; https://doi.org/10.3390/sym16050521 (registering DOI) - 25 Apr 2024
Abstract
In this research paper, we establish geometric inequalities that characterize the relationship between the squared mean curvature and the warping functions of a doubly warped product pointwise bi-slant submanifold. Our investigation takes place in the context of locally conformal almost cosymplectic manifolds, which [...] Read more.
In this research paper, we establish geometric inequalities that characterize the relationship between the squared mean curvature and the warping functions of a doubly warped product pointwise bi-slant submanifold. Our investigation takes place in the context of locally conformal almost cosymplectic manifolds, which are equipped with a quarter-symmetric metric connection. We also consider the cases of equality in these inequalities. Additionally, we derive some geometric applications of our obtained results. Full article
Article
Constrained State Regulation Problem of Descriptor Fractional-Order Linear Continuous-Time Systems
by Hongli Yang, Xindong Si and Ivan G. Ivanov
Fractal Fract. 2024, 8(5), 255; https://doi.org/10.3390/fractalfract8050255 (registering DOI) - 25 Apr 2024
Abstract
This paper deals with the constrained state regulation problem (CSRP) of descriptor fractional-order linear continuous-time systems (DFOLCS) with order 0<α<1. The objective is to establish the existence of conditions for a linear feedback control law within state constraints [...] Read more.
This paper deals with the constrained state regulation problem (CSRP) of descriptor fractional-order linear continuous-time systems (DFOLCS) with order 0<α<1. The objective is to establish the existence of conditions for a linear feedback control law within state constraints and to propose a method for solving the CSRP of DFOLCS. First, based on the decomposition and separation method and coordinate transformation, the DFOLCS can be transformed into an equivalent fractional-order reduced system; hence, the CSRP of the DFOLCS is equivalent to the CSRP of the reduced system. By means of positive invariant sets theory, Lyapunov stability theory, and some mathematical techniques, necessary and sufficient conditions for the polyhedral positive invariant set of the equivalent reduced system are presented. Models and corresponding algorithms for solving the CSRP of a linear feedback controller are also presented by the obtained conditions. Under the condition that the resulting closed system is positive, the given model of the CSRP in this paper for the DFOLCS is formulated as nonlinear programming with a linear objective function and quadratic mixed constraints. Two numerical examples illustrate the proposed method. Full article
Review
Silicone Nanocomposites with Enhanced Thermal Resistance: A Short Review
by Maria Zielecka and Anna Rabajczyk
Materials 2024, 17(9), 2016; https://doi.org/10.3390/ma17092016 (registering DOI) - 25 Apr 2024
Abstract
Continuous technological progress places significant demands on the materials used in increasingly modern devices. An important parameter is often the long-term thermal resistance of the material. The use of heat-resistant polymer materials worked well in technologically advanced products. An economically justified direction in [...] Read more.
Continuous technological progress places significant demands on the materials used in increasingly modern devices. An important parameter is often the long-term thermal resistance of the material. The use of heat-resistant polymer materials worked well in technologically advanced products. An economically justified direction in searching for new materials is the area of polymer nanocomposite materials. It is necessary to appropriately select both the polymer matrix and the nanofillers best able to demonstrate the synergistic effect. A promising area of exploration for such nanocomposites is the use of organosilicon polymers, which results from the unique properties of these polymers related to their structure. This review presents the results of the analysis of the most important literature reports regarding organosilicon polymer nanocomposites with increased thermal resistance. Particular attention was paid to modification methods of silicone nanocomposites, focusing on increasing their thermal resistance related to the modification of siloxane molecular structure and by making nanocomposites using inorganic additives and carbon nanomaterials. Attention was also paid to such important issues as the influence of the dispersion of additives in the polymer matrix on the thermal resistance of silicone nanocomposites and the possibility of modifying the polymer matrix and permanently introducing nanofillers thanks to the presence of various reactive groups. The thermal stability mechanism of these nanocomposites was also analysed. Full article
(This article belongs to the Section Advanced Composites)
Article
Assessment of Inter- and Intraspecific P Efficiency in Forage Legumes as Affected by Recycling Fertiliser
by Yue Hu, Klaus J. Dehmer, Evelin Willner, Veysel Turan and Bettina Eichler-Löbermann
Agronomy 2024, 14(5), 901; https://doi.org/10.3390/agronomy14050901 (registering DOI) - 25 Apr 2024
Abstract
Legumes have a high demand for phosphorus (P) due to energetically costly biological nitrogen fixation, but they also have effective physiological and morphological strategies for P mobilization. To evaluate the inter- and intraspecific P efficiency of small-grain legumes supplied with different P recycling [...] Read more.
Legumes have a high demand for phosphorus (P) due to energetically costly biological nitrogen fixation, but they also have effective physiological and morphological strategies for P mobilization. To evaluate the inter- and intraspecific P efficiency of small-grain legumes supplied with different P recycling fertilisers, eight accessions each of alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) were cultivated in two pot experiments under greenhouse conditions until the flowering stage. To substantiate the results, some accessions were used in both experiments. Five treatments (no P, triple-superphosphate (TSP), sewage sludge ash (SSA), biowaste compost (compost), and struvite) were considered P sources. In addition to plant P uptake, the soil P pools were analysed in detail. Red clover showed higher yields and nutrient uptakes compared to alfalfa, but intraspecific effects were marginal. The addition of P resulted only partly in an increase in yield, despite the low P content in the soil. While struvite application clearly enhanced the P uptake of the plants in both experiments, SSA application had no effect compared to the control. The same treatment effect occurs with the bio-available soil P contents, which were on average 72.6 mg kg−1 after struvite and 44.3 mg kg−1 after SSA addition. Struvite as a P source was especially effective when applied to red clover. Our study aligns with previous field results and underscores the high potential of P mobilization of small-grain legumes without pronounced inter- or intraspecific differences. While struvite is suitable as a P fertiliser, the application of SSA to legumes is not recommended. Full article
Review
The Benefits of the Mediterranean Diet on Inflamm-Aging in Childhood Obesity
by Valeria Calcaterra, Elvira Verduci, Chiara Milanta, Marta Agostinelli, Federica Bona, Stefania Croce, Chiara Valsecchi, Maria Antonietta Avanzini and Gianvincenzo Zuccotti
Nutrients 2024, 16(9), 1286; https://doi.org/10.3390/nu16091286 (registering DOI) - 25 Apr 2024
Abstract
(1) Background: Numerous elements of the Mediterranean diet (MD) have antioxidant and anti-inflammatory qualities. (2) Methods: We present a narrative review of the potential benefits of the Mediterranean dietary pattern (MD) in mitigating aging-related inflammation (inflamm-aging) associated with childhood obesity. The mechanisms underlying [...] Read more.
(1) Background: Numerous elements of the Mediterranean diet (MD) have antioxidant and anti-inflammatory qualities. (2) Methods: We present a narrative review of the potential benefits of the Mediterranean dietary pattern (MD) in mitigating aging-related inflammation (inflamm-aging) associated with childhood obesity. The mechanisms underlying chronic inflammation in obesity are also discussed. A total of 130 papers were included after screening abstracts and full texts. (3) Results: A complex interplay between obesity, chronic inflammation, and related comorbidities is documented. The MD emerges as a promising dietary pattern for mitigating inflammation. Studies suggest that the MD may contribute to weight control, improved lipid profiles, insulin sensitivity, and endothelial function, thereby reducing the risk of metabolic syndrome in children and adolescents with obesity. (4) Conclusions: While evidence supporting the anti-inflammatory effects of the MD in pediatric obesity is still evolving, the existing literature underscores its potential as a preventive and therapeutic strategy. However, MD adherence remains low among children and adolescents, necessitating targeted interventions to promote healthier dietary habits. Future high-quality intervention studies are necessary to elucidate the specific impact of the MD on inflammation in diverse pediatric populations with obesity and associated comorbidities. Full article
Article
Study on the Fabrication and Acoustic Properties of Near-Stoichiometric Lithium Tantalate Crystal Surface Acoustic Wave Filters
by Jiashun Si, Xuefeng Xiao, Yan Huang, Yan Zhang, Shuaijie Liang, Qingyan Xu, Huan Zhang, Lingling Ma, Cui Yang and Xuefeng Zhang
Crystals 2024, 14(5), 400; https://doi.org/10.3390/cryst14050400 (registering DOI) - 25 Apr 2024
Abstract
Near-stoichiometric lithium tantalate (NSLT) wafers with different Li contents were prepared by vapour transfer equilibrium (VTE) method and fabricated into surface acoustic wave filters. The temperature coefficient of frequency, insertion loss, and bandwidth of the surface acoustic wave filters were tested using a [...] Read more.
Near-stoichiometric lithium tantalate (NSLT) wafers with different Li contents were prepared by vapour transfer equilibrium (VTE) method and fabricated into surface acoustic wave filters. The temperature coefficient of frequency, insertion loss, and bandwidth of the surface acoustic wave filters were tested using a special chip test bench and a network analyzer. The results show that the temperature coefficient of frequency shows a trend of first decreasing and then increasing with the increase in Li content, and the temperature stability of the surface acoustic wave filters is best when the Li content is 49.75%. It is also found that the surface acoustic wave filter fabricated from NSLT wafers has 21.18% lower temperature coefficient of frequency, 7.3% lower insertion loss, and 2.8% lower bandwidth than those fabricated from congruent lithium tantalate wafers. Therefore, NSLT crystals are more suitable for applications in acoustic devices, providing a new idea for performance enhancement of 5G communication devices. Full article
(This article belongs to the Section Inorganic Crystalline Materials)
11 pages, 536 KiB  
Article
Prognostic Value of KRAS Mutations in Relation to PDL1 Expression and Immunotherapy Treatment in Adenocarcinoma and Squamous Cell Carcinoma Patients: A Greek Cohort Study
by Theodora Tsiouda, Kalliopi Domvri, Efimia Boutsikou, Vasileios Bikos, Krystallia Kyrka, Konstantina Papadaki, Persefoni Pezirkianidou, Konstantinos Porpodis and Angeliki Cheva
J. Pers. Med. 2024, 14(5), 457; https://doi.org/10.3390/jpm14050457 (registering DOI) - 25 Apr 2024
Abstract
Background: Factors that could predict which patients will benefit from Immune Checkpoint Inhibitors (ICIs) are not fully understood. This study aimed to investigate the prognostic value of KRAS biomarker in patients with advanced non-small cell lung cancer (NSCLC) in relation to clinical characteristics, [...] Read more.
Background: Factors that could predict which patients will benefit from Immune Checkpoint Inhibitors (ICIs) are not fully understood. This study aimed to investigate the prognostic value of KRAS biomarker in patients with advanced non-small cell lung cancer (NSCLC) in relation to clinical characteristics, treatment response and PDL1 expression. Patients and methods: The study included 100 patients with NSCLC who received immunotherapy with or without chemotherapy as 1st line treatment. In biopsy samples, the PDL1 biomarker expression rate and somatic mutations of KRAS gene were determined. Results: The mean age of the patients was 67 ± 8 years. Patients were all male and 66% were found with adenocarcinoma whereas 34% with squamous cell carcinoma. The KRAS G12C mutation was found with the highest percentage (73%). In the Kaplan-Meier survival analysis, patients with PDL1 > 49% in combination with a negative KRAS result had a median overall survival of 40 months compared to patients with a positive KRAS result (9 months, p < 0.05). In addition, patients diagnosed with adenocarcinoma, PDL1 < 49% and negative KRAS result had a median overall survival of 39 months compared to patients with a positive result (28 months, p < 0.05). Conclusions: Our study suggests that the presence of KRAS mutations in advanced NSCLC patients has a poor prognostic value, regardless of their PDL1 expression values, after receiving immunotherapy as first-line treatment. Full article
(This article belongs to the Section Disease Biomarker)
12 pages, 5840 KiB  
Article
An Experimental Study on the Distribution of Grease in Cylindrical Roller Bearings
by He Liang, Yan Lu, Wenzhong Wang, Yi Sun, Jingjing Zhao and Yulong Guo
Lubricants 2024, 12(5), 145; https://doi.org/10.3390/lubricants12050145 (registering DOI) - 25 Apr 2024
Abstract
The lubrication performance of bearings is greatly influenced by the distribution of the lubricant. In this study, a cylindrical rolling bearing test rig was constructed and presented. The distribution of grease and lubricating oil along the contact region was examined using the laser-induced [...] Read more.
The lubrication performance of bearings is greatly influenced by the distribution of the lubricant. In this study, a cylindrical rolling bearing test rig was constructed and presented. The distribution of grease and lubricating oil along the contact region was examined using the laser-induced fluorescence technique, and the thickness of the layer was determined. The lubricating oil and grease layer thickness distribution map was acquired. The effects of supply amount, thickener content, and speed on grease distribution were examined. Mechanisms for replenishing the line contact area were investigated. Full article
(This article belongs to the Special Issue Tribological Study in Rolling Bearing)
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Article
Self-Perceived Stress in Association with Emotional Experiences following Patient Death and Coping Adequacy among Clinical Nurses in Lithuania: A Cross-Sectional Study
by Marius Baranauskas, Marius Kalpokas, Ingrida Kupčiūnaitė, Jurgita Lieponienė and Rimantas Stukas
J. Clin. Med. 2024, 13(9), 2533; https://doi.org/10.3390/jcm13092533 (registering DOI) - 25 Apr 2024
Abstract
(1) Background: Stress is defined as a psychological sensation related to a change in both human physiology and behavior in response to a threat or challenge. As the prevalence of stress is increasing globally, nurses represent a risk group for exposure to stress-related [...] Read more.
(1) Background: Stress is defined as a psychological sensation related to a change in both human physiology and behavior in response to a threat or challenge. As the prevalence of stress is increasing globally, nurses represent a risk group for exposure to stress-related psychological alterations. The aim of this study was to explore how clinical nurses in Lithuania cope with the perceived chronic stress in relation to additional emotional experiences following the death of a patient. (2) Methods: During a four-week period of October 2023, a total of 283 female nurses, aged between 20 and 70 years old, were enrolled in a single cross-sectional study. The PSS-10 (perceived stress scale) and the Brief-COPE (Coping Orientation to Problems Experienced) questionnaires were applied to assess the level of self-perceived stress and the use of coping styles along with the adequate strategies. Furthermore, the nurses’ emotions, evoked following patient death, were classified depending on their valence. Both the multiple linear and logistic regression statistical analyses were conducted to examine the associations between dependent and independent variables. (3) Results: The study identified that more than half of the nurses experienced patient death several times a month. A moderate-to-high level of the symptoms of mental chronic stress were suffered by 76% of caregivers. The psychological arousal following the death of a patient may induce the occurrence of emotional complexity that refers to competitive feelings, namely, helplessness (adjusted odd ratio (AOR) 1.7, 95% confidence interval (95% CI) 1.1; 2.9), disappointment (AOR 1.9, 95% CI 1.1; 3.5), anxiety (AOR 1.9, 95% CI 1.2; 4.2), and guilt (ORadj 4.7, 95% CI 1.4; 5.7), and can serve as a potential trigger for chronic stress development in clinical nurses. In terms of emotion-focused stress control (β 0.1, 95% CI −0.1; −0.2, R2 = 0.12), Lithuanian nurses had low control of the perceived chronic stress. The use of problem-focused coping (β −0.2, 95% CI −0.3; −0.1, R2 = 0.09) was also not addressed to an appropriate extent. The use of the avoidance coping style was associated with moderate–high levels of chronic stress perceived by nurses (β 0.5, 95% CI 0.4; 0.7, R2 = 0.24). Furthermore, the avoidant coping strategy related to behavioral disengagement was significantly related to resilience to chronic stress in an adverse way. The cognitive process of self-blame was considered as a meaningful maladaptive behavior component for magnifying chronic stress in nurses. (4) Conclusions: The study highlights the need to implement the recommendations for boosting the nurses’ mental health. Hospitals should contribute to psychological assistance along with providing necessary training on stress-coping strategies for clinical nurses. In order to promote the sustainability of mental health through additional social support interventions, it would be useful to upgrade the clinical nurses’ daily routines with mindfulness-based trainings. Full article
25 pages, 8771 KiB  
Article
Relation between Central European Climate Change and Eifel Volcanism during the Last 130,000 Years: The ELSA-23-Tephra-Stack
by Frank Sirocko, Frederik Krebsbach, Johannes Albert, Sarah Britzius, Fiona Schenk and Michael W. Förster
Quaternary 2024, 7(2), 21; https://doi.org/10.3390/quat7020021 - 25 Apr 2024
Abstract
The analysis of tephra layers in maar lake sediments of the Eifel shows 14 well-visible tephra during the last glacial cycle from the Holocene to the Eemian (0–130,000 yr b2k). These tephra were analyzed for their petrographic composition, which allows us to connect [...] Read more.
The analysis of tephra layers in maar lake sediments of the Eifel shows 14 well-visible tephra during the last glacial cycle from the Holocene to the Eemian (0–130,000 yr b2k). These tephra were analyzed for their petrographic composition, which allows us to connect several tephra to eruption sites. All tephra were dated by application of the ELSA-20 chronology, developed using the late Pleistocene infilled maar lake of Auel and the Holocene lake Holzmaar (0–60,000 yr b2k). We extend the ELSA-20 chronology with this paper for the millennia of 60,000–130,000 yr b2k (ELSA-23 chronology), which is based on the infilled maar lake records from Dehner, Hoher List, and Jungferweiher. The evaluation of the tephra from the entire last glacial cycle shows that all 14 tephra were close to interstadial warming of the North Atlantic sea surface temperatures. In particular, phreatomagmatic maar eruptions were systematically associated with Heinrich events or C-events. These events represent times of warming of the Southern Hemisphere, global sea level rise, and CO2 increase, which predate the abrupt interstadial warming events of the Northern Hemisphere. This synchroneity indicates a physical relationship between endogenic and exogenic processes. Changes in the lithospheric stress field in response to changes in continental ice loads have already been suggested as a potential candidate to explain the exogenic forcing of endogenic processes. The chronology of volcanic activity in the Eifel demonstrates that intraplate mantle plumes are also affected by the exogenic forcing of endogenic processes. Full article
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26 pages, 12425 KiB  
Article
Topic Modelling: Going beyond Token Outputs
by Lowri Williams, Eirini Anthi, Laura Arman and Pete Burnap
Big Data Cogn. Comput. 2024, 8(5), 44; https://doi.org/10.3390/bdcc8050044 - 25 Apr 2024
Abstract
Topic modelling is a text mining technique for identifying salient themes from a number of documents. The output is commonly a set of topics consisting of isolated tokens that often co-occur in such documents. Manual effort is often associated with interpreting a topic’s [...] Read more.
Topic modelling is a text mining technique for identifying salient themes from a number of documents. The output is commonly a set of topics consisting of isolated tokens that often co-occur in such documents. Manual effort is often associated with interpreting a topic’s description from such tokens. However, from a human’s perspective, such outputs may not adequately provide enough information to infer the meaning of the topics; thus, their interpretability is often inaccurately understood. Although several studies have attempted to automatically extend topic descriptions as a means of enhancing the interpretation of topic models, they rely on external language sources that may become unavailable, must be kept up to date to generate relevant results, and present privacy issues when training on or processing data. This paper presents a novel approach towards extending the output of traditional topic modelling methods beyond a list of isolated tokens. This approach removes the dependence on external sources by using the textual data themselves by extracting high-scoring keywords and mapping them to the topic model’s token outputs. To compare how the proposed method benchmarks against the state of the art, a comparative analysis against results produced by Large Language Models (LLMs) is presented. Such results report that the proposed method resonates with the thematic coverage found in LLMs and often surpasses such models by bridging the gap between broad thematic elements and granular details. In addition, to demonstrate and reinforce the generalisation of the proposed method, the approach was further evaluated using two other topic modelling methods as the underlying models and when using a heterogeneous unseen dataset. To measure the interpretability of the proposed outputs against those of the traditional topic modelling approach, independent annotators manually scored each output based on their quality and usefulness as well as the efficiency of the annotation task. The proposed approach demonstrated higher quality and usefulness, as well as higher efficiency in the annotation task, in comparison to the outputs of a traditional topic modelling method, demonstrating an increase in their interpretability. Full article
(This article belongs to the Special Issue Advances in Natural Language Processing and Text Mining)
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22 pages, 6185 KiB  
Article
Stability-Indicating UPLC-PDA-QDa Methodology for Carvedilol and Felodipine in Fixed-Dose Combinations Using AQbD Principles
by Jesús Alberto Afonso Urich, Viktoria Marko, Katharina Boehm, Raymar Andreina Lara Garcia, Anna Fedorko, Sharareh Salar-Behzadi and Dalibor Jeremic
Sci. Pharm. 2024, 92(2), 22; https://doi.org/10.3390/scipharm92020022 - 25 Apr 2024
Abstract
The development of analytical procedures, in line with the recent regulatory requirements ICH Q2 (R2) and ICH Q14, is progressing, and it must be able to manage the entire life cycle of the methodology. This is also applicable to and especially challenging for [...] Read more.
The development of analytical procedures, in line with the recent regulatory requirements ICH Q2 (R2) and ICH Q14, is progressing, and it must be able to manage the entire life cycle of the methodology. This is also applicable to and especially challenging for combinations of drug substances and dosage form. A reliable and efficient, stability-indicating, MS-compatible, reverse-phase ultra-performance liquid chromatographic (UPLC®) method was developed for the determination of carvedilol and felodipine in a combination oral dosage form. The development of the method, performed using analytical quality by design (AQbD) principles, was in line with the future regulatory requirements. Furthermore, the fixed-dose combination dosage forms are a clear solution to the polypharmacy phenomenon in the elderly population. The main factors evaluated were the mobile phase buffer, organic modifier, column, flow, and column temperature. The optimum conditions were achieved with a Waters Acquity HSS T3 (100 × 2.1 mm i.d., 1.8 µm) column at 38 °C, using ammonium acetate buffer (5 mM, pH 4.5) (Solution A) and MeOH (Solution B) as mobile phases in gradient elution (t = 0 min, 10% B; t = 1.5 min, 10% B; t = 12.0 min, 90% B; t = 13.0 min, 10% B; t = 15.5 min, 10% B) at a flow rate of 0.2 mL/min and UV Detection of 240 and 362 nm for carvedilol (CAV) and felodipine (FLP), respectively. The linearity was demonstrated over concentration ranges of 30–650 µg/mL (R2 = 0.9984) (CAV) and 32–260 µg/mL (R2 = 0.9996) (FLP). Forced degradation studies were performed by subjecting the samples to hydrolytic (acid and base), oxidative, and thermal stress conditions. Standard solution stability was also performed. The proposed validated method was successfully used for the quantitative analysis of bulk, stability, and fixed-dose combination dosage form samples of the desired drug product. Using the AQbD principles, it is possible to generate methodologies with improved knowledge, leading to high-quality data, lower operation costs, and minimum regulatory risk. Furthermore, this work paves the way for providing a platform of robust analytical methods for the simultaneous quantification of innovative on-demand new dose combinations. Full article
(This article belongs to the Special Issue Feature Papers in Scientia Pharmaceutica)
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20 pages, 927 KiB  
Review
Changing Conditions: Global Warming-Related Hazards and Vulnerable Rural Populations in Mediterranean Europe
by Sandra Graus, Tiago Miguel Ferreira, Graça Vasconcelos and Javier Ortega
Urban Sci. 2024, 8(2), 42; https://doi.org/10.3390/urbansci8020042 - 25 Apr 2024
Abstract
Human-induced climate change has profound effects on extreme events, particularly those linked to global warming, such as heatwaves, droughts, and wildfires. These events disrupt ecosystems, emphasizing the imperative to understand the interactions among them to gauge the risks faced by vulnerable communities. Vulnerability [...] Read more.
Human-induced climate change has profound effects on extreme events, particularly those linked to global warming, such as heatwaves, droughts, and wildfires. These events disrupt ecosystems, emphasizing the imperative to understand the interactions among them to gauge the risks faced by vulnerable communities. Vulnerability levels vary primarily based on a community’s resources. Rural areas, especially in the Mediterranean region of Europe, are experiencing acute depopulation, creating a complex situation affecting various aspects of society, from economic declines to cultural heritage loss. Population decline in rural regions weakens resources, leading to the abandonment of built environments, fostering desertification, and elevating the risk of wildfires. Communities undergoing this deterioration process become exceptionally vulnerable, especially when dealing with and recovering from extreme natural phenomena. This review offers insights into the dynamics of these hazards and the predominant challenges in rural areas. By focusing on a topic that has received limited attention, the aim is to inform future research initiatives, ultimately improving risk assessment and mitigation strategies for these vulnerable communities. Full article
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17 pages, 1977 KiB  
Review
From Block to City Scale: Greenery’s Contribution to Cooling the Urban Environment
by Jesús Abelardo Licón-Portillo, Karen Estrella Martínez-Torres, Peter Chung-Alonso and Eduardo Florencio Herrera Peraza
Urban Sci. 2024, 8(2), 41; https://doi.org/10.3390/urbansci8020041 - 25 Apr 2024
Abstract
Urban greenery is a strategy to improve the thermal environment in urban areas affected by heat islands and global warming. These phenomena can harm the citizens’ quality of life. Researchers have investigated the thermal benefits of urban vegetation, but only a few have [...] Read more.
Urban greenery is a strategy to improve the thermal environment in urban areas affected by heat islands and global warming. These phenomena can harm the citizens’ quality of life. Researchers have investigated the thermal benefits of urban vegetation, but only a few have explored its complexities across diverse urban scales. Understanding these variations is critical for precise analysis, customized solutions, efficient resource allocation, and enhancing urban living quality while promoting sustainability and climate resilience. This paper reviews 250 scientific articles about the relationship between greenspace and the urban thermal environment published between 2010 and 2023 through urban scales. It summarizes the parameters and findings of greenery’s contribution to cooling the urban environment. The data reveal that most studies concentrated on the block scale, public open spaces, neighborhoods, parks, grouped vegetation, mixed arrangements, high vegetation, spatial parameters, and the use of air temperature data to report their findings. The cooling-effect evidence shows that the block scale has an average mitigation range of 0.7–2.7 °C, the neighborhood scale of 1.1–2.9 °C, and the city scale of 0.5–2.2 °C. Furthermore, it is critical to define reliable research methods and perform thorough software validation to assess model performance and establish guidelines for urban-landscape design accurately. Full article
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15 pages, 1695 KiB  
Article
Enhancing Smart Communication Security: A Novel Cost Function for Efficient S-Box Generation in Symmetric Key Cryptography
by Oleksandr Kuznetsov, Nikolay Poluyanenko, Emanuele Frontoni and Sergey Kandiy
Cryptography 2024, 8(2), 17; https://doi.org/10.3390/cryptography8020017 - 25 Apr 2024
Abstract
In the realm of smart communication systems, where the ubiquity of 5G/6G networks and IoT applications demands robust data confidentiality, the cryptographic integrity of block and stream cipher mechanisms plays a pivotal role. This paper focuses on the enhancement of cryptographic strength in [...] Read more.
In the realm of smart communication systems, where the ubiquity of 5G/6G networks and IoT applications demands robust data confidentiality, the cryptographic integrity of block and stream cipher mechanisms plays a pivotal role. This paper focuses on the enhancement of cryptographic strength in these systems through an innovative approach to generating substitution boxes (S-boxes), which are integral in achieving confusion and diffusion properties in substitution–permutation networks. These properties are critical in thwarting statistical, differential, linear, and other forms of cryptanalysis, and are equally vital in pseudorandom number generation and cryptographic hashing algorithms. The paper addresses the challenge of rapidly producing random S-boxes with desired cryptographic attributes, a task notably arduous given the complexity of existing generation algorithms. We delve into the hill climbing algorithm, exploring various cost functions and their impact on computational complexity for generating S-boxes with a target nonlinearity of 104. Our contribution lies in proposing a new cost function that markedly reduces the generation complexity, bringing down the iteration count to under 50,000 for achieving the desired S-box. This advancement is particularly significant in the context of smart communication environments, where the balance between security and performance is paramount. Full article
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21 pages, 280 KiB  
Article
Child Soldiers/Child Slaves: Africa’s Weaponised Unfree Children in Blood Diamond (2006) and Beasts of No Nation (2015)
by Lauren Van der Rede
Genealogy 2024, 8(2), 46; https://doi.org/10.3390/genealogy8020046 - 25 Apr 2024
Abstract
The figure of the child is one that, at least in the Westernised imagination, is entangled with notions of innocence, naivety, and freedom. But what of the child who is unfree, who has been stripped of innocence, and for whom naivety is a [...] Read more.
The figure of the child is one that, at least in the Westernised imagination, is entangled with notions of innocence, naivety, and freedom. But what of the child who is unfree, who has been stripped of innocence, and for whom naivety is a danger? One expression of this iteration of the figure of the child is the child soldier, which has been a centralising figure in various narratives set during and concerned with African experiences of warfare. This paper is concerned with the figure of the child soldier as it is staged in both Edward Zwick’s Blood Diamond (2006) and Cary Joji Fukunaga’s filmic adaptation of Uzodinma Iweala’s novel, Beasts of No Nation (2015). In turning to Ashis Nandy’s articulation of the tension held within “the child” as being both emblematic of a fantasy of childhood produced by adult nostalgia—hopeful, joyous and free—and always potentially dangerous, this paper pivots the notions of soldiering and slaving on and around the child as a figure. In doing so, the paper asks what it might mean to think of the condition of being a child soldier as being akin to that of being a child slave, weaponised for political and economic ends. Full article
(This article belongs to the Special Issue Retrospectives on Child Slavery in Africa)
16 pages, 8982 KiB  
Article
Design of Bionic Foot Inspired by the Anti-Slip Cushioning Mechanism of Yak Feet
by Weijun Tian, Kuiyue Zhou, Zhu Chen, Ziteng Shen, Zhirui Wang, Lei Jiang and Qian Cong
Biomimetics 2024, 9(5), 260; https://doi.org/10.3390/biomimetics9050260 - 25 Apr 2024
Abstract
In recent years, legged robots have been more and more widely used on non-structured terrain, and their foot structure has an important impact on the robot’s motion performance and stability. The structural characteristics of the yak foot sole with a high outer edge [...] Read more.
In recent years, legged robots have been more and more widely used on non-structured terrain, and their foot structure has an important impact on the robot’s motion performance and stability. The structural characteristics of the yak foot sole with a high outer edge and low middle, which has excellent soil fixation ability and is an excellent bionic prototype, can improve the friction between the foot and the ground. At the same time, the foot hooves can effectively alleviate the larger impact load when contacting with the ground, which is an excellent anti-slip buffer mechanism. The bionic foot end design was carried out based on the morphology of the yak sole; the bionic foot design was carried out based on the biological anatomy observation of yak foot skeletal muscles. The virtual models of the bionic foot end and the bionic foot were established and simulated using Solidworks 2022 and Abaqus 2023, and the anti-slip performance on different ground surfaces and the influence of each parameter of the bionic foot on the cushioning effect were investigated. The results show that (1) the curved shape of the yak sole has a good anti-slip performance on both soil ground and rocky ground, and the anti-slip performance is better on soil ground; (2) the curved shape of the yak sole has a larger maximum static friction than the traditional foot, and the anti-slip performance is stronger under the same pressure conditions; (3) the finger pillow–hoof ball structure of the bionic foot has the greatest influence on the buffering effect, and the buffering effect of the bionic foot is best when the tip of the bionic foot touches the ground first. Full article
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19 pages, 1129 KiB  
Article
Fruit Agronomic and Quality Traits of Tomato F1 Hybrids Derived from Traditional Varieties
by Alicia Sánchez Sánchez, Pilar Flores, Virginia Hernández, Elena Sánchez, Elia Molina, Nuria López, Adrián Rodríguez-Burruezo, José Fenoll and Pilar Hellín
Horticulturae 2024, 10(5), 440; https://doi.org/10.3390/horticulturae10050440 - 25 Apr 2024
Abstract
The high genetic diversity of the tomato and its high micronutrient content make this fruit very interesting from an economic and nutritional point of view. The genetic erosion suffered by this crop, due to breeding objectives based on yield and marketing, makes it [...] Read more.
The high genetic diversity of the tomato and its high micronutrient content make this fruit very interesting from an economic and nutritional point of view. The genetic erosion suffered by this crop, due to breeding objectives based on yield and marketing, makes it necessary to return to the origins in search of the nutritional and organoleptic quality lost in traditional varieties. In this study, the agronomic, physical, organoleptic, and nutritional characteristics of eighteen F1 hybrids, obtained by crossing fourteen traditional varieties, previously selected for their quality, were studied in order to select genotypes of superior quality that could be candidates for new varieties. All the parameters studied were strongly influenced by genotype, with a wide range between varieties. Most of the experimental hybrids showed higher quality scores than the commercial hybrids used as controls, due to the extensive selection process carried out on the parents in previous work. Principal component analysis revealed the characteristics of each hybrid that distinguished it from the others. Some hybrids (H1, H2, and H4) stood out for their high concentration of active compounds, others (H14, H13, H8, H15, H7, and H9) for their agronomic performance and high β-carotene content, and H3 was the only one to contain chlorophyll in its ripe fruits. Finally, the evaluation index allowed the selection of five hybrids with interesting characteristics, combining good yield performance and high quality. The results of this work have allowed for the selection of a group of hybrids with high organoleptic and nutritional quality which will be used as parents in a breeding programme, in which their characteristics will be fixed and their resilience will be increased through the introduction of virus resistance. Full article
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14 pages, 2396 KiB  
Article
MdSGR2 Negatively Regulates Chlorophyll Degradation in Apple
by Shiyi Xue, Pei Yao, Jiwei Kang, Xiong Zheng, Chang Liu, Yan Gao, Dehui Zhang, Xiaojun Zhang and Yanyan Hao
Horticulturae 2024, 10(5), 439; https://doi.org/10.3390/horticulturae10050439 - 25 Apr 2024
Abstract
The color of an apple is an important index of its appearance quality, which affects the fruit’s marketability and value. The green variety “Granny Smith” remains green when ripe, and the pigment in the peel is mainly chlorophyll. The chlorophyll in the peel [...] Read more.
The color of an apple is an important index of its appearance quality, which affects the fruit’s marketability and value. The green variety “Granny Smith” remains green when ripe, and the pigment in the peel is mainly chlorophyll. The chlorophyll in the peel of the yellow variety “Golden Delicious” degrades as the fruit ripens. To explore the different mechanisms of chlorophyll degradation in the “Golden Delicious” and “Granny Smith” varieties, transcriptomic analysis was performed on the mature peels of both cultivars. High-quality sequences totaling 48,206,940 and 48,796,646 raw bases, as well as 9632 differentially expressed genes (DEGs), were identified. A total of 1206 DEGs were classified in 118 KEGG metabolic pathways. Additionally, 3258 transcription factors from 428 gene families were predicted, and DEGs associated with chlorophyll degradation, including MdSGR2, MdNYC1 and MdHCAR, were identified. Subsequently, the MdSGR2 gene was isolated from the mature peel of “Granny Smith” apples. Subsequent subcellular localization analysis confirmed that MdSGR2 specifically targets chloroplasts. The transient overexpression of MdSGR2 was found to negatively regulate chlorophyll degradation, leading to the inhibition or deceleration of chlorophyll breakdown, thereby maintaining green coloration in the leaves and peel. Conversely, silencing MdSGR2 positively regulated chlorophyll degradation, resulting in chlorosis in the leaves and peel. These findings offer valuable insights into the regulatory mechanism governing apple fruit coloration and lays a solid foundation for further investigation in this field. Full article
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25 pages, 23569 KiB  
Article
Analyzing the Influence of Dean Number on an Accelerated Toroidal: Insights from Particle Imaging Velocimetry Gyroscope (PIVG)
by Ramy Elaswad, Naser El-Sheimy and Abdulmajeed Mohamad
Fluids 2024, 9(5), 103; https://doi.org/10.3390/fluids9050103 - 25 Apr 2024
Abstract
Computational Fluid Dynamics (CFD) simulations were utilized in this study to comprehensively explore the fluid dynamics within an accelerated toroidal vessel, specifically those central to Particle Imaging Velocimetry Gyroscope (PIVG) technology. To ensure the robustness of our simulations, we systematically conducted grid convergence [...] Read more.
Computational Fluid Dynamics (CFD) simulations were utilized in this study to comprehensively explore the fluid dynamics within an accelerated toroidal vessel, specifically those central to Particle Imaging Velocimetry Gyroscope (PIVG) technology. To ensure the robustness of our simulations, we systematically conducted grid convergence studies and quantified uncertainties, affirming the stability, accuracy, and reliability of our computational grid and results. Comprehensive validation against experimental data further confirmed our simulations’ fidelity, emphasizing the model’s fidelity. As the PIVG is set up to address the primary flow through the toroidal pipe, we focused on the interaction between the primary and secondary flows to provide insights into the relevant dynamics of the fluid. In our investigation covering Dean numbers (De) from 10 to 70, we analyzed diverse aspects, including primary flow, secondary flow patterns, pressure distribution, and the interrelation between primary and secondary flows within toroidal structures, offering a comprehensive view across this range. Our research indicated stability and fully developed fluid dynamics within the toroidal pipe under accelerated angular velocity, particularly for low De. Furthermore, we identified an optimal Dean number of 11, which corresponded to ideal dimensions for the toroidal geometry with a curvature radius of 25 mm and a cross-sectional diameter of 5 mm. This study enhances our understanding of toroidal fluid dynamics and highlights the pivotal role of CFD in optimizing toroidal vessel design for advanced navigation technologies. Full article
(This article belongs to the Special Issue Flow Visualization: Experiments and Techniques)
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16 pages, 3462 KiB  
Article
Fluorescence ‘Turn-on’ Probe for Chromium Reduction, Adsorption and Detection Based on Cellulosic Nitrogen-Doped Carbon Quantum Dots Hydrogels
by Hebat-Allah S. Tohamy
Gels 2024, 10(5), 296; https://doi.org/10.3390/gels10050296 - 25 Apr 2024
Abstract
This paper proposes a new, highly effective fluorescence test for Cr(VI) detection. This method utilizes a hydrogel composed of hydroxyethyl cellulose (HEC), nitrogen-doped carbon quantum dots (N–CQDs), and poly(co-acrylamido-2-methyl-1-propane sulfonic acid) (AMPS). The N–CQDs were successfully synthesized using a simple microwave method, and [...] Read more.
This paper proposes a new, highly effective fluorescence test for Cr(VI) detection. This method utilizes a hydrogel composed of hydroxyethyl cellulose (HEC), nitrogen-doped carbon quantum dots (N–CQDs), and poly(co-acrylamido-2-methyl-1-propane sulfonic acid) (AMPS). The N–CQDs were successfully synthesized using a simple microwave method, and then conjugated with HEC and AMPS. The higher adsorption (99.41%) and higher reduction rate in H1 likely stems from both the presence of N–CQDs (absent in HB) and their increased free functional groups (compared to H2/H3, where N–CQDs block them). This facilitates the release (desorption) of Cr(VI) from the hydrogels, making it more available for reduction to the less toxic Cr(III). The fluorescent brightness of the HEC-N–CQDs-g-poly(AMPS) hydrogel increases gradually when Cr(VI) is added in amounts ranging from 15 to 120 mg/L. The fluorescent enhancement of the HEC-N–CQDs-g-poly(AMPS) hydrogel appeared to exhibit a good linear relationship with the 15–120 mg of the Cr(VI) concentration, with a detection limit of 0.0053 mg/L, which is lower than the standard value published by WHO. Our study found that the HEC-N–CQDs-g-poly(AMPS) hydrogel served effectively as a fluorescent probe for Cr(VI) detection in aqueous solutions, demonstrating high sensitivity. Full article
(This article belongs to the Special Issue Recent Progress of Hydrogel Sensors and Biosensors)
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28 pages, 3351 KiB  
Review
Biomedical Trends in Stimuli-Responsive Hydrogels with Emphasis on Chitosan-Based Formulations
by Weronika Kruczkowska, Julia Gałęziewska, Katarzyna Grabowska, Gabriela Liese, Paulina Buczek, Karol Kamil Kłosiński, Mateusz Kciuk, Zbigniew Pasieka, Żaneta Kałuzińska-Kołat and Damian Kołat
Gels 2024, 10(5), 295; https://doi.org/10.3390/gels10050295 - 25 Apr 2024
Abstract
Biomedicine is constantly evolving to ensure a significant and positive impact on healthcare, which has resulted in innovative and distinct requisites such as hydrogels. Chitosan-based formulations stand out for their versatile utilization in drug encapsulation, transport, and controlled release, which is complemented by [...] Read more.
Biomedicine is constantly evolving to ensure a significant and positive impact on healthcare, which has resulted in innovative and distinct requisites such as hydrogels. Chitosan-based formulations stand out for their versatile utilization in drug encapsulation, transport, and controlled release, which is complemented by their biocompatibility, biodegradability, and non-immunogenic nature. Stimuli-responsive hydrogels, also known as smart hydrogels, have strictly regulated release patterns since they respond and adapt based on various external stimuli. Moreover, they can imitate the intrinsic tissues’ mechanical, biological, and physicochemical properties. These characteristics allow stimuli-responsive hydrogels to provide cutting-edge, effective, and safe treatment. Constant progress in the field necessitates an up-to-date summary of current trends and breakthroughs in the biomedical application of stimuli-responsive chitosan-based hydrogels, which was the aim of this review. General data about hydrogels sensitive to ions, pH, redox potential, light, electric field, temperature, and magnetic field are recapitulated. Additionally, formulations responsive to multiple stimuli are mentioned. Focusing on chitosan-based smart hydrogels, their multifaceted utilization was thoroughly described. The vast application spectrum encompasses neurological disorders, tumors, wound healing, and dermal infections. Available data on smart chitosan hydrogels strongly support the idea that current approaches and developing novel solutions are worth improving. The present paper constitutes a valuable resource for researchers and practitioners in the currently evolving field. Full article
(This article belongs to the Special Issue Recent Developments in Chitosan Hydrogels)
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