bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncovering Challenges and Pitfalls in Identifying Threshold Concepts: A Comprehensive Review
Authors: Correia Paulo R. M. , Soida Ivan A. I. , de Souza Izabela , Lima Manolita C.
Published: January 2024

The exploration of threshold concepts, which represent a transformed way of understanding, interpreting, or viewing something necessary for a learner’s progress, has significantly influenced teaching and learning in higher education, gaining broad acceptance in academic circles. Despite widespread enthusiasm, the scientific development of the field faces obstacles, especially epistemological and ontological uncertainties, directly implying the reliability of identification techniques and, by extension, raising questions about the validity of previous findings. This comprehensive review delves into 60 articles sourced from the Web of Science database to scrutinize the literature on threshold concept identification. The findings confirm the adaptability of threshold concepts across diverse disciplines. However, the fluid definition inherent in these concepts introduces ontological challenges, influencing biases in the identification process. The review highlights the diverse identification methods influenced by knowledge area specificities, community affinities, and research practice traditions. A diagram depicting the methods employed to identify threshold concepts is offered to highlight five central decisions to be considered. Acknowledging professors as pivotal mediators adept at navigating the epistemological and ontological dimensions of threshold concepts while integrating theoretical and applied knowledge, this study enhances our nuanced understanding of threshold concept identification. Emphasizing methodological validity and reliability, it acknowledges the crucial role of experienced educators in this issue and presents future perspectives for advancing current research, fostering the maturation of the field.
Study of Regional Spatial and Temporal Changes of Net Ecosystem Productivity of Crops from Remotely Sensed Data
Authors: Wang Peng , Xue Yong , Yan Zhigang , Yin Wenping , He Botao , Li Pei
Published: January 2024

Net ecosystem productivity (NEP) is a crucial indicator of the carbon balance and health of an ecosystem. Until now, few studies have estimated the NEP of crops and analyzed it in space and time. The study of NEP in crops is crucial for comprehending the carbon cycle of agroecosystems and determining the status of carbon sources and sinks in farmland at the regional scale. In this study, we calculated the net primary productivity (NPP) and NEP of agricultural crops in Jiangsu Province, China, from 2001 to 2022 by using remote sensing data, land cover data and meteorological data. The modified Carnegie Ames Stanford Approach (CASA) model was employed to estimate the NPP, and the soil heterotrophic respiration model was used to calculate the soil heterotrophic respiration (Rh). Then, the availability of the NPP was evaluated. On this basis, the NEP was obtained by calculating the difference between the NPP and Rh. We explored the spatial and temporal changes in the NEP of crops and analyzed the correlation between the NEP and crop cultivation activities and climatic factors under the context of agricultural production information using the NEP datasets of agricultural crops. The study indicated that (1) the NEP of crops in Jiangsu Province showed a north-to-south pattern, being higher in the north and lower in the south. Over the course of 22 years, the average NEP of the crops in Jiangsu Province stands at 163.4 gC/m2, highlighting a positive carbon sink performance. Nonetheless, up to 88.04% of the crops exhibited declining NEP trends. (2) The monthly fluctuations in the NEP of crops in Jiangsu Province exhibited a bimodal pattern, with peaks occurring during spring and summer. The changes in the NEP of the crops were significantly associated with various agricultural production activities. (3) Significant regional differences were observed in the NEP of the crop response to temperature and precipitation, both of which directly impacted the annual performance of the NEP. This study could serve as a reference for research on the carbon cycle in agriculture and the development of policies aimed at reducing emissions and enhancing carbon sinks in local farmland.
Automatic Extraction for Land Parcels Based on Multi-Scale Segmentation
Authors: Liu Fei , Lu Huizhong , Wu Lilei , Li Rui , Wang Xinjun , Cao Longxi
Published: January 2024

Different land parcels possess unique microclimates, soils, and biological conditions, which in turn significantly influence the land parcels themselves, impacting biodiversity, hydrological relationships, land degradation, geological disasters, and other ecological environments. Therefore, researching an efficient and accurate method capable of extracting land parcels with the least internal heterogeneity at the macro, meso, and micro scales is extremely important. Multi-scale segmentation, based on scale and resolution analysis techniques, is a bottom-up merging technology that minimizes internal heterogeneity within regions and maximizes heterogeneity between different units. This approach is extensively applied in multi-scale spectral feature extraction and classification and is further combined with deep learning techniques to enhance the accuracy of image classification. This study, using Xinghai County in Qinghai Province as an example, employs multi-scale segmentation and hydrological analysis methods to extract land parcels at different spatial scales. The results show (1) that the land parcels extracted using the hydrological analysis method are catchment units centered around rivers, including slopes on both sides of the river. In contrast, multi-scale segmentation extracts regions comprising land parcels with similar properties, enabling the segregation of slopes and channels into independent units. (2) At a classification threshold of 19, multi-scale segmentation divides the study area into five different types of land parcels, reflecting the heterogeneity of terrain undulations and their hydrological connections. When the classification threshold is set to 31, the study area is divided into 15 types of land parcels, primarily highlighting micro-topographic features. (3) Multi-scale segmentation can merge and categorize areas with the least heterogeneity in land parcels, facilitating subsequent statistical analysis. Therefore, mesoscale land parcels extracted through multi-scale segmentation are invaluable for analyzing regional Earth surface processes such as soil erosion, sediment distribution and transportation. Microscale land parcels are significantly important for identifying high-risk areas in relation to geological disasters like landslides and collapses.
Preferences and Willingness to Pay for Preservation: The Case of a Proposed Hydropower Project in Southern Iceland
Authors: Cook Clint , Sæþórsdóttir Anna Dóra , Cook David
Published: January 2024

When decision makers use a financial approach to review the costs and benefits of new renewable energy projects, the economic value of changes in social welfare resulting from impacts on natural resources is not included in the analysis. Iceland’s policy objective for carbon neutrality by 2040 will require constructing new power plants. This study aimed to estimate the economic preservation value for the Hólmsá and Tungufljót river basins in southern Iceland using the contingent valuation method. A web-based survey of Icelandic residents was conducted between 13 November 2022 and 19 December 2022 using a stratified random sample of 2909 adults. The response rate was 46.6%, with 35.1% of respondents indicating a willingness to pay (WTP) to protect the area from hydropower development. After excluding protest voters and accounting for those with and without WTP, the estimated mean WTP equaled ISK 5515. When scaled to the adult population of Icelandic residents, that equates to a total environmental and social cost of between ISK 1.52 and 1.70 billion. Compared to the estimated levelized cost of energy for the Hólmsárvirkjun at Atley hydropower project, this aggregation equates to an estimated 5.6% markup in total project costs, excluding transmission lines. Accounting for these economic costs in decision making allows for a more holistic understanding of new energy project costs and net present benefits.
Regularization and Innovation: A Usage-Based Approach to Past Participle Variation in Brazilian Portuguese
Authors: Dickinson Kendra V.
Published: January 2024

This project explores the synchronic variation of participle forms in Brazilian Portuguese (BP). Despite general systematicity, the language maintains many historically irregular participles, which often compete with regularized variants. The language has also developed innovative participles, which tend to exist in variation with regular forms. Adopting a usage-based framework, the study examines how analogical processes affect persistent irregular participles and short-form forms in BP, emphasizing the role of grammatical context and frequency. Data are drawn from the Portuguese Web 2011 corpus, including 12 verbs with long-form Latinate irregulars (n = 4800) and 8 verbs with short-form forms (n = 3200). The results show that long-form Latinate irregulars are more common as adjectives and with the verb estar, while regularized forms are prevalent with ser and in perfect constructions. Conversely, short-form participles occur least frequently in perfect constructions, showing a tendency towards the maintenance of regularity in this context. Additionally, verbs that occur more often in perfect constructions are most resistant to innovation. These findings indicate that perfect constructions play a dual role in promoting and preserving regularity in BP and shed light on how grammar–internal relationships and contexts of occurrence play a role in language variation and change.
PARP Inhibitors in Metastatic Castration-Resistant Prostate Cancer: Unraveling the Therapeutic Landscape
Authors: Al-Akhras Ashaar , Hage Chehade Chadi , Narang Arshit , Swami Umang
Published: January 2024

The treatment landscape of metastatic prostate cancer (mPCa) is rapidly evolving with the recent approvals of poly-ADP ribose polymerase inhibitors (PARPis) as monotherapy or as part of combination therapy with androgen receptor pathway inhibitors in patients with metastatic castration-resistant prostate cancer (mCRPC). Already part of the therapeutic armamentarium in different types of advanced cancers, these molecules have shaped a new era in mPCa by targeting genomic pathways altered in these patients, leading to promising responses. These agents act by inhibiting poly-ADP ribose polymerase (PARP) enzymes involved in repairing single-strand breaks in the DNA. Based on the PROfound and TRITON3 trials, olaparib and rucaparib were respectively approved as monotherapy in pretreated patients with mCRPC and alterations in prespecified genes. The combinations of olaparib with abiraterone (PROpel) and niraparib with abiraterone (MAGNITUDE) were approved as first-line options in patients with mCRPC and alterations in BRCA1/2, whereas the combination of talazoparib with enzalutamide (TALAPRO-2) was approved in the same setting in patients with alterations in any of the HRR genes, which are found in around a quarter of patients with advanced prostate cancer. Additional trials are already underway to assess these agents in an earlier hormone-sensitive setting. Future directions will include refining the treatment sequencing in patients with mCRPC in the clinic while taking into account the financial toxicity as well as the potential side effects encountered with these therapies and elucidating their mechanism of action in patients with non-altered HRR genes. Herein, we review the biological rationale behind using PARPis in mCRPC and the key aforementioned clinical trials that paved the way for these approvals.
The Influence of the Molecular Structure of Compounds on Their Properties and the Occurrence of Chiral Smectic Phases
Authors: Urbańska Magdalena , Zając Monika , Perkowski Paweł , Deptuch Aleksandra
Published: January 2024

We have designed new chiral smectic mesogens with the -CH2O group near the chiral center. We synthesized two unique rod-like compounds. We determined the mesomorphic properties of these mesogens and confirmed the phase identification using dielectric spectroscopy. Depending on the length of the oligomethylene spacer (i.e., the number of methylene groups) in the achiral part of the molecules, the studied materials show different phase sequences. Moreover, the temperature ranges of the observed smectic phases are different. It can be seen that as the length of the alkyl chain increases, the liquid crystalline material shows more mesophases. Additionally, its clearing (isotropization) temperature increases. The studied compounds are compared with the structurally similar smectogens previously synthesized. The helical pitch measurements were performed using the selective reflection method. These materials can be useful and effective as chiral components and dopants in smectic mixtures targeted for optoelectronics and photonics.
Mechanical Properties and Microstructure of Inconel 718 Lattice Structures Produced by Selective Laser Melting Process
Authors: Zaharia Sebastian-Marian , Lancea Camil , Kruk Adam , Cempura Grzegorz , Gruszczyński Adam , Chicos Lucia-Antoneta , Pop Mihai Alin
Published: January 2024

This article presents the results of an analysis regarding the microstructure, mechanical strength, and microhardness of two kinds of samples built through selective laser melting with Inconel 718, the most frequently used alloy in metal additive manufacturing due to its excellent mechanical properties. The sample geometry was made up of two types of lattice structures with spherical and hyperbolical stiffness elements. The goals of these studies are to determine how homogenization heat treatment influences the microhardness and the mechanical properties of the specimens and to identify the structure with the best mechanical properties. The analysis showed that heat treatment was beneficial because the regular dendritic structure disappears, the δ phase precipitates at the grain boundaries, and both the γ and γ″ phases dissolve. It has also been shown that the structures with hyperbolical stiffness elements have better compressive strength than the structures with the elliptical structures, with a 47.6% increase for the as-fabricated structures and an approximate 50% increase for the heat-treated structure.
Performance Improvement for the CuCrZr Alloy Produced by Laser Powder Bed Fusion Using the Remelting Process
Authors: Xu Lianyong , Zhang Yaqing , Zhao Lei , Ren Wenjing , Han Yongdian
Published: January 2024

Owing to the high optical reflectivity of copper powder, the high-performance fabrication of copper alloys in the laser additive manufacturing (AM) field is problematic. To tackle this issue, this study employs the remelting process during laser powder bed fusion AM to fabricate defect-free and high-performance CuCrZr alloy. Compared to the non-remelting process, the remelting process yields finer grains, smaller precipitates, denser dislocations, and smaller dislocation cells. It realizes not only the dense molding of high laser reflectivity powders but also excellent mechanical properties and electrical conductivity (with an ultimate tensile strength of 329 MPa and conductivity of 96% IACS) without post-heat treatment. Furthermore, this study elucidates the influence of complex thermal gradients and multiple thermal cycles on the manufacturing process under the remelting process, as well as the internal mechanisms of microstructure evolution and performance improvement.
Phosphamide-Based Washing-Durable Flame Retardant for Cotton Fabrics
Authors: Li Jinhao , Zhang Guangxian , Zhang Fengxiu
Published: January 2024

A formaldehyde-free reactive flame retardant, an ammonium salt of triethylenetetramine phosphoryl dimethyl ester phosphamide phosphoric acid (ATPEPDPA), was synthesized and characterized using nuclear magnetic resonance (NMR). Fourier transform infrared spectroscopy test (FT-IR), durability test and scanning electron microscopy (SEM) results suggested that ATPEPDPA was successfully grafted on cotton fabrics through a -N-P(=O)-O-C covalent bond. Moreover, the limiting oxygen index (LOI) value of 20 wt% ATPEPDPA-treated cotton was 44.6%, which met stringent washing standard after 50 laundering cycles (LCs). The high washing resistance of the ATPEPDPA-treated cotton was due to the p-π conjugation between the N atom and the P(=O) group in the flame-retardant molecule, which strengthened the stability of the -N-P(=O)-O-C bonds between ATPEPDPA and cellulose, and the -N-P(=O)-(O-CH3)2 groups in the ATPEPDPA. The cone calorimetric test showed that the treated cotton had excellent flame retardance. In addition, the TG and TG-IR tests suggested that ATPEPDPA performed a condensed flame retardance mechanism. Furthermore, the physical properties and hand feel of the treated cotton were well maintained. These results suggested that introducing -N-P(=O)-(O-CH3)2 and -N-P(=O)-(ONH4)2 groups into ATPEPDPA could significantly increase the fire resistance and durability of cotton fabrics.
Eco-Design and Characterization of Sustainable Lightweight Gypsum Composites for Panel Manufacturing including End-of-Life Tyre Wastes
Authors: Ferrández Daniel , Álvarez Manuel , Zaragoza-Benzal Alicia , Santos Paulo
Published: January 2024

The incorporation of rubber recycled aggregates from end-of-life tyres (ELT) in the manufacturing process of sustainable building materials has gained great interest in recent decades as a result of the large volume of this waste being generated annually. In this work, the objective is to make a contribution towards the circularity of construction products by carrying out a physico-mechanical characterisation of new gypsum composites made with the incorporation of these recycled rubber aggregates. To this end, up to 30% by volume of the original raw material has been substituted, analysing the mechanical resistance to bending and compression. Although lower than those of traditional gypsum material, both properties exceed the limits set at 1 and 2 MPa, respectively, by the current regulations. In addition, water absorption by capillarity significantly decreases, and thermal conductivity is reduced by more than 35% with respect to the reference material. Finally, in order to provide the research with a practical application, a prefabricated plate design has been proposed that incorporates the gypsum materials studied and an agglomerated rubber band that increases the thermal resistance and improves the efficiency of the designed construction system. In this way, this research reflects the potential of these novel building materials and explores new avenues for their application in building construction.
Near Net Shape Manufacturing of Sheets from Al-Cu-Li-Mg-Sc-Zr Alloy
Authors: Kihoulou Barbora , Králík Rostislav , Bajtošová Lucia , Grydin Olexandr , Stolbchenko Mykhailo , Schaper Mirko , Cieslar Miroslav
Published: January 2024

Thin twin-roll cast strips from a model Al-Cu-Mg-Li-Zr alloy with a small addition of Sc were prepared. A combination of a fast solidification rate and a favorable effect of Sc microalloying refines the grain size and the size of primary phase particles and reduces eutectic cell dimensions to 10–15 μm. Long-term homogenization annealings used in conventionally cast materials lasting several tens of hours followed by a necessary dimension reduction through rolling/extruding could be substituted by energy and material-saving procedure. It consists of two-step short annealings at 300 °C/30 min and 450 °C/30 min, followed by the refinement and hardening of the structure using constrained groove pressing. A dense dispersion of 10–20 nm spherical Al3(Sc,Zr) precipitates intensively forms during this treatment and effectively stabilizes the structure and inhibits the grain growth during subsequent solution treatment at 530 °C/30 min. Small (3%) pre-straining after quenching assures more uniform precipitation of strengthening Al2Cu (θ′), Al2CuMg (S′), and Al2CuLi (T1) particles during subsequent age-hardening annealing at 180 °C/14 h. The material does not contain a directional and anisotropic structure unavoidable in rolled or extruded sheets. The proposed procedure thus represents a model near net shape processing strategy for manufacturing lightweight high-strength sheets for cryogenic applications in aeronautics.
Enhancing the Thermal Conductivity of Epoxy Composites via Constructing Oriented ZnO Nanowire-Decorated Carbon Fibers Networks
Authors: Lin Wei , Yu Chang , Sun Chang , Wang Baokai , Niu Mengyang , Li Mengyi , Xuan Weiwei , Wang Qi
Published: January 2024

With the miniaturization and high integration of electronic devices, high-performance thermally conductive composites have received increasing attention. The construction of hierarchical structures is an effective strategy to reduce interfacial thermal resistance and enhance composite thermal conductivity. In this study, by decorating carbon fibers (CF) with needle-like ZnO nanowires, hierarchical hybrid fillers (CF@ZnO) were rationally designed and synthesized using the hydrothermal method, which was further used to construct oriented aligned filler networks via the simple freeze-casting process. Subsequently, epoxy (EP)-based composites were prepared using the vacuum impregnation method. Compared with the pure CF, the CF@ZnO hybrid fillers led to a significant increase in thermal conductivity, which was mainly due to the fact that the ZnO nanowires could act as bridging links between CF to increase more thermally conductive pathways, which in turn reduced interfacial thermal resistance. In addition, the introduction of CF@ZnO fillers was also beneficial in improving the thermal stability of the EP-based composites, which was favorable for practical thermal management applications.
Damage Monitoring and Localization Imaging of Aluminum Alloy Thin-Walled Structure Based on Remote Bonding Fiber Bragg Gratings Sensing
Authors: Han Lu , Wang Mi , Chai Lindong , Liu Dingyun , Zhang Weifang , Zhang Wei
Published: January 2024

In this paper, the damage monitoring investigation based on the remote bonding fiber Bragg grating sensing is performed on the aerospace aluminum alloy thin-walled structure with prefabricated damage. Firstly, an ultrasonic excitation-fiber Bragg gratings (UE-FBGs) sensing experimental platform is established for the simulation of defects monitoring, in which the sensors are placed at a certain distance from the bonding area. Secondly, different arrangements of exciters and receivers are utilized for the original signals and the damage signals. Subsequently, the raw signals are processed by filter and feature extraction in order to denoise the signals and acquire the parameters sensitive to the damage. Finally, an improved Reconstruction for Image Defects (RAPID) algorithm is used to locate and reconstruct the pre-existing damage. The results show that the proposed system improves the sensitivity of the FBG receiver signal and the accuracy of the damage imaging.
Correction: Krbata et al. Effect of Supercritical Bending on the Mechanical & Tribological Properties of Inconel 625 Welded Using the Cold Metal Transfer Method on a 16Mo3 Steel Pipe. Materials 2023, 16, 5014
Authors: Krbata Michal , Ciger Robert , Kohutiar Marcel , Sozańska Maria , Eckert Maroš , Barenyi Igor , Kianicova Marta , Jus Milan , Beronská Nad’a , Mendala Bogusław , Slaný Martin
Published: January 2024

In the original publication [...]
Incorporation of Bismuth(III) Oxide Nanoparticles into Carbon Ceramic Composite: Electrode Material with Improved Electroanalytical Performance in 4-Chloro-3-Methylphenol Determination
Authors: Brycht Mariola , Leniart Andrzej , Skrzypek Sławomira , Burnat Barbara
Published: January 2024

In this study, a carbon ceramic electrode (CCE) with improved electroanalytical performance was developed by bulk-modifying it with bismuth(III) oxide nanoparticles (Bi-CCE). Characterization of the Bi-CCE was conducted employing atomic force microscopy, scanning electron microscopy with energy-dispersive X-ray spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy. Comparative analysis was conducted using an unmodified CCE. The findings proved that the incorporation of Bi2O3 nanoparticles into the CCE significantly altered the morphology and topography of the ceramic composite, and it improved the electrochemical properties of CCE. Notably, the Bi-CCE demonstrated a prolonged operational lifespan of at least three months, and there was a high reproducibility of the electrode preparation procedure. The developed Bi-CCE was effectively employed to explore the electrochemical behavior and quantify the priority environmental pollutant 4-chloro-3-methylphenol (PCMC) using CV and square-wave voltammetry (SWV), respectively. Notably, the developed SWV procedure utilizing Bi-CCE exhibited significantly enhanced sensitivity (0.115 µA L mol−1), an extended linearity (0.5–58.0 µmol L−1), and a lower limit of detection (0.17 µmol L−1) in comparison with the unmodified electrode. Furthermore, the Bi-CCE was utilized effectively for the detection of PCMC in a river water sample intentionally spiked with the compound. The selectivity toward PCMC determination was also successfully assessed.
Development of FSW Process Parameters for Lap Joints Made of Thin 7075 Aluminum Alloy Sheets
Authors: Lacki Piotr , Derlatka Anna , Więckowski Wojciech , Adamus Janina
Published: January 2024

The article describes machine learning using artificial neural networks (ANNs) to develop the parameters of the friction stir welding (FSW) process for three types of aluminum joints (EN AW 7075). The ANNs were built using a total of 608 experimental data. Two types of networks were built. The first one was used to classify good/bad joints with MLP 7-19-2 topology (one input layer with 7 neurons, one hidden layer with 19 neurons, and one output layer with 2 neurons), and the second one was used to regress the tensile load-bearing capacity with MLP 7-19-1 topology (one input layer with 7 neurons, one hidden layer with 19 neurons, and one output layer with 1 neuron). FSW parameters, such as rotational speed, welding speed, and joint and tool geometry, were used as input data for ANN training. The quality of the FSW joint was assessed in terms of microstructure and mechanical properties based on a case study. The usefulness of both trained neural networks has been demonstrated. The quality of the validation set for the regression network was approximately 93.6%, while the errors for the confusion matrix of the test set never exceeded 6%. Only 184 epochs were needed to train the regression network. The quality of the validation set was approximately 87.1%. Predictive maps were developed and presented in the work, allowing for the selection of optimal parameters of the FSW process for three types of joints.
Plant-Based Proteins and Their Modification and Processing for Vegan Cheese Production
Authors: Kovačević Jelica , Bechtold Thomas , Pham Tung
Published: January 2024

Plant-based proteins are important macronutrients in the human diet, crucial for cell development in our bodies and for supporting the immune system. Given their nutritional and functional properties, plant-based proteins are excellent candidates for the development of plant-based food. Among other things, plant-based cheese has been identified as a potential enabler for future innovation through improvements in ingredient technology. Unlike traditional dairy cheeses, plant-based cheeses are made from a variety of ingredients such as nuts and legumes that can be fortified with nutrients also found in traditional cheese. Of course, plant-based cheeses still have some nutritional drawbacks, and most of them are processed, which means they contain preservatives, colour additives and high sodium content. Nevertheless, the physicochemical and functional properties of plant-based proteins are of great interest to the food industry and the initial interest in natural sources of plant proteins has recently shifted to the field of modification and processing. This review discusses the natural sources and classification of plant-based proteins and summarises recent studies on processing methods in the production of plant-based cheese.
Weak Convergence of the Conditional Set-Indexed Empirical Process for Missing at Random Functional Ergodic Data
Authors: Bouzebda Salim , Souddi Youssouf , Madani Fethi
Published: January 2024

This work examines the asymptotic characteristics of a conditional set-indexed empirical process composed of functional ergodic random variables with missing at random (MAR). This paper’s findings enlarge the previous advancements in functional data analysis through the use of empirical process methodologies. These results are shown under specific structural hypotheses regarding entropy and under appealing situations regarding the model. The regression operator’s asymptotic (1−α)-confidence interval is provided for 0<α<1 as an application. Additionally, we offer a classification example to demonstrate the practical importance of the methodology.
The Structure, Functions and Potential Medicinal Effects of Chlorophylls Derived from Microalgae
Authors: Sun Danni , Wu Songlin , Li Xiaohui , Ge Baosheng , Zhou Chengxu , Yan Xiaojun , Ruan Roger , Cheng Pengfei
Published: January 2024

Microalgae are considered to be natural producers of bioactive pigments, with the production of pigments from microalgae being a sustainable and economical strategy that promises to alleviate growing demand. Chlorophyll, as the main pigment of photosynthesis, has been widely studied, but its medicinal applications as an antioxidant, antibacterial, and antitumor reagent are still poorly understood. Chlorophyll is the most important pigment in plants and algae, which not only provides food for organisms throughout the biosphere, but also plays an important role in a variety of human and man-made applications. The biological activity of chlorophyll is closely related to its chemical structure; its specific structure offers the possibility for its medicinal applications. This paper reviews the structural and functional roles of microalgal chlorophylls, commonly used extraction methods, and recent advances in medicine, to provide a theoretical basis for the standardization and commercial production and application of chlorophylls.
Rare c.302C>T TTR Variant Associated with Transthyretin Amyloidosis
Authors: Žebrauskienė Dovilė , Sadauskienė Eglė , Masiulienė Rūta , Aidietienė Sigita , Šiaudinienė Agnė , Pečeliūnas Valdas , Žukauskaitė Gabrielė , Žurauskas Edvardas , Valevičienė Nomeda , Barysienė Jūratė , Preikšaitienė Eglė
Published: January 2024

Background and Objectives: Hereditary transthyretin amyloidosis (ATTRv) is a rare disease caused by pathogenic variants in the transthyretin (TTR) gene. More than 140 different disease-causing variants in TTR have been reported. Only a few individuals with a rare TTR variant, c.302C>T, p.(Ala101Val) (historically known as p.(Ala81Val)), primarily associated with cardiac ATTRv, have been described. Therefore, our aim was to analyze the clinical characteristics of individuals with the identified c.302C>T TTR variant at our center. Materials and Methods: We analyzed data from individuals with ATTRv who were diagnosed and treated at Vilnius University Hospital Santaros Klinikos. ATTRv was confirmed by negative hematological analysis for monoclonal protein, positive tissue biopsy or bone scintigraphy and a pathogenic TTR variant. Results: During 2018-2021, the TTR NM_000371.3:c.302C>T, NP_000362.1:p.(Ala101Val) variant was found in one individual in a homozygous state and in three individuals in a heterozygous state. The age of onset of symptoms ranged from 44 to 74 years. The earliest onset of symptoms was in the individual with the homozygous variant. A history of carpal tunnel syndrome was identified in two individuals. On ECG, three individuals had low QRS voltage in limb leads. All individuals had elevated NT-proBNP and hsTroponine I levels on baseline laboratory tests and concentric left ventricular hypertrophy on transthoracic echocardiography. The individual with the homozygous c.302C>T TTR variant had the most pronounced polyneuropathy with tetraparesis. Other patients with the heterozygous variant had more significant amyloid cardiomyopathy. When screening family members, the c.302C>T TTR variant was identified in two phenotypically negative relatives at the ages of 33 and 47 years. Conclusions: c.302C>T is a rare TTR variant associated with ATTRv cardiomyopathy. The homozygous state of this variant was not reported before, and is associated with earlier disease onset and neurological involvement compared to the heterozygote state.
Interleukin-1 Blockers in Recurrent and Acute Pericarditis: State of the Art and Future Directions
Authors: Gallo Antonella , Massaro Maria Grazia , Camilli Sara , Di Francesco Silvino , Gerardino Laura , Verrecchia Elena , Sicignano Ludovico Luca , Landi Francesco , Manna Raffaele , Montalto Massimo
Published: January 2024

Diseases of the pericardium encompass a spectrum of conditions, including acute and recurrent pericarditis, where inflammation plays a pivotal role in the pathogenesis and clinical manifestations. Anti-inflammatory therapy indeed forms the cornerstone of treating these conditions: NSAIDs, colchicine, and corticosteroids (as a second-line treatment) are recommended by current guidelines. However, these medications come with several contraindications and are not devoid of adverse effects. In recent years, there has been an increased focus on the role of the inflammasome and potential therapeutic targets. Recurrent pericarditis also shares numerous characteristics with other autoinflammatory diseases, in which interleukin-1 antagonists have already been employed with good efficacy and safety. The objective of this review is to summarize the available studies on the use of anti-IL-1 drugs both in acute and recurrent pericarditis.
Brazing of Copper Pipes for Heat Pump and Refrigeration Applications
Authors: Pereira António B. , Dias João M. S. , Rios José P. , Silva Nélia M. , Duraisamy Sathishkumar , Horovistiz Ana
Published: January 2024

In heat pumps and refrigeration systems, copper parts play a crucial role. Since heat pumps for space and water heating work under high pressure and are susceptible to vibrations, it is crucial to perfectly weld the copper pipes and heat exchangers to avoid system failures and prevent the leakage of the circulating refrigerants, which are harmful to the environment. The welding of the copper pipes is usually performed by the brazing process in a furnace. The components are subjected to a period of approximately 50 min inside a continuously open oven, varying the temperature from 710 °C to 830 °C. The oven inlets and outlets are protected by nitrogen curtains to guarantee a suitable internal environment and prevent the contamination of the gas inside the oven. This work analyses which welding methods are most suitable for welding copper, the best joint shape, process time, brazing specimens of a copper alloy, tightness tests, and mechanical properties and composition of the welding samples. From the tests carried out, the appearance of small and large defects is reduced by using a 1 mm thick external ring of filler material and a brazing temperature of 820 °C.
Impact of Boundary Parameters Accuracy on Modeling of Directed Energy Deposition Thermal Field
Authors: Gallo Calogero , Duchêne Laurent , Quy Duc Pham Thinh , Jardin Ruben , Tuninetti Víctor , Habraken Anne-Marie
Published: January 2024

Within the large Additive Manufacturing (AM) process family, Directed Energy Deposition (DED) can be used to create low-cost prototypes and coatings, or to repair cracks. In the case of M4 HSS (High Speed Steel), a reliable computed temperature field during DED process allows the optimization of the substrate preheating temperature value and other process parameters. Such optimization is required to avoid failure during the process, as well as high residual stresses. If 3D DED simulations provide accurate thermal fields, they also induce huge computation time, which motivates simplifications. This article uses a 2D Finite Element (FE) model that decreases the computation cost through dividing the CPU time by around 100 in our studied case, but it needs some calibrations. As described, the identification of a correct data set solely based on local temperature measurements can lead to various sets of parameters with variations of up to 100%. In this study, the melt pool depth was used as an additional experimental measurement to identify the input data set, and a sensitivity analysis was conducted to estimate the impact of each identified parameter on the cooling rate and the melt pool dimension.
Association between Dyslipidemia and Glycated Hemoglobin in a Population-Based Study
Authors: Kang Purum , Kim Ka Young , Shin Hye Young
Published: January 2024

Diabetes mellitus and dyslipidemia are well-known risk factors for cardiovascular disease. Unfortunately, the prevalence of dyslipidemia and diabetes mellitus among individuals over 30 years of age in Korea has continuously increased. The current study therefore investigated the association between dyslipidemia and high glycated hemoglobin (Hemoglobin A1c, HbA1c) levels according to age group in adults over 20 years old. We used data from the 7th Korea National Health and Nutrition Examination Survey conducted by the Korea Centers for Disease Control and Prevention from 2016 to 2017. Glycated hemoglobin, a well-established marker for elevated glucose levels, was categorized into three groups, normal (<5.7%), prediabetes (5.7–6.4%), and diabetes (≥6.5%). The presence of dyslipidemia was defined based on a diagnosis of dyslipidemia by a physician. Logistic regression analyses were performed to evaluate the association between the prevalence of dyslipidemia and glycated hemoglobin according to age group. After adjusting for possible confounders, including age, sex, body mass index, marital status, education, occupation, household income, drinking, and smoking, we found a significant increase in the odds ratios (ORs) for dyslipidemia in the prediabetes (OR; 1.915, 95% CI; 1.696 to 2.163) and diabetes (OR; 3.533, 95% CI; 3.019 to 4.134) groups. Among subjects with higher glycated hemoglobin levels, those in their 40s or over had significantly increased odds for dyslipidemia. The current study found an association between high glycated hemoglobin levels and a diagnosis of dyslipidemia among Korean adults. Markers of lipid metabolism in adults with high glycated hemoglobin levels may need to be monitored, especially those in their 40s and older.
Metabolic Connectome and Its Role in the Prediction, Diagnosis, and Treatment of Complex Diseases
Authors: Meng Weiyu , Pan Hongxin , Sha Yuyang , Zhai Xiaobing , Xing Abao , Lingampelly Sai Sachin , Sripathi Srinivasa R. , Wang Yuefei , Li Kefeng
Published: January 2024

The interconnectivity of advanced biological systems is essential for their proper functioning. In modern connectomics, biological entities such as proteins, genes, RNA, DNA, and metabolites are often represented as nodes, while the physical, biochemical, or functional interactions between them are represented as edges. Among these entities, metabolites are particularly significant as they exhibit a closer relationship to an organism’s phenotype compared to genes or proteins. Moreover, the metabolome has the ability to amplify small proteomic and transcriptomic changes, even those from minor genomic changes. Metabolic networks, which consist of complex systems comprising hundreds of metabolites and their interactions, play a critical role in biological research by mediating energy conversion and chemical reactions within cells. This review provides an introduction to common metabolic network models and their construction methods. It also explores the diverse applications of metabolic networks in elucidating disease mechanisms, predicting and diagnosing diseases, and facilitating drug development. Additionally, it discusses potential future directions for research in metabolic networks. Ultimately, this review serves as a valuable reference for researchers interested in metabolic network modeling, analysis, and their applications.
New Implications of Metabolites and Free Fatty Acids in Quality Control of Crossbred Wagyu Beef during Wet Aging Cold Storage
Authors: Ueda Shuji , Yoshida Yuka , Kebede Biniam , Kitamura Chiaki , Sasaki Ryo , Shinohara Masakazu , Fukuda Itsuko , Shirai Yasuhito
Published: January 2024

Efficient cold-chain delivery is essential for maintaining a sustainable global food supply. This study used metabolomic analysis to examine meat quality changes during the “wet aging” of crossbred Wagyu beef during cold storage. The longissimus thoracic (Loin) and adductor muscles (Round) of hybrid Wagyu beef, a cross between the Japanese Black and Holstein–Friesian breeds, were packaged in vacuum film and refrigerated for up to 40 days. Sensory evaluation indicated an increase in the umami and kokumi taste owing to wet aging. Comprehensive analysis using gas chromatography-mass spectrometry identified metabolite changes during wet aging. In the Loin, 94 metabolites increased, and 24 decreased; in the Round, 91 increased and 18 decreased. Metabolites contributing to the umami taste of the meat showed different profiles during wet aging. Glutamic acid increased in a cold storage-dependent manner, whereas creatinine and inosinic acid degraded rapidly even during cold storage. In terms of lipids, wet aging led to an increase in free fatty acids. In particular, linoleic acid, a polyunsaturated fatty acid, increased significantly among the free fatty acids. These results provide new insight into the effects of wet aging on Wagyu-type beef, emphasizing the role of free amino acids, organic acids, and free fatty acids generated during cold storage.
Integrated Transcriptomics and Metabolomics Analysis Reveals the Effects of Cutting on the Synthesis of Flavonoids and Saponins in Chinese Herbal Medicine Astragalus mongholious
Authors: Guo Xu , Yan Xiang , Wang Yuanyuan , Shi Zhiyong , Niu Jingping , Liang Jianping , Jia Xiaoyun
Published: January 2024

Astragali Radix, derived from the roots of Astragalus mongholicus, is a traditional Chinese medicine containing flavonoids and saponins as its key ingredients. With a shortage in the wild sources of the herbal plant, it is especially important to explore a cultivation mode for A. mongholicus for medicinal purposes. Cutting, a physical environmental stress method, was used in this study with the objective of improving the quality of this herbal legume. We found that cutting of the top 1/3 of the aboveground part of A. mongholicus during the fruiting period resulted in a significant increase in the content of flavonoids and saponins, as well as in root growth, including length, diameter, and dry weight. Furthermore, the leaves were sampled and analyzed using a combined transcriptome and metabolome analysis approach at five different time points after the treatment. Sixteen differentially expressed unigenes (DEGs) involved in the biosynthesis of flavonoids were identified; these were found to stimulate the synthesis of flavonoids such as formononetin and calycosin–7–O–β–D–glucoside. Moreover, we identified 10 DEGs that were associated with the biosynthesis of saponins, including astragaloside IV and soyasaponin I, and found that they only regulated the mevalonic acid (MVA) pathway. These findings provide new insights into cultivating high-quality A. mongholicus, which could potentially alleviate the scarcity of this valuable medicinal plant.
Hot-Carrier Damage in N-Channel EDMOS Used in Single Photon Avalanche Diode Cell through Quasi-Static Modeling
Authors: Bravaix Alain , Pitard Hugo , Federspiel Xavier , Cacho Florian
Published: January 2024

A single photon avalanche diode (SPAD) cell using N-channel extended-drain metal oxide semiconductor (N-EDMOS) is tested for its hot-carrier damage (HCD) resistance. The stressing gate-voltage (VGS) dependence is compared to hot-hole (HH) injection, positive bias temperature (PBT) instability and off-mode (VGS = 0). The goal was to check an accurate device lifetime extraction using accelerated DC to AC stressing by applying the quasi-static (QS) lifetime technique. N-EDMOS device is devoted to 3D bonding with CMOS imagers obtained by an optimized process with an effective gate-length Leff = 0.25 µm and a SiO2 gate-oxide thickness Tox = 5 nm. The operating frequency is 10 MHz at maximum supply voltage VDDmax = 5.5 V. TCAD simulations are used to determine the real voltage and timing configurations for the device in a mixed structure of the SPAD cell. AC device lifetime is obtained using worst-case DC accelerating degradation, which is transferred by QS technique to the AC waveforms applied to N-EDMOS device. This allows us to accurately obtain the AC device lifetime as a function of the delay and load for a fixed pulse shape. It shows the predominance of the high energy hot-carriers involved in the first substrate current peak during transients.
Actively Tunable “Single Peak/Broadband” Absorbent, Highly Sensitive Terahertz Smart Device Based on VO2
Authors: Fan Baodian , Tang Hao , Wu Pinghui , Qiu Yu , Jiang Linqin , Lin Lingyan , Su Jianzhi , Zhou Bomeng , Pan Miao
Published: January 2024

In recent years, the development of terahertz (THz) technology has attracted significant attention. Various tunable devices for THz waves (0.1 THz–10 THz) have been proposed, including devices that modulate the amplitude, polarization, phase, and absorption. Traditional metal materials are often faced with the problem of non-adjustment, so the designed terahertz devices play a single role and do not have multiple uses, which greatly limits their development. As an excellent phase change material, VO2’s properties can be transformed by external temperature stimulation, which provides new inspiration for the development of terahertz devices. To address these issues, this study innovatively combines metamaterials with phase change materials, leveraging their design flexibility and temperature-induced phase transition characteristics. We have designed a THz intelligent absorber that not only enables flexible switching between multiple functionalities but also achieves precise performance tuning through temperature stimulation. Furthermore, we have taken into consideration factors such as the polarization mode, environmental temperature, structural parameters, and incident angle, ensuring the device’s process tolerance and environmental adaptability. Additionally, by exploiting the principle of localized surface plasmon resonance (LSPR) accompanied by local field enhancement, we have monitored and analyzed the resonant process through electric field characterization. In summary, the innovative approach and superior performance of this structure provide broader insights and methods for THz device design, contributing to its theoretical research value. Moreover, the proposed absorber holds potential for practical applications in electromagnetic invisibility, shielding, modulation, and detection scenarios.